xref: /illumos-gate/usr/src/uts/common/vm/seg_vn.c (revision af4c679f)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 /*
30  * University Copyright- Copyright (c) 1982, 1986, 1988
31  * The Regents of the University of California
32  * All Rights Reserved
33  *
34  * University Acknowledgment- Portions of this document are derived from
35  * software developed by the University of California, Berkeley, and its
36  * contributors.
37  */
38 
39 /*
40  * VM - shared or copy-on-write from a vnode/anonymous memory.
41  */
42 
43 #include <sys/types.h>
44 #include <sys/param.h>
45 #include <sys/t_lock.h>
46 #include <sys/errno.h>
47 #include <sys/systm.h>
48 #include <sys/mman.h>
49 #include <sys/debug.h>
50 #include <sys/cred.h>
51 #include <sys/vmsystm.h>
52 #include <sys/tuneable.h>
53 #include <sys/bitmap.h>
54 #include <sys/swap.h>
55 #include <sys/kmem.h>
56 #include <sys/sysmacros.h>
57 #include <sys/vtrace.h>
58 #include <sys/cmn_err.h>
59 #include <sys/callb.h>
60 #include <sys/vm.h>
61 #include <sys/dumphdr.h>
62 #include <sys/lgrp.h>
63 
64 #include <vm/hat.h>
65 #include <vm/as.h>
66 #include <vm/seg.h>
67 #include <vm/seg_vn.h>
68 #include <vm/pvn.h>
69 #include <vm/anon.h>
70 #include <vm/page.h>
71 #include <vm/vpage.h>
72 #include <sys/proc.h>
73 #include <sys/task.h>
74 #include <sys/project.h>
75 #include <sys/zone.h>
76 #include <sys/shm_impl.h>
77 /*
78  * Private seg op routines.
79  */
80 static int	segvn_dup(struct seg *seg, struct seg *newseg);
81 static int	segvn_unmap(struct seg *seg, caddr_t addr, size_t len);
82 static void	segvn_free(struct seg *seg);
83 static faultcode_t segvn_fault(struct hat *hat, struct seg *seg,
84 		    caddr_t addr, size_t len, enum fault_type type,
85 		    enum seg_rw rw);
86 static faultcode_t segvn_faulta(struct seg *seg, caddr_t addr);
87 static int	segvn_setprot(struct seg *seg, caddr_t addr,
88 		    size_t len, uint_t prot);
89 static int	segvn_checkprot(struct seg *seg, caddr_t addr,
90 		    size_t len, uint_t prot);
91 static int	segvn_kluster(struct seg *seg, caddr_t addr, ssize_t delta);
92 static size_t	segvn_swapout(struct seg *seg);
93 static int	segvn_sync(struct seg *seg, caddr_t addr, size_t len,
94 		    int attr, uint_t flags);
95 static size_t	segvn_incore(struct seg *seg, caddr_t addr, size_t len,
96 		    char *vec);
97 static int	segvn_lockop(struct seg *seg, caddr_t addr, size_t len,
98 		    int attr, int op, ulong_t *lockmap, size_t pos);
99 static int	segvn_getprot(struct seg *seg, caddr_t addr, size_t len,
100 		    uint_t *protv);
101 static u_offset_t	segvn_getoffset(struct seg *seg, caddr_t addr);
102 static int	segvn_gettype(struct seg *seg, caddr_t addr);
103 static int	segvn_getvp(struct seg *seg, caddr_t addr,
104 		    struct vnode **vpp);
105 static int	segvn_advise(struct seg *seg, caddr_t addr, size_t len,
106 		    uint_t behav);
107 static void	segvn_dump(struct seg *seg);
108 static int	segvn_pagelock(struct seg *seg, caddr_t addr, size_t len,
109 		    struct page ***ppp, enum lock_type type, enum seg_rw rw);
110 static int	segvn_setpagesize(struct seg *seg, caddr_t addr, size_t len,
111 		    uint_t szc);
112 static int	segvn_getmemid(struct seg *seg, caddr_t addr,
113 		    memid_t *memidp);
114 static lgrp_mem_policy_info_t	*segvn_getpolicy(struct seg *, caddr_t);
115 static int	segvn_capable(struct seg *seg, segcapability_t capable);
116 
117 struct	seg_ops segvn_ops = {
118 	segvn_dup,
119 	segvn_unmap,
120 	segvn_free,
121 	segvn_fault,
122 	segvn_faulta,
123 	segvn_setprot,
124 	segvn_checkprot,
125 	segvn_kluster,
126 	segvn_swapout,
127 	segvn_sync,
128 	segvn_incore,
129 	segvn_lockop,
130 	segvn_getprot,
131 	segvn_getoffset,
132 	segvn_gettype,
133 	segvn_getvp,
134 	segvn_advise,
135 	segvn_dump,
136 	segvn_pagelock,
137 	segvn_setpagesize,
138 	segvn_getmemid,
139 	segvn_getpolicy,
140 	segvn_capable,
141 };
142 
143 /*
144  * Common zfod structures, provided as a shorthand for others to use.
145  */
146 static segvn_crargs_t zfod_segvn_crargs =
147 	SEGVN_ZFOD_ARGS(PROT_ZFOD, PROT_ALL);
148 static segvn_crargs_t kzfod_segvn_crargs =
149 	SEGVN_ZFOD_ARGS(PROT_ZFOD & ~PROT_USER,
150 	PROT_ALL & ~PROT_USER);
151 static segvn_crargs_t stack_noexec_crargs =
152 	SEGVN_ZFOD_ARGS(PROT_ZFOD & ~PROT_EXEC, PROT_ALL);
153 
154 caddr_t	zfod_argsp = (caddr_t)&zfod_segvn_crargs;	/* user zfod argsp */
155 caddr_t	kzfod_argsp = (caddr_t)&kzfod_segvn_crargs;	/* kernel zfod argsp */
156 caddr_t	stack_exec_argsp = (caddr_t)&zfod_segvn_crargs;	/* executable stack */
157 caddr_t	stack_noexec_argsp = (caddr_t)&stack_noexec_crargs; /* noexec stack */
158 
159 #define	vpgtob(n)	((n) * sizeof (struct vpage))	/* For brevity */
160 
161 size_t	segvn_comb_thrshld = UINT_MAX;	/* patchable -- see 1196681 */
162 
163 size_t	segvn_pglock_comb_thrshld = (1UL << 16);	/* 64K */
164 size_t	segvn_pglock_comb_balign = (1UL << 16);		/* 64K */
165 uint_t	segvn_pglock_comb_bshift;
166 size_t	segvn_pglock_comb_palign;
167 
168 static int	segvn_concat(struct seg *, struct seg *, int);
169 static int	segvn_extend_prev(struct seg *, struct seg *,
170 		    struct segvn_crargs *, size_t);
171 static int	segvn_extend_next(struct seg *, struct seg *,
172 		    struct segvn_crargs *, size_t);
173 static void	segvn_softunlock(struct seg *, caddr_t, size_t, enum seg_rw);
174 static void	segvn_pagelist_rele(page_t **);
175 static void	segvn_setvnode_mpss(vnode_t *);
176 static void	segvn_relocate_pages(page_t **, page_t *);
177 static int	segvn_full_szcpages(page_t **, uint_t, int *, uint_t *);
178 static int	segvn_fill_vp_pages(struct segvn_data *, vnode_t *, u_offset_t,
179     uint_t, page_t **, page_t **, uint_t *, int *);
180 static faultcode_t segvn_fault_vnodepages(struct hat *, struct seg *, caddr_t,
181     caddr_t, enum fault_type, enum seg_rw, caddr_t, caddr_t, int);
182 static faultcode_t segvn_fault_anonpages(struct hat *, struct seg *, caddr_t,
183     caddr_t, enum fault_type, enum seg_rw, caddr_t, caddr_t, int);
184 static faultcode_t segvn_faultpage(struct hat *, struct seg *, caddr_t,
185     u_offset_t, struct vpage *, page_t **, uint_t,
186     enum fault_type, enum seg_rw, int);
187 static void	segvn_vpage(struct seg *);
188 static size_t	segvn_count_swap_by_vpages(struct seg *);
189 
190 static void segvn_purge(struct seg *seg);
191 static int segvn_reclaim(void *, caddr_t, size_t, struct page **,
192     enum seg_rw, int);
193 static int shamp_reclaim(void *, caddr_t, size_t, struct page **,
194     enum seg_rw, int);
195 
196 static int sameprot(struct seg *, caddr_t, size_t);
197 
198 static int segvn_demote_range(struct seg *, caddr_t, size_t, int, uint_t);
199 static int segvn_clrszc(struct seg *);
200 static struct seg *segvn_split_seg(struct seg *, caddr_t);
201 static int segvn_claim_pages(struct seg *, struct vpage *, u_offset_t,
202     ulong_t, uint_t);
203 
204 static void segvn_hat_rgn_unload_callback(caddr_t, caddr_t, caddr_t,
205     size_t, void *, u_offset_t);
206 
207 static struct kmem_cache *segvn_cache;
208 static struct kmem_cache **segvn_szc_cache;
209 
210 #ifdef VM_STATS
211 static struct segvnvmstats_str {
212 	ulong_t	fill_vp_pages[31];
213 	ulong_t fltvnpages[49];
214 	ulong_t	fullszcpages[10];
215 	ulong_t	relocatepages[3];
216 	ulong_t	fltanpages[17];
217 	ulong_t pagelock[2];
218 	ulong_t	demoterange[3];
219 } segvnvmstats;
220 #endif /* VM_STATS */
221 
222 #define	SDR_RANGE	1		/* demote entire range */
223 #define	SDR_END		2		/* demote non aligned ends only */
224 
225 #define	CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr) {	    \
226 		if ((len) != 0) { 		      	      		      \
227 			lpgaddr = (caddr_t)P2ALIGN((uintptr_t)(addr), pgsz);  \
228 			ASSERT(lpgaddr >= (seg)->s_base);	      	      \
229 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)((addr) +    \
230 			    (len)), pgsz);				      \
231 			ASSERT(lpgeaddr > lpgaddr);		      	      \
232 			ASSERT(lpgeaddr <= (seg)->s_base + (seg)->s_size);    \
233 		} else {					      	      \
234 			lpgeaddr = lpgaddr = (addr);	      		      \
235 		}							      \
236 	}
237 
238 /*ARGSUSED*/
239 static int
240 segvn_cache_constructor(void *buf, void *cdrarg, int kmflags)
241 {
242 	struct segvn_data *svd = buf;
243 
244 	rw_init(&svd->lock, NULL, RW_DEFAULT, NULL);
245 	mutex_init(&svd->segfree_syncmtx, NULL, MUTEX_DEFAULT, NULL);
246 	svd->svn_trnext = svd->svn_trprev = NULL;
247 	return (0);
248 }
249 
250 /*ARGSUSED1*/
251 static void
252 segvn_cache_destructor(void *buf, void *cdrarg)
253 {
254 	struct segvn_data *svd = buf;
255 
256 	rw_destroy(&svd->lock);
257 	mutex_destroy(&svd->segfree_syncmtx);
258 }
259 
260 /*ARGSUSED*/
261 static int
262 svntr_cache_constructor(void *buf, void *cdrarg, int kmflags)
263 {
264 	bzero(buf, sizeof (svntr_t));
265 	return (0);
266 }
267 
268 /*
269  * Patching this variable to non-zero allows the system to run with
270  * stacks marked as "not executable".  It's a bit of a kludge, but is
271  * provided as a tweakable for platforms that export those ABIs
272  * (e.g. sparc V8) that have executable stacks enabled by default.
273  * There are also some restrictions for platforms that don't actually
274  * implement 'noexec' protections.
275  *
276  * Once enabled, the system is (therefore) unable to provide a fully
277  * ABI-compliant execution environment, though practically speaking,
278  * most everything works.  The exceptions are generally some interpreters
279  * and debuggers that create executable code on the stack and jump
280  * into it (without explicitly mprotecting the address range to include
281  * PROT_EXEC).
282  *
283  * One important class of applications that are disabled are those
284  * that have been transformed into malicious agents using one of the
285  * numerous "buffer overflow" attacks.  See 4007890.
286  */
287 int noexec_user_stack = 0;
288 int noexec_user_stack_log = 1;
289 
290 int segvn_lpg_disable = 0;
291 uint_t segvn_maxpgszc = 0;
292 
293 ulong_t segvn_vmpss_clrszc_cnt;
294 ulong_t segvn_vmpss_clrszc_err;
295 ulong_t segvn_fltvnpages_clrszc_cnt;
296 ulong_t segvn_fltvnpages_clrszc_err;
297 ulong_t segvn_setpgsz_align_err;
298 ulong_t segvn_setpgsz_anon_align_err;
299 ulong_t segvn_setpgsz_getattr_err;
300 ulong_t segvn_setpgsz_eof_err;
301 ulong_t segvn_faultvnmpss_align_err1;
302 ulong_t segvn_faultvnmpss_align_err2;
303 ulong_t segvn_faultvnmpss_align_err3;
304 ulong_t segvn_faultvnmpss_align_err4;
305 ulong_t segvn_faultvnmpss_align_err5;
306 ulong_t	segvn_vmpss_pageio_deadlk_err;
307 
308 int segvn_use_regions = 1;
309 
310 /*
311  * Segvn supports text replication optimization for NUMA platforms. Text
312  * replica's are represented by anon maps (amp). There's one amp per text file
313  * region per lgroup. A process chooses the amp for each of its text mappings
314  * based on the lgroup assignment of its main thread (t_tid = 1). All
315  * processes that want a replica on a particular lgroup for the same text file
316  * mapping share the same amp. amp's are looked up in svntr_hashtab hash table
317  * with vp,off,size,szc used as a key. Text replication segments are read only
318  * MAP_PRIVATE|MAP_TEXT segments that map vnode. Replication is achieved by
319  * forcing COW faults from vnode to amp and mapping amp pages instead of vnode
320  * pages. Replication amp is assigned to a segment when it gets its first
321  * pagefault. To handle main thread lgroup rehoming segvn_trasync_thread
322  * rechecks periodically if the process still maps an amp local to the main
323  * thread. If not async thread forces process to remap to an amp in the new
324  * home lgroup of the main thread. Current text replication implementation
325  * only provides the benefit to workloads that do most of their work in the
326  * main thread of a process or all the threads of a process run in the same
327  * lgroup. To extend text replication benefit to different types of
328  * multithreaded workloads further work would be needed in the hat layer to
329  * allow the same virtual address in the same hat to simultaneously map
330  * different physical addresses (i.e. page table replication would be needed
331  * for x86).
332  *
333  * amp pages are used instead of vnode pages as long as segment has a very
334  * simple life cycle.  It's created via segvn_create(), handles S_EXEC
335  * (S_READ) pagefaults and is fully unmapped.  If anything more complicated
336  * happens such as protection is changed, real COW fault happens, pagesize is
337  * changed, MC_LOCK is requested or segment is partially unmapped we turn off
338  * text replication by converting the segment back to vnode only segment
339  * (unmap segment's address range and set svd->amp to NULL).
340  *
341  * The original file can be changed after amp is inserted into
342  * svntr_hashtab. Processes that are launched after the file is already
343  * changed can't use the replica's created prior to the file change. To
344  * implement this functionality hash entries are timestamped. Replica's can
345  * only be used if current file modification time is the same as the timestamp
346  * saved when hash entry was created. However just timestamps alone are not
347  * sufficient to detect file modification via mmap(MAP_SHARED) mappings. We
348  * deal with file changes via MAP_SHARED mappings differently. When writable
349  * MAP_SHARED mappings are created to vnodes marked as executable we mark all
350  * existing replica's for this vnode as not usable for future text
351  * mappings. And we don't create new replica's for files that currently have
352  * potentially writable MAP_SHARED mappings (i.e. vn_is_mapped(V_WRITE) is
353  * true).
354  */
355 
356 #define	SEGVN_TEXTREPL_MAXBYTES_FACTOR	(20)
357 size_t	segvn_textrepl_max_bytes_factor = SEGVN_TEXTREPL_MAXBYTES_FACTOR;
358 
359 static ulong_t			svntr_hashtab_sz = 512;
360 static svntr_bucket_t		*svntr_hashtab = NULL;
361 static struct kmem_cache	*svntr_cache;
362 static svntr_stats_t		*segvn_textrepl_stats;
363 static ksema_t 			segvn_trasync_sem;
364 
365 int				segvn_disable_textrepl = 1;
366 size_t				textrepl_size_thresh = (size_t)-1;
367 size_t				segvn_textrepl_bytes = 0;
368 size_t				segvn_textrepl_max_bytes = 0;
369 clock_t				segvn_update_textrepl_interval = 0;
370 int				segvn_update_tr_time = 10;
371 int				segvn_disable_textrepl_update = 0;
372 
373 static void segvn_textrepl(struct seg *);
374 static void segvn_textunrepl(struct seg *, int);
375 static void segvn_inval_trcache(vnode_t *);
376 static void segvn_trasync_thread(void);
377 static void segvn_trupdate_wakeup(void *);
378 static void segvn_trupdate(void);
379 static void segvn_trupdate_seg(struct seg *, segvn_data_t *, svntr_t *,
380     ulong_t);
381 
382 /*
383  * Initialize segvn data structures
384  */
385 void
386 segvn_init(void)
387 {
388 	uint_t maxszc;
389 	uint_t szc;
390 	size_t pgsz;
391 
392 	segvn_cache = kmem_cache_create("segvn_cache",
393 	    sizeof (struct segvn_data), 0,
394 	    segvn_cache_constructor, segvn_cache_destructor, NULL,
395 	    NULL, NULL, 0);
396 
397 	if (segvn_lpg_disable == 0) {
398 		szc = maxszc = page_num_pagesizes() - 1;
399 		if (szc == 0) {
400 			segvn_lpg_disable = 1;
401 		}
402 		if (page_get_pagesize(0) != PAGESIZE) {
403 			panic("segvn_init: bad szc 0");
404 			/*NOTREACHED*/
405 		}
406 		while (szc != 0) {
407 			pgsz = page_get_pagesize(szc);
408 			if (pgsz <= PAGESIZE || !IS_P2ALIGNED(pgsz, pgsz)) {
409 				panic("segvn_init: bad szc %d", szc);
410 				/*NOTREACHED*/
411 			}
412 			szc--;
413 		}
414 		if (segvn_maxpgszc == 0 || segvn_maxpgszc > maxszc)
415 			segvn_maxpgszc = maxszc;
416 	}
417 
418 	if (segvn_maxpgszc) {
419 		segvn_szc_cache = (struct kmem_cache **)kmem_alloc(
420 		    (segvn_maxpgszc + 1) * sizeof (struct kmem_cache *),
421 		    KM_SLEEP);
422 	}
423 
424 	for (szc = 1; szc <= segvn_maxpgszc; szc++) {
425 		char	str[32];
426 
427 		(void) sprintf(str, "segvn_szc_cache%d", szc);
428 		segvn_szc_cache[szc] = kmem_cache_create(str,
429 		    page_get_pagecnt(szc) * sizeof (page_t *), 0,
430 		    NULL, NULL, NULL, NULL, NULL, KMC_NODEBUG);
431 	}
432 
433 
434 	if (segvn_use_regions && !hat_supported(HAT_SHARED_REGIONS, NULL))
435 		segvn_use_regions = 0;
436 
437 	/*
438 	 * For now shared regions and text replication segvn support
439 	 * are mutually exclusive. This is acceptable because
440 	 * currently significant benefit from text replication was
441 	 * only observed on AMD64 NUMA platforms (due to relatively
442 	 * small L2$ size) and currently we don't support shared
443 	 * regions on x86.
444 	 */
445 	if (segvn_use_regions && !segvn_disable_textrepl) {
446 		segvn_disable_textrepl = 1;
447 	}
448 
449 #if defined(_LP64)
450 	if (lgrp_optimizations() && textrepl_size_thresh != (size_t)-1 &&
451 	    !segvn_disable_textrepl) {
452 		ulong_t i;
453 		size_t hsz = svntr_hashtab_sz * sizeof (svntr_bucket_t);
454 
455 		svntr_cache = kmem_cache_create("svntr_cache",
456 		    sizeof (svntr_t), 0, svntr_cache_constructor, NULL,
457 		    NULL, NULL, NULL, 0);
458 		svntr_hashtab = kmem_zalloc(hsz, KM_SLEEP);
459 		for (i = 0; i < svntr_hashtab_sz; i++) {
460 			mutex_init(&svntr_hashtab[i].tr_lock,  NULL,
461 			    MUTEX_DEFAULT, NULL);
462 		}
463 		segvn_textrepl_max_bytes = ptob(physmem) /
464 		    segvn_textrepl_max_bytes_factor;
465 		segvn_textrepl_stats = kmem_zalloc(NCPU *
466 		    sizeof (svntr_stats_t), KM_SLEEP);
467 		sema_init(&segvn_trasync_sem, 0, NULL, SEMA_DEFAULT, NULL);
468 		(void) thread_create(NULL, 0, segvn_trasync_thread,
469 		    NULL, 0, &p0, TS_RUN, minclsyspri);
470 	}
471 #endif
472 
473 	if (!ISP2(segvn_pglock_comb_balign) ||
474 	    segvn_pglock_comb_balign < PAGESIZE) {
475 		segvn_pglock_comb_balign = 1UL << 16; /* 64K */
476 	}
477 	segvn_pglock_comb_bshift = highbit(segvn_pglock_comb_balign) - 1;
478 	segvn_pglock_comb_palign = btop(segvn_pglock_comb_balign);
479 }
480 
481 #define	SEGVN_PAGEIO	((void *)0x1)
482 #define	SEGVN_NOPAGEIO	((void *)0x2)
483 
484 static void
485 segvn_setvnode_mpss(vnode_t *vp)
486 {
487 	int err;
488 
489 	ASSERT(vp->v_mpssdata == NULL ||
490 	    vp->v_mpssdata == SEGVN_PAGEIO ||
491 	    vp->v_mpssdata == SEGVN_NOPAGEIO);
492 
493 	if (vp->v_mpssdata == NULL) {
494 		if (vn_vmpss_usepageio(vp)) {
495 			err = VOP_PAGEIO(vp, (page_t *)NULL,
496 			    (u_offset_t)0, 0, 0, CRED(), NULL);
497 		} else {
498 			err = ENOSYS;
499 		}
500 		/*
501 		 * set v_mpssdata just once per vnode life
502 		 * so that it never changes.
503 		 */
504 		mutex_enter(&vp->v_lock);
505 		if (vp->v_mpssdata == NULL) {
506 			if (err == EINVAL) {
507 				vp->v_mpssdata = SEGVN_PAGEIO;
508 			} else {
509 				vp->v_mpssdata = SEGVN_NOPAGEIO;
510 			}
511 		}
512 		mutex_exit(&vp->v_lock);
513 	}
514 }
515 
516 int
517 segvn_create(struct seg *seg, void *argsp)
518 {
519 	struct segvn_crargs *a = (struct segvn_crargs *)argsp;
520 	struct segvn_data *svd;
521 	size_t swresv = 0;
522 	struct cred *cred;
523 	struct anon_map *amp;
524 	int error = 0;
525 	size_t pgsz;
526 	lgrp_mem_policy_t mpolicy = LGRP_MEM_POLICY_DEFAULT;
527 	int use_rgn = 0;
528 	int trok = 0;
529 
530 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
531 
532 	if (a->type != MAP_PRIVATE && a->type != MAP_SHARED) {
533 		panic("segvn_create type");
534 		/*NOTREACHED*/
535 	}
536 
537 	/*
538 	 * Check arguments.  If a shared anon structure is given then
539 	 * it is illegal to also specify a vp.
540 	 */
541 	if (a->amp != NULL && a->vp != NULL) {
542 		panic("segvn_create anon_map");
543 		/*NOTREACHED*/
544 	}
545 
546 	if (a->type == MAP_PRIVATE && (a->flags & MAP_TEXT) &&
547 	    a->vp != NULL && a->prot == (PROT_USER | PROT_READ | PROT_EXEC) &&
548 	    segvn_use_regions) {
549 		use_rgn = 1;
550 	}
551 
552 	/* MAP_NORESERVE on a MAP_SHARED segment is meaningless. */
553 	if (a->type == MAP_SHARED)
554 		a->flags &= ~MAP_NORESERVE;
555 
556 	if (a->szc != 0) {
557 		if (segvn_lpg_disable != 0 || (a->szc == AS_MAP_NO_LPOOB) ||
558 		    (a->amp != NULL && a->type == MAP_PRIVATE) ||
559 		    (a->flags & MAP_NORESERVE) || seg->s_as == &kas) {
560 			a->szc = 0;
561 		} else {
562 			if (a->szc > segvn_maxpgszc)
563 				a->szc = segvn_maxpgszc;
564 			pgsz = page_get_pagesize(a->szc);
565 			if (!IS_P2ALIGNED(seg->s_base, pgsz) ||
566 			    !IS_P2ALIGNED(seg->s_size, pgsz)) {
567 				a->szc = 0;
568 			} else if (a->vp != NULL) {
569 				if (IS_SWAPFSVP(a->vp) || VN_ISKAS(a->vp)) {
570 					/*
571 					 * paranoid check.
572 					 * hat_page_demote() is not supported
573 					 * on swapfs pages.
574 					 */
575 					a->szc = 0;
576 				} else if (map_addr_vacalign_check(seg->s_base,
577 				    a->offset & PAGEMASK)) {
578 					a->szc = 0;
579 				}
580 			} else if (a->amp != NULL) {
581 				pgcnt_t anum = btopr(a->offset);
582 				pgcnt_t pgcnt = page_get_pagecnt(a->szc);
583 				if (!IS_P2ALIGNED(anum, pgcnt)) {
584 					a->szc = 0;
585 				}
586 			}
587 		}
588 	}
589 
590 	/*
591 	 * If segment may need private pages, reserve them now.
592 	 */
593 	if (!(a->flags & MAP_NORESERVE) && ((a->vp == NULL && a->amp == NULL) ||
594 	    (a->type == MAP_PRIVATE && (a->prot & PROT_WRITE)))) {
595 		if (anon_resv_zone(seg->s_size,
596 		    seg->s_as->a_proc->p_zone) == 0)
597 			return (EAGAIN);
598 		swresv = seg->s_size;
599 		TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
600 		    seg, swresv, 1);
601 	}
602 
603 	/*
604 	 * Reserve any mapping structures that may be required.
605 	 *
606 	 * Don't do it for segments that may use regions. It's currently a
607 	 * noop in the hat implementations anyway.
608 	 */
609 	if (!use_rgn) {
610 		hat_map(seg->s_as->a_hat, seg->s_base, seg->s_size, HAT_MAP);
611 	}
612 
613 	if (a->cred) {
614 		cred = a->cred;
615 		crhold(cred);
616 	} else {
617 		crhold(cred = CRED());
618 	}
619 
620 	/* Inform the vnode of the new mapping */
621 	if (a->vp != NULL) {
622 		error = VOP_ADDMAP(a->vp, a->offset & PAGEMASK,
623 		    seg->s_as, seg->s_base, seg->s_size, a->prot,
624 		    a->maxprot, a->type, cred, NULL);
625 		if (error) {
626 			if (swresv != 0) {
627 				anon_unresv_zone(swresv,
628 				    seg->s_as->a_proc->p_zone);
629 				TRACE_3(TR_FAC_VM, TR_ANON_PROC,
630 				    "anon proc:%p %lu %u", seg, swresv, 0);
631 			}
632 			crfree(cred);
633 			if (!use_rgn) {
634 				hat_unload(seg->s_as->a_hat, seg->s_base,
635 				    seg->s_size, HAT_UNLOAD_UNMAP);
636 			}
637 			return (error);
638 		}
639 		/*
640 		 * svntr_hashtab will be NULL if we support shared regions.
641 		 */
642 		trok = ((a->flags & MAP_TEXT) &&
643 		    (seg->s_size > textrepl_size_thresh ||
644 		    (a->flags & _MAP_TEXTREPL)) &&
645 		    lgrp_optimizations() && svntr_hashtab != NULL &&
646 		    a->type == MAP_PRIVATE && swresv == 0 &&
647 		    !(a->flags & MAP_NORESERVE) &&
648 		    seg->s_as != &kas && a->vp->v_type == VREG);
649 
650 		ASSERT(!trok || !use_rgn);
651 	}
652 
653 	/*
654 	 * If more than one segment in the address space, and they're adjacent
655 	 * virtually, try to concatenate them.  Don't concatenate if an
656 	 * explicit anon_map structure was supplied (e.g., SystemV shared
657 	 * memory) or if we'll use text replication for this segment.
658 	 */
659 	if (a->amp == NULL && !use_rgn && !trok) {
660 		struct seg *pseg, *nseg;
661 		struct segvn_data *psvd, *nsvd;
662 		lgrp_mem_policy_t ppolicy, npolicy;
663 		uint_t	lgrp_mem_policy_flags = 0;
664 		extern lgrp_mem_policy_t lgrp_mem_default_policy;
665 
666 		/*
667 		 * Memory policy flags (lgrp_mem_policy_flags) is valid when
668 		 * extending stack/heap segments.
669 		 */
670 		if ((a->vp == NULL) && (a->type == MAP_PRIVATE) &&
671 		    !(a->flags & MAP_NORESERVE) && (seg->s_as != &kas)) {
672 			lgrp_mem_policy_flags = a->lgrp_mem_policy_flags;
673 		} else {
674 			/*
675 			 * Get policy when not extending it from another segment
676 			 */
677 			mpolicy = lgrp_mem_policy_default(seg->s_size, a->type);
678 		}
679 
680 		/*
681 		 * First, try to concatenate the previous and new segments
682 		 */
683 		pseg = AS_SEGPREV(seg->s_as, seg);
684 		if (pseg != NULL &&
685 		    pseg->s_base + pseg->s_size == seg->s_base &&
686 		    pseg->s_ops == &segvn_ops) {
687 			/*
688 			 * Get memory allocation policy from previous segment.
689 			 * When extension is specified (e.g. for heap) apply
690 			 * this policy to the new segment regardless of the
691 			 * outcome of segment concatenation.  Extension occurs
692 			 * for non-default policy otherwise default policy is
693 			 * used and is based on extended segment size.
694 			 */
695 			psvd = (struct segvn_data *)pseg->s_data;
696 			ppolicy = psvd->policy_info.mem_policy;
697 			if (lgrp_mem_policy_flags ==
698 			    LGRP_MP_FLAG_EXTEND_UP) {
699 				if (ppolicy != lgrp_mem_default_policy) {
700 					mpolicy = ppolicy;
701 				} else {
702 					mpolicy = lgrp_mem_policy_default(
703 					    pseg->s_size + seg->s_size,
704 					    a->type);
705 				}
706 			}
707 
708 			if (mpolicy == ppolicy &&
709 			    (pseg->s_size + seg->s_size <=
710 			    segvn_comb_thrshld || psvd->amp == NULL) &&
711 			    segvn_extend_prev(pseg, seg, a, swresv) == 0) {
712 				/*
713 				 * success! now try to concatenate
714 				 * with following seg
715 				 */
716 				crfree(cred);
717 				nseg = AS_SEGNEXT(pseg->s_as, pseg);
718 				if (nseg != NULL &&
719 				    nseg != pseg &&
720 				    nseg->s_ops == &segvn_ops &&
721 				    pseg->s_base + pseg->s_size ==
722 				    nseg->s_base)
723 					(void) segvn_concat(pseg, nseg, 0);
724 				ASSERT(pseg->s_szc == 0 ||
725 				    (a->szc == pseg->s_szc &&
726 				    IS_P2ALIGNED(pseg->s_base, pgsz) &&
727 				    IS_P2ALIGNED(pseg->s_size, pgsz)));
728 				return (0);
729 			}
730 		}
731 
732 		/*
733 		 * Failed, so try to concatenate with following seg
734 		 */
735 		nseg = AS_SEGNEXT(seg->s_as, seg);
736 		if (nseg != NULL &&
737 		    seg->s_base + seg->s_size == nseg->s_base &&
738 		    nseg->s_ops == &segvn_ops) {
739 			/*
740 			 * Get memory allocation policy from next segment.
741 			 * When extension is specified (e.g. for stack) apply
742 			 * this policy to the new segment regardless of the
743 			 * outcome of segment concatenation.  Extension occurs
744 			 * for non-default policy otherwise default policy is
745 			 * used and is based on extended segment size.
746 			 */
747 			nsvd = (struct segvn_data *)nseg->s_data;
748 			npolicy = nsvd->policy_info.mem_policy;
749 			if (lgrp_mem_policy_flags ==
750 			    LGRP_MP_FLAG_EXTEND_DOWN) {
751 				if (npolicy != lgrp_mem_default_policy) {
752 					mpolicy = npolicy;
753 				} else {
754 					mpolicy = lgrp_mem_policy_default(
755 					    nseg->s_size + seg->s_size,
756 					    a->type);
757 				}
758 			}
759 
760 			if (mpolicy == npolicy &&
761 			    segvn_extend_next(seg, nseg, a, swresv) == 0) {
762 				crfree(cred);
763 				ASSERT(nseg->s_szc == 0 ||
764 				    (a->szc == nseg->s_szc &&
765 				    IS_P2ALIGNED(nseg->s_base, pgsz) &&
766 				    IS_P2ALIGNED(nseg->s_size, pgsz)));
767 				return (0);
768 			}
769 		}
770 	}
771 
772 	if (a->vp != NULL) {
773 		VN_HOLD(a->vp);
774 		if (a->type == MAP_SHARED)
775 			lgrp_shm_policy_init(NULL, a->vp);
776 	}
777 	svd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
778 
779 	seg->s_ops = &segvn_ops;
780 	seg->s_data = (void *)svd;
781 	seg->s_szc = a->szc;
782 
783 	svd->seg = seg;
784 	svd->vp = a->vp;
785 	/*
786 	 * Anonymous mappings have no backing file so the offset is meaningless.
787 	 */
788 	svd->offset = a->vp ? (a->offset & PAGEMASK) : 0;
789 	svd->prot = a->prot;
790 	svd->maxprot = a->maxprot;
791 	svd->pageprot = 0;
792 	svd->type = a->type;
793 	svd->vpage = NULL;
794 	svd->cred = cred;
795 	svd->advice = MADV_NORMAL;
796 	svd->pageadvice = 0;
797 	svd->flags = (ushort_t)a->flags;
798 	svd->softlockcnt = 0;
799 	svd->softlockcnt_sbase = 0;
800 	svd->softlockcnt_send = 0;
801 	svd->rcookie = HAT_INVALID_REGION_COOKIE;
802 	svd->pageswap = 0;
803 
804 	if (a->szc != 0 && a->vp != NULL) {
805 		segvn_setvnode_mpss(a->vp);
806 	}
807 	if (svd->type == MAP_SHARED && svd->vp != NULL &&
808 	    (svd->vp->v_flag & VVMEXEC) && (svd->prot & PROT_WRITE)) {
809 		ASSERT(vn_is_mapped(svd->vp, V_WRITE));
810 		segvn_inval_trcache(svd->vp);
811 	}
812 
813 	amp = a->amp;
814 	if ((svd->amp = amp) == NULL) {
815 		svd->anon_index = 0;
816 		if (svd->type == MAP_SHARED) {
817 			svd->swresv = 0;
818 			/*
819 			 * Shared mappings to a vp need no other setup.
820 			 * If we have a shared mapping to an anon_map object
821 			 * which hasn't been allocated yet,  allocate the
822 			 * struct now so that it will be properly shared
823 			 * by remembering the swap reservation there.
824 			 */
825 			if (a->vp == NULL) {
826 				svd->amp = anonmap_alloc(seg->s_size, swresv,
827 				    ANON_SLEEP);
828 				svd->amp->a_szc = seg->s_szc;
829 			}
830 		} else {
831 			/*
832 			 * Private mapping (with or without a vp).
833 			 * Allocate anon_map when needed.
834 			 */
835 			svd->swresv = swresv;
836 		}
837 	} else {
838 		pgcnt_t anon_num;
839 
840 		/*
841 		 * Mapping to an existing anon_map structure without a vp.
842 		 * For now we will insure that the segment size isn't larger
843 		 * than the size - offset gives us.  Later on we may wish to
844 		 * have the anon array dynamically allocated itself so that
845 		 * we don't always have to allocate all the anon pointer slots.
846 		 * This of course involves adding extra code to check that we
847 		 * aren't trying to use an anon pointer slot beyond the end
848 		 * of the currently allocated anon array.
849 		 */
850 		if ((amp->size - a->offset) < seg->s_size) {
851 			panic("segvn_create anon_map size");
852 			/*NOTREACHED*/
853 		}
854 
855 		anon_num = btopr(a->offset);
856 
857 		if (a->type == MAP_SHARED) {
858 			/*
859 			 * SHARED mapping to a given anon_map.
860 			 */
861 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
862 			amp->refcnt++;
863 			if (a->szc > amp->a_szc) {
864 				amp->a_szc = a->szc;
865 			}
866 			ANON_LOCK_EXIT(&amp->a_rwlock);
867 			svd->anon_index = anon_num;
868 			svd->swresv = 0;
869 		} else {
870 			/*
871 			 * PRIVATE mapping to a given anon_map.
872 			 * Make sure that all the needed anon
873 			 * structures are created (so that we will
874 			 * share the underlying pages if nothing
875 			 * is written by this mapping) and then
876 			 * duplicate the anon array as is done
877 			 * when a privately mapped segment is dup'ed.
878 			 */
879 			struct anon *ap;
880 			caddr_t addr;
881 			caddr_t eaddr;
882 			ulong_t	anon_idx;
883 			int hat_flag = HAT_LOAD;
884 
885 			if (svd->flags & MAP_TEXT) {
886 				hat_flag |= HAT_LOAD_TEXT;
887 			}
888 
889 			svd->amp = anonmap_alloc(seg->s_size, 0, ANON_SLEEP);
890 			svd->amp->a_szc = seg->s_szc;
891 			svd->anon_index = 0;
892 			svd->swresv = swresv;
893 
894 			/*
895 			 * Prevent 2 threads from allocating anon
896 			 * slots simultaneously.
897 			 */
898 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
899 			eaddr = seg->s_base + seg->s_size;
900 
901 			for (anon_idx = anon_num, addr = seg->s_base;
902 			    addr < eaddr; addr += PAGESIZE, anon_idx++) {
903 				page_t *pp;
904 
905 				if ((ap = anon_get_ptr(amp->ahp,
906 				    anon_idx)) != NULL)
907 					continue;
908 
909 				/*
910 				 * Allocate the anon struct now.
911 				 * Might as well load up translation
912 				 * to the page while we're at it...
913 				 */
914 				pp = anon_zero(seg, addr, &ap, cred);
915 				if (ap == NULL || pp == NULL) {
916 					panic("segvn_create anon_zero");
917 					/*NOTREACHED*/
918 				}
919 
920 				/*
921 				 * Re-acquire the anon_map lock and
922 				 * initialize the anon array entry.
923 				 */
924 				ASSERT(anon_get_ptr(amp->ahp,
925 				    anon_idx) == NULL);
926 				(void) anon_set_ptr(amp->ahp, anon_idx, ap,
927 				    ANON_SLEEP);
928 
929 				ASSERT(seg->s_szc == 0);
930 				ASSERT(!IS_VMODSORT(pp->p_vnode));
931 
932 				ASSERT(use_rgn == 0);
933 				hat_memload(seg->s_as->a_hat, addr, pp,
934 				    svd->prot & ~PROT_WRITE, hat_flag);
935 
936 				page_unlock(pp);
937 			}
938 			ASSERT(seg->s_szc == 0);
939 			anon_dup(amp->ahp, anon_num, svd->amp->ahp,
940 			    0, seg->s_size);
941 			ANON_LOCK_EXIT(&amp->a_rwlock);
942 		}
943 	}
944 
945 	/*
946 	 * Set default memory allocation policy for segment
947 	 *
948 	 * Always set policy for private memory at least for initialization
949 	 * even if this is a shared memory segment
950 	 */
951 	(void) lgrp_privm_policy_set(mpolicy, &svd->policy_info, seg->s_size);
952 
953 	if (svd->type == MAP_SHARED)
954 		(void) lgrp_shm_policy_set(mpolicy, svd->amp, svd->anon_index,
955 		    svd->vp, svd->offset, seg->s_size);
956 
957 	if (use_rgn) {
958 		ASSERT(!trok);
959 		ASSERT(svd->amp == NULL);
960 		svd->rcookie = hat_join_region(seg->s_as->a_hat, seg->s_base,
961 		    seg->s_size, (void *)svd->vp, svd->offset, svd->prot,
962 		    (uchar_t)seg->s_szc, segvn_hat_rgn_unload_callback,
963 		    HAT_REGION_TEXT);
964 	}
965 
966 	ASSERT(!trok || !(svd->prot & PROT_WRITE));
967 	svd->tr_state = trok ? SEGVN_TR_INIT : SEGVN_TR_OFF;
968 
969 	return (0);
970 }
971 
972 /*
973  * Concatenate two existing segments, if possible.
974  * Return 0 on success, -1 if two segments are not compatible
975  * or -2 on memory allocation failure.
976  * If amp_cat == 1 then try and concat segments with anon maps
977  */
978 static int
979 segvn_concat(struct seg *seg1, struct seg *seg2, int amp_cat)
980 {
981 	struct segvn_data *svd1 = seg1->s_data;
982 	struct segvn_data *svd2 = seg2->s_data;
983 	struct anon_map *amp1 = svd1->amp;
984 	struct anon_map *amp2 = svd2->amp;
985 	struct vpage *vpage1 = svd1->vpage;
986 	struct vpage *vpage2 = svd2->vpage, *nvpage = NULL;
987 	size_t size, nvpsize;
988 	pgcnt_t npages1, npages2;
989 
990 	ASSERT(seg1->s_as && seg2->s_as && seg1->s_as == seg2->s_as);
991 	ASSERT(AS_WRITE_HELD(seg1->s_as, &seg1->s_as->a_lock));
992 	ASSERT(seg1->s_ops == seg2->s_ops);
993 
994 	if (HAT_IS_REGION_COOKIE_VALID(svd1->rcookie) ||
995 	    HAT_IS_REGION_COOKIE_VALID(svd2->rcookie)) {
996 		return (-1);
997 	}
998 
999 	/* both segments exist, try to merge them */
1000 #define	incompat(x)	(svd1->x != svd2->x)
1001 	if (incompat(vp) || incompat(maxprot) ||
1002 	    (!svd1->pageadvice && !svd2->pageadvice && incompat(advice)) ||
1003 	    (!svd1->pageprot && !svd2->pageprot && incompat(prot)) ||
1004 	    incompat(type) || incompat(cred) || incompat(flags) ||
1005 	    seg1->s_szc != seg2->s_szc || incompat(policy_info.mem_policy) ||
1006 	    (svd2->softlockcnt > 0) || svd1->softlockcnt_send > 0)
1007 		return (-1);
1008 #undef incompat
1009 
1010 	/*
1011 	 * vp == NULL implies zfod, offset doesn't matter
1012 	 */
1013 	if (svd1->vp != NULL &&
1014 	    svd1->offset + seg1->s_size != svd2->offset) {
1015 		return (-1);
1016 	}
1017 
1018 	/*
1019 	 * Don't concatenate if either segment uses text replication.
1020 	 */
1021 	if (svd1->tr_state != SEGVN_TR_OFF || svd2->tr_state != SEGVN_TR_OFF) {
1022 		return (-1);
1023 	}
1024 
1025 	/*
1026 	 * Fail early if we're not supposed to concatenate
1027 	 * segments with non NULL amp.
1028 	 */
1029 	if (amp_cat == 0 && (amp1 != NULL || amp2 != NULL)) {
1030 		return (-1);
1031 	}
1032 
1033 	if (svd1->vp == NULL && svd1->type == MAP_SHARED) {
1034 		if (amp1 != amp2) {
1035 			return (-1);
1036 		}
1037 		if (amp1 != NULL && svd1->anon_index + btop(seg1->s_size) !=
1038 		    svd2->anon_index) {
1039 			return (-1);
1040 		}
1041 		ASSERT(amp1 == NULL || amp1->refcnt >= 2);
1042 	}
1043 
1044 	/*
1045 	 * If either seg has vpages, create a new merged vpage array.
1046 	 */
1047 	if (vpage1 != NULL || vpage2 != NULL) {
1048 		struct vpage *vp, *evp;
1049 
1050 		npages1 = seg_pages(seg1);
1051 		npages2 = seg_pages(seg2);
1052 		nvpsize = vpgtob(npages1 + npages2);
1053 
1054 		if ((nvpage = kmem_zalloc(nvpsize, KM_NOSLEEP)) == NULL) {
1055 			return (-2);
1056 		}
1057 
1058 		if (vpage1 != NULL) {
1059 			bcopy(vpage1, nvpage, vpgtob(npages1));
1060 		} else {
1061 			evp = nvpage + npages1;
1062 			for (vp = nvpage; vp < evp; vp++) {
1063 				VPP_SETPROT(vp, svd1->prot);
1064 				VPP_SETADVICE(vp, svd1->advice);
1065 			}
1066 		}
1067 
1068 		if (vpage2 != NULL) {
1069 			bcopy(vpage2, nvpage + npages1, vpgtob(npages2));
1070 		} else {
1071 			evp = nvpage + npages1 + npages2;
1072 			for (vp = nvpage + npages1; vp < evp; vp++) {
1073 				VPP_SETPROT(vp, svd2->prot);
1074 				VPP_SETADVICE(vp, svd2->advice);
1075 			}
1076 		}
1077 
1078 		if (svd2->pageswap && (!svd1->pageswap && svd1->swresv)) {
1079 			ASSERT(svd1->swresv == seg1->s_size);
1080 			ASSERT(!(svd1->flags & MAP_NORESERVE));
1081 			ASSERT(!(svd2->flags & MAP_NORESERVE));
1082 			evp = nvpage + npages1;
1083 			for (vp = nvpage; vp < evp; vp++) {
1084 				VPP_SETSWAPRES(vp);
1085 			}
1086 		}
1087 
1088 		if (svd1->pageswap && (!svd2->pageswap && svd2->swresv)) {
1089 			ASSERT(svd2->swresv == seg2->s_size);
1090 			ASSERT(!(svd1->flags & MAP_NORESERVE));
1091 			ASSERT(!(svd2->flags & MAP_NORESERVE));
1092 			vp = nvpage + npages1;
1093 			evp = vp + npages2;
1094 			for (; vp < evp; vp++) {
1095 				VPP_SETSWAPRES(vp);
1096 			}
1097 		}
1098 	}
1099 	ASSERT((vpage1 != NULL || vpage2 != NULL) ||
1100 	    (svd1->pageswap == 0 && svd2->pageswap == 0));
1101 
1102 	/*
1103 	 * If either segment has private pages, create a new merged anon
1104 	 * array. If mergeing shared anon segments just decrement anon map's
1105 	 * refcnt.
1106 	 */
1107 	if (amp1 != NULL && svd1->type == MAP_SHARED) {
1108 		ASSERT(amp1 == amp2 && svd1->vp == NULL);
1109 		ANON_LOCK_ENTER(&amp1->a_rwlock, RW_WRITER);
1110 		ASSERT(amp1->refcnt >= 2);
1111 		amp1->refcnt--;
1112 		ANON_LOCK_EXIT(&amp1->a_rwlock);
1113 		svd2->amp = NULL;
1114 	} else if (amp1 != NULL || amp2 != NULL) {
1115 		struct anon_hdr *nahp;
1116 		struct anon_map *namp = NULL;
1117 		size_t asize;
1118 
1119 		ASSERT(svd1->type == MAP_PRIVATE);
1120 
1121 		asize = seg1->s_size + seg2->s_size;
1122 		if ((nahp = anon_create(btop(asize), ANON_NOSLEEP)) == NULL) {
1123 			if (nvpage != NULL) {
1124 				kmem_free(nvpage, nvpsize);
1125 			}
1126 			return (-2);
1127 		}
1128 		if (amp1 != NULL) {
1129 			/*
1130 			 * XXX anon rwlock is not really needed because
1131 			 * this is a private segment and we are writers.
1132 			 */
1133 			ANON_LOCK_ENTER(&amp1->a_rwlock, RW_WRITER);
1134 			ASSERT(amp1->refcnt == 1);
1135 			if (anon_copy_ptr(amp1->ahp, svd1->anon_index,
1136 			    nahp, 0, btop(seg1->s_size), ANON_NOSLEEP)) {
1137 				anon_release(nahp, btop(asize));
1138 				ANON_LOCK_EXIT(&amp1->a_rwlock);
1139 				if (nvpage != NULL) {
1140 					kmem_free(nvpage, nvpsize);
1141 				}
1142 				return (-2);
1143 			}
1144 		}
1145 		if (amp2 != NULL) {
1146 			ANON_LOCK_ENTER(&amp2->a_rwlock, RW_WRITER);
1147 			ASSERT(amp2->refcnt == 1);
1148 			if (anon_copy_ptr(amp2->ahp, svd2->anon_index,
1149 			    nahp, btop(seg1->s_size), btop(seg2->s_size),
1150 			    ANON_NOSLEEP)) {
1151 				anon_release(nahp, btop(asize));
1152 				ANON_LOCK_EXIT(&amp2->a_rwlock);
1153 				if (amp1 != NULL) {
1154 					ANON_LOCK_EXIT(&amp1->a_rwlock);
1155 				}
1156 				if (nvpage != NULL) {
1157 					kmem_free(nvpage, nvpsize);
1158 				}
1159 				return (-2);
1160 			}
1161 		}
1162 		if (amp1 != NULL) {
1163 			namp = amp1;
1164 			anon_release(amp1->ahp, btop(amp1->size));
1165 		}
1166 		if (amp2 != NULL) {
1167 			if (namp == NULL) {
1168 				ASSERT(amp1 == NULL);
1169 				namp = amp2;
1170 				anon_release(amp2->ahp, btop(amp2->size));
1171 			} else {
1172 				amp2->refcnt--;
1173 				ANON_LOCK_EXIT(&amp2->a_rwlock);
1174 				anonmap_free(amp2);
1175 			}
1176 			svd2->amp = NULL; /* needed for seg_free */
1177 		}
1178 		namp->ahp = nahp;
1179 		namp->size = asize;
1180 		svd1->amp = namp;
1181 		svd1->anon_index = 0;
1182 		ANON_LOCK_EXIT(&namp->a_rwlock);
1183 	}
1184 	/*
1185 	 * Now free the old vpage structures.
1186 	 */
1187 	if (nvpage != NULL) {
1188 		if (vpage1 != NULL) {
1189 			kmem_free(vpage1, vpgtob(npages1));
1190 		}
1191 		if (vpage2 != NULL) {
1192 			svd2->vpage = NULL;
1193 			kmem_free(vpage2, vpgtob(npages2));
1194 		}
1195 		if (svd2->pageprot) {
1196 			svd1->pageprot = 1;
1197 		}
1198 		if (svd2->pageadvice) {
1199 			svd1->pageadvice = 1;
1200 		}
1201 		if (svd2->pageswap) {
1202 			svd1->pageswap = 1;
1203 		}
1204 		svd1->vpage = nvpage;
1205 	}
1206 
1207 	/* all looks ok, merge segments */
1208 	svd1->swresv += svd2->swresv;
1209 	svd2->swresv = 0;  /* so seg_free doesn't release swap space */
1210 	size = seg2->s_size;
1211 	seg_free(seg2);
1212 	seg1->s_size += size;
1213 	return (0);
1214 }
1215 
1216 /*
1217  * Extend the previous segment (seg1) to include the
1218  * new segment (seg2 + a), if possible.
1219  * Return 0 on success.
1220  */
1221 static int
1222 segvn_extend_prev(seg1, seg2, a, swresv)
1223 	struct seg *seg1, *seg2;
1224 	struct segvn_crargs *a;
1225 	size_t swresv;
1226 {
1227 	struct segvn_data *svd1 = (struct segvn_data *)seg1->s_data;
1228 	size_t size;
1229 	struct anon_map *amp1;
1230 	struct vpage *new_vpage;
1231 
1232 	/*
1233 	 * We don't need any segment level locks for "segvn" data
1234 	 * since the address space is "write" locked.
1235 	 */
1236 	ASSERT(seg1->s_as && AS_WRITE_HELD(seg1->s_as, &seg1->s_as->a_lock));
1237 
1238 	if (HAT_IS_REGION_COOKIE_VALID(svd1->rcookie)) {
1239 		return (-1);
1240 	}
1241 
1242 	/* second segment is new, try to extend first */
1243 	/* XXX - should also check cred */
1244 	if (svd1->vp != a->vp || svd1->maxprot != a->maxprot ||
1245 	    (!svd1->pageprot && (svd1->prot != a->prot)) ||
1246 	    svd1->type != a->type || svd1->flags != a->flags ||
1247 	    seg1->s_szc != a->szc || svd1->softlockcnt_send > 0)
1248 		return (-1);
1249 
1250 	/* vp == NULL implies zfod, offset doesn't matter */
1251 	if (svd1->vp != NULL &&
1252 	    svd1->offset + seg1->s_size != (a->offset & PAGEMASK))
1253 		return (-1);
1254 
1255 	if (svd1->tr_state != SEGVN_TR_OFF) {
1256 		return (-1);
1257 	}
1258 
1259 	amp1 = svd1->amp;
1260 	if (amp1) {
1261 		pgcnt_t newpgs;
1262 
1263 		/*
1264 		 * Segment has private pages, can data structures
1265 		 * be expanded?
1266 		 *
1267 		 * Acquire the anon_map lock to prevent it from changing,
1268 		 * if it is shared.  This ensures that the anon_map
1269 		 * will not change while a thread which has a read/write
1270 		 * lock on an address space references it.
1271 		 * XXX - Don't need the anon_map lock at all if "refcnt"
1272 		 * is 1.
1273 		 *
1274 		 * Can't grow a MAP_SHARED segment with an anonmap because
1275 		 * there may be existing anon slots where we want to extend
1276 		 * the segment and we wouldn't know what to do with them
1277 		 * (e.g., for tmpfs right thing is to just leave them there,
1278 		 * for /dev/zero they should be cleared out).
1279 		 */
1280 		if (svd1->type == MAP_SHARED)
1281 			return (-1);
1282 
1283 		ANON_LOCK_ENTER(&amp1->a_rwlock, RW_WRITER);
1284 		if (amp1->refcnt > 1) {
1285 			ANON_LOCK_EXIT(&amp1->a_rwlock);
1286 			return (-1);
1287 		}
1288 		newpgs = anon_grow(amp1->ahp, &svd1->anon_index,
1289 		    btop(seg1->s_size), btop(seg2->s_size), ANON_NOSLEEP);
1290 
1291 		if (newpgs == 0) {
1292 			ANON_LOCK_EXIT(&amp1->a_rwlock);
1293 			return (-1);
1294 		}
1295 		amp1->size = ptob(newpgs);
1296 		ANON_LOCK_EXIT(&amp1->a_rwlock);
1297 	}
1298 	if (svd1->vpage != NULL) {
1299 		struct vpage *vp, *evp;
1300 		new_vpage =
1301 		    kmem_zalloc(vpgtob(seg_pages(seg1) + seg_pages(seg2)),
1302 			KM_NOSLEEP);
1303 		if (new_vpage == NULL)
1304 			return (-1);
1305 		bcopy(svd1->vpage, new_vpage, vpgtob(seg_pages(seg1)));
1306 		kmem_free(svd1->vpage, vpgtob(seg_pages(seg1)));
1307 		svd1->vpage = new_vpage;
1308 
1309 		vp = new_vpage + seg_pages(seg1);
1310 		evp = vp + seg_pages(seg2);
1311 		for (; vp < evp; vp++)
1312 			VPP_SETPROT(vp, a->prot);
1313 		if (svd1->pageswap && swresv) {
1314 			ASSERT(!(svd1->flags & MAP_NORESERVE));
1315 			ASSERT(swresv == seg2->s_size);
1316 			vp = new_vpage + seg_pages(seg1);
1317 			for (; vp < evp; vp++) {
1318 				VPP_SETSWAPRES(vp);
1319 			}
1320 		}
1321 	}
1322 	ASSERT(svd1->vpage != NULL || svd1->pageswap == 0);
1323 	size = seg2->s_size;
1324 	seg_free(seg2);
1325 	seg1->s_size += size;
1326 	svd1->swresv += swresv;
1327 	if (svd1->pageprot && (a->prot & PROT_WRITE) &&
1328 	    svd1->type == MAP_SHARED && svd1->vp != NULL &&
1329 	    (svd1->vp->v_flag & VVMEXEC)) {
1330 		ASSERT(vn_is_mapped(svd1->vp, V_WRITE));
1331 		segvn_inval_trcache(svd1->vp);
1332 	}
1333 	return (0);
1334 }
1335 
1336 /*
1337  * Extend the next segment (seg2) to include the
1338  * new segment (seg1 + a), if possible.
1339  * Return 0 on success.
1340  */
1341 static int
1342 segvn_extend_next(
1343 	struct seg *seg1,
1344 	struct seg *seg2,
1345 	struct segvn_crargs *a,
1346 	size_t swresv)
1347 {
1348 	struct segvn_data *svd2 = (struct segvn_data *)seg2->s_data;
1349 	size_t size;
1350 	struct anon_map *amp2;
1351 	struct vpage *new_vpage;
1352 
1353 	/*
1354 	 * We don't need any segment level locks for "segvn" data
1355 	 * since the address space is "write" locked.
1356 	 */
1357 	ASSERT(seg2->s_as && AS_WRITE_HELD(seg2->s_as, &seg2->s_as->a_lock));
1358 
1359 	if (HAT_IS_REGION_COOKIE_VALID(svd2->rcookie)) {
1360 		return (-1);
1361 	}
1362 
1363 	/* first segment is new, try to extend second */
1364 	/* XXX - should also check cred */
1365 	if (svd2->vp != a->vp || svd2->maxprot != a->maxprot ||
1366 	    (!svd2->pageprot && (svd2->prot != a->prot)) ||
1367 	    svd2->type != a->type || svd2->flags != a->flags ||
1368 	    seg2->s_szc != a->szc || svd2->softlockcnt_sbase > 0)
1369 		return (-1);
1370 	/* vp == NULL implies zfod, offset doesn't matter */
1371 	if (svd2->vp != NULL &&
1372 	    (a->offset & PAGEMASK) + seg1->s_size != svd2->offset)
1373 		return (-1);
1374 
1375 	if (svd2->tr_state != SEGVN_TR_OFF) {
1376 		return (-1);
1377 	}
1378 
1379 	amp2 = svd2->amp;
1380 	if (amp2) {
1381 		pgcnt_t newpgs;
1382 
1383 		/*
1384 		 * Segment has private pages, can data structures
1385 		 * be expanded?
1386 		 *
1387 		 * Acquire the anon_map lock to prevent it from changing,
1388 		 * if it is shared.  This ensures that the anon_map
1389 		 * will not change while a thread which has a read/write
1390 		 * lock on an address space references it.
1391 		 *
1392 		 * XXX - Don't need the anon_map lock at all if "refcnt"
1393 		 * is 1.
1394 		 */
1395 		if (svd2->type == MAP_SHARED)
1396 			return (-1);
1397 
1398 		ANON_LOCK_ENTER(&amp2->a_rwlock, RW_WRITER);
1399 		if (amp2->refcnt > 1) {
1400 			ANON_LOCK_EXIT(&amp2->a_rwlock);
1401 			return (-1);
1402 		}
1403 		newpgs = anon_grow(amp2->ahp, &svd2->anon_index,
1404 		    btop(seg2->s_size), btop(seg1->s_size),
1405 		    ANON_NOSLEEP | ANON_GROWDOWN);
1406 
1407 		if (newpgs == 0) {
1408 			ANON_LOCK_EXIT(&amp2->a_rwlock);
1409 			return (-1);
1410 		}
1411 		amp2->size = ptob(newpgs);
1412 		ANON_LOCK_EXIT(&amp2->a_rwlock);
1413 	}
1414 	if (svd2->vpage != NULL) {
1415 		struct vpage *vp, *evp;
1416 		new_vpage =
1417 		    kmem_zalloc(vpgtob(seg_pages(seg1) + seg_pages(seg2)),
1418 		    KM_NOSLEEP);
1419 		if (new_vpage == NULL) {
1420 			/* Not merging segments so adjust anon_index back */
1421 			if (amp2)
1422 				svd2->anon_index += seg_pages(seg1);
1423 			return (-1);
1424 		}
1425 		bcopy(svd2->vpage, new_vpage + seg_pages(seg1),
1426 		    vpgtob(seg_pages(seg2)));
1427 		kmem_free(svd2->vpage, vpgtob(seg_pages(seg2)));
1428 		svd2->vpage = new_vpage;
1429 
1430 		vp = new_vpage;
1431 		evp = vp + seg_pages(seg1);
1432 		for (; vp < evp; vp++)
1433 			VPP_SETPROT(vp, a->prot);
1434 		if (svd2->pageswap && swresv) {
1435 			ASSERT(!(svd2->flags & MAP_NORESERVE));
1436 			ASSERT(swresv == seg1->s_size);
1437 			vp = new_vpage;
1438 			for (; vp < evp; vp++) {
1439 				VPP_SETSWAPRES(vp);
1440 			}
1441 		}
1442 	}
1443 	ASSERT(svd2->vpage != NULL || svd2->pageswap == 0);
1444 	size = seg1->s_size;
1445 	seg_free(seg1);
1446 	seg2->s_size += size;
1447 	seg2->s_base -= size;
1448 	svd2->offset -= size;
1449 	svd2->swresv += swresv;
1450 	if (svd2->pageprot && (a->prot & PROT_WRITE) &&
1451 	    svd2->type == MAP_SHARED && svd2->vp != NULL &&
1452 	    (svd2->vp->v_flag & VVMEXEC)) {
1453 		ASSERT(vn_is_mapped(svd2->vp, V_WRITE));
1454 		segvn_inval_trcache(svd2->vp);
1455 	}
1456 	return (0);
1457 }
1458 
1459 static int
1460 segvn_dup(struct seg *seg, struct seg *newseg)
1461 {
1462 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
1463 	struct segvn_data *newsvd;
1464 	pgcnt_t npages = seg_pages(seg);
1465 	int error = 0;
1466 	uint_t prot;
1467 	size_t len;
1468 	struct anon_map *amp;
1469 
1470 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1471 	ASSERT(newseg->s_as->a_proc->p_parent == curproc);
1472 
1473 	/*
1474 	 * If segment has anon reserved, reserve more for the new seg.
1475 	 * For a MAP_NORESERVE segment swresv will be a count of all the
1476 	 * allocated anon slots; thus we reserve for the child as many slots
1477 	 * as the parent has allocated. This semantic prevents the child or
1478 	 * parent from dieing during a copy-on-write fault caused by trying
1479 	 * to write a shared pre-existing anon page.
1480 	 */
1481 	if ((len = svd->swresv) != 0) {
1482 		if (anon_resv(svd->swresv) == 0)
1483 			return (ENOMEM);
1484 
1485 		TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
1486 		    seg, len, 0);
1487 	}
1488 
1489 	newsvd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
1490 
1491 	newseg->s_ops = &segvn_ops;
1492 	newseg->s_data = (void *)newsvd;
1493 	newseg->s_szc = seg->s_szc;
1494 
1495 	newsvd->seg = newseg;
1496 	if ((newsvd->vp = svd->vp) != NULL) {
1497 		VN_HOLD(svd->vp);
1498 		if (svd->type == MAP_SHARED)
1499 			lgrp_shm_policy_init(NULL, svd->vp);
1500 	}
1501 	newsvd->offset = svd->offset;
1502 	newsvd->prot = svd->prot;
1503 	newsvd->maxprot = svd->maxprot;
1504 	newsvd->pageprot = svd->pageprot;
1505 	newsvd->type = svd->type;
1506 	newsvd->cred = svd->cred;
1507 	crhold(newsvd->cred);
1508 	newsvd->advice = svd->advice;
1509 	newsvd->pageadvice = svd->pageadvice;
1510 	newsvd->swresv = svd->swresv;
1511 	newsvd->pageswap = svd->pageswap;
1512 	newsvd->flags = svd->flags;
1513 	newsvd->softlockcnt = 0;
1514 	newsvd->softlockcnt_sbase = 0;
1515 	newsvd->softlockcnt_send = 0;
1516 	newsvd->policy_info = svd->policy_info;
1517 	newsvd->rcookie = HAT_INVALID_REGION_COOKIE;
1518 
1519 	if ((amp = svd->amp) == NULL || svd->tr_state == SEGVN_TR_ON) {
1520 		/*
1521 		 * Not attaching to a shared anon object.
1522 		 */
1523 		ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie) ||
1524 		    svd->tr_state == SEGVN_TR_OFF);
1525 		if (svd->tr_state == SEGVN_TR_ON) {
1526 			ASSERT(newsvd->vp != NULL && amp != NULL);
1527 			newsvd->tr_state = SEGVN_TR_INIT;
1528 		} else {
1529 			newsvd->tr_state = svd->tr_state;
1530 		}
1531 		newsvd->amp = NULL;
1532 		newsvd->anon_index = 0;
1533 	} else {
1534 		/* regions for now are only used on pure vnode segments */
1535 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
1536 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
1537 		newsvd->tr_state = SEGVN_TR_OFF;
1538 		if (svd->type == MAP_SHARED) {
1539 			newsvd->amp = amp;
1540 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
1541 			amp->refcnt++;
1542 			ANON_LOCK_EXIT(&amp->a_rwlock);
1543 			newsvd->anon_index = svd->anon_index;
1544 		} else {
1545 			int reclaim = 1;
1546 
1547 			/*
1548 			 * Allocate and initialize new anon_map structure.
1549 			 */
1550 			newsvd->amp = anonmap_alloc(newseg->s_size, 0,
1551 			    ANON_SLEEP);
1552 			newsvd->amp->a_szc = newseg->s_szc;
1553 			newsvd->anon_index = 0;
1554 
1555 			/*
1556 			 * We don't have to acquire the anon_map lock
1557 			 * for the new segment (since it belongs to an
1558 			 * address space that is still not associated
1559 			 * with any process), or the segment in the old
1560 			 * address space (since all threads in it
1561 			 * are stopped while duplicating the address space).
1562 			 */
1563 
1564 			/*
1565 			 * The goal of the following code is to make sure that
1566 			 * softlocked pages do not end up as copy on write
1567 			 * pages.  This would cause problems where one
1568 			 * thread writes to a page that is COW and a different
1569 			 * thread in the same process has softlocked it.  The
1570 			 * softlock lock would move away from this process
1571 			 * because the write would cause this process to get
1572 			 * a copy (without the softlock).
1573 			 *
1574 			 * The strategy here is to just break the
1575 			 * sharing on pages that could possibly be
1576 			 * softlocked.
1577 			 */
1578 retry:
1579 			if (svd->softlockcnt) {
1580 				struct anon *ap, *newap;
1581 				size_t i;
1582 				uint_t vpprot;
1583 				page_t *anon_pl[1+1], *pp;
1584 				caddr_t addr;
1585 				ulong_t old_idx = svd->anon_index;
1586 				ulong_t new_idx = 0;
1587 
1588 				/*
1589 				 * The softlock count might be non zero
1590 				 * because some pages are still stuck in the
1591 				 * cache for lazy reclaim. Flush the cache
1592 				 * now. This should drop the count to zero.
1593 				 * [or there is really I/O going on to these
1594 				 * pages]. Note, we have the writers lock so
1595 				 * nothing gets inserted during the flush.
1596 				 */
1597 				if (reclaim == 1) {
1598 					segvn_purge(seg);
1599 					reclaim = 0;
1600 					goto retry;
1601 				}
1602 				i = btopr(seg->s_size);
1603 				addr = seg->s_base;
1604 				/*
1605 				 * XXX break cow sharing using PAGESIZE
1606 				 * pages. They will be relocated into larger
1607 				 * pages at fault time.
1608 				 */
1609 				while (i-- > 0) {
1610 					if (ap = anon_get_ptr(amp->ahp,
1611 					    old_idx)) {
1612 						error = anon_getpage(&ap,
1613 						    &vpprot, anon_pl, PAGESIZE,
1614 						    seg, addr, S_READ,
1615 						    svd->cred);
1616 						if (error) {
1617 							newsvd->vpage = NULL;
1618 							goto out;
1619 						}
1620 						/*
1621 						 * prot need not be computed
1622 						 * below 'cause anon_private is
1623 						 * going to ignore it anyway
1624 						 * as child doesn't inherit
1625 						 * pagelock from parent.
1626 						 */
1627 						prot = svd->pageprot ?
1628 						    VPP_PROT(
1629 						    &svd->vpage[
1630 						    seg_page(seg, addr)])
1631 						    : svd->prot;
1632 						pp = anon_private(&newap,
1633 						    newseg, addr, prot,
1634 						    anon_pl[0],	0,
1635 						    newsvd->cred);
1636 						if (pp == NULL) {
1637 							/* no mem abort */
1638 							newsvd->vpage = NULL;
1639 							error = ENOMEM;
1640 							goto out;
1641 						}
1642 						(void) anon_set_ptr(
1643 						    newsvd->amp->ahp, new_idx,
1644 						    newap, ANON_SLEEP);
1645 						page_unlock(pp);
1646 					}
1647 					addr += PAGESIZE;
1648 					old_idx++;
1649 					new_idx++;
1650 				}
1651 			} else {	/* common case */
1652 				if (seg->s_szc != 0) {
1653 					/*
1654 					 * If at least one of anon slots of a
1655 					 * large page exists then make sure
1656 					 * all anon slots of a large page
1657 					 * exist to avoid partial cow sharing
1658 					 * of a large page in the future.
1659 					 */
1660 					anon_dup_fill_holes(amp->ahp,
1661 					    svd->anon_index, newsvd->amp->ahp,
1662 					    0, seg->s_size, seg->s_szc,
1663 					    svd->vp != NULL);
1664 				} else {
1665 					anon_dup(amp->ahp, svd->anon_index,
1666 					    newsvd->amp->ahp, 0, seg->s_size);
1667 				}
1668 
1669 				hat_clrattr(seg->s_as->a_hat, seg->s_base,
1670 				    seg->s_size, PROT_WRITE);
1671 			}
1672 		}
1673 	}
1674 	/*
1675 	 * If necessary, create a vpage structure for the new segment.
1676 	 * Do not copy any page lock indications.
1677 	 */
1678 	if (svd->vpage != NULL) {
1679 		uint_t i;
1680 		struct vpage *ovp = svd->vpage;
1681 		struct vpage *nvp;
1682 
1683 		nvp = newsvd->vpage =
1684 		    kmem_alloc(vpgtob(npages), KM_SLEEP);
1685 		for (i = 0; i < npages; i++) {
1686 			*nvp = *ovp++;
1687 			VPP_CLRPPLOCK(nvp++);
1688 		}
1689 	} else
1690 		newsvd->vpage = NULL;
1691 
1692 	/* Inform the vnode of the new mapping */
1693 	if (newsvd->vp != NULL) {
1694 		error = VOP_ADDMAP(newsvd->vp, (offset_t)newsvd->offset,
1695 		    newseg->s_as, newseg->s_base, newseg->s_size, newsvd->prot,
1696 		    newsvd->maxprot, newsvd->type, newsvd->cred, NULL);
1697 	}
1698 out:
1699 	if (error == 0 && HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
1700 		ASSERT(newsvd->amp == NULL);
1701 		ASSERT(newsvd->tr_state == SEGVN_TR_OFF);
1702 		newsvd->rcookie = svd->rcookie;
1703 		hat_dup_region(newseg->s_as->a_hat, newsvd->rcookie);
1704 	}
1705 	return (error);
1706 }
1707 
1708 
1709 /*
1710  * callback function to invoke free_vp_pages() for only those pages actually
1711  * processed by the HAT when a shared region is destroyed.
1712  */
1713 extern int free_pages;
1714 
1715 static void
1716 segvn_hat_rgn_unload_callback(caddr_t saddr, caddr_t eaddr, caddr_t r_saddr,
1717     size_t r_size, void *r_obj, u_offset_t r_objoff)
1718 {
1719 	u_offset_t off;
1720 	size_t len;
1721 	vnode_t *vp = (vnode_t *)r_obj;
1722 
1723 	ASSERT(eaddr > saddr);
1724 	ASSERT(saddr >= r_saddr);
1725 	ASSERT(saddr < r_saddr + r_size);
1726 	ASSERT(eaddr > r_saddr);
1727 	ASSERT(eaddr <= r_saddr + r_size);
1728 	ASSERT(vp != NULL);
1729 
1730 	if (!free_pages) {
1731 		return;
1732 	}
1733 
1734 	len = eaddr - saddr;
1735 	off = (saddr - r_saddr) + r_objoff;
1736 	free_vp_pages(vp, off, len);
1737 }
1738 
1739 /*
1740  * callback function used by segvn_unmap to invoke free_vp_pages() for only
1741  * those pages actually processed by the HAT
1742  */
1743 static void
1744 segvn_hat_unload_callback(hat_callback_t *cb)
1745 {
1746 	struct seg		*seg = cb->hcb_data;
1747 	struct segvn_data	*svd = (struct segvn_data *)seg->s_data;
1748 	size_t			len;
1749 	u_offset_t		off;
1750 
1751 	ASSERT(svd->vp != NULL);
1752 	ASSERT(cb->hcb_end_addr > cb->hcb_start_addr);
1753 	ASSERT(cb->hcb_start_addr >= seg->s_base);
1754 
1755 	len = cb->hcb_end_addr - cb->hcb_start_addr;
1756 	off = cb->hcb_start_addr - seg->s_base;
1757 	free_vp_pages(svd->vp, svd->offset + off, len);
1758 }
1759 
1760 /*
1761  * This function determines the number of bytes of swap reserved by
1762  * a segment for which per-page accounting is present. It is used to
1763  * calculate the correct value of a segvn_data's swresv.
1764  */
1765 static size_t
1766 segvn_count_swap_by_vpages(struct seg *seg)
1767 {
1768 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
1769 	struct vpage *vp, *evp;
1770 	size_t nswappages = 0;
1771 
1772 	ASSERT(svd->pageswap);
1773 	ASSERT(svd->vpage != NULL);
1774 
1775 	evp = &svd->vpage[seg_page(seg, seg->s_base + seg->s_size)];
1776 
1777 	for (vp = svd->vpage; vp < evp; vp++) {
1778 		if (VPP_ISSWAPRES(vp))
1779 			nswappages++;
1780 	}
1781 
1782 	return (nswappages << PAGESHIFT);
1783 }
1784 
1785 static int
1786 segvn_unmap(struct seg *seg, caddr_t addr, size_t len)
1787 {
1788 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
1789 	struct segvn_data *nsvd;
1790 	struct seg *nseg;
1791 	struct anon_map *amp;
1792 	pgcnt_t	opages;		/* old segment size in pages */
1793 	pgcnt_t	npages;		/* new segment size in pages */
1794 	pgcnt_t	dpages;		/* pages being deleted (unmapped) */
1795 	hat_callback_t callback;	/* used for free_vp_pages() */
1796 	hat_callback_t *cbp = NULL;
1797 	caddr_t nbase;
1798 	size_t nsize;
1799 	size_t oswresv;
1800 	int reclaim = 1;
1801 
1802 	/*
1803 	 * We don't need any segment level locks for "segvn" data
1804 	 * since the address space is "write" locked.
1805 	 */
1806 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1807 
1808 	/*
1809 	 * Fail the unmap if pages are SOFTLOCKed through this mapping.
1810 	 * softlockcnt is protected from change by the as write lock.
1811 	 */
1812 retry:
1813 	if (svd->softlockcnt > 0) {
1814 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
1815 
1816 		/*
1817 		 * If this is shared segment non 0 softlockcnt
1818 		 * means locked pages are still in use.
1819 		 */
1820 		if (svd->type == MAP_SHARED) {
1821 			return (EAGAIN);
1822 		}
1823 
1824 		/*
1825 		 * since we do have the writers lock nobody can fill
1826 		 * the cache during the purge. The flush either succeeds
1827 		 * or we still have pending I/Os.
1828 		 */
1829 		if (reclaim == 1) {
1830 			segvn_purge(seg);
1831 			reclaim = 0;
1832 			goto retry;
1833 		}
1834 		return (EAGAIN);
1835 	}
1836 
1837 	/*
1838 	 * Check for bad sizes
1839 	 */
1840 	if (addr < seg->s_base || addr + len > seg->s_base + seg->s_size ||
1841 	    (len & PAGEOFFSET) || ((uintptr_t)addr & PAGEOFFSET)) {
1842 		panic("segvn_unmap");
1843 		/*NOTREACHED*/
1844 	}
1845 
1846 	if (seg->s_szc != 0) {
1847 		size_t pgsz = page_get_pagesize(seg->s_szc);
1848 		int err;
1849 		if (!IS_P2ALIGNED(addr, pgsz) || !IS_P2ALIGNED(len, pgsz)) {
1850 			ASSERT(seg->s_base != addr || seg->s_size != len);
1851 			if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
1852 				ASSERT(svd->amp == NULL);
1853 				ASSERT(svd->tr_state == SEGVN_TR_OFF);
1854 				hat_leave_region(seg->s_as->a_hat,
1855 				    svd->rcookie, HAT_REGION_TEXT);
1856 				svd->rcookie = HAT_INVALID_REGION_COOKIE;
1857 				/*
1858 				 * could pass a flag to segvn_demote_range()
1859 				 * below to tell it not to do any unloads but
1860 				 * this case is rare enough to not bother for
1861 				 * now.
1862 				 */
1863 			} else if (svd->tr_state == SEGVN_TR_INIT) {
1864 				svd->tr_state = SEGVN_TR_OFF;
1865 			} else if (svd->tr_state == SEGVN_TR_ON) {
1866 				ASSERT(svd->amp != NULL);
1867 				segvn_textunrepl(seg, 1);
1868 				ASSERT(svd->amp == NULL);
1869 				ASSERT(svd->tr_state == SEGVN_TR_OFF);
1870 			}
1871 			VM_STAT_ADD(segvnvmstats.demoterange[0]);
1872 			err = segvn_demote_range(seg, addr, len, SDR_END, 0);
1873 			if (err == 0) {
1874 				return (IE_RETRY);
1875 			}
1876 			return (err);
1877 		}
1878 	}
1879 
1880 	/* Inform the vnode of the unmapping. */
1881 	if (svd->vp) {
1882 		int error;
1883 
1884 		error = VOP_DELMAP(svd->vp,
1885 		    (offset_t)svd->offset + (uintptr_t)(addr - seg->s_base),
1886 		    seg->s_as, addr, len, svd->prot, svd->maxprot,
1887 		    svd->type, svd->cred, NULL);
1888 
1889 		if (error == EAGAIN)
1890 			return (error);
1891 	}
1892 
1893 	/*
1894 	 * Remove any page locks set through this mapping.
1895 	 * If text replication is not off no page locks could have been
1896 	 * established via this mapping.
1897 	 */
1898 	if (svd->tr_state == SEGVN_TR_OFF) {
1899 		(void) segvn_lockop(seg, addr, len, 0, MC_UNLOCK, NULL, 0);
1900 	}
1901 
1902 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
1903 		ASSERT(svd->amp == NULL);
1904 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
1905 		ASSERT(svd->type == MAP_PRIVATE);
1906 		hat_leave_region(seg->s_as->a_hat, svd->rcookie,
1907 		    HAT_REGION_TEXT);
1908 		svd->rcookie = HAT_INVALID_REGION_COOKIE;
1909 	} else if (svd->tr_state == SEGVN_TR_ON) {
1910 		ASSERT(svd->amp != NULL);
1911 		ASSERT(svd->pageprot == 0 && !(svd->prot & PROT_WRITE));
1912 		segvn_textunrepl(seg, 1);
1913 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
1914 	} else {
1915 		if (svd->tr_state != SEGVN_TR_OFF) {
1916 			ASSERT(svd->tr_state == SEGVN_TR_INIT);
1917 			svd->tr_state = SEGVN_TR_OFF;
1918 		}
1919 		/*
1920 		 * Unload any hardware translations in the range to be taken
1921 		 * out. Use a callback to invoke free_vp_pages() effectively.
1922 		 */
1923 		if (svd->vp != NULL && free_pages != 0) {
1924 			callback.hcb_data = seg;
1925 			callback.hcb_function = segvn_hat_unload_callback;
1926 			cbp = &callback;
1927 		}
1928 		hat_unload_callback(seg->s_as->a_hat, addr, len,
1929 		    HAT_UNLOAD_UNMAP, cbp);
1930 
1931 		if (svd->type == MAP_SHARED && svd->vp != NULL &&
1932 		    (svd->vp->v_flag & VVMEXEC) &&
1933 		    ((svd->prot & PROT_WRITE) || svd->pageprot)) {
1934 			segvn_inval_trcache(svd->vp);
1935 		}
1936 	}
1937 
1938 	/*
1939 	 * Check for entire segment
1940 	 */
1941 	if (addr == seg->s_base && len == seg->s_size) {
1942 		seg_free(seg);
1943 		return (0);
1944 	}
1945 
1946 	opages = seg_pages(seg);
1947 	dpages = btop(len);
1948 	npages = opages - dpages;
1949 	amp = svd->amp;
1950 	ASSERT(amp == NULL || amp->a_szc >= seg->s_szc);
1951 
1952 	/*
1953 	 * Check for beginning of segment
1954 	 */
1955 	if (addr == seg->s_base) {
1956 		if (svd->vpage != NULL) {
1957 			size_t nbytes;
1958 			struct vpage *ovpage;
1959 
1960 			ovpage = svd->vpage;	/* keep pointer to vpage */
1961 
1962 			nbytes = vpgtob(npages);
1963 			svd->vpage = kmem_alloc(nbytes, KM_SLEEP);
1964 			bcopy(&ovpage[dpages], svd->vpage, nbytes);
1965 
1966 			/* free up old vpage */
1967 			kmem_free(ovpage, vpgtob(opages));
1968 		}
1969 		if (amp != NULL) {
1970 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
1971 			if (amp->refcnt == 1 || svd->type == MAP_PRIVATE) {
1972 				/*
1973 				 * Shared anon map is no longer in use. Before
1974 				 * freeing its pages purge all entries from
1975 				 * pcache that belong to this amp.
1976 				 */
1977 				if (svd->type == MAP_SHARED) {
1978 					ASSERT(amp->refcnt == 1);
1979 					ASSERT(svd->softlockcnt == 0);
1980 					anonmap_purge(amp);
1981 				}
1982 				/*
1983 				 * Free up now unused parts of anon_map array.
1984 				 */
1985 				if (amp->a_szc == seg->s_szc) {
1986 					if (seg->s_szc != 0) {
1987 						anon_free_pages(amp->ahp,
1988 						    svd->anon_index, len,
1989 						    seg->s_szc);
1990 					} else {
1991 						anon_free(amp->ahp,
1992 						    svd->anon_index,
1993 						    len);
1994 					}
1995 				} else {
1996 					ASSERT(svd->type == MAP_SHARED);
1997 					ASSERT(amp->a_szc > seg->s_szc);
1998 					anon_shmap_free_pages(amp,
1999 					    svd->anon_index, len);
2000 				}
2001 
2002 				/*
2003 				 * Unreserve swap space for the
2004 				 * unmapped chunk of this segment in
2005 				 * case it's MAP_SHARED
2006 				 */
2007 				if (svd->type == MAP_SHARED) {
2008 					anon_unresv_zone(len,
2009 					    seg->s_as->a_proc->p_zone);
2010 					amp->swresv -= len;
2011 				}
2012 			}
2013 			ANON_LOCK_EXIT(&amp->a_rwlock);
2014 			svd->anon_index += dpages;
2015 		}
2016 		if (svd->vp != NULL)
2017 			svd->offset += len;
2018 
2019 		seg->s_base += len;
2020 		seg->s_size -= len;
2021 
2022 		if (svd->swresv) {
2023 			if (svd->flags & MAP_NORESERVE) {
2024 				ASSERT(amp);
2025 				oswresv = svd->swresv;
2026 
2027 				svd->swresv = ptob(anon_pages(amp->ahp,
2028 				    svd->anon_index, npages));
2029 				anon_unresv_zone(oswresv - svd->swresv,
2030 				    seg->s_as->a_proc->p_zone);
2031 				if (SEG_IS_PARTIAL_RESV(seg))
2032 					seg->s_as->a_resvsize -= oswresv -
2033 					    svd->swresv;
2034 			} else {
2035 				size_t unlen;
2036 
2037 				if (svd->pageswap) {
2038 					oswresv = svd->swresv;
2039 					svd->swresv =
2040 					    segvn_count_swap_by_vpages(seg);
2041 					ASSERT(oswresv >= svd->swresv);
2042 					unlen = oswresv - svd->swresv;
2043 				} else {
2044 					svd->swresv -= len;
2045 					ASSERT(svd->swresv == seg->s_size);
2046 					unlen = len;
2047 				}
2048 				anon_unresv_zone(unlen,
2049 				    seg->s_as->a_proc->p_zone);
2050 			}
2051 			TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
2052 			    seg, len, 0);
2053 		}
2054 
2055 		return (0);
2056 	}
2057 
2058 	/*
2059 	 * Check for end of segment
2060 	 */
2061 	if (addr + len == seg->s_base + seg->s_size) {
2062 		if (svd->vpage != NULL) {
2063 			size_t nbytes;
2064 			struct vpage *ovpage;
2065 
2066 			ovpage = svd->vpage;	/* keep pointer to vpage */
2067 
2068 			nbytes = vpgtob(npages);
2069 			svd->vpage = kmem_alloc(nbytes, KM_SLEEP);
2070 			bcopy(ovpage, svd->vpage, nbytes);
2071 
2072 			/* free up old vpage */
2073 			kmem_free(ovpage, vpgtob(opages));
2074 
2075 		}
2076 		if (amp != NULL) {
2077 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2078 			if (amp->refcnt == 1 || svd->type == MAP_PRIVATE) {
2079 				/*
2080 				 * Free up now unused parts of anon_map array.
2081 				 */
2082 				ulong_t an_idx = svd->anon_index + npages;
2083 
2084 				/*
2085 				 * Shared anon map is no longer in use. Before
2086 				 * freeing its pages purge all entries from
2087 				 * pcache that belong to this amp.
2088 				 */
2089 				if (svd->type == MAP_SHARED) {
2090 					ASSERT(amp->refcnt == 1);
2091 					ASSERT(svd->softlockcnt == 0);
2092 					anonmap_purge(amp);
2093 				}
2094 
2095 				if (amp->a_szc == seg->s_szc) {
2096 					if (seg->s_szc != 0) {
2097 						anon_free_pages(amp->ahp,
2098 						    an_idx, len,
2099 						    seg->s_szc);
2100 					} else {
2101 						anon_free(amp->ahp, an_idx,
2102 						    len);
2103 					}
2104 				} else {
2105 					ASSERT(svd->type == MAP_SHARED);
2106 					ASSERT(amp->a_szc > seg->s_szc);
2107 					anon_shmap_free_pages(amp,
2108 					    an_idx, len);
2109 				}
2110 
2111 				/*
2112 				 * Unreserve swap space for the
2113 				 * unmapped chunk of this segment in
2114 				 * case it's MAP_SHARED
2115 				 */
2116 				if (svd->type == MAP_SHARED) {
2117 					anon_unresv_zone(len,
2118 					    seg->s_as->a_proc->p_zone);
2119 					amp->swresv -= len;
2120 				}
2121 			}
2122 			ANON_LOCK_EXIT(&amp->a_rwlock);
2123 		}
2124 
2125 		seg->s_size -= len;
2126 
2127 		if (svd->swresv) {
2128 			if (svd->flags & MAP_NORESERVE) {
2129 				ASSERT(amp);
2130 				oswresv = svd->swresv;
2131 				svd->swresv = ptob(anon_pages(amp->ahp,
2132 				    svd->anon_index, npages));
2133 				anon_unresv_zone(oswresv - svd->swresv,
2134 				    seg->s_as->a_proc->p_zone);
2135 				if (SEG_IS_PARTIAL_RESV(seg))
2136 					seg->s_as->a_resvsize -= oswresv -
2137 					    svd->swresv;
2138 			} else {
2139 				size_t unlen;
2140 
2141 				if (svd->pageswap) {
2142 					oswresv = svd->swresv;
2143 					svd->swresv =
2144 					    segvn_count_swap_by_vpages(seg);
2145 					ASSERT(oswresv >= svd->swresv);
2146 					unlen = oswresv - svd->swresv;
2147 				} else {
2148 					svd->swresv -= len;
2149 					ASSERT(svd->swresv == seg->s_size);
2150 					unlen = len;
2151 				}
2152 				anon_unresv_zone(unlen,
2153 				    seg->s_as->a_proc->p_zone);
2154 			}
2155 			TRACE_3(TR_FAC_VM, TR_ANON_PROC,
2156 			    "anon proc:%p %lu %u", seg, len, 0);
2157 		}
2158 
2159 		return (0);
2160 	}
2161 
2162 	/*
2163 	 * The section to go is in the middle of the segment,
2164 	 * have to make it into two segments.  nseg is made for
2165 	 * the high end while seg is cut down at the low end.
2166 	 */
2167 	nbase = addr + len;				/* new seg base */
2168 	nsize = (seg->s_base + seg->s_size) - nbase;	/* new seg size */
2169 	seg->s_size = addr - seg->s_base;		/* shrink old seg */
2170 	nseg = seg_alloc(seg->s_as, nbase, nsize);
2171 	if (nseg == NULL) {
2172 		panic("segvn_unmap seg_alloc");
2173 		/*NOTREACHED*/
2174 	}
2175 	nseg->s_ops = seg->s_ops;
2176 	nsvd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
2177 	nseg->s_data = (void *)nsvd;
2178 	nseg->s_szc = seg->s_szc;
2179 	*nsvd = *svd;
2180 	nsvd->seg = nseg;
2181 	nsvd->offset = svd->offset + (uintptr_t)(nseg->s_base - seg->s_base);
2182 	nsvd->swresv = 0;
2183 	nsvd->softlockcnt = 0;
2184 	nsvd->softlockcnt_sbase = 0;
2185 	nsvd->softlockcnt_send = 0;
2186 	ASSERT(nsvd->rcookie == HAT_INVALID_REGION_COOKIE);
2187 
2188 	if (svd->vp != NULL) {
2189 		VN_HOLD(nsvd->vp);
2190 		if (nsvd->type == MAP_SHARED)
2191 			lgrp_shm_policy_init(NULL, nsvd->vp);
2192 	}
2193 	crhold(svd->cred);
2194 
2195 	if (svd->vpage == NULL) {
2196 		nsvd->vpage = NULL;
2197 	} else {
2198 		/* need to split vpage into two arrays */
2199 		size_t nbytes;
2200 		struct vpage *ovpage;
2201 
2202 		ovpage = svd->vpage;		/* keep pointer to vpage */
2203 
2204 		npages = seg_pages(seg);	/* seg has shrunk */
2205 		nbytes = vpgtob(npages);
2206 		svd->vpage = kmem_alloc(nbytes, KM_SLEEP);
2207 
2208 		bcopy(ovpage, svd->vpage, nbytes);
2209 
2210 		npages = seg_pages(nseg);
2211 		nbytes = vpgtob(npages);
2212 		nsvd->vpage = kmem_alloc(nbytes, KM_SLEEP);
2213 
2214 		bcopy(&ovpage[opages - npages], nsvd->vpage, nbytes);
2215 
2216 		/* free up old vpage */
2217 		kmem_free(ovpage, vpgtob(opages));
2218 	}
2219 
2220 	if (amp == NULL) {
2221 		nsvd->amp = NULL;
2222 		nsvd->anon_index = 0;
2223 	} else {
2224 		/*
2225 		 * Need to create a new anon map for the new segment.
2226 		 * We'll also allocate a new smaller array for the old
2227 		 * smaller segment to save space.
2228 		 */
2229 		opages = btop((uintptr_t)(addr - seg->s_base));
2230 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2231 		if (amp->refcnt == 1 || svd->type == MAP_PRIVATE) {
2232 			/*
2233 			 * Free up now unused parts of anon_map array.
2234 			 */
2235 			ulong_t an_idx = svd->anon_index + opages;
2236 
2237 			/*
2238 			 * Shared anon map is no longer in use. Before
2239 			 * freeing its pages purge all entries from
2240 			 * pcache that belong to this amp.
2241 			 */
2242 			if (svd->type == MAP_SHARED) {
2243 				ASSERT(amp->refcnt == 1);
2244 				ASSERT(svd->softlockcnt == 0);
2245 				anonmap_purge(amp);
2246 			}
2247 
2248 			if (amp->a_szc == seg->s_szc) {
2249 				if (seg->s_szc != 0) {
2250 					anon_free_pages(amp->ahp, an_idx, len,
2251 					    seg->s_szc);
2252 				} else {
2253 					anon_free(amp->ahp, an_idx,
2254 					    len);
2255 				}
2256 			} else {
2257 				ASSERT(svd->type == MAP_SHARED);
2258 				ASSERT(amp->a_szc > seg->s_szc);
2259 				anon_shmap_free_pages(amp, an_idx, len);
2260 			}
2261 
2262 			/*
2263 			 * Unreserve swap space for the
2264 			 * unmapped chunk of this segment in
2265 			 * case it's MAP_SHARED
2266 			 */
2267 			if (svd->type == MAP_SHARED) {
2268 				anon_unresv_zone(len,
2269 				    seg->s_as->a_proc->p_zone);
2270 				amp->swresv -= len;
2271 			}
2272 		}
2273 		nsvd->anon_index = svd->anon_index +
2274 		    btop((uintptr_t)(nseg->s_base - seg->s_base));
2275 		if (svd->type == MAP_SHARED) {
2276 			amp->refcnt++;
2277 			nsvd->amp = amp;
2278 		} else {
2279 			struct anon_map *namp;
2280 			struct anon_hdr *nahp;
2281 
2282 			ASSERT(svd->type == MAP_PRIVATE);
2283 			nahp = anon_create(btop(seg->s_size), ANON_SLEEP);
2284 			namp = anonmap_alloc(nseg->s_size, 0, ANON_SLEEP);
2285 			namp->a_szc = seg->s_szc;
2286 			(void) anon_copy_ptr(amp->ahp, svd->anon_index, nahp,
2287 			    0, btop(seg->s_size), ANON_SLEEP);
2288 			(void) anon_copy_ptr(amp->ahp, nsvd->anon_index,
2289 			    namp->ahp, 0, btop(nseg->s_size), ANON_SLEEP);
2290 			anon_release(amp->ahp, btop(amp->size));
2291 			svd->anon_index = 0;
2292 			nsvd->anon_index = 0;
2293 			amp->ahp = nahp;
2294 			amp->size = seg->s_size;
2295 			nsvd->amp = namp;
2296 		}
2297 		ANON_LOCK_EXIT(&amp->a_rwlock);
2298 	}
2299 	if (svd->swresv) {
2300 		if (svd->flags & MAP_NORESERVE) {
2301 			ASSERT(amp);
2302 			oswresv = svd->swresv;
2303 			svd->swresv = ptob(anon_pages(amp->ahp,
2304 			    svd->anon_index, btop(seg->s_size)));
2305 			nsvd->swresv = ptob(anon_pages(nsvd->amp->ahp,
2306 			    nsvd->anon_index, btop(nseg->s_size)));
2307 			ASSERT(oswresv >= (svd->swresv + nsvd->swresv));
2308 			anon_unresv_zone(oswresv - (svd->swresv + nsvd->swresv),
2309 			    seg->s_as->a_proc->p_zone);
2310 			if (SEG_IS_PARTIAL_RESV(seg))
2311 				seg->s_as->a_resvsize -= oswresv -
2312 				    (svd->swresv + nsvd->swresv);
2313 		} else {
2314 			size_t unlen;
2315 
2316 			if (svd->pageswap) {
2317 				oswresv = svd->swresv;
2318 				svd->swresv = segvn_count_swap_by_vpages(seg);
2319 				nsvd->swresv = segvn_count_swap_by_vpages(nseg);
2320 				ASSERT(oswresv >= (svd->swresv + nsvd->swresv));
2321 				unlen = oswresv - (svd->swresv + nsvd->swresv);
2322 			} else {
2323 				if (seg->s_size + nseg->s_size + len !=
2324 				    svd->swresv) {
2325 					panic("segvn_unmap: cannot split "
2326 					    "swap reservation");
2327 					/*NOTREACHED*/
2328 				}
2329 				svd->swresv = seg->s_size;
2330 				nsvd->swresv = nseg->s_size;
2331 				unlen = len;
2332 			}
2333 			anon_unresv_zone(unlen,
2334 			    seg->s_as->a_proc->p_zone);
2335 		}
2336 		TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
2337 		    seg, len, 0);
2338 	}
2339 
2340 	return (0);			/* I'm glad that's all over with! */
2341 }
2342 
2343 static void
2344 segvn_free(struct seg *seg)
2345 {
2346 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
2347 	pgcnt_t npages = seg_pages(seg);
2348 	struct anon_map *amp;
2349 	size_t len;
2350 
2351 	/*
2352 	 * We don't need any segment level locks for "segvn" data
2353 	 * since the address space is "write" locked.
2354 	 */
2355 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
2356 	ASSERT(svd->tr_state == SEGVN_TR_OFF);
2357 
2358 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2359 
2360 	/*
2361 	 * Be sure to unlock pages. XXX Why do things get free'ed instead
2362 	 * of unmapped? XXX
2363 	 */
2364 	(void) segvn_lockop(seg, seg->s_base, seg->s_size,
2365 	    0, MC_UNLOCK, NULL, 0);
2366 
2367 	/*
2368 	 * Deallocate the vpage and anon pointers if necessary and possible.
2369 	 */
2370 	if (svd->vpage != NULL) {
2371 		kmem_free(svd->vpage, vpgtob(npages));
2372 		svd->vpage = NULL;
2373 	}
2374 	if ((amp = svd->amp) != NULL) {
2375 		/*
2376 		 * If there are no more references to this anon_map
2377 		 * structure, then deallocate the structure after freeing
2378 		 * up all the anon slot pointers that we can.
2379 		 */
2380 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2381 		ASSERT(amp->a_szc >= seg->s_szc);
2382 		if (--amp->refcnt == 0) {
2383 			if (svd->type == MAP_PRIVATE) {
2384 				/*
2385 				 * Private - we only need to anon_free
2386 				 * the part that this segment refers to.
2387 				 */
2388 				if (seg->s_szc != 0) {
2389 					anon_free_pages(amp->ahp,
2390 					    svd->anon_index, seg->s_size,
2391 					    seg->s_szc);
2392 				} else {
2393 					anon_free(amp->ahp, svd->anon_index,
2394 					    seg->s_size);
2395 				}
2396 			} else {
2397 
2398 				/*
2399 				 * Shared anon map is no longer in use. Before
2400 				 * freeing its pages purge all entries from
2401 				 * pcache that belong to this amp.
2402 				 */
2403 				ASSERT(svd->softlockcnt == 0);
2404 				anonmap_purge(amp);
2405 
2406 				/*
2407 				 * Shared - anon_free the entire
2408 				 * anon_map's worth of stuff and
2409 				 * release any swap reservation.
2410 				 */
2411 				if (amp->a_szc != 0) {
2412 					anon_shmap_free_pages(amp, 0,
2413 					    amp->size);
2414 				} else {
2415 					anon_free(amp->ahp, 0, amp->size);
2416 				}
2417 				if ((len = amp->swresv) != 0) {
2418 					anon_unresv_zone(len,
2419 					    seg->s_as->a_proc->p_zone);
2420 					TRACE_3(TR_FAC_VM, TR_ANON_PROC,
2421 					    "anon proc:%p %lu %u", seg, len, 0);
2422 				}
2423 			}
2424 			svd->amp = NULL;
2425 			ANON_LOCK_EXIT(&amp->a_rwlock);
2426 			anonmap_free(amp);
2427 		} else if (svd->type == MAP_PRIVATE) {
2428 			/*
2429 			 * We had a private mapping which still has
2430 			 * a held anon_map so just free up all the
2431 			 * anon slot pointers that we were using.
2432 			 */
2433 			if (seg->s_szc != 0) {
2434 				anon_free_pages(amp->ahp, svd->anon_index,
2435 				    seg->s_size, seg->s_szc);
2436 			} else {
2437 				anon_free(amp->ahp, svd->anon_index,
2438 				    seg->s_size);
2439 			}
2440 			ANON_LOCK_EXIT(&amp->a_rwlock);
2441 		} else {
2442 			ANON_LOCK_EXIT(&amp->a_rwlock);
2443 		}
2444 	}
2445 
2446 	/*
2447 	 * Release swap reservation.
2448 	 */
2449 	if ((len = svd->swresv) != 0) {
2450 		anon_unresv_zone(svd->swresv,
2451 		    seg->s_as->a_proc->p_zone);
2452 		TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
2453 		    seg, len, 0);
2454 		if (SEG_IS_PARTIAL_RESV(seg))
2455 			seg->s_as->a_resvsize -= svd->swresv;
2456 		svd->swresv = 0;
2457 	}
2458 	/*
2459 	 * Release claim on vnode, credentials, and finally free the
2460 	 * private data.
2461 	 */
2462 	if (svd->vp != NULL) {
2463 		if (svd->type == MAP_SHARED)
2464 			lgrp_shm_policy_fini(NULL, svd->vp);
2465 		VN_RELE(svd->vp);
2466 		svd->vp = NULL;
2467 	}
2468 	crfree(svd->cred);
2469 	svd->pageprot = 0;
2470 	svd->pageadvice = 0;
2471 	svd->pageswap = 0;
2472 	svd->cred = NULL;
2473 
2474 	/*
2475 	 * Take segfree_syncmtx lock to let segvn_reclaim() finish if it's
2476 	 * still working with this segment without holding as lock (in case
2477 	 * it's called by pcache async thread).
2478 	 */
2479 	ASSERT(svd->softlockcnt == 0);
2480 	mutex_enter(&svd->segfree_syncmtx);
2481 	mutex_exit(&svd->segfree_syncmtx);
2482 
2483 	seg->s_data = NULL;
2484 	kmem_cache_free(segvn_cache, svd);
2485 }
2486 
2487 /*
2488  * Do a F_SOFTUNLOCK call over the range requested.  The range must have
2489  * already been F_SOFTLOCK'ed.
2490  * Caller must always match addr and len of a softunlock with a previous
2491  * softlock with exactly the same addr and len.
2492  */
2493 static void
2494 segvn_softunlock(struct seg *seg, caddr_t addr, size_t len, enum seg_rw rw)
2495 {
2496 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
2497 	page_t *pp;
2498 	caddr_t adr;
2499 	struct vnode *vp;
2500 	u_offset_t offset;
2501 	ulong_t anon_index;
2502 	struct anon_map *amp;
2503 	struct anon *ap = NULL;
2504 
2505 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2506 	ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
2507 
2508 	if ((amp = svd->amp) != NULL)
2509 		anon_index = svd->anon_index + seg_page(seg, addr);
2510 
2511 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
2512 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
2513 		hat_unlock_region(seg->s_as->a_hat, addr, len, svd->rcookie);
2514 	} else {
2515 		hat_unlock(seg->s_as->a_hat, addr, len);
2516 	}
2517 	for (adr = addr; adr < addr + len; adr += PAGESIZE) {
2518 		if (amp != NULL) {
2519 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2520 			if ((ap = anon_get_ptr(amp->ahp, anon_index++))
2521 			    != NULL) {
2522 				swap_xlate(ap, &vp, &offset);
2523 			} else {
2524 				vp = svd->vp;
2525 				offset = svd->offset +
2526 				    (uintptr_t)(adr - seg->s_base);
2527 			}
2528 			ANON_LOCK_EXIT(&amp->a_rwlock);
2529 		} else {
2530 			vp = svd->vp;
2531 			offset = svd->offset +
2532 			    (uintptr_t)(adr - seg->s_base);
2533 		}
2534 
2535 		/*
2536 		 * Use page_find() instead of page_lookup() to
2537 		 * find the page since we know that it is locked.
2538 		 */
2539 		pp = page_find(vp, offset);
2540 		if (pp == NULL) {
2541 			panic(
2542 			    "segvn_softunlock: addr %p, ap %p, vp %p, off %llx",
2543 			    (void *)adr, (void *)ap, (void *)vp, offset);
2544 			/*NOTREACHED*/
2545 		}
2546 
2547 		if (rw == S_WRITE) {
2548 			hat_setrefmod(pp);
2549 			if (seg->s_as->a_vbits)
2550 				hat_setstat(seg->s_as, adr, PAGESIZE,
2551 				    P_REF | P_MOD);
2552 		} else if (rw != S_OTHER) {
2553 			hat_setref(pp);
2554 			if (seg->s_as->a_vbits)
2555 				hat_setstat(seg->s_as, adr, PAGESIZE, P_REF);
2556 		}
2557 		TRACE_3(TR_FAC_VM, TR_SEGVN_FAULT,
2558 		    "segvn_fault:pp %p vp %p offset %llx", pp, vp, offset);
2559 		page_unlock(pp);
2560 	}
2561 	ASSERT(svd->softlockcnt >= btop(len));
2562 	if (!atomic_add_long_nv((ulong_t *)&svd->softlockcnt, -btop(len))) {
2563 		/*
2564 		 * All SOFTLOCKS are gone. Wakeup any waiting
2565 		 * unmappers so they can try again to unmap.
2566 		 * Check for waiters first without the mutex
2567 		 * held so we don't always grab the mutex on
2568 		 * softunlocks.
2569 		 */
2570 		if (AS_ISUNMAPWAIT(seg->s_as)) {
2571 			mutex_enter(&seg->s_as->a_contents);
2572 			if (AS_ISUNMAPWAIT(seg->s_as)) {
2573 				AS_CLRUNMAPWAIT(seg->s_as);
2574 				cv_broadcast(&seg->s_as->a_cv);
2575 			}
2576 			mutex_exit(&seg->s_as->a_contents);
2577 		}
2578 	}
2579 }
2580 
2581 #define	PAGE_HANDLED	((page_t *)-1)
2582 
2583 /*
2584  * Release all the pages in the NULL terminated ppp list
2585  * which haven't already been converted to PAGE_HANDLED.
2586  */
2587 static void
2588 segvn_pagelist_rele(page_t **ppp)
2589 {
2590 	for (; *ppp != NULL; ppp++) {
2591 		if (*ppp != PAGE_HANDLED)
2592 			page_unlock(*ppp);
2593 	}
2594 }
2595 
2596 static int stealcow = 1;
2597 
2598 /*
2599  * Workaround for viking chip bug.  See bug id 1220902.
2600  * To fix this down in pagefault() would require importing so
2601  * much as and segvn code as to be unmaintainable.
2602  */
2603 int enable_mbit_wa = 0;
2604 
2605 /*
2606  * Handles all the dirty work of getting the right
2607  * anonymous pages and loading up the translations.
2608  * This routine is called only from segvn_fault()
2609  * when looping over the range of addresses requested.
2610  *
2611  * The basic algorithm here is:
2612  * 	If this is an anon_zero case
2613  *		Call anon_zero to allocate page
2614  *		Load up translation
2615  *		Return
2616  *	endif
2617  *	If this is an anon page
2618  *		Use anon_getpage to get the page
2619  *	else
2620  *		Find page in pl[] list passed in
2621  *	endif
2622  *	If not a cow
2623  *		Load up the translation to the page
2624  *		return
2625  *	endif
2626  *	Call anon_private to handle cow
2627  *	Load up (writable) translation to new page
2628  */
2629 static faultcode_t
2630 segvn_faultpage(
2631 	struct hat *hat,		/* the hat to use for mapping */
2632 	struct seg *seg,		/* seg_vn of interest */
2633 	caddr_t addr,			/* address in as */
2634 	u_offset_t off,			/* offset in vp */
2635 	struct vpage *vpage,		/* pointer to vpage for vp, off */
2636 	page_t *pl[],			/* object source page pointer */
2637 	uint_t vpprot,			/* access allowed to object pages */
2638 	enum fault_type type,		/* type of fault */
2639 	enum seg_rw rw,			/* type of access at fault */
2640 	int brkcow)			/* we may need to break cow */
2641 {
2642 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
2643 	page_t *pp, **ppp;
2644 	uint_t pageflags = 0;
2645 	page_t *anon_pl[1 + 1];
2646 	page_t *opp = NULL;		/* original page */
2647 	uint_t prot;
2648 	int err;
2649 	int cow;
2650 	int claim;
2651 	int steal = 0;
2652 	ulong_t anon_index;
2653 	struct anon *ap, *oldap;
2654 	struct anon_map *amp;
2655 	int hat_flag = (type == F_SOFTLOCK) ? HAT_LOAD_LOCK : HAT_LOAD;
2656 	int anon_lock = 0;
2657 	anon_sync_obj_t cookie;
2658 
2659 	if (svd->flags & MAP_TEXT) {
2660 		hat_flag |= HAT_LOAD_TEXT;
2661 	}
2662 
2663 	ASSERT(SEGVN_READ_HELD(seg->s_as, &svd->lock));
2664 	ASSERT(seg->s_szc == 0);
2665 	ASSERT(svd->tr_state != SEGVN_TR_INIT);
2666 
2667 	/*
2668 	 * Initialize protection value for this page.
2669 	 * If we have per page protection values check it now.
2670 	 */
2671 	if (svd->pageprot) {
2672 		uint_t protchk;
2673 
2674 		switch (rw) {
2675 		case S_READ:
2676 			protchk = PROT_READ;
2677 			break;
2678 		case S_WRITE:
2679 			protchk = PROT_WRITE;
2680 			break;
2681 		case S_EXEC:
2682 			protchk = PROT_EXEC;
2683 			break;
2684 		case S_OTHER:
2685 		default:
2686 			protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
2687 			break;
2688 		}
2689 
2690 		prot = VPP_PROT(vpage);
2691 		if ((prot & protchk) == 0)
2692 			return (FC_PROT);	/* illegal access type */
2693 	} else {
2694 		prot = svd->prot;
2695 	}
2696 
2697 	if (type == F_SOFTLOCK) {
2698 		atomic_add_long((ulong_t *)&svd->softlockcnt, 1);
2699 	}
2700 
2701 	/*
2702 	 * Always acquire the anon array lock to prevent 2 threads from
2703 	 * allocating separate anon slots for the same "addr".
2704 	 */
2705 
2706 	if ((amp = svd->amp) != NULL) {
2707 		ASSERT(RW_READ_HELD(&amp->a_rwlock));
2708 		anon_index = svd->anon_index + seg_page(seg, addr);
2709 		anon_array_enter(amp, anon_index, &cookie);
2710 		anon_lock = 1;
2711 	}
2712 
2713 	if (svd->vp == NULL && amp != NULL) {
2714 		if ((ap = anon_get_ptr(amp->ahp, anon_index)) == NULL) {
2715 			/*
2716 			 * Allocate a (normally) writable anonymous page of
2717 			 * zeroes. If no advance reservations, reserve now.
2718 			 */
2719 			if (svd->flags & MAP_NORESERVE) {
2720 				if (anon_resv_zone(ptob(1),
2721 				    seg->s_as->a_proc->p_zone)) {
2722 					atomic_add_long(&svd->swresv, ptob(1));
2723 					atomic_add_long(&seg->s_as->a_resvsize,
2724 					    ptob(1));
2725 				} else {
2726 					err = ENOMEM;
2727 					goto out;
2728 				}
2729 			}
2730 			if ((pp = anon_zero(seg, addr, &ap,
2731 			    svd->cred)) == NULL) {
2732 				err = ENOMEM;
2733 				goto out;	/* out of swap space */
2734 			}
2735 			/*
2736 			 * Re-acquire the anon_map lock and
2737 			 * initialize the anon array entry.
2738 			 */
2739 			(void) anon_set_ptr(amp->ahp, anon_index, ap,
2740 			    ANON_SLEEP);
2741 
2742 			ASSERT(pp->p_szc == 0);
2743 
2744 			/*
2745 			 * Handle pages that have been marked for migration
2746 			 */
2747 			if (lgrp_optimizations())
2748 				page_migrate(seg, addr, &pp, 1);
2749 
2750 			if (enable_mbit_wa) {
2751 				if (rw == S_WRITE)
2752 					hat_setmod(pp);
2753 				else if (!hat_ismod(pp))
2754 					prot &= ~PROT_WRITE;
2755 			}
2756 			/*
2757 			 * If AS_PAGLCK is set in a_flags (via memcntl(2)
2758 			 * with MC_LOCKAS, MCL_FUTURE) and this is a
2759 			 * MAP_NORESERVE segment, we may need to
2760 			 * permanently lock the page as it is being faulted
2761 			 * for the first time. The following text applies
2762 			 * only to MAP_NORESERVE segments:
2763 			 *
2764 			 * As per memcntl(2), if this segment was created
2765 			 * after MCL_FUTURE was applied (a "future"
2766 			 * segment), its pages must be locked.  If this
2767 			 * segment existed at MCL_FUTURE application (a
2768 			 * "past" segment), the interface is unclear.
2769 			 *
2770 			 * We decide to lock only if vpage is present:
2771 			 *
2772 			 * - "future" segments will have a vpage array (see
2773 			 *    as_map), and so will be locked as required
2774 			 *
2775 			 * - "past" segments may not have a vpage array,
2776 			 *    depending on whether events (such as
2777 			 *    mprotect) have occurred. Locking if vpage
2778 			 *    exists will preserve legacy behavior.  Not
2779 			 *    locking if vpage is absent, will not break
2780 			 *    the interface or legacy behavior.  Note that
2781 			 *    allocating vpage here if it's absent requires
2782 			 *    upgrading the segvn reader lock, the cost of
2783 			 *    which does not seem worthwhile.
2784 			 *
2785 			 * Usually testing and setting VPP_ISPPLOCK and
2786 			 * VPP_SETPPLOCK requires holding the segvn lock as
2787 			 * writer, but in this case all readers are
2788 			 * serializing on the anon array lock.
2789 			 */
2790 			if (AS_ISPGLCK(seg->s_as) && vpage != NULL &&
2791 			    (svd->flags & MAP_NORESERVE) &&
2792 			    !VPP_ISPPLOCK(vpage)) {
2793 				proc_t *p = seg->s_as->a_proc;
2794 				ASSERT(svd->type == MAP_PRIVATE);
2795 				mutex_enter(&p->p_lock);
2796 				if (rctl_incr_locked_mem(p, NULL, PAGESIZE,
2797 				    1) == 0) {
2798 					claim = VPP_PROT(vpage) & PROT_WRITE;
2799 					if (page_pp_lock(pp, claim, 0)) {
2800 						VPP_SETPPLOCK(vpage);
2801 					} else {
2802 						rctl_decr_locked_mem(p, NULL,
2803 						    PAGESIZE, 1);
2804 					}
2805 				}
2806 				mutex_exit(&p->p_lock);
2807 			}
2808 
2809 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2810 			hat_memload(hat, addr, pp, prot, hat_flag);
2811 
2812 			if (!(hat_flag & HAT_LOAD_LOCK))
2813 				page_unlock(pp);
2814 
2815 			anon_array_exit(&cookie);
2816 			return (0);
2817 		}
2818 	}
2819 
2820 	/*
2821 	 * Obtain the page structure via anon_getpage() if it is
2822 	 * a private copy of an object (the result of a previous
2823 	 * copy-on-write).
2824 	 */
2825 	if (amp != NULL) {
2826 		if ((ap = anon_get_ptr(amp->ahp, anon_index)) != NULL) {
2827 			err = anon_getpage(&ap, &vpprot, anon_pl, PAGESIZE,
2828 			    seg, addr, rw, svd->cred);
2829 			if (err)
2830 				goto out;
2831 
2832 			if (svd->type == MAP_SHARED) {
2833 				/*
2834 				 * If this is a shared mapping to an
2835 				 * anon_map, then ignore the write
2836 				 * permissions returned by anon_getpage().
2837 				 * They apply to the private mappings
2838 				 * of this anon_map.
2839 				 */
2840 				vpprot |= PROT_WRITE;
2841 			}
2842 			opp = anon_pl[0];
2843 		}
2844 	}
2845 
2846 	/*
2847 	 * Search the pl[] list passed in if it is from the
2848 	 * original object (i.e., not a private copy).
2849 	 */
2850 	if (opp == NULL) {
2851 		/*
2852 		 * Find original page.  We must be bringing it in
2853 		 * from the list in pl[].
2854 		 */
2855 		for (ppp = pl; (opp = *ppp) != NULL; ppp++) {
2856 			if (opp == PAGE_HANDLED)
2857 				continue;
2858 			ASSERT(opp->p_vnode == svd->vp); /* XXX */
2859 			if (opp->p_offset == off)
2860 				break;
2861 		}
2862 		if (opp == NULL) {
2863 			panic("segvn_faultpage not found");
2864 			/*NOTREACHED*/
2865 		}
2866 		*ppp = PAGE_HANDLED;
2867 
2868 	}
2869 
2870 	ASSERT(PAGE_LOCKED(opp));
2871 
2872 	TRACE_3(TR_FAC_VM, TR_SEGVN_FAULT,
2873 	    "segvn_fault:pp %p vp %p offset %llx", opp, NULL, 0);
2874 
2875 	/*
2876 	 * The fault is treated as a copy-on-write fault if a
2877 	 * write occurs on a private segment and the object
2878 	 * page (i.e., mapping) is write protected.  We assume
2879 	 * that fatal protection checks have already been made.
2880 	 */
2881 
2882 	if (brkcow) {
2883 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
2884 		cow = !(vpprot & PROT_WRITE);
2885 	} else if (svd->tr_state == SEGVN_TR_ON) {
2886 		/*
2887 		 * If we are doing text replication COW on first touch.
2888 		 */
2889 		ASSERT(amp != NULL);
2890 		ASSERT(svd->vp != NULL);
2891 		ASSERT(rw != S_WRITE);
2892 		cow = (ap == NULL);
2893 	} else {
2894 		cow = 0;
2895 	}
2896 
2897 	/*
2898 	 * If not a copy-on-write case load the translation
2899 	 * and return.
2900 	 */
2901 	if (cow == 0) {
2902 
2903 		/*
2904 		 * Handle pages that have been marked for migration
2905 		 */
2906 		if (lgrp_optimizations())
2907 			page_migrate(seg, addr, &opp, 1);
2908 
2909 		if (IS_VMODSORT(opp->p_vnode) || enable_mbit_wa) {
2910 			if (rw == S_WRITE)
2911 				hat_setmod(opp);
2912 			else if (rw != S_OTHER && !hat_ismod(opp))
2913 				prot &= ~PROT_WRITE;
2914 		}
2915 
2916 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE ||
2917 		    (!svd->pageprot && svd->prot == (prot & vpprot)));
2918 		ASSERT(amp == NULL ||
2919 		    svd->rcookie == HAT_INVALID_REGION_COOKIE);
2920 		hat_memload_region(hat, addr, opp, prot & vpprot, hat_flag,
2921 		    svd->rcookie);
2922 
2923 		if (!(hat_flag & HAT_LOAD_LOCK))
2924 			page_unlock(opp);
2925 
2926 		if (anon_lock) {
2927 			anon_array_exit(&cookie);
2928 		}
2929 		return (0);
2930 	}
2931 
2932 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2933 
2934 	hat_setref(opp);
2935 
2936 	ASSERT(amp != NULL && anon_lock);
2937 
2938 	/*
2939 	 * Steal the page only if it isn't a private page
2940 	 * since stealing a private page is not worth the effort.
2941 	 */
2942 	if ((ap = anon_get_ptr(amp->ahp, anon_index)) == NULL)
2943 		steal = 1;
2944 
2945 	/*
2946 	 * Steal the original page if the following conditions are true:
2947 	 *
2948 	 * We are low on memory, the page is not private, page is not large,
2949 	 * not shared, not modified, not `locked' or if we have it `locked'
2950 	 * (i.e., p_cowcnt == 1 and p_lckcnt == 0, which also implies
2951 	 * that the page is not shared) and if it doesn't have any
2952 	 * translations. page_struct_lock isn't needed to look at p_cowcnt
2953 	 * and p_lckcnt because we first get exclusive lock on page.
2954 	 */
2955 	(void) hat_pagesync(opp, HAT_SYNC_DONTZERO | HAT_SYNC_STOPON_MOD);
2956 
2957 	if (stealcow && freemem < minfree && steal && opp->p_szc == 0 &&
2958 	    page_tryupgrade(opp) && !hat_ismod(opp) &&
2959 	    ((opp->p_lckcnt == 0 && opp->p_cowcnt == 0) ||
2960 	    (opp->p_lckcnt == 0 && opp->p_cowcnt == 1 &&
2961 	    vpage != NULL && VPP_ISPPLOCK(vpage)))) {
2962 		/*
2963 		 * Check if this page has other translations
2964 		 * after unloading our translation.
2965 		 */
2966 		if (hat_page_is_mapped(opp)) {
2967 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2968 			hat_unload(seg->s_as->a_hat, addr, PAGESIZE,
2969 			    HAT_UNLOAD);
2970 		}
2971 
2972 		/*
2973 		 * hat_unload() might sync back someone else's recent
2974 		 * modification, so check again.
2975 		 */
2976 		if (!hat_ismod(opp) && !hat_page_is_mapped(opp))
2977 			pageflags |= STEAL_PAGE;
2978 	}
2979 
2980 	/*
2981 	 * If we have a vpage pointer, see if it indicates that we have
2982 	 * ``locked'' the page we map -- if so, tell anon_private to
2983 	 * transfer the locking resource to the new page.
2984 	 *
2985 	 * See Statement at the beginning of segvn_lockop regarding
2986 	 * the way lockcnts/cowcnts are handled during COW.
2987 	 *
2988 	 */
2989 	if (vpage != NULL && VPP_ISPPLOCK(vpage))
2990 		pageflags |= LOCK_PAGE;
2991 
2992 	/*
2993 	 * Allocate a private page and perform the copy.
2994 	 * For MAP_NORESERVE reserve swap space now, unless this
2995 	 * is a cow fault on an existing anon page in which case
2996 	 * MAP_NORESERVE will have made advance reservations.
2997 	 */
2998 	if ((svd->flags & MAP_NORESERVE) && (ap == NULL)) {
2999 		if (anon_resv_zone(ptob(1), seg->s_as->a_proc->p_zone)) {
3000 			atomic_add_long(&svd->swresv, ptob(1));
3001 			atomic_add_long(&seg->s_as->a_resvsize, ptob(1));
3002 		} else {
3003 			page_unlock(opp);
3004 			err = ENOMEM;
3005 			goto out;
3006 		}
3007 	}
3008 	oldap = ap;
3009 	pp = anon_private(&ap, seg, addr, prot, opp, pageflags, svd->cred);
3010 	if (pp == NULL) {
3011 		err = ENOMEM;	/* out of swap space */
3012 		goto out;
3013 	}
3014 
3015 	/*
3016 	 * If we copied away from an anonymous page, then
3017 	 * we are one step closer to freeing up an anon slot.
3018 	 *
3019 	 * NOTE:  The original anon slot must be released while
3020 	 * holding the "anon_map" lock.  This is necessary to prevent
3021 	 * other threads from obtaining a pointer to the anon slot
3022 	 * which may be freed if its "refcnt" is 1.
3023 	 */
3024 	if (oldap != NULL)
3025 		anon_decref(oldap);
3026 
3027 	(void) anon_set_ptr(amp->ahp, anon_index, ap, ANON_SLEEP);
3028 
3029 	/*
3030 	 * Handle pages that have been marked for migration
3031 	 */
3032 	if (lgrp_optimizations())
3033 		page_migrate(seg, addr, &pp, 1);
3034 
3035 	ASSERT(pp->p_szc == 0);
3036 
3037 	ASSERT(!IS_VMODSORT(pp->p_vnode));
3038 	if (enable_mbit_wa) {
3039 		if (rw == S_WRITE)
3040 			hat_setmod(pp);
3041 		else if (!hat_ismod(pp))
3042 			prot &= ~PROT_WRITE;
3043 	}
3044 
3045 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
3046 	hat_memload(hat, addr, pp, prot, hat_flag);
3047 
3048 	if (!(hat_flag & HAT_LOAD_LOCK))
3049 		page_unlock(pp);
3050 
3051 	ASSERT(anon_lock);
3052 	anon_array_exit(&cookie);
3053 	return (0);
3054 out:
3055 	if (anon_lock)
3056 		anon_array_exit(&cookie);
3057 
3058 	if (type == F_SOFTLOCK) {
3059 		atomic_add_long((ulong_t *)&svd->softlockcnt, -1);
3060 	}
3061 	return (FC_MAKE_ERR(err));
3062 }
3063 
3064 /*
3065  * relocate a bunch of smaller targ pages into one large repl page. all targ
3066  * pages must be complete pages smaller than replacement pages.
3067  * it's assumed that no page's szc can change since they are all PAGESIZE or
3068  * complete large pages locked SHARED.
3069  */
3070 static void
3071 segvn_relocate_pages(page_t **targ, page_t *replacement)
3072 {
3073 	page_t *pp;
3074 	pgcnt_t repl_npgs, curnpgs;
3075 	pgcnt_t i;
3076 	uint_t repl_szc = replacement->p_szc;
3077 	page_t *first_repl = replacement;
3078 	page_t *repl;
3079 	spgcnt_t npgs;
3080 
3081 	VM_STAT_ADD(segvnvmstats.relocatepages[0]);
3082 
3083 	ASSERT(repl_szc != 0);
3084 	npgs = repl_npgs = page_get_pagecnt(repl_szc);
3085 
3086 	i = 0;
3087 	while (repl_npgs) {
3088 		spgcnt_t nreloc;
3089 		int err;
3090 		ASSERT(replacement != NULL);
3091 		pp = targ[i];
3092 		ASSERT(pp->p_szc < repl_szc);
3093 		ASSERT(PAGE_EXCL(pp));
3094 		ASSERT(!PP_ISFREE(pp));
3095 		curnpgs = page_get_pagecnt(pp->p_szc);
3096 		if (curnpgs == 1) {
3097 			VM_STAT_ADD(segvnvmstats.relocatepages[1]);
3098 			repl = replacement;
3099 			page_sub(&replacement, repl);
3100 			ASSERT(PAGE_EXCL(repl));
3101 			ASSERT(!PP_ISFREE(repl));
3102 			ASSERT(repl->p_szc == repl_szc);
3103 		} else {
3104 			page_t *repl_savepp;
3105 			int j;
3106 			VM_STAT_ADD(segvnvmstats.relocatepages[2]);
3107 			repl_savepp = replacement;
3108 			for (j = 0; j < curnpgs; j++) {
3109 				repl = replacement;
3110 				page_sub(&replacement, repl);
3111 				ASSERT(PAGE_EXCL(repl));
3112 				ASSERT(!PP_ISFREE(repl));
3113 				ASSERT(repl->p_szc == repl_szc);
3114 				ASSERT(page_pptonum(targ[i + j]) ==
3115 				    page_pptonum(targ[i]) + j);
3116 			}
3117 			repl = repl_savepp;
3118 			ASSERT(IS_P2ALIGNED(page_pptonum(repl), curnpgs));
3119 		}
3120 		err = page_relocate(&pp, &repl, 0, 1, &nreloc, NULL);
3121 		if (err || nreloc != curnpgs) {
3122 			panic("segvn_relocate_pages: "
3123 			    "page_relocate failed err=%d curnpgs=%ld "
3124 			    "nreloc=%ld", err, curnpgs, nreloc);
3125 		}
3126 		ASSERT(curnpgs <= repl_npgs);
3127 		repl_npgs -= curnpgs;
3128 		i += curnpgs;
3129 	}
3130 	ASSERT(replacement == NULL);
3131 
3132 	repl = first_repl;
3133 	repl_npgs = npgs;
3134 	for (i = 0; i < repl_npgs; i++) {
3135 		ASSERT(PAGE_EXCL(repl));
3136 		ASSERT(!PP_ISFREE(repl));
3137 		targ[i] = repl;
3138 		page_downgrade(targ[i]);
3139 		repl++;
3140 	}
3141 }
3142 
3143 /*
3144  * Check if all pages in ppa array are complete smaller than szc pages and
3145  * their roots will still be aligned relative to their current size if the
3146  * entire ppa array is relocated into one szc page. If these conditions are
3147  * not met return 0.
3148  *
3149  * If all pages are properly aligned attempt to upgrade their locks
3150  * to exclusive mode. If it fails set *upgrdfail to 1 and return 0.
3151  * upgrdfail was set to 0 by caller.
3152  *
3153  * Return 1 if all pages are aligned and locked exclusively.
3154  *
3155  * If all pages in ppa array happen to be physically contiguous to make one
3156  * szc page and all exclusive locks are successfully obtained promote the page
3157  * size to szc and set *pszc to szc. Return 1 with pages locked shared.
3158  */
3159 static int
3160 segvn_full_szcpages(page_t **ppa, uint_t szc, int *upgrdfail, uint_t *pszc)
3161 {
3162 	page_t *pp;
3163 	pfn_t pfn;
3164 	pgcnt_t totnpgs = page_get_pagecnt(szc);
3165 	pfn_t first_pfn;
3166 	int contig = 1;
3167 	pgcnt_t i;
3168 	pgcnt_t j;
3169 	uint_t curszc;
3170 	pgcnt_t curnpgs;
3171 	int root = 0;
3172 
3173 	ASSERT(szc > 0);
3174 
3175 	VM_STAT_ADD(segvnvmstats.fullszcpages[0]);
3176 
3177 	for (i = 0; i < totnpgs; i++) {
3178 		pp = ppa[i];
3179 		ASSERT(PAGE_SHARED(pp));
3180 		ASSERT(!PP_ISFREE(pp));
3181 		pfn = page_pptonum(pp);
3182 		if (i == 0) {
3183 			if (!IS_P2ALIGNED(pfn, totnpgs)) {
3184 				contig = 0;
3185 			} else {
3186 				first_pfn = pfn;
3187 			}
3188 		} else if (contig && pfn != first_pfn + i) {
3189 			contig = 0;
3190 		}
3191 		if (pp->p_szc == 0) {
3192 			if (root) {
3193 				VM_STAT_ADD(segvnvmstats.fullszcpages[1]);
3194 				return (0);
3195 			}
3196 		} else if (!root) {
3197 			if ((curszc = pp->p_szc) >= szc) {
3198 				VM_STAT_ADD(segvnvmstats.fullszcpages[2]);
3199 				return (0);
3200 			}
3201 			if (curszc == 0) {
3202 				/*
3203 				 * p_szc changed means we don't have all pages
3204 				 * locked. return failure.
3205 				 */
3206 				VM_STAT_ADD(segvnvmstats.fullszcpages[3]);
3207 				return (0);
3208 			}
3209 			curnpgs = page_get_pagecnt(curszc);
3210 			if (!IS_P2ALIGNED(pfn, curnpgs) ||
3211 			    !IS_P2ALIGNED(i, curnpgs)) {
3212 				VM_STAT_ADD(segvnvmstats.fullszcpages[4]);
3213 				return (0);
3214 			}
3215 			root = 1;
3216 		} else {
3217 			ASSERT(i > 0);
3218 			VM_STAT_ADD(segvnvmstats.fullszcpages[5]);
3219 			if (pp->p_szc != curszc) {
3220 				VM_STAT_ADD(segvnvmstats.fullszcpages[6]);
3221 				return (0);
3222 			}
3223 			if (pfn - 1 != page_pptonum(ppa[i - 1])) {
3224 				panic("segvn_full_szcpages: "
3225 				    "large page not physically contiguous");
3226 			}
3227 			if (P2PHASE(pfn, curnpgs) == curnpgs - 1) {
3228 				root = 0;
3229 			}
3230 		}
3231 	}
3232 
3233 	for (i = 0; i < totnpgs; i++) {
3234 		ASSERT(ppa[i]->p_szc < szc);
3235 		if (!page_tryupgrade(ppa[i])) {
3236 			for (j = 0; j < i; j++) {
3237 				page_downgrade(ppa[j]);
3238 			}
3239 			*pszc = ppa[i]->p_szc;
3240 			*upgrdfail = 1;
3241 			VM_STAT_ADD(segvnvmstats.fullszcpages[7]);
3242 			return (0);
3243 		}
3244 	}
3245 
3246 	/*
3247 	 * When a page is put a free cachelist its szc is set to 0.  if file
3248 	 * system reclaimed pages from cachelist targ pages will be physically
3249 	 * contiguous with 0 p_szc.  in this case just upgrade szc of targ
3250 	 * pages without any relocations.
3251 	 * To avoid any hat issues with previous small mappings
3252 	 * hat_pageunload() the target pages first.
3253 	 */
3254 	if (contig) {
3255 		VM_STAT_ADD(segvnvmstats.fullszcpages[8]);
3256 		for (i = 0; i < totnpgs; i++) {
3257 			(void) hat_pageunload(ppa[i], HAT_FORCE_PGUNLOAD);
3258 		}
3259 		for (i = 0; i < totnpgs; i++) {
3260 			ppa[i]->p_szc = szc;
3261 		}
3262 		for (i = 0; i < totnpgs; i++) {
3263 			ASSERT(PAGE_EXCL(ppa[i]));
3264 			page_downgrade(ppa[i]);
3265 		}
3266 		if (pszc != NULL) {
3267 			*pszc = szc;
3268 		}
3269 	}
3270 	VM_STAT_ADD(segvnvmstats.fullszcpages[9]);
3271 	return (1);
3272 }
3273 
3274 /*
3275  * Create physically contiguous pages for [vp, off] - [vp, off +
3276  * page_size(szc)) range and for private segment return them in ppa array.
3277  * Pages are created either via IO or relocations.
3278  *
3279  * Return 1 on success and 0 on failure.
3280  *
3281  * If physically contiguous pages already exist for this range return 1 without
3282  * filling ppa array. Caller initializes ppa[0] as NULL to detect that ppa
3283  * array wasn't filled. In this case caller fills ppa array via VOP_GETPAGE().
3284  */
3285 
3286 static int
3287 segvn_fill_vp_pages(struct segvn_data *svd, vnode_t *vp, u_offset_t off,
3288     uint_t szc, page_t **ppa, page_t **ppplist, uint_t *ret_pszc,
3289     int *downsize)
3290 
3291 {
3292 	page_t *pplist = *ppplist;
3293 	size_t pgsz = page_get_pagesize(szc);
3294 	pgcnt_t pages = btop(pgsz);
3295 	ulong_t start_off = off;
3296 	u_offset_t eoff = off + pgsz;
3297 	spgcnt_t nreloc;
3298 	u_offset_t io_off = off;
3299 	size_t io_len;
3300 	page_t *io_pplist = NULL;
3301 	page_t *done_pplist = NULL;
3302 	pgcnt_t pgidx = 0;
3303 	page_t *pp;
3304 	page_t *newpp;
3305 	page_t *targpp;
3306 	int io_err = 0;
3307 	int i;
3308 	pfn_t pfn;
3309 	ulong_t ppages;
3310 	page_t *targ_pplist = NULL;
3311 	page_t *repl_pplist = NULL;
3312 	page_t *tmp_pplist;
3313 	int nios = 0;
3314 	uint_t pszc;
3315 	struct vattr va;
3316 
3317 	VM_STAT_ADD(segvnvmstats.fill_vp_pages[0]);
3318 
3319 	ASSERT(szc != 0);
3320 	ASSERT(pplist->p_szc == szc);
3321 
3322 	/*
3323 	 * downsize will be set to 1 only if we fail to lock pages. this will
3324 	 * allow subsequent faults to try to relocate the page again. If we
3325 	 * fail due to misalignment don't downsize and let the caller map the
3326 	 * whole region with small mappings to avoid more faults into the area
3327 	 * where we can't get large pages anyway.
3328 	 */
3329 	*downsize = 0;
3330 
3331 	while (off < eoff) {
3332 		newpp = pplist;
3333 		ASSERT(newpp != NULL);
3334 		ASSERT(PAGE_EXCL(newpp));
3335 		ASSERT(!PP_ISFREE(newpp));
3336 		/*
3337 		 * we pass NULL for nrelocp to page_lookup_create()
3338 		 * so that it doesn't relocate. We relocate here
3339 		 * later only after we make sure we can lock all
3340 		 * pages in the range we handle and they are all
3341 		 * aligned.
3342 		 */
3343 		pp = page_lookup_create(vp, off, SE_SHARED, newpp, NULL, 0);
3344 		ASSERT(pp != NULL);
3345 		ASSERT(!PP_ISFREE(pp));
3346 		ASSERT(pp->p_vnode == vp);
3347 		ASSERT(pp->p_offset == off);
3348 		if (pp == newpp) {
3349 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[1]);
3350 			page_sub(&pplist, pp);
3351 			ASSERT(PAGE_EXCL(pp));
3352 			ASSERT(page_iolock_assert(pp));
3353 			page_list_concat(&io_pplist, &pp);
3354 			off += PAGESIZE;
3355 			continue;
3356 		}
3357 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[2]);
3358 		pfn = page_pptonum(pp);
3359 		pszc = pp->p_szc;
3360 		if (pszc >= szc && targ_pplist == NULL && io_pplist == NULL &&
3361 		    IS_P2ALIGNED(pfn, pages)) {
3362 			ASSERT(repl_pplist == NULL);
3363 			ASSERT(done_pplist == NULL);
3364 			ASSERT(pplist == *ppplist);
3365 			page_unlock(pp);
3366 			page_free_replacement_page(pplist);
3367 			page_create_putback(pages);
3368 			*ppplist = NULL;
3369 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[3]);
3370 			return (1);
3371 		}
3372 		if (pszc >= szc) {
3373 			page_unlock(pp);
3374 			segvn_faultvnmpss_align_err1++;
3375 			goto out;
3376 		}
3377 		ppages = page_get_pagecnt(pszc);
3378 		if (!IS_P2ALIGNED(pfn, ppages)) {
3379 			ASSERT(pszc > 0);
3380 			/*
3381 			 * sizing down to pszc won't help.
3382 			 */
3383 			page_unlock(pp);
3384 			segvn_faultvnmpss_align_err2++;
3385 			goto out;
3386 		}
3387 		pfn = page_pptonum(newpp);
3388 		if (!IS_P2ALIGNED(pfn, ppages)) {
3389 			ASSERT(pszc > 0);
3390 			/*
3391 			 * sizing down to pszc won't help.
3392 			 */
3393 			page_unlock(pp);
3394 			segvn_faultvnmpss_align_err3++;
3395 			goto out;
3396 		}
3397 		if (!PAGE_EXCL(pp)) {
3398 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[4]);
3399 			page_unlock(pp);
3400 			*downsize = 1;
3401 			*ret_pszc = pp->p_szc;
3402 			goto out;
3403 		}
3404 		targpp = pp;
3405 		if (io_pplist != NULL) {
3406 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[5]);
3407 			io_len = off - io_off;
3408 			/*
3409 			 * Some file systems like NFS don't check EOF
3410 			 * conditions in VOP_PAGEIO(). Check it here
3411 			 * now that pages are locked SE_EXCL. Any file
3412 			 * truncation will wait until the pages are
3413 			 * unlocked so no need to worry that file will
3414 			 * be truncated after we check its size here.
3415 			 * XXX fix NFS to remove this check.
3416 			 */
3417 			va.va_mask = AT_SIZE;
3418 			if (VOP_GETATTR(vp, &va, ATTR_HINT, svd->cred, NULL)) {
3419 				VM_STAT_ADD(segvnvmstats.fill_vp_pages[6]);
3420 				page_unlock(targpp);
3421 				goto out;
3422 			}
3423 			if (btopr(va.va_size) < btopr(io_off + io_len)) {
3424 				VM_STAT_ADD(segvnvmstats.fill_vp_pages[7]);
3425 				*downsize = 1;
3426 				*ret_pszc = 0;
3427 				page_unlock(targpp);
3428 				goto out;
3429 			}
3430 			io_err = VOP_PAGEIO(vp, io_pplist, io_off, io_len,
3431 				B_READ, svd->cred, NULL);
3432 			if (io_err) {
3433 				VM_STAT_ADD(segvnvmstats.fill_vp_pages[8]);
3434 				page_unlock(targpp);
3435 				if (io_err == EDEADLK) {
3436 					segvn_vmpss_pageio_deadlk_err++;
3437 				}
3438 				goto out;
3439 			}
3440 			nios++;
3441 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[9]);
3442 			while (io_pplist != NULL) {
3443 				pp = io_pplist;
3444 				page_sub(&io_pplist, pp);
3445 				ASSERT(page_iolock_assert(pp));
3446 				page_io_unlock(pp);
3447 				pgidx = (pp->p_offset - start_off) >>
3448 				    PAGESHIFT;
3449 				ASSERT(pgidx < pages);
3450 				ppa[pgidx] = pp;
3451 				page_list_concat(&done_pplist, &pp);
3452 			}
3453 		}
3454 		pp = targpp;
3455 		ASSERT(PAGE_EXCL(pp));
3456 		ASSERT(pp->p_szc <= pszc);
3457 		if (pszc != 0 && !group_page_trylock(pp, SE_EXCL)) {
3458 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[10]);
3459 			page_unlock(pp);
3460 			*downsize = 1;
3461 			*ret_pszc = pp->p_szc;
3462 			goto out;
3463 		}
3464 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[11]);
3465 		/*
3466 		 * page szc chould have changed before the entire group was
3467 		 * locked. reread page szc.
3468 		 */
3469 		pszc = pp->p_szc;
3470 		ppages = page_get_pagecnt(pszc);
3471 
3472 		/* link just the roots */
3473 		page_list_concat(&targ_pplist, &pp);
3474 		page_sub(&pplist, newpp);
3475 		page_list_concat(&repl_pplist, &newpp);
3476 		off += PAGESIZE;
3477 		while (--ppages != 0) {
3478 			newpp = pplist;
3479 			page_sub(&pplist, newpp);
3480 			off += PAGESIZE;
3481 		}
3482 		io_off = off;
3483 	}
3484 	if (io_pplist != NULL) {
3485 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[12]);
3486 		io_len = eoff - io_off;
3487 		va.va_mask = AT_SIZE;
3488 		if (VOP_GETATTR(vp, &va, ATTR_HINT, svd->cred, NULL) != 0) {
3489 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[13]);
3490 			goto out;
3491 		}
3492 		if (btopr(va.va_size) < btopr(io_off + io_len)) {
3493 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[14]);
3494 			*downsize = 1;
3495 			*ret_pszc = 0;
3496 			goto out;
3497 		}
3498 		io_err = VOP_PAGEIO(vp, io_pplist, io_off, io_len,
3499 		    B_READ, svd->cred, NULL);
3500 		if (io_err) {
3501 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[15]);
3502 			if (io_err == EDEADLK) {
3503 				segvn_vmpss_pageio_deadlk_err++;
3504 			}
3505 			goto out;
3506 		}
3507 		nios++;
3508 		while (io_pplist != NULL) {
3509 			pp = io_pplist;
3510 			page_sub(&io_pplist, pp);
3511 			ASSERT(page_iolock_assert(pp));
3512 			page_io_unlock(pp);
3513 			pgidx = (pp->p_offset - start_off) >> PAGESHIFT;
3514 			ASSERT(pgidx < pages);
3515 			ppa[pgidx] = pp;
3516 		}
3517 	}
3518 	/*
3519 	 * we're now bound to succeed or panic.
3520 	 * remove pages from done_pplist. it's not needed anymore.
3521 	 */
3522 	while (done_pplist != NULL) {
3523 		pp = done_pplist;
3524 		page_sub(&done_pplist, pp);
3525 	}
3526 	VM_STAT_ADD(segvnvmstats.fill_vp_pages[16]);
3527 	ASSERT(pplist == NULL);
3528 	*ppplist = NULL;
3529 	while (targ_pplist != NULL) {
3530 		int ret;
3531 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[17]);
3532 		ASSERT(repl_pplist);
3533 		pp = targ_pplist;
3534 		page_sub(&targ_pplist, pp);
3535 		pgidx = (pp->p_offset - start_off) >> PAGESHIFT;
3536 		newpp = repl_pplist;
3537 		page_sub(&repl_pplist, newpp);
3538 #ifdef DEBUG
3539 		pfn = page_pptonum(pp);
3540 		pszc = pp->p_szc;
3541 		ppages = page_get_pagecnt(pszc);
3542 		ASSERT(IS_P2ALIGNED(pfn, ppages));
3543 		pfn = page_pptonum(newpp);
3544 		ASSERT(IS_P2ALIGNED(pfn, ppages));
3545 		ASSERT(P2PHASE(pfn, pages) == pgidx);
3546 #endif
3547 		nreloc = 0;
3548 		ret = page_relocate(&pp, &newpp, 0, 1, &nreloc, NULL);
3549 		if (ret != 0 || nreloc == 0) {
3550 			panic("segvn_fill_vp_pages: "
3551 			    "page_relocate failed");
3552 		}
3553 		pp = newpp;
3554 		while (nreloc-- != 0) {
3555 			ASSERT(PAGE_EXCL(pp));
3556 			ASSERT(pp->p_vnode == vp);
3557 			ASSERT(pgidx ==
3558 			    ((pp->p_offset - start_off) >> PAGESHIFT));
3559 			ppa[pgidx++] = pp;
3560 			pp++;
3561 		}
3562 	}
3563 
3564 	if (svd->type == MAP_PRIVATE) {
3565 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[18]);
3566 		for (i = 0; i < pages; i++) {
3567 			ASSERT(ppa[i] != NULL);
3568 			ASSERT(PAGE_EXCL(ppa[i]));
3569 			ASSERT(ppa[i]->p_vnode == vp);
3570 			ASSERT(ppa[i]->p_offset ==
3571 			    start_off + (i << PAGESHIFT));
3572 			page_downgrade(ppa[i]);
3573 		}
3574 		ppa[pages] = NULL;
3575 	} else {
3576 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[19]);
3577 		/*
3578 		 * the caller will still call VOP_GETPAGE() for shared segments
3579 		 * to check FS write permissions. For private segments we map
3580 		 * file read only anyway.  so no VOP_GETPAGE is needed.
3581 		 */
3582 		for (i = 0; i < pages; i++) {
3583 			ASSERT(ppa[i] != NULL);
3584 			ASSERT(PAGE_EXCL(ppa[i]));
3585 			ASSERT(ppa[i]->p_vnode == vp);
3586 			ASSERT(ppa[i]->p_offset ==
3587 			    start_off + (i << PAGESHIFT));
3588 			page_unlock(ppa[i]);
3589 		}
3590 		ppa[0] = NULL;
3591 	}
3592 
3593 	return (1);
3594 out:
3595 	/*
3596 	 * Do the cleanup. Unlock target pages we didn't relocate. They are
3597 	 * linked on targ_pplist by root pages. reassemble unused replacement
3598 	 * and io pages back to pplist.
3599 	 */
3600 	if (io_pplist != NULL) {
3601 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[20]);
3602 		pp = io_pplist;
3603 		do {
3604 			ASSERT(pp->p_vnode == vp);
3605 			ASSERT(pp->p_offset == io_off);
3606 			ASSERT(page_iolock_assert(pp));
3607 			page_io_unlock(pp);
3608 			page_hashout(pp, NULL);
3609 			io_off += PAGESIZE;
3610 		} while ((pp = pp->p_next) != io_pplist);
3611 		page_list_concat(&io_pplist, &pplist);
3612 		pplist = io_pplist;
3613 	}
3614 	tmp_pplist = NULL;
3615 	while (targ_pplist != NULL) {
3616 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[21]);
3617 		pp = targ_pplist;
3618 		ASSERT(PAGE_EXCL(pp));
3619 		page_sub(&targ_pplist, pp);
3620 
3621 		pszc = pp->p_szc;
3622 		ppages = page_get_pagecnt(pszc);
3623 		ASSERT(IS_P2ALIGNED(page_pptonum(pp), ppages));
3624 
3625 		if (pszc != 0) {
3626 			group_page_unlock(pp);
3627 		}
3628 		page_unlock(pp);
3629 
3630 		pp = repl_pplist;
3631 		ASSERT(pp != NULL);
3632 		ASSERT(PAGE_EXCL(pp));
3633 		ASSERT(pp->p_szc == szc);
3634 		page_sub(&repl_pplist, pp);
3635 
3636 		ASSERT(IS_P2ALIGNED(page_pptonum(pp), ppages));
3637 
3638 		/* relink replacement page */
3639 		page_list_concat(&tmp_pplist, &pp);
3640 		while (--ppages != 0) {
3641 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[22]);
3642 			pp++;
3643 			ASSERT(PAGE_EXCL(pp));
3644 			ASSERT(pp->p_szc == szc);
3645 			page_list_concat(&tmp_pplist, &pp);
3646 		}
3647 	}
3648 	if (tmp_pplist != NULL) {
3649 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[23]);
3650 		page_list_concat(&tmp_pplist, &pplist);
3651 		pplist = tmp_pplist;
3652 	}
3653 	/*
3654 	 * at this point all pages are either on done_pplist or
3655 	 * pplist. They can't be all on done_pplist otherwise
3656 	 * we'd've been done.
3657 	 */
3658 	ASSERT(pplist != NULL);
3659 	if (nios != 0) {
3660 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[24]);
3661 		pp = pplist;
3662 		do {
3663 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[25]);
3664 			ASSERT(pp->p_szc == szc);
3665 			ASSERT(PAGE_EXCL(pp));
3666 			ASSERT(pp->p_vnode != vp);
3667 			pp->p_szc = 0;
3668 		} while ((pp = pp->p_next) != pplist);
3669 
3670 		pp = done_pplist;
3671 		do {
3672 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[26]);
3673 			ASSERT(pp->p_szc == szc);
3674 			ASSERT(PAGE_EXCL(pp));
3675 			ASSERT(pp->p_vnode == vp);
3676 			pp->p_szc = 0;
3677 		} while ((pp = pp->p_next) != done_pplist);
3678 
3679 		while (pplist != NULL) {
3680 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[27]);
3681 			pp = pplist;
3682 			page_sub(&pplist, pp);
3683 			page_free(pp, 0);
3684 		}
3685 
3686 		while (done_pplist != NULL) {
3687 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[28]);
3688 			pp = done_pplist;
3689 			page_sub(&done_pplist, pp);
3690 			page_unlock(pp);
3691 		}
3692 		*ppplist = NULL;
3693 		return (0);
3694 	}
3695 	ASSERT(pplist == *ppplist);
3696 	if (io_err) {
3697 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[29]);
3698 		/*
3699 		 * don't downsize on io error.
3700 		 * see if vop_getpage succeeds.
3701 		 * pplist may still be used in this case
3702 		 * for relocations.
3703 		 */
3704 		return (0);
3705 	}
3706 	VM_STAT_ADD(segvnvmstats.fill_vp_pages[30]);
3707 	page_free_replacement_page(pplist);
3708 	page_create_putback(pages);
3709 	*ppplist = NULL;
3710 	return (0);
3711 }
3712 
3713 int segvn_anypgsz = 0;
3714 
3715 #define	SEGVN_RESTORE_SOFTLOCK_VP(type, pages) 				\
3716 		if ((type) == F_SOFTLOCK) {				\
3717 			atomic_add_long((ulong_t *)&(svd)->softlockcnt, \
3718 			    -(pages));					\
3719 		}
3720 
3721 #define	SEGVN_UPDATE_MODBITS(ppa, pages, rw, prot, vpprot)		\
3722 		if (IS_VMODSORT((ppa)[0]->p_vnode)) {			\
3723 			if ((rw) == S_WRITE) {				\
3724 				for (i = 0; i < (pages); i++) {		\
3725 					ASSERT((ppa)[i]->p_vnode ==	\
3726 					    (ppa)[0]->p_vnode);		\
3727 					hat_setmod((ppa)[i]);		\
3728 				}					\
3729 			} else if ((rw) != S_OTHER &&			\
3730 			    ((prot) & (vpprot) & PROT_WRITE)) {		\
3731 				for (i = 0; i < (pages); i++) {		\
3732 					ASSERT((ppa)[i]->p_vnode ==	\
3733 					    (ppa)[0]->p_vnode);		\
3734 					if (!hat_ismod((ppa)[i])) {	\
3735 						prot &= ~PROT_WRITE;	\
3736 						break;			\
3737 					}				\
3738 				}					\
3739 			}						\
3740 		}
3741 
3742 #ifdef  VM_STATS
3743 
3744 #define	SEGVN_VMSTAT_FLTVNPAGES(idx)					\
3745 		VM_STAT_ADD(segvnvmstats.fltvnpages[(idx)]);
3746 
3747 #else /* VM_STATS */
3748 
3749 #define	SEGVN_VMSTAT_FLTVNPAGES(idx)
3750 
3751 #endif
3752 
3753 static faultcode_t
3754 segvn_fault_vnodepages(struct hat *hat, struct seg *seg, caddr_t lpgaddr,
3755     caddr_t lpgeaddr, enum fault_type type, enum seg_rw rw, caddr_t addr,
3756     caddr_t eaddr, int brkcow)
3757 {
3758 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
3759 	struct anon_map *amp = svd->amp;
3760 	uchar_t segtype = svd->type;
3761 	uint_t szc = seg->s_szc;
3762 	size_t pgsz = page_get_pagesize(szc);
3763 	size_t maxpgsz = pgsz;
3764 	pgcnt_t pages = btop(pgsz);
3765 	pgcnt_t maxpages = pages;
3766 	size_t ppasize = (pages + 1) * sizeof (page_t *);
3767 	caddr_t a = lpgaddr;
3768 	caddr_t	maxlpgeaddr = lpgeaddr;
3769 	u_offset_t off = svd->offset + (uintptr_t)(a - seg->s_base);
3770 	ulong_t aindx = svd->anon_index + seg_page(seg, a);
3771 	struct vpage *vpage = (svd->vpage != NULL) ?
3772 	    &svd->vpage[seg_page(seg, a)] : NULL;
3773 	vnode_t *vp = svd->vp;
3774 	page_t **ppa;
3775 	uint_t	pszc;
3776 	size_t	ppgsz;
3777 	pgcnt_t	ppages;
3778 	faultcode_t err = 0;
3779 	int ierr;
3780 	int vop_size_err = 0;
3781 	uint_t protchk, prot, vpprot;
3782 	ulong_t i;
3783 	int hat_flag = (type == F_SOFTLOCK) ? HAT_LOAD_LOCK : HAT_LOAD;
3784 	anon_sync_obj_t an_cookie;
3785 	enum seg_rw arw;
3786 	int alloc_failed = 0;
3787 	int adjszc_chk;
3788 	struct vattr va;
3789 	int xhat = 0;
3790 	page_t *pplist;
3791 	pfn_t pfn;
3792 	int physcontig;
3793 	int upgrdfail;
3794 	int segvn_anypgsz_vnode = 0; /* for now map vnode with 2 page sizes */
3795 	int tron = (svd->tr_state == SEGVN_TR_ON);
3796 
3797 	ASSERT(szc != 0);
3798 	ASSERT(vp != NULL);
3799 	ASSERT(brkcow == 0 || amp != NULL);
3800 	ASSERT(tron == 0 || amp != NULL);
3801 	ASSERT(enable_mbit_wa == 0); /* no mbit simulations with large pages */
3802 	ASSERT(!(svd->flags & MAP_NORESERVE));
3803 	ASSERT(type != F_SOFTUNLOCK);
3804 	ASSERT(IS_P2ALIGNED(a, maxpgsz));
3805 	ASSERT(amp == NULL || IS_P2ALIGNED(aindx, maxpages));
3806 	ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
3807 	ASSERT(seg->s_szc < NBBY * sizeof (int));
3808 	ASSERT(type != F_SOFTLOCK || lpgeaddr - a == maxpgsz);
3809 	ASSERT(svd->tr_state != SEGVN_TR_INIT);
3810 
3811 	VM_STAT_COND_ADD(type == F_SOFTLOCK, segvnvmstats.fltvnpages[0]);
3812 	VM_STAT_COND_ADD(type != F_SOFTLOCK, segvnvmstats.fltvnpages[1]);
3813 
3814 	if (svd->flags & MAP_TEXT) {
3815 		hat_flag |= HAT_LOAD_TEXT;
3816 	}
3817 
3818 	if (svd->pageprot) {
3819 		switch (rw) {
3820 		case S_READ:
3821 			protchk = PROT_READ;
3822 			break;
3823 		case S_WRITE:
3824 			protchk = PROT_WRITE;
3825 			break;
3826 		case S_EXEC:
3827 			protchk = PROT_EXEC;
3828 			break;
3829 		case S_OTHER:
3830 		default:
3831 			protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
3832 			break;
3833 		}
3834 	} else {
3835 		prot = svd->prot;
3836 		/* caller has already done segment level protection check. */
3837 	}
3838 
3839 	if (seg->s_as->a_hat != hat) {
3840 		xhat = 1;
3841 	}
3842 
3843 	if (rw == S_WRITE && segtype == MAP_PRIVATE) {
3844 		SEGVN_VMSTAT_FLTVNPAGES(2);
3845 		arw = S_READ;
3846 	} else {
3847 		arw = rw;
3848 	}
3849 
3850 	ppa = kmem_alloc(ppasize, KM_SLEEP);
3851 
3852 	VM_STAT_COND_ADD(amp != NULL, segvnvmstats.fltvnpages[3]);
3853 
3854 	for (;;) {
3855 		adjszc_chk = 0;
3856 		for (; a < lpgeaddr; a += pgsz, off += pgsz, aindx += pages) {
3857 			if (adjszc_chk) {
3858 				while (szc < seg->s_szc) {
3859 					uintptr_t e;
3860 					uint_t tszc;
3861 					tszc = segvn_anypgsz_vnode ? szc + 1 :
3862 					    seg->s_szc;
3863 					ppgsz = page_get_pagesize(tszc);
3864 					if (!IS_P2ALIGNED(a, ppgsz) ||
3865 					    ((alloc_failed >> tszc) & 0x1)) {
3866 						break;
3867 					}
3868 					SEGVN_VMSTAT_FLTVNPAGES(4);
3869 					szc = tszc;
3870 					pgsz = ppgsz;
3871 					pages = btop(pgsz);
3872 					e = P2ROUNDUP((uintptr_t)eaddr, pgsz);
3873 					lpgeaddr = (caddr_t)e;
3874 				}
3875 			}
3876 
3877 		again:
3878 			if (IS_P2ALIGNED(a, maxpgsz) && amp != NULL) {
3879 				ASSERT(IS_P2ALIGNED(aindx, maxpages));
3880 				ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
3881 				anon_array_enter(amp, aindx, &an_cookie);
3882 				if (anon_get_ptr(amp->ahp, aindx) != NULL) {
3883 					SEGVN_VMSTAT_FLTVNPAGES(5);
3884 					ASSERT(anon_pages(amp->ahp, aindx,
3885 					    maxpages) == maxpages);
3886 					anon_array_exit(&an_cookie);
3887 					ANON_LOCK_EXIT(&amp->a_rwlock);
3888 					err = segvn_fault_anonpages(hat, seg,
3889 					    a, a + maxpgsz, type, rw,
3890 					    MAX(a, addr),
3891 					    MIN(a + maxpgsz, eaddr), brkcow);
3892 					if (err != 0) {
3893 						SEGVN_VMSTAT_FLTVNPAGES(6);
3894 						goto out;
3895 					}
3896 					if (szc < seg->s_szc) {
3897 						szc = seg->s_szc;
3898 						pgsz = maxpgsz;
3899 						pages = maxpages;
3900 						lpgeaddr = maxlpgeaddr;
3901 					}
3902 					goto next;
3903 				} else {
3904 					ASSERT(anon_pages(amp->ahp, aindx,
3905 					    maxpages) == 0);
3906 					SEGVN_VMSTAT_FLTVNPAGES(7);
3907 					anon_array_exit(&an_cookie);
3908 					ANON_LOCK_EXIT(&amp->a_rwlock);
3909 				}
3910 			}
3911 			ASSERT(!brkcow || IS_P2ALIGNED(a, maxpgsz));
3912 			ASSERT(!tron || IS_P2ALIGNED(a, maxpgsz));
3913 
3914 			if (svd->pageprot != 0 && IS_P2ALIGNED(a, maxpgsz)) {
3915 				ASSERT(vpage != NULL);
3916 				prot = VPP_PROT(vpage);
3917 				ASSERT(sameprot(seg, a, maxpgsz));
3918 				if ((prot & protchk) == 0) {
3919 					SEGVN_VMSTAT_FLTVNPAGES(8);
3920 					err = FC_PROT;
3921 					goto out;
3922 				}
3923 			}
3924 			if (type == F_SOFTLOCK) {
3925 				atomic_add_long((ulong_t *)&svd->softlockcnt,
3926 				    pages);
3927 			}
3928 
3929 			pplist = NULL;
3930 			physcontig = 0;
3931 			ppa[0] = NULL;
3932 			if (!brkcow && !tron && szc &&
3933 			    !page_exists_physcontig(vp, off, szc,
3934 			    segtype == MAP_PRIVATE ? ppa : NULL)) {
3935 				SEGVN_VMSTAT_FLTVNPAGES(9);
3936 				if (page_alloc_pages(vp, seg, a, &pplist, NULL,
3937 				    szc, 0, 0) && type != F_SOFTLOCK) {
3938 					SEGVN_VMSTAT_FLTVNPAGES(10);
3939 					pszc = 0;
3940 					ierr = -1;
3941 					alloc_failed |= (1 << szc);
3942 					break;
3943 				}
3944 				if (pplist != NULL &&
3945 				    vp->v_mpssdata == SEGVN_PAGEIO) {
3946 					int downsize;
3947 					SEGVN_VMSTAT_FLTVNPAGES(11);
3948 					physcontig = segvn_fill_vp_pages(svd,
3949 					    vp, off, szc, ppa, &pplist,
3950 					    &pszc, &downsize);
3951 					ASSERT(!physcontig || pplist == NULL);
3952 					if (!physcontig && downsize &&
3953 					    type != F_SOFTLOCK) {
3954 						ASSERT(pplist == NULL);
3955 						SEGVN_VMSTAT_FLTVNPAGES(12);
3956 						ierr = -1;
3957 						break;
3958 					}
3959 					ASSERT(!physcontig ||
3960 					    segtype == MAP_PRIVATE ||
3961 					    ppa[0] == NULL);
3962 					if (physcontig && ppa[0] == NULL) {
3963 						physcontig = 0;
3964 					}
3965 				}
3966 			} else if (!brkcow && !tron && szc && ppa[0] != NULL) {
3967 				SEGVN_VMSTAT_FLTVNPAGES(13);
3968 				ASSERT(segtype == MAP_PRIVATE);
3969 				physcontig = 1;
3970 			}
3971 
3972 			if (!physcontig) {
3973 				SEGVN_VMSTAT_FLTVNPAGES(14);
3974 				ppa[0] = NULL;
3975 				ierr = VOP_GETPAGE(vp, (offset_t)off, pgsz,
3976 				    &vpprot, ppa, pgsz, seg, a, arw,
3977 				    svd->cred, NULL);
3978 #ifdef DEBUG
3979 				if (ierr == 0) {
3980 					for (i = 0; i < pages; i++) {
3981 						ASSERT(PAGE_LOCKED(ppa[i]));
3982 						ASSERT(!PP_ISFREE(ppa[i]));
3983 						ASSERT(ppa[i]->p_vnode == vp);
3984 						ASSERT(ppa[i]->p_offset ==
3985 						    off + (i << PAGESHIFT));
3986 					}
3987 				}
3988 #endif /* DEBUG */
3989 				if (segtype == MAP_PRIVATE) {
3990 					SEGVN_VMSTAT_FLTVNPAGES(15);
3991 					vpprot &= ~PROT_WRITE;
3992 				}
3993 			} else {
3994 				ASSERT(segtype == MAP_PRIVATE);
3995 				SEGVN_VMSTAT_FLTVNPAGES(16);
3996 				vpprot = PROT_ALL & ~PROT_WRITE;
3997 				ierr = 0;
3998 			}
3999 
4000 			if (ierr != 0) {
4001 				SEGVN_VMSTAT_FLTVNPAGES(17);
4002 				if (pplist != NULL) {
4003 					SEGVN_VMSTAT_FLTVNPAGES(18);
4004 					page_free_replacement_page(pplist);
4005 					page_create_putback(pages);
4006 				}
4007 				SEGVN_RESTORE_SOFTLOCK_VP(type, pages);
4008 				if (a + pgsz <= eaddr) {
4009 					SEGVN_VMSTAT_FLTVNPAGES(19);
4010 					err = FC_MAKE_ERR(ierr);
4011 					goto out;
4012 				}
4013 				va.va_mask = AT_SIZE;
4014 				if (VOP_GETATTR(vp, &va, 0, svd->cred, NULL)) {
4015 					SEGVN_VMSTAT_FLTVNPAGES(20);
4016 					err = FC_MAKE_ERR(EIO);
4017 					goto out;
4018 				}
4019 				if (btopr(va.va_size) >= btopr(off + pgsz)) {
4020 					SEGVN_VMSTAT_FLTVNPAGES(21);
4021 					err = FC_MAKE_ERR(ierr);
4022 					goto out;
4023 				}
4024 				if (btopr(va.va_size) <
4025 				    btopr(off + (eaddr - a))) {
4026 					SEGVN_VMSTAT_FLTVNPAGES(22);
4027 					err = FC_MAKE_ERR(ierr);
4028 					goto out;
4029 				}
4030 				if (brkcow || tron || type == F_SOFTLOCK) {
4031 					/* can't reduce map area */
4032 					SEGVN_VMSTAT_FLTVNPAGES(23);
4033 					vop_size_err = 1;
4034 					goto out;
4035 				}
4036 				SEGVN_VMSTAT_FLTVNPAGES(24);
4037 				ASSERT(szc != 0);
4038 				pszc = 0;
4039 				ierr = -1;
4040 				break;
4041 			}
4042 
4043 			if (amp != NULL) {
4044 				ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
4045 				anon_array_enter(amp, aindx, &an_cookie);
4046 			}
4047 			if (amp != NULL &&
4048 			    anon_get_ptr(amp->ahp, aindx) != NULL) {
4049 				ulong_t taindx = P2ALIGN(aindx, maxpages);
4050 
4051 				SEGVN_VMSTAT_FLTVNPAGES(25);
4052 				ASSERT(anon_pages(amp->ahp, taindx,
4053 				    maxpages) == maxpages);
4054 				for (i = 0; i < pages; i++) {
4055 					page_unlock(ppa[i]);
4056 				}
4057 				anon_array_exit(&an_cookie);
4058 				ANON_LOCK_EXIT(&amp->a_rwlock);
4059 				if (pplist != NULL) {
4060 					page_free_replacement_page(pplist);
4061 					page_create_putback(pages);
4062 				}
4063 				SEGVN_RESTORE_SOFTLOCK_VP(type, pages);
4064 				if (szc < seg->s_szc) {
4065 					SEGVN_VMSTAT_FLTVNPAGES(26);
4066 					/*
4067 					 * For private segments SOFTLOCK
4068 					 * either always breaks cow (any rw
4069 					 * type except S_READ_NOCOW) or
4070 					 * address space is locked as writer
4071 					 * (S_READ_NOCOW case) and anon slots
4072 					 * can't show up on second check.
4073 					 * Therefore if we are here for
4074 					 * SOFTLOCK case it must be a cow
4075 					 * break but cow break never reduces
4076 					 * szc. text replication (tron) in
4077 					 * this case works as cow break.
4078 					 * Thus the assert below.
4079 					 */
4080 					ASSERT(!brkcow && !tron &&
4081 					    type != F_SOFTLOCK);
4082 					pszc = seg->s_szc;
4083 					ierr = -2;
4084 					break;
4085 				}
4086 				ASSERT(IS_P2ALIGNED(a, maxpgsz));
4087 				goto again;
4088 			}
4089 #ifdef DEBUG
4090 			if (amp != NULL) {
4091 				ulong_t taindx = P2ALIGN(aindx, maxpages);
4092 				ASSERT(!anon_pages(amp->ahp, taindx, maxpages));
4093 			}
4094 #endif /* DEBUG */
4095 
4096 			if (brkcow || tron) {
4097 				ASSERT(amp != NULL);
4098 				ASSERT(pplist == NULL);
4099 				ASSERT(szc == seg->s_szc);
4100 				ASSERT(IS_P2ALIGNED(a, maxpgsz));
4101 				ASSERT(IS_P2ALIGNED(aindx, maxpages));
4102 				SEGVN_VMSTAT_FLTVNPAGES(27);
4103 				ierr = anon_map_privatepages(amp, aindx, szc,
4104 				    seg, a, prot, ppa, vpage, segvn_anypgsz,
4105 				    tron ? PG_LOCAL : 0, svd->cred);
4106 				if (ierr != 0) {
4107 					SEGVN_VMSTAT_FLTVNPAGES(28);
4108 					anon_array_exit(&an_cookie);
4109 					ANON_LOCK_EXIT(&amp->a_rwlock);
4110 					SEGVN_RESTORE_SOFTLOCK_VP(type, pages);
4111 					err = FC_MAKE_ERR(ierr);
4112 					goto out;
4113 				}
4114 
4115 				ASSERT(!IS_VMODSORT(ppa[0]->p_vnode));
4116 				/*
4117 				 * p_szc can't be changed for locked
4118 				 * swapfs pages.
4119 				 */
4120 				ASSERT(svd->rcookie ==
4121 				    HAT_INVALID_REGION_COOKIE);
4122 				hat_memload_array(hat, a, pgsz, ppa, prot,
4123 				    hat_flag);
4124 
4125 				if (!(hat_flag & HAT_LOAD_LOCK)) {
4126 					SEGVN_VMSTAT_FLTVNPAGES(29);
4127 					for (i = 0; i < pages; i++) {
4128 						page_unlock(ppa[i]);
4129 					}
4130 				}
4131 				anon_array_exit(&an_cookie);
4132 				ANON_LOCK_EXIT(&amp->a_rwlock);
4133 				goto next;
4134 			}
4135 
4136 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE ||
4137 			    (!svd->pageprot && svd->prot == (prot & vpprot)));
4138 
4139 			pfn = page_pptonum(ppa[0]);
4140 			/*
4141 			 * hat_page_demote() needs an SE_EXCL lock on one of
4142 			 * constituent page_t's and it decreases root's p_szc
4143 			 * last. This means if root's p_szc is equal szc and
4144 			 * all its constituent pages are locked
4145 			 * hat_page_demote() that could have changed p_szc to
4146 			 * szc is already done and no new have page_demote()
4147 			 * can start for this large page.
4148 			 */
4149 
4150 			/*
4151 			 * we need to make sure same mapping size is used for
4152 			 * the same address range if there's a possibility the
4153 			 * adddress is already mapped because hat layer panics
4154 			 * when translation is loaded for the range already
4155 			 * mapped with a different page size.  We achieve it
4156 			 * by always using largest page size possible subject
4157 			 * to the constraints of page size, segment page size
4158 			 * and page alignment.  Since mappings are invalidated
4159 			 * when those constraints change and make it
4160 			 * impossible to use previously used mapping size no
4161 			 * mapping size conflicts should happen.
4162 			 */
4163 
4164 		chkszc:
4165 			if ((pszc = ppa[0]->p_szc) == szc &&
4166 			    IS_P2ALIGNED(pfn, pages)) {
4167 
4168 				SEGVN_VMSTAT_FLTVNPAGES(30);
4169 #ifdef DEBUG
4170 				for (i = 0; i < pages; i++) {
4171 					ASSERT(PAGE_LOCKED(ppa[i]));
4172 					ASSERT(!PP_ISFREE(ppa[i]));
4173 					ASSERT(page_pptonum(ppa[i]) ==
4174 					    pfn + i);
4175 					ASSERT(ppa[i]->p_szc == szc);
4176 					ASSERT(ppa[i]->p_vnode == vp);
4177 					ASSERT(ppa[i]->p_offset ==
4178 					    off + (i << PAGESHIFT));
4179 				}
4180 #endif /* DEBUG */
4181 				/*
4182 				 * All pages are of szc we need and they are
4183 				 * all locked so they can't change szc. load
4184 				 * translations.
4185 				 *
4186 				 * if page got promoted since last check
4187 				 * we don't need pplist.
4188 				 */
4189 				if (pplist != NULL) {
4190 					page_free_replacement_page(pplist);
4191 					page_create_putback(pages);
4192 				}
4193 				if (PP_ISMIGRATE(ppa[0])) {
4194 					page_migrate(seg, a, ppa, pages);
4195 				}
4196 				SEGVN_UPDATE_MODBITS(ppa, pages, rw,
4197 				    prot, vpprot);
4198 				if (!xhat) {
4199 					hat_memload_array_region(hat, a, pgsz,
4200 					    ppa, prot & vpprot, hat_flag,
4201 					    svd->rcookie);
4202 				} else {
4203 					/*
4204 					 * avoid large xhat mappings to FS
4205 					 * pages so that hat_page_demote()
4206 					 * doesn't need to check for xhat
4207 					 * large mappings.
4208 					 * Don't use regions with xhats.
4209 					 */
4210 					for (i = 0; i < pages; i++) {
4211 						hat_memload(hat,
4212 						    a + (i << PAGESHIFT),
4213 						    ppa[i], prot & vpprot,
4214 						    hat_flag);
4215 					}
4216 				}
4217 
4218 				if (!(hat_flag & HAT_LOAD_LOCK)) {
4219 					for (i = 0; i < pages; i++) {
4220 						page_unlock(ppa[i]);
4221 					}
4222 				}
4223 				if (amp != NULL) {
4224 					anon_array_exit(&an_cookie);
4225 					ANON_LOCK_EXIT(&amp->a_rwlock);
4226 				}
4227 				goto next;
4228 			}
4229 
4230 			/*
4231 			 * See if upsize is possible.
4232 			 */
4233 			if (pszc > szc && szc < seg->s_szc &&
4234 			    (segvn_anypgsz_vnode || pszc >= seg->s_szc)) {
4235 				pgcnt_t aphase;
4236 				uint_t pszc1 = MIN(pszc, seg->s_szc);
4237 				ppgsz = page_get_pagesize(pszc1);
4238 				ppages = btop(ppgsz);
4239 				aphase = btop(P2PHASE((uintptr_t)a, ppgsz));
4240 
4241 				ASSERT(type != F_SOFTLOCK);
4242 
4243 				SEGVN_VMSTAT_FLTVNPAGES(31);
4244 				if (aphase != P2PHASE(pfn, ppages)) {
4245 					segvn_faultvnmpss_align_err4++;
4246 				} else {
4247 					SEGVN_VMSTAT_FLTVNPAGES(32);
4248 					if (pplist != NULL) {
4249 						page_t *pl = pplist;
4250 						page_free_replacement_page(pl);
4251 						page_create_putback(pages);
4252 					}
4253 					for (i = 0; i < pages; i++) {
4254 						page_unlock(ppa[i]);
4255 					}
4256 					if (amp != NULL) {
4257 						anon_array_exit(&an_cookie);
4258 						ANON_LOCK_EXIT(&amp->a_rwlock);
4259 					}
4260 					pszc = pszc1;
4261 					ierr = -2;
4262 					break;
4263 				}
4264 			}
4265 
4266 			/*
4267 			 * check if we should use smallest mapping size.
4268 			 */
4269 			upgrdfail = 0;
4270 			if (szc == 0 || xhat ||
4271 			    (pszc >= szc &&
4272 			    !IS_P2ALIGNED(pfn, pages)) ||
4273 			    (pszc < szc &&
4274 			    !segvn_full_szcpages(ppa, szc, &upgrdfail,
4275 			    &pszc))) {
4276 
4277 				if (upgrdfail && type != F_SOFTLOCK) {
4278 					/*
4279 					 * segvn_full_szcpages failed to lock
4280 					 * all pages EXCL. Size down.
4281 					 */
4282 					ASSERT(pszc < szc);
4283 
4284 					SEGVN_VMSTAT_FLTVNPAGES(33);
4285 
4286 					if (pplist != NULL) {
4287 						page_t *pl = pplist;
4288 						page_free_replacement_page(pl);
4289 						page_create_putback(pages);
4290 					}
4291 
4292 					for (i = 0; i < pages; i++) {
4293 						page_unlock(ppa[i]);
4294 					}
4295 					if (amp != NULL) {
4296 						anon_array_exit(&an_cookie);
4297 						ANON_LOCK_EXIT(&amp->a_rwlock);
4298 					}
4299 					ierr = -1;
4300 					break;
4301 				}
4302 				if (szc != 0 && !xhat && !upgrdfail) {
4303 					segvn_faultvnmpss_align_err5++;
4304 				}
4305 				SEGVN_VMSTAT_FLTVNPAGES(34);
4306 				if (pplist != NULL) {
4307 					page_free_replacement_page(pplist);
4308 					page_create_putback(pages);
4309 				}
4310 				SEGVN_UPDATE_MODBITS(ppa, pages, rw,
4311 				    prot, vpprot);
4312 				if (upgrdfail && segvn_anypgsz_vnode) {
4313 					/* SOFTLOCK case */
4314 					hat_memload_array_region(hat, a, pgsz,
4315 					    ppa, prot & vpprot, hat_flag,
4316 					    svd->rcookie);
4317 				} else {
4318 					for (i = 0; i < pages; i++) {
4319 						hat_memload_region(hat,
4320 						    a + (i << PAGESHIFT),
4321 						    ppa[i], prot & vpprot,
4322 						    hat_flag, svd->rcookie);
4323 					}
4324 				}
4325 				if (!(hat_flag & HAT_LOAD_LOCK)) {
4326 					for (i = 0; i < pages; i++) {
4327 						page_unlock(ppa[i]);
4328 					}
4329 				}
4330 				if (amp != NULL) {
4331 					anon_array_exit(&an_cookie);
4332 					ANON_LOCK_EXIT(&amp->a_rwlock);
4333 				}
4334 				goto next;
4335 			}
4336 
4337 			if (pszc == szc) {
4338 				/*
4339 				 * segvn_full_szcpages() upgraded pages szc.
4340 				 */
4341 				ASSERT(pszc == ppa[0]->p_szc);
4342 				ASSERT(IS_P2ALIGNED(pfn, pages));
4343 				goto chkszc;
4344 			}
4345 
4346 			if (pszc > szc) {
4347 				kmutex_t *szcmtx;
4348 				SEGVN_VMSTAT_FLTVNPAGES(35);
4349 				/*
4350 				 * p_szc of ppa[0] can change since we haven't
4351 				 * locked all constituent pages. Call
4352 				 * page_lock_szc() to prevent szc changes.
4353 				 * This should be a rare case that happens when
4354 				 * multiple segments use a different page size
4355 				 * to map the same file offsets.
4356 				 */
4357 				szcmtx = page_szc_lock(ppa[0]);
4358 				pszc = ppa[0]->p_szc;
4359 				ASSERT(szcmtx != NULL || pszc == 0);
4360 				ASSERT(ppa[0]->p_szc <= pszc);
4361 				if (pszc <= szc) {
4362 					SEGVN_VMSTAT_FLTVNPAGES(36);
4363 					if (szcmtx != NULL) {
4364 						mutex_exit(szcmtx);
4365 					}
4366 					goto chkszc;
4367 				}
4368 				if (pplist != NULL) {
4369 					/*
4370 					 * page got promoted since last check.
4371 					 * we don't need preaalocated large
4372 					 * page.
4373 					 */
4374 					SEGVN_VMSTAT_FLTVNPAGES(37);
4375 					page_free_replacement_page(pplist);
4376 					page_create_putback(pages);
4377 				}
4378 				SEGVN_UPDATE_MODBITS(ppa, pages, rw,
4379 				    prot, vpprot);
4380 				hat_memload_array_region(hat, a, pgsz, ppa,
4381 				    prot & vpprot, hat_flag, svd->rcookie);
4382 				mutex_exit(szcmtx);
4383 				if (!(hat_flag & HAT_LOAD_LOCK)) {
4384 					for (i = 0; i < pages; i++) {
4385 						page_unlock(ppa[i]);
4386 					}
4387 				}
4388 				if (amp != NULL) {
4389 					anon_array_exit(&an_cookie);
4390 					ANON_LOCK_EXIT(&amp->a_rwlock);
4391 				}
4392 				goto next;
4393 			}
4394 
4395 			/*
4396 			 * if page got demoted since last check
4397 			 * we could have not allocated larger page.
4398 			 * allocate now.
4399 			 */
4400 			if (pplist == NULL &&
4401 			    page_alloc_pages(vp, seg, a, &pplist, NULL,
4402 			    szc, 0, 0) && type != F_SOFTLOCK) {
4403 				SEGVN_VMSTAT_FLTVNPAGES(38);
4404 				for (i = 0; i < pages; i++) {
4405 					page_unlock(ppa[i]);
4406 				}
4407 				if (amp != NULL) {
4408 					anon_array_exit(&an_cookie);
4409 					ANON_LOCK_EXIT(&amp->a_rwlock);
4410 				}
4411 				ierr = -1;
4412 				alloc_failed |= (1 << szc);
4413 				break;
4414 			}
4415 
4416 			SEGVN_VMSTAT_FLTVNPAGES(39);
4417 
4418 			if (pplist != NULL) {
4419 				segvn_relocate_pages(ppa, pplist);
4420 #ifdef DEBUG
4421 			} else {
4422 				ASSERT(type == F_SOFTLOCK);
4423 				SEGVN_VMSTAT_FLTVNPAGES(40);
4424 #endif /* DEBUG */
4425 			}
4426 
4427 			SEGVN_UPDATE_MODBITS(ppa, pages, rw, prot, vpprot);
4428 
4429 			if (pplist == NULL && segvn_anypgsz_vnode == 0) {
4430 				ASSERT(type == F_SOFTLOCK);
4431 				for (i = 0; i < pages; i++) {
4432 					ASSERT(ppa[i]->p_szc < szc);
4433 					hat_memload_region(hat,
4434 					    a + (i << PAGESHIFT),
4435 					    ppa[i], prot & vpprot, hat_flag,
4436 					    svd->rcookie);
4437 				}
4438 			} else {
4439 				ASSERT(pplist != NULL || type == F_SOFTLOCK);
4440 				hat_memload_array_region(hat, a, pgsz, ppa,
4441 				    prot & vpprot, hat_flag, svd->rcookie);
4442 			}
4443 			if (!(hat_flag & HAT_LOAD_LOCK)) {
4444 				for (i = 0; i < pages; i++) {
4445 					ASSERT(PAGE_SHARED(ppa[i]));
4446 					page_unlock(ppa[i]);
4447 				}
4448 			}
4449 			if (amp != NULL) {
4450 				anon_array_exit(&an_cookie);
4451 				ANON_LOCK_EXIT(&amp->a_rwlock);
4452 			}
4453 
4454 		next:
4455 			if (vpage != NULL) {
4456 				vpage += pages;
4457 			}
4458 			adjszc_chk = 1;
4459 		}
4460 		if (a == lpgeaddr)
4461 			break;
4462 		ASSERT(a < lpgeaddr);
4463 
4464 		ASSERT(!brkcow && !tron && type != F_SOFTLOCK);
4465 
4466 		/*
4467 		 * ierr == -1 means we failed to map with a large page.
4468 		 * (either due to allocation/relocation failures or
4469 		 * misalignment with other mappings to this file.
4470 		 *
4471 		 * ierr == -2 means some other thread allocated a large page
4472 		 * after we gave up tp map with a large page.  retry with
4473 		 * larger mapping.
4474 		 */
4475 		ASSERT(ierr == -1 || ierr == -2);
4476 		ASSERT(ierr == -2 || szc != 0);
4477 		ASSERT(ierr == -1 || szc < seg->s_szc);
4478 		if (ierr == -2) {
4479 			SEGVN_VMSTAT_FLTVNPAGES(41);
4480 			ASSERT(pszc > szc && pszc <= seg->s_szc);
4481 			szc = pszc;
4482 		} else if (segvn_anypgsz_vnode) {
4483 			SEGVN_VMSTAT_FLTVNPAGES(42);
4484 			szc--;
4485 		} else {
4486 			SEGVN_VMSTAT_FLTVNPAGES(43);
4487 			ASSERT(pszc < szc);
4488 			/*
4489 			 * other process created pszc large page.
4490 			 * but we still have to drop to 0 szc.
4491 			 */
4492 			szc = 0;
4493 		}
4494 
4495 		pgsz = page_get_pagesize(szc);
4496 		pages = btop(pgsz);
4497 		if (ierr == -2) {
4498 			/*
4499 			 * Size up case. Note lpgaddr may only be needed for
4500 			 * softlock case so we don't adjust it here.
4501 			 */
4502 			a = (caddr_t)P2ALIGN((uintptr_t)a, pgsz);
4503 			ASSERT(a >= lpgaddr);
4504 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4505 			off = svd->offset + (uintptr_t)(a - seg->s_base);
4506 			aindx = svd->anon_index + seg_page(seg, a);
4507 			vpage = (svd->vpage != NULL) ?
4508 			    &svd->vpage[seg_page(seg, a)] : NULL;
4509 		} else {
4510 			/*
4511 			 * Size down case. Note lpgaddr may only be needed for
4512 			 * softlock case so we don't adjust it here.
4513 			 */
4514 			ASSERT(IS_P2ALIGNED(a, pgsz));
4515 			ASSERT(IS_P2ALIGNED(lpgeaddr, pgsz));
4516 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4517 			ASSERT(a < lpgeaddr);
4518 			if (a < addr) {
4519 				SEGVN_VMSTAT_FLTVNPAGES(44);
4520 				/*
4521 				 * The beginning of the large page region can
4522 				 * be pulled to the right to make a smaller
4523 				 * region. We haven't yet faulted a single
4524 				 * page.
4525 				 */
4526 				a = (caddr_t)P2ALIGN((uintptr_t)addr, pgsz);
4527 				ASSERT(a >= lpgaddr);
4528 				off = svd->offset +
4529 				    (uintptr_t)(a - seg->s_base);
4530 				aindx = svd->anon_index + seg_page(seg, a);
4531 				vpage = (svd->vpage != NULL) ?
4532 				    &svd->vpage[seg_page(seg, a)] : NULL;
4533 			}
4534 		}
4535 	}
4536 out:
4537 	kmem_free(ppa, ppasize);
4538 	if (!err && !vop_size_err) {
4539 		SEGVN_VMSTAT_FLTVNPAGES(45);
4540 		return (0);
4541 	}
4542 	if (type == F_SOFTLOCK && a > lpgaddr) {
4543 		SEGVN_VMSTAT_FLTVNPAGES(46);
4544 		segvn_softunlock(seg, lpgaddr, a - lpgaddr, S_OTHER);
4545 	}
4546 	if (!vop_size_err) {
4547 		SEGVN_VMSTAT_FLTVNPAGES(47);
4548 		return (err);
4549 	}
4550 	ASSERT(brkcow || tron || type == F_SOFTLOCK);
4551 	/*
4552 	 * Large page end is mapped beyond the end of file and it's a cow
4553 	 * fault (can be a text replication induced cow) or softlock so we can't
4554 	 * reduce the map area.  For now just demote the segment. This should
4555 	 * really only happen if the end of the file changed after the mapping
4556 	 * was established since when large page segments are created we make
4557 	 * sure they don't extend beyond the end of the file.
4558 	 */
4559 	SEGVN_VMSTAT_FLTVNPAGES(48);
4560 
4561 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4562 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4563 	err = 0;
4564 	if (seg->s_szc != 0) {
4565 		segvn_fltvnpages_clrszc_cnt++;
4566 		ASSERT(svd->softlockcnt == 0);
4567 		err = segvn_clrszc(seg);
4568 		if (err != 0) {
4569 			segvn_fltvnpages_clrszc_err++;
4570 		}
4571 	}
4572 	ASSERT(err || seg->s_szc == 0);
4573 	SEGVN_LOCK_DOWNGRADE(seg->s_as, &svd->lock);
4574 	/* segvn_fault will do its job as if szc had been zero to begin with */
4575 	return (err == 0 ? IE_RETRY : FC_MAKE_ERR(err));
4576 }
4577 
4578 /*
4579  * This routine will attempt to fault in one large page.
4580  * it will use smaller pages if that fails.
4581  * It should only be called for pure anonymous segments.
4582  */
4583 static faultcode_t
4584 segvn_fault_anonpages(struct hat *hat, struct seg *seg, caddr_t lpgaddr,
4585     caddr_t lpgeaddr, enum fault_type type, enum seg_rw rw, caddr_t addr,
4586     caddr_t eaddr, int brkcow)
4587 {
4588 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
4589 	struct anon_map *amp = svd->amp;
4590 	uchar_t segtype = svd->type;
4591 	uint_t szc = seg->s_szc;
4592 	size_t pgsz = page_get_pagesize(szc);
4593 	size_t maxpgsz = pgsz;
4594 	pgcnt_t pages = btop(pgsz);
4595 	uint_t ppaszc = szc;
4596 	caddr_t a = lpgaddr;
4597 	ulong_t aindx = svd->anon_index + seg_page(seg, a);
4598 	struct vpage *vpage = (svd->vpage != NULL) ?
4599 	    &svd->vpage[seg_page(seg, a)] : NULL;
4600 	page_t **ppa;
4601 	uint_t	ppa_szc;
4602 	faultcode_t err;
4603 	int ierr;
4604 	uint_t protchk, prot, vpprot;
4605 	ulong_t i;
4606 	int hat_flag = (type == F_SOFTLOCK) ? HAT_LOAD_LOCK : HAT_LOAD;
4607 	anon_sync_obj_t cookie;
4608 	int adjszc_chk;
4609 	int pgflags = (svd->tr_state == SEGVN_TR_ON) ? PG_LOCAL : 0;
4610 
4611 	ASSERT(szc != 0);
4612 	ASSERT(amp != NULL);
4613 	ASSERT(enable_mbit_wa == 0); /* no mbit simulations with large pages */
4614 	ASSERT(!(svd->flags & MAP_NORESERVE));
4615 	ASSERT(type != F_SOFTUNLOCK);
4616 	ASSERT(IS_P2ALIGNED(a, maxpgsz));
4617 	ASSERT(!brkcow || svd->tr_state == SEGVN_TR_OFF);
4618 	ASSERT(svd->tr_state != SEGVN_TR_INIT);
4619 
4620 	ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
4621 
4622 	VM_STAT_COND_ADD(type == F_SOFTLOCK, segvnvmstats.fltanpages[0]);
4623 	VM_STAT_COND_ADD(type != F_SOFTLOCK, segvnvmstats.fltanpages[1]);
4624 
4625 	if (svd->flags & MAP_TEXT) {
4626 		hat_flag |= HAT_LOAD_TEXT;
4627 	}
4628 
4629 	if (svd->pageprot) {
4630 		switch (rw) {
4631 		case S_READ:
4632 			protchk = PROT_READ;
4633 			break;
4634 		case S_WRITE:
4635 			protchk = PROT_WRITE;
4636 			break;
4637 		case S_EXEC:
4638 			protchk = PROT_EXEC;
4639 			break;
4640 		case S_OTHER:
4641 		default:
4642 			protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
4643 			break;
4644 		}
4645 		VM_STAT_ADD(segvnvmstats.fltanpages[2]);
4646 	} else {
4647 		prot = svd->prot;
4648 		/* caller has already done segment level protection check. */
4649 	}
4650 
4651 	ppa = kmem_cache_alloc(segvn_szc_cache[ppaszc], KM_SLEEP);
4652 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
4653 	for (;;) {
4654 		adjszc_chk = 0;
4655 		for (; a < lpgeaddr; a += pgsz, aindx += pages) {
4656 			if (svd->pageprot != 0 && IS_P2ALIGNED(a, maxpgsz)) {
4657 				VM_STAT_ADD(segvnvmstats.fltanpages[3]);
4658 				ASSERT(vpage != NULL);
4659 				prot = VPP_PROT(vpage);
4660 				ASSERT(sameprot(seg, a, maxpgsz));
4661 				if ((prot & protchk) == 0) {
4662 					err = FC_PROT;
4663 					goto error;
4664 				}
4665 			}
4666 			if (adjszc_chk && IS_P2ALIGNED(a, maxpgsz) &&
4667 			    pgsz < maxpgsz) {
4668 				ASSERT(a > lpgaddr);
4669 				szc = seg->s_szc;
4670 				pgsz = maxpgsz;
4671 				pages = btop(pgsz);
4672 				ASSERT(IS_P2ALIGNED(aindx, pages));
4673 				lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr,
4674 				    pgsz);
4675 			}
4676 			if (type == F_SOFTLOCK) {
4677 				atomic_add_long((ulong_t *)&svd->softlockcnt,
4678 				    pages);
4679 			}
4680 			anon_array_enter(amp, aindx, &cookie);
4681 			ppa_szc = (uint_t)-1;
4682 			ierr = anon_map_getpages(amp, aindx, szc, seg, a,
4683 			    prot, &vpprot, ppa, &ppa_szc, vpage, rw, brkcow,
4684 			    segvn_anypgsz, pgflags, svd->cred);
4685 			if (ierr != 0) {
4686 				anon_array_exit(&cookie);
4687 				VM_STAT_ADD(segvnvmstats.fltanpages[4]);
4688 				if (type == F_SOFTLOCK) {
4689 					atomic_add_long(
4690 					    (ulong_t *)&svd->softlockcnt,
4691 					    -pages);
4692 				}
4693 				if (ierr > 0) {
4694 					VM_STAT_ADD(segvnvmstats.fltanpages[6]);
4695 					err = FC_MAKE_ERR(ierr);
4696 					goto error;
4697 				}
4698 				break;
4699 			}
4700 
4701 			ASSERT(!IS_VMODSORT(ppa[0]->p_vnode));
4702 
4703 			ASSERT(segtype == MAP_SHARED ||
4704 			    ppa[0]->p_szc <= szc);
4705 			ASSERT(segtype == MAP_PRIVATE ||
4706 			    ppa[0]->p_szc >= szc);
4707 
4708 			/*
4709 			 * Handle pages that have been marked for migration
4710 			 */
4711 			if (lgrp_optimizations())
4712 				page_migrate(seg, a, ppa, pages);
4713 
4714 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
4715 
4716 			if (segtype == MAP_SHARED) {
4717 				vpprot |= PROT_WRITE;
4718 			}
4719 
4720 			hat_memload_array(hat, a, pgsz, ppa,
4721 			    prot & vpprot, hat_flag);
4722 
4723 			if (hat_flag & HAT_LOAD_LOCK) {
4724 				VM_STAT_ADD(segvnvmstats.fltanpages[7]);
4725 			} else {
4726 				VM_STAT_ADD(segvnvmstats.fltanpages[8]);
4727 				for (i = 0; i < pages; i++)
4728 					page_unlock(ppa[i]);
4729 			}
4730 			if (vpage != NULL)
4731 				vpage += pages;
4732 
4733 			anon_array_exit(&cookie);
4734 			adjszc_chk = 1;
4735 		}
4736 		if (a == lpgeaddr)
4737 			break;
4738 		ASSERT(a < lpgeaddr);
4739 		/*
4740 		 * ierr == -1 means we failed to allocate a large page.
4741 		 * so do a size down operation.
4742 		 *
4743 		 * ierr == -2 means some other process that privately shares
4744 		 * pages with this process has allocated a larger page and we
4745 		 * need to retry with larger pages. So do a size up
4746 		 * operation. This relies on the fact that large pages are
4747 		 * never partially shared i.e. if we share any constituent
4748 		 * page of a large page with another process we must share the
4749 		 * entire large page. Note this cannot happen for SOFTLOCK
4750 		 * case, unless current address (a) is at the beginning of the
4751 		 * next page size boundary because the other process couldn't
4752 		 * have relocated locked pages.
4753 		 */
4754 		ASSERT(ierr == -1 || ierr == -2);
4755 
4756 		if (segvn_anypgsz) {
4757 			ASSERT(ierr == -2 || szc != 0);
4758 			ASSERT(ierr == -1 || szc < seg->s_szc);
4759 			szc = (ierr == -1) ? szc - 1 : szc + 1;
4760 		} else {
4761 			/*
4762 			 * For non COW faults and segvn_anypgsz == 0
4763 			 * we need to be careful not to loop forever
4764 			 * if existing page is found with szc other
4765 			 * than 0 or seg->s_szc. This could be due
4766 			 * to page relocations on behalf of DR or
4767 			 * more likely large page creation. For this
4768 			 * case simply re-size to existing page's szc
4769 			 * if returned by anon_map_getpages().
4770 			 */
4771 			if (ppa_szc == (uint_t)-1) {
4772 				szc = (ierr == -1) ? 0 : seg->s_szc;
4773 			} else {
4774 				ASSERT(ppa_szc <= seg->s_szc);
4775 				ASSERT(ierr == -2 || ppa_szc < szc);
4776 				ASSERT(ierr == -1 || ppa_szc > szc);
4777 				szc = ppa_szc;
4778 			}
4779 		}
4780 
4781 		pgsz = page_get_pagesize(szc);
4782 		pages = btop(pgsz);
4783 		ASSERT(type != F_SOFTLOCK || ierr == -1 ||
4784 		    (IS_P2ALIGNED(a, pgsz) && IS_P2ALIGNED(lpgeaddr, pgsz)));
4785 		if (type == F_SOFTLOCK) {
4786 			/*
4787 			 * For softlocks we cannot reduce the fault area
4788 			 * (calculated based on the largest page size for this
4789 			 * segment) for size down and a is already next
4790 			 * page size aligned as assertted above for size
4791 			 * ups. Therefore just continue in case of softlock.
4792 			 */
4793 			VM_STAT_ADD(segvnvmstats.fltanpages[9]);
4794 			continue; /* keep lint happy */
4795 		} else if (ierr == -2) {
4796 
4797 			/*
4798 			 * Size up case. Note lpgaddr may only be needed for
4799 			 * softlock case so we don't adjust it here.
4800 			 */
4801 			VM_STAT_ADD(segvnvmstats.fltanpages[10]);
4802 			a = (caddr_t)P2ALIGN((uintptr_t)a, pgsz);
4803 			ASSERT(a >= lpgaddr);
4804 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4805 			aindx = svd->anon_index + seg_page(seg, a);
4806 			vpage = (svd->vpage != NULL) ?
4807 			    &svd->vpage[seg_page(seg, a)] : NULL;
4808 		} else {
4809 			/*
4810 			 * Size down case. Note lpgaddr may only be needed for
4811 			 * softlock case so we don't adjust it here.
4812 			 */
4813 			VM_STAT_ADD(segvnvmstats.fltanpages[11]);
4814 			ASSERT(IS_P2ALIGNED(a, pgsz));
4815 			ASSERT(IS_P2ALIGNED(lpgeaddr, pgsz));
4816 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4817 			ASSERT(a < lpgeaddr);
4818 			if (a < addr) {
4819 				/*
4820 				 * The beginning of the large page region can
4821 				 * be pulled to the right to make a smaller
4822 				 * region. We haven't yet faulted a single
4823 				 * page.
4824 				 */
4825 				VM_STAT_ADD(segvnvmstats.fltanpages[12]);
4826 				a = (caddr_t)P2ALIGN((uintptr_t)addr, pgsz);
4827 				ASSERT(a >= lpgaddr);
4828 				aindx = svd->anon_index + seg_page(seg, a);
4829 				vpage = (svd->vpage != NULL) ?
4830 				    &svd->vpage[seg_page(seg, a)] : NULL;
4831 			}
4832 		}
4833 	}
4834 	VM_STAT_ADD(segvnvmstats.fltanpages[13]);
4835 	ANON_LOCK_EXIT(&amp->a_rwlock);
4836 	kmem_cache_free(segvn_szc_cache[ppaszc], ppa);
4837 	return (0);
4838 error:
4839 	VM_STAT_ADD(segvnvmstats.fltanpages[14]);
4840 	ANON_LOCK_EXIT(&amp->a_rwlock);
4841 	kmem_cache_free(segvn_szc_cache[ppaszc], ppa);
4842 	if (type == F_SOFTLOCK && a > lpgaddr) {
4843 		VM_STAT_ADD(segvnvmstats.fltanpages[15]);
4844 		segvn_softunlock(seg, lpgaddr, a - lpgaddr, S_OTHER);
4845 	}
4846 	return (err);
4847 }
4848 
4849 int fltadvice = 1;	/* set to free behind pages for sequential access */
4850 
4851 /*
4852  * This routine is called via a machine specific fault handling routine.
4853  * It is also called by software routines wishing to lock or unlock
4854  * a range of addresses.
4855  *
4856  * Here is the basic algorithm:
4857  *	If unlocking
4858  *		Call segvn_softunlock
4859  *		Return
4860  *	endif
4861  *	Checking and set up work
4862  *	If we will need some non-anonymous pages
4863  *		Call VOP_GETPAGE over the range of non-anonymous pages
4864  *	endif
4865  *	Loop over all addresses requested
4866  *		Call segvn_faultpage passing in page list
4867  *		    to load up translations and handle anonymous pages
4868  *	endloop
4869  *	Load up translation to any additional pages in page list not
4870  *	    already handled that fit into this segment
4871  */
4872 static faultcode_t
4873 segvn_fault(struct hat *hat, struct seg *seg, caddr_t addr, size_t len,
4874     enum fault_type type, enum seg_rw rw)
4875 {
4876 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
4877 	page_t **plp, **ppp, *pp;
4878 	u_offset_t off;
4879 	caddr_t a;
4880 	struct vpage *vpage;
4881 	uint_t vpprot, prot;
4882 	int err;
4883 	page_t *pl[PVN_GETPAGE_NUM + 1];
4884 	size_t plsz, pl_alloc_sz;
4885 	size_t page;
4886 	ulong_t anon_index;
4887 	struct anon_map *amp;
4888 	int dogetpage = 0;
4889 	caddr_t	lpgaddr, lpgeaddr;
4890 	size_t pgsz;
4891 	anon_sync_obj_t cookie;
4892 	int brkcow = BREAK_COW_SHARE(rw, type, svd->type);
4893 
4894 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
4895 	ASSERT(svd->amp == NULL || svd->rcookie == HAT_INVALID_REGION_COOKIE);
4896 
4897 	/*
4898 	 * First handle the easy stuff
4899 	 */
4900 	if (type == F_SOFTUNLOCK) {
4901 		if (rw == S_READ_NOCOW) {
4902 			rw = S_READ;
4903 			ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
4904 		}
4905 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
4906 		pgsz = (seg->s_szc == 0) ? PAGESIZE :
4907 		    page_get_pagesize(seg->s_szc);
4908 		VM_STAT_COND_ADD(pgsz > PAGESIZE, segvnvmstats.fltanpages[16]);
4909 		CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
4910 		segvn_softunlock(seg, lpgaddr, lpgeaddr - lpgaddr, rw);
4911 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4912 		return (0);
4913 	}
4914 
4915 	ASSERT(svd->tr_state == SEGVN_TR_OFF ||
4916 	    !HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
4917 	if (brkcow == 0) {
4918 		if (svd->tr_state == SEGVN_TR_INIT) {
4919 			SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4920 			if (svd->tr_state == SEGVN_TR_INIT) {
4921 				ASSERT(svd->vp != NULL && svd->amp == NULL);
4922 				ASSERT(svd->flags & MAP_TEXT);
4923 				ASSERT(svd->type == MAP_PRIVATE);
4924 				segvn_textrepl(seg);
4925 				ASSERT(svd->tr_state != SEGVN_TR_INIT);
4926 				ASSERT(svd->tr_state != SEGVN_TR_ON ||
4927 				    svd->amp != NULL);
4928 			}
4929 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4930 		}
4931 	} else if (svd->tr_state != SEGVN_TR_OFF) {
4932 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4933 
4934 		if (rw == S_WRITE && svd->tr_state != SEGVN_TR_OFF) {
4935 			ASSERT(!svd->pageprot && !(svd->prot & PROT_WRITE));
4936 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4937 			return (FC_PROT);
4938 		}
4939 
4940 		if (svd->tr_state == SEGVN_TR_ON) {
4941 			ASSERT(svd->vp != NULL && svd->amp != NULL);
4942 			segvn_textunrepl(seg, 0);
4943 			ASSERT(svd->amp == NULL &&
4944 			    svd->tr_state == SEGVN_TR_OFF);
4945 		} else if (svd->tr_state != SEGVN_TR_OFF) {
4946 			svd->tr_state = SEGVN_TR_OFF;
4947 		}
4948 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
4949 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4950 	}
4951 
4952 top:
4953 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
4954 
4955 	/*
4956 	 * If we have the same protections for the entire segment,
4957 	 * insure that the access being attempted is legitimate.
4958 	 */
4959 
4960 	if (svd->pageprot == 0) {
4961 		uint_t protchk;
4962 
4963 		switch (rw) {
4964 		case S_READ:
4965 		case S_READ_NOCOW:
4966 			protchk = PROT_READ;
4967 			break;
4968 		case S_WRITE:
4969 			protchk = PROT_WRITE;
4970 			break;
4971 		case S_EXEC:
4972 			protchk = PROT_EXEC;
4973 			break;
4974 		case S_OTHER:
4975 		default:
4976 			protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
4977 			break;
4978 		}
4979 
4980 		if ((svd->prot & protchk) == 0) {
4981 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4982 			return (FC_PROT);	/* illegal access type */
4983 		}
4984 	}
4985 
4986 	if (brkcow && HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
4987 		/* this must be SOFTLOCK S_READ fault */
4988 		ASSERT(svd->amp == NULL);
4989 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
4990 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4991 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4992 		if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
4993 			/*
4994 			 * this must be the first ever non S_READ_NOCOW
4995 			 * softlock for this segment.
4996 			 */
4997 			ASSERT(svd->softlockcnt == 0);
4998 			hat_leave_region(seg->s_as->a_hat, svd->rcookie,
4999 			    HAT_REGION_TEXT);
5000 			svd->rcookie = HAT_INVALID_REGION_COOKIE;
5001 		}
5002 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5003 		goto top;
5004 	}
5005 
5006 	/*
5007 	 * We can't allow the long term use of softlocks for vmpss segments,
5008 	 * because in some file truncation cases we should be able to demote
5009 	 * the segment, which requires that there are no softlocks.  The
5010 	 * only case where it's ok to allow a SOFTLOCK fault against a vmpss
5011 	 * segment is S_READ_NOCOW, where the caller holds the address space
5012 	 * locked as writer and calls softunlock before dropping the as lock.
5013 	 * S_READ_NOCOW is used by /proc to read memory from another user.
5014 	 *
5015 	 * Another deadlock between SOFTLOCK and file truncation can happen
5016 	 * because segvn_fault_vnodepages() calls the FS one pagesize at
5017 	 * a time. A second VOP_GETPAGE() call by segvn_fault_vnodepages()
5018 	 * can cause a deadlock because the first set of page_t's remain
5019 	 * locked SE_SHARED.  To avoid this, we demote segments on a first
5020 	 * SOFTLOCK if they have a length greater than the segment's
5021 	 * page size.
5022 	 *
5023 	 * So for now, we only avoid demoting a segment on a SOFTLOCK when
5024 	 * the access type is S_READ_NOCOW and the fault length is less than
5025 	 * or equal to the segment's page size. While this is quite restrictive,
5026 	 * it should be the most common case of SOFTLOCK against a vmpss
5027 	 * segment.
5028 	 *
5029 	 * For S_READ_NOCOW, it's safe not to do a copy on write because the
5030 	 * caller makes sure no COW will be caused by another thread for a
5031 	 * softlocked page.
5032 	 */
5033 	if (type == F_SOFTLOCK && svd->vp != NULL && seg->s_szc != 0) {
5034 		int demote = 0;
5035 
5036 		if (rw != S_READ_NOCOW) {
5037 			demote = 1;
5038 		}
5039 		if (!demote && len > PAGESIZE) {
5040 			pgsz = page_get_pagesize(seg->s_szc);
5041 			CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr,
5042 			    lpgeaddr);
5043 			if (lpgeaddr - lpgaddr > pgsz) {
5044 				demote = 1;
5045 			}
5046 		}
5047 
5048 		ASSERT(demote || AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
5049 
5050 		if (demote) {
5051 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5052 			SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
5053 			if (seg->s_szc != 0) {
5054 				segvn_vmpss_clrszc_cnt++;
5055 				ASSERT(svd->softlockcnt == 0);
5056 				err = segvn_clrszc(seg);
5057 				if (err) {
5058 					segvn_vmpss_clrszc_err++;
5059 					SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5060 					return (FC_MAKE_ERR(err));
5061 				}
5062 			}
5063 			ASSERT(seg->s_szc == 0);
5064 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5065 			goto top;
5066 		}
5067 	}
5068 
5069 	/*
5070 	 * Check to see if we need to allocate an anon_map structure.
5071 	 */
5072 	if (svd->amp == NULL && (svd->vp == NULL || brkcow)) {
5073 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
5074 		/*
5075 		 * Drop the "read" lock on the segment and acquire
5076 		 * the "write" version since we have to allocate the
5077 		 * anon_map.
5078 		 */
5079 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5080 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
5081 
5082 		if (svd->amp == NULL) {
5083 			svd->amp = anonmap_alloc(seg->s_size, 0, ANON_SLEEP);
5084 			svd->amp->a_szc = seg->s_szc;
5085 		}
5086 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5087 
5088 		/*
5089 		 * Start all over again since segment protections
5090 		 * may have changed after we dropped the "read" lock.
5091 		 */
5092 		goto top;
5093 	}
5094 
5095 	/*
5096 	 * S_READ_NOCOW vs S_READ distinction was
5097 	 * only needed for the code above. After
5098 	 * that we treat it as S_READ.
5099 	 */
5100 	if (rw == S_READ_NOCOW) {
5101 		ASSERT(type == F_SOFTLOCK);
5102 		ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
5103 		rw = S_READ;
5104 	}
5105 
5106 	amp = svd->amp;
5107 
5108 	/*
5109 	 * MADV_SEQUENTIAL work is ignored for large page segments.
5110 	 */
5111 	if (seg->s_szc != 0) {
5112 		pgsz = page_get_pagesize(seg->s_szc);
5113 		ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
5114 		CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
5115 		if (svd->vp == NULL) {
5116 			err = segvn_fault_anonpages(hat, seg, lpgaddr,
5117 			    lpgeaddr, type, rw, addr, addr + len, brkcow);
5118 		} else {
5119 			err = segvn_fault_vnodepages(hat, seg, lpgaddr,
5120 			    lpgeaddr, type, rw, addr, addr + len, brkcow);
5121 			if (err == IE_RETRY) {
5122 				ASSERT(seg->s_szc == 0);
5123 				ASSERT(SEGVN_READ_HELD(seg->s_as, &svd->lock));
5124 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5125 				goto top;
5126 			}
5127 		}
5128 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5129 		return (err);
5130 	}
5131 
5132 	page = seg_page(seg, addr);
5133 	if (amp != NULL) {
5134 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
5135 		anon_index = svd->anon_index + page;
5136 
5137 		if (type == F_PROT && rw == S_READ &&
5138 		    svd->tr_state == SEGVN_TR_OFF &&
5139 		    svd->type == MAP_PRIVATE && svd->pageprot == 0) {
5140 			size_t index = anon_index;
5141 			struct anon *ap;
5142 
5143 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5144 			/*
5145 			 * The fast path could apply to S_WRITE also, except
5146 			 * that the protection fault could be caused by lazy
5147 			 * tlb flush when ro->rw. In this case, the pte is
5148 			 * RW already. But RO in the other cpu's tlb causes
5149 			 * the fault. Since hat_chgprot won't do anything if
5150 			 * pte doesn't change, we may end up faulting
5151 			 * indefinitely until the RO tlb entry gets replaced.
5152 			 */
5153 			for (a = addr; a < addr + len; a += PAGESIZE, index++) {
5154 				anon_array_enter(amp, index, &cookie);
5155 				ap = anon_get_ptr(amp->ahp, index);
5156 				anon_array_exit(&cookie);
5157 				if ((ap == NULL) || (ap->an_refcnt != 1)) {
5158 					ANON_LOCK_EXIT(&amp->a_rwlock);
5159 					goto slow;
5160 				}
5161 			}
5162 			hat_chgprot(seg->s_as->a_hat, addr, len, svd->prot);
5163 			ANON_LOCK_EXIT(&amp->a_rwlock);
5164 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5165 			return (0);
5166 		}
5167 	}
5168 slow:
5169 
5170 	if (svd->vpage == NULL)
5171 		vpage = NULL;
5172 	else
5173 		vpage = &svd->vpage[page];
5174 
5175 	off = svd->offset + (uintptr_t)(addr - seg->s_base);
5176 
5177 	/*
5178 	 * If MADV_SEQUENTIAL has been set for the particular page we
5179 	 * are faulting on, free behind all pages in the segment and put
5180 	 * them on the free list.
5181 	 */
5182 
5183 	if ((page != 0) && fltadvice && svd->tr_state != SEGVN_TR_ON) {
5184 		struct vpage *vpp;
5185 		ulong_t fanon_index;
5186 		size_t fpage;
5187 		u_offset_t pgoff, fpgoff;
5188 		struct vnode *fvp;
5189 		struct anon *fap = NULL;
5190 
5191 		if (svd->advice == MADV_SEQUENTIAL ||
5192 		    (svd->pageadvice &&
5193 		    VPP_ADVICE(vpage) == MADV_SEQUENTIAL)) {
5194 			pgoff = off - PAGESIZE;
5195 			fpage = page - 1;
5196 			if (vpage != NULL)
5197 				vpp = &svd->vpage[fpage];
5198 			if (amp != NULL)
5199 				fanon_index = svd->anon_index + fpage;
5200 
5201 			while (pgoff > svd->offset) {
5202 				if (svd->advice != MADV_SEQUENTIAL &&
5203 				    (!svd->pageadvice || (vpage &&
5204 				    VPP_ADVICE(vpp) != MADV_SEQUENTIAL)))
5205 					break;
5206 
5207 				/*
5208 				 * If this is an anon page, we must find the
5209 				 * correct <vp, offset> for it
5210 				 */
5211 				fap = NULL;
5212 				if (amp != NULL) {
5213 					ANON_LOCK_ENTER(&amp->a_rwlock,
5214 					    RW_READER);
5215 					anon_array_enter(amp, fanon_index,
5216 					    &cookie);
5217 					fap = anon_get_ptr(amp->ahp,
5218 					    fanon_index);
5219 					if (fap != NULL) {
5220 						swap_xlate(fap, &fvp, &fpgoff);
5221 					} else {
5222 						fpgoff = pgoff;
5223 						fvp = svd->vp;
5224 					}
5225 					anon_array_exit(&cookie);
5226 					ANON_LOCK_EXIT(&amp->a_rwlock);
5227 				} else {
5228 					fpgoff = pgoff;
5229 					fvp = svd->vp;
5230 				}
5231 				if (fvp == NULL)
5232 					break;	/* XXX */
5233 				/*
5234 				 * Skip pages that are free or have an
5235 				 * "exclusive" lock.
5236 				 */
5237 				pp = page_lookup_nowait(fvp, fpgoff, SE_SHARED);
5238 				if (pp == NULL)
5239 					break;
5240 				/*
5241 				 * We don't need the page_struct_lock to test
5242 				 * as this is only advisory; even if we
5243 				 * acquire it someone might race in and lock
5244 				 * the page after we unlock and before the
5245 				 * PUTPAGE, then VOP_PUTPAGE will do nothing.
5246 				 */
5247 				if (pp->p_lckcnt == 0 && pp->p_cowcnt == 0) {
5248 					/*
5249 					 * Hold the vnode before releasing
5250 					 * the page lock to prevent it from
5251 					 * being freed and re-used by some
5252 					 * other thread.
5253 					 */
5254 					VN_HOLD(fvp);
5255 					page_unlock(pp);
5256 					/*
5257 					 * We should build a page list
5258 					 * to kluster putpages XXX
5259 					 */
5260 					(void) VOP_PUTPAGE(fvp,
5261 					    (offset_t)fpgoff, PAGESIZE,
5262 					    (B_DONTNEED|B_FREE|B_ASYNC),
5263 					    svd->cred, NULL);
5264 					VN_RELE(fvp);
5265 				} else {
5266 					/*
5267 					 * XXX - Should the loop terminate if
5268 					 * the page is `locked'?
5269 					 */
5270 					page_unlock(pp);
5271 				}
5272 				--vpp;
5273 				--fanon_index;
5274 				pgoff -= PAGESIZE;
5275 			}
5276 		}
5277 	}
5278 
5279 	plp = pl;
5280 	*plp = NULL;
5281 	pl_alloc_sz = 0;
5282 
5283 	/*
5284 	 * See if we need to call VOP_GETPAGE for
5285 	 * *any* of the range being faulted on.
5286 	 * We can skip all of this work if there
5287 	 * was no original vnode.
5288 	 */
5289 	if (svd->vp != NULL) {
5290 		u_offset_t vp_off;
5291 		size_t vp_len;
5292 		struct anon *ap;
5293 		vnode_t *vp;
5294 
5295 		vp_off = off;
5296 		vp_len = len;
5297 
5298 		if (amp == NULL)
5299 			dogetpage = 1;
5300 		else {
5301 			/*
5302 			 * Only acquire reader lock to prevent amp->ahp
5303 			 * from being changed.  It's ok to miss pages,
5304 			 * hence we don't do anon_array_enter
5305 			 */
5306 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5307 			ap = anon_get_ptr(amp->ahp, anon_index);
5308 
5309 			if (len <= PAGESIZE)
5310 				/* inline non_anon() */
5311 				dogetpage = (ap == NULL);
5312 			else
5313 				dogetpage = non_anon(amp->ahp, anon_index,
5314 				    &vp_off, &vp_len);
5315 			ANON_LOCK_EXIT(&amp->a_rwlock);
5316 		}
5317 
5318 		if (dogetpage) {
5319 			enum seg_rw arw;
5320 			struct as *as = seg->s_as;
5321 
5322 			if (len > ptob((sizeof (pl) / sizeof (pl[0])) - 1)) {
5323 				/*
5324 				 * Page list won't fit in local array,
5325 				 * allocate one of the needed size.
5326 				 */
5327 				pl_alloc_sz =
5328 				    (btop(len) + 1) * sizeof (page_t *);
5329 				plp = kmem_alloc(pl_alloc_sz, KM_SLEEP);
5330 				plp[0] = NULL;
5331 				plsz = len;
5332 			} else if (rw == S_WRITE && svd->type == MAP_PRIVATE ||
5333 			    svd->tr_state == SEGVN_TR_ON || rw == S_OTHER ||
5334 			    (((size_t)(addr + PAGESIZE) <
5335 			    (size_t)(seg->s_base + seg->s_size)) &&
5336 			    hat_probe(as->a_hat, addr + PAGESIZE))) {
5337 				/*
5338 				 * Ask VOP_GETPAGE to return the exact number
5339 				 * of pages if
5340 				 * (a) this is a COW fault, or
5341 				 * (b) this is a software fault, or
5342 				 * (c) next page is already mapped.
5343 				 */
5344 				plsz = len;
5345 			} else {
5346 				/*
5347 				 * Ask VOP_GETPAGE to return adjacent pages
5348 				 * within the segment.
5349 				 */
5350 				plsz = MIN((size_t)PVN_GETPAGE_SZ, (size_t)
5351 				    ((seg->s_base + seg->s_size) - addr));
5352 				ASSERT((addr + plsz) <=
5353 				    (seg->s_base + seg->s_size));
5354 			}
5355 
5356 			/*
5357 			 * Need to get some non-anonymous pages.
5358 			 * We need to make only one call to GETPAGE to do
5359 			 * this to prevent certain deadlocking conditions
5360 			 * when we are doing locking.  In this case
5361 			 * non_anon() should have picked up the smallest
5362 			 * range which includes all the non-anonymous
5363 			 * pages in the requested range.  We have to
5364 			 * be careful regarding which rw flag to pass in
5365 			 * because on a private mapping, the underlying
5366 			 * object is never allowed to be written.
5367 			 */
5368 			if (rw == S_WRITE && svd->type == MAP_PRIVATE) {
5369 				arw = S_READ;
5370 			} else {
5371 				arw = rw;
5372 			}
5373 			vp = svd->vp;
5374 			TRACE_3(TR_FAC_VM, TR_SEGVN_GETPAGE,
5375 			    "segvn_getpage:seg %p addr %p vp %p",
5376 			    seg, addr, vp);
5377 			err = VOP_GETPAGE(vp, (offset_t)vp_off, vp_len,
5378 			    &vpprot, plp, plsz, seg, addr + (vp_off - off), arw,
5379 			    svd->cred, NULL);
5380 			if (err) {
5381 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5382 				segvn_pagelist_rele(plp);
5383 				if (pl_alloc_sz)
5384 					kmem_free(plp, pl_alloc_sz);
5385 				return (FC_MAKE_ERR(err));
5386 			}
5387 			if (svd->type == MAP_PRIVATE)
5388 				vpprot &= ~PROT_WRITE;
5389 		}
5390 	}
5391 
5392 	/*
5393 	 * N.B. at this time the plp array has all the needed non-anon
5394 	 * pages in addition to (possibly) having some adjacent pages.
5395 	 */
5396 
5397 	/*
5398 	 * Always acquire the anon_array_lock to prevent
5399 	 * 2 threads from allocating separate anon slots for
5400 	 * the same "addr".
5401 	 *
5402 	 * If this is a copy-on-write fault and we don't already
5403 	 * have the anon_array_lock, acquire it to prevent the
5404 	 * fault routine from handling multiple copy-on-write faults
5405 	 * on the same "addr" in the same address space.
5406 	 *
5407 	 * Only one thread should deal with the fault since after
5408 	 * it is handled, the other threads can acquire a translation
5409 	 * to the newly created private page.  This prevents two or
5410 	 * more threads from creating different private pages for the
5411 	 * same fault.
5412 	 *
5413 	 * We grab "serialization" lock here if this is a MAP_PRIVATE segment
5414 	 * to prevent deadlock between this thread and another thread
5415 	 * which has soft-locked this page and wants to acquire serial_lock.
5416 	 * ( bug 4026339 )
5417 	 *
5418 	 * The fix for bug 4026339 becomes unnecessary when using the
5419 	 * locking scheme with per amp rwlock and a global set of hash
5420 	 * lock, anon_array_lock.  If we steal a vnode page when low
5421 	 * on memory and upgrad the page lock through page_rename,
5422 	 * then the page is PAGE_HANDLED, nothing needs to be done
5423 	 * for this page after returning from segvn_faultpage.
5424 	 *
5425 	 * But really, the page lock should be downgraded after
5426 	 * the stolen page is page_rename'd.
5427 	 */
5428 
5429 	if (amp != NULL)
5430 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5431 
5432 	/*
5433 	 * Ok, now loop over the address range and handle faults
5434 	 */
5435 	for (a = addr; a < addr + len; a += PAGESIZE, off += PAGESIZE) {
5436 		err = segvn_faultpage(hat, seg, a, off, vpage, plp, vpprot,
5437 		    type, rw, brkcow);
5438 		if (err) {
5439 			if (amp != NULL)
5440 				ANON_LOCK_EXIT(&amp->a_rwlock);
5441 			if (type == F_SOFTLOCK && a > addr) {
5442 				segvn_softunlock(seg, addr, (a - addr),
5443 				    S_OTHER);
5444 			}
5445 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5446 			segvn_pagelist_rele(plp);
5447 			if (pl_alloc_sz)
5448 				kmem_free(plp, pl_alloc_sz);
5449 			return (err);
5450 		}
5451 		if (vpage) {
5452 			vpage++;
5453 		} else if (svd->vpage) {
5454 			page = seg_page(seg, addr);
5455 			vpage = &svd->vpage[++page];
5456 		}
5457 	}
5458 
5459 	/* Didn't get pages from the underlying fs so we're done */
5460 	if (!dogetpage)
5461 		goto done;
5462 
5463 	/*
5464 	 * Now handle any other pages in the list returned.
5465 	 * If the page can be used, load up the translations now.
5466 	 * Note that the for loop will only be entered if "plp"
5467 	 * is pointing to a non-NULL page pointer which means that
5468 	 * VOP_GETPAGE() was called and vpprot has been initialized.
5469 	 */
5470 	if (svd->pageprot == 0)
5471 		prot = svd->prot & vpprot;
5472 
5473 
5474 	/*
5475 	 * Large Files: diff should be unsigned value because we started
5476 	 * supporting > 2GB segment sizes from 2.5.1 and when a
5477 	 * large file of size > 2GB gets mapped to address space
5478 	 * the diff value can be > 2GB.
5479 	 */
5480 
5481 	for (ppp = plp; (pp = *ppp) != NULL; ppp++) {
5482 		size_t diff;
5483 		struct anon *ap;
5484 		int anon_index;
5485 		anon_sync_obj_t cookie;
5486 		int hat_flag = HAT_LOAD_ADV;
5487 
5488 		if (svd->flags & MAP_TEXT) {
5489 			hat_flag |= HAT_LOAD_TEXT;
5490 		}
5491 
5492 		if (pp == PAGE_HANDLED)
5493 			continue;
5494 
5495 		if (svd->tr_state != SEGVN_TR_ON &&
5496 		    pp->p_offset >=  svd->offset &&
5497 		    pp->p_offset < svd->offset + seg->s_size) {
5498 
5499 			diff = pp->p_offset - svd->offset;
5500 
5501 			/*
5502 			 * Large Files: Following is the assertion
5503 			 * validating the above cast.
5504 			 */
5505 			ASSERT(svd->vp == pp->p_vnode);
5506 
5507 			page = btop(diff);
5508 			if (svd->pageprot)
5509 				prot = VPP_PROT(&svd->vpage[page]) & vpprot;
5510 
5511 			/*
5512 			 * Prevent other threads in the address space from
5513 			 * creating private pages (i.e., allocating anon slots)
5514 			 * while we are in the process of loading translations
5515 			 * to additional pages returned by the underlying
5516 			 * object.
5517 			 */
5518 			if (amp != NULL) {
5519 				anon_index = svd->anon_index + page;
5520 				anon_array_enter(amp, anon_index, &cookie);
5521 				ap = anon_get_ptr(amp->ahp, anon_index);
5522 			}
5523 			if ((amp == NULL) || (ap == NULL)) {
5524 				if (IS_VMODSORT(pp->p_vnode) ||
5525 				    enable_mbit_wa) {
5526 					if (rw == S_WRITE)
5527 						hat_setmod(pp);
5528 					else if (rw != S_OTHER &&
5529 					    !hat_ismod(pp))
5530 						prot &= ~PROT_WRITE;
5531 				}
5532 				/*
5533 				 * Skip mapping read ahead pages marked
5534 				 * for migration, so they will get migrated
5535 				 * properly on fault
5536 				 */
5537 				ASSERT(amp == NULL ||
5538 				    svd->rcookie == HAT_INVALID_REGION_COOKIE);
5539 				if ((prot & PROT_READ) && !PP_ISMIGRATE(pp)) {
5540 					hat_memload_region(hat,
5541 					    seg->s_base + diff,
5542 					    pp, prot, hat_flag,
5543 					    svd->rcookie);
5544 				}
5545 			}
5546 			if (amp != NULL)
5547 				anon_array_exit(&cookie);
5548 		}
5549 		page_unlock(pp);
5550 	}
5551 done:
5552 	if (amp != NULL)
5553 		ANON_LOCK_EXIT(&amp->a_rwlock);
5554 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5555 	if (pl_alloc_sz)
5556 		kmem_free(plp, pl_alloc_sz);
5557 	return (0);
5558 }
5559 
5560 /*
5561  * This routine is used to start I/O on pages asynchronously.  XXX it will
5562  * only create PAGESIZE pages. At fault time they will be relocated into
5563  * larger pages.
5564  */
5565 static faultcode_t
5566 segvn_faulta(struct seg *seg, caddr_t addr)
5567 {
5568 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
5569 	int err;
5570 	struct anon_map *amp;
5571 	vnode_t *vp;
5572 
5573 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
5574 
5575 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
5576 	if ((amp = svd->amp) != NULL) {
5577 		struct anon *ap;
5578 
5579 		/*
5580 		 * Reader lock to prevent amp->ahp from being changed.
5581 		 * This is advisory, it's ok to miss a page, so
5582 		 * we don't do anon_array_enter lock.
5583 		 */
5584 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5585 		if ((ap = anon_get_ptr(amp->ahp,
5586 		    svd->anon_index + seg_page(seg, addr))) != NULL) {
5587 
5588 			err = anon_getpage(&ap, NULL, NULL,
5589 			    0, seg, addr, S_READ, svd->cred);
5590 
5591 			ANON_LOCK_EXIT(&amp->a_rwlock);
5592 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5593 			if (err)
5594 				return (FC_MAKE_ERR(err));
5595 			return (0);
5596 		}
5597 		ANON_LOCK_EXIT(&amp->a_rwlock);
5598 	}
5599 
5600 	if (svd->vp == NULL) {
5601 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5602 		return (0);			/* zfod page - do nothing now */
5603 	}
5604 
5605 	vp = svd->vp;
5606 	TRACE_3(TR_FAC_VM, TR_SEGVN_GETPAGE,
5607 	    "segvn_getpage:seg %p addr %p vp %p", seg, addr, vp);
5608 	err = VOP_GETPAGE(vp,
5609 	    (offset_t)(svd->offset + (uintptr_t)(addr - seg->s_base)),
5610 	    PAGESIZE, NULL, NULL, 0, seg, addr,
5611 	    S_OTHER, svd->cred, NULL);
5612 
5613 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5614 	if (err)
5615 		return (FC_MAKE_ERR(err));
5616 	return (0);
5617 }
5618 
5619 static int
5620 segvn_setprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
5621 {
5622 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
5623 	struct vpage *cvp, *svp, *evp;
5624 	struct vnode *vp;
5625 	size_t pgsz;
5626 	pgcnt_t pgcnt;
5627 	anon_sync_obj_t cookie;
5628 	int unload_done = 0;
5629 
5630 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
5631 
5632 	if ((svd->maxprot & prot) != prot)
5633 		return (EACCES);			/* violated maxprot */
5634 
5635 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
5636 
5637 	/* return if prot is the same */
5638 	if (!svd->pageprot && svd->prot == prot) {
5639 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5640 		return (0);
5641 	}
5642 
5643 	/*
5644 	 * Since we change protections we first have to flush the cache.
5645 	 * This makes sure all the pagelock calls have to recheck
5646 	 * protections.
5647 	 */
5648 	if (svd->softlockcnt > 0) {
5649 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
5650 
5651 		/*
5652 		 * If this is shared segment non 0 softlockcnt
5653 		 * means locked pages are still in use.
5654 		 */
5655 		if (svd->type == MAP_SHARED) {
5656 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5657 			return (EAGAIN);
5658 		}
5659 
5660 		/*
5661 		 * Since we do have the segvn writers lock nobody can fill
5662 		 * the cache with entries belonging to this seg during
5663 		 * the purge. The flush either succeeds or we still have
5664 		 * pending I/Os.
5665 		 */
5666 		segvn_purge(seg);
5667 		if (svd->softlockcnt > 0) {
5668 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5669 			return (EAGAIN);
5670 		}
5671 	}
5672 
5673 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
5674 		ASSERT(svd->amp == NULL);
5675 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
5676 		hat_leave_region(seg->s_as->a_hat, svd->rcookie,
5677 		    HAT_REGION_TEXT);
5678 		svd->rcookie = HAT_INVALID_REGION_COOKIE;
5679 		unload_done = 1;
5680 	} else if (svd->tr_state == SEGVN_TR_INIT) {
5681 		svd->tr_state = SEGVN_TR_OFF;
5682 	} else if (svd->tr_state == SEGVN_TR_ON) {
5683 		ASSERT(svd->amp != NULL);
5684 		segvn_textunrepl(seg, 0);
5685 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
5686 		unload_done = 1;
5687 	}
5688 
5689 	if ((prot & PROT_WRITE) && svd->type == MAP_SHARED &&
5690 	    svd->vp != NULL && (svd->vp->v_flag & VVMEXEC)) {
5691 		ASSERT(vn_is_mapped(svd->vp, V_WRITE));
5692 		segvn_inval_trcache(svd->vp);
5693 	}
5694 	if (seg->s_szc != 0) {
5695 		int err;
5696 		pgsz = page_get_pagesize(seg->s_szc);
5697 		pgcnt = pgsz >> PAGESHIFT;
5698 		ASSERT(IS_P2ALIGNED(pgcnt, pgcnt));
5699 		if (!IS_P2ALIGNED(addr, pgsz) || !IS_P2ALIGNED(len, pgsz)) {
5700 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5701 			ASSERT(seg->s_base != addr || seg->s_size != len);
5702 			/*
5703 			 * If we are holding the as lock as a reader then
5704 			 * we need to return IE_RETRY and let the as
5705 			 * layer drop and re-acquire the lock as a writer.
5706 			 */
5707 			if (AS_READ_HELD(seg->s_as, &seg->s_as->a_lock))
5708 				return (IE_RETRY);
5709 			VM_STAT_ADD(segvnvmstats.demoterange[1]);
5710 			if (svd->type == MAP_PRIVATE || svd->vp != NULL) {
5711 				err = segvn_demote_range(seg, addr, len,
5712 				    SDR_END, 0);
5713 			} else {
5714 				uint_t szcvec = map_pgszcvec(seg->s_base,
5715 				    pgsz, (uintptr_t)seg->s_base,
5716 				    (svd->flags & MAP_TEXT), MAPPGSZC_SHM, 0);
5717 				err = segvn_demote_range(seg, addr, len,
5718 				    SDR_END, szcvec);
5719 			}
5720 			if (err == 0)
5721 				return (IE_RETRY);
5722 			if (err == ENOMEM)
5723 				return (IE_NOMEM);
5724 			return (err);
5725 		}
5726 	}
5727 
5728 
5729 	/*
5730 	 * If it's a private mapping and we're making it writable then we
5731 	 * may have to reserve the additional swap space now. If we are
5732 	 * making writable only a part of the segment then we use its vpage
5733 	 * array to keep a record of the pages for which we have reserved
5734 	 * swap. In this case we set the pageswap field in the segment's
5735 	 * segvn structure to record this.
5736 	 *
5737 	 * If it's a private mapping to a file (i.e., vp != NULL) and we're
5738 	 * removing write permission on the entire segment and we haven't
5739 	 * modified any pages, we can release the swap space.
5740 	 */
5741 	if (svd->type == MAP_PRIVATE) {
5742 		if (prot & PROT_WRITE) {
5743 			if (!(svd->flags & MAP_NORESERVE) &&
5744 			    !(svd->swresv && svd->pageswap == 0)) {
5745 				size_t sz = 0;
5746 
5747 				/*
5748 				 * Start by determining how much swap
5749 				 * space is required.
5750 				 */
5751 				if (addr == seg->s_base &&
5752 				    len == seg->s_size &&
5753 				    svd->pageswap == 0) {
5754 					/* The whole segment */
5755 					sz = seg->s_size;
5756 				} else {
5757 					/*
5758 					 * Make sure that the vpage array
5759 					 * exists, and make a note of the
5760 					 * range of elements corresponding
5761 					 * to len.
5762 					 */
5763 					segvn_vpage(seg);
5764 					svp = &svd->vpage[seg_page(seg, addr)];
5765 					evp = &svd->vpage[seg_page(seg,
5766 					    addr + len)];
5767 
5768 					if (svd->pageswap == 0) {
5769 						/*
5770 						 * This is the first time we've
5771 						 * asked for a part of this
5772 						 * segment, so we need to
5773 						 * reserve everything we've
5774 						 * been asked for.
5775 						 */
5776 						sz = len;
5777 					} else {
5778 						/*
5779 						 * We have to count the number
5780 						 * of pages required.
5781 						 */
5782 						for (cvp = svp;  cvp < evp;
5783 						    cvp++) {
5784 							if (!VPP_ISSWAPRES(cvp))
5785 								sz++;
5786 						}
5787 						sz <<= PAGESHIFT;
5788 					}
5789 				}
5790 
5791 				/* Try to reserve the necessary swap. */
5792 				if (anon_resv_zone(sz,
5793 				    seg->s_as->a_proc->p_zone) == 0) {
5794 					SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5795 					return (IE_NOMEM);
5796 				}
5797 
5798 				/*
5799 				 * Make a note of how much swap space
5800 				 * we've reserved.
5801 				 */
5802 				if (svd->pageswap == 0 && sz == seg->s_size) {
5803 					svd->swresv = sz;
5804 				} else {
5805 					ASSERT(svd->vpage != NULL);
5806 					svd->swresv += sz;
5807 					svd->pageswap = 1;
5808 					for (cvp = svp; cvp < evp; cvp++) {
5809 						if (!VPP_ISSWAPRES(cvp))
5810 							VPP_SETSWAPRES(cvp);
5811 					}
5812 				}
5813 			}
5814 		} else {
5815 			/*
5816 			 * Swap space is released only if this segment
5817 			 * does not map anonymous memory, since read faults
5818 			 * on such segments still need an anon slot to read
5819 			 * in the data.
5820 			 */
5821 			if (svd->swresv != 0 && svd->vp != NULL &&
5822 			    svd->amp == NULL && addr == seg->s_base &&
5823 			    len == seg->s_size && svd->pageprot == 0) {
5824 				ASSERT(svd->pageswap == 0);
5825 				anon_unresv_zone(svd->swresv,
5826 				    seg->s_as->a_proc->p_zone);
5827 				svd->swresv = 0;
5828 				TRACE_3(TR_FAC_VM, TR_ANON_PROC,
5829 				    "anon proc:%p %lu %u", seg, 0, 0);
5830 			}
5831 		}
5832 	}
5833 
5834 	if (addr == seg->s_base && len == seg->s_size && svd->vpage == NULL) {
5835 		if (svd->prot == prot) {
5836 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5837 			return (0);			/* all done */
5838 		}
5839 		svd->prot = (uchar_t)prot;
5840 	} else if (svd->type == MAP_PRIVATE) {
5841 		struct anon *ap = NULL;
5842 		page_t *pp;
5843 		u_offset_t offset, off;
5844 		struct anon_map *amp;
5845 		ulong_t anon_idx = 0;
5846 
5847 		/*
5848 		 * A vpage structure exists or else the change does not
5849 		 * involve the entire segment.  Establish a vpage structure
5850 		 * if none is there.  Then, for each page in the range,
5851 		 * adjust its individual permissions.  Note that write-
5852 		 * enabling a MAP_PRIVATE page can affect the claims for
5853 		 * locked down memory.  Overcommitting memory terminates
5854 		 * the operation.
5855 		 */
5856 		segvn_vpage(seg);
5857 		svd->pageprot = 1;
5858 		if ((amp = svd->amp) != NULL) {
5859 			anon_idx = svd->anon_index + seg_page(seg, addr);
5860 			ASSERT(seg->s_szc == 0 ||
5861 			    IS_P2ALIGNED(anon_idx, pgcnt));
5862 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5863 		}
5864 
5865 		offset = svd->offset + (uintptr_t)(addr - seg->s_base);
5866 		evp = &svd->vpage[seg_page(seg, addr + len)];
5867 
5868 		/*
5869 		 * See Statement at the beginning of segvn_lockop regarding
5870 		 * the way cowcnts and lckcnts are handled.
5871 		 */
5872 		for (svp = &svd->vpage[seg_page(seg, addr)]; svp < evp; svp++) {
5873 
5874 			if (seg->s_szc != 0) {
5875 				if (amp != NULL) {
5876 					anon_array_enter(amp, anon_idx,
5877 					    &cookie);
5878 				}
5879 				if (IS_P2ALIGNED(anon_idx, pgcnt) &&
5880 				    !segvn_claim_pages(seg, svp, offset,
5881 				    anon_idx, prot)) {
5882 					if (amp != NULL) {
5883 						anon_array_exit(&cookie);
5884 					}
5885 					break;
5886 				}
5887 				if (amp != NULL) {
5888 					anon_array_exit(&cookie);
5889 				}
5890 				anon_idx++;
5891 			} else {
5892 				if (amp != NULL) {
5893 					anon_array_enter(amp, anon_idx,
5894 					    &cookie);
5895 					ap = anon_get_ptr(amp->ahp, anon_idx++);
5896 				}
5897 
5898 				if (VPP_ISPPLOCK(svp) &&
5899 				    VPP_PROT(svp) != prot) {
5900 
5901 					if (amp == NULL || ap == NULL) {
5902 						vp = svd->vp;
5903 						off = offset;
5904 					} else
5905 						swap_xlate(ap, &vp, &off);
5906 					if (amp != NULL)
5907 						anon_array_exit(&cookie);
5908 
5909 					if ((pp = page_lookup(vp, off,
5910 					    SE_SHARED)) == NULL) {
5911 						panic("segvn_setprot: no page");
5912 						/*NOTREACHED*/
5913 					}
5914 					ASSERT(seg->s_szc == 0);
5915 					if ((VPP_PROT(svp) ^ prot) &
5916 					    PROT_WRITE) {
5917 						if (prot & PROT_WRITE) {
5918 							if (!page_addclaim(
5919 							    pp)) {
5920 								page_unlock(pp);
5921 								break;
5922 							}
5923 						} else {
5924 							if (!page_subclaim(
5925 							    pp)) {
5926 								page_unlock(pp);
5927 								break;
5928 							}
5929 						}
5930 					}
5931 					page_unlock(pp);
5932 				} else if (amp != NULL)
5933 					anon_array_exit(&cookie);
5934 			}
5935 			VPP_SETPROT(svp, prot);
5936 			offset += PAGESIZE;
5937 		}
5938 		if (amp != NULL)
5939 			ANON_LOCK_EXIT(&amp->a_rwlock);
5940 
5941 		/*
5942 		 * Did we terminate prematurely?  If so, simply unload
5943 		 * the translations to the things we've updated so far.
5944 		 */
5945 		if (svp != evp) {
5946 			if (unload_done) {
5947 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5948 				return (IE_NOMEM);
5949 			}
5950 			len = (svp - &svd->vpage[seg_page(seg, addr)]) *
5951 			    PAGESIZE;
5952 			ASSERT(seg->s_szc == 0 || IS_P2ALIGNED(len, pgsz));
5953 			if (len != 0)
5954 				hat_unload(seg->s_as->a_hat, addr,
5955 				    len, HAT_UNLOAD);
5956 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5957 			return (IE_NOMEM);
5958 		}
5959 	} else {
5960 		segvn_vpage(seg);
5961 		svd->pageprot = 1;
5962 		evp = &svd->vpage[seg_page(seg, addr + len)];
5963 		for (svp = &svd->vpage[seg_page(seg, addr)]; svp < evp; svp++) {
5964 			VPP_SETPROT(svp, prot);
5965 		}
5966 	}
5967 
5968 	if (unload_done) {
5969 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5970 		return (0);
5971 	}
5972 
5973 	if (((prot & PROT_WRITE) != 0 &&
5974 	    (svd->vp != NULL || svd->type == MAP_PRIVATE)) ||
5975 	    (prot & ~PROT_USER) == PROT_NONE) {
5976 		/*
5977 		 * Either private or shared data with write access (in
5978 		 * which case we need to throw out all former translations
5979 		 * so that we get the right translations set up on fault
5980 		 * and we don't allow write access to any copy-on-write pages
5981 		 * that might be around or to prevent write access to pages
5982 		 * representing holes in a file), or we don't have permission
5983 		 * to access the memory at all (in which case we have to
5984 		 * unload any current translations that might exist).
5985 		 */
5986 		hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD);
5987 	} else {
5988 		/*
5989 		 * A shared mapping or a private mapping in which write
5990 		 * protection is going to be denied - just change all the
5991 		 * protections over the range of addresses in question.
5992 		 * segvn does not support any other attributes other
5993 		 * than prot so we can use hat_chgattr.
5994 		 */
5995 		hat_chgattr(seg->s_as->a_hat, addr, len, prot);
5996 	}
5997 
5998 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5999 
6000 	return (0);
6001 }
6002 
6003 /*
6004  * segvn_setpagesize is called via SEGOP_SETPAGESIZE from as_setpagesize,
6005  * to determine if the seg is capable of mapping the requested szc.
6006  */
6007 static int
6008 segvn_setpagesize(struct seg *seg, caddr_t addr, size_t len, uint_t szc)
6009 {
6010 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6011 	struct segvn_data *nsvd;
6012 	struct anon_map *amp = svd->amp;
6013 	struct seg *nseg;
6014 	caddr_t eaddr = addr + len, a;
6015 	size_t pgsz = page_get_pagesize(szc);
6016 	pgcnt_t pgcnt = page_get_pagecnt(szc);
6017 	int err;
6018 	u_offset_t off = svd->offset + (uintptr_t)(addr - seg->s_base);
6019 
6020 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
6021 	ASSERT(addr >= seg->s_base && eaddr <= seg->s_base + seg->s_size);
6022 
6023 	if (seg->s_szc == szc || segvn_lpg_disable != 0) {
6024 		return (0);
6025 	}
6026 
6027 	/*
6028 	 * addr should always be pgsz aligned but eaddr may be misaligned if
6029 	 * it's at the end of the segment.
6030 	 *
6031 	 * XXX we should assert this condition since as_setpagesize() logic
6032 	 * guarantees it.
6033 	 */
6034 	if (!IS_P2ALIGNED(addr, pgsz) ||
6035 	    (!IS_P2ALIGNED(eaddr, pgsz) &&
6036 	    eaddr != seg->s_base + seg->s_size)) {
6037 
6038 		segvn_setpgsz_align_err++;
6039 		return (EINVAL);
6040 	}
6041 
6042 	if (amp != NULL && svd->type == MAP_SHARED) {
6043 		ulong_t an_idx = svd->anon_index + seg_page(seg, addr);
6044 		if (!IS_P2ALIGNED(an_idx, pgcnt)) {
6045 
6046 			segvn_setpgsz_anon_align_err++;
6047 			return (EINVAL);
6048 		}
6049 	}
6050 
6051 	if ((svd->flags & MAP_NORESERVE) || seg->s_as == &kas ||
6052 	    szc > segvn_maxpgszc) {
6053 		return (EINVAL);
6054 	}
6055 
6056 	/* paranoid check */
6057 	if (svd->vp != NULL &&
6058 	    (IS_SWAPFSVP(svd->vp) || VN_ISKAS(svd->vp))) {
6059 		return (EINVAL);
6060 	}
6061 
6062 	if (seg->s_szc == 0 && svd->vp != NULL &&
6063 	    map_addr_vacalign_check(addr, off)) {
6064 		return (EINVAL);
6065 	}
6066 
6067 	/*
6068 	 * Check that protections are the same within new page
6069 	 * size boundaries.
6070 	 */
6071 	if (svd->pageprot) {
6072 		for (a = addr; a < eaddr; a += pgsz) {
6073 			if ((a + pgsz) > eaddr) {
6074 				if (!sameprot(seg, a, eaddr - a)) {
6075 					return (EINVAL);
6076 				}
6077 			} else {
6078 				if (!sameprot(seg, a, pgsz)) {
6079 					return (EINVAL);
6080 				}
6081 			}
6082 		}
6083 	}
6084 
6085 	/*
6086 	 * Since we are changing page size we first have to flush
6087 	 * the cache. This makes sure all the pagelock calls have
6088 	 * to recheck protections.
6089 	 */
6090 	if (svd->softlockcnt > 0) {
6091 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
6092 
6093 		/*
6094 		 * If this is shared segment non 0 softlockcnt
6095 		 * means locked pages are still in use.
6096 		 */
6097 		if (svd->type == MAP_SHARED) {
6098 			return (EAGAIN);
6099 		}
6100 
6101 		/*
6102 		 * Since we do have the segvn writers lock nobody can fill
6103 		 * the cache with entries belonging to this seg during
6104 		 * the purge. The flush either succeeds or we still have
6105 		 * pending I/Os.
6106 		 */
6107 		segvn_purge(seg);
6108 		if (svd->softlockcnt > 0) {
6109 			return (EAGAIN);
6110 		}
6111 	}
6112 
6113 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
6114 		ASSERT(svd->amp == NULL);
6115 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
6116 		hat_leave_region(seg->s_as->a_hat, svd->rcookie,
6117 		    HAT_REGION_TEXT);
6118 		svd->rcookie = HAT_INVALID_REGION_COOKIE;
6119 	} else if (svd->tr_state == SEGVN_TR_INIT) {
6120 		svd->tr_state = SEGVN_TR_OFF;
6121 	} else if (svd->tr_state == SEGVN_TR_ON) {
6122 		ASSERT(svd->amp != NULL);
6123 		segvn_textunrepl(seg, 1);
6124 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
6125 		amp = NULL;
6126 	}
6127 
6128 	/*
6129 	 * Operation for sub range of existing segment.
6130 	 */
6131 	if (addr != seg->s_base || eaddr != (seg->s_base + seg->s_size)) {
6132 		if (szc < seg->s_szc) {
6133 			VM_STAT_ADD(segvnvmstats.demoterange[2]);
6134 			err = segvn_demote_range(seg, addr, len, SDR_RANGE, 0);
6135 			if (err == 0) {
6136 				return (IE_RETRY);
6137 			}
6138 			if (err == ENOMEM) {
6139 				return (IE_NOMEM);
6140 			}
6141 			return (err);
6142 		}
6143 		if (addr != seg->s_base) {
6144 			nseg = segvn_split_seg(seg, addr);
6145 			if (eaddr != (nseg->s_base + nseg->s_size)) {
6146 				/* eaddr is szc aligned */
6147 				(void) segvn_split_seg(nseg, eaddr);
6148 			}
6149 			return (IE_RETRY);
6150 		}
6151 		if (eaddr != (seg->s_base + seg->s_size)) {
6152 			/* eaddr is szc aligned */
6153 			(void) segvn_split_seg(seg, eaddr);
6154 		}
6155 		return (IE_RETRY);
6156 	}
6157 
6158 	/*
6159 	 * Break any low level sharing and reset seg->s_szc to 0.
6160 	 */
6161 	if ((err = segvn_clrszc(seg)) != 0) {
6162 		if (err == ENOMEM) {
6163 			err = IE_NOMEM;
6164 		}
6165 		return (err);
6166 	}
6167 	ASSERT(seg->s_szc == 0);
6168 
6169 	/*
6170 	 * If the end of the current segment is not pgsz aligned
6171 	 * then attempt to concatenate with the next segment.
6172 	 */
6173 	if (!IS_P2ALIGNED(eaddr, pgsz)) {
6174 		nseg = AS_SEGNEXT(seg->s_as, seg);
6175 		if (nseg == NULL || nseg == seg || eaddr != nseg->s_base) {
6176 			return (ENOMEM);
6177 		}
6178 		if (nseg->s_ops != &segvn_ops) {
6179 			return (EINVAL);
6180 		}
6181 		nsvd = (struct segvn_data *)nseg->s_data;
6182 		if (nsvd->softlockcnt > 0) {
6183 			/*
6184 			 * If this is shared segment non 0 softlockcnt
6185 			 * means locked pages are still in use.
6186 			 */
6187 			if (nsvd->type == MAP_SHARED) {
6188 				return (EAGAIN);
6189 			}
6190 			segvn_purge(nseg);
6191 			if (nsvd->softlockcnt > 0) {
6192 				return (EAGAIN);
6193 			}
6194 		}
6195 		err = segvn_clrszc(nseg);
6196 		if (err == ENOMEM) {
6197 			err = IE_NOMEM;
6198 		}
6199 		if (err != 0) {
6200 			return (err);
6201 		}
6202 		ASSERT(nsvd->rcookie == HAT_INVALID_REGION_COOKIE);
6203 		err = segvn_concat(seg, nseg, 1);
6204 		if (err == -1) {
6205 			return (EINVAL);
6206 		}
6207 		if (err == -2) {
6208 			return (IE_NOMEM);
6209 		}
6210 		return (IE_RETRY);
6211 	}
6212 
6213 	/*
6214 	 * May need to re-align anon array to
6215 	 * new szc.
6216 	 */
6217 	if (amp != NULL) {
6218 		if (!IS_P2ALIGNED(svd->anon_index, pgcnt)) {
6219 			struct anon_hdr *nahp;
6220 
6221 			ASSERT(svd->type == MAP_PRIVATE);
6222 
6223 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
6224 			ASSERT(amp->refcnt == 1);
6225 			nahp = anon_create(btop(amp->size), ANON_NOSLEEP);
6226 			if (nahp == NULL) {
6227 				ANON_LOCK_EXIT(&amp->a_rwlock);
6228 				return (IE_NOMEM);
6229 			}
6230 			if (anon_copy_ptr(amp->ahp, svd->anon_index,
6231 			    nahp, 0, btop(seg->s_size), ANON_NOSLEEP)) {
6232 				anon_release(nahp, btop(amp->size));
6233 				ANON_LOCK_EXIT(&amp->a_rwlock);
6234 				return (IE_NOMEM);
6235 			}
6236 			anon_release(amp->ahp, btop(amp->size));
6237 			amp->ahp = nahp;
6238 			svd->anon_index = 0;
6239 			ANON_LOCK_EXIT(&amp->a_rwlock);
6240 		}
6241 	}
6242 	if (svd->vp != NULL && szc != 0) {
6243 		struct vattr va;
6244 		u_offset_t eoffpage = svd->offset;
6245 		va.va_mask = AT_SIZE;
6246 		eoffpage += seg->s_size;
6247 		eoffpage = btopr(eoffpage);
6248 		if (VOP_GETATTR(svd->vp, &va, 0, svd->cred, NULL) != 0) {
6249 			segvn_setpgsz_getattr_err++;
6250 			return (EINVAL);
6251 		}
6252 		if (btopr(va.va_size) < eoffpage) {
6253 			segvn_setpgsz_eof_err++;
6254 			return (EINVAL);
6255 		}
6256 		if (amp != NULL) {
6257 			/*
6258 			 * anon_fill_cow_holes() may call VOP_GETPAGE().
6259 			 * don't take anon map lock here to avoid holding it
6260 			 * across VOP_GETPAGE() calls that may call back into
6261 			 * segvn for klsutering checks. We don't really need
6262 			 * anon map lock here since it's a private segment and
6263 			 * we hold as level lock as writers.
6264 			 */
6265 			if ((err = anon_fill_cow_holes(seg, seg->s_base,
6266 			    amp->ahp, svd->anon_index, svd->vp, svd->offset,
6267 			    seg->s_size, szc, svd->prot, svd->vpage,
6268 			    svd->cred)) != 0) {
6269 				return (EINVAL);
6270 			}
6271 		}
6272 		segvn_setvnode_mpss(svd->vp);
6273 	}
6274 
6275 	if (amp != NULL) {
6276 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
6277 		if (svd->type == MAP_PRIVATE) {
6278 			amp->a_szc = szc;
6279 		} else if (szc > amp->a_szc) {
6280 			amp->a_szc = szc;
6281 		}
6282 		ANON_LOCK_EXIT(&amp->a_rwlock);
6283 	}
6284 
6285 	seg->s_szc = szc;
6286 
6287 	return (0);
6288 }
6289 
6290 static int
6291 segvn_clrszc(struct seg *seg)
6292 {
6293 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6294 	struct anon_map *amp = svd->amp;
6295 	size_t pgsz;
6296 	pgcnt_t pages;
6297 	int err = 0;
6298 	caddr_t a = seg->s_base;
6299 	caddr_t ea = a + seg->s_size;
6300 	ulong_t an_idx = svd->anon_index;
6301 	vnode_t *vp = svd->vp;
6302 	struct vpage *vpage = svd->vpage;
6303 	page_t *anon_pl[1 + 1], *pp;
6304 	struct anon *ap, *oldap;
6305 	uint_t prot = svd->prot, vpprot;
6306 	int pageflag = 0;
6307 
6308 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock) ||
6309 	    SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
6310 	ASSERT(svd->softlockcnt == 0);
6311 
6312 	if (vp == NULL && amp == NULL) {
6313 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
6314 		seg->s_szc = 0;
6315 		return (0);
6316 	}
6317 
6318 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
6319 		ASSERT(svd->amp == NULL);
6320 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
6321 		hat_leave_region(seg->s_as->a_hat, svd->rcookie,
6322 		    HAT_REGION_TEXT);
6323 		svd->rcookie = HAT_INVALID_REGION_COOKIE;
6324 	} else if (svd->tr_state == SEGVN_TR_ON) {
6325 		ASSERT(svd->amp != NULL);
6326 		segvn_textunrepl(seg, 1);
6327 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
6328 		amp = NULL;
6329 	} else {
6330 		if (svd->tr_state != SEGVN_TR_OFF) {
6331 			ASSERT(svd->tr_state == SEGVN_TR_INIT);
6332 			svd->tr_state = SEGVN_TR_OFF;
6333 		}
6334 
6335 		/*
6336 		 * do HAT_UNLOAD_UNMAP since we are changing the pagesize.
6337 		 * unload argument is 0 when we are freeing the segment
6338 		 * and unload was already done.
6339 		 */
6340 		hat_unload(seg->s_as->a_hat, seg->s_base, seg->s_size,
6341 		    HAT_UNLOAD_UNMAP);
6342 	}
6343 
6344 	if (amp == NULL || svd->type == MAP_SHARED) {
6345 		seg->s_szc = 0;
6346 		return (0);
6347 	}
6348 
6349 	pgsz = page_get_pagesize(seg->s_szc);
6350 	pages = btop(pgsz);
6351 
6352 	/*
6353 	 * XXX anon rwlock is not really needed because this is a
6354 	 * private segment and we are writers.
6355 	 */
6356 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
6357 
6358 	for (; a < ea; a += pgsz, an_idx += pages) {
6359 		if ((oldap = anon_get_ptr(amp->ahp, an_idx)) != NULL) {
6360 			ASSERT(vpage != NULL || svd->pageprot == 0);
6361 			if (vpage != NULL) {
6362 				ASSERT(sameprot(seg, a, pgsz));
6363 				prot = VPP_PROT(vpage);
6364 				pageflag = VPP_ISPPLOCK(vpage) ? LOCK_PAGE : 0;
6365 			}
6366 			if (seg->s_szc != 0) {
6367 				ASSERT(vp == NULL || anon_pages(amp->ahp,
6368 				    an_idx, pages) == pages);
6369 				if ((err = anon_map_demotepages(amp, an_idx,
6370 				    seg, a, prot, vpage, svd->cred)) != 0) {
6371 					goto out;
6372 				}
6373 			} else {
6374 				if (oldap->an_refcnt == 1) {
6375 					continue;
6376 				}
6377 				if ((err = anon_getpage(&oldap, &vpprot,
6378 				    anon_pl, PAGESIZE, seg, a, S_READ,
6379 				    svd->cred))) {
6380 					goto out;
6381 				}
6382 				if ((pp = anon_private(&ap, seg, a, prot,
6383 				    anon_pl[0], pageflag, svd->cred)) == NULL) {
6384 					err = ENOMEM;
6385 					goto out;
6386 				}
6387 				anon_decref(oldap);
6388 				(void) anon_set_ptr(amp->ahp, an_idx, ap,
6389 				    ANON_SLEEP);
6390 				page_unlock(pp);
6391 			}
6392 		}
6393 		vpage = (vpage == NULL) ? NULL : vpage + pages;
6394 	}
6395 
6396 	amp->a_szc = 0;
6397 	seg->s_szc = 0;
6398 out:
6399 	ANON_LOCK_EXIT(&amp->a_rwlock);
6400 	return (err);
6401 }
6402 
6403 static int
6404 segvn_claim_pages(
6405 	struct seg *seg,
6406 	struct vpage *svp,
6407 	u_offset_t off,
6408 	ulong_t anon_idx,
6409 	uint_t prot)
6410 {
6411 	pgcnt_t	pgcnt = page_get_pagecnt(seg->s_szc);
6412 	size_t ppasize = (pgcnt + 1) * sizeof (page_t *);
6413 	page_t	**ppa;
6414 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6415 	struct anon_map *amp = svd->amp;
6416 	struct vpage *evp = svp + pgcnt;
6417 	caddr_t addr = ((uintptr_t)(svp - svd->vpage) << PAGESHIFT)
6418 	    + seg->s_base;
6419 	struct anon *ap;
6420 	struct vnode *vp = svd->vp;
6421 	page_t *pp;
6422 	pgcnt_t pg_idx, i;
6423 	int err = 0;
6424 	anoff_t aoff;
6425 	int anon = (amp != NULL) ? 1 : 0;
6426 
6427 	ASSERT(svd->type == MAP_PRIVATE);
6428 	ASSERT(svd->vpage != NULL);
6429 	ASSERT(seg->s_szc != 0);
6430 	ASSERT(IS_P2ALIGNED(pgcnt, pgcnt));
6431 	ASSERT(amp == NULL || IS_P2ALIGNED(anon_idx, pgcnt));
6432 	ASSERT(sameprot(seg, addr, pgcnt << PAGESHIFT));
6433 
6434 	if (VPP_PROT(svp) == prot)
6435 		return (1);
6436 	if (!((VPP_PROT(svp) ^ prot) & PROT_WRITE))
6437 		return (1);
6438 
6439 	ppa = kmem_alloc(ppasize, KM_SLEEP);
6440 	if (anon && vp != NULL) {
6441 		if (anon_get_ptr(amp->ahp, anon_idx) == NULL) {
6442 			anon = 0;
6443 			ASSERT(!anon_pages(amp->ahp, anon_idx, pgcnt));
6444 		}
6445 		ASSERT(!anon ||
6446 		    anon_pages(amp->ahp, anon_idx, pgcnt) == pgcnt);
6447 	}
6448 
6449 	for (*ppa = NULL, pg_idx = 0; svp < evp; svp++, anon_idx++) {
6450 		if (!VPP_ISPPLOCK(svp))
6451 			continue;
6452 		if (anon) {
6453 			ap = anon_get_ptr(amp->ahp, anon_idx);
6454 			if (ap == NULL) {
6455 				panic("segvn_claim_pages: no anon slot");
6456 			}
6457 			swap_xlate(ap, &vp, &aoff);
6458 			off = (u_offset_t)aoff;
6459 		}
6460 		ASSERT(vp != NULL);
6461 		if ((pp = page_lookup(vp,
6462 		    (u_offset_t)off, SE_SHARED)) == NULL) {
6463 			panic("segvn_claim_pages: no page");
6464 		}
6465 		ppa[pg_idx++] = pp;
6466 		off += PAGESIZE;
6467 	}
6468 
6469 	if (ppa[0] == NULL) {
6470 		kmem_free(ppa, ppasize);
6471 		return (1);
6472 	}
6473 
6474 	ASSERT(pg_idx <= pgcnt);
6475 	ppa[pg_idx] = NULL;
6476 
6477 	if (prot & PROT_WRITE)
6478 		err = page_addclaim_pages(ppa);
6479 	else
6480 		err = page_subclaim_pages(ppa);
6481 
6482 	for (i = 0; i < pg_idx; i++) {
6483 		ASSERT(ppa[i] != NULL);
6484 		page_unlock(ppa[i]);
6485 	}
6486 
6487 	kmem_free(ppa, ppasize);
6488 	return (err);
6489 }
6490 
6491 /*
6492  * Returns right (upper address) segment if split occurred.
6493  * If the address is equal to the beginning or end of its segment it returns
6494  * the current segment.
6495  */
6496 static struct seg *
6497 segvn_split_seg(struct seg *seg, caddr_t addr)
6498 {
6499 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6500 	struct seg *nseg;
6501 	size_t nsize;
6502 	struct segvn_data *nsvd;
6503 
6504 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
6505 	ASSERT(svd->tr_state == SEGVN_TR_OFF);
6506 
6507 	ASSERT(addr >= seg->s_base);
6508 	ASSERT(addr <= seg->s_base + seg->s_size);
6509 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
6510 
6511 	if (addr == seg->s_base || addr == seg->s_base + seg->s_size)
6512 		return (seg);
6513 
6514 	nsize = seg->s_base + seg->s_size - addr;
6515 	seg->s_size = addr - seg->s_base;
6516 	nseg = seg_alloc(seg->s_as, addr, nsize);
6517 	ASSERT(nseg != NULL);
6518 	nseg->s_ops = seg->s_ops;
6519 	nsvd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
6520 	nseg->s_data = (void *)nsvd;
6521 	nseg->s_szc = seg->s_szc;
6522 	*nsvd = *svd;
6523 	ASSERT(nsvd->rcookie == HAT_INVALID_REGION_COOKIE);
6524 	nsvd->seg = nseg;
6525 	rw_init(&nsvd->lock, NULL, RW_DEFAULT, NULL);
6526 
6527 	if (nsvd->vp != NULL) {
6528 		VN_HOLD(nsvd->vp);
6529 		nsvd->offset = svd->offset +
6530 		    (uintptr_t)(nseg->s_base - seg->s_base);
6531 		if (nsvd->type == MAP_SHARED)
6532 			lgrp_shm_policy_init(NULL, nsvd->vp);
6533 	} else {
6534 		/*
6535 		 * The offset for an anonymous segment has no signifigance in
6536 		 * terms of an offset into a file. If we were to use the above
6537 		 * calculation instead, the structures read out of
6538 		 * /proc/<pid>/xmap would be more difficult to decipher since
6539 		 * it would be unclear whether two seemingly contiguous
6540 		 * prxmap_t structures represented different segments or a
6541 		 * single segment that had been split up into multiple prxmap_t
6542 		 * structures (e.g. if some part of the segment had not yet
6543 		 * been faulted in).
6544 		 */
6545 		nsvd->offset = 0;
6546 	}
6547 
6548 	ASSERT(svd->softlockcnt == 0);
6549 	ASSERT(svd->softlockcnt_sbase == 0);
6550 	ASSERT(svd->softlockcnt_send == 0);
6551 	crhold(svd->cred);
6552 
6553 	if (svd->vpage != NULL) {
6554 		size_t bytes = vpgtob(seg_pages(seg));
6555 		size_t nbytes = vpgtob(seg_pages(nseg));
6556 		struct vpage *ovpage = svd->vpage;
6557 
6558 		svd->vpage = kmem_alloc(bytes, KM_SLEEP);
6559 		bcopy(ovpage, svd->vpage, bytes);
6560 		nsvd->vpage = kmem_alloc(nbytes, KM_SLEEP);
6561 		bcopy(ovpage + seg_pages(seg), nsvd->vpage, nbytes);
6562 		kmem_free(ovpage, bytes + nbytes);
6563 	}
6564 	if (svd->amp != NULL && svd->type == MAP_PRIVATE) {
6565 		struct anon_map *oamp = svd->amp, *namp;
6566 		struct anon_hdr *nahp;
6567 
6568 		ANON_LOCK_ENTER(&oamp->a_rwlock, RW_WRITER);
6569 		ASSERT(oamp->refcnt == 1);
6570 		nahp = anon_create(btop(seg->s_size), ANON_SLEEP);
6571 		(void) anon_copy_ptr(oamp->ahp, svd->anon_index,
6572 		    nahp, 0, btop(seg->s_size), ANON_SLEEP);
6573 
6574 		namp = anonmap_alloc(nseg->s_size, 0, ANON_SLEEP);
6575 		namp->a_szc = nseg->s_szc;
6576 		(void) anon_copy_ptr(oamp->ahp,
6577 		    svd->anon_index + btop(seg->s_size),
6578 		    namp->ahp, 0, btop(nseg->s_size), ANON_SLEEP);
6579 		anon_release(oamp->ahp, btop(oamp->size));
6580 		oamp->ahp = nahp;
6581 		oamp->size = seg->s_size;
6582 		svd->anon_index = 0;
6583 		nsvd->amp = namp;
6584 		nsvd->anon_index = 0;
6585 		ANON_LOCK_EXIT(&oamp->a_rwlock);
6586 	} else if (svd->amp != NULL) {
6587 		pgcnt_t pgcnt = page_get_pagecnt(seg->s_szc);
6588 		ASSERT(svd->amp == nsvd->amp);
6589 		ASSERT(seg->s_szc <= svd->amp->a_szc);
6590 		nsvd->anon_index = svd->anon_index + seg_pages(seg);
6591 		ASSERT(IS_P2ALIGNED(nsvd->anon_index, pgcnt));
6592 		ANON_LOCK_ENTER(&svd->amp->a_rwlock, RW_WRITER);
6593 		svd->amp->refcnt++;
6594 		ANON_LOCK_EXIT(&svd->amp->a_rwlock);
6595 	}
6596 
6597 	/*
6598 	 * Split the amount of swap reserved.
6599 	 */
6600 	if (svd->swresv) {
6601 		/*
6602 		 * For MAP_NORESERVE, only allocate swap reserve for pages
6603 		 * being used.  Other segments get enough to cover whole
6604 		 * segment.
6605 		 */
6606 		if (svd->flags & MAP_NORESERVE) {
6607 			size_t	oswresv;
6608 
6609 			ASSERT(svd->amp);
6610 			oswresv = svd->swresv;
6611 			svd->swresv = ptob(anon_pages(svd->amp->ahp,
6612 			    svd->anon_index, btop(seg->s_size)));
6613 			nsvd->swresv = ptob(anon_pages(nsvd->amp->ahp,
6614 			    nsvd->anon_index, btop(nseg->s_size)));
6615 			ASSERT(oswresv >= (svd->swresv + nsvd->swresv));
6616 		} else {
6617 			if (svd->pageswap) {
6618 				svd->swresv = segvn_count_swap_by_vpages(seg);
6619 				ASSERT(nsvd->swresv >= svd->swresv);
6620 				nsvd->swresv -= svd->swresv;
6621 			} else {
6622 				ASSERT(svd->swresv == seg->s_size +
6623 				    nseg->s_size);
6624 				svd->swresv = seg->s_size;
6625 				nsvd->swresv = nseg->s_size;
6626 			}
6627 		}
6628 	}
6629 
6630 	return (nseg);
6631 }
6632 
6633 /*
6634  * called on memory operations (unmap, setprot, setpagesize) for a subset
6635  * of a large page segment to either demote the memory range (SDR_RANGE)
6636  * or the ends (SDR_END) by addr/len.
6637  *
6638  * returns 0 on success. returns errno, including ENOMEM, on failure.
6639  */
6640 static int
6641 segvn_demote_range(
6642 	struct seg *seg,
6643 	caddr_t addr,
6644 	size_t len,
6645 	int flag,
6646 	uint_t szcvec)
6647 {
6648 	caddr_t eaddr = addr + len;
6649 	caddr_t lpgaddr, lpgeaddr;
6650 	struct seg *nseg;
6651 	struct seg *badseg1 = NULL;
6652 	struct seg *badseg2 = NULL;
6653 	size_t pgsz;
6654 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6655 	int err;
6656 	uint_t szc = seg->s_szc;
6657 	uint_t tszcvec;
6658 
6659 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
6660 	ASSERT(svd->tr_state == SEGVN_TR_OFF);
6661 	ASSERT(szc != 0);
6662 	pgsz = page_get_pagesize(szc);
6663 	ASSERT(seg->s_base != addr || seg->s_size != len);
6664 	ASSERT(addr >= seg->s_base && eaddr <= seg->s_base + seg->s_size);
6665 	ASSERT(svd->softlockcnt == 0);
6666 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
6667 	ASSERT(szcvec == 0 || (flag == SDR_END && svd->type == MAP_SHARED));
6668 
6669 	CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
6670 	ASSERT(flag == SDR_RANGE || eaddr < lpgeaddr || addr > lpgaddr);
6671 	if (flag == SDR_RANGE) {
6672 		/* demote entire range */
6673 		badseg1 = nseg = segvn_split_seg(seg, lpgaddr);
6674 		(void) segvn_split_seg(nseg, lpgeaddr);
6675 		ASSERT(badseg1->s_base == lpgaddr);
6676 		ASSERT(badseg1->s_size == lpgeaddr - lpgaddr);
6677 	} else if (addr != lpgaddr) {
6678 		ASSERT(flag == SDR_END);
6679 		badseg1 = nseg = segvn_split_seg(seg, lpgaddr);
6680 		if (eaddr != lpgeaddr && eaddr > lpgaddr + pgsz &&
6681 		    eaddr < lpgaddr + 2 * pgsz) {
6682 			(void) segvn_split_seg(nseg, lpgeaddr);
6683 			ASSERT(badseg1->s_base == lpgaddr);
6684 			ASSERT(badseg1->s_size == 2 * pgsz);
6685 		} else {
6686 			nseg = segvn_split_seg(nseg, lpgaddr + pgsz);
6687 			ASSERT(badseg1->s_base == lpgaddr);
6688 			ASSERT(badseg1->s_size == pgsz);
6689 			if (eaddr != lpgeaddr && eaddr > lpgaddr + pgsz) {
6690 				ASSERT(lpgeaddr - lpgaddr > 2 * pgsz);
6691 				nseg = segvn_split_seg(nseg, lpgeaddr - pgsz);
6692 				badseg2 = nseg;
6693 				(void) segvn_split_seg(nseg, lpgeaddr);
6694 				ASSERT(badseg2->s_base == lpgeaddr - pgsz);
6695 				ASSERT(badseg2->s_size == pgsz);
6696 			}
6697 		}
6698 	} else {
6699 		ASSERT(flag == SDR_END);
6700 		ASSERT(eaddr < lpgeaddr);
6701 		badseg1 = nseg = segvn_split_seg(seg, lpgeaddr - pgsz);
6702 		(void) segvn_split_seg(nseg, lpgeaddr);
6703 		ASSERT(badseg1->s_base == lpgeaddr - pgsz);
6704 		ASSERT(badseg1->s_size == pgsz);
6705 	}
6706 
6707 	ASSERT(badseg1 != NULL);
6708 	ASSERT(badseg1->s_szc == szc);
6709 	ASSERT(flag == SDR_RANGE || badseg1->s_size == pgsz ||
6710 	    badseg1->s_size == 2 * pgsz);
6711 	ASSERT(sameprot(badseg1, badseg1->s_base, pgsz));
6712 	ASSERT(badseg1->s_size == pgsz ||
6713 	    sameprot(badseg1, badseg1->s_base + pgsz, pgsz));
6714 	if (err = segvn_clrszc(badseg1)) {
6715 		return (err);
6716 	}
6717 	ASSERT(badseg1->s_szc == 0);
6718 
6719 	if (szc > 1 && (tszcvec = P2PHASE(szcvec, 1 << szc)) > 1) {
6720 		uint_t tszc = highbit(tszcvec) - 1;
6721 		caddr_t ta = MAX(addr, badseg1->s_base);
6722 		caddr_t te;
6723 		size_t tpgsz = page_get_pagesize(tszc);
6724 
6725 		ASSERT(svd->type == MAP_SHARED);
6726 		ASSERT(flag == SDR_END);
6727 		ASSERT(tszc < szc && tszc > 0);
6728 
6729 		if (eaddr > badseg1->s_base + badseg1->s_size) {
6730 			te = badseg1->s_base + badseg1->s_size;
6731 		} else {
6732 			te = eaddr;
6733 		}
6734 
6735 		ASSERT(ta <= te);
6736 		badseg1->s_szc = tszc;
6737 		if (!IS_P2ALIGNED(ta, tpgsz) || !IS_P2ALIGNED(te, tpgsz)) {
6738 			if (badseg2 != NULL) {
6739 				err = segvn_demote_range(badseg1, ta, te - ta,
6740 				    SDR_END, tszcvec);
6741 				if (err != 0) {
6742 					return (err);
6743 				}
6744 			} else {
6745 				return (segvn_demote_range(badseg1, ta,
6746 				    te - ta, SDR_END, tszcvec));
6747 			}
6748 		}
6749 	}
6750 
6751 	if (badseg2 == NULL)
6752 		return (0);
6753 	ASSERT(badseg2->s_szc == szc);
6754 	ASSERT(badseg2->s_size == pgsz);
6755 	ASSERT(sameprot(badseg2, badseg2->s_base, badseg2->s_size));
6756 	if (err = segvn_clrszc(badseg2)) {
6757 		return (err);
6758 	}
6759 	ASSERT(badseg2->s_szc == 0);
6760 
6761 	if (szc > 1 && (tszcvec = P2PHASE(szcvec, 1 << szc)) > 1) {
6762 		uint_t tszc = highbit(tszcvec) - 1;
6763 		size_t tpgsz = page_get_pagesize(tszc);
6764 
6765 		ASSERT(svd->type == MAP_SHARED);
6766 		ASSERT(flag == SDR_END);
6767 		ASSERT(tszc < szc && tszc > 0);
6768 		ASSERT(badseg2->s_base > addr);
6769 		ASSERT(eaddr > badseg2->s_base);
6770 		ASSERT(eaddr < badseg2->s_base + badseg2->s_size);
6771 
6772 		badseg2->s_szc = tszc;
6773 		if (!IS_P2ALIGNED(eaddr, tpgsz)) {
6774 			return (segvn_demote_range(badseg2, badseg2->s_base,
6775 			    eaddr - badseg2->s_base, SDR_END, tszcvec));
6776 		}
6777 	}
6778 
6779 	return (0);
6780 }
6781 
6782 static int
6783 segvn_checkprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
6784 {
6785 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6786 	struct vpage *vp, *evp;
6787 
6788 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6789 
6790 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
6791 	/*
6792 	 * If segment protection can be used, simply check against them.
6793 	 */
6794 	if (svd->pageprot == 0) {
6795 		int err;
6796 
6797 		err = ((svd->prot & prot) != prot) ? EACCES : 0;
6798 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6799 		return (err);
6800 	}
6801 
6802 	/*
6803 	 * Have to check down to the vpage level.
6804 	 */
6805 	evp = &svd->vpage[seg_page(seg, addr + len)];
6806 	for (vp = &svd->vpage[seg_page(seg, addr)]; vp < evp; vp++) {
6807 		if ((VPP_PROT(vp) & prot) != prot) {
6808 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6809 			return (EACCES);
6810 		}
6811 	}
6812 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6813 	return (0);
6814 }
6815 
6816 static int
6817 segvn_getprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv)
6818 {
6819 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6820 	size_t pgno = seg_page(seg, addr + len) - seg_page(seg, addr) + 1;
6821 
6822 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6823 
6824 	if (pgno != 0) {
6825 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
6826 		if (svd->pageprot == 0) {
6827 			do {
6828 				protv[--pgno] = svd->prot;
6829 			} while (pgno != 0);
6830 		} else {
6831 			size_t pgoff = seg_page(seg, addr);
6832 
6833 			do {
6834 				pgno--;
6835 				protv[pgno] = VPP_PROT(&svd->vpage[pgno+pgoff]);
6836 			} while (pgno != 0);
6837 		}
6838 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6839 	}
6840 	return (0);
6841 }
6842 
6843 static u_offset_t
6844 segvn_getoffset(struct seg *seg, caddr_t addr)
6845 {
6846 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6847 
6848 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6849 
6850 	return (svd->offset + (uintptr_t)(addr - seg->s_base));
6851 }
6852 
6853 /*ARGSUSED*/
6854 static int
6855 segvn_gettype(struct seg *seg, caddr_t addr)
6856 {
6857 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6858 
6859 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6860 
6861 	return (svd->type | (svd->flags & (MAP_NORESERVE | MAP_TEXT |
6862 	    MAP_INITDATA)));
6863 }
6864 
6865 /*ARGSUSED*/
6866 static int
6867 segvn_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp)
6868 {
6869 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6870 
6871 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6872 
6873 	*vpp = svd->vp;
6874 	return (0);
6875 }
6876 
6877 /*
6878  * Check to see if it makes sense to do kluster/read ahead to
6879  * addr + delta relative to the mapping at addr.  We assume here
6880  * that delta is a signed PAGESIZE'd multiple (which can be negative).
6881  *
6882  * For segvn, we currently "approve" of the action if we are
6883  * still in the segment and it maps from the same vp/off,
6884  * or if the advice stored in segvn_data or vpages allows it.
6885  * Currently, klustering is not allowed only if MADV_RANDOM is set.
6886  */
6887 static int
6888 segvn_kluster(struct seg *seg, caddr_t addr, ssize_t delta)
6889 {
6890 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6891 	struct anon *oap, *ap;
6892 	ssize_t pd;
6893 	size_t page;
6894 	struct vnode *vp1, *vp2;
6895 	u_offset_t off1, off2;
6896 	struct anon_map *amp;
6897 
6898 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6899 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock) ||
6900 	    SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
6901 
6902 	if (addr + delta < seg->s_base ||
6903 	    addr + delta >= (seg->s_base + seg->s_size))
6904 		return (-1);		/* exceeded segment bounds */
6905 
6906 	pd = delta / (ssize_t)PAGESIZE;	/* divide to preserve sign bit */
6907 	page = seg_page(seg, addr);
6908 
6909 	/*
6910 	 * Check to see if either of the pages addr or addr + delta
6911 	 * have advice set that prevents klustering (if MADV_RANDOM advice
6912 	 * is set for entire segment, or MADV_SEQUENTIAL is set and delta
6913 	 * is negative).
6914 	 */
6915 	if (svd->advice == MADV_RANDOM ||
6916 	    svd->advice == MADV_SEQUENTIAL && delta < 0)
6917 		return (-1);
6918 	else if (svd->pageadvice && svd->vpage) {
6919 		struct vpage *bvpp, *evpp;
6920 
6921 		bvpp = &svd->vpage[page];
6922 		evpp = &svd->vpage[page + pd];
6923 		if (VPP_ADVICE(bvpp) == MADV_RANDOM ||
6924 		    VPP_ADVICE(evpp) == MADV_SEQUENTIAL && delta < 0)
6925 			return (-1);
6926 		if (VPP_ADVICE(bvpp) != VPP_ADVICE(evpp) &&
6927 		    VPP_ADVICE(evpp) == MADV_RANDOM)
6928 			return (-1);
6929 	}
6930 
6931 	if (svd->type == MAP_SHARED)
6932 		return (0);		/* shared mapping - all ok */
6933 
6934 	if ((amp = svd->amp) == NULL)
6935 		return (0);		/* off original vnode */
6936 
6937 	page += svd->anon_index;
6938 
6939 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
6940 
6941 	oap = anon_get_ptr(amp->ahp, page);
6942 	ap = anon_get_ptr(amp->ahp, page + pd);
6943 
6944 	ANON_LOCK_EXIT(&amp->a_rwlock);
6945 
6946 	if ((oap == NULL && ap != NULL) || (oap != NULL && ap == NULL)) {
6947 		return (-1);		/* one with and one without an anon */
6948 	}
6949 
6950 	if (oap == NULL) {		/* implies that ap == NULL */
6951 		return (0);		/* off original vnode */
6952 	}
6953 
6954 	/*
6955 	 * Now we know we have two anon pointers - check to
6956 	 * see if they happen to be properly allocated.
6957 	 */
6958 
6959 	/*
6960 	 * XXX We cheat here and don't lock the anon slots. We can't because
6961 	 * we may have been called from the anon layer which might already
6962 	 * have locked them. We are holding a refcnt on the slots so they
6963 	 * can't disappear. The worst that will happen is we'll get the wrong
6964 	 * names (vp, off) for the slots and make a poor klustering decision.
6965 	 */
6966 	swap_xlate(ap, &vp1, &off1);
6967 	swap_xlate(oap, &vp2, &off2);
6968 
6969 
6970 	if (!VOP_CMP(vp1, vp2, NULL) || off1 - off2 != delta)
6971 		return (-1);
6972 	return (0);
6973 }
6974 
6975 /*
6976  * Swap the pages of seg out to secondary storage, returning the
6977  * number of bytes of storage freed.
6978  *
6979  * The basic idea is first to unload all translations and then to call
6980  * VOP_PUTPAGE() for all newly-unmapped pages, to push them out to the
6981  * swap device.  Pages to which other segments have mappings will remain
6982  * mapped and won't be swapped.  Our caller (as_swapout) has already
6983  * performed the unloading step.
6984  *
6985  * The value returned is intended to correlate well with the process's
6986  * memory requirements.  However, there are some caveats:
6987  * 1)	When given a shared segment as argument, this routine will
6988  *	only succeed in swapping out pages for the last sharer of the
6989  *	segment.  (Previous callers will only have decremented mapping
6990  *	reference counts.)
6991  * 2)	We assume that the hat layer maintains a large enough translation
6992  *	cache to capture process reference patterns.
6993  */
6994 static size_t
6995 segvn_swapout(struct seg *seg)
6996 {
6997 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6998 	struct anon_map *amp;
6999 	pgcnt_t pgcnt = 0;
7000 	pgcnt_t npages;
7001 	pgcnt_t page;
7002 	ulong_t anon_index;
7003 
7004 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7005 
7006 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
7007 	/*
7008 	 * Find pages unmapped by our caller and force them
7009 	 * out to the virtual swap device.
7010 	 */
7011 	if ((amp = svd->amp) != NULL)
7012 		anon_index = svd->anon_index;
7013 	npages = seg->s_size >> PAGESHIFT;
7014 	for (page = 0; page < npages; page++) {
7015 		page_t *pp;
7016 		struct anon *ap;
7017 		struct vnode *vp;
7018 		u_offset_t off;
7019 		anon_sync_obj_t cookie;
7020 
7021 		/*
7022 		 * Obtain <vp, off> pair for the page, then look it up.
7023 		 *
7024 		 * Note that this code is willing to consider regular
7025 		 * pages as well as anon pages.  Is this appropriate here?
7026 		 */
7027 		ap = NULL;
7028 		if (amp != NULL) {
7029 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7030 			if (anon_array_try_enter(amp, anon_index + page,
7031 			    &cookie)) {
7032 				ANON_LOCK_EXIT(&amp->a_rwlock);
7033 				continue;
7034 			}
7035 			ap = anon_get_ptr(amp->ahp, anon_index + page);
7036 			if (ap != NULL) {
7037 				swap_xlate(ap, &vp, &off);
7038 			} else {
7039 				vp = svd->vp;
7040 				off = svd->offset + ptob(page);
7041 			}
7042 			anon_array_exit(&cookie);
7043 			ANON_LOCK_EXIT(&amp->a_rwlock);
7044 		} else {
7045 			vp = svd->vp;
7046 			off = svd->offset + ptob(page);
7047 		}
7048 		if (vp == NULL) {		/* untouched zfod page */
7049 			ASSERT(ap == NULL);
7050 			continue;
7051 		}
7052 
7053 		pp = page_lookup_nowait(vp, off, SE_SHARED);
7054 		if (pp == NULL)
7055 			continue;
7056 
7057 
7058 		/*
7059 		 * Examine the page to see whether it can be tossed out,
7060 		 * keeping track of how many we've found.
7061 		 */
7062 		if (!page_tryupgrade(pp)) {
7063 			/*
7064 			 * If the page has an i/o lock and no mappings,
7065 			 * it's very likely that the page is being
7066 			 * written out as a result of klustering.
7067 			 * Assume this is so and take credit for it here.
7068 			 */
7069 			if (!page_io_trylock(pp)) {
7070 				if (!hat_page_is_mapped(pp))
7071 					pgcnt++;
7072 			} else {
7073 				page_io_unlock(pp);
7074 			}
7075 			page_unlock(pp);
7076 			continue;
7077 		}
7078 		ASSERT(!page_iolock_assert(pp));
7079 
7080 
7081 		/*
7082 		 * Skip if page is locked or has mappings.
7083 		 * We don't need the page_struct_lock to look at lckcnt
7084 		 * and cowcnt because the page is exclusive locked.
7085 		 */
7086 		if (pp->p_lckcnt != 0 || pp->p_cowcnt != 0 ||
7087 		    hat_page_is_mapped(pp)) {
7088 			page_unlock(pp);
7089 			continue;
7090 		}
7091 
7092 		/*
7093 		 * dispose skips large pages so try to demote first.
7094 		 */
7095 		if (pp->p_szc != 0 && !page_try_demote_pages(pp)) {
7096 			page_unlock(pp);
7097 			/*
7098 			 * XXX should skip the remaining page_t's of this
7099 			 * large page.
7100 			 */
7101 			continue;
7102 		}
7103 
7104 		ASSERT(pp->p_szc == 0);
7105 
7106 		/*
7107 		 * No longer mapped -- we can toss it out.  How
7108 		 * we do so depends on whether or not it's dirty.
7109 		 */
7110 		if (hat_ismod(pp) && pp->p_vnode) {
7111 			/*
7112 			 * We must clean the page before it can be
7113 			 * freed.  Setting B_FREE will cause pvn_done
7114 			 * to free the page when the i/o completes.
7115 			 * XXX:	This also causes it to be accounted
7116 			 *	as a pageout instead of a swap: need
7117 			 *	B_SWAPOUT bit to use instead of B_FREE.
7118 			 *
7119 			 * Hold the vnode before releasing the page lock
7120 			 * to prevent it from being freed and re-used by
7121 			 * some other thread.
7122 			 */
7123 			VN_HOLD(vp);
7124 			page_unlock(pp);
7125 
7126 			/*
7127 			 * Queue all i/o requests for the pageout thread
7128 			 * to avoid saturating the pageout devices.
7129 			 */
7130 			if (!queue_io_request(vp, off))
7131 				VN_RELE(vp);
7132 		} else {
7133 			/*
7134 			 * The page was clean, free it.
7135 			 *
7136 			 * XXX:	Can we ever encounter modified pages
7137 			 *	with no associated vnode here?
7138 			 */
7139 			ASSERT(pp->p_vnode != NULL);
7140 			/*LINTED: constant in conditional context*/
7141 			VN_DISPOSE(pp, B_FREE, 0, kcred);
7142 		}
7143 
7144 		/*
7145 		 * Credit now even if i/o is in progress.
7146 		 */
7147 		pgcnt++;
7148 	}
7149 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7150 
7151 	/*
7152 	 * Wakeup pageout to initiate i/o on all queued requests.
7153 	 */
7154 	cv_signal_pageout();
7155 	return (ptob(pgcnt));
7156 }
7157 
7158 /*
7159  * Synchronize primary storage cache with real object in virtual memory.
7160  *
7161  * XXX - Anonymous pages should not be sync'ed out at all.
7162  */
7163 static int
7164 segvn_sync(struct seg *seg, caddr_t addr, size_t len, int attr, uint_t flags)
7165 {
7166 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7167 	struct vpage *vpp;
7168 	page_t *pp;
7169 	u_offset_t offset;
7170 	struct vnode *vp;
7171 	u_offset_t off;
7172 	caddr_t eaddr;
7173 	int bflags;
7174 	int err = 0;
7175 	int segtype;
7176 	int pageprot;
7177 	int prot;
7178 	ulong_t anon_index;
7179 	struct anon_map *amp;
7180 	struct anon *ap;
7181 	anon_sync_obj_t cookie;
7182 
7183 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7184 
7185 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
7186 
7187 	if (svd->softlockcnt > 0) {
7188 		/*
7189 		 * If this is shared segment non 0 softlockcnt
7190 		 * means locked pages are still in use.
7191 		 */
7192 		if (svd->type == MAP_SHARED) {
7193 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7194 			return (EAGAIN);
7195 		}
7196 
7197 		/*
7198 		 * flush all pages from seg cache
7199 		 * otherwise we may deadlock in swap_putpage
7200 		 * for B_INVAL page (4175402).
7201 		 *
7202 		 * Even if we grab segvn WRITER's lock
7203 		 * here, there might be another thread which could've
7204 		 * successfully performed lookup/insert just before
7205 		 * we acquired the lock here.  So, grabbing either
7206 		 * lock here is of not much use.  Until we devise
7207 		 * a strategy at upper layers to solve the
7208 		 * synchronization issues completely, we expect
7209 		 * applications to handle this appropriately.
7210 		 */
7211 		segvn_purge(seg);
7212 		if (svd->softlockcnt > 0) {
7213 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7214 			return (EAGAIN);
7215 		}
7216 	} else if (svd->type == MAP_SHARED && svd->amp != NULL &&
7217 	    svd->amp->a_softlockcnt > 0) {
7218 		/*
7219 		 * Try to purge this amp's entries from pcache. It will
7220 		 * succeed only if other segments that share the amp have no
7221 		 * outstanding softlock's.
7222 		 */
7223 		segvn_purge(seg);
7224 		if (svd->amp->a_softlockcnt > 0 || svd->softlockcnt > 0) {
7225 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7226 			return (EAGAIN);
7227 		}
7228 	}
7229 
7230 	vpp = svd->vpage;
7231 	offset = svd->offset + (uintptr_t)(addr - seg->s_base);
7232 	bflags = ((flags & MS_ASYNC) ? B_ASYNC : 0) |
7233 	    ((flags & MS_INVALIDATE) ? B_INVAL : 0);
7234 
7235 	if (attr) {
7236 		pageprot = attr & ~(SHARED|PRIVATE);
7237 		segtype = (attr & SHARED) ? MAP_SHARED : MAP_PRIVATE;
7238 
7239 		/*
7240 		 * We are done if the segment types don't match
7241 		 * or if we have segment level protections and
7242 		 * they don't match.
7243 		 */
7244 		if (svd->type != segtype) {
7245 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7246 			return (0);
7247 		}
7248 		if (vpp == NULL) {
7249 			if (svd->prot != pageprot) {
7250 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7251 				return (0);
7252 			}
7253 			prot = svd->prot;
7254 		} else
7255 			vpp = &svd->vpage[seg_page(seg, addr)];
7256 
7257 	} else if (svd->vp && svd->amp == NULL &&
7258 	    (flags & MS_INVALIDATE) == 0) {
7259 
7260 		/*
7261 		 * No attributes, no anonymous pages and MS_INVALIDATE flag
7262 		 * is not on, just use one big request.
7263 		 */
7264 		err = VOP_PUTPAGE(svd->vp, (offset_t)offset, len,
7265 		    bflags, svd->cred, NULL);
7266 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7267 		return (err);
7268 	}
7269 
7270 	if ((amp = svd->amp) != NULL)
7271 		anon_index = svd->anon_index + seg_page(seg, addr);
7272 
7273 	for (eaddr = addr + len; addr < eaddr; addr += PAGESIZE) {
7274 		ap = NULL;
7275 		if (amp != NULL) {
7276 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7277 			anon_array_enter(amp, anon_index, &cookie);
7278 			ap = anon_get_ptr(amp->ahp, anon_index++);
7279 			if (ap != NULL) {
7280 				swap_xlate(ap, &vp, &off);
7281 			} else {
7282 				vp = svd->vp;
7283 				off = offset;
7284 			}
7285 			anon_array_exit(&cookie);
7286 			ANON_LOCK_EXIT(&amp->a_rwlock);
7287 		} else {
7288 			vp = svd->vp;
7289 			off = offset;
7290 		}
7291 		offset += PAGESIZE;
7292 
7293 		if (vp == NULL)		/* untouched zfod page */
7294 			continue;
7295 
7296 		if (attr) {
7297 			if (vpp) {
7298 				prot = VPP_PROT(vpp);
7299 				vpp++;
7300 			}
7301 			if (prot != pageprot) {
7302 				continue;
7303 			}
7304 		}
7305 
7306 		/*
7307 		 * See if any of these pages are locked --  if so, then we
7308 		 * will have to truncate an invalidate request at the first
7309 		 * locked one. We don't need the page_struct_lock to test
7310 		 * as this is only advisory; even if we acquire it someone
7311 		 * might race in and lock the page after we unlock and before
7312 		 * we do the PUTPAGE, then PUTPAGE simply does nothing.
7313 		 */
7314 		if (flags & MS_INVALIDATE) {
7315 			if ((pp = page_lookup(vp, off, SE_SHARED)) != NULL) {
7316 				if (pp->p_lckcnt != 0 || pp->p_cowcnt != 0) {
7317 					page_unlock(pp);
7318 					SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7319 					return (EBUSY);
7320 				}
7321 				if (ap != NULL && pp->p_szc != 0 &&
7322 				    page_tryupgrade(pp)) {
7323 					if (pp->p_lckcnt == 0 &&
7324 					    pp->p_cowcnt == 0) {
7325 						/*
7326 						 * swapfs VN_DISPOSE() won't
7327 						 * invalidate large pages.
7328 						 * Attempt to demote.
7329 						 * XXX can't help it if it
7330 						 * fails. But for swapfs
7331 						 * pages it is no big deal.
7332 						 */
7333 						(void) page_try_demote_pages(
7334 						    pp);
7335 					}
7336 				}
7337 				page_unlock(pp);
7338 			}
7339 		} else if (svd->type == MAP_SHARED && amp != NULL) {
7340 			/*
7341 			 * Avoid writing out to disk ISM's large pages
7342 			 * because segspt_free_pages() relies on NULL an_pvp
7343 			 * of anon slots of such pages.
7344 			 */
7345 
7346 			ASSERT(svd->vp == NULL);
7347 			/*
7348 			 * swapfs uses page_lookup_nowait if not freeing or
7349 			 * invalidating and skips a page if
7350 			 * page_lookup_nowait returns NULL.
7351 			 */
7352 			pp = page_lookup_nowait(vp, off, SE_SHARED);
7353 			if (pp == NULL) {
7354 				continue;
7355 			}
7356 			if (pp->p_szc != 0) {
7357 				page_unlock(pp);
7358 				continue;
7359 			}
7360 
7361 			/*
7362 			 * Note ISM pages are created large so (vp, off)'s
7363 			 * page cannot suddenly become large after we unlock
7364 			 * pp.
7365 			 */
7366 			page_unlock(pp);
7367 		}
7368 		/*
7369 		 * XXX - Should ultimately try to kluster
7370 		 * calls to VOP_PUTPAGE() for performance.
7371 		 */
7372 		VN_HOLD(vp);
7373 		err = VOP_PUTPAGE(vp, (offset_t)off, PAGESIZE,
7374 		    (bflags | (IS_SWAPFSVP(vp) ? B_PAGE_NOWAIT : 0)),
7375 		    svd->cred, NULL);
7376 
7377 		VN_RELE(vp);
7378 		if (err)
7379 			break;
7380 	}
7381 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7382 	return (err);
7383 }
7384 
7385 /*
7386  * Determine if we have data corresponding to pages in the
7387  * primary storage virtual memory cache (i.e., "in core").
7388  */
7389 static size_t
7390 segvn_incore(struct seg *seg, caddr_t addr, size_t len, char *vec)
7391 {
7392 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7393 	struct vnode *vp, *avp;
7394 	u_offset_t offset, aoffset;
7395 	size_t p, ep;
7396 	int ret;
7397 	struct vpage *vpp;
7398 	page_t *pp;
7399 	uint_t start;
7400 	struct anon_map *amp;		/* XXX - for locknest */
7401 	struct anon *ap;
7402 	uint_t attr;
7403 	anon_sync_obj_t cookie;
7404 
7405 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7406 
7407 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
7408 	if (svd->amp == NULL && svd->vp == NULL) {
7409 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7410 		bzero(vec, btopr(len));
7411 		return (len);	/* no anonymous pages created yet */
7412 	}
7413 
7414 	p = seg_page(seg, addr);
7415 	ep = seg_page(seg, addr + len);
7416 	start = svd->vp ? SEG_PAGE_VNODEBACKED : 0;
7417 
7418 	amp = svd->amp;
7419 	for (; p < ep; p++, addr += PAGESIZE) {
7420 		vpp = (svd->vpage) ? &svd->vpage[p]: NULL;
7421 		ret = start;
7422 		ap = NULL;
7423 		avp = NULL;
7424 		/* Grab the vnode/offset for the anon slot */
7425 		if (amp != NULL) {
7426 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7427 			anon_array_enter(amp, svd->anon_index + p, &cookie);
7428 			ap = anon_get_ptr(amp->ahp, svd->anon_index + p);
7429 			if (ap != NULL) {
7430 				swap_xlate(ap, &avp, &aoffset);
7431 			}
7432 			anon_array_exit(&cookie);
7433 			ANON_LOCK_EXIT(&amp->a_rwlock);
7434 		}
7435 		if ((avp != NULL) && page_exists(avp, aoffset)) {
7436 			/* A page exists for the anon slot */
7437 			ret |= SEG_PAGE_INCORE;
7438 
7439 			/*
7440 			 * If page is mapped and writable
7441 			 */
7442 			attr = (uint_t)0;
7443 			if ((hat_getattr(seg->s_as->a_hat, addr,
7444 			    &attr) != -1) && (attr & PROT_WRITE)) {
7445 				ret |= SEG_PAGE_ANON;
7446 			}
7447 			/*
7448 			 * Don't get page_struct lock for lckcnt and cowcnt,
7449 			 * since this is purely advisory.
7450 			 */
7451 			if ((pp = page_lookup_nowait(avp, aoffset,
7452 			    SE_SHARED)) != NULL) {
7453 				if (pp->p_lckcnt)
7454 					ret |= SEG_PAGE_SOFTLOCK;
7455 				if (pp->p_cowcnt)
7456 					ret |= SEG_PAGE_HASCOW;
7457 				page_unlock(pp);
7458 			}
7459 		}
7460 
7461 		/* Gather vnode statistics */
7462 		vp = svd->vp;
7463 		offset = svd->offset + (uintptr_t)(addr - seg->s_base);
7464 
7465 		if (vp != NULL) {
7466 			/*
7467 			 * Try to obtain a "shared" lock on the page
7468 			 * without blocking.  If this fails, determine
7469 			 * if the page is in memory.
7470 			 */
7471 			pp = page_lookup_nowait(vp, offset, SE_SHARED);
7472 			if ((pp == NULL) && (page_exists(vp, offset))) {
7473 				/* Page is incore, and is named */
7474 				ret |= (SEG_PAGE_INCORE | SEG_PAGE_VNODE);
7475 			}
7476 			/*
7477 			 * Don't get page_struct lock for lckcnt and cowcnt,
7478 			 * since this is purely advisory.
7479 			 */
7480 			if (pp != NULL) {
7481 				ret |= (SEG_PAGE_INCORE | SEG_PAGE_VNODE);
7482 				if (pp->p_lckcnt)
7483 					ret |= SEG_PAGE_SOFTLOCK;
7484 				if (pp->p_cowcnt)
7485 					ret |= SEG_PAGE_HASCOW;
7486 				page_unlock(pp);
7487 			}
7488 		}
7489 
7490 		/* Gather virtual page information */
7491 		if (vpp) {
7492 			if (VPP_ISPPLOCK(vpp))
7493 				ret |= SEG_PAGE_LOCKED;
7494 			vpp++;
7495 		}
7496 
7497 		*vec++ = (char)ret;
7498 	}
7499 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7500 	return (len);
7501 }
7502 
7503 /*
7504  * Statement for p_cowcnts/p_lckcnts.
7505  *
7506  * p_cowcnt is updated while mlock/munlocking MAP_PRIVATE and PROT_WRITE region
7507  * irrespective of the following factors or anything else:
7508  *
7509  *	(1) anon slots are populated or not
7510  *	(2) cow is broken or not
7511  *	(3) refcnt on ap is 1 or greater than 1
7512  *
7513  * If it's not MAP_PRIVATE and PROT_WRITE, p_lckcnt is updated during mlock
7514  * and munlock.
7515  *
7516  *
7517  * Handling p_cowcnts/p_lckcnts during copy-on-write fault:
7518  *
7519  *	if vpage has PROT_WRITE
7520  *		transfer cowcnt on the oldpage -> cowcnt on the newpage
7521  *	else
7522  *		transfer lckcnt on the oldpage -> lckcnt on the newpage
7523  *
7524  *	During copy-on-write, decrement p_cowcnt on the oldpage and increment
7525  *	p_cowcnt on the newpage *if* the corresponding vpage has PROT_WRITE.
7526  *
7527  *	We may also break COW if softlocking on read access in the physio case.
7528  *	In this case, vpage may not have PROT_WRITE. So, we need to decrement
7529  *	p_lckcnt on the oldpage and increment p_lckcnt on the newpage *if* the
7530  *	vpage doesn't have PROT_WRITE.
7531  *
7532  *
7533  * Handling p_cowcnts/p_lckcnts during mprotect on mlocked region:
7534  *
7535  * 	If a MAP_PRIVATE region loses PROT_WRITE, we decrement p_cowcnt and
7536  *	increment p_lckcnt by calling page_subclaim() which takes care of
7537  * 	availrmem accounting and p_lckcnt overflow.
7538  *
7539  *	If a MAP_PRIVATE region gains PROT_WRITE, we decrement p_lckcnt and
7540  *	increment p_cowcnt by calling page_addclaim() which takes care of
7541  *	availrmem availability and p_cowcnt overflow.
7542  */
7543 
7544 /*
7545  * Lock down (or unlock) pages mapped by this segment.
7546  *
7547  * XXX only creates PAGESIZE pages if anon slots are not initialized.
7548  * At fault time they will be relocated into larger pages.
7549  */
7550 static int
7551 segvn_lockop(struct seg *seg, caddr_t addr, size_t len,
7552     int attr, int op, ulong_t *lockmap, size_t pos)
7553 {
7554 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7555 	struct vpage *vpp;
7556 	struct vpage *evp;
7557 	page_t *pp;
7558 	u_offset_t offset;
7559 	u_offset_t off;
7560 	int segtype;
7561 	int pageprot;
7562 	int claim;
7563 	struct vnode *vp;
7564 	ulong_t anon_index;
7565 	struct anon_map *amp;
7566 	struct anon *ap;
7567 	struct vattr va;
7568 	anon_sync_obj_t cookie;
7569 	struct kshmid *sp = NULL;
7570 	struct proc	*p = curproc;
7571 	kproject_t	*proj = NULL;
7572 	int chargeproc = 1;
7573 	size_t locked_bytes = 0;
7574 	size_t unlocked_bytes = 0;
7575 	int err = 0;
7576 
7577 	/*
7578 	 * Hold write lock on address space because may split or concatenate
7579 	 * segments
7580 	 */
7581 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7582 
7583 	/*
7584 	 * If this is a shm, use shm's project and zone, else use
7585 	 * project and zone of calling process
7586 	 */
7587 
7588 	/* Determine if this segment backs a sysV shm */
7589 	if (svd->amp != NULL && svd->amp->a_sp != NULL) {
7590 		ASSERT(svd->type == MAP_SHARED);
7591 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
7592 		sp = svd->amp->a_sp;
7593 		proj = sp->shm_perm.ipc_proj;
7594 		chargeproc = 0;
7595 	}
7596 
7597 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
7598 	if (attr) {
7599 		pageprot = attr & ~(SHARED|PRIVATE);
7600 		segtype = attr & SHARED ? MAP_SHARED : MAP_PRIVATE;
7601 
7602 		/*
7603 		 * We are done if the segment types don't match
7604 		 * or if we have segment level protections and
7605 		 * they don't match.
7606 		 */
7607 		if (svd->type != segtype) {
7608 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7609 			return (0);
7610 		}
7611 		if (svd->pageprot == 0 && svd->prot != pageprot) {
7612 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7613 			return (0);
7614 		}
7615 	}
7616 
7617 	if (op == MC_LOCK) {
7618 		if (svd->tr_state == SEGVN_TR_INIT) {
7619 			svd->tr_state = SEGVN_TR_OFF;
7620 		} else if (svd->tr_state == SEGVN_TR_ON) {
7621 			ASSERT(svd->amp != NULL);
7622 			segvn_textunrepl(seg, 0);
7623 			ASSERT(svd->amp == NULL &&
7624 			    svd->tr_state == SEGVN_TR_OFF);
7625 		}
7626 	}
7627 
7628 	/*
7629 	 * If we're locking, then we must create a vpage structure if
7630 	 * none exists.  If we're unlocking, then check to see if there
7631 	 * is a vpage --  if not, then we could not have locked anything.
7632 	 */
7633 
7634 	if ((vpp = svd->vpage) == NULL) {
7635 		if (op == MC_LOCK)
7636 			segvn_vpage(seg);
7637 		else {
7638 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7639 			return (0);
7640 		}
7641 	}
7642 
7643 	/*
7644 	 * The anonymous data vector (i.e., previously
7645 	 * unreferenced mapping to swap space) can be allocated
7646 	 * by lazily testing for its existence.
7647 	 */
7648 	if (op == MC_LOCK && svd->amp == NULL && svd->vp == NULL) {
7649 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
7650 		svd->amp = anonmap_alloc(seg->s_size, 0, ANON_SLEEP);
7651 		svd->amp->a_szc = seg->s_szc;
7652 	}
7653 
7654 	if ((amp = svd->amp) != NULL) {
7655 		anon_index = svd->anon_index + seg_page(seg, addr);
7656 	}
7657 
7658 	offset = svd->offset + (uintptr_t)(addr - seg->s_base);
7659 	evp = &svd->vpage[seg_page(seg, addr + len)];
7660 
7661 	if (sp != NULL)
7662 		mutex_enter(&sp->shm_mlock);
7663 
7664 	/* determine number of unlocked bytes in range for lock operation */
7665 	if (op == MC_LOCK) {
7666 
7667 		if (sp == NULL) {
7668 			for (vpp = &svd->vpage[seg_page(seg, addr)]; vpp < evp;
7669 			    vpp++) {
7670 				if (!VPP_ISPPLOCK(vpp))
7671 					unlocked_bytes += PAGESIZE;
7672 			}
7673 		} else {
7674 			ulong_t		i_idx, i_edx;
7675 			anon_sync_obj_t	i_cookie;
7676 			struct anon	*i_ap;
7677 			struct vnode	*i_vp;
7678 			u_offset_t	i_off;
7679 
7680 			/* Only count sysV pages once for locked memory */
7681 			i_edx = svd->anon_index + seg_page(seg, addr + len);
7682 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7683 			for (i_idx = anon_index; i_idx < i_edx; i_idx++) {
7684 				anon_array_enter(amp, i_idx, &i_cookie);
7685 				i_ap = anon_get_ptr(amp->ahp, i_idx);
7686 				if (i_ap == NULL) {
7687 					unlocked_bytes += PAGESIZE;
7688 					anon_array_exit(&i_cookie);
7689 					continue;
7690 				}
7691 				swap_xlate(i_ap, &i_vp, &i_off);
7692 				anon_array_exit(&i_cookie);
7693 				pp = page_lookup(i_vp, i_off, SE_SHARED);
7694 				if (pp == NULL) {
7695 					unlocked_bytes += PAGESIZE;
7696 					continue;
7697 				} else if (pp->p_lckcnt == 0)
7698 					unlocked_bytes += PAGESIZE;
7699 				page_unlock(pp);
7700 			}
7701 			ANON_LOCK_EXIT(&amp->a_rwlock);
7702 		}
7703 
7704 		mutex_enter(&p->p_lock);
7705 		err = rctl_incr_locked_mem(p, proj, unlocked_bytes,
7706 		    chargeproc);
7707 		mutex_exit(&p->p_lock);
7708 
7709 		if (err) {
7710 			if (sp != NULL)
7711 				mutex_exit(&sp->shm_mlock);
7712 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7713 			return (err);
7714 		}
7715 	}
7716 	/*
7717 	 * Loop over all pages in the range.  Process if we're locking and
7718 	 * page has not already been locked in this mapping; or if we're
7719 	 * unlocking and the page has been locked.
7720 	 */
7721 	for (vpp = &svd->vpage[seg_page(seg, addr)]; vpp < evp;
7722 	    vpp++, pos++, addr += PAGESIZE, offset += PAGESIZE, anon_index++) {
7723 		if ((attr == 0 || VPP_PROT(vpp) == pageprot) &&
7724 		    ((op == MC_LOCK && !VPP_ISPPLOCK(vpp)) ||
7725 		    (op == MC_UNLOCK && VPP_ISPPLOCK(vpp)))) {
7726 
7727 			if (amp != NULL)
7728 				ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7729 			/*
7730 			 * If this isn't a MAP_NORESERVE segment and
7731 			 * we're locking, allocate anon slots if they
7732 			 * don't exist.  The page is brought in later on.
7733 			 */
7734 			if (op == MC_LOCK && svd->vp == NULL &&
7735 			    ((svd->flags & MAP_NORESERVE) == 0) &&
7736 			    amp != NULL &&
7737 			    ((ap = anon_get_ptr(amp->ahp, anon_index))
7738 			    == NULL)) {
7739 				anon_array_enter(amp, anon_index, &cookie);
7740 
7741 				if ((ap = anon_get_ptr(amp->ahp,
7742 				    anon_index)) == NULL) {
7743 					pp = anon_zero(seg, addr, &ap,
7744 					    svd->cred);
7745 					if (pp == NULL) {
7746 						anon_array_exit(&cookie);
7747 						ANON_LOCK_EXIT(&amp->a_rwlock);
7748 						err = ENOMEM;
7749 						goto out;
7750 					}
7751 					ASSERT(anon_get_ptr(amp->ahp,
7752 					    anon_index) == NULL);
7753 					(void) anon_set_ptr(amp->ahp,
7754 					    anon_index, ap, ANON_SLEEP);
7755 					page_unlock(pp);
7756 				}
7757 				anon_array_exit(&cookie);
7758 			}
7759 
7760 			/*
7761 			 * Get name for page, accounting for
7762 			 * existence of private copy.
7763 			 */
7764 			ap = NULL;
7765 			if (amp != NULL) {
7766 				anon_array_enter(amp, anon_index, &cookie);
7767 				ap = anon_get_ptr(amp->ahp, anon_index);
7768 				if (ap != NULL) {
7769 					swap_xlate(ap, &vp, &off);
7770 				} else {
7771 					if (svd->vp == NULL &&
7772 					    (svd->flags & MAP_NORESERVE)) {
7773 						anon_array_exit(&cookie);
7774 						ANON_LOCK_EXIT(&amp->a_rwlock);
7775 						continue;
7776 					}
7777 					vp = svd->vp;
7778 					off = offset;
7779 				}
7780 				if (op != MC_LOCK || ap == NULL) {
7781 					anon_array_exit(&cookie);
7782 					ANON_LOCK_EXIT(&amp->a_rwlock);
7783 				}
7784 			} else {
7785 				vp = svd->vp;
7786 				off = offset;
7787 			}
7788 
7789 			/*
7790 			 * Get page frame.  It's ok if the page is
7791 			 * not available when we're unlocking, as this
7792 			 * may simply mean that a page we locked got
7793 			 * truncated out of existence after we locked it.
7794 			 *
7795 			 * Invoke VOP_GETPAGE() to obtain the page struct
7796 			 * since we may need to read it from disk if its
7797 			 * been paged out.
7798 			 */
7799 			if (op != MC_LOCK)
7800 				pp = page_lookup(vp, off, SE_SHARED);
7801 			else {
7802 				page_t *pl[1 + 1];
7803 				int error;
7804 
7805 				ASSERT(vp != NULL);
7806 
7807 				error = VOP_GETPAGE(vp, (offset_t)off, PAGESIZE,
7808 				    (uint_t *)NULL, pl, PAGESIZE, seg, addr,
7809 				    S_OTHER, svd->cred, NULL);
7810 
7811 				if (error && ap != NULL) {
7812 					anon_array_exit(&cookie);
7813 					ANON_LOCK_EXIT(&amp->a_rwlock);
7814 				}
7815 
7816 				/*
7817 				 * If the error is EDEADLK then we must bounce
7818 				 * up and drop all vm subsystem locks and then
7819 				 * retry the operation later
7820 				 * This behavior is a temporary measure because
7821 				 * ufs/sds logging is badly designed and will
7822 				 * deadlock if we don't allow this bounce to
7823 				 * happen.  The real solution is to re-design
7824 				 * the logging code to work properly.  See bug
7825 				 * 4125102 for details of the problem.
7826 				 */
7827 				if (error == EDEADLK) {
7828 					err = error;
7829 					goto out;
7830 				}
7831 				/*
7832 				 * Quit if we fail to fault in the page.  Treat
7833 				 * the failure as an error, unless the addr
7834 				 * is mapped beyond the end of a file.
7835 				 */
7836 				if (error && svd->vp) {
7837 					va.va_mask = AT_SIZE;
7838 					if (VOP_GETATTR(svd->vp, &va, 0,
7839 					    svd->cred, NULL) != 0) {
7840 						err = EIO;
7841 						goto out;
7842 					}
7843 					if (btopr(va.va_size) >=
7844 					    btopr(off + 1)) {
7845 						err = EIO;
7846 						goto out;
7847 					}
7848 					goto out;
7849 
7850 				} else if (error) {
7851 					err = EIO;
7852 					goto out;
7853 				}
7854 				pp = pl[0];
7855 				ASSERT(pp != NULL);
7856 			}
7857 
7858 			/*
7859 			 * See Statement at the beginning of this routine.
7860 			 *
7861 			 * claim is always set if MAP_PRIVATE and PROT_WRITE
7862 			 * irrespective of following factors:
7863 			 *
7864 			 * (1) anon slots are populated or not
7865 			 * (2) cow is broken or not
7866 			 * (3) refcnt on ap is 1 or greater than 1
7867 			 *
7868 			 * See 4140683 for details
7869 			 */
7870 			claim = ((VPP_PROT(vpp) & PROT_WRITE) &&
7871 			    (svd->type == MAP_PRIVATE));
7872 
7873 			/*
7874 			 * Perform page-level operation appropriate to
7875 			 * operation.  If locking, undo the SOFTLOCK
7876 			 * performed to bring the page into memory
7877 			 * after setting the lock.  If unlocking,
7878 			 * and no page was found, account for the claim
7879 			 * separately.
7880 			 */
7881 			if (op == MC_LOCK) {
7882 				int ret = 1;	/* Assume success */
7883 
7884 				ASSERT(!VPP_ISPPLOCK(vpp));
7885 
7886 				ret = page_pp_lock(pp, claim, 0);
7887 				if (ap != NULL) {
7888 					if (ap->an_pvp != NULL) {
7889 						anon_swap_free(ap, pp);
7890 					}
7891 					anon_array_exit(&cookie);
7892 					ANON_LOCK_EXIT(&amp->a_rwlock);
7893 				}
7894 				if (ret == 0) {
7895 					/* locking page failed */
7896 					page_unlock(pp);
7897 					err = EAGAIN;
7898 					goto out;
7899 				}
7900 				VPP_SETPPLOCK(vpp);
7901 				if (sp != NULL) {
7902 					if (pp->p_lckcnt == 1)
7903 						locked_bytes += PAGESIZE;
7904 				} else
7905 					locked_bytes += PAGESIZE;
7906 
7907 				if (lockmap != (ulong_t *)NULL)
7908 					BT_SET(lockmap, pos);
7909 
7910 				page_unlock(pp);
7911 			} else {
7912 				ASSERT(VPP_ISPPLOCK(vpp));
7913 				if (pp != NULL) {
7914 					/* sysV pages should be locked */
7915 					ASSERT(sp == NULL || pp->p_lckcnt > 0);
7916 					page_pp_unlock(pp, claim, 0);
7917 					if (sp != NULL) {
7918 						if (pp->p_lckcnt == 0)
7919 							unlocked_bytes
7920 							    += PAGESIZE;
7921 					} else
7922 						unlocked_bytes += PAGESIZE;
7923 					page_unlock(pp);
7924 				} else {
7925 					ASSERT(sp == NULL);
7926 					unlocked_bytes += PAGESIZE;
7927 				}
7928 				VPP_CLRPPLOCK(vpp);
7929 			}
7930 		}
7931 	}
7932 out:
7933 	if (op == MC_LOCK) {
7934 		/* Credit back bytes that did not get locked */
7935 		if ((unlocked_bytes - locked_bytes) > 0) {
7936 			if (proj == NULL)
7937 				mutex_enter(&p->p_lock);
7938 			rctl_decr_locked_mem(p, proj,
7939 			    (unlocked_bytes - locked_bytes), chargeproc);
7940 			if (proj == NULL)
7941 				mutex_exit(&p->p_lock);
7942 		}
7943 
7944 	} else {
7945 		/* Account bytes that were unlocked */
7946 		if (unlocked_bytes > 0) {
7947 			if (proj == NULL)
7948 				mutex_enter(&p->p_lock);
7949 			rctl_decr_locked_mem(p, proj, unlocked_bytes,
7950 			    chargeproc);
7951 			if (proj == NULL)
7952 				mutex_exit(&p->p_lock);
7953 		}
7954 	}
7955 	if (sp != NULL)
7956 		mutex_exit(&sp->shm_mlock);
7957 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7958 
7959 	return (err);
7960 }
7961 
7962 /*
7963  * Set advice from user for specified pages
7964  * There are 5 types of advice:
7965  *	MADV_NORMAL	- Normal (default) behavior (whatever that is)
7966  *	MADV_RANDOM	- Random page references
7967  *				do not allow readahead or 'klustering'
7968  *	MADV_SEQUENTIAL	- Sequential page references
7969  *				Pages previous to the one currently being
7970  *				accessed (determined by fault) are 'not needed'
7971  *				and are freed immediately
7972  *	MADV_WILLNEED	- Pages are likely to be used (fault ahead in mctl)
7973  *	MADV_DONTNEED	- Pages are not needed (synced out in mctl)
7974  *	MADV_FREE	- Contents can be discarded
7975  *	MADV_ACCESS_DEFAULT- Default access
7976  *	MADV_ACCESS_LWP	- Next LWP will access heavily
7977  *	MADV_ACCESS_MANY- Many LWPs or processes will access heavily
7978  */
7979 static int
7980 segvn_advise(struct seg *seg, caddr_t addr, size_t len, uint_t behav)
7981 {
7982 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7983 	size_t page;
7984 	int err = 0;
7985 	int already_set;
7986 	struct anon_map *amp;
7987 	ulong_t anon_index;
7988 	struct seg *next;
7989 	lgrp_mem_policy_t policy;
7990 	struct seg *prev;
7991 	struct vnode *vp;
7992 
7993 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7994 
7995 	/*
7996 	 * In case of MADV_FREE, we won't be modifying any segment private
7997 	 * data structures; so, we only need to grab READER's lock
7998 	 */
7999 	if (behav != MADV_FREE) {
8000 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
8001 		if (svd->tr_state != SEGVN_TR_OFF) {
8002 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8003 			return (0);
8004 		}
8005 	} else {
8006 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
8007 	}
8008 
8009 	/*
8010 	 * Large pages are assumed to be only turned on when accesses to the
8011 	 * segment's address range have spatial and temporal locality. That
8012 	 * justifies ignoring MADV_SEQUENTIAL for large page segments.
8013 	 * Also, ignore advice affecting lgroup memory allocation
8014 	 * if don't need to do lgroup optimizations on this system
8015 	 */
8016 
8017 	if ((behav == MADV_SEQUENTIAL &&
8018 	    (seg->s_szc != 0 || HAT_IS_REGION_COOKIE_VALID(svd->rcookie))) ||
8019 	    (!lgrp_optimizations() && (behav == MADV_ACCESS_DEFAULT ||
8020 	    behav == MADV_ACCESS_LWP || behav == MADV_ACCESS_MANY))) {
8021 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8022 		return (0);
8023 	}
8024 
8025 	if (behav == MADV_SEQUENTIAL || behav == MADV_ACCESS_DEFAULT ||
8026 	    behav == MADV_ACCESS_LWP || behav == MADV_ACCESS_MANY) {
8027 		/*
8028 		 * Since we are going to unload hat mappings
8029 		 * we first have to flush the cache. Otherwise
8030 		 * this might lead to system panic if another
8031 		 * thread is doing physio on the range whose
8032 		 * mappings are unloaded by madvise(3C).
8033 		 */
8034 		if (svd->softlockcnt > 0) {
8035 			/*
8036 			 * If this is shared segment non 0 softlockcnt
8037 			 * means locked pages are still in use.
8038 			 */
8039 			if (svd->type == MAP_SHARED) {
8040 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8041 				return (EAGAIN);
8042 			}
8043 			/*
8044 			 * Since we do have the segvn writers lock
8045 			 * nobody can fill the cache with entries
8046 			 * belonging to this seg during the purge.
8047 			 * The flush either succeeds or we still
8048 			 * have pending I/Os. In the later case,
8049 			 * madvise(3C) fails.
8050 			 */
8051 			segvn_purge(seg);
8052 			if (svd->softlockcnt > 0) {
8053 				/*
8054 				 * Since madvise(3C) is advisory and
8055 				 * it's not part of UNIX98, madvise(3C)
8056 				 * failure here doesn't cause any hardship.
8057 				 * Note that we don't block in "as" layer.
8058 				 */
8059 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8060 				return (EAGAIN);
8061 			}
8062 		} else if (svd->type == MAP_SHARED && svd->amp != NULL &&
8063 		    svd->amp->a_softlockcnt > 0) {
8064 			/*
8065 			 * Try to purge this amp's entries from pcache. It
8066 			 * will succeed only if other segments that share the
8067 			 * amp have no outstanding softlock's.
8068 			 */
8069 			segvn_purge(seg);
8070 		}
8071 	}
8072 
8073 	amp = svd->amp;
8074 	vp = svd->vp;
8075 	if (behav == MADV_FREE) {
8076 		/*
8077 		 * MADV_FREE is not supported for segments with
8078 		 * underlying object; if anonmap is NULL, anon slots
8079 		 * are not yet populated and there is nothing for
8080 		 * us to do. As MADV_FREE is advisory, we don't
8081 		 * return error in either case.
8082 		 */
8083 		if (vp != NULL || amp == NULL) {
8084 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8085 			return (0);
8086 		}
8087 
8088 		segvn_purge(seg);
8089 
8090 		page = seg_page(seg, addr);
8091 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
8092 		anon_disclaim(amp, svd->anon_index + page, len);
8093 		ANON_LOCK_EXIT(&amp->a_rwlock);
8094 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8095 		return (0);
8096 	}
8097 
8098 	/*
8099 	 * If advice is to be applied to entire segment,
8100 	 * use advice field in seg_data structure
8101 	 * otherwise use appropriate vpage entry.
8102 	 */
8103 	if ((addr == seg->s_base) && (len == seg->s_size)) {
8104 		switch (behav) {
8105 		case MADV_ACCESS_LWP:
8106 		case MADV_ACCESS_MANY:
8107 		case MADV_ACCESS_DEFAULT:
8108 			/*
8109 			 * Set memory allocation policy for this segment
8110 			 */
8111 			policy = lgrp_madv_to_policy(behav, len, svd->type);
8112 			if (svd->type == MAP_SHARED)
8113 				already_set = lgrp_shm_policy_set(policy, amp,
8114 				    svd->anon_index, vp, svd->offset, len);
8115 			else {
8116 				/*
8117 				 * For private memory, need writers lock on
8118 				 * address space because the segment may be
8119 				 * split or concatenated when changing policy
8120 				 */
8121 				if (AS_READ_HELD(seg->s_as,
8122 				    &seg->s_as->a_lock)) {
8123 					SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8124 					return (IE_RETRY);
8125 				}
8126 
8127 				already_set = lgrp_privm_policy_set(policy,
8128 				    &svd->policy_info, len);
8129 			}
8130 
8131 			/*
8132 			 * If policy set already and it shouldn't be reapplied,
8133 			 * don't do anything.
8134 			 */
8135 			if (already_set &&
8136 			    !LGRP_MEM_POLICY_REAPPLICABLE(policy))
8137 				break;
8138 
8139 			/*
8140 			 * Mark any existing pages in given range for
8141 			 * migration
8142 			 */
8143 			page_mark_migrate(seg, addr, len, amp, svd->anon_index,
8144 			    vp, svd->offset, 1);
8145 
8146 			/*
8147 			 * If same policy set already or this is a shared
8148 			 * memory segment, don't need to try to concatenate
8149 			 * segment with adjacent ones.
8150 			 */
8151 			if (already_set || svd->type == MAP_SHARED)
8152 				break;
8153 
8154 			/*
8155 			 * Try to concatenate this segment with previous
8156 			 * one and next one, since we changed policy for
8157 			 * this one and it may be compatible with adjacent
8158 			 * ones now.
8159 			 */
8160 			prev = AS_SEGPREV(seg->s_as, seg);
8161 			next = AS_SEGNEXT(seg->s_as, seg);
8162 
8163 			if (next && next->s_ops == &segvn_ops &&
8164 			    addr + len == next->s_base)
8165 				(void) segvn_concat(seg, next, 1);
8166 
8167 			if (prev && prev->s_ops == &segvn_ops &&
8168 			    addr == prev->s_base + prev->s_size) {
8169 				/*
8170 				 * Drop lock for private data of current
8171 				 * segment before concatenating (deleting) it
8172 				 * and return IE_REATTACH to tell as_ctl() that
8173 				 * current segment has changed
8174 				 */
8175 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8176 				if (!segvn_concat(prev, seg, 1))
8177 					err = IE_REATTACH;
8178 
8179 				return (err);
8180 			}
8181 			break;
8182 
8183 		case MADV_SEQUENTIAL:
8184 			/*
8185 			 * unloading mapping guarantees
8186 			 * detection in segvn_fault
8187 			 */
8188 			ASSERT(seg->s_szc == 0);
8189 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
8190 			hat_unload(seg->s_as->a_hat, addr, len,
8191 			    HAT_UNLOAD);
8192 			/* FALLTHROUGH */
8193 		case MADV_NORMAL:
8194 		case MADV_RANDOM:
8195 			svd->advice = (uchar_t)behav;
8196 			svd->pageadvice = 0;
8197 			break;
8198 		case MADV_WILLNEED:	/* handled in memcntl */
8199 		case MADV_DONTNEED:	/* handled in memcntl */
8200 		case MADV_FREE:		/* handled above */
8201 			break;
8202 		default:
8203 			err = EINVAL;
8204 		}
8205 	} else {
8206 		caddr_t			eaddr;
8207 		struct seg		*new_seg;
8208 		struct segvn_data	*new_svd;
8209 		u_offset_t		off;
8210 		caddr_t			oldeaddr;
8211 
8212 		page = seg_page(seg, addr);
8213 
8214 		segvn_vpage(seg);
8215 
8216 		switch (behav) {
8217 			struct vpage *bvpp, *evpp;
8218 
8219 		case MADV_ACCESS_LWP:
8220 		case MADV_ACCESS_MANY:
8221 		case MADV_ACCESS_DEFAULT:
8222 			/*
8223 			 * Set memory allocation policy for portion of this
8224 			 * segment
8225 			 */
8226 
8227 			/*
8228 			 * Align address and length of advice to page
8229 			 * boundaries for large pages
8230 			 */
8231 			if (seg->s_szc != 0) {
8232 				size_t	pgsz;
8233 
8234 				pgsz = page_get_pagesize(seg->s_szc);
8235 				addr = (caddr_t)P2ALIGN((uintptr_t)addr, pgsz);
8236 				len = P2ROUNDUP(len, pgsz);
8237 			}
8238 
8239 			/*
8240 			 * Check to see whether policy is set already
8241 			 */
8242 			policy = lgrp_madv_to_policy(behav, len, svd->type);
8243 
8244 			anon_index = svd->anon_index + page;
8245 			off = svd->offset + (uintptr_t)(addr - seg->s_base);
8246 
8247 			if (svd->type == MAP_SHARED)
8248 				already_set = lgrp_shm_policy_set(policy, amp,
8249 				    anon_index, vp, off, len);
8250 			else
8251 				already_set =
8252 				    (policy == svd->policy_info.mem_policy);
8253 
8254 			/*
8255 			 * If policy set already and it shouldn't be reapplied,
8256 			 * don't do anything.
8257 			 */
8258 			if (already_set &&
8259 			    !LGRP_MEM_POLICY_REAPPLICABLE(policy))
8260 				break;
8261 
8262 			/*
8263 			 * For private memory, need writers lock on
8264 			 * address space because the segment may be
8265 			 * split or concatenated when changing policy
8266 			 */
8267 			if (svd->type == MAP_PRIVATE &&
8268 			    AS_READ_HELD(seg->s_as, &seg->s_as->a_lock)) {
8269 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8270 				return (IE_RETRY);
8271 			}
8272 
8273 			/*
8274 			 * Mark any existing pages in given range for
8275 			 * migration
8276 			 */
8277 			page_mark_migrate(seg, addr, len, amp, svd->anon_index,
8278 			    vp, svd->offset, 1);
8279 
8280 			/*
8281 			 * Don't need to try to split or concatenate
8282 			 * segments, since policy is same or this is a shared
8283 			 * memory segment
8284 			 */
8285 			if (already_set || svd->type == MAP_SHARED)
8286 				break;
8287 
8288 			if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
8289 				ASSERT(svd->amp == NULL);
8290 				ASSERT(svd->tr_state == SEGVN_TR_OFF);
8291 				ASSERT(svd->softlockcnt == 0);
8292 				hat_leave_region(seg->s_as->a_hat, svd->rcookie,
8293 				    HAT_REGION_TEXT);
8294 				svd->rcookie = HAT_INVALID_REGION_COOKIE;
8295 			}
8296 
8297 			/*
8298 			 * Split off new segment if advice only applies to a
8299 			 * portion of existing segment starting in middle
8300 			 */
8301 			new_seg = NULL;
8302 			eaddr = addr + len;
8303 			oldeaddr = seg->s_base + seg->s_size;
8304 			if (addr > seg->s_base) {
8305 				/*
8306 				 * Must flush I/O page cache
8307 				 * before splitting segment
8308 				 */
8309 				if (svd->softlockcnt > 0)
8310 					segvn_purge(seg);
8311 
8312 				/*
8313 				 * Split segment and return IE_REATTACH to tell
8314 				 * as_ctl() that current segment changed
8315 				 */
8316 				new_seg = segvn_split_seg(seg, addr);
8317 				new_svd = (struct segvn_data *)new_seg->s_data;
8318 				err = IE_REATTACH;
8319 
8320 				/*
8321 				 * If new segment ends where old one
8322 				 * did, try to concatenate the new
8323 				 * segment with next one.
8324 				 */
8325 				if (eaddr == oldeaddr) {
8326 					/*
8327 					 * Set policy for new segment
8328 					 */
8329 					(void) lgrp_privm_policy_set(policy,
8330 					    &new_svd->policy_info,
8331 					    new_seg->s_size);
8332 
8333 					next = AS_SEGNEXT(new_seg->s_as,
8334 					    new_seg);
8335 
8336 					if (next &&
8337 					    next->s_ops == &segvn_ops &&
8338 					    eaddr == next->s_base)
8339 						(void) segvn_concat(new_seg,
8340 						    next, 1);
8341 				}
8342 			}
8343 
8344 			/*
8345 			 * Split off end of existing segment if advice only
8346 			 * applies to a portion of segment ending before
8347 			 * end of the existing segment
8348 			 */
8349 			if (eaddr < oldeaddr) {
8350 				/*
8351 				 * Must flush I/O page cache
8352 				 * before splitting segment
8353 				 */
8354 				if (svd->softlockcnt > 0)
8355 					segvn_purge(seg);
8356 
8357 				/*
8358 				 * If beginning of old segment was already
8359 				 * split off, use new segment to split end off
8360 				 * from.
8361 				 */
8362 				if (new_seg != NULL && new_seg != seg) {
8363 					/*
8364 					 * Split segment
8365 					 */
8366 					(void) segvn_split_seg(new_seg, eaddr);
8367 
8368 					/*
8369 					 * Set policy for new segment
8370 					 */
8371 					(void) lgrp_privm_policy_set(policy,
8372 					    &new_svd->policy_info,
8373 					    new_seg->s_size);
8374 				} else {
8375 					/*
8376 					 * Split segment and return IE_REATTACH
8377 					 * to tell as_ctl() that current
8378 					 * segment changed
8379 					 */
8380 					(void) segvn_split_seg(seg, eaddr);
8381 					err = IE_REATTACH;
8382 
8383 					(void) lgrp_privm_policy_set(policy,
8384 					    &svd->policy_info, seg->s_size);
8385 
8386 					/*
8387 					 * If new segment starts where old one
8388 					 * did, try to concatenate it with
8389 					 * previous segment.
8390 					 */
8391 					if (addr == seg->s_base) {
8392 						prev = AS_SEGPREV(seg->s_as,
8393 						    seg);
8394 
8395 						/*
8396 						 * Drop lock for private data
8397 						 * of current segment before
8398 						 * concatenating (deleting) it
8399 						 */
8400 						if (prev &&
8401 						    prev->s_ops ==
8402 						    &segvn_ops &&
8403 						    addr == prev->s_base +
8404 						    prev->s_size) {
8405 							SEGVN_LOCK_EXIT(
8406 							    seg->s_as,
8407 							    &svd->lock);
8408 							(void) segvn_concat(
8409 							    prev, seg, 1);
8410 							return (err);
8411 						}
8412 					}
8413 				}
8414 			}
8415 			break;
8416 		case MADV_SEQUENTIAL:
8417 			ASSERT(seg->s_szc == 0);
8418 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
8419 			hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD);
8420 			/* FALLTHROUGH */
8421 		case MADV_NORMAL:
8422 		case MADV_RANDOM:
8423 			bvpp = &svd->vpage[page];
8424 			evpp = &svd->vpage[page + (len >> PAGESHIFT)];
8425 			for (; bvpp < evpp; bvpp++)
8426 				VPP_SETADVICE(bvpp, behav);
8427 			svd->advice = MADV_NORMAL;
8428 			break;
8429 		case MADV_WILLNEED:	/* handled in memcntl */
8430 		case MADV_DONTNEED:	/* handled in memcntl */
8431 		case MADV_FREE:		/* handled above */
8432 			break;
8433 		default:
8434 			err = EINVAL;
8435 		}
8436 	}
8437 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8438 	return (err);
8439 }
8440 
8441 /*
8442  * Create a vpage structure for this seg.
8443  */
8444 static void
8445 segvn_vpage(struct seg *seg)
8446 {
8447 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
8448 	struct vpage *vp, *evp;
8449 
8450 	ASSERT(SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
8451 
8452 	/*
8453 	 * If no vpage structure exists, allocate one.  Copy the protections
8454 	 * and the advice from the segment itself to the individual pages.
8455 	 */
8456 	if (svd->vpage == NULL) {
8457 		svd->pageadvice = 1;
8458 		svd->vpage = kmem_zalloc(seg_pages(seg) * sizeof (struct vpage),
8459 		    KM_SLEEP);
8460 		evp = &svd->vpage[seg_page(seg, seg->s_base + seg->s_size)];
8461 		for (vp = svd->vpage; vp < evp; vp++) {
8462 			VPP_SETPROT(vp, svd->prot);
8463 			VPP_SETADVICE(vp, svd->advice);
8464 		}
8465 	}
8466 }
8467 
8468 /*
8469  * Dump the pages belonging to this segvn segment.
8470  */
8471 static void
8472 segvn_dump(struct seg *seg)
8473 {
8474 	struct segvn_data *svd;
8475 	page_t *pp;
8476 	struct anon_map *amp;
8477 	ulong_t	anon_index;
8478 	struct vnode *vp;
8479 	u_offset_t off, offset;
8480 	pfn_t pfn;
8481 	pgcnt_t page, npages;
8482 	caddr_t addr;
8483 
8484 	npages = seg_pages(seg);
8485 	svd = (struct segvn_data *)seg->s_data;
8486 	vp = svd->vp;
8487 	off = offset = svd->offset;
8488 	addr = seg->s_base;
8489 
8490 	if ((amp = svd->amp) != NULL) {
8491 		anon_index = svd->anon_index;
8492 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
8493 	}
8494 
8495 	for (page = 0; page < npages; page++, offset += PAGESIZE) {
8496 		struct anon *ap;
8497 		int we_own_it = 0;
8498 
8499 		if (amp && (ap = anon_get_ptr(svd->amp->ahp, anon_index++))) {
8500 			swap_xlate_nopanic(ap, &vp, &off);
8501 		} else {
8502 			vp = svd->vp;
8503 			off = offset;
8504 		}
8505 
8506 		/*
8507 		 * If pp == NULL, the page either does not exist
8508 		 * or is exclusively locked.  So determine if it
8509 		 * exists before searching for it.
8510 		 */
8511 
8512 		if ((pp = page_lookup_nowait(vp, off, SE_SHARED)))
8513 			we_own_it = 1;
8514 		else
8515 			pp = page_exists(vp, off);
8516 
8517 		if (pp) {
8518 			pfn = page_pptonum(pp);
8519 			dump_addpage(seg->s_as, addr, pfn);
8520 			if (we_own_it)
8521 				page_unlock(pp);
8522 		}
8523 		addr += PAGESIZE;
8524 		dump_timeleft = dump_timeout;
8525 	}
8526 
8527 	if (amp != NULL)
8528 		ANON_LOCK_EXIT(&amp->a_rwlock);
8529 }
8530 
8531 #ifdef DEBUG
8532 static uint32_t segvn_pglock_mtbf = 0;
8533 #endif
8534 
8535 #define	PCACHE_SHWLIST		((page_t *)-2)
8536 #define	NOPCACHE_SHWLIST	((page_t *)-1)
8537 
8538 /*
8539  * Lock/Unlock anon pages over a given range. Return shadow list. This routine
8540  * uses global segment pcache to cache shadow lists (i.e. pp arrays) of pages
8541  * to avoid the overhead of per page locking, unlocking for subsequent IOs to
8542  * the same parts of the segment. Currently shadow list creation is only
8543  * supported for pure anon segments. MAP_PRIVATE segment pcache entries are
8544  * tagged with segment pointer, starting virtual address and length. This
8545  * approach for MAP_SHARED segments may add many pcache entries for the same
8546  * set of pages and lead to long hash chains that decrease pcache lookup
8547  * performance. To avoid this issue for shared segments shared anon map and
8548  * starting anon index are used for pcache entry tagging. This allows all
8549  * segments to share pcache entries for the same anon range and reduces pcache
8550  * chain's length as well as memory overhead from duplicate shadow lists and
8551  * pcache entries.
8552  *
8553  * softlockcnt field in segvn_data structure counts the number of F_SOFTLOCK'd
8554  * pages via segvn_fault() and pagelock'd pages via this routine. But pagelock
8555  * part of softlockcnt accounting is done differently for private and shared
8556  * segments. In private segment case softlock is only incremented when a new
8557  * shadow list is created but not when an existing one is found via
8558  * seg_plookup(). pcache entries have reference count incremented/decremented
8559  * by each seg_plookup()/seg_pinactive() operation. Only entries that have 0
8560  * reference count can be purged (and purging is needed before segment can be
8561  * freed). When a private segment pcache entry is purged segvn_reclaim() will
8562  * decrement softlockcnt. Since in private segment case each of its pcache
8563  * entries only belongs to this segment we can expect that when
8564  * segvn_pagelock(L_PAGEUNLOCK) was called for all outstanding IOs in this
8565  * segment purge will succeed and softlockcnt will drop to 0. In shared
8566  * segment case reference count in pcache entry counts active locks from many
8567  * different segments so we can't expect segment purging to succeed even when
8568  * segvn_pagelock(L_PAGEUNLOCK) was called for all outstanding IOs in this
8569  * segment. To be able to determine when there're no pending pagelocks in
8570  * shared segment case we don't rely on purging to make softlockcnt drop to 0
8571  * but instead softlockcnt is incremented and decremented for every
8572  * segvn_pagelock(L_PAGELOCK/L_PAGEUNLOCK) call regardless if a new shadow
8573  * list was created or an existing one was found. When softlockcnt drops to 0
8574  * this segment no longer has any claims for pcached shadow lists and the
8575  * segment can be freed even if there're still active pcache entries
8576  * shared by this segment anon map. Shared segment pcache entries belong to
8577  * anon map and are typically removed when anon map is freed after all
8578  * processes destroy the segments that use this anon map.
8579  */
8580 static int
8581 segvn_pagelock(struct seg *seg, caddr_t addr, size_t len, struct page ***ppp,
8582     enum lock_type type, enum seg_rw rw)
8583 {
8584 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
8585 	size_t np;
8586 	pgcnt_t adjustpages;
8587 	pgcnt_t npages;
8588 	ulong_t anon_index;
8589 	uint_t protchk = (rw == S_READ) ? PROT_READ : PROT_WRITE;
8590 	uint_t error;
8591 	struct anon_map *amp;
8592 	pgcnt_t anpgcnt;
8593 	struct page **pplist, **pl, *pp;
8594 	caddr_t a;
8595 	size_t page;
8596 	caddr_t lpgaddr, lpgeaddr;
8597 	anon_sync_obj_t cookie;
8598 	int anlock;
8599 	struct anon_map *pamp;
8600 	caddr_t paddr;
8601 	seg_preclaim_cbfunc_t preclaim_callback;
8602 	size_t pgsz;
8603 	int use_pcache;
8604 	size_t wlen;
8605 	uint_t pflags = 0;
8606 	int sftlck_sbase = 0;
8607 	int sftlck_send = 0;
8608 
8609 #ifdef DEBUG
8610 	if (type == L_PAGELOCK && segvn_pglock_mtbf) {
8611 		hrtime_t ts = gethrtime();
8612 		if ((ts % segvn_pglock_mtbf) == 0) {
8613 			return (ENOTSUP);
8614 		}
8615 		if ((ts % segvn_pglock_mtbf) == 1) {
8616 			return (EFAULT);
8617 		}
8618 	}
8619 #endif
8620 
8621 	TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_START,
8622 	    "segvn_pagelock: start seg %p addr %p", seg, addr);
8623 
8624 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
8625 	ASSERT(type == L_PAGELOCK || type == L_PAGEUNLOCK);
8626 
8627 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
8628 
8629 	/*
8630 	 * for now we only support pagelock to anon memory. We would have to
8631 	 * check protections for vnode objects and call into the vnode driver.
8632 	 * That's too much for a fast path. Let the fault entry point handle
8633 	 * it.
8634 	 */
8635 	if (svd->vp != NULL) {
8636 		if (type == L_PAGELOCK) {
8637 			error = ENOTSUP;
8638 			goto out;
8639 		}
8640 		panic("segvn_pagelock(L_PAGEUNLOCK): vp != NULL");
8641 	}
8642 	if ((amp = svd->amp) == NULL) {
8643 		if (type == L_PAGELOCK) {
8644 			error = EFAULT;
8645 			goto out;
8646 		}
8647 		panic("segvn_pagelock(L_PAGEUNLOCK): amp == NULL");
8648 	}
8649 	if (rw != S_READ && rw != S_WRITE) {
8650 		if (type == L_PAGELOCK) {
8651 			error = ENOTSUP;
8652 			goto out;
8653 		}
8654 		panic("segvn_pagelock(L_PAGEUNLOCK): bad rw");
8655 	}
8656 
8657 	if (seg->s_szc != 0) {
8658 		/*
8659 		 * We are adjusting the pagelock region to the large page size
8660 		 * boundary because the unlocked part of a large page cannot
8661 		 * be freed anyway unless all constituent pages of a large
8662 		 * page are locked. Bigger regions reduce pcache chain length
8663 		 * and improve lookup performance. The tradeoff is that the
8664 		 * very first segvn_pagelock() call for a given page is more
8665 		 * expensive if only 1 page_t is needed for IO. This is only
8666 		 * an issue if pcache entry doesn't get reused by several
8667 		 * subsequent calls. We optimize here for the case when pcache
8668 		 * is heavily used by repeated IOs to the same address range.
8669 		 *
8670 		 * Note segment's page size cannot change while we are holding
8671 		 * as lock.  And then it cannot change while softlockcnt is
8672 		 * not 0. This will allow us to correctly recalculate large
8673 		 * page size region for the matching pageunlock/reclaim call
8674 		 * since as_pageunlock() caller must always match
8675 		 * as_pagelock() call's addr and len.
8676 		 *
8677 		 * For pageunlock *ppp points to the pointer of page_t that
8678 		 * corresponds to the real unadjusted start address. Similar
8679 		 * for pagelock *ppp must point to the pointer of page_t that
8680 		 * corresponds to the real unadjusted start address.
8681 		 */
8682 		pgsz = page_get_pagesize(seg->s_szc);
8683 		CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
8684 		adjustpages = btop((uintptr_t)(addr - lpgaddr));
8685 	} else if (len < segvn_pglock_comb_thrshld) {
8686 		lpgaddr = addr;
8687 		lpgeaddr = addr + len;
8688 		adjustpages = 0;
8689 		pgsz = PAGESIZE;
8690 	} else {
8691 		/*
8692 		 * Align the address range of large enough requests to allow
8693 		 * combining of different shadow lists into 1 to reduce memory
8694 		 * overhead from potentially overlapping large shadow lists
8695 		 * (worst case is we have a 1MB IO into buffers with start
8696 		 * addresses separated by 4K).  Alignment is only possible if
8697 		 * padded chunks have sufficient access permissions. Note
8698 		 * permissions won't change between L_PAGELOCK and
8699 		 * L_PAGEUNLOCK calls since non 0 softlockcnt will force
8700 		 * segvn_setprot() to wait until softlockcnt drops to 0. This
8701 		 * allows us to determine in L_PAGEUNLOCK the same range we
8702 		 * computed in L_PAGELOCK.
8703 		 *
8704 		 * If alignment is limited by segment ends set
8705 		 * sftlck_sbase/sftlck_send flags. In L_PAGELOCK case when
8706 		 * these flags are set bump softlockcnt_sbase/softlockcnt_send
8707 		 * per segment counters. In L_PAGEUNLOCK case decrease
8708 		 * softlockcnt_sbase/softlockcnt_send counters if
8709 		 * sftlck_sbase/sftlck_send flags are set.  When
8710 		 * softlockcnt_sbase/softlockcnt_send are non 0
8711 		 * segvn_concat()/segvn_extend_prev()/segvn_extend_next()
8712 		 * won't merge the segments. This restriction combined with
8713 		 * restriction on segment unmapping and splitting for segments
8714 		 * that have non 0 softlockcnt allows L_PAGEUNLOCK to
8715 		 * correctly determine the same range that was previously
8716 		 * locked by matching L_PAGELOCK.
8717 		 */
8718 		pflags = SEGP_PSHIFT | (segvn_pglock_comb_bshift << 16);
8719 		pgsz = PAGESIZE;
8720 		if (svd->type == MAP_PRIVATE) {
8721 			lpgaddr = (caddr_t)P2ALIGN((uintptr_t)addr,
8722 			    segvn_pglock_comb_balign);
8723 			if (lpgaddr < seg->s_base) {
8724 				lpgaddr = seg->s_base;
8725 				sftlck_sbase = 1;
8726 			}
8727 		} else {
8728 			ulong_t aix = svd->anon_index + seg_page(seg, addr);
8729 			ulong_t aaix = P2ALIGN(aix, segvn_pglock_comb_palign);
8730 			if (aaix < svd->anon_index) {
8731 				lpgaddr = seg->s_base;
8732 				sftlck_sbase = 1;
8733 			} else {
8734 				lpgaddr = addr - ptob(aix - aaix);
8735 				ASSERT(lpgaddr >= seg->s_base);
8736 			}
8737 		}
8738 		if (svd->pageprot && lpgaddr != addr) {
8739 			struct vpage *vp = &svd->vpage[seg_page(seg, lpgaddr)];
8740 			struct vpage *evp = &svd->vpage[seg_page(seg, addr)];
8741 			while (vp < evp) {
8742 				if ((VPP_PROT(vp) & protchk) == 0) {
8743 					break;
8744 				}
8745 				vp++;
8746 			}
8747 			if (vp < evp) {
8748 				lpgaddr = addr;
8749 				pflags = 0;
8750 			}
8751 		}
8752 		lpgeaddr = addr + len;
8753 		if (pflags) {
8754 			if (svd->type == MAP_PRIVATE) {
8755 				lpgeaddr = (caddr_t)P2ROUNDUP(
8756 				    (uintptr_t)lpgeaddr,
8757 				    segvn_pglock_comb_balign);
8758 			} else {
8759 				ulong_t aix = svd->anon_index +
8760 				    seg_page(seg, lpgeaddr);
8761 				ulong_t aaix = P2ROUNDUP(aix,
8762 				    segvn_pglock_comb_palign);
8763 				if (aaix < aix) {
8764 					lpgeaddr = 0;
8765 				} else {
8766 					lpgeaddr += ptob(aaix - aix);
8767 				}
8768 			}
8769 			if (lpgeaddr == 0 ||
8770 			    lpgeaddr > seg->s_base + seg->s_size) {
8771 				lpgeaddr = seg->s_base + seg->s_size;
8772 				sftlck_send = 1;
8773 			}
8774 		}
8775 		if (svd->pageprot && lpgeaddr != addr + len) {
8776 			struct vpage *vp;
8777 			struct vpage *evp;
8778 
8779 			vp = &svd->vpage[seg_page(seg, addr + len)];
8780 			evp = &svd->vpage[seg_page(seg, lpgeaddr)];
8781 
8782 			while (vp < evp) {
8783 				if ((VPP_PROT(vp) & protchk) == 0) {
8784 					break;
8785 				}
8786 				vp++;
8787 			}
8788 			if (vp < evp) {
8789 				lpgeaddr = addr + len;
8790 			}
8791 		}
8792 		adjustpages = btop((uintptr_t)(addr - lpgaddr));
8793 	}
8794 
8795 	/*
8796 	 * For MAP_SHARED segments we create pcache entries tagged by amp and
8797 	 * anon index so that we can share pcache entries with other segments
8798 	 * that map this amp.  For private segments pcache entries are tagged
8799 	 * with segment and virtual address.
8800 	 */
8801 	if (svd->type == MAP_SHARED) {
8802 		pamp = amp;
8803 		paddr = (caddr_t)((lpgaddr - seg->s_base) +
8804 		    ptob(svd->anon_index));
8805 		preclaim_callback = shamp_reclaim;
8806 	} else {
8807 		pamp = NULL;
8808 		paddr = lpgaddr;
8809 		preclaim_callback = segvn_reclaim;
8810 	}
8811 
8812 	if (type == L_PAGEUNLOCK) {
8813 		VM_STAT_ADD(segvnvmstats.pagelock[0]);
8814 
8815 		/*
8816 		 * update hat ref bits for /proc. We need to make sure
8817 		 * that threads tracing the ref and mod bits of the
8818 		 * address space get the right data.
8819 		 * Note: page ref and mod bits are updated at reclaim time
8820 		 */
8821 		if (seg->s_as->a_vbits) {
8822 			for (a = addr; a < addr + len; a += PAGESIZE) {
8823 				if (rw == S_WRITE) {
8824 					hat_setstat(seg->s_as, a,
8825 					    PAGESIZE, P_REF | P_MOD);
8826 				} else {
8827 					hat_setstat(seg->s_as, a,
8828 					    PAGESIZE, P_REF);
8829 				}
8830 			}
8831 		}
8832 
8833 		/*
8834 		 * Check the shadow list entry after the last page used in
8835 		 * this IO request. If it's NOPCACHE_SHWLIST the shadow list
8836 		 * was not inserted into pcache and is not large page
8837 		 * adjusted.  In this case call reclaim callback directly and
8838 		 * don't adjust the shadow list start and size for large
8839 		 * pages.
8840 		 */
8841 		npages = btop(len);
8842 		if ((*ppp)[npages] == NOPCACHE_SHWLIST) {
8843 			void *ptag;
8844 			if (pamp != NULL) {
8845 				ASSERT(svd->type == MAP_SHARED);
8846 				ptag = (void *)pamp;
8847 				paddr = (caddr_t)((addr - seg->s_base) +
8848 				    ptob(svd->anon_index));
8849 			} else {
8850 				ptag = (void *)seg;
8851 				paddr = addr;
8852 			}
8853 			(*preclaim_callback)(ptag, paddr, len, *ppp, rw, 0);
8854 		} else {
8855 			ASSERT((*ppp)[npages] == PCACHE_SHWLIST ||
8856 			    IS_SWAPFSVP((*ppp)[npages]->p_vnode));
8857 			len = lpgeaddr - lpgaddr;
8858 			npages = btop(len);
8859 			seg_pinactive(seg, pamp, paddr, len,
8860 			    *ppp - adjustpages, rw, pflags, preclaim_callback);
8861 		}
8862 
8863 		if (pamp != NULL) {
8864 			ASSERT(svd->type == MAP_SHARED);
8865 			ASSERT(svd->softlockcnt >= npages);
8866 			atomic_add_long((ulong_t *)&svd->softlockcnt, -npages);
8867 		}
8868 
8869 		if (sftlck_sbase) {
8870 			ASSERT(svd->softlockcnt_sbase > 0);
8871 			atomic_add_long((ulong_t *)&svd->softlockcnt_sbase, -1);
8872 		}
8873 		if (sftlck_send) {
8874 			ASSERT(svd->softlockcnt_send > 0);
8875 			atomic_add_long((ulong_t *)&svd->softlockcnt_send, -1);
8876 		}
8877 
8878 		/*
8879 		 * If someone is blocked while unmapping, we purge
8880 		 * segment page cache and thus reclaim pplist synchronously
8881 		 * without waiting for seg_pasync_thread. This speeds up
8882 		 * unmapping in cases where munmap(2) is called, while
8883 		 * raw async i/o is still in progress or where a thread
8884 		 * exits on data fault in a multithreaded application.
8885 		 */
8886 		if (AS_ISUNMAPWAIT(seg->s_as)) {
8887 			if (svd->softlockcnt == 0) {
8888 				mutex_enter(&seg->s_as->a_contents);
8889 				if (AS_ISUNMAPWAIT(seg->s_as)) {
8890 					AS_CLRUNMAPWAIT(seg->s_as);
8891 					cv_broadcast(&seg->s_as->a_cv);
8892 				}
8893 				mutex_exit(&seg->s_as->a_contents);
8894 			} else if (pamp == NULL) {
8895 				/*
8896 				 * softlockcnt is not 0 and this is a
8897 				 * MAP_PRIVATE segment. Try to purge its
8898 				 * pcache entries to reduce softlockcnt.
8899 				 * If it drops to 0 segvn_reclaim()
8900 				 * will wake up a thread waiting on
8901 				 * unmapwait flag.
8902 				 *
8903 				 * We don't purge MAP_SHARED segments with non
8904 				 * 0 softlockcnt since IO is still in progress
8905 				 * for such segments.
8906 				 */
8907 				ASSERT(svd->type == MAP_PRIVATE);
8908 				segvn_purge(seg);
8909 			}
8910 		}
8911 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8912 		TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_UNLOCK_END,
8913 		    "segvn_pagelock: unlock seg %p addr %p", seg, addr);
8914 		return (0);
8915 	}
8916 
8917 	/* The L_PAGELOCK case ... */
8918 
8919 	VM_STAT_ADD(segvnvmstats.pagelock[1]);
8920 
8921 	/*
8922 	 * For MAP_SHARED segments we have to check protections before
8923 	 * seg_plookup() since pcache entries may be shared by many segments
8924 	 * with potentially different page protections.
8925 	 */
8926 	if (pamp != NULL) {
8927 		ASSERT(svd->type == MAP_SHARED);
8928 		if (svd->pageprot == 0) {
8929 			if ((svd->prot & protchk) == 0) {
8930 				error = EACCES;
8931 				goto out;
8932 			}
8933 		} else {
8934 			/*
8935 			 * check page protections
8936 			 */
8937 			caddr_t ea;
8938 
8939 			if (seg->s_szc) {
8940 				a = lpgaddr;
8941 				ea = lpgeaddr;
8942 			} else {
8943 				a = addr;
8944 				ea = addr + len;
8945 			}
8946 			for (; a < ea; a += pgsz) {
8947 				struct vpage *vp;
8948 
8949 				ASSERT(seg->s_szc == 0 ||
8950 				    sameprot(seg, a, pgsz));
8951 				vp = &svd->vpage[seg_page(seg, a)];
8952 				if ((VPP_PROT(vp) & protchk) == 0) {
8953 					error = EACCES;
8954 					goto out;
8955 				}
8956 			}
8957 		}
8958 	}
8959 
8960 	/*
8961 	 * try to find pages in segment page cache
8962 	 */
8963 	pplist = seg_plookup(seg, pamp, paddr, lpgeaddr - lpgaddr, rw, pflags);
8964 	if (pplist != NULL) {
8965 		if (pamp != NULL) {
8966 			npages = btop((uintptr_t)(lpgeaddr - lpgaddr));
8967 			ASSERT(svd->type == MAP_SHARED);
8968 			atomic_add_long((ulong_t *)&svd->softlockcnt,
8969 			    npages);
8970 		}
8971 		if (sftlck_sbase) {
8972 			atomic_add_long((ulong_t *)&svd->softlockcnt_sbase, 1);
8973 		}
8974 		if (sftlck_send) {
8975 			atomic_add_long((ulong_t *)&svd->softlockcnt_send, 1);
8976 		}
8977 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8978 		*ppp = pplist + adjustpages;
8979 		TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_HIT_END,
8980 		    "segvn_pagelock: cache hit seg %p addr %p", seg, addr);
8981 		return (0);
8982 	}
8983 
8984 	/*
8985 	 * For MAP_SHARED segments we already verified above that segment
8986 	 * protections allow this pagelock operation.
8987 	 */
8988 	if (pamp == NULL) {
8989 		ASSERT(svd->type == MAP_PRIVATE);
8990 		if (svd->pageprot == 0) {
8991 			if ((svd->prot & protchk) == 0) {
8992 				error = EACCES;
8993 				goto out;
8994 			}
8995 			if (svd->prot & PROT_WRITE) {
8996 				wlen = lpgeaddr - lpgaddr;
8997 			} else {
8998 				wlen = 0;
8999 				ASSERT(rw == S_READ);
9000 			}
9001 		} else {
9002 			int wcont = 1;
9003 			/*
9004 			 * check page protections
9005 			 */
9006 			for (a = lpgaddr, wlen = 0; a < lpgeaddr; a += pgsz) {
9007 				struct vpage *vp;
9008 
9009 				ASSERT(seg->s_szc == 0 ||
9010 				    sameprot(seg, a, pgsz));
9011 				vp = &svd->vpage[seg_page(seg, a)];
9012 				if ((VPP_PROT(vp) & protchk) == 0) {
9013 					error = EACCES;
9014 					goto out;
9015 				}
9016 				if (wcont && (VPP_PROT(vp) & PROT_WRITE)) {
9017 					wlen += pgsz;
9018 				} else {
9019 					wcont = 0;
9020 					ASSERT(rw == S_READ);
9021 				}
9022 			}
9023 		}
9024 		ASSERT(rw == S_READ || wlen == lpgeaddr - lpgaddr);
9025 		ASSERT(rw == S_WRITE || wlen <= lpgeaddr - lpgaddr);
9026 	}
9027 
9028 	/*
9029 	 * Only build large page adjusted shadow list if we expect to insert
9030 	 * it into pcache. For large enough pages it's a big overhead to
9031 	 * create a shadow list of the entire large page. But this overhead
9032 	 * should be amortized over repeated pcache hits on subsequent reuse
9033 	 * of this shadow list (IO into any range within this shadow list will
9034 	 * find it in pcache since we large page align the request for pcache
9035 	 * lookups). pcache performance is improved with bigger shadow lists
9036 	 * as it reduces the time to pcache the entire big segment and reduces
9037 	 * pcache chain length.
9038 	 */
9039 	if (seg_pinsert_check(seg, pamp, paddr,
9040 	    lpgeaddr - lpgaddr, pflags) == SEGP_SUCCESS) {
9041 		addr = lpgaddr;
9042 		len = lpgeaddr - lpgaddr;
9043 		use_pcache = 1;
9044 	} else {
9045 		use_pcache = 0;
9046 		/*
9047 		 * Since this entry will not be inserted into the pcache, we
9048 		 * will not do any adjustments to the starting address or
9049 		 * size of the memory to be locked.
9050 		 */
9051 		adjustpages = 0;
9052 	}
9053 	npages = btop(len);
9054 
9055 	pplist = kmem_alloc(sizeof (page_t *) * (npages + 1), KM_SLEEP);
9056 	pl = pplist;
9057 	*ppp = pplist + adjustpages;
9058 	/*
9059 	 * If use_pcache is 0 this shadow list is not large page adjusted.
9060 	 * Record this info in the last entry of shadow array so that
9061 	 * L_PAGEUNLOCK can determine if it should large page adjust the
9062 	 * address range to find the real range that was locked.
9063 	 */
9064 	pl[npages] = use_pcache ? PCACHE_SHWLIST : NOPCACHE_SHWLIST;
9065 
9066 	page = seg_page(seg, addr);
9067 	anon_index = svd->anon_index + page;
9068 
9069 	anlock = 0;
9070 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
9071 	ASSERT(amp->a_szc >= seg->s_szc);
9072 	anpgcnt = page_get_pagecnt(amp->a_szc);
9073 	for (a = addr; a < addr + len; a += PAGESIZE, anon_index++) {
9074 		struct anon *ap;
9075 		struct vnode *vp;
9076 		u_offset_t off;
9077 
9078 		/*
9079 		 * Lock and unlock anon array only once per large page.
9080 		 * anon_array_enter() locks the root anon slot according to
9081 		 * a_szc which can't change while anon map is locked.  We lock
9082 		 * anon the first time through this loop and each time we
9083 		 * reach anon index that corresponds to a root of a large
9084 		 * page.
9085 		 */
9086 		if (a == addr || P2PHASE(anon_index, anpgcnt) == 0) {
9087 			ASSERT(anlock == 0);
9088 			anon_array_enter(amp, anon_index, &cookie);
9089 			anlock = 1;
9090 		}
9091 		ap = anon_get_ptr(amp->ahp, anon_index);
9092 
9093 		/*
9094 		 * We must never use seg_pcache for COW pages
9095 		 * because we might end up with original page still
9096 		 * lying in seg_pcache even after private page is
9097 		 * created. This leads to data corruption as
9098 		 * aio_write refers to the page still in cache
9099 		 * while all other accesses refer to the private
9100 		 * page.
9101 		 */
9102 		if (ap == NULL || ap->an_refcnt != 1) {
9103 			struct vpage *vpage;
9104 
9105 			if (seg->s_szc) {
9106 				error = EFAULT;
9107 				break;
9108 			}
9109 			if (svd->vpage != NULL) {
9110 				vpage = &svd->vpage[seg_page(seg, a)];
9111 			} else {
9112 				vpage = NULL;
9113 			}
9114 			ASSERT(anlock);
9115 			anon_array_exit(&cookie);
9116 			anlock = 0;
9117 			pp = NULL;
9118 			error = segvn_faultpage(seg->s_as->a_hat, seg, a, 0,
9119 			    vpage, &pp, 0, F_INVAL, rw, 1);
9120 			if (error) {
9121 				error = fc_decode(error);
9122 				break;
9123 			}
9124 			anon_array_enter(amp, anon_index, &cookie);
9125 			anlock = 1;
9126 			ap = anon_get_ptr(amp->ahp, anon_index);
9127 			if (ap == NULL || ap->an_refcnt != 1) {
9128 				error = EFAULT;
9129 				break;
9130 			}
9131 		}
9132 		swap_xlate(ap, &vp, &off);
9133 		pp = page_lookup_nowait(vp, off, SE_SHARED);
9134 		if (pp == NULL) {
9135 			error = EFAULT;
9136 			break;
9137 		}
9138 		if (ap->an_pvp != NULL) {
9139 			anon_swap_free(ap, pp);
9140 		}
9141 		/*
9142 		 * Unlock anon if this is the last slot in a large page.
9143 		 */
9144 		if (P2PHASE(anon_index, anpgcnt) == anpgcnt - 1) {
9145 			ASSERT(anlock);
9146 			anon_array_exit(&cookie);
9147 			anlock = 0;
9148 		}
9149 		*pplist++ = pp;
9150 	}
9151 	if (anlock) {		/* Ensure the lock is dropped */
9152 		anon_array_exit(&cookie);
9153 	}
9154 	ANON_LOCK_EXIT(&amp->a_rwlock);
9155 
9156 	if (a >= addr + len) {
9157 		atomic_add_long((ulong_t *)&svd->softlockcnt, npages);
9158 		if (pamp != NULL) {
9159 			ASSERT(svd->type == MAP_SHARED);
9160 			atomic_add_long((ulong_t *)&pamp->a_softlockcnt,
9161 			    npages);
9162 			wlen = len;
9163 		}
9164 		if (sftlck_sbase) {
9165 			atomic_add_long((ulong_t *)&svd->softlockcnt_sbase, 1);
9166 		}
9167 		if (sftlck_send) {
9168 			atomic_add_long((ulong_t *)&svd->softlockcnt_send, 1);
9169 		}
9170 		if (use_pcache) {
9171 			(void) seg_pinsert(seg, pamp, paddr, len, wlen, pl,
9172 			    rw, pflags, preclaim_callback);
9173 		}
9174 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9175 		TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_FILL_END,
9176 		    "segvn_pagelock: cache fill seg %p addr %p", seg, addr);
9177 		return (0);
9178 	}
9179 
9180 	pplist = pl;
9181 	np = ((uintptr_t)(a - addr)) >> PAGESHIFT;
9182 	while (np > (uint_t)0) {
9183 		ASSERT(PAGE_LOCKED(*pplist));
9184 		page_unlock(*pplist);
9185 		np--;
9186 		pplist++;
9187 	}
9188 	kmem_free(pl, sizeof (page_t *) * (npages + 1));
9189 out:
9190 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9191 	*ppp = NULL;
9192 	TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_MISS_END,
9193 	    "segvn_pagelock: cache miss seg %p addr %p", seg, addr);
9194 	return (error);
9195 }
9196 
9197 /*
9198  * purge any cached pages in the I/O page cache
9199  */
9200 static void
9201 segvn_purge(struct seg *seg)
9202 {
9203 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9204 
9205 	/*
9206 	 * pcache is only used by pure anon segments.
9207 	 */
9208 	if (svd->amp == NULL || svd->vp != NULL) {
9209 		return;
9210 	}
9211 
9212 	/*
9213 	 * For MAP_SHARED segments non 0 segment's softlockcnt means
9214 	 * active IO is still in progress via this segment. So we only
9215 	 * purge MAP_SHARED segments when their softlockcnt is 0.
9216 	 */
9217 	if (svd->type == MAP_PRIVATE) {
9218 		if (svd->softlockcnt) {
9219 			seg_ppurge(seg, NULL, 0);
9220 		}
9221 	} else if (svd->softlockcnt == 0 && svd->amp->a_softlockcnt != 0) {
9222 		seg_ppurge(seg, svd->amp, 0);
9223 	}
9224 }
9225 
9226 /*
9227  * If async argument is not 0 we are called from pcache async thread and don't
9228  * hold AS lock.
9229  */
9230 
9231 /*ARGSUSED*/
9232 static int
9233 segvn_reclaim(void *ptag, caddr_t addr, size_t len, struct page **pplist,
9234 	enum seg_rw rw, int async)
9235 {
9236 	struct seg *seg = (struct seg *)ptag;
9237 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9238 	pgcnt_t np, npages;
9239 	struct page **pl;
9240 
9241 	npages = np = btop(len);
9242 	ASSERT(npages);
9243 
9244 	ASSERT(svd->vp == NULL && svd->amp != NULL);
9245 	ASSERT(svd->softlockcnt >= npages);
9246 	ASSERT(async || AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
9247 
9248 	pl = pplist;
9249 
9250 	ASSERT(pl[np] == NOPCACHE_SHWLIST || pl[np] == PCACHE_SHWLIST);
9251 	ASSERT(!async || pl[np] == PCACHE_SHWLIST);
9252 
9253 	while (np > (uint_t)0) {
9254 		if (rw == S_WRITE) {
9255 			hat_setrefmod(*pplist);
9256 		} else {
9257 			hat_setref(*pplist);
9258 		}
9259 		page_unlock(*pplist);
9260 		np--;
9261 		pplist++;
9262 	}
9263 
9264 	kmem_free(pl, sizeof (page_t *) * (npages + 1));
9265 
9266 	/*
9267 	 * If we are pcache async thread we don't hold AS lock. This means if
9268 	 * softlockcnt drops to 0 after the decrement below address space may
9269 	 * get freed. We can't allow it since after softlock derement to 0 we
9270 	 * still need to access as structure for possible wakeup of unmap
9271 	 * waiters. To prevent the disappearance of as we take this segment
9272 	 * segfree_syncmtx. segvn_free() also takes this mutex as a barrier to
9273 	 * make sure this routine completes before segment is freed.
9274 	 *
9275 	 * The second complication we have to deal with in async case is a
9276 	 * possibility of missed wake up of unmap wait thread. When we don't
9277 	 * hold as lock here we may take a_contents lock before unmap wait
9278 	 * thread that was first to see softlockcnt was still not 0. As a
9279 	 * result we'll fail to wake up an unmap wait thread. To avoid this
9280 	 * race we set nounmapwait flag in as structure if we drop softlockcnt
9281 	 * to 0 when we were called by pcache async thread.  unmapwait thread
9282 	 * will not block if this flag is set.
9283 	 */
9284 	if (async) {
9285 		mutex_enter(&svd->segfree_syncmtx);
9286 	}
9287 
9288 	if (!atomic_add_long_nv((ulong_t *)&svd->softlockcnt, -npages)) {
9289 		if (async || AS_ISUNMAPWAIT(seg->s_as)) {
9290 			mutex_enter(&seg->s_as->a_contents);
9291 			if (async) {
9292 				AS_SETNOUNMAPWAIT(seg->s_as);
9293 			}
9294 			if (AS_ISUNMAPWAIT(seg->s_as)) {
9295 				AS_CLRUNMAPWAIT(seg->s_as);
9296 				cv_broadcast(&seg->s_as->a_cv);
9297 			}
9298 			mutex_exit(&seg->s_as->a_contents);
9299 		}
9300 	}
9301 
9302 	if (async) {
9303 		mutex_exit(&svd->segfree_syncmtx);
9304 	}
9305 	return (0);
9306 }
9307 
9308 /*ARGSUSED*/
9309 static int
9310 shamp_reclaim(void *ptag, caddr_t addr, size_t len, struct page **pplist,
9311 	enum seg_rw rw, int async)
9312 {
9313 	amp_t *amp = (amp_t *)ptag;
9314 	pgcnt_t np, npages;
9315 	struct page **pl;
9316 
9317 	npages = np = btop(len);
9318 	ASSERT(npages);
9319 	ASSERT(amp->a_softlockcnt >= npages);
9320 
9321 	pl = pplist;
9322 
9323 	ASSERT(pl[np] == NOPCACHE_SHWLIST || pl[np] == PCACHE_SHWLIST);
9324 	ASSERT(!async || pl[np] == PCACHE_SHWLIST);
9325 
9326 	while (np > (uint_t)0) {
9327 		if (rw == S_WRITE) {
9328 			hat_setrefmod(*pplist);
9329 		} else {
9330 			hat_setref(*pplist);
9331 		}
9332 		page_unlock(*pplist);
9333 		np--;
9334 		pplist++;
9335 	}
9336 
9337 	kmem_free(pl, sizeof (page_t *) * (npages + 1));
9338 
9339 	/*
9340 	 * If somebody sleeps in anonmap_purge() wake them up if a_softlockcnt
9341 	 * drops to 0. anon map can't be freed until a_softlockcnt drops to 0
9342 	 * and anonmap_purge() acquires a_purgemtx.
9343 	 */
9344 	mutex_enter(&amp->a_purgemtx);
9345 	if (!atomic_add_long_nv((ulong_t *)&amp->a_softlockcnt, -npages) &&
9346 	    amp->a_purgewait) {
9347 		amp->a_purgewait = 0;
9348 		cv_broadcast(&amp->a_purgecv);
9349 	}
9350 	mutex_exit(&amp->a_purgemtx);
9351 	return (0);
9352 }
9353 
9354 /*
9355  * get a memory ID for an addr in a given segment
9356  *
9357  * XXX only creates PAGESIZE pages if anon slots are not initialized.
9358  * At fault time they will be relocated into larger pages.
9359  */
9360 static int
9361 segvn_getmemid(struct seg *seg, caddr_t addr, memid_t *memidp)
9362 {
9363 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9364 	struct anon 	*ap = NULL;
9365 	ulong_t		anon_index;
9366 	struct anon_map	*amp;
9367 	anon_sync_obj_t cookie;
9368 
9369 	if (svd->type == MAP_PRIVATE) {
9370 		memidp->val[0] = (uintptr_t)seg->s_as;
9371 		memidp->val[1] = (uintptr_t)addr;
9372 		return (0);
9373 	}
9374 
9375 	if (svd->type == MAP_SHARED) {
9376 		if (svd->vp) {
9377 			memidp->val[0] = (uintptr_t)svd->vp;
9378 			memidp->val[1] = (u_longlong_t)svd->offset +
9379 			    (uintptr_t)(addr - seg->s_base);
9380 			return (0);
9381 		} else {
9382 
9383 			SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
9384 			if ((amp = svd->amp) != NULL) {
9385 				anon_index = svd->anon_index +
9386 				    seg_page(seg, addr);
9387 			}
9388 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9389 
9390 			ASSERT(amp != NULL);
9391 
9392 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
9393 			anon_array_enter(amp, anon_index, &cookie);
9394 			ap = anon_get_ptr(amp->ahp, anon_index);
9395 			if (ap == NULL) {
9396 				page_t		*pp;
9397 
9398 				pp = anon_zero(seg, addr, &ap, svd->cred);
9399 				if (pp == NULL) {
9400 					anon_array_exit(&cookie);
9401 					ANON_LOCK_EXIT(&amp->a_rwlock);
9402 					return (ENOMEM);
9403 				}
9404 				ASSERT(anon_get_ptr(amp->ahp, anon_index)
9405 				    == NULL);
9406 				(void) anon_set_ptr(amp->ahp, anon_index,
9407 				    ap, ANON_SLEEP);
9408 				page_unlock(pp);
9409 			}
9410 
9411 			anon_array_exit(&cookie);
9412 			ANON_LOCK_EXIT(&amp->a_rwlock);
9413 
9414 			memidp->val[0] = (uintptr_t)ap;
9415 			memidp->val[1] = (uintptr_t)addr & PAGEOFFSET;
9416 			return (0);
9417 		}
9418 	}
9419 	return (EINVAL);
9420 }
9421 
9422 static int
9423 sameprot(struct seg *seg, caddr_t a, size_t len)
9424 {
9425 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9426 	struct vpage *vpage;
9427 	spgcnt_t pages = btop(len);
9428 	uint_t prot;
9429 
9430 	if (svd->pageprot == 0)
9431 		return (1);
9432 
9433 	ASSERT(svd->vpage != NULL);
9434 
9435 	vpage = &svd->vpage[seg_page(seg, a)];
9436 	prot = VPP_PROT(vpage);
9437 	vpage++;
9438 	pages--;
9439 	while (pages-- > 0) {
9440 		if (prot != VPP_PROT(vpage))
9441 			return (0);
9442 		vpage++;
9443 	}
9444 	return (1);
9445 }
9446 
9447 /*
9448  * Get memory allocation policy info for specified address in given segment
9449  */
9450 static lgrp_mem_policy_info_t *
9451 segvn_getpolicy(struct seg *seg, caddr_t addr)
9452 {
9453 	struct anon_map		*amp;
9454 	ulong_t			anon_index;
9455 	lgrp_mem_policy_info_t	*policy_info;
9456 	struct segvn_data	*svn_data;
9457 	u_offset_t		vn_off;
9458 	vnode_t			*vp;
9459 
9460 	ASSERT(seg != NULL);
9461 
9462 	svn_data = (struct segvn_data *)seg->s_data;
9463 	if (svn_data == NULL)
9464 		return (NULL);
9465 
9466 	/*
9467 	 * Get policy info for private or shared memory
9468 	 */
9469 	if (svn_data->type != MAP_SHARED) {
9470 		if (svn_data->tr_state != SEGVN_TR_ON) {
9471 			policy_info = &svn_data->policy_info;
9472 		} else {
9473 			policy_info = &svn_data->tr_policy_info;
9474 			ASSERT(policy_info->mem_policy ==
9475 			    LGRP_MEM_POLICY_NEXT_SEG);
9476 		}
9477 	} else {
9478 		amp = svn_data->amp;
9479 		anon_index = svn_data->anon_index + seg_page(seg, addr);
9480 		vp = svn_data->vp;
9481 		vn_off = svn_data->offset + (uintptr_t)(addr - seg->s_base);
9482 		policy_info = lgrp_shm_policy_get(amp, anon_index, vp, vn_off);
9483 	}
9484 
9485 	return (policy_info);
9486 }
9487 
9488 /*ARGSUSED*/
9489 static int
9490 segvn_capable(struct seg *seg, segcapability_t capability)
9491 {
9492 	return (0);
9493 }
9494 
9495 /*
9496  * Bind text vnode segment to an amp. If we bind successfully mappings will be
9497  * established to per vnode mapping per lgroup amp pages instead of to vnode
9498  * pages. There's one amp per vnode text mapping per lgroup. Many processes
9499  * may share the same text replication amp. If a suitable amp doesn't already
9500  * exist in svntr hash table create a new one.  We may fail to bind to amp if
9501  * segment is not eligible for text replication.  Code below first checks for
9502  * these conditions. If binding is successful segment tr_state is set to on
9503  * and svd->amp points to the amp to use. Otherwise tr_state is set to off and
9504  * svd->amp remains as NULL.
9505  */
9506 static void
9507 segvn_textrepl(struct seg *seg)
9508 {
9509 	struct segvn_data	*svd = (struct segvn_data *)seg->s_data;
9510 	vnode_t			*vp = svd->vp;
9511 	u_offset_t		off = svd->offset;
9512 	size_t			size = seg->s_size;
9513 	u_offset_t		eoff = off + size;
9514 	uint_t			szc = seg->s_szc;
9515 	ulong_t			hash = SVNTR_HASH_FUNC(vp);
9516 	svntr_t			*svntrp;
9517 	struct vattr		va;
9518 	proc_t			*p = seg->s_as->a_proc;
9519 	lgrp_id_t		lgrp_id;
9520 	lgrp_id_t		olid;
9521 	int			first;
9522 	struct anon_map		*amp;
9523 
9524 	ASSERT(AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
9525 	ASSERT(SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
9526 	ASSERT(p != NULL);
9527 	ASSERT(svd->tr_state == SEGVN_TR_INIT);
9528 	ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
9529 	ASSERT(svd->flags & MAP_TEXT);
9530 	ASSERT(svd->type == MAP_PRIVATE);
9531 	ASSERT(vp != NULL && svd->amp == NULL);
9532 	ASSERT(!svd->pageprot && !(svd->prot & PROT_WRITE));
9533 	ASSERT(!(svd->flags & MAP_NORESERVE) && svd->swresv == 0);
9534 	ASSERT(seg->s_as != &kas);
9535 	ASSERT(off < eoff);
9536 	ASSERT(svntr_hashtab != NULL);
9537 
9538 	/*
9539 	 * If numa optimizations are no longer desired bail out.
9540 	 */
9541 	if (!lgrp_optimizations()) {
9542 		svd->tr_state = SEGVN_TR_OFF;
9543 		return;
9544 	}
9545 
9546 	/*
9547 	 * Avoid creating anon maps with size bigger than the file size.
9548 	 * If VOP_GETATTR() call fails bail out.
9549 	 */
9550 	va.va_mask = AT_SIZE | AT_MTIME | AT_CTIME;
9551 	if (VOP_GETATTR(vp, &va, 0, svd->cred, NULL) != 0) {
9552 		svd->tr_state = SEGVN_TR_OFF;
9553 		SEGVN_TR_ADDSTAT(gaerr);
9554 		return;
9555 	}
9556 	if (btopr(va.va_size) < btopr(eoff)) {
9557 		svd->tr_state = SEGVN_TR_OFF;
9558 		SEGVN_TR_ADDSTAT(overmap);
9559 		return;
9560 	}
9561 
9562 	/*
9563 	 * VVMEXEC may not be set yet if exec() prefaults text segment. Set
9564 	 * this flag now before vn_is_mapped(V_WRITE) so that MAP_SHARED
9565 	 * mapping that checks if trcache for this vnode needs to be
9566 	 * invalidated can't miss us.
9567 	 */
9568 	if (!(vp->v_flag & VVMEXEC)) {
9569 		mutex_enter(&vp->v_lock);
9570 		vp->v_flag |= VVMEXEC;
9571 		mutex_exit(&vp->v_lock);
9572 	}
9573 	mutex_enter(&svntr_hashtab[hash].tr_lock);
9574 	/*
9575 	 * Bail out if potentially MAP_SHARED writable mappings exist to this
9576 	 * vnode.  We don't want to use old file contents from existing
9577 	 * replicas if this mapping was established after the original file
9578 	 * was changed.
9579 	 */
9580 	if (vn_is_mapped(vp, V_WRITE)) {
9581 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9582 		svd->tr_state = SEGVN_TR_OFF;
9583 		SEGVN_TR_ADDSTAT(wrcnt);
9584 		return;
9585 	}
9586 	svntrp = svntr_hashtab[hash].tr_head;
9587 	for (; svntrp != NULL; svntrp = svntrp->tr_next) {
9588 		ASSERT(svntrp->tr_refcnt != 0);
9589 		if (svntrp->tr_vp != vp) {
9590 			continue;
9591 		}
9592 
9593 		/*
9594 		 * Bail out if the file or its attributes were changed after
9595 		 * this replication entry was created since we need to use the
9596 		 * latest file contents. Note that mtime test alone is not
9597 		 * sufficient because a user can explicitly change mtime via
9598 		 * utimes(2) interfaces back to the old value after modifiying
9599 		 * the file contents. To detect this case we also have to test
9600 		 * ctime which among other things records the time of the last
9601 		 * mtime change by utimes(2). ctime is not changed when the file
9602 		 * is only read or executed so we expect that typically existing
9603 		 * replication amp's can be used most of the time.
9604 		 */
9605 		if (!svntrp->tr_valid ||
9606 		    svntrp->tr_mtime.tv_sec != va.va_mtime.tv_sec ||
9607 		    svntrp->tr_mtime.tv_nsec != va.va_mtime.tv_nsec ||
9608 		    svntrp->tr_ctime.tv_sec != va.va_ctime.tv_sec ||
9609 		    svntrp->tr_ctime.tv_nsec != va.va_ctime.tv_nsec) {
9610 			mutex_exit(&svntr_hashtab[hash].tr_lock);
9611 			svd->tr_state = SEGVN_TR_OFF;
9612 			SEGVN_TR_ADDSTAT(stale);
9613 			return;
9614 		}
9615 		/*
9616 		 * if off, eoff and szc match current segment we found the
9617 		 * existing entry we can use.
9618 		 */
9619 		if (svntrp->tr_off == off && svntrp->tr_eoff == eoff &&
9620 		    svntrp->tr_szc == szc) {
9621 			break;
9622 		}
9623 		/*
9624 		 * Don't create different but overlapping in file offsets
9625 		 * entries to avoid replication of the same file pages more
9626 		 * than once per lgroup.
9627 		 */
9628 		if ((off >= svntrp->tr_off && off < svntrp->tr_eoff) ||
9629 		    (eoff > svntrp->tr_off && eoff <= svntrp->tr_eoff)) {
9630 			mutex_exit(&svntr_hashtab[hash].tr_lock);
9631 			svd->tr_state = SEGVN_TR_OFF;
9632 			SEGVN_TR_ADDSTAT(overlap);
9633 			return;
9634 		}
9635 	}
9636 	/*
9637 	 * If we didn't find existing entry create a new one.
9638 	 */
9639 	if (svntrp == NULL) {
9640 		svntrp = kmem_cache_alloc(svntr_cache, KM_NOSLEEP);
9641 		if (svntrp == NULL) {
9642 			mutex_exit(&svntr_hashtab[hash].tr_lock);
9643 			svd->tr_state = SEGVN_TR_OFF;
9644 			SEGVN_TR_ADDSTAT(nokmem);
9645 			return;
9646 		}
9647 #ifdef DEBUG
9648 		{
9649 			lgrp_id_t i;
9650 			for (i = 0; i < NLGRPS_MAX; i++) {
9651 				ASSERT(svntrp->tr_amp[i] == NULL);
9652 			}
9653 		}
9654 #endif /* DEBUG */
9655 		svntrp->tr_vp = vp;
9656 		svntrp->tr_off = off;
9657 		svntrp->tr_eoff = eoff;
9658 		svntrp->tr_szc = szc;
9659 		svntrp->tr_valid = 1;
9660 		svntrp->tr_mtime = va.va_mtime;
9661 		svntrp->tr_ctime = va.va_ctime;
9662 		svntrp->tr_refcnt = 0;
9663 		svntrp->tr_next = svntr_hashtab[hash].tr_head;
9664 		svntr_hashtab[hash].tr_head = svntrp;
9665 	}
9666 	first = 1;
9667 again:
9668 	/*
9669 	 * We want to pick a replica with pages on main thread's (t_tid = 1,
9670 	 * aka T1) lgrp. Currently text replication is only optimized for
9671 	 * workloads that either have all threads of a process on the same
9672 	 * lgrp or execute their large text primarily on main thread.
9673 	 */
9674 	lgrp_id = p->p_t1_lgrpid;
9675 	if (lgrp_id == LGRP_NONE) {
9676 		/*
9677 		 * In case exec() prefaults text on non main thread use
9678 		 * current thread lgrpid.  It will become main thread anyway
9679 		 * soon.
9680 		 */
9681 		lgrp_id = lgrp_home_id(curthread);
9682 	}
9683 	/*
9684 	 * Set p_tr_lgrpid to lgrpid if it hasn't been set yet.  Otherwise
9685 	 * just set it to NLGRPS_MAX if it's different from current process T1
9686 	 * home lgrp.  p_tr_lgrpid is used to detect if process uses text
9687 	 * replication and T1 new home is different from lgrp used for text
9688 	 * replication. When this happens asyncronous segvn thread rechecks if
9689 	 * segments should change lgrps used for text replication.  If we fail
9690 	 * to set p_tr_lgrpid with cas32 then set it to NLGRPS_MAX without cas
9691 	 * if it's not already NLGRPS_MAX and not equal lgrp_id we want to
9692 	 * use.  We don't need to use cas in this case because another thread
9693 	 * that races in between our non atomic check and set may only change
9694 	 * p_tr_lgrpid to NLGRPS_MAX at this point.
9695 	 */
9696 	ASSERT(lgrp_id != LGRP_NONE && lgrp_id < NLGRPS_MAX);
9697 	olid = p->p_tr_lgrpid;
9698 	if (lgrp_id != olid && olid != NLGRPS_MAX) {
9699 		lgrp_id_t nlid = (olid == LGRP_NONE) ? lgrp_id : NLGRPS_MAX;
9700 		if (cas32((uint32_t *)&p->p_tr_lgrpid, olid, nlid) != olid) {
9701 			olid = p->p_tr_lgrpid;
9702 			ASSERT(olid != LGRP_NONE);
9703 			if (olid != lgrp_id && olid != NLGRPS_MAX) {
9704 				p->p_tr_lgrpid = NLGRPS_MAX;
9705 			}
9706 		}
9707 		ASSERT(p->p_tr_lgrpid != LGRP_NONE);
9708 		membar_producer();
9709 		/*
9710 		 * lgrp_move_thread() won't schedule async recheck after
9711 		 * p->p_t1_lgrpid update unless p->p_tr_lgrpid is not
9712 		 * LGRP_NONE. Recheck p_t1_lgrpid once now that p->p_tr_lgrpid
9713 		 * is not LGRP_NONE.
9714 		 */
9715 		if (first && p->p_t1_lgrpid != LGRP_NONE &&
9716 		    p->p_t1_lgrpid != lgrp_id) {
9717 			first = 0;
9718 			goto again;
9719 		}
9720 	}
9721 	/*
9722 	 * If no amp was created yet for lgrp_id create a new one as long as
9723 	 * we have enough memory to afford it.
9724 	 */
9725 	if ((amp = svntrp->tr_amp[lgrp_id]) == NULL) {
9726 		size_t trmem = atomic_add_long_nv(&segvn_textrepl_bytes, size);
9727 		if (trmem > segvn_textrepl_max_bytes) {
9728 			SEGVN_TR_ADDSTAT(normem);
9729 			goto fail;
9730 		}
9731 		if (anon_try_resv_zone(size, NULL) == 0) {
9732 			SEGVN_TR_ADDSTAT(noanon);
9733 			goto fail;
9734 		}
9735 		amp = anonmap_alloc(size, size, ANON_NOSLEEP);
9736 		if (amp == NULL) {
9737 			anon_unresv_zone(size, NULL);
9738 			SEGVN_TR_ADDSTAT(nokmem);
9739 			goto fail;
9740 		}
9741 		ASSERT(amp->refcnt == 1);
9742 		amp->a_szc = szc;
9743 		svntrp->tr_amp[lgrp_id] = amp;
9744 		SEGVN_TR_ADDSTAT(newamp);
9745 	}
9746 	svntrp->tr_refcnt++;
9747 	ASSERT(svd->svn_trnext == NULL);
9748 	ASSERT(svd->svn_trprev == NULL);
9749 	svd->svn_trnext = svntrp->tr_svnhead;
9750 	svd->svn_trprev = NULL;
9751 	if (svntrp->tr_svnhead != NULL) {
9752 		svntrp->tr_svnhead->svn_trprev = svd;
9753 	}
9754 	svntrp->tr_svnhead = svd;
9755 	ASSERT(amp->a_szc == szc && amp->size == size && amp->swresv == size);
9756 	ASSERT(amp->refcnt >= 1);
9757 	svd->amp = amp;
9758 	svd->anon_index = 0;
9759 	svd->tr_policy_info.mem_policy = LGRP_MEM_POLICY_NEXT_SEG;
9760 	svd->tr_policy_info.mem_lgrpid = lgrp_id;
9761 	svd->tr_state = SEGVN_TR_ON;
9762 	mutex_exit(&svntr_hashtab[hash].tr_lock);
9763 	SEGVN_TR_ADDSTAT(repl);
9764 	return;
9765 fail:
9766 	ASSERT(segvn_textrepl_bytes >= size);
9767 	atomic_add_long(&segvn_textrepl_bytes, -size);
9768 	ASSERT(svntrp != NULL);
9769 	ASSERT(svntrp->tr_amp[lgrp_id] == NULL);
9770 	if (svntrp->tr_refcnt == 0) {
9771 		ASSERT(svntrp == svntr_hashtab[hash].tr_head);
9772 		svntr_hashtab[hash].tr_head = svntrp->tr_next;
9773 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9774 		kmem_cache_free(svntr_cache, svntrp);
9775 	} else {
9776 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9777 	}
9778 	svd->tr_state = SEGVN_TR_OFF;
9779 }
9780 
9781 /*
9782  * Convert seg back to regular vnode mapping seg by unbinding it from its text
9783  * replication amp.  This routine is most typically called when segment is
9784  * unmapped but can also be called when segment no longer qualifies for text
9785  * replication (e.g. due to protection changes). If unload_unmap is set use
9786  * HAT_UNLOAD_UNMAP flag in hat_unload_callback().  If we are the last user of
9787  * svntr free all its anon maps and remove it from the hash table.
9788  */
9789 static void
9790 segvn_textunrepl(struct seg *seg, int unload_unmap)
9791 {
9792 	struct segvn_data	*svd = (struct segvn_data *)seg->s_data;
9793 	vnode_t			*vp = svd->vp;
9794 	u_offset_t		off = svd->offset;
9795 	size_t			size = seg->s_size;
9796 	u_offset_t		eoff = off + size;
9797 	uint_t			szc = seg->s_szc;
9798 	ulong_t			hash = SVNTR_HASH_FUNC(vp);
9799 	svntr_t			*svntrp;
9800 	svntr_t			**prv_svntrp;
9801 	lgrp_id_t		lgrp_id = svd->tr_policy_info.mem_lgrpid;
9802 	lgrp_id_t		i;
9803 
9804 	ASSERT(AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
9805 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock) ||
9806 	    SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
9807 	ASSERT(svd->tr_state == SEGVN_TR_ON);
9808 	ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
9809 	ASSERT(svd->amp != NULL);
9810 	ASSERT(svd->amp->refcnt >= 1);
9811 	ASSERT(svd->anon_index == 0);
9812 	ASSERT(lgrp_id != LGRP_NONE && lgrp_id < NLGRPS_MAX);
9813 	ASSERT(svntr_hashtab != NULL);
9814 
9815 	mutex_enter(&svntr_hashtab[hash].tr_lock);
9816 	prv_svntrp = &svntr_hashtab[hash].tr_head;
9817 	for (; (svntrp = *prv_svntrp) != NULL; prv_svntrp = &svntrp->tr_next) {
9818 		ASSERT(svntrp->tr_refcnt != 0);
9819 		if (svntrp->tr_vp == vp && svntrp->tr_off == off &&
9820 		    svntrp->tr_eoff == eoff && svntrp->tr_szc == szc) {
9821 			break;
9822 		}
9823 	}
9824 	if (svntrp == NULL) {
9825 		panic("segvn_textunrepl: svntr record not found");
9826 	}
9827 	if (svntrp->tr_amp[lgrp_id] != svd->amp) {
9828 		panic("segvn_textunrepl: amp mismatch");
9829 	}
9830 	svd->tr_state = SEGVN_TR_OFF;
9831 	svd->amp = NULL;
9832 	if (svd->svn_trprev == NULL) {
9833 		ASSERT(svntrp->tr_svnhead == svd);
9834 		svntrp->tr_svnhead = svd->svn_trnext;
9835 		if (svntrp->tr_svnhead != NULL) {
9836 			svntrp->tr_svnhead->svn_trprev = NULL;
9837 		}
9838 		svd->svn_trnext = NULL;
9839 	} else {
9840 		svd->svn_trprev->svn_trnext = svd->svn_trnext;
9841 		if (svd->svn_trnext != NULL) {
9842 			svd->svn_trnext->svn_trprev = svd->svn_trprev;
9843 			svd->svn_trnext = NULL;
9844 		}
9845 		svd->svn_trprev = NULL;
9846 	}
9847 	if (--svntrp->tr_refcnt) {
9848 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9849 		goto done;
9850 	}
9851 	*prv_svntrp = svntrp->tr_next;
9852 	mutex_exit(&svntr_hashtab[hash].tr_lock);
9853 	for (i = 0; i < NLGRPS_MAX; i++) {
9854 		struct anon_map *amp = svntrp->tr_amp[i];
9855 		if (amp == NULL) {
9856 			continue;
9857 		}
9858 		ASSERT(amp->refcnt == 1);
9859 		ASSERT(amp->swresv == size);
9860 		ASSERT(amp->size == size);
9861 		ASSERT(amp->a_szc == szc);
9862 		if (amp->a_szc != 0) {
9863 			anon_free_pages(amp->ahp, 0, size, szc);
9864 		} else {
9865 			anon_free(amp->ahp, 0, size);
9866 		}
9867 		svntrp->tr_amp[i] = NULL;
9868 		ASSERT(segvn_textrepl_bytes >= size);
9869 		atomic_add_long(&segvn_textrepl_bytes, -size);
9870 		anon_unresv_zone(amp->swresv, NULL);
9871 		amp->refcnt = 0;
9872 		anonmap_free(amp);
9873 	}
9874 	kmem_cache_free(svntr_cache, svntrp);
9875 done:
9876 	hat_unload_callback(seg->s_as->a_hat, seg->s_base, size,
9877 	    unload_unmap ? HAT_UNLOAD_UNMAP : 0, NULL);
9878 }
9879 
9880 /*
9881  * This is called when a MAP_SHARED writable mapping is created to a vnode
9882  * that is currently used for execution (VVMEXEC flag is set). In this case we
9883  * need to prevent further use of existing replicas.
9884  */
9885 static void
9886 segvn_inval_trcache(vnode_t *vp)
9887 {
9888 	ulong_t			hash = SVNTR_HASH_FUNC(vp);
9889 	svntr_t			*svntrp;
9890 
9891 	ASSERT(vp->v_flag & VVMEXEC);
9892 
9893 	if (svntr_hashtab == NULL) {
9894 		return;
9895 	}
9896 
9897 	mutex_enter(&svntr_hashtab[hash].tr_lock);
9898 	svntrp = svntr_hashtab[hash].tr_head;
9899 	for (; svntrp != NULL; svntrp = svntrp->tr_next) {
9900 		ASSERT(svntrp->tr_refcnt != 0);
9901 		if (svntrp->tr_vp == vp && svntrp->tr_valid) {
9902 			svntrp->tr_valid = 0;
9903 		}
9904 	}
9905 	mutex_exit(&svntr_hashtab[hash].tr_lock);
9906 }
9907 
9908 static void
9909 segvn_trasync_thread(void)
9910 {
9911 	callb_cpr_t cpr_info;
9912 	kmutex_t cpr_lock;	/* just for CPR stuff */
9913 
9914 	mutex_init(&cpr_lock, NULL, MUTEX_DEFAULT, NULL);
9915 
9916 	CALLB_CPR_INIT(&cpr_info, &cpr_lock,
9917 	    callb_generic_cpr, "segvn_async");
9918 
9919 	if (segvn_update_textrepl_interval == 0) {
9920 		segvn_update_textrepl_interval = segvn_update_tr_time * hz;
9921 	} else {
9922 		segvn_update_textrepl_interval *= hz;
9923 	}
9924 	(void) timeout(segvn_trupdate_wakeup, NULL,
9925 	    segvn_update_textrepl_interval);
9926 
9927 	for (;;) {
9928 		mutex_enter(&cpr_lock);
9929 		CALLB_CPR_SAFE_BEGIN(&cpr_info);
9930 		mutex_exit(&cpr_lock);
9931 		sema_p(&segvn_trasync_sem);
9932 		mutex_enter(&cpr_lock);
9933 		CALLB_CPR_SAFE_END(&cpr_info, &cpr_lock);
9934 		mutex_exit(&cpr_lock);
9935 		segvn_trupdate();
9936 	}
9937 }
9938 
9939 static uint64_t segvn_lgrp_trthr_migrs_snpsht = 0;
9940 
9941 static void
9942 segvn_trupdate_wakeup(void *dummy)
9943 {
9944 	uint64_t cur_lgrp_trthr_migrs = lgrp_get_trthr_migrations();
9945 
9946 	if (cur_lgrp_trthr_migrs != segvn_lgrp_trthr_migrs_snpsht) {
9947 		segvn_lgrp_trthr_migrs_snpsht = cur_lgrp_trthr_migrs;
9948 		sema_v(&segvn_trasync_sem);
9949 	}
9950 
9951 	if (!segvn_disable_textrepl_update &&
9952 	    segvn_update_textrepl_interval != 0) {
9953 		(void) timeout(segvn_trupdate_wakeup, dummy,
9954 		    segvn_update_textrepl_interval);
9955 	}
9956 }
9957 
9958 static void
9959 segvn_trupdate(void)
9960 {
9961 	ulong_t		hash;
9962 	svntr_t		*svntrp;
9963 	segvn_data_t	*svd;
9964 
9965 	ASSERT(svntr_hashtab != NULL);
9966 
9967 	for (hash = 0; hash < svntr_hashtab_sz; hash++) {
9968 		mutex_enter(&svntr_hashtab[hash].tr_lock);
9969 		svntrp = svntr_hashtab[hash].tr_head;
9970 		for (; svntrp != NULL; svntrp = svntrp->tr_next) {
9971 			ASSERT(svntrp->tr_refcnt != 0);
9972 			svd = svntrp->tr_svnhead;
9973 			for (; svd != NULL; svd = svd->svn_trnext) {
9974 				segvn_trupdate_seg(svd->seg, svd, svntrp,
9975 				    hash);
9976 			}
9977 		}
9978 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9979 	}
9980 }
9981 
9982 static void
9983 segvn_trupdate_seg(struct seg *seg,
9984 	segvn_data_t *svd,
9985 	svntr_t *svntrp,
9986 	ulong_t hash)
9987 {
9988 	proc_t			*p;
9989 	lgrp_id_t		lgrp_id;
9990 	struct as		*as;
9991 	size_t			size;
9992 	struct anon_map		*amp;
9993 
9994 	ASSERT(svd->vp != NULL);
9995 	ASSERT(svd->vp == svntrp->tr_vp);
9996 	ASSERT(svd->offset == svntrp->tr_off);
9997 	ASSERT(svd->offset + seg->s_size == svntrp->tr_eoff);
9998 	ASSERT(seg != NULL);
9999 	ASSERT(svd->seg == seg);
10000 	ASSERT(seg->s_data == (void *)svd);
10001 	ASSERT(seg->s_szc == svntrp->tr_szc);
10002 	ASSERT(svd->tr_state == SEGVN_TR_ON);
10003 	ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
10004 	ASSERT(svd->amp != NULL);
10005 	ASSERT(svd->tr_policy_info.mem_policy == LGRP_MEM_POLICY_NEXT_SEG);
10006 	ASSERT(svd->tr_policy_info.mem_lgrpid != LGRP_NONE);
10007 	ASSERT(svd->tr_policy_info.mem_lgrpid < NLGRPS_MAX);
10008 	ASSERT(svntrp->tr_amp[svd->tr_policy_info.mem_lgrpid] == svd->amp);
10009 	ASSERT(svntrp->tr_refcnt != 0);
10010 	ASSERT(mutex_owned(&svntr_hashtab[hash].tr_lock));
10011 
10012 	as = seg->s_as;
10013 	ASSERT(as != NULL && as != &kas);
10014 	p = as->a_proc;
10015 	ASSERT(p != NULL);
10016 	ASSERT(p->p_tr_lgrpid != LGRP_NONE);
10017 	lgrp_id = p->p_t1_lgrpid;
10018 	if (lgrp_id == LGRP_NONE) {
10019 		return;
10020 	}
10021 	ASSERT(lgrp_id < NLGRPS_MAX);
10022 	if (svd->tr_policy_info.mem_lgrpid == lgrp_id) {
10023 		return;
10024 	}
10025 
10026 	/*
10027 	 * Use tryenter locking since we are locking as/seg and svntr hash
10028 	 * lock in reverse from syncrounous thread order.
10029 	 */
10030 	if (!AS_LOCK_TRYENTER(as, &as->a_lock, RW_READER)) {
10031 		SEGVN_TR_ADDSTAT(nolock);
10032 		if (segvn_lgrp_trthr_migrs_snpsht) {
10033 			segvn_lgrp_trthr_migrs_snpsht = 0;
10034 		}
10035 		return;
10036 	}
10037 	if (!SEGVN_LOCK_TRYENTER(seg->s_as, &svd->lock, RW_WRITER)) {
10038 		AS_LOCK_EXIT(as, &as->a_lock);
10039 		SEGVN_TR_ADDSTAT(nolock);
10040 		if (segvn_lgrp_trthr_migrs_snpsht) {
10041 			segvn_lgrp_trthr_migrs_snpsht = 0;
10042 		}
10043 		return;
10044 	}
10045 	size = seg->s_size;
10046 	if (svntrp->tr_amp[lgrp_id] == NULL) {
10047 		size_t trmem = atomic_add_long_nv(&segvn_textrepl_bytes, size);
10048 		if (trmem > segvn_textrepl_max_bytes) {
10049 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10050 			AS_LOCK_EXIT(as, &as->a_lock);
10051 			atomic_add_long(&segvn_textrepl_bytes, -size);
10052 			SEGVN_TR_ADDSTAT(normem);
10053 			return;
10054 		}
10055 		if (anon_try_resv_zone(size, NULL) == 0) {
10056 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10057 			AS_LOCK_EXIT(as, &as->a_lock);
10058 			atomic_add_long(&segvn_textrepl_bytes, -size);
10059 			SEGVN_TR_ADDSTAT(noanon);
10060 			return;
10061 		}
10062 		amp = anonmap_alloc(size, size, KM_NOSLEEP);
10063 		if (amp == NULL) {
10064 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10065 			AS_LOCK_EXIT(as, &as->a_lock);
10066 			atomic_add_long(&segvn_textrepl_bytes, -size);
10067 			anon_unresv_zone(size, NULL);
10068 			SEGVN_TR_ADDSTAT(nokmem);
10069 			return;
10070 		}
10071 		ASSERT(amp->refcnt == 1);
10072 		amp->a_szc = seg->s_szc;
10073 		svntrp->tr_amp[lgrp_id] = amp;
10074 	}
10075 	/*
10076 	 * We don't need to drop the bucket lock but here we give other
10077 	 * threads a chance.  svntr and svd can't be unlinked as long as
10078 	 * segment lock is held as a writer and AS held as well.  After we
10079 	 * retake bucket lock we'll continue from where we left. We'll be able
10080 	 * to reach the end of either list since new entries are always added
10081 	 * to the beginning of the lists.
10082 	 */
10083 	mutex_exit(&svntr_hashtab[hash].tr_lock);
10084 	hat_unload_callback(as->a_hat, seg->s_base, size, 0, NULL);
10085 	mutex_enter(&svntr_hashtab[hash].tr_lock);
10086 
10087 	ASSERT(svd->tr_state == SEGVN_TR_ON);
10088 	ASSERT(svd->amp != NULL);
10089 	ASSERT(svd->tr_policy_info.mem_policy == LGRP_MEM_POLICY_NEXT_SEG);
10090 	ASSERT(svd->tr_policy_info.mem_lgrpid != lgrp_id);
10091 	ASSERT(svd->amp != svntrp->tr_amp[lgrp_id]);
10092 
10093 	svd->tr_policy_info.mem_lgrpid = lgrp_id;
10094 	svd->amp = svntrp->tr_amp[lgrp_id];
10095 	p->p_tr_lgrpid = NLGRPS_MAX;
10096 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10097 	AS_LOCK_EXIT(as, &as->a_lock);
10098 
10099 	ASSERT(svntrp->tr_refcnt != 0);
10100 	ASSERT(svd->vp == svntrp->tr_vp);
10101 	ASSERT(svd->tr_policy_info.mem_lgrpid == lgrp_id);
10102 	ASSERT(svd->amp != NULL && svd->amp == svntrp->tr_amp[lgrp_id]);
10103 	ASSERT(svd->seg == seg);
10104 	ASSERT(svd->tr_state == SEGVN_TR_ON);
10105 
10106 	SEGVN_TR_ADDSTAT(asyncrepl);
10107 }
10108