xref: /illumos-gate/usr/src/uts/i86pc/vm/hat_i86.c (revision 7173d045a5480c5b188850a799de5efebdbf8af1)
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 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 /*
29  * VM - Hardware Address Translation management for i386 and amd64
30  *
31  * Implementation of the interfaces described in <common/vm/hat.h>
32  *
33  * Nearly all the details of how the hardware is managed should not be
34  * visible outside this layer except for misc. machine specific functions
35  * that work in conjunction with this code.
36  *
37  * Routines used only inside of i86pc/vm start with hati_ for HAT Internal.
38  */
39 
40 #include <sys/machparam.h>
41 #include <sys/machsystm.h>
42 #include <sys/mman.h>
43 #include <sys/types.h>
44 #include <sys/systm.h>
45 #include <sys/cpuvar.h>
46 #include <sys/thread.h>
47 #include <sys/proc.h>
48 #include <sys/cpu.h>
49 #include <sys/kmem.h>
50 #include <sys/disp.h>
51 #include <sys/shm.h>
52 #include <sys/sysmacros.h>
53 #include <sys/machparam.h>
54 #include <sys/vmem.h>
55 #include <sys/vmsystm.h>
56 #include <sys/promif.h>
57 #include <sys/var.h>
58 #include <sys/x86_archext.h>
59 #include <sys/atomic.h>
60 #include <sys/bitmap.h>
61 #include <sys/controlregs.h>
62 #include <sys/bootconf.h>
63 #include <sys/bootsvcs.h>
64 #include <sys/bootinfo.h>
65 #include <sys/archsystm.h>
66 
67 #include <vm/seg_kmem.h>
68 #include <vm/hat_i86.h>
69 #include <vm/as.h>
70 #include <vm/seg.h>
71 #include <vm/page.h>
72 #include <vm/seg_kp.h>
73 #include <vm/seg_kpm.h>
74 #include <vm/vm_dep.h>
75 #include <vm/kboot_mmu.h>
76 #include <vm/seg_spt.h>
77 
78 #include <sys/cmn_err.h>
79 
80 /*
81  * Basic parameters for hat operation.
82  */
83 struct hat_mmu_info mmu;
84 
85 /*
86  * The page that is the kernel's top level pagetable.
87  *
88  * For 32 bit VLP support, the kernel hat will use the 1st 4 entries
89  * on this 4K page for its top level page table. The remaining groups of
90  * 4 entries are used for per processor copies of user VLP pagetables for
91  * running threads.  See hat_switch() and reload_pae32() for details.
92  *
93  * vlp_page[0] - 0th level==2 PTE for kernel HAT (will be zero)
94  * vlp_page[1] - 1st level==2 PTE for kernel HAT (will be zero)
95  * vlp_page[2] - 2nd level==2 PTE for kernel HAT (zero for small memory)
96  * vlp_page[3] - 3rd level==2 PTE for kernel
97  *
98  * vlp_page[4] - 0th level==2 PTE for user thread on cpu 0
99  * vlp_page[5] - 1st level==2 PTE for user thread on cpu 0
100  * vlp_page[6] - 2nd level==2 PTE for user thread on cpu 0
101  * vlp_page[7] - probably copy of kernel PTE
102  *
103  * vlp_page[8]  - 0th level==2 PTE for user thread on cpu 1
104  * vlp_page[9]  - 1st level==2 PTE for user thread on cpu 1
105  * vlp_page[10] - 2nd level==2 PTE for user thread on cpu 1
106  * vlp_page[11] - probably copy of kernel PTE
107  * ...
108  *
109  * when / where the kernel PTE's are (entry 2 or 3 or none) depends
110  * on kernelbase.
111  */
112 static x86pte_t *vlp_page;
113 
114 /*
115  * forward declaration of internal utility routines
116  */
117 static x86pte_t hati_update_pte(htable_t *ht, uint_t entry, x86pte_t expected,
118 	x86pte_t new);
119 
120 /*
121  * The kernel address space exists in all HATs. To implement this the
122  * kernel reserves a fixed number of entries in every topmost level page
123  * table. The values are setup in hat_init() and then copied to every hat
124  * created by hat_alloc(). This means that kernelbase must be:
125  *
126  *	  4Meg aligned for 32 bit kernels
127  *	512Gig aligned for x86_64 64 bit kernel
128  *
129  * The PAE 32 bit hat is handled as a special case. Otherwise requiring 1Gig
130  * alignment would use too much VA for the kernel.
131  *
132  */
133 static uint_t	khat_start;	/* index of 1st entry in kernel's top ptable */
134 static uint_t	khat_entries;	/* number of entries in kernel's top ptable */
135 
136 #if defined(__i386)
137 
138 static htable_t	*khat_pae32_htable = NULL;
139 static uint_t	khat_pae32_start;
140 static uint_t	khat_pae32_entries;
141 
142 #endif
143 
144 uint_t use_boot_reserve = 1;	/* cleared after early boot process */
145 uint_t can_steal_post_boot = 0;	/* set late in boot to enable stealing */
146 
147 /*
148  * A cpuset for all cpus. This is used for kernel address cross calls, since
149  * the kernel addresses apply to all cpus.
150  */
151 cpuset_t khat_cpuset;
152 
153 /*
154  * management stuff for hat structures
155  */
156 kmutex_t	hat_list_lock;
157 kcondvar_t	hat_list_cv;
158 kmem_cache_t	*hat_cache;
159 kmem_cache_t	*hat_hash_cache;
160 kmem_cache_t	*vlp_hash_cache;
161 
162 /*
163  * Simple statistics
164  */
165 struct hatstats hatstat;
166 
167 /*
168  * useful stuff for atomic access/clearing/setting REF/MOD/RO bits in page_t's.
169  */
170 extern void atomic_orb(uchar_t *addr, uchar_t val);
171 extern void atomic_andb(uchar_t *addr, uchar_t val);
172 
173 #define	PP_GETRM(pp, rmmask)    (pp->p_nrm & rmmask)
174 #define	PP_ISMOD(pp)		PP_GETRM(pp, P_MOD)
175 #define	PP_ISREF(pp)		PP_GETRM(pp, P_REF)
176 #define	PP_ISRO(pp)		PP_GETRM(pp, P_RO)
177 
178 #define	PP_SETRM(pp, rm)	atomic_orb(&(pp->p_nrm), rm)
179 #define	PP_SETMOD(pp)		PP_SETRM(pp, P_MOD)
180 #define	PP_SETREF(pp)		PP_SETRM(pp, P_REF)
181 #define	PP_SETRO(pp)		PP_SETRM(pp, P_RO)
182 
183 #define	PP_CLRRM(pp, rm)	atomic_andb(&(pp->p_nrm), ~(rm))
184 #define	PP_CLRMOD(pp)   	PP_CLRRM(pp, P_MOD)
185 #define	PP_CLRREF(pp)   	PP_CLRRM(pp, P_REF)
186 #define	PP_CLRRO(pp)    	PP_CLRRM(pp, P_RO)
187 #define	PP_CLRALL(pp)		PP_CLRRM(pp, P_MOD | P_REF | P_RO)
188 
189 /*
190  * kmem cache constructor for struct hat
191  */
192 /*ARGSUSED*/
193 static int
194 hati_constructor(void *buf, void *handle, int kmflags)
195 {
196 	hat_t	*hat = buf;
197 
198 	mutex_init(&hat->hat_mutex, NULL, MUTEX_DEFAULT, NULL);
199 	bzero(hat->hat_pages_mapped,
200 	    sizeof (pgcnt_t) * (mmu.max_page_level + 1));
201 	hat->hat_ism_pgcnt = 0;
202 	hat->hat_stats = 0;
203 	hat->hat_flags = 0;
204 	CPUSET_ZERO(hat->hat_cpus);
205 	hat->hat_htable = NULL;
206 	hat->hat_ht_hash = NULL;
207 	return (0);
208 }
209 
210 /*
211  * Allocate a hat structure for as. We also create the top level
212  * htable and initialize it to contain the kernel hat entries.
213  */
214 hat_t *
215 hat_alloc(struct as *as)
216 {
217 	hat_t		*hat;
218 	htable_t	*ht;	/* top level htable */
219 	uint_t		use_vlp;
220 
221 	/*
222 	 * Once we start creating user process HATs we can enable
223 	 * the htable_steal() code.
224 	 */
225 	if (can_steal_post_boot == 0)
226 		can_steal_post_boot = 1;
227 
228 	ASSERT(AS_WRITE_HELD(as, &as->a_lock));
229 	hat = kmem_cache_alloc(hat_cache, KM_SLEEP);
230 	hat->hat_as = as;
231 	mutex_init(&hat->hat_mutex, NULL, MUTEX_DEFAULT, NULL);
232 	ASSERT(hat->hat_flags == 0);
233 
234 	/*
235 	 * a 32 bit process uses a VLP style hat when using PAE
236 	 */
237 #if defined(__amd64)
238 	use_vlp = (ttoproc(curthread)->p_model == DATAMODEL_ILP32);
239 #elif defined(__i386)
240 	use_vlp = mmu.pae_hat;
241 #endif
242 	if (use_vlp) {
243 		hat->hat_flags = HAT_VLP;
244 		bzero(hat->hat_vlp_ptes, VLP_SIZE);
245 	}
246 
247 	/*
248 	 * Allocate the htable hash
249 	 */
250 	if ((hat->hat_flags & HAT_VLP)) {
251 		hat->hat_num_hash = mmu.vlp_hash_cnt;
252 		hat->hat_ht_hash = kmem_cache_alloc(vlp_hash_cache, KM_SLEEP);
253 	} else {
254 		hat->hat_num_hash = mmu.hash_cnt;
255 		hat->hat_ht_hash = kmem_cache_alloc(hat_hash_cache, KM_SLEEP);
256 	}
257 	bzero(hat->hat_ht_hash, hat->hat_num_hash * sizeof (htable_t *));
258 
259 	/*
260 	 * Initialize Kernel HAT entries at the top of the top level page
261 	 * table for the new hat.
262 	 *
263 	 * Note that we don't call htable_release() for the top level, that
264 	 * happens when the hat is destroyed in hat_free_end()
265 	 */
266 	hat->hat_htable = NULL;
267 	hat->hat_ht_cached = NULL;
268 	ht = htable_create(hat, (uintptr_t)0, TOP_LEVEL(hat), NULL);
269 
270 	if (!(hat->hat_flags & HAT_VLP))
271 		x86pte_copy(kas.a_hat->hat_htable, ht, khat_start,
272 		    khat_entries);
273 #if defined(__i386)
274 	else if (khat_entries > 0)
275 		bcopy(vlp_page + khat_start, hat->hat_vlp_ptes + khat_start,
276 		    khat_entries * sizeof (x86pte_t));
277 #endif
278 	hat->hat_htable = ht;
279 
280 #if defined(__i386)
281 	/*
282 	 * PAE32 HAT alignment is less restrictive than the others to keep
283 	 * the kernel from using too much VA. Because of this we may need
284 	 * one layer further down when kernelbase isn't 1Gig aligned.
285 	 * See hat_free_end() for the htable_release() that goes with this
286 	 * htable_create()
287 	 */
288 	if (khat_pae32_htable != NULL) {
289 		ht = htable_create(hat, kernelbase,
290 		    khat_pae32_htable->ht_level, NULL);
291 		x86pte_copy(khat_pae32_htable, ht, khat_pae32_start,
292 		    khat_pae32_entries);
293 		ht->ht_valid_cnt = khat_pae32_entries;
294 	}
295 #endif
296 
297 	/*
298 	 * Put it at the start of the global list of all hats (used by stealing)
299 	 *
300 	 * kas.a_hat is not in the list but is instead used to find the
301 	 * first and last items in the list.
302 	 *
303 	 * - kas.a_hat->hat_next points to the start of the user hats.
304 	 *   The list ends where hat->hat_next == NULL
305 	 *
306 	 * - kas.a_hat->hat_prev points to the last of the user hats.
307 	 *   The list begins where hat->hat_prev == NULL
308 	 */
309 	mutex_enter(&hat_list_lock);
310 	hat->hat_prev = NULL;
311 	hat->hat_next = kas.a_hat->hat_next;
312 	if (hat->hat_next)
313 		hat->hat_next->hat_prev = hat;
314 	else
315 		kas.a_hat->hat_prev = hat;
316 	kas.a_hat->hat_next = hat;
317 	mutex_exit(&hat_list_lock);
318 
319 	return (hat);
320 }
321 
322 /*
323  * process has finished executing but as has not been cleaned up yet.
324  */
325 /*ARGSUSED*/
326 void
327 hat_free_start(hat_t *hat)
328 {
329 	ASSERT(AS_WRITE_HELD(hat->hat_as, &hat->hat_as->a_lock));
330 
331 	/*
332 	 * If the hat is currently a stealing victim, wait for the stealing
333 	 * to finish.  Once we mark it as HAT_FREEING, htable_steal()
334 	 * won't look at its pagetables anymore.
335 	 */
336 	mutex_enter(&hat_list_lock);
337 	while (hat->hat_flags & HAT_VICTIM)
338 		cv_wait(&hat_list_cv, &hat_list_lock);
339 	hat->hat_flags |= HAT_FREEING;
340 	mutex_exit(&hat_list_lock);
341 }
342 
343 /*
344  * An address space is being destroyed, so we destroy the associated hat.
345  */
346 void
347 hat_free_end(hat_t *hat)
348 {
349 	int i;
350 	kmem_cache_t *cache;
351 
352 #ifdef DEBUG
353 	for (i = 0; i <= mmu.max_page_level; i++)
354 		ASSERT(hat->hat_pages_mapped[i] == 0);
355 #endif
356 	ASSERT(hat->hat_flags & HAT_FREEING);
357 
358 	/*
359 	 * must not be running on the given hat
360 	 */
361 	ASSERT(CPU->cpu_current_hat != hat);
362 
363 	/*
364 	 * Remove it from the list of HATs
365 	 */
366 	mutex_enter(&hat_list_lock);
367 	if (hat->hat_prev)
368 		hat->hat_prev->hat_next = hat->hat_next;
369 	else
370 		kas.a_hat->hat_next = hat->hat_next;
371 	if (hat->hat_next)
372 		hat->hat_next->hat_prev = hat->hat_prev;
373 	else
374 		kas.a_hat->hat_prev = hat->hat_prev;
375 	mutex_exit(&hat_list_lock);
376 	hat->hat_next = hat->hat_prev = NULL;
377 
378 	/*
379 	 * Make a pass through the htables freeing them all up.
380 	 */
381 	htable_purge_hat(hat);
382 
383 	/*
384 	 * Decide which kmem cache the hash table came from, then free it.
385 	 */
386 	if (hat->hat_flags & HAT_VLP)
387 		cache = vlp_hash_cache;
388 	else
389 		cache = hat_hash_cache;
390 	kmem_cache_free(cache, hat->hat_ht_hash);
391 	hat->hat_ht_hash = NULL;
392 
393 	hat->hat_flags = 0;
394 	kmem_cache_free(hat_cache, hat);
395 }
396 
397 /*
398  * round kernelbase down to a supported value to use for _userlimit
399  *
400  * userlimit must be aligned down to an entry in the top level htable.
401  * The one exception is for 32 bit HAT's running PAE.
402  */
403 uintptr_t
404 hat_kernelbase(uintptr_t va)
405 {
406 #if defined(__i386)
407 	va &= LEVEL_MASK(1);
408 #endif
409 	if (IN_VA_HOLE(va))
410 		panic("_userlimit %p will fall in VA hole\n", (void *)va);
411 	return (va);
412 }
413 
414 /*
415  * Initialize hat data structures based on processor MMU information.
416  */
417 void
418 mmu_init(void)
419 {
420 	uint_t max_htables;
421 	uint_t pa_bits;
422 	uint_t va_bits;
423 	int i;
424 
425 	/*
426 	 * If CPU enabled the page table global bit, use it for the kernel
427 	 * This is bit 7 in CR4 (PGE - Page Global Enable).
428 	 */
429 	if ((x86_feature & X86_PGE) != 0 && (getcr4() & CR4_PGE) != 0)
430 		mmu.pt_global = PT_GLOBAL;
431 
432 	/*
433 	 * Detect NX and PAE usage.
434 	 */
435 	mmu.pae_hat = kbm_pae_support;
436 	if (kbm_nx_support)
437 		mmu.pt_nx = PT_NX;
438 	else
439 		mmu.pt_nx = 0;
440 
441 	/*
442 	 * Use CPU info to set various MMU parameters
443 	 */
444 	cpuid_get_addrsize(CPU, &pa_bits, &va_bits);
445 
446 	if (va_bits < sizeof (void *) * NBBY) {
447 		mmu.hole_start = (1ul << (va_bits - 1));
448 		mmu.hole_end = 0ul - mmu.hole_start - 1;
449 	} else {
450 		mmu.hole_end = 0;
451 		mmu.hole_start = mmu.hole_end - 1;
452 	}
453 #if defined(OPTERON_ERRATUM_121)
454 	/*
455 	 * If erratum 121 has already been detected at this time, hole_start
456 	 * contains the value to be subtracted from mmu.hole_start.
457 	 */
458 	ASSERT(hole_start == 0 || opteron_erratum_121 != 0);
459 	hole_start = mmu.hole_start - hole_start;
460 #else
461 	hole_start = mmu.hole_start;
462 #endif
463 	hole_end = mmu.hole_end;
464 
465 	mmu.highest_pfn = mmu_btop((1ull << pa_bits) - 1);
466 	if (mmu.pae_hat == 0 && pa_bits > 32)
467 		mmu.highest_pfn = PFN_4G - 1;
468 
469 	if (mmu.pae_hat) {
470 		mmu.pte_size = 8;	/* 8 byte PTEs */
471 		mmu.pte_size_shift = 3;
472 	} else {
473 		mmu.pte_size = 4;	/* 4 byte PTEs */
474 		mmu.pte_size_shift = 2;
475 	}
476 
477 	if (mmu.pae_hat && (x86_feature & X86_PAE) == 0)
478 		panic("Processor does not support PAE");
479 
480 	if ((x86_feature & X86_CX8) == 0)
481 		panic("Processor does not support cmpxchg8b instruction");
482 
483 	/*
484 	 * Initialize parameters based on the 64 or 32 bit kernels and
485 	 * for the 32 bit kernel decide if we should use PAE.
486 	 */
487 	if (kbm_largepage_support)
488 		mmu.max_page_level = 1;
489 	else
490 		mmu.max_page_level = 0;
491 	mmu_page_sizes = mmu.max_page_level + 1;
492 	mmu_exported_page_sizes = mmu_page_sizes;
493 
494 #if defined(__amd64)
495 
496 	mmu.num_level = 4;
497 	mmu.max_level = 3;
498 	mmu.ptes_per_table = 512;
499 	mmu.top_level_count = 512;
500 
501 	mmu.level_shift[0] = 12;
502 	mmu.level_shift[1] = 21;
503 	mmu.level_shift[2] = 30;
504 	mmu.level_shift[3] = 39;
505 
506 #elif defined(__i386)
507 
508 	if (mmu.pae_hat) {
509 		mmu.num_level = 3;
510 		mmu.max_level = 2;
511 		mmu.ptes_per_table = 512;
512 		mmu.top_level_count = 4;
513 
514 		mmu.level_shift[0] = 12;
515 		mmu.level_shift[1] = 21;
516 		mmu.level_shift[2] = 30;
517 
518 	} else {
519 		mmu.num_level = 2;
520 		mmu.max_level = 1;
521 		mmu.ptes_per_table = 1024;
522 		mmu.top_level_count = 1024;
523 
524 		mmu.level_shift[0] = 12;
525 		mmu.level_shift[1] = 22;
526 	}
527 
528 #endif	/* __i386 */
529 
530 	for (i = 0; i < mmu.num_level; ++i) {
531 		mmu.level_size[i] = 1UL << mmu.level_shift[i];
532 		mmu.level_offset[i] = mmu.level_size[i] - 1;
533 		mmu.level_mask[i] = ~mmu.level_offset[i];
534 	}
535 
536 	for (i = 0; i <= mmu.max_page_level; ++i) {
537 		mmu.pte_bits[i] = PT_VALID;
538 		if (i > 0)
539 			mmu.pte_bits[i] |= PT_PAGESIZE;
540 	}
541 
542 	/*
543 	 * NOTE Legacy 32 bit PAE mode only has the P_VALID bit at top level.
544 	 */
545 	for (i = 1; i < mmu.num_level; ++i)
546 		mmu.ptp_bits[i] = PT_PTPBITS;
547 
548 #if defined(__i386)
549 	mmu.ptp_bits[2] = PT_VALID;
550 #endif
551 
552 	/*
553 	 * Compute how many hash table entries to have per process for htables.
554 	 * We start with 1 page's worth of entries.
555 	 *
556 	 * If physical memory is small, reduce the amount need to cover it.
557 	 */
558 	max_htables = physmax / mmu.ptes_per_table;
559 	mmu.hash_cnt = MMU_PAGESIZE / sizeof (htable_t *);
560 	while (mmu.hash_cnt > 16 && mmu.hash_cnt >= max_htables)
561 		mmu.hash_cnt >>= 1;
562 	mmu.vlp_hash_cnt = mmu.hash_cnt;
563 
564 #if defined(__amd64)
565 	/*
566 	 * If running in 64 bits and physical memory is large,
567 	 * increase the size of the cache to cover all of memory for
568 	 * a 64 bit process.
569 	 */
570 #define	HASH_MAX_LENGTH 4
571 	while (mmu.hash_cnt * HASH_MAX_LENGTH < max_htables)
572 		mmu.hash_cnt <<= 1;
573 #endif
574 }
575 
576 
577 /*
578  * initialize hat data structures
579  */
580 void
581 hat_init()
582 {
583 #if defined(__i386)
584 	/*
585 	 * _userlimit must be aligned correctly
586 	 */
587 	if ((_userlimit & LEVEL_MASK(1)) != _userlimit) {
588 		prom_printf("hat_init(): _userlimit=%p, not aligned at %p\n",
589 		    (void *)_userlimit, (void *)LEVEL_SIZE(1));
590 		halt("hat_init(): Unable to continue");
591 	}
592 #endif
593 
594 	cv_init(&hat_list_cv, NULL, CV_DEFAULT, NULL);
595 
596 	/*
597 	 * initialize kmem caches
598 	 */
599 	htable_init();
600 	hment_init();
601 
602 	hat_cache = kmem_cache_create("hat_t",
603 	    sizeof (hat_t), 0, hati_constructor, NULL, NULL,
604 	    NULL, 0, 0);
605 
606 	hat_hash_cache = kmem_cache_create("HatHash",
607 	    mmu.hash_cnt * sizeof (htable_t *), 0, NULL, NULL, NULL,
608 	    NULL, 0, 0);
609 
610 	/*
611 	 * VLP hats can use a smaller hash table size on large memroy machines
612 	 */
613 	if (mmu.hash_cnt == mmu.vlp_hash_cnt) {
614 		vlp_hash_cache = hat_hash_cache;
615 	} else {
616 		vlp_hash_cache = kmem_cache_create("HatVlpHash",
617 		    mmu.vlp_hash_cnt * sizeof (htable_t *), 0, NULL, NULL, NULL,
618 		    NULL, 0, 0);
619 	}
620 
621 	/*
622 	 * Set up the kernel's hat
623 	 */
624 	AS_LOCK_ENTER(&kas, &kas.a_lock, RW_WRITER);
625 	kas.a_hat = kmem_cache_alloc(hat_cache, KM_NOSLEEP);
626 	mutex_init(&kas.a_hat->hat_mutex, NULL, MUTEX_DEFAULT, NULL);
627 	kas.a_hat->hat_as = &kas;
628 	kas.a_hat->hat_flags = 0;
629 	AS_LOCK_EXIT(&kas, &kas.a_lock);
630 
631 	CPUSET_ZERO(khat_cpuset);
632 	CPUSET_ADD(khat_cpuset, CPU->cpu_id);
633 
634 	/*
635 	 * The kernel hat's next pointer serves as the head of the hat list .
636 	 * The kernel hat's prev pointer tracks the last hat on the list for
637 	 * htable_steal() to use.
638 	 */
639 	kas.a_hat->hat_next = NULL;
640 	kas.a_hat->hat_prev = NULL;
641 
642 	/*
643 	 * Allocate an htable hash bucket for the kernel
644 	 * XX64 - tune for 64 bit procs
645 	 */
646 	kas.a_hat->hat_num_hash = mmu.hash_cnt;
647 	kas.a_hat->hat_ht_hash = kmem_cache_alloc(hat_hash_cache, KM_NOSLEEP);
648 	bzero(kas.a_hat->hat_ht_hash, mmu.hash_cnt * sizeof (htable_t *));
649 
650 	/*
651 	 * zero out the top level and cached htable pointers
652 	 */
653 	kas.a_hat->hat_ht_cached = NULL;
654 	kas.a_hat->hat_htable = NULL;
655 
656 	/*
657 	 * Pre-allocate hrm_hashtab before enabling the collection of
658 	 * refmod statistics.  Allocating on the fly would mean us
659 	 * running the risk of suffering recursive mutex enters or
660 	 * deadlocks.
661 	 */
662 	hrm_hashtab = kmem_zalloc(HRM_HASHSIZE * sizeof (struct hrmstat *),
663 	    KM_SLEEP);
664 }
665 
666 /*
667  * Prepare CPU specific pagetables for VLP processes on 64 bit kernels.
668  *
669  * Each CPU has a set of 2 pagetables that are reused for any 32 bit
670  * process it runs. They are the top level pagetable, hci_vlp_l3ptes, and
671  * the next to top level table for the bottom 512 Gig, hci_vlp_l2ptes.
672  */
673 /*ARGSUSED*/
674 static void
675 hat_vlp_setup(struct cpu *cpu)
676 {
677 #if defined(__amd64)
678 	struct hat_cpu_info *hci = cpu->cpu_hat_info;
679 	pfn_t pfn;
680 
681 	/*
682 	 * allocate the level==2 page table for the bottom most
683 	 * 512Gig of address space (this is where 32 bit apps live)
684 	 */
685 	ASSERT(hci != NULL);
686 	hci->hci_vlp_l2ptes = kmem_zalloc(MMU_PAGESIZE, KM_SLEEP);
687 
688 	/*
689 	 * Allocate a top level pagetable and copy the kernel's
690 	 * entries into it. Then link in hci_vlp_l2ptes in the 1st entry.
691 	 */
692 	hci->hci_vlp_l3ptes = kmem_zalloc(MMU_PAGESIZE, KM_SLEEP);
693 	hci->hci_vlp_pfn =
694 	    hat_getpfnum(kas.a_hat, (caddr_t)hci->hci_vlp_l3ptes);
695 	ASSERT(hci->hci_vlp_pfn != PFN_INVALID);
696 	bcopy(vlp_page + khat_start, hci->hci_vlp_l3ptes + khat_start,
697 	    khat_entries * sizeof (x86pte_t));
698 
699 	pfn = hat_getpfnum(kas.a_hat, (caddr_t)hci->hci_vlp_l2ptes);
700 	ASSERT(pfn != PFN_INVALID);
701 	hci->hci_vlp_l3ptes[0] = MAKEPTP(pfn, 2);
702 #endif /* __amd64 */
703 }
704 
705 /*ARGSUSED*/
706 static void
707 hat_vlp_teardown(cpu_t *cpu)
708 {
709 #if defined(__amd64)
710 	struct hat_cpu_info *hci;
711 
712 	if ((hci = cpu->cpu_hat_info) == NULL)
713 		return;
714 	if (hci->hci_vlp_l2ptes)
715 		kmem_free(hci->hci_vlp_l2ptes, MMU_PAGESIZE);
716 	if (hci->hci_vlp_l3ptes)
717 		kmem_free(hci->hci_vlp_l3ptes, MMU_PAGESIZE);
718 #endif	/* __amd64 */
719 }
720 
721 /*
722  * Finish filling in the kernel hat.
723  * Pre fill in all top level kernel page table entries for the kernel's
724  * part of the address range.  From this point on we can't use any new
725  * kernel large pages if they need PTE's at max_level
726  *
727  * create the kmap mappings.
728  */
729 void
730 hat_init_finish(void)
731 {
732 	htable_t	*top = kas.a_hat->hat_htable;
733 	htable_t	*ht;
734 	uint_t		e;
735 	x86pte_t	pte;
736 	uintptr_t	va = kernelbase;
737 	size_t		size;
738 
739 
740 #if defined(__i386)
741 	ASSERT((va & LEVEL_MASK(1)) == va);
742 
743 	/*
744 	 * Deal with kernelbase not 1Gig aligned for 32 bit PAE hats.
745 	 */
746 	if (!mmu.pae_hat || (va & LEVEL_OFFSET(mmu.max_level)) == 0) {
747 		khat_pae32_htable = NULL;
748 	} else {
749 		ASSERT(mmu.max_level == 2);
750 		ASSERT((va & LEVEL_OFFSET(mmu.max_level - 1)) == 0);
751 		khat_pae32_htable =
752 		    htable_create(kas.a_hat, va, mmu.max_level - 1, NULL);
753 		khat_pae32_start = htable_va2entry(va, khat_pae32_htable);
754 		khat_pae32_entries = mmu.ptes_per_table - khat_pae32_start;
755 		for (e = khat_pae32_start; e < mmu.ptes_per_table;
756 		    ++e, va += LEVEL_SIZE(mmu.max_level - 1)) {
757 			pte = x86pte_get(khat_pae32_htable, e);
758 			if (PTE_ISVALID(pte))
759 				continue;
760 			ht = htable_create(kas.a_hat, va, mmu.max_level - 2,
761 			    NULL);
762 			ASSERT(ht != NULL);
763 		}
764 	}
765 #endif
766 
767 	/*
768 	 * The kernel hat will need fixed values in the highest level
769 	 * ptable for copying to all other hat's. This implies
770 	 * alignment restrictions on _userlimit.
771 	 *
772 	 * Note we don't htable_release() these htables. This keeps them
773 	 * from ever being stolen or free'd.
774 	 *
775 	 * top_level_count is used instead of ptes_per_table, since
776 	 * on 32-bit PAE we only have 4 usable entries at the top level ptable.
777 	 */
778 	if (va == 0)
779 		khat_start = mmu.top_level_count;
780 	else
781 		khat_start = htable_va2entry(va, kas.a_hat->hat_htable);
782 	khat_entries = mmu.top_level_count - khat_start;
783 	for (e = khat_start; e < mmu.top_level_count;
784 	    ++e, va += LEVEL_SIZE(mmu.max_level)) {
785 		if (IN_HYPERVISOR_VA(va))
786 			continue;
787 		pte = x86pte_get(top, e);
788 		if (PTE_ISVALID(pte))
789 			continue;
790 		ht = htable_create(kas.a_hat, va, mmu.max_level - 1, NULL);
791 		ASSERT(ht != NULL);
792 	}
793 
794 	/*
795 	 * We are now effectively running on the kernel hat.
796 	 * Clearing use_boot_reserve shuts off using the pre-allocated boot
797 	 * reserve for all HAT allocations.  From here on, the reserves are
798 	 * only used when mapping in memory for the hat's own allocations.
799 	 */
800 	use_boot_reserve = 0;
801 	htable_adjust_reserve();
802 
803 	/*
804 	 * 32 bit kernels use only 4 of the 512 entries in its top level
805 	 * pagetable. We'll use the remainder for the "per CPU" page tables
806 	 * for VLP processes.
807 	 *
808 	 * We also map the top level kernel pagetable into the kernel to make
809 	 * it easy to use bcopy to initialize new address spaces.
810 	 */
811 	if (mmu.pae_hat) {
812 		vlp_page = vmem_alloc(heap_arena, MMU_PAGESIZE, VM_SLEEP);
813 		hat_devload(kas.a_hat, (caddr_t)vlp_page, MMU_PAGESIZE,
814 		    kas.a_hat->hat_htable->ht_pfn,
815 		    PROT_WRITE |
816 		    PROT_READ | HAT_NOSYNC | HAT_UNORDERED_OK,
817 		    HAT_LOAD | HAT_LOAD_NOCONSIST);
818 	}
819 	hat_vlp_setup(CPU);
820 
821 	/*
822 	 * Create kmap (cached mappings of kernel PTEs)
823 	 * for 32 bit we map from segmap_start .. ekernelheap
824 	 * for 64 bit we map from segmap_start .. segmap_start + segmapsize;
825 	 */
826 #if defined(__i386)
827 	size = (uintptr_t)ekernelheap - segmap_start;
828 #elif defined(__amd64)
829 	size = segmapsize;
830 #endif
831 	hat_kmap_init((uintptr_t)segmap_start, size);
832 }
833 
834 /*
835  * On 32 bit PAE mode, PTE's are 64 bits, but ordinary atomic memory references
836  * are 32 bit, so for safety we must use cas64() to install these.
837  */
838 #ifdef __i386
839 static void
840 reload_pae32(hat_t *hat, cpu_t *cpu)
841 {
842 	x86pte_t *src;
843 	x86pte_t *dest;
844 	x86pte_t pte;
845 	int i;
846 
847 	/*
848 	 * Load the 4 entries of the level 2 page table into this
849 	 * cpu's range of the vlp_page and point cr3 at them.
850 	 */
851 	ASSERT(mmu.pae_hat);
852 	src = hat->hat_vlp_ptes;
853 	dest = vlp_page + (cpu->cpu_id + 1) * VLP_NUM_PTES;
854 	for (i = 0; i < VLP_NUM_PTES; ++i) {
855 		for (;;) {
856 			pte = dest[i];
857 			if (pte == src[i])
858 				break;
859 			if (cas64(dest + i, pte, src[i]) != src[i])
860 				break;
861 		}
862 	}
863 }
864 #endif
865 
866 /*
867  * Switch to a new active hat, maintaining bit masks to track active CPUs.
868  */
869 void
870 hat_switch(hat_t *hat)
871 {
872 	uintptr_t	newcr3;
873 	cpu_t		*cpu = CPU;
874 	hat_t		*old = cpu->cpu_current_hat;
875 
876 	/*
877 	 * set up this information first, so we don't miss any cross calls
878 	 */
879 	if (old != NULL) {
880 		if (old == hat)
881 			return;
882 		if (old != kas.a_hat)
883 			CPUSET_ATOMIC_DEL(old->hat_cpus, cpu->cpu_id);
884 	}
885 
886 	/*
887 	 * Add this CPU to the active set for this HAT.
888 	 */
889 	if (hat != kas.a_hat) {
890 		CPUSET_ATOMIC_ADD(hat->hat_cpus, cpu->cpu_id);
891 	}
892 	cpu->cpu_current_hat = hat;
893 
894 	/*
895 	 * now go ahead and load cr3
896 	 */
897 	if (hat->hat_flags & HAT_VLP) {
898 #if defined(__amd64)
899 		x86pte_t *vlpptep = cpu->cpu_hat_info->hci_vlp_l2ptes;
900 
901 		VLP_COPY(hat->hat_vlp_ptes, vlpptep);
902 		newcr3 = MAKECR3(cpu->cpu_hat_info->hci_vlp_pfn);
903 #elif defined(__i386)
904 		reload_pae32(hat, cpu);
905 		newcr3 = MAKECR3(kas.a_hat->hat_htable->ht_pfn) +
906 		    (cpu->cpu_id + 1) * VLP_SIZE;
907 #endif
908 	} else {
909 		newcr3 = MAKECR3(hat->hat_htable->ht_pfn);
910 	}
911 	setcr3(newcr3);
912 	ASSERT(cpu == CPU);
913 }
914 
915 /*
916  * Utility to return a valid x86pte_t from protections, pfn, and level number
917  */
918 static x86pte_t
919 hati_mkpte(pfn_t pfn, uint_t attr, level_t level, uint_t flags)
920 {
921 	x86pte_t	pte;
922 	uint_t		cache_attr = attr & HAT_ORDER_MASK;
923 
924 	pte = MAKEPTE(pfn, level);
925 
926 	if (attr & PROT_WRITE)
927 		PTE_SET(pte, PT_WRITABLE);
928 
929 	if (attr & PROT_USER)
930 		PTE_SET(pte, PT_USER);
931 
932 	if (!(attr & PROT_EXEC))
933 		PTE_SET(pte, mmu.pt_nx);
934 
935 	/*
936 	 * Set the software bits used track ref/mod sync's and hments.
937 	 * If not using REF/MOD, set them to avoid h/w rewriting PTEs.
938 	 */
939 	if (flags & HAT_LOAD_NOCONSIST)
940 		PTE_SET(pte, PT_NOCONSIST | PT_REF | PT_MOD);
941 	else if (attr & HAT_NOSYNC)
942 		PTE_SET(pte, PT_NOSYNC | PT_REF | PT_MOD);
943 
944 	/*
945 	 * Set the caching attributes in the PTE. The combination
946 	 * of attributes are poorly defined, so we pay attention
947 	 * to them in the given order.
948 	 *
949 	 * The test for HAT_STRICTORDER is different because it's defined
950 	 * as "0" - which was a stupid thing to do, but is too late to change!
951 	 */
952 	if (cache_attr == HAT_STRICTORDER) {
953 		PTE_SET(pte, PT_NOCACHE);
954 	/*LINTED [Lint hates empty ifs, but it's the obvious way to do this] */
955 	} else if (cache_attr & (HAT_UNORDERED_OK | HAT_STORECACHING_OK)) {
956 		/* nothing to set */;
957 	} else if (cache_attr & (HAT_MERGING_OK | HAT_LOADCACHING_OK)) {
958 		PTE_SET(pte, PT_NOCACHE);
959 		if (x86_feature & X86_PAT)
960 			PTE_SET(pte, (level == 0) ? PT_PAT_4K : PT_PAT_LARGE);
961 		else
962 			PTE_SET(pte, PT_WRITETHRU);
963 	} else {
964 		panic("hati_mkpte(): bad caching attributes: %x\n", cache_attr);
965 	}
966 
967 	return (pte);
968 }
969 
970 /*
971  * Duplicate address translations of the parent to the child.
972  * This function really isn't used anymore.
973  */
974 /*ARGSUSED*/
975 int
976 hat_dup(hat_t *old, hat_t *new, caddr_t addr, size_t len, uint_t flag)
977 {
978 	ASSERT((uintptr_t)addr < kernelbase);
979 	ASSERT(new != kas.a_hat);
980 	ASSERT(old != kas.a_hat);
981 	return (0);
982 }
983 
984 /*
985  * Allocate any hat resources required for a process being swapped in.
986  */
987 /*ARGSUSED*/
988 void
989 hat_swapin(hat_t *hat)
990 {
991 	/* do nothing - we let everything fault back in */
992 }
993 
994 /*
995  * Unload all translations associated with an address space of a process
996  * that is being swapped out.
997  */
998 void
999 hat_swapout(hat_t *hat)
1000 {
1001 	uintptr_t	vaddr = (uintptr_t)0;
1002 	uintptr_t	eaddr = _userlimit;
1003 	htable_t	*ht = NULL;
1004 	level_t		l;
1005 
1006 	/*
1007 	 * We can't just call hat_unload(hat, 0, _userlimit...)  here, because
1008 	 * seg_spt and shared pagetables can't be swapped out.
1009 	 * Take a look at segspt_shmswapout() - it's a big no-op.
1010 	 *
1011 	 * Instead we'll walk through all the address space and unload
1012 	 * any mappings which we are sure are not shared, not locked.
1013 	 */
1014 	ASSERT(IS_PAGEALIGNED(vaddr));
1015 	ASSERT(IS_PAGEALIGNED(eaddr));
1016 	ASSERT(AS_LOCK_HELD(hat->hat_as, &hat->hat_as->a_lock));
1017 	if ((uintptr_t)hat->hat_as->a_userlimit < eaddr)
1018 		eaddr = (uintptr_t)hat->hat_as->a_userlimit;
1019 
1020 	while (vaddr < eaddr) {
1021 		(void) htable_walk(hat, &ht, &vaddr, eaddr);
1022 		if (ht == NULL)
1023 			break;
1024 
1025 		ASSERT(!IN_VA_HOLE(vaddr));
1026 
1027 		/*
1028 		 * If the page table is shared skip its entire range.
1029 		 * This code knows that only level 0 page tables are shared
1030 		 */
1031 		l = ht->ht_level;
1032 		if (ht->ht_flags & HTABLE_SHARED_PFN) {
1033 			ASSERT(l == 0);
1034 			vaddr = ht->ht_vaddr + LEVEL_SIZE(1);
1035 			htable_release(ht);
1036 			ht = NULL;
1037 			continue;
1038 		}
1039 
1040 		/*
1041 		 * If the page table has no locked entries, unload this one.
1042 		 */
1043 		if (ht->ht_lock_cnt == 0)
1044 			hat_unload(hat, (caddr_t)vaddr, LEVEL_SIZE(l),
1045 			    HAT_UNLOAD_UNMAP);
1046 
1047 		/*
1048 		 * If we have a level 0 page table with locked entries,
1049 		 * skip the entire page table, otherwise skip just one entry.
1050 		 */
1051 		if (ht->ht_lock_cnt > 0 && l == 0)
1052 			vaddr = ht->ht_vaddr + LEVEL_SIZE(1);
1053 		else
1054 			vaddr += LEVEL_SIZE(l);
1055 	}
1056 	if (ht)
1057 		htable_release(ht);
1058 
1059 	/*
1060 	 * We're in swapout because the system is low on memory, so
1061 	 * go back and flush all the htables off the cached list.
1062 	 */
1063 	htable_purge_hat(hat);
1064 }
1065 
1066 /*
1067  * returns number of bytes that have valid mappings in hat.
1068  */
1069 size_t
1070 hat_get_mapped_size(hat_t *hat)
1071 {
1072 	size_t total = 0;
1073 	int l;
1074 
1075 	for (l = 0; l <= mmu.max_page_level; l++)
1076 		total += (hat->hat_pages_mapped[l] << LEVEL_SHIFT(l));
1077 	total += hat->hat_ism_pgcnt;
1078 
1079 	return (total);
1080 }
1081 
1082 /*
1083  * enable/disable collection of stats for hat.
1084  */
1085 int
1086 hat_stats_enable(hat_t *hat)
1087 {
1088 	atomic_add_32(&hat->hat_stats, 1);
1089 	return (1);
1090 }
1091 
1092 void
1093 hat_stats_disable(hat_t *hat)
1094 {
1095 	atomic_add_32(&hat->hat_stats, -1);
1096 }
1097 
1098 /*
1099  * Utility to sync the ref/mod bits from a page table entry to the page_t
1100  * We must be holding the mapping list lock when this is called.
1101  */
1102 static void
1103 hati_sync_pte_to_page(page_t *pp, x86pte_t pte, level_t level)
1104 {
1105 	uint_t	rm = 0;
1106 	pgcnt_t	pgcnt;
1107 
1108 	if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC)
1109 		return;
1110 
1111 	if (PTE_GET(pte, PT_REF))
1112 		rm |= P_REF;
1113 
1114 	if (PTE_GET(pte, PT_MOD))
1115 		rm |= P_MOD;
1116 
1117 	if (rm == 0)
1118 		return;
1119 
1120 	/*
1121 	 * sync to all constituent pages of a large page
1122 	 */
1123 	ASSERT(x86_hm_held(pp));
1124 	pgcnt = page_get_pagecnt(level);
1125 	ASSERT(IS_P2ALIGNED(pp->p_pagenum, pgcnt));
1126 	for (; pgcnt > 0; --pgcnt) {
1127 		/*
1128 		 * hat_page_demote() can't decrease
1129 		 * pszc below this mapping size
1130 		 * since this large mapping existed after we
1131 		 * took mlist lock.
1132 		 */
1133 		ASSERT(pp->p_szc >= level);
1134 		hat_page_setattr(pp, rm);
1135 		++pp;
1136 	}
1137 }
1138 
1139 /*
1140  * This the set of PTE bits for PFN, permissions and caching
1141  * that require a TLB flush (hat_tlb_inval) if changed on a HAT_LOAD_REMAP
1142  */
1143 #define	PT_REMAP_BITS							\
1144 	(PT_PADDR | PT_NX | PT_WRITABLE | PT_WRITETHRU |		\
1145 	PT_NOCACHE | PT_PAT_4K | PT_PAT_LARGE)
1146 
1147 #define	REMAPASSERT(EX)	if (!(EX)) panic("hati_pte_map: " #EX)
1148 /*
1149  * Do the low-level work to get a mapping entered into a HAT's pagetables
1150  * and in the mapping list of the associated page_t.
1151  */
1152 static int
1153 hati_pte_map(
1154 	htable_t	*ht,
1155 	uint_t		entry,
1156 	page_t		*pp,
1157 	x86pte_t	pte,
1158 	int		flags,
1159 	void		*pte_ptr)
1160 {
1161 	hat_t		*hat = ht->ht_hat;
1162 	x86pte_t	old_pte;
1163 	level_t		l = ht->ht_level;
1164 	hment_t		*hm;
1165 	uint_t		is_consist;
1166 	int		rv = 0;
1167 
1168 	/*
1169 	 * Is this a consistant (ie. need mapping list lock) mapping?
1170 	 */
1171 	is_consist = (pp != NULL && (flags & HAT_LOAD_NOCONSIST) == 0);
1172 
1173 	/*
1174 	 * Track locked mapping count in the htable.  Do this first,
1175 	 * as we track locking even if there already is a mapping present.
1176 	 */
1177 	if ((flags & HAT_LOAD_LOCK) != 0 && hat != kas.a_hat)
1178 		HTABLE_LOCK_INC(ht);
1179 
1180 	/*
1181 	 * Acquire the page's mapping list lock and get an hment to use.
1182 	 * Note that hment_prepare() might return NULL.
1183 	 */
1184 	if (is_consist) {
1185 		x86_hm_enter(pp);
1186 		hm = hment_prepare(ht, entry, pp);
1187 	}
1188 
1189 	/*
1190 	 * Set the new pte, retrieving the old one at the same time.
1191 	 */
1192 	old_pte = x86pte_set(ht, entry, pte, pte_ptr);
1193 
1194 	/*
1195 	 * did we get a large page / page table collision?
1196 	 */
1197 	if (old_pte == LPAGE_ERROR) {
1198 		rv = -1;
1199 		goto done;
1200 	}
1201 
1202 	/*
1203 	 * If the mapping didn't change there is nothing more to do.
1204 	 */
1205 	if (PTE_EQUIV(pte, old_pte))
1206 		goto done;
1207 
1208 	/*
1209 	 * Install a new mapping in the page's mapping list
1210 	 */
1211 	if (!PTE_ISVALID(old_pte)) {
1212 		if (is_consist) {
1213 			hment_assign(ht, entry, pp, hm);
1214 			x86_hm_exit(pp);
1215 		} else {
1216 			ASSERT(flags & HAT_LOAD_NOCONSIST);
1217 		}
1218 		HTABLE_INC(ht->ht_valid_cnt);
1219 		PGCNT_INC(hat, l);
1220 		return (rv);
1221 	}
1222 
1223 	/*
1224 	 * Remap's are more complicated:
1225 	 *  - HAT_LOAD_REMAP must be specified if changing the pfn.
1226 	 *    We also require that NOCONSIST be specified.
1227 	 *  - Otherwise only permission or caching bits may change.
1228 	 */
1229 	if (!PTE_ISPAGE(old_pte, l))
1230 		panic("non-null/page mapping pte=" FMT_PTE, old_pte);
1231 
1232 	if (PTE2PFN(old_pte, l) != PTE2PFN(pte, l)) {
1233 		REMAPASSERT(flags & HAT_LOAD_REMAP);
1234 		REMAPASSERT(flags & HAT_LOAD_NOCONSIST);
1235 		REMAPASSERT(PTE_GET(old_pte, PT_SOFTWARE) >= PT_NOCONSIST);
1236 		REMAPASSERT(pf_is_memory(PTE2PFN(old_pte, l)) ==
1237 		    pf_is_memory(PTE2PFN(pte, l)));
1238 		REMAPASSERT(!is_consist);
1239 	}
1240 
1241 	/*
1242 	 * We only let remaps change the bits for PFNs, permissions
1243 	 * or caching type.
1244 	 */
1245 	ASSERT(PTE_GET(old_pte, ~(PT_REMAP_BITS | PT_REF | PT_MOD)) ==
1246 	    PTE_GET(pte, ~PT_REMAP_BITS));
1247 
1248 	/*
1249 	 * We don't create any mapping list entries on a remap, so release
1250 	 * any allocated hment after we drop the mapping list lock.
1251 	 */
1252 done:
1253 	if (is_consist) {
1254 		x86_hm_exit(pp);
1255 		if (hm != NULL)
1256 			hment_free(hm);
1257 	}
1258 	return (rv);
1259 }
1260 
1261 /*
1262  * Internal routine to load a single page table entry. This only fails if
1263  * we attempt to overwrite a page table link with a large page.
1264  */
1265 static int
1266 hati_load_common(
1267 	hat_t		*hat,
1268 	uintptr_t	va,
1269 	page_t		*pp,
1270 	uint_t		attr,
1271 	uint_t		flags,
1272 	level_t		level,
1273 	pfn_t		pfn)
1274 {
1275 	htable_t	*ht;
1276 	uint_t		entry;
1277 	x86pte_t	pte;
1278 	int		rv = 0;
1279 
1280 	/*
1281 	 * The number 16 is arbitrary and here to catch a recursion problem
1282 	 * early before we blow out the kernel stack.
1283 	 */
1284 	++curthread->t_hatdepth;
1285 	ASSERT(curthread->t_hatdepth < 16);
1286 
1287 	ASSERT(hat == kas.a_hat ||
1288 	    AS_LOCK_HELD(hat->hat_as, &hat->hat_as->a_lock));
1289 
1290 	if (flags & HAT_LOAD_SHARE)
1291 		hat->hat_flags |= HAT_SHARED;
1292 
1293 	/*
1294 	 * Find the page table that maps this page if it already exists.
1295 	 */
1296 	ht = htable_lookup(hat, va, level);
1297 
1298 	/*
1299 	 * We must have HAT_LOAD_NOCONSIST if page_t is NULL.
1300 	 */
1301 	if (pp == NULL)
1302 		flags |= HAT_LOAD_NOCONSIST;
1303 
1304 	if (ht == NULL) {
1305 		ht = htable_create(hat, va, level, NULL);
1306 		ASSERT(ht != NULL);
1307 	}
1308 	entry = htable_va2entry(va, ht);
1309 
1310 	/*
1311 	 * a bunch of paranoid error checking
1312 	 */
1313 	ASSERT(ht->ht_busy > 0);
1314 	if (ht->ht_vaddr > va || va > HTABLE_LAST_PAGE(ht))
1315 		panic("hati_load_common: bad htable %p, va %p", ht, (void *)va);
1316 	ASSERT(ht->ht_level == level);
1317 
1318 	/*
1319 	 * construct the new PTE
1320 	 */
1321 	if (hat == kas.a_hat)
1322 		attr &= ~PROT_USER;
1323 	pte = hati_mkpte(pfn, attr, level, flags);
1324 	if (hat == kas.a_hat && va >= kernelbase)
1325 		PTE_SET(pte, mmu.pt_global);
1326 
1327 	/*
1328 	 * establish the mapping
1329 	 */
1330 	rv = hati_pte_map(ht, entry, pp, pte, flags, NULL);
1331 
1332 	/*
1333 	 * release the htable and any reserves
1334 	 */
1335 	htable_release(ht);
1336 	--curthread->t_hatdepth;
1337 	return (rv);
1338 }
1339 
1340 /*
1341  * special case of hat_memload to deal with some kernel addrs for performance
1342  */
1343 static void
1344 hat_kmap_load(
1345 	caddr_t		addr,
1346 	page_t		*pp,
1347 	uint_t		attr,
1348 	uint_t		flags)
1349 {
1350 	uintptr_t	va = (uintptr_t)addr;
1351 	x86pte_t	pte;
1352 	pfn_t		pfn = page_pptonum(pp);
1353 	pgcnt_t		pg_off = mmu_btop(va - mmu.kmap_addr);
1354 	htable_t	*ht;
1355 	uint_t		entry;
1356 	void		*pte_ptr;
1357 
1358 	/*
1359 	 * construct the requested PTE
1360 	 */
1361 	attr &= ~PROT_USER;
1362 	attr |= HAT_STORECACHING_OK;
1363 	pte = hati_mkpte(pfn, attr, 0, flags);
1364 	PTE_SET(pte, mmu.pt_global);
1365 
1366 	/*
1367 	 * Figure out the pte_ptr and htable and use common code to finish up
1368 	 */
1369 	if (mmu.pae_hat)
1370 		pte_ptr = mmu.kmap_ptes + pg_off;
1371 	else
1372 		pte_ptr = (x86pte32_t *)mmu.kmap_ptes + pg_off;
1373 	ht = mmu.kmap_htables[(va - mmu.kmap_htables[0]->ht_vaddr) >>
1374 	    LEVEL_SHIFT(1)];
1375 	entry = htable_va2entry(va, ht);
1376 	++curthread->t_hatdepth;
1377 	ASSERT(curthread->t_hatdepth < 16);
1378 	(void) hati_pte_map(ht, entry, pp, pte, flags, pte_ptr);
1379 	--curthread->t_hatdepth;
1380 }
1381 
1382 /*
1383  * hat_memload() - load a translation to the given page struct
1384  *
1385  * Flags for hat_memload/hat_devload/hat_*attr.
1386  *
1387  * 	HAT_LOAD	Default flags to load a translation to the page.
1388  *
1389  * 	HAT_LOAD_LOCK	Lock down mapping resources; hat_map(), hat_memload(),
1390  *			and hat_devload().
1391  *
1392  *	HAT_LOAD_NOCONSIST Do not add mapping to page_t mapping list.
1393  *			sets PT_NOCONSIST
1394  *
1395  *	HAT_LOAD_SHARE	A flag to hat_memload() to indicate h/w page tables
1396  *			that map some user pages (not kas) is shared by more
1397  *			than one process (eg. ISM).
1398  *
1399  *	HAT_LOAD_REMAP	Reload a valid pte with a different page frame.
1400  *
1401  *	HAT_NO_KALLOC	Do not kmem_alloc while creating the mapping; at this
1402  *			point, it's setting up mapping to allocate internal
1403  *			hat layer data structures.  This flag forces hat layer
1404  *			to tap its reserves in order to prevent infinite
1405  *			recursion.
1406  *
1407  * The following is a protection attribute (like PROT_READ, etc.)
1408  *
1409  *	HAT_NOSYNC	set PT_NOSYNC - this mapping's ref/mod bits
1410  *			are never cleared.
1411  *
1412  * Installing new valid PTE's and creation of the mapping list
1413  * entry are controlled under the same lock. It's derived from the
1414  * page_t being mapped.
1415  */
1416 static uint_t supported_memload_flags =
1417 	HAT_LOAD | HAT_LOAD_LOCK | HAT_LOAD_ADV | HAT_LOAD_NOCONSIST |
1418 	HAT_LOAD_SHARE | HAT_NO_KALLOC | HAT_LOAD_REMAP | HAT_LOAD_TEXT;
1419 
1420 void
1421 hat_memload(
1422 	hat_t		*hat,
1423 	caddr_t		addr,
1424 	page_t		*pp,
1425 	uint_t		attr,
1426 	uint_t		flags)
1427 {
1428 	uintptr_t	va = (uintptr_t)addr;
1429 	level_t		level = 0;
1430 	pfn_t		pfn = page_pptonum(pp);
1431 
1432 	ASSERT(IS_PAGEALIGNED(va));
1433 	ASSERT(hat == kas.a_hat || va < _userlimit);
1434 	ASSERT(hat == kas.a_hat ||
1435 	    AS_LOCK_HELD(hat->hat_as, &hat->hat_as->a_lock));
1436 	ASSERT((flags & supported_memload_flags) == flags);
1437 
1438 	ASSERT(!IN_VA_HOLE(va));
1439 	ASSERT(!PP_ISFREE(pp));
1440 
1441 	/*
1442 	 * kernel address special case for performance.
1443 	 */
1444 	if (mmu.kmap_addr <= va && va < mmu.kmap_eaddr) {
1445 		ASSERT(hat == kas.a_hat);
1446 		hat_kmap_load(addr, pp, attr, flags);
1447 		return;
1448 	}
1449 
1450 	/*
1451 	 * This is used for memory with normal caching enabled, so
1452 	 * always set HAT_STORECACHING_OK.
1453 	 */
1454 	attr |= HAT_STORECACHING_OK;
1455 	if (hati_load_common(hat, va, pp, attr, flags, level, pfn) != 0)
1456 		panic("unexpected hati_load_common() failure");
1457 }
1458 
1459 /* ARGSUSED */
1460 void
1461 hat_memload_region(struct hat *hat, caddr_t addr, struct page *pp,
1462     uint_t attr, uint_t flags, hat_region_cookie_t rcookie)
1463 {
1464 	hat_memload(hat, addr, pp, attr, flags);
1465 }
1466 
1467 /*
1468  * Load the given array of page structs using large pages when possible
1469  */
1470 void
1471 hat_memload_array(
1472 	hat_t		*hat,
1473 	caddr_t		addr,
1474 	size_t		len,
1475 	page_t		**pages,
1476 	uint_t		attr,
1477 	uint_t		flags)
1478 {
1479 	uintptr_t	va = (uintptr_t)addr;
1480 	uintptr_t	eaddr = va + len;
1481 	level_t		level;
1482 	size_t		pgsize;
1483 	pgcnt_t		pgindx = 0;
1484 	pfn_t		pfn;
1485 	pgcnt_t		i;
1486 
1487 	ASSERT(IS_PAGEALIGNED(va));
1488 	ASSERT(hat == kas.a_hat || va + len <= _userlimit);
1489 	ASSERT(hat == kas.a_hat ||
1490 	    AS_LOCK_HELD(hat->hat_as, &hat->hat_as->a_lock));
1491 	ASSERT((flags & supported_memload_flags) == flags);
1492 
1493 	/*
1494 	 * memload is used for memory with full caching enabled, so
1495 	 * set HAT_STORECACHING_OK.
1496 	 */
1497 	attr |= HAT_STORECACHING_OK;
1498 
1499 	/*
1500 	 * handle all pages using largest possible pagesize
1501 	 */
1502 	while (va < eaddr) {
1503 		/*
1504 		 * decide what level mapping to use (ie. pagesize)
1505 		 */
1506 		pfn = page_pptonum(pages[pgindx]);
1507 		for (level = mmu.max_page_level; ; --level) {
1508 			pgsize = LEVEL_SIZE(level);
1509 			if (level == 0)
1510 				break;
1511 
1512 			if (!IS_P2ALIGNED(va, pgsize) ||
1513 			    (eaddr - va) < pgsize ||
1514 			    !IS_P2ALIGNED(pfn_to_pa(pfn), pgsize))
1515 				continue;
1516 
1517 			/*
1518 			 * To use a large mapping of this size, all the
1519 			 * pages we are passed must be sequential subpages
1520 			 * of the large page.
1521 			 * hat_page_demote() can't change p_szc because
1522 			 * all pages are locked.
1523 			 */
1524 			if (pages[pgindx]->p_szc >= level) {
1525 				for (i = 0; i < mmu_btop(pgsize); ++i) {
1526 					if (pfn + i !=
1527 					    page_pptonum(pages[pgindx + i]))
1528 						break;
1529 					ASSERT(pages[pgindx + i]->p_szc >=
1530 					    level);
1531 					ASSERT(pages[pgindx] + i ==
1532 					    pages[pgindx + i]);
1533 				}
1534 				if (i == mmu_btop(pgsize))
1535 					break;
1536 			}
1537 		}
1538 
1539 		/*
1540 		 * Load this page mapping. If the load fails, try a smaller
1541 		 * pagesize.
1542 		 */
1543 		ASSERT(!IN_VA_HOLE(va));
1544 		while (hati_load_common(hat, va, pages[pgindx], attr,
1545 		    flags, level, pfn) != 0) {
1546 			if (level == 0)
1547 				panic("unexpected hati_load_common() failure");
1548 			--level;
1549 			pgsize = LEVEL_SIZE(level);
1550 		}
1551 
1552 		/*
1553 		 * move to next page
1554 		 */
1555 		va += pgsize;
1556 		pgindx += mmu_btop(pgsize);
1557 	}
1558 }
1559 
1560 /* ARGSUSED */
1561 void
1562 hat_memload_array_region(struct hat *hat, caddr_t addr, size_t len,
1563     struct page **pps, uint_t attr, uint_t flags,
1564     hat_region_cookie_t rcookie)
1565 {
1566 	hat_memload_array(hat, addr, len, pps, attr, flags);
1567 }
1568 
1569 /*
1570  * void hat_devload(hat, addr, len, pf, attr, flags)
1571  *	load/lock the given page frame number
1572  *
1573  * Advisory ordering attributes. Apply only to device mappings.
1574  *
1575  * HAT_STRICTORDER: the CPU must issue the references in order, as the
1576  *	programmer specified.  This is the default.
1577  * HAT_UNORDERED_OK: the CPU may reorder the references (this is all kinds
1578  *	of reordering; store or load with store or load).
1579  * HAT_MERGING_OK: merging and batching: the CPU may merge individual stores
1580  *	to consecutive locations (for example, turn two consecutive byte
1581  *	stores into one halfword store), and it may batch individual loads
1582  *	(for example, turn two consecutive byte loads into one halfword load).
1583  *	This also implies re-ordering.
1584  * HAT_LOADCACHING_OK: the CPU may cache the data it fetches and reuse it
1585  *	until another store occurs.  The default is to fetch new data
1586  *	on every load.  This also implies merging.
1587  * HAT_STORECACHING_OK: the CPU may keep the data in the cache and push it to
1588  *	the device (perhaps with other data) at a later time.  The default is
1589  *	to push the data right away.  This also implies load caching.
1590  *
1591  * Equivalent of hat_memload(), but can be used for device memory where
1592  * there are no page_t's and we support additional flags (write merging, etc).
1593  * Note that we can have large page mappings with this interface.
1594  */
1595 int supported_devload_flags = HAT_LOAD | HAT_LOAD_LOCK |
1596 	HAT_LOAD_NOCONSIST | HAT_STRICTORDER | HAT_UNORDERED_OK |
1597 	HAT_MERGING_OK | HAT_LOADCACHING_OK | HAT_STORECACHING_OK;
1598 
1599 void
1600 hat_devload(
1601 	hat_t		*hat,
1602 	caddr_t		addr,
1603 	size_t		len,
1604 	pfn_t		pfn,
1605 	uint_t		attr,
1606 	int		flags)
1607 {
1608 	uintptr_t	va = ALIGN2PAGE(addr);
1609 	uintptr_t	eva = va + len;
1610 	level_t		level;
1611 	size_t		pgsize;
1612 	page_t		*pp;
1613 	int		f;	/* per PTE copy of flags  - maybe modified */
1614 	uint_t		a;	/* per PTE copy of attr */
1615 
1616 	ASSERT(IS_PAGEALIGNED(va));
1617 	ASSERT(hat == kas.a_hat || eva <= _userlimit);
1618 	ASSERT(hat == kas.a_hat ||
1619 	    AS_LOCK_HELD(hat->hat_as, &hat->hat_as->a_lock));
1620 	ASSERT((flags & supported_devload_flags) == flags);
1621 
1622 	/*
1623 	 * handle all pages
1624 	 */
1625 	while (va < eva) {
1626 
1627 		/*
1628 		 * decide what level mapping to use (ie. pagesize)
1629 		 */
1630 		for (level = mmu.max_page_level; ; --level) {
1631 			pgsize = LEVEL_SIZE(level);
1632 			if (level == 0)
1633 				break;
1634 			if (IS_P2ALIGNED(va, pgsize) &&
1635 			    (eva - va) >= pgsize &&
1636 			    IS_P2ALIGNED(pfn, mmu_btop(pgsize)))
1637 				break;
1638 		}
1639 
1640 		/*
1641 		 * If this is just memory then allow caching (this happens
1642 		 * for the nucleus pages) - though HAT_PLAT_NOCACHE can be used
1643 		 * to override that. If we don't have a page_t then make sure
1644 		 * NOCONSIST is set.
1645 		 */
1646 		a = attr;
1647 		f = flags;
1648 		if (pf_is_memory(pfn)) {
1649 			if (!(a & HAT_PLAT_NOCACHE))
1650 				a |= HAT_STORECACHING_OK;
1651 
1652 			if (f & HAT_LOAD_NOCONSIST)
1653 				pp = NULL;
1654 			else
1655 				pp = page_numtopp_nolock(pfn);
1656 		} else {
1657 			pp = NULL;
1658 			f |= HAT_LOAD_NOCONSIST;
1659 		}
1660 
1661 		/*
1662 		 * load this page mapping
1663 		 */
1664 		ASSERT(!IN_VA_HOLE(va));
1665 		while (hati_load_common(hat, va, pp, a, f, level, pfn) != 0) {
1666 			if (level == 0)
1667 				panic("unexpected hati_load_common() failure");
1668 			--level;
1669 			pgsize = LEVEL_SIZE(level);
1670 		}
1671 
1672 		/*
1673 		 * move to next page
1674 		 */
1675 		va += pgsize;
1676 		pfn += mmu_btop(pgsize);
1677 	}
1678 }
1679 
1680 /*
1681  * void hat_unlock(hat, addr, len)
1682  *	unlock the mappings to a given range of addresses
1683  *
1684  * Locks are tracked by ht_lock_cnt in the htable.
1685  */
1686 void
1687 hat_unlock(hat_t *hat, caddr_t addr, size_t len)
1688 {
1689 	uintptr_t	vaddr = (uintptr_t)addr;
1690 	uintptr_t	eaddr = vaddr + len;
1691 	htable_t	*ht = NULL;
1692 
1693 	/*
1694 	 * kernel entries are always locked, we don't track lock counts
1695 	 */
1696 	ASSERT(hat == kas.a_hat || eaddr <= _userlimit);
1697 	ASSERT(IS_PAGEALIGNED(vaddr));
1698 	ASSERT(IS_PAGEALIGNED(eaddr));
1699 	if (hat == kas.a_hat)
1700 		return;
1701 	if (eaddr > _userlimit)
1702 		panic("hat_unlock() address out of range - above _userlimit");
1703 
1704 	ASSERT(AS_LOCK_HELD(hat->hat_as, &hat->hat_as->a_lock));
1705 	while (vaddr < eaddr) {
1706 		(void) htable_walk(hat, &ht, &vaddr, eaddr);
1707 		if (ht == NULL)
1708 			break;
1709 
1710 		ASSERT(!IN_VA_HOLE(vaddr));
1711 
1712 		if (ht->ht_lock_cnt < 1)
1713 			panic("hat_unlock(): lock_cnt < 1, "
1714 			    "htable=%p, vaddr=%p\n", ht, (caddr_t)vaddr);
1715 		HTABLE_LOCK_DEC(ht);
1716 
1717 		vaddr += LEVEL_SIZE(ht->ht_level);
1718 	}
1719 	if (ht)
1720 		htable_release(ht);
1721 }
1722 
1723 /* ARGSUSED */
1724 void
1725 hat_unlock_region(struct hat *sfmmup, caddr_t addr, size_t len,
1726     hat_region_cookie_t rcookie)
1727 {
1728 	panic("No shared region support on x86");
1729 }
1730 
1731 /*
1732  * Cross call service routine to demap a virtual page on
1733  * the current CPU or flush all mappings in TLB.
1734  */
1735 /*ARGSUSED*/
1736 static int
1737 hati_demap_func(xc_arg_t a1, xc_arg_t a2, xc_arg_t a3)
1738 {
1739 	hat_t	*hat = (hat_t *)a1;
1740 	caddr_t	addr = (caddr_t)a2;
1741 
1742 	/*
1743 	 * If the target hat isn't the kernel and this CPU isn't operating
1744 	 * in the target hat, we can ignore the cross call.
1745 	 */
1746 	if (hat != kas.a_hat && hat != CPU->cpu_current_hat)
1747 		return (0);
1748 
1749 	/*
1750 	 * For a normal address, we just flush one page mapping
1751 	 */
1752 	if ((uintptr_t)addr != DEMAP_ALL_ADDR) {
1753 		mmu_tlbflush_entry(addr);
1754 		return (0);
1755 	}
1756 
1757 	/*
1758 	 * Otherwise we reload cr3 to effect a complete TLB flush.
1759 	 *
1760 	 * A reload of cr3 on a VLP process also means we must also recopy in
1761 	 * the pte values from the struct hat
1762 	 */
1763 	if (hat->hat_flags & HAT_VLP) {
1764 #if defined(__amd64)
1765 		x86pte_t *vlpptep = CPU->cpu_hat_info->hci_vlp_l2ptes;
1766 
1767 		VLP_COPY(hat->hat_vlp_ptes, vlpptep);
1768 #elif defined(__i386)
1769 		reload_pae32(hat, CPU);
1770 #endif
1771 	}
1772 	reload_cr3();
1773 	return (0);
1774 }
1775 
1776 /*
1777  * Flush all TLB entries, including global (ie. kernel) ones.
1778  */
1779 static void
1780 flush_all_tlb_entries(void)
1781 {
1782 	ulong_t cr4 = getcr4();
1783 
1784 	if (cr4 & CR4_PGE) {
1785 		setcr4(cr4 & ~(ulong_t)CR4_PGE);
1786 		setcr4(cr4);
1787 
1788 		/*
1789 		 * 32 bit PAE also needs to always reload_cr3()
1790 		 */
1791 		if (mmu.max_level == 2)
1792 			reload_cr3();
1793 	} else {
1794 		reload_cr3();
1795 	}
1796 }
1797 
1798 #define	TLB_CPU_HALTED	(01ul)
1799 #define	TLB_INVAL_ALL	(02ul)
1800 #define	CAS_TLB_INFO(cpu, old, new)	\
1801 	caslong((ulong_t *)&(cpu)->cpu_m.mcpu_tlb_info, (old), (new))
1802 
1803 /*
1804  * Record that a CPU is going idle
1805  */
1806 void
1807 tlb_going_idle(void)
1808 {
1809 	atomic_or_long((ulong_t *)&CPU->cpu_m.mcpu_tlb_info, TLB_CPU_HALTED);
1810 }
1811 
1812 /*
1813  * Service a delayed TLB flush if coming out of being idle.
1814  */
1815 void
1816 tlb_service(void)
1817 {
1818 	ulong_t flags = getflags();
1819 	ulong_t tlb_info;
1820 	ulong_t found;
1821 
1822 	/*
1823 	 * Be sure interrupts are off while doing this so that
1824 	 * higher level interrupts correctly wait for flushes to finish.
1825 	 */
1826 	if (flags & PS_IE)
1827 		flags = intr_clear();
1828 
1829 	/*
1830 	 * We only have to do something if coming out of being idle.
1831 	 */
1832 	tlb_info = CPU->cpu_m.mcpu_tlb_info;
1833 	if (tlb_info & TLB_CPU_HALTED) {
1834 		ASSERT(CPU->cpu_current_hat == kas.a_hat);
1835 
1836 		/*
1837 		 * Atomic clear and fetch of old state.
1838 		 */
1839 		while ((found = CAS_TLB_INFO(CPU, tlb_info, 0)) != tlb_info) {
1840 			ASSERT(found & TLB_CPU_HALTED);
1841 			tlb_info = found;
1842 			SMT_PAUSE();
1843 		}
1844 		if (tlb_info & TLB_INVAL_ALL)
1845 			flush_all_tlb_entries();
1846 	}
1847 
1848 	/*
1849 	 * Restore interrupt enable control bit.
1850 	 */
1851 	if (flags & PS_IE)
1852 		sti();
1853 }
1854 
1855 /*
1856  * Internal routine to do cross calls to invalidate a range of pages on
1857  * all CPUs using a given hat.
1858  */
1859 void
1860 hat_tlb_inval(hat_t *hat, uintptr_t va)
1861 {
1862 	extern int	flushes_require_xcalls;	/* from mp_startup.c */
1863 	cpuset_t	justme;
1864 	cpuset_t	check_cpus;
1865 	cpuset_t	cpus_to_shootdown;
1866 	cpu_t		*cpup;
1867 	int		c;
1868 
1869 	/*
1870 	 * If the hat is being destroyed, there are no more users, so
1871 	 * demap need not do anything.
1872 	 */
1873 	if (hat->hat_flags & HAT_FREEING)
1874 		return;
1875 
1876 	/*
1877 	 * If demapping from a shared pagetable, we best demap the
1878 	 * entire set of user TLBs, since we don't know what addresses
1879 	 * these were shared at.
1880 	 */
1881 	if (hat->hat_flags & HAT_SHARED) {
1882 		hat = kas.a_hat;
1883 		va = DEMAP_ALL_ADDR;
1884 	}
1885 
1886 	/*
1887 	 * if not running with multiple CPUs, don't use cross calls
1888 	 */
1889 	if (panicstr || !flushes_require_xcalls) {
1890 		(void) hati_demap_func((xc_arg_t)hat, (xc_arg_t)va, NULL);
1891 		return;
1892 	}
1893 
1894 
1895 	/*
1896 	 * Determine CPUs to shootdown. Kernel changes always do all CPUs.
1897 	 * Otherwise it's just CPUs currently executing in this hat.
1898 	 */
1899 	kpreempt_disable();
1900 	CPUSET_ONLY(justme, CPU->cpu_id);
1901 	if (hat == kas.a_hat)
1902 		cpus_to_shootdown = khat_cpuset;
1903 	else
1904 		cpus_to_shootdown = hat->hat_cpus;
1905 
1906 	/*
1907 	 * If any CPUs in the set are idle, just request a delayed flush
1908 	 * and avoid waking them up.
1909 	 */
1910 	check_cpus = cpus_to_shootdown;
1911 	for (c = 0; c < NCPU && !CPUSET_ISNULL(check_cpus); ++c) {
1912 		ulong_t tlb_info;
1913 
1914 		if (!CPU_IN_SET(check_cpus, c))
1915 			continue;
1916 		CPUSET_DEL(check_cpus, c);
1917 		cpup = cpu[c];
1918 		if (cpup == NULL)
1919 			continue;
1920 
1921 		tlb_info = cpup->cpu_m.mcpu_tlb_info;
1922 		while (tlb_info == TLB_CPU_HALTED) {
1923 			(void) CAS_TLB_INFO(cpup, TLB_CPU_HALTED,
1924 			    TLB_CPU_HALTED | TLB_INVAL_ALL);
1925 			SMT_PAUSE();
1926 			tlb_info = cpup->cpu_m.mcpu_tlb_info;
1927 		}
1928 		if (tlb_info == (TLB_CPU_HALTED | TLB_INVAL_ALL)) {
1929 			HATSTAT_INC(hs_tlb_inval_delayed);
1930 			CPUSET_DEL(cpus_to_shootdown, c);
1931 		}
1932 	}
1933 
1934 	if (CPUSET_ISNULL(cpus_to_shootdown) ||
1935 	    CPUSET_ISEQUAL(cpus_to_shootdown, justme)) {
1936 
1937 		(void) hati_demap_func((xc_arg_t)hat, (xc_arg_t)va, NULL);
1938 
1939 	} else {
1940 
1941 		CPUSET_ADD(cpus_to_shootdown, CPU->cpu_id);
1942 		xc_call((xc_arg_t)hat, (xc_arg_t)va, NULL, X_CALL_HIPRI,
1943 		    cpus_to_shootdown, hati_demap_func);
1944 
1945 	}
1946 	kpreempt_enable();
1947 }
1948 
1949 /*
1950  * Interior routine for HAT_UNLOADs from hat_unload_callback(),
1951  * hat_kmap_unload() OR from hat_steal() code.  This routine doesn't
1952  * handle releasing of the htables.
1953  */
1954 void
1955 hat_pte_unmap(
1956 	htable_t	*ht,
1957 	uint_t		entry,
1958 	uint_t		flags,
1959 	x86pte_t	old_pte,
1960 	void		*pte_ptr)
1961 {
1962 	hat_t		*hat = ht->ht_hat;
1963 	hment_t		*hm = NULL;
1964 	page_t		*pp = NULL;
1965 	level_t		l = ht->ht_level;
1966 	pfn_t		pfn;
1967 
1968 	/*
1969 	 * We always track the locking counts, even if nothing is unmapped
1970 	 */
1971 	if ((flags & HAT_UNLOAD_UNLOCK) != 0 && hat != kas.a_hat) {
1972 		ASSERT(ht->ht_lock_cnt > 0);
1973 		HTABLE_LOCK_DEC(ht);
1974 	}
1975 
1976 	/*
1977 	 * Figure out which page's mapping list lock to acquire using the PFN
1978 	 * passed in "old" PTE. We then attempt to invalidate the PTE.
1979 	 * If another thread, probably a hat_pageunload, has asynchronously
1980 	 * unmapped/remapped this address we'll loop here.
1981 	 */
1982 	ASSERT(ht->ht_busy > 0);
1983 	while (PTE_ISVALID(old_pte)) {
1984 		pfn = PTE2PFN(old_pte, l);
1985 		if (PTE_GET(old_pte, PT_SOFTWARE) >= PT_NOCONSIST) {
1986 			pp = NULL;
1987 		} else {
1988 			pp = page_numtopp_nolock(pfn);
1989 			if (pp == NULL) {
1990 				panic("no page_t, not NOCONSIST: old_pte="
1991 				    FMT_PTE " ht=%lx entry=0x%x pte_ptr=%lx",
1992 				    old_pte, (uintptr_t)ht, entry,
1993 				    (uintptr_t)pte_ptr);
1994 			}
1995 			x86_hm_enter(pp);
1996 		}
1997 
1998 		/*
1999 		 * If freeing the address space, check that the PTE
2000 		 * hasn't changed, as the mappings are no longer in use by
2001 		 * any thread, invalidation is unnecessary.
2002 		 * If not freeing, do a full invalidate.
2003 		 */
2004 		if (hat->hat_flags & HAT_FREEING)
2005 			old_pte = x86pte_get(ht, entry);
2006 		else
2007 			old_pte = x86pte_inval(ht, entry, old_pte, pte_ptr);
2008 
2009 		/*
2010 		 * If the page hadn't changed we've unmapped it and can proceed
2011 		 */
2012 		if (PTE_ISVALID(old_pte) && PTE2PFN(old_pte, l) == pfn)
2013 			break;
2014 
2015 		/*
2016 		 * Otherwise, we'll have to retry with the current old_pte.
2017 		 * Drop the hment lock, since the pfn may have changed.
2018 		 */
2019 		if (pp != NULL) {
2020 			x86_hm_exit(pp);
2021 			pp = NULL;
2022 		} else {
2023 			ASSERT(PTE_GET(old_pte, PT_SOFTWARE) >= PT_NOCONSIST);
2024 		}
2025 	}
2026 
2027 	/*
2028 	 * If the old mapping wasn't valid, there's nothing more to do
2029 	 */
2030 	if (!PTE_ISVALID(old_pte)) {
2031 		if (pp != NULL)
2032 			x86_hm_exit(pp);
2033 		return;
2034 	}
2035 
2036 	/*
2037 	 * Take care of syncing any MOD/REF bits and removing the hment.
2038 	 */
2039 	if (pp != NULL) {
2040 		if (!(flags & HAT_UNLOAD_NOSYNC))
2041 			hati_sync_pte_to_page(pp, old_pte, l);
2042 		hm = hment_remove(pp, ht, entry);
2043 		x86_hm_exit(pp);
2044 		if (hm != NULL)
2045 			hment_free(hm);
2046 	}
2047 
2048 	/*
2049 	 * Handle book keeping in the htable and hat
2050 	 */
2051 	ASSERT(ht->ht_valid_cnt > 0);
2052 	HTABLE_DEC(ht->ht_valid_cnt);
2053 	PGCNT_DEC(hat, l);
2054 }
2055 
2056 /*
2057  * very cheap unload implementation to special case some kernel addresses
2058  */
2059 static void
2060 hat_kmap_unload(caddr_t addr, size_t len, uint_t flags)
2061 {
2062 	uintptr_t	va = (uintptr_t)addr;
2063 	uintptr_t	eva = va + len;
2064 	pgcnt_t		pg_index;
2065 	htable_t	*ht;
2066 	uint_t		entry;
2067 	x86pte_t	*pte_ptr;
2068 	x86pte_t	old_pte;
2069 
2070 	for (; va < eva; va += MMU_PAGESIZE) {
2071 		/*
2072 		 * Get the PTE
2073 		 */
2074 		pg_index = mmu_btop(va - mmu.kmap_addr);
2075 		pte_ptr = PT_INDEX_PTR(mmu.kmap_ptes, pg_index);
2076 		old_pte = GET_PTE(pte_ptr);
2077 
2078 		/*
2079 		 * get the htable / entry
2080 		 */
2081 		ht = mmu.kmap_htables[(va - mmu.kmap_htables[0]->ht_vaddr)
2082 		    >> LEVEL_SHIFT(1)];
2083 		entry = htable_va2entry(va, ht);
2084 
2085 		/*
2086 		 * use mostly common code to unmap it.
2087 		 */
2088 		hat_pte_unmap(ht, entry, flags, old_pte, pte_ptr);
2089 	}
2090 }
2091 
2092 
2093 /*
2094  * unload a range of virtual address space (no callback)
2095  */
2096 void
2097 hat_unload(hat_t *hat, caddr_t addr, size_t len, uint_t flags)
2098 {
2099 	uintptr_t va = (uintptr_t)addr;
2100 
2101 	ASSERT(hat == kas.a_hat || va + len <= _userlimit);
2102 
2103 	/*
2104 	 * special case for performance.
2105 	 */
2106 	if (mmu.kmap_addr <= va && va < mmu.kmap_eaddr) {
2107 		ASSERT(hat == kas.a_hat);
2108 		hat_kmap_unload(addr, len, flags);
2109 	} else {
2110 		hat_unload_callback(hat, addr, len, flags, NULL);
2111 	}
2112 }
2113 
2114 /*
2115  * Do the callbacks for ranges being unloaded.
2116  */
2117 typedef struct range_info {
2118 	uintptr_t	rng_va;
2119 	ulong_t		rng_cnt;
2120 	level_t		rng_level;
2121 } range_info_t;
2122 
2123 static void
2124 handle_ranges(hat_callback_t *cb, uint_t cnt, range_info_t *range)
2125 {
2126 	/*
2127 	 * do callbacks to upper level VM system
2128 	 */
2129 	while (cb != NULL && cnt > 0) {
2130 		--cnt;
2131 		cb->hcb_start_addr = (caddr_t)range[cnt].rng_va;
2132 		cb->hcb_end_addr = cb->hcb_start_addr;
2133 		cb->hcb_end_addr +=
2134 		    range[cnt].rng_cnt << LEVEL_SIZE(range[cnt].rng_level);
2135 		cb->hcb_function(cb);
2136 	}
2137 }
2138 
2139 /*
2140  * Unload a given range of addresses (has optional callback)
2141  *
2142  * Flags:
2143  * define	HAT_UNLOAD		0x00
2144  * define	HAT_UNLOAD_NOSYNC	0x02
2145  * define	HAT_UNLOAD_UNLOCK	0x04
2146  * define	HAT_UNLOAD_OTHER	0x08 - not used
2147  * define	HAT_UNLOAD_UNMAP	0x10 - same as HAT_UNLOAD
2148  */
2149 #define	MAX_UNLOAD_CNT (8)
2150 void
2151 hat_unload_callback(
2152 	hat_t		*hat,
2153 	caddr_t		addr,
2154 	size_t		len,
2155 	uint_t		flags,
2156 	hat_callback_t	*cb)
2157 {
2158 	uintptr_t	vaddr = (uintptr_t)addr;
2159 	uintptr_t	eaddr = vaddr + len;
2160 	htable_t	*ht = NULL;
2161 	uint_t		entry;
2162 	uintptr_t	contig_va = (uintptr_t)-1L;
2163 	range_info_t	r[MAX_UNLOAD_CNT];
2164 	uint_t		r_cnt = 0;
2165 	x86pte_t	old_pte;
2166 
2167 	ASSERT(hat == kas.a_hat || eaddr <= _userlimit);
2168 	ASSERT(IS_PAGEALIGNED(vaddr));
2169 	ASSERT(IS_PAGEALIGNED(eaddr));
2170 
2171 	/*
2172 	 * Special case a single page being unloaded for speed. This happens
2173 	 * quite frequently, COW faults after a fork() for example.
2174 	 */
2175 	if (cb == NULL && len == MMU_PAGESIZE) {
2176 		ht = htable_getpte(hat, vaddr, &entry, &old_pte, 0);
2177 		if (ht != NULL) {
2178 			if (PTE_ISVALID(old_pte))
2179 				hat_pte_unmap(ht, entry, flags, old_pte, NULL);
2180 			htable_release(ht);
2181 		}
2182 		return;
2183 	}
2184 
2185 	while (vaddr < eaddr) {
2186 		old_pte = htable_walk(hat, &ht, &vaddr, eaddr);
2187 		if (ht == NULL)
2188 			break;
2189 
2190 		ASSERT(!IN_VA_HOLE(vaddr));
2191 
2192 		if (vaddr < (uintptr_t)addr)
2193 			panic("hat_unload_callback(): unmap inside large page");
2194 
2195 		/*
2196 		 * We'll do the call backs for contiguous ranges
2197 		 */
2198 		if (vaddr != contig_va ||
2199 		    (r_cnt > 0 && r[r_cnt - 1].rng_level != ht->ht_level)) {
2200 			if (r_cnt == MAX_UNLOAD_CNT) {
2201 				handle_ranges(cb, r_cnt, r);
2202 				r_cnt = 0;
2203 			}
2204 			r[r_cnt].rng_va = vaddr;
2205 			r[r_cnt].rng_cnt = 0;
2206 			r[r_cnt].rng_level = ht->ht_level;
2207 			++r_cnt;
2208 		}
2209 
2210 		/*
2211 		 * Unload one mapping from the page tables.
2212 		 */
2213 		entry = htable_va2entry(vaddr, ht);
2214 		hat_pte_unmap(ht, entry, flags, old_pte, NULL);
2215 		ASSERT(ht->ht_level <= mmu.max_page_level);
2216 		vaddr += LEVEL_SIZE(ht->ht_level);
2217 		contig_va = vaddr;
2218 		++r[r_cnt - 1].rng_cnt;
2219 	}
2220 	if (ht)
2221 		htable_release(ht);
2222 
2223 	/*
2224 	 * handle last range for callbacks
2225 	 */
2226 	if (r_cnt > 0)
2227 		handle_ranges(cb, r_cnt, r);
2228 }
2229 
2230 /*
2231  * synchronize mapping with software data structures
2232  *
2233  * This interface is currently only used by the working set monitor
2234  * driver.
2235  */
2236 /*ARGSUSED*/
2237 void
2238 hat_sync(hat_t *hat, caddr_t addr, size_t len, uint_t flags)
2239 {
2240 	uintptr_t	vaddr = (uintptr_t)addr;
2241 	uintptr_t	eaddr = vaddr + len;
2242 	htable_t	*ht = NULL;
2243 	uint_t		entry;
2244 	x86pte_t	pte;
2245 	x86pte_t	save_pte;
2246 	x86pte_t	new;
2247 	page_t		*pp;
2248 
2249 	ASSERT(!IN_VA_HOLE(vaddr));
2250 	ASSERT(IS_PAGEALIGNED(vaddr));
2251 	ASSERT(IS_PAGEALIGNED(eaddr));
2252 	ASSERT(hat == kas.a_hat || eaddr <= _userlimit);
2253 
2254 	for (; vaddr < eaddr; vaddr += LEVEL_SIZE(ht->ht_level)) {
2255 try_again:
2256 		pte = htable_walk(hat, &ht, &vaddr, eaddr);
2257 		if (ht == NULL)
2258 			break;
2259 		entry = htable_va2entry(vaddr, ht);
2260 
2261 		if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC ||
2262 		    PTE_GET(pte, PT_REF | PT_MOD) == 0)
2263 			continue;
2264 
2265 		/*
2266 		 * We need to acquire the mapping list lock to protect
2267 		 * against hat_pageunload(), hat_unload(), etc.
2268 		 */
2269 		pp = page_numtopp_nolock(PTE2PFN(pte, ht->ht_level));
2270 		if (pp == NULL)
2271 			break;
2272 		x86_hm_enter(pp);
2273 		save_pte = pte;
2274 		pte = x86pte_get(ht, entry);
2275 		if (pte != save_pte) {
2276 			x86_hm_exit(pp);
2277 			goto try_again;
2278 		}
2279 		if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC ||
2280 		    PTE_GET(pte, PT_REF | PT_MOD) == 0) {
2281 			x86_hm_exit(pp);
2282 			continue;
2283 		}
2284 
2285 		/*
2286 		 * Need to clear ref or mod bits. We may compete with
2287 		 * hardware updating the R/M bits and have to try again.
2288 		 */
2289 		if (flags == HAT_SYNC_ZERORM) {
2290 			new = pte;
2291 			PTE_CLR(new, PT_REF | PT_MOD);
2292 			pte = hati_update_pte(ht, entry, pte, new);
2293 			if (pte != 0) {
2294 				x86_hm_exit(pp);
2295 				goto try_again;
2296 			}
2297 		} else {
2298 			/*
2299 			 * sync the PTE to the page_t
2300 			 */
2301 			hati_sync_pte_to_page(pp, save_pte, ht->ht_level);
2302 		}
2303 		x86_hm_exit(pp);
2304 	}
2305 	if (ht)
2306 		htable_release(ht);
2307 }
2308 
2309 /*
2310  * void	hat_map(hat, addr, len, flags)
2311  */
2312 /*ARGSUSED*/
2313 void
2314 hat_map(hat_t *hat, caddr_t addr, size_t len, uint_t flags)
2315 {
2316 	/* does nothing */
2317 }
2318 
2319 /*
2320  * uint_t hat_getattr(hat, addr, *attr)
2321  *	returns attr for <hat,addr> in *attr.  returns 0 if there was a
2322  *	mapping and *attr is valid, nonzero if there was no mapping and
2323  *	*attr is not valid.
2324  */
2325 uint_t
2326 hat_getattr(hat_t *hat, caddr_t addr, uint_t *attr)
2327 {
2328 	uintptr_t	vaddr = ALIGN2PAGE(addr);
2329 	htable_t	*ht = NULL;
2330 	x86pte_t	pte;
2331 
2332 	ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
2333 
2334 	if (IN_VA_HOLE(vaddr))
2335 		return ((uint_t)-1);
2336 
2337 	ht = htable_getpte(hat, vaddr, NULL, &pte, mmu.max_page_level);
2338 	if (ht == NULL)
2339 		return ((uint_t)-1);
2340 
2341 	if (!PTE_ISVALID(pte) || !PTE_ISPAGE(pte, ht->ht_level)) {
2342 		htable_release(ht);
2343 		return ((uint_t)-1);
2344 	}
2345 
2346 	*attr = PROT_READ;
2347 	if (PTE_GET(pte, PT_WRITABLE))
2348 		*attr |= PROT_WRITE;
2349 	if (PTE_GET(pte, PT_USER))
2350 		*attr |= PROT_USER;
2351 	if (!PTE_GET(pte, mmu.pt_nx))
2352 		*attr |= PROT_EXEC;
2353 	if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC)
2354 		*attr |= HAT_NOSYNC;
2355 	htable_release(ht);
2356 	return (0);
2357 }
2358 
2359 /*
2360  * hat_updateattr() applies the given attribute change to an existing mapping
2361  */
2362 #define	HAT_LOAD_ATTR		1
2363 #define	HAT_SET_ATTR		2
2364 #define	HAT_CLR_ATTR		3
2365 
2366 static void
2367 hat_updateattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr, int what)
2368 {
2369 	uintptr_t	vaddr = (uintptr_t)addr;
2370 	uintptr_t	eaddr = (uintptr_t)addr + len;
2371 	htable_t	*ht = NULL;
2372 	uint_t		entry;
2373 	x86pte_t	oldpte, newpte;
2374 	page_t		*pp;
2375 
2376 	ASSERT(IS_PAGEALIGNED(vaddr));
2377 	ASSERT(IS_PAGEALIGNED(eaddr));
2378 	ASSERT(hat == kas.a_hat ||
2379 	    AS_LOCK_HELD(hat->hat_as, &hat->hat_as->a_lock));
2380 	for (; vaddr < eaddr; vaddr += LEVEL_SIZE(ht->ht_level)) {
2381 try_again:
2382 		oldpte = htable_walk(hat, &ht, &vaddr, eaddr);
2383 		if (ht == NULL)
2384 			break;
2385 		if (PTE_GET(oldpte, PT_SOFTWARE) >= PT_NOCONSIST)
2386 			continue;
2387 
2388 		pp = page_numtopp_nolock(PTE2PFN(oldpte, ht->ht_level));
2389 		if (pp == NULL)
2390 			continue;
2391 		x86_hm_enter(pp);
2392 
2393 		newpte = oldpte;
2394 		/*
2395 		 * We found a page table entry in the desired range,
2396 		 * figure out the new attributes.
2397 		 */
2398 		if (what == HAT_SET_ATTR || what == HAT_LOAD_ATTR) {
2399 			if ((attr & PROT_WRITE) &&
2400 			    !PTE_GET(oldpte, PT_WRITABLE))
2401 				newpte |= PT_WRITABLE;
2402 
2403 			if ((attr & HAT_NOSYNC) &&
2404 			    PTE_GET(oldpte, PT_SOFTWARE) < PT_NOSYNC)
2405 				newpte |= PT_NOSYNC;
2406 
2407 			if ((attr & PROT_EXEC) && PTE_GET(oldpte, mmu.pt_nx))
2408 				newpte &= ~mmu.pt_nx;
2409 		}
2410 
2411 		if (what == HAT_LOAD_ATTR) {
2412 			if (!(attr & PROT_WRITE) &&
2413 			    PTE_GET(oldpte, PT_WRITABLE))
2414 				newpte &= ~PT_WRITABLE;
2415 
2416 			if (!(attr & HAT_NOSYNC) &&
2417 			    PTE_GET(oldpte, PT_SOFTWARE) >= PT_NOSYNC)
2418 				newpte &= ~PT_SOFTWARE;
2419 
2420 			if (!(attr & PROT_EXEC) && !PTE_GET(oldpte, mmu.pt_nx))
2421 				newpte |= mmu.pt_nx;
2422 		}
2423 
2424 		if (what == HAT_CLR_ATTR) {
2425 			if ((attr & PROT_WRITE) && PTE_GET(oldpte, PT_WRITABLE))
2426 				newpte &= ~PT_WRITABLE;
2427 
2428 			if ((attr & HAT_NOSYNC) &&
2429 			    PTE_GET(oldpte, PT_SOFTWARE) >= PT_NOSYNC)
2430 				newpte &= ~PT_SOFTWARE;
2431 
2432 			if ((attr & PROT_EXEC) && !PTE_GET(oldpte, mmu.pt_nx))
2433 				newpte |= mmu.pt_nx;
2434 		}
2435 
2436 		/*
2437 		 * Ensure NOSYNC/NOCONSIST mappings have REF and MOD set.
2438 		 * x86pte_set() depends on this.
2439 		 */
2440 		if (PTE_GET(newpte, PT_SOFTWARE) >= PT_NOSYNC)
2441 			newpte |= PT_REF | PT_MOD;
2442 
2443 		/*
2444 		 * what about PROT_READ or others? this code only handles:
2445 		 * EXEC, WRITE, NOSYNC
2446 		 */
2447 
2448 		/*
2449 		 * If new PTE really changed, update the table.
2450 		 */
2451 		if (newpte != oldpte) {
2452 			entry = htable_va2entry(vaddr, ht);
2453 			oldpte = hati_update_pte(ht, entry, oldpte, newpte);
2454 			if (oldpte != 0) {
2455 				x86_hm_exit(pp);
2456 				goto try_again;
2457 			}
2458 		}
2459 		x86_hm_exit(pp);
2460 	}
2461 	if (ht)
2462 		htable_release(ht);
2463 }
2464 
2465 /*
2466  * Various wrappers for hat_updateattr()
2467  */
2468 void
2469 hat_setattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr)
2470 {
2471 	ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
2472 	hat_updateattr(hat, addr, len, attr, HAT_SET_ATTR);
2473 }
2474 
2475 void
2476 hat_clrattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr)
2477 {
2478 	ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
2479 	hat_updateattr(hat, addr, len, attr, HAT_CLR_ATTR);
2480 }
2481 
2482 void
2483 hat_chgattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr)
2484 {
2485 	ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
2486 	hat_updateattr(hat, addr, len, attr, HAT_LOAD_ATTR);
2487 }
2488 
2489 void
2490 hat_chgprot(hat_t *hat, caddr_t addr, size_t len, uint_t vprot)
2491 {
2492 	ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
2493 	hat_updateattr(hat, addr, len, vprot & HAT_PROT_MASK, HAT_LOAD_ATTR);
2494 }
2495 
2496 /*
2497  * size_t hat_getpagesize(hat, addr)
2498  *	returns pagesize in bytes for <hat, addr>. returns -1 of there is
2499  *	no mapping. This is an advisory call.
2500  */
2501 ssize_t
2502 hat_getpagesize(hat_t *hat, caddr_t addr)
2503 {
2504 	uintptr_t	vaddr = ALIGN2PAGE(addr);
2505 	htable_t	*ht;
2506 	size_t		pagesize;
2507 
2508 	ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
2509 	if (IN_VA_HOLE(vaddr))
2510 		return (-1);
2511 	ht = htable_getpage(hat, vaddr, NULL);
2512 	if (ht == NULL)
2513 		return (-1);
2514 	pagesize = LEVEL_SIZE(ht->ht_level);
2515 	htable_release(ht);
2516 	return (pagesize);
2517 }
2518 
2519 
2520 
2521 /*
2522  * pfn_t hat_getpfnum(hat, addr)
2523  *	returns pfn for <hat, addr> or PFN_INVALID if mapping is invalid.
2524  */
2525 pfn_t
2526 hat_getpfnum(hat_t *hat, caddr_t addr)
2527 {
2528 	uintptr_t	vaddr = ALIGN2PAGE(addr);
2529 	htable_t	*ht;
2530 	uint_t		entry;
2531 	pfn_t		pfn = PFN_INVALID;
2532 
2533 	ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
2534 	if (khat_running == 0)
2535 		return (PFN_INVALID);
2536 
2537 	if (IN_VA_HOLE(vaddr))
2538 		return (PFN_INVALID);
2539 
2540 	/*
2541 	 * A very common use of hat_getpfnum() is from the DDI for kernel pages.
2542 	 * Use the kmap_ptes (which also covers the 32 bit heap) to speed
2543 	 * this up.
2544 	 */
2545 	if (mmu.kmap_addr <= vaddr && vaddr < mmu.kmap_eaddr) {
2546 		x86pte_t pte;
2547 		pgcnt_t pg_index;
2548 
2549 		pg_index = mmu_btop(vaddr - mmu.kmap_addr);
2550 		pte = GET_PTE(PT_INDEX_PTR(mmu.kmap_ptes, pg_index));
2551 		if (!PTE_ISVALID(pte))
2552 			return (PFN_INVALID);
2553 		/*LINTED [use of constant 0 causes a silly lint warning] */
2554 		return (PTE2PFN(pte, 0));
2555 	}
2556 
2557 	ht = htable_getpage(hat, vaddr, &entry);
2558 	if (ht == NULL)
2559 		return (PFN_INVALID);
2560 	ASSERT(vaddr >= ht->ht_vaddr);
2561 	ASSERT(vaddr <= HTABLE_LAST_PAGE(ht));
2562 	pfn = PTE2PFN(x86pte_get(ht, entry), ht->ht_level);
2563 	if (ht->ht_level > 0)
2564 		pfn += mmu_btop(vaddr & LEVEL_OFFSET(ht->ht_level));
2565 	htable_release(ht);
2566 	return (pfn);
2567 }
2568 
2569 /*
2570  * hat_getkpfnum() is an obsolete DDI routine, and its use is discouraged.
2571  * Use hat_getpfnum(kas.a_hat, ...) instead.
2572  *
2573  * We'd like to return PFN_INVALID if the mappings have underlying page_t's
2574  * but can't right now due to the fact that some software has grown to use
2575  * this interface incorrectly. So for now when the interface is misused,
2576  * return a warning to the user that in the future it won't work in the
2577  * way they're abusing it, and carry on.
2578  *
2579  * Note that hat_getkpfnum() is never supported on amd64.
2580  */
2581 #if !defined(__amd64)
2582 pfn_t
2583 hat_getkpfnum(caddr_t addr)
2584 {
2585 	pfn_t	pfn;
2586 	int badcaller = 0;
2587 
2588 	if (khat_running == 0)
2589 		panic("hat_getkpfnum(): called too early\n");
2590 	if ((uintptr_t)addr < kernelbase)
2591 		return (PFN_INVALID);
2592 
2593 
2594 	if (segkpm && IS_KPM_ADDR(addr)) {
2595 		badcaller = 1;
2596 		pfn = hat_kpm_va2pfn(addr);
2597 	} else {
2598 		pfn = hat_getpfnum(kas.a_hat, addr);
2599 		badcaller = pf_is_memory(pfn);
2600 	}
2601 
2602 	if (badcaller)
2603 		hat_getkpfnum_badcall(caller());
2604 	return (pfn);
2605 }
2606 #endif /* __amd64 */
2607 
2608 /*
2609  * int hat_probe(hat, addr)
2610  *	return 0 if no valid mapping is present.  Faster version
2611  *	of hat_getattr in certain architectures.
2612  */
2613 int
2614 hat_probe(hat_t *hat, caddr_t addr)
2615 {
2616 	uintptr_t	vaddr = ALIGN2PAGE(addr);
2617 	uint_t		entry;
2618 	htable_t	*ht;
2619 	pgcnt_t		pg_off;
2620 
2621 	ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
2622 	ASSERT(hat == kas.a_hat ||
2623 	    AS_LOCK_HELD(hat->hat_as, &hat->hat_as->a_lock));
2624 	if (IN_VA_HOLE(vaddr))
2625 		return (0);
2626 
2627 	/*
2628 	 * Most common use of hat_probe is from segmap. We special case it
2629 	 * for performance.
2630 	 */
2631 	if (mmu.kmap_addr <= vaddr && vaddr < mmu.kmap_eaddr) {
2632 		pg_off = mmu_btop(vaddr - mmu.kmap_addr);
2633 		if (mmu.pae_hat)
2634 			return (PTE_ISVALID(mmu.kmap_ptes[pg_off]));
2635 		else
2636 			return (PTE_ISVALID(
2637 			    ((x86pte32_t *)mmu.kmap_ptes)[pg_off]));
2638 	}
2639 
2640 	ht = htable_getpage(hat, vaddr, &entry);
2641 	if (ht == NULL)
2642 		return (0);
2643 	htable_release(ht);
2644 	return (1);
2645 }
2646 
2647 /*
2648  * Find out if the segment for hat_share()/hat_unshare() is DISM or locked ISM.
2649  */
2650 static int
2651 is_it_dism(hat_t *hat, caddr_t va)
2652 {
2653 	struct seg *seg;
2654 	struct shm_data *shmd;
2655 	struct spt_data *sptd;
2656 
2657 	seg = as_findseg(hat->hat_as, va, 0);
2658 	ASSERT(seg != NULL);
2659 	ASSERT(seg->s_base <= va);
2660 	shmd = (struct shm_data *)seg->s_data;
2661 	ASSERT(shmd != NULL);
2662 	sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2663 	ASSERT(sptd != NULL);
2664 	if (sptd->spt_flags & SHM_PAGEABLE)
2665 		return (1);
2666 	return (0);
2667 }
2668 
2669 /*
2670  * Simple implementation of ISM. hat_share() is similar to hat_memload_array(),
2671  * except that we use the ism_hat's existing mappings to determine the pages
2672  * and protections to use for this hat. If we find a full properly aligned
2673  * and sized pagetable, we will attempt to share the pagetable itself.
2674  */
2675 /*ARGSUSED*/
2676 int
2677 hat_share(
2678 	hat_t		*hat,
2679 	caddr_t		addr,
2680 	hat_t		*ism_hat,
2681 	caddr_t		src_addr,
2682 	size_t		len,	/* almost useless value, see below.. */
2683 	uint_t		ismszc)
2684 {
2685 	uintptr_t	vaddr_start = (uintptr_t)addr;
2686 	uintptr_t	vaddr;
2687 	uintptr_t	eaddr = vaddr_start + len;
2688 	uintptr_t	ism_addr_start = (uintptr_t)src_addr;
2689 	uintptr_t	ism_addr = ism_addr_start;
2690 	uintptr_t	e_ism_addr = ism_addr + len;
2691 	htable_t	*ism_ht = NULL;
2692 	htable_t	*ht;
2693 	x86pte_t	pte;
2694 	page_t		*pp;
2695 	pfn_t		pfn;
2696 	level_t		l;
2697 	pgcnt_t		pgcnt;
2698 	uint_t		prot;
2699 	int		is_dism;
2700 	int		flags;
2701 
2702 	/*
2703 	 * We might be asked to share an empty DISM hat by as_dup()
2704 	 */
2705 	ASSERT(hat != kas.a_hat);
2706 	ASSERT(eaddr <= _userlimit);
2707 	if (!(ism_hat->hat_flags & HAT_SHARED)) {
2708 		ASSERT(hat_get_mapped_size(ism_hat) == 0);
2709 		return (0);
2710 	}
2711 
2712 	/*
2713 	 * The SPT segment driver often passes us a size larger than there are
2714 	 * valid mappings. That's because it rounds the segment size up to a
2715 	 * large pagesize, even if the actual memory mapped by ism_hat is less.
2716 	 */
2717 	ASSERT(IS_PAGEALIGNED(vaddr_start));
2718 	ASSERT(IS_PAGEALIGNED(ism_addr_start));
2719 	ASSERT(ism_hat->hat_flags & HAT_SHARED);
2720 	is_dism = is_it_dism(hat, addr);
2721 	while (ism_addr < e_ism_addr) {
2722 		/*
2723 		 * use htable_walk to get the next valid ISM mapping
2724 		 */
2725 		pte = htable_walk(ism_hat, &ism_ht, &ism_addr, e_ism_addr);
2726 		if (ism_ht == NULL)
2727 			break;
2728 
2729 		/*
2730 		 * First check to see if we already share the page table.
2731 		 */
2732 		l = ism_ht->ht_level;
2733 		vaddr = vaddr_start + (ism_addr - ism_addr_start);
2734 		ht = htable_lookup(hat, vaddr, l);
2735 		if (ht != NULL) {
2736 			if (ht->ht_flags & HTABLE_SHARED_PFN)
2737 				goto shared;
2738 			htable_release(ht);
2739 			goto not_shared;
2740 		}
2741 
2742 		/*
2743 		 * Can't ever share top table.
2744 		 */
2745 		if (l == mmu.max_level)
2746 			goto not_shared;
2747 
2748 		/*
2749 		 * Avoid level mismatches later due to DISM faults.
2750 		 */
2751 		if (is_dism && l > 0)
2752 			goto not_shared;
2753 
2754 		/*
2755 		 * addresses and lengths must align
2756 		 * table must be fully populated
2757 		 * no lower level page tables
2758 		 */
2759 		if (ism_addr != ism_ht->ht_vaddr ||
2760 		    (vaddr & LEVEL_OFFSET(l + 1)) != 0)
2761 			goto not_shared;
2762 
2763 		/*
2764 		 * The range of address space must cover a full table.
2765 		 */
2766 		if (e_ism_addr - ism_addr < LEVEL_SIZE(1 + 1))
2767 			goto not_shared;
2768 
2769 		/*
2770 		 * All entries in the ISM page table must be leaf PTEs.
2771 		 */
2772 		if (l > 0) {
2773 			int e;
2774 
2775 			/*
2776 			 * We know the 0th is from htable_walk() above.
2777 			 */
2778 			for (e = 1; e < HTABLE_NUM_PTES(ism_ht); ++e) {
2779 				x86pte_t pte;
2780 				pte = x86pte_get(ism_ht, e);
2781 				if (!PTE_ISPAGE(pte, l))
2782 					goto not_shared;
2783 			}
2784 		}
2785 
2786 		/*
2787 		 * share the page table
2788 		 */
2789 		ht = htable_create(hat, vaddr, l, ism_ht);
2790 shared:
2791 		ASSERT(ht->ht_flags & HTABLE_SHARED_PFN);
2792 		ASSERT(ht->ht_shares == ism_ht);
2793 		hat->hat_ism_pgcnt +=
2794 		    (ism_ht->ht_valid_cnt - ht->ht_valid_cnt) <<
2795 		    (LEVEL_SHIFT(ht->ht_level) - MMU_PAGESHIFT);
2796 		ht->ht_valid_cnt = ism_ht->ht_valid_cnt;
2797 		htable_release(ht);
2798 		ism_addr = ism_ht->ht_vaddr + LEVEL_SIZE(l + 1);
2799 		htable_release(ism_ht);
2800 		ism_ht = NULL;
2801 		continue;
2802 
2803 not_shared:
2804 		/*
2805 		 * Unable to share the page table. Instead we will
2806 		 * create new mappings from the values in the ISM mappings.
2807 		 * Figure out what level size mappings to use;
2808 		 */
2809 		for (l = ism_ht->ht_level; l > 0; --l) {
2810 			if (LEVEL_SIZE(l) <= eaddr - vaddr &&
2811 			    (vaddr & LEVEL_OFFSET(l)) == 0)
2812 				break;
2813 		}
2814 
2815 		/*
2816 		 * The ISM mapping might be larger than the share area,
2817 		 * be careful to truncate it if needed.
2818 		 */
2819 		if (eaddr - vaddr >= LEVEL_SIZE(ism_ht->ht_level)) {
2820 			pgcnt = mmu_btop(LEVEL_SIZE(ism_ht->ht_level));
2821 		} else {
2822 			pgcnt = mmu_btop(eaddr - vaddr);
2823 			l = 0;
2824 		}
2825 
2826 		pfn = PTE2PFN(pte, ism_ht->ht_level);
2827 		ASSERT(pfn != PFN_INVALID);
2828 		while (pgcnt > 0) {
2829 			/*
2830 			 * Make a new pte for the PFN for this level.
2831 			 * Copy protections for the pte from the ISM pte.
2832 			 */
2833 			pp = page_numtopp_nolock(pfn);
2834 			ASSERT(pp != NULL);
2835 
2836 			prot = PROT_USER | PROT_READ | HAT_UNORDERED_OK;
2837 			if (PTE_GET(pte, PT_WRITABLE))
2838 				prot |= PROT_WRITE;
2839 			if (!PTE_GET(pte, PT_NX))
2840 				prot |= PROT_EXEC;
2841 
2842 			flags = HAT_LOAD;
2843 			if (!is_dism)
2844 				flags |= HAT_LOAD_LOCK | HAT_LOAD_NOCONSIST;
2845 			while (hati_load_common(hat, vaddr, pp, prot, flags,
2846 			    l, pfn) != 0) {
2847 				if (l == 0)
2848 					panic("hati_load_common() failure");
2849 				--l;
2850 			}
2851 
2852 			vaddr += LEVEL_SIZE(l);
2853 			ism_addr += LEVEL_SIZE(l);
2854 			pfn += mmu_btop(LEVEL_SIZE(l));
2855 			pgcnt -= mmu_btop(LEVEL_SIZE(l));
2856 		}
2857 	}
2858 	if (ism_ht != NULL)
2859 		htable_release(ism_ht);
2860 	return (0);
2861 }
2862 
2863 
2864 /*
2865  * hat_unshare() is similar to hat_unload_callback(), but
2866  * we have to look for empty shared pagetables. Note that
2867  * hat_unshare() is always invoked against an entire segment.
2868  */
2869 /*ARGSUSED*/
2870 void
2871 hat_unshare(hat_t *hat, caddr_t addr, size_t len, uint_t ismszc)
2872 {
2873 	uint64_t	vaddr = (uintptr_t)addr;
2874 	uintptr_t	eaddr = vaddr + len;
2875 	htable_t	*ht = NULL;
2876 	uint_t		need_demaps = 0;
2877 	int		flags = HAT_UNLOAD_UNMAP;
2878 	level_t		l;
2879 
2880 	ASSERT(hat != kas.a_hat);
2881 	ASSERT(eaddr <= _userlimit);
2882 	ASSERT(IS_PAGEALIGNED(vaddr));
2883 	ASSERT(IS_PAGEALIGNED(eaddr));
2884 
2885 	/*
2886 	 * First go through and remove any shared pagetables.
2887 	 *
2888 	 * Note that it's ok to delay the TLB shootdown till the entire range is
2889 	 * finished, because if hat_pageunload() were to unload a shared
2890 	 * pagetable page, its hat_tlb_inval() will do a global TLB invalidate.
2891 	 */
2892 	l = mmu.max_page_level;
2893 	if (l == mmu.max_level)
2894 		--l;
2895 	for (; l >= 0; --l) {
2896 		for (vaddr = (uintptr_t)addr; vaddr < eaddr;
2897 		    vaddr = (vaddr & LEVEL_MASK(l + 1)) + LEVEL_SIZE(l + 1)) {
2898 			ASSERT(!IN_VA_HOLE(vaddr));
2899 			/*
2900 			 * find a pagetable that maps the current address
2901 			 */
2902 			ht = htable_lookup(hat, vaddr, l);
2903 			if (ht == NULL)
2904 				continue;
2905 			if (ht->ht_flags & HTABLE_SHARED_PFN) {
2906 				/*
2907 				 * clear page count, set valid_cnt to 0,
2908 				 * let htable_release() finish the job
2909 				 */
2910 				hat->hat_ism_pgcnt -= ht->ht_valid_cnt <<
2911 				    (LEVEL_SHIFT(ht->ht_level) - MMU_PAGESHIFT);
2912 				ht->ht_valid_cnt = 0;
2913 				need_demaps = 1;
2914 			}
2915 			htable_release(ht);
2916 		}
2917 	}
2918 
2919 	/*
2920 	 * flush the TLBs - since we're probably dealing with MANY mappings
2921 	 * we do just one CR3 reload.
2922 	 */
2923 	if (!(hat->hat_flags & HAT_FREEING) && need_demaps)
2924 		hat_tlb_inval(hat, DEMAP_ALL_ADDR);
2925 
2926 	/*
2927 	 * Now go back and clean up any unaligned mappings that
2928 	 * couldn't share pagetables.
2929 	 */
2930 	if (!is_it_dism(hat, addr))
2931 		flags |= HAT_UNLOAD_UNLOCK;
2932 	hat_unload(hat, addr, len, flags);
2933 }
2934 
2935 
2936 /*
2937  * hat_reserve() does nothing
2938  */
2939 /*ARGSUSED*/
2940 void
2941 hat_reserve(struct as *as, caddr_t addr, size_t len)
2942 {
2943 }
2944 
2945 
2946 /*
2947  * Called when all mappings to a page should have write permission removed.
2948  * Mostly stolem from hat_pagesync()
2949  */
2950 static void
2951 hati_page_clrwrt(struct page *pp)
2952 {
2953 	hment_t		*hm = NULL;
2954 	htable_t	*ht;
2955 	uint_t		entry;
2956 	x86pte_t	old;
2957 	x86pte_t	new;
2958 	uint_t		pszc = 0;
2959 
2960 next_size:
2961 	/*
2962 	 * walk thru the mapping list clearing write permission
2963 	 */
2964 	x86_hm_enter(pp);
2965 	while ((hm = hment_walk(pp, &ht, &entry, hm)) != NULL) {
2966 		if (ht->ht_level < pszc)
2967 			continue;
2968 		old = x86pte_get(ht, entry);
2969 
2970 		for (;;) {
2971 			/*
2972 			 * Is this mapping of interest?
2973 			 */
2974 			if (PTE2PFN(old, ht->ht_level) != pp->p_pagenum ||
2975 			    PTE_GET(old, PT_WRITABLE) == 0)
2976 				break;
2977 
2978 			/*
2979 			 * Clear ref/mod writable bits. This requires cross
2980 			 * calls to ensure any executing TLBs see cleared bits.
2981 			 */
2982 			new = old;
2983 			PTE_CLR(new, PT_REF | PT_MOD | PT_WRITABLE);
2984 			old = hati_update_pte(ht, entry, old, new);
2985 			if (old != 0)
2986 				continue;
2987 
2988 			break;
2989 		}
2990 	}
2991 	x86_hm_exit(pp);
2992 	while (pszc < pp->p_szc) {
2993 		page_t *tpp;
2994 		pszc++;
2995 		tpp = PP_GROUPLEADER(pp, pszc);
2996 		if (pp != tpp) {
2997 			pp = tpp;
2998 			goto next_size;
2999 		}
3000 	}
3001 }
3002 
3003 /*
3004  * void hat_page_setattr(pp, flag)
3005  * void hat_page_clrattr(pp, flag)
3006  *	used to set/clr ref/mod bits.
3007  */
3008 void
3009 hat_page_setattr(struct page *pp, uint_t flag)
3010 {
3011 	vnode_t		*vp = pp->p_vnode;
3012 	kmutex_t	*vphm = NULL;
3013 	page_t		**listp;
3014 	int		noshuffle;
3015 
3016 	noshuffle = flag & P_NSH;
3017 	flag &= ~P_NSH;
3018 
3019 	if (PP_GETRM(pp, flag) == flag)
3020 		return;
3021 
3022 	if ((flag & P_MOD) != 0 && vp != NULL && IS_VMODSORT(vp) &&
3023 	    !noshuffle) {
3024 		vphm = page_vnode_mutex(vp);
3025 		mutex_enter(vphm);
3026 	}
3027 
3028 	PP_SETRM(pp, flag);
3029 
3030 	if (vphm != NULL) {
3031 
3032 		/*
3033 		 * Some File Systems examine v_pages for NULL w/o
3034 		 * grabbing the vphm mutex. Must not let it become NULL when
3035 		 * pp is the only page on the list.
3036 		 */
3037 		if (pp->p_vpnext != pp) {
3038 			page_vpsub(&vp->v_pages, pp);
3039 			if (vp->v_pages != NULL)
3040 				listp = &vp->v_pages->p_vpprev->p_vpnext;
3041 			else
3042 				listp = &vp->v_pages;
3043 			page_vpadd(listp, pp);
3044 		}
3045 		mutex_exit(vphm);
3046 	}
3047 }
3048 
3049 void
3050 hat_page_clrattr(struct page *pp, uint_t flag)
3051 {
3052 	vnode_t		*vp = pp->p_vnode;
3053 	ASSERT(!(flag & ~(P_MOD | P_REF | P_RO)));
3054 
3055 	/*
3056 	 * Caller is expected to hold page's io lock for VMODSORT to work
3057 	 * correctly with pvn_vplist_dirty() and pvn_getdirty() when mod
3058 	 * bit is cleared.
3059 	 * We don't have assert to avoid tripping some existing third party
3060 	 * code. The dirty page is moved back to top of the v_page list
3061 	 * after IO is done in pvn_write_done().
3062 	 */
3063 	PP_CLRRM(pp, flag);
3064 
3065 	if ((flag & P_MOD) != 0 && vp != NULL && IS_VMODSORT(vp)) {
3066 
3067 		/*
3068 		 * VMODSORT works by removing write permissions and getting
3069 		 * a fault when a page is made dirty. At this point
3070 		 * we need to remove write permission from all mappings
3071 		 * to this page.
3072 		 */
3073 		hati_page_clrwrt(pp);
3074 	}
3075 }
3076 
3077 /*
3078  *	If flag is specified, returns 0 if attribute is disabled
3079  *	and non zero if enabled.  If flag specifes multiple attributs
3080  *	then returns 0 if ALL atriibutes are disabled.  This is an advisory
3081  *	call.
3082  */
3083 uint_t
3084 hat_page_getattr(struct page *pp, uint_t flag)
3085 {
3086 	return (PP_GETRM(pp, flag));
3087 }
3088 
3089 
3090 /*
3091  * common code used by hat_pageunload() and hment_steal()
3092  */
3093 hment_t *
3094 hati_page_unmap(page_t *pp, htable_t *ht, uint_t entry)
3095 {
3096 	x86pte_t old_pte;
3097 	pfn_t pfn = pp->p_pagenum;
3098 	hment_t *hm;
3099 
3100 	/*
3101 	 * We need to acquire a hold on the htable in order to
3102 	 * do the invalidate. We know the htable must exist, since
3103 	 * unmap's don't release the htable until after removing any
3104 	 * hment. Having x86_hm_enter() keeps that from proceeding.
3105 	 */
3106 	htable_acquire(ht);
3107 
3108 	/*
3109 	 * Invalidate the PTE and remove the hment.
3110 	 */
3111 	old_pte = x86pte_inval(ht, entry, 0, NULL);
3112 	if (PTE2PFN(old_pte, ht->ht_level) != pfn) {
3113 		panic("x86pte_inval() failure found PTE = " FMT_PTE
3114 		    " pfn being unmapped is %lx ht=0x%lx entry=0x%x",
3115 		    old_pte, pfn, (uintptr_t)ht, entry);
3116 	}
3117 
3118 	/*
3119 	 * Clean up all the htable information for this mapping
3120 	 */
3121 	ASSERT(ht->ht_valid_cnt > 0);
3122 	HTABLE_DEC(ht->ht_valid_cnt);
3123 	PGCNT_DEC(ht->ht_hat, ht->ht_level);
3124 
3125 	/*
3126 	 * sync ref/mod bits to the page_t
3127 	 */
3128 	if (PTE_GET(old_pte, PT_SOFTWARE) < PT_NOSYNC)
3129 		hati_sync_pte_to_page(pp, old_pte, ht->ht_level);
3130 
3131 	/*
3132 	 * Remove the mapping list entry for this page.
3133 	 */
3134 	hm = hment_remove(pp, ht, entry);
3135 
3136 	/*
3137 	 * drop the mapping list lock so that we might free the
3138 	 * hment and htable.
3139 	 */
3140 	x86_hm_exit(pp);
3141 	htable_release(ht);
3142 	return (hm);
3143 }
3144 
3145 extern int	vpm_enable;
3146 /*
3147  * Unload all translations to a page. If the page is a subpage of a large
3148  * page, the large page mappings are also removed.
3149  *
3150  * The forceflags are unused.
3151  */
3152 
3153 /*ARGSUSED*/
3154 static int
3155 hati_pageunload(struct page *pp, uint_t pg_szcd, uint_t forceflag)
3156 {
3157 	page_t		*cur_pp = pp;
3158 	hment_t		*hm;
3159 	hment_t		*prev;
3160 	htable_t	*ht;
3161 	uint_t		entry;
3162 	level_t		level;
3163 
3164 #if defined(__amd64)
3165 	/*
3166 	 * clear the vpm ref.
3167 	 */
3168 	if (vpm_enable) {
3169 		pp->p_vpmref = 0;
3170 	}
3171 #endif
3172 	/*
3173 	 * The loop with next_size handles pages with multiple pagesize mappings
3174 	 */
3175 next_size:
3176 	for (;;) {
3177 
3178 		/*
3179 		 * Get a mapping list entry
3180 		 */
3181 		x86_hm_enter(cur_pp);
3182 		for (prev = NULL; ; prev = hm) {
3183 			hm = hment_walk(cur_pp, &ht, &entry, prev);
3184 			if (hm == NULL) {
3185 				x86_hm_exit(cur_pp);
3186 
3187 				/*
3188 				 * If not part of a larger page, we're done.
3189 				 */
3190 				if (cur_pp->p_szc <= pg_szcd) {
3191 					return (0);
3192 				}
3193 
3194 				/*
3195 				 * Else check the next larger page size.
3196 				 * hat_page_demote() may decrease p_szc
3197 				 * but that's ok we'll just take an extra
3198 				 * trip discover there're no larger mappings
3199 				 * and return.
3200 				 */
3201 				++pg_szcd;
3202 				cur_pp = PP_GROUPLEADER(cur_pp, pg_szcd);
3203 				goto next_size;
3204 			}
3205 
3206 			/*
3207 			 * If this mapping size matches, remove it.
3208 			 */
3209 			level = ht->ht_level;
3210 			if (level == pg_szcd)
3211 				break;
3212 		}
3213 
3214 		/*
3215 		 * Remove the mapping list entry for this page.
3216 		 * Note this does the x86_hm_exit() for us.
3217 		 */
3218 		hm = hati_page_unmap(cur_pp, ht, entry);
3219 		if (hm != NULL)
3220 			hment_free(hm);
3221 	}
3222 }
3223 
3224 int
3225 hat_pageunload(struct page *pp, uint_t forceflag)
3226 {
3227 	ASSERT(PAGE_EXCL(pp));
3228 	return (hati_pageunload(pp, 0, forceflag));
3229 }
3230 
3231 /*
3232  * Unload all large mappings to pp and reduce by 1 p_szc field of every large
3233  * page level that included pp.
3234  *
3235  * pp must be locked EXCL. Even though no other constituent pages are locked
3236  * it's legal to unload large mappings to pp because all constituent pages of
3237  * large locked mappings have to be locked SHARED.  therefore if we have EXCL
3238  * lock on one of constituent pages none of the large mappings to pp are
3239  * locked.
3240  *
3241  * Change (always decrease) p_szc field starting from the last constituent
3242  * page and ending with root constituent page so that root's pszc always shows
3243  * the area where hat_page_demote() may be active.
3244  *
3245  * This mechanism is only used for file system pages where it's not always
3246  * possible to get EXCL locks on all constituent pages to demote the size code
3247  * (as is done for anonymous or kernel large pages).
3248  */
3249 void
3250 hat_page_demote(page_t *pp)
3251 {
3252 	uint_t		pszc;
3253 	uint_t		rszc;
3254 	uint_t		szc;
3255 	page_t		*rootpp;
3256 	page_t		*firstpp;
3257 	page_t		*lastpp;
3258 	pgcnt_t		pgcnt;
3259 
3260 	ASSERT(PAGE_EXCL(pp));
3261 	ASSERT(!PP_ISFREE(pp));
3262 	ASSERT(page_szc_lock_assert(pp));
3263 
3264 	if (pp->p_szc == 0)
3265 		return;
3266 
3267 	rootpp = PP_GROUPLEADER(pp, 1);
3268 	(void) hati_pageunload(rootpp, 1, HAT_FORCE_PGUNLOAD);
3269 
3270 	/*
3271 	 * all large mappings to pp are gone
3272 	 * and no new can be setup since pp is locked exclusively.
3273 	 *
3274 	 * Lock the root to make sure there's only one hat_page_demote()
3275 	 * outstanding within the area of this root's pszc.
3276 	 *
3277 	 * Second potential hat_page_demote() is already eliminated by upper
3278 	 * VM layer via page_szc_lock() but we don't rely on it and use our
3279 	 * own locking (so that upper layer locking can be changed without
3280 	 * assumptions that hat depends on upper layer VM to prevent multiple
3281 	 * hat_page_demote() to be issued simultaneously to the same large
3282 	 * page).
3283 	 */
3284 again:
3285 	pszc = pp->p_szc;
3286 	if (pszc == 0)
3287 		return;
3288 	rootpp = PP_GROUPLEADER(pp, pszc);
3289 	x86_hm_enter(rootpp);
3290 	/*
3291 	 * If root's p_szc is different from pszc we raced with another
3292 	 * hat_page_demote().  Drop the lock and try to find the root again.
3293 	 * If root's p_szc is greater than pszc previous hat_page_demote() is
3294 	 * not done yet.  Take and release mlist lock of root's root to wait
3295 	 * for previous hat_page_demote() to complete.
3296 	 */
3297 	if ((rszc = rootpp->p_szc) != pszc) {
3298 		x86_hm_exit(rootpp);
3299 		if (rszc > pszc) {
3300 			/* p_szc of a locked non free page can't increase */
3301 			ASSERT(pp != rootpp);
3302 
3303 			rootpp = PP_GROUPLEADER(rootpp, rszc);
3304 			x86_hm_enter(rootpp);
3305 			x86_hm_exit(rootpp);
3306 		}
3307 		goto again;
3308 	}
3309 	ASSERT(pp->p_szc == pszc);
3310 
3311 	/*
3312 	 * Decrement by 1 p_szc of every constituent page of a region that
3313 	 * covered pp. For example if original szc is 3 it gets changed to 2
3314 	 * everywhere except in region 2 that covered pp. Region 2 that
3315 	 * covered pp gets demoted to 1 everywhere except in region 1 that
3316 	 * covered pp. The region 1 that covered pp is demoted to region
3317 	 * 0. It's done this way because from region 3 we removed level 3
3318 	 * mappings, from region 2 that covered pp we removed level 2 mappings
3319 	 * and from region 1 that covered pp we removed level 1 mappings.  All
3320 	 * changes are done from from high pfn's to low pfn's so that roots
3321 	 * are changed last allowing one to know the largest region where
3322 	 * hat_page_demote() is stil active by only looking at the root page.
3323 	 *
3324 	 * This algorithm is implemented in 2 while loops. First loop changes
3325 	 * p_szc of pages to the right of pp's level 1 region and second
3326 	 * loop changes p_szc of pages of level 1 region that covers pp
3327 	 * and all pages to the left of level 1 region that covers pp.
3328 	 * In the first loop p_szc keeps dropping with every iteration
3329 	 * and in the second loop it keeps increasing with every iteration.
3330 	 *
3331 	 * First loop description: Demote pages to the right of pp outside of
3332 	 * level 1 region that covers pp.  In every iteration of the while
3333 	 * loop below find the last page of szc region and the first page of
3334 	 * (szc - 1) region that is immediately to the right of (szc - 1)
3335 	 * region that covers pp.  From last such page to first such page
3336 	 * change every page's szc to szc - 1. Decrement szc and continue
3337 	 * looping until szc is 1. If pp belongs to the last (szc - 1) region
3338 	 * of szc region skip to the next iteration.
3339 	 */
3340 	szc = pszc;
3341 	while (szc > 1) {
3342 		lastpp = PP_GROUPLEADER(pp, szc);
3343 		pgcnt = page_get_pagecnt(szc);
3344 		lastpp += pgcnt - 1;
3345 		firstpp = PP_GROUPLEADER(pp, (szc - 1));
3346 		pgcnt = page_get_pagecnt(szc - 1);
3347 		if (lastpp - firstpp < pgcnt) {
3348 			szc--;
3349 			continue;
3350 		}
3351 		firstpp += pgcnt;
3352 		while (lastpp != firstpp) {
3353 			ASSERT(lastpp->p_szc == pszc);
3354 			lastpp->p_szc = szc - 1;
3355 			lastpp--;
3356 		}
3357 		firstpp->p_szc = szc - 1;
3358 		szc--;
3359 	}
3360 
3361 	/*
3362 	 * Second loop description:
3363 	 * First iteration changes p_szc to 0 of every
3364 	 * page of level 1 region that covers pp.
3365 	 * Subsequent iterations find last page of szc region
3366 	 * immediately to the left of szc region that covered pp
3367 	 * and first page of (szc + 1) region that covers pp.
3368 	 * From last to first page change p_szc of every page to szc.
3369 	 * Increment szc and continue looping until szc is pszc.
3370 	 * If pp belongs to the fist szc region of (szc + 1) region
3371 	 * skip to the next iteration.
3372 	 *
3373 	 */
3374 	szc = 0;
3375 	while (szc < pszc) {
3376 		firstpp = PP_GROUPLEADER(pp, (szc + 1));
3377 		if (szc == 0) {
3378 			pgcnt = page_get_pagecnt(1);
3379 			lastpp = firstpp + (pgcnt - 1);
3380 		} else {
3381 			lastpp = PP_GROUPLEADER(pp, szc);
3382 			if (firstpp == lastpp) {
3383 				szc++;
3384 				continue;
3385 			}
3386 			lastpp--;
3387 			pgcnt = page_get_pagecnt(szc);
3388 		}
3389 		while (lastpp != firstpp) {
3390 			ASSERT(lastpp->p_szc == pszc);
3391 			lastpp->p_szc = szc;
3392 			lastpp--;
3393 		}
3394 		firstpp->p_szc = szc;
3395 		if (firstpp == rootpp)
3396 			break;
3397 		szc++;
3398 	}
3399 	x86_hm_exit(rootpp);
3400 }
3401 
3402 /*
3403  * get hw stats from hardware into page struct and reset hw stats
3404  * returns attributes of page
3405  * Flags for hat_pagesync, hat_getstat, hat_sync
3406  *
3407  * define	HAT_SYNC_ZERORM		0x01
3408  *
3409  * Additional flags for hat_pagesync
3410  *
3411  * define	HAT_SYNC_STOPON_REF	0x02
3412  * define	HAT_SYNC_STOPON_MOD	0x04
3413  * define	HAT_SYNC_STOPON_RM	0x06
3414  * define	HAT_SYNC_STOPON_SHARED	0x08
3415  */
3416 uint_t
3417 hat_pagesync(struct page *pp, uint_t flags)
3418 {
3419 	hment_t		*hm = NULL;
3420 	htable_t	*ht;
3421 	uint_t		entry;
3422 	x86pte_t	old, save_old;
3423 	x86pte_t	new;
3424 	uchar_t		nrmbits = P_REF|P_MOD|P_RO;
3425 	extern ulong_t	po_share;
3426 	page_t		*save_pp = pp;
3427 	uint_t		pszc = 0;
3428 
3429 	ASSERT(PAGE_LOCKED(pp) || panicstr);
3430 
3431 	if (PP_ISRO(pp) && (flags & HAT_SYNC_STOPON_MOD))
3432 		return (pp->p_nrm & nrmbits);
3433 
3434 	if ((flags & HAT_SYNC_ZERORM) == 0) {
3435 
3436 		if ((flags & HAT_SYNC_STOPON_REF) != 0 && PP_ISREF(pp))
3437 			return (pp->p_nrm & nrmbits);
3438 
3439 		if ((flags & HAT_SYNC_STOPON_MOD) != 0 && PP_ISMOD(pp))
3440 			return (pp->p_nrm & nrmbits);
3441 
3442 		if ((flags & HAT_SYNC_STOPON_SHARED) != 0 &&
3443 		    hat_page_getshare(pp) > po_share) {
3444 			if (PP_ISRO(pp))
3445 				PP_SETREF(pp);
3446 			return (pp->p_nrm & nrmbits);
3447 		}
3448 	}
3449 
3450 next_size:
3451 	/*
3452 	 * walk thru the mapping list syncing (and clearing) ref/mod bits.
3453 	 */
3454 	x86_hm_enter(pp);
3455 	while ((hm = hment_walk(pp, &ht, &entry, hm)) != NULL) {
3456 		if (ht->ht_level < pszc)
3457 			continue;
3458 		old = x86pte_get(ht, entry);
3459 try_again:
3460 
3461 		ASSERT(PTE2PFN(old, ht->ht_level) == pp->p_pagenum);
3462 
3463 		if (PTE_GET(old, PT_REF | PT_MOD) == 0)
3464 			continue;
3465 
3466 		save_old = old;
3467 		if ((flags & HAT_SYNC_ZERORM) != 0) {
3468 
3469 			/*
3470 			 * Need to clear ref or mod bits. Need to demap
3471 			 * to make sure any executing TLBs see cleared bits.
3472 			 */
3473 			new = old;
3474 			PTE_CLR(new, PT_REF | PT_MOD);
3475 			old = hati_update_pte(ht, entry, old, new);
3476 			if (old != 0)
3477 				goto try_again;
3478 
3479 			old = save_old;
3480 		}
3481 
3482 		/*
3483 		 * Sync the PTE
3484 		 */
3485 		if (!(flags & HAT_SYNC_ZERORM) &&
3486 		    PTE_GET(old, PT_SOFTWARE) <= PT_NOSYNC)
3487 			hati_sync_pte_to_page(pp, old, ht->ht_level);
3488 
3489 		/*
3490 		 * can stop short if we found a ref'd or mod'd page
3491 		 */
3492 		if ((flags & HAT_SYNC_STOPON_MOD) && PP_ISMOD(save_pp) ||
3493 		    (flags & HAT_SYNC_STOPON_REF) && PP_ISREF(save_pp)) {
3494 			x86_hm_exit(pp);
3495 			goto done;
3496 		}
3497 	}
3498 	x86_hm_exit(pp);
3499 	while (pszc < pp->p_szc) {
3500 		page_t *tpp;
3501 		pszc++;
3502 		tpp = PP_GROUPLEADER(pp, pszc);
3503 		if (pp != tpp) {
3504 			pp = tpp;
3505 			goto next_size;
3506 		}
3507 	}
3508 done:
3509 	return (save_pp->p_nrm & nrmbits);
3510 }
3511 
3512 /*
3513  * returns approx number of mappings to this pp.  A return of 0 implies
3514  * there are no mappings to the page.
3515  */
3516 ulong_t
3517 hat_page_getshare(page_t *pp)
3518 {
3519 	uint_t cnt;
3520 	cnt = hment_mapcnt(pp);
3521 #if defined(__amd64)
3522 	if (vpm_enable && pp->p_vpmref) {
3523 		cnt += 1;
3524 	}
3525 #endif
3526 	return (cnt);
3527 }
3528 
3529 /*
3530  * Return 1 the number of mappings exceeds sh_thresh. Return 0
3531  * otherwise.
3532  */
3533 int
3534 hat_page_checkshare(page_t *pp, ulong_t sh_thresh)
3535 {
3536 	return (hat_page_getshare(pp) > sh_thresh);
3537 }
3538 
3539 /*
3540  * hat_softlock isn't supported anymore
3541  */
3542 /*ARGSUSED*/
3543 faultcode_t
3544 hat_softlock(
3545 	hat_t *hat,
3546 	caddr_t addr,
3547 	size_t *len,
3548 	struct page **page_array,
3549 	uint_t flags)
3550 {
3551 	return (FC_NOSUPPORT);
3552 }
3553 
3554 
3555 
3556 /*
3557  * Routine to expose supported HAT features to platform independent code.
3558  */
3559 /*ARGSUSED*/
3560 int
3561 hat_supported(enum hat_features feature, void *arg)
3562 {
3563 	switch (feature) {
3564 
3565 	case HAT_SHARED_PT:	/* this is really ISM */
3566 		return (1);
3567 
3568 	case HAT_DYNAMIC_ISM_UNMAP:
3569 		return (0);
3570 
3571 	case HAT_VMODSORT:
3572 		return (1);
3573 
3574 	case HAT_SHARED_REGIONS:
3575 		return (0);
3576 
3577 	default:
3578 		panic("hat_supported() - unknown feature");
3579 	}
3580 	return (0);
3581 }
3582 
3583 /*
3584  * Called when a thread is exiting and has been switched to the kernel AS
3585  */
3586 void
3587 hat_thread_exit(kthread_t *thd)
3588 {
3589 	ASSERT(thd->t_procp->p_as == &kas);
3590 	hat_switch(thd->t_procp->p_as->a_hat);
3591 }
3592 
3593 /*
3594  * Setup the given brand new hat structure as the new HAT on this cpu's mmu.
3595  */
3596 /*ARGSUSED*/
3597 void
3598 hat_setup(hat_t *hat, int flags)
3599 {
3600 	kpreempt_disable();
3601 
3602 	hat_switch(hat);
3603 
3604 	kpreempt_enable();
3605 }
3606 
3607 /*
3608  * Prepare for a CPU private mapping for the given address.
3609  *
3610  * The address can only be used from a single CPU and can be remapped
3611  * using hat_mempte_remap().  Return the address of the PTE.
3612  *
3613  * We do the htable_create() if necessary and increment the valid count so
3614  * the htable can't disappear.  We also hat_devload() the page table into
3615  * kernel so that the PTE is quickly accessed.
3616  */
3617 hat_mempte_t
3618 hat_mempte_setup(caddr_t addr)
3619 {
3620 	uintptr_t	va = (uintptr_t)addr;
3621 	htable_t	*ht;
3622 	uint_t		entry;
3623 	x86pte_t	oldpte;
3624 	hat_mempte_t	p;
3625 
3626 	ASSERT(IS_PAGEALIGNED(va));
3627 	ASSERT(!IN_VA_HOLE(va));
3628 	++curthread->t_hatdepth;
3629 	ht = htable_getpte(kas.a_hat, va, &entry, &oldpte, 0);
3630 	if (ht == NULL) {
3631 		ht = htable_create(kas.a_hat, va, 0, NULL);
3632 		entry = htable_va2entry(va, ht);
3633 		ASSERT(ht->ht_level == 0);
3634 		oldpte = x86pte_get(ht, entry);
3635 	}
3636 	if (PTE_ISVALID(oldpte))
3637 		panic("hat_mempte_setup(): address already mapped"
3638 		    "ht=%p, entry=%d, pte=" FMT_PTE, ht, entry, oldpte);
3639 
3640 	/*
3641 	 * increment ht_valid_cnt so that the pagetable can't disappear
3642 	 */
3643 	HTABLE_INC(ht->ht_valid_cnt);
3644 
3645 	/*
3646 	 * return the PTE physical address to the caller.
3647 	 */
3648 	htable_release(ht);
3649 	p = PT_INDEX_PHYSADDR(pfn_to_pa(ht->ht_pfn), entry);
3650 	--curthread->t_hatdepth;
3651 	return (p);
3652 }
3653 
3654 /*
3655  * Release a CPU private mapping for the given address.
3656  * We decrement the htable valid count so it might be destroyed.
3657  */
3658 /*ARGSUSED1*/
3659 void
3660 hat_mempte_release(caddr_t addr, hat_mempte_t pte_pa)
3661 {
3662 	htable_t	*ht;
3663 
3664 	/*
3665 	 * invalidate any left over mapping and decrement the htable valid count
3666 	 */
3667 	{
3668 		x86pte_t *pteptr;
3669 
3670 		pteptr = x86pte_mapin(mmu_btop(pte_pa),
3671 		    (pte_pa & MMU_PAGEOFFSET) >> mmu.pte_size_shift, NULL);
3672 		if (mmu.pae_hat)
3673 			*pteptr = 0;
3674 		else
3675 			*(x86pte32_t *)pteptr = 0;
3676 		mmu_tlbflush_entry(addr);
3677 		x86pte_mapout();
3678 	}
3679 
3680 	ht = htable_getpte(kas.a_hat, ALIGN2PAGE(addr), NULL, NULL, 0);
3681 	if (ht == NULL)
3682 		panic("hat_mempte_release(): invalid address");
3683 	ASSERT(ht->ht_level == 0);
3684 	HTABLE_DEC(ht->ht_valid_cnt);
3685 	htable_release(ht);
3686 }
3687 
3688 /*
3689  * Apply a temporary CPU private mapping to a page. We flush the TLB only
3690  * on this CPU, so this ought to have been called with preemption disabled.
3691  */
3692 void
3693 hat_mempte_remap(
3694 	pfn_t		pfn,
3695 	caddr_t		addr,
3696 	hat_mempte_t	pte_pa,
3697 	uint_t		attr,
3698 	uint_t		flags)
3699 {
3700 	uintptr_t	va = (uintptr_t)addr;
3701 	x86pte_t	pte;
3702 
3703 	/*
3704 	 * Remap the given PTE to the new page's PFN. Invalidate only
3705 	 * on this CPU.
3706 	 */
3707 #ifdef DEBUG
3708 	htable_t	*ht;
3709 	uint_t		entry;
3710 
3711 	ASSERT(IS_PAGEALIGNED(va));
3712 	ASSERT(!IN_VA_HOLE(va));
3713 	ht = htable_getpte(kas.a_hat, va, &entry, NULL, 0);
3714 	ASSERT(ht != NULL);
3715 	ASSERT(ht->ht_level == 0);
3716 	ASSERT(ht->ht_valid_cnt > 0);
3717 	ASSERT(ht->ht_pfn == mmu_btop(pte_pa));
3718 	htable_release(ht);
3719 #endif
3720 	pte = hati_mkpte(pfn, attr, 0, flags);
3721 	{
3722 		x86pte_t *pteptr;
3723 
3724 		pteptr = x86pte_mapin(mmu_btop(pte_pa),
3725 		    (pte_pa & MMU_PAGEOFFSET) >> mmu.pte_size_shift, NULL);
3726 		if (mmu.pae_hat)
3727 			*(x86pte_t *)pteptr = pte;
3728 		else
3729 			*(x86pte32_t *)pteptr = (x86pte32_t)pte;
3730 		mmu_tlbflush_entry(addr);
3731 		x86pte_mapout();
3732 	}
3733 }
3734 
3735 
3736 
3737 /*
3738  * Hat locking functions
3739  * XXX - these two functions are currently being used by hatstats
3740  * 	they can be removed by using a per-as mutex for hatstats.
3741  */
3742 void
3743 hat_enter(hat_t *hat)
3744 {
3745 	mutex_enter(&hat->hat_mutex);
3746 }
3747 
3748 void
3749 hat_exit(hat_t *hat)
3750 {
3751 	mutex_exit(&hat->hat_mutex);
3752 }
3753 
3754 /*
3755  * HAT part of cpu initialization.
3756  */
3757 void
3758 hat_cpu_online(struct cpu *cpup)
3759 {
3760 	if (cpup != CPU) {
3761 		x86pte_cpu_init(cpup);
3762 		hat_vlp_setup(cpup);
3763 	}
3764 	CPUSET_ATOMIC_ADD(khat_cpuset, cpup->cpu_id);
3765 }
3766 
3767 /*
3768  * HAT part of cpu deletion.
3769  * (currently, we only call this after the cpu is safely passivated.)
3770  */
3771 void
3772 hat_cpu_offline(struct cpu *cpup)
3773 {
3774 	ASSERT(cpup != CPU);
3775 
3776 	CPUSET_ATOMIC_DEL(khat_cpuset, cpup->cpu_id);
3777 	x86pte_cpu_fini(cpup);
3778 	hat_vlp_teardown(cpup);
3779 }
3780 
3781 /*
3782  * Function called after all CPUs are brought online.
3783  * Used to remove low address boot mappings.
3784  */
3785 void
3786 clear_boot_mappings(uintptr_t low, uintptr_t high)
3787 {
3788 	uintptr_t vaddr = low;
3789 	htable_t *ht = NULL;
3790 	level_t level;
3791 	uint_t entry;
3792 	x86pte_t pte;
3793 
3794 	/*
3795 	 * On 1st CPU we can unload the prom mappings, basically we blow away
3796 	 * all virtual mappings under _userlimit.
3797 	 */
3798 	while (vaddr < high) {
3799 		pte = htable_walk(kas.a_hat, &ht, &vaddr, high);
3800 		if (ht == NULL)
3801 			break;
3802 
3803 		level = ht->ht_level;
3804 		entry = htable_va2entry(vaddr, ht);
3805 		ASSERT(level <= mmu.max_page_level);
3806 		ASSERT(PTE_ISPAGE(pte, level));
3807 
3808 		/*
3809 		 * Unload the mapping from the page tables.
3810 		 */
3811 		(void) x86pte_inval(ht, entry, 0, NULL);
3812 		ASSERT(ht->ht_valid_cnt > 0);
3813 		HTABLE_DEC(ht->ht_valid_cnt);
3814 		PGCNT_DEC(ht->ht_hat, ht->ht_level);
3815 
3816 		vaddr += LEVEL_SIZE(ht->ht_level);
3817 	}
3818 	if (ht)
3819 		htable_release(ht);
3820 }
3821 
3822 /*
3823  * Atomically update a new translation for a single page.  If the
3824  * currently installed PTE doesn't match the value we expect to find,
3825  * it's not updated and we return the PTE we found.
3826  *
3827  * If activating nosync or NOWRITE and the page was modified we need to sync
3828  * with the page_t. Also sync with page_t if clearing ref/mod bits.
3829  */
3830 static x86pte_t
3831 hati_update_pte(htable_t *ht, uint_t entry, x86pte_t expected, x86pte_t new)
3832 {
3833 	page_t		*pp;
3834 	uint_t		rm = 0;
3835 	x86pte_t	replaced;
3836 
3837 	if (PTE_GET(expected, PT_SOFTWARE) < PT_NOSYNC &&
3838 	    PTE_GET(expected, PT_MOD | PT_REF) &&
3839 	    (PTE_GET(new, PT_NOSYNC) || !PTE_GET(new, PT_WRITABLE) ||
3840 	    !PTE_GET(new, PT_MOD | PT_REF))) {
3841 
3842 		ASSERT(!pfn_is_foreign(PTE2PFN(expected, ht->ht_level)));
3843 		pp = page_numtopp_nolock(PTE2PFN(expected, ht->ht_level));
3844 		ASSERT(pp != NULL);
3845 		if (PTE_GET(expected, PT_MOD))
3846 			rm |= P_MOD;
3847 		if (PTE_GET(expected, PT_REF))
3848 			rm |= P_REF;
3849 		PTE_CLR(new, PT_MOD | PT_REF);
3850 	}
3851 
3852 	replaced = x86pte_update(ht, entry, expected, new);
3853 	if (replaced != expected)
3854 		return (replaced);
3855 
3856 	if (rm) {
3857 		/*
3858 		 * sync to all constituent pages of a large page
3859 		 */
3860 		pgcnt_t pgcnt = page_get_pagecnt(ht->ht_level);
3861 		ASSERT(IS_P2ALIGNED(pp->p_pagenum, pgcnt));
3862 		while (pgcnt-- > 0) {
3863 			/*
3864 			 * hat_page_demote() can't decrease
3865 			 * pszc below this mapping size
3866 			 * since large mapping existed after we
3867 			 * took mlist lock.
3868 			 */
3869 			ASSERT(pp->p_szc >= ht->ht_level);
3870 			hat_page_setattr(pp, rm);
3871 			++pp;
3872 		}
3873 	}
3874 
3875 	return (0);
3876 }
3877 
3878 /* ARGSUSED */
3879 void
3880 hat_join_srd(struct hat *sfmmup, vnode_t *evp)
3881 {
3882 }
3883 
3884 /* ARGSUSED */
3885 hat_region_cookie_t
3886 hat_join_region(struct hat *sfmmup,
3887     caddr_t r_saddr,
3888     size_t r_size,
3889     void *r_obj,
3890     u_offset_t r_objoff,
3891     uchar_t r_perm,
3892     uchar_t r_pgszc,
3893     hat_rgn_cb_func_t r_cb_function,
3894     uint_t flags)
3895 {
3896 	panic("No shared region support on x86");
3897 	return (HAT_INVALID_REGION_COOKIE);
3898 }
3899 
3900 /* ARGSUSED */
3901 void
3902 hat_leave_region(struct hat *sfmmup, hat_region_cookie_t rcookie, uint_t flags)
3903 {
3904 	panic("No shared region support on x86");
3905 }
3906 
3907 /* ARGSUSED */
3908 void
3909 hat_dup_region(struct hat *sfmmup, hat_region_cookie_t rcookie)
3910 {
3911 	panic("No shared region support on x86");
3912 }
3913 
3914 
3915 /*
3916  * Kernel Physical Mapping (kpm) facility
3917  *
3918  * Most of the routines needed to support segkpm are almost no-ops on the
3919  * x86 platform.  We map in the entire segment when it is created and leave
3920  * it mapped in, so there is no additional work required to set up and tear
3921  * down individual mappings.  All of these routines were created to support
3922  * SPARC platforms that have to avoid aliasing in their virtually indexed
3923  * caches.
3924  *
3925  * Most of the routines have sanity checks in them (e.g. verifying that the
3926  * passed-in page is locked).  We don't actually care about most of these
3927  * checks on x86, but we leave them in place to identify problems in the
3928  * upper levels.
3929  */
3930 
3931 /*
3932  * Map in a locked page and return the vaddr.
3933  */
3934 /*ARGSUSED*/
3935 caddr_t
3936 hat_kpm_mapin(struct page *pp, struct kpme *kpme)
3937 {
3938 	caddr_t		vaddr;
3939 
3940 #ifdef DEBUG
3941 	if (kpm_enable == 0) {
3942 		cmn_err(CE_WARN, "hat_kpm_mapin: kpm_enable not set\n");
3943 		return ((caddr_t)NULL);
3944 	}
3945 
3946 	if (pp == NULL || PAGE_LOCKED(pp) == 0) {
3947 		cmn_err(CE_WARN, "hat_kpm_mapin: pp zero or not locked\n");
3948 		return ((caddr_t)NULL);
3949 	}
3950 #endif
3951 
3952 	vaddr = hat_kpm_page2va(pp, 1);
3953 
3954 	return (vaddr);
3955 }
3956 
3957 /*
3958  * Mapout a locked page.
3959  */
3960 /*ARGSUSED*/
3961 void
3962 hat_kpm_mapout(struct page *pp, struct kpme *kpme, caddr_t vaddr)
3963 {
3964 #ifdef DEBUG
3965 	if (kpm_enable == 0) {
3966 		cmn_err(CE_WARN, "hat_kpm_mapout: kpm_enable not set\n");
3967 		return;
3968 	}
3969 
3970 	if (IS_KPM_ADDR(vaddr) == 0) {
3971 		cmn_err(CE_WARN, "hat_kpm_mapout: no kpm address\n");
3972 		return;
3973 	}
3974 
3975 	if (pp == NULL || PAGE_LOCKED(pp) == 0) {
3976 		cmn_err(CE_WARN, "hat_kpm_mapout: page zero or not locked\n");
3977 		return;
3978 	}
3979 #endif
3980 }
3981 
3982 /*
3983  * Return the kpm virtual address for a specific pfn
3984  */
3985 caddr_t
3986 hat_kpm_pfn2va(pfn_t pfn)
3987 {
3988 	uintptr_t vaddr = (uintptr_t)kpm_vbase + mmu_ptob(pfn);
3989 
3990 	return ((caddr_t)vaddr);
3991 }
3992 
3993 /*
3994  * Return the kpm virtual address for the page at pp.
3995  */
3996 /*ARGSUSED*/
3997 caddr_t
3998 hat_kpm_page2va(struct page *pp, int checkswap)
3999 {
4000 	return (hat_kpm_pfn2va(pp->p_pagenum));
4001 }
4002 
4003 /*
4004  * Return the page frame number for the kpm virtual address vaddr.
4005  */
4006 pfn_t
4007 hat_kpm_va2pfn(caddr_t vaddr)
4008 {
4009 	pfn_t		pfn;
4010 
4011 	ASSERT(IS_KPM_ADDR(vaddr));
4012 
4013 	pfn = (pfn_t)btop(vaddr - kpm_vbase);
4014 
4015 	return (pfn);
4016 }
4017 
4018 
4019 /*
4020  * Return the page for the kpm virtual address vaddr.
4021  */
4022 page_t *
4023 hat_kpm_vaddr2page(caddr_t vaddr)
4024 {
4025 	pfn_t		pfn;
4026 
4027 	ASSERT(IS_KPM_ADDR(vaddr));
4028 
4029 	pfn = hat_kpm_va2pfn(vaddr);
4030 
4031 	return (page_numtopp_nolock(pfn));
4032 }
4033 
4034 /*
4035  * hat_kpm_fault is called from segkpm_fault when we take a page fault on a
4036  * KPM page.  This should never happen on x86
4037  */
4038 int
4039 hat_kpm_fault(hat_t *hat, caddr_t vaddr)
4040 {
4041 	panic("pagefault in seg_kpm.  hat: 0x%p  vaddr: 0x%p", hat, vaddr);
4042 
4043 	return (0);
4044 }
4045 
4046 /*ARGSUSED*/
4047 void
4048 hat_kpm_mseghash_clear(int nentries)
4049 {}
4050 
4051 /*ARGSUSED*/
4052 void
4053 hat_kpm_mseghash_update(pgcnt_t inx, struct memseg *msp)
4054 {}
4055