xref: /illumos-gate/usr/src/uts/i86pc/vm/hat_i86.c (revision e3092845)
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 (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 /*
25  * Copyright (c) 2010, Intel Corporation.
26  * All rights reserved.
27  */
28 /*
29  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
30  * Copyright 2018 Joyent, Inc.  All rights reserved.
31  * Copyright (c) 2014, 2015 by Delphix. All rights reserved.
32  * Copyright 2022 Tintri by DDN, Inc. All rights reserved.
33  */
34 
35 /*
36  * VM - Hardware Address Translation management for i386 and amd64
37  *
38  * Implementation of the interfaces described in <common/vm/hat.h>
39  *
40  * Nearly all the details of how the hardware is managed should not be
41  * visible outside this layer except for misc. machine specific functions
42  * that work in conjunction with this code.
43  *
44  * Routines used only inside of i86pc/vm start with hati_ for HAT Internal.
45  */
46 
47 /*
48  * amd64 HAT Design
49  *
50  * ----------
51  * Background
52  * ----------
53  *
54  * On x86, the address space is shared between a user process and the kernel.
55  * This is different from SPARC. Conventionally, the kernel lives at the top of
56  * the address space and the user process gets to enjoy the rest of it. If you
57  * look at the image of the address map in uts/i86pc/os/startup.c, you'll get a
58  * rough sense of how the address space is laid out and used.
59  *
60  * Every unique address space is represented by an instance of a HAT structure
61  * called a 'hat_t'. In addition to a hat_t structure for each process, there is
62  * also one that is used for the kernel (kas.a_hat), and each CPU ultimately
63  * also has a HAT.
64  *
65  * Each HAT contains a pointer to its root page table. This root page table is
66  * what we call an L3 page table in illumos and Intel calls the PML4. It is the
67  * physical address of the L3 table that we place in the %cr3 register which the
68  * processor uses.
69  *
70  * Each of the many layers of the page table is represented by a structure
71  * called an htable_t. The htable_t manages a set of 512 8-byte entries. The
72  * number of entries in a given page table is constant across all different
73  * level page tables. Note, this is only true on amd64. This has not always been
74  * the case on x86.
75  *
76  * Each entry in a page table, generally referred to as a PTE, may refer to
77  * another page table or a memory location, depending on the level of the page
78  * table and the use of large pages. Importantly, the top-level L3 page table
79  * (PML4) only supports linking to further page tables. This is also true on
80  * systems which support a 5th level page table (which we do not currently
81  * support).
82  *
83  * Historically, on x86, when a process was running on CPU, the root of the page
84  * table was inserted into %cr3 on each CPU on which it was currently running.
85  * When processes would switch (by calling hat_switch()), then the value in %cr3
86  * on that CPU would change to that of the new HAT. While this behavior is still
87  * maintained in the xpv kernel, this is not what is done today.
88  *
89  * -------------------
90  * Per-CPU Page Tables
91  * -------------------
92  *
93  * Throughout the system the 64-bit kernel has a notion of what it calls a
94  * per-CPU page table or PCP. The notion of a per-CPU page table was originally
95  * introduced as part of the original work to support x86 PAE. On the 64-bit
96  * kernel, it was originally used for 32-bit processes running on the 64-bit
97  * kernel. The rationale behind this was that each 32-bit process could have all
98  * of its memory represented in a single L2 page table as each L2 page table
99  * entry represents 1 GbE of memory.
100  *
101  * Following on from this, the idea was that given that all of the L3 page table
102  * entries for 32-bit processes are basically going to be identical with the
103  * exception of the first entry in the page table, why not share those page
104  * table entries. This gave rise to the idea of a per-CPU page table.
105  *
106  * The way this works is that we have a member in the machcpu_t called the
107  * mcpu_hat_info. That structure contains two different 4k pages: one that
108  * represents the L3 page table and one that represents an L2 page table. When
109  * the CPU starts up, the L3 page table entries are copied in from the kernel's
110  * page table. The L3 kernel entries do not change throughout the lifetime of
111  * the kernel. The kernel portion of these L3 pages for each CPU have the same
112  * records, meaning that they point to the same L2 page tables and thus see a
113  * consistent view of the world.
114  *
115  * When a 32-bit process is loaded into this world, we copy the 32-bit process's
116  * four top-level page table entries into the CPU's L2 page table and then set
117  * the CPU's first L3 page table entry to point to the CPU's L2 page.
118  * Specifically, in hat_pcp_update(), we're copying from the process's
119  * HAT_COPIED_32 HAT into the page tables specific to this CPU.
120  *
121  * As part of the implementation of kernel page table isolation, this was also
122  * extended to 64-bit processes. When a 64-bit process runs, we'll copy their L3
123  * PTEs across into the current CPU's L3 page table. (As we can't do the
124  * first-L3-entry trick for 64-bit processes, ->hci_pcp_l2ptes is unused in this
125  * case.)
126  *
127  * The use of per-CPU page tables has a lot of implementation ramifications. A
128  * HAT that runs a user process will be flagged with the HAT_COPIED flag to
129  * indicate that it is using the per-CPU page table functionality. In tandem
130  * with the HAT, the top-level htable_t will be flagged with the HTABLE_COPIED
131  * flag. If the HAT represents a 32-bit process, then we will also set the
132  * HAT_COPIED_32 flag on that hat_t.
133  *
134  * These two flags work together. The top-level htable_t when using per-CPU page
135  * tables is 'virtual'. We never allocate a ptable for this htable_t (i.e.
136  * ht->ht_pfn is PFN_INVALID).  Instead, when we need to modify a PTE in an
137  * HTABLE_COPIED ptable, x86pte_access_pagetable() will redirect any accesses to
138  * ht_hat->hat_copied_ptes.
139  *
140  * Of course, such a modification won't actually modify the HAT_PCP page tables
141  * that were copied from the HAT_COPIED htable. When we change the top level
142  * page table entries (L2 PTEs for a 32-bit process and L3 PTEs for a 64-bit
143  * process), we need to make sure to trigger hat_pcp_update() on all CPUs that
144  * are currently tied to this HAT (including the current CPU).
145  *
146  * To do this, PCP piggy-backs on TLB invalidation, specifically via the
147  * hat_tlb_inval() path from link_ptp() and unlink_ptp().
148  *
149  * (Importantly, in all such cases, when this is in operation, the top-level
150  * entry should not be able to refer to an actual page table entry that can be
151  * changed and consolidated into a large page. If large page consolidation is
152  * required here, then there will be much that needs to be reconsidered.)
153  *
154  * -----------------------------------------------
155  * Kernel Page Table Isolation and the Per-CPU HAT
156  * -----------------------------------------------
157  *
158  * All Intel CPUs that support speculative execution and paging are subject to a
159  * series of bugs that have been termed 'Meltdown'. These exploits allow a user
160  * process to read kernel memory through cache side channels and speculative
161  * execution. To mitigate this on vulnerable CPUs, we need to use a technique
162  * called kernel page table isolation. What this requires is that we have two
163  * different page table roots. When executing in kernel mode, we will use a %cr3
164  * value that has both the user and kernel pages. However when executing in user
165  * mode, we will need to have a %cr3 that has all of the user pages; however,
166  * only a subset of the kernel pages required to operate.
167  *
168  * These kernel pages that we need mapped are:
169  *
170  *   o Kernel Text that allows us to switch between the cr3 values.
171  *   o The current global descriptor table (GDT)
172  *   o The current interrupt descriptor table (IDT)
173  *   o The current task switching state (TSS)
174  *   o The current local descriptor table (LDT)
175  *   o Stacks and scratch space used by the interrupt handlers
176  *
177  * For more information on the stack switching techniques, construction of the
178  * trampolines, and more, please see i86pc/ml/kpti_trampolines.s. The most
179  * important part of these mappings are the following two constraints:
180  *
181  *   o The mappings are all per-CPU (except for read-only text)
182  *   o The mappings are static. They are all established before the CPU is
183  *     started (with the exception of the boot CPU).
184  *
185  * To facilitate the kernel page table isolation we employ our per-CPU
186  * page tables discussed in the previous section and add the notion of a per-CPU
187  * HAT. Fundamentally we have a second page table root. There is both a kernel
188  * page table (hci_pcp_l3ptes), and a user L3 page table (hci_user_l3ptes).
189  * Both will have the user page table entries copied into them, the same way
190  * that we discussed in the section 'Per-CPU Page Tables'.
191  *
192  * The complex part of this is how do we construct the set of kernel mappings
193  * that should be present when running with the user page table. To answer that,
194  * we add the notion of a per-CPU HAT. This HAT functions like a normal HAT,
195  * except that it's not really associated with an address space the same way
196  * that other HATs are.
197  *
198  * This HAT lives off of the 'struct hat_cpu_info' which is a member of the
199  * machcpu in the member hci_user_hat. We use this per-CPU HAT to create the set
200  * of kernel mappings that should be present on this CPU. The kernel mappings
201  * are added to the per-CPU HAT through the function hati_cpu_punchin(). Once a
202  * mapping has been punched in, it may not be punched out. The reason that we
203  * opt to leverage a HAT structure is that it knows how to allocate and manage
204  * all of the lower level page tables as required.
205  *
206  * Because all of the mappings are present at the beginning of time for this CPU
207  * and none of the mappings are in the kernel pageable segment, we don't have to
208  * worry about faulting on these HAT structures and thus the notion of the
209  * current HAT that we're using is always the appropriate HAT for the process
210  * (usually a user HAT or the kernel's HAT).
211  *
212  * A further constraint we place on the system with these per-CPU HATs is that
213  * they are not subject to htable_steal(). Because each CPU will have a rather
214  * fixed number of page tables, the same way that we don't steal from the
215  * kernel's HAT, it was determined that we should not steal from this HAT due to
216  * the complications involved and somewhat criminal nature of htable_steal().
217  *
218  * The per-CPU HAT is initialized in hat_pcp_setup() which is called as part of
219  * onlining the CPU, but before the CPU is actually started. The per-CPU HAT is
220  * removed in hat_pcp_teardown() which is called when a CPU is being offlined to
221  * be removed from the system (which is different from what psradm usually
222  * does).
223  *
224  * Finally, once the CPU has been onlined, the set of mappings in the per-CPU
225  * HAT must not change. The HAT related functions that we call are not meant to
226  * be called when we're switching between processes. For example, it is quite
227  * possible that if they were, they would try to grab an htable mutex which
228  * another thread might have. One needs to treat hat_switch() as though they
229  * were above LOCK_LEVEL and therefore _must not_ block under any circumstance.
230  */
231 
232 #include <sys/machparam.h>
233 #include <sys/machsystm.h>
234 #include <sys/mman.h>
235 #include <sys/types.h>
236 #include <sys/systm.h>
237 #include <sys/cpuvar.h>
238 #include <sys/thread.h>
239 #include <sys/proc.h>
240 #include <sys/cpu.h>
241 #include <sys/kmem.h>
242 #include <sys/disp.h>
243 #include <sys/shm.h>
244 #include <sys/sysmacros.h>
245 #include <sys/machparam.h>
246 #include <sys/vmem.h>
247 #include <sys/vmsystm.h>
248 #include <sys/promif.h>
249 #include <sys/var.h>
250 #include <sys/x86_archext.h>
251 #include <sys/atomic.h>
252 #include <sys/bitmap.h>
253 #include <sys/controlregs.h>
254 #include <sys/bootconf.h>
255 #include <sys/bootsvcs.h>
256 #include <sys/bootinfo.h>
257 #include <sys/archsystm.h>
258 
259 #include <vm/seg_kmem.h>
260 #include <vm/hat_i86.h>
261 #include <vm/as.h>
262 #include <vm/seg.h>
263 #include <vm/page.h>
264 #include <vm/seg_kp.h>
265 #include <vm/seg_kpm.h>
266 #include <vm/vm_dep.h>
267 #ifdef __xpv
268 #include <sys/hypervisor.h>
269 #endif
270 #include <vm/kboot_mmu.h>
271 #include <vm/seg_spt.h>
272 
273 #include <sys/cmn_err.h>
274 
275 /*
276  * Basic parameters for hat operation.
277  */
278 struct hat_mmu_info mmu;
279 
280 /*
281  * The page that is the kernel's top level pagetable.
282  *
283  * For 32 bit PAE support on i86pc, the kernel hat will use the 1st 4 entries
284  * on this 4K page for its top level page table. The remaining groups of
285  * 4 entries are used for per processor copies of user PCP pagetables for
286  * running threads.  See hat_switch() and reload_pae32() for details.
287  *
288  * pcp_page[0..3] - level==2 PTEs for kernel HAT
289  * pcp_page[4..7] - level==2 PTEs for user thread on cpu 0
290  * pcp_page[8..11]  - level==2 PTE for user thread on cpu 1
291  * etc...
292  *
293  * On the 64-bit kernel, this is the normal root of the page table and there is
294  * nothing special about it when used for other CPUs.
295  */
296 static x86pte_t *pcp_page;
297 
298 /*
299  * forward declaration of internal utility routines
300  */
301 static x86pte_t hati_update_pte(htable_t *ht, uint_t entry, x86pte_t expected,
302 	x86pte_t new);
303 
304 /*
305  * The kernel address space exists in all non-HAT_COPIED HATs. To implement this
306  * the kernel reserves a fixed number of entries in the topmost level(s) of page
307  * tables. The values are setup during startup and then copied to every user hat
308  * created by hat_alloc(). This means that kernelbase must be:
309  *
310  *	  4Meg aligned for 32 bit kernels
311  *	512Gig aligned for x86_64 64 bit kernel
312  *
313  * The hat_kernel_range_ts describe what needs to be copied from kernel hat
314  * to each user hat.
315  */
316 typedef struct hat_kernel_range {
317 	level_t		hkr_level;
318 	uintptr_t	hkr_start_va;
319 	uintptr_t	hkr_end_va;	/* zero means to end of memory */
320 } hat_kernel_range_t;
321 #define	NUM_KERNEL_RANGE 2
322 static hat_kernel_range_t kernel_ranges[NUM_KERNEL_RANGE];
323 static int num_kernel_ranges;
324 
325 uint_t use_boot_reserve = 1;	/* cleared after early boot process */
326 uint_t can_steal_post_boot = 0;	/* set late in boot to enable stealing */
327 
328 /*
329  * enable_1gpg: controls 1g page support for user applications.
330  * By default, 1g pages are exported to user applications. enable_1gpg can
331  * be set to 0 to not export.
332  */
333 int	enable_1gpg = 1;
334 
335 /*
336  * AMD shanghai processors provide better management of 1gb ptes in its tlb.
337  * By default, 1g page support will be disabled for pre-shanghai AMD
338  * processors that don't have optimal tlb support for the 1g page size.
339  * chk_optimal_1gtlb can be set to 0 to force 1g page support on sub-optimal
340  * processors.
341  */
342 int	chk_optimal_1gtlb = 1;
343 
344 
345 #ifdef DEBUG
346 uint_t	map1gcnt;
347 #endif
348 
349 
350 /*
351  * A cpuset for all cpus. This is used for kernel address cross calls, since
352  * the kernel addresses apply to all cpus.
353  */
354 cpuset_t khat_cpuset;
355 
356 /*
357  * management stuff for hat structures
358  */
359 kmutex_t	hat_list_lock;
360 kcondvar_t	hat_list_cv;
361 kmem_cache_t	*hat_cache;
362 kmem_cache_t	*hat_hash_cache;
363 kmem_cache_t	*hat32_hash_cache;
364 
365 /*
366  * Simple statistics
367  */
368 struct hatstats hatstat;
369 
370 /*
371  * Some earlier hypervisor versions do not emulate cmpxchg of PTEs
372  * correctly.  For such hypervisors we must set PT_USER for kernel
373  * entries ourselves (normally the emulation would set PT_USER for
374  * kernel entries and PT_USER|PT_GLOBAL for user entries).  pt_kern is
375  * thus set appropriately.  Note that dboot/kbm is OK, as only the full
376  * HAT uses cmpxchg() and the other paths (hypercall etc.) were never
377  * incorrect.
378  */
379 int pt_kern;
380 
381 #ifndef __xpv
382 extern pfn_t memseg_get_start(struct memseg *);
383 #endif
384 
385 #define	PP_GETRM(pp, rmmask)    (pp->p_nrm & rmmask)
386 #define	PP_ISMOD(pp)		PP_GETRM(pp, P_MOD)
387 #define	PP_ISREF(pp)		PP_GETRM(pp, P_REF)
388 #define	PP_ISRO(pp)		PP_GETRM(pp, P_RO)
389 
390 #define	PP_SETRM(pp, rm)	atomic_orb(&(pp->p_nrm), rm)
391 #define	PP_SETMOD(pp)		PP_SETRM(pp, P_MOD)
392 #define	PP_SETREF(pp)		PP_SETRM(pp, P_REF)
393 #define	PP_SETRO(pp)		PP_SETRM(pp, P_RO)
394 
395 #define	PP_CLRRM(pp, rm)	atomic_andb(&(pp->p_nrm), ~(rm))
396 #define	PP_CLRMOD(pp)		PP_CLRRM(pp, P_MOD)
397 #define	PP_CLRREF(pp)		PP_CLRRM(pp, P_REF)
398 #define	PP_CLRRO(pp)		PP_CLRRM(pp, P_RO)
399 #define	PP_CLRALL(pp)		PP_CLRRM(pp, P_MOD | P_REF | P_RO)
400 
401 /*
402  * kmem cache constructor for struct hat
403  */
404 /*ARGSUSED*/
405 static int
hati_constructor(void * buf,void * handle,int kmflags)406 hati_constructor(void *buf, void *handle, int kmflags)
407 {
408 	hat_t	*hat = buf;
409 
410 	mutex_init(&hat->hat_mutex, NULL, MUTEX_DEFAULT, NULL);
411 	bzero(hat->hat_pages_mapped,
412 	    sizeof (pgcnt_t) * (mmu.max_page_level + 1));
413 	hat->hat_ism_pgcnt = 0;
414 	hat->hat_stats = 0;
415 	hat->hat_flags = 0;
416 	CPUSET_ZERO(hat->hat_cpus);
417 	hat->hat_htable = NULL;
418 	hat->hat_ht_hash = NULL;
419 	return (0);
420 }
421 
422 /*
423  * Put it at the start of the global list of all hats (used by stealing)
424  *
425  * kas.a_hat is not in the list but is instead used to find the
426  * first and last items in the list.
427  *
428  * - kas.a_hat->hat_next points to the start of the user hats.
429  *   The list ends where hat->hat_next == NULL
430  *
431  * - kas.a_hat->hat_prev points to the last of the user hats.
432  *   The list begins where hat->hat_prev == NULL
433  */
434 static void
hat_list_append(hat_t * hat)435 hat_list_append(hat_t *hat)
436 {
437 	mutex_enter(&hat_list_lock);
438 	hat->hat_prev = NULL;
439 	hat->hat_next = kas.a_hat->hat_next;
440 	if (hat->hat_next)
441 		hat->hat_next->hat_prev = hat;
442 	else
443 		kas.a_hat->hat_prev = hat;
444 	kas.a_hat->hat_next = hat;
445 	mutex_exit(&hat_list_lock);
446 }
447 
448 /*
449  * Allocate a hat structure for as. We also create the top level
450  * htable and initialize it to contain the kernel hat entries.
451  */
452 hat_t *
hat_alloc(struct as * as)453 hat_alloc(struct as *as)
454 {
455 	hat_t			*hat;
456 	htable_t		*ht;	/* top level htable */
457 	uint_t			use_copied;
458 	uint_t			r;
459 	hat_kernel_range_t	*rp;
460 	uintptr_t		va;
461 	uintptr_t		eva;
462 	uint_t			start;
463 	uint_t			cnt;
464 	htable_t		*src;
465 	boolean_t		use_hat32_cache;
466 
467 	/*
468 	 * Once we start creating user process HATs we can enable
469 	 * the htable_steal() code.
470 	 */
471 	if (can_steal_post_boot == 0)
472 		can_steal_post_boot = 1;
473 
474 	ASSERT(AS_WRITE_HELD(as));
475 	hat = kmem_cache_alloc(hat_cache, KM_SLEEP);
476 	hat->hat_as = as;
477 	mutex_init(&hat->hat_mutex, NULL, MUTEX_DEFAULT, NULL);
478 	ASSERT(hat->hat_flags == 0);
479 
480 #if defined(__xpv)
481 	/*
482 	 * No PCP stuff on the hypervisor due to the 64-bit split top level
483 	 * page tables.  On 32-bit it's not needed as the hypervisor takes
484 	 * care of copying the top level PTEs to a below 4Gig page.
485 	 */
486 	use_copied = 0;
487 	use_hat32_cache = B_FALSE;
488 	hat->hat_max_level = mmu.max_level;
489 	hat->hat_num_copied = 0;
490 	hat->hat_flags = 0;
491 #else	/* __xpv */
492 
493 	/*
494 	 * All processes use HAT_COPIED on the 64-bit kernel if KPTI is
495 	 * turned on.
496 	 */
497 	if (ttoproc(curthread)->p_model == DATAMODEL_ILP32) {
498 		use_copied = 1;
499 		hat->hat_max_level = mmu.max_level32;
500 		hat->hat_num_copied = mmu.num_copied_ents32;
501 		use_hat32_cache = B_TRUE;
502 		hat->hat_flags |= HAT_COPIED_32;
503 		HATSTAT_INC(hs_hat_copied32);
504 	} else if (kpti_enable == 1) {
505 		use_copied = 1;
506 		hat->hat_max_level = mmu.max_level;
507 		hat->hat_num_copied = mmu.num_copied_ents;
508 		use_hat32_cache = B_FALSE;
509 		HATSTAT_INC(hs_hat_copied64);
510 	} else {
511 		use_copied = 0;
512 		use_hat32_cache = B_FALSE;
513 		hat->hat_max_level = mmu.max_level;
514 		hat->hat_num_copied = 0;
515 		hat->hat_flags = 0;
516 		HATSTAT_INC(hs_hat_normal64);
517 	}
518 #endif	/* __xpv */
519 	if (use_copied) {
520 		hat->hat_flags |= HAT_COPIED;
521 		bzero(hat->hat_copied_ptes, sizeof (hat->hat_copied_ptes));
522 	}
523 
524 	/*
525 	 * Allocate the htable hash. For 32-bit PCP processes we use the
526 	 * hat32_hash_cache. However, for 64-bit PCP processes we do not as the
527 	 * number of entries that they have to handle is closer to
528 	 * hat_hash_cache in count (though there will be more wastage when we
529 	 * have more DRAM in the system and thus push down the user address
530 	 * range).
531 	 */
532 	if (use_hat32_cache) {
533 		hat->hat_num_hash = mmu.hat32_hash_cnt;
534 		hat->hat_ht_hash = kmem_cache_alloc(hat32_hash_cache, KM_SLEEP);
535 	} else {
536 		hat->hat_num_hash = mmu.hash_cnt;
537 		hat->hat_ht_hash = kmem_cache_alloc(hat_hash_cache, KM_SLEEP);
538 	}
539 	bzero(hat->hat_ht_hash, hat->hat_num_hash * sizeof (htable_t *));
540 
541 	/*
542 	 * Initialize Kernel HAT entries at the top of the top level page
543 	 * tables for the new hat.
544 	 */
545 	hat->hat_htable = NULL;
546 	hat->hat_ht_cached = NULL;
547 	XPV_DISALLOW_MIGRATE();
548 	ht = htable_create(hat, (uintptr_t)0, TOP_LEVEL(hat), NULL);
549 	hat->hat_htable = ht;
550 
551 	if (hat->hat_flags & HAT_COPIED)
552 		goto init_done;
553 
554 	for (r = 0; r < num_kernel_ranges; ++r) {
555 		rp = &kernel_ranges[r];
556 		for (va = rp->hkr_start_va; va != rp->hkr_end_va;
557 		    va += cnt * LEVEL_SIZE(rp->hkr_level)) {
558 
559 			if (rp->hkr_level == TOP_LEVEL(hat))
560 				ht = hat->hat_htable;
561 			else
562 				ht = htable_create(hat, va, rp->hkr_level,
563 				    NULL);
564 
565 			start = htable_va2entry(va, ht);
566 			cnt = HTABLE_NUM_PTES(ht) - start;
567 			eva = va +
568 			    ((uintptr_t)cnt << LEVEL_SHIFT(rp->hkr_level));
569 			if (rp->hkr_end_va != 0 &&
570 			    (eva > rp->hkr_end_va || eva == 0))
571 				cnt = htable_va2entry(rp->hkr_end_va, ht) -
572 				    start;
573 
574 			src = htable_lookup(kas.a_hat, va, rp->hkr_level);
575 			ASSERT(src != NULL);
576 			x86pte_copy(src, ht, start, cnt);
577 			htable_release(src);
578 		}
579 	}
580 
581 init_done:
582 
583 #if defined(__xpv)
584 	/*
585 	 * Pin top level page tables after initializing them
586 	 */
587 	xen_pin(hat->hat_htable->ht_pfn, mmu.max_level);
588 	xen_pin(hat->hat_user_ptable, mmu.max_level);
589 #endif
590 	XPV_ALLOW_MIGRATE();
591 
592 	hat_list_append(hat);
593 
594 	return (hat);
595 }
596 
597 #if !defined(__xpv)
598 /*
599  * Cons up a HAT for a CPU. This represents the user mappings. This will have
600  * various kernel pages punched into it manually. Importantly, this hat is
601  * ineligible for stealing. We really don't want to deal with this ever
602  * faulting and figuring out that this is happening, much like we don't with
603  * kas.
604  */
605 static hat_t *
hat_cpu_alloc(cpu_t * cpu)606 hat_cpu_alloc(cpu_t *cpu)
607 {
608 	hat_t *hat;
609 	htable_t *ht;
610 
611 	hat = kmem_cache_alloc(hat_cache, KM_SLEEP);
612 	hat->hat_as = NULL;
613 	mutex_init(&hat->hat_mutex, NULL, MUTEX_DEFAULT, NULL);
614 	hat->hat_max_level = mmu.max_level;
615 	hat->hat_num_copied = 0;
616 	hat->hat_flags = HAT_PCP;
617 
618 	hat->hat_num_hash = mmu.hash_cnt;
619 	hat->hat_ht_hash = kmem_cache_alloc(hat_hash_cache, KM_SLEEP);
620 	bzero(hat->hat_ht_hash, hat->hat_num_hash * sizeof (htable_t *));
621 
622 	hat->hat_next = hat->hat_prev = NULL;
623 
624 	/*
625 	 * Because this HAT will only ever be used by the current CPU, we'll go
626 	 * ahead and set the CPUSET up to only point to the CPU in question.
627 	 */
628 	CPUSET_ADD(hat->hat_cpus, cpu->cpu_id);
629 
630 	hat->hat_htable = NULL;
631 	hat->hat_ht_cached = NULL;
632 	ht = htable_create(hat, (uintptr_t)0, TOP_LEVEL(hat), NULL);
633 	hat->hat_htable = ht;
634 
635 	hat_list_append(hat);
636 
637 	return (hat);
638 }
639 #endif /* !__xpv */
640 
641 /*
642  * process has finished executing but as has not been cleaned up yet.
643  */
644 /*ARGSUSED*/
645 void
hat_free_start(hat_t * hat)646 hat_free_start(hat_t *hat)
647 {
648 	ASSERT(AS_WRITE_HELD(hat->hat_as));
649 
650 	/*
651 	 * If the hat is currently a stealing victim, wait for the stealing
652 	 * to finish.  Once we mark it as HAT_FREEING, htable_steal()
653 	 * won't look at its pagetables anymore.
654 	 */
655 	mutex_enter(&hat_list_lock);
656 	while (hat->hat_flags & HAT_VICTIM)
657 		cv_wait(&hat_list_cv, &hat_list_lock);
658 	hat->hat_flags |= HAT_FREEING;
659 	mutex_exit(&hat_list_lock);
660 }
661 
662 /*
663  * An address space is being destroyed, so we destroy the associated hat.
664  */
665 void
hat_free_end(hat_t * hat)666 hat_free_end(hat_t *hat)
667 {
668 	kmem_cache_t *cache;
669 
670 	ASSERT(hat->hat_flags & HAT_FREEING);
671 
672 	/*
673 	 * must not be running on the given hat
674 	 */
675 	ASSERT(CPU->cpu_current_hat != hat);
676 
677 	/*
678 	 * Remove it from the list of HATs
679 	 */
680 	mutex_enter(&hat_list_lock);
681 	if (hat->hat_prev)
682 		hat->hat_prev->hat_next = hat->hat_next;
683 	else
684 		kas.a_hat->hat_next = hat->hat_next;
685 	if (hat->hat_next)
686 		hat->hat_next->hat_prev = hat->hat_prev;
687 	else
688 		kas.a_hat->hat_prev = hat->hat_prev;
689 	mutex_exit(&hat_list_lock);
690 	hat->hat_next = hat->hat_prev = NULL;
691 
692 #if defined(__xpv)
693 	/*
694 	 * On the hypervisor, unpin top level page table(s)
695 	 */
696 	VERIFY3U(hat->hat_flags & HAT_PCP, ==, 0);
697 	xen_unpin(hat->hat_htable->ht_pfn);
698 	xen_unpin(hat->hat_user_ptable);
699 #endif
700 
701 	/*
702 	 * Make a pass through the htables freeing them all up.
703 	 */
704 	htable_purge_hat(hat);
705 
706 	/*
707 	 * Decide which kmem cache the hash table came from, then free it.
708 	 */
709 	if (hat->hat_flags & HAT_COPIED) {
710 		if (hat->hat_flags & HAT_COPIED_32) {
711 			cache = hat32_hash_cache;
712 		} else {
713 			cache = hat_hash_cache;
714 		}
715 	} else {
716 		cache = hat_hash_cache;
717 	}
718 	kmem_cache_free(cache, hat->hat_ht_hash);
719 	hat->hat_ht_hash = NULL;
720 
721 	hat->hat_flags = 0;
722 	hat->hat_max_level = 0;
723 	hat->hat_num_copied = 0;
724 	kmem_cache_free(hat_cache, hat);
725 }
726 
727 /*
728  * round kernelbase down to a supported value to use for _userlimit
729  *
730  * userlimit must be aligned down to an entry in the top level htable.
731  * The one exception is for 32 bit HAT's running PAE.
732  */
733 uintptr_t
hat_kernelbase(uintptr_t va)734 hat_kernelbase(uintptr_t va)
735 {
736 	if (IN_VA_HOLE(va))
737 		panic("_userlimit %p will fall in VA hole\n", (void *)va);
738 	return (va);
739 }
740 
741 /*
742  *
743  */
744 static void
set_max_page_level()745 set_max_page_level()
746 {
747 	level_t lvl;
748 
749 	if (!kbm_largepage_support) {
750 		lvl = 0;
751 	} else {
752 		if (is_x86_feature(x86_featureset, X86FSET_1GPG)) {
753 			lvl = 2;
754 			if (chk_optimal_1gtlb &&
755 			    cpuid_opteron_erratum(CPU, 6671130)) {
756 				lvl = 1;
757 			}
758 			if (plat_mnode_xcheck(LEVEL_SIZE(2) >>
759 			    LEVEL_SHIFT(0))) {
760 				lvl = 1;
761 			}
762 		} else {
763 			lvl = 1;
764 		}
765 	}
766 	mmu.max_page_level = lvl;
767 
768 	if ((lvl == 2) && (enable_1gpg == 0))
769 		mmu.umax_page_level = 1;
770 	else
771 		mmu.umax_page_level = lvl;
772 }
773 
774 /*
775  * Determine the number of slots that are in used in the top-most level page
776  * table for user memory. This is based on _userlimit. In effect this is similar
777  * to htable_va2entry, but without the convenience of having an htable.
778  */
779 void
mmu_calc_user_slots(void)780 mmu_calc_user_slots(void)
781 {
782 	uint_t ent, nptes;
783 	uintptr_t shift;
784 
785 	nptes = mmu.top_level_count;
786 	shift = _userlimit >> mmu.level_shift[mmu.max_level];
787 	ent = shift & (nptes - 1);
788 
789 	/*
790 	 * Ent tells us the slot that the page for _userlimit would fit in. We
791 	 * need to add one to this to cover the total number of entries.
792 	 */
793 	mmu.top_level_uslots = ent + 1;
794 
795 	/*
796 	 * When running 32-bit compatability processes on a 64-bit kernel, we
797 	 * will only need to use one slot.
798 	 */
799 	mmu.top_level_uslots32 = 1;
800 
801 	/*
802 	 * Record the number of PCP page table entries that we'll need to copy
803 	 * around. For 64-bit processes this is the number of user slots. For
804 	 * 32-bit proceses, this is 4 1 GiB pages.
805 	 */
806 	mmu.num_copied_ents = mmu.top_level_uslots;
807 	mmu.num_copied_ents32 = 4;
808 }
809 
810 /*
811  * Initialize hat data structures based on processor MMU information.
812  */
813 void
mmu_init(void)814 mmu_init(void)
815 {
816 	uint_t max_htables;
817 	uint_t pa_bits;
818 	uint_t va_bits;
819 	int i;
820 
821 	/*
822 	 * If CPU enabled the page table global bit, use it for the kernel
823 	 * This is bit 7 in CR4 (PGE - Page Global Enable).
824 	 */
825 	if (is_x86_feature(x86_featureset, X86FSET_PGE) &&
826 	    (getcr4() & CR4_PGE) != 0)
827 		mmu.pt_global = PT_GLOBAL;
828 
829 #if !defined(__xpv)
830 	/*
831 	 * The 64-bit x86 kernel has split user/kernel page tables. As such we
832 	 * cannot have the global bit set. The simplest way for us to deal with
833 	 * this is to just say that pt_global is zero, so the global bit isn't
834 	 * present.
835 	 */
836 	if (kpti_enable == 1)
837 		mmu.pt_global = 0;
838 #endif
839 
840 	/*
841 	 * Detect NX and PAE usage.
842 	 */
843 	mmu.pae_hat = kbm_pae_support;
844 	if (kbm_nx_support)
845 		mmu.pt_nx = PT_NX;
846 	else
847 		mmu.pt_nx = 0;
848 
849 	/*
850 	 * Use CPU info to set various MMU parameters
851 	 */
852 	cpuid_get_addrsize(CPU, &pa_bits, &va_bits);
853 
854 	/*
855 	 * Check if 5 level paging is on, we dont support that (yet).
856 	 * X86_64 processors that support 5 level paging report
857 	 * the number of va bits for 5 level paging even if
858 	 * not in 5 level paging mode.  So we need
859 	 * to adjust va_bits to max for 4 level paging if not in 5 level mode.
860 	 */
861 	if ((getcr4() & CR4_LA57) != 0)
862 		panic("5 Level paging enabled but not yet supported");
863 	else if (va_bits > MMU_MAX4LEVELVABITS)
864 		va_bits = MMU_MAX4LEVELVABITS;
865 
866 	if (va_bits < sizeof (void *) * NBBY) {
867 		mmu.hole_start = (1ul << (va_bits - 1));
868 		mmu.hole_end = 0ul - mmu.hole_start - 1;
869 	} else {
870 		mmu.hole_end = 0;
871 		mmu.hole_start = mmu.hole_end - 1;
872 	}
873 #if defined(OPTERON_ERRATUM_121)
874 	/*
875 	 * If erratum 121 has already been detected at this time, hole_start
876 	 * contains the value to be subtracted from mmu.hole_start.
877 	 */
878 	ASSERT(hole_start == 0 || opteron_erratum_121 != 0);
879 	hole_start = mmu.hole_start - hole_start;
880 #else
881 	hole_start = mmu.hole_start;
882 #endif
883 	hole_end = mmu.hole_end;
884 
885 	mmu.highest_pfn = mmu_btop((1ull << pa_bits) - 1);
886 	if (mmu.pae_hat == 0 && pa_bits > 32)
887 		mmu.highest_pfn = PFN_4G - 1;
888 
889 	if (mmu.pae_hat) {
890 		mmu.pte_size = 8;	/* 8 byte PTEs */
891 		mmu.pte_size_shift = 3;
892 	} else {
893 		mmu.pte_size = 4;	/* 4 byte PTEs */
894 		mmu.pte_size_shift = 2;
895 	}
896 
897 	if (mmu.pae_hat && !is_x86_feature(x86_featureset, X86FSET_PAE))
898 		panic("Processor does not support PAE");
899 
900 	if (!is_x86_feature(x86_featureset, X86FSET_CX8))
901 		panic("Processor does not support cmpxchg8b instruction");
902 
903 
904 	mmu.num_level = 4;
905 	mmu.max_level = 3;
906 	mmu.ptes_per_table = 512;
907 	mmu.top_level_count = 512;
908 
909 	/*
910 	 * 32-bit processes only use 1 GB ptes.
911 	 */
912 	mmu.max_level32 = 2;
913 
914 	mmu.level_shift[0] = 12;
915 	mmu.level_shift[1] = 21;
916 	mmu.level_shift[2] = 30;
917 	mmu.level_shift[3] = 39;
918 
919 
920 	for (i = 0; i < mmu.num_level; ++i) {
921 		mmu.level_size[i] = 1UL << mmu.level_shift[i];
922 		mmu.level_offset[i] = mmu.level_size[i] - 1;
923 		mmu.level_mask[i] = ~mmu.level_offset[i];
924 	}
925 
926 	set_max_page_level();
927 	mmu_calc_user_slots();
928 
929 	mmu_page_sizes = mmu.max_page_level + 1;
930 	mmu_exported_page_sizes = mmu.umax_page_level + 1;
931 
932 	/* restrict legacy applications from using pagesizes 1g and above */
933 	mmu_legacy_page_sizes =
934 	    (mmu_exported_page_sizes > 2) ? 2 : mmu_exported_page_sizes;
935 
936 
937 	for (i = 0; i <= mmu.max_page_level; ++i) {
938 		mmu.pte_bits[i] = PT_VALID | pt_kern;
939 		if (i > 0)
940 			mmu.pte_bits[i] |= PT_PAGESIZE;
941 	}
942 
943 	/*
944 	 * NOTE Legacy 32 bit PAE mode only has the P_VALID bit at top level.
945 	 */
946 	for (i = 1; i < mmu.num_level; ++i)
947 		mmu.ptp_bits[i] = PT_PTPBITS;
948 
949 	/*
950 	 * Compute how many hash table entries to have per process for htables.
951 	 * We start with 1 page's worth of entries.
952 	 *
953 	 * If physical memory is small, reduce the amount need to cover it.
954 	 */
955 	max_htables = physmax / mmu.ptes_per_table;
956 	mmu.hash_cnt = MMU_PAGESIZE / sizeof (htable_t *);
957 	while (mmu.hash_cnt > 16 && mmu.hash_cnt >= max_htables)
958 		mmu.hash_cnt >>= 1;
959 	mmu.hat32_hash_cnt = mmu.hash_cnt;
960 
961 	/*
962 	 * If running in 64 bits and physical memory is large,
963 	 * increase the size of the cache to cover all of memory for
964 	 * a 64 bit process.
965 	 */
966 #define	HASH_MAX_LENGTH 4
967 	while (mmu.hash_cnt * HASH_MAX_LENGTH < max_htables)
968 		mmu.hash_cnt <<= 1;
969 }
970 
971 
972 /*
973  * initialize hat data structures
974  */
975 void
hat_init()976 hat_init()
977 {
978 	cv_init(&hat_list_cv, NULL, CV_DEFAULT, NULL);
979 
980 	/*
981 	 * initialize kmem caches
982 	 */
983 	htable_init();
984 	hment_init();
985 
986 	hat_cache = kmem_cache_create("hat_t",
987 	    sizeof (hat_t), 0, hati_constructor, NULL, NULL,
988 	    NULL, 0, 0);
989 
990 	hat_hash_cache = kmem_cache_create("HatHash",
991 	    mmu.hash_cnt * sizeof (htable_t *), 0, NULL, NULL, NULL,
992 	    NULL, 0, 0);
993 
994 	/*
995 	 * 32-bit PCP hats can use a smaller hash table size on large memory
996 	 * machines
997 	 */
998 	if (mmu.hash_cnt == mmu.hat32_hash_cnt) {
999 		hat32_hash_cache = hat_hash_cache;
1000 	} else {
1001 		hat32_hash_cache = kmem_cache_create("Hat32Hash",
1002 		    mmu.hat32_hash_cnt * sizeof (htable_t *), 0, NULL, NULL,
1003 		    NULL, NULL, 0, 0);
1004 	}
1005 
1006 	/*
1007 	 * Set up the kernel's hat
1008 	 */
1009 	AS_LOCK_ENTER(&kas, RW_WRITER);
1010 	kas.a_hat = kmem_cache_alloc(hat_cache, KM_NOSLEEP);
1011 	mutex_init(&kas.a_hat->hat_mutex, NULL, MUTEX_DEFAULT, NULL);
1012 	kas.a_hat->hat_as = &kas;
1013 	kas.a_hat->hat_flags = 0;
1014 	AS_LOCK_EXIT(&kas);
1015 
1016 	CPUSET_ZERO(khat_cpuset);
1017 	CPUSET_ADD(khat_cpuset, CPU->cpu_id);
1018 
1019 	/*
1020 	 * The kernel HAT doesn't use PCP regardless of architectures.
1021 	 */
1022 	ASSERT3U(mmu.max_level, >, 0);
1023 	kas.a_hat->hat_max_level = mmu.max_level;
1024 	kas.a_hat->hat_num_copied = 0;
1025 
1026 	/*
1027 	 * The kernel hat's next pointer serves as the head of the hat list .
1028 	 * The kernel hat's prev pointer tracks the last hat on the list for
1029 	 * htable_steal() to use.
1030 	 */
1031 	kas.a_hat->hat_next = NULL;
1032 	kas.a_hat->hat_prev = NULL;
1033 
1034 	/*
1035 	 * Allocate an htable hash bucket for the kernel
1036 	 * XX64 - tune for 64 bit procs
1037 	 */
1038 	kas.a_hat->hat_num_hash = mmu.hash_cnt;
1039 	kas.a_hat->hat_ht_hash = kmem_cache_alloc(hat_hash_cache, KM_NOSLEEP);
1040 	bzero(kas.a_hat->hat_ht_hash, mmu.hash_cnt * sizeof (htable_t *));
1041 
1042 	/*
1043 	 * zero out the top level and cached htable pointers
1044 	 */
1045 	kas.a_hat->hat_ht_cached = NULL;
1046 	kas.a_hat->hat_htable = NULL;
1047 
1048 	/*
1049 	 * Pre-allocate hrm_hashtab before enabling the collection of
1050 	 * refmod statistics.  Allocating on the fly would mean us
1051 	 * running the risk of suffering recursive mutex enters or
1052 	 * deadlocks.
1053 	 */
1054 	hrm_hashtab = kmem_zalloc(HRM_HASHSIZE * sizeof (struct hrmstat *),
1055 	    KM_SLEEP);
1056 }
1057 
1058 
1059 extern void kpti_tramp_start();
1060 extern void kpti_tramp_end();
1061 
1062 extern void kdi_isr_start();
1063 extern void kdi_isr_end();
1064 
1065 extern gate_desc_t kdi_idt[NIDT];
1066 
1067 /*
1068  * Prepare per-CPU pagetables for all processes on the 64 bit kernel.
1069  *
1070  * Each CPU has a set of 2 pagetables that are reused for any 32 bit
1071  * process it runs. They are the top level pagetable, hci_pcp_l3ptes, and
1072  * the next to top level table for the bottom 512 Gig, hci_pcp_l2ptes.
1073  */
1074 /*ARGSUSED*/
1075 static void
hat_pcp_setup(struct cpu * cpu)1076 hat_pcp_setup(struct cpu *cpu)
1077 {
1078 #if !defined(__xpv)
1079 	struct hat_cpu_info *hci = cpu->cpu_hat_info;
1080 	uintptr_t va;
1081 	size_t len;
1082 
1083 	/*
1084 	 * allocate the level==2 page table for the bottom most
1085 	 * 512Gig of address space (this is where 32 bit apps live)
1086 	 */
1087 	ASSERT(hci != NULL);
1088 	hci->hci_pcp_l2ptes = kmem_zalloc(MMU_PAGESIZE, KM_SLEEP);
1089 
1090 	/*
1091 	 * Allocate a top level pagetable and copy the kernel's
1092 	 * entries into it. Then link in hci_pcp_l2ptes in the 1st entry.
1093 	 */
1094 	hci->hci_pcp_l3ptes = kmem_zalloc(MMU_PAGESIZE, KM_SLEEP);
1095 	hci->hci_pcp_l3pfn =
1096 	    hat_getpfnum(kas.a_hat, (caddr_t)hci->hci_pcp_l3ptes);
1097 	ASSERT3U(hci->hci_pcp_l3pfn, !=, PFN_INVALID);
1098 	bcopy(pcp_page, hci->hci_pcp_l3ptes, MMU_PAGESIZE);
1099 
1100 	hci->hci_pcp_l2pfn =
1101 	    hat_getpfnum(kas.a_hat, (caddr_t)hci->hci_pcp_l2ptes);
1102 	ASSERT3U(hci->hci_pcp_l2pfn, !=, PFN_INVALID);
1103 
1104 	/*
1105 	 * Now go through and allocate the user version of these structures.
1106 	 * Unlike with the kernel version, we allocate a hat to represent the
1107 	 * top-level page table as that will make it much simpler when we need
1108 	 * to patch through user entries.
1109 	 */
1110 	hci->hci_user_hat = hat_cpu_alloc(cpu);
1111 	hci->hci_user_l3pfn = hci->hci_user_hat->hat_htable->ht_pfn;
1112 	ASSERT3U(hci->hci_user_l3pfn, !=, PFN_INVALID);
1113 	hci->hci_user_l3ptes =
1114 	    (x86pte_t *)hat_kpm_mapin_pfn(hci->hci_user_l3pfn);
1115 
1116 	/* Skip the rest of this if KPTI is switched off at boot. */
1117 	if (kpti_enable != 1)
1118 		return;
1119 
1120 	/*
1121 	 * OK, now that we have this we need to go through and punch the normal
1122 	 * holes in the CPU's hat for this. At this point we'll punch in the
1123 	 * following:
1124 	 *
1125 	 *   o GDT
1126 	 *   o IDT
1127 	 *   o LDT
1128 	 *   o Trampoline Code
1129 	 *   o machcpu KPTI page
1130 	 *   o kmdb ISR code page (just trampolines)
1131 	 *
1132 	 * If this is cpu0, then we also can initialize the following because
1133 	 * they'll have already been allocated.
1134 	 *
1135 	 *   o TSS for CPU 0
1136 	 *   o Double Fault for CPU 0
1137 	 *
1138 	 * The following items have yet to be allocated and have not been
1139 	 * punched in yet. They will be punched in later:
1140 	 *
1141 	 *   o TSS (mach_cpucontext_alloc_tables())
1142 	 *   o Double Fault Stack (mach_cpucontext_alloc_tables())
1143 	 */
1144 	hati_cpu_punchin(cpu, (uintptr_t)cpu->cpu_gdt, PROT_READ);
1145 	hati_cpu_punchin(cpu, (uintptr_t)cpu->cpu_idt, PROT_READ);
1146 
1147 	/*
1148 	 * As the KDI IDT is only active during kmdb sessions (including single
1149 	 * stepping), typically we don't actually need this punched in (we
1150 	 * consider the routines that switch to the user cr3 to be toxic).  But
1151 	 * if we ever accidentally end up on the user cr3 while on this IDT,
1152 	 * we'd prefer not to triple fault.
1153 	 */
1154 	hati_cpu_punchin(cpu, (uintptr_t)&kdi_idt, PROT_READ);
1155 
1156 	VERIFY0((uintptr_t)&kpti_tramp_start % MMU_PAGESIZE);
1157 	VERIFY0((uintptr_t)&kpti_tramp_end % MMU_PAGESIZE);
1158 	for (va = (uintptr_t)&kpti_tramp_start;
1159 	    va < (uintptr_t)&kpti_tramp_end; va += MMU_PAGESIZE) {
1160 		hati_cpu_punchin(cpu, va, PROT_READ | PROT_EXEC);
1161 	}
1162 
1163 	VERIFY3U(((uintptr_t)cpu->cpu_m.mcpu_ldt) % MMU_PAGESIZE, ==, 0);
1164 	for (va = (uintptr_t)cpu->cpu_m.mcpu_ldt, len = LDT_CPU_SIZE;
1165 	    len >= MMU_PAGESIZE; va += MMU_PAGESIZE, len -= MMU_PAGESIZE) {
1166 		hati_cpu_punchin(cpu, va, PROT_READ);
1167 	}
1168 
1169 	/* mcpu_pad2 is the start of the page containing the kpti_frames. */
1170 	hati_cpu_punchin(cpu, (uintptr_t)&cpu->cpu_m.mcpu_pad2[0],
1171 	    PROT_READ | PROT_WRITE);
1172 
1173 	if (cpu == &cpus[0]) {
1174 		/*
1175 		 * CPU0 uses a global for its double fault stack to deal with
1176 		 * the chicken and egg problem. We need to punch it into its
1177 		 * user HAT.
1178 		 */
1179 		extern char dblfault_stack0[];
1180 
1181 		hati_cpu_punchin(cpu, (uintptr_t)cpu->cpu_m.mcpu_tss,
1182 		    PROT_READ);
1183 
1184 		for (va = (uintptr_t)dblfault_stack0,
1185 		    len = DEFAULTSTKSZ; len >= MMU_PAGESIZE;
1186 		    va += MMU_PAGESIZE, len -= MMU_PAGESIZE) {
1187 			hati_cpu_punchin(cpu, va, PROT_READ | PROT_WRITE);
1188 		}
1189 	}
1190 
1191 	VERIFY0((uintptr_t)&kdi_isr_start % MMU_PAGESIZE);
1192 	VERIFY0((uintptr_t)&kdi_isr_end % MMU_PAGESIZE);
1193 	for (va = (uintptr_t)&kdi_isr_start;
1194 	    va < (uintptr_t)&kdi_isr_end; va += MMU_PAGESIZE) {
1195 		hati_cpu_punchin(cpu, va, PROT_READ | PROT_EXEC);
1196 	}
1197 #endif /* !__xpv */
1198 }
1199 
1200 /*ARGSUSED*/
1201 static void
hat_pcp_teardown(cpu_t * cpu)1202 hat_pcp_teardown(cpu_t *cpu)
1203 {
1204 #if !defined(__xpv)
1205 	struct hat_cpu_info *hci;
1206 
1207 	if ((hci = cpu->cpu_hat_info) == NULL)
1208 		return;
1209 	if (hci->hci_pcp_l2ptes != NULL)
1210 		kmem_free(hci->hci_pcp_l2ptes, MMU_PAGESIZE);
1211 	if (hci->hci_pcp_l3ptes != NULL)
1212 		kmem_free(hci->hci_pcp_l3ptes, MMU_PAGESIZE);
1213 	if (hci->hci_user_hat != NULL) {
1214 		hat_free_start(hci->hci_user_hat);
1215 		hat_free_end(hci->hci_user_hat);
1216 	}
1217 #endif
1218 }
1219 
1220 #define	NEXT_HKR(r, l, s, e) {			\
1221 	kernel_ranges[r].hkr_level = l;		\
1222 	kernel_ranges[r].hkr_start_va = s;	\
1223 	kernel_ranges[r].hkr_end_va = e;	\
1224 	++r;					\
1225 }
1226 
1227 /*
1228  * Finish filling in the kernel hat.
1229  * Pre fill in all top level kernel page table entries for the kernel's
1230  * part of the address range.  From this point on we can't use any new
1231  * kernel large pages if they need PTE's at max_level
1232  *
1233  * create the kmap mappings.
1234  */
1235 void
hat_init_finish(void)1236 hat_init_finish(void)
1237 {
1238 	size_t		size;
1239 	uint_t		r = 0;
1240 	uintptr_t	va;
1241 	hat_kernel_range_t *rp;
1242 
1243 
1244 	/*
1245 	 * We are now effectively running on the kernel hat.
1246 	 * Clearing use_boot_reserve shuts off using the pre-allocated boot
1247 	 * reserve for all HAT allocations.  From here on, the reserves are
1248 	 * only used when avoiding recursion in kmem_alloc().
1249 	 */
1250 	use_boot_reserve = 0;
1251 	htable_adjust_reserve();
1252 
1253 	/*
1254 	 * User HATs are initialized with copies of all kernel mappings in
1255 	 * higher level page tables. Ensure that those entries exist.
1256 	 */
1257 
1258 	NEXT_HKR(r, 3, kernelbase, 0);
1259 #if defined(__xpv)
1260 	NEXT_HKR(r, 3, HYPERVISOR_VIRT_START, HYPERVISOR_VIRT_END);
1261 #endif
1262 
1263 	num_kernel_ranges = r;
1264 
1265 	/*
1266 	 * Create all the kernel pagetables that will have entries
1267 	 * shared to user HATs.
1268 	 */
1269 	for (r = 0; r < num_kernel_ranges; ++r) {
1270 		rp = &kernel_ranges[r];
1271 		for (va = rp->hkr_start_va; va != rp->hkr_end_va;
1272 		    va += LEVEL_SIZE(rp->hkr_level)) {
1273 			htable_t *ht;
1274 
1275 			if (IN_HYPERVISOR_VA(va))
1276 				continue;
1277 
1278 			/* can/must skip if a page mapping already exists */
1279 			if (rp->hkr_level <= mmu.max_page_level &&
1280 			    (ht = htable_getpage(kas.a_hat, va, NULL)) !=
1281 			    NULL) {
1282 				htable_release(ht);
1283 				continue;
1284 			}
1285 
1286 			(void) htable_create(kas.a_hat, va, rp->hkr_level - 1,
1287 			    NULL);
1288 		}
1289 	}
1290 
1291 	/*
1292 	 * 32 bit PAE metal kernels use only 4 of the 512 entries in the
1293 	 * page holding the top level pagetable. We use the remainder for
1294 	 * the "per CPU" page tables for PCP processes.
1295 	 * Map the top level kernel pagetable into the kernel to make
1296 	 * it easy to use bcopy access these tables.
1297 	 *
1298 	 * PAE is required for the 64-bit kernel which uses this as well to
1299 	 * perform the per-CPU pagetables. See the big theory statement.
1300 	 */
1301 	if (mmu.pae_hat) {
1302 		pcp_page = vmem_alloc(heap_arena, MMU_PAGESIZE, VM_SLEEP);
1303 		hat_devload(kas.a_hat, (caddr_t)pcp_page, MMU_PAGESIZE,
1304 		    kas.a_hat->hat_htable->ht_pfn,
1305 #if !defined(__xpv)
1306 		    PROT_WRITE |
1307 #endif
1308 		    PROT_READ | HAT_NOSYNC | HAT_UNORDERED_OK,
1309 		    HAT_LOAD | HAT_LOAD_NOCONSIST);
1310 	}
1311 	hat_pcp_setup(CPU);
1312 
1313 	/*
1314 	 * Create kmap (cached mappings of kernel PTEs)
1315 	 * for 32 bit we map from segmap_start .. ekernelheap
1316 	 * for 64 bit we map from segmap_start .. segmap_start + segmapsize;
1317 	 */
1318 	size = segmapsize;
1319 	hat_kmap_init((uintptr_t)segmap_start, size);
1320 
1321 #if !defined(__xpv)
1322 	ASSERT3U(kas.a_hat->hat_htable->ht_pfn, !=, PFN_INVALID);
1323 	ASSERT3U(kpti_safe_cr3, ==,
1324 	    MAKECR3(kas.a_hat->hat_htable->ht_pfn, PCID_KERNEL));
1325 #endif
1326 }
1327 
1328 /*
1329  * Update the PCP data on the CPU cpu to the one on the hat. If this is a 32-bit
1330  * process, then we must update the L2 pages and then the L3. If this is a
1331  * 64-bit process then we must update the L3 entries.
1332  */
1333 static void
hat_pcp_update(cpu_t * cpu,const hat_t * hat)1334 hat_pcp_update(cpu_t *cpu, const hat_t *hat)
1335 {
1336 	ASSERT3U(hat->hat_flags & HAT_COPIED, !=, 0);
1337 
1338 	if ((hat->hat_flags & HAT_COPIED_32) != 0) {
1339 		const x86pte_t *l2src;
1340 		x86pte_t *l2dst, *l3ptes, *l3uptes;
1341 		/*
1342 		 * This is a 32-bit process. To set this up, we need to do the
1343 		 * following:
1344 		 *
1345 		 *  - Copy the 4 L2 PTEs into the dedicated L2 table
1346 		 *  - Zero the user L3 PTEs in the user and kernel page table
1347 		 *  - Set the first L3 PTE to point to the CPU L2 table
1348 		 */
1349 		l2src = hat->hat_copied_ptes;
1350 		l2dst = cpu->cpu_hat_info->hci_pcp_l2ptes;
1351 		l3ptes = cpu->cpu_hat_info->hci_pcp_l3ptes;
1352 		l3uptes = cpu->cpu_hat_info->hci_user_l3ptes;
1353 
1354 		l2dst[0] = l2src[0];
1355 		l2dst[1] = l2src[1];
1356 		l2dst[2] = l2src[2];
1357 		l2dst[3] = l2src[3];
1358 
1359 		/*
1360 		 * Make sure to use the mmu to get the number of slots. The
1361 		 * number of PLP entries that this has will always be less as
1362 		 * it's a 32-bit process.
1363 		 */
1364 		bzero(l3ptes, sizeof (x86pte_t) * mmu.top_level_uslots);
1365 		l3ptes[0] = MAKEPTP(cpu->cpu_hat_info->hci_pcp_l2pfn, 2);
1366 		bzero(l3uptes, sizeof (x86pte_t) * mmu.top_level_uslots);
1367 		l3uptes[0] = MAKEPTP(cpu->cpu_hat_info->hci_pcp_l2pfn, 2);
1368 	} else {
1369 		/*
1370 		 * This is a 64-bit process. To set this up, we need to do the
1371 		 * following:
1372 		 *
1373 		 *  - Zero the 4 L2 PTEs in the CPU structure for safety
1374 		 *  - Copy over the new user L3 PTEs into the kernel page table
1375 		 *  - Copy over the new user L3 PTEs into the user page table
1376 		 */
1377 		ASSERT3S(kpti_enable, ==, 1);
1378 		bzero(cpu->cpu_hat_info->hci_pcp_l2ptes, sizeof (x86pte_t) * 4);
1379 		bcopy(hat->hat_copied_ptes, cpu->cpu_hat_info->hci_pcp_l3ptes,
1380 		    sizeof (x86pte_t) * mmu.top_level_uslots);
1381 		bcopy(hat->hat_copied_ptes, cpu->cpu_hat_info->hci_user_l3ptes,
1382 		    sizeof (x86pte_t) * mmu.top_level_uslots);
1383 	}
1384 }
1385 
1386 static void
reset_kpti(struct kpti_frame * fr,uint64_t kcr3,uint64_t ucr3)1387 reset_kpti(struct kpti_frame *fr, uint64_t kcr3, uint64_t ucr3)
1388 {
1389 	ASSERT3U(fr->kf_tr_flag, ==, 0);
1390 #if DEBUG
1391 	if (fr->kf_kernel_cr3 != 0) {
1392 		ASSERT3U(fr->kf_lower_redzone, ==, 0xdeadbeefdeadbeef);
1393 		ASSERT3U(fr->kf_middle_redzone, ==, 0xdeadbeefdeadbeef);
1394 		ASSERT3U(fr->kf_upper_redzone, ==, 0xdeadbeefdeadbeef);
1395 	}
1396 #endif
1397 
1398 	bzero(fr, offsetof(struct kpti_frame, kf_kernel_cr3));
1399 	bzero(&fr->kf_unused, sizeof (struct kpti_frame) -
1400 	    offsetof(struct kpti_frame, kf_unused));
1401 
1402 	fr->kf_kernel_cr3 = kcr3;
1403 	fr->kf_user_cr3 = ucr3;
1404 	fr->kf_tr_ret_rsp = (uintptr_t)&fr->kf_tr_rsp;
1405 
1406 	fr->kf_lower_redzone = 0xdeadbeefdeadbeef;
1407 	fr->kf_middle_redzone = 0xdeadbeefdeadbeef;
1408 	fr->kf_upper_redzone = 0xdeadbeefdeadbeef;
1409 }
1410 
1411 #ifdef __xpv
1412 static void
hat_switch_xen(hat_t * hat)1413 hat_switch_xen(hat_t *hat)
1414 {
1415 	struct mmuext_op t[2];
1416 	uint_t retcnt;
1417 	uint_t opcnt = 1;
1418 	uint64_t newcr3;
1419 
1420 	ASSERT(!(hat->hat_flags & HAT_COPIED));
1421 	ASSERT(!(getcr4() & CR4_PCIDE));
1422 
1423 	newcr3 = MAKECR3((uint64_t)hat->hat_htable->ht_pfn, PCID_NONE);
1424 
1425 	t[0].cmd = MMUEXT_NEW_BASEPTR;
1426 	t[0].arg1.mfn = mmu_btop(pa_to_ma(newcr3));
1427 
1428 	/*
1429 	 * There's an interesting problem here, as to what to actually specify
1430 	 * when switching to the kernel hat.  For now we'll reuse the kernel hat
1431 	 * again.
1432 	 */
1433 	t[1].cmd = MMUEXT_NEW_USER_BASEPTR;
1434 	if (hat == kas.a_hat)
1435 		t[1].arg1.mfn = mmu_btop(pa_to_ma(newcr3));
1436 	else
1437 		t[1].arg1.mfn = pfn_to_mfn(hat->hat_user_ptable);
1438 	++opcnt;
1439 
1440 	if (HYPERVISOR_mmuext_op(t, opcnt, &retcnt, DOMID_SELF) < 0)
1441 		panic("HYPERVISOR_mmu_update() failed");
1442 	ASSERT(retcnt == opcnt);
1443 }
1444 #endif /* __xpv */
1445 
1446 /*
1447  * Switch to a new active hat, maintaining bit masks to track active CPUs.
1448  *
1449  * With KPTI, all our HATs except kas should be using PCP.  Thus, to switch
1450  * HATs, we need to copy over the new user PTEs, then set our trampoline context
1451  * as appropriate.
1452  *
1453  * If lacking PCID, we then load our new cr3, which will flush the TLB: we may
1454  * have established userspace TLB entries via kernel accesses, and these are no
1455  * longer valid.  We have to do this eagerly, as we just deleted this CPU from
1456  * ->hat_cpus, so would no longer see any TLB shootdowns.
1457  *
1458  * With PCID enabled, things get a little more complicated.  We would like to
1459  * keep TLB context around when entering and exiting the kernel, and to do this,
1460  * we partition the TLB into two different spaces:
1461  *
1462  * PCID_KERNEL is defined as zero, and used both by kas and all other address
1463  * spaces while in the kernel (post-trampoline).
1464  *
1465  * PCID_USER is used while in userspace.  Therefore, userspace cannot use any
1466  * lingering PCID_KERNEL entries to kernel addresses it should not be able to
1467  * read.
1468  *
1469  * The trampoline cr3s are set not to invalidate on a mov to %cr3. This means if
1470  * we take a journey through the kernel without switching HATs, we have some
1471  * hope of keeping our TLB state around.
1472  *
1473  * On a hat switch, rather than deal with any necessary flushes on the way out
1474  * of the trampolines, we do them upfront here. If we're switching from kas, we
1475  * shouldn't need any invalidation.
1476  *
1477  * Otherwise, we can have stale userspace entries for both PCID_USER (what
1478  * happened before we move onto the kcr3) and PCID_KERNEL (any subsequent
1479  * userspace accesses such as ddi_copyin()).  Since setcr3() won't do these
1480  * flushes on its own in PCIDE, we'll do a non-flushing load and then
1481  * invalidate everything.
1482  */
1483 void
hat_switch(hat_t * hat)1484 hat_switch(hat_t *hat)
1485 {
1486 	cpu_t *cpu = CPU;
1487 	hat_t *old = cpu->cpu_current_hat;
1488 
1489 	/*
1490 	 * set up this information first, so we don't miss any cross calls
1491 	 */
1492 	if (old != NULL) {
1493 		if (old == hat)
1494 			return;
1495 		if (old != kas.a_hat)
1496 			CPUSET_ATOMIC_DEL(old->hat_cpus, cpu->cpu_id);
1497 	}
1498 
1499 	/*
1500 	 * Add this CPU to the active set for this HAT.
1501 	 */
1502 	if (hat != kas.a_hat) {
1503 		CPUSET_ATOMIC_ADD(hat->hat_cpus, cpu->cpu_id);
1504 	}
1505 	cpu->cpu_current_hat = hat;
1506 
1507 #if defined(__xpv)
1508 	hat_switch_xen(hat);
1509 #else
1510 	struct hat_cpu_info *info = cpu->cpu_m.mcpu_hat_info;
1511 	uint64_t pcide = getcr4() & CR4_PCIDE;
1512 	uint64_t kcr3, ucr3;
1513 	pfn_t tl_kpfn;
1514 	ulong_t	flag;
1515 
1516 	EQUIV(kpti_enable, !mmu.pt_global);
1517 
1518 	if (hat->hat_flags & HAT_COPIED) {
1519 		hat_pcp_update(cpu, hat);
1520 		tl_kpfn = info->hci_pcp_l3pfn;
1521 	} else {
1522 		IMPLY(kpti_enable, hat == kas.a_hat);
1523 		tl_kpfn = hat->hat_htable->ht_pfn;
1524 	}
1525 
1526 	if (pcide) {
1527 		ASSERT(kpti_enable);
1528 
1529 		kcr3 = MAKECR3(tl_kpfn, PCID_KERNEL) | CR3_NOINVL_BIT;
1530 		ucr3 = MAKECR3(info->hci_user_l3pfn, PCID_USER) |
1531 		    CR3_NOINVL_BIT;
1532 
1533 		setcr3(kcr3);
1534 		if (old != kas.a_hat)
1535 			mmu_flush_tlb(FLUSH_TLB_ALL, NULL);
1536 	} else {
1537 		kcr3 = MAKECR3(tl_kpfn, PCID_NONE);
1538 		ucr3 = kpti_enable ?
1539 		    MAKECR3(info->hci_user_l3pfn, PCID_NONE) :
1540 		    0;
1541 
1542 		setcr3(kcr3);
1543 	}
1544 
1545 	/*
1546 	 * We will already be taking shootdowns for our new HAT, and as KPTI
1547 	 * invpcid emulation needs to use kf_user_cr3, make sure we don't get
1548 	 * any cross calls while we're inconsistent.  Note that it's harmless to
1549 	 * have a *stale* kf_user_cr3 (we just did a FLUSH_TLB_ALL), but a
1550 	 * *zero* kf_user_cr3 is not going to go very well.
1551 	 */
1552 	if (pcide)
1553 		flag = intr_clear();
1554 
1555 	reset_kpti(&cpu->cpu_m.mcpu_kpti, kcr3, ucr3);
1556 	reset_kpti(&cpu->cpu_m.mcpu_kpti_flt, kcr3, ucr3);
1557 	reset_kpti(&cpu->cpu_m.mcpu_kpti_dbg, kcr3, ucr3);
1558 
1559 	if (pcide)
1560 		intr_restore(flag);
1561 
1562 #endif /* !__xpv */
1563 
1564 	ASSERT(cpu == CPU);
1565 }
1566 
1567 /*
1568  * Utility to return a valid x86pte_t from protections, pfn, and level number
1569  */
1570 static x86pte_t
hati_mkpte(pfn_t pfn,uint_t attr,level_t level,uint_t flags)1571 hati_mkpte(pfn_t pfn, uint_t attr, level_t level, uint_t flags)
1572 {
1573 	x86pte_t	pte;
1574 	uint_t		cache_attr = attr & HAT_ORDER_MASK;
1575 
1576 	pte = MAKEPTE(pfn, level);
1577 
1578 	if (attr & PROT_WRITE)
1579 		PTE_SET(pte, PT_WRITABLE);
1580 
1581 	if (attr & PROT_USER)
1582 		PTE_SET(pte, PT_USER);
1583 
1584 	if (!(attr & PROT_EXEC))
1585 		PTE_SET(pte, mmu.pt_nx);
1586 
1587 	/*
1588 	 * Set the software bits used track ref/mod sync's and hments.
1589 	 * If not using REF/MOD, set them to avoid h/w rewriting PTEs.
1590 	 */
1591 	if (flags & HAT_LOAD_NOCONSIST)
1592 		PTE_SET(pte, PT_NOCONSIST | PT_REF | PT_MOD);
1593 	else if (attr & HAT_NOSYNC)
1594 		PTE_SET(pte, PT_NOSYNC | PT_REF | PT_MOD);
1595 
1596 	/*
1597 	 * Set the caching attributes in the PTE. The combination
1598 	 * of attributes are poorly defined, so we pay attention
1599 	 * to them in the given order.
1600 	 *
1601 	 * The test for HAT_STRICTORDER is different because it's defined
1602 	 * as "0" - which was a stupid thing to do, but is too late to change!
1603 	 */
1604 	if (cache_attr == HAT_STRICTORDER) {
1605 		PTE_SET(pte, PT_NOCACHE);
1606 	/*LINTED [Lint hates empty ifs, but it's the obvious way to do this] */
1607 	} else if (cache_attr & (HAT_UNORDERED_OK | HAT_STORECACHING_OK)) {
1608 		/* nothing to set */;
1609 	} else if (cache_attr & (HAT_MERGING_OK | HAT_LOADCACHING_OK)) {
1610 		PTE_SET(pte, PT_NOCACHE);
1611 		if (is_x86_feature(x86_featureset, X86FSET_PAT))
1612 			PTE_SET(pte, (level == 0) ? PT_PAT_4K : PT_PAT_LARGE);
1613 		else
1614 			PTE_SET(pte, PT_WRITETHRU);
1615 	} else {
1616 		panic("hati_mkpte(): bad caching attributes: %x\n", cache_attr);
1617 	}
1618 
1619 	return (pte);
1620 }
1621 
1622 /*
1623  * Duplicate address translations of the parent to the child.
1624  * This function really isn't used anymore.
1625  */
1626 /*ARGSUSED*/
1627 int
hat_dup(hat_t * old,hat_t * new,caddr_t addr,size_t len,uint_t flag)1628 hat_dup(hat_t *old, hat_t *new, caddr_t addr, size_t len, uint_t flag)
1629 {
1630 	ASSERT((uintptr_t)addr < kernelbase);
1631 	ASSERT(new != kas.a_hat);
1632 	ASSERT(old != kas.a_hat);
1633 	return (0);
1634 }
1635 
1636 /*
1637  * Allocate any hat resources required for a process being swapped in.
1638  */
1639 /*ARGSUSED*/
1640 void
hat_swapin(hat_t * hat)1641 hat_swapin(hat_t *hat)
1642 {
1643 	/* do nothing - we let everything fault back in */
1644 }
1645 
1646 /*
1647  * Unload all translations associated with an address space of a process
1648  * that is being swapped out.
1649  */
1650 void
hat_swapout(hat_t * hat)1651 hat_swapout(hat_t *hat)
1652 {
1653 	uintptr_t	vaddr = (uintptr_t)0;
1654 	uintptr_t	eaddr = _userlimit;
1655 	htable_t	*ht = NULL;
1656 	level_t		l;
1657 
1658 	XPV_DISALLOW_MIGRATE();
1659 	/*
1660 	 * We can't just call hat_unload(hat, 0, _userlimit...)  here, because
1661 	 * seg_spt and shared pagetables can't be swapped out.
1662 	 * Take a look at segspt_shmswapout() - it's a big no-op.
1663 	 *
1664 	 * Instead we'll walk through all the address space and unload
1665 	 * any mappings which we are sure are not shared, not locked.
1666 	 */
1667 	ASSERT(IS_PAGEALIGNED(vaddr));
1668 	ASSERT(IS_PAGEALIGNED(eaddr));
1669 	ASSERT(AS_LOCK_HELD(hat->hat_as));
1670 	if ((uintptr_t)hat->hat_as->a_userlimit < eaddr)
1671 		eaddr = (uintptr_t)hat->hat_as->a_userlimit;
1672 
1673 	while (vaddr < eaddr) {
1674 		(void) htable_walk(hat, &ht, &vaddr, eaddr);
1675 		if (ht == NULL)
1676 			break;
1677 
1678 		ASSERT(!IN_VA_HOLE(vaddr));
1679 
1680 		/*
1681 		 * If the page table is shared skip its entire range.
1682 		 */
1683 		l = ht->ht_level;
1684 		if (ht->ht_flags & HTABLE_SHARED_PFN) {
1685 			vaddr = ht->ht_vaddr + LEVEL_SIZE(l + 1);
1686 			htable_release(ht);
1687 			ht = NULL;
1688 			continue;
1689 		}
1690 
1691 		/*
1692 		 * If the page table has no locked entries, unload this one.
1693 		 */
1694 		if (ht->ht_lock_cnt == 0)
1695 			hat_unload(hat, (caddr_t)vaddr, LEVEL_SIZE(l),
1696 			    HAT_UNLOAD_UNMAP);
1697 
1698 		/*
1699 		 * If we have a level 0 page table with locked entries,
1700 		 * skip the entire page table, otherwise skip just one entry.
1701 		 */
1702 		if (ht->ht_lock_cnt > 0 && l == 0)
1703 			vaddr = ht->ht_vaddr + LEVEL_SIZE(1);
1704 		else
1705 			vaddr += LEVEL_SIZE(l);
1706 	}
1707 	if (ht)
1708 		htable_release(ht);
1709 
1710 	/*
1711 	 * We're in swapout because the system is low on memory, so
1712 	 * go back and flush all the htables off the cached list.
1713 	 */
1714 	htable_purge_hat(hat);
1715 	XPV_ALLOW_MIGRATE();
1716 }
1717 
1718 /*
1719  * returns number of bytes that have valid mappings in hat.
1720  */
1721 size_t
hat_get_mapped_size(hat_t * hat)1722 hat_get_mapped_size(hat_t *hat)
1723 {
1724 	size_t total = 0;
1725 	int l;
1726 
1727 	for (l = 0; l <= mmu.max_page_level; l++)
1728 		total += (hat->hat_pages_mapped[l] << LEVEL_SHIFT(l));
1729 	total += hat->hat_ism_pgcnt;
1730 
1731 	return (total);
1732 }
1733 
1734 /*
1735  * enable/disable collection of stats for hat.
1736  */
1737 int
hat_stats_enable(hat_t * hat)1738 hat_stats_enable(hat_t *hat)
1739 {
1740 	atomic_inc_32(&hat->hat_stats);
1741 	return (1);
1742 }
1743 
1744 void
hat_stats_disable(hat_t * hat)1745 hat_stats_disable(hat_t *hat)
1746 {
1747 	atomic_dec_32(&hat->hat_stats);
1748 }
1749 
1750 /*
1751  * Utility to sync the ref/mod bits from a page table entry to the page_t
1752  * We must be holding the mapping list lock when this is called.
1753  */
1754 static void
hati_sync_pte_to_page(page_t * pp,x86pte_t pte,level_t level)1755 hati_sync_pte_to_page(page_t *pp, x86pte_t pte, level_t level)
1756 {
1757 	uint_t	rm = 0;
1758 	pgcnt_t	pgcnt;
1759 
1760 	if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC)
1761 		return;
1762 
1763 	if (PTE_GET(pte, PT_REF))
1764 		rm |= P_REF;
1765 
1766 	if (PTE_GET(pte, PT_MOD))
1767 		rm |= P_MOD;
1768 
1769 	if (rm == 0)
1770 		return;
1771 
1772 	/*
1773 	 * sync to all constituent pages of a large page
1774 	 */
1775 	ASSERT(x86_hm_held(pp));
1776 	pgcnt = page_get_pagecnt(level);
1777 	ASSERT(IS_P2ALIGNED(pp->p_pagenum, pgcnt));
1778 	for (; pgcnt > 0; --pgcnt) {
1779 		/*
1780 		 * hat_page_demote() can't decrease
1781 		 * pszc below this mapping size
1782 		 * since this large mapping existed after we
1783 		 * took mlist lock.
1784 		 */
1785 		ASSERT(pp->p_szc >= level);
1786 		hat_page_setattr(pp, rm);
1787 		++pp;
1788 	}
1789 }
1790 
1791 /*
1792  * This the set of PTE bits for PFN, permissions and caching
1793  * that are allowed to change on a HAT_LOAD_REMAP
1794  */
1795 #define	PT_REMAP_BITS							\
1796 	(PT_PADDR | PT_NX | PT_WRITABLE | PT_WRITETHRU |		\
1797 	PT_NOCACHE | PT_PAT_4K | PT_PAT_LARGE | PT_IGNORE | PT_REF | PT_MOD)
1798 
1799 #define	REMAPASSERT(EX)	if (!(EX)) panic("hati_pte_map: " #EX)
1800 /*
1801  * Do the low-level work to get a mapping entered into a HAT's pagetables
1802  * and in the mapping list of the associated page_t.
1803  */
1804 static int
hati_pte_map(htable_t * ht,uint_t entry,page_t * pp,x86pte_t pte,int flags,void * pte_ptr)1805 hati_pte_map(
1806 	htable_t	*ht,
1807 	uint_t		entry,
1808 	page_t		*pp,
1809 	x86pte_t	pte,
1810 	int		flags,
1811 	void		*pte_ptr)
1812 {
1813 	hat_t		*hat = ht->ht_hat;
1814 	x86pte_t	old_pte;
1815 	level_t		l = ht->ht_level;
1816 	hment_t		*hm;
1817 	uint_t		is_consist;
1818 	uint_t		is_locked;
1819 	int		rv = 0;
1820 
1821 	/*
1822 	 * Is this a consistent (ie. need mapping list lock) mapping?
1823 	 */
1824 	is_consist = (pp != NULL && (flags & HAT_LOAD_NOCONSIST) == 0);
1825 
1826 	/*
1827 	 * Track locked mapping count in the htable.  Do this first,
1828 	 * as we track locking even if there already is a mapping present.
1829 	 */
1830 	is_locked = (flags & HAT_LOAD_LOCK) != 0 && hat != kas.a_hat;
1831 	if (is_locked)
1832 		HTABLE_LOCK_INC(ht);
1833 
1834 	/*
1835 	 * Acquire the page's mapping list lock and get an hment to use.
1836 	 * Note that hment_prepare() might return NULL.
1837 	 */
1838 	if (is_consist) {
1839 		x86_hm_enter(pp);
1840 		hm = hment_prepare(ht, entry, pp);
1841 	}
1842 
1843 	/*
1844 	 * Set the new pte, retrieving the old one at the same time.
1845 	 */
1846 	old_pte = x86pte_set(ht, entry, pte, pte_ptr);
1847 
1848 	/*
1849 	 * Did we get a large page / page table collision?
1850 	 */
1851 	if (old_pte == LPAGE_ERROR) {
1852 		if (is_locked)
1853 			HTABLE_LOCK_DEC(ht);
1854 		rv = -1;
1855 		goto done;
1856 	}
1857 
1858 	/*
1859 	 * If the mapping didn't change there is nothing more to do.
1860 	 */
1861 	if (PTE_EQUIV(pte, old_pte))
1862 		goto done;
1863 
1864 	/*
1865 	 * Install a new mapping in the page's mapping list
1866 	 */
1867 	if (!PTE_ISVALID(old_pte)) {
1868 		if (is_consist) {
1869 			hment_assign(ht, entry, pp, hm);
1870 			x86_hm_exit(pp);
1871 		} else {
1872 			ASSERT(flags & HAT_LOAD_NOCONSIST);
1873 		}
1874 		if (ht->ht_flags & HTABLE_COPIED) {
1875 			cpu_t *cpu = CPU;
1876 			hat_pcp_update(cpu, hat);
1877 		}
1878 		HTABLE_INC(ht->ht_valid_cnt);
1879 		PGCNT_INC(hat, l);
1880 		return (rv);
1881 	}
1882 
1883 	/*
1884 	 * Remap's are more complicated:
1885 	 *  - HAT_LOAD_REMAP must be specified if changing the pfn.
1886 	 *    We also require that NOCONSIST be specified.
1887 	 *  - Otherwise only permission or caching bits may change.
1888 	 */
1889 	if (!PTE_ISPAGE(old_pte, l))
1890 		panic("non-null/page mapping pte=" FMT_PTE, old_pte);
1891 
1892 	if (PTE2PFN(old_pte, l) != PTE2PFN(pte, l)) {
1893 		REMAPASSERT(flags & HAT_LOAD_REMAP);
1894 		REMAPASSERT(flags & HAT_LOAD_NOCONSIST);
1895 		REMAPASSERT(PTE_GET(old_pte, PT_SOFTWARE) >= PT_NOCONSIST);
1896 		REMAPASSERT(pf_is_memory(PTE2PFN(old_pte, l)) ==
1897 		    pf_is_memory(PTE2PFN(pte, l)));
1898 		REMAPASSERT(!is_consist);
1899 	}
1900 
1901 	/*
1902 	 * We only let remaps change the certain bits in the PTE.
1903 	 */
1904 	if (PTE_GET(old_pte, ~PT_REMAP_BITS) != PTE_GET(pte, ~PT_REMAP_BITS))
1905 		panic("remap bits changed: old_pte="FMT_PTE", pte="FMT_PTE"\n",
1906 		    old_pte, pte);
1907 
1908 	/*
1909 	 * We don't create any mapping list entries on a remap, so release
1910 	 * any allocated hment after we drop the mapping list lock.
1911 	 */
1912 done:
1913 	if (is_consist) {
1914 		x86_hm_exit(pp);
1915 		if (hm != NULL)
1916 			hment_free(hm);
1917 	}
1918 	return (rv);
1919 }
1920 
1921 /*
1922  * Internal routine to load a single page table entry. This only fails if
1923  * we attempt to overwrite a page table link with a large page.
1924  */
1925 static int
hati_load_common(hat_t * hat,uintptr_t va,page_t * pp,uint_t attr,uint_t flags,level_t level,pfn_t pfn)1926 hati_load_common(
1927 	hat_t		*hat,
1928 	uintptr_t	va,
1929 	page_t		*pp,
1930 	uint_t		attr,
1931 	uint_t		flags,
1932 	level_t		level,
1933 	pfn_t		pfn)
1934 {
1935 	htable_t	*ht;
1936 	uint_t		entry;
1937 	x86pte_t	pte;
1938 	int		rv = 0;
1939 
1940 	/*
1941 	 * The number 16 is arbitrary and here to catch a recursion problem
1942 	 * early before we blow out the kernel stack.
1943 	 */
1944 	++curthread->t_hatdepth;
1945 	ASSERT(curthread->t_hatdepth < 16);
1946 
1947 	ASSERT(hat == kas.a_hat || (hat->hat_flags & HAT_PCP) != 0 ||
1948 	    AS_LOCK_HELD(hat->hat_as));
1949 
1950 	if (flags & HAT_LOAD_SHARE)
1951 		hat->hat_flags |= HAT_SHARED;
1952 
1953 	/*
1954 	 * Find the page table that maps this page if it already exists.
1955 	 */
1956 	ht = htable_lookup(hat, va, level);
1957 
1958 	/*
1959 	 * We must have HAT_LOAD_NOCONSIST if page_t is NULL.
1960 	 */
1961 	if (pp == NULL)
1962 		flags |= HAT_LOAD_NOCONSIST;
1963 
1964 	if (ht == NULL) {
1965 		ht = htable_create(hat, va, level, NULL);
1966 		ASSERT(ht != NULL);
1967 	}
1968 	/*
1969 	 * htable_va2entry checks this condition as well, but it won't include
1970 	 * much useful info in the panic. So we do it in advance here to include
1971 	 * all the context.
1972 	 */
1973 	if (ht->ht_vaddr > va || va > HTABLE_LAST_PAGE(ht)) {
1974 		panic("hati_load_common: bad htable: va=%p, last page=%p, "
1975 		    "ht->ht_vaddr=%p, ht->ht_level=%d", (void *)va,
1976 		    (void *)HTABLE_LAST_PAGE(ht), (void *)ht->ht_vaddr,
1977 		    (int)ht->ht_level);
1978 	}
1979 	entry = htable_va2entry(va, ht);
1980 
1981 	/*
1982 	 * a bunch of paranoid error checking
1983 	 */
1984 	ASSERT(ht->ht_busy > 0);
1985 	ASSERT(ht->ht_level == level);
1986 
1987 	/*
1988 	 * construct the new PTE
1989 	 */
1990 	if (hat == kas.a_hat)
1991 		attr &= ~PROT_USER;
1992 	pte = hati_mkpte(pfn, attr, level, flags);
1993 	if (hat == kas.a_hat && va >= kernelbase)
1994 		PTE_SET(pte, mmu.pt_global);
1995 
1996 	/*
1997 	 * establish the mapping
1998 	 */
1999 	rv = hati_pte_map(ht, entry, pp, pte, flags, NULL);
2000 
2001 	/*
2002 	 * release the htable and any reserves
2003 	 */
2004 	htable_release(ht);
2005 	--curthread->t_hatdepth;
2006 	return (rv);
2007 }
2008 
2009 /*
2010  * special case of hat_memload to deal with some kernel addrs for performance
2011  */
2012 static void
hat_kmap_load(caddr_t addr,page_t * pp,uint_t attr,uint_t flags)2013 hat_kmap_load(
2014 	caddr_t		addr,
2015 	page_t		*pp,
2016 	uint_t		attr,
2017 	uint_t		flags)
2018 {
2019 	uintptr_t	va = (uintptr_t)addr;
2020 	x86pte_t	pte;
2021 	pfn_t		pfn = page_pptonum(pp);
2022 	pgcnt_t		pg_off = mmu_btop(va - mmu.kmap_addr);
2023 	htable_t	*ht;
2024 	uint_t		entry;
2025 	void		*pte_ptr;
2026 
2027 	/*
2028 	 * construct the requested PTE
2029 	 */
2030 	attr &= ~PROT_USER;
2031 	attr |= HAT_STORECACHING_OK;
2032 	pte = hati_mkpte(pfn, attr, 0, flags);
2033 	PTE_SET(pte, mmu.pt_global);
2034 
2035 	/*
2036 	 * Figure out the pte_ptr and htable and use common code to finish up
2037 	 */
2038 	if (mmu.pae_hat)
2039 		pte_ptr = mmu.kmap_ptes + pg_off;
2040 	else
2041 		pte_ptr = (x86pte32_t *)mmu.kmap_ptes + pg_off;
2042 	ht = mmu.kmap_htables[(va - mmu.kmap_htables[0]->ht_vaddr) >>
2043 	    LEVEL_SHIFT(1)];
2044 	entry = htable_va2entry(va, ht);
2045 	++curthread->t_hatdepth;
2046 	ASSERT(curthread->t_hatdepth < 16);
2047 	(void) hati_pte_map(ht, entry, pp, pte, flags, pte_ptr);
2048 	--curthread->t_hatdepth;
2049 }
2050 
2051 /*
2052  * hat_memload() - load a translation to the given page struct
2053  *
2054  * Flags for hat_memload/hat_devload/hat_*attr.
2055  *
2056  *	HAT_LOAD	Default flags to load a translation to the page.
2057  *
2058  *	HAT_LOAD_LOCK	Lock down mapping resources; hat_map(), hat_memload(),
2059  *			and hat_devload().
2060  *
2061  *	HAT_LOAD_NOCONSIST Do not add mapping to page_t mapping list.
2062  *			sets PT_NOCONSIST
2063  *
2064  *	HAT_LOAD_SHARE	A flag to hat_memload() to indicate h/w page tables
2065  *			that map some user pages (not kas) is shared by more
2066  *			than one process (eg. ISM).
2067  *
2068  *	HAT_LOAD_REMAP	Reload a valid pte with a different page frame.
2069  *
2070  *	HAT_NO_KALLOC	Do not kmem_alloc while creating the mapping; at this
2071  *			point, it's setting up mapping to allocate internal
2072  *			hat layer data structures.  This flag forces hat layer
2073  *			to tap its reserves in order to prevent infinite
2074  *			recursion.
2075  *
2076  * The following is a protection attribute (like PROT_READ, etc.)
2077  *
2078  *	HAT_NOSYNC	set PT_NOSYNC - this mapping's ref/mod bits
2079  *			are never cleared.
2080  *
2081  * Installing new valid PTE's and creation of the mapping list
2082  * entry are controlled under the same lock. It's derived from the
2083  * page_t being mapped.
2084  */
2085 static uint_t supported_memload_flags =
2086 	HAT_LOAD | HAT_LOAD_LOCK | HAT_LOAD_ADV | HAT_LOAD_NOCONSIST |
2087 	HAT_LOAD_SHARE | HAT_NO_KALLOC | HAT_LOAD_REMAP | HAT_LOAD_TEXT;
2088 
2089 void
hat_memload(hat_t * hat,caddr_t addr,page_t * pp,uint_t attr,uint_t flags)2090 hat_memload(
2091 	hat_t		*hat,
2092 	caddr_t		addr,
2093 	page_t		*pp,
2094 	uint_t		attr,
2095 	uint_t		flags)
2096 {
2097 	uintptr_t	va = (uintptr_t)addr;
2098 	level_t		level = 0;
2099 	pfn_t		pfn = page_pptonum(pp);
2100 
2101 	XPV_DISALLOW_MIGRATE();
2102 	ASSERT(IS_PAGEALIGNED(va));
2103 	ASSERT(hat == kas.a_hat || va < _userlimit);
2104 	ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
2105 	ASSERT((flags & supported_memload_flags) == flags);
2106 
2107 	ASSERT(!IN_VA_HOLE(va));
2108 	ASSERT(!PP_ISFREE(pp));
2109 
2110 	/*
2111 	 * kernel address special case for performance.
2112 	 */
2113 	if (mmu.kmap_addr <= va && va < mmu.kmap_eaddr) {
2114 		ASSERT(hat == kas.a_hat);
2115 		hat_kmap_load(addr, pp, attr, flags);
2116 		XPV_ALLOW_MIGRATE();
2117 		return;
2118 	}
2119 
2120 	/*
2121 	 * This is used for memory with normal caching enabled, so
2122 	 * always set HAT_STORECACHING_OK.
2123 	 */
2124 	attr |= HAT_STORECACHING_OK;
2125 	if (hati_load_common(hat, va, pp, attr, flags, level, pfn) != 0)
2126 		panic("unexpected hati_load_common() failure");
2127 	XPV_ALLOW_MIGRATE();
2128 }
2129 
2130 /* ARGSUSED */
2131 void
hat_memload_region(struct hat * hat,caddr_t addr,struct page * pp,uint_t attr,uint_t flags,hat_region_cookie_t rcookie)2132 hat_memload_region(struct hat *hat, caddr_t addr, struct page *pp,
2133     uint_t attr, uint_t flags, hat_region_cookie_t rcookie)
2134 {
2135 	hat_memload(hat, addr, pp, attr, flags);
2136 }
2137 
2138 /*
2139  * Load the given array of page structs using large pages when possible
2140  */
2141 void
hat_memload_array(hat_t * hat,caddr_t addr,size_t len,page_t ** pages,uint_t attr,uint_t flags)2142 hat_memload_array(
2143 	hat_t		*hat,
2144 	caddr_t		addr,
2145 	size_t		len,
2146 	page_t		**pages,
2147 	uint_t		attr,
2148 	uint_t		flags)
2149 {
2150 	uintptr_t	va = (uintptr_t)addr;
2151 	uintptr_t	eaddr = va + len;
2152 	level_t		level;
2153 	size_t		pgsize;
2154 	pgcnt_t		pgindx = 0;
2155 	pfn_t		pfn;
2156 	pgcnt_t		i;
2157 
2158 	XPV_DISALLOW_MIGRATE();
2159 	ASSERT(IS_PAGEALIGNED(va));
2160 	ASSERT(hat == kas.a_hat || va + len <= _userlimit);
2161 	ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
2162 	ASSERT((flags & supported_memload_flags) == flags);
2163 
2164 	/*
2165 	 * memload is used for memory with full caching enabled, so
2166 	 * set HAT_STORECACHING_OK.
2167 	 */
2168 	attr |= HAT_STORECACHING_OK;
2169 
2170 	/*
2171 	 * handle all pages using largest possible pagesize
2172 	 */
2173 	while (va < eaddr) {
2174 		/*
2175 		 * decide what level mapping to use (ie. pagesize)
2176 		 */
2177 		pfn = page_pptonum(pages[pgindx]);
2178 		for (level = mmu.max_page_level; ; --level) {
2179 			pgsize = LEVEL_SIZE(level);
2180 			if (level == 0)
2181 				break;
2182 
2183 			if (!IS_P2ALIGNED(va, pgsize) ||
2184 			    (eaddr - va) < pgsize ||
2185 			    !IS_P2ALIGNED(pfn_to_pa(pfn), pgsize))
2186 				continue;
2187 
2188 			/*
2189 			 * To use a large mapping of this size, all the
2190 			 * pages we are passed must be sequential subpages
2191 			 * of the large page.
2192 			 * hat_page_demote() can't change p_szc because
2193 			 * all pages are locked.
2194 			 */
2195 			if (pages[pgindx]->p_szc >= level) {
2196 				for (i = 0; i < mmu_btop(pgsize); ++i) {
2197 					if (pfn + i !=
2198 					    page_pptonum(pages[pgindx + i]))
2199 						break;
2200 					ASSERT(pages[pgindx + i]->p_szc >=
2201 					    level);
2202 					ASSERT(pages[pgindx] + i ==
2203 					    pages[pgindx + i]);
2204 				}
2205 				if (i == mmu_btop(pgsize)) {
2206 #ifdef DEBUG
2207 					if (level == 2)
2208 						map1gcnt++;
2209 #endif
2210 					break;
2211 				}
2212 			}
2213 		}
2214 
2215 		/*
2216 		 * Load this page mapping. If the load fails, try a smaller
2217 		 * pagesize.
2218 		 */
2219 		ASSERT(!IN_VA_HOLE(va));
2220 		while (hati_load_common(hat, va, pages[pgindx], attr,
2221 		    flags, level, pfn) != 0) {
2222 			if (level == 0)
2223 				panic("unexpected hati_load_common() failure");
2224 			--level;
2225 			pgsize = LEVEL_SIZE(level);
2226 		}
2227 
2228 		/*
2229 		 * move to next page
2230 		 */
2231 		va += pgsize;
2232 		pgindx += mmu_btop(pgsize);
2233 	}
2234 	XPV_ALLOW_MIGRATE();
2235 }
2236 
2237 /* ARGSUSED */
2238 void
hat_memload_array_region(struct hat * hat,caddr_t addr,size_t len,struct page ** pps,uint_t attr,uint_t flags,hat_region_cookie_t rcookie)2239 hat_memload_array_region(struct hat *hat, caddr_t addr, size_t len,
2240     struct page **pps, uint_t attr, uint_t flags,
2241     hat_region_cookie_t rcookie)
2242 {
2243 	hat_memload_array(hat, addr, len, pps, attr, flags);
2244 }
2245 
2246 /*
2247  * void hat_devload(hat, addr, len, pf, attr, flags)
2248  *	load/lock the given page frame number
2249  *
2250  * Advisory ordering attributes. Apply only to device mappings.
2251  *
2252  * HAT_STRICTORDER: the CPU must issue the references in order, as the
2253  *	programmer specified.  This is the default.
2254  * HAT_UNORDERED_OK: the CPU may reorder the references (this is all kinds
2255  *	of reordering; store or load with store or load).
2256  * HAT_MERGING_OK: merging and batching: the CPU may merge individual stores
2257  *	to consecutive locations (for example, turn two consecutive byte
2258  *	stores into one halfword store), and it may batch individual loads
2259  *	(for example, turn two consecutive byte loads into one halfword load).
2260  *	This also implies re-ordering.
2261  * HAT_LOADCACHING_OK: the CPU may cache the data it fetches and reuse it
2262  *	until another store occurs.  The default is to fetch new data
2263  *	on every load.  This also implies merging.
2264  * HAT_STORECACHING_OK: the CPU may keep the data in the cache and push it to
2265  *	the device (perhaps with other data) at a later time.  The default is
2266  *	to push the data right away.  This also implies load caching.
2267  *
2268  * Equivalent of hat_memload(), but can be used for device memory where
2269  * there are no page_t's and we support additional flags (write merging, etc).
2270  * Note that we can have large page mappings with this interface.
2271  */
2272 int supported_devload_flags = HAT_LOAD | HAT_LOAD_LOCK |
2273 	HAT_LOAD_NOCONSIST | HAT_STRICTORDER | HAT_UNORDERED_OK |
2274 	HAT_MERGING_OK | HAT_LOADCACHING_OK | HAT_STORECACHING_OK;
2275 
2276 void
hat_devload(hat_t * hat,caddr_t addr,size_t len,pfn_t pfn,uint_t attr,int flags)2277 hat_devload(
2278 	hat_t		*hat,
2279 	caddr_t		addr,
2280 	size_t		len,
2281 	pfn_t		pfn,
2282 	uint_t		attr,
2283 	int		flags)
2284 {
2285 	uintptr_t	va = ALIGN2PAGE(addr);
2286 	uintptr_t	eva = va + len;
2287 	level_t		level;
2288 	size_t		pgsize;
2289 	page_t		*pp;
2290 	int		f;	/* per PTE copy of flags  - maybe modified */
2291 	uint_t		a;	/* per PTE copy of attr */
2292 
2293 	XPV_DISALLOW_MIGRATE();
2294 	ASSERT(IS_PAGEALIGNED(va));
2295 	ASSERT(hat == kas.a_hat || eva <= _userlimit);
2296 	ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
2297 	ASSERT((flags & supported_devload_flags) == flags);
2298 
2299 	/*
2300 	 * handle all pages
2301 	 */
2302 	while (va < eva) {
2303 
2304 		/*
2305 		 * decide what level mapping to use (ie. pagesize)
2306 		 */
2307 		for (level = mmu.max_page_level; ; --level) {
2308 			pgsize = LEVEL_SIZE(level);
2309 			if (level == 0)
2310 				break;
2311 			if (IS_P2ALIGNED(va, pgsize) &&
2312 			    (eva - va) >= pgsize &&
2313 			    IS_P2ALIGNED(pfn, mmu_btop(pgsize))) {
2314 #ifdef DEBUG
2315 				if (level == 2)
2316 					map1gcnt++;
2317 #endif
2318 				break;
2319 			}
2320 		}
2321 
2322 		/*
2323 		 * If this is just memory then allow caching (this happens
2324 		 * for the nucleus pages) - though HAT_PLAT_NOCACHE can be used
2325 		 * to override that. If we don't have a page_t then make sure
2326 		 * NOCONSIST is set.
2327 		 */
2328 		a = attr;
2329 		f = flags;
2330 		if (!pf_is_memory(pfn))
2331 			f |= HAT_LOAD_NOCONSIST;
2332 		else if (!(a & HAT_PLAT_NOCACHE))
2333 			a |= HAT_STORECACHING_OK;
2334 
2335 		if (f & HAT_LOAD_NOCONSIST)
2336 			pp = NULL;
2337 		else
2338 			pp = page_numtopp_nolock(pfn);
2339 
2340 		/*
2341 		 * Check to make sure we are really trying to map a valid
2342 		 * memory page. The caller wishing to intentionally map
2343 		 * free memory pages will have passed the HAT_LOAD_NOCONSIST
2344 		 * flag, then pp will be NULL.
2345 		 */
2346 		if (pp != NULL) {
2347 			if (PP_ISFREE(pp)) {
2348 				panic("hat_devload: loading "
2349 				    "a mapping to free page %p", (void *)pp);
2350 			}
2351 
2352 			if (!PAGE_LOCKED(pp) && !PP_ISNORELOC(pp)) {
2353 				panic("hat_devload: loading a mapping "
2354 				    "to an unlocked page %p",
2355 				    (void *)pp);
2356 			}
2357 		}
2358 
2359 		/*
2360 		 * load this page mapping
2361 		 */
2362 		ASSERT(!IN_VA_HOLE(va));
2363 		while (hati_load_common(hat, va, pp, a, f, level, pfn) != 0) {
2364 			if (level == 0)
2365 				panic("unexpected hati_load_common() failure");
2366 			--level;
2367 			pgsize = LEVEL_SIZE(level);
2368 		}
2369 
2370 		/*
2371 		 * move to next page
2372 		 */
2373 		va += pgsize;
2374 		pfn += mmu_btop(pgsize);
2375 	}
2376 	XPV_ALLOW_MIGRATE();
2377 }
2378 
2379 /*
2380  * void hat_unlock(hat, addr, len)
2381  *	unlock the mappings to a given range of addresses
2382  *
2383  * Locks are tracked by ht_lock_cnt in the htable.
2384  */
2385 void
hat_unlock(hat_t * hat,caddr_t addr,size_t len)2386 hat_unlock(hat_t *hat, caddr_t addr, size_t len)
2387 {
2388 	uintptr_t	vaddr = (uintptr_t)addr;
2389 	uintptr_t	eaddr = vaddr + len;
2390 	htable_t	*ht = NULL;
2391 
2392 	/*
2393 	 * kernel entries are always locked, we don't track lock counts
2394 	 */
2395 	ASSERT(hat == kas.a_hat || eaddr <= _userlimit);
2396 	ASSERT(IS_PAGEALIGNED(vaddr));
2397 	ASSERT(IS_PAGEALIGNED(eaddr));
2398 	if (hat == kas.a_hat)
2399 		return;
2400 	if (eaddr > _userlimit)
2401 		panic("hat_unlock() address out of range - above _userlimit");
2402 
2403 	XPV_DISALLOW_MIGRATE();
2404 	ASSERT(AS_LOCK_HELD(hat->hat_as));
2405 	while (vaddr < eaddr) {
2406 		(void) htable_walk(hat, &ht, &vaddr, eaddr);
2407 		if (ht == NULL)
2408 			break;
2409 
2410 		ASSERT(!IN_VA_HOLE(vaddr));
2411 
2412 		if (ht->ht_lock_cnt < 1)
2413 			panic("hat_unlock(): lock_cnt < 1, "
2414 			    "htable=%p, vaddr=%p\n", (void *)ht, (void *)vaddr);
2415 		HTABLE_LOCK_DEC(ht);
2416 
2417 		vaddr += LEVEL_SIZE(ht->ht_level);
2418 	}
2419 	if (ht)
2420 		htable_release(ht);
2421 	XPV_ALLOW_MIGRATE();
2422 }
2423 
2424 /* ARGSUSED */
2425 void
hat_unlock_region(struct hat * hat,caddr_t addr,size_t len,hat_region_cookie_t rcookie)2426 hat_unlock_region(struct hat *hat, caddr_t addr, size_t len,
2427     hat_region_cookie_t rcookie)
2428 {
2429 	panic("No shared region support on x86");
2430 }
2431 
2432 #if !defined(__xpv)
2433 /*
2434  * Cross call service routine to demap a range of virtual
2435  * pages on the current CPU or flush all mappings in TLB.
2436  */
2437 static int
hati_demap_func(xc_arg_t a1,xc_arg_t a2,xc_arg_t a3)2438 hati_demap_func(xc_arg_t a1, xc_arg_t a2, xc_arg_t a3)
2439 {
2440 	_NOTE(ARGUNUSED(a3));
2441 	hat_t		*hat = (hat_t *)a1;
2442 	tlb_range_t	*range = (tlb_range_t *)a2;
2443 
2444 	/*
2445 	 * If the target hat isn't the kernel and this CPU isn't operating
2446 	 * in the target hat, we can ignore the cross call.
2447 	 */
2448 	if (hat != kas.a_hat && hat != CPU->cpu_current_hat)
2449 		return (0);
2450 
2451 	if (range->tr_va != DEMAP_ALL_ADDR) {
2452 		mmu_flush_tlb(FLUSH_TLB_RANGE, range);
2453 		return (0);
2454 	}
2455 
2456 	/*
2457 	 * We are flushing all of userspace.
2458 	 *
2459 	 * When using PCP, we first need to update this CPU's idea of the PCP
2460 	 * PTEs.
2461 	 */
2462 	if (hat->hat_flags & HAT_COPIED) {
2463 		hat_pcp_update(CPU, hat);
2464 	}
2465 
2466 	mmu_flush_tlb(FLUSH_TLB_NONGLOBAL, NULL);
2467 	return (0);
2468 }
2469 
2470 #define	TLBIDLE_CPU_HALTED	(0x1UL)
2471 #define	TLBIDLE_INVAL_ALL	(0x2UL)
2472 #define	CAS_TLB_INFO(cpu, old, new)	\
2473 	atomic_cas_ulong((ulong_t *)&(cpu)->cpu_m.mcpu_tlb_info, (old), (new))
2474 
2475 /*
2476  * Record that a CPU is going idle
2477  */
2478 void
tlb_going_idle(void)2479 tlb_going_idle(void)
2480 {
2481 	atomic_or_ulong((ulong_t *)&CPU->cpu_m.mcpu_tlb_info,
2482 	    TLBIDLE_CPU_HALTED);
2483 }
2484 
2485 /*
2486  * Service a delayed TLB flush if coming out of being idle.
2487  * It will be called from cpu idle notification with interrupt disabled.
2488  */
2489 void
tlb_service(void)2490 tlb_service(void)
2491 {
2492 	ulong_t tlb_info;
2493 	ulong_t found;
2494 
2495 	/*
2496 	 * We only have to do something if coming out of being idle.
2497 	 */
2498 	tlb_info = CPU->cpu_m.mcpu_tlb_info;
2499 	if (tlb_info & TLBIDLE_CPU_HALTED) {
2500 		ASSERT(CPU->cpu_current_hat == kas.a_hat);
2501 
2502 		/*
2503 		 * Atomic clear and fetch of old state.
2504 		 */
2505 		while ((found = CAS_TLB_INFO(CPU, tlb_info, 0)) != tlb_info) {
2506 			ASSERT(found & TLBIDLE_CPU_HALTED);
2507 			tlb_info = found;
2508 			SMT_PAUSE();
2509 		}
2510 		if (tlb_info & TLBIDLE_INVAL_ALL)
2511 			mmu_flush_tlb(FLUSH_TLB_ALL, NULL);
2512 	}
2513 }
2514 #endif /* !__xpv */
2515 
2516 /*
2517  * Internal routine to do cross calls to invalidate a range of pages on
2518  * all CPUs using a given hat.
2519  */
2520 void
hat_tlb_inval_range(hat_t * hat,tlb_range_t * in_range)2521 hat_tlb_inval_range(hat_t *hat, tlb_range_t *in_range)
2522 {
2523 	extern int	flushes_require_xcalls;	/* from mp_startup.c */
2524 	cpuset_t	justme;
2525 	cpuset_t	cpus_to_shootdown;
2526 	tlb_range_t	range = *in_range;
2527 #ifndef __xpv
2528 	cpuset_t	check_cpus;
2529 	cpu_t		*cpup;
2530 	int		c;
2531 #endif
2532 
2533 	/*
2534 	 * If the hat is being destroyed, there are no more users, so
2535 	 * demap need not do anything.
2536 	 */
2537 	if (hat->hat_flags & HAT_FREEING)
2538 		return;
2539 
2540 	/*
2541 	 * If demapping from a shared pagetable, we best demap the
2542 	 * entire set of user TLBs, since we don't know what addresses
2543 	 * these were shared at.
2544 	 */
2545 	if (hat->hat_flags & HAT_SHARED) {
2546 		hat = kas.a_hat;
2547 		range.tr_va = DEMAP_ALL_ADDR;
2548 	}
2549 
2550 	/*
2551 	 * if not running with multiple CPUs, don't use cross calls
2552 	 */
2553 	if (panicstr || !flushes_require_xcalls) {
2554 #ifdef __xpv
2555 		if (range.tr_va == DEMAP_ALL_ADDR) {
2556 			xen_flush_tlb();
2557 		} else {
2558 			for (size_t i = 0; i < TLB_RANGE_LEN(&range);
2559 			    i += MMU_PAGESIZE) {
2560 				xen_flush_va((caddr_t)(range.tr_va + i));
2561 			}
2562 		}
2563 #else
2564 		(void) hati_demap_func((xc_arg_t)hat, (xc_arg_t)&range, 0);
2565 #endif
2566 		return;
2567 	}
2568 
2569 
2570 	/*
2571 	 * Determine CPUs to shootdown. Kernel changes always do all CPUs.
2572 	 * Otherwise it's just CPUs currently executing in this hat.
2573 	 */
2574 	kpreempt_disable();
2575 	CPUSET_ONLY(justme, CPU->cpu_id);
2576 	if (hat == kas.a_hat)
2577 		cpus_to_shootdown = khat_cpuset;
2578 	else
2579 		cpus_to_shootdown = hat->hat_cpus;
2580 
2581 #ifndef __xpv
2582 	/*
2583 	 * If any CPUs in the set are idle, just request a delayed flush
2584 	 * and avoid waking them up.
2585 	 */
2586 	check_cpus = cpus_to_shootdown;
2587 	for (c = 0; c < NCPU && !CPUSET_ISNULL(check_cpus); ++c) {
2588 		ulong_t tlb_info;
2589 
2590 		if (!CPU_IN_SET(check_cpus, c))
2591 			continue;
2592 		CPUSET_DEL(check_cpus, c);
2593 		cpup = cpu[c];
2594 		if (cpup == NULL)
2595 			continue;
2596 
2597 		tlb_info = cpup->cpu_m.mcpu_tlb_info;
2598 		while (tlb_info == TLBIDLE_CPU_HALTED) {
2599 			(void) CAS_TLB_INFO(cpup, TLBIDLE_CPU_HALTED,
2600 			    TLBIDLE_CPU_HALTED | TLBIDLE_INVAL_ALL);
2601 			SMT_PAUSE();
2602 			tlb_info = cpup->cpu_m.mcpu_tlb_info;
2603 		}
2604 		if (tlb_info == (TLBIDLE_CPU_HALTED | TLBIDLE_INVAL_ALL)) {
2605 			HATSTAT_INC(hs_tlb_inval_delayed);
2606 			CPUSET_DEL(cpus_to_shootdown, c);
2607 		}
2608 	}
2609 #endif
2610 
2611 	if (CPUSET_ISNULL(cpus_to_shootdown) ||
2612 	    CPUSET_ISEQUAL(cpus_to_shootdown, justme)) {
2613 
2614 #ifdef __xpv
2615 		if (range.tr_va == DEMAP_ALL_ADDR) {
2616 			xen_flush_tlb();
2617 		} else {
2618 			for (size_t i = 0; i < TLB_RANGE_LEN(&range);
2619 			    i += MMU_PAGESIZE) {
2620 				xen_flush_va((caddr_t)(range.tr_va + i));
2621 			}
2622 		}
2623 #else
2624 		(void) hati_demap_func((xc_arg_t)hat, (xc_arg_t)&range, 0);
2625 #endif
2626 
2627 	} else {
2628 
2629 		CPUSET_ADD(cpus_to_shootdown, CPU->cpu_id);
2630 #ifdef __xpv
2631 		if (range.tr_va == DEMAP_ALL_ADDR) {
2632 			xen_gflush_tlb(cpus_to_shootdown);
2633 		} else {
2634 			for (size_t i = 0; i < TLB_RANGE_LEN(&range);
2635 			    i += MMU_PAGESIZE) {
2636 				xen_gflush_va((caddr_t)(range.tr_va + i),
2637 				    cpus_to_shootdown);
2638 			}
2639 		}
2640 #else
2641 		xc_call((xc_arg_t)hat, (xc_arg_t)&range, 0,
2642 		    CPUSET2BV(cpus_to_shootdown), hati_demap_func);
2643 #endif
2644 
2645 	}
2646 	kpreempt_enable();
2647 }
2648 
2649 void
hat_tlb_inval(hat_t * hat,uintptr_t va)2650 hat_tlb_inval(hat_t *hat, uintptr_t va)
2651 {
2652 	/*
2653 	 * Create range for a single page.
2654 	 */
2655 	tlb_range_t range;
2656 	range.tr_va = va;
2657 	range.tr_cnt = 1; /* one page */
2658 	range.tr_level = MIN_PAGE_LEVEL; /* pages are MMU_PAGESIZE */
2659 
2660 	hat_tlb_inval_range(hat, &range);
2661 }
2662 
2663 /*
2664  * Interior routine for HAT_UNLOADs from hat_unload_callback(),
2665  * hat_kmap_unload() OR from hat_steal() code.  This routine doesn't
2666  * handle releasing of the htables.
2667  */
2668 void
hat_pte_unmap(htable_t * ht,uint_t entry,uint_t flags,x86pte_t old_pte,void * pte_ptr,boolean_t tlb)2669 hat_pte_unmap(
2670 	htable_t	*ht,
2671 	uint_t		entry,
2672 	uint_t		flags,
2673 	x86pte_t	old_pte,
2674 	void		*pte_ptr,
2675 	boolean_t	tlb)
2676 {
2677 	hat_t		*hat = ht->ht_hat;
2678 	hment_t		*hm = NULL;
2679 	page_t		*pp = NULL;
2680 	level_t		l = ht->ht_level;
2681 	pfn_t		pfn;
2682 
2683 	/*
2684 	 * We always track the locking counts, even if nothing is unmapped
2685 	 */
2686 	if ((flags & HAT_UNLOAD_UNLOCK) != 0 && hat != kas.a_hat) {
2687 		ASSERT(ht->ht_lock_cnt > 0);
2688 		HTABLE_LOCK_DEC(ht);
2689 	}
2690 
2691 	/*
2692 	 * Figure out which page's mapping list lock to acquire using the PFN
2693 	 * passed in "old" PTE. We then attempt to invalidate the PTE.
2694 	 * If another thread, probably a hat_pageunload, has asynchronously
2695 	 * unmapped/remapped this address we'll loop here.
2696 	 */
2697 	ASSERT(ht->ht_busy > 0);
2698 	while (PTE_ISVALID(old_pte)) {
2699 		pfn = PTE2PFN(old_pte, l);
2700 		if (PTE_GET(old_pte, PT_SOFTWARE) >= PT_NOCONSIST) {
2701 			pp = NULL;
2702 		} else {
2703 #ifdef __xpv
2704 			if (pfn == PFN_INVALID)
2705 				panic("Invalid PFN, but not PT_NOCONSIST");
2706 #endif
2707 			pp = page_numtopp_nolock(pfn);
2708 			if (pp == NULL) {
2709 				panic("no page_t, not NOCONSIST: old_pte="
2710 				    FMT_PTE " ht=%lx entry=0x%x pte_ptr=%lx",
2711 				    old_pte, (uintptr_t)ht, entry,
2712 				    (uintptr_t)pte_ptr);
2713 			}
2714 			x86_hm_enter(pp);
2715 		}
2716 
2717 		old_pte = x86pte_inval(ht, entry, old_pte, pte_ptr, tlb);
2718 
2719 		/*
2720 		 * If the page hadn't changed we've unmapped it and can proceed
2721 		 */
2722 		if (PTE_ISVALID(old_pte) && PTE2PFN(old_pte, l) == pfn)
2723 			break;
2724 
2725 		/*
2726 		 * Otherwise, we'll have to retry with the current old_pte.
2727 		 * Drop the hment lock, since the pfn may have changed.
2728 		 */
2729 		if (pp != NULL) {
2730 			x86_hm_exit(pp);
2731 			pp = NULL;
2732 		} else {
2733 			ASSERT(PTE_GET(old_pte, PT_SOFTWARE) >= PT_NOCONSIST);
2734 		}
2735 	}
2736 
2737 	/*
2738 	 * If the old mapping wasn't valid, there's nothing more to do
2739 	 */
2740 	if (!PTE_ISVALID(old_pte)) {
2741 		if (pp != NULL)
2742 			x86_hm_exit(pp);
2743 		return;
2744 	}
2745 
2746 	/*
2747 	 * Take care of syncing any MOD/REF bits and removing the hment.
2748 	 */
2749 	if (pp != NULL) {
2750 		if (!(flags & HAT_UNLOAD_NOSYNC))
2751 			hati_sync_pte_to_page(pp, old_pte, l);
2752 		hm = hment_remove(pp, ht, entry);
2753 		x86_hm_exit(pp);
2754 		if (hm != NULL)
2755 			hment_free(hm);
2756 	}
2757 
2758 	/*
2759 	 * Handle book keeping in the htable and hat
2760 	 */
2761 	ASSERT(ht->ht_valid_cnt > 0);
2762 	HTABLE_DEC(ht->ht_valid_cnt);
2763 	PGCNT_DEC(hat, l);
2764 }
2765 
2766 /*
2767  * very cheap unload implementation to special case some kernel addresses
2768  */
2769 static void
hat_kmap_unload(caddr_t addr,size_t len,uint_t flags)2770 hat_kmap_unload(caddr_t addr, size_t len, uint_t flags)
2771 {
2772 	uintptr_t	va = (uintptr_t)addr;
2773 	uintptr_t	eva = va + len;
2774 	pgcnt_t		pg_index;
2775 	htable_t	*ht;
2776 	uint_t		entry;
2777 	x86pte_t	*pte_ptr;
2778 	x86pte_t	old_pte;
2779 
2780 	for (; va < eva; va += MMU_PAGESIZE) {
2781 		/*
2782 		 * Get the PTE
2783 		 */
2784 		pg_index = mmu_btop(va - mmu.kmap_addr);
2785 		pte_ptr = PT_INDEX_PTR(mmu.kmap_ptes, pg_index);
2786 		old_pte = GET_PTE(pte_ptr);
2787 
2788 		/*
2789 		 * get the htable / entry
2790 		 */
2791 		ht = mmu.kmap_htables[(va - mmu.kmap_htables[0]->ht_vaddr)
2792 		    >> LEVEL_SHIFT(1)];
2793 		entry = htable_va2entry(va, ht);
2794 
2795 		/*
2796 		 * use mostly common code to unmap it.
2797 		 */
2798 		hat_pte_unmap(ht, entry, flags, old_pte, pte_ptr, B_TRUE);
2799 	}
2800 }
2801 
2802 
2803 /*
2804  * unload a range of virtual address space (no callback)
2805  */
2806 void
hat_unload(hat_t * hat,caddr_t addr,size_t len,uint_t flags)2807 hat_unload(hat_t *hat, caddr_t addr, size_t len, uint_t flags)
2808 {
2809 	uintptr_t va = (uintptr_t)addr;
2810 
2811 	XPV_DISALLOW_MIGRATE();
2812 	ASSERT(hat == kas.a_hat || va + len <= _userlimit);
2813 
2814 	/*
2815 	 * special case for performance.
2816 	 */
2817 	if (mmu.kmap_addr <= va && va < mmu.kmap_eaddr) {
2818 		ASSERT(hat == kas.a_hat);
2819 		hat_kmap_unload(addr, len, flags);
2820 	} else {
2821 		hat_unload_callback(hat, addr, len, flags, NULL);
2822 	}
2823 	XPV_ALLOW_MIGRATE();
2824 }
2825 
2826 /*
2827  * Invalidate the TLB, and perform the callback to the upper level VM system,
2828  * for the specified ranges of contiguous pages.
2829  */
2830 static void
handle_ranges(hat_t * hat,hat_callback_t * cb,uint_t cnt,tlb_range_t * range)2831 handle_ranges(hat_t *hat, hat_callback_t *cb, uint_t cnt, tlb_range_t *range)
2832 {
2833 	while (cnt > 0) {
2834 		--cnt;
2835 		hat_tlb_inval_range(hat, &range[cnt]);
2836 
2837 		if (cb != NULL) {
2838 			cb->hcb_start_addr = (caddr_t)range[cnt].tr_va;
2839 			cb->hcb_end_addr = cb->hcb_start_addr;
2840 			cb->hcb_end_addr += range[cnt].tr_cnt <<
2841 			    LEVEL_SHIFT(range[cnt].tr_level);
2842 			cb->hcb_function(cb);
2843 		}
2844 	}
2845 }
2846 
2847 /*
2848  * Unload a given range of addresses (has optional callback)
2849  *
2850  * Flags:
2851  * define	HAT_UNLOAD		0x00
2852  * define	HAT_UNLOAD_NOSYNC	0x02
2853  * define	HAT_UNLOAD_UNLOCK	0x04
2854  * define	HAT_UNLOAD_OTHER	0x08 - not used
2855  * define	HAT_UNLOAD_UNMAP	0x10 - same as HAT_UNLOAD
2856  */
2857 #define	MAX_UNLOAD_CNT (8)
2858 void
hat_unload_callback(hat_t * hat,caddr_t addr,size_t len,uint_t flags,hat_callback_t * cb)2859 hat_unload_callback(
2860 	hat_t		*hat,
2861 	caddr_t		addr,
2862 	size_t		len,
2863 	uint_t		flags,
2864 	hat_callback_t	*cb)
2865 {
2866 	uintptr_t	vaddr = (uintptr_t)addr;
2867 	uintptr_t	eaddr = vaddr + len;
2868 	htable_t	*ht = NULL;
2869 	uint_t		entry;
2870 	uintptr_t	contig_va = (uintptr_t)-1L;
2871 	tlb_range_t	r[MAX_UNLOAD_CNT];
2872 	uint_t		r_cnt = 0;
2873 	x86pte_t	old_pte;
2874 
2875 	XPV_DISALLOW_MIGRATE();
2876 	ASSERT(hat == kas.a_hat || eaddr <= _userlimit);
2877 	ASSERT(IS_PAGEALIGNED(vaddr));
2878 	ASSERT(IS_PAGEALIGNED(eaddr));
2879 
2880 	/*
2881 	 * Special case a single page being unloaded for speed. This happens
2882 	 * quite frequently, COW faults after a fork() for example.
2883 	 */
2884 	if (cb == NULL && len == MMU_PAGESIZE) {
2885 		ht = htable_getpte(hat, vaddr, &entry, &old_pte, 0);
2886 		if (ht != NULL) {
2887 			if (PTE_ISVALID(old_pte)) {
2888 				hat_pte_unmap(ht, entry, flags, old_pte,
2889 				    NULL, B_TRUE);
2890 			}
2891 			htable_release(ht);
2892 		}
2893 		XPV_ALLOW_MIGRATE();
2894 		return;
2895 	}
2896 
2897 	while (vaddr < eaddr) {
2898 		old_pte = htable_walk(hat, &ht, &vaddr, eaddr);
2899 		if (ht == NULL)
2900 			break;
2901 
2902 		ASSERT(!IN_VA_HOLE(vaddr));
2903 
2904 		if (vaddr < (uintptr_t)addr)
2905 			panic("hat_unload_callback(): unmap inside large page");
2906 
2907 		/*
2908 		 * We'll do the call backs for contiguous ranges
2909 		 */
2910 		if (vaddr != contig_va ||
2911 		    (r_cnt > 0 && r[r_cnt - 1].tr_level != ht->ht_level)) {
2912 			if (r_cnt == MAX_UNLOAD_CNT) {
2913 				handle_ranges(hat, cb, r_cnt, r);
2914 				r_cnt = 0;
2915 			}
2916 			r[r_cnt].tr_va = vaddr;
2917 			r[r_cnt].tr_cnt = 0;
2918 			r[r_cnt].tr_level = ht->ht_level;
2919 			++r_cnt;
2920 		}
2921 
2922 		/*
2923 		 * Unload one mapping (for a single page) from the page tables.
2924 		 * Note that we do not remove the mapping from the TLB yet,
2925 		 * as indicated by the tlb=FALSE argument to hat_pte_unmap().
2926 		 * handle_ranges() will clear the TLB entries with one call to
2927 		 * hat_tlb_inval_range() per contiguous range.  This is
2928 		 * safe because the page can not be reused until the
2929 		 * callback is made (or we return).
2930 		 */
2931 		entry = htable_va2entry(vaddr, ht);
2932 		hat_pte_unmap(ht, entry, flags, old_pte, NULL, B_FALSE);
2933 		ASSERT(ht->ht_level <= mmu.max_page_level);
2934 		vaddr += LEVEL_SIZE(ht->ht_level);
2935 		contig_va = vaddr;
2936 		++r[r_cnt - 1].tr_cnt;
2937 	}
2938 	if (ht)
2939 		htable_release(ht);
2940 
2941 	/*
2942 	 * handle last range for callbacks
2943 	 */
2944 	if (r_cnt > 0)
2945 		handle_ranges(hat, cb, r_cnt, r);
2946 	XPV_ALLOW_MIGRATE();
2947 }
2948 
2949 /*
2950  * Invalidate a virtual address translation on a slave CPU during
2951  * panic() dumps.
2952  */
2953 void
hat_flush_range(hat_t * hat,caddr_t va,size_t size)2954 hat_flush_range(hat_t *hat, caddr_t va, size_t size)
2955 {
2956 	ssize_t sz;
2957 	caddr_t endva = va + size;
2958 
2959 	while (va < endva) {
2960 		sz = hat_getpagesize(hat, va);
2961 		if (sz < 0) {
2962 #ifdef __xpv
2963 			xen_flush_tlb();
2964 #else
2965 			mmu_flush_tlb(FLUSH_TLB_ALL, NULL);
2966 #endif
2967 			break;
2968 		}
2969 #ifdef __xpv
2970 		xen_flush_va(va);
2971 #else
2972 		mmu_flush_tlb_kpage((uintptr_t)va);
2973 #endif
2974 		va += sz;
2975 	}
2976 }
2977 
2978 /*
2979  * synchronize mapping with software data structures
2980  *
2981  * This interface is currently only used by the working set monitor
2982  * driver.
2983  */
2984 /*ARGSUSED*/
2985 void
hat_sync(hat_t * hat,caddr_t addr,size_t len,uint_t flags)2986 hat_sync(hat_t *hat, caddr_t addr, size_t len, uint_t flags)
2987 {
2988 	uintptr_t	vaddr = (uintptr_t)addr;
2989 	uintptr_t	eaddr = vaddr + len;
2990 	htable_t	*ht = NULL;
2991 	uint_t		entry;
2992 	x86pte_t	pte;
2993 	x86pte_t	save_pte;
2994 	x86pte_t	new;
2995 	page_t		*pp;
2996 
2997 	ASSERT(!IN_VA_HOLE(vaddr));
2998 	ASSERT(IS_PAGEALIGNED(vaddr));
2999 	ASSERT(IS_PAGEALIGNED(eaddr));
3000 	ASSERT(hat == kas.a_hat || eaddr <= _userlimit);
3001 
3002 	XPV_DISALLOW_MIGRATE();
3003 	for (; vaddr < eaddr; vaddr += LEVEL_SIZE(ht->ht_level)) {
3004 try_again:
3005 		pte = htable_walk(hat, &ht, &vaddr, eaddr);
3006 		if (ht == NULL)
3007 			break;
3008 		entry = htable_va2entry(vaddr, ht);
3009 
3010 		if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC ||
3011 		    PTE_GET(pte, PT_REF | PT_MOD) == 0)
3012 			continue;
3013 
3014 		/*
3015 		 * We need to acquire the mapping list lock to protect
3016 		 * against hat_pageunload(), hat_unload(), etc.
3017 		 */
3018 		pp = page_numtopp_nolock(PTE2PFN(pte, ht->ht_level));
3019 		if (pp == NULL)
3020 			break;
3021 		x86_hm_enter(pp);
3022 		save_pte = pte;
3023 		pte = x86pte_get(ht, entry);
3024 		if (pte != save_pte) {
3025 			x86_hm_exit(pp);
3026 			goto try_again;
3027 		}
3028 		if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC ||
3029 		    PTE_GET(pte, PT_REF | PT_MOD) == 0) {
3030 			x86_hm_exit(pp);
3031 			continue;
3032 		}
3033 
3034 		/*
3035 		 * Need to clear ref or mod bits. We may compete with
3036 		 * hardware updating the R/M bits and have to try again.
3037 		 */
3038 		if (flags == HAT_SYNC_ZERORM) {
3039 			new = pte;
3040 			PTE_CLR(new, PT_REF | PT_MOD);
3041 			pte = hati_update_pte(ht, entry, pte, new);
3042 			if (pte != 0) {
3043 				x86_hm_exit(pp);
3044 				goto try_again;
3045 			}
3046 		} else {
3047 			/*
3048 			 * sync the PTE to the page_t
3049 			 */
3050 			hati_sync_pte_to_page(pp, save_pte, ht->ht_level);
3051 		}
3052 		x86_hm_exit(pp);
3053 	}
3054 	if (ht)
3055 		htable_release(ht);
3056 	XPV_ALLOW_MIGRATE();
3057 }
3058 
3059 /*
3060  * void	hat_map(hat, addr, len, flags)
3061  */
3062 /*ARGSUSED*/
3063 void
hat_map(hat_t * hat,caddr_t addr,size_t len,uint_t flags)3064 hat_map(hat_t *hat, caddr_t addr, size_t len, uint_t flags)
3065 {
3066 	/* does nothing */
3067 }
3068 
3069 /*
3070  * uint_t hat_getattr(hat, addr, *attr)
3071  *	returns attr for <hat,addr> in *attr.  returns 0 if there was a
3072  *	mapping and *attr is valid, nonzero if there was no mapping and
3073  *	*attr is not valid.
3074  */
3075 uint_t
hat_getattr(hat_t * hat,caddr_t addr,uint_t * attr)3076 hat_getattr(hat_t *hat, caddr_t addr, uint_t *attr)
3077 {
3078 	uintptr_t	vaddr = ALIGN2PAGE(addr);
3079 	htable_t	*ht = NULL;
3080 	x86pte_t	pte;
3081 
3082 	ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
3083 
3084 	if (IN_VA_HOLE(vaddr))
3085 		return ((uint_t)-1);
3086 
3087 	ht = htable_getpte(hat, vaddr, NULL, &pte, mmu.max_page_level);
3088 	if (ht == NULL)
3089 		return ((uint_t)-1);
3090 
3091 	if (!PTE_ISVALID(pte) || !PTE_ISPAGE(pte, ht->ht_level)) {
3092 		htable_release(ht);
3093 		return ((uint_t)-1);
3094 	}
3095 
3096 	*attr = PROT_READ;
3097 	if (PTE_GET(pte, PT_WRITABLE))
3098 		*attr |= PROT_WRITE;
3099 	if (PTE_GET(pte, PT_USER))
3100 		*attr |= PROT_USER;
3101 	if (!PTE_GET(pte, mmu.pt_nx))
3102 		*attr |= PROT_EXEC;
3103 	if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC)
3104 		*attr |= HAT_NOSYNC;
3105 	htable_release(ht);
3106 	return (0);
3107 }
3108 
3109 /*
3110  * hat_updateattr() applies the given attribute change to an existing mapping
3111  */
3112 #define	HAT_LOAD_ATTR		1
3113 #define	HAT_SET_ATTR		2
3114 #define	HAT_CLR_ATTR		3
3115 
3116 static void
hat_updateattr(hat_t * hat,caddr_t addr,size_t len,uint_t attr,int what)3117 hat_updateattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr, int what)
3118 {
3119 	uintptr_t	vaddr = (uintptr_t)addr;
3120 	uintptr_t	eaddr = (uintptr_t)addr + len;
3121 	htable_t	*ht = NULL;
3122 	uint_t		entry;
3123 	x86pte_t	oldpte, newpte;
3124 	page_t		*pp;
3125 
3126 	XPV_DISALLOW_MIGRATE();
3127 	ASSERT(IS_PAGEALIGNED(vaddr));
3128 	ASSERT(IS_PAGEALIGNED(eaddr));
3129 	ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
3130 	for (; vaddr < eaddr; vaddr += LEVEL_SIZE(ht->ht_level)) {
3131 try_again:
3132 		oldpte = htable_walk(hat, &ht, &vaddr, eaddr);
3133 		if (ht == NULL)
3134 			break;
3135 		if (PTE_GET(oldpte, PT_SOFTWARE) >= PT_NOCONSIST)
3136 			continue;
3137 
3138 		pp = page_numtopp_nolock(PTE2PFN(oldpte, ht->ht_level));
3139 		if (pp == NULL)
3140 			continue;
3141 		x86_hm_enter(pp);
3142 
3143 		newpte = oldpte;
3144 		/*
3145 		 * We found a page table entry in the desired range,
3146 		 * figure out the new attributes.
3147 		 */
3148 		if (what == HAT_SET_ATTR || what == HAT_LOAD_ATTR) {
3149 			if ((attr & PROT_WRITE) &&
3150 			    !PTE_GET(oldpte, PT_WRITABLE))
3151 				newpte |= PT_WRITABLE;
3152 
3153 			if ((attr & HAT_NOSYNC) &&
3154 			    PTE_GET(oldpte, PT_SOFTWARE) < PT_NOSYNC)
3155 				newpte |= PT_NOSYNC;
3156 
3157 			if ((attr & PROT_EXEC) && PTE_GET(oldpte, mmu.pt_nx))
3158 				newpte &= ~mmu.pt_nx;
3159 		}
3160 
3161 		if (what == HAT_LOAD_ATTR) {
3162 			if (!(attr & PROT_WRITE) &&
3163 			    PTE_GET(oldpte, PT_WRITABLE))
3164 				newpte &= ~PT_WRITABLE;
3165 
3166 			if (!(attr & HAT_NOSYNC) &&
3167 			    PTE_GET(oldpte, PT_SOFTWARE) >= PT_NOSYNC)
3168 				newpte &= ~PT_SOFTWARE;
3169 
3170 			if (!(attr & PROT_EXEC) && !PTE_GET(oldpte, mmu.pt_nx))
3171 				newpte |= mmu.pt_nx;
3172 		}
3173 
3174 		if (what == HAT_CLR_ATTR) {
3175 			if ((attr & PROT_WRITE) && PTE_GET(oldpte, PT_WRITABLE))
3176 				newpte &= ~PT_WRITABLE;
3177 
3178 			if ((attr & HAT_NOSYNC) &&
3179 			    PTE_GET(oldpte, PT_SOFTWARE) >= PT_NOSYNC)
3180 				newpte &= ~PT_SOFTWARE;
3181 
3182 			if ((attr & PROT_EXEC) && !PTE_GET(oldpte, mmu.pt_nx))
3183 				newpte |= mmu.pt_nx;
3184 		}
3185 
3186 		/*
3187 		 * Ensure NOSYNC/NOCONSIST mappings have REF and MOD set.
3188 		 * x86pte_set() depends on this.
3189 		 */
3190 		if (PTE_GET(newpte, PT_SOFTWARE) >= PT_NOSYNC)
3191 			newpte |= PT_REF | PT_MOD;
3192 
3193 		/*
3194 		 * what about PROT_READ or others? this code only handles:
3195 		 * EXEC, WRITE, NOSYNC
3196 		 */
3197 
3198 		/*
3199 		 * If new PTE really changed, update the table.
3200 		 */
3201 		if (newpte != oldpte) {
3202 			entry = htable_va2entry(vaddr, ht);
3203 			oldpte = hati_update_pte(ht, entry, oldpte, newpte);
3204 			if (oldpte != 0) {
3205 				x86_hm_exit(pp);
3206 				goto try_again;
3207 			}
3208 		}
3209 		x86_hm_exit(pp);
3210 	}
3211 	if (ht)
3212 		htable_release(ht);
3213 	XPV_ALLOW_MIGRATE();
3214 }
3215 
3216 /*
3217  * Various wrappers for hat_updateattr()
3218  */
3219 void
hat_setattr(hat_t * hat,caddr_t addr,size_t len,uint_t attr)3220 hat_setattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr)
3221 {
3222 	ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
3223 	hat_updateattr(hat, addr, len, attr, HAT_SET_ATTR);
3224 }
3225 
3226 void
hat_clrattr(hat_t * hat,caddr_t addr,size_t len,uint_t attr)3227 hat_clrattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr)
3228 {
3229 	ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
3230 	hat_updateattr(hat, addr, len, attr, HAT_CLR_ATTR);
3231 }
3232 
3233 void
hat_chgattr(hat_t * hat,caddr_t addr,size_t len,uint_t attr)3234 hat_chgattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr)
3235 {
3236 	ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
3237 	hat_updateattr(hat, addr, len, attr, HAT_LOAD_ATTR);
3238 }
3239 
3240 void
hat_chgprot(hat_t * hat,caddr_t addr,size_t len,uint_t vprot)3241 hat_chgprot(hat_t *hat, caddr_t addr, size_t len, uint_t vprot)
3242 {
3243 	ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
3244 	hat_updateattr(hat, addr, len, vprot & HAT_PROT_MASK, HAT_LOAD_ATTR);
3245 }
3246 
3247 /*
3248  * size_t hat_getpagesize(hat, addr)
3249  *	returns pagesize in bytes for <hat, addr>. returns -1 of there is
3250  *	no mapping. This is an advisory call.
3251  */
3252 ssize_t
hat_getpagesize(hat_t * hat,caddr_t addr)3253 hat_getpagesize(hat_t *hat, caddr_t addr)
3254 {
3255 	uintptr_t	vaddr = ALIGN2PAGE(addr);
3256 	htable_t	*ht;
3257 	size_t		pagesize;
3258 
3259 	ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
3260 	if (IN_VA_HOLE(vaddr))
3261 		return (-1);
3262 	ht = htable_getpage(hat, vaddr, NULL);
3263 	if (ht == NULL)
3264 		return (-1);
3265 	pagesize = LEVEL_SIZE(ht->ht_level);
3266 	htable_release(ht);
3267 	return (pagesize);
3268 }
3269 
3270 
3271 
3272 /*
3273  * pfn_t hat_getpfnum(hat, addr)
3274  *	returns pfn for <hat, addr> or PFN_INVALID if mapping is invalid.
3275  */
3276 pfn_t
hat_getpfnum(hat_t * hat,caddr_t addr)3277 hat_getpfnum(hat_t *hat, caddr_t addr)
3278 {
3279 	uintptr_t	vaddr = ALIGN2PAGE(addr);
3280 	htable_t	*ht;
3281 	uint_t		entry;
3282 	pfn_t		pfn = PFN_INVALID;
3283 
3284 	ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
3285 	if (khat_running == 0)
3286 		return (PFN_INVALID);
3287 
3288 	if (IN_VA_HOLE(vaddr))
3289 		return (PFN_INVALID);
3290 
3291 	XPV_DISALLOW_MIGRATE();
3292 	/*
3293 	 * A very common use of hat_getpfnum() is from the DDI for kernel pages.
3294 	 * Use the kmap_ptes (which also covers the 32 bit heap) to speed
3295 	 * this up.
3296 	 */
3297 	if (mmu.kmap_addr <= vaddr && vaddr < mmu.kmap_eaddr) {
3298 		x86pte_t pte;
3299 		pgcnt_t pg_index;
3300 
3301 		pg_index = mmu_btop(vaddr - mmu.kmap_addr);
3302 		pte = GET_PTE(PT_INDEX_PTR(mmu.kmap_ptes, pg_index));
3303 		if (PTE_ISVALID(pte))
3304 			/*LINTED [use of constant 0 causes a lint warning] */
3305 			pfn = PTE2PFN(pte, 0);
3306 		XPV_ALLOW_MIGRATE();
3307 		return (pfn);
3308 	}
3309 
3310 	ht = htable_getpage(hat, vaddr, &entry);
3311 	if (ht == NULL) {
3312 		XPV_ALLOW_MIGRATE();
3313 		return (PFN_INVALID);
3314 	}
3315 	ASSERT(vaddr >= ht->ht_vaddr);
3316 	ASSERT(vaddr <= HTABLE_LAST_PAGE(ht));
3317 	pfn = PTE2PFN(x86pte_get(ht, entry), ht->ht_level);
3318 	if (ht->ht_level > 0)
3319 		pfn += mmu_btop(vaddr & LEVEL_OFFSET(ht->ht_level));
3320 	htable_release(ht);
3321 	XPV_ALLOW_MIGRATE();
3322 	return (pfn);
3323 }
3324 
3325 /*
3326  * int hat_probe(hat, addr)
3327  *	return 0 if no valid mapping is present.  Faster version
3328  *	of hat_getattr in certain architectures.
3329  */
3330 int
hat_probe(hat_t * hat,caddr_t addr)3331 hat_probe(hat_t *hat, caddr_t addr)
3332 {
3333 	uintptr_t	vaddr = ALIGN2PAGE(addr);
3334 	uint_t		entry;
3335 	htable_t	*ht;
3336 	pgcnt_t		pg_off;
3337 
3338 	ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
3339 	ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
3340 	if (IN_VA_HOLE(vaddr))
3341 		return (0);
3342 
3343 	/*
3344 	 * Most common use of hat_probe is from segmap. We special case it
3345 	 * for performance.
3346 	 */
3347 	if (mmu.kmap_addr <= vaddr && vaddr < mmu.kmap_eaddr) {
3348 		pg_off = mmu_btop(vaddr - mmu.kmap_addr);
3349 		if (mmu.pae_hat)
3350 			return (PTE_ISVALID(mmu.kmap_ptes[pg_off]));
3351 		else
3352 			return (PTE_ISVALID(
3353 			    ((x86pte32_t *)mmu.kmap_ptes)[pg_off]));
3354 	}
3355 
3356 	ht = htable_getpage(hat, vaddr, &entry);
3357 	htable_release(ht);
3358 	return (ht != NULL);
3359 }
3360 
3361 /*
3362  * Find out if the segment for hat_share()/hat_unshare() is DISM or locked ISM.
3363  */
3364 static int
is_it_dism(hat_t * hat,caddr_t va)3365 is_it_dism(hat_t *hat, caddr_t va)
3366 {
3367 	struct seg *seg;
3368 	struct shm_data *shmd;
3369 	struct spt_data *sptd;
3370 
3371 	seg = as_findseg(hat->hat_as, va, 0);
3372 	ASSERT(seg != NULL);
3373 	ASSERT(seg->s_base <= va);
3374 	shmd = (struct shm_data *)seg->s_data;
3375 	ASSERT(shmd != NULL);
3376 	sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
3377 	ASSERT(sptd != NULL);
3378 	if (sptd->spt_flags & SHM_PAGEABLE)
3379 		return (1);
3380 	return (0);
3381 }
3382 
3383 /*
3384  * Simple implementation of ISM. hat_share() is similar to hat_memload_array(),
3385  * except that we use the ism_hat's existing mappings to determine the pages
3386  * and protections to use for this hat. If we find a full properly aligned
3387  * and sized pagetable, we will attempt to share the pagetable itself.
3388  */
3389 /*ARGSUSED*/
3390 int
hat_share(hat_t * hat,caddr_t addr,hat_t * ism_hat,caddr_t src_addr,size_t len,uint_t ismszc)3391 hat_share(
3392 	hat_t		*hat,
3393 	caddr_t		addr,
3394 	hat_t		*ism_hat,
3395 	caddr_t		src_addr,
3396 	size_t		len,	/* almost useless value, see below.. */
3397 	uint_t		ismszc)
3398 {
3399 	uintptr_t	vaddr_start = (uintptr_t)addr;
3400 	uintptr_t	vaddr;
3401 	uintptr_t	eaddr = vaddr_start + len;
3402 	uintptr_t	ism_addr_start = (uintptr_t)src_addr;
3403 	uintptr_t	ism_addr = ism_addr_start;
3404 	uintptr_t	e_ism_addr = ism_addr + len;
3405 	htable_t	*ism_ht = NULL;
3406 	htable_t	*ht;
3407 	x86pte_t	pte;
3408 	page_t		*pp;
3409 	pfn_t		pfn;
3410 	level_t		l;
3411 	pgcnt_t		pgcnt;
3412 	uint_t		prot;
3413 	int		is_dism;
3414 	int		flags;
3415 
3416 	/*
3417 	 * We might be asked to share an empty DISM hat by as_dup()
3418 	 */
3419 	ASSERT(hat != kas.a_hat);
3420 	ASSERT(eaddr <= _userlimit);
3421 	if (!(ism_hat->hat_flags & HAT_SHARED)) {
3422 		ASSERT(hat_get_mapped_size(ism_hat) == 0);
3423 		return (0);
3424 	}
3425 	XPV_DISALLOW_MIGRATE();
3426 
3427 	/*
3428 	 * The SPT segment driver often passes us a size larger than there are
3429 	 * valid mappings. That's because it rounds the segment size up to a
3430 	 * large pagesize, even if the actual memory mapped by ism_hat is less.
3431 	 */
3432 	ASSERT(IS_PAGEALIGNED(vaddr_start));
3433 	ASSERT(IS_PAGEALIGNED(ism_addr_start));
3434 	ASSERT(ism_hat->hat_flags & HAT_SHARED);
3435 	is_dism = is_it_dism(hat, addr);
3436 	while (ism_addr < e_ism_addr) {
3437 		/*
3438 		 * use htable_walk to get the next valid ISM mapping
3439 		 */
3440 		pte = htable_walk(ism_hat, &ism_ht, &ism_addr, e_ism_addr);
3441 		if (ism_ht == NULL)
3442 			break;
3443 
3444 		/*
3445 		 * First check to see if we already share the page table.
3446 		 */
3447 		l = ism_ht->ht_level;
3448 		vaddr = vaddr_start + (ism_addr - ism_addr_start);
3449 		ht = htable_lookup(hat, vaddr, l);
3450 		if (ht != NULL) {
3451 			if (ht->ht_flags & HTABLE_SHARED_PFN)
3452 				goto shared;
3453 			htable_release(ht);
3454 			goto not_shared;
3455 		}
3456 
3457 		/*
3458 		 * Can't ever share top table.
3459 		 */
3460 		if (l == mmu.max_level)
3461 			goto not_shared;
3462 
3463 		/*
3464 		 * Avoid level mismatches later due to DISM faults.
3465 		 */
3466 		if (is_dism && l > 0)
3467 			goto not_shared;
3468 
3469 		/*
3470 		 * addresses and lengths must align
3471 		 * table must be fully populated
3472 		 * no lower level page tables
3473 		 */
3474 		if (ism_addr != ism_ht->ht_vaddr ||
3475 		    (vaddr & LEVEL_OFFSET(l + 1)) != 0)
3476 			goto not_shared;
3477 
3478 		/*
3479 		 * The range of address space must cover a full table.
3480 		 */
3481 		if (e_ism_addr - ism_addr < LEVEL_SIZE(l + 1))
3482 			goto not_shared;
3483 
3484 		/*
3485 		 * All entries in the ISM page table must be leaf PTEs.
3486 		 */
3487 		if (l > 0) {
3488 			int e;
3489 
3490 			/*
3491 			 * We know the 0th is from htable_walk() above.
3492 			 */
3493 			for (e = 1; e < HTABLE_NUM_PTES(ism_ht); ++e) {
3494 				x86pte_t pte;
3495 				pte = x86pte_get(ism_ht, e);
3496 				if (!PTE_ISPAGE(pte, l))
3497 					goto not_shared;
3498 			}
3499 		}
3500 
3501 		/*
3502 		 * share the page table
3503 		 */
3504 		ht = htable_create(hat, vaddr, l, ism_ht);
3505 shared:
3506 		ASSERT(ht->ht_flags & HTABLE_SHARED_PFN);
3507 		ASSERT(ht->ht_shares == ism_ht);
3508 		hat->hat_ism_pgcnt +=
3509 		    (ism_ht->ht_valid_cnt - ht->ht_valid_cnt) <<
3510 		    (LEVEL_SHIFT(ht->ht_level) - MMU_PAGESHIFT);
3511 		ht->ht_valid_cnt = ism_ht->ht_valid_cnt;
3512 		htable_release(ht);
3513 		ism_addr = ism_ht->ht_vaddr + LEVEL_SIZE(l + 1);
3514 		htable_release(ism_ht);
3515 		ism_ht = NULL;
3516 		continue;
3517 
3518 not_shared:
3519 		/*
3520 		 * Unable to share the page table. Instead we will
3521 		 * create new mappings from the values in the ISM mappings.
3522 		 * Figure out what level size mappings to use;
3523 		 */
3524 		for (l = ism_ht->ht_level; l > 0; --l) {
3525 			if (LEVEL_SIZE(l) <= eaddr - vaddr &&
3526 			    (vaddr & LEVEL_OFFSET(l)) == 0)
3527 				break;
3528 		}
3529 
3530 		/*
3531 		 * The ISM mapping might be larger than the share area,
3532 		 * be careful to truncate it if needed.
3533 		 */
3534 		if (eaddr - vaddr >= LEVEL_SIZE(ism_ht->ht_level)) {
3535 			pgcnt = mmu_btop(LEVEL_SIZE(ism_ht->ht_level));
3536 		} else {
3537 			pgcnt = mmu_btop(eaddr - vaddr);
3538 			l = 0;
3539 		}
3540 
3541 		pfn = PTE2PFN(pte, ism_ht->ht_level);
3542 		ASSERT(pfn != PFN_INVALID);
3543 		while (pgcnt > 0) {
3544 			/*
3545 			 * Make a new pte for the PFN for this level.
3546 			 * Copy protections for the pte from the ISM pte.
3547 			 */
3548 			pp = page_numtopp_nolock(pfn);
3549 			ASSERT(pp != NULL);
3550 
3551 			prot = PROT_USER | PROT_READ | HAT_UNORDERED_OK;
3552 			if (PTE_GET(pte, PT_WRITABLE))
3553 				prot |= PROT_WRITE;
3554 			if (!PTE_GET(pte, PT_NX))
3555 				prot |= PROT_EXEC;
3556 
3557 			flags = HAT_LOAD;
3558 			if (!is_dism)
3559 				flags |= HAT_LOAD_LOCK | HAT_LOAD_NOCONSIST;
3560 			while (hati_load_common(hat, vaddr, pp, prot, flags,
3561 			    l, pfn) != 0) {
3562 				if (l == 0)
3563 					panic("hati_load_common() failure");
3564 				--l;
3565 			}
3566 
3567 			vaddr += LEVEL_SIZE(l);
3568 			ism_addr += LEVEL_SIZE(l);
3569 			pfn += mmu_btop(LEVEL_SIZE(l));
3570 			pgcnt -= mmu_btop(LEVEL_SIZE(l));
3571 		}
3572 	}
3573 	if (ism_ht != NULL)
3574 		htable_release(ism_ht);
3575 	XPV_ALLOW_MIGRATE();
3576 	return (0);
3577 }
3578 
3579 
3580 /*
3581  * hat_unshare() is similar to hat_unload_callback(), but
3582  * we have to look for empty shared pagetables. Note that
3583  * hat_unshare() is always invoked against an entire segment.
3584  */
3585 /*ARGSUSED*/
3586 void
hat_unshare(hat_t * hat,caddr_t addr,size_t len,uint_t ismszc)3587 hat_unshare(hat_t *hat, caddr_t addr, size_t len, uint_t ismszc)
3588 {
3589 	uint64_t	vaddr = (uintptr_t)addr;
3590 	uintptr_t	eaddr = vaddr + len;
3591 	htable_t	*ht = NULL;
3592 	uint_t		need_demaps = 0;
3593 	int		flags = HAT_UNLOAD_UNMAP;
3594 	level_t		l;
3595 
3596 	ASSERT(hat != kas.a_hat);
3597 	ASSERT(eaddr <= _userlimit);
3598 	ASSERT(IS_PAGEALIGNED(vaddr));
3599 	ASSERT(IS_PAGEALIGNED(eaddr));
3600 	XPV_DISALLOW_MIGRATE();
3601 
3602 	/*
3603 	 * First go through and remove any shared pagetables.
3604 	 *
3605 	 * Note that it's ok to delay the TLB shootdown till the entire range is
3606 	 * finished, because if hat_pageunload() were to unload a shared
3607 	 * pagetable page, its hat_tlb_inval() will do a global TLB invalidate.
3608 	 */
3609 	l = mmu.max_page_level;
3610 	if (l == mmu.max_level)
3611 		--l;
3612 	for (; l >= 0; --l) {
3613 		for (vaddr = (uintptr_t)addr; vaddr < eaddr;
3614 		    vaddr = (vaddr & LEVEL_MASK(l + 1)) + LEVEL_SIZE(l + 1)) {
3615 			ASSERT(!IN_VA_HOLE(vaddr));
3616 			/*
3617 			 * find a pagetable that maps the current address
3618 			 */
3619 			ht = htable_lookup(hat, vaddr, l);
3620 			if (ht == NULL)
3621 				continue;
3622 			if (ht->ht_flags & HTABLE_SHARED_PFN) {
3623 				/*
3624 				 * clear page count, set valid_cnt to 0,
3625 				 * let htable_release() finish the job
3626 				 */
3627 				hat->hat_ism_pgcnt -= ht->ht_valid_cnt <<
3628 				    (LEVEL_SHIFT(ht->ht_level) - MMU_PAGESHIFT);
3629 				ht->ht_valid_cnt = 0;
3630 				need_demaps = 1;
3631 			}
3632 			htable_release(ht);
3633 		}
3634 	}
3635 
3636 	/*
3637 	 * flush the TLBs - since we're probably dealing with MANY mappings
3638 	 * we just do a full invalidation.
3639 	 */
3640 	if (!(hat->hat_flags & HAT_FREEING) && need_demaps)
3641 		hat_tlb_inval(hat, DEMAP_ALL_ADDR);
3642 
3643 	/*
3644 	 * Now go back and clean up any unaligned mappings that
3645 	 * couldn't share pagetables.
3646 	 */
3647 	if (!is_it_dism(hat, addr))
3648 		flags |= HAT_UNLOAD_UNLOCK;
3649 	hat_unload(hat, addr, len, flags);
3650 	XPV_ALLOW_MIGRATE();
3651 }
3652 
3653 
3654 /*
3655  * hat_reserve() does nothing
3656  */
3657 /*ARGSUSED*/
3658 void
hat_reserve(struct as * as,caddr_t addr,size_t len)3659 hat_reserve(struct as *as, caddr_t addr, size_t len)
3660 {
3661 }
3662 
3663 
3664 /*
3665  * Called when all mappings to a page should have write permission removed.
3666  * Mostly stolen from hat_pagesync()
3667  */
3668 static void
hati_page_clrwrt(struct page * pp)3669 hati_page_clrwrt(struct page *pp)
3670 {
3671 	hment_t		*hm = NULL;
3672 	htable_t	*ht;
3673 	uint_t		entry;
3674 	x86pte_t	old;
3675 	x86pte_t	new;
3676 	uint_t		pszc = 0;
3677 
3678 	XPV_DISALLOW_MIGRATE();
3679 next_size:
3680 	/*
3681 	 * walk thru the mapping list clearing write permission
3682 	 */
3683 	x86_hm_enter(pp);
3684 	while ((hm = hment_walk(pp, &ht, &entry, hm)) != NULL) {
3685 		if (ht->ht_level < pszc)
3686 			continue;
3687 		old = x86pte_get(ht, entry);
3688 
3689 		for (;;) {
3690 			/*
3691 			 * Is this mapping of interest?
3692 			 */
3693 			if (PTE2PFN(old, ht->ht_level) != pp->p_pagenum ||
3694 			    PTE_GET(old, PT_WRITABLE) == 0)
3695 				break;
3696 
3697 			/*
3698 			 * Clear ref/mod writable bits. This requires cross
3699 			 * calls to ensure any executing TLBs see cleared bits.
3700 			 */
3701 			new = old;
3702 			PTE_CLR(new, PT_REF | PT_MOD | PT_WRITABLE);
3703 			old = hati_update_pte(ht, entry, old, new);
3704 			if (old != 0)
3705 				continue;
3706 
3707 			break;
3708 		}
3709 	}
3710 	x86_hm_exit(pp);
3711 	while (pszc < pp->p_szc) {
3712 		page_t *tpp;
3713 		pszc++;
3714 		tpp = PP_GROUPLEADER(pp, pszc);
3715 		if (pp != tpp) {
3716 			pp = tpp;
3717 			goto next_size;
3718 		}
3719 	}
3720 	XPV_ALLOW_MIGRATE();
3721 }
3722 
3723 /*
3724  * void hat_page_setattr(pp, flag)
3725  * void hat_page_clrattr(pp, flag)
3726  *	used to set/clr ref/mod bits.
3727  */
3728 void
hat_page_setattr(struct page * pp,uint_t flag)3729 hat_page_setattr(struct page *pp, uint_t flag)
3730 {
3731 	vnode_t		*vp = pp->p_vnode;
3732 	kmutex_t	*vphm = NULL;
3733 	page_t		**listp;
3734 	int		noshuffle;
3735 
3736 	noshuffle = flag & P_NSH;
3737 	flag &= ~P_NSH;
3738 
3739 	if (PP_GETRM(pp, flag) == flag)
3740 		return;
3741 
3742 	if ((flag & P_MOD) != 0 && vp != NULL && IS_VMODSORT(vp) &&
3743 	    !noshuffle) {
3744 		vphm = page_vnode_mutex(vp);
3745 		mutex_enter(vphm);
3746 	}
3747 
3748 	PP_SETRM(pp, flag);
3749 
3750 	if (vphm != NULL) {
3751 
3752 		/*
3753 		 * Some File Systems examine v_pages for NULL w/o
3754 		 * grabbing the vphm mutex. Must not let it become NULL when
3755 		 * pp is the only page on the list.
3756 		 */
3757 		if (pp->p_vpnext != pp) {
3758 			page_vpsub(&vp->v_pages, pp);
3759 			if (vp->v_pages != NULL)
3760 				listp = &vp->v_pages->p_vpprev->p_vpnext;
3761 			else
3762 				listp = &vp->v_pages;
3763 			page_vpadd(listp, pp);
3764 		}
3765 		mutex_exit(vphm);
3766 	}
3767 }
3768 
3769 void
hat_page_clrattr(struct page * pp,uint_t flag)3770 hat_page_clrattr(struct page *pp, uint_t flag)
3771 {
3772 	vnode_t		*vp = pp->p_vnode;
3773 	ASSERT(!(flag & ~(P_MOD | P_REF | P_RO)));
3774 
3775 	/*
3776 	 * Caller is expected to hold page's io lock for VMODSORT to work
3777 	 * correctly with pvn_vplist_dirty() and pvn_getdirty() when mod
3778 	 * bit is cleared.
3779 	 * We don't have assert to avoid tripping some existing third party
3780 	 * code. The dirty page is moved back to top of the v_page list
3781 	 * after IO is done in pvn_write_done().
3782 	 */
3783 	PP_CLRRM(pp, flag);
3784 
3785 	if ((flag & P_MOD) != 0 && vp != NULL && IS_VMODSORT(vp)) {
3786 
3787 		/*
3788 		 * VMODSORT works by removing write permissions and getting
3789 		 * a fault when a page is made dirty. At this point
3790 		 * we need to remove write permission from all mappings
3791 		 * to this page.
3792 		 */
3793 		hati_page_clrwrt(pp);
3794 	}
3795 }
3796 
3797 /*
3798  *	If flag is specified, returns 0 if attribute is disabled
3799  *	and non zero if enabled.  If flag specifes multiple attributes
3800  *	then returns 0 if ALL attributes are disabled.  This is an advisory
3801  *	call.
3802  */
3803 uint_t
hat_page_getattr(struct page * pp,uint_t flag)3804 hat_page_getattr(struct page *pp, uint_t flag)
3805 {
3806 	return (PP_GETRM(pp, flag));
3807 }
3808 
3809 
3810 /*
3811  * common code used by hat_pageunload() and hment_steal()
3812  */
3813 hment_t *
hati_page_unmap(page_t * pp,htable_t * ht,uint_t entry)3814 hati_page_unmap(page_t *pp, htable_t *ht, uint_t entry)
3815 {
3816 	x86pte_t old_pte;
3817 	pfn_t pfn = pp->p_pagenum;
3818 	hment_t *hm;
3819 
3820 	/*
3821 	 * We need to acquire a hold on the htable in order to
3822 	 * do the invalidate. We know the htable must exist, since
3823 	 * unmap's don't release the htable until after removing any
3824 	 * hment. Having x86_hm_enter() keeps that from proceeding.
3825 	 */
3826 	htable_acquire(ht);
3827 
3828 	/*
3829 	 * Invalidate the PTE and remove the hment.
3830 	 */
3831 	old_pte = x86pte_inval(ht, entry, 0, NULL, B_TRUE);
3832 	if (PTE2PFN(old_pte, ht->ht_level) != pfn) {
3833 		panic("x86pte_inval() failure found PTE = " FMT_PTE
3834 		    " pfn being unmapped is %lx ht=0x%lx entry=0x%x",
3835 		    old_pte, pfn, (uintptr_t)ht, entry);
3836 	}
3837 
3838 	/*
3839 	 * Clean up all the htable information for this mapping
3840 	 */
3841 	ASSERT(ht->ht_valid_cnt > 0);
3842 	HTABLE_DEC(ht->ht_valid_cnt);
3843 	PGCNT_DEC(ht->ht_hat, ht->ht_level);
3844 
3845 	/*
3846 	 * sync ref/mod bits to the page_t
3847 	 */
3848 	if (PTE_GET(old_pte, PT_SOFTWARE) < PT_NOSYNC)
3849 		hati_sync_pte_to_page(pp, old_pte, ht->ht_level);
3850 
3851 	/*
3852 	 * Remove the mapping list entry for this page.
3853 	 */
3854 	hm = hment_remove(pp, ht, entry);
3855 
3856 	/*
3857 	 * drop the mapping list lock so that we might free the
3858 	 * hment and htable.
3859 	 */
3860 	x86_hm_exit(pp);
3861 	htable_release(ht);
3862 	return (hm);
3863 }
3864 
3865 extern int	vpm_enable;
3866 /*
3867  * Unload all translations to a page. If the page is a subpage of a large
3868  * page, the large page mappings are also removed.
3869  *
3870  * The forceflags are unused.
3871  */
3872 
3873 /*ARGSUSED*/
3874 static int
hati_pageunload(struct page * pp,uint_t pg_szcd,uint_t forceflag)3875 hati_pageunload(struct page *pp, uint_t pg_szcd, uint_t forceflag)
3876 {
3877 	page_t		*cur_pp = pp;
3878 	hment_t		*hm;
3879 	hment_t		*prev;
3880 	htable_t	*ht;
3881 	uint_t		entry;
3882 	level_t		level;
3883 
3884 	XPV_DISALLOW_MIGRATE();
3885 
3886 	/*
3887 	 * prevent recursion due to kmem_free()
3888 	 */
3889 	++curthread->t_hatdepth;
3890 	ASSERT(curthread->t_hatdepth < 16);
3891 
3892 	/*
3893 	 * clear the vpm ref.
3894 	 */
3895 	if (vpm_enable) {
3896 		pp->p_vpmref = 0;
3897 	}
3898 	/*
3899 	 * The loop with next_size handles pages with multiple pagesize mappings
3900 	 */
3901 next_size:
3902 	for (;;) {
3903 
3904 		/*
3905 		 * Get a mapping list entry
3906 		 */
3907 		x86_hm_enter(cur_pp);
3908 		for (prev = NULL; ; prev = hm) {
3909 			hm = hment_walk(cur_pp, &ht, &entry, prev);
3910 			if (hm == NULL) {
3911 				x86_hm_exit(cur_pp);
3912 
3913 				/*
3914 				 * If not part of a larger page, we're done.
3915 				 */
3916 				if (cur_pp->p_szc <= pg_szcd) {
3917 					ASSERT(curthread->t_hatdepth > 0);
3918 					--curthread->t_hatdepth;
3919 					XPV_ALLOW_MIGRATE();
3920 					return (0);
3921 				}
3922 
3923 				/*
3924 				 * Else check the next larger page size.
3925 				 * hat_page_demote() may decrease p_szc
3926 				 * but that's ok we'll just take an extra
3927 				 * trip discover there're no larger mappings
3928 				 * and return.
3929 				 */
3930 				++pg_szcd;
3931 				cur_pp = PP_GROUPLEADER(cur_pp, pg_szcd);
3932 				goto next_size;
3933 			}
3934 
3935 			/*
3936 			 * If this mapping size matches, remove it.
3937 			 */
3938 			level = ht->ht_level;
3939 			if (level == pg_szcd)
3940 				break;
3941 		}
3942 
3943 		/*
3944 		 * Remove the mapping list entry for this page.
3945 		 * Note this does the x86_hm_exit() for us.
3946 		 */
3947 		hm = hati_page_unmap(cur_pp, ht, entry);
3948 		if (hm != NULL)
3949 			hment_free(hm);
3950 	}
3951 }
3952 
3953 int
hat_pageunload(struct page * pp,uint_t forceflag)3954 hat_pageunload(struct page *pp, uint_t forceflag)
3955 {
3956 	ASSERT(PAGE_EXCL(pp));
3957 	return (hati_pageunload(pp, 0, forceflag));
3958 }
3959 
3960 /*
3961  * Unload all large mappings to pp and reduce by 1 p_szc field of every large
3962  * page level that included pp.
3963  *
3964  * pp must be locked EXCL. Even though no other constituent pages are locked
3965  * it's legal to unload large mappings to pp because all constituent pages of
3966  * large locked mappings have to be locked SHARED.  therefore if we have EXCL
3967  * lock on one of constituent pages none of the large mappings to pp are
3968  * locked.
3969  *
3970  * Change (always decrease) p_szc field starting from the last constituent
3971  * page and ending with root constituent page so that root's pszc always shows
3972  * the area where hat_page_demote() may be active.
3973  *
3974  * This mechanism is only used for file system pages where it's not always
3975  * possible to get EXCL locks on all constituent pages to demote the size code
3976  * (as is done for anonymous or kernel large pages).
3977  */
3978 void
hat_page_demote(page_t * pp)3979 hat_page_demote(page_t *pp)
3980 {
3981 	uint_t		pszc;
3982 	uint_t		rszc;
3983 	uint_t		szc;
3984 	page_t		*rootpp;
3985 	page_t		*firstpp;
3986 	page_t		*lastpp;
3987 	pgcnt_t		pgcnt;
3988 
3989 	ASSERT(PAGE_EXCL(pp));
3990 	ASSERT(!PP_ISFREE(pp));
3991 	ASSERT(page_szc_lock_assert(pp));
3992 
3993 	if (pp->p_szc == 0)
3994 		return;
3995 
3996 	rootpp = PP_GROUPLEADER(pp, 1);
3997 	(void) hati_pageunload(rootpp, 1, HAT_FORCE_PGUNLOAD);
3998 
3999 	/*
4000 	 * all large mappings to pp are gone
4001 	 * and no new can be setup since pp is locked exclusively.
4002 	 *
4003 	 * Lock the root to make sure there's only one hat_page_demote()
4004 	 * outstanding within the area of this root's pszc.
4005 	 *
4006 	 * Second potential hat_page_demote() is already eliminated by upper
4007 	 * VM layer via page_szc_lock() but we don't rely on it and use our
4008 	 * own locking (so that upper layer locking can be changed without
4009 	 * assumptions that hat depends on upper layer VM to prevent multiple
4010 	 * hat_page_demote() to be issued simultaneously to the same large
4011 	 * page).
4012 	 */
4013 again:
4014 	pszc = pp->p_szc;
4015 	if (pszc == 0)
4016 		return;
4017 	rootpp = PP_GROUPLEADER(pp, pszc);
4018 	x86_hm_enter(rootpp);
4019 	/*
4020 	 * If root's p_szc is different from pszc we raced with another
4021 	 * hat_page_demote().  Drop the lock and try to find the root again.
4022 	 * If root's p_szc is greater than pszc previous hat_page_demote() is
4023 	 * not done yet.  Take and release mlist lock of root's root to wait
4024 	 * for previous hat_page_demote() to complete.
4025 	 */
4026 	if ((rszc = rootpp->p_szc) != pszc) {
4027 		x86_hm_exit(rootpp);
4028 		if (rszc > pszc) {
4029 			/* p_szc of a locked non free page can't increase */
4030 			ASSERT(pp != rootpp);
4031 
4032 			rootpp = PP_GROUPLEADER(rootpp, rszc);
4033 			x86_hm_enter(rootpp);
4034 			x86_hm_exit(rootpp);
4035 		}
4036 		goto again;
4037 	}
4038 	ASSERT(pp->p_szc == pszc);
4039 
4040 	/*
4041 	 * Decrement by 1 p_szc of every constituent page of a region that
4042 	 * covered pp. For example if original szc is 3 it gets changed to 2
4043 	 * everywhere except in region 2 that covered pp. Region 2 that
4044 	 * covered pp gets demoted to 1 everywhere except in region 1 that
4045 	 * covered pp. The region 1 that covered pp is demoted to region
4046 	 * 0. It's done this way because from region 3 we removed level 3
4047 	 * mappings, from region 2 that covered pp we removed level 2 mappings
4048 	 * and from region 1 that covered pp we removed level 1 mappings.  All
4049 	 * changes are done from from high pfn's to low pfn's so that roots
4050 	 * are changed last allowing one to know the largest region where
4051 	 * hat_page_demote() is stil active by only looking at the root page.
4052 	 *
4053 	 * This algorithm is implemented in 2 while loops. First loop changes
4054 	 * p_szc of pages to the right of pp's level 1 region and second
4055 	 * loop changes p_szc of pages of level 1 region that covers pp
4056 	 * and all pages to the left of level 1 region that covers pp.
4057 	 * In the first loop p_szc keeps dropping with every iteration
4058 	 * and in the second loop it keeps increasing with every iteration.
4059 	 *
4060 	 * First loop description: Demote pages to the right of pp outside of
4061 	 * level 1 region that covers pp.  In every iteration of the while
4062 	 * loop below find the last page of szc region and the first page of
4063 	 * (szc - 1) region that is immediately to the right of (szc - 1)
4064 	 * region that covers pp.  From last such page to first such page
4065 	 * change every page's szc to szc - 1. Decrement szc and continue
4066 	 * looping until szc is 1. If pp belongs to the last (szc - 1) region
4067 	 * of szc region skip to the next iteration.
4068 	 */
4069 	szc = pszc;
4070 	while (szc > 1) {
4071 		lastpp = PP_GROUPLEADER(pp, szc);
4072 		pgcnt = page_get_pagecnt(szc);
4073 		lastpp += pgcnt - 1;
4074 		firstpp = PP_GROUPLEADER(pp, (szc - 1));
4075 		pgcnt = page_get_pagecnt(szc - 1);
4076 		if (lastpp - firstpp < pgcnt) {
4077 			szc--;
4078 			continue;
4079 		}
4080 		firstpp += pgcnt;
4081 		while (lastpp != firstpp) {
4082 			ASSERT(lastpp->p_szc == pszc);
4083 			lastpp->p_szc = szc - 1;
4084 			lastpp--;
4085 		}
4086 		firstpp->p_szc = szc - 1;
4087 		szc--;
4088 	}
4089 
4090 	/*
4091 	 * Second loop description:
4092 	 * First iteration changes p_szc to 0 of every
4093 	 * page of level 1 region that covers pp.
4094 	 * Subsequent iterations find last page of szc region
4095 	 * immediately to the left of szc region that covered pp
4096 	 * and first page of (szc + 1) region that covers pp.
4097 	 * From last to first page change p_szc of every page to szc.
4098 	 * Increment szc and continue looping until szc is pszc.
4099 	 * If pp belongs to the fist szc region of (szc + 1) region
4100 	 * skip to the next iteration.
4101 	 *
4102 	 */
4103 	szc = 0;
4104 	while (szc < pszc) {
4105 		firstpp = PP_GROUPLEADER(pp, (szc + 1));
4106 		if (szc == 0) {
4107 			pgcnt = page_get_pagecnt(1);
4108 			lastpp = firstpp + (pgcnt - 1);
4109 		} else {
4110 			lastpp = PP_GROUPLEADER(pp, szc);
4111 			if (firstpp == lastpp) {
4112 				szc++;
4113 				continue;
4114 			}
4115 			lastpp--;
4116 			pgcnt = page_get_pagecnt(szc);
4117 		}
4118 		while (lastpp != firstpp) {
4119 			ASSERT(lastpp->p_szc == pszc);
4120 			lastpp->p_szc = szc;
4121 			lastpp--;
4122 		}
4123 		firstpp->p_szc = szc;
4124 		if (firstpp == rootpp)
4125 			break;
4126 		szc++;
4127 	}
4128 	x86_hm_exit(rootpp);
4129 }
4130 
4131 /*
4132  * get hw stats from hardware into page struct and reset hw stats
4133  * returns attributes of page
4134  * Flags for hat_pagesync, hat_getstat, hat_sync
4135  *
4136  * define	HAT_SYNC_ZERORM		0x01
4137  *
4138  * Additional flags for hat_pagesync
4139  *
4140  * define	HAT_SYNC_STOPON_REF	0x02
4141  * define	HAT_SYNC_STOPON_MOD	0x04
4142  * define	HAT_SYNC_STOPON_RM	0x06
4143  * define	HAT_SYNC_STOPON_SHARED	0x08
4144  */
4145 uint_t
hat_pagesync(struct page * pp,uint_t flags)4146 hat_pagesync(struct page *pp, uint_t flags)
4147 {
4148 	hment_t		*hm = NULL;
4149 	htable_t	*ht;
4150 	uint_t		entry;
4151 	x86pte_t	old, save_old;
4152 	x86pte_t	new;
4153 	uchar_t		nrmbits = P_REF|P_MOD|P_RO;
4154 	extern ulong_t	po_share;
4155 	page_t		*save_pp = pp;
4156 	uint_t		pszc = 0;
4157 
4158 	ASSERT(PAGE_LOCKED(pp) || panicstr);
4159 
4160 	if (PP_ISRO(pp) && (flags & HAT_SYNC_STOPON_MOD))
4161 		return (pp->p_nrm & nrmbits);
4162 
4163 	if ((flags & HAT_SYNC_ZERORM) == 0) {
4164 
4165 		if ((flags & HAT_SYNC_STOPON_REF) != 0 && PP_ISREF(pp))
4166 			return (pp->p_nrm & nrmbits);
4167 
4168 		if ((flags & HAT_SYNC_STOPON_MOD) != 0 && PP_ISMOD(pp))
4169 			return (pp->p_nrm & nrmbits);
4170 
4171 		if ((flags & HAT_SYNC_STOPON_SHARED) != 0 &&
4172 		    hat_page_getshare(pp) > po_share) {
4173 			if (PP_ISRO(pp))
4174 				PP_SETREF(pp);
4175 			return (pp->p_nrm & nrmbits);
4176 		}
4177 	}
4178 
4179 	XPV_DISALLOW_MIGRATE();
4180 next_size:
4181 	/*
4182 	 * walk thru the mapping list syncing (and clearing) ref/mod bits.
4183 	 */
4184 	x86_hm_enter(pp);
4185 	while ((hm = hment_walk(pp, &ht, &entry, hm)) != NULL) {
4186 		if (ht->ht_level < pszc)
4187 			continue;
4188 		old = x86pte_get(ht, entry);
4189 try_again:
4190 
4191 		ASSERT(PTE2PFN(old, ht->ht_level) == pp->p_pagenum);
4192 
4193 		if (PTE_GET(old, PT_REF | PT_MOD) == 0)
4194 			continue;
4195 
4196 		save_old = old;
4197 		if ((flags & HAT_SYNC_ZERORM) != 0) {
4198 
4199 			/*
4200 			 * Need to clear ref or mod bits. Need to demap
4201 			 * to make sure any executing TLBs see cleared bits.
4202 			 */
4203 			new = old;
4204 			PTE_CLR(new, PT_REF | PT_MOD);
4205 			old = hati_update_pte(ht, entry, old, new);
4206 			if (old != 0)
4207 				goto try_again;
4208 
4209 			old = save_old;
4210 		}
4211 
4212 		/*
4213 		 * Sync the PTE
4214 		 */
4215 		if (!(flags & HAT_SYNC_ZERORM) &&
4216 		    PTE_GET(old, PT_SOFTWARE) <= PT_NOSYNC)
4217 			hati_sync_pte_to_page(pp, old, ht->ht_level);
4218 
4219 		/*
4220 		 * can stop short if we found a ref'd or mod'd page
4221 		 */
4222 		if (((flags & HAT_SYNC_STOPON_MOD) && PP_ISMOD(save_pp)) ||
4223 		    ((flags & HAT_SYNC_STOPON_REF) && PP_ISREF(save_pp))) {
4224 			x86_hm_exit(pp);
4225 			goto done;
4226 		}
4227 	}
4228 	x86_hm_exit(pp);
4229 	while (pszc < pp->p_szc) {
4230 		page_t *tpp;
4231 		pszc++;
4232 		tpp = PP_GROUPLEADER(pp, pszc);
4233 		if (pp != tpp) {
4234 			pp = tpp;
4235 			goto next_size;
4236 		}
4237 	}
4238 done:
4239 	XPV_ALLOW_MIGRATE();
4240 	return (save_pp->p_nrm & nrmbits);
4241 }
4242 
4243 /*
4244  * returns approx number of mappings to this pp.  A return of 0 implies
4245  * there are no mappings to the page.
4246  */
4247 ulong_t
hat_page_getshare(page_t * pp)4248 hat_page_getshare(page_t *pp)
4249 {
4250 	uint_t cnt;
4251 	cnt = hment_mapcnt(pp);
4252 	if (vpm_enable && pp->p_vpmref) {
4253 		cnt += 1;
4254 	}
4255 	return (cnt);
4256 }
4257 
4258 /*
4259  * Return 1 the number of mappings exceeds sh_thresh. Return 0
4260  * otherwise.
4261  */
4262 int
hat_page_checkshare(page_t * pp,ulong_t sh_thresh)4263 hat_page_checkshare(page_t *pp, ulong_t sh_thresh)
4264 {
4265 	return (hat_page_getshare(pp) > sh_thresh);
4266 }
4267 
4268 /*
4269  * hat_softlock isn't supported anymore
4270  */
4271 /*ARGSUSED*/
4272 faultcode_t
hat_softlock(hat_t * hat,caddr_t addr,size_t * len,struct page ** page_array,uint_t flags)4273 hat_softlock(
4274 	hat_t *hat,
4275 	caddr_t addr,
4276 	size_t *len,
4277 	struct page **page_array,
4278 	uint_t flags)
4279 {
4280 	return (FC_NOSUPPORT);
4281 }
4282 
4283 
4284 
4285 /*
4286  * Routine to expose supported HAT features to platform independent code.
4287  */
4288 /*ARGSUSED*/
4289 int
hat_supported(enum hat_features feature,void * arg)4290 hat_supported(enum hat_features feature, void *arg)
4291 {
4292 	switch (feature) {
4293 
4294 	case HAT_SHARED_PT:	/* this is really ISM */
4295 		return (1);
4296 
4297 	case HAT_DYNAMIC_ISM_UNMAP:
4298 		return (0);
4299 
4300 	case HAT_VMODSORT:
4301 		return (1);
4302 
4303 	case HAT_SHARED_REGIONS:
4304 		return (0);
4305 
4306 	default:
4307 		panic("hat_supported() - unknown feature");
4308 	}
4309 	return (0);
4310 }
4311 
4312 /*
4313  * Called when a thread is exiting and has been switched to the kernel AS
4314  */
4315 void
hat_thread_exit(kthread_t * thd)4316 hat_thread_exit(kthread_t *thd)
4317 {
4318 	ASSERT(thd->t_procp->p_as == &kas);
4319 	XPV_DISALLOW_MIGRATE();
4320 	hat_switch(thd->t_procp->p_as->a_hat);
4321 	XPV_ALLOW_MIGRATE();
4322 }
4323 
4324 /*
4325  * Setup the given brand new hat structure as the new HAT on this cpu's mmu.
4326  */
4327 /*ARGSUSED*/
4328 void
hat_setup(hat_t * hat,int flags)4329 hat_setup(hat_t *hat, int flags)
4330 {
4331 	XPV_DISALLOW_MIGRATE();
4332 	kpreempt_disable();
4333 
4334 	hat_switch(hat);
4335 
4336 	kpreempt_enable();
4337 	XPV_ALLOW_MIGRATE();
4338 }
4339 
4340 /*
4341  * Prepare for a CPU private mapping for the given address.
4342  *
4343  * The address can only be used from a single CPU and can be remapped
4344  * using hat_mempte_remap().  Return the address of the PTE.
4345  *
4346  * We do the htable_create() if necessary and increment the valid count so
4347  * the htable can't disappear.  We also hat_devload() the page table into
4348  * kernel so that the PTE is quickly accessed.
4349  */
4350 hat_mempte_t
hat_mempte_setup(caddr_t addr)4351 hat_mempte_setup(caddr_t addr)
4352 {
4353 	uintptr_t	va = (uintptr_t)addr;
4354 	htable_t	*ht;
4355 	uint_t		entry;
4356 	x86pte_t	oldpte;
4357 	hat_mempte_t	p;
4358 
4359 	ASSERT(IS_PAGEALIGNED(va));
4360 	ASSERT(!IN_VA_HOLE(va));
4361 	++curthread->t_hatdepth;
4362 	XPV_DISALLOW_MIGRATE();
4363 	ht = htable_getpte(kas.a_hat, va, &entry, &oldpte, 0);
4364 	if (ht == NULL) {
4365 		ht = htable_create(kas.a_hat, va, 0, NULL);
4366 		entry = htable_va2entry(va, ht);
4367 		ASSERT(ht->ht_level == 0);
4368 		oldpte = x86pte_get(ht, entry);
4369 	}
4370 	if (PTE_ISVALID(oldpte))
4371 		panic("hat_mempte_setup(): address already mapped"
4372 		    "ht=%p, entry=%d, pte=" FMT_PTE, (void *)ht, entry, oldpte);
4373 
4374 	/*
4375 	 * increment ht_valid_cnt so that the pagetable can't disappear
4376 	 */
4377 	HTABLE_INC(ht->ht_valid_cnt);
4378 
4379 	/*
4380 	 * return the PTE physical address to the caller.
4381 	 */
4382 	htable_release(ht);
4383 	XPV_ALLOW_MIGRATE();
4384 	p = PT_INDEX_PHYSADDR(pfn_to_pa(ht->ht_pfn), entry);
4385 	--curthread->t_hatdepth;
4386 	return (p);
4387 }
4388 
4389 /*
4390  * Release a CPU private mapping for the given address.
4391  * We decrement the htable valid count so it might be destroyed.
4392  */
4393 /*ARGSUSED1*/
4394 void
hat_mempte_release(caddr_t addr,hat_mempte_t pte_pa)4395 hat_mempte_release(caddr_t addr, hat_mempte_t pte_pa)
4396 {
4397 	htable_t	*ht;
4398 
4399 	XPV_DISALLOW_MIGRATE();
4400 	/*
4401 	 * invalidate any left over mapping and decrement the htable valid count
4402 	 */
4403 #ifdef __xpv
4404 	if (HYPERVISOR_update_va_mapping((uintptr_t)addr, 0,
4405 	    UVMF_INVLPG | UVMF_LOCAL))
4406 		panic("HYPERVISOR_update_va_mapping() failed");
4407 #else
4408 	{
4409 		x86pte_t *pteptr;
4410 
4411 		pteptr = x86pte_mapin(mmu_btop(pte_pa),
4412 		    (pte_pa & MMU_PAGEOFFSET) >> mmu.pte_size_shift, NULL);
4413 		if (mmu.pae_hat)
4414 			*pteptr = 0;
4415 		else
4416 			*(x86pte32_t *)pteptr = 0;
4417 		mmu_flush_tlb_kpage((uintptr_t)addr);
4418 		x86pte_mapout();
4419 	}
4420 #endif
4421 
4422 	ht = htable_getpte(kas.a_hat, ALIGN2PAGE(addr), NULL, NULL, 0);
4423 	if (ht == NULL)
4424 		panic("hat_mempte_release(): invalid address");
4425 	ASSERT(ht->ht_level == 0);
4426 	HTABLE_DEC(ht->ht_valid_cnt);
4427 	htable_release(ht);
4428 	XPV_ALLOW_MIGRATE();
4429 }
4430 
4431 /*
4432  * Apply a temporary CPU private mapping to a page. We flush the TLB only
4433  * on this CPU, so this ought to have been called with preemption disabled.
4434  */
4435 void
hat_mempte_remap(pfn_t pfn,caddr_t addr,hat_mempte_t pte_pa,uint_t attr,uint_t flags)4436 hat_mempte_remap(
4437 	pfn_t		pfn,
4438 	caddr_t		addr,
4439 	hat_mempte_t	pte_pa,
4440 	uint_t		attr,
4441 	uint_t		flags)
4442 {
4443 	uintptr_t	va = (uintptr_t)addr;
4444 	x86pte_t	pte;
4445 
4446 	/*
4447 	 * Remap the given PTE to the new page's PFN. Invalidate only
4448 	 * on this CPU.
4449 	 */
4450 #ifdef DEBUG
4451 	htable_t	*ht;
4452 	uint_t		entry;
4453 
4454 	ASSERT(IS_PAGEALIGNED(va));
4455 	ASSERT(!IN_VA_HOLE(va));
4456 	ht = htable_getpte(kas.a_hat, va, &entry, NULL, 0);
4457 	ASSERT(ht != NULL);
4458 	ASSERT(ht->ht_level == 0);
4459 	ASSERT(ht->ht_valid_cnt > 0);
4460 	ASSERT(ht->ht_pfn == mmu_btop(pte_pa));
4461 	htable_release(ht);
4462 #endif
4463 	XPV_DISALLOW_MIGRATE();
4464 	pte = hati_mkpte(pfn, attr, 0, flags);
4465 #ifdef __xpv
4466 	if (HYPERVISOR_update_va_mapping(va, pte, UVMF_INVLPG | UVMF_LOCAL))
4467 		panic("HYPERVISOR_update_va_mapping() failed");
4468 #else
4469 	{
4470 		x86pte_t *pteptr;
4471 
4472 		pteptr = x86pte_mapin(mmu_btop(pte_pa),
4473 		    (pte_pa & MMU_PAGEOFFSET) >> mmu.pte_size_shift, NULL);
4474 		if (mmu.pae_hat)
4475 			*(x86pte_t *)pteptr = pte;
4476 		else
4477 			*(x86pte32_t *)pteptr = (x86pte32_t)pte;
4478 		mmu_flush_tlb_kpage((uintptr_t)addr);
4479 		x86pte_mapout();
4480 	}
4481 #endif
4482 	XPV_ALLOW_MIGRATE();
4483 }
4484 
4485 
4486 
4487 /*
4488  * Hat locking functions
4489  * XXX - these two functions are currently being used by hatstats
4490  *	they can be removed by using a per-as mutex for hatstats.
4491  */
4492 void
hat_enter(hat_t * hat)4493 hat_enter(hat_t *hat)
4494 {
4495 	mutex_enter(&hat->hat_mutex);
4496 }
4497 
4498 void
hat_exit(hat_t * hat)4499 hat_exit(hat_t *hat)
4500 {
4501 	mutex_exit(&hat->hat_mutex);
4502 }
4503 
4504 /*
4505  * HAT part of cpu initialization.
4506  */
4507 void
hat_cpu_online(struct cpu * cpup)4508 hat_cpu_online(struct cpu *cpup)
4509 {
4510 	if (cpup != CPU) {
4511 		x86pte_cpu_init(cpup);
4512 		hat_pcp_setup(cpup);
4513 	}
4514 	CPUSET_ATOMIC_ADD(khat_cpuset, cpup->cpu_id);
4515 }
4516 
4517 /*
4518  * HAT part of cpu deletion.
4519  * (currently, we only call this after the cpu is safely passivated.)
4520  */
4521 void
hat_cpu_offline(struct cpu * cpup)4522 hat_cpu_offline(struct cpu *cpup)
4523 {
4524 	ASSERT(cpup != CPU);
4525 
4526 	CPUSET_ATOMIC_DEL(khat_cpuset, cpup->cpu_id);
4527 	hat_pcp_teardown(cpup);
4528 	x86pte_cpu_fini(cpup);
4529 }
4530 
4531 /*
4532  * Function called after all CPUs are brought online.
4533  * Used to remove low address boot mappings.
4534  */
4535 void
clear_boot_mappings(uintptr_t low,uintptr_t high)4536 clear_boot_mappings(uintptr_t low, uintptr_t high)
4537 {
4538 	uintptr_t vaddr = low;
4539 	htable_t *ht = NULL;
4540 	level_t level;
4541 	uint_t entry;
4542 	x86pte_t pte;
4543 
4544 	/*
4545 	 * On 1st CPU we can unload the prom mappings, basically we blow away
4546 	 * all virtual mappings under _userlimit.
4547 	 */
4548 	while (vaddr < high) {
4549 		pte = htable_walk(kas.a_hat, &ht, &vaddr, high);
4550 		if (ht == NULL)
4551 			break;
4552 
4553 		level = ht->ht_level;
4554 		entry = htable_va2entry(vaddr, ht);
4555 		ASSERT(level <= mmu.max_page_level);
4556 		ASSERT(PTE_ISPAGE(pte, level));
4557 
4558 		/*
4559 		 * Unload the mapping from the page tables.
4560 		 */
4561 		(void) x86pte_inval(ht, entry, 0, NULL, B_TRUE);
4562 		ASSERT(ht->ht_valid_cnt > 0);
4563 		HTABLE_DEC(ht->ht_valid_cnt);
4564 		PGCNT_DEC(ht->ht_hat, ht->ht_level);
4565 
4566 		vaddr += LEVEL_SIZE(ht->ht_level);
4567 	}
4568 	if (ht)
4569 		htable_release(ht);
4570 }
4571 
4572 /*
4573  * Atomically update a new translation for a single page.  If the
4574  * currently installed PTE doesn't match the value we expect to find,
4575  * it's not updated and we return the PTE we found.
4576  *
4577  * If activating nosync or NOWRITE and the page was modified we need to sync
4578  * with the page_t. Also sync with page_t if clearing ref/mod bits.
4579  */
4580 static x86pte_t
hati_update_pte(htable_t * ht,uint_t entry,x86pte_t expected,x86pte_t new)4581 hati_update_pte(htable_t *ht, uint_t entry, x86pte_t expected, x86pte_t new)
4582 {
4583 	page_t		*pp;
4584 	uint_t		rm = 0;
4585 	x86pte_t	replaced;
4586 
4587 	if (PTE_GET(expected, PT_SOFTWARE) < PT_NOSYNC &&
4588 	    PTE_GET(expected, PT_MOD | PT_REF) &&
4589 	    (PTE_GET(new, PT_NOSYNC) || !PTE_GET(new, PT_WRITABLE) ||
4590 	    !PTE_GET(new, PT_MOD | PT_REF))) {
4591 
4592 		ASSERT(!pfn_is_foreign(PTE2PFN(expected, ht->ht_level)));
4593 		pp = page_numtopp_nolock(PTE2PFN(expected, ht->ht_level));
4594 		ASSERT(pp != NULL);
4595 		if (PTE_GET(expected, PT_MOD))
4596 			rm |= P_MOD;
4597 		if (PTE_GET(expected, PT_REF))
4598 			rm |= P_REF;
4599 		PTE_CLR(new, PT_MOD | PT_REF);
4600 	}
4601 
4602 	replaced = x86pte_update(ht, entry, expected, new);
4603 	if (replaced != expected)
4604 		return (replaced);
4605 
4606 	if (rm) {
4607 		/*
4608 		 * sync to all constituent pages of a large page
4609 		 */
4610 		pgcnt_t pgcnt = page_get_pagecnt(ht->ht_level);
4611 		ASSERT(IS_P2ALIGNED(pp->p_pagenum, pgcnt));
4612 		while (pgcnt-- > 0) {
4613 			/*
4614 			 * hat_page_demote() can't decrease
4615 			 * pszc below this mapping size
4616 			 * since large mapping existed after we
4617 			 * took mlist lock.
4618 			 */
4619 			ASSERT(pp->p_szc >= ht->ht_level);
4620 			hat_page_setattr(pp, rm);
4621 			++pp;
4622 		}
4623 	}
4624 
4625 	return (0);
4626 }
4627 
4628 /* ARGSUSED */
4629 void
hat_join_srd(struct hat * hat,vnode_t * evp)4630 hat_join_srd(struct hat *hat, vnode_t *evp)
4631 {
4632 }
4633 
4634 /* ARGSUSED */
4635 hat_region_cookie_t
hat_join_region(struct hat * hat,caddr_t r_saddr,size_t r_size,void * r_obj,u_offset_t r_objoff,uchar_t r_perm,uchar_t r_pgszc,hat_rgn_cb_func_t r_cb_function,uint_t flags)4636 hat_join_region(struct hat *hat,
4637     caddr_t r_saddr,
4638     size_t r_size,
4639     void *r_obj,
4640     u_offset_t r_objoff,
4641     uchar_t r_perm,
4642     uchar_t r_pgszc,
4643     hat_rgn_cb_func_t r_cb_function,
4644     uint_t flags)
4645 {
4646 	panic("No shared region support on x86");
4647 	return (HAT_INVALID_REGION_COOKIE);
4648 }
4649 
4650 /* ARGSUSED */
4651 void
hat_leave_region(struct hat * hat,hat_region_cookie_t rcookie,uint_t flags)4652 hat_leave_region(struct hat *hat, hat_region_cookie_t rcookie, uint_t flags)
4653 {
4654 	panic("No shared region support on x86");
4655 }
4656 
4657 /* ARGSUSED */
4658 void
hat_dup_region(struct hat * hat,hat_region_cookie_t rcookie)4659 hat_dup_region(struct hat *hat, hat_region_cookie_t rcookie)
4660 {
4661 	panic("No shared region support on x86");
4662 }
4663 
4664 
4665 /*
4666  * Kernel Physical Mapping (kpm) facility
4667  *
4668  * Most of the routines needed to support segkpm are almost no-ops on the
4669  * x86 platform.  We map in the entire segment when it is created and leave
4670  * it mapped in, so there is no additional work required to set up and tear
4671  * down individual mappings.  All of these routines were created to support
4672  * SPARC platforms that have to avoid aliasing in their virtually indexed
4673  * caches.
4674  *
4675  * Most of the routines have sanity checks in them (e.g. verifying that the
4676  * passed-in page is locked).  We don't actually care about most of these
4677  * checks on x86, but we leave them in place to identify problems in the
4678  * upper levels.
4679  */
4680 
4681 /*
4682  * Map in a locked page and return the vaddr.
4683  */
4684 /*ARGSUSED*/
4685 caddr_t
hat_kpm_mapin(struct page * pp,struct kpme * kpme)4686 hat_kpm_mapin(struct page *pp, struct kpme *kpme)
4687 {
4688 	caddr_t		vaddr;
4689 
4690 #ifdef DEBUG
4691 	if (kpm_enable == 0) {
4692 		cmn_err(CE_WARN, "hat_kpm_mapin: kpm_enable not set\n");
4693 		return ((caddr_t)NULL);
4694 	}
4695 
4696 	if (pp == NULL || PAGE_LOCKED(pp) == 0) {
4697 		cmn_err(CE_WARN, "hat_kpm_mapin: pp zero or not locked\n");
4698 		return ((caddr_t)NULL);
4699 	}
4700 #endif
4701 
4702 	vaddr = hat_kpm_page2va(pp, 1);
4703 
4704 	return (vaddr);
4705 }
4706 
4707 /*
4708  * Mapout a locked page.
4709  */
4710 /*ARGSUSED*/
4711 void
hat_kpm_mapout(struct page * pp,struct kpme * kpme,caddr_t vaddr)4712 hat_kpm_mapout(struct page *pp, struct kpme *kpme, caddr_t vaddr)
4713 {
4714 #ifdef DEBUG
4715 	if (kpm_enable == 0) {
4716 		cmn_err(CE_WARN, "hat_kpm_mapout: kpm_enable not set\n");
4717 		return;
4718 	}
4719 
4720 	if (IS_KPM_ADDR(vaddr) == 0) {
4721 		cmn_err(CE_WARN, "hat_kpm_mapout: no kpm address\n");
4722 		return;
4723 	}
4724 
4725 	if (pp == NULL || PAGE_LOCKED(pp) == 0) {
4726 		cmn_err(CE_WARN, "hat_kpm_mapout: page zero or not locked\n");
4727 		return;
4728 	}
4729 #endif
4730 }
4731 
4732 /*
4733  * hat_kpm_mapin_pfn is used to obtain a kpm mapping for physical
4734  * memory addresses that are not described by a page_t.  It can
4735  * also be used for normal pages that are not locked, but beware
4736  * this is dangerous - no locking is performed, so the identity of
4737  * the page could change.  hat_kpm_mapin_pfn is not supported when
4738  * vac_colors > 1, because the chosen va depends on the page identity,
4739  * which could change.
4740  * The caller must only pass pfn's for valid physical addresses; violation
4741  * of this rule will cause panic.
4742  */
4743 caddr_t
hat_kpm_mapin_pfn(pfn_t pfn)4744 hat_kpm_mapin_pfn(pfn_t pfn)
4745 {
4746 	caddr_t paddr, vaddr;
4747 
4748 	if (kpm_enable == 0)
4749 		return ((caddr_t)NULL);
4750 
4751 	paddr = (caddr_t)ptob(pfn);
4752 	vaddr = (uintptr_t)kpm_vbase + paddr;
4753 
4754 	return ((caddr_t)vaddr);
4755 }
4756 
4757 /*ARGSUSED*/
4758 void
hat_kpm_mapout_pfn(pfn_t pfn)4759 hat_kpm_mapout_pfn(pfn_t pfn)
4760 {
4761 	/* empty */
4762 }
4763 
4764 /*
4765  * Return the kpm virtual address for a specific pfn
4766  */
4767 caddr_t
hat_kpm_pfn2va(pfn_t pfn)4768 hat_kpm_pfn2va(pfn_t pfn)
4769 {
4770 	uintptr_t vaddr = (uintptr_t)kpm_vbase + mmu_ptob(pfn);
4771 
4772 	ASSERT(!pfn_is_foreign(pfn));
4773 	return ((caddr_t)vaddr);
4774 }
4775 
4776 /*
4777  * Return the kpm virtual address for the page at pp.
4778  */
4779 /*ARGSUSED*/
4780 caddr_t
hat_kpm_page2va(struct page * pp,int checkswap)4781 hat_kpm_page2va(struct page *pp, int checkswap)
4782 {
4783 	return (hat_kpm_pfn2va(pp->p_pagenum));
4784 }
4785 
4786 /*
4787  * Return the page frame number for the kpm virtual address vaddr.
4788  */
4789 pfn_t
hat_kpm_va2pfn(caddr_t vaddr)4790 hat_kpm_va2pfn(caddr_t vaddr)
4791 {
4792 	pfn_t		pfn;
4793 
4794 	ASSERT(IS_KPM_ADDR(vaddr));
4795 
4796 	pfn = (pfn_t)btop(vaddr - kpm_vbase);
4797 
4798 	return (pfn);
4799 }
4800 
4801 
4802 /*
4803  * Return the page for the kpm virtual address vaddr.
4804  */
4805 page_t *
hat_kpm_vaddr2page(caddr_t vaddr)4806 hat_kpm_vaddr2page(caddr_t vaddr)
4807 {
4808 	pfn_t		pfn;
4809 
4810 	ASSERT(IS_KPM_ADDR(vaddr));
4811 
4812 	pfn = hat_kpm_va2pfn(vaddr);
4813 
4814 	return (page_numtopp_nolock(pfn));
4815 }
4816 
4817 /*
4818  * hat_kpm_fault is called from segkpm_fault when we take a page fault on a
4819  * KPM page.  This should never happen on x86
4820  */
4821 int
hat_kpm_fault(hat_t * hat,caddr_t vaddr)4822 hat_kpm_fault(hat_t *hat, caddr_t vaddr)
4823 {
4824 	panic("pagefault in seg_kpm.  hat: 0x%p  vaddr: 0x%p",
4825 	    (void *)hat, (void *)vaddr);
4826 
4827 	return (0);
4828 }
4829 
4830 /*ARGSUSED*/
4831 void
hat_kpm_mseghash_clear(int nentries)4832 hat_kpm_mseghash_clear(int nentries)
4833 {}
4834 
4835 /*ARGSUSED*/
4836 void
hat_kpm_mseghash_update(pgcnt_t inx,struct memseg * msp)4837 hat_kpm_mseghash_update(pgcnt_t inx, struct memseg *msp)
4838 {}
4839 
4840 #ifndef	__xpv
4841 void
hat_kpm_addmem_mseg_update(struct memseg * msp,pgcnt_t nkpmpgs,offset_t kpm_pages_off)4842 hat_kpm_addmem_mseg_update(struct memseg *msp, pgcnt_t nkpmpgs,
4843     offset_t kpm_pages_off)
4844 {
4845 	_NOTE(ARGUNUSED(nkpmpgs, kpm_pages_off));
4846 	pfn_t base, end;
4847 
4848 	/*
4849 	 * kphysm_add_memory_dynamic() does not set nkpmpgs
4850 	 * when page_t memory is externally allocated.  That
4851 	 * code must properly calculate nkpmpgs in all cases
4852 	 * if nkpmpgs needs to be used at some point.
4853 	 */
4854 
4855 	/*
4856 	 * The meta (page_t) pages for dynamically added memory are allocated
4857 	 * either from the incoming memory itself or from existing memory.
4858 	 * In the former case the base of the incoming pages will be different
4859 	 * than the base of the dynamic segment so call memseg_get_start() to
4860 	 * get the actual base of the incoming memory for each case.
4861 	 */
4862 
4863 	base = memseg_get_start(msp);
4864 	end = msp->pages_end;
4865 
4866 	hat_devload(kas.a_hat, kpm_vbase + mmu_ptob(base),
4867 	    mmu_ptob(end - base), base, PROT_READ | PROT_WRITE,
4868 	    HAT_LOAD | HAT_LOAD_LOCK | HAT_LOAD_NOCONSIST);
4869 }
4870 
4871 void
hat_kpm_addmem_mseg_insert(struct memseg * msp)4872 hat_kpm_addmem_mseg_insert(struct memseg *msp)
4873 {
4874 	_NOTE(ARGUNUSED(msp));
4875 }
4876 
4877 void
hat_kpm_addmem_memsegs_update(struct memseg * msp)4878 hat_kpm_addmem_memsegs_update(struct memseg *msp)
4879 {
4880 	_NOTE(ARGUNUSED(msp));
4881 }
4882 
4883 /*
4884  * Return end of metadata for an already setup memseg.
4885  * X86 platforms don't need per-page meta data to support kpm.
4886  */
4887 caddr_t
hat_kpm_mseg_reuse(struct memseg * msp)4888 hat_kpm_mseg_reuse(struct memseg *msp)
4889 {
4890 	return ((caddr_t)msp->epages);
4891 }
4892 
4893 void
hat_kpm_delmem_mseg_update(struct memseg * msp,struct memseg ** mspp)4894 hat_kpm_delmem_mseg_update(struct memseg *msp, struct memseg **mspp)
4895 {
4896 	_NOTE(ARGUNUSED(msp, mspp));
4897 	ASSERT(0);
4898 }
4899 
4900 void
hat_kpm_split_mseg_update(struct memseg * msp,struct memseg ** mspp,struct memseg * lo,struct memseg * mid,struct memseg * hi)4901 hat_kpm_split_mseg_update(struct memseg *msp, struct memseg **mspp,
4902     struct memseg *lo, struct memseg *mid, struct memseg *hi)
4903 {
4904 	_NOTE(ARGUNUSED(msp, mspp, lo, mid, hi));
4905 	ASSERT(0);
4906 }
4907 
4908 /*
4909  * Walk the memsegs chain, applying func to each memseg span.
4910  */
4911 void
hat_kpm_walk(void (* func)(void *,void *,size_t),void * arg)4912 hat_kpm_walk(void (*func)(void *, void *, size_t), void *arg)
4913 {
4914 	pfn_t	pbase, pend;
4915 	void	*base;
4916 	size_t	size;
4917 	struct memseg *msp;
4918 
4919 	for (msp = memsegs; msp; msp = msp->next) {
4920 		pbase = msp->pages_base;
4921 		pend = msp->pages_end;
4922 		base = ptob(pbase) + kpm_vbase;
4923 		size = ptob(pend - pbase);
4924 		func(arg, base, size);
4925 	}
4926 }
4927 
4928 #else	/* __xpv */
4929 
4930 /*
4931  * There are specific Hypervisor calls to establish and remove mappings
4932  * to grant table references and the privcmd driver. We have to ensure
4933  * that a page table actually exists.
4934  */
4935 void
hat_prepare_mapping(hat_t * hat,caddr_t addr,uint64_t * pte_ma)4936 hat_prepare_mapping(hat_t *hat, caddr_t addr, uint64_t *pte_ma)
4937 {
4938 	maddr_t base_ma;
4939 	htable_t *ht;
4940 	uint_t entry;
4941 
4942 	ASSERT(IS_P2ALIGNED((uintptr_t)addr, MMU_PAGESIZE));
4943 	XPV_DISALLOW_MIGRATE();
4944 	ht = htable_create(hat, (uintptr_t)addr, 0, NULL);
4945 
4946 	/*
4947 	 * if an address for pte_ma is passed in, return the MA of the pte
4948 	 * for this specific address.  This address is only valid as long
4949 	 * as the htable stays locked.
4950 	 */
4951 	if (pte_ma != NULL) {
4952 		entry = htable_va2entry((uintptr_t)addr, ht);
4953 		base_ma = pa_to_ma(ptob(ht->ht_pfn));
4954 		*pte_ma = base_ma + (entry << mmu.pte_size_shift);
4955 	}
4956 	XPV_ALLOW_MIGRATE();
4957 }
4958 
4959 void
hat_release_mapping(hat_t * hat,caddr_t addr)4960 hat_release_mapping(hat_t *hat, caddr_t addr)
4961 {
4962 	htable_t *ht;
4963 
4964 	ASSERT(IS_P2ALIGNED((uintptr_t)addr, MMU_PAGESIZE));
4965 	XPV_DISALLOW_MIGRATE();
4966 	ht = htable_lookup(hat, (uintptr_t)addr, 0);
4967 	ASSERT(ht != NULL);
4968 	ASSERT(ht->ht_busy >= 2);
4969 	htable_release(ht);
4970 	htable_release(ht);
4971 	XPV_ALLOW_MIGRATE();
4972 }
4973 #endif	/* __xpv */
4974 
4975 /*
4976  * Helper function to punch in a mapping that we need with the specified
4977  * attributes.
4978  */
4979 void
hati_cpu_punchin(cpu_t * cpu,uintptr_t va,uint_t attrs)4980 hati_cpu_punchin(cpu_t *cpu, uintptr_t va, uint_t attrs)
4981 {
4982 	int ret;
4983 	pfn_t pfn;
4984 	hat_t *cpu_hat = cpu->cpu_hat_info->hci_user_hat;
4985 
4986 	ASSERT3S(kpti_enable, ==, 1);
4987 	ASSERT3P(cpu_hat, !=, NULL);
4988 	ASSERT3U(cpu_hat->hat_flags & HAT_PCP, ==, HAT_PCP);
4989 	ASSERT3U(va & MMU_PAGEOFFSET, ==, 0);
4990 
4991 	pfn = hat_getpfnum(kas.a_hat, (caddr_t)va);
4992 	VERIFY3U(pfn, !=, PFN_INVALID);
4993 
4994 	/*
4995 	 * We purposefully don't try to find the page_t. This means that this
4996 	 * will be marked PT_NOCONSIST; however, given that this is pretty much
4997 	 * a static mapping that we're using we should be relatively OK.
4998 	 */
4999 	attrs |= HAT_STORECACHING_OK;
5000 	ret = hati_load_common(cpu_hat, va, NULL, attrs, 0, 0, pfn);
5001 	VERIFY3S(ret, ==, 0);
5002 }
5003