Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0 */
2 : #ifndef _LINUX_MMU_NOTIFIER_H
3 : #define _LINUX_MMU_NOTIFIER_H
4 :
5 : #include <linux/list.h>
6 : #include <linux/spinlock.h>
7 : #include <linux/mm_types.h>
8 : #include <linux/mmap_lock.h>
9 : #include <linux/srcu.h>
10 : #include <linux/interval_tree.h>
11 :
12 : struct mmu_notifier_subscriptions;
13 : struct mmu_notifier;
14 : struct mmu_notifier_range;
15 : struct mmu_interval_notifier;
16 :
17 : /**
18 : * enum mmu_notifier_event - reason for the mmu notifier callback
19 : * @MMU_NOTIFY_UNMAP: either munmap() that unmap the range or a mremap() that
20 : * move the range
21 : *
22 : * @MMU_NOTIFY_CLEAR: clear page table entry (many reasons for this like
23 : * madvise() or replacing a page by another one, ...).
24 : *
25 : * @MMU_NOTIFY_PROTECTION_VMA: update is due to protection change for the range
26 : * ie using the vma access permission (vm_page_prot) to update the whole range
27 : * is enough no need to inspect changes to the CPU page table (mprotect()
28 : * syscall)
29 : *
30 : * @MMU_NOTIFY_PROTECTION_PAGE: update is due to change in read/write flag for
31 : * pages in the range so to mirror those changes the user must inspect the CPU
32 : * page table (from the end callback).
33 : *
34 : * @MMU_NOTIFY_SOFT_DIRTY: soft dirty accounting (still same page and same
35 : * access flags). User should soft dirty the page in the end callback to make
36 : * sure that anyone relying on soft dirtyness catch pages that might be written
37 : * through non CPU mappings.
38 : *
39 : * @MMU_NOTIFY_RELEASE: used during mmu_interval_notifier invalidate to signal
40 : * that the mm refcount is zero and the range is no longer accessible.
41 : *
42 : * @MMU_NOTIFY_MIGRATE: used during migrate_vma_collect() invalidate to signal
43 : * a device driver to possibly ignore the invalidation if the
44 : * migrate_pgmap_owner field matches the driver's device private pgmap owner.
45 : */
46 : enum mmu_notifier_event {
47 : MMU_NOTIFY_UNMAP = 0,
48 : MMU_NOTIFY_CLEAR,
49 : MMU_NOTIFY_PROTECTION_VMA,
50 : MMU_NOTIFY_PROTECTION_PAGE,
51 : MMU_NOTIFY_SOFT_DIRTY,
52 : MMU_NOTIFY_RELEASE,
53 : MMU_NOTIFY_MIGRATE,
54 : };
55 :
56 : #define MMU_NOTIFIER_RANGE_BLOCKABLE (1 << 0)
57 :
58 : struct mmu_notifier_ops {
59 : /*
60 : * Called either by mmu_notifier_unregister or when the mm is
61 : * being destroyed by exit_mmap, always before all pages are
62 : * freed. This can run concurrently with other mmu notifier
63 : * methods (the ones invoked outside the mm context) and it
64 : * should tear down all secondary mmu mappings and freeze the
65 : * secondary mmu. If this method isn't implemented you've to
66 : * be sure that nothing could possibly write to the pages
67 : * through the secondary mmu by the time the last thread with
68 : * tsk->mm == mm exits.
69 : *
70 : * As side note: the pages freed after ->release returns could
71 : * be immediately reallocated by the gart at an alias physical
72 : * address with a different cache model, so if ->release isn't
73 : * implemented because all _software_ driven memory accesses
74 : * through the secondary mmu are terminated by the time the
75 : * last thread of this mm quits, you've also to be sure that
76 : * speculative _hardware_ operations can't allocate dirty
77 : * cachelines in the cpu that could not be snooped and made
78 : * coherent with the other read and write operations happening
79 : * through the gart alias address, so leading to memory
80 : * corruption.
81 : */
82 : void (*release)(struct mmu_notifier *subscription,
83 : struct mm_struct *mm);
84 :
85 : /*
86 : * clear_flush_young is called after the VM is
87 : * test-and-clearing the young/accessed bitflag in the
88 : * pte. This way the VM will provide proper aging to the
89 : * accesses to the page through the secondary MMUs and not
90 : * only to the ones through the Linux pte.
91 : * Start-end is necessary in case the secondary MMU is mapping the page
92 : * at a smaller granularity than the primary MMU.
93 : */
94 : int (*clear_flush_young)(struct mmu_notifier *subscription,
95 : struct mm_struct *mm,
96 : unsigned long start,
97 : unsigned long end);
98 :
99 : /*
100 : * clear_young is a lightweight version of clear_flush_young. Like the
101 : * latter, it is supposed to test-and-clear the young/accessed bitflag
102 : * in the secondary pte, but it may omit flushing the secondary tlb.
103 : */
104 : int (*clear_young)(struct mmu_notifier *subscription,
105 : struct mm_struct *mm,
106 : unsigned long start,
107 : unsigned long end);
108 :
109 : /*
110 : * test_young is called to check the young/accessed bitflag in
111 : * the secondary pte. This is used to know if the page is
112 : * frequently used without actually clearing the flag or tearing
113 : * down the secondary mapping on the page.
114 : */
115 : int (*test_young)(struct mmu_notifier *subscription,
116 : struct mm_struct *mm,
117 : unsigned long address);
118 :
119 : /*
120 : * change_pte is called in cases that pte mapping to page is changed:
121 : * for example, when ksm remaps pte to point to a new shared page.
122 : */
123 : void (*change_pte)(struct mmu_notifier *subscription,
124 : struct mm_struct *mm,
125 : unsigned long address,
126 : pte_t pte);
127 :
128 : /*
129 : * invalidate_range_start() and invalidate_range_end() must be
130 : * paired and are called only when the mmap_lock and/or the
131 : * locks protecting the reverse maps are held. If the subsystem
132 : * can't guarantee that no additional references are taken to
133 : * the pages in the range, it has to implement the
134 : * invalidate_range() notifier to remove any references taken
135 : * after invalidate_range_start().
136 : *
137 : * Invalidation of multiple concurrent ranges may be
138 : * optionally permitted by the driver. Either way the
139 : * establishment of sptes is forbidden in the range passed to
140 : * invalidate_range_begin/end for the whole duration of the
141 : * invalidate_range_begin/end critical section.
142 : *
143 : * invalidate_range_start() is called when all pages in the
144 : * range are still mapped and have at least a refcount of one.
145 : *
146 : * invalidate_range_end() is called when all pages in the
147 : * range have been unmapped and the pages have been freed by
148 : * the VM.
149 : *
150 : * The VM will remove the page table entries and potentially
151 : * the page between invalidate_range_start() and
152 : * invalidate_range_end(). If the page must not be freed
153 : * because of pending I/O or other circumstances then the
154 : * invalidate_range_start() callback (or the initial mapping
155 : * by the driver) must make sure that the refcount is kept
156 : * elevated.
157 : *
158 : * If the driver increases the refcount when the pages are
159 : * initially mapped into an address space then either
160 : * invalidate_range_start() or invalidate_range_end() may
161 : * decrease the refcount. If the refcount is decreased on
162 : * invalidate_range_start() then the VM can free pages as page
163 : * table entries are removed. If the refcount is only
164 : * droppped on invalidate_range_end() then the driver itself
165 : * will drop the last refcount but it must take care to flush
166 : * any secondary tlb before doing the final free on the
167 : * page. Pages will no longer be referenced by the linux
168 : * address space but may still be referenced by sptes until
169 : * the last refcount is dropped.
170 : *
171 : * If blockable argument is set to false then the callback cannot
172 : * sleep and has to return with -EAGAIN. 0 should be returned
173 : * otherwise. Please note that if invalidate_range_start approves
174 : * a non-blocking behavior then the same applies to
175 : * invalidate_range_end.
176 : *
177 : */
178 : int (*invalidate_range_start)(struct mmu_notifier *subscription,
179 : const struct mmu_notifier_range *range);
180 : void (*invalidate_range_end)(struct mmu_notifier *subscription,
181 : const struct mmu_notifier_range *range);
182 :
183 : /*
184 : * invalidate_range() is either called between
185 : * invalidate_range_start() and invalidate_range_end() when the
186 : * VM has to free pages that where unmapped, but before the
187 : * pages are actually freed, or outside of _start()/_end() when
188 : * a (remote) TLB is necessary.
189 : *
190 : * If invalidate_range() is used to manage a non-CPU TLB with
191 : * shared page-tables, it not necessary to implement the
192 : * invalidate_range_start()/end() notifiers, as
193 : * invalidate_range() alread catches the points in time when an
194 : * external TLB range needs to be flushed. For more in depth
195 : * discussion on this see Documentation/vm/mmu_notifier.rst
196 : *
197 : * Note that this function might be called with just a sub-range
198 : * of what was passed to invalidate_range_start()/end(), if
199 : * called between those functions.
200 : */
201 : void (*invalidate_range)(struct mmu_notifier *subscription,
202 : struct mm_struct *mm,
203 : unsigned long start,
204 : unsigned long end);
205 :
206 : /*
207 : * These callbacks are used with the get/put interface to manage the
208 : * lifetime of the mmu_notifier memory. alloc_notifier() returns a new
209 : * notifier for use with the mm.
210 : *
211 : * free_notifier() is only called after the mmu_notifier has been
212 : * fully put, calls to any ops callback are prevented and no ops
213 : * callbacks are currently running. It is called from a SRCU callback
214 : * and cannot sleep.
215 : */
216 : struct mmu_notifier *(*alloc_notifier)(struct mm_struct *mm);
217 : void (*free_notifier)(struct mmu_notifier *subscription);
218 : };
219 :
220 : /*
221 : * The notifier chains are protected by mmap_lock and/or the reverse map
222 : * semaphores. Notifier chains are only changed when all reverse maps and
223 : * the mmap_lock locks are taken.
224 : *
225 : * Therefore notifier chains can only be traversed when either
226 : *
227 : * 1. mmap_lock is held.
228 : * 2. One of the reverse map locks is held (i_mmap_rwsem or anon_vma->rwsem).
229 : * 3. No other concurrent thread can access the list (release)
230 : */
231 : struct mmu_notifier {
232 : struct hlist_node hlist;
233 : const struct mmu_notifier_ops *ops;
234 : struct mm_struct *mm;
235 : struct rcu_head rcu;
236 : unsigned int users;
237 : };
238 :
239 : /**
240 : * struct mmu_interval_notifier_ops
241 : * @invalidate: Upon return the caller must stop using any SPTEs within this
242 : * range. This function can sleep. Return false only if sleeping
243 : * was required but mmu_notifier_range_blockable(range) is false.
244 : */
245 : struct mmu_interval_notifier_ops {
246 : bool (*invalidate)(struct mmu_interval_notifier *interval_sub,
247 : const struct mmu_notifier_range *range,
248 : unsigned long cur_seq);
249 : };
250 :
251 : struct mmu_interval_notifier {
252 : struct interval_tree_node interval_tree;
253 : const struct mmu_interval_notifier_ops *ops;
254 : struct mm_struct *mm;
255 : struct hlist_node deferred_item;
256 : unsigned long invalidate_seq;
257 : };
258 :
259 : #ifdef CONFIG_MMU_NOTIFIER
260 :
261 : #ifdef CONFIG_LOCKDEP
262 : extern struct lockdep_map __mmu_notifier_invalidate_range_start_map;
263 : #endif
264 :
265 : struct mmu_notifier_range {
266 : struct vm_area_struct *vma;
267 : struct mm_struct *mm;
268 : unsigned long start;
269 : unsigned long end;
270 : unsigned flags;
271 : enum mmu_notifier_event event;
272 : void *migrate_pgmap_owner;
273 : };
274 :
275 : static inline int mm_has_notifiers(struct mm_struct *mm)
276 : {
277 : return unlikely(mm->notifier_subscriptions);
278 : }
279 :
280 : struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops,
281 : struct mm_struct *mm);
282 : static inline struct mmu_notifier *
283 : mmu_notifier_get(const struct mmu_notifier_ops *ops, struct mm_struct *mm)
284 : {
285 : struct mmu_notifier *ret;
286 :
287 : mmap_write_lock(mm);
288 : ret = mmu_notifier_get_locked(ops, mm);
289 : mmap_write_unlock(mm);
290 : return ret;
291 : }
292 : void mmu_notifier_put(struct mmu_notifier *subscription);
293 : void mmu_notifier_synchronize(void);
294 :
295 : extern int mmu_notifier_register(struct mmu_notifier *subscription,
296 : struct mm_struct *mm);
297 : extern int __mmu_notifier_register(struct mmu_notifier *subscription,
298 : struct mm_struct *mm);
299 : extern void mmu_notifier_unregister(struct mmu_notifier *subscription,
300 : struct mm_struct *mm);
301 :
302 : unsigned long
303 : mmu_interval_read_begin(struct mmu_interval_notifier *interval_sub);
304 : int mmu_interval_notifier_insert(struct mmu_interval_notifier *interval_sub,
305 : struct mm_struct *mm, unsigned long start,
306 : unsigned long length,
307 : const struct mmu_interval_notifier_ops *ops);
308 : int mmu_interval_notifier_insert_locked(
309 : struct mmu_interval_notifier *interval_sub, struct mm_struct *mm,
310 : unsigned long start, unsigned long length,
311 : const struct mmu_interval_notifier_ops *ops);
312 : void mmu_interval_notifier_remove(struct mmu_interval_notifier *interval_sub);
313 :
314 : /**
315 : * mmu_interval_set_seq - Save the invalidation sequence
316 : * @interval_sub - The subscription passed to invalidate
317 : * @cur_seq - The cur_seq passed to the invalidate() callback
318 : *
319 : * This must be called unconditionally from the invalidate callback of a
320 : * struct mmu_interval_notifier_ops under the same lock that is used to call
321 : * mmu_interval_read_retry(). It updates the sequence number for later use by
322 : * mmu_interval_read_retry(). The provided cur_seq will always be odd.
323 : *
324 : * If the caller does not call mmu_interval_read_begin() or
325 : * mmu_interval_read_retry() then this call is not required.
326 : */
327 : static inline void
328 : mmu_interval_set_seq(struct mmu_interval_notifier *interval_sub,
329 : unsigned long cur_seq)
330 : {
331 : WRITE_ONCE(interval_sub->invalidate_seq, cur_seq);
332 : }
333 :
334 : /**
335 : * mmu_interval_read_retry - End a read side critical section against a VA range
336 : * interval_sub: The subscription
337 : * seq: The return of the paired mmu_interval_read_begin()
338 : *
339 : * This MUST be called under a user provided lock that is also held
340 : * unconditionally by op->invalidate() when it calls mmu_interval_set_seq().
341 : *
342 : * Each call should be paired with a single mmu_interval_read_begin() and
343 : * should be used to conclude the read side.
344 : *
345 : * Returns true if an invalidation collided with this critical section, and
346 : * the caller should retry.
347 : */
348 : static inline bool
349 : mmu_interval_read_retry(struct mmu_interval_notifier *interval_sub,
350 : unsigned long seq)
351 : {
352 : return interval_sub->invalidate_seq != seq;
353 : }
354 :
355 : /**
356 : * mmu_interval_check_retry - Test if a collision has occurred
357 : * interval_sub: The subscription
358 : * seq: The return of the matching mmu_interval_read_begin()
359 : *
360 : * This can be used in the critical section between mmu_interval_read_begin()
361 : * and mmu_interval_read_retry(). A return of true indicates an invalidation
362 : * has collided with this critical region and a future
363 : * mmu_interval_read_retry() will return true.
364 : *
365 : * False is not reliable and only suggests a collision may not have
366 : * occured. It can be called many times and does not have to hold the user
367 : * provided lock.
368 : *
369 : * This call can be used as part of loops and other expensive operations to
370 : * expedite a retry.
371 : */
372 : static inline bool
373 : mmu_interval_check_retry(struct mmu_interval_notifier *interval_sub,
374 : unsigned long seq)
375 : {
376 : /* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */
377 : return READ_ONCE(interval_sub->invalidate_seq) != seq;
378 : }
379 :
380 : extern void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm);
381 : extern void __mmu_notifier_release(struct mm_struct *mm);
382 : extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
383 : unsigned long start,
384 : unsigned long end);
385 : extern int __mmu_notifier_clear_young(struct mm_struct *mm,
386 : unsigned long start,
387 : unsigned long end);
388 : extern int __mmu_notifier_test_young(struct mm_struct *mm,
389 : unsigned long address);
390 : extern void __mmu_notifier_change_pte(struct mm_struct *mm,
391 : unsigned long address, pte_t pte);
392 : extern int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *r);
393 : extern void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *r,
394 : bool only_end);
395 : extern void __mmu_notifier_invalidate_range(struct mm_struct *mm,
396 : unsigned long start, unsigned long end);
397 : extern bool
398 : mmu_notifier_range_update_to_read_only(const struct mmu_notifier_range *range);
399 :
400 : static inline bool
401 : mmu_notifier_range_blockable(const struct mmu_notifier_range *range)
402 : {
403 : return (range->flags & MMU_NOTIFIER_RANGE_BLOCKABLE);
404 : }
405 :
406 : static inline void mmu_notifier_release(struct mm_struct *mm)
407 : {
408 : if (mm_has_notifiers(mm))
409 : __mmu_notifier_release(mm);
410 : }
411 :
412 : static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
413 : unsigned long start,
414 : unsigned long end)
415 : {
416 : if (mm_has_notifiers(mm))
417 : return __mmu_notifier_clear_flush_young(mm, start, end);
418 : return 0;
419 : }
420 :
421 : static inline int mmu_notifier_clear_young(struct mm_struct *mm,
422 : unsigned long start,
423 : unsigned long end)
424 : {
425 : if (mm_has_notifiers(mm))
426 : return __mmu_notifier_clear_young(mm, start, end);
427 : return 0;
428 : }
429 :
430 : static inline int mmu_notifier_test_young(struct mm_struct *mm,
431 : unsigned long address)
432 : {
433 : if (mm_has_notifiers(mm))
434 : return __mmu_notifier_test_young(mm, address);
435 : return 0;
436 : }
437 :
438 : static inline void mmu_notifier_change_pte(struct mm_struct *mm,
439 : unsigned long address, pte_t pte)
440 : {
441 : if (mm_has_notifiers(mm))
442 : __mmu_notifier_change_pte(mm, address, pte);
443 : }
444 :
445 : static inline void
446 : mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
447 : {
448 : might_sleep();
449 :
450 : lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
451 : if (mm_has_notifiers(range->mm)) {
452 : range->flags |= MMU_NOTIFIER_RANGE_BLOCKABLE;
453 : __mmu_notifier_invalidate_range_start(range);
454 : }
455 : lock_map_release(&__mmu_notifier_invalidate_range_start_map);
456 : }
457 :
458 : static inline int
459 : mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
460 : {
461 : int ret = 0;
462 :
463 : lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
464 : if (mm_has_notifiers(range->mm)) {
465 : range->flags &= ~MMU_NOTIFIER_RANGE_BLOCKABLE;
466 : ret = __mmu_notifier_invalidate_range_start(range);
467 : }
468 : lock_map_release(&__mmu_notifier_invalidate_range_start_map);
469 : return ret;
470 : }
471 :
472 : static inline void
473 : mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range)
474 : {
475 : if (mmu_notifier_range_blockable(range))
476 : might_sleep();
477 :
478 : if (mm_has_notifiers(range->mm))
479 : __mmu_notifier_invalidate_range_end(range, false);
480 : }
481 :
482 : static inline void
483 : mmu_notifier_invalidate_range_only_end(struct mmu_notifier_range *range)
484 : {
485 : if (mm_has_notifiers(range->mm))
486 : __mmu_notifier_invalidate_range_end(range, true);
487 : }
488 :
489 : static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
490 : unsigned long start, unsigned long end)
491 : {
492 : if (mm_has_notifiers(mm))
493 : __mmu_notifier_invalidate_range(mm, start, end);
494 : }
495 :
496 : static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
497 : {
498 : mm->notifier_subscriptions = NULL;
499 : }
500 :
501 : static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
502 : {
503 : if (mm_has_notifiers(mm))
504 : __mmu_notifier_subscriptions_destroy(mm);
505 : }
506 :
507 :
508 : static inline void mmu_notifier_range_init(struct mmu_notifier_range *range,
509 : enum mmu_notifier_event event,
510 : unsigned flags,
511 : struct vm_area_struct *vma,
512 : struct mm_struct *mm,
513 : unsigned long start,
514 : unsigned long end)
515 : {
516 : range->vma = vma;
517 : range->event = event;
518 : range->mm = mm;
519 : range->start = start;
520 : range->end = end;
521 : range->flags = flags;
522 : }
523 :
524 : static inline void mmu_notifier_range_init_migrate(
525 : struct mmu_notifier_range *range, unsigned int flags,
526 : struct vm_area_struct *vma, struct mm_struct *mm,
527 : unsigned long start, unsigned long end, void *pgmap)
528 : {
529 : mmu_notifier_range_init(range, MMU_NOTIFY_MIGRATE, flags, vma, mm,
530 : start, end);
531 : range->migrate_pgmap_owner = pgmap;
532 : }
533 :
534 : #define ptep_clear_flush_young_notify(__vma, __address, __ptep) \
535 : ({ \
536 : int __young; \
537 : struct vm_area_struct *___vma = __vma; \
538 : unsigned long ___address = __address; \
539 : __young = ptep_clear_flush_young(___vma, ___address, __ptep); \
540 : __young |= mmu_notifier_clear_flush_young(___vma->vm_mm, \
541 : ___address, \
542 : ___address + \
543 : PAGE_SIZE); \
544 : __young; \
545 : })
546 :
547 : #define pmdp_clear_flush_young_notify(__vma, __address, __pmdp) \
548 : ({ \
549 : int __young; \
550 : struct vm_area_struct *___vma = __vma; \
551 : unsigned long ___address = __address; \
552 : __young = pmdp_clear_flush_young(___vma, ___address, __pmdp); \
553 : __young |= mmu_notifier_clear_flush_young(___vma->vm_mm, \
554 : ___address, \
555 : ___address + \
556 : PMD_SIZE); \
557 : __young; \
558 : })
559 :
560 : #define ptep_clear_young_notify(__vma, __address, __ptep) \
561 : ({ \
562 : int __young; \
563 : struct vm_area_struct *___vma = __vma; \
564 : unsigned long ___address = __address; \
565 : __young = ptep_test_and_clear_young(___vma, ___address, __ptep);\
566 : __young |= mmu_notifier_clear_young(___vma->vm_mm, ___address, \
567 : ___address + PAGE_SIZE); \
568 : __young; \
569 : })
570 :
571 : #define pmdp_clear_young_notify(__vma, __address, __pmdp) \
572 : ({ \
573 : int __young; \
574 : struct vm_area_struct *___vma = __vma; \
575 : unsigned long ___address = __address; \
576 : __young = pmdp_test_and_clear_young(___vma, ___address, __pmdp);\
577 : __young |= mmu_notifier_clear_young(___vma->vm_mm, ___address, \
578 : ___address + PMD_SIZE); \
579 : __young; \
580 : })
581 :
582 : #define ptep_clear_flush_notify(__vma, __address, __ptep) \
583 : ({ \
584 : unsigned long ___addr = __address & PAGE_MASK; \
585 : struct mm_struct *___mm = (__vma)->vm_mm; \
586 : pte_t ___pte; \
587 : \
588 : ___pte = ptep_clear_flush(__vma, __address, __ptep); \
589 : mmu_notifier_invalidate_range(___mm, ___addr, \
590 : ___addr + PAGE_SIZE); \
591 : \
592 : ___pte; \
593 : })
594 :
595 : #define pmdp_huge_clear_flush_notify(__vma, __haddr, __pmd) \
596 : ({ \
597 : unsigned long ___haddr = __haddr & HPAGE_PMD_MASK; \
598 : struct mm_struct *___mm = (__vma)->vm_mm; \
599 : pmd_t ___pmd; \
600 : \
601 : ___pmd = pmdp_huge_clear_flush(__vma, __haddr, __pmd); \
602 : mmu_notifier_invalidate_range(___mm, ___haddr, \
603 : ___haddr + HPAGE_PMD_SIZE); \
604 : \
605 : ___pmd; \
606 : })
607 :
608 : #define pudp_huge_clear_flush_notify(__vma, __haddr, __pud) \
609 : ({ \
610 : unsigned long ___haddr = __haddr & HPAGE_PUD_MASK; \
611 : struct mm_struct *___mm = (__vma)->vm_mm; \
612 : pud_t ___pud; \
613 : \
614 : ___pud = pudp_huge_clear_flush(__vma, __haddr, __pud); \
615 : mmu_notifier_invalidate_range(___mm, ___haddr, \
616 : ___haddr + HPAGE_PUD_SIZE); \
617 : \
618 : ___pud; \
619 : })
620 :
621 : /*
622 : * set_pte_at_notify() sets the pte _after_ running the notifier.
623 : * This is safe to start by updating the secondary MMUs, because the primary MMU
624 : * pte invalidate must have already happened with a ptep_clear_flush() before
625 : * set_pte_at_notify() has been invoked. Updating the secondary MMUs first is
626 : * required when we change both the protection of the mapping from read-only to
627 : * read-write and the pfn (like during copy on write page faults). Otherwise the
628 : * old page would remain mapped readonly in the secondary MMUs after the new
629 : * page is already writable by some CPU through the primary MMU.
630 : */
631 : #define set_pte_at_notify(__mm, __address, __ptep, __pte) \
632 : ({ \
633 : struct mm_struct *___mm = __mm; \
634 : unsigned long ___address = __address; \
635 : pte_t ___pte = __pte; \
636 : \
637 : mmu_notifier_change_pte(___mm, ___address, ___pte); \
638 : set_pte_at(___mm, ___address, __ptep, ___pte); \
639 : })
640 :
641 : #else /* CONFIG_MMU_NOTIFIER */
642 :
643 : struct mmu_notifier_range {
644 : unsigned long start;
645 : unsigned long end;
646 : };
647 :
648 80385 : static inline void _mmu_notifier_range_init(struct mmu_notifier_range *range,
649 : unsigned long start,
650 : unsigned long end)
651 : {
652 80385 : range->start = start;
653 59953 : range->end = end;
654 21444 : }
655 :
656 : #define mmu_notifier_range_init(range,event,flags,vma,mm,start,end) \
657 : _mmu_notifier_range_init(range, start, end)
658 : #define mmu_notifier_range_init_migrate(range, flags, vma, mm, start, end, \
659 : pgmap) \
660 : _mmu_notifier_range_init(range, start, end)
661 :
662 : static inline bool
663 : mmu_notifier_range_blockable(const struct mmu_notifier_range *range)
664 : {
665 : return true;
666 : }
667 :
668 : static inline int mm_has_notifiers(struct mm_struct *mm)
669 : {
670 : return 0;
671 : }
672 :
673 3728 : static inline void mmu_notifier_release(struct mm_struct *mm)
674 : {
675 3728 : }
676 :
677 : static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
678 : unsigned long start,
679 : unsigned long end)
680 : {
681 : return 0;
682 : }
683 :
684 : static inline int mmu_notifier_test_young(struct mm_struct *mm,
685 : unsigned long address)
686 : {
687 : return 0;
688 : }
689 :
690 : static inline void mmu_notifier_change_pte(struct mm_struct *mm,
691 : unsigned long address, pte_t pte)
692 : {
693 : }
694 :
695 : static inline void
696 2100 : mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
697 : {
698 58937 : }
699 :
700 : static inline int
701 0 : mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
702 : {
703 0 : return 0;
704 : }
705 :
706 : static inline
707 48246 : void mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range)
708 : {
709 27812 : }
710 :
711 : static inline void
712 32147 : mmu_notifier_invalidate_range_only_end(struct mmu_notifier_range *range)
713 : {
714 32147 : }
715 :
716 6182 : static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
717 : unsigned long start, unsigned long end)
718 : {
719 6182 : }
720 :
721 2019 : static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
722 : {
723 2019 : }
724 :
725 1992 : static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
726 : {
727 1992 : }
728 :
729 : #define mmu_notifier_range_update_to_read_only(r) false
730 :
731 : #define ptep_clear_flush_young_notify ptep_clear_flush_young
732 : #define pmdp_clear_flush_young_notify pmdp_clear_flush_young
733 : #define ptep_clear_young_notify ptep_test_and_clear_young
734 : #define pmdp_clear_young_notify pmdp_test_and_clear_young
735 : #define ptep_clear_flush_notify ptep_clear_flush
736 : #define pmdp_huge_clear_flush_notify pmdp_huge_clear_flush
737 : #define pudp_huge_clear_flush_notify pudp_huge_clear_flush
738 : #define set_pte_at_notify set_pte_at
739 :
740 : static inline void mmu_notifier_synchronize(void)
741 : {
742 : }
743 :
744 : #endif /* CONFIG_MMU_NOTIFIER */
745 :
746 : #endif /* _LINUX_MMU_NOTIFIER_H */
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