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