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 | * invalidate_range() is either called between |
191 | * invalidate_range_start() and invalidate_range_end() when the |
192 | * VM has to free pages that where unmapped, but before the |
193 | * pages are actually freed, or outside of _start()/_end() when |
194 | * a (remote) TLB is necessary. |
195 | * |
196 | * If invalidate_range() is used to manage a non-CPU TLB with |
197 | * shared page-tables, it not necessary to implement the |
198 | * invalidate_range_start()/end() notifiers, as |
199 | * invalidate_range() already catches the points in time when an |
200 | * external TLB range needs to be flushed. For more in depth |
201 | * discussion on this see Documentation/mm/mmu_notifier.rst |
202 | * |
203 | * Note that this function might be called with just a sub-range |
204 | * of what was passed to invalidate_range_start()/end(), if |
205 | * called between those functions. |
206 | */ |
207 | void (*invalidate_range)(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 vm_area_struct *vma; |
273 | struct mm_struct *mm; |
274 | unsigned long start; |
275 | unsigned long end; |
276 | unsigned flags; |
277 | enum mmu_notifier_event event; |
278 | void *owner; |
279 | }; |
280 | |
281 | static inline int mm_has_notifiers(struct mm_struct *mm) |
282 | { |
283 | return unlikely(mm->notifier_subscriptions); |
284 | } |
285 | |
286 | struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops, |
287 | struct mm_struct *mm); |
288 | static inline struct mmu_notifier * |
289 | mmu_notifier_get(const struct mmu_notifier_ops *ops, struct mm_struct *mm) |
290 | { |
291 | struct mmu_notifier *ret; |
292 | |
293 | mmap_write_lock(mm); |
294 | ret = mmu_notifier_get_locked(ops, mm); |
295 | mmap_write_unlock(mm); |
296 | return ret; |
297 | } |
298 | void mmu_notifier_put(struct mmu_notifier *subscription); |
299 | void mmu_notifier_synchronize(void); |
300 | |
301 | extern int mmu_notifier_register(struct mmu_notifier *subscription, |
302 | struct mm_struct *mm); |
303 | extern int __mmu_notifier_register(struct mmu_notifier *subscription, |
304 | struct mm_struct *mm); |
305 | extern void mmu_notifier_unregister(struct mmu_notifier *subscription, |
306 | struct mm_struct *mm); |
307 | |
308 | unsigned long |
309 | mmu_interval_read_begin(struct mmu_interval_notifier *interval_sub); |
310 | int mmu_interval_notifier_insert(struct mmu_interval_notifier *interval_sub, |
311 | struct mm_struct *mm, unsigned long start, |
312 | unsigned long length, |
313 | const struct mmu_interval_notifier_ops *ops); |
314 | int mmu_interval_notifier_insert_locked( |
315 | struct mmu_interval_notifier *interval_sub, struct mm_struct *mm, |
316 | unsigned long start, unsigned long length, |
317 | const struct mmu_interval_notifier_ops *ops); |
318 | void mmu_interval_notifier_remove(struct mmu_interval_notifier *interval_sub); |
319 | |
320 | /** |
321 | * mmu_interval_set_seq - Save the invalidation sequence |
322 | * @interval_sub - The subscription passed to invalidate |
323 | * @cur_seq - The cur_seq passed to the invalidate() callback |
324 | * |
325 | * This must be called unconditionally from the invalidate callback of a |
326 | * struct mmu_interval_notifier_ops under the same lock that is used to call |
327 | * mmu_interval_read_retry(). It updates the sequence number for later use by |
328 | * mmu_interval_read_retry(). The provided cur_seq will always be odd. |
329 | * |
330 | * If the caller does not call mmu_interval_read_begin() or |
331 | * mmu_interval_read_retry() then this call is not required. |
332 | */ |
333 | static inline void |
334 | mmu_interval_set_seq(struct mmu_interval_notifier *interval_sub, |
335 | unsigned long cur_seq) |
336 | { |
337 | WRITE_ONCE(interval_sub->invalidate_seq, cur_seq); |
338 | } |
339 | |
340 | /** |
341 | * mmu_interval_read_retry - End a read side critical section against a VA range |
342 | * interval_sub: The subscription |
343 | * seq: The return of the paired mmu_interval_read_begin() |
344 | * |
345 | * This MUST be called under a user provided lock that is also held |
346 | * unconditionally by op->invalidate() when it calls mmu_interval_set_seq(). |
347 | * |
348 | * Each call should be paired with a single mmu_interval_read_begin() and |
349 | * should be used to conclude the read side. |
350 | * |
351 | * Returns true if an invalidation collided with this critical section, and |
352 | * the caller should retry. |
353 | */ |
354 | static inline bool |
355 | mmu_interval_read_retry(struct mmu_interval_notifier *interval_sub, |
356 | unsigned long seq) |
357 | { |
358 | return interval_sub->invalidate_seq != seq; |
359 | } |
360 | |
361 | /** |
362 | * mmu_interval_check_retry - Test if a collision has occurred |
363 | * interval_sub: The subscription |
364 | * seq: The return of the matching mmu_interval_read_begin() |
365 | * |
366 | * This can be used in the critical section between mmu_interval_read_begin() |
367 | * and mmu_interval_read_retry(). A return of true indicates an invalidation |
368 | * has collided with this critical region and a future |
369 | * mmu_interval_read_retry() will return true. |
370 | * |
371 | * False is not reliable and only suggests a collision may not have |
372 | * occurred. It can be called many times and does not have to hold the user |
373 | * provided lock. |
374 | * |
375 | * This call can be used as part of loops and other expensive operations to |
376 | * expedite a retry. |
377 | */ |
378 | static inline bool |
379 | mmu_interval_check_retry(struct mmu_interval_notifier *interval_sub, |
380 | unsigned long seq) |
381 | { |
382 | /* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */ |
383 | return READ_ONCE(interval_sub->invalidate_seq) != seq; |
384 | } |
385 | |
386 | extern void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm); |
387 | extern void __mmu_notifier_release(struct mm_struct *mm); |
388 | extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm, |
389 | unsigned long start, |
390 | unsigned long end); |
391 | extern int __mmu_notifier_clear_young(struct mm_struct *mm, |
392 | unsigned long start, |
393 | unsigned long end); |
394 | extern int __mmu_notifier_test_young(struct mm_struct *mm, |
395 | unsigned long address); |
396 | extern void __mmu_notifier_change_pte(struct mm_struct *mm, |
397 | unsigned long address, pte_t pte); |
398 | extern int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *r); |
399 | extern void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *r, |
400 | bool only_end); |
401 | extern void __mmu_notifier_invalidate_range(struct mm_struct *mm, |
402 | unsigned long start, unsigned long end); |
403 | extern bool |
404 | mmu_notifier_range_update_to_read_only(const struct mmu_notifier_range *range); |
405 | |
406 | static inline bool |
407 | mmu_notifier_range_blockable(const struct mmu_notifier_range *range) |
408 | { |
409 | return (range->flags & MMU_NOTIFIER_RANGE_BLOCKABLE); |
410 | } |
411 | |
412 | static inline void mmu_notifier_release(struct mm_struct *mm) |
413 | { |
414 | if (mm_has_notifiers(mm)) |
415 | __mmu_notifier_release(mm); |
416 | } |
417 | |
418 | static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm, |
419 | unsigned long start, |
420 | unsigned long end) |
421 | { |
422 | if (mm_has_notifiers(mm)) |
423 | return __mmu_notifier_clear_flush_young(mm, start, end); |
424 | return 0; |
425 | } |
426 | |
427 | static inline int mmu_notifier_clear_young(struct mm_struct *mm, |
428 | unsigned long start, |
429 | unsigned long end) |
430 | { |
431 | if (mm_has_notifiers(mm)) |
432 | return __mmu_notifier_clear_young(mm, start, end); |
433 | return 0; |
434 | } |
435 | |
436 | static inline int mmu_notifier_test_young(struct mm_struct *mm, |
437 | unsigned long address) |
438 | { |
439 | if (mm_has_notifiers(mm)) |
440 | return __mmu_notifier_test_young(mm, address); |
441 | return 0; |
442 | } |
443 | |
444 | static inline void mmu_notifier_change_pte(struct mm_struct *mm, |
445 | unsigned long address, pte_t pte) |
446 | { |
447 | if (mm_has_notifiers(mm)) |
448 | __mmu_notifier_change_pte(mm, address, pte); |
449 | } |
450 | |
451 | static inline void |
452 | mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range) |
453 | { |
454 | might_sleep(); |
455 | |
456 | lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); |
457 | if (mm_has_notifiers(range->mm)) { |
458 | range->flags |= MMU_NOTIFIER_RANGE_BLOCKABLE; |
459 | __mmu_notifier_invalidate_range_start(range); |
460 | } |
461 | lock_map_release(&__mmu_notifier_invalidate_range_start_map); |
462 | } |
463 | |
464 | static inline int |
465 | mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range) |
466 | { |
467 | int ret = 0; |
468 | |
469 | lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); |
470 | if (mm_has_notifiers(range->mm)) { |
471 | range->flags &= ~MMU_NOTIFIER_RANGE_BLOCKABLE; |
472 | ret = __mmu_notifier_invalidate_range_start(range); |
473 | } |
474 | lock_map_release(&__mmu_notifier_invalidate_range_start_map); |
475 | return ret; |
476 | } |
477 | |
478 | static inline void |
479 | mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range) |
480 | { |
481 | if (mmu_notifier_range_blockable(range)) |
482 | might_sleep(); |
483 | |
484 | if (mm_has_notifiers(range->mm)) |
485 | __mmu_notifier_invalidate_range_end(range, false); |
486 | } |
487 | |
488 | static inline void |
489 | mmu_notifier_invalidate_range_only_end(struct mmu_notifier_range *range) |
490 | { |
491 | if (mm_has_notifiers(range->mm)) |
492 | __mmu_notifier_invalidate_range_end(range, true); |
493 | } |
494 | |
495 | static inline void mmu_notifier_invalidate_range(struct mm_struct *mm, |
496 | unsigned long start, unsigned long end) |
497 | { |
498 | if (mm_has_notifiers(mm)) |
499 | __mmu_notifier_invalidate_range(mm, start, end); |
500 | } |
501 | |
502 | static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm) |
503 | { |
504 | mm->notifier_subscriptions = NULL; |
505 | } |
506 | |
507 | static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm) |
508 | { |
509 | if (mm_has_notifiers(mm)) |
510 | __mmu_notifier_subscriptions_destroy(mm); |
511 | } |
512 | |
513 | |
514 | static inline void mmu_notifier_range_init(struct mmu_notifier_range *range, |
515 | enum mmu_notifier_event event, |
516 | unsigned flags, |
517 | struct vm_area_struct *vma, |
518 | struct mm_struct *mm, |
519 | unsigned long start, |
520 | unsigned long end) |
521 | { |
522 | range->vma = vma; |
523 | range->event = event; |
524 | range->mm = mm; |
525 | range->start = start; |
526 | range->end = end; |
527 | range->flags = flags; |
528 | } |
529 | |
530 | static inline void mmu_notifier_range_init_owner( |
531 | struct mmu_notifier_range *range, |
532 | enum mmu_notifier_event event, unsigned int flags, |
533 | struct vm_area_struct *vma, struct mm_struct *mm, |
534 | unsigned long start, unsigned long end, void *owner) |
535 | { |
536 | mmu_notifier_range_init(range, event, flags, vma, mm, start, end); |
537 | range->owner = owner; |
538 | } |
539 | |
540 | #define ptep_clear_flush_young_notify(__vma, __address, __ptep) \ |
541 | ({ \ |
542 | int __young; \ |
543 | struct vm_area_struct *___vma = __vma; \ |
544 | unsigned long ___address = __address; \ |
545 | __young = ptep_clear_flush_young(___vma, ___address, __ptep); \ |
546 | __young |= mmu_notifier_clear_flush_young(___vma->vm_mm, \ |
547 | ___address, \ |
548 | ___address + \ |
549 | PAGE_SIZE); \ |
550 | __young; \ |
551 | }) |
552 | |
553 | #define pmdp_clear_flush_young_notify(__vma, __address, __pmdp) \ |
554 | ({ \ |
555 | int __young; \ |
556 | struct vm_area_struct *___vma = __vma; \ |
557 | unsigned long ___address = __address; \ |
558 | __young = pmdp_clear_flush_young(___vma, ___address, __pmdp); \ |
559 | __young |= mmu_notifier_clear_flush_young(___vma->vm_mm, \ |
560 | ___address, \ |
561 | ___address + \ |
562 | PMD_SIZE); \ |
563 | __young; \ |
564 | }) |
565 | |
566 | #define ptep_clear_young_notify(__vma, __address, __ptep) \ |
567 | ({ \ |
568 | int __young; \ |
569 | struct vm_area_struct *___vma = __vma; \ |
570 | unsigned long ___address = __address; \ |
571 | __young = ptep_test_and_clear_young(___vma, ___address, __ptep);\ |
572 | __young |= mmu_notifier_clear_young(___vma->vm_mm, ___address, \ |
573 | ___address + PAGE_SIZE); \ |
574 | __young; \ |
575 | }) |
576 | |
577 | #define pmdp_clear_young_notify(__vma, __address, __pmdp) \ |
578 | ({ \ |
579 | int __young; \ |
580 | struct vm_area_struct *___vma = __vma; \ |
581 | unsigned long ___address = __address; \ |
582 | __young = pmdp_test_and_clear_young(___vma, ___address, __pmdp);\ |
583 | __young |= mmu_notifier_clear_young(___vma->vm_mm, ___address, \ |
584 | ___address + PMD_SIZE); \ |
585 | __young; \ |
586 | }) |
587 | |
588 | #define ptep_clear_flush_notify(__vma, __address, __ptep) \ |
589 | ({ \ |
590 | unsigned long ___addr = __address & PAGE_MASK; \ |
591 | struct mm_struct *___mm = (__vma)->vm_mm; \ |
592 | pte_t ___pte; \ |
593 | \ |
594 | ___pte = ptep_clear_flush(__vma, __address, __ptep); \ |
595 | mmu_notifier_invalidate_range(___mm, ___addr, \ |
596 | ___addr + PAGE_SIZE); \ |
597 | \ |
598 | ___pte; \ |
599 | }) |
600 | |
601 | #define pmdp_huge_clear_flush_notify(__vma, __haddr, __pmd) \ |
602 | ({ \ |
603 | unsigned long ___haddr = __haddr & HPAGE_PMD_MASK; \ |
604 | struct mm_struct *___mm = (__vma)->vm_mm; \ |
605 | pmd_t ___pmd; \ |
606 | \ |
607 | ___pmd = pmdp_huge_clear_flush(__vma, __haddr, __pmd); \ |
608 | mmu_notifier_invalidate_range(___mm, ___haddr, \ |
609 | ___haddr + HPAGE_PMD_SIZE); \ |
610 | \ |
611 | ___pmd; \ |
612 | }) |
613 | |
614 | #define pudp_huge_clear_flush_notify(__vma, __haddr, __pud) \ |
615 | ({ \ |
616 | unsigned long ___haddr = __haddr & HPAGE_PUD_MASK; \ |
617 | struct mm_struct *___mm = (__vma)->vm_mm; \ |
618 | pud_t ___pud; \ |
619 | \ |
620 | ___pud = pudp_huge_clear_flush(__vma, __haddr, __pud); \ |
621 | mmu_notifier_invalidate_range(___mm, ___haddr, \ |
622 | ___haddr + HPAGE_PUD_SIZE); \ |
623 | \ |
624 | ___pud; \ |
625 | }) |
626 | |
627 | /* |
628 | * set_pte_at_notify() sets the pte _after_ running the notifier. |
629 | * This is safe to start by updating the secondary MMUs, because the primary MMU |
630 | * pte invalidate must have already happened with a ptep_clear_flush() before |
631 | * set_pte_at_notify() has been invoked. Updating the secondary MMUs first is |
632 | * required when we change both the protection of the mapping from read-only to |
633 | * read-write and the pfn (like during copy on write page faults). Otherwise the |
634 | * old page would remain mapped readonly in the secondary MMUs after the new |
635 | * page is already writable by some CPU through the primary MMU. |
636 | */ |
637 | #define set_pte_at_notify(__mm, __address, __ptep, __pte) \ |
638 | ({ \ |
639 | struct mm_struct *___mm = __mm; \ |
640 | unsigned long ___address = __address; \ |
641 | pte_t ___pte = __pte; \ |
642 | \ |
643 | mmu_notifier_change_pte(___mm, ___address, ___pte); \ |
644 | set_pte_at(___mm, ___address, __ptep, ___pte); \ |
645 | }) |
646 | |
647 | #else /* CONFIG_MMU_NOTIFIER */ |
648 | |
649 | struct mmu_notifier_range { |
650 | unsigned long start; |
651 | unsigned long end; |
652 | }; |
653 | |
654 | static inline void _mmu_notifier_range_init(struct mmu_notifier_range *range, |
655 | unsigned long start, |
656 | unsigned long end) |
657 | { |
658 | range->start = start; |
659 | range->end = end; |
660 | } |
661 | |
662 | #define mmu_notifier_range_init(range,event,flags,vma,mm,start,end) \ |
663 | _mmu_notifier_range_init(range, start, end) |
664 | #define mmu_notifier_range_init_owner(range, event, flags, vma, mm, start, \ |
665 | end, owner) \ |
666 | _mmu_notifier_range_init(range, start, end) |
667 | |
668 | static inline bool |
669 | mmu_notifier_range_blockable(const struct mmu_notifier_range *range) |
670 | { |
671 | return true; |
672 | } |
673 | |
674 | static inline int mm_has_notifiers(struct mm_struct *mm) |
675 | { |
676 | return 0; |
677 | } |
678 | |
679 | static inline void mmu_notifier_release(struct mm_struct *mm) |
680 | { |
681 | } |
682 | |
683 | static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm, |
684 | unsigned long start, |
685 | unsigned long end) |
686 | { |
687 | return 0; |
688 | } |
689 | |
690 | static inline int mmu_notifier_test_young(struct mm_struct *mm, |
691 | unsigned long address) |
692 | { |
693 | return 0; |
694 | } |
695 | |
696 | static inline void mmu_notifier_change_pte(struct mm_struct *mm, |
697 | unsigned long address, pte_t pte) |
698 | { |
699 | } |
700 | |
701 | static inline void |
702 | mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range) |
703 | { |
704 | } |
705 | |
706 | static inline int |
707 | mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range) |
708 | { |
709 | return 0; |
710 | } |
711 | |
712 | static inline |
713 | void mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range) |
714 | { |
715 | } |
716 | |
717 | static inline void |
718 | mmu_notifier_invalidate_range_only_end(struct mmu_notifier_range *range) |
719 | { |
720 | } |
721 | |
722 | static inline void mmu_notifier_invalidate_range(struct mm_struct *mm, |
723 | unsigned long start, unsigned long end) |
724 | { |
725 | } |
726 | |
727 | static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm) |
728 | { |
729 | } |
730 | |
731 | static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm) |
732 | { |
733 | } |
734 | |
735 | #define mmu_notifier_range_update_to_read_only(r) false |
736 | |
737 | #define ptep_clear_flush_young_notify ptep_clear_flush_young |
738 | #define pmdp_clear_flush_young_notify pmdp_clear_flush_young |
739 | #define ptep_clear_young_notify ptep_test_and_clear_young |
740 | #define pmdp_clear_young_notify pmdp_test_and_clear_young |
741 | #define ptep_clear_flush_notify ptep_clear_flush |
742 | #define pmdp_huge_clear_flush_notify pmdp_huge_clear_flush |
743 | #define pudp_huge_clear_flush_notify pudp_huge_clear_flush |
744 | #define set_pte_at_notify set_pte_at |
745 | |
746 | static inline void mmu_notifier_synchronize(void) |
747 | { |
748 | } |
749 | |
750 | #endif /* CONFIG_MMU_NOTIFIER */ |
751 | |
752 | #endif /* _LINUX_MMU_NOTIFIER_H */ |
753 | |