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 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 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 : bool only_end);
400 : extern void __mmu_notifier_invalidate_range(struct mm_struct *mm,
401 : unsigned long start, unsigned long end);
402 : extern bool
403 : mmu_notifier_range_update_to_read_only(const struct mmu_notifier_range *range);
404 :
405 : static inline bool
406 : mmu_notifier_range_blockable(const struct mmu_notifier_range *range)
407 : {
408 : return (range->flags & MMU_NOTIFIER_RANGE_BLOCKABLE);
409 : }
410 :
411 : static inline void mmu_notifier_release(struct mm_struct *mm)
412 : {
413 : if (mm_has_notifiers(mm))
414 : __mmu_notifier_release(mm);
415 : }
416 :
417 : static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
418 : unsigned long start,
419 : unsigned long end)
420 : {
421 : if (mm_has_notifiers(mm))
422 : return __mmu_notifier_clear_flush_young(mm, start, end);
423 : return 0;
424 : }
425 :
426 : static inline int mmu_notifier_clear_young(struct mm_struct *mm,
427 : unsigned long start,
428 : unsigned long end)
429 : {
430 : if (mm_has_notifiers(mm))
431 : return __mmu_notifier_clear_young(mm, start, end);
432 : return 0;
433 : }
434 :
435 : static inline int mmu_notifier_test_young(struct mm_struct *mm,
436 : unsigned long address)
437 : {
438 : if (mm_has_notifiers(mm))
439 : return __mmu_notifier_test_young(mm, address);
440 : return 0;
441 : }
442 :
443 : static inline void mmu_notifier_change_pte(struct mm_struct *mm,
444 : unsigned long address, pte_t pte)
445 : {
446 : if (mm_has_notifiers(mm))
447 : __mmu_notifier_change_pte(mm, address, pte);
448 : }
449 :
450 : static inline void
451 : mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
452 : {
453 : might_sleep();
454 :
455 : lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
456 : if (mm_has_notifiers(range->mm)) {
457 : range->flags |= MMU_NOTIFIER_RANGE_BLOCKABLE;
458 : __mmu_notifier_invalidate_range_start(range);
459 : }
460 : lock_map_release(&__mmu_notifier_invalidate_range_start_map);
461 : }
462 :
463 : static inline int
464 : mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
465 : {
466 : int ret = 0;
467 :
468 : lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
469 : if (mm_has_notifiers(range->mm)) {
470 : range->flags &= ~MMU_NOTIFIER_RANGE_BLOCKABLE;
471 : ret = __mmu_notifier_invalidate_range_start(range);
472 : }
473 : lock_map_release(&__mmu_notifier_invalidate_range_start_map);
474 : return ret;
475 : }
476 :
477 : static inline void
478 : mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range)
479 : {
480 : if (mmu_notifier_range_blockable(range))
481 : might_sleep();
482 :
483 : if (mm_has_notifiers(range->mm))
484 : __mmu_notifier_invalidate_range_end(range, false);
485 : }
486 :
487 : static inline void
488 : mmu_notifier_invalidate_range_only_end(struct mmu_notifier_range *range)
489 : {
490 : if (mm_has_notifiers(range->mm))
491 : __mmu_notifier_invalidate_range_end(range, true);
492 : }
493 :
494 : static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
495 : unsigned long start, unsigned long end)
496 : {
497 : if (mm_has_notifiers(mm))
498 : __mmu_notifier_invalidate_range(mm, start, end);
499 : }
500 :
501 : static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
502 : {
503 : mm->notifier_subscriptions = NULL;
504 : }
505 :
506 : static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
507 : {
508 : if (mm_has_notifiers(mm))
509 : __mmu_notifier_subscriptions_destroy(mm);
510 : }
511 :
512 :
513 : static inline void mmu_notifier_range_init(struct mmu_notifier_range *range,
514 : enum mmu_notifier_event event,
515 : unsigned flags,
516 : struct mm_struct *mm,
517 : unsigned long start,
518 : unsigned long end)
519 : {
520 : range->event = event;
521 : range->mm = mm;
522 : range->start = start;
523 : range->end = end;
524 : range->flags = flags;
525 : }
526 :
527 : static inline void mmu_notifier_range_init_owner(
528 : struct mmu_notifier_range *range,
529 : enum mmu_notifier_event event, unsigned int flags,
530 : struct mm_struct *mm, unsigned long start,
531 : unsigned long end, void *owner)
532 : {
533 : mmu_notifier_range_init(range, event, flags, mm, start, end);
534 : range->owner = owner;
535 : }
536 :
537 : #define ptep_clear_flush_young_notify(__vma, __address, __ptep) \
538 : ({ \
539 : int __young; \
540 : struct vm_area_struct *___vma = __vma; \
541 : unsigned long ___address = __address; \
542 : __young = ptep_clear_flush_young(___vma, ___address, __ptep); \
543 : __young |= mmu_notifier_clear_flush_young(___vma->vm_mm, \
544 : ___address, \
545 : ___address + \
546 : PAGE_SIZE); \
547 : __young; \
548 : })
549 :
550 : #define pmdp_clear_flush_young_notify(__vma, __address, __pmdp) \
551 : ({ \
552 : int __young; \
553 : struct vm_area_struct *___vma = __vma; \
554 : unsigned long ___address = __address; \
555 : __young = pmdp_clear_flush_young(___vma, ___address, __pmdp); \
556 : __young |= mmu_notifier_clear_flush_young(___vma->vm_mm, \
557 : ___address, \
558 : ___address + \
559 : PMD_SIZE); \
560 : __young; \
561 : })
562 :
563 : #define ptep_clear_young_notify(__vma, __address, __ptep) \
564 : ({ \
565 : int __young; \
566 : struct vm_area_struct *___vma = __vma; \
567 : unsigned long ___address = __address; \
568 : __young = ptep_test_and_clear_young(___vma, ___address, __ptep);\
569 : __young |= mmu_notifier_clear_young(___vma->vm_mm, ___address, \
570 : ___address + PAGE_SIZE); \
571 : __young; \
572 : })
573 :
574 : #define pmdp_clear_young_notify(__vma, __address, __pmdp) \
575 : ({ \
576 : int __young; \
577 : struct vm_area_struct *___vma = __vma; \
578 : unsigned long ___address = __address; \
579 : __young = pmdp_test_and_clear_young(___vma, ___address, __pmdp);\
580 : __young |= mmu_notifier_clear_young(___vma->vm_mm, ___address, \
581 : ___address + PMD_SIZE); \
582 : __young; \
583 : })
584 :
585 : #define ptep_clear_flush_notify(__vma, __address, __ptep) \
586 : ({ \
587 : unsigned long ___addr = __address & PAGE_MASK; \
588 : struct mm_struct *___mm = (__vma)->vm_mm; \
589 : pte_t ___pte; \
590 : \
591 : ___pte = ptep_clear_flush(__vma, __address, __ptep); \
592 : mmu_notifier_invalidate_range(___mm, ___addr, \
593 : ___addr + PAGE_SIZE); \
594 : \
595 : ___pte; \
596 : })
597 :
598 : #define pmdp_huge_clear_flush_notify(__vma, __haddr, __pmd) \
599 : ({ \
600 : unsigned long ___haddr = __haddr & HPAGE_PMD_MASK; \
601 : struct mm_struct *___mm = (__vma)->vm_mm; \
602 : pmd_t ___pmd; \
603 : \
604 : ___pmd = pmdp_huge_clear_flush(__vma, __haddr, __pmd); \
605 : mmu_notifier_invalidate_range(___mm, ___haddr, \
606 : ___haddr + HPAGE_PMD_SIZE); \
607 : \
608 : ___pmd; \
609 : })
610 :
611 : #define pudp_huge_clear_flush_notify(__vma, __haddr, __pud) \
612 : ({ \
613 : unsigned long ___haddr = __haddr & HPAGE_PUD_MASK; \
614 : struct mm_struct *___mm = (__vma)->vm_mm; \
615 : pud_t ___pud; \
616 : \
617 : ___pud = pudp_huge_clear_flush(__vma, __haddr, __pud); \
618 : mmu_notifier_invalidate_range(___mm, ___haddr, \
619 : ___haddr + HPAGE_PUD_SIZE); \
620 : \
621 : ___pud; \
622 : })
623 :
624 : /*
625 : * set_pte_at_notify() sets the pte _after_ running the notifier.
626 : * This is safe to start by updating the secondary MMUs, because the primary MMU
627 : * pte invalidate must have already happened with a ptep_clear_flush() before
628 : * set_pte_at_notify() has been invoked. Updating the secondary MMUs first is
629 : * required when we change both the protection of the mapping from read-only to
630 : * read-write and the pfn (like during copy on write page faults). Otherwise the
631 : * old page would remain mapped readonly in the secondary MMUs after the new
632 : * page is already writable by some CPU through the primary MMU.
633 : */
634 : #define set_pte_at_notify(__mm, __address, __ptep, __pte) \
635 : ({ \
636 : struct mm_struct *___mm = __mm; \
637 : unsigned long ___address = __address; \
638 : pte_t ___pte = __pte; \
639 : \
640 : mmu_notifier_change_pte(___mm, ___address, ___pte); \
641 : set_pte_at(___mm, ___address, __ptep, ___pte); \
642 : })
643 :
644 : #else /* CONFIG_MMU_NOTIFIER */
645 :
646 : struct mmu_notifier_range {
647 : unsigned long start;
648 : unsigned long end;
649 : };
650 :
651 : static inline void _mmu_notifier_range_init(struct mmu_notifier_range *range,
652 : unsigned long start,
653 : unsigned long end)
654 : {
655 0 : range->start = start;
656 0 : range->end = end;
657 : }
658 :
659 : #define mmu_notifier_range_init(range,event,flags,mm,start,end) \
660 : _mmu_notifier_range_init(range, start, end)
661 : #define mmu_notifier_range_init_owner(range, event, flags, mm, start, \
662 : end, owner) \
663 : _mmu_notifier_range_init(range, start, end)
664 :
665 : static inline bool
666 : mmu_notifier_range_blockable(const struct mmu_notifier_range *range)
667 : {
668 : return true;
669 : }
670 :
671 : static inline int mm_has_notifiers(struct mm_struct *mm)
672 : {
673 : return 0;
674 : }
675 :
676 : static inline void mmu_notifier_release(struct mm_struct *mm)
677 : {
678 : }
679 :
680 : static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
681 : unsigned long start,
682 : unsigned long end)
683 : {
684 : return 0;
685 : }
686 :
687 : static inline int mmu_notifier_test_young(struct mm_struct *mm,
688 : unsigned long address)
689 : {
690 : return 0;
691 : }
692 :
693 : static inline void mmu_notifier_change_pte(struct mm_struct *mm,
694 : unsigned long address, pte_t pte)
695 : {
696 : }
697 :
698 : static inline void
699 : mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
700 : {
701 : }
702 :
703 : static inline int
704 : mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
705 : {
706 : return 0;
707 : }
708 :
709 : static inline
710 : void mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range)
711 : {
712 : }
713 :
714 : static inline void
715 : mmu_notifier_invalidate_range_only_end(struct mmu_notifier_range *range)
716 : {
717 : }
718 :
719 : static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
720 : unsigned long start, unsigned long end)
721 : {
722 : }
723 :
724 : static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
725 : {
726 : }
727 :
728 : static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
729 : {
730 : }
731 :
732 : #define mmu_notifier_range_update_to_read_only(r) false
733 :
734 : #define ptep_clear_flush_young_notify ptep_clear_flush_young
735 : #define pmdp_clear_flush_young_notify pmdp_clear_flush_young
736 : #define ptep_clear_young_notify ptep_test_and_clear_young
737 : #define pmdp_clear_young_notify pmdp_test_and_clear_young
738 : #define ptep_clear_flush_notify ptep_clear_flush
739 : #define pmdp_huge_clear_flush_notify pmdp_huge_clear_flush
740 : #define pudp_huge_clear_flush_notify pudp_huge_clear_flush
741 : #define set_pte_at_notify set_pte_at
742 :
743 : static inline void mmu_notifier_synchronize(void)
744 : {
745 : }
746 :
747 : #endif /* CONFIG_MMU_NOTIFIER */
748 :
749 : #endif /* _LINUX_MMU_NOTIFIER_H */
|
