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