Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0-or-later */
2 : /* include/asm-generic/tlb.h
3 : *
4 : * Generic TLB shootdown code
5 : *
6 : * Copyright 2001 Red Hat, Inc.
7 : * Based on code from mm/memory.c Copyright Linus Torvalds and others.
8 : *
9 : * Copyright 2011 Red Hat, Inc., Peter Zijlstra
10 : */
11 : #ifndef _ASM_GENERIC__TLB_H
12 : #define _ASM_GENERIC__TLB_H
13 :
14 : #include <linux/mmu_notifier.h>
15 : #include <linux/swap.h>
16 : #include <linux/hugetlb_inline.h>
17 : #include <asm/tlbflush.h>
18 : #include <asm/cacheflush.h>
19 :
20 : /*
21 : * Blindly accessing user memory from NMI context can be dangerous
22 : * if we're in the middle of switching the current user task or switching
23 : * the loaded mm.
24 : */
25 : #ifndef nmi_uaccess_okay
26 : # define nmi_uaccess_okay() true
27 : #endif
28 :
29 : #ifdef CONFIG_MMU
30 :
31 : /*
32 : * Generic MMU-gather implementation.
33 : *
34 : * The mmu_gather data structure is used by the mm code to implement the
35 : * correct and efficient ordering of freeing pages and TLB invalidations.
36 : *
37 : * This correct ordering is:
38 : *
39 : * 1) unhook page
40 : * 2) TLB invalidate page
41 : * 3) free page
42 : *
43 : * That is, we must never free a page before we have ensured there are no live
44 : * translations left to it. Otherwise it might be possible to observe (or
45 : * worse, change) the page content after it has been reused.
46 : *
47 : * The mmu_gather API consists of:
48 : *
49 : * - tlb_gather_mmu() / tlb_gather_mmu_fullmm() / tlb_finish_mmu()
50 : *
51 : * start and finish a mmu_gather
52 : *
53 : * Finish in particular will issue a (final) TLB invalidate and free
54 : * all (remaining) queued pages.
55 : *
56 : * - tlb_start_vma() / tlb_end_vma(); marks the start / end of a VMA
57 : *
58 : * Defaults to flushing at tlb_end_vma() to reset the range; helps when
59 : * there's large holes between the VMAs.
60 : *
61 : * - tlb_remove_table()
62 : *
63 : * tlb_remove_table() is the basic primitive to free page-table directories
64 : * (__p*_free_tlb()). In it's most primitive form it is an alias for
65 : * tlb_remove_page() below, for when page directories are pages and have no
66 : * additional constraints.
67 : *
68 : * See also MMU_GATHER_TABLE_FREE and MMU_GATHER_RCU_TABLE_FREE.
69 : *
70 : * - tlb_remove_page() / __tlb_remove_page()
71 : * - tlb_remove_page_size() / __tlb_remove_page_size()
72 : *
73 : * __tlb_remove_page_size() is the basic primitive that queues a page for
74 : * freeing. __tlb_remove_page() assumes PAGE_SIZE. Both will return a
75 : * boolean indicating if the queue is (now) full and a call to
76 : * tlb_flush_mmu() is required.
77 : *
78 : * tlb_remove_page() and tlb_remove_page_size() imply the call to
79 : * tlb_flush_mmu() when required and has no return value.
80 : *
81 : * - tlb_change_page_size()
82 : *
83 : * call before __tlb_remove_page*() to set the current page-size; implies a
84 : * possible tlb_flush_mmu() call.
85 : *
86 : * - tlb_flush_mmu() / tlb_flush_mmu_tlbonly()
87 : *
88 : * tlb_flush_mmu_tlbonly() - does the TLB invalidate (and resets
89 : * related state, like the range)
90 : *
91 : * tlb_flush_mmu() - in addition to the above TLB invalidate, also frees
92 : * whatever pages are still batched.
93 : *
94 : * - mmu_gather::fullmm
95 : *
96 : * A flag set by tlb_gather_mmu_fullmm() to indicate we're going to free
97 : * the entire mm; this allows a number of optimizations.
98 : *
99 : * - We can ignore tlb_{start,end}_vma(); because we don't
100 : * care about ranges. Everything will be shot down.
101 : *
102 : * - (RISC) architectures that use ASIDs can cycle to a new ASID
103 : * and delay the invalidation until ASID space runs out.
104 : *
105 : * - mmu_gather::need_flush_all
106 : *
107 : * A flag that can be set by the arch code if it wants to force
108 : * flush the entire TLB irrespective of the range. For instance
109 : * x86-PAE needs this when changing top-level entries.
110 : *
111 : * And allows the architecture to provide and implement tlb_flush():
112 : *
113 : * tlb_flush() may, in addition to the above mentioned mmu_gather fields, make
114 : * use of:
115 : *
116 : * - mmu_gather::start / mmu_gather::end
117 : *
118 : * which provides the range that needs to be flushed to cover the pages to
119 : * be freed.
120 : *
121 : * - mmu_gather::freed_tables
122 : *
123 : * set when we freed page table pages
124 : *
125 : * - tlb_get_unmap_shift() / tlb_get_unmap_size()
126 : *
127 : * returns the smallest TLB entry size unmapped in this range.
128 : *
129 : * If an architecture does not provide tlb_flush() a default implementation
130 : * based on flush_tlb_range() will be used, unless MMU_GATHER_NO_RANGE is
131 : * specified, in which case we'll default to flush_tlb_mm().
132 : *
133 : * Additionally there are a few opt-in features:
134 : *
135 : * MMU_GATHER_PAGE_SIZE
136 : *
137 : * This ensures we call tlb_flush() every time tlb_change_page_size() actually
138 : * changes the size and provides mmu_gather::page_size to tlb_flush().
139 : *
140 : * This might be useful if your architecture has size specific TLB
141 : * invalidation instructions.
142 : *
143 : * MMU_GATHER_TABLE_FREE
144 : *
145 : * This provides tlb_remove_table(), to be used instead of tlb_remove_page()
146 : * for page directores (__p*_free_tlb()).
147 : *
148 : * Useful if your architecture has non-page page directories.
149 : *
150 : * When used, an architecture is expected to provide __tlb_remove_table()
151 : * which does the actual freeing of these pages.
152 : *
153 : * MMU_GATHER_RCU_TABLE_FREE
154 : *
155 : * Like MMU_GATHER_TABLE_FREE, and adds semi-RCU semantics to the free (see
156 : * comment below).
157 : *
158 : * Useful if your architecture doesn't use IPIs for remote TLB invalidates
159 : * and therefore doesn't naturally serialize with software page-table walkers.
160 : *
161 : * MMU_GATHER_NO_FLUSH_CACHE
162 : *
163 : * Indicates the architecture has flush_cache_range() but it needs *NOT* be called
164 : * before unmapping a VMA.
165 : *
166 : * NOTE: strictly speaking we shouldn't have this knob and instead rely on
167 : * flush_cache_range() being a NOP, except Sparc64 seems to be
168 : * different here.
169 : *
170 : * MMU_GATHER_MERGE_VMAS
171 : *
172 : * Indicates the architecture wants to merge ranges over VMAs; typical when
173 : * multiple range invalidates are more expensive than a full invalidate.
174 : *
175 : * MMU_GATHER_NO_RANGE
176 : *
177 : * Use this if your architecture lacks an efficient flush_tlb_range(). This
178 : * option implies MMU_GATHER_MERGE_VMAS above.
179 : *
180 : * MMU_GATHER_NO_GATHER
181 : *
182 : * If the option is set the mmu_gather will not track individual pages for
183 : * delayed page free anymore. A platform that enables the option needs to
184 : * provide its own implementation of the __tlb_remove_page_size() function to
185 : * free pages.
186 : *
187 : * This is useful if your architecture already flushes TLB entries in the
188 : * various ptep_get_and_clear() functions.
189 : */
190 :
191 : #ifdef CONFIG_MMU_GATHER_TABLE_FREE
192 :
193 : struct mmu_table_batch {
194 : #ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE
195 : struct rcu_head rcu;
196 : #endif
197 : unsigned int nr;
198 : void *tables[];
199 : };
200 :
201 : #define MAX_TABLE_BATCH \
202 : ((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *))
203 :
204 : extern void tlb_remove_table(struct mmu_gather *tlb, void *table);
205 :
206 : #else /* !CONFIG_MMU_GATHER_HAVE_TABLE_FREE */
207 :
208 : /*
209 : * Without MMU_GATHER_TABLE_FREE the architecture is assumed to have page based
210 : * page directories and we can use the normal page batching to free them.
211 : */
212 : #define tlb_remove_table(tlb, page) tlb_remove_page((tlb), (page))
213 :
214 : #endif /* CONFIG_MMU_GATHER_TABLE_FREE */
215 :
216 : #ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE
217 : /*
218 : * This allows an architecture that does not use the linux page-tables for
219 : * hardware to skip the TLBI when freeing page tables.
220 : */
221 : #ifndef tlb_needs_table_invalidate
222 : #define tlb_needs_table_invalidate() (true)
223 : #endif
224 :
225 : void tlb_remove_table_sync_one(void);
226 :
227 : #else
228 :
229 : #ifdef tlb_needs_table_invalidate
230 : #error tlb_needs_table_invalidate() requires MMU_GATHER_RCU_TABLE_FREE
231 : #endif
232 :
233 : static inline void tlb_remove_table_sync_one(void) { }
234 :
235 : #endif /* CONFIG_MMU_GATHER_RCU_TABLE_FREE */
236 :
237 :
238 : #ifndef CONFIG_MMU_GATHER_NO_GATHER
239 : /*
240 : * If we can't allocate a page to make a big batch of page pointers
241 : * to work on, then just handle a few from the on-stack structure.
242 : */
243 : #define MMU_GATHER_BUNDLE 8
244 :
245 : struct mmu_gather_batch {
246 : struct mmu_gather_batch *next;
247 : unsigned int nr;
248 : unsigned int max;
249 : struct encoded_page *encoded_pages[];
250 : };
251 :
252 : #define MAX_GATHER_BATCH \
253 : ((PAGE_SIZE - sizeof(struct mmu_gather_batch)) / sizeof(void *))
254 :
255 : /*
256 : * Limit the maximum number of mmu_gather batches to reduce a risk of soft
257 : * lockups for non-preemptible kernels on huge machines when a lot of memory
258 : * is zapped during unmapping.
259 : * 10K pages freed at once should be safe even without a preemption point.
260 : */
261 : #define MAX_GATHER_BATCH_COUNT (10000UL/MAX_GATHER_BATCH)
262 :
263 : extern bool __tlb_remove_page_size(struct mmu_gather *tlb,
264 : struct encoded_page *page,
265 : int page_size);
266 :
267 : #ifdef CONFIG_SMP
268 : /*
269 : * This both sets 'delayed_rmap', and returns true. It would be an inline
270 : * function, except we define it before the 'struct mmu_gather'.
271 : */
272 : #define tlb_delay_rmap(tlb) (((tlb)->delayed_rmap = 1), true)
273 : extern void tlb_flush_rmaps(struct mmu_gather *tlb, struct vm_area_struct *vma);
274 : #endif
275 :
276 : #endif
277 :
278 : /*
279 : * We have a no-op version of the rmap removal that doesn't
280 : * delay anything. That is used on S390, which flushes remote
281 : * TLBs synchronously, and on UP, which doesn't have any
282 : * remote TLBs to flush and is not preemptible due to this
283 : * all happening under the page table lock.
284 : */
285 : #ifndef tlb_delay_rmap
286 : #define tlb_delay_rmap(tlb) (false)
287 : static inline void tlb_flush_rmaps(struct mmu_gather *tlb, struct vm_area_struct *vma) { }
288 : #endif
289 :
290 : /*
291 : * struct mmu_gather is an opaque type used by the mm code for passing around
292 : * any data needed by arch specific code for tlb_remove_page.
293 : */
294 : struct mmu_gather {
295 : struct mm_struct *mm;
296 :
297 : #ifdef CONFIG_MMU_GATHER_TABLE_FREE
298 : struct mmu_table_batch *batch;
299 : #endif
300 :
301 : unsigned long start;
302 : unsigned long end;
303 : /*
304 : * we are in the middle of an operation to clear
305 : * a full mm and can make some optimizations
306 : */
307 : unsigned int fullmm : 1;
308 :
309 : /*
310 : * we have performed an operation which
311 : * requires a complete flush of the tlb
312 : */
313 : unsigned int need_flush_all : 1;
314 :
315 : /*
316 : * we have removed page directories
317 : */
318 : unsigned int freed_tables : 1;
319 :
320 : /*
321 : * Do we have pending delayed rmap removals?
322 : */
323 : unsigned int delayed_rmap : 1;
324 :
325 : /*
326 : * at which levels have we cleared entries?
327 : */
328 : unsigned int cleared_ptes : 1;
329 : unsigned int cleared_pmds : 1;
330 : unsigned int cleared_puds : 1;
331 : unsigned int cleared_p4ds : 1;
332 :
333 : /*
334 : * tracks VM_EXEC | VM_HUGETLB in tlb_start_vma
335 : */
336 : unsigned int vma_exec : 1;
337 : unsigned int vma_huge : 1;
338 : unsigned int vma_pfn : 1;
339 :
340 : unsigned int batch_count;
341 :
342 : #ifndef CONFIG_MMU_GATHER_NO_GATHER
343 : struct mmu_gather_batch *active;
344 : struct mmu_gather_batch local;
345 : struct page *__pages[MMU_GATHER_BUNDLE];
346 :
347 : #ifdef CONFIG_MMU_GATHER_PAGE_SIZE
348 : unsigned int page_size;
349 : #endif
350 : #endif
351 : };
352 :
353 : void tlb_flush_mmu(struct mmu_gather *tlb);
354 :
355 : static inline void __tlb_adjust_range(struct mmu_gather *tlb,
356 : unsigned long address,
357 : unsigned int range_size)
358 : {
359 0 : tlb->start = min(tlb->start, address);
360 0 : tlb->end = max(tlb->end, address + range_size);
361 : }
362 :
363 : static inline void __tlb_reset_range(struct mmu_gather *tlb)
364 : {
365 0 : if (tlb->fullmm) {
366 0 : tlb->start = tlb->end = ~0;
367 : } else {
368 0 : tlb->start = TASK_SIZE;
369 0 : tlb->end = 0;
370 : }
371 0 : tlb->freed_tables = 0;
372 0 : tlb->cleared_ptes = 0;
373 0 : tlb->cleared_pmds = 0;
374 0 : tlb->cleared_puds = 0;
375 0 : tlb->cleared_p4ds = 0;
376 : /*
377 : * Do not reset mmu_gather::vma_* fields here, we do not
378 : * call into tlb_start_vma() again to set them if there is an
379 : * intermediate flush.
380 : */
381 : }
382 :
383 : #ifdef CONFIG_MMU_GATHER_NO_RANGE
384 :
385 : #if defined(tlb_flush)
386 : #error MMU_GATHER_NO_RANGE relies on default tlb_flush()
387 : #endif
388 :
389 : /*
390 : * When an architecture does not have efficient means of range flushing TLBs
391 : * there is no point in doing intermediate flushes on tlb_end_vma() to keep the
392 : * range small. We equally don't have to worry about page granularity or other
393 : * things.
394 : *
395 : * All we need to do is issue a full flush for any !0 range.
396 : */
397 : static inline void tlb_flush(struct mmu_gather *tlb)
398 : {
399 : if (tlb->end)
400 : flush_tlb_mm(tlb->mm);
401 : }
402 :
403 : #else /* CONFIG_MMU_GATHER_NO_RANGE */
404 :
405 : #ifndef tlb_flush
406 : /*
407 : * When an architecture does not provide its own tlb_flush() implementation
408 : * but does have a reasonably efficient flush_vma_range() implementation
409 : * use that.
410 : */
411 0 : static inline void tlb_flush(struct mmu_gather *tlb)
412 : {
413 0 : if (tlb->fullmm || tlb->need_flush_all) {
414 0 : flush_tlb_mm(tlb->mm);
415 0 : } else if (tlb->end) {
416 0 : struct vm_area_struct vma = {
417 0 : .vm_mm = tlb->mm,
418 0 : .vm_flags = (tlb->vma_exec ? VM_EXEC : 0) |
419 0 : (tlb->vma_huge ? VM_HUGETLB : 0),
420 : };
421 :
422 0 : flush_tlb_range(&vma, tlb->start, tlb->end);
423 : }
424 0 : }
425 : #endif
426 :
427 : #endif /* CONFIG_MMU_GATHER_NO_RANGE */
428 :
429 : static inline void
430 : tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma)
431 : {
432 : /*
433 : * flush_tlb_range() implementations that look at VM_HUGETLB (tile,
434 : * mips-4k) flush only large pages.
435 : *
436 : * flush_tlb_range() implementations that flush I-TLB also flush D-TLB
437 : * (tile, xtensa, arm), so it's ok to just add VM_EXEC to an existing
438 : * range.
439 : *
440 : * We rely on tlb_end_vma() to issue a flush, such that when we reset
441 : * these values the batch is empty.
442 : */
443 0 : tlb->vma_huge = is_vm_hugetlb_page(vma);
444 0 : tlb->vma_exec = !!(vma->vm_flags & VM_EXEC);
445 0 : tlb->vma_pfn = !!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP));
446 : }
447 :
448 0 : static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
449 : {
450 : /*
451 : * Anything calling __tlb_adjust_range() also sets at least one of
452 : * these bits.
453 : */
454 0 : if (!(tlb->freed_tables || tlb->cleared_ptes || tlb->cleared_pmds ||
455 : tlb->cleared_puds || tlb->cleared_p4ds))
456 : return;
457 :
458 0 : tlb_flush(tlb);
459 0 : mmu_notifier_invalidate_range(tlb->mm, tlb->start, tlb->end);
460 : __tlb_reset_range(tlb);
461 : }
462 :
463 0 : static inline void tlb_remove_page_size(struct mmu_gather *tlb,
464 : struct page *page, int page_size)
465 : {
466 0 : if (__tlb_remove_page_size(tlb, encode_page(page, 0), page_size))
467 0 : tlb_flush_mmu(tlb);
468 0 : }
469 :
470 : static __always_inline bool __tlb_remove_page(struct mmu_gather *tlb, struct page *page, unsigned int flags)
471 : {
472 0 : return __tlb_remove_page_size(tlb, encode_page(page, flags), PAGE_SIZE);
473 : }
474 :
475 : /* tlb_remove_page
476 : * Similar to __tlb_remove_page but will call tlb_flush_mmu() itself when
477 : * required.
478 : */
479 : static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
480 : {
481 0 : return tlb_remove_page_size(tlb, page, PAGE_SIZE);
482 : }
483 :
484 : static inline void tlb_change_page_size(struct mmu_gather *tlb,
485 : unsigned int page_size)
486 : {
487 : #ifdef CONFIG_MMU_GATHER_PAGE_SIZE
488 : if (tlb->page_size && tlb->page_size != page_size) {
489 : if (!tlb->fullmm && !tlb->need_flush_all)
490 : tlb_flush_mmu(tlb);
491 : }
492 :
493 : tlb->page_size = page_size;
494 : #endif
495 : }
496 :
497 : static inline unsigned long tlb_get_unmap_shift(struct mmu_gather *tlb)
498 : {
499 : if (tlb->cleared_ptes)
500 : return PAGE_SHIFT;
501 : if (tlb->cleared_pmds)
502 : return PMD_SHIFT;
503 : if (tlb->cleared_puds)
504 : return PUD_SHIFT;
505 : if (tlb->cleared_p4ds)
506 : return P4D_SHIFT;
507 :
508 : return PAGE_SHIFT;
509 : }
510 :
511 : static inline unsigned long tlb_get_unmap_size(struct mmu_gather *tlb)
512 : {
513 : return 1UL << tlb_get_unmap_shift(tlb);
514 : }
515 :
516 : /*
517 : * In the case of tlb vma handling, we can optimise these away in the
518 : * case where we're doing a full MM flush. When we're doing a munmap,
519 : * the vmas are adjusted to only cover the region to be torn down.
520 : */
521 : static inline void tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
522 : {
523 0 : if (tlb->fullmm)
524 : return;
525 :
526 0 : tlb_update_vma_flags(tlb, vma);
527 : #ifndef CONFIG_MMU_GATHER_NO_FLUSH_CACHE
528 0 : flush_cache_range(vma, vma->vm_start, vma->vm_end);
529 : #endif
530 : }
531 :
532 : static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
533 : {
534 0 : if (tlb->fullmm)
535 : return;
536 :
537 : /*
538 : * VM_PFNMAP is more fragile because the core mm will not track the
539 : * page mapcount -- there might not be page-frames for these PFNs after
540 : * all. Force flush TLBs for such ranges to avoid munmap() vs
541 : * unmap_mapping_range() races.
542 : */
543 : if (tlb->vma_pfn || !IS_ENABLED(CONFIG_MMU_GATHER_MERGE_VMAS)) {
544 : /*
545 : * Do a TLB flush and reset the range at VMA boundaries; this avoids
546 : * the ranges growing with the unused space between consecutive VMAs.
547 : */
548 0 : tlb_flush_mmu_tlbonly(tlb);
549 : }
550 : }
551 :
552 : /*
553 : * tlb_flush_{pte|pmd|pud|p4d}_range() adjust the tlb->start and tlb->end,
554 : * and set corresponding cleared_*.
555 : */
556 : static inline void tlb_flush_pte_range(struct mmu_gather *tlb,
557 : unsigned long address, unsigned long size)
558 : {
559 0 : __tlb_adjust_range(tlb, address, size);
560 0 : tlb->cleared_ptes = 1;
561 : }
562 :
563 : static inline void tlb_flush_pmd_range(struct mmu_gather *tlb,
564 : unsigned long address, unsigned long size)
565 : {
566 0 : __tlb_adjust_range(tlb, address, size);
567 0 : tlb->cleared_pmds = 1;
568 : }
569 :
570 : static inline void tlb_flush_pud_range(struct mmu_gather *tlb,
571 : unsigned long address, unsigned long size)
572 : {
573 0 : __tlb_adjust_range(tlb, address, size);
574 0 : tlb->cleared_puds = 1;
575 : }
576 :
577 : static inline void tlb_flush_p4d_range(struct mmu_gather *tlb,
578 : unsigned long address, unsigned long size)
579 : {
580 : __tlb_adjust_range(tlb, address, size);
581 : tlb->cleared_p4ds = 1;
582 : }
583 :
584 : #ifndef __tlb_remove_tlb_entry
585 : #define __tlb_remove_tlb_entry(tlb, ptep, address) do { } while (0)
586 : #endif
587 :
588 : /**
589 : * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
590 : *
591 : * Record the fact that pte's were really unmapped by updating the range,
592 : * so we can later optimise away the tlb invalidate. This helps when
593 : * userspace is unmapping already-unmapped pages, which happens quite a lot.
594 : */
595 : #define tlb_remove_tlb_entry(tlb, ptep, address) \
596 : do { \
597 : tlb_flush_pte_range(tlb, address, PAGE_SIZE); \
598 : __tlb_remove_tlb_entry(tlb, ptep, address); \
599 : } while (0)
600 :
601 : #define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \
602 : do { \
603 : unsigned long _sz = huge_page_size(h); \
604 : if (_sz >= P4D_SIZE) \
605 : tlb_flush_p4d_range(tlb, address, _sz); \
606 : else if (_sz >= PUD_SIZE) \
607 : tlb_flush_pud_range(tlb, address, _sz); \
608 : else if (_sz >= PMD_SIZE) \
609 : tlb_flush_pmd_range(tlb, address, _sz); \
610 : else \
611 : tlb_flush_pte_range(tlb, address, _sz); \
612 : __tlb_remove_tlb_entry(tlb, ptep, address); \
613 : } while (0)
614 :
615 : /**
616 : * tlb_remove_pmd_tlb_entry - remember a pmd mapping for later tlb invalidation
617 : * This is a nop so far, because only x86 needs it.
618 : */
619 : #ifndef __tlb_remove_pmd_tlb_entry
620 : #define __tlb_remove_pmd_tlb_entry(tlb, pmdp, address) do {} while (0)
621 : #endif
622 :
623 : #define tlb_remove_pmd_tlb_entry(tlb, pmdp, address) \
624 : do { \
625 : tlb_flush_pmd_range(tlb, address, HPAGE_PMD_SIZE); \
626 : __tlb_remove_pmd_tlb_entry(tlb, pmdp, address); \
627 : } while (0)
628 :
629 : /**
630 : * tlb_remove_pud_tlb_entry - remember a pud mapping for later tlb
631 : * invalidation. This is a nop so far, because only x86 needs it.
632 : */
633 : #ifndef __tlb_remove_pud_tlb_entry
634 : #define __tlb_remove_pud_tlb_entry(tlb, pudp, address) do {} while (0)
635 : #endif
636 :
637 : #define tlb_remove_pud_tlb_entry(tlb, pudp, address) \
638 : do { \
639 : tlb_flush_pud_range(tlb, address, HPAGE_PUD_SIZE); \
640 : __tlb_remove_pud_tlb_entry(tlb, pudp, address); \
641 : } while (0)
642 :
643 : /*
644 : * For things like page tables caches (ie caching addresses "inside" the
645 : * page tables, like x86 does), for legacy reasons, flushing an
646 : * individual page had better flush the page table caches behind it. This
647 : * is definitely how x86 works, for example. And if you have an
648 : * architected non-legacy page table cache (which I'm not aware of
649 : * anybody actually doing), you're going to have some architecturally
650 : * explicit flushing for that, likely *separate* from a regular TLB entry
651 : * flush, and thus you'd need more than just some range expansion..
652 : *
653 : * So if we ever find an architecture
654 : * that would want something that odd, I think it is up to that
655 : * architecture to do its own odd thing, not cause pain for others
656 : * http://lkml.kernel.org/r/CA+55aFzBggoXtNXQeng5d_mRoDnaMBE5Y+URs+PHR67nUpMtaw@mail.gmail.com
657 : *
658 : * For now w.r.t page table cache, mark the range_size as PAGE_SIZE
659 : */
660 :
661 : #ifndef pte_free_tlb
662 : #define pte_free_tlb(tlb, ptep, address) \
663 : do { \
664 : tlb_flush_pmd_range(tlb, address, PAGE_SIZE); \
665 : tlb->freed_tables = 1; \
666 : __pte_free_tlb(tlb, ptep, address); \
667 : } while (0)
668 : #endif
669 :
670 : #ifndef pmd_free_tlb
671 : #define pmd_free_tlb(tlb, pmdp, address) \
672 : do { \
673 : tlb_flush_pud_range(tlb, address, PAGE_SIZE); \
674 : tlb->freed_tables = 1; \
675 : __pmd_free_tlb(tlb, pmdp, address); \
676 : } while (0)
677 : #endif
678 :
679 : #ifndef pud_free_tlb
680 : #define pud_free_tlb(tlb, pudp, address) \
681 : do { \
682 : tlb_flush_p4d_range(tlb, address, PAGE_SIZE); \
683 : tlb->freed_tables = 1; \
684 : __pud_free_tlb(tlb, pudp, address); \
685 : } while (0)
686 : #endif
687 :
688 : #ifndef p4d_free_tlb
689 : #define p4d_free_tlb(tlb, pudp, address) \
690 : do { \
691 : __tlb_adjust_range(tlb, address, PAGE_SIZE); \
692 : tlb->freed_tables = 1; \
693 : __p4d_free_tlb(tlb, pudp, address); \
694 : } while (0)
695 : #endif
696 :
697 : #ifndef pte_needs_flush
698 : static inline bool pte_needs_flush(pte_t oldpte, pte_t newpte)
699 : {
700 : return true;
701 : }
702 : #endif
703 :
704 : #ifndef huge_pmd_needs_flush
705 : static inline bool huge_pmd_needs_flush(pmd_t oldpmd, pmd_t newpmd)
706 : {
707 : return true;
708 : }
709 : #endif
710 :
711 : #endif /* CONFIG_MMU */
712 :
713 : #endif /* _ASM_GENERIC__TLB_H */
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