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_size()
71 * - __tlb_remove_folio_pages() / __tlb_remove_page_size()
72 * - __tlb_remove_folio_pages_size()
73 *
74 * __tlb_remove_folio_pages_size() is the basic primitive that queues pages
75 * for freeing. It will return a boolean indicating if the queue is (now)
76 * full and a call to 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_remove_folio_pages() is similar to __tlb_remove_page_size(),
82 * however, instead of removing a single page, assume PAGE_SIZE and remove
83 * the given number of consecutive pages that are all part of the
84 * same (large) folio.
85 *
86 * - tlb_change_page_size()
87 *
88 * call before __tlb_remove_page*() to set the current page-size; implies a
89 * possible tlb_flush_mmu() call.
90 *
91 * - tlb_flush_mmu() / tlb_flush_mmu_tlbonly()
92 *
93 * tlb_flush_mmu_tlbonly() - does the TLB invalidate (and resets
94 * related state, like the range)
95 *
96 * tlb_flush_mmu() - in addition to the above TLB invalidate, also frees
97 * whatever pages are still batched.
98 *
99 * - mmu_gather::fullmm
100 *
101 * A flag set by tlb_gather_mmu_fullmm() to indicate we're going to free
102 * the entire mm; this allows a number of optimizations.
103 *
104 * - We can ignore tlb_{start,end}_vma(); because we don't
105 * care about ranges. Everything will be shot down.
106 *
107 * - (RISC) architectures that use ASIDs can cycle to a new ASID
108 * and delay the invalidation until ASID space runs out.
109 *
110 * - mmu_gather::need_flush_all
111 *
112 * A flag that can be set by the arch code if it wants to force
113 * flush the entire TLB irrespective of the range. For instance
114 * x86-PAE needs this when changing top-level entries.
115 *
116 * And allows the architecture to provide and implement tlb_flush():
117 *
118 * tlb_flush() may, in addition to the above mentioned mmu_gather fields, make
119 * use of:
120 *
121 * - mmu_gather::start / mmu_gather::end
122 *
123 * which provides the range that needs to be flushed to cover the pages to
124 * be freed.
125 *
126 * - mmu_gather::freed_tables
127 *
128 * set when we freed page table pages
129 *
130 * - tlb_get_unmap_shift() / tlb_get_unmap_size()
131 *
132 * returns the smallest TLB entry size unmapped in this range.
133 *
134 * If an architecture does not provide tlb_flush() a default implementation
135 * based on flush_tlb_range() will be used, unless MMU_GATHER_NO_RANGE is
136 * specified, in which case we'll default to flush_tlb_mm().
137 *
138 * Additionally there are a few opt-in features:
139 *
140 * MMU_GATHER_PAGE_SIZE
141 *
142 * This ensures we call tlb_flush() every time tlb_change_page_size() actually
143 * changes the size and provides mmu_gather::page_size to tlb_flush().
144 *
145 * This might be useful if your architecture has size specific TLB
146 * invalidation instructions.
147 *
148 * MMU_GATHER_TABLE_FREE
149 *
150 * This provides tlb_remove_table(), to be used instead of tlb_remove_page()
151 * for page directores (__p*_free_tlb()).
152 *
153 * Useful if your architecture has non-page page directories.
154 *
155 * When used, an architecture is expected to provide __tlb_remove_table() or
156 * use the generic __tlb_remove_table(), which does the actual freeing of these
157 * pages.
158 *
159 * MMU_GATHER_RCU_TABLE_FREE
160 *
161 * Like MMU_GATHER_TABLE_FREE, and adds semi-RCU semantics to the free (see
162 * comment below).
163 *
164 * Useful if your architecture doesn't use IPIs for remote TLB invalidates
165 * and therefore doesn't naturally serialize with software page-table walkers.
166 *
167 * MMU_GATHER_NO_FLUSH_CACHE
168 *
169 * Indicates the architecture has flush_cache_range() but it needs *NOT* be called
170 * before unmapping a VMA.
171 *
172 * NOTE: strictly speaking we shouldn't have this knob and instead rely on
173 * flush_cache_range() being a NOP, except Sparc64 seems to be
174 * different here.
175 *
176 * MMU_GATHER_MERGE_VMAS
177 *
178 * Indicates the architecture wants to merge ranges over VMAs; typical when
179 * multiple range invalidates are more expensive than a full invalidate.
180 *
181 * MMU_GATHER_NO_RANGE
182 *
183 * Use this if your architecture lacks an efficient flush_tlb_range(). This
184 * option implies MMU_GATHER_MERGE_VMAS above.
185 *
186 * MMU_GATHER_NO_GATHER
187 *
188 * If the option is set the mmu_gather will not track individual pages for
189 * delayed page free anymore. A platform that enables the option needs to
190 * provide its own implementation of the __tlb_remove_page_size() function to
191 * free pages.
192 *
193 * This is useful if your architecture already flushes TLB entries in the
194 * various ptep_get_and_clear() functions.
195 */
196
197 #ifdef CONFIG_MMU_GATHER_TABLE_FREE
198
199 struct mmu_table_batch {
200 #ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE
201 struct rcu_head rcu;
202 #endif
203 unsigned int nr;
204 void *tables[];
205 };
206
207 #define MAX_TABLE_BATCH \
208 ((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *))
209
210 #ifndef __HAVE_ARCH_TLB_REMOVE_TABLE
__tlb_remove_table(void * table)211 static inline void __tlb_remove_table(void *table)
212 {
213 struct ptdesc *ptdesc = (struct ptdesc *)table;
214
215 pagetable_dtor_free(ptdesc);
216 }
217 #endif
218
219 extern void tlb_remove_table(struct mmu_gather *tlb, void *table);
220
221 #else /* !CONFIG_MMU_GATHER_TABLE_FREE */
222
223 static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page);
224 /*
225 * Without MMU_GATHER_TABLE_FREE the architecture is assumed to have page based
226 * page directories and we can use the normal page batching to free them.
227 */
tlb_remove_table(struct mmu_gather * tlb,void * table)228 static inline void tlb_remove_table(struct mmu_gather *tlb, void *table)
229 {
230 struct ptdesc *ptdesc = (struct ptdesc *)table;
231
232 pagetable_dtor(ptdesc);
233 tlb_remove_page(tlb, ptdesc_page(ptdesc));
234 }
235 #endif /* CONFIG_MMU_GATHER_TABLE_FREE */
236
237 #ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE
238 /*
239 * This allows an architecture that does not use the linux page-tables for
240 * hardware to skip the TLBI when freeing page tables.
241 */
242 #ifndef tlb_needs_table_invalidate
243 #define tlb_needs_table_invalidate() (true)
244 #endif
245
246 void tlb_remove_table_sync_one(void);
247
248 #else
249
250 #ifdef tlb_needs_table_invalidate
251 #error tlb_needs_table_invalidate() requires MMU_GATHER_RCU_TABLE_FREE
252 #endif
253
tlb_remove_table_sync_one(void)254 static inline void tlb_remove_table_sync_one(void) { }
255
256 #endif /* CONFIG_MMU_GATHER_RCU_TABLE_FREE */
257
258
259 #ifndef CONFIG_MMU_GATHER_NO_GATHER
260 /*
261 * If we can't allocate a page to make a big batch of page pointers
262 * to work on, then just handle a few from the on-stack structure.
263 */
264 #define MMU_GATHER_BUNDLE 8
265
266 struct mmu_gather_batch {
267 struct mmu_gather_batch *next;
268 unsigned int nr;
269 unsigned int max;
270 struct encoded_page *encoded_pages[];
271 };
272
273 #define MAX_GATHER_BATCH \
274 ((PAGE_SIZE - sizeof(struct mmu_gather_batch)) / sizeof(void *))
275
276 /*
277 * Limit the maximum number of mmu_gather batches to reduce a risk of soft
278 * lockups for non-preemptible kernels on huge machines when a lot of memory
279 * is zapped during unmapping.
280 * 10K pages freed at once should be safe even without a preemption point.
281 */
282 #define MAX_GATHER_BATCH_COUNT (10000UL/MAX_GATHER_BATCH)
283
284 extern bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page,
285 bool delay_rmap, int page_size);
286 bool __tlb_remove_folio_pages(struct mmu_gather *tlb, struct page *page,
287 unsigned int nr_pages, bool delay_rmap);
288
289 #ifdef CONFIG_SMP
290 /*
291 * This both sets 'delayed_rmap', and returns true. It would be an inline
292 * function, except we define it before the 'struct mmu_gather'.
293 */
294 #define tlb_delay_rmap(tlb) (((tlb)->delayed_rmap = 1), true)
295 extern void tlb_flush_rmaps(struct mmu_gather *tlb, struct vm_area_struct *vma);
296 #endif
297
298 #endif
299
300 /*
301 * We have a no-op version of the rmap removal that doesn't
302 * delay anything. That is used on S390, which flushes remote
303 * TLBs synchronously, and on UP, which doesn't have any
304 * remote TLBs to flush and is not preemptible due to this
305 * all happening under the page table lock.
306 */
307 #ifndef tlb_delay_rmap
308 #define tlb_delay_rmap(tlb) (false)
tlb_flush_rmaps(struct mmu_gather * tlb,struct vm_area_struct * vma)309 static inline void tlb_flush_rmaps(struct mmu_gather *tlb, struct vm_area_struct *vma) { }
310 #endif
311
312 /*
313 * struct mmu_gather is an opaque type used by the mm code for passing around
314 * any data needed by arch specific code for tlb_remove_page.
315 */
316 struct mmu_gather {
317 struct mm_struct *mm;
318
319 #ifdef CONFIG_MMU_GATHER_TABLE_FREE
320 struct mmu_table_batch *batch;
321 #endif
322
323 unsigned long start;
324 unsigned long end;
325 /*
326 * we are in the middle of an operation to clear
327 * a full mm and can make some optimizations
328 */
329 unsigned int fullmm : 1;
330
331 /*
332 * we have performed an operation which
333 * requires a complete flush of the tlb
334 */
335 unsigned int need_flush_all : 1;
336
337 /*
338 * we have removed page directories
339 */
340 unsigned int freed_tables : 1;
341
342 /*
343 * Do we have pending delayed rmap removals?
344 */
345 unsigned int delayed_rmap : 1;
346
347 /*
348 * at which levels have we cleared entries?
349 */
350 unsigned int cleared_ptes : 1;
351 unsigned int cleared_pmds : 1;
352 unsigned int cleared_puds : 1;
353 unsigned int cleared_p4ds : 1;
354
355 /*
356 * tracks VM_EXEC | VM_HUGETLB in tlb_start_vma
357 */
358 unsigned int vma_exec : 1;
359 unsigned int vma_huge : 1;
360 unsigned int vma_pfn : 1;
361
362 unsigned int batch_count;
363
364 #ifndef CONFIG_MMU_GATHER_NO_GATHER
365 struct mmu_gather_batch *active;
366 struct mmu_gather_batch local;
367 struct page *__pages[MMU_GATHER_BUNDLE];
368
369 #ifdef CONFIG_MMU_GATHER_PAGE_SIZE
370 unsigned int page_size;
371 #endif
372 #endif
373 };
374
375 void tlb_flush_mmu(struct mmu_gather *tlb);
376
__tlb_adjust_range(struct mmu_gather * tlb,unsigned long address,unsigned int range_size)377 static inline void __tlb_adjust_range(struct mmu_gather *tlb,
378 unsigned long address,
379 unsigned int range_size)
380 {
381 tlb->start = min(tlb->start, address);
382 tlb->end = max(tlb->end, address + range_size);
383 }
384
__tlb_reset_range(struct mmu_gather * tlb)385 static inline void __tlb_reset_range(struct mmu_gather *tlb)
386 {
387 if (tlb->fullmm) {
388 tlb->start = tlb->end = ~0;
389 } else {
390 tlb->start = TASK_SIZE;
391 tlb->end = 0;
392 }
393 tlb->freed_tables = 0;
394 tlb->cleared_ptes = 0;
395 tlb->cleared_pmds = 0;
396 tlb->cleared_puds = 0;
397 tlb->cleared_p4ds = 0;
398 /*
399 * Do not reset mmu_gather::vma_* fields here, we do not
400 * call into tlb_start_vma() again to set them if there is an
401 * intermediate flush.
402 */
403 }
404
405 #ifdef CONFIG_MMU_GATHER_NO_RANGE
406
407 #if defined(tlb_flush)
408 #error MMU_GATHER_NO_RANGE relies on default tlb_flush()
409 #endif
410
411 /*
412 * When an architecture does not have efficient means of range flushing TLBs
413 * there is no point in doing intermediate flushes on tlb_end_vma() to keep the
414 * range small. We equally don't have to worry about page granularity or other
415 * things.
416 *
417 * All we need to do is issue a full flush for any !0 range.
418 */
tlb_flush(struct mmu_gather * tlb)419 static inline void tlb_flush(struct mmu_gather *tlb)
420 {
421 if (tlb->end)
422 flush_tlb_mm(tlb->mm);
423 }
424
425 #else /* CONFIG_MMU_GATHER_NO_RANGE */
426
427 #ifndef tlb_flush
428 /*
429 * When an architecture does not provide its own tlb_flush() implementation
430 * but does have a reasonably efficient flush_vma_range() implementation
431 * use that.
432 */
tlb_flush(struct mmu_gather * tlb)433 static inline void tlb_flush(struct mmu_gather *tlb)
434 {
435 if (tlb->fullmm || tlb->need_flush_all) {
436 flush_tlb_mm(tlb->mm);
437 } else if (tlb->end) {
438 struct vm_area_struct vma = {
439 .vm_mm = tlb->mm,
440 .vm_flags = (tlb->vma_exec ? VM_EXEC : 0) |
441 (tlb->vma_huge ? VM_HUGETLB : 0),
442 };
443
444 flush_tlb_range(&vma, tlb->start, tlb->end);
445 }
446 }
447 #endif
448
449 #endif /* CONFIG_MMU_GATHER_NO_RANGE */
450
451 static inline void
tlb_update_vma_flags(struct mmu_gather * tlb,struct vm_area_struct * vma)452 tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma)
453 {
454 /*
455 * flush_tlb_range() implementations that look at VM_HUGETLB (tile,
456 * mips-4k) flush only large pages.
457 *
458 * flush_tlb_range() implementations that flush I-TLB also flush D-TLB
459 * (tile, xtensa, arm), so it's ok to just add VM_EXEC to an existing
460 * range.
461 *
462 * We rely on tlb_end_vma() to issue a flush, such that when we reset
463 * these values the batch is empty.
464 */
465 tlb->vma_huge = is_vm_hugetlb_page(vma);
466 tlb->vma_exec = !!(vma->vm_flags & VM_EXEC);
467 tlb->vma_pfn = !!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP));
468 }
469
tlb_flush_mmu_tlbonly(struct mmu_gather * tlb)470 static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
471 {
472 /*
473 * Anything calling __tlb_adjust_range() also sets at least one of
474 * these bits.
475 */
476 if (!(tlb->freed_tables || tlb->cleared_ptes || tlb->cleared_pmds ||
477 tlb->cleared_puds || tlb->cleared_p4ds))
478 return;
479
480 tlb_flush(tlb);
481 __tlb_reset_range(tlb);
482 }
483
tlb_remove_page_size(struct mmu_gather * tlb,struct page * page,int page_size)484 static inline void tlb_remove_page_size(struct mmu_gather *tlb,
485 struct page *page, int page_size)
486 {
487 if (__tlb_remove_page_size(tlb, page, false, page_size))
488 tlb_flush_mmu(tlb);
489 }
490
tlb_remove_page(struct mmu_gather * tlb,struct page * page)491 static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
492 {
493 return tlb_remove_page_size(tlb, page, PAGE_SIZE);
494 }
495
tlb_remove_ptdesc(struct mmu_gather * tlb,struct ptdesc * pt)496 static inline void tlb_remove_ptdesc(struct mmu_gather *tlb, struct ptdesc *pt)
497 {
498 tlb_remove_table(tlb, pt);
499 }
500
tlb_change_page_size(struct mmu_gather * tlb,unsigned int page_size)501 static inline void tlb_change_page_size(struct mmu_gather *tlb,
502 unsigned int page_size)
503 {
504 #ifdef CONFIG_MMU_GATHER_PAGE_SIZE
505 if (tlb->page_size && tlb->page_size != page_size) {
506 if (!tlb->fullmm && !tlb->need_flush_all)
507 tlb_flush_mmu(tlb);
508 }
509
510 tlb->page_size = page_size;
511 #endif
512 }
513
tlb_get_unmap_shift(struct mmu_gather * tlb)514 static inline unsigned long tlb_get_unmap_shift(struct mmu_gather *tlb)
515 {
516 if (tlb->cleared_ptes)
517 return PAGE_SHIFT;
518 if (tlb->cleared_pmds)
519 return PMD_SHIFT;
520 if (tlb->cleared_puds)
521 return PUD_SHIFT;
522 if (tlb->cleared_p4ds)
523 return P4D_SHIFT;
524
525 return PAGE_SHIFT;
526 }
527
tlb_get_unmap_size(struct mmu_gather * tlb)528 static inline unsigned long tlb_get_unmap_size(struct mmu_gather *tlb)
529 {
530 return 1UL << tlb_get_unmap_shift(tlb);
531 }
532
533 /*
534 * In the case of tlb vma handling, we can optimise these away in the
535 * case where we're doing a full MM flush. When we're doing a munmap,
536 * the vmas are adjusted to only cover the region to be torn down.
537 */
tlb_start_vma(struct mmu_gather * tlb,struct vm_area_struct * vma)538 static inline void tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
539 {
540 if (tlb->fullmm)
541 return;
542
543 tlb_update_vma_flags(tlb, vma);
544 #ifndef CONFIG_MMU_GATHER_NO_FLUSH_CACHE
545 flush_cache_range(vma, vma->vm_start, vma->vm_end);
546 #endif
547 }
548
tlb_end_vma(struct mmu_gather * tlb,struct vm_area_struct * vma)549 static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
550 {
551 if (tlb->fullmm)
552 return;
553
554 /*
555 * VM_PFNMAP is more fragile because the core mm will not track the
556 * page mapcount -- there might not be page-frames for these PFNs after
557 * all. Force flush TLBs for such ranges to avoid munmap() vs
558 * unmap_mapping_range() races.
559 */
560 if (tlb->vma_pfn || !IS_ENABLED(CONFIG_MMU_GATHER_MERGE_VMAS)) {
561 /*
562 * Do a TLB flush and reset the range at VMA boundaries; this avoids
563 * the ranges growing with the unused space between consecutive VMAs.
564 */
565 tlb_flush_mmu_tlbonly(tlb);
566 }
567 }
568
569 /*
570 * tlb_flush_{pte|pmd|pud|p4d}_range() adjust the tlb->start and tlb->end,
571 * and set corresponding cleared_*.
572 */
tlb_flush_pte_range(struct mmu_gather * tlb,unsigned long address,unsigned long size)573 static inline void tlb_flush_pte_range(struct mmu_gather *tlb,
574 unsigned long address, unsigned long size)
575 {
576 __tlb_adjust_range(tlb, address, size);
577 tlb->cleared_ptes = 1;
578 }
579
tlb_flush_pmd_range(struct mmu_gather * tlb,unsigned long address,unsigned long size)580 static inline void tlb_flush_pmd_range(struct mmu_gather *tlb,
581 unsigned long address, unsigned long size)
582 {
583 __tlb_adjust_range(tlb, address, size);
584 tlb->cleared_pmds = 1;
585 }
586
tlb_flush_pud_range(struct mmu_gather * tlb,unsigned long address,unsigned long size)587 static inline void tlb_flush_pud_range(struct mmu_gather *tlb,
588 unsigned long address, unsigned long size)
589 {
590 __tlb_adjust_range(tlb, address, size);
591 tlb->cleared_puds = 1;
592 }
593
tlb_flush_p4d_range(struct mmu_gather * tlb,unsigned long address,unsigned long size)594 static inline void tlb_flush_p4d_range(struct mmu_gather *tlb,
595 unsigned long address, unsigned long size)
596 {
597 __tlb_adjust_range(tlb, address, size);
598 tlb->cleared_p4ds = 1;
599 }
600
601 #ifndef __tlb_remove_tlb_entry
__tlb_remove_tlb_entry(struct mmu_gather * tlb,pte_t * ptep,unsigned long address)602 static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, unsigned long address)
603 {
604 }
605 #endif
606
607 /**
608 * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
609 *
610 * Record the fact that pte's were really unmapped by updating the range,
611 * so we can later optimise away the tlb invalidate. This helps when
612 * userspace is unmapping already-unmapped pages, which happens quite a lot.
613 */
614 #define tlb_remove_tlb_entry(tlb, ptep, address) \
615 do { \
616 tlb_flush_pte_range(tlb, address, PAGE_SIZE); \
617 __tlb_remove_tlb_entry(tlb, ptep, address); \
618 } while (0)
619
620 /**
621 * tlb_remove_tlb_entries - remember unmapping of multiple consecutive ptes for
622 * later tlb invalidation.
623 *
624 * Similar to tlb_remove_tlb_entry(), but remember unmapping of multiple
625 * consecutive ptes instead of only a single one.
626 */
tlb_remove_tlb_entries(struct mmu_gather * tlb,pte_t * ptep,unsigned int nr,unsigned long address)627 static inline void tlb_remove_tlb_entries(struct mmu_gather *tlb,
628 pte_t *ptep, unsigned int nr, unsigned long address)
629 {
630 tlb_flush_pte_range(tlb, address, PAGE_SIZE * nr);
631 for (;;) {
632 __tlb_remove_tlb_entry(tlb, ptep, address);
633 if (--nr == 0)
634 break;
635 ptep++;
636 address += PAGE_SIZE;
637 }
638 }
639
640 #define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \
641 do { \
642 unsigned long _sz = huge_page_size(h); \
643 if (_sz >= P4D_SIZE) \
644 tlb_flush_p4d_range(tlb, address, _sz); \
645 else if (_sz >= PUD_SIZE) \
646 tlb_flush_pud_range(tlb, address, _sz); \
647 else if (_sz >= PMD_SIZE) \
648 tlb_flush_pmd_range(tlb, address, _sz); \
649 else \
650 tlb_flush_pte_range(tlb, address, _sz); \
651 __tlb_remove_tlb_entry(tlb, ptep, address); \
652 } while (0)
653
654 /**
655 * tlb_remove_pmd_tlb_entry - remember a pmd mapping for later tlb invalidation
656 * This is a nop so far, because only x86 needs it.
657 */
658 #ifndef __tlb_remove_pmd_tlb_entry
659 #define __tlb_remove_pmd_tlb_entry(tlb, pmdp, address) do {} while (0)
660 #endif
661
662 #define tlb_remove_pmd_tlb_entry(tlb, pmdp, address) \
663 do { \
664 tlb_flush_pmd_range(tlb, address, HPAGE_PMD_SIZE); \
665 __tlb_remove_pmd_tlb_entry(tlb, pmdp, address); \
666 } while (0)
667
668 /**
669 * tlb_remove_pud_tlb_entry - remember a pud mapping for later tlb
670 * invalidation. This is a nop so far, because only x86 needs it.
671 */
672 #ifndef __tlb_remove_pud_tlb_entry
673 #define __tlb_remove_pud_tlb_entry(tlb, pudp, address) do {} while (0)
674 #endif
675
676 #define tlb_remove_pud_tlb_entry(tlb, pudp, address) \
677 do { \
678 tlb_flush_pud_range(tlb, address, HPAGE_PUD_SIZE); \
679 __tlb_remove_pud_tlb_entry(tlb, pudp, address); \
680 } while (0)
681
682 /*
683 * For things like page tables caches (ie caching addresses "inside" the
684 * page tables, like x86 does), for legacy reasons, flushing an
685 * individual page had better flush the page table caches behind it. This
686 * is definitely how x86 works, for example. And if you have an
687 * architected non-legacy page table cache (which I'm not aware of
688 * anybody actually doing), you're going to have some architecturally
689 * explicit flushing for that, likely *separate* from a regular TLB entry
690 * flush, and thus you'd need more than just some range expansion..
691 *
692 * So if we ever find an architecture
693 * that would want something that odd, I think it is up to that
694 * architecture to do its own odd thing, not cause pain for others
695 * http://lkml.kernel.org/r/CA+55aFzBggoXtNXQeng5d_mRoDnaMBE5Y+URs+PHR67nUpMtaw@mail.gmail.com
696 *
697 * For now w.r.t page table cache, mark the range_size as PAGE_SIZE
698 */
699
700 #ifndef pte_free_tlb
701 #define pte_free_tlb(tlb, ptep, address) \
702 do { \
703 tlb_flush_pmd_range(tlb, address, PAGE_SIZE); \
704 tlb->freed_tables = 1; \
705 __pte_free_tlb(tlb, ptep, address); \
706 } while (0)
707 #endif
708
709 #ifndef pmd_free_tlb
710 #define pmd_free_tlb(tlb, pmdp, address) \
711 do { \
712 tlb_flush_pud_range(tlb, address, PAGE_SIZE); \
713 tlb->freed_tables = 1; \
714 __pmd_free_tlb(tlb, pmdp, address); \
715 } while (0)
716 #endif
717
718 #ifndef pud_free_tlb
719 #define pud_free_tlb(tlb, pudp, address) \
720 do { \
721 tlb_flush_p4d_range(tlb, address, PAGE_SIZE); \
722 tlb->freed_tables = 1; \
723 __pud_free_tlb(tlb, pudp, address); \
724 } while (0)
725 #endif
726
727 #ifndef p4d_free_tlb
728 #define p4d_free_tlb(tlb, pudp, address) \
729 do { \
730 __tlb_adjust_range(tlb, address, PAGE_SIZE); \
731 tlb->freed_tables = 1; \
732 __p4d_free_tlb(tlb, pudp, address); \
733 } while (0)
734 #endif
735
736 #ifndef pte_needs_flush
pte_needs_flush(pte_t oldpte,pte_t newpte)737 static inline bool pte_needs_flush(pte_t oldpte, pte_t newpte)
738 {
739 return true;
740 }
741 #endif
742
743 #ifndef huge_pmd_needs_flush
huge_pmd_needs_flush(pmd_t oldpmd,pmd_t newpmd)744 static inline bool huge_pmd_needs_flush(pmd_t oldpmd, pmd_t newpmd)
745 {
746 return true;
747 }
748 #endif
749
750 #endif /* CONFIG_MMU */
751
752 #endif /* _ASM_GENERIC__TLB_H */
753