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 *  - __tlb_remove_folio_pages()
73 *
74 *    __tlb_remove_page_size() is the basic primitive that queues a page for
75 *    freeing. __tlb_remove_page() assumes PAGE_SIZE. Both will return a
76 *    boolean indicating if the queue is (now) full and a call to
77 *    tlb_flush_mmu() is required.
78 *
79 *    tlb_remove_page() and tlb_remove_page_size() imply the call to
80 *    tlb_flush_mmu() when required and has no return value.
81 *
82 *    __tlb_remove_folio_pages() is similar to __tlb_remove_page(), however,
83 *    instead of removing a single page, remove the given number of consecutive
84 *    pages that are all part of the same (large) folio: just like calling
85 *    __tlb_remove_page() on each page individually.
86 *
87 *  - tlb_change_page_size()
88 *
89 *    call before __tlb_remove_page*() to set the current page-size; implies a
90 *    possible tlb_flush_mmu() call.
91 *
92 *  - tlb_flush_mmu() / tlb_flush_mmu_tlbonly()
93 *
94 *    tlb_flush_mmu_tlbonly() - does the TLB invalidate (and resets
95 *                              related state, like the range)
96 *
97 *    tlb_flush_mmu() - in addition to the above TLB invalidate, also frees
98 *			whatever pages are still batched.
99 *
100 *  - mmu_gather::fullmm
101 *
102 *    A flag set by tlb_gather_mmu_fullmm() to indicate we're going to free
103 *    the entire mm; this allows a number of optimizations.
104 *
105 *    - We can ignore tlb_{start,end}_vma(); because we don't
106 *      care about ranges. Everything will be shot down.
107 *
108 *    - (RISC) architectures that use ASIDs can cycle to a new ASID
109 *      and delay the invalidation until ASID space runs out.
110 *
111 *  - mmu_gather::need_flush_all
112 *
113 *    A flag that can be set by the arch code if it wants to force
114 *    flush the entire TLB irrespective of the range. For instance
115 *    x86-PAE needs this when changing top-level entries.
116 *
117 * And allows the architecture to provide and implement tlb_flush():
118 *
119 * tlb_flush() may, in addition to the above mentioned mmu_gather fields, make
120 * use of:
121 *
122 *  - mmu_gather::start / mmu_gather::end
123 *
124 *    which provides the range that needs to be flushed to cover the pages to
125 *    be freed.
126 *
127 *  - mmu_gather::freed_tables
128 *
129 *    set when we freed page table pages
130 *
131 *  - tlb_get_unmap_shift() / tlb_get_unmap_size()
132 *
133 *    returns the smallest TLB entry size unmapped in this range.
134 *
135 * If an architecture does not provide tlb_flush() a default implementation
136 * based on flush_tlb_range() will be used, unless MMU_GATHER_NO_RANGE is
137 * specified, in which case we'll default to flush_tlb_mm().
138 *
139 * Additionally there are a few opt-in features:
140 *
141 *  MMU_GATHER_PAGE_SIZE
142 *
143 *  This ensures we call tlb_flush() every time tlb_change_page_size() actually
144 *  changes the size and provides mmu_gather::page_size to tlb_flush().
145 *
146 *  This might be useful if your architecture has size specific TLB
147 *  invalidation instructions.
148 *
149 *  MMU_GATHER_TABLE_FREE
150 *
151 *  This provides tlb_remove_table(), to be used instead of tlb_remove_page()
152 *  for page directores (__p*_free_tlb()).
153 *
154 *  Useful if your architecture has non-page page directories.
155 *
156 *  When used, an architecture is expected to provide __tlb_remove_table()
157 *  which does the actual freeing of these 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
199struct 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
210extern void tlb_remove_table(struct mmu_gather *tlb, void *table);
211
212#else /* !CONFIG_MMU_GATHER_HAVE_TABLE_FREE */
213
214/*
215 * Without MMU_GATHER_TABLE_FREE the architecture is assumed to have page based
216 * page directories and we can use the normal page batching to free them.
217 */
218#define tlb_remove_table(tlb, page) tlb_remove_page((tlb), (page))
219
220#endif /* CONFIG_MMU_GATHER_TABLE_FREE */
221
222#ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE
223/*
224 * This allows an architecture that does not use the linux page-tables for
225 * hardware to skip the TLBI when freeing page tables.
226 */
227#ifndef tlb_needs_table_invalidate
228#define tlb_needs_table_invalidate() (true)
229#endif
230
231void tlb_remove_table_sync_one(void);
232
233#else
234
235#ifdef tlb_needs_table_invalidate
236#error tlb_needs_table_invalidate() requires MMU_GATHER_RCU_TABLE_FREE
237#endif
238
239static inline void tlb_remove_table_sync_one(void) { }
240
241#endif /* CONFIG_MMU_GATHER_RCU_TABLE_FREE */
242
243
244#ifndef CONFIG_MMU_GATHER_NO_GATHER
245/*
246 * If we can't allocate a page to make a big batch of page pointers
247 * to work on, then just handle a few from the on-stack structure.
248 */
249#define MMU_GATHER_BUNDLE	8
250
251struct mmu_gather_batch {
252	struct mmu_gather_batch	*next;
253	unsigned int		nr;
254	unsigned int		max;
255	struct encoded_page	*encoded_pages[];
256};
257
258#define MAX_GATHER_BATCH	\
259	((PAGE_SIZE - sizeof(struct mmu_gather_batch)) / sizeof(void *))
260
261/*
262 * Limit the maximum number of mmu_gather batches to reduce a risk of soft
263 * lockups for non-preemptible kernels on huge machines when a lot of memory
264 * is zapped during unmapping.
265 * 10K pages freed at once should be safe even without a preemption point.
266 */
267#define MAX_GATHER_BATCH_COUNT	(10000UL/MAX_GATHER_BATCH)
268
269extern bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page,
270		bool delay_rmap, int page_size);
271bool __tlb_remove_folio_pages(struct mmu_gather *tlb, struct page *page,
272		unsigned int nr_pages, bool delay_rmap);
273
274#ifdef CONFIG_SMP
275/*
276 * This both sets 'delayed_rmap', and returns true. It would be an inline
277 * function, except we define it before the 'struct mmu_gather'.
278 */
279#define tlb_delay_rmap(tlb) (((tlb)->delayed_rmap = 1), true)
280extern void tlb_flush_rmaps(struct mmu_gather *tlb, struct vm_area_struct *vma);
281#endif
282
283#endif
284
285/*
286 * We have a no-op version of the rmap removal that doesn't
287 * delay anything. That is used on S390, which flushes remote
288 * TLBs synchronously, and on UP, which doesn't have any
289 * remote TLBs to flush and is not preemptible due to this
290 * all happening under the page table lock.
291 */
292#ifndef tlb_delay_rmap
293#define tlb_delay_rmap(tlb) (false)
294static inline void tlb_flush_rmaps(struct mmu_gather *tlb, struct vm_area_struct *vma) { }
295#endif
296
297/*
298 * struct mmu_gather is an opaque type used by the mm code for passing around
299 * any data needed by arch specific code for tlb_remove_page.
300 */
301struct mmu_gather {
302	struct mm_struct	*mm;
303
304#ifdef CONFIG_MMU_GATHER_TABLE_FREE
305	struct mmu_table_batch	*batch;
306#endif
307
308	unsigned long		start;
309	unsigned long		end;
310	/*
311	 * we are in the middle of an operation to clear
312	 * a full mm and can make some optimizations
313	 */
314	unsigned int		fullmm : 1;
315
316	/*
317	 * we have performed an operation which
318	 * requires a complete flush of the tlb
319	 */
320	unsigned int		need_flush_all : 1;
321
322	/*
323	 * we have removed page directories
324	 */
325	unsigned int		freed_tables : 1;
326
327	/*
328	 * Do we have pending delayed rmap removals?
329	 */
330	unsigned int		delayed_rmap : 1;
331
332	/*
333	 * at which levels have we cleared entries?
334	 */
335	unsigned int		cleared_ptes : 1;
336	unsigned int		cleared_pmds : 1;
337	unsigned int		cleared_puds : 1;
338	unsigned int		cleared_p4ds : 1;
339
340	/*
341	 * tracks VM_EXEC | VM_HUGETLB in tlb_start_vma
342	 */
343	unsigned int		vma_exec : 1;
344	unsigned int		vma_huge : 1;
345	unsigned int		vma_pfn  : 1;
346
347	unsigned int		batch_count;
348
349#ifndef CONFIG_MMU_GATHER_NO_GATHER
350	struct mmu_gather_batch *active;
351	struct mmu_gather_batch	local;
352	struct page		*__pages[MMU_GATHER_BUNDLE];
353
354#ifdef CONFIG_MMU_GATHER_PAGE_SIZE
355	unsigned int page_size;
356#endif
357#endif
358};
359
360void tlb_flush_mmu(struct mmu_gather *tlb);
361
362static inline void __tlb_adjust_range(struct mmu_gather *tlb,
363				      unsigned long address,
364				      unsigned int range_size)
365{
366	tlb->start = min(tlb->start, address);
367	tlb->end = max(tlb->end, address + range_size);
368}
369
370static inline void __tlb_reset_range(struct mmu_gather *tlb)
371{
372	if (tlb->fullmm) {
373		tlb->start = tlb->end = ~0;
374	} else {
375		tlb->start = TASK_SIZE;
376		tlb->end = 0;
377	}
378	tlb->freed_tables = 0;
379	tlb->cleared_ptes = 0;
380	tlb->cleared_pmds = 0;
381	tlb->cleared_puds = 0;
382	tlb->cleared_p4ds = 0;
383	/*
384	 * Do not reset mmu_gather::vma_* fields here, we do not
385	 * call into tlb_start_vma() again to set them if there is an
386	 * intermediate flush.
387	 */
388}
389
390#ifdef CONFIG_MMU_GATHER_NO_RANGE
391
392#if defined(tlb_flush)
393#error MMU_GATHER_NO_RANGE relies on default tlb_flush()
394#endif
395
396/*
397 * When an architecture does not have efficient means of range flushing TLBs
398 * there is no point in doing intermediate flushes on tlb_end_vma() to keep the
399 * range small. We equally don't have to worry about page granularity or other
400 * things.
401 *
402 * All we need to do is issue a full flush for any !0 range.
403 */
404static inline void tlb_flush(struct mmu_gather *tlb)
405{
406	if (tlb->end)
407		flush_tlb_mm(tlb->mm);
408}
409
410#else /* CONFIG_MMU_GATHER_NO_RANGE */
411
412#ifndef tlb_flush
413/*
414 * When an architecture does not provide its own tlb_flush() implementation
415 * but does have a reasonably efficient flush_vma_range() implementation
416 * use that.
417 */
418static inline void tlb_flush(struct mmu_gather *tlb)
419{
420	if (tlb->fullmm || tlb->need_flush_all) {
421		flush_tlb_mm(tlb->mm);
422	} else if (tlb->end) {
423		struct vm_area_struct vma = {
424			.vm_mm = tlb->mm,
425			.vm_flags = (tlb->vma_exec ? VM_EXEC    : 0) |
426				    (tlb->vma_huge ? VM_HUGETLB : 0),
427		};
428
429		flush_tlb_range(&vma, tlb->start, tlb->end);
430	}
431}
432#endif
433
434#endif /* CONFIG_MMU_GATHER_NO_RANGE */
435
436static inline void
437tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma)
438{
439	/*
440	 * flush_tlb_range() implementations that look at VM_HUGETLB (tile,
441	 * mips-4k) flush only large pages.
442	 *
443	 * flush_tlb_range() implementations that flush I-TLB also flush D-TLB
444	 * (tile, xtensa, arm), so it's ok to just add VM_EXEC to an existing
445	 * range.
446	 *
447	 * We rely on tlb_end_vma() to issue a flush, such that when we reset
448	 * these values the batch is empty.
449	 */
450	tlb->vma_huge = is_vm_hugetlb_page(vma);
451	tlb->vma_exec = !!(vma->vm_flags & VM_EXEC);
452	tlb->vma_pfn  = !!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP));
453}
454
455static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
456{
457	/*
458	 * Anything calling __tlb_adjust_range() also sets at least one of
459	 * these bits.
460	 */
461	if (!(tlb->freed_tables || tlb->cleared_ptes || tlb->cleared_pmds ||
462	      tlb->cleared_puds || tlb->cleared_p4ds))
463		return;
464
465	tlb_flush(tlb);
466	__tlb_reset_range(tlb);
467}
468
469static inline void tlb_remove_page_size(struct mmu_gather *tlb,
470					struct page *page, int page_size)
471{
472	if (__tlb_remove_page_size(tlb, page, false, page_size))
473		tlb_flush_mmu(tlb);
474}
475
476static __always_inline bool __tlb_remove_page(struct mmu_gather *tlb,
477		struct page *page, bool delay_rmap)
478{
479	return __tlb_remove_page_size(tlb, page, delay_rmap, PAGE_SIZE);
480}
481
482/* tlb_remove_page
483 *	Similar to __tlb_remove_page but will call tlb_flush_mmu() itself when
484 *	required.
485 */
486static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
487{
488	return tlb_remove_page_size(tlb, page, PAGE_SIZE);
489}
490
491static inline void tlb_remove_ptdesc(struct mmu_gather *tlb, void *pt)
492{
493	tlb_remove_table(tlb, pt);
494}
495
496/* Like tlb_remove_ptdesc, but for page-like page directories. */
497static inline void tlb_remove_page_ptdesc(struct mmu_gather *tlb, struct ptdesc *pt)
498{
499	tlb_remove_page(tlb, ptdesc_page(pt));
500}
501
502static inline void tlb_change_page_size(struct mmu_gather *tlb,
503						     unsigned int page_size)
504{
505#ifdef CONFIG_MMU_GATHER_PAGE_SIZE
506	if (tlb->page_size && tlb->page_size != page_size) {
507		if (!tlb->fullmm && !tlb->need_flush_all)
508			tlb_flush_mmu(tlb);
509	}
510
511	tlb->page_size = page_size;
512#endif
513}
514
515static inline unsigned long tlb_get_unmap_shift(struct mmu_gather *tlb)
516{
517	if (tlb->cleared_ptes)
518		return PAGE_SHIFT;
519	if (tlb->cleared_pmds)
520		return PMD_SHIFT;
521	if (tlb->cleared_puds)
522		return PUD_SHIFT;
523	if (tlb->cleared_p4ds)
524		return P4D_SHIFT;
525
526	return PAGE_SHIFT;
527}
528
529static inline unsigned long tlb_get_unmap_size(struct mmu_gather *tlb)
530{
531	return 1UL << tlb_get_unmap_shift(tlb);
532}
533
534/*
535 * In the case of tlb vma handling, we can optimise these away in the
536 * case where we're doing a full MM flush.  When we're doing a munmap,
537 * the vmas are adjusted to only cover the region to be torn down.
538 */
539static inline void tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
540{
541	if (tlb->fullmm)
542		return;
543
544	tlb_update_vma_flags(tlb, vma);
545#ifndef CONFIG_MMU_GATHER_NO_FLUSH_CACHE
546	flush_cache_range(vma, vma->vm_start, vma->vm_end);
547#endif
548}
549
550static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
551{
552	if (tlb->fullmm)
553		return;
554
555	/*
556	 * VM_PFNMAP is more fragile because the core mm will not track the
557	 * page mapcount -- there might not be page-frames for these PFNs after
558	 * all. Force flush TLBs for such ranges to avoid munmap() vs
559	 * unmap_mapping_range() races.
560	 */
561	if (tlb->vma_pfn || !IS_ENABLED(CONFIG_MMU_GATHER_MERGE_VMAS)) {
562		/*
563		 * Do a TLB flush and reset the range at VMA boundaries; this avoids
564		 * the ranges growing with the unused space between consecutive VMAs.
565		 */
566		tlb_flush_mmu_tlbonly(tlb);
567	}
568}
569
570/*
571 * tlb_flush_{pte|pmd|pud|p4d}_range() adjust the tlb->start and tlb->end,
572 * and set corresponding cleared_*.
573 */
574static inline void tlb_flush_pte_range(struct mmu_gather *tlb,
575				     unsigned long address, unsigned long size)
576{
577	__tlb_adjust_range(tlb, address, size);
578	tlb->cleared_ptes = 1;
579}
580
581static inline void tlb_flush_pmd_range(struct mmu_gather *tlb,
582				     unsigned long address, unsigned long size)
583{
584	__tlb_adjust_range(tlb, address, size);
585	tlb->cleared_pmds = 1;
586}
587
588static inline void tlb_flush_pud_range(struct mmu_gather *tlb,
589				     unsigned long address, unsigned long size)
590{
591	__tlb_adjust_range(tlb, address, size);
592	tlb->cleared_puds = 1;
593}
594
595static inline void tlb_flush_p4d_range(struct mmu_gather *tlb,
596				     unsigned long address, unsigned long size)
597{
598	__tlb_adjust_range(tlb, address, size);
599	tlb->cleared_p4ds = 1;
600}
601
602#ifndef __tlb_remove_tlb_entry
603static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, unsigned long address)
604{
605}
606#endif
607
608/**
609 * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
610 *
611 * Record the fact that pte's were really unmapped by updating the range,
612 * so we can later optimise away the tlb invalidate.   This helps when
613 * userspace is unmapping already-unmapped pages, which happens quite a lot.
614 */
615#define tlb_remove_tlb_entry(tlb, ptep, address)		\
616	do {							\
617		tlb_flush_pte_range(tlb, address, PAGE_SIZE);	\
618		__tlb_remove_tlb_entry(tlb, ptep, address);	\
619	} while (0)
620
621/**
622 * tlb_remove_tlb_entries - remember unmapping of multiple consecutive ptes for
623 *			    later tlb invalidation.
624 *
625 * Similar to tlb_remove_tlb_entry(), but remember unmapping of multiple
626 * consecutive ptes instead of only a single one.
627 */
628static inline void tlb_remove_tlb_entries(struct mmu_gather *tlb,
629		pte_t *ptep, unsigned int nr, unsigned long address)
630{
631	tlb_flush_pte_range(tlb, address, PAGE_SIZE * nr);
632	for (;;) {
633		__tlb_remove_tlb_entry(tlb, ptep, address);
634		if (--nr == 0)
635			break;
636		ptep++;
637		address += PAGE_SIZE;
638	}
639}
640
641#define tlb_remove_huge_tlb_entry(h, tlb, ptep, address)	\
642	do {							\
643		unsigned long _sz = huge_page_size(h);		\
644		if (_sz >= P4D_SIZE)				\
645			tlb_flush_p4d_range(tlb, address, _sz);	\
646		else if (_sz >= PUD_SIZE)			\
647			tlb_flush_pud_range(tlb, address, _sz);	\
648		else if (_sz >= PMD_SIZE)			\
649			tlb_flush_pmd_range(tlb, address, _sz);	\
650		else						\
651			tlb_flush_pte_range(tlb, address, _sz);	\
652		__tlb_remove_tlb_entry(tlb, ptep, address);	\
653	} while (0)
654
655/**
656 * tlb_remove_pmd_tlb_entry - remember a pmd mapping for later tlb invalidation
657 * This is a nop so far, because only x86 needs it.
658 */
659#ifndef __tlb_remove_pmd_tlb_entry
660#define __tlb_remove_pmd_tlb_entry(tlb, pmdp, address) do {} while (0)
661#endif
662
663#define tlb_remove_pmd_tlb_entry(tlb, pmdp, address)			\
664	do {								\
665		tlb_flush_pmd_range(tlb, address, HPAGE_PMD_SIZE);	\
666		__tlb_remove_pmd_tlb_entry(tlb, pmdp, address);		\
667	} while (0)
668
669/**
670 * tlb_remove_pud_tlb_entry - remember a pud mapping for later tlb
671 * invalidation. This is a nop so far, because only x86 needs it.
672 */
673#ifndef __tlb_remove_pud_tlb_entry
674#define __tlb_remove_pud_tlb_entry(tlb, pudp, address) do {} while (0)
675#endif
676
677#define tlb_remove_pud_tlb_entry(tlb, pudp, address)			\
678	do {								\
679		tlb_flush_pud_range(tlb, address, HPAGE_PUD_SIZE);	\
680		__tlb_remove_pud_tlb_entry(tlb, pudp, address);		\
681	} while (0)
682
683/*
684 * For things like page tables caches (ie caching addresses "inside" the
685 * page tables, like x86 does), for legacy reasons, flushing an
686 * individual page had better flush the page table caches behind it. This
687 * is definitely how x86 works, for example. And if you have an
688 * architected non-legacy page table cache (which I'm not aware of
689 * anybody actually doing), you're going to have some architecturally
690 * explicit flushing for that, likely *separate* from a regular TLB entry
691 * flush, and thus you'd need more than just some range expansion..
692 *
693 * So if we ever find an architecture
694 * that would want something that odd, I think it is up to that
695 * architecture to do its own odd thing, not cause pain for others
696 * http://lkml.kernel.org/r/CA+55aFzBggoXtNXQeng5d_mRoDnaMBE5Y+URs+PHR67nUpMtaw@mail.gmail.com
697 *
698 * For now w.r.t page table cache, mark the range_size as PAGE_SIZE
699 */
700
701#ifndef pte_free_tlb
702#define pte_free_tlb(tlb, ptep, address)			\
703	do {							\
704		tlb_flush_pmd_range(tlb, address, PAGE_SIZE);	\
705		tlb->freed_tables = 1;				\
706		__pte_free_tlb(tlb, ptep, address);		\
707	} while (0)
708#endif
709
710#ifndef pmd_free_tlb
711#define pmd_free_tlb(tlb, pmdp, address)			\
712	do {							\
713		tlb_flush_pud_range(tlb, address, PAGE_SIZE);	\
714		tlb->freed_tables = 1;				\
715		__pmd_free_tlb(tlb, pmdp, address);		\
716	} while (0)
717#endif
718
719#ifndef pud_free_tlb
720#define pud_free_tlb(tlb, pudp, address)			\
721	do {							\
722		tlb_flush_p4d_range(tlb, address, PAGE_SIZE);	\
723		tlb->freed_tables = 1;				\
724		__pud_free_tlb(tlb, pudp, address);		\
725	} while (0)
726#endif
727
728#ifndef p4d_free_tlb
729#define p4d_free_tlb(tlb, pudp, address)			\
730	do {							\
731		__tlb_adjust_range(tlb, address, PAGE_SIZE);	\
732		tlb->freed_tables = 1;				\
733		__p4d_free_tlb(tlb, pudp, address);		\
734	} while (0)
735#endif
736
737#ifndef pte_needs_flush
738static inline bool pte_needs_flush(pte_t oldpte, pte_t newpte)
739{
740	return true;
741}
742#endif
743
744#ifndef huge_pmd_needs_flush
745static inline bool huge_pmd_needs_flush(pmd_t oldpmd, pmd_t newpmd)
746{
747	return true;
748}
749#endif
750
751#endif /* CONFIG_MMU */
752
753#endif /* _ASM_GENERIC__TLB_H */
754