1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* internal.h: mm/ internal definitions
3 *
4 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7#ifndef __MM_INTERNAL_H
8#define __MM_INTERNAL_H
9
10#include <linux/fs.h>
11#include <linux/khugepaged.h>
12#include <linux/mm.h>
13#include <linux/mm_inline.h>
14#include <linux/pagemap.h>
15#include <linux/pagewalk.h>
16#include <linux/rmap.h>
17#include <linux/swap.h>
18#include <linux/swapops.h>
19#include <linux/swap_cgroup.h>
20#include <linux/tracepoint-defs.h>
21
22/* Internal core VMA manipulation functions. */
23#include "vma.h"
24
25struct folio_batch;
26
27/*
28 * Maintains state across a page table move. The operation assumes both source
29 * and destination VMAs already exist and are specified by the user.
30 *
31 * Partial moves are permitted, but the old and new ranges must both reside
32 * within a VMA.
33 *
34 * mmap lock must be held in write and VMA write locks must be held on any VMA
35 * that is visible.
36 *
37 * Use the PAGETABLE_MOVE() macro to initialise this struct.
38 *
39 * The old_addr and new_addr fields are updated as the page table move is
40 * executed.
41 *
42 * NOTE: The page table move is affected by reading from [old_addr, old_end),
43 * and old_addr may be updated for better page table alignment, so len_in
44 * represents the length of the range being copied as specified by the user.
45 */
46struct pagetable_move_control {
47 struct vm_area_struct *old; /* Source VMA. */
48 struct vm_area_struct *new; /* Destination VMA. */
49 unsigned long old_addr; /* Address from which the move begins. */
50 unsigned long old_end; /* Exclusive address at which old range ends. */
51 unsigned long new_addr; /* Address to move page tables to. */
52 unsigned long len_in; /* Bytes to remap specified by user. */
53
54 bool need_rmap_locks; /* Do rmap locks need to be taken? */
55 bool for_stack; /* Is this an early temp stack being moved? */
56};
57
58#define PAGETABLE_MOVE(name, old_, new_, old_addr_, new_addr_, len_) \
59 struct pagetable_move_control name = { \
60 .old = old_, \
61 .new = new_, \
62 .old_addr = old_addr_, \
63 .old_end = (old_addr_) + (len_), \
64 .new_addr = new_addr_, \
65 .len_in = len_, \
66 }
67
68/*
69 * The set of flags that only affect watermark checking and reclaim
70 * behaviour. This is used by the MM to obey the caller constraints
71 * about IO, FS and watermark checking while ignoring placement
72 * hints such as HIGHMEM usage.
73 */
74#define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\
75 __GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\
76 __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\
77 __GFP_NOLOCKDEP)
78
79/* The GFP flags allowed during early boot */
80#define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))
81
82/* Control allocation cpuset and node placement constraints */
83#define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
84
85/* Do not use these with a slab allocator */
86#define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
87
88/*
89 * Different from WARN_ON_ONCE(), no warning will be issued
90 * when we specify __GFP_NOWARN.
91 */
92#define WARN_ON_ONCE_GFP(cond, gfp) ({ \
93 static bool __section(".data..once") __warned; \
94 int __ret_warn_once = !!(cond); \
95 \
96 if (unlikely(!(gfp & __GFP_NOWARN) && __ret_warn_once && !__warned)) { \
97 __warned = true; \
98 WARN_ON(1); \
99 } \
100 unlikely(__ret_warn_once); \
101})
102
103void page_writeback_init(void);
104
105/*
106 * If a 16GB hugetlb folio were mapped by PTEs of all of its 4kB pages,
107 * its nr_pages_mapped would be 0x400000: choose the ENTIRELY_MAPPED bit
108 * above that range, instead of 2*(PMD_SIZE/PAGE_SIZE). Hugetlb currently
109 * leaves nr_pages_mapped at 0, but avoid surprise if it participates later.
110 */
111#define ENTIRELY_MAPPED 0x800000
112#define FOLIO_PAGES_MAPPED (ENTIRELY_MAPPED - 1)
113
114/*
115 * Flags passed to __show_mem() and show_free_areas() to suppress output in
116 * various contexts.
117 */
118#define SHOW_MEM_FILTER_NODES (0x0001u) /* disallowed nodes */
119
120/*
121 * How many individual pages have an elevated _mapcount. Excludes
122 * the folio's entire_mapcount.
123 *
124 * Don't use this function outside of debugging code.
125 */
126static inline int folio_nr_pages_mapped(const struct folio *folio)
127{
128 if (IS_ENABLED(CONFIG_NO_PAGE_MAPCOUNT))
129 return -1;
130 return atomic_read(v: &folio->_nr_pages_mapped) & FOLIO_PAGES_MAPPED;
131}
132
133/*
134 * Retrieve the first entry of a folio based on a provided entry within the
135 * folio. We cannot rely on folio->swap as there is no guarantee that it has
136 * been initialized. Used for calling arch_swap_restore()
137 */
138static inline swp_entry_t folio_swap(swp_entry_t entry,
139 const struct folio *folio)
140{
141 swp_entry_t swap = {
142 .val = ALIGN_DOWN(entry.val, folio_nr_pages(folio)),
143 };
144
145 return swap;
146}
147
148static inline void *folio_raw_mapping(const struct folio *folio)
149{
150 unsigned long mapping = (unsigned long)folio->mapping;
151
152 return (void *)(mapping & ~PAGE_MAPPING_FLAGS);
153}
154
155/*
156 * This is a file-backed mapping, and is about to be memory mapped - invoke its
157 * mmap hook and safely handle error conditions. On error, VMA hooks will be
158 * mutated.
159 *
160 * @file: File which backs the mapping.
161 * @vma: VMA which we are mapping.
162 *
163 * Returns: 0 if success, error otherwise.
164 */
165static inline int mmap_file(struct file *file, struct vm_area_struct *vma)
166{
167 int err = call_mmap(file, vma);
168
169 if (likely(!err))
170 return 0;
171
172 /*
173 * OK, we tried to call the file hook for mmap(), but an error
174 * arose. The mapping is in an inconsistent state and we most not invoke
175 * any further hooks on it.
176 */
177 vma->vm_ops = &vma_dummy_vm_ops;
178
179 return err;
180}
181
182/*
183 * If the VMA has a close hook then close it, and since closing it might leave
184 * it in an inconsistent state which makes the use of any hooks suspect, clear
185 * them down by installing dummy empty hooks.
186 */
187static inline void vma_close(struct vm_area_struct *vma)
188{
189 if (vma->vm_ops && vma->vm_ops->close) {
190 vma->vm_ops->close(vma);
191
192 /*
193 * The mapping is in an inconsistent state, and no further hooks
194 * may be invoked upon it.
195 */
196 vma->vm_ops = &vma_dummy_vm_ops;
197 }
198}
199
200#ifdef CONFIG_MMU
201
202/* Flags for folio_pte_batch(). */
203typedef int __bitwise fpb_t;
204
205/* Compare PTEs after pte_mkclean(), ignoring the dirty bit. */
206#define FPB_IGNORE_DIRTY ((__force fpb_t)BIT(0))
207
208/* Compare PTEs after pte_clear_soft_dirty(), ignoring the soft-dirty bit. */
209#define FPB_IGNORE_SOFT_DIRTY ((__force fpb_t)BIT(1))
210
211static inline pte_t __pte_batch_clear_ignored(pte_t pte, fpb_t flags)
212{
213 if (flags & FPB_IGNORE_DIRTY)
214 pte = pte_mkclean(pte);
215 if (likely(flags & FPB_IGNORE_SOFT_DIRTY))
216 pte = pte_clear_soft_dirty(pte);
217 return pte_wrprotect(pte: pte_mkold(pte));
218}
219
220/**
221 * folio_pte_batch - detect a PTE batch for a large folio
222 * @folio: The large folio to detect a PTE batch for.
223 * @addr: The user virtual address the first page is mapped at.
224 * @start_ptep: Page table pointer for the first entry.
225 * @pte: Page table entry for the first page.
226 * @max_nr: The maximum number of table entries to consider.
227 * @flags: Flags to modify the PTE batch semantics.
228 * @any_writable: Optional pointer to indicate whether any entry except the
229 * first one is writable.
230 * @any_young: Optional pointer to indicate whether any entry except the
231 * first one is young.
232 * @any_dirty: Optional pointer to indicate whether any entry except the
233 * first one is dirty.
234 *
235 * Detect a PTE batch: consecutive (present) PTEs that map consecutive
236 * pages of the same large folio.
237 *
238 * All PTEs inside a PTE batch have the same PTE bits set, excluding the PFN,
239 * the accessed bit, writable bit, dirty bit (with FPB_IGNORE_DIRTY) and
240 * soft-dirty bit (with FPB_IGNORE_SOFT_DIRTY).
241 *
242 * start_ptep must map any page of the folio. max_nr must be at least one and
243 * must be limited by the caller so scanning cannot exceed a single page table.
244 *
245 * Return: the number of table entries in the batch.
246 */
247static inline int folio_pte_batch(struct folio *folio, unsigned long addr,
248 pte_t *start_ptep, pte_t pte, int max_nr, fpb_t flags,
249 bool *any_writable, bool *any_young, bool *any_dirty)
250{
251 pte_t expected_pte, *ptep;
252 bool writable, young, dirty;
253 int nr, cur_nr;
254
255 if (any_writable)
256 *any_writable = false;
257 if (any_young)
258 *any_young = false;
259 if (any_dirty)
260 *any_dirty = false;
261
262 VM_WARN_ON_FOLIO(!pte_present(pte), folio);
263 VM_WARN_ON_FOLIO(!folio_test_large(folio) || max_nr < 1, folio);
264 VM_WARN_ON_FOLIO(page_folio(pfn_to_page(pte_pfn(pte))) != folio, folio);
265
266 /* Limit max_nr to the actual remaining PFNs in the folio we could batch. */
267 max_nr = min_t(unsigned long, max_nr,
268 folio_pfn(folio) + folio_nr_pages(folio) - pte_pfn(pte));
269
270 nr = pte_batch_hint(ptep: start_ptep, pte);
271 expected_pte = __pte_batch_clear_ignored(pte_advance_pfn(pte, nr), flags);
272 ptep = start_ptep + nr;
273
274 while (nr < max_nr) {
275 pte = ptep_get(ptep);
276 if (any_writable)
277 writable = !!pte_write(pte);
278 if (any_young)
279 young = !!pte_young(pte);
280 if (any_dirty)
281 dirty = !!pte_dirty(pte);
282 pte = __pte_batch_clear_ignored(pte, flags);
283
284 if (!pte_same(a: pte, b: expected_pte))
285 break;
286
287 if (any_writable)
288 *any_writable |= writable;
289 if (any_young)
290 *any_young |= young;
291 if (any_dirty)
292 *any_dirty |= dirty;
293
294 cur_nr = pte_batch_hint(ptep, pte);
295 expected_pte = pte_advance_pfn(pte: expected_pte, nr: cur_nr);
296 ptep += cur_nr;
297 nr += cur_nr;
298 }
299
300 return min(nr, max_nr);
301}
302
303/**
304 * pte_move_swp_offset - Move the swap entry offset field of a swap pte
305 * forward or backward by delta
306 * @pte: The initial pte state; is_swap_pte(pte) must be true and
307 * non_swap_entry() must be false.
308 * @delta: The direction and the offset we are moving; forward if delta
309 * is positive; backward if delta is negative
310 *
311 * Moves the swap offset, while maintaining all other fields, including
312 * swap type, and any swp pte bits. The resulting pte is returned.
313 */
314static inline pte_t pte_move_swp_offset(pte_t pte, long delta)
315{
316 swp_entry_t entry = pte_to_swp_entry(pte);
317 pte_t new = __swp_entry_to_pte(__swp_entry(swp_type(entry),
318 (swp_offset(entry) + delta)));
319
320 if (pte_swp_soft_dirty(pte))
321 new = pte_swp_mksoft_dirty(pte: new);
322 if (pte_swp_exclusive(pte))
323 new = pte_swp_mkexclusive(pte: new);
324 if (pte_swp_uffd_wp(pte))
325 new = pte_swp_mkuffd_wp(pte: new);
326
327 return new;
328}
329
330
331/**
332 * pte_next_swp_offset - Increment the swap entry offset field of a swap pte.
333 * @pte: The initial pte state; is_swap_pte(pte) must be true and
334 * non_swap_entry() must be false.
335 *
336 * Increments the swap offset, while maintaining all other fields, including
337 * swap type, and any swp pte bits. The resulting pte is returned.
338 */
339static inline pte_t pte_next_swp_offset(pte_t pte)
340{
341 return pte_move_swp_offset(pte, delta: 1);
342}
343
344/**
345 * swap_pte_batch - detect a PTE batch for a set of contiguous swap entries
346 * @start_ptep: Page table pointer for the first entry.
347 * @max_nr: The maximum number of table entries to consider.
348 * @pte: Page table entry for the first entry.
349 *
350 * Detect a batch of contiguous swap entries: consecutive (non-present) PTEs
351 * containing swap entries all with consecutive offsets and targeting the same
352 * swap type, all with matching swp pte bits.
353 *
354 * max_nr must be at least one and must be limited by the caller so scanning
355 * cannot exceed a single page table.
356 *
357 * Return: the number of table entries in the batch.
358 */
359static inline int swap_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte)
360{
361 pte_t expected_pte = pte_next_swp_offset(pte);
362 const pte_t *end_ptep = start_ptep + max_nr;
363 swp_entry_t entry = pte_to_swp_entry(pte);
364 pte_t *ptep = start_ptep + 1;
365 unsigned short cgroup_id;
366
367 VM_WARN_ON(max_nr < 1);
368 VM_WARN_ON(!is_swap_pte(pte));
369 VM_WARN_ON(non_swap_entry(entry));
370
371 cgroup_id = lookup_swap_cgroup_id(ent: entry);
372 while (ptep < end_ptep) {
373 pte = ptep_get(ptep);
374
375 if (!pte_same(a: pte, b: expected_pte))
376 break;
377 if (lookup_swap_cgroup_id(ent: pte_to_swp_entry(pte)) != cgroup_id)
378 break;
379 expected_pte = pte_next_swp_offset(pte: expected_pte);
380 ptep++;
381 }
382
383 return ptep - start_ptep;
384}
385#endif /* CONFIG_MMU */
386
387void __acct_reclaim_writeback(pg_data_t *pgdat, struct folio *folio,
388 int nr_throttled);
389static inline void acct_reclaim_writeback(struct folio *folio)
390{
391 pg_data_t *pgdat = folio_pgdat(folio);
392 int nr_throttled = atomic_read(v: &pgdat->nr_writeback_throttled);
393
394 if (nr_throttled)
395 __acct_reclaim_writeback(pgdat, folio, nr_throttled);
396}
397
398static inline void wake_throttle_isolated(pg_data_t *pgdat)
399{
400 wait_queue_head_t *wqh;
401
402 wqh = &pgdat->reclaim_wait[VMSCAN_THROTTLE_ISOLATED];
403 if (waitqueue_active(wq_head: wqh))
404 wake_up(wqh);
405}
406
407vm_fault_t __vmf_anon_prepare(struct vm_fault *vmf);
408static inline vm_fault_t vmf_anon_prepare(struct vm_fault *vmf)
409{
410 vm_fault_t ret = __vmf_anon_prepare(vmf);
411
412 if (unlikely(ret & VM_FAULT_RETRY))
413 vma_end_read(vma: vmf->vma);
414 return ret;
415}
416
417vm_fault_t do_swap_page(struct vm_fault *vmf);
418void folio_rotate_reclaimable(struct folio *folio);
419bool __folio_end_writeback(struct folio *folio);
420void deactivate_file_folio(struct folio *folio);
421void folio_activate(struct folio *folio);
422
423void free_pgtables(struct mmu_gather *tlb, struct ma_state *mas,
424 struct vm_area_struct *start_vma, unsigned long floor,
425 unsigned long ceiling, bool mm_wr_locked);
426void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte);
427
428struct zap_details;
429void unmap_page_range(struct mmu_gather *tlb,
430 struct vm_area_struct *vma,
431 unsigned long addr, unsigned long end,
432 struct zap_details *details);
433void zap_page_range_single_batched(struct mmu_gather *tlb,
434 struct vm_area_struct *vma, unsigned long addr,
435 unsigned long size, struct zap_details *details);
436int folio_unmap_invalidate(struct address_space *mapping, struct folio *folio,
437 gfp_t gfp);
438
439void page_cache_ra_order(struct readahead_control *, struct file_ra_state *,
440 unsigned int order);
441void force_page_cache_ra(struct readahead_control *, unsigned long nr);
442static inline void force_page_cache_readahead(struct address_space *mapping,
443 struct file *file, pgoff_t index, unsigned long nr_to_read)
444{
445 DEFINE_READAHEAD(ractl, file, &file->f_ra, mapping, index);
446 force_page_cache_ra(&ractl, nr: nr_to_read);
447}
448
449unsigned find_lock_entries(struct address_space *mapping, pgoff_t *start,
450 pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices);
451unsigned find_get_entries(struct address_space *mapping, pgoff_t *start,
452 pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices);
453void filemap_free_folio(struct address_space *mapping, struct folio *folio);
454int truncate_inode_folio(struct address_space *mapping, struct folio *folio);
455bool truncate_inode_partial_folio(struct folio *folio, loff_t start,
456 loff_t end);
457long mapping_evict_folio(struct address_space *mapping, struct folio *folio);
458unsigned long mapping_try_invalidate(struct address_space *mapping,
459 pgoff_t start, pgoff_t end, unsigned long *nr_failed);
460
461/**
462 * folio_evictable - Test whether a folio is evictable.
463 * @folio: The folio to test.
464 *
465 * Test whether @folio is evictable -- i.e., should be placed on
466 * active/inactive lists vs unevictable list.
467 *
468 * Reasons folio might not be evictable:
469 * 1. folio's mapping marked unevictable
470 * 2. One of the pages in the folio is part of an mlocked VMA
471 */
472static inline bool folio_evictable(struct folio *folio)
473{
474 bool ret;
475
476 /* Prevent address_space of inode and swap cache from being freed */
477 rcu_read_lock();
478 ret = !mapping_unevictable(mapping: folio_mapping(folio)) &&
479 !folio_test_mlocked(folio);
480 rcu_read_unlock();
481 return ret;
482}
483
484/*
485 * Turn a non-refcounted page (->_refcount == 0) into refcounted with
486 * a count of one.
487 */
488static inline void set_page_refcounted(struct page *page)
489{
490 VM_BUG_ON_PAGE(PageTail(page), page);
491 VM_BUG_ON_PAGE(page_ref_count(page), page);
492 set_page_count(page, v: 1);
493}
494
495/*
496 * Return true if a folio needs ->release_folio() calling upon it.
497 */
498static inline bool folio_needs_release(struct folio *folio)
499{
500 struct address_space *mapping = folio_mapping(folio);
501
502 return folio_has_private(folio) ||
503 (mapping && mapping_release_always(mapping));
504}
505
506extern unsigned long highest_memmap_pfn;
507
508/*
509 * Maximum number of reclaim retries without progress before the OOM
510 * killer is consider the only way forward.
511 */
512#define MAX_RECLAIM_RETRIES 16
513
514/*
515 * in mm/vmscan.c:
516 */
517bool folio_isolate_lru(struct folio *folio);
518void folio_putback_lru(struct folio *folio);
519extern void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason);
520
521/*
522 * in mm/rmap.c:
523 */
524pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
525
526/*
527 * in mm/page_alloc.c
528 */
529#define K(x) ((x) << (PAGE_SHIFT-10))
530
531extern char * const zone_names[MAX_NR_ZONES];
532
533/* perform sanity checks on struct pages being allocated or freed */
534DECLARE_STATIC_KEY_MAYBE(CONFIG_DEBUG_VM, check_pages_enabled);
535
536extern int min_free_kbytes;
537extern int defrag_mode;
538
539void setup_per_zone_wmarks(void);
540void calculate_min_free_kbytes(void);
541int __meminit init_per_zone_wmark_min(void);
542void page_alloc_sysctl_init(void);
543
544/*
545 * Structure for holding the mostly immutable allocation parameters passed
546 * between functions involved in allocations, including the alloc_pages*
547 * family of functions.
548 *
549 * nodemask, migratetype and highest_zoneidx are initialized only once in
550 * __alloc_pages() and then never change.
551 *
552 * zonelist, preferred_zone and highest_zoneidx are set first in
553 * __alloc_pages() for the fast path, and might be later changed
554 * in __alloc_pages_slowpath(). All other functions pass the whole structure
555 * by a const pointer.
556 */
557struct alloc_context {
558 struct zonelist *zonelist;
559 nodemask_t *nodemask;
560 struct zoneref *preferred_zoneref;
561 int migratetype;
562
563 /*
564 * highest_zoneidx represents highest usable zone index of
565 * the allocation request. Due to the nature of the zone,
566 * memory on lower zone than the highest_zoneidx will be
567 * protected by lowmem_reserve[highest_zoneidx].
568 *
569 * highest_zoneidx is also used by reclaim/compaction to limit
570 * the target zone since higher zone than this index cannot be
571 * usable for this allocation request.
572 */
573 enum zone_type highest_zoneidx;
574 bool spread_dirty_pages;
575};
576
577/*
578 * This function returns the order of a free page in the buddy system. In
579 * general, page_zone(page)->lock must be held by the caller to prevent the
580 * page from being allocated in parallel and returning garbage as the order.
581 * If a caller does not hold page_zone(page)->lock, it must guarantee that the
582 * page cannot be allocated or merged in parallel. Alternatively, it must
583 * handle invalid values gracefully, and use buddy_order_unsafe() below.
584 */
585static inline unsigned int buddy_order(struct page *page)
586{
587 /* PageBuddy() must be checked by the caller */
588 return page_private(page);
589}
590
591/*
592 * Like buddy_order(), but for callers who cannot afford to hold the zone lock.
593 * PageBuddy() should be checked first by the caller to minimize race window,
594 * and invalid values must be handled gracefully.
595 *
596 * READ_ONCE is used so that if the caller assigns the result into a local
597 * variable and e.g. tests it for valid range before using, the compiler cannot
598 * decide to remove the variable and inline the page_private(page) multiple
599 * times, potentially observing different values in the tests and the actual
600 * use of the result.
601 */
602#define buddy_order_unsafe(page) READ_ONCE(page_private(page))
603
604/*
605 * This function checks whether a page is free && is the buddy
606 * we can coalesce a page and its buddy if
607 * (a) the buddy is not in a hole (check before calling!) &&
608 * (b) the buddy is in the buddy system &&
609 * (c) a page and its buddy have the same order &&
610 * (d) a page and its buddy are in the same zone.
611 *
612 * For recording whether a page is in the buddy system, we set PageBuddy.
613 * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
614 *
615 * For recording page's order, we use page_private(page).
616 */
617static inline bool page_is_buddy(struct page *page, struct page *buddy,
618 unsigned int order)
619{
620 if (!page_is_guard(page: buddy) && !PageBuddy(page: buddy))
621 return false;
622
623 if (buddy_order(page: buddy) != order)
624 return false;
625
626 /*
627 * zone check is done late to avoid uselessly calculating
628 * zone/node ids for pages that could never merge.
629 */
630 if (page_zone_id(page) != page_zone_id(page: buddy))
631 return false;
632
633 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
634
635 return true;
636}
637
638/*
639 * Locate the struct page for both the matching buddy in our
640 * pair (buddy1) and the combined O(n+1) page they form (page).
641 *
642 * 1) Any buddy B1 will have an order O twin B2 which satisfies
643 * the following equation:
644 * B2 = B1 ^ (1 << O)
645 * For example, if the starting buddy (buddy2) is #8 its order
646 * 1 buddy is #10:
647 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
648 *
649 * 2) Any buddy B will have an order O+1 parent P which
650 * satisfies the following equation:
651 * P = B & ~(1 << O)
652 *
653 * Assumption: *_mem_map is contiguous at least up to MAX_PAGE_ORDER
654 */
655static inline unsigned long
656__find_buddy_pfn(unsigned long page_pfn, unsigned int order)
657{
658 return page_pfn ^ (1 << order);
659}
660
661/*
662 * Find the buddy of @page and validate it.
663 * @page: The input page
664 * @pfn: The pfn of the page, it saves a call to page_to_pfn() when the
665 * function is used in the performance-critical __free_one_page().
666 * @order: The order of the page
667 * @buddy_pfn: The output pointer to the buddy pfn, it also saves a call to
668 * page_to_pfn().
669 *
670 * The found buddy can be a non PageBuddy, out of @page's zone, or its order is
671 * not the same as @page. The validation is necessary before use it.
672 *
673 * Return: the found buddy page or NULL if not found.
674 */
675static inline struct page *find_buddy_page_pfn(struct page *page,
676 unsigned long pfn, unsigned int order, unsigned long *buddy_pfn)
677{
678 unsigned long __buddy_pfn = __find_buddy_pfn(page_pfn: pfn, order);
679 struct page *buddy;
680
681 buddy = page + (__buddy_pfn - pfn);
682 if (buddy_pfn)
683 *buddy_pfn = __buddy_pfn;
684
685 if (page_is_buddy(page, buddy, order))
686 return buddy;
687 return NULL;
688}
689
690extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
691 unsigned long end_pfn, struct zone *zone);
692
693static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
694 unsigned long end_pfn, struct zone *zone)
695{
696 if (zone->contiguous)
697 return pfn_to_page(start_pfn);
698
699 return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
700}
701
702void set_zone_contiguous(struct zone *zone);
703bool pfn_range_intersects_zones(int nid, unsigned long start_pfn,
704 unsigned long nr_pages);
705
706static inline void clear_zone_contiguous(struct zone *zone)
707{
708 zone->contiguous = false;
709}
710
711extern int __isolate_free_page(struct page *page, unsigned int order);
712extern void __putback_isolated_page(struct page *page, unsigned int order,
713 int mt);
714extern void memblock_free_pages(struct page *page, unsigned long pfn,
715 unsigned int order);
716extern void __free_pages_core(struct page *page, unsigned int order,
717 enum meminit_context context);
718
719/*
720 * This will have no effect, other than possibly generating a warning, if the
721 * caller passes in a non-large folio.
722 */
723static inline void folio_set_order(struct folio *folio, unsigned int order)
724{
725 if (WARN_ON_ONCE(!order || !folio_test_large(folio)))
726 return;
727
728 folio->_flags_1 = (folio->_flags_1 & ~0xffUL) | order;
729#ifdef NR_PAGES_IN_LARGE_FOLIO
730 folio->_nr_pages = 1U << order;
731#endif
732}
733
734bool __folio_unqueue_deferred_split(struct folio *folio);
735static inline bool folio_unqueue_deferred_split(struct folio *folio)
736{
737 if (folio_order(folio) <= 1 || !folio_test_large_rmappable(folio))
738 return false;
739
740 /*
741 * At this point, there is no one trying to add the folio to
742 * deferred_list. If folio is not in deferred_list, it's safe
743 * to check without acquiring the split_queue_lock.
744 */
745 if (data_race(list_empty(&folio->_deferred_list)))
746 return false;
747
748 return __folio_unqueue_deferred_split(folio);
749}
750
751static inline struct folio *page_rmappable_folio(struct page *page)
752{
753 struct folio *folio = (struct folio *)page;
754
755 if (folio && folio_test_large(folio))
756 folio_set_large_rmappable(folio);
757 return folio;
758}
759
760static inline void prep_compound_head(struct page *page, unsigned int order)
761{
762 struct folio *folio = (struct folio *)page;
763
764 folio_set_order(folio, order);
765 atomic_set(v: &folio->_large_mapcount, i: -1);
766 if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT))
767 atomic_set(v: &folio->_nr_pages_mapped, i: 0);
768 if (IS_ENABLED(CONFIG_MM_ID)) {
769 folio->_mm_ids = 0;
770 folio->_mm_id_mapcount[0] = -1;
771 folio->_mm_id_mapcount[1] = -1;
772 }
773 if (IS_ENABLED(CONFIG_64BIT) || order > 1) {
774 atomic_set(v: &folio->_pincount, i: 0);
775 atomic_set(v: &folio->_entire_mapcount, i: -1);
776 }
777 if (order > 1)
778 INIT_LIST_HEAD(list: &folio->_deferred_list);
779}
780
781static inline void prep_compound_tail(struct page *head, int tail_idx)
782{
783 struct page *p = head + tail_idx;
784
785 p->mapping = TAIL_MAPPING;
786 set_compound_head(page: p, head);
787 set_page_private(page: p, private: 0);
788}
789
790void post_alloc_hook(struct page *page, unsigned int order, gfp_t gfp_flags);
791extern bool free_pages_prepare(struct page *page, unsigned int order);
792
793extern int user_min_free_kbytes;
794
795struct page *__alloc_frozen_pages_noprof(gfp_t, unsigned int order, int nid,
796 nodemask_t *);
797#define __alloc_frozen_pages(...) \
798 alloc_hooks(__alloc_frozen_pages_noprof(__VA_ARGS__))
799void free_frozen_pages(struct page *page, unsigned int order);
800void free_unref_folios(struct folio_batch *fbatch);
801
802#ifdef CONFIG_NUMA
803struct page *alloc_frozen_pages_noprof(gfp_t, unsigned int order);
804#else
805static inline struct page *alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order)
806{
807 return __alloc_frozen_pages_noprof(gfp, order, numa_node_id(), NULL);
808}
809#endif
810
811#define alloc_frozen_pages(...) \
812 alloc_hooks(alloc_frozen_pages_noprof(__VA_ARGS__))
813
814extern void zone_pcp_reset(struct zone *zone);
815extern void zone_pcp_disable(struct zone *zone);
816extern void zone_pcp_enable(struct zone *zone);
817extern void zone_pcp_init(struct zone *zone);
818
819extern void *memmap_alloc(phys_addr_t size, phys_addr_t align,
820 phys_addr_t min_addr,
821 int nid, bool exact_nid);
822
823void memmap_init_range(unsigned long, int, unsigned long, unsigned long,
824 unsigned long, enum meminit_context, struct vmem_altmap *, int);
825
826#if defined CONFIG_COMPACTION || defined CONFIG_CMA
827
828/*
829 * in mm/compaction.c
830 */
831/*
832 * compact_control is used to track pages being migrated and the free pages
833 * they are being migrated to during memory compaction. The free_pfn starts
834 * at the end of a zone and migrate_pfn begins at the start. Movable pages
835 * are moved to the end of a zone during a compaction run and the run
836 * completes when free_pfn <= migrate_pfn
837 */
838struct compact_control {
839 struct list_head freepages[NR_PAGE_ORDERS]; /* List of free pages to migrate to */
840 struct list_head migratepages; /* List of pages being migrated */
841 unsigned int nr_freepages; /* Number of isolated free pages */
842 unsigned int nr_migratepages; /* Number of pages to migrate */
843 unsigned long free_pfn; /* isolate_freepages search base */
844 /*
845 * Acts as an in/out parameter to page isolation for migration.
846 * isolate_migratepages uses it as a search base.
847 * isolate_migratepages_block will update the value to the next pfn
848 * after the last isolated one.
849 */
850 unsigned long migrate_pfn;
851 unsigned long fast_start_pfn; /* a pfn to start linear scan from */
852 struct zone *zone;
853 unsigned long total_migrate_scanned;
854 unsigned long total_free_scanned;
855 unsigned short fast_search_fail;/* failures to use free list searches */
856 short search_order; /* order to start a fast search at */
857 const gfp_t gfp_mask; /* gfp mask of a direct compactor */
858 int order; /* order a direct compactor needs */
859 int migratetype; /* migratetype of direct compactor */
860 const unsigned int alloc_flags; /* alloc flags of a direct compactor */
861 const int highest_zoneidx; /* zone index of a direct compactor */
862 enum migrate_mode mode; /* Async or sync migration mode */
863 bool ignore_skip_hint; /* Scan blocks even if marked skip */
864 bool no_set_skip_hint; /* Don't mark blocks for skipping */
865 bool ignore_block_suitable; /* Scan blocks considered unsuitable */
866 bool direct_compaction; /* False from kcompactd or /proc/... */
867 bool proactive_compaction; /* kcompactd proactive compaction */
868 bool whole_zone; /* Whole zone should/has been scanned */
869 bool contended; /* Signal lock contention */
870 bool finish_pageblock; /* Scan the remainder of a pageblock. Used
871 * when there are potentially transient
872 * isolation or migration failures to
873 * ensure forward progress.
874 */
875 bool alloc_contig; /* alloc_contig_range allocation */
876};
877
878/*
879 * Used in direct compaction when a page should be taken from the freelists
880 * immediately when one is created during the free path.
881 */
882struct capture_control {
883 struct compact_control *cc;
884 struct page *page;
885};
886
887unsigned long
888isolate_freepages_range(struct compact_control *cc,
889 unsigned long start_pfn, unsigned long end_pfn);
890int
891isolate_migratepages_range(struct compact_control *cc,
892 unsigned long low_pfn, unsigned long end_pfn);
893
894/* Free whole pageblock and set its migration type to MIGRATE_CMA. */
895void init_cma_reserved_pageblock(struct page *page);
896
897#endif /* CONFIG_COMPACTION || CONFIG_CMA */
898
899struct cma;
900
901#ifdef CONFIG_CMA
902void *cma_reserve_early(struct cma *cma, unsigned long size);
903void init_cma_pageblock(struct page *page);
904#else
905static inline void *cma_reserve_early(struct cma *cma, unsigned long size)
906{
907 return NULL;
908}
909static inline void init_cma_pageblock(struct page *page)
910{
911}
912#endif
913
914
915int find_suitable_fallback(struct free_area *area, unsigned int order,
916 int migratetype, bool claimable);
917
918static inline bool free_area_empty(struct free_area *area, int migratetype)
919{
920 return list_empty(head: &area->free_list[migratetype]);
921}
922
923/* mm/util.c */
924struct anon_vma *folio_anon_vma(const struct folio *folio);
925
926#ifdef CONFIG_MMU
927void unmap_mapping_folio(struct folio *folio);
928extern long populate_vma_page_range(struct vm_area_struct *vma,
929 unsigned long start, unsigned long end, int *locked);
930extern long faultin_page_range(struct mm_struct *mm, unsigned long start,
931 unsigned long end, bool write, int *locked);
932extern bool mlock_future_ok(struct mm_struct *mm, unsigned long flags,
933 unsigned long bytes);
934
935/*
936 * NOTE: This function can't tell whether the folio is "fully mapped" in the
937 * range.
938 * "fully mapped" means all the pages of folio is associated with the page
939 * table of range while this function just check whether the folio range is
940 * within the range [start, end). Function caller needs to do page table
941 * check if it cares about the page table association.
942 *
943 * Typical usage (like mlock or madvise) is:
944 * Caller knows at least 1 page of folio is associated with page table of VMA
945 * and the range [start, end) is intersect with the VMA range. Caller wants
946 * to know whether the folio is fully associated with the range. It calls
947 * this function to check whether the folio is in the range first. Then checks
948 * the page table to know whether the folio is fully mapped to the range.
949 */
950static inline bool
951folio_within_range(struct folio *folio, struct vm_area_struct *vma,
952 unsigned long start, unsigned long end)
953{
954 pgoff_t pgoff, addr;
955 unsigned long vma_pglen = vma_pages(vma);
956
957 VM_WARN_ON_FOLIO(folio_test_ksm(folio), folio);
958 if (start > end)
959 return false;
960
961 if (start < vma->vm_start)
962 start = vma->vm_start;
963
964 if (end > vma->vm_end)
965 end = vma->vm_end;
966
967 pgoff = folio_pgoff(folio);
968
969 /* if folio start address is not in vma range */
970 if (!in_range(pgoff, vma->vm_pgoff, vma_pglen))
971 return false;
972
973 addr = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
974
975 return !(addr < start || end - addr < folio_size(folio));
976}
977
978static inline bool
979folio_within_vma(struct folio *folio, struct vm_area_struct *vma)
980{
981 return folio_within_range(folio, vma, start: vma->vm_start, end: vma->vm_end);
982}
983
984/*
985 * mlock_vma_folio() and munlock_vma_folio():
986 * should be called with vma's mmap_lock held for read or write,
987 * under page table lock for the pte/pmd being added or removed.
988 *
989 * mlock is usually called at the end of folio_add_*_rmap_*(), munlock at
990 * the end of folio_remove_rmap_*(); but new anon folios are managed by
991 * folio_add_lru_vma() calling mlock_new_folio().
992 */
993void mlock_folio(struct folio *folio);
994static inline void mlock_vma_folio(struct folio *folio,
995 struct vm_area_struct *vma)
996{
997 /*
998 * The VM_SPECIAL check here serves two purposes.
999 * 1) VM_IO check prevents migration from double-counting during mlock.
1000 * 2) Although mmap_region() and mlock_fixup() take care that VM_LOCKED
1001 * is never left set on a VM_SPECIAL vma, there is an interval while
1002 * file->f_op->mmap() is using vm_insert_page(s), when VM_LOCKED may
1003 * still be set while VM_SPECIAL bits are added: so ignore it then.
1004 */
1005 if (unlikely((vma->vm_flags & (VM_LOCKED|VM_SPECIAL)) == VM_LOCKED))
1006 mlock_folio(folio);
1007}
1008
1009void munlock_folio(struct folio *folio);
1010static inline void munlock_vma_folio(struct folio *folio,
1011 struct vm_area_struct *vma)
1012{
1013 /*
1014 * munlock if the function is called. Ideally, we should only
1015 * do munlock if any page of folio is unmapped from VMA and
1016 * cause folio not fully mapped to VMA.
1017 *
1018 * But it's not easy to confirm that's the situation. So we
1019 * always munlock the folio and page reclaim will correct it
1020 * if it's wrong.
1021 */
1022 if (unlikely(vma->vm_flags & VM_LOCKED))
1023 munlock_folio(folio);
1024}
1025
1026void mlock_new_folio(struct folio *folio);
1027bool need_mlock_drain(int cpu);
1028void mlock_drain_local(void);
1029void mlock_drain_remote(int cpu);
1030
1031extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
1032
1033/**
1034 * vma_address - Find the virtual address a page range is mapped at
1035 * @vma: The vma which maps this object.
1036 * @pgoff: The page offset within its object.
1037 * @nr_pages: The number of pages to consider.
1038 *
1039 * If any page in this range is mapped by this VMA, return the first address
1040 * where any of these pages appear. Otherwise, return -EFAULT.
1041 */
1042static inline unsigned long vma_address(const struct vm_area_struct *vma,
1043 pgoff_t pgoff, unsigned long nr_pages)
1044{
1045 unsigned long address;
1046
1047 if (pgoff >= vma->vm_pgoff) {
1048 address = vma->vm_start +
1049 ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
1050 /* Check for address beyond vma (or wrapped through 0?) */
1051 if (address < vma->vm_start || address >= vma->vm_end)
1052 address = -EFAULT;
1053 } else if (pgoff + nr_pages - 1 >= vma->vm_pgoff) {
1054 /* Test above avoids possibility of wrap to 0 on 32-bit */
1055 address = vma->vm_start;
1056 } else {
1057 address = -EFAULT;
1058 }
1059 return address;
1060}
1061
1062/*
1063 * Then at what user virtual address will none of the range be found in vma?
1064 * Assumes that vma_address() already returned a good starting address.
1065 */
1066static inline unsigned long vma_address_end(struct page_vma_mapped_walk *pvmw)
1067{
1068 struct vm_area_struct *vma = pvmw->vma;
1069 pgoff_t pgoff;
1070 unsigned long address;
1071
1072 /* Common case, plus ->pgoff is invalid for KSM */
1073 if (pvmw->nr_pages == 1)
1074 return pvmw->address + PAGE_SIZE;
1075
1076 pgoff = pvmw->pgoff + pvmw->nr_pages;
1077 address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
1078 /* Check for address beyond vma (or wrapped through 0?) */
1079 if (address < vma->vm_start || address > vma->vm_end)
1080 address = vma->vm_end;
1081 return address;
1082}
1083
1084static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
1085 struct file *fpin)
1086{
1087 int flags = vmf->flags;
1088
1089 if (fpin)
1090 return fpin;
1091
1092 /*
1093 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or
1094 * anything, so we only pin the file and drop the mmap_lock if only
1095 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt.
1096 */
1097 if (fault_flag_allow_retry_first(flags) &&
1098 !(flags & FAULT_FLAG_RETRY_NOWAIT)) {
1099 fpin = get_file(f: vmf->vma->vm_file);
1100 release_fault_lock(vmf);
1101 }
1102 return fpin;
1103}
1104#else /* !CONFIG_MMU */
1105static inline void unmap_mapping_folio(struct folio *folio) { }
1106static inline void mlock_new_folio(struct folio *folio) { }
1107static inline bool need_mlock_drain(int cpu) { return false; }
1108static inline void mlock_drain_local(void) { }
1109static inline void mlock_drain_remote(int cpu) { }
1110static inline void vunmap_range_noflush(unsigned long start, unsigned long end)
1111{
1112}
1113#endif /* !CONFIG_MMU */
1114
1115/* Memory initialisation debug and verification */
1116#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1117DECLARE_STATIC_KEY_TRUE(deferred_pages);
1118
1119bool __init deferred_grow_zone(struct zone *zone, unsigned int order);
1120#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1121
1122void init_deferred_page(unsigned long pfn, int nid);
1123
1124enum mminit_level {
1125 MMINIT_WARNING,
1126 MMINIT_VERIFY,
1127 MMINIT_TRACE
1128};
1129
1130#ifdef CONFIG_DEBUG_MEMORY_INIT
1131
1132extern int mminit_loglevel;
1133
1134#define mminit_dprintk(level, prefix, fmt, arg...) \
1135do { \
1136 if (level < mminit_loglevel) { \
1137 if (level <= MMINIT_WARNING) \
1138 pr_warn("mminit::" prefix " " fmt, ##arg); \
1139 else \
1140 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
1141 } \
1142} while (0)
1143
1144extern void mminit_verify_pageflags_layout(void);
1145extern void mminit_verify_zonelist(void);
1146#else
1147
1148static inline void mminit_dprintk(enum mminit_level level,
1149 const char *prefix, const char *fmt, ...)
1150{
1151}
1152
1153static inline void mminit_verify_pageflags_layout(void)
1154{
1155}
1156
1157static inline void mminit_verify_zonelist(void)
1158{
1159}
1160#endif /* CONFIG_DEBUG_MEMORY_INIT */
1161
1162#define NODE_RECLAIM_NOSCAN -2
1163#define NODE_RECLAIM_FULL -1
1164#define NODE_RECLAIM_SOME 0
1165#define NODE_RECLAIM_SUCCESS 1
1166
1167#ifdef CONFIG_NUMA
1168extern int node_reclaim_mode;
1169
1170extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
1171extern int find_next_best_node(int node, nodemask_t *used_node_mask);
1172#else
1173#define node_reclaim_mode 0
1174
1175static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
1176 unsigned int order)
1177{
1178 return NODE_RECLAIM_NOSCAN;
1179}
1180static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
1181{
1182 return NUMA_NO_NODE;
1183}
1184#endif
1185
1186static inline bool node_reclaim_enabled(void)
1187{
1188 /* Is any node_reclaim_mode bit set? */
1189 return node_reclaim_mode & (RECLAIM_ZONE|RECLAIM_WRITE|RECLAIM_UNMAP);
1190}
1191
1192/*
1193 * mm/memory-failure.c
1194 */
1195#ifdef CONFIG_MEMORY_FAILURE
1196int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill);
1197void shake_folio(struct folio *folio);
1198extern int hwpoison_filter(struct page *p);
1199
1200extern u32 hwpoison_filter_dev_major;
1201extern u32 hwpoison_filter_dev_minor;
1202extern u64 hwpoison_filter_flags_mask;
1203extern u64 hwpoison_filter_flags_value;
1204extern u64 hwpoison_filter_memcg;
1205extern u32 hwpoison_filter_enable;
1206#define MAGIC_HWPOISON 0x48575053U /* HWPS */
1207void SetPageHWPoisonTakenOff(struct page *page);
1208void ClearPageHWPoisonTakenOff(struct page *page);
1209bool take_page_off_buddy(struct page *page);
1210bool put_page_back_buddy(struct page *page);
1211struct task_struct *task_early_kill(struct task_struct *tsk, int force_early);
1212void add_to_kill_ksm(struct task_struct *tsk, const struct page *p,
1213 struct vm_area_struct *vma, struct list_head *to_kill,
1214 unsigned long ksm_addr);
1215unsigned long page_mapped_in_vma(const struct page *page,
1216 struct vm_area_struct *vma);
1217
1218#else
1219static inline int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill)
1220{
1221 return -EBUSY;
1222}
1223#endif
1224
1225extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long,
1226 unsigned long, unsigned long,
1227 unsigned long, unsigned long);
1228
1229extern void set_pageblock_order(void);
1230struct folio *alloc_migrate_folio(struct folio *src, unsigned long private);
1231unsigned long reclaim_pages(struct list_head *folio_list);
1232unsigned int reclaim_clean_pages_from_list(struct zone *zone,
1233 struct list_head *folio_list);
1234/* The ALLOC_WMARK bits are used as an index to zone->watermark */
1235#define ALLOC_WMARK_MIN WMARK_MIN
1236#define ALLOC_WMARK_LOW WMARK_LOW
1237#define ALLOC_WMARK_HIGH WMARK_HIGH
1238#define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1239
1240/* Mask to get the watermark bits */
1241#define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1242
1243/*
1244 * Only MMU archs have async oom victim reclaim - aka oom_reaper so we
1245 * cannot assume a reduced access to memory reserves is sufficient for
1246 * !MMU
1247 */
1248#ifdef CONFIG_MMU
1249#define ALLOC_OOM 0x08
1250#else
1251#define ALLOC_OOM ALLOC_NO_WATERMARKS
1252#endif
1253
1254#define ALLOC_NON_BLOCK 0x10 /* Caller cannot block. Allow access
1255 * to 25% of the min watermark or
1256 * 62.5% if __GFP_HIGH is set.
1257 */
1258#define ALLOC_MIN_RESERVE 0x20 /* __GFP_HIGH set. Allow access to 50%
1259 * of the min watermark.
1260 */
1261#define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1262#define ALLOC_CMA 0x80 /* allow allocations from CMA areas */
1263#ifdef CONFIG_ZONE_DMA32
1264#define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */
1265#else
1266#define ALLOC_NOFRAGMENT 0x0
1267#endif
1268#define ALLOC_HIGHATOMIC 0x200 /* Allows access to MIGRATE_HIGHATOMIC */
1269#define ALLOC_TRYLOCK 0x400 /* Only use spin_trylock in allocation path */
1270#define ALLOC_KSWAPD 0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */
1271
1272/* Flags that allow allocations below the min watermark. */
1273#define ALLOC_RESERVES (ALLOC_NON_BLOCK|ALLOC_MIN_RESERVE|ALLOC_HIGHATOMIC|ALLOC_OOM)
1274
1275enum ttu_flags;
1276struct tlbflush_unmap_batch;
1277
1278
1279/*
1280 * only for MM internal work items which do not depend on
1281 * any allocations or locks which might depend on allocations
1282 */
1283extern struct workqueue_struct *mm_percpu_wq;
1284
1285#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
1286void try_to_unmap_flush(void);
1287void try_to_unmap_flush_dirty(void);
1288void flush_tlb_batched_pending(struct mm_struct *mm);
1289#else
1290static inline void try_to_unmap_flush(void)
1291{
1292}
1293static inline void try_to_unmap_flush_dirty(void)
1294{
1295}
1296static inline void flush_tlb_batched_pending(struct mm_struct *mm)
1297{
1298}
1299#endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
1300
1301extern const struct trace_print_flags pageflag_names[];
1302extern const struct trace_print_flags vmaflag_names[];
1303extern const struct trace_print_flags gfpflag_names[];
1304
1305static inline bool is_migrate_highatomic(enum migratetype migratetype)
1306{
1307 return migratetype == MIGRATE_HIGHATOMIC;
1308}
1309
1310void setup_zone_pageset(struct zone *zone);
1311
1312struct migration_target_control {
1313 int nid; /* preferred node id */
1314 nodemask_t *nmask;
1315 gfp_t gfp_mask;
1316 enum migrate_reason reason;
1317};
1318
1319/*
1320 * mm/filemap.c
1321 */
1322size_t splice_folio_into_pipe(struct pipe_inode_info *pipe,
1323 struct folio *folio, loff_t fpos, size_t size);
1324
1325/*
1326 * mm/vmalloc.c
1327 */
1328#ifdef CONFIG_MMU
1329void __init vmalloc_init(void);
1330int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end,
1331 pgprot_t prot, struct page **pages, unsigned int page_shift);
1332unsigned int get_vm_area_page_order(struct vm_struct *vm);
1333#else
1334static inline void vmalloc_init(void)
1335{
1336}
1337
1338static inline
1339int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end,
1340 pgprot_t prot, struct page **pages, unsigned int page_shift)
1341{
1342 return -EINVAL;
1343}
1344#endif
1345
1346int __must_check __vmap_pages_range_noflush(unsigned long addr,
1347 unsigned long end, pgprot_t prot,
1348 struct page **pages, unsigned int page_shift);
1349
1350void vunmap_range_noflush(unsigned long start, unsigned long end);
1351
1352void __vunmap_range_noflush(unsigned long start, unsigned long end);
1353
1354int numa_migrate_check(struct folio *folio, struct vm_fault *vmf,
1355 unsigned long addr, int *flags, bool writable,
1356 int *last_cpupid);
1357
1358void free_zone_device_folio(struct folio *folio);
1359int migrate_device_coherent_folio(struct folio *folio);
1360
1361struct vm_struct *__get_vm_area_node(unsigned long size,
1362 unsigned long align, unsigned long shift,
1363 unsigned long flags, unsigned long start,
1364 unsigned long end, int node, gfp_t gfp_mask,
1365 const void *caller);
1366
1367/*
1368 * mm/gup.c
1369 */
1370int __must_check try_grab_folio(struct folio *folio, int refs,
1371 unsigned int flags);
1372
1373/*
1374 * mm/huge_memory.c
1375 */
1376void touch_pud(struct vm_area_struct *vma, unsigned long addr,
1377 pud_t *pud, bool write);
1378void touch_pmd(struct vm_area_struct *vma, unsigned long addr,
1379 pmd_t *pmd, bool write);
1380
1381/*
1382 * Parses a string with mem suffixes into its order. Useful to parse kernel
1383 * parameters.
1384 */
1385static inline int get_order_from_str(const char *size_str,
1386 unsigned long valid_orders)
1387{
1388 unsigned long size;
1389 char *endptr;
1390 int order;
1391
1392 size = memparse(ptr: size_str, retptr: &endptr);
1393
1394 if (!is_power_of_2(n: size))
1395 return -EINVAL;
1396 order = get_order(size);
1397 if (BIT(order) & ~valid_orders)
1398 return -EINVAL;
1399
1400 return order;
1401}
1402
1403enum {
1404 /* mark page accessed */
1405 FOLL_TOUCH = 1 << 16,
1406 /* a retry, previous pass started an IO */
1407 FOLL_TRIED = 1 << 17,
1408 /* we are working on non-current tsk/mm */
1409 FOLL_REMOTE = 1 << 18,
1410 /* pages must be released via unpin_user_page */
1411 FOLL_PIN = 1 << 19,
1412 /* gup_fast: prevent fall-back to slow gup */
1413 FOLL_FAST_ONLY = 1 << 20,
1414 /* allow unlocking the mmap lock */
1415 FOLL_UNLOCKABLE = 1 << 21,
1416 /* VMA lookup+checks compatible with MADV_POPULATE_(READ|WRITE) */
1417 FOLL_MADV_POPULATE = 1 << 22,
1418};
1419
1420#define INTERNAL_GUP_FLAGS (FOLL_TOUCH | FOLL_TRIED | FOLL_REMOTE | FOLL_PIN | \
1421 FOLL_FAST_ONLY | FOLL_UNLOCKABLE | \
1422 FOLL_MADV_POPULATE)
1423
1424/*
1425 * Indicates for which pages that are write-protected in the page table,
1426 * whether GUP has to trigger unsharing via FAULT_FLAG_UNSHARE such that the
1427 * GUP pin will remain consistent with the pages mapped into the page tables
1428 * of the MM.
1429 *
1430 * Temporary unmapping of PageAnonExclusive() pages or clearing of
1431 * PageAnonExclusive() has to protect against concurrent GUP:
1432 * * Ordinary GUP: Using the PT lock
1433 * * GUP-fast and fork(): mm->write_protect_seq
1434 * * GUP-fast and KSM or temporary unmapping (swap, migration): see
1435 * folio_try_share_anon_rmap_*()
1436 *
1437 * Must be called with the (sub)page that's actually referenced via the
1438 * page table entry, which might not necessarily be the head page for a
1439 * PTE-mapped THP.
1440 *
1441 * If the vma is NULL, we're coming from the GUP-fast path and might have
1442 * to fallback to the slow path just to lookup the vma.
1443 */
1444static inline bool gup_must_unshare(struct vm_area_struct *vma,
1445 unsigned int flags, struct page *page)
1446{
1447 /*
1448 * FOLL_WRITE is implicitly handled correctly as the page table entry
1449 * has to be writable -- and if it references (part of) an anonymous
1450 * folio, that part is required to be marked exclusive.
1451 */
1452 if ((flags & (FOLL_WRITE | FOLL_PIN)) != FOLL_PIN)
1453 return false;
1454 /*
1455 * Note: PageAnon(page) is stable until the page is actually getting
1456 * freed.
1457 */
1458 if (!PageAnon(page)) {
1459 /*
1460 * We only care about R/O long-term pining: R/O short-term
1461 * pinning does not have the semantics to observe successive
1462 * changes through the process page tables.
1463 */
1464 if (!(flags & FOLL_LONGTERM))
1465 return false;
1466
1467 /* We really need the vma ... */
1468 if (!vma)
1469 return true;
1470
1471 /*
1472 * ... because we only care about writable private ("COW")
1473 * mappings where we have to break COW early.
1474 */
1475 return is_cow_mapping(flags: vma->vm_flags);
1476 }
1477
1478 /* Paired with a memory barrier in folio_try_share_anon_rmap_*(). */
1479 if (IS_ENABLED(CONFIG_HAVE_GUP_FAST))
1480 smp_rmb();
1481
1482 /*
1483 * Note that KSM pages cannot be exclusive, and consequently,
1484 * cannot get pinned.
1485 */
1486 return !PageAnonExclusive(page);
1487}
1488
1489extern bool mirrored_kernelcore;
1490bool memblock_has_mirror(void);
1491void memblock_free_all(void);
1492
1493static __always_inline void vma_set_range(struct vm_area_struct *vma,
1494 unsigned long start, unsigned long end,
1495 pgoff_t pgoff)
1496{
1497 vma->vm_start = start;
1498 vma->vm_end = end;
1499 vma->vm_pgoff = pgoff;
1500}
1501
1502static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma)
1503{
1504 /*
1505 * NOTE: we must check this before VM_SOFTDIRTY on soft-dirty
1506 * enablements, because when without soft-dirty being compiled in,
1507 * VM_SOFTDIRTY is defined as 0x0, then !(vm_flags & VM_SOFTDIRTY)
1508 * will be constantly true.
1509 */
1510 if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
1511 return false;
1512
1513 /*
1514 * Soft-dirty is kind of special: its tracking is enabled when the
1515 * vma flags not set.
1516 */
1517 return !(vma->vm_flags & VM_SOFTDIRTY);
1518}
1519
1520static inline bool pmd_needs_soft_dirty_wp(struct vm_area_struct *vma, pmd_t pmd)
1521{
1522 return vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd);
1523}
1524
1525static inline bool pte_needs_soft_dirty_wp(struct vm_area_struct *vma, pte_t pte)
1526{
1527 return vma_soft_dirty_enabled(vma) && !pte_soft_dirty(pte);
1528}
1529
1530void __meminit __init_single_page(struct page *page, unsigned long pfn,
1531 unsigned long zone, int nid);
1532void __meminit __init_page_from_nid(unsigned long pfn, int nid);
1533
1534/* shrinker related functions */
1535unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg,
1536 int priority);
1537
1538#ifdef CONFIG_SHRINKER_DEBUG
1539static inline __printf(2, 0) int shrinker_debugfs_name_alloc(
1540 struct shrinker *shrinker, const char *fmt, va_list ap)
1541{
1542 shrinker->name = kvasprintf_const(GFP_KERNEL, fmt, args: ap);
1543
1544 return shrinker->name ? 0 : -ENOMEM;
1545}
1546
1547static inline void shrinker_debugfs_name_free(struct shrinker *shrinker)
1548{
1549 kfree_const(x: shrinker->name);
1550 shrinker->name = NULL;
1551}
1552
1553extern int shrinker_debugfs_add(struct shrinker *shrinker);
1554extern struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker,
1555 int *debugfs_id);
1556extern void shrinker_debugfs_remove(struct dentry *debugfs_entry,
1557 int debugfs_id);
1558#else /* CONFIG_SHRINKER_DEBUG */
1559static inline int shrinker_debugfs_add(struct shrinker *shrinker)
1560{
1561 return 0;
1562}
1563static inline int shrinker_debugfs_name_alloc(struct shrinker *shrinker,
1564 const char *fmt, va_list ap)
1565{
1566 return 0;
1567}
1568static inline void shrinker_debugfs_name_free(struct shrinker *shrinker)
1569{
1570}
1571static inline struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker,
1572 int *debugfs_id)
1573{
1574 *debugfs_id = -1;
1575 return NULL;
1576}
1577static inline void shrinker_debugfs_remove(struct dentry *debugfs_entry,
1578 int debugfs_id)
1579{
1580}
1581#endif /* CONFIG_SHRINKER_DEBUG */
1582
1583/* Only track the nodes of mappings with shadow entries */
1584void workingset_update_node(struct xa_node *node);
1585extern struct list_lru shadow_nodes;
1586#define mapping_set_update(xas, mapping) do { \
1587 if (!dax_mapping(mapping) && !shmem_mapping(mapping)) { \
1588 xas_set_update(xas, workingset_update_node); \
1589 xas_set_lru(xas, &shadow_nodes); \
1590 } \
1591} while (0)
1592
1593/* mremap.c */
1594unsigned long move_page_tables(struct pagetable_move_control *pmc);
1595
1596#ifdef CONFIG_UNACCEPTED_MEMORY
1597void accept_page(struct page *page);
1598#else /* CONFIG_UNACCEPTED_MEMORY */
1599static inline void accept_page(struct page *page)
1600{
1601}
1602#endif /* CONFIG_UNACCEPTED_MEMORY */
1603
1604/* pagewalk.c */
1605int walk_page_range_mm(struct mm_struct *mm, unsigned long start,
1606 unsigned long end, const struct mm_walk_ops *ops,
1607 void *private);
1608
1609/* pt_reclaim.c */
1610bool try_get_and_clear_pmd(struct mm_struct *mm, pmd_t *pmd, pmd_t *pmdval);
1611void free_pte(struct mm_struct *mm, unsigned long addr, struct mmu_gather *tlb,
1612 pmd_t pmdval);
1613void try_to_free_pte(struct mm_struct *mm, pmd_t *pmd, unsigned long addr,
1614 struct mmu_gather *tlb);
1615
1616#ifdef CONFIG_PT_RECLAIM
1617bool reclaim_pt_is_enabled(unsigned long start, unsigned long end,
1618 struct zap_details *details);
1619#else
1620static inline bool reclaim_pt_is_enabled(unsigned long start, unsigned long end,
1621 struct zap_details *details)
1622{
1623 return false;
1624}
1625#endif /* CONFIG_PT_RECLAIM */
1626
1627void dup_mm_exe_file(struct mm_struct *mm, struct mm_struct *oldmm);
1628int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm);
1629
1630#endif /* __MM_INTERNAL_H */
1631

source code of linux/mm/internal.h