1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* internal.h: mm/ internal definitions
4 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
7 #ifndef __MM_INTERNAL_H
8 #define __MM_INTERNAL_H
12 #include <linux/pagemap.h>
13 #include <linux/tracepoint-defs.h>
18 * The set of flags that only affect watermark checking and reclaim
19 * behaviour. This is used by the MM to obey the caller constraints
20 * about IO, FS and watermark checking while ignoring placement
21 * hints such as HIGHMEM usage.
23 #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\
24 __GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\
25 __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\
28 /* The GFP flags allowed during early boot */
29 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))
31 /* Control allocation cpuset and node placement constraints */
32 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
34 /* Do not use these with a slab allocator */
35 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
37 void page_writeback_init(void);
39 static inline void *folio_raw_mapping(struct folio *folio)
41 unsigned long mapping = (unsigned long)folio->mapping;
43 return (void *)(mapping & ~PAGE_MAPPING_FLAGS);
46 void __acct_reclaim_writeback(pg_data_t *pgdat, struct folio *folio,
48 static inline void acct_reclaim_writeback(struct folio *folio)
50 pg_data_t *pgdat = folio_pgdat(folio);
51 int nr_throttled = atomic_read(&pgdat->nr_writeback_throttled);
54 __acct_reclaim_writeback(pgdat, folio, nr_throttled);
57 static inline void wake_throttle_isolated(pg_data_t *pgdat)
59 wait_queue_head_t *wqh;
61 wqh = &pgdat->reclaim_wait[VMSCAN_THROTTLE_ISOLATED];
62 if (waitqueue_active(wqh))
66 vm_fault_t do_swap_page(struct vm_fault *vmf);
67 void folio_rotate_reclaimable(struct folio *folio);
68 bool __folio_end_writeback(struct folio *folio);
70 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
71 unsigned long floor, unsigned long ceiling);
72 void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte);
74 static inline bool can_madv_lru_vma(struct vm_area_struct *vma)
76 return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP));
80 void unmap_page_range(struct mmu_gather *tlb,
81 struct vm_area_struct *vma,
82 unsigned long addr, unsigned long end,
83 struct zap_details *details);
85 void do_page_cache_ra(struct readahead_control *, unsigned long nr_to_read,
86 unsigned long lookahead_size);
87 void force_page_cache_ra(struct readahead_control *, unsigned long nr);
88 static inline void force_page_cache_readahead(struct address_space *mapping,
89 struct file *file, pgoff_t index, unsigned long nr_to_read)
91 DEFINE_READAHEAD(ractl, file, &file->f_ra, mapping, index);
92 force_page_cache_ra(&ractl, nr_to_read);
95 unsigned find_lock_entries(struct address_space *mapping, pgoff_t start,
96 pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices);
97 unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
98 pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices);
99 void filemap_free_folio(struct address_space *mapping, struct folio *folio);
100 int truncate_inode_folio(struct address_space *mapping, struct folio *folio);
101 bool truncate_inode_partial_folio(struct folio *folio, loff_t start,
105 * folio_evictable - Test whether a folio is evictable.
106 * @folio: The folio to test.
108 * Test whether @folio is evictable -- i.e., should be placed on
109 * active/inactive lists vs unevictable list.
111 * Reasons folio might not be evictable:
112 * 1. folio's mapping marked unevictable
113 * 2. One of the pages in the folio is part of an mlocked VMA
115 static inline bool folio_evictable(struct folio *folio)
119 /* Prevent address_space of inode and swap cache from being freed */
121 ret = !mapping_unevictable(folio_mapping(folio)) &&
122 !folio_test_mlocked(folio);
127 static inline bool page_evictable(struct page *page)
131 /* Prevent address_space of inode and swap cache from being freed */
133 ret = !mapping_unevictable(page_mapping(page)) && !PageMlocked(page);
139 * Turn a non-refcounted page (->_refcount == 0) into refcounted with
142 static inline void set_page_refcounted(struct page *page)
144 VM_BUG_ON_PAGE(PageTail(page), page);
145 VM_BUG_ON_PAGE(page_ref_count(page), page);
146 set_page_count(page, 1);
149 extern unsigned long highest_memmap_pfn;
152 * Maximum number of reclaim retries without progress before the OOM
153 * killer is consider the only way forward.
155 #define MAX_RECLAIM_RETRIES 16
160 extern int isolate_lru_page(struct page *page);
161 extern void putback_lru_page(struct page *page);
162 extern void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason);
167 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
170 * in mm/memcontrol.c:
172 extern bool cgroup_memory_nokmem;
179 * Structure for holding the mostly immutable allocation parameters passed
180 * between functions involved in allocations, including the alloc_pages*
181 * family of functions.
183 * nodemask, migratetype and highest_zoneidx are initialized only once in
184 * __alloc_pages() and then never change.
186 * zonelist, preferred_zone and highest_zoneidx are set first in
187 * __alloc_pages() for the fast path, and might be later changed
188 * in __alloc_pages_slowpath(). All other functions pass the whole structure
189 * by a const pointer.
191 struct alloc_context {
192 struct zonelist *zonelist;
193 nodemask_t *nodemask;
194 struct zoneref *preferred_zoneref;
198 * highest_zoneidx represents highest usable zone index of
199 * the allocation request. Due to the nature of the zone,
200 * memory on lower zone than the highest_zoneidx will be
201 * protected by lowmem_reserve[highest_zoneidx].
203 * highest_zoneidx is also used by reclaim/compaction to limit
204 * the target zone since higher zone than this index cannot be
205 * usable for this allocation request.
207 enum zone_type highest_zoneidx;
208 bool spread_dirty_pages;
212 * Locate the struct page for both the matching buddy in our
213 * pair (buddy1) and the combined O(n+1) page they form (page).
215 * 1) Any buddy B1 will have an order O twin B2 which satisfies
216 * the following equation:
218 * For example, if the starting buddy (buddy2) is #8 its order
220 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
222 * 2) Any buddy B will have an order O+1 parent P which
223 * satisfies the following equation:
226 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
228 static inline unsigned long
229 __find_buddy_pfn(unsigned long page_pfn, unsigned int order)
231 return page_pfn ^ (1 << order);
234 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
235 unsigned long end_pfn, struct zone *zone);
237 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
238 unsigned long end_pfn, struct zone *zone)
240 if (zone->contiguous)
241 return pfn_to_page(start_pfn);
243 return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
246 extern int __isolate_free_page(struct page *page, unsigned int order);
247 extern void __putback_isolated_page(struct page *page, unsigned int order,
249 extern void memblock_free_pages(struct page *page, unsigned long pfn,
251 extern void __free_pages_core(struct page *page, unsigned int order);
252 extern void prep_compound_page(struct page *page, unsigned int order);
253 extern void post_alloc_hook(struct page *page, unsigned int order,
255 extern int user_min_free_kbytes;
257 extern void free_unref_page(struct page *page, unsigned int order);
258 extern void free_unref_page_list(struct list_head *list);
260 extern void zone_pcp_update(struct zone *zone, int cpu_online);
261 extern void zone_pcp_reset(struct zone *zone);
262 extern void zone_pcp_disable(struct zone *zone);
263 extern void zone_pcp_enable(struct zone *zone);
265 extern void *memmap_alloc(phys_addr_t size, phys_addr_t align,
266 phys_addr_t min_addr,
267 int nid, bool exact_nid);
269 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
275 * compact_control is used to track pages being migrated and the free pages
276 * they are being migrated to during memory compaction. The free_pfn starts
277 * at the end of a zone and migrate_pfn begins at the start. Movable pages
278 * are moved to the end of a zone during a compaction run and the run
279 * completes when free_pfn <= migrate_pfn
281 struct compact_control {
282 struct list_head freepages; /* List of free pages to migrate to */
283 struct list_head migratepages; /* List of pages being migrated */
284 unsigned int nr_freepages; /* Number of isolated free pages */
285 unsigned int nr_migratepages; /* Number of pages to migrate */
286 unsigned long free_pfn; /* isolate_freepages search base */
288 * Acts as an in/out parameter to page isolation for migration.
289 * isolate_migratepages uses it as a search base.
290 * isolate_migratepages_block will update the value to the next pfn
291 * after the last isolated one.
293 unsigned long migrate_pfn;
294 unsigned long fast_start_pfn; /* a pfn to start linear scan from */
296 unsigned long total_migrate_scanned;
297 unsigned long total_free_scanned;
298 unsigned short fast_search_fail;/* failures to use free list searches */
299 short search_order; /* order to start a fast search at */
300 const gfp_t gfp_mask; /* gfp mask of a direct compactor */
301 int order; /* order a direct compactor needs */
302 int migratetype; /* migratetype of direct compactor */
303 const unsigned int alloc_flags; /* alloc flags of a direct compactor */
304 const int highest_zoneidx; /* zone index of a direct compactor */
305 enum migrate_mode mode; /* Async or sync migration mode */
306 bool ignore_skip_hint; /* Scan blocks even if marked skip */
307 bool no_set_skip_hint; /* Don't mark blocks for skipping */
308 bool ignore_block_suitable; /* Scan blocks considered unsuitable */
309 bool direct_compaction; /* False from kcompactd or /proc/... */
310 bool proactive_compaction; /* kcompactd proactive compaction */
311 bool whole_zone; /* Whole zone should/has been scanned */
312 bool contended; /* Signal lock or sched contention */
313 bool rescan; /* Rescanning the same pageblock */
314 bool alloc_contig; /* alloc_contig_range allocation */
318 * Used in direct compaction when a page should be taken from the freelists
319 * immediately when one is created during the free path.
321 struct capture_control {
322 struct compact_control *cc;
327 isolate_freepages_range(struct compact_control *cc,
328 unsigned long start_pfn, unsigned long end_pfn);
330 isolate_migratepages_range(struct compact_control *cc,
331 unsigned long low_pfn, unsigned long end_pfn);
333 int find_suitable_fallback(struct free_area *area, unsigned int order,
334 int migratetype, bool only_stealable, bool *can_steal);
337 * This function returns the order of a free page in the buddy system. In
338 * general, page_zone(page)->lock must be held by the caller to prevent the
339 * page from being allocated in parallel and returning garbage as the order.
340 * If a caller does not hold page_zone(page)->lock, it must guarantee that the
341 * page cannot be allocated or merged in parallel. Alternatively, it must
342 * handle invalid values gracefully, and use buddy_order_unsafe() below.
344 static inline unsigned int buddy_order(struct page *page)
346 /* PageBuddy() must be checked by the caller */
347 return page_private(page);
351 * Like buddy_order(), but for callers who cannot afford to hold the zone lock.
352 * PageBuddy() should be checked first by the caller to minimize race window,
353 * and invalid values must be handled gracefully.
355 * READ_ONCE is used so that if the caller assigns the result into a local
356 * variable and e.g. tests it for valid range before using, the compiler cannot
357 * decide to remove the variable and inline the page_private(page) multiple
358 * times, potentially observing different values in the tests and the actual
361 #define buddy_order_unsafe(page) READ_ONCE(page_private(page))
364 * These three helpers classifies VMAs for virtual memory accounting.
368 * Executable code area - executable, not writable, not stack
370 static inline bool is_exec_mapping(vm_flags_t flags)
372 return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
376 * Stack area - automatically grows in one direction
378 * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
379 * do_mmap() forbids all other combinations.
381 static inline bool is_stack_mapping(vm_flags_t flags)
383 return (flags & VM_STACK) == VM_STACK;
387 * Data area - private, writable, not stack
389 static inline bool is_data_mapping(vm_flags_t flags)
391 return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
395 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
396 struct vm_area_struct *prev);
397 void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma);
400 void unmap_mapping_folio(struct folio *folio);
401 extern long populate_vma_page_range(struct vm_area_struct *vma,
402 unsigned long start, unsigned long end, int *locked);
403 extern long faultin_vma_page_range(struct vm_area_struct *vma,
404 unsigned long start, unsigned long end,
405 bool write, int *locked);
406 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
407 unsigned long start, unsigned long end);
408 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
410 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
414 * must be called with vma's mmap_lock held for read or write, and page locked.
416 extern void mlock_vma_page(struct page *page);
417 extern unsigned int munlock_vma_page(struct page *page);
419 extern int mlock_future_check(struct mm_struct *mm, unsigned long flags,
423 * Clear the page's PageMlocked(). This can be useful in a situation where
424 * we want to unconditionally remove a page from the pagecache -- e.g.,
425 * on truncation or freeing.
427 * It is legal to call this function for any page, mlocked or not.
428 * If called for a page that is still mapped by mlocked vmas, all we do
429 * is revert to lazy LRU behaviour -- semantics are not broken.
431 extern void clear_page_mlock(struct page *page);
433 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
436 * At what user virtual address is page expected in vma?
437 * Returns -EFAULT if all of the page is outside the range of vma.
438 * If page is a compound head, the entire compound page is considered.
440 static inline unsigned long
441 vma_address(struct page *page, struct vm_area_struct *vma)
444 unsigned long address;
446 VM_BUG_ON_PAGE(PageKsm(page), page); /* KSM page->index unusable */
447 pgoff = page_to_pgoff(page);
448 if (pgoff >= vma->vm_pgoff) {
449 address = vma->vm_start +
450 ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
451 /* Check for address beyond vma (or wrapped through 0?) */
452 if (address < vma->vm_start || address >= vma->vm_end)
454 } else if (PageHead(page) &&
455 pgoff + compound_nr(page) - 1 >= vma->vm_pgoff) {
456 /* Test above avoids possibility of wrap to 0 on 32-bit */
457 address = vma->vm_start;
465 * Then at what user virtual address will none of the page be found in vma?
466 * Assumes that vma_address() already returned a good starting address.
467 * If page is a compound head, the entire compound page is considered.
469 static inline unsigned long
470 vma_address_end(struct page *page, struct vm_area_struct *vma)
473 unsigned long address;
475 VM_BUG_ON_PAGE(PageKsm(page), page); /* KSM page->index unusable */
476 pgoff = page_to_pgoff(page) + compound_nr(page);
477 address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
478 /* Check for address beyond vma (or wrapped through 0?) */
479 if (address < vma->vm_start || address > vma->vm_end)
480 address = vma->vm_end;
484 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
487 int flags = vmf->flags;
493 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or
494 * anything, so we only pin the file and drop the mmap_lock if only
495 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt.
497 if (fault_flag_allow_retry_first(flags) &&
498 !(flags & FAULT_FLAG_RETRY_NOWAIT)) {
499 fpin = get_file(vmf->vma->vm_file);
500 mmap_read_unlock(vmf->vma->vm_mm);
504 #else /* !CONFIG_MMU */
505 static inline void unmap_mapping_folio(struct folio *folio) { }
506 static inline void clear_page_mlock(struct page *page) { }
507 static inline void mlock_vma_page(struct page *page) { }
508 static inline void vunmap_range_noflush(unsigned long start, unsigned long end)
511 #endif /* !CONFIG_MMU */
514 * Return the mem_map entry representing the 'offset' subpage within
515 * the maximally aligned gigantic page 'base'. Handle any discontiguity
516 * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
518 static inline struct page *mem_map_offset(struct page *base, int offset)
520 if (unlikely(offset >= MAX_ORDER_NR_PAGES))
521 return nth_page(base, offset);
522 return base + offset;
526 * Iterator over all subpages within the maximally aligned gigantic
527 * page 'base'. Handle any discontiguity in the mem_map.
529 static inline struct page *mem_map_next(struct page *iter,
530 struct page *base, int offset)
532 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
533 unsigned long pfn = page_to_pfn(base) + offset;
536 return pfn_to_page(pfn);
541 /* Memory initialisation debug and verification */
548 #ifdef CONFIG_DEBUG_MEMORY_INIT
550 extern int mminit_loglevel;
552 #define mminit_dprintk(level, prefix, fmt, arg...) \
554 if (level < mminit_loglevel) { \
555 if (level <= MMINIT_WARNING) \
556 pr_warn("mminit::" prefix " " fmt, ##arg); \
558 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
562 extern void mminit_verify_pageflags_layout(void);
563 extern void mminit_verify_zonelist(void);
566 static inline void mminit_dprintk(enum mminit_level level,
567 const char *prefix, const char *fmt, ...)
571 static inline void mminit_verify_pageflags_layout(void)
575 static inline void mminit_verify_zonelist(void)
578 #endif /* CONFIG_DEBUG_MEMORY_INIT */
580 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
581 #if defined(CONFIG_SPARSEMEM)
582 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
583 unsigned long *end_pfn);
585 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
586 unsigned long *end_pfn)
589 #endif /* CONFIG_SPARSEMEM */
591 #define NODE_RECLAIM_NOSCAN -2
592 #define NODE_RECLAIM_FULL -1
593 #define NODE_RECLAIM_SOME 0
594 #define NODE_RECLAIM_SUCCESS 1
597 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
598 extern int find_next_best_node(int node, nodemask_t *used_node_mask);
600 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
603 return NODE_RECLAIM_NOSCAN;
605 static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
611 extern int hwpoison_filter(struct page *p);
613 extern u32 hwpoison_filter_dev_major;
614 extern u32 hwpoison_filter_dev_minor;
615 extern u64 hwpoison_filter_flags_mask;
616 extern u64 hwpoison_filter_flags_value;
617 extern u64 hwpoison_filter_memcg;
618 extern u32 hwpoison_filter_enable;
620 extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long,
621 unsigned long, unsigned long,
622 unsigned long, unsigned long);
624 extern void set_pageblock_order(void);
625 unsigned int reclaim_clean_pages_from_list(struct zone *zone,
626 struct list_head *page_list);
627 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
628 #define ALLOC_WMARK_MIN WMARK_MIN
629 #define ALLOC_WMARK_LOW WMARK_LOW
630 #define ALLOC_WMARK_HIGH WMARK_HIGH
631 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
633 /* Mask to get the watermark bits */
634 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
637 * Only MMU archs have async oom victim reclaim - aka oom_reaper so we
638 * cannot assume a reduced access to memory reserves is sufficient for
642 #define ALLOC_OOM 0x08
644 #define ALLOC_OOM ALLOC_NO_WATERMARKS
647 #define ALLOC_HARDER 0x10 /* try to alloc harder */
648 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
649 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
650 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */
651 #ifdef CONFIG_ZONE_DMA32
652 #define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */
654 #define ALLOC_NOFRAGMENT 0x0
656 #define ALLOC_KSWAPD 0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */
659 struct tlbflush_unmap_batch;
663 * only for MM internal work items which do not depend on
664 * any allocations or locks which might depend on allocations
666 extern struct workqueue_struct *mm_percpu_wq;
668 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
669 void try_to_unmap_flush(void);
670 void try_to_unmap_flush_dirty(void);
671 void flush_tlb_batched_pending(struct mm_struct *mm);
673 static inline void try_to_unmap_flush(void)
676 static inline void try_to_unmap_flush_dirty(void)
679 static inline void flush_tlb_batched_pending(struct mm_struct *mm)
682 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
684 extern const struct trace_print_flags pageflag_names[];
685 extern const struct trace_print_flags vmaflag_names[];
686 extern const struct trace_print_flags gfpflag_names[];
688 static inline bool is_migrate_highatomic(enum migratetype migratetype)
690 return migratetype == MIGRATE_HIGHATOMIC;
693 static inline bool is_migrate_highatomic_page(struct page *page)
695 return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
698 void setup_zone_pageset(struct zone *zone);
700 struct migration_target_control {
701 int nid; /* preferred node id */
710 int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
711 pgprot_t prot, struct page **pages, unsigned int page_shift);
714 int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
715 pgprot_t prot, struct page **pages, unsigned int page_shift)
721 void vunmap_range_noflush(unsigned long start, unsigned long end);
723 int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
724 unsigned long addr, int page_nid, int *flags);
726 #endif /* __MM_INTERNAL_H */