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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/mm.h>
12#include <linux/pagemap.h>
13#include <linux/tracepoint-defs.h>
14
15/*
16 * The set of flags that only affect watermark checking and reclaim
17 * behaviour. This is used by the MM to obey the caller constraints
18 * about IO, FS and watermark checking while ignoring placement
19 * hints such as HIGHMEM usage.
20 */
21#define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\
22 __GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\
23 __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\
24 __GFP_ATOMIC)
25
26/* The GFP flags allowed during early boot */
27#define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))
28
29/* Control allocation cpuset and node placement constraints */
30#define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
31
32/* Do not use these with a slab allocator */
33#define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
34
35void page_writeback_init(void);
36
37vm_fault_t do_swap_page(struct vm_fault *vmf);
38
39void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
40 unsigned long floor, unsigned long ceiling);
41
42static inline bool can_madv_lru_vma(struct vm_area_struct *vma)
43{
44 return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP));
45}
46
47void unmap_page_range(struct mmu_gather *tlb,
48 struct vm_area_struct *vma,
49 unsigned long addr, unsigned long end,
50 struct zap_details *details);
51
52extern unsigned int __do_page_cache_readahead(struct address_space *mapping,
53 struct file *filp, pgoff_t offset, unsigned long nr_to_read,
54 unsigned long lookahead_size);
55
56/*
57 * Submit IO for the read-ahead request in file_ra_state.
58 */
59static inline unsigned long ra_submit(struct file_ra_state *ra,
60 struct address_space *mapping, struct file *filp)
61{
62 return __do_page_cache_readahead(mapping, filp,
63 ra->start, ra->size, ra->async_size);
64}
65
66/*
67 * Turn a non-refcounted page (->_refcount == 0) into refcounted with
68 * a count of one.
69 */
70static inline void set_page_refcounted(struct page *page)
71{
72 VM_BUG_ON_PAGE(PageTail(page), page);
73 VM_BUG_ON_PAGE(page_ref_count(page), page);
74 set_page_count(page, 1);
75}
76
77extern unsigned long highest_memmap_pfn;
78
79/*
80 * Maximum number of reclaim retries without progress before the OOM
81 * killer is consider the only way forward.
82 */
83#define MAX_RECLAIM_RETRIES 16
84
85/*
86 * in mm/vmscan.c:
87 */
88extern int isolate_lru_page(struct page *page);
89extern void putback_lru_page(struct page *page);
90
91/*
92 * in mm/rmap.c:
93 */
94extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
95
96/*
97 * in mm/page_alloc.c
98 */
99
100/*
101 * Structure for holding the mostly immutable allocation parameters passed
102 * between functions involved in allocations, including the alloc_pages*
103 * family of functions.
104 *
105 * nodemask, migratetype and high_zoneidx are initialized only once in
106 * __alloc_pages_nodemask() and then never change.
107 *
108 * zonelist, preferred_zone and classzone_idx are set first in
109 * __alloc_pages_nodemask() for the fast path, and might be later changed
110 * in __alloc_pages_slowpath(). All other functions pass the whole strucure
111 * by a const pointer.
112 */
113struct alloc_context {
114 struct zonelist *zonelist;
115 nodemask_t *nodemask;
116 struct zoneref *preferred_zoneref;
117 int migratetype;
118 enum zone_type high_zoneidx;
119 bool spread_dirty_pages;
120};
121
122#define ac_classzone_idx(ac) zonelist_zone_idx(ac->preferred_zoneref)
123
124/*
125 * Locate the struct page for both the matching buddy in our
126 * pair (buddy1) and the combined O(n+1) page they form (page).
127 *
128 * 1) Any buddy B1 will have an order O twin B2 which satisfies
129 * the following equation:
130 * B2 = B1 ^ (1 << O)
131 * For example, if the starting buddy (buddy2) is #8 its order
132 * 1 buddy is #10:
133 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
134 *
135 * 2) Any buddy B will have an order O+1 parent P which
136 * satisfies the following equation:
137 * P = B & ~(1 << O)
138 *
139 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
140 */
141static inline unsigned long
142__find_buddy_pfn(unsigned long page_pfn, unsigned int order)
143{
144 return page_pfn ^ (1 << order);
145}
146
147extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
148 unsigned long end_pfn, struct zone *zone);
149
150static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
151 unsigned long end_pfn, struct zone *zone)
152{
153 if (zone->contiguous)
154 return pfn_to_page(start_pfn);
155
156 return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
157}
158
159extern int __isolate_free_page(struct page *page, unsigned int order);
160extern void memblock_free_pages(struct page *page, unsigned long pfn,
161 unsigned int order);
162extern void __free_pages_core(struct page *page, unsigned int order);
163extern void prep_compound_page(struct page *page, unsigned int order);
164extern void post_alloc_hook(struct page *page, unsigned int order,
165 gfp_t gfp_flags);
166extern int user_min_free_kbytes;
167
168#if defined CONFIG_COMPACTION || defined CONFIG_CMA
169
170/*
171 * in mm/compaction.c
172 */
173/*
174 * compact_control is used to track pages being migrated and the free pages
175 * they are being migrated to during memory compaction. The free_pfn starts
176 * at the end of a zone and migrate_pfn begins at the start. Movable pages
177 * are moved to the end of a zone during a compaction run and the run
178 * completes when free_pfn <= migrate_pfn
179 */
180struct compact_control {
181 struct list_head freepages; /* List of free pages to migrate to */
182 struct list_head migratepages; /* List of pages being migrated */
183 unsigned int nr_freepages; /* Number of isolated free pages */
184 unsigned int nr_migratepages; /* Number of pages to migrate */
185 unsigned long free_pfn; /* isolate_freepages search base */
186 unsigned long migrate_pfn; /* isolate_migratepages search base */
187 unsigned long fast_start_pfn; /* a pfn to start linear scan from */
188 struct zone *zone;
189 unsigned long total_migrate_scanned;
190 unsigned long total_free_scanned;
191 unsigned short fast_search_fail;/* failures to use free list searches */
192 short search_order; /* order to start a fast search at */
193 const gfp_t gfp_mask; /* gfp mask of a direct compactor */
194 int order; /* order a direct compactor needs */
195 int migratetype; /* migratetype of direct compactor */
196 const unsigned int alloc_flags; /* alloc flags of a direct compactor */
197 const int classzone_idx; /* zone index of a direct compactor */
198 enum migrate_mode mode; /* Async or sync migration mode */
199 bool ignore_skip_hint; /* Scan blocks even if marked skip */
200 bool no_set_skip_hint; /* Don't mark blocks for skipping */
201 bool ignore_block_suitable; /* Scan blocks considered unsuitable */
202 bool direct_compaction; /* False from kcompactd or /proc/... */
203 bool whole_zone; /* Whole zone should/has been scanned */
204 bool contended; /* Signal lock or sched contention */
205 bool rescan; /* Rescanning the same pageblock */
206};
207
208/*
209 * Used in direct compaction when a page should be taken from the freelists
210 * immediately when one is created during the free path.
211 */
212struct capture_control {
213 struct compact_control *cc;
214 struct page *page;
215};
216
217unsigned long
218isolate_freepages_range(struct compact_control *cc,
219 unsigned long start_pfn, unsigned long end_pfn);
220unsigned long
221isolate_migratepages_range(struct compact_control *cc,
222 unsigned long low_pfn, unsigned long end_pfn);
223int find_suitable_fallback(struct free_area *area, unsigned int order,
224 int migratetype, bool only_stealable, bool *can_steal);
225
226#endif
227
228/*
229 * This function returns the order of a free page in the buddy system. In
230 * general, page_zone(page)->lock must be held by the caller to prevent the
231 * page from being allocated in parallel and returning garbage as the order.
232 * If a caller does not hold page_zone(page)->lock, it must guarantee that the
233 * page cannot be allocated or merged in parallel. Alternatively, it must
234 * handle invalid values gracefully, and use page_order_unsafe() below.
235 */
236static inline unsigned int page_order(struct page *page)
237{
238 /* PageBuddy() must be checked by the caller */
239 return page_private(page);
240}
241
242/*
243 * Like page_order(), but for callers who cannot afford to hold the zone lock.
244 * PageBuddy() should be checked first by the caller to minimize race window,
245 * and invalid values must be handled gracefully.
246 *
247 * READ_ONCE is used so that if the caller assigns the result into a local
248 * variable and e.g. tests it for valid range before using, the compiler cannot
249 * decide to remove the variable and inline the page_private(page) multiple
250 * times, potentially observing different values in the tests and the actual
251 * use of the result.
252 */
253#define page_order_unsafe(page) READ_ONCE(page_private(page))
254
255static inline bool is_cow_mapping(vm_flags_t flags)
256{
257 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
258}
259
260/*
261 * These three helpers classifies VMAs for virtual memory accounting.
262 */
263
264/*
265 * Executable code area - executable, not writable, not stack
266 */
267static inline bool is_exec_mapping(vm_flags_t flags)
268{
269 return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
270}
271
272/*
273 * Stack area - atomatically grows in one direction
274 *
275 * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
276 * do_mmap() forbids all other combinations.
277 */
278static inline bool is_stack_mapping(vm_flags_t flags)
279{
280 return (flags & VM_STACK) == VM_STACK;
281}
282
283/*
284 * Data area - private, writable, not stack
285 */
286static inline bool is_data_mapping(vm_flags_t flags)
287{
288 return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
289}
290
291/* mm/util.c */
292void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
293 struct vm_area_struct *prev, struct rb_node *rb_parent);
294
295#ifdef CONFIG_MMU
296extern long populate_vma_page_range(struct vm_area_struct *vma,
297 unsigned long start, unsigned long end, int *nonblocking);
298extern void munlock_vma_pages_range(struct vm_area_struct *vma,
299 unsigned long start, unsigned long end);
300static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
301{
302 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
303}
304
305/*
306 * must be called with vma's mmap_sem held for read or write, and page locked.
307 */
308extern void mlock_vma_page(struct page *page);
309extern unsigned int munlock_vma_page(struct page *page);
310
311/*
312 * Clear the page's PageMlocked(). This can be useful in a situation where
313 * we want to unconditionally remove a page from the pagecache -- e.g.,
314 * on truncation or freeing.
315 *
316 * It is legal to call this function for any page, mlocked or not.
317 * If called for a page that is still mapped by mlocked vmas, all we do
318 * is revert to lazy LRU behaviour -- semantics are not broken.
319 */
320extern void clear_page_mlock(struct page *page);
321
322/*
323 * mlock_migrate_page - called only from migrate_misplaced_transhuge_page()
324 * (because that does not go through the full procedure of migration ptes):
325 * to migrate the Mlocked page flag; update statistics.
326 */
327static inline void mlock_migrate_page(struct page *newpage, struct page *page)
328{
329 if (TestClearPageMlocked(page)) {
330 int nr_pages = hpage_nr_pages(page);
331
332 /* Holding pmd lock, no change in irq context: __mod is safe */
333 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
334 SetPageMlocked(newpage);
335 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages);
336 }
337}
338
339extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
340
341/*
342 * At what user virtual address is page expected in @vma?
343 */
344static inline unsigned long
345__vma_address(struct page *page, struct vm_area_struct *vma)
346{
347 pgoff_t pgoff = page_to_pgoff(page);
348 return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
349}
350
351static inline unsigned long
352vma_address(struct page *page, struct vm_area_struct *vma)
353{
354 unsigned long start, end;
355
356 start = __vma_address(page, vma);
357 end = start + PAGE_SIZE * (hpage_nr_pages(page) - 1);
358
359 /* page should be within @vma mapping range */
360 VM_BUG_ON_VMA(end < vma->vm_start || start >= vma->vm_end, vma);
361
362 return max(start, vma->vm_start);
363}
364
365#else /* !CONFIG_MMU */
366static inline void clear_page_mlock(struct page *page) { }
367static inline void mlock_vma_page(struct page *page) { }
368static inline void mlock_migrate_page(struct page *new, struct page *old) { }
369
370#endif /* !CONFIG_MMU */
371
372/*
373 * Return the mem_map entry representing the 'offset' subpage within
374 * the maximally aligned gigantic page 'base'. Handle any discontiguity
375 * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
376 */
377static inline struct page *mem_map_offset(struct page *base, int offset)
378{
379 if (unlikely(offset >= MAX_ORDER_NR_PAGES))
380 return nth_page(base, offset);
381 return base + offset;
382}
383
384/*
385 * Iterator over all subpages within the maximally aligned gigantic
386 * page 'base'. Handle any discontiguity in the mem_map.
387 */
388static inline struct page *mem_map_next(struct page *iter,
389 struct page *base, int offset)
390{
391 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
392 unsigned long pfn = page_to_pfn(base) + offset;
393 if (!pfn_valid(pfn))
394 return NULL;
395 return pfn_to_page(pfn);
396 }
397 return iter + 1;
398}
399
400/* Memory initialisation debug and verification */
401enum mminit_level {
402 MMINIT_WARNING,
403 MMINIT_VERIFY,
404 MMINIT_TRACE
405};
406
407#ifdef CONFIG_DEBUG_MEMORY_INIT
408
409extern int mminit_loglevel;
410
411#define mminit_dprintk(level, prefix, fmt, arg...) \
412do { \
413 if (level < mminit_loglevel) { \
414 if (level <= MMINIT_WARNING) \
415 pr_warn("mminit::" prefix " " fmt, ##arg); \
416 else \
417 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
418 } \
419} while (0)
420
421extern void mminit_verify_pageflags_layout(void);
422extern void mminit_verify_zonelist(void);
423#else
424
425static inline void mminit_dprintk(enum mminit_level level,
426 const char *prefix, const char *fmt, ...)
427{
428}
429
430static inline void mminit_verify_pageflags_layout(void)
431{
432}
433
434static inline void mminit_verify_zonelist(void)
435{
436}
437#endif /* CONFIG_DEBUG_MEMORY_INIT */
438
439/* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
440#if defined(CONFIG_SPARSEMEM)
441extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
442 unsigned long *end_pfn);
443#else
444static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
445 unsigned long *end_pfn)
446{
447}
448#endif /* CONFIG_SPARSEMEM */
449
450#define NODE_RECLAIM_NOSCAN -2
451#define NODE_RECLAIM_FULL -1
452#define NODE_RECLAIM_SOME 0
453#define NODE_RECLAIM_SUCCESS 1
454
455#ifdef CONFIG_NUMA
456extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
457#else
458static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
459 unsigned int order)
460{
461 return NODE_RECLAIM_NOSCAN;
462}
463#endif
464
465extern int hwpoison_filter(struct page *p);
466
467extern u32 hwpoison_filter_dev_major;
468extern u32 hwpoison_filter_dev_minor;
469extern u64 hwpoison_filter_flags_mask;
470extern u64 hwpoison_filter_flags_value;
471extern u64 hwpoison_filter_memcg;
472extern u32 hwpoison_filter_enable;
473
474extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long,
475 unsigned long, unsigned long,
476 unsigned long, unsigned long);
477
478extern void set_pageblock_order(void);
479unsigned long reclaim_clean_pages_from_list(struct zone *zone,
480 struct list_head *page_list);
481/* The ALLOC_WMARK bits are used as an index to zone->watermark */
482#define ALLOC_WMARK_MIN WMARK_MIN
483#define ALLOC_WMARK_LOW WMARK_LOW
484#define ALLOC_WMARK_HIGH WMARK_HIGH
485#define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
486
487/* Mask to get the watermark bits */
488#define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
489
490/*
491 * Only MMU archs have async oom victim reclaim - aka oom_reaper so we
492 * cannot assume a reduced access to memory reserves is sufficient for
493 * !MMU
494 */
495#ifdef CONFIG_MMU
496#define ALLOC_OOM 0x08
497#else
498#define ALLOC_OOM ALLOC_NO_WATERMARKS
499#endif
500
501#define ALLOC_HARDER 0x10 /* try to alloc harder */
502#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
503#define ALLOC_CPUSET 0x40 /* check for correct cpuset */
504#define ALLOC_CMA 0x80 /* allow allocations from CMA areas */
505#ifdef CONFIG_ZONE_DMA32
506#define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */
507#else
508#define ALLOC_NOFRAGMENT 0x0
509#endif
510#define ALLOC_KSWAPD 0x200 /* allow waking of kswapd */
511
512enum ttu_flags;
513struct tlbflush_unmap_batch;
514
515
516/*
517 * only for MM internal work items which do not depend on
518 * any allocations or locks which might depend on allocations
519 */
520extern struct workqueue_struct *mm_percpu_wq;
521
522#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
523void try_to_unmap_flush(void);
524void try_to_unmap_flush_dirty(void);
525void flush_tlb_batched_pending(struct mm_struct *mm);
526#else
527static inline void try_to_unmap_flush(void)
528{
529}
530static inline void try_to_unmap_flush_dirty(void)
531{
532}
533static inline void flush_tlb_batched_pending(struct mm_struct *mm)
534{
535}
536#endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
537
538extern const struct trace_print_flags pageflag_names[];
539extern const struct trace_print_flags vmaflag_names[];
540extern const struct trace_print_flags gfpflag_names[];
541
542static inline bool is_migrate_highatomic(enum migratetype migratetype)
543{
544 return migratetype == MIGRATE_HIGHATOMIC;
545}
546
547static inline bool is_migrate_highatomic_page(struct page *page)
548{
549 return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
550}
551
552void setup_zone_pageset(struct zone *zone);
553extern struct page *alloc_new_node_page(struct page *page, unsigned long node);
554#endif /* __MM_INTERNAL_H */
1/* internal.h: mm/ internal definitions
2 *
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11#ifndef __MM_INTERNAL_H
12#define __MM_INTERNAL_H
13
14#include <linux/fs.h>
15#include <linux/mm.h>
16#include <linux/pagemap.h>
17#include <linux/tracepoint-defs.h>
18
19/*
20 * The set of flags that only affect watermark checking and reclaim
21 * behaviour. This is used by the MM to obey the caller constraints
22 * about IO, FS and watermark checking while ignoring placement
23 * hints such as HIGHMEM usage.
24 */
25#define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\
26 __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
27 __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\
28 __GFP_ATOMIC)
29
30/* The GFP flags allowed during early boot */
31#define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))
32
33/* Control allocation cpuset and node placement constraints */
34#define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
35
36/* Do not use these with a slab allocator */
37#define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
38
39void page_writeback_init(void);
40
41int do_swap_page(struct vm_fault *vmf);
42
43void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
44 unsigned long floor, unsigned long ceiling);
45
46void unmap_page_range(struct mmu_gather *tlb,
47 struct vm_area_struct *vma,
48 unsigned long addr, unsigned long end,
49 struct zap_details *details);
50
51extern int __do_page_cache_readahead(struct address_space *mapping,
52 struct file *filp, pgoff_t offset, unsigned long nr_to_read,
53 unsigned long lookahead_size);
54
55/*
56 * Submit IO for the read-ahead request in file_ra_state.
57 */
58static inline unsigned long ra_submit(struct file_ra_state *ra,
59 struct address_space *mapping, struct file *filp)
60{
61 return __do_page_cache_readahead(mapping, filp,
62 ra->start, ra->size, ra->async_size);
63}
64
65/*
66 * Turn a non-refcounted page (->_refcount == 0) into refcounted with
67 * a count of one.
68 */
69static inline void set_page_refcounted(struct page *page)
70{
71 VM_BUG_ON_PAGE(PageTail(page), page);
72 VM_BUG_ON_PAGE(page_ref_count(page), page);
73 set_page_count(page, 1);
74}
75
76extern unsigned long highest_memmap_pfn;
77
78/*
79 * in mm/vmscan.c:
80 */
81extern int isolate_lru_page(struct page *page);
82extern void putback_lru_page(struct page *page);
83extern bool pgdat_reclaimable(struct pglist_data *pgdat);
84
85/*
86 * in mm/rmap.c:
87 */
88extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
89
90/*
91 * in mm/page_alloc.c
92 */
93
94/*
95 * Structure for holding the mostly immutable allocation parameters passed
96 * between functions involved in allocations, including the alloc_pages*
97 * family of functions.
98 *
99 * nodemask, migratetype and high_zoneidx are initialized only once in
100 * __alloc_pages_nodemask() and then never change.
101 *
102 * zonelist, preferred_zone and classzone_idx are set first in
103 * __alloc_pages_nodemask() for the fast path, and might be later changed
104 * in __alloc_pages_slowpath(). All other functions pass the whole strucure
105 * by a const pointer.
106 */
107struct alloc_context {
108 struct zonelist *zonelist;
109 nodemask_t *nodemask;
110 struct zoneref *preferred_zoneref;
111 int migratetype;
112 enum zone_type high_zoneidx;
113 bool spread_dirty_pages;
114};
115
116#define ac_classzone_idx(ac) zonelist_zone_idx(ac->preferred_zoneref)
117
118/*
119 * Locate the struct page for both the matching buddy in our
120 * pair (buddy1) and the combined O(n+1) page they form (page).
121 *
122 * 1) Any buddy B1 will have an order O twin B2 which satisfies
123 * the following equation:
124 * B2 = B1 ^ (1 << O)
125 * For example, if the starting buddy (buddy2) is #8 its order
126 * 1 buddy is #10:
127 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
128 *
129 * 2) Any buddy B will have an order O+1 parent P which
130 * satisfies the following equation:
131 * P = B & ~(1 << O)
132 *
133 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
134 */
135static inline unsigned long
136__find_buddy_index(unsigned long page_idx, unsigned int order)
137{
138 return page_idx ^ (1 << order);
139}
140
141extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
142 unsigned long end_pfn, struct zone *zone);
143
144static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
145 unsigned long end_pfn, struct zone *zone)
146{
147 if (zone->contiguous)
148 return pfn_to_page(start_pfn);
149
150 return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
151}
152
153extern int __isolate_free_page(struct page *page, unsigned int order);
154extern void __free_pages_bootmem(struct page *page, unsigned long pfn,
155 unsigned int order);
156extern void prep_compound_page(struct page *page, unsigned int order);
157extern void post_alloc_hook(struct page *page, unsigned int order,
158 gfp_t gfp_flags);
159extern int user_min_free_kbytes;
160
161#if defined CONFIG_COMPACTION || defined CONFIG_CMA
162
163/*
164 * in mm/compaction.c
165 */
166/*
167 * compact_control is used to track pages being migrated and the free pages
168 * they are being migrated to during memory compaction. The free_pfn starts
169 * at the end of a zone and migrate_pfn begins at the start. Movable pages
170 * are moved to the end of a zone during a compaction run and the run
171 * completes when free_pfn <= migrate_pfn
172 */
173struct compact_control {
174 struct list_head freepages; /* List of free pages to migrate to */
175 struct list_head migratepages; /* List of pages being migrated */
176 unsigned long nr_freepages; /* Number of isolated free pages */
177 unsigned long nr_migratepages; /* Number of pages to migrate */
178 unsigned long free_pfn; /* isolate_freepages search base */
179 unsigned long migrate_pfn; /* isolate_migratepages search base */
180 unsigned long last_migrated_pfn;/* Not yet flushed page being freed */
181 enum migrate_mode mode; /* Async or sync migration mode */
182 bool ignore_skip_hint; /* Scan blocks even if marked skip */
183 bool ignore_block_suitable; /* Scan blocks considered unsuitable */
184 bool direct_compaction; /* False from kcompactd or /proc/... */
185 bool whole_zone; /* Whole zone should/has been scanned */
186 int order; /* order a direct compactor needs */
187 const gfp_t gfp_mask; /* gfp mask of a direct compactor */
188 const unsigned int alloc_flags; /* alloc flags of a direct compactor */
189 const int classzone_idx; /* zone index of a direct compactor */
190 struct zone *zone;
191 bool contended; /* Signal lock or sched contention */
192};
193
194unsigned long
195isolate_freepages_range(struct compact_control *cc,
196 unsigned long start_pfn, unsigned long end_pfn);
197unsigned long
198isolate_migratepages_range(struct compact_control *cc,
199 unsigned long low_pfn, unsigned long end_pfn);
200int find_suitable_fallback(struct free_area *area, unsigned int order,
201 int migratetype, bool only_stealable, bool *can_steal);
202
203#endif
204
205/*
206 * This function returns the order of a free page in the buddy system. In
207 * general, page_zone(page)->lock must be held by the caller to prevent the
208 * page from being allocated in parallel and returning garbage as the order.
209 * If a caller does not hold page_zone(page)->lock, it must guarantee that the
210 * page cannot be allocated or merged in parallel. Alternatively, it must
211 * handle invalid values gracefully, and use page_order_unsafe() below.
212 */
213static inline unsigned int page_order(struct page *page)
214{
215 /* PageBuddy() must be checked by the caller */
216 return page_private(page);
217}
218
219/*
220 * Like page_order(), but for callers who cannot afford to hold the zone lock.
221 * PageBuddy() should be checked first by the caller to minimize race window,
222 * and invalid values must be handled gracefully.
223 *
224 * READ_ONCE is used so that if the caller assigns the result into a local
225 * variable and e.g. tests it for valid range before using, the compiler cannot
226 * decide to remove the variable and inline the page_private(page) multiple
227 * times, potentially observing different values in the tests and the actual
228 * use of the result.
229 */
230#define page_order_unsafe(page) READ_ONCE(page_private(page))
231
232static inline bool is_cow_mapping(vm_flags_t flags)
233{
234 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
235}
236
237/*
238 * These three helpers classifies VMAs for virtual memory accounting.
239 */
240
241/*
242 * Executable code area - executable, not writable, not stack
243 */
244static inline bool is_exec_mapping(vm_flags_t flags)
245{
246 return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
247}
248
249/*
250 * Stack area - atomatically grows in one direction
251 *
252 * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
253 * do_mmap() forbids all other combinations.
254 */
255static inline bool is_stack_mapping(vm_flags_t flags)
256{
257 return (flags & VM_STACK) == VM_STACK;
258}
259
260/*
261 * Data area - private, writable, not stack
262 */
263static inline bool is_data_mapping(vm_flags_t flags)
264{
265 return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
266}
267
268/* mm/util.c */
269void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
270 struct vm_area_struct *prev, struct rb_node *rb_parent);
271
272#ifdef CONFIG_MMU
273extern long populate_vma_page_range(struct vm_area_struct *vma,
274 unsigned long start, unsigned long end, int *nonblocking);
275extern void munlock_vma_pages_range(struct vm_area_struct *vma,
276 unsigned long start, unsigned long end);
277static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
278{
279 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
280}
281
282/*
283 * must be called with vma's mmap_sem held for read or write, and page locked.
284 */
285extern void mlock_vma_page(struct page *page);
286extern unsigned int munlock_vma_page(struct page *page);
287
288/*
289 * Clear the page's PageMlocked(). This can be useful in a situation where
290 * we want to unconditionally remove a page from the pagecache -- e.g.,
291 * on truncation or freeing.
292 *
293 * It is legal to call this function for any page, mlocked or not.
294 * If called for a page that is still mapped by mlocked vmas, all we do
295 * is revert to lazy LRU behaviour -- semantics are not broken.
296 */
297extern void clear_page_mlock(struct page *page);
298
299/*
300 * mlock_migrate_page - called only from migrate_misplaced_transhuge_page()
301 * (because that does not go through the full procedure of migration ptes):
302 * to migrate the Mlocked page flag; update statistics.
303 */
304static inline void mlock_migrate_page(struct page *newpage, struct page *page)
305{
306 if (TestClearPageMlocked(page)) {
307 int nr_pages = hpage_nr_pages(page);
308
309 /* Holding pmd lock, no change in irq context: __mod is safe */
310 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
311 SetPageMlocked(newpage);
312 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages);
313 }
314}
315
316extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
317
318/*
319 * At what user virtual address is page expected in @vma?
320 */
321static inline unsigned long
322__vma_address(struct page *page, struct vm_area_struct *vma)
323{
324 pgoff_t pgoff = page_to_pgoff(page);
325 return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
326}
327
328static inline unsigned long
329vma_address(struct page *page, struct vm_area_struct *vma)
330{
331 unsigned long address = __vma_address(page, vma);
332
333 /* page should be within @vma mapping range */
334 VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma);
335
336 return address;
337}
338
339#else /* !CONFIG_MMU */
340static inline void clear_page_mlock(struct page *page) { }
341static inline void mlock_vma_page(struct page *page) { }
342static inline void mlock_migrate_page(struct page *new, struct page *old) { }
343
344#endif /* !CONFIG_MMU */
345
346/*
347 * Return the mem_map entry representing the 'offset' subpage within
348 * the maximally aligned gigantic page 'base'. Handle any discontiguity
349 * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
350 */
351static inline struct page *mem_map_offset(struct page *base, int offset)
352{
353 if (unlikely(offset >= MAX_ORDER_NR_PAGES))
354 return nth_page(base, offset);
355 return base + offset;
356}
357
358/*
359 * Iterator over all subpages within the maximally aligned gigantic
360 * page 'base'. Handle any discontiguity in the mem_map.
361 */
362static inline struct page *mem_map_next(struct page *iter,
363 struct page *base, int offset)
364{
365 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
366 unsigned long pfn = page_to_pfn(base) + offset;
367 if (!pfn_valid(pfn))
368 return NULL;
369 return pfn_to_page(pfn);
370 }
371 return iter + 1;
372}
373
374/*
375 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
376 * so all functions starting at paging_init should be marked __init
377 * in those cases. SPARSEMEM, however, allows for memory hotplug,
378 * and alloc_bootmem_node is not used.
379 */
380#ifdef CONFIG_SPARSEMEM
381#define __paginginit __meminit
382#else
383#define __paginginit __init
384#endif
385
386/* Memory initialisation debug and verification */
387enum mminit_level {
388 MMINIT_WARNING,
389 MMINIT_VERIFY,
390 MMINIT_TRACE
391};
392
393#ifdef CONFIG_DEBUG_MEMORY_INIT
394
395extern int mminit_loglevel;
396
397#define mminit_dprintk(level, prefix, fmt, arg...) \
398do { \
399 if (level < mminit_loglevel) { \
400 if (level <= MMINIT_WARNING) \
401 pr_warn("mminit::" prefix " " fmt, ##arg); \
402 else \
403 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
404 } \
405} while (0)
406
407extern void mminit_verify_pageflags_layout(void);
408extern void mminit_verify_zonelist(void);
409#else
410
411static inline void mminit_dprintk(enum mminit_level level,
412 const char *prefix, const char *fmt, ...)
413{
414}
415
416static inline void mminit_verify_pageflags_layout(void)
417{
418}
419
420static inline void mminit_verify_zonelist(void)
421{
422}
423#endif /* CONFIG_DEBUG_MEMORY_INIT */
424
425/* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
426#if defined(CONFIG_SPARSEMEM)
427extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
428 unsigned long *end_pfn);
429#else
430static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
431 unsigned long *end_pfn)
432{
433}
434#endif /* CONFIG_SPARSEMEM */
435
436#define NODE_RECLAIM_NOSCAN -2
437#define NODE_RECLAIM_FULL -1
438#define NODE_RECLAIM_SOME 0
439#define NODE_RECLAIM_SUCCESS 1
440
441extern int hwpoison_filter(struct page *p);
442
443extern u32 hwpoison_filter_dev_major;
444extern u32 hwpoison_filter_dev_minor;
445extern u64 hwpoison_filter_flags_mask;
446extern u64 hwpoison_filter_flags_value;
447extern u64 hwpoison_filter_memcg;
448extern u32 hwpoison_filter_enable;
449
450extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long,
451 unsigned long, unsigned long,
452 unsigned long, unsigned long);
453
454extern void set_pageblock_order(void);
455unsigned long reclaim_clean_pages_from_list(struct zone *zone,
456 struct list_head *page_list);
457/* The ALLOC_WMARK bits are used as an index to zone->watermark */
458#define ALLOC_WMARK_MIN WMARK_MIN
459#define ALLOC_WMARK_LOW WMARK_LOW
460#define ALLOC_WMARK_HIGH WMARK_HIGH
461#define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
462
463/* Mask to get the watermark bits */
464#define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
465
466#define ALLOC_HARDER 0x10 /* try to alloc harder */
467#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
468#define ALLOC_CPUSET 0x40 /* check for correct cpuset */
469#define ALLOC_CMA 0x80 /* allow allocations from CMA areas */
470
471enum ttu_flags;
472struct tlbflush_unmap_batch;
473
474#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
475void try_to_unmap_flush(void);
476void try_to_unmap_flush_dirty(void);
477#else
478static inline void try_to_unmap_flush(void)
479{
480}
481static inline void try_to_unmap_flush_dirty(void)
482{
483}
484
485#endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
486
487extern const struct trace_print_flags pageflag_names[];
488extern const struct trace_print_flags vmaflag_names[];
489extern const struct trace_print_flags gfpflag_names[];
490
491#endif /* __MM_INTERNAL_H */