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_RETRY_MAYFAIL|__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
41vm_fault_t 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
46static inline bool can_madv_dontneed_vma(struct vm_area_struct *vma)
47{
48 return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP));
49}
50
51void unmap_page_range(struct mmu_gather *tlb,
52 struct vm_area_struct *vma,
53 unsigned long addr, unsigned long end,
54 struct zap_details *details);
55
56extern unsigned int __do_page_cache_readahead(struct address_space *mapping,
57 struct file *filp, pgoff_t offset, unsigned long nr_to_read,
58 unsigned long lookahead_size);
59
60/*
61 * Submit IO for the read-ahead request in file_ra_state.
62 */
63static inline unsigned long ra_submit(struct file_ra_state *ra,
64 struct address_space *mapping, struct file *filp)
65{
66 return __do_page_cache_readahead(mapping, filp,
67 ra->start, ra->size, ra->async_size);
68}
69
70/*
71 * Turn a non-refcounted page (->_refcount == 0) into refcounted with
72 * a count of one.
73 */
74static inline void set_page_refcounted(struct page *page)
75{
76 VM_BUG_ON_PAGE(PageTail(page), page);
77 VM_BUG_ON_PAGE(page_ref_count(page), page);
78 set_page_count(page, 1);
79}
80
81extern unsigned long highest_memmap_pfn;
82
83/*
84 * Maximum number of reclaim retries without progress before the OOM
85 * killer is consider the only way forward.
86 */
87#define MAX_RECLAIM_RETRIES 16
88
89/*
90 * in mm/vmscan.c:
91 */
92extern int isolate_lru_page(struct page *page);
93extern void putback_lru_page(struct page *page);
94
95/*
96 * in mm/rmap.c:
97 */
98extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
99
100/*
101 * in mm/page_alloc.c
102 */
103
104/*
105 * Structure for holding the mostly immutable allocation parameters passed
106 * between functions involved in allocations, including the alloc_pages*
107 * family of functions.
108 *
109 * nodemask, migratetype and high_zoneidx are initialized only once in
110 * __alloc_pages_nodemask() and then never change.
111 *
112 * zonelist, preferred_zone and classzone_idx are set first in
113 * __alloc_pages_nodemask() for the fast path, and might be later changed
114 * in __alloc_pages_slowpath(). All other functions pass the whole strucure
115 * by a const pointer.
116 */
117struct alloc_context {
118 struct zonelist *zonelist;
119 nodemask_t *nodemask;
120 struct zoneref *preferred_zoneref;
121 int migratetype;
122 enum zone_type high_zoneidx;
123 bool spread_dirty_pages;
124};
125
126#define ac_classzone_idx(ac) zonelist_zone_idx(ac->preferred_zoneref)
127
128/*
129 * Locate the struct page for both the matching buddy in our
130 * pair (buddy1) and the combined O(n+1) page they form (page).
131 *
132 * 1) Any buddy B1 will have an order O twin B2 which satisfies
133 * the following equation:
134 * B2 = B1 ^ (1 << O)
135 * For example, if the starting buddy (buddy2) is #8 its order
136 * 1 buddy is #10:
137 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
138 *
139 * 2) Any buddy B will have an order O+1 parent P which
140 * satisfies the following equation:
141 * P = B & ~(1 << O)
142 *
143 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
144 */
145static inline unsigned long
146__find_buddy_pfn(unsigned long page_pfn, unsigned int order)
147{
148 return page_pfn ^ (1 << order);
149}
150
151extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
152 unsigned long end_pfn, struct zone *zone);
153
154static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
155 unsigned long end_pfn, struct zone *zone)
156{
157 if (zone->contiguous)
158 return pfn_to_page(start_pfn);
159
160 return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
161}
162
163extern int __isolate_free_page(struct page *page, unsigned int order);
164extern void memblock_free_pages(struct page *page, unsigned long pfn,
165 unsigned int order);
166extern void __free_pages_core(struct page *page, unsigned int order);
167extern void prep_compound_page(struct page *page, unsigned int order);
168extern void post_alloc_hook(struct page *page, unsigned int order,
169 gfp_t gfp_flags);
170extern int user_min_free_kbytes;
171
172#if defined CONFIG_COMPACTION || defined CONFIG_CMA
173
174/*
175 * in mm/compaction.c
176 */
177/*
178 * compact_control is used to track pages being migrated and the free pages
179 * they are being migrated to during memory compaction. The free_pfn starts
180 * at the end of a zone and migrate_pfn begins at the start. Movable pages
181 * are moved to the end of a zone during a compaction run and the run
182 * completes when free_pfn <= migrate_pfn
183 */
184struct compact_control {
185 struct list_head freepages; /* List of free pages to migrate to */
186 struct list_head migratepages; /* List of pages being migrated */
187 unsigned int nr_freepages; /* Number of isolated free pages */
188 unsigned int nr_migratepages; /* Number of pages to migrate */
189 unsigned long free_pfn; /* isolate_freepages search base */
190 unsigned long migrate_pfn; /* isolate_migratepages search base */
191 unsigned long fast_start_pfn; /* a pfn to start linear scan from */
192 struct zone *zone;
193 unsigned long total_migrate_scanned;
194 unsigned long total_free_scanned;
195 unsigned short fast_search_fail;/* failures to use free list searches */
196 short search_order; /* order to start a fast search at */
197 const gfp_t gfp_mask; /* gfp mask of a direct compactor */
198 int order; /* order a direct compactor needs */
199 int migratetype; /* migratetype of direct compactor */
200 const unsigned int alloc_flags; /* alloc flags of a direct compactor */
201 const int classzone_idx; /* zone index of a direct compactor */
202 enum migrate_mode mode; /* Async or sync migration mode */
203 bool ignore_skip_hint; /* Scan blocks even if marked skip */
204 bool no_set_skip_hint; /* Don't mark blocks for skipping */
205 bool ignore_block_suitable; /* Scan blocks considered unsuitable */
206 bool direct_compaction; /* False from kcompactd or /proc/... */
207 bool whole_zone; /* Whole zone should/has been scanned */
208 bool contended; /* Signal lock or sched contention */
209 bool rescan; /* Rescanning the same pageblock */
210};
211
212/*
213 * Used in direct compaction when a page should be taken from the freelists
214 * immediately when one is created during the free path.
215 */
216struct capture_control {
217 struct compact_control *cc;
218 struct page *page;
219};
220
221unsigned long
222isolate_freepages_range(struct compact_control *cc,
223 unsigned long start_pfn, unsigned long end_pfn);
224unsigned long
225isolate_migratepages_range(struct compact_control *cc,
226 unsigned long low_pfn, unsigned long end_pfn);
227int find_suitable_fallback(struct free_area *area, unsigned int order,
228 int migratetype, bool only_stealable, bool *can_steal);
229
230#endif
231
232/*
233 * This function returns the order of a free page in the buddy system. In
234 * general, page_zone(page)->lock must be held by the caller to prevent the
235 * page from being allocated in parallel and returning garbage as the order.
236 * If a caller does not hold page_zone(page)->lock, it must guarantee that the
237 * page cannot be allocated or merged in parallel. Alternatively, it must
238 * handle invalid values gracefully, and use page_order_unsafe() below.
239 */
240static inline unsigned int page_order(struct page *page)
241{
242 /* PageBuddy() must be checked by the caller */
243 return page_private(page);
244}
245
246/*
247 * Like page_order(), but for callers who cannot afford to hold the zone lock.
248 * PageBuddy() should be checked first by the caller to minimize race window,
249 * and invalid values must be handled gracefully.
250 *
251 * READ_ONCE is used so that if the caller assigns the result into a local
252 * variable and e.g. tests it for valid range before using, the compiler cannot
253 * decide to remove the variable and inline the page_private(page) multiple
254 * times, potentially observing different values in the tests and the actual
255 * use of the result.
256 */
257#define page_order_unsafe(page) READ_ONCE(page_private(page))
258
259static inline bool is_cow_mapping(vm_flags_t flags)
260{
261 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
262}
263
264/*
265 * These three helpers classifies VMAs for virtual memory accounting.
266 */
267
268/*
269 * Executable code area - executable, not writable, not stack
270 */
271static inline bool is_exec_mapping(vm_flags_t flags)
272{
273 return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
274}
275
276/*
277 * Stack area - atomatically grows in one direction
278 *
279 * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
280 * do_mmap() forbids all other combinations.
281 */
282static inline bool is_stack_mapping(vm_flags_t flags)
283{
284 return (flags & VM_STACK) == VM_STACK;
285}
286
287/*
288 * Data area - private, writable, not stack
289 */
290static inline bool is_data_mapping(vm_flags_t flags)
291{
292 return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
293}
294
295/* mm/util.c */
296void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
297 struct vm_area_struct *prev, struct rb_node *rb_parent);
298
299#ifdef CONFIG_MMU
300extern long populate_vma_page_range(struct vm_area_struct *vma,
301 unsigned long start, unsigned long end, int *nonblocking);
302extern void munlock_vma_pages_range(struct vm_area_struct *vma,
303 unsigned long start, unsigned long end);
304static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
305{
306 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
307}
308
309/*
310 * must be called with vma's mmap_sem held for read or write, and page locked.
311 */
312extern void mlock_vma_page(struct page *page);
313extern unsigned int munlock_vma_page(struct page *page);
314
315/*
316 * Clear the page's PageMlocked(). This can be useful in a situation where
317 * we want to unconditionally remove a page from the pagecache -- e.g.,
318 * on truncation or freeing.
319 *
320 * It is legal to call this function for any page, mlocked or not.
321 * If called for a page that is still mapped by mlocked vmas, all we do
322 * is revert to lazy LRU behaviour -- semantics are not broken.
323 */
324extern void clear_page_mlock(struct page *page);
325
326/*
327 * mlock_migrate_page - called only from migrate_misplaced_transhuge_page()
328 * (because that does not go through the full procedure of migration ptes):
329 * to migrate the Mlocked page flag; update statistics.
330 */
331static inline void mlock_migrate_page(struct page *newpage, struct page *page)
332{
333 if (TestClearPageMlocked(page)) {
334 int nr_pages = hpage_nr_pages(page);
335
336 /* Holding pmd lock, no change in irq context: __mod is safe */
337 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
338 SetPageMlocked(newpage);
339 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages);
340 }
341}
342
343extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
344
345/*
346 * At what user virtual address is page expected in @vma?
347 */
348static inline unsigned long
349__vma_address(struct page *page, struct vm_area_struct *vma)
350{
351 pgoff_t pgoff = page_to_pgoff(page);
352 return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
353}
354
355static inline unsigned long
356vma_address(struct page *page, struct vm_area_struct *vma)
357{
358 unsigned long start, end;
359
360 start = __vma_address(page, vma);
361 end = start + PAGE_SIZE * (hpage_nr_pages(page) - 1);
362
363 /* page should be within @vma mapping range */
364 VM_BUG_ON_VMA(end < vma->vm_start || start >= vma->vm_end, vma);
365
366 return max(start, vma->vm_start);
367}
368
369#else /* !CONFIG_MMU */
370static inline void clear_page_mlock(struct page *page) { }
371static inline void mlock_vma_page(struct page *page) { }
372static inline void mlock_migrate_page(struct page *new, struct page *old) { }
373
374#endif /* !CONFIG_MMU */
375
376/*
377 * Return the mem_map entry representing the 'offset' subpage within
378 * the maximally aligned gigantic page 'base'. Handle any discontiguity
379 * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
380 */
381static inline struct page *mem_map_offset(struct page *base, int offset)
382{
383 if (unlikely(offset >= MAX_ORDER_NR_PAGES))
384 return nth_page(base, offset);
385 return base + offset;
386}
387
388/*
389 * Iterator over all subpages within the maximally aligned gigantic
390 * page 'base'. Handle any discontiguity in the mem_map.
391 */
392static inline struct page *mem_map_next(struct page *iter,
393 struct page *base, int offset)
394{
395 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
396 unsigned long pfn = page_to_pfn(base) + offset;
397 if (!pfn_valid(pfn))
398 return NULL;
399 return pfn_to_page(pfn);
400 }
401 return iter + 1;
402}
403
404/* Memory initialisation debug and verification */
405enum mminit_level {
406 MMINIT_WARNING,
407 MMINIT_VERIFY,
408 MMINIT_TRACE
409};
410
411#ifdef CONFIG_DEBUG_MEMORY_INIT
412
413extern int mminit_loglevel;
414
415#define mminit_dprintk(level, prefix, fmt, arg...) \
416do { \
417 if (level < mminit_loglevel) { \
418 if (level <= MMINIT_WARNING) \
419 pr_warn("mminit::" prefix " " fmt, ##arg); \
420 else \
421 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
422 } \
423} while (0)
424
425extern void mminit_verify_pageflags_layout(void);
426extern void mminit_verify_zonelist(void);
427#else
428
429static inline void mminit_dprintk(enum mminit_level level,
430 const char *prefix, const char *fmt, ...)
431{
432}
433
434static inline void mminit_verify_pageflags_layout(void)
435{
436}
437
438static inline void mminit_verify_zonelist(void)
439{
440}
441#endif /* CONFIG_DEBUG_MEMORY_INIT */
442
443/* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
444#if defined(CONFIG_SPARSEMEM)
445extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
446 unsigned long *end_pfn);
447#else
448static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
449 unsigned long *end_pfn)
450{
451}
452#endif /* CONFIG_SPARSEMEM */
453
454#define NODE_RECLAIM_NOSCAN -2
455#define NODE_RECLAIM_FULL -1
456#define NODE_RECLAIM_SOME 0
457#define NODE_RECLAIM_SUCCESS 1
458
459#ifdef CONFIG_NUMA
460extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
461#else
462static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
463 unsigned int order)
464{
465 return NODE_RECLAIM_NOSCAN;
466}
467#endif
468
469extern int hwpoison_filter(struct page *p);
470
471extern u32 hwpoison_filter_dev_major;
472extern u32 hwpoison_filter_dev_minor;
473extern u64 hwpoison_filter_flags_mask;
474extern u64 hwpoison_filter_flags_value;
475extern u64 hwpoison_filter_memcg;
476extern u32 hwpoison_filter_enable;
477
478extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long,
479 unsigned long, unsigned long,
480 unsigned long, unsigned long);
481
482extern void set_pageblock_order(void);
483unsigned long reclaim_clean_pages_from_list(struct zone *zone,
484 struct list_head *page_list);
485/* The ALLOC_WMARK bits are used as an index to zone->watermark */
486#define ALLOC_WMARK_MIN WMARK_MIN
487#define ALLOC_WMARK_LOW WMARK_LOW
488#define ALLOC_WMARK_HIGH WMARK_HIGH
489#define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
490
491/* Mask to get the watermark bits */
492#define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
493
494/*
495 * Only MMU archs have async oom victim reclaim - aka oom_reaper so we
496 * cannot assume a reduced access to memory reserves is sufficient for
497 * !MMU
498 */
499#ifdef CONFIG_MMU
500#define ALLOC_OOM 0x08
501#else
502#define ALLOC_OOM ALLOC_NO_WATERMARKS
503#endif
504
505#define ALLOC_HARDER 0x10 /* try to alloc harder */
506#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
507#define ALLOC_CPUSET 0x40 /* check for correct cpuset */
508#define ALLOC_CMA 0x80 /* allow allocations from CMA areas */
509#ifdef CONFIG_ZONE_DMA32
510#define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */
511#else
512#define ALLOC_NOFRAGMENT 0x0
513#endif
514#define ALLOC_KSWAPD 0x200 /* allow waking of kswapd */
515
516enum ttu_flags;
517struct tlbflush_unmap_batch;
518
519
520/*
521 * only for MM internal work items which do not depend on
522 * any allocations or locks which might depend on allocations
523 */
524extern struct workqueue_struct *mm_percpu_wq;
525
526#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
527void try_to_unmap_flush(void);
528void try_to_unmap_flush_dirty(void);
529void flush_tlb_batched_pending(struct mm_struct *mm);
530#else
531static inline void try_to_unmap_flush(void)
532{
533}
534static inline void try_to_unmap_flush_dirty(void)
535{
536}
537static inline void flush_tlb_batched_pending(struct mm_struct *mm)
538{
539}
540#endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
541
542extern const struct trace_print_flags pageflag_names[];
543extern const struct trace_print_flags vmaflag_names[];
544extern const struct trace_print_flags gfpflag_names[];
545
546static inline bool is_migrate_highatomic(enum migratetype migratetype)
547{
548 return migratetype == MIGRATE_HIGHATOMIC;
549}
550
551static inline bool is_migrate_highatomic_page(struct page *page)
552{
553 return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
554}
555
556void setup_zone_pageset(struct zone *zone);
557extern struct page *alloc_new_node_page(struct page *page, unsigned long node);
558#endif /* __MM_INTERNAL_H */
559