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
35 void page_writeback_init(void);
36
37 vm_fault_t do_swap_page(struct vm_fault *vmf);
38
39 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
40 unsigned long floor, unsigned long ceiling);
41
can_madv_lru_vma(struct vm_area_struct * vma)42 static 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
47 void 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
52 extern 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 */
ra_submit(struct file_ra_state * ra,struct address_space * mapping,struct file * filp)59 static 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 */
set_page_refcounted(struct page * page)70 static 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
77 extern 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 */
88 extern int isolate_lru_page(struct page *page);
89 extern void putback_lru_page(struct page *page);
90
91 /*
92 * in mm/rmap.c:
93 */
94 extern 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 */
113 struct 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 */
141 static inline unsigned long
__find_buddy_pfn(unsigned long page_pfn,unsigned int order)142 __find_buddy_pfn(unsigned long page_pfn, unsigned int order)
143 {
144 return page_pfn ^ (1 << order);
145 }
146
147 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
148 unsigned long end_pfn, struct zone *zone);
149
pageblock_pfn_to_page(unsigned long start_pfn,unsigned long end_pfn,struct zone * zone)150 static 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
159 extern int __isolate_free_page(struct page *page, unsigned int order);
160 extern void memblock_free_pages(struct page *page, unsigned long pfn,
161 unsigned int order);
162 extern void __free_pages_core(struct page *page, unsigned int order);
163 extern void prep_compound_page(struct page *page, unsigned int order);
164 extern void post_alloc_hook(struct page *page, unsigned int order,
165 gfp_t gfp_flags);
166 extern 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 */
180 struct 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 */
212 struct capture_control {
213 struct compact_control *cc;
214 struct page *page;
215 };
216
217 unsigned long
218 isolate_freepages_range(struct compact_control *cc,
219 unsigned long start_pfn, unsigned long end_pfn);
220 unsigned long
221 isolate_migratepages_range(struct compact_control *cc,
222 unsigned long low_pfn, unsigned long end_pfn);
223 int 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 */
page_order(struct page * page)236 static 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
is_cow_mapping(vm_flags_t flags)255 static 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 */
is_exec_mapping(vm_flags_t flags)267 static 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 */
is_stack_mapping(vm_flags_t flags)278 static 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 */
is_data_mapping(vm_flags_t flags)286 static 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 */
292 void __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
296 extern long populate_vma_page_range(struct vm_area_struct *vma,
297 unsigned long start, unsigned long end, int *nonblocking);
298 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
299 unsigned long start, unsigned long end);
munlock_vma_pages_all(struct vm_area_struct * vma)300 static 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 */
308 extern void mlock_vma_page(struct page *page);
309 extern 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 */
320 extern 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 */
mlock_migrate_page(struct page * newpage,struct page * page)327 static 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
339 extern 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 */
344 static inline unsigned long
__vma_address(struct page * page,struct vm_area_struct * vma)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
351 static inline unsigned long
vma_address(struct page * page,struct vm_area_struct * vma)352 vma_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 */
clear_page_mlock(struct page * page)366 static inline void clear_page_mlock(struct page *page) { }
mlock_vma_page(struct page * page)367 static inline void mlock_vma_page(struct page *page) { }
mlock_migrate_page(struct page * new,struct page * old)368 static 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 */
mem_map_offset(struct page * base,int offset)377 static 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 */
mem_map_next(struct page * iter,struct page * base,int offset)388 static 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 */
401 enum mminit_level {
402 MMINIT_WARNING,
403 MMINIT_VERIFY,
404 MMINIT_TRACE
405 };
406
407 #ifdef CONFIG_DEBUG_MEMORY_INIT
408
409 extern int mminit_loglevel;
410
411 #define mminit_dprintk(level, prefix, fmt, arg...) \
412 do { \
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
421 extern void mminit_verify_pageflags_layout(void);
422 extern void mminit_verify_zonelist(void);
423 #else
424
mminit_dprintk(enum mminit_level level,const char * prefix,const char * fmt,...)425 static inline void mminit_dprintk(enum mminit_level level,
426 const char *prefix, const char *fmt, ...)
427 {
428 }
429
mminit_verify_pageflags_layout(void)430 static inline void mminit_verify_pageflags_layout(void)
431 {
432 }
433
mminit_verify_zonelist(void)434 static 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)
441 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
442 unsigned long *end_pfn);
443 #else
mminit_validate_memmodel_limits(unsigned long * start_pfn,unsigned long * end_pfn)444 static 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
456 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
457 #else
node_reclaim(struct pglist_data * pgdat,gfp_t mask,unsigned int order)458 static 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
465 extern int hwpoison_filter(struct page *p);
466
467 extern u32 hwpoison_filter_dev_major;
468 extern u32 hwpoison_filter_dev_minor;
469 extern u64 hwpoison_filter_flags_mask;
470 extern u64 hwpoison_filter_flags_value;
471 extern u64 hwpoison_filter_memcg;
472 extern u32 hwpoison_filter_enable;
473
474 extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long,
475 unsigned long, unsigned long,
476 unsigned long, unsigned long);
477
478 extern void set_pageblock_order(void);
479 unsigned 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
512 enum ttu_flags;
513 struct 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 */
520 extern struct workqueue_struct *mm_percpu_wq;
521
522 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
523 void try_to_unmap_flush(void);
524 void try_to_unmap_flush_dirty(void);
525 void flush_tlb_batched_pending(struct mm_struct *mm);
526 #else
try_to_unmap_flush(void)527 static inline void try_to_unmap_flush(void)
528 {
529 }
try_to_unmap_flush_dirty(void)530 static inline void try_to_unmap_flush_dirty(void)
531 {
532 }
flush_tlb_batched_pending(struct mm_struct * mm)533 static inline void flush_tlb_batched_pending(struct mm_struct *mm)
534 {
535 }
536 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
537
538 extern const struct trace_print_flags pageflag_names[];
539 extern const struct trace_print_flags vmaflag_names[];
540 extern const struct trace_print_flags gfpflag_names[];
541
is_migrate_highatomic(enum migratetype migratetype)542 static inline bool is_migrate_highatomic(enum migratetype migratetype)
543 {
544 return migratetype == MIGRATE_HIGHATOMIC;
545 }
546
is_migrate_highatomic_page(struct page * page)547 static inline bool is_migrate_highatomic_page(struct page *page)
548 {
549 return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
550 }
551
552 void setup_zone_pageset(struct zone *zone);
553 extern struct page *alloc_new_node_page(struct page *page, unsigned long node);
554 #endif /* __MM_INTERNAL_H */
555
