1 /* internal.h: mm/ internal definitions
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
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.
11 #ifndef __MM_INTERNAL_H
12 #define __MM_INTERNAL_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_REPEAT|__GFP_NOFAIL|\
25 __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC)
27 /* The GFP flags allowed during early boot */
28 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))
30 /* Control allocation cpuset and node placement constraints */
31 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
33 /* Do not use these with a slab allocator */
34 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
36 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
37 unsigned long floor, unsigned long ceiling);
39 static inline void set_page_count(struct page *page, int v)
41 atomic_set(&page->_count, v);
44 extern int __do_page_cache_readahead(struct address_space *mapping,
45 struct file *filp, pgoff_t offset, unsigned long nr_to_read,
46 unsigned long lookahead_size);
49 * Submit IO for the read-ahead request in file_ra_state.
51 static inline unsigned long ra_submit(struct file_ra_state *ra,
52 struct address_space *mapping, struct file *filp)
54 return __do_page_cache_readahead(mapping, filp,
55 ra->start, ra->size, ra->async_size);
59 * Turn a non-refcounted page (->_count == 0) into refcounted with
62 static inline void set_page_refcounted(struct page *page)
64 VM_BUG_ON_PAGE(PageTail(page), page);
65 VM_BUG_ON_PAGE(atomic_read(&page->_count), page);
66 set_page_count(page, 1);
69 static inline void __get_page_tail_foll(struct page *page,
73 * If we're getting a tail page, the elevated page->_count is
74 * required only in the head page and we will elevate the head
75 * page->_count and tail page->_mapcount.
77 * We elevate page_tail->_mapcount for tail pages to force
78 * page_tail->_count to be zero at all times to avoid getting
79 * false positives from get_page_unless_zero() with
80 * speculative page access (like in
81 * page_cache_get_speculative()) on tail pages.
83 VM_BUG_ON_PAGE(atomic_read(&compound_head(page)->_count) <= 0, page);
85 atomic_inc(&compound_head(page)->_count);
86 get_huge_page_tail(page);
90 * This is meant to be called as the FOLL_GET operation of
91 * follow_page() and it must be called while holding the proper PT
92 * lock while the pte (or pmd_trans_huge) is still mapping the page.
94 static inline void get_page_foll(struct page *page)
96 if (unlikely(PageTail(page)))
98 * This is safe only because
99 * __split_huge_page_refcount() can't run under
100 * get_page_foll() because we hold the proper PT lock.
102 __get_page_tail_foll(page, true);
105 * Getting a normal page or the head of a compound page
106 * requires to already have an elevated page->_count.
108 VM_BUG_ON_PAGE(atomic_read(&page->_count) <= 0, page);
109 atomic_inc(&page->_count);
113 extern unsigned long highest_memmap_pfn;
118 extern int isolate_lru_page(struct page *page);
119 extern void putback_lru_page(struct page *page);
120 extern bool zone_reclaimable(struct zone *zone);
122 #define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
127 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
134 * Structure for holding the mostly immutable allocation parameters passed
135 * between functions involved in allocations, including the alloc_pages*
136 * family of functions.
138 * nodemask, migratetype and high_zoneidx are initialized only once in
139 * __alloc_pages_nodemask() and then never change.
141 * zonelist, preferred_zone and classzone_idx are set first in
142 * __alloc_pages_nodemask() for the fast path, and might be later changed
143 * in __alloc_pages_slowpath(). All other functions pass the whole strucure
144 * by a const pointer.
146 struct alloc_context {
147 struct zonelist *zonelist;
148 nodemask_t *nodemask;
149 struct zone *preferred_zone;
152 enum zone_type high_zoneidx;
153 bool spread_dirty_pages;
157 * Locate the struct page for both the matching buddy in our
158 * pair (buddy1) and the combined O(n+1) page they form (page).
160 * 1) Any buddy B1 will have an order O twin B2 which satisfies
161 * the following equation:
163 * For example, if the starting buddy (buddy2) is #8 its order
165 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
167 * 2) Any buddy B will have an order O+1 parent P which
168 * satisfies the following equation:
171 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
173 static inline unsigned long
174 __find_buddy_index(unsigned long page_idx, unsigned int order)
176 return page_idx ^ (1 << order);
179 extern int __isolate_free_page(struct page *page, unsigned int order);
180 extern void __free_pages_bootmem(struct page *page, unsigned long pfn,
182 extern void prep_compound_page(struct page *page, unsigned int order);
183 #ifdef CONFIG_MEMORY_FAILURE
184 extern bool is_free_buddy_page(struct page *page);
186 extern int user_min_free_kbytes;
188 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
194 * compact_control is used to track pages being migrated and the free pages
195 * they are being migrated to during memory compaction. The free_pfn starts
196 * at the end of a zone and migrate_pfn begins at the start. Movable pages
197 * are moved to the end of a zone during a compaction run and the run
198 * completes when free_pfn <= migrate_pfn
200 struct compact_control {
201 struct list_head freepages; /* List of free pages to migrate to */
202 struct list_head migratepages; /* List of pages being migrated */
203 unsigned long nr_freepages; /* Number of isolated free pages */
204 unsigned long nr_migratepages; /* Number of pages to migrate */
205 unsigned long free_pfn; /* isolate_freepages search base */
206 unsigned long migrate_pfn; /* isolate_migratepages search base */
207 unsigned long last_migrated_pfn;/* Not yet flushed page being freed */
208 enum migrate_mode mode; /* Async or sync migration mode */
209 bool ignore_skip_hint; /* Scan blocks even if marked skip */
210 int order; /* order a direct compactor needs */
211 const gfp_t gfp_mask; /* gfp mask of a direct compactor */
212 const int alloc_flags; /* alloc flags of a direct compactor */
213 const int classzone_idx; /* zone index of a direct compactor */
215 int contended; /* Signal need_sched() or lock
216 * contention detected during
222 isolate_freepages_range(struct compact_control *cc,
223 unsigned long start_pfn, unsigned long end_pfn);
225 isolate_migratepages_range(struct compact_control *cc,
226 unsigned long low_pfn, unsigned long end_pfn);
227 int find_suitable_fallback(struct free_area *area, unsigned int order,
228 int migratetype, bool only_stealable, bool *can_steal);
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.
240 static inline unsigned int page_order(struct page *page)
242 /* PageBuddy() must be checked by the caller */
243 return page_private(page);
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.
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
257 #define page_order_unsafe(page) READ_ONCE(page_private(page))
259 static inline bool is_cow_mapping(vm_flags_t flags)
261 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
265 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
266 struct vm_area_struct *prev, struct rb_node *rb_parent);
269 extern long populate_vma_page_range(struct vm_area_struct *vma,
270 unsigned long start, unsigned long end, int *nonblocking);
271 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
272 unsigned long start, unsigned long end);
273 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
275 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
279 * must be called with vma's mmap_sem held for read or write, and page locked.
281 extern void mlock_vma_page(struct page *page);
282 extern unsigned int munlock_vma_page(struct page *page);
285 * Clear the page's PageMlocked(). This can be useful in a situation where
286 * we want to unconditionally remove a page from the pagecache -- e.g.,
287 * on truncation or freeing.
289 * It is legal to call this function for any page, mlocked or not.
290 * If called for a page that is still mapped by mlocked vmas, all we do
291 * is revert to lazy LRU behaviour -- semantics are not broken.
293 extern void clear_page_mlock(struct page *page);
296 * mlock_migrate_page - called only from migrate_misplaced_transhuge_page()
297 * (because that does not go through the full procedure of migration ptes):
298 * to migrate the Mlocked page flag; update statistics.
300 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
302 if (TestClearPageMlocked(page)) {
303 int nr_pages = hpage_nr_pages(page);
305 /* Holding pmd lock, no change in irq context: __mod is safe */
306 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
307 SetPageMlocked(newpage);
308 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages);
312 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
314 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
315 extern unsigned long vma_address(struct page *page,
316 struct vm_area_struct *vma);
318 #else /* !CONFIG_MMU */
319 static inline void clear_page_mlock(struct page *page) { }
320 static inline void mlock_vma_page(struct page *page) { }
321 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
323 #endif /* !CONFIG_MMU */
326 * Return the mem_map entry representing the 'offset' subpage within
327 * the maximally aligned gigantic page 'base'. Handle any discontiguity
328 * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
330 static inline struct page *mem_map_offset(struct page *base, int offset)
332 if (unlikely(offset >= MAX_ORDER_NR_PAGES))
333 return nth_page(base, offset);
334 return base + offset;
338 * Iterator over all subpages within the maximally aligned gigantic
339 * page 'base'. Handle any discontiguity in the mem_map.
341 static inline struct page *mem_map_next(struct page *iter,
342 struct page *base, int offset)
344 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
345 unsigned long pfn = page_to_pfn(base) + offset;
348 return pfn_to_page(pfn);
354 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
355 * so all functions starting at paging_init should be marked __init
356 * in those cases. SPARSEMEM, however, allows for memory hotplug,
357 * and alloc_bootmem_node is not used.
359 #ifdef CONFIG_SPARSEMEM
360 #define __paginginit __meminit
362 #define __paginginit __init
365 /* Memory initialisation debug and verification */
372 #ifdef CONFIG_DEBUG_MEMORY_INIT
374 extern int mminit_loglevel;
376 #define mminit_dprintk(level, prefix, fmt, arg...) \
378 if (level < mminit_loglevel) { \
379 if (level <= MMINIT_WARNING) \
380 printk(KERN_WARNING "mminit::" prefix " " fmt, ##arg); \
382 printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
386 extern void mminit_verify_pageflags_layout(void);
387 extern void mminit_verify_zonelist(void);
390 static inline void mminit_dprintk(enum mminit_level level,
391 const char *prefix, const char *fmt, ...)
395 static inline void mminit_verify_pageflags_layout(void)
399 static inline void mminit_verify_zonelist(void)
402 #endif /* CONFIG_DEBUG_MEMORY_INIT */
404 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
405 #if defined(CONFIG_SPARSEMEM)
406 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
407 unsigned long *end_pfn);
409 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
410 unsigned long *end_pfn)
413 #endif /* CONFIG_SPARSEMEM */
415 #define ZONE_RECLAIM_NOSCAN -2
416 #define ZONE_RECLAIM_FULL -1
417 #define ZONE_RECLAIM_SOME 0
418 #define ZONE_RECLAIM_SUCCESS 1
420 extern int hwpoison_filter(struct page *p);
422 extern u32 hwpoison_filter_dev_major;
423 extern u32 hwpoison_filter_dev_minor;
424 extern u64 hwpoison_filter_flags_mask;
425 extern u64 hwpoison_filter_flags_value;
426 extern u64 hwpoison_filter_memcg;
427 extern u32 hwpoison_filter_enable;
429 extern unsigned long vm_mmap_pgoff(struct file *, unsigned long,
430 unsigned long, unsigned long,
431 unsigned long, unsigned long);
433 extern void set_pageblock_order(void);
434 unsigned long reclaim_clean_pages_from_list(struct zone *zone,
435 struct list_head *page_list);
436 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
437 #define ALLOC_WMARK_MIN WMARK_MIN
438 #define ALLOC_WMARK_LOW WMARK_LOW
439 #define ALLOC_WMARK_HIGH WMARK_HIGH
440 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
442 /* Mask to get the watermark bits */
443 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
445 #define ALLOC_HARDER 0x10 /* try to alloc harder */
446 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
447 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
448 #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */
449 #define ALLOC_FAIR 0x100 /* fair zone allocation */
452 struct tlbflush_unmap_batch;
454 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
455 void try_to_unmap_flush(void);
456 void try_to_unmap_flush_dirty(void);
458 static inline void try_to_unmap_flush(void)
461 static inline void try_to_unmap_flush_dirty(void)
465 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
466 #endif /* __MM_INTERNAL_H */