LCOV - code coverage report
Current view: top level - mm - internal.h (source / functions) Hit Total Coverage
Test: coverage.info Lines: 6 13 46.2 %
Date: 2014-02-18 Functions: 0 0 -
Branches: 4 10 40.0 %

           Branch data     Line data    Source code
       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/mm.h>
      15                 :            : 
      16                 :            : void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
      17                 :            :                 unsigned long floor, unsigned long ceiling);
      18                 :            : 
      19                 :            : static inline void set_page_count(struct page *page, int v)
      20                 :            : {
      21                 :          0 :         atomic_set(&page->_count, v);
      22                 :            : }
      23                 :            : 
      24                 :            : /*
      25                 :            :  * Turn a non-refcounted page (->_count == 0) into refcounted with
      26                 :            :  * a count of one.
      27                 :            :  */
      28                 :            : static inline void set_page_refcounted(struct page *page)
      29                 :            : {
      30                 :            :         VM_BUG_ON(PageTail(page));
      31                 :            :         VM_BUG_ON(atomic_read(&page->_count));
      32                 :            :         set_page_count(page, 1);
      33                 :            : }
      34                 :            : 
      35                 :            : static inline void __get_page_tail_foll(struct page *page,
      36                 :            :                                         bool get_page_head)
      37                 :            : {
      38                 :            :         /*
      39                 :            :          * If we're getting a tail page, the elevated page->_count is
      40                 :            :          * required only in the head page and we will elevate the head
      41                 :            :          * page->_count and tail page->_mapcount.
      42                 :            :          *
      43                 :            :          * We elevate page_tail->_mapcount for tail pages to force
      44                 :            :          * page_tail->_count to be zero at all times to avoid getting
      45                 :            :          * false positives from get_page_unless_zero() with
      46                 :            :          * speculative page access (like in
      47                 :            :          * page_cache_get_speculative()) on tail pages.
      48                 :            :          */
      49                 :            :         VM_BUG_ON(atomic_read(&page->first_page->_count) <= 0);
      50                 :            :         VM_BUG_ON(atomic_read(&page->_count) != 0);
      51                 :            :         VM_BUG_ON(page_mapcount(page) < 0);
      52                 :            :         if (get_page_head)
      53                 :          0 :                 atomic_inc(&page->first_page->_count);
      54                 :          0 :         atomic_inc(&page->_mapcount);
      55                 :            : }
      56                 :            : 
      57                 :            : /*
      58                 :            :  * This is meant to be called as the FOLL_GET operation of
      59                 :            :  * follow_page() and it must be called while holding the proper PT
      60                 :            :  * lock while the pte (or pmd_trans_huge) is still mapping the page.
      61                 :            :  */
      62                 :            : static inline void get_page_foll(struct page *page)
      63                 :            : {
      64         [ -  + ]:    2556839 :         if (unlikely(PageTail(page)))
      65                 :            :                 /*
      66                 :            :                  * This is safe only because
      67                 :            :                  * __split_huge_page_refcount() can't run under
      68                 :            :                  * get_page_foll() because we hold the proper PT lock.
      69                 :            :                  */
      70                 :            :                 __get_page_tail_foll(page, true);
      71                 :            :         else {
      72                 :            :                 /*
      73                 :            :                  * Getting a normal page or the head of a compound page
      74                 :            :                  * requires to already have an elevated page->_count.
      75                 :            :                  */
      76                 :            :                 VM_BUG_ON(atomic_read(&page->_count) <= 0);
      77                 :    2556839 :                 atomic_inc(&page->_count);
      78                 :            :         }
      79                 :            : }
      80                 :            : 
      81                 :            : extern unsigned long highest_memmap_pfn;
      82                 :            : 
      83                 :            : /*
      84                 :            :  * in mm/vmscan.c:
      85                 :            :  */
      86                 :            : extern int isolate_lru_page(struct page *page);
      87                 :            : extern void putback_lru_page(struct page *page);
      88                 :            : extern unsigned long zone_reclaimable_pages(struct zone *zone);
      89                 :            : extern bool zone_reclaimable(struct zone *zone);
      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                 :            : extern void __free_pages_bootmem(struct page *page, unsigned int order);
     100                 :            : extern void prep_compound_page(struct page *page, unsigned long order);
     101                 :            : #ifdef CONFIG_MEMORY_FAILURE
     102                 :            : extern bool is_free_buddy_page(struct page *page);
     103                 :            : #endif
     104                 :            : 
     105                 :            : #if defined CONFIG_COMPACTION || defined CONFIG_CMA
     106                 :            : 
     107                 :            : /*
     108                 :            :  * in mm/compaction.c
     109                 :            :  */
     110                 :            : /*
     111                 :            :  * compact_control is used to track pages being migrated and the free pages
     112                 :            :  * they are being migrated to during memory compaction. The free_pfn starts
     113                 :            :  * at the end of a zone and migrate_pfn begins at the start. Movable pages
     114                 :            :  * are moved to the end of a zone during a compaction run and the run
     115                 :            :  * completes when free_pfn <= migrate_pfn
     116                 :            :  */
     117                 :            : struct compact_control {
     118                 :            :         struct list_head freepages;     /* List of free pages to migrate to */
     119                 :            :         struct list_head migratepages;  /* List of pages being migrated */
     120                 :            :         unsigned long nr_freepages;     /* Number of isolated free pages */
     121                 :            :         unsigned long nr_migratepages;  /* Number of pages to migrate */
     122                 :            :         unsigned long free_pfn;         /* isolate_freepages search base */
     123                 :            :         unsigned long migrate_pfn;      /* isolate_migratepages search base */
     124                 :            :         bool sync;                      /* Synchronous migration */
     125                 :            :         bool ignore_skip_hint;          /* Scan blocks even if marked skip */
     126                 :            :         bool finished_update_free;      /* True when the zone cached pfns are
     127                 :            :                                          * no longer being updated
     128                 :            :                                          */
     129                 :            :         bool finished_update_migrate;
     130                 :            : 
     131                 :            :         int order;                      /* order a direct compactor needs */
     132                 :            :         int migratetype;                /* MOVABLE, RECLAIMABLE etc */
     133                 :            :         struct zone *zone;
     134                 :            :         bool contended;                 /* True if a lock was contended */
     135                 :            : };
     136                 :            : 
     137                 :            : unsigned long
     138                 :            : isolate_freepages_range(struct compact_control *cc,
     139                 :            :                         unsigned long start_pfn, unsigned long end_pfn);
     140                 :            : unsigned long
     141                 :            : isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
     142                 :            :         unsigned long low_pfn, unsigned long end_pfn, bool unevictable);
     143                 :            : 
     144                 :            : #endif
     145                 :            : 
     146                 :            : /*
     147                 :            :  * function for dealing with page's order in buddy system.
     148                 :            :  * zone->lock is already acquired when we use these.
     149                 :            :  * So, we don't need atomic page->flags operations here.
     150                 :            :  */
     151                 :            : static inline unsigned long page_order(struct page *page)
     152                 :            : {
     153                 :            :         /* PageBuddy() must be checked by the caller */
     154                 :            :         return page_private(page);
     155                 :            : }
     156                 :            : 
     157                 :            : /* mm/util.c */
     158                 :            : void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
     159                 :            :                 struct vm_area_struct *prev, struct rb_node *rb_parent);
     160                 :            : 
     161                 :            : #ifdef CONFIG_MMU
     162                 :            : extern long __mlock_vma_pages_range(struct vm_area_struct *vma,
     163                 :            :                 unsigned long start, unsigned long end, int *nonblocking);
     164                 :            : extern void munlock_vma_pages_range(struct vm_area_struct *vma,
     165                 :            :                         unsigned long start, unsigned long end);
     166                 :            : static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
     167                 :            : {
     168                 :        232 :         munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
     169                 :            : }
     170                 :            : 
     171                 :            : /*
     172                 :            :  * Called only in fault path, to determine if a new page is being
     173                 :            :  * mapped into a LOCKED vma.  If it is, mark page as mlocked.
     174                 :            :  */
     175                 :            : static inline int mlocked_vma_newpage(struct vm_area_struct *vma,
     176                 :            :                                     struct page *page)
     177                 :            : {
     178                 :            :         VM_BUG_ON(PageLRU(page));
     179                 :            : 
     180         [ +  + ]:   26811056 :         if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
     181                 :            :                 return 0;
     182                 :            : 
     183         [ +  - ]:       6278 :         if (!TestSetPageMlocked(page)) {
     184                 :       6278 :                 mod_zone_page_state(page_zone(page), NR_MLOCK,
     185                 :            :                                     hpage_nr_pages(page));
     186                 :            :                 count_vm_event(UNEVICTABLE_PGMLOCKED);
     187                 :            :         }
     188                 :            :         return 1;
     189                 :            : }
     190                 :            : 
     191                 :            : /*
     192                 :            :  * must be called with vma's mmap_sem held for read or write, and page locked.
     193                 :            :  */
     194                 :            : extern void mlock_vma_page(struct page *page);
     195                 :            : extern unsigned int munlock_vma_page(struct page *page);
     196                 :            : 
     197                 :            : /*
     198                 :            :  * Clear the page's PageMlocked().  This can be useful in a situation where
     199                 :            :  * we want to unconditionally remove a page from the pagecache -- e.g.,
     200                 :            :  * on truncation or freeing.
     201                 :            :  *
     202                 :            :  * It is legal to call this function for any page, mlocked or not.
     203                 :            :  * If called for a page that is still mapped by mlocked vmas, all we do
     204                 :            :  * is revert to lazy LRU behaviour -- semantics are not broken.
     205                 :            :  */
     206                 :            : extern void clear_page_mlock(struct page *page);
     207                 :            : 
     208                 :            : /*
     209                 :            :  * mlock_migrate_page - called only from migrate_page_copy() to
     210                 :            :  * migrate the Mlocked page flag; update statistics.
     211                 :            :  */
     212                 :            : static inline void mlock_migrate_page(struct page *newpage, struct page *page)
     213                 :            : {
     214         [ #  # ]:          0 :         if (TestClearPageMlocked(page)) {
     215                 :            :                 unsigned long flags;
     216                 :            :                 int nr_pages = hpage_nr_pages(page);
     217                 :            : 
     218                 :            :                 local_irq_save(flags);
     219                 :          0 :                 __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
     220                 :            :                 SetPageMlocked(newpage);
     221                 :          0 :                 __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages);
     222         [ #  # ]:          0 :                 local_irq_restore(flags);
     223                 :            :         }
     224                 :            : }
     225                 :            : 
     226                 :            : extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
     227                 :            : 
     228                 :            : #ifdef CONFIG_TRANSPARENT_HUGEPAGE
     229                 :            : extern unsigned long vma_address(struct page *page,
     230                 :            :                                  struct vm_area_struct *vma);
     231                 :            : #endif
     232                 :            : #else /* !CONFIG_MMU */
     233                 :            : static inline int mlocked_vma_newpage(struct vm_area_struct *v, struct page *p)
     234                 :            : {
     235                 :            :         return 0;
     236                 :            : }
     237                 :            : static inline void clear_page_mlock(struct page *page) { }
     238                 :            : static inline void mlock_vma_page(struct page *page) { }
     239                 :            : static inline void mlock_migrate_page(struct page *new, struct page *old) { }
     240                 :            : 
     241                 :            : #endif /* !CONFIG_MMU */
     242                 :            : 
     243                 :            : /*
     244                 :            :  * Return the mem_map entry representing the 'offset' subpage within
     245                 :            :  * the maximally aligned gigantic page 'base'.  Handle any discontiguity
     246                 :            :  * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
     247                 :            :  */
     248                 :            : static inline struct page *mem_map_offset(struct page *base, int offset)
     249                 :            : {
     250                 :            :         if (unlikely(offset >= MAX_ORDER_NR_PAGES))
     251                 :            :                 return pfn_to_page(page_to_pfn(base) + offset);
     252                 :            :         return base + offset;
     253                 :            : }
     254                 :            : 
     255                 :            : /*
     256                 :            :  * Iterator over all subpages within the maximally aligned gigantic
     257                 :            :  * page 'base'.  Handle any discontiguity in the mem_map.
     258                 :            :  */
     259                 :            : static inline struct page *mem_map_next(struct page *iter,
     260                 :            :                                                 struct page *base, int offset)
     261                 :            : {
     262                 :            :         if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
     263                 :            :                 unsigned long pfn = page_to_pfn(base) + offset;
     264                 :            :                 if (!pfn_valid(pfn))
     265                 :            :                         return NULL;
     266                 :            :                 return pfn_to_page(pfn);
     267                 :            :         }
     268                 :            :         return iter + 1;
     269                 :            : }
     270                 :            : 
     271                 :            : /*
     272                 :            :  * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
     273                 :            :  * so all functions starting at paging_init should be marked __init
     274                 :            :  * in those cases. SPARSEMEM, however, allows for memory hotplug,
     275                 :            :  * and alloc_bootmem_node is not used.
     276                 :            :  */
     277                 :            : #ifdef CONFIG_SPARSEMEM
     278                 :            : #define __paginginit __meminit
     279                 :            : #else
     280                 :            : #define __paginginit __init
     281                 :            : #endif
     282                 :            : 
     283                 :            : /* Memory initialisation debug and verification */
     284                 :            : enum mminit_level {
     285                 :            :         MMINIT_WARNING,
     286                 :            :         MMINIT_VERIFY,
     287                 :            :         MMINIT_TRACE
     288                 :            : };
     289                 :            : 
     290                 :            : #ifdef CONFIG_DEBUG_MEMORY_INIT
     291                 :            : 
     292                 :            : extern int mminit_loglevel;
     293                 :            : 
     294                 :            : #define mminit_dprintk(level, prefix, fmt, arg...) \
     295                 :            : do { \
     296                 :            :         if (level < mminit_loglevel) { \
     297                 :            :                 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
     298                 :            :                 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
     299                 :            :         } \
     300                 :            : } while (0)
     301                 :            : 
     302                 :            : extern void mminit_verify_pageflags_layout(void);
     303                 :            : extern void mminit_verify_page_links(struct page *page,
     304                 :            :                 enum zone_type zone, unsigned long nid, unsigned long pfn);
     305                 :            : extern void mminit_verify_zonelist(void);
     306                 :            : 
     307                 :            : #else
     308                 :            : 
     309                 :            : static inline void mminit_dprintk(enum mminit_level level,
     310                 :            :                                 const char *prefix, const char *fmt, ...)
     311                 :            : {
     312                 :            : }
     313                 :            : 
     314                 :            : static inline void mminit_verify_pageflags_layout(void)
     315                 :            : {
     316                 :            : }
     317                 :            : 
     318                 :            : static inline void mminit_verify_page_links(struct page *page,
     319                 :            :                 enum zone_type zone, unsigned long nid, unsigned long pfn)
     320                 :            : {
     321                 :            : }
     322                 :            : 
     323                 :            : static inline void mminit_verify_zonelist(void)
     324                 :            : {
     325                 :            : }
     326                 :            : #endif /* CONFIG_DEBUG_MEMORY_INIT */
     327                 :            : 
     328                 :            : /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
     329                 :            : #if defined(CONFIG_SPARSEMEM)
     330                 :            : extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
     331                 :            :                                 unsigned long *end_pfn);
     332                 :            : #else
     333                 :            : static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
     334                 :            :                                 unsigned long *end_pfn)
     335                 :            : {
     336                 :            : }
     337                 :            : #endif /* CONFIG_SPARSEMEM */
     338                 :            : 
     339                 :            : #define ZONE_RECLAIM_NOSCAN     -2
     340                 :            : #define ZONE_RECLAIM_FULL       -1
     341                 :            : #define ZONE_RECLAIM_SOME       0
     342                 :            : #define ZONE_RECLAIM_SUCCESS    1
     343                 :            : 
     344                 :            : extern int hwpoison_filter(struct page *p);
     345                 :            : 
     346                 :            : extern u32 hwpoison_filter_dev_major;
     347                 :            : extern u32 hwpoison_filter_dev_minor;
     348                 :            : extern u64 hwpoison_filter_flags_mask;
     349                 :            : extern u64 hwpoison_filter_flags_value;
     350                 :            : extern u64 hwpoison_filter_memcg;
     351                 :            : extern u32 hwpoison_filter_enable;
     352                 :            : 
     353                 :            : extern unsigned long vm_mmap_pgoff(struct file *, unsigned long,
     354                 :            :         unsigned long, unsigned long,
     355                 :            :         unsigned long, unsigned long);
     356                 :            : 
     357                 :            : extern void set_pageblock_order(void);
     358                 :            : unsigned long reclaim_clean_pages_from_list(struct zone *zone,
     359                 :            :                                             struct list_head *page_list);
     360                 :            : /* The ALLOC_WMARK bits are used as an index to zone->watermark */
     361                 :            : #define ALLOC_WMARK_MIN         WMARK_MIN
     362                 :            : #define ALLOC_WMARK_LOW         WMARK_LOW
     363                 :            : #define ALLOC_WMARK_HIGH        WMARK_HIGH
     364                 :            : #define ALLOC_NO_WATERMARKS     0x04 /* don't check watermarks at all */
     365                 :            : 
     366                 :            : /* Mask to get the watermark bits */
     367                 :            : #define ALLOC_WMARK_MASK        (ALLOC_NO_WATERMARKS-1)
     368                 :            : 
     369                 :            : #define ALLOC_HARDER            0x10 /* try to alloc harder */
     370                 :            : #define ALLOC_HIGH              0x20 /* __GFP_HIGH set */
     371                 :            : #define ALLOC_CPUSET            0x40 /* check for correct cpuset */
     372                 :            : #define ALLOC_CMA               0x80 /* allow allocations from CMA areas */
     373                 :            : 
     374                 :            : #endif  /* __MM_INTERNAL_H */

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