4 * Declarations for Reverse Mapping functions in mm/rmap.c
7 #include <linux/list.h>
8 #include <linux/slab.h>
10 #include <linux/spinlock.h>
11 #include <linux/memcontrol.h>
14 * The anon_vma heads a list of private "related" vmas, to scan if
15 * an anonymous page pointing to this anon_vma needs to be unmapped:
16 * the vmas on the list will be related by forking, or by splitting.
18 * Since vmas come and go as they are split and merged (particularly
19 * in mprotect), the mapping field of an anonymous page cannot point
20 * directly to a vma: instead it points to an anon_vma, on whose list
21 * the related vmas can be easily linked or unlinked.
23 * After unlinking the last vma on the list, we must garbage collect
24 * the anon_vma object itself: we're guaranteed no page can be
25 * pointing to this anon_vma once its vma list is empty.
28 spinlock_t lock; /* Serialize access to vma list */
30 * NOTE: the LSB of the head.next is set by
31 * mm_take_all_locks() _after_ taking the above lock. So the
32 * head must only be read/written after taking the above lock
33 * to be sure to see a valid next pointer. The LSB bit itself
34 * is serialized by a system wide lock only visible to
35 * mm_take_all_locks() (mm_all_locks_mutex).
37 struct list_head head; /* List of private "related" vmas */
42 static inline struct anon_vma *page_anon_vma(struct page *page)
44 if (((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) !=
47 return page_rmapping(page);
50 static inline void anon_vma_lock(struct vm_area_struct *vma)
52 struct anon_vma *anon_vma = vma->anon_vma;
54 spin_lock(&anon_vma->lock);
57 static inline void anon_vma_unlock(struct vm_area_struct *vma)
59 struct anon_vma *anon_vma = vma->anon_vma;
61 spin_unlock(&anon_vma->lock);
65 * anon_vma helper functions.
67 void anon_vma_init(void); /* create anon_vma_cachep */
68 int anon_vma_prepare(struct vm_area_struct *);
69 void __anon_vma_merge(struct vm_area_struct *, struct vm_area_struct *);
70 void anon_vma_unlink(struct vm_area_struct *);
71 void anon_vma_link(struct vm_area_struct *);
72 void __anon_vma_link(struct vm_area_struct *);
75 * rmap interfaces called when adding or removing pte of page
77 void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
78 void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
79 void page_add_file_rmap(struct page *);
80 void page_remove_rmap(struct page *);
82 static inline void page_dup_rmap(struct page *page)
84 atomic_inc(&page->_mapcount);
88 * Called from mm/vmscan.c to handle paging out
90 int page_referenced(struct page *, int is_locked,
91 struct mem_cgroup *cnt, unsigned long *vm_flags);
92 int page_referenced_one(struct page *, struct vm_area_struct *,
93 unsigned long address, unsigned int *mapcount, unsigned long *vm_flags);
96 TTU_UNMAP = 0, /* unmap mode */
97 TTU_MIGRATION = 1, /* migration mode */
98 TTU_MUNLOCK = 2, /* munlock mode */
99 TTU_ACTION_MASK = 0xff,
101 TTU_IGNORE_MLOCK = (1 << 8), /* ignore mlock */
102 TTU_IGNORE_ACCESS = (1 << 9), /* don't age */
103 TTU_IGNORE_HWPOISON = (1 << 10),/* corrupted page is recoverable */
105 #define TTU_ACTION(x) ((x) & TTU_ACTION_MASK)
107 int try_to_unmap(struct page *, enum ttu_flags flags);
108 int try_to_unmap_one(struct page *, struct vm_area_struct *,
109 unsigned long address, enum ttu_flags flags);
112 * Called from mm/filemap_xip.c to unmap empty zero page
114 pte_t *page_check_address(struct page *, struct mm_struct *,
115 unsigned long, spinlock_t **, int);
118 * Used by swapoff to help locate where page is expected in vma.
120 unsigned long page_address_in_vma(struct page *, struct vm_area_struct *);
123 * Cleans the PTEs of shared mappings.
124 * (and since clean PTEs should also be readonly, write protects them too)
126 * returns the number of cleaned PTEs.
128 int page_mkclean(struct page *);
131 * called in munlock()/munmap() path to check for other vmas holding
134 int try_to_munlock(struct page *);
137 * Called by memory-failure.c to kill processes.
139 struct anon_vma *page_lock_anon_vma(struct page *page);
140 void page_unlock_anon_vma(struct anon_vma *anon_vma);
141 int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
143 #else /* !CONFIG_MMU */
145 #define anon_vma_init() do {} while (0)
146 #define anon_vma_prepare(vma) (0)
147 #define anon_vma_link(vma) do {} while (0)
149 static inline int page_referenced(struct page *page, int is_locked,
150 struct mem_cgroup *cnt,
151 unsigned long *vm_flags)
154 return TestClearPageReferenced(page);
157 #define try_to_unmap(page, refs) SWAP_FAIL
159 static inline int page_mkclean(struct page *page)
165 #endif /* CONFIG_MMU */
168 * Return values of try_to_unmap
170 #define SWAP_SUCCESS 0
175 #endif /* _LINUX_RMAP_H */