[JFFS2] Correct parameter names of jffs2_compress() in comments
[linux-2.6/mini2440.git] / include / linux / rmap.h
blobfed6f5e0b41139070dd9c99b84ee324e7254f63f
1 #ifndef _LINUX_RMAP_H
2 #define _LINUX_RMAP_H
3 /*
4 * Declarations for Reverse Mapping functions in mm/rmap.c
5 */
7 #include <linux/list.h>
8 #include <linux/slab.h>
9 #include <linux/mm.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.
27 struct anon_vma {
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 */
40 #ifdef CONFIG_MMU
42 extern struct kmem_cache *anon_vma_cachep;
44 static inline struct anon_vma *anon_vma_alloc(void)
46 return kmem_cache_alloc(anon_vma_cachep, GFP_KERNEL);
49 static inline void anon_vma_free(struct anon_vma *anon_vma)
51 kmem_cache_free(anon_vma_cachep, anon_vma);
54 static inline void anon_vma_lock(struct vm_area_struct *vma)
56 struct anon_vma *anon_vma = vma->anon_vma;
57 if (anon_vma)
58 spin_lock(&anon_vma->lock);
61 static inline void anon_vma_unlock(struct vm_area_struct *vma)
63 struct anon_vma *anon_vma = vma->anon_vma;
64 if (anon_vma)
65 spin_unlock(&anon_vma->lock);
69 * anon_vma helper functions.
71 void anon_vma_init(void); /* create anon_vma_cachep */
72 int anon_vma_prepare(struct vm_area_struct *);
73 void __anon_vma_merge(struct vm_area_struct *, struct vm_area_struct *);
74 void anon_vma_unlink(struct vm_area_struct *);
75 void anon_vma_link(struct vm_area_struct *);
76 void __anon_vma_link(struct vm_area_struct *);
79 * rmap interfaces called when adding or removing pte of page
81 void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
82 void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
83 void page_add_file_rmap(struct page *);
84 void page_remove_rmap(struct page *, struct vm_area_struct *);
86 #ifdef CONFIG_DEBUG_VM
87 void page_dup_rmap(struct page *page, struct vm_area_struct *vma, unsigned long address);
88 #else
89 static inline void page_dup_rmap(struct page *page, struct vm_area_struct *vma, unsigned long address)
91 atomic_inc(&page->_mapcount);
93 #endif
96 * Called from mm/vmscan.c to handle paging out
98 int page_referenced(struct page *, int is_locked, struct mem_cgroup *cnt);
99 int try_to_unmap(struct page *, int ignore_refs);
102 * Called from mm/filemap_xip.c to unmap empty zero page
104 pte_t *page_check_address(struct page *, struct mm_struct *,
105 unsigned long, spinlock_t **, int);
108 * Used by swapoff to help locate where page is expected in vma.
110 unsigned long page_address_in_vma(struct page *, struct vm_area_struct *);
113 * Cleans the PTEs of shared mappings.
114 * (and since clean PTEs should also be readonly, write protects them too)
116 * returns the number of cleaned PTEs.
118 int page_mkclean(struct page *);
120 #else /* !CONFIG_MMU */
122 #define anon_vma_init() do {} while (0)
123 #define anon_vma_prepare(vma) (0)
124 #define anon_vma_link(vma) do {} while (0)
126 #define page_referenced(page,l,cnt) TestClearPageReferenced(page)
127 #define try_to_unmap(page, refs) SWAP_FAIL
129 static inline int page_mkclean(struct page *page)
131 return 0;
135 #endif /* CONFIG_MMU */
138 * Return values of try_to_unmap
140 #define SWAP_SUCCESS 0
141 #define SWAP_AGAIN 1
142 #define SWAP_FAIL 2
144 #endif /* _LINUX_RMAP_H */