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1da177e4 LT |
1 | #ifndef _LINUX_RMAP_H |
2 | #define _LINUX_RMAP_H | |
3 | /* | |
4 | * Declarations for Reverse Mapping functions in mm/rmap.c | |
5 | */ | |
6 | ||
1da177e4 LT |
7 | #include <linux/list.h> |
8 | #include <linux/slab.h> | |
9 | #include <linux/mm.h> | |
10 | #include <linux/spinlock.h> | |
bed7161a | 11 | #include <linux/memcontrol.h> |
1da177e4 LT |
12 | |
13 | /* | |
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. | |
17 | * | |
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. | |
22 | * | |
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. | |
26 | */ | |
27 | struct anon_vma { | |
28 | spinlock_t lock; /* Serialize access to vma list */ | |
7906d00c AA |
29 | /* |
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). | |
36 | */ | |
1da177e4 LT |
37 | struct list_head head; /* List of private "related" vmas */ |
38 | }; | |
39 | ||
40 | #ifdef CONFIG_MMU | |
41 | ||
1da177e4 LT |
42 | static inline void anon_vma_lock(struct vm_area_struct *vma) |
43 | { | |
44 | struct anon_vma *anon_vma = vma->anon_vma; | |
45 | if (anon_vma) | |
46 | spin_lock(&anon_vma->lock); | |
47 | } | |
48 | ||
49 | static inline void anon_vma_unlock(struct vm_area_struct *vma) | |
50 | { | |
51 | struct anon_vma *anon_vma = vma->anon_vma; | |
52 | if (anon_vma) | |
53 | spin_unlock(&anon_vma->lock); | |
54 | } | |
55 | ||
56 | /* | |
57 | * anon_vma helper functions. | |
58 | */ | |
59 | void anon_vma_init(void); /* create anon_vma_cachep */ | |
60 | int anon_vma_prepare(struct vm_area_struct *); | |
61 | void __anon_vma_merge(struct vm_area_struct *, struct vm_area_struct *); | |
62 | void anon_vma_unlink(struct vm_area_struct *); | |
63 | void anon_vma_link(struct vm_area_struct *); | |
64 | void __anon_vma_link(struct vm_area_struct *); | |
65 | ||
66 | /* | |
67 | * rmap interfaces called when adding or removing pte of page | |
68 | */ | |
69 | void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long); | |
9617d95e | 70 | void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned long); |
1da177e4 | 71 | void page_add_file_rmap(struct page *); |
7de6b805 | 72 | void page_remove_rmap(struct page *, struct vm_area_struct *); |
1da177e4 | 73 | |
c97a9e10 NP |
74 | #ifdef CONFIG_DEBUG_VM |
75 | void page_dup_rmap(struct page *page, struct vm_area_struct *vma, unsigned long address); | |
76 | #else | |
77 | static inline void page_dup_rmap(struct page *page, struct vm_area_struct *vma, unsigned long address) | |
1da177e4 LT |
78 | { |
79 | atomic_inc(&page->_mapcount); | |
80 | } | |
c97a9e10 | 81 | #endif |
1da177e4 LT |
82 | |
83 | /* | |
84 | * Called from mm/vmscan.c to handle paging out | |
85 | */ | |
bed7161a | 86 | int page_referenced(struct page *, int is_locked, struct mem_cgroup *cnt); |
a48d07af | 87 | int try_to_unmap(struct page *, int ignore_refs); |
1da177e4 | 88 | |
ceffc078 CO |
89 | /* |
90 | * Called from mm/filemap_xip.c to unmap empty zero page | |
91 | */ | |
c0718806 | 92 | pte_t *page_check_address(struct page *, struct mm_struct *, |
479db0bf | 93 | unsigned long, spinlock_t **, int); |
ceffc078 | 94 | |
1da177e4 LT |
95 | /* |
96 | * Used by swapoff to help locate where page is expected in vma. | |
97 | */ | |
98 | unsigned long page_address_in_vma(struct page *, struct vm_area_struct *); | |
99 | ||
d08b3851 PZ |
100 | /* |
101 | * Cleans the PTEs of shared mappings. | |
102 | * (and since clean PTEs should also be readonly, write protects them too) | |
103 | * | |
104 | * returns the number of cleaned PTEs. | |
105 | */ | |
106 | int page_mkclean(struct page *); | |
107 | ||
b291f000 NP |
108 | #ifdef CONFIG_UNEVICTABLE_LRU |
109 | /* | |
110 | * called in munlock()/munmap() path to check for other vmas holding | |
111 | * the page mlocked. | |
112 | */ | |
113 | int try_to_munlock(struct page *); | |
114 | #else | |
115 | static inline int try_to_munlock(struct page *page) | |
116 | { | |
117 | return 0; /* a.k.a. SWAP_SUCCESS */ | |
118 | } | |
119 | #endif | |
120 | ||
1da177e4 LT |
121 | #else /* !CONFIG_MMU */ |
122 | ||
123 | #define anon_vma_init() do {} while (0) | |
124 | #define anon_vma_prepare(vma) (0) | |
125 | #define anon_vma_link(vma) do {} while (0) | |
126 | ||
bed7161a | 127 | #define page_referenced(page,l,cnt) TestClearPageReferenced(page) |
a48d07af | 128 | #define try_to_unmap(page, refs) SWAP_FAIL |
1da177e4 | 129 | |
d08b3851 PZ |
130 | static inline int page_mkclean(struct page *page) |
131 | { | |
132 | return 0; | |
133 | } | |
134 | ||
135 | ||
1da177e4 LT |
136 | #endif /* CONFIG_MMU */ |
137 | ||
138 | /* | |
139 | * Return values of try_to_unmap | |
140 | */ | |
141 | #define SWAP_SUCCESS 0 | |
142 | #define SWAP_AGAIN 1 | |
143 | #define SWAP_FAIL 2 | |
b291f000 | 144 | #define SWAP_MLOCK 3 |
1da177e4 LT |
145 | |
146 | #endif /* _LINUX_RMAP_H */ |