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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 *); |
edc315fd | 72 | void page_remove_rmap(struct page *); |
1da177e4 | 73 | |
21333b2b | 74 | static inline void page_dup_rmap(struct page *page) |
1da177e4 LT |
75 | { |
76 | atomic_inc(&page->_mapcount); | |
77 | } | |
78 | ||
79 | /* | |
80 | * Called from mm/vmscan.c to handle paging out | |
81 | */ | |
6fe6b7e3 WF |
82 | int page_referenced(struct page *, int is_locked, |
83 | struct mem_cgroup *cnt, unsigned long *vm_flags); | |
14fa31b8 AK |
84 | enum ttu_flags { |
85 | TTU_UNMAP = 0, /* unmap mode */ | |
86 | TTU_MIGRATION = 1, /* migration mode */ | |
87 | TTU_MUNLOCK = 2, /* munlock mode */ | |
88 | TTU_ACTION_MASK = 0xff, | |
89 | ||
90 | TTU_IGNORE_MLOCK = (1 << 8), /* ignore mlock */ | |
91 | TTU_IGNORE_ACCESS = (1 << 9), /* don't age */ | |
888b9f7c | 92 | TTU_IGNORE_HWPOISON = (1 << 10),/* corrupted page is recoverable */ |
14fa31b8 AK |
93 | }; |
94 | #define TTU_ACTION(x) ((x) & TTU_ACTION_MASK) | |
95 | ||
96 | int try_to_unmap(struct page *, enum ttu_flags flags); | |
1da177e4 | 97 | |
ceffc078 CO |
98 | /* |
99 | * Called from mm/filemap_xip.c to unmap empty zero page | |
100 | */ | |
c0718806 | 101 | pte_t *page_check_address(struct page *, struct mm_struct *, |
479db0bf | 102 | unsigned long, spinlock_t **, int); |
ceffc078 | 103 | |
1da177e4 LT |
104 | /* |
105 | * Used by swapoff to help locate where page is expected in vma. | |
106 | */ | |
107 | unsigned long page_address_in_vma(struct page *, struct vm_area_struct *); | |
108 | ||
d08b3851 PZ |
109 | /* |
110 | * Cleans the PTEs of shared mappings. | |
111 | * (and since clean PTEs should also be readonly, write protects them too) | |
112 | * | |
113 | * returns the number of cleaned PTEs. | |
114 | */ | |
115 | int page_mkclean(struct page *); | |
116 | ||
b291f000 NP |
117 | /* |
118 | * called in munlock()/munmap() path to check for other vmas holding | |
119 | * the page mlocked. | |
120 | */ | |
121 | int try_to_munlock(struct page *); | |
b291f000 | 122 | |
10be22df AK |
123 | /* |
124 | * Called by memory-failure.c to kill processes. | |
125 | */ | |
126 | struct anon_vma *page_lock_anon_vma(struct page *page); | |
127 | void page_unlock_anon_vma(struct anon_vma *anon_vma); | |
6a46079c | 128 | int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma); |
10be22df | 129 | |
1da177e4 LT |
130 | #else /* !CONFIG_MMU */ |
131 | ||
132 | #define anon_vma_init() do {} while (0) | |
133 | #define anon_vma_prepare(vma) (0) | |
134 | #define anon_vma_link(vma) do {} while (0) | |
135 | ||
01ff53f4 MF |
136 | static inline int page_referenced(struct page *page, int is_locked, |
137 | struct mem_cgroup *cnt, | |
138 | unsigned long *vm_flags) | |
139 | { | |
140 | *vm_flags = 0; | |
141 | return TestClearPageReferenced(page); | |
142 | } | |
143 | ||
a48d07af | 144 | #define try_to_unmap(page, refs) SWAP_FAIL |
1da177e4 | 145 | |
d08b3851 PZ |
146 | static inline int page_mkclean(struct page *page) |
147 | { | |
148 | return 0; | |
149 | } | |
150 | ||
151 | ||
1da177e4 LT |
152 | #endif /* CONFIG_MMU */ |
153 | ||
154 | /* | |
155 | * Return values of try_to_unmap | |
156 | */ | |
157 | #define SWAP_SUCCESS 0 | |
158 | #define SWAP_AGAIN 1 | |
159 | #define SWAP_FAIL 2 | |
b291f000 | 160 | #define SWAP_MLOCK 3 |
1da177e4 LT |
161 | |
162 | #endif /* _LINUX_RMAP_H */ |