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gerrit-public.fairphone.software / kernel / msm-4.9 / c3ba9698152b17fdc2c7cd0f7cbeb571e3367e9d / . / include / linux / frontswap.h
blob: 68ff7af5c5fb64fdf2cf3777b670f50803b7cffc [file] [log] [blame]
Dan Magenheimerc3ba9692012-04-09 17:06:54 -0600[diff] [blame^]1#ifndef _LINUX_FRONTSWAP_H
2#define _LINUX_FRONTSWAP_H
3
4#include <linux/swap.h>
5#include <linux/mm.h>
6#include <linux/bitops.h>
7
8struct frontswap_ops {
9 void (*init)(unsigned);
10 int (*put_page)(unsigned, pgoff_t, struct page *);
11 int (*get_page)(unsigned, pgoff_t, struct page *);
12 void (*invalidate_page)(unsigned, pgoff_t);
13 void (*invalidate_area)(unsigned);
14};
15
16extern bool frontswap_enabled;
17extern struct frontswap_ops
18 frontswap_register_ops(struct frontswap_ops *ops);
19extern void frontswap_shrink(unsigned long);
20extern unsigned long frontswap_curr_pages(void);
21extern void frontswap_writethrough(bool);
22
23extern void __frontswap_init(unsigned type);
24extern int __frontswap_put_page(struct page *page);
25extern int __frontswap_get_page(struct page *page);
26extern void __frontswap_invalidate_page(unsigned, pgoff_t);
27extern void __frontswap_invalidate_area(unsigned);
28
29#ifdef CONFIG_FRONTSWAP
30
31static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
32{
33 bool ret = false;
34
35 if (frontswap_enabled && sis->frontswap_map)
36 ret = test_bit(offset, sis->frontswap_map);
37 return ret;
38}
39
40static inline void frontswap_set(struct swap_info_struct *sis, pgoff_t offset)
41{
42 if (frontswap_enabled && sis->frontswap_map)
43 set_bit(offset, sis->frontswap_map);
44}
45
46static inline void frontswap_clear(struct swap_info_struct *sis, pgoff_t offset)
47{
48 if (frontswap_enabled && sis->frontswap_map)
49 clear_bit(offset, sis->frontswap_map);
50}
51
52static inline void frontswap_map_set(struct swap_info_struct *p,
53 unsigned long *map)
54{
55 p->frontswap_map = map;
56}
57
58static inline unsigned long *frontswap_map_get(struct swap_info_struct *p)
59{
60 return p->frontswap_map;
61}
62#else
63/* all inline routines become no-ops and all externs are ignored */
64
65#define frontswap_enabled (0)
66
67static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
68{
69 return false;
70}
71
72static inline void frontswap_set(struct swap_info_struct *sis, pgoff_t offset)
73{
74}
75
76static inline void frontswap_clear(struct swap_info_struct *sis, pgoff_t offset)
77{
78}
79
80static inline void frontswap_map_set(struct swap_info_struct *p,
81 unsigned long *map)
82{
83}
84
85static inline unsigned long *frontswap_map_get(struct swap_info_struct *p)
86{
87 return NULL;
88}
89#endif
90
91static inline int frontswap_put_page(struct page *page)
92{
93 int ret = -1;
94
95 if (frontswap_enabled)
96 ret = __frontswap_put_page(page);
97 return ret;
98}
99
100static inline int frontswap_get_page(struct page *page)
101{
102 int ret = -1;
103
104 if (frontswap_enabled)
105 ret = __frontswap_get_page(page);
106 return ret;
107}
108
109static inline void frontswap_invalidate_page(unsigned type, pgoff_t offset)
110{
111 if (frontswap_enabled)
112 __frontswap_invalidate_page(type, offset);
113}
114
115static inline void frontswap_invalidate_area(unsigned type)
116{
117 if (frontswap_enabled)
118 __frontswap_invalidate_area(type);
119}
120
121static inline void frontswap_init(unsigned type)
122{
123 if (frontswap_enabled)
124 __frontswap_init(type);
125}
126
127#endif /* _LINUX_FRONTSWAP_H */