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
8 struct frontswap_ops {
9 void (*init)(unsigned);
10 int (*store)(unsigned, pgoff_t, struct page *);
11 int (*load)(unsigned, pgoff_t, struct page *);
12 void (*invalidate_page)(unsigned, pgoff_t);
13 void (*invalidate_area)(unsigned);
14 };
15
16 extern bool frontswap_enabled;
17 extern struct frontswap_ops *
18 frontswap_register_ops(struct frontswap_ops *ops);
19 extern void frontswap_shrink(unsigned long);
20 extern unsigned long frontswap_curr_pages(void);
21 extern void frontswap_writethrough(bool);
22 #define FRONTSWAP_HAS_EXCLUSIVE_GETS
23 extern void frontswap_tmem_exclusive_gets(bool);
24
25 extern bool __frontswap_test(struct swap_info_struct *, pgoff_t);
26 extern void __frontswap_init(unsigned type, unsigned long *map);
27 extern int __frontswap_store(struct page *page);
28 extern int __frontswap_load(struct page *page);
29 extern void __frontswap_invalidate_page(unsigned, pgoff_t);
30 extern void __frontswap_invalidate_area(unsigned);
31
32 #ifdef CONFIG_FRONTSWAP
33 #define frontswap_enabled (1)
34
frontswap_test(struct swap_info_struct * sis,pgoff_t offset)35 static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
36 {
37 return __frontswap_test(sis, offset);
38 }
39
frontswap_map_set(struct swap_info_struct * p,unsigned long * map)40 static inline void frontswap_map_set(struct swap_info_struct *p,
41 unsigned long *map)
42 {
43 p->frontswap_map = map;
44 }
45
frontswap_map_get(struct swap_info_struct * p)46 static inline unsigned long *frontswap_map_get(struct swap_info_struct *p)
47 {
48 return p->frontswap_map;
49 }
50 #else
51 /* all inline routines become no-ops and all externs are ignored */
52
53 #define frontswap_enabled (0)
54
frontswap_test(struct swap_info_struct * sis,pgoff_t offset)55 static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
56 {
57 return false;
58 }
59
frontswap_map_set(struct swap_info_struct * p,unsigned long * map)60 static inline void frontswap_map_set(struct swap_info_struct *p,
61 unsigned long *map)
62 {
63 }
64
frontswap_map_get(struct swap_info_struct * p)65 static inline unsigned long *frontswap_map_get(struct swap_info_struct *p)
66 {
67 return NULL;
68 }
69 #endif
70
frontswap_store(struct page * page)71 static inline int frontswap_store(struct page *page)
72 {
73 int ret = -1;
74
75 if (frontswap_enabled)
76 ret = __frontswap_store(page);
77 return ret;
78 }
79
frontswap_load(struct page * page)80 static inline int frontswap_load(struct page *page)
81 {
82 int ret = -1;
83
84 if (frontswap_enabled)
85 ret = __frontswap_load(page);
86 return ret;
87 }
88
frontswap_invalidate_page(unsigned type,pgoff_t offset)89 static inline void frontswap_invalidate_page(unsigned type, pgoff_t offset)
90 {
91 if (frontswap_enabled)
92 __frontswap_invalidate_page(type, offset);
93 }
94
frontswap_invalidate_area(unsigned type)95 static inline void frontswap_invalidate_area(unsigned type)
96 {
97 if (frontswap_enabled)
98 __frontswap_invalidate_area(type);
99 }
100
frontswap_init(unsigned type,unsigned long * map)101 static inline void frontswap_init(unsigned type, unsigned long *map)
102 {
103 if (frontswap_enabled)
104 __frontswap_init(type, map);
105 }
106
107 #endif /* _LINUX_FRONTSWAP_H */
108