Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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#include <linux/jump_label.h>
8
9struct frontswap_ops {
10 void (*init)(unsigned); /* this swap type was just swapon'ed */
11 int (*store)(unsigned, pgoff_t, struct page *); /* store a page */
12 int (*load)(unsigned, pgoff_t, struct page *); /* load a page */
13 void (*invalidate_page)(unsigned, pgoff_t); /* page no longer needed */
14 void (*invalidate_area)(unsigned); /* swap type just swapoff'ed */
15 struct frontswap_ops *next; /* private pointer to next ops */
16};
17
18extern void 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#define FRONTSWAP_HAS_EXCLUSIVE_GETS
23extern void frontswap_tmem_exclusive_gets(bool);
24
25extern bool __frontswap_test(struct swap_info_struct *, pgoff_t);
26extern void __frontswap_init(unsigned type, unsigned long *map);
27extern int __frontswap_store(struct page *page);
28extern int __frontswap_load(struct page *page);
29extern void __frontswap_invalidate_page(unsigned, pgoff_t);
30extern void __frontswap_invalidate_area(unsigned);
31
32#ifdef CONFIG_FRONTSWAP
33extern struct static_key_false frontswap_enabled_key;
34
35static inline bool frontswap_enabled(void)
36{
37 return static_branch_unlikely(&frontswap_enabled_key);
38}
39
40static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
41{
42 return __frontswap_test(sis, offset);
43}
44
45static inline void frontswap_map_set(struct swap_info_struct *p,
46 unsigned long *map)
47{
48 p->frontswap_map = map;
49}
50
51static inline unsigned long *frontswap_map_get(struct swap_info_struct *p)
52{
53 return p->frontswap_map;
54}
55#else
56/* all inline routines become no-ops and all externs are ignored */
57
58static inline bool frontswap_enabled(void)
59{
60 return false;
61}
62
63static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
64{
65 return false;
66}
67
68static inline void frontswap_map_set(struct swap_info_struct *p,
69 unsigned long *map)
70{
71}
72
73static inline unsigned long *frontswap_map_get(struct swap_info_struct *p)
74{
75 return NULL;
76}
77#endif
78
79static inline int frontswap_store(struct page *page)
80{
81 if (frontswap_enabled())
82 return __frontswap_store(page);
83
84 return -1;
85}
86
87static inline int frontswap_load(struct page *page)
88{
89 if (frontswap_enabled())
90 return __frontswap_load(page);
91
92 return -1;
93}
94
95static inline void frontswap_invalidate_page(unsigned type, pgoff_t offset)
96{
97 if (frontswap_enabled())
98 __frontswap_invalidate_page(type, offset);
99}
100
101static inline void frontswap_invalidate_area(unsigned type)
102{
103 if (frontswap_enabled())
104 __frontswap_invalidate_area(type);
105}
106
107static inline void frontswap_init(unsigned type, unsigned long *map)
108{
109#ifdef CONFIG_FRONTSWAP
110 __frontswap_init(type, map);
111#endif
112}
113
114#endif /* _LINUX_FRONTSWAP_H */