Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_FRONTSWAP_H
3#define _LINUX_FRONTSWAP_H
4
5#include <linux/swap.h>
6#include <linux/mm.h>
7#include <linux/bitops.h>
8#include <linux/jump_label.h>
9
10struct frontswap_ops {
11 void (*init)(unsigned); /* this swap type was just swapon'ed */
12 int (*store)(unsigned, pgoff_t, struct page *); /* store a page */
13 int (*load)(unsigned, pgoff_t, struct page *); /* load a page */
14 void (*invalidate_page)(unsigned, pgoff_t); /* page no longer needed */
15 void (*invalidate_area)(unsigned); /* swap type just swapoff'ed */
16 struct frontswap_ops *next; /* private pointer to next ops */
17};
18
19extern void frontswap_register_ops(struct frontswap_ops *ops);
20extern void frontswap_shrink(unsigned long);
21extern unsigned long frontswap_curr_pages(void);
22extern void frontswap_writethrough(bool);
23#define FRONTSWAP_HAS_EXCLUSIVE_GETS
24extern void frontswap_tmem_exclusive_gets(bool);
25
26extern bool __frontswap_test(struct swap_info_struct *, pgoff_t);
27extern void __frontswap_init(unsigned type, unsigned long *map);
28extern int __frontswap_store(struct page *page);
29extern int __frontswap_load(struct page *page);
30extern void __frontswap_invalidate_page(unsigned, pgoff_t);
31extern void __frontswap_invalidate_area(unsigned);
32
33#ifdef CONFIG_FRONTSWAP
34extern struct static_key_false frontswap_enabled_key;
35
36static inline bool frontswap_enabled(void)
37{
38 return static_branch_unlikely(&frontswap_enabled_key);
39}
40
41static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
42{
43 return __frontswap_test(sis, offset);
44}
45
46static inline void frontswap_map_set(struct swap_info_struct *p,
47 unsigned long *map)
48{
49 p->frontswap_map = map;
50}
51
52static inline unsigned long *frontswap_map_get(struct swap_info_struct *p)
53{
54 return p->frontswap_map;
55}
56#else
57/* all inline routines become no-ops and all externs are ignored */
58
59static inline bool frontswap_enabled(void)
60{
61 return false;
62}
63
64static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
65{
66 return false;
67}
68
69static inline void frontswap_map_set(struct swap_info_struct *p,
70 unsigned long *map)
71{
72}
73
74static inline unsigned long *frontswap_map_get(struct swap_info_struct *p)
75{
76 return NULL;
77}
78#endif
79
80static inline int frontswap_store(struct page *page)
81{
82 if (frontswap_enabled())
83 return __frontswap_store(page);
84
85 return -1;
86}
87
88static inline int frontswap_load(struct page *page)
89{
90 if (frontswap_enabled())
91 return __frontswap_load(page);
92
93 return -1;
94}
95
96static inline void frontswap_invalidate_page(unsigned type, pgoff_t offset)
97{
98 if (frontswap_enabled())
99 __frontswap_invalidate_page(type, offset);
100}
101
102static inline void frontswap_invalidate_area(unsigned type)
103{
104 if (frontswap_enabled())
105 __frontswap_invalidate_area(type);
106}
107
108static inline void frontswap_init(unsigned type, unsigned long *map)
109{
110#ifdef CONFIG_FRONTSWAP
111 __frontswap_init(type, map);
112#endif
113}
114
115#endif /* _LINUX_FRONTSWAP_H */