1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _MM_SWAP_H
3 #define _MM_SWAP_H
4
5 #ifdef CONFIG_SWAP
6 #include <linux/blk_types.h> /* for bio_end_io_t */
7
8 /* linux/mm/page_io.c */
9 int sio_pool_init(void);
10 struct swap_iocb;
11 int swap_readpage(struct page *page, bool do_poll,
12 struct swap_iocb **plug);
13 void __swap_read_unplug(struct swap_iocb *plug);
swap_read_unplug(struct swap_iocb * plug)14 static inline void swap_read_unplug(struct swap_iocb *plug)
15 {
16 if (unlikely(plug))
17 __swap_read_unplug(plug);
18 }
19 void swap_write_unplug(struct swap_iocb *sio);
20 int swap_writepage(struct page *page, struct writeback_control *wbc);
21 void end_swap_bio_write(struct bio *bio);
22 int __swap_writepage(struct page *page, struct writeback_control *wbc,
23 bio_end_io_t end_write_func);
24
25 /* linux/mm/swap_state.c */
26 /* One swap address space for each 64M swap space */
27 #define SWAP_ADDRESS_SPACE_SHIFT 14
28 #define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT)
29 extern struct address_space *swapper_spaces[];
30 #define swap_address_space(entry) \
31 (&swapper_spaces[swp_type(entry)][swp_offset(entry) \
32 >> SWAP_ADDRESS_SPACE_SHIFT])
33
34 void show_swap_cache_info(void);
35 bool add_to_swap(struct folio *folio);
36 void *get_shadow_from_swap_cache(swp_entry_t entry);
37 int add_to_swap_cache(struct page *page, swp_entry_t entry,
38 gfp_t gfp, void **shadowp);
39 void __delete_from_swap_cache(struct page *page,
40 swp_entry_t entry, void *shadow);
41 void delete_from_swap_cache(struct page *page);
42 void clear_shadow_from_swap_cache(int type, unsigned long begin,
43 unsigned long end);
44 void free_swap_cache(struct page *page);
45 struct page *lookup_swap_cache(swp_entry_t entry,
46 struct vm_area_struct *vma,
47 unsigned long addr);
48 struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index);
49
50 struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
51 struct vm_area_struct *vma,
52 unsigned long addr,
53 bool do_poll,
54 struct swap_iocb **plug);
55 struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
56 struct vm_area_struct *vma,
57 unsigned long addr,
58 bool *new_page_allocated);
59 struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
60 struct vm_fault *vmf);
61 struct page *swapin_readahead(swp_entry_t entry, gfp_t flag,
62 struct vm_fault *vmf);
63
page_swap_flags(struct page * page)64 static inline unsigned int page_swap_flags(struct page *page)
65 {
66 return page_swap_info(page)->flags;
67 }
68 #else /* CONFIG_SWAP */
69 struct swap_iocb;
swap_readpage(struct page * page,bool do_poll,struct swap_iocb ** plug)70 static inline int swap_readpage(struct page *page, bool do_poll,
71 struct swap_iocb **plug)
72 {
73 return 0;
74 }
swap_write_unplug(struct swap_iocb * sio)75 static inline void swap_write_unplug(struct swap_iocb *sio)
76 {
77 }
78
swap_address_space(swp_entry_t entry)79 static inline struct address_space *swap_address_space(swp_entry_t entry)
80 {
81 return NULL;
82 }
83
free_swap_cache(struct page * page)84 static inline void free_swap_cache(struct page *page)
85 {
86 }
87
show_swap_cache_info(void)88 static inline void show_swap_cache_info(void)
89 {
90 }
91
swap_cluster_readahead(swp_entry_t entry,gfp_t gfp_mask,struct vm_fault * vmf)92 static inline struct page *swap_cluster_readahead(swp_entry_t entry,
93 gfp_t gfp_mask, struct vm_fault *vmf)
94 {
95 return NULL;
96 }
97
swapin_readahead(swp_entry_t swp,gfp_t gfp_mask,struct vm_fault * vmf)98 static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
99 struct vm_fault *vmf)
100 {
101 return NULL;
102 }
103
swap_writepage(struct page * p,struct writeback_control * wbc)104 static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
105 {
106 return 0;
107 }
108
lookup_swap_cache(swp_entry_t swp,struct vm_area_struct * vma,unsigned long addr)109 static inline struct page *lookup_swap_cache(swp_entry_t swp,
110 struct vm_area_struct *vma,
111 unsigned long addr)
112 {
113 return NULL;
114 }
115
116 static inline
find_get_incore_page(struct address_space * mapping,pgoff_t index)117 struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
118 {
119 return find_get_page(mapping, index);
120 }
121
add_to_swap(struct folio * folio)122 static inline bool add_to_swap(struct folio *folio)
123 {
124 return false;
125 }
126
get_shadow_from_swap_cache(swp_entry_t entry)127 static inline void *get_shadow_from_swap_cache(swp_entry_t entry)
128 {
129 return NULL;
130 }
131
add_to_swap_cache(struct page * page,swp_entry_t entry,gfp_t gfp_mask,void ** shadowp)132 static inline int add_to_swap_cache(struct page *page, swp_entry_t entry,
133 gfp_t gfp_mask, void **shadowp)
134 {
135 return -1;
136 }
137
__delete_from_swap_cache(struct page * page,swp_entry_t entry,void * shadow)138 static inline void __delete_from_swap_cache(struct page *page,
139 swp_entry_t entry, void *shadow)
140 {
141 }
142
delete_from_swap_cache(struct page * page)143 static inline void delete_from_swap_cache(struct page *page)
144 {
145 }
146
clear_shadow_from_swap_cache(int type,unsigned long begin,unsigned long end)147 static inline void clear_shadow_from_swap_cache(int type, unsigned long begin,
148 unsigned long end)
149 {
150 }
151
page_swap_flags(struct page * page)152 static inline unsigned int page_swap_flags(struct page *page)
153 {
154 return 0;
155 }
156 #endif /* CONFIG_SWAP */
157 #endif /* _MM_SWAP_H */
158