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