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