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 bool do_poll,
50 struct swap_iocb **plug);
51 struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
52 struct vm_area_struct *vma,
53 unsigned long addr,
54 bool *new_page_allocated);
55 struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
56 struct vm_fault *vmf);
57 struct page *swapin_readahead(swp_entry_t entry, gfp_t flag,
58 struct vm_fault *vmf);
59
folio_swap_flags(struct folio * folio)60 static inline unsigned int folio_swap_flags(struct folio *folio)
61 {
62 return page_swap_info(&folio->page)->flags;
63 }
64 #else /* CONFIG_SWAP */
65 struct swap_iocb;
swap_readpage(struct page * page,bool do_poll,struct swap_iocb ** plug)66 static inline void swap_readpage(struct page *page, bool do_poll,
67 struct swap_iocb **plug)
68 {
69 }
swap_write_unplug(struct swap_iocb * sio)70 static inline void swap_write_unplug(struct swap_iocb *sio)
71 {
72 }
73
swap_address_space(swp_entry_t entry)74 static inline struct address_space *swap_address_space(swp_entry_t entry)
75 {
76 return NULL;
77 }
78
show_swap_cache_info(void)79 static inline void show_swap_cache_info(void)
80 {
81 }
82
swap_cluster_readahead(swp_entry_t entry,gfp_t gfp_mask,struct vm_fault * vmf)83 static inline struct page *swap_cluster_readahead(swp_entry_t entry,
84 gfp_t gfp_mask, struct vm_fault *vmf)
85 {
86 return NULL;
87 }
88
swapin_readahead(swp_entry_t swp,gfp_t gfp_mask,struct vm_fault * vmf)89 static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
90 struct vm_fault *vmf)
91 {
92 return NULL;
93 }
94
swap_writepage(struct page * p,struct writeback_control * wbc)95 static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
96 {
97 return 0;
98 }
99
swap_cache_get_folio(swp_entry_t entry,struct vm_area_struct * vma,unsigned long addr)100 static inline struct folio *swap_cache_get_folio(swp_entry_t entry,
101 struct vm_area_struct *vma, unsigned long addr)
102 {
103 return NULL;
104 }
105
106 static inline
filemap_get_incore_folio(struct address_space * mapping,pgoff_t index)107 struct folio *filemap_get_incore_folio(struct address_space *mapping,
108 pgoff_t index)
109 {
110 return filemap_get_folio(mapping, index);
111 }
112
add_to_swap(struct folio * folio)113 static inline bool add_to_swap(struct folio *folio)
114 {
115 return false;
116 }
117
get_shadow_from_swap_cache(swp_entry_t entry)118 static inline void *get_shadow_from_swap_cache(swp_entry_t entry)
119 {
120 return NULL;
121 }
122
add_to_swap_cache(struct folio * folio,swp_entry_t entry,gfp_t gfp_mask,void ** shadowp)123 static inline int add_to_swap_cache(struct folio *folio, swp_entry_t entry,
124 gfp_t gfp_mask, void **shadowp)
125 {
126 return -1;
127 }
128
__delete_from_swap_cache(struct folio * folio,swp_entry_t entry,void * shadow)129 static inline void __delete_from_swap_cache(struct folio *folio,
130 swp_entry_t entry, void *shadow)
131 {
132 }
133
delete_from_swap_cache(struct folio * folio)134 static inline void delete_from_swap_cache(struct folio *folio)
135 {
136 }
137
clear_shadow_from_swap_cache(int type,unsigned long begin,unsigned long end)138 static inline void clear_shadow_from_swap_cache(int type, unsigned long begin,
139 unsigned long end)
140 {
141 }
142
folio_swap_flags(struct folio * folio)143 static inline unsigned int folio_swap_flags(struct folio *folio)
144 {
145 return 0;
146 }
147 #endif /* CONFIG_SWAP */
148 #endif /* _MM_SWAP_H */
149