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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _MM_SWAP_H
3#define _MM_SWAP_H
4
5struct mempolicy;
6
7#ifdef CONFIG_SWAP
8#include <linux/blk_types.h> /* for bio_end_io_t */
9
10/* linux/mm/page_io.c */
11int sio_pool_init(void);
12struct swap_iocb;
13void swap_read_folio(struct folio *folio, bool do_poll,
14 struct swap_iocb **plug);
15void __swap_read_unplug(struct swap_iocb *plug);
16static inline void swap_read_unplug(struct swap_iocb *plug)
17{
18 if (unlikely(plug))
19 __swap_read_unplug(plug);
20}
21void swap_write_unplug(struct swap_iocb *sio);
22int swap_writepage(struct page *page, struct writeback_control *wbc);
23void __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)
29extern 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
34void show_swap_cache_info(void);
35bool add_to_swap(struct folio *folio);
36void *get_shadow_from_swap_cache(swp_entry_t entry);
37int add_to_swap_cache(struct folio *folio, swp_entry_t entry,
38 gfp_t gfp, void **shadowp);
39void __delete_from_swap_cache(struct folio *folio,
40 swp_entry_t entry, void *shadow);
41void delete_from_swap_cache(struct folio *folio);
42void clear_shadow_from_swap_cache(int type, unsigned long begin,
43 unsigned long end);
44void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry);
45struct folio *swap_cache_get_folio(swp_entry_t entry,
46 struct vm_area_struct *vma, unsigned long addr);
47struct folio *filemap_get_incore_folio(struct address_space *mapping,
48 pgoff_t index);
49
50struct 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);
53struct 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);
56struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
57 struct mempolicy *mpol, pgoff_t ilx);
58struct page *swapin_readahead(swp_entry_t entry, gfp_t flag,
59 struct vm_fault *vmf);
60
61static inline unsigned int folio_swap_flags(struct folio *folio)
62{
63 return swp_swap_info(folio->swap)->flags;
64}
65#else /* CONFIG_SWAP */
66struct swap_iocb;
67static inline void swap_read_folio(struct folio *folio, bool do_poll,
68 struct swap_iocb **plug)
69{
70}
71static inline void swap_write_unplug(struct swap_iocb *sio)
72{
73}
74
75static inline struct address_space *swap_address_space(swp_entry_t entry)
76{
77 return NULL;
78}
79
80static inline void show_swap_cache_info(void)
81{
82}
83
84static 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
90static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
91 struct vm_fault *vmf)
92{
93 return NULL;
94}
95
96static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
97{
98 return 0;
99}
100
101static inline void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry)
102{
103}
104
105static 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
111static inline
112struct folio *filemap_get_incore_folio(struct address_space *mapping,
113 pgoff_t index)
114{
115 return filemap_get_folio(mapping, index);
116}
117
118static inline bool add_to_swap(struct folio *folio)
119{
120 return false;
121}
122
123static inline void *get_shadow_from_swap_cache(swp_entry_t entry)
124{
125 return NULL;
126}
127
128static 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
134static inline void __delete_from_swap_cache(struct folio *folio,
135 swp_entry_t entry, void *shadow)
136{
137}
138
139static inline void delete_from_swap_cache(struct folio *folio)
140{
141}
142
143static inline void clear_shadow_from_swap_cache(int type, unsigned long begin,
144 unsigned long end)
145{
146}
147
148static inline unsigned int folio_swap_flags(struct folio *folio)
149{
150 return 0;
151}
152#endif /* CONFIG_SWAP */
153#endif /* _MM_SWAP_H */
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _MM_SWAP_H
3#define _MM_SWAP_H
4
5struct mempolicy;
6
7#ifdef CONFIG_SWAP
8#include <linux/swapops.h> /* for swp_offset */
9#include <linux/blk_types.h> /* for bio_end_io_t */
10
11/* linux/mm/page_io.c */
12int sio_pool_init(void);
13struct swap_iocb;
14void swap_read_folio(struct folio *folio, struct swap_iocb **plug);
15void __swap_read_unplug(struct swap_iocb *plug);
16static inline void swap_read_unplug(struct swap_iocb *plug)
17{
18 if (unlikely(plug))
19 __swap_read_unplug(plug);
20}
21void swap_write_unplug(struct swap_iocb *sio);
22int swap_writepage(struct page *page, struct writeback_control *wbc);
23void __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#define SWAP_ADDRESS_SPACE_MASK (SWAP_ADDRESS_SPACE_PAGES - 1)
30extern struct address_space *swapper_spaces[];
31#define swap_address_space(entry) \
32 (&swapper_spaces[swp_type(entry)][swp_offset(entry) \
33 >> SWAP_ADDRESS_SPACE_SHIFT])
34
35/*
36 * Return the swap device position of the swap entry.
37 */
38static inline loff_t swap_dev_pos(swp_entry_t entry)
39{
40 return ((loff_t)swp_offset(entry)) << PAGE_SHIFT;
41}
42
43/*
44 * Return the swap cache index of the swap entry.
45 */
46static inline pgoff_t swap_cache_index(swp_entry_t entry)
47{
48 BUILD_BUG_ON((SWP_OFFSET_MASK | SWAP_ADDRESS_SPACE_MASK) != SWP_OFFSET_MASK);
49 return swp_offset(entry) & SWAP_ADDRESS_SPACE_MASK;
50}
51
52void show_swap_cache_info(void);
53bool add_to_swap(struct folio *folio);
54void *get_shadow_from_swap_cache(swp_entry_t entry);
55int add_to_swap_cache(struct folio *folio, swp_entry_t entry,
56 gfp_t gfp, void **shadowp);
57void __delete_from_swap_cache(struct folio *folio,
58 swp_entry_t entry, void *shadow);
59void delete_from_swap_cache(struct folio *folio);
60void clear_shadow_from_swap_cache(int type, unsigned long begin,
61 unsigned long end);
62void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry, int nr);
63struct folio *swap_cache_get_folio(swp_entry_t entry,
64 struct vm_area_struct *vma, unsigned long addr);
65struct folio *filemap_get_incore_folio(struct address_space *mapping,
66 pgoff_t index);
67
68struct folio *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
69 struct vm_area_struct *vma, unsigned long addr,
70 struct swap_iocb **plug);
71struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_flags,
72 struct mempolicy *mpol, pgoff_t ilx, bool *new_page_allocated,
73 bool skip_if_exists);
74struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
75 struct mempolicy *mpol, pgoff_t ilx);
76struct folio *swapin_readahead(swp_entry_t entry, gfp_t flag,
77 struct vm_fault *vmf);
78
79static inline unsigned int folio_swap_flags(struct folio *folio)
80{
81 return swp_swap_info(folio->swap)->flags;
82}
83
84/*
85 * Return the count of contiguous swap entries that share the same
86 * zeromap status as the starting entry. If is_zeromap is not NULL,
87 * it will return the zeromap status of the starting entry.
88 */
89static inline int swap_zeromap_batch(swp_entry_t entry, int max_nr,
90 bool *is_zeromap)
91{
92 struct swap_info_struct *sis = swp_swap_info(entry);
93 unsigned long start = swp_offset(entry);
94 unsigned long end = start + max_nr;
95 bool first_bit;
96
97 first_bit = test_bit(start, sis->zeromap);
98 if (is_zeromap)
99 *is_zeromap = first_bit;
100
101 if (max_nr <= 1)
102 return max_nr;
103 if (first_bit)
104 return find_next_zero_bit(sis->zeromap, end, start) - start;
105 else
106 return find_next_bit(sis->zeromap, end, start) - start;
107}
108
109#else /* CONFIG_SWAP */
110struct swap_iocb;
111static inline void swap_read_folio(struct folio *folio, struct swap_iocb **plug)
112{
113}
114static inline void swap_write_unplug(struct swap_iocb *sio)
115{
116}
117
118static inline struct address_space *swap_address_space(swp_entry_t entry)
119{
120 return NULL;
121}
122
123static inline pgoff_t swap_cache_index(swp_entry_t entry)
124{
125 return 0;
126}
127
128static inline void show_swap_cache_info(void)
129{
130}
131
132static inline struct folio *swap_cluster_readahead(swp_entry_t entry,
133 gfp_t gfp_mask, struct mempolicy *mpol, pgoff_t ilx)
134{
135 return NULL;
136}
137
138static inline struct folio *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
139 struct vm_fault *vmf)
140{
141 return NULL;
142}
143
144static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
145{
146 return 0;
147}
148
149static inline void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry, int nr)
150{
151}
152
153static inline struct folio *swap_cache_get_folio(swp_entry_t entry,
154 struct vm_area_struct *vma, unsigned long addr)
155{
156 return NULL;
157}
158
159static inline
160struct folio *filemap_get_incore_folio(struct address_space *mapping,
161 pgoff_t index)
162{
163 return filemap_get_folio(mapping, index);
164}
165
166static inline bool add_to_swap(struct folio *folio)
167{
168 return false;
169}
170
171static inline void *get_shadow_from_swap_cache(swp_entry_t entry)
172{
173 return NULL;
174}
175
176static inline int add_to_swap_cache(struct folio *folio, swp_entry_t entry,
177 gfp_t gfp_mask, void **shadowp)
178{
179 return -1;
180}
181
182static inline void __delete_from_swap_cache(struct folio *folio,
183 swp_entry_t entry, void *shadow)
184{
185}
186
187static inline void delete_from_swap_cache(struct folio *folio)
188{
189}
190
191static inline void clear_shadow_from_swap_cache(int type, unsigned long begin,
192 unsigned long end)
193{
194}
195
196static inline unsigned int folio_swap_flags(struct folio *folio)
197{
198 return 0;
199}
200
201static inline int swap_zeromap_batch(swp_entry_t entry, int max_nr,
202 bool *has_zeromap)
203{
204 return 0;
205}
206
207#endif /* CONFIG_SWAP */
208
209#endif /* _MM_SWAP_H */