Linux kernel mirror (for testing)
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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 */
9int sio_pool_init(void);
10struct swap_iocb;
11void swap_readpage(struct page *page, bool do_poll, struct swap_iocb **plug);
12void __swap_read_unplug(struct swap_iocb *plug);
13static inline void swap_read_unplug(struct swap_iocb *plug)
14{
15 if (unlikely(plug))
16 __swap_read_unplug(plug);
17}
18void swap_write_unplug(struct swap_iocb *sio);
19int swap_writepage(struct page *page, struct writeback_control *wbc);
20void __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)
26extern 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
31void show_swap_cache_info(void);
32bool add_to_swap(struct folio *folio);
33void *get_shadow_from_swap_cache(swp_entry_t entry);
34int add_to_swap_cache(struct folio *folio, swp_entry_t entry,
35 gfp_t gfp, void **shadowp);
36void __delete_from_swap_cache(struct folio *folio,
37 swp_entry_t entry, void *shadow);
38void delete_from_swap_cache(struct folio *folio);
39void clear_shadow_from_swap_cache(int type, unsigned long begin,
40 unsigned long end);
41struct folio *swap_cache_get_folio(swp_entry_t entry,
42 struct vm_area_struct *vma, unsigned long addr);
43struct folio *filemap_get_incore_folio(struct address_space *mapping,
44 pgoff_t index);
45
46struct 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);
51struct 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);
55struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
56 struct vm_fault *vmf);
57struct page *swapin_readahead(swp_entry_t entry, gfp_t flag,
58 struct vm_fault *vmf);
59
60static inline unsigned int folio_swap_flags(struct folio *folio)
61{
62 return page_swap_info(&folio->page)->flags;
63}
64#else /* CONFIG_SWAP */
65struct swap_iocb;
66static inline void swap_readpage(struct page *page, bool do_poll,
67 struct swap_iocb **plug)
68{
69}
70static inline void swap_write_unplug(struct swap_iocb *sio)
71{
72}
73
74static inline struct address_space *swap_address_space(swp_entry_t entry)
75{
76 return NULL;
77}
78
79static inline void show_swap_cache_info(void)
80{
81}
82
83static 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
89static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
90 struct vm_fault *vmf)
91{
92 return NULL;
93}
94
95static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
96{
97 return 0;
98}
99
100static 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
106static inline
107struct folio *filemap_get_incore_folio(struct address_space *mapping,
108 pgoff_t index)
109{
110 return filemap_get_folio(mapping, index);
111}
112
113static inline bool add_to_swap(struct folio *folio)
114{
115 return false;
116}
117
118static inline void *get_shadow_from_swap_cache(swp_entry_t entry)
119{
120 return NULL;
121}
122
123static 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
129static inline void __delete_from_swap_cache(struct folio *folio,
130 swp_entry_t entry, void *shadow)
131{
132}
133
134static inline void delete_from_swap_cache(struct folio *folio)
135{
136}
137
138static inline void clear_shadow_from_swap_cache(int type, unsigned long begin,
139 unsigned long end)
140{
141}
142
143static inline unsigned int folio_swap_flags(struct folio *folio)
144{
145 return 0;
146}
147#endif /* CONFIG_SWAP */
148#endif /* _MM_SWAP_H */