summaryrefslogtreecommitdiff
path: root/mm/swap.h
blob: fc2f6ade7f80b399707bcc67c44f813aea0b846d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _MM_SWAP_H
#define _MM_SWAP_H

struct mempolicy;

#ifdef CONFIG_SWAP
#include <linux/blk_types.h> /* for bio_end_io_t */

/* linux/mm/page_io.c */
int sio_pool_init(void);
struct swap_iocb;
void swap_read_folio(struct folio *folio, bool do_poll,
		struct swap_iocb **plug);
void __swap_read_unplug(struct swap_iocb *plug);
static inline void swap_read_unplug(struct swap_iocb *plug)
{
	if (unlikely(plug))
		__swap_read_unplug(plug);
}
void swap_write_unplug(struct swap_iocb *sio);
int swap_writepage(struct page *page, struct writeback_control *wbc);
void __swap_writepage(struct folio *folio, struct writeback_control *wbc);

/* linux/mm/swap_state.c */
/* One swap address space for each 64M swap space */
#define SWAP_ADDRESS_SPACE_SHIFT	14
#define SWAP_ADDRESS_SPACE_PAGES	(1 << SWAP_ADDRESS_SPACE_SHIFT)
extern struct address_space *swapper_spaces[];
#define swap_address_space(entry)			    \
	(&swapper_spaces[swp_type(entry)][swp_offset(entry) \
		>> SWAP_ADDRESS_SPACE_SHIFT])

void show_swap_cache_info(void);
bool add_to_swap(struct folio *folio);
void *get_shadow_from_swap_cache(swp_entry_t entry);
int add_to_swap_cache(struct folio *folio, swp_entry_t entry,
		      gfp_t gfp, void **shadowp);
void __delete_from_swap_cache(struct folio *folio,
			      swp_entry_t entry, void *shadow);
void delete_from_swap_cache(struct folio *folio);
void clear_shadow_from_swap_cache(int type, unsigned long begin,
				  unsigned long end);
void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry);
struct folio *swap_cache_get_folio(swp_entry_t entry,
		struct vm_area_struct *vma, unsigned long addr);
struct folio *filemap_get_incore_folio(struct address_space *mapping,
		pgoff_t index);

struct folio *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
		struct vm_area_struct *vma, unsigned long addr,
		struct swap_iocb **plug);
struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_flags,
		struct mempolicy *mpol, pgoff_t ilx, bool *new_page_allocated,
		bool skip_if_exists);
struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
		struct mempolicy *mpol, pgoff_t ilx);
struct page *swapin_readahead(swp_entry_t entry, gfp_t flag,
			      struct vm_fault *vmf);

static inline unsigned int folio_swap_flags(struct folio *folio)
{
	return swp_swap_info(folio->swap)->flags;
}
#else /* CONFIG_SWAP */
struct swap_iocb;
static inline void swap_read_folio(struct folio *folio, bool do_poll,
		struct swap_iocb **plug)
{
}
static inline void swap_write_unplug(struct swap_iocb *sio)
{
}

static inline struct address_space *swap_address_space(swp_entry_t entry)
{
	return NULL;
}

static inline void show_swap_cache_info(void)
{
}

static inline struct folio *swap_cluster_readahead(swp_entry_t entry,
			gfp_t gfp_mask, struct mempolicy *mpol, pgoff_t ilx)
{
	return NULL;
}

static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
			struct vm_fault *vmf)
{
	return NULL;
}

static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
{
	return 0;
}

static inline void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry)
{
}

static inline struct folio *swap_cache_get_folio(swp_entry_t entry,
		struct vm_area_struct *vma, unsigned long addr)
{
	return NULL;
}

static inline
struct folio *filemap_get_incore_folio(struct address_space *mapping,
		pgoff_t index)
{
	return filemap_get_folio(mapping, index);
}

static inline bool add_to_swap(struct folio *folio)
{
	return false;
}

static inline void *get_shadow_from_swap_cache(swp_entry_t entry)
{
	return NULL;
}

static inline int add_to_swap_cache(struct folio *folio, swp_entry_t entry,
					gfp_t gfp_mask, void **shadowp)
{
	return -1;
}

static inline void __delete_from_swap_cache(struct folio *folio,
					swp_entry_t entry, void *shadow)
{
}

static inline void delete_from_swap_cache(struct folio *folio)
{
}

static inline void clear_shadow_from_swap_cache(int type, unsigned long begin,
				unsigned long end)
{
}

static inline unsigned int folio_swap_flags(struct folio *folio)
{
	return 0;
}
#endif /* CONFIG_SWAP */
#endif /* _MM_SWAP_H */