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[thirdparty/linux.git] / include / linux / swap.h
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b2441318 1/* SPDX-License-Identifier: GPL-2.0 */
1da177e4
LT
2#ifndef _LINUX_SWAP_H
3#define _LINUX_SWAP_H
4
1da177e4
LT
5#include <linux/spinlock.h>
6#include <linux/linkage.h>
7#include <linux/mmzone.h>
8#include <linux/list.h>
66e1707b 9#include <linux/memcontrol.h>
1da177e4 10#include <linux/sched.h>
af936a16 11#include <linux/node.h>
33806f06 12#include <linux/fs.h>
4ee60ec1 13#include <linux/pagemap.h>
60063497 14#include <linux/atomic.h>
c53954a0 15#include <linux/page-flags.h>
202e35db 16#include <uapi/linux/mempolicy.h>
1da177e4
LT
17#include <asm/page.h>
18
8bc719d3
MS
19struct notifier_block;
20
ab954160
AM
21struct bio;
22
64e3d12f
KHY
23struct pagevec;
24
1da177e4
LT
25#define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */
26#define SWAP_FLAG_PRIO_MASK 0x7fff
dcf6b7dd
RA
27#define SWAP_FLAG_DISCARD 0x10000 /* enable discard for swap */
28#define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */
29#define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */
1da177e4 30
d15cab97 31#define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \
dcf6b7dd
RA
32 SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \
33 SWAP_FLAG_DISCARD_PAGES)
36005bae 34#define SWAP_BATCH 64
d15cab97 35
1da177e4
LT
36static inline int current_is_kswapd(void)
37{
38 return current->flags & PF_KSWAPD;
39}
40
41/*
42 * MAX_SWAPFILES defines the maximum number of swaptypes: things which can
43 * be swapped to. The swap type and the offset into that swap type are
44 * encoded into pte's and into pgoff_t's in the swapcache. Using five bits
45 * for the type means that the maximum number of swapcache pages is 27 bits
46 * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs
47 * the type/offset into the pte as 5/27 as well.
48 */
49#define MAX_SWAPFILES_SHIFT 5
a7420aa5
AK
50
51/*
52 * Use some of the swap files numbers for other purposes. This
53 * is a convenient way to hook into the VM to trigger special
54 * actions on faults.
55 */
56
679d1033 57/*
ca92ea3d
PX
58 * PTE markers are used to persist information onto PTEs that otherwise
59 * should be a none pte. As its name "PTE" hints, it should only be
60 * applied to the leaves of pgtables.
679d1033 61 */
679d1033
PX
62#define SWP_PTE_MARKER_NUM 1
63#define SWP_PTE_MARKER (MAX_SWAPFILES + SWP_HWPOISON_NUM + \
64 SWP_MIGRATION_NUM + SWP_DEVICE_NUM)
679d1033 65
5042db43
JG
66/*
67 * Unaddressable device memory support. See include/linux/hmm.h and
ee65728e 68 * Documentation/mm/hmm.rst. Short description is we need struct pages for
5042db43
JG
69 * device memory that is unaddressable (inaccessible) by CPU, so that we can
70 * migrate part of a process memory to device memory.
71 *
72 * When a page is migrated from CPU to device, we set the CPU page table entry
b756a3b5
AP
73 * to a special SWP_DEVICE_{READ|WRITE} entry.
74 *
75 * When a page is mapped by the device for exclusive access we set the CPU page
c25465eb 76 * table entries to a special SWP_DEVICE_EXCLUSIVE entry.
5042db43
JG
77 */
78#ifdef CONFIG_DEVICE_PRIVATE
c25465eb 79#define SWP_DEVICE_NUM 3
5042db43
JG
80#define SWP_DEVICE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM)
81#define SWP_DEVICE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+1)
c25465eb 82#define SWP_DEVICE_EXCLUSIVE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+2)
5042db43
JG
83#else
84#define SWP_DEVICE_NUM 0
85#endif
86
a7420aa5 87/*
6c287605
DH
88 * Page migration support.
89 *
90 * SWP_MIGRATION_READ_EXCLUSIVE is only applicable to anonymous pages and
91 * indicates that the referenced (part of) an anonymous page is exclusive to
92 * a single process. For SWP_MIGRATION_WRITE, that information is implicit:
93 * (part of) an anonymous page that are mapped writable are exclusive to a
94 * single process.
a7420aa5
AK
95 */
96#ifdef CONFIG_MIGRATION
6c287605
DH
97#define SWP_MIGRATION_NUM 3
98#define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM)
99#define SWP_MIGRATION_READ_EXCLUSIVE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1)
100#define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 2)
0697212a 101#else
a7420aa5 102#define SWP_MIGRATION_NUM 0
0697212a 103#endif
1da177e4 104
a7420aa5
AK
105/*
106 * Handling of hardware poisoned pages with memory corruption.
107 */
108#ifdef CONFIG_MEMORY_FAILURE
109#define SWP_HWPOISON_NUM 1
110#define SWP_HWPOISON MAX_SWAPFILES
111#else
112#define SWP_HWPOISON_NUM 0
113#endif
114
115#define MAX_SWAPFILES \
5042db43 116 ((1 << MAX_SWAPFILES_SHIFT) - SWP_DEVICE_NUM - \
9f186f9e 117 SWP_MIGRATION_NUM - SWP_HWPOISON_NUM - \
15520a3f 118 SWP_PTE_MARKER_NUM)
a7420aa5 119
1da177e4
LT
120/*
121 * Magic header for a swap area. The first part of the union is
122 * what the swap magic looks like for the old (limited to 128MB)
123 * swap area format, the second part of the union adds - in the
124 * old reserved area - some extra information. Note that the first
125 * kilobyte is reserved for boot loader or disk label stuff...
126 *
127 * Having the magic at the end of the PAGE_SIZE makes detecting swap
128 * areas somewhat tricky on machines that support multiple page sizes.
129 * For 2.5 we'll probably want to move the magic to just beyond the
130 * bootbits...
131 */
132union swap_header {
133 struct {
134 char reserved[PAGE_SIZE - 10];
135 char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */
136 } magic;
137 struct {
e8f03d02
AD
138 char bootbits[1024]; /* Space for disklabel etc. */
139 __u32 version;
140 __u32 last_page;
141 __u32 nr_badpages;
142 unsigned char sws_uuid[16];
143 unsigned char sws_volume[16];
144 __u32 padding[117];
145 __u32 badpages[1];
1da177e4
LT
146 } info;
147};
148
1da177e4
LT
149/*
150 * current->reclaim_state points to one of these when a task is running
151 * memory reclaim
152 */
153struct reclaim_state {
c7b23b68
YA
154 /* pages reclaimed outside of LRU-based reclaim */
155 unsigned long reclaimed;
bd74fdae
YZ
156#ifdef CONFIG_LRU_GEN
157 /* per-thread mm walk data */
158 struct lru_gen_mm_walk *mm_walk;
159#endif
1da177e4
LT
160};
161
c7b23b68
YA
162/*
163 * mm_account_reclaimed_pages(): account reclaimed pages outside of LRU-based
164 * reclaim
165 * @pages: number of pages reclaimed
166 *
167 * If the current process is undergoing a reclaim operation, increment the
168 * number of reclaimed pages by @pages.
169 */
170static inline void mm_account_reclaimed_pages(unsigned long pages)
171{
172 if (current->reclaim_state)
173 current->reclaim_state->reclaimed += pages;
174}
175
1da177e4
LT
176#ifdef __KERNEL__
177
178struct address_space;
179struct sysinfo;
180struct writeback_control;
181struct zone;
182
183/*
184 * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of
ff351f4b
ML
185 * disk blocks. A rbtree of swap extents maps the entire swapfile (Where the
186 * term `swapfile' refers to either a blockdevice or an IS_REG file). Apart
1da177e4
LT
187 * from setup, they're handled identically.
188 *
189 * We always assume that blocks are of size PAGE_SIZE.
190 */
191struct swap_extent {
4efaceb1 192 struct rb_node rb_node;
1da177e4
LT
193 pgoff_t start_page;
194 pgoff_t nr_pages;
195 sector_t start_block;
196};
197
198/*
199 * Max bad pages in the new format..
200 */
1da177e4 201#define MAX_SWAP_BADPAGES \
a4046c06
PHS
202 ((offsetof(union swap_header, magic.magic) - \
203 offsetof(union swap_header, info.badpages)) / sizeof(int))
1da177e4
LT
204
205enum {
206 SWP_USED = (1 << 0), /* is slot in swap_info[] used? */
207 SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */
dcf6b7dd 208 SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */
7992fde7 209 SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */
20137a49 210 SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */
570a335b 211 SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */
b2725643 212 SWP_BLKDEV = (1 << 6), /* its a block device */
bc4ae27d 213 SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */
32646315 214 SWP_FS_OPS = (1 << 8), /* swapfile operations go through fs */
bc4ae27d
OS
215 SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */
216 SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */
217 SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */
218 SWP_SYNCHRONOUS_IO = (1 << 12), /* synchronous IO is efficient */
52b7efdb 219 /* add others here before... */
1da177e4
LT
220};
221
d778df51 222#define SWAP_CLUSTER_MAX 32UL
1c7b17cf 223#define SWAP_CLUSTER_MAX_SKIPPED (SWAP_CLUSTER_MAX << 10)
748446bb 224#define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX
1da177e4 225
4b4bb6bb 226/* Bit flag in swap_map */
570a335b 227#define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */
4b4bb6bb
WY
228#define COUNT_CONTINUED 0x80 /* Flag swap_map continuation for full count */
229
230/* Special value in first swap_map */
231#define SWAP_MAP_MAX 0x3e /* Max count */
232#define SWAP_MAP_BAD 0x3f /* Note page is bad */
233#define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs */
234
235/* Special value in each swap_map continuation */
236#define SWAP_CONT_MAX 0x7f /* Max count */
253d553b 237
2a8f9449
SL
238/*
239 * We use this to track usage of a cluster. A cluster is a block of swap disk
240 * space with SWAPFILE_CLUSTER pages long and naturally aligns in disk. All
241 * free clusters are organized into a list. We fetch an entry from the list to
242 * get a free cluster.
243 *
73ed0baa
CL
244 * The flags field determines if a cluster is free. This is
245 * protected by cluster lock.
2a8f9449
SL
246 */
247struct swap_cluster_info {
235b6217
YH
248 spinlock_t lock; /*
249 * Protect swap_cluster_info fields
73ed0baa
CL
250 * other than list, and swap_info_struct->swap_map
251 * elements corresponding to the swap cluster.
235b6217 252 */
73ed0baa
CL
253 u16 count;
254 u8 flags;
d07a46a4 255 u8 order;
73ed0baa 256 struct list_head list;
2a8f9449 257};
3494d184
KS
258
259/* All on-list cluster must have a non-zero flag. */
260enum swap_cluster_flags {
261 CLUSTER_FLAG_NONE = 0, /* For temporary off-list cluster */
262 CLUSTER_FLAG_FREE,
263 CLUSTER_FLAG_NONFULL,
264 CLUSTER_FLAG_FRAG,
265 /* Clusters with flags above are allocatable */
266 CLUSTER_FLAG_USABLE = CLUSTER_FLAG_FRAG,
267 CLUSTER_FLAG_FULL,
268 CLUSTER_FLAG_DISCARD,
269 CLUSTER_FLAG_MAX,
270};
2a8f9449 271
14c62da2
RR
272/*
273 * The first page in the swap file is the swap header, which is always marked
274 * bad to prevent it from being allocated as an entry. This also prevents the
275 * cluster to which it belongs being marked free. Therefore 0 is safe to use as
e3ae2dec 276 * a sentinel to indicate an entry is not valid.
14c62da2 277 */
e3ae2dec 278#define SWAP_ENTRY_INVALID 0
14c62da2 279
845982eb
RR
280#ifdef CONFIG_THP_SWAP
281#define SWAP_NR_ORDERS (PMD_ORDER + 1)
282#else
283#define SWAP_NR_ORDERS 1
284#endif
285
ebc2a1a6 286/*
1b7e9002
KS
287 * We keep using same cluster for rotational device so IO will be sequential.
288 * The purpose is to optimize SWAP throughput on these device.
ebc2a1a6 289 */
1b7e9002 290struct swap_sequential_cluster {
845982eb 291 unsigned int next[SWAP_NR_ORDERS]; /* Likely next allocation offset */
ebc2a1a6
SL
292};
293
1da177e4
LT
294/*
295 * The in-memory structure used to track swap areas.
1da177e4
LT
296 */
297struct swap_info_struct {
63d8620e 298 struct percpu_ref users; /* indicate and keep swap device valid. */
efa90a98
HD
299 unsigned long flags; /* SWP_USED etc: see above */
300 signed short prio; /* swap priority of this type */
18ab4d4c 301 struct plist_node list; /* entry in swap_active_head */
efa90a98 302 signed char type; /* strange name for an index */
7509765a
HD
303 unsigned int max; /* extent of the swap_map */
304 unsigned char *swap_map; /* vmalloc'ed array of usage counts */
0ca0c24e 305 unsigned long *zeromap; /* kvmalloc'ed bitmap to track zero pages */
2a8f9449 306 struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */
73ed0baa 307 struct list_head free_clusters; /* free clusters list */
2cacbdfd 308 struct list_head full_clusters; /* full clusters list */
d07a46a4
CL
309 struct list_head nonfull_clusters[SWAP_NR_ORDERS];
310 /* list of cluster that contains at least one free slot */
477cb7ba
KS
311 struct list_head frag_clusters[SWAP_NR_ORDERS];
312 /* list of cluster that are fragmented or contented */
3b644773 313 atomic_long_t frag_cluster_nr[SWAP_NR_ORDERS];
7509765a 314 unsigned int pages; /* total of usable pages of swap */
b228386c 315 atomic_long_t inuse_pages; /* number of those currently in use */
1b7e9002 316 struct swap_sequential_cluster *global_cluster; /* Use one global cluster for rotating device */
bae8a4ef 317 spinlock_t global_cluster_lock; /* Serialize usage of global cluster */
4efaceb1 318 struct rb_root swap_extent_root;/* root of the swap extent rbtree */
7509765a
HD
319 struct block_device *bdev; /* swap device or bdev of swap file */
320 struct file *swap_file; /* seldom referenced */
63d8620e 321 struct completion comp; /* seldom referenced */
ec8acf20
SL
322 spinlock_t lock; /*
323 * protect map scan related fields like
324 * swap_map, lowest_bit, highest_bit,
325 * inuse_pages, cluster_next,
815c2c54
SL
326 * cluster_nr, lowest_alloc,
327 * highest_alloc, free/discard cluster
328 * list. other fields are only changed
329 * at swapon/swapoff, so are protected
330 * by swap_lock. changing flags need
331 * hold this lock and swap_lock. If
332 * both locks need hold, hold swap_lock
333 * first.
ec8acf20 334 */
2628bd6f
YH
335 spinlock_t cont_lock; /*
336 * protect swap count continuation page
337 * list.
338 */
815c2c54 339 struct work_struct discard_work; /* discard worker */
5168a68e 340 struct work_struct reclaim_work; /* reclaim worker */
73ed0baa 341 struct list_head discard_clusters; /* discard clusters list */
16c3380f 342 struct plist_node avail_lists[]; /*
66f71da9
AL
343 * entries in swap_avail_heads, one
344 * entry per node.
345 * Must be last as the number of the
346 * array is nr_node_ids, which is not
347 * a fixed value so have to allocate
348 * dynamically.
349 * And it has to be an array so that
350 * plist_for_each_* can work.
351 */
1da177e4
LT
352};
353
cfeed8ff
DH
354static inline swp_entry_t page_swap_entry(struct page *page)
355{
356 struct folio *folio = page_folio(page);
3d2c9087 357 swp_entry_t entry = folio->swap;
cfeed8ff
DH
358
359 entry.val += folio_page_idx(folio, page);
360 return entry;
361}
362
a528910e 363/* linux/mm/workingset.c */
5a4d8944
NP
364bool workingset_test_recent(void *shadow, bool file, bool *workingset,
365 bool flush);
31d8fcac 366void workingset_age_nonresident(struct lruvec *lruvec, unsigned long nr_pages);
8927f647 367void *workingset_eviction(struct folio *folio, struct mem_cgroup *target_memcg);
0995d7e5 368void workingset_refault(struct folio *folio, void *shadow);
c5ce619a 369void workingset_activation(struct folio *folio);
c7df8ad2 370
1da177e4 371/* linux/mm/page_alloc.c */
cb45b0e9 372extern unsigned long totalreserve_pages;
1da177e4 373
c41f012a
MH
374/* Definition of global_zone_page_state not available yet */
375#define nr_free_pages() global_zone_page_state(NR_FREE_PAGES)
96177299
CL
376
377
1da177e4 378/* linux/mm/swap.c */
0538a82c
JW
379void lru_note_cost(struct lruvec *lruvec, bool file,
380 unsigned int nr_io, unsigned int nr_rotated);
381void lru_note_cost_refault(struct folio *);
681ecf63
MWO
382void folio_add_lru(struct folio *);
383void folio_add_lru_vma(struct folio *, struct vm_area_struct *);
76580b65
MWO
384void mark_page_accessed(struct page *);
385void folio_mark_accessed(struct folio *);
d479960e
MK
386
387extern atomic_t lru_disable_count;
388
389static inline bool lru_cache_disabled(void)
390{
391 return atomic_read(&lru_disable_count);
392}
393
394static inline void lru_cache_enable(void)
395{
396 atomic_dec(&lru_disable_count);
397}
398
399extern void lru_cache_disable(void);
1da177e4 400extern void lru_add_drain(void);
f0cb3c76 401extern void lru_add_drain_cpu(int cpu);
b01b2141 402extern void lru_add_drain_cpu_zone(struct zone *zone);
5fbc4616 403extern void lru_add_drain_all(void);
5a9e3474 404void folio_deactivate(struct folio *folio);
6a6fe9eb 405void folio_mark_lazyfree(struct folio *folio);
1da177e4
LT
406extern void swap_setup(void);
407
408/* linux/mm/vmscan.c */
5a1c84b4 409extern unsigned long zone_reclaimable_pages(struct zone *zone);
dac1d27b 410extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
327c0e96 411 gfp_t gfp_mask, nodemask_t *mask);
73b73bac
YA
412
413#define MEMCG_RECLAIM_MAY_SWAP (1 << 1)
414#define MEMCG_RECLAIM_PROACTIVE (1 << 2)
410abb20
DS
415#define MIN_SWAPPINESS 0
416#define MAX_SWAPPINESS 200
68a1436b
ZH
417
418/* Just recliam from anon folios in proactive memory reclaim */
419#define SWAPPINESS_ANON_ONLY (MAX_SWAPPINESS + 1)
420
b70a2a21
JW
421extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
422 unsigned long nr_pages,
423 gfp_t gfp_mask,
68cd9050
DS
424 unsigned int reclaim_options,
425 int *swappiness);
a9dd0a83 426extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem,
185efc0f 427 gfp_t gfp_mask, bool noswap,
ef8f2327 428 pg_data_t *pgdat,
185efc0f 429 unsigned long *nr_scanned);
69e05944 430extern unsigned long shrink_all_memory(unsigned long nr_pages);
1da177e4 431extern int vm_swappiness;
5100da38 432long remove_mapping(struct address_space *mapping, struct folio *folio);
b20a3503 433
9eeff239 434#ifdef CONFIG_NUMA
9614634f 435extern int sysctl_min_unmapped_ratio;
0ff38490 436extern int sysctl_min_slab_ratio;
9eeff239
CL
437#endif
438
77414d19 439void check_move_unevictable_folios(struct folio_batch *fbatch);
af936a16 440
e5797dc0
ML
441extern void __meminit kswapd_run(int nid);
442extern void __meminit kswapd_stop(int nid);
33398cf2 443
1da177e4 444#ifdef CONFIG_SWAP
be297968 445
a509bc1a
MG
446int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page,
447 unsigned long nr_pages, sector_t start_block);
448int generic_swapfile_activate(struct swap_info_struct *, struct file *,
449 sector_t *);
450
b6038942
SB
451static inline unsigned long total_swapcache_pages(void)
452{
453 return global_node_page_state(NR_SWAPCACHE);
454}
455
63b77499 456void free_swap_cache(struct folio *folio);
06340b92 457void free_folio_and_swap_cache(struct folio *folio);
63b77499 458void free_pages_and_swap_cache(struct encoded_page **, int);
1da177e4 459/* linux/mm/swapfile.c */
ec8acf20 460extern atomic_long_t nr_swap_pages;
1da177e4 461extern long total_swap_pages;
81a0298b 462extern atomic_t nr_rotate_swap;
ec8acf20
SL
463
464/* Swap 50% full? Release swapcache more aggressively.. */
465static inline bool vm_swap_full(void)
466{
467 return atomic_long_read(&nr_swap_pages) * 2 < total_swap_pages;
468}
469
470static inline long get_nr_swap_pages(void)
471{
472 return atomic_long_read(&nr_swap_pages);
473}
474
1da177e4 475extern void si_swapinfo(struct sysinfo *);
b487a2da 476int folio_alloc_swap(struct folio *folio, gfp_t gfp_mask);
bdb0ed54 477bool folio_free_swap(struct folio *folio);
4081f744 478void put_swap_folio(struct folio *folio, swp_entry_t entry);
910321ea 479extern swp_entry_t get_swap_page_of_type(int);
570a335b 480extern int add_swap_count_continuation(swp_entry_t, gfp_t);
65018076 481extern void swap_shmem_alloc(swp_entry_t, int);
570a335b 482extern int swap_duplicate(swp_entry_t);
9f101bef 483extern int swapcache_prepare(swp_entry_t entry, int nr);
ebfba004 484extern void swap_free_nr(swp_entry_t entry, int nr_pages);
a62fb92a 485extern void free_swap_and_cache_nr(swp_entry_t entry, int nr);
21bd9005
CH
486int swap_type_of(dev_t device, sector_t offset);
487int find_first_swap(dev_t *device);
f577eb30 488extern unsigned int count_swap_pages(int, int);
3aef83e0 489extern sector_t swapdev_block(int, pgoff_t);
eb085574 490extern int __swap_count(swp_entry_t entry);
c523aa89 491extern bool swap_entry_swapped(struct swap_info_struct *si, swp_entry_t entry);
8334b962 492extern int swp_swapcount(swp_entry_t entry);
69fe7d67 493struct swap_info_struct *swp_swap_info(swp_entry_t entry);
1da177e4 494struct backing_dev_info;
4b3ef9da
YH
495extern int init_swap_address_space(unsigned int type, unsigned long nr_pages);
496extern void exit_swap_address_space(unsigned int type);
eb085574 497extern struct swap_info_struct *get_swap_device(swp_entry_t entry);
3a61e6f6 498sector_t swap_folio_sector(struct folio *folio);
eb085574
YH
499
500static inline void put_swap_device(struct swap_info_struct *si)
501{
63d8620e 502 percpu_ref_put(&si->users);
eb085574 503}
1da177e4 504
1da177e4 505#else /* CONFIG_SWAP */
0bcac06f
MK
506static inline struct swap_info_struct *swp_swap_info(swp_entry_t entry)
507{
508 return NULL;
509}
510
2799e775
ML
511static inline struct swap_info_struct *get_swap_device(swp_entry_t entry)
512{
513 return NULL;
514}
515
516static inline void put_swap_device(struct swap_info_struct *si)
517{
518}
519
ec8acf20 520#define get_nr_swap_pages() 0L
b962716b 521#define total_swap_pages 0L
33806f06 522#define total_swapcache_pages() 0UL
ec8acf20 523#define vm_swap_full() 0
1da177e4
LT
524
525#define si_swapinfo(val) \
526 do { (val)->freeswap = (val)->totalswap = 0; } while (0)
06340b92
FN
527#define free_folio_and_swap_cache(folio) \
528 folio_put(folio)
1da177e4 529#define free_pages_and_swap_cache(pages, nr) \
c6f92f9f 530 release_pages((pages), (nr));
1da177e4 531
a62fb92a
RR
532static inline void free_swap_and_cache_nr(swp_entry_t entry, int nr)
533{
534}
bd96b9eb 535
63b77499 536static inline void free_swap_cache(struct folio *folio)
1baec203
ML
537{
538}
539
570a335b 540static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask)
355cfa73 541{
570a335b
HD
542 return 0;
543}
544
65018076 545static inline void swap_shmem_alloc(swp_entry_t swp, int nr)
aaa46865
HD
546{
547}
548
570a335b
HD
549static inline int swap_duplicate(swp_entry_t swp)
550{
551 return 0;
355cfa73
KH
552}
553
9f101bef 554static inline int swapcache_prepare(swp_entry_t swp, int nr)
13ddaf26
KS
555{
556 return 0;
557}
558
ebfba004
CH
559static inline void swap_free_nr(swp_entry_t entry, int nr_pages)
560{
561}
562
4081f744 563static inline void put_swap_folio(struct folio *folio, swp_entry_t swp)
cb4b86ba
KH
564{
565}
566
eb085574 567static inline int __swap_count(swp_entry_t entry)
aa8d22a1
MK
568{
569 return 0;
570}
571
c523aa89 572static inline bool swap_entry_swapped(struct swap_info_struct *si, swp_entry_t entry)
e8c26ab6 573{
c523aa89 574 return false;
e8c26ab6
TC
575}
576
8334b962
MK
577static inline int swp_swapcount(swp_entry_t entry)
578{
579 return 0;
580}
581
b487a2da 582static inline int folio_alloc_swap(struct folio *folio, gfp_t gfp_mask)
1da177e4 583{
b487a2da 584 return -EINVAL;
1da177e4
LT
585}
586
bdb0ed54
MWO
587static inline bool folio_free_swap(struct folio *folio)
588{
589 return false;
590}
591
4b60c0ff
N
592static inline int add_swap_extent(struct swap_info_struct *sis,
593 unsigned long start_page,
594 unsigned long nr_pages, sector_t start_block)
595{
596 return -EINVAL;
597}
1da177e4 598#endif /* CONFIG_SWAP */
6f2cb2f1 599
a62fb92a
RR
600static inline void free_swap_and_cache(swp_entry_t entry)
601{
602 free_swap_and_cache_nr(entry, 1);
603}
604
54f7a49c
BS
605static inline void swap_free(swp_entry_t entry)
606{
607 swap_free_nr(entry, 1);
608}
609
6f2cb2f1
VD
610#ifdef CONFIG_MEMCG
611static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg)
612{
4550c4e1
JW
613 /* Cgroup2 doesn't have per-cgroup swappiness */
614 if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
82b3aa26 615 return READ_ONCE(vm_swappiness);
4550c4e1 616
6f2cb2f1 617 /* root ? */
59118c42 618 if (mem_cgroup_disabled() || mem_cgroup_is_root(memcg))
82b3aa26 619 return READ_ONCE(vm_swappiness);
6f2cb2f1 620
82b3aa26 621 return READ_ONCE(memcg->swappiness);
6f2cb2f1 622}
6f2cb2f1
VD
623#else
624static inline int mem_cgroup_swappiness(struct mem_cgroup *mem)
625{
82b3aa26 626 return READ_ONCE(vm_swappiness);
6f2cb2f1
VD
627}
628#endif
629
2cf85583 630#if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
3e4fb13a
KW
631void __folio_throttle_swaprate(struct folio *folio, gfp_t gfp);
632static inline void folio_throttle_swaprate(struct folio *folio, gfp_t gfp)
01c4b28c
SB
633{
634 if (mem_cgroup_disabled())
635 return;
3e4fb13a 636 __folio_throttle_swaprate(folio, gfp);
01c4b28c 637}
2cf85583 638#else
039bc124
MWO
639static inline void folio_throttle_swaprate(struct folio *folio, gfp_t gfp)
640{
039bc124 641}
3e4fb13a 642#endif
2cf85583 643
e55b9f96 644#if defined(CONFIG_MEMCG) && defined(CONFIG_SWAP)
e2e3fdc7
MWO
645int __mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry);
646static inline int mem_cgroup_try_charge_swap(struct folio *folio,
647 swp_entry_t entry)
01c4b28c
SB
648{
649 if (mem_cgroup_disabled())
650 return 0;
e2e3fdc7 651 return __mem_cgroup_try_charge_swap(folio, entry);
01c4b28c
SB
652}
653
654extern void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages);
655static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)
656{
657 if (mem_cgroup_disabled())
658 return;
659 __mem_cgroup_uncharge_swap(entry, nr_pages);
660}
661
d8b38438 662extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg);
9202d527 663extern bool mem_cgroup_swap_full(struct folio *folio);
6f2cb2f1 664#else
e2e3fdc7 665static inline int mem_cgroup_try_charge_swap(struct folio *folio,
6f2cb2f1
VD
666 swp_entry_t entry)
667{
668 return 0;
669}
670
38d8b4e6
YH
671static inline void mem_cgroup_uncharge_swap(swp_entry_t entry,
672 unsigned int nr_pages)
6f2cb2f1
VD
673{
674}
d8b38438
VD
675
676static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
677{
678 return get_nr_swap_pages();
679}
5ccc5aba 680
9202d527 681static inline bool mem_cgroup_swap_full(struct folio *folio)
5ccc5aba
VD
682{
683 return vm_swap_full();
684}
6f2cb2f1
VD
685#endif
686
1da177e4
LT
687#endif /* __KERNEL__*/
688#endif /* _LINUX_SWAP_H */