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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> |
60063497 | 13 | #include <linux/atomic.h> |
c53954a0 | 14 | #include <linux/page-flags.h> |
1da177e4 LT |
15 | #include <asm/page.h> |
16 | ||
8bc719d3 MS |
17 | struct notifier_block; |
18 | ||
ab954160 AM |
19 | struct bio; |
20 | ||
1da177e4 LT |
21 | #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */ |
22 | #define SWAP_FLAG_PRIO_MASK 0x7fff | |
23 | #define SWAP_FLAG_PRIO_SHIFT 0 | |
dcf6b7dd RA |
24 | #define SWAP_FLAG_DISCARD 0x10000 /* enable discard for swap */ |
25 | #define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */ | |
26 | #define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */ | |
1da177e4 | 27 | |
d15cab97 | 28 | #define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \ |
dcf6b7dd RA |
29 | SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \ |
30 | SWAP_FLAG_DISCARD_PAGES) | |
36005bae | 31 | #define SWAP_BATCH 64 |
d15cab97 | 32 | |
1da177e4 LT |
33 | static inline int current_is_kswapd(void) |
34 | { | |
35 | return current->flags & PF_KSWAPD; | |
36 | } | |
37 | ||
38 | /* | |
39 | * MAX_SWAPFILES defines the maximum number of swaptypes: things which can | |
40 | * be swapped to. The swap type and the offset into that swap type are | |
41 | * encoded into pte's and into pgoff_t's in the swapcache. Using five bits | |
42 | * for the type means that the maximum number of swapcache pages is 27 bits | |
43 | * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs | |
44 | * the type/offset into the pte as 5/27 as well. | |
45 | */ | |
46 | #define MAX_SWAPFILES_SHIFT 5 | |
a7420aa5 AK |
47 | |
48 | /* | |
49 | * Use some of the swap files numbers for other purposes. This | |
50 | * is a convenient way to hook into the VM to trigger special | |
51 | * actions on faults. | |
52 | */ | |
53 | ||
5042db43 JG |
54 | /* |
55 | * Unaddressable device memory support. See include/linux/hmm.h and | |
56 | * Documentation/vm/hmm.txt. Short description is we need struct pages for | |
57 | * device memory that is unaddressable (inaccessible) by CPU, so that we can | |
58 | * migrate part of a process memory to device memory. | |
59 | * | |
60 | * When a page is migrated from CPU to device, we set the CPU page table entry | |
61 | * to a special SWP_DEVICE_* entry. | |
62 | */ | |
63 | #ifdef CONFIG_DEVICE_PRIVATE | |
64 | #define SWP_DEVICE_NUM 2 | |
65 | #define SWP_DEVICE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM) | |
66 | #define SWP_DEVICE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+1) | |
67 | #else | |
68 | #define SWP_DEVICE_NUM 0 | |
69 | #endif | |
70 | ||
a7420aa5 AK |
71 | /* |
72 | * NUMA node memory migration support | |
73 | */ | |
74 | #ifdef CONFIG_MIGRATION | |
75 | #define SWP_MIGRATION_NUM 2 | |
76 | #define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM) | |
77 | #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1) | |
0697212a | 78 | #else |
a7420aa5 | 79 | #define SWP_MIGRATION_NUM 0 |
0697212a | 80 | #endif |
1da177e4 | 81 | |
a7420aa5 AK |
82 | /* |
83 | * Handling of hardware poisoned pages with memory corruption. | |
84 | */ | |
85 | #ifdef CONFIG_MEMORY_FAILURE | |
86 | #define SWP_HWPOISON_NUM 1 | |
87 | #define SWP_HWPOISON MAX_SWAPFILES | |
88 | #else | |
89 | #define SWP_HWPOISON_NUM 0 | |
90 | #endif | |
91 | ||
92 | #define MAX_SWAPFILES \ | |
5042db43 JG |
93 | ((1 << MAX_SWAPFILES_SHIFT) - SWP_DEVICE_NUM - \ |
94 | SWP_MIGRATION_NUM - SWP_HWPOISON_NUM) | |
a7420aa5 | 95 | |
1da177e4 LT |
96 | /* |
97 | * Magic header for a swap area. The first part of the union is | |
98 | * what the swap magic looks like for the old (limited to 128MB) | |
99 | * swap area format, the second part of the union adds - in the | |
100 | * old reserved area - some extra information. Note that the first | |
101 | * kilobyte is reserved for boot loader or disk label stuff... | |
102 | * | |
103 | * Having the magic at the end of the PAGE_SIZE makes detecting swap | |
104 | * areas somewhat tricky on machines that support multiple page sizes. | |
105 | * For 2.5 we'll probably want to move the magic to just beyond the | |
106 | * bootbits... | |
107 | */ | |
108 | union swap_header { | |
109 | struct { | |
110 | char reserved[PAGE_SIZE - 10]; | |
111 | char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ | |
112 | } magic; | |
113 | struct { | |
e8f03d02 AD |
114 | char bootbits[1024]; /* Space for disklabel etc. */ |
115 | __u32 version; | |
116 | __u32 last_page; | |
117 | __u32 nr_badpages; | |
118 | unsigned char sws_uuid[16]; | |
119 | unsigned char sws_volume[16]; | |
120 | __u32 padding[117]; | |
121 | __u32 badpages[1]; | |
1da177e4 LT |
122 | } info; |
123 | }; | |
124 | ||
1da177e4 LT |
125 | /* |
126 | * current->reclaim_state points to one of these when a task is running | |
127 | * memory reclaim | |
128 | */ | |
129 | struct reclaim_state { | |
130 | unsigned long reclaimed_slab; | |
131 | }; | |
132 | ||
133 | #ifdef __KERNEL__ | |
134 | ||
135 | struct address_space; | |
136 | struct sysinfo; | |
137 | struct writeback_control; | |
138 | struct zone; | |
139 | ||
140 | /* | |
141 | * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of | |
142 | * disk blocks. A list of swap extents maps the entire swapfile. (Where the | |
143 | * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart | |
144 | * from setup, they're handled identically. | |
145 | * | |
146 | * We always assume that blocks are of size PAGE_SIZE. | |
147 | */ | |
148 | struct swap_extent { | |
149 | struct list_head list; | |
150 | pgoff_t start_page; | |
151 | pgoff_t nr_pages; | |
152 | sector_t start_block; | |
153 | }; | |
154 | ||
155 | /* | |
156 | * Max bad pages in the new format.. | |
157 | */ | |
158 | #define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x) | |
159 | #define MAX_SWAP_BADPAGES \ | |
160 | ((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int)) | |
161 | ||
162 | enum { | |
163 | SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ | |
164 | SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ | |
dcf6b7dd | 165 | SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */ |
7992fde7 | 166 | SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */ |
20137a49 | 167 | SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ |
570a335b | 168 | SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */ |
b2725643 | 169 | SWP_BLKDEV = (1 << 6), /* its a block device */ |
62c230bc | 170 | SWP_FILE = (1 << 7), /* set after swap_activate success */ |
dcf6b7dd RA |
171 | SWP_AREA_DISCARD = (1 << 8), /* single-time swap area discards */ |
172 | SWP_PAGE_DISCARD = (1 << 9), /* freed swap page-cluster discards */ | |
f0571429 | 173 | SWP_STABLE_WRITES = (1 << 10), /* no overwrite PG_writeback pages */ |
539a6fea | 174 | SWP_SYNCHRONOUS_IO = (1 << 11), /* synchronous IO is efficient */ |
52b7efdb | 175 | /* add others here before... */ |
539a6fea | 176 | SWP_SCANNING = (1 << 12), /* refcount in scan_swap_map */ |
1da177e4 LT |
177 | }; |
178 | ||
d778df51 | 179 | #define SWAP_CLUSTER_MAX 32UL |
748446bb | 180 | #define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX |
1da177e4 | 181 | |
570a335b HD |
182 | #define SWAP_MAP_MAX 0x3e /* Max duplication count, in first swap_map */ |
183 | #define SWAP_MAP_BAD 0x3f /* Note pageblock is bad, in first swap_map */ | |
184 | #define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */ | |
185 | #define SWAP_CONT_MAX 0x7f /* Max count, in each swap_map continuation */ | |
186 | #define COUNT_CONTINUED 0x80 /* See swap_map continuation for full count */ | |
aaa46865 | 187 | #define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs, in first swap_map */ |
253d553b | 188 | |
2a8f9449 SL |
189 | /* |
190 | * We use this to track usage of a cluster. A cluster is a block of swap disk | |
191 | * space with SWAPFILE_CLUSTER pages long and naturally aligns in disk. All | |
192 | * free clusters are organized into a list. We fetch an entry from the list to | |
193 | * get a free cluster. | |
194 | * | |
195 | * The data field stores next cluster if the cluster is free or cluster usage | |
196 | * counter otherwise. The flags field determines if a cluster is free. This is | |
197 | * protected by swap_info_struct.lock. | |
198 | */ | |
199 | struct swap_cluster_info { | |
235b6217 HY |
200 | spinlock_t lock; /* |
201 | * Protect swap_cluster_info fields | |
202 | * and swap_info_struct->swap_map | |
203 | * elements correspond to the swap | |
204 | * cluster | |
205 | */ | |
2a8f9449 SL |
206 | unsigned int data:24; |
207 | unsigned int flags:8; | |
208 | }; | |
209 | #define CLUSTER_FLAG_FREE 1 /* This cluster is free */ | |
210 | #define CLUSTER_FLAG_NEXT_NULL 2 /* This cluster has no next cluster */ | |
e0709829 | 211 | #define CLUSTER_FLAG_HUGE 4 /* This cluster is backing a transparent huge page */ |
2a8f9449 | 212 | |
ebc2a1a6 SL |
213 | /* |
214 | * We assign a cluster to each CPU, so each CPU can allocate swap entry from | |
215 | * its own cluster and swapout sequentially. The purpose is to optimize swapout | |
216 | * throughput. | |
217 | */ | |
218 | struct percpu_cluster { | |
219 | struct swap_cluster_info index; /* Current cluster index */ | |
220 | unsigned int next; /* Likely next allocation offset */ | |
221 | }; | |
222 | ||
6b534915 HY |
223 | struct swap_cluster_list { |
224 | struct swap_cluster_info head; | |
225 | struct swap_cluster_info tail; | |
226 | }; | |
227 | ||
1da177e4 LT |
228 | /* |
229 | * The in-memory structure used to track swap areas. | |
1da177e4 LT |
230 | */ |
231 | struct swap_info_struct { | |
efa90a98 HD |
232 | unsigned long flags; /* SWP_USED etc: see above */ |
233 | signed short prio; /* swap priority of this type */ | |
18ab4d4c | 234 | struct plist_node list; /* entry in swap_active_head */ |
a2468cc9 | 235 | struct plist_node avail_lists[MAX_NUMNODES];/* entry in swap_avail_heads */ |
efa90a98 | 236 | signed char type; /* strange name for an index */ |
7509765a HD |
237 | unsigned int max; /* extent of the swap_map */ |
238 | unsigned char *swap_map; /* vmalloc'ed array of usage counts */ | |
2a8f9449 | 239 | struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */ |
6b534915 | 240 | struct swap_cluster_list free_clusters; /* free clusters list */ |
7509765a HD |
241 | unsigned int lowest_bit; /* index of first free in swap_map */ |
242 | unsigned int highest_bit; /* index of last free in swap_map */ | |
243 | unsigned int pages; /* total of usable pages of swap */ | |
244 | unsigned int inuse_pages; /* number of those currently in use */ | |
245 | unsigned int cluster_next; /* likely index for next allocation */ | |
246 | unsigned int cluster_nr; /* countdown to next cluster search */ | |
ebc2a1a6 | 247 | struct percpu_cluster __percpu *percpu_cluster; /* per cpu's swap location */ |
7509765a HD |
248 | struct swap_extent *curr_swap_extent; |
249 | struct swap_extent first_swap_extent; | |
250 | struct block_device *bdev; /* swap device or bdev of swap file */ | |
251 | struct file *swap_file; /* seldom referenced */ | |
252 | unsigned int old_block_size; /* seldom referenced */ | |
38b5faf4 DM |
253 | #ifdef CONFIG_FRONTSWAP |
254 | unsigned long *frontswap_map; /* frontswap in-use, one bit per page */ | |
255 | atomic_t frontswap_pages; /* frontswap pages in-use counter */ | |
256 | #endif | |
ec8acf20 SL |
257 | spinlock_t lock; /* |
258 | * protect map scan related fields like | |
259 | * swap_map, lowest_bit, highest_bit, | |
260 | * inuse_pages, cluster_next, | |
815c2c54 SL |
261 | * cluster_nr, lowest_alloc, |
262 | * highest_alloc, free/discard cluster | |
263 | * list. other fields are only changed | |
264 | * at swapon/swapoff, so are protected | |
265 | * by swap_lock. changing flags need | |
266 | * hold this lock and swap_lock. If | |
267 | * both locks need hold, hold swap_lock | |
268 | * first. | |
ec8acf20 | 269 | */ |
2628bd6f HY |
270 | spinlock_t cont_lock; /* |
271 | * protect swap count continuation page | |
272 | * list. | |
273 | */ | |
815c2c54 | 274 | struct work_struct discard_work; /* discard worker */ |
6b534915 | 275 | struct swap_cluster_list discard_clusters; /* discard clusters list */ |
1da177e4 LT |
276 | }; |
277 | ||
ec560175 HY |
278 | #ifdef CONFIG_64BIT |
279 | #define SWAP_RA_ORDER_CEILING 5 | |
280 | #else | |
281 | /* Avoid stack overflow, because we need to save part of page table */ | |
282 | #define SWAP_RA_ORDER_CEILING 3 | |
283 | #define SWAP_RA_PTE_CACHE_SIZE (1 << SWAP_RA_ORDER_CEILING) | |
284 | #endif | |
285 | ||
286 | struct vma_swap_readahead { | |
287 | unsigned short win; | |
288 | unsigned short offset; | |
289 | unsigned short nr_pte; | |
290 | #ifdef CONFIG_64BIT | |
291 | pte_t *ptes; | |
292 | #else | |
293 | pte_t ptes[SWAP_RA_PTE_CACHE_SIZE]; | |
294 | #endif | |
295 | }; | |
296 | ||
a528910e JW |
297 | /* linux/mm/workingset.c */ |
298 | void *workingset_eviction(struct address_space *mapping, struct page *page); | |
299 | bool workingset_refault(void *shadow); | |
300 | void workingset_activation(struct page *page); | |
c7df8ad2 MG |
301 | |
302 | /* Do not use directly, use workingset_lookup_update */ | |
303 | void workingset_update_node(struct radix_tree_node *node); | |
304 | ||
305 | /* Returns workingset_update_node() if the mapping has shadow entries. */ | |
306 | #define workingset_lookup_update(mapping) \ | |
307 | ({ \ | |
308 | radix_tree_update_node_t __helper = workingset_update_node; \ | |
309 | if (dax_mapping(mapping) || shmem_mapping(mapping)) \ | |
310 | __helper = NULL; \ | |
311 | __helper; \ | |
312 | }) | |
a528910e | 313 | |
1da177e4 LT |
314 | /* linux/mm/page_alloc.c */ |
315 | extern unsigned long totalram_pages; | |
cb45b0e9 | 316 | extern unsigned long totalreserve_pages; |
ebec3862 ZY |
317 | extern unsigned long nr_free_buffer_pages(void); |
318 | extern unsigned long nr_free_pagecache_pages(void); | |
1da177e4 | 319 | |
c41f012a MH |
320 | /* Definition of global_zone_page_state not available yet */ |
321 | #define nr_free_pages() global_zone_page_state(NR_FREE_PAGES) | |
96177299 CL |
322 | |
323 | ||
1da177e4 | 324 | /* linux/mm/swap.c */ |
c53954a0 | 325 | extern void lru_cache_add(struct page *); |
2329d375 JZ |
326 | extern void lru_cache_add_anon(struct page *page); |
327 | extern void lru_cache_add_file(struct page *page); | |
fa9add64 | 328 | extern void lru_add_page_tail(struct page *page, struct page *page_tail, |
5bc7b8ac | 329 | struct lruvec *lruvec, struct list_head *head); |
b3c97528 HH |
330 | extern void activate_page(struct page *); |
331 | extern void mark_page_accessed(struct page *); | |
1da177e4 | 332 | extern void lru_add_drain(void); |
f0cb3c76 | 333 | extern void lru_add_drain_cpu(int cpu); |
5fbc4616 | 334 | extern void lru_add_drain_all(void); |
ac6aadb2 | 335 | extern void rotate_reclaimable_page(struct page *page); |
cc5993bd | 336 | extern void deactivate_file_page(struct page *page); |
f7ad2a6c | 337 | extern void mark_page_lazyfree(struct page *page); |
1da177e4 LT |
338 | extern void swap_setup(void); |
339 | ||
894bc310 LS |
340 | extern void add_page_to_unevictable_list(struct page *page); |
341 | ||
00501b53 JW |
342 | extern void lru_cache_add_active_or_unevictable(struct page *page, |
343 | struct vm_area_struct *vma); | |
344 | ||
1da177e4 | 345 | /* linux/mm/vmscan.c */ |
5a1c84b4 | 346 | extern unsigned long zone_reclaimable_pages(struct zone *zone); |
dac1d27b | 347 | extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, |
327c0e96 | 348 | gfp_t gfp_mask, nodemask_t *mask); |
f3fd4a61 | 349 | extern int __isolate_lru_page(struct page *page, isolate_mode_t mode); |
b70a2a21 JW |
350 | extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, |
351 | unsigned long nr_pages, | |
352 | gfp_t gfp_mask, | |
353 | bool may_swap); | |
a9dd0a83 | 354 | extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem, |
185efc0f | 355 | gfp_t gfp_mask, bool noswap, |
ef8f2327 | 356 | pg_data_t *pgdat, |
185efc0f | 357 | unsigned long *nr_scanned); |
69e05944 | 358 | extern unsigned long shrink_all_memory(unsigned long nr_pages); |
1da177e4 | 359 | extern int vm_swappiness; |
b20a3503 | 360 | extern int remove_mapping(struct address_space *mapping, struct page *page); |
b21e0b90 | 361 | extern unsigned long vm_total_pages; |
b20a3503 | 362 | |
9eeff239 | 363 | #ifdef CONFIG_NUMA |
a5f5f91d | 364 | extern int node_reclaim_mode; |
9614634f | 365 | extern int sysctl_min_unmapped_ratio; |
0ff38490 | 366 | extern int sysctl_min_slab_ratio; |
a5f5f91d | 367 | extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int); |
9eeff239 | 368 | #else |
a5f5f91d MG |
369 | #define node_reclaim_mode 0 |
370 | static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask, | |
371 | unsigned int order) | |
9eeff239 CL |
372 | { |
373 | return 0; | |
374 | } | |
375 | #endif | |
376 | ||
39b5f29a | 377 | extern int page_evictable(struct page *page); |
24513264 | 378 | extern void check_move_unevictable_pages(struct page **, int nr_pages); |
af936a16 | 379 | |
3218ae14 | 380 | extern int kswapd_run(int nid); |
8fe23e05 | 381 | extern void kswapd_stop(int nid); |
33398cf2 | 382 | |
1da177e4 | 383 | #ifdef CONFIG_SWAP |
be297968 CH |
384 | |
385 | #include <linux/blk_types.h> /* for bio_end_io_t */ | |
386 | ||
1da177e4 | 387 | /* linux/mm/page_io.c */ |
23955622 | 388 | extern int swap_readpage(struct page *page, bool do_poll); |
1da177e4 | 389 | extern int swap_writepage(struct page *page, struct writeback_control *wbc); |
4246a0b6 | 390 | extern void end_swap_bio_write(struct bio *bio); |
1eec6702 | 391 | extern int __swap_writepage(struct page *page, struct writeback_control *wbc, |
4246a0b6 | 392 | bio_end_io_t end_write_func); |
62c230bc | 393 | extern int swap_set_page_dirty(struct page *page); |
1da177e4 | 394 | |
a509bc1a MG |
395 | int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page, |
396 | unsigned long nr_pages, sector_t start_block); | |
397 | int generic_swapfile_activate(struct swap_info_struct *, struct file *, | |
398 | sector_t *); | |
399 | ||
1da177e4 | 400 | /* linux/mm/swap_state.c */ |
4b3ef9da HY |
401 | /* One swap address space for each 64M swap space */ |
402 | #define SWAP_ADDRESS_SPACE_SHIFT 14 | |
403 | #define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT) | |
404 | extern struct address_space *swapper_spaces[]; | |
ec560175 | 405 | extern bool swap_vma_readahead; |
4b3ef9da HY |
406 | #define swap_address_space(entry) \ |
407 | (&swapper_spaces[swp_type(entry)][swp_offset(entry) \ | |
408 | >> SWAP_ADDRESS_SPACE_SHIFT]) | |
33806f06 | 409 | extern unsigned long total_swapcache_pages(void); |
1da177e4 | 410 | extern void show_swap_cache_info(void); |
0f074658 | 411 | extern int add_to_swap(struct page *page); |
73b1262f | 412 | extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t); |
2f772e6c | 413 | extern int __add_to_swap_cache(struct page *page, swp_entry_t entry); |
1da177e4 LT |
414 | extern void __delete_from_swap_cache(struct page *); |
415 | extern void delete_from_swap_cache(struct page *); | |
1da177e4 LT |
416 | extern void free_page_and_swap_cache(struct page *); |
417 | extern void free_pages_and_swap_cache(struct page **, int); | |
ec560175 HY |
418 | extern struct page *lookup_swap_cache(swp_entry_t entry, |
419 | struct vm_area_struct *vma, | |
420 | unsigned long addr); | |
02098fea | 421 | extern struct page *read_swap_cache_async(swp_entry_t, gfp_t, |
23955622 SL |
422 | struct vm_area_struct *vma, unsigned long addr, |
423 | bool do_poll); | |
5b999aad DS |
424 | extern struct page *__read_swap_cache_async(swp_entry_t, gfp_t, |
425 | struct vm_area_struct *vma, unsigned long addr, | |
426 | bool *new_page_allocated); | |
02098fea | 427 | extern struct page *swapin_readahead(swp_entry_t, gfp_t, |
46017e95 HD |
428 | struct vm_area_struct *vma, unsigned long addr); |
429 | ||
ec560175 HY |
430 | extern struct page *swap_readahead_detect(struct vm_fault *vmf, |
431 | struct vma_swap_readahead *swap_ra); | |
432 | extern struct page *do_swap_page_readahead(swp_entry_t fentry, gfp_t gfp_mask, | |
433 | struct vm_fault *vmf, | |
434 | struct vma_swap_readahead *swap_ra); | |
435 | ||
1da177e4 | 436 | /* linux/mm/swapfile.c */ |
ec8acf20 | 437 | extern atomic_long_t nr_swap_pages; |
1da177e4 | 438 | extern long total_swap_pages; |
81a0298b | 439 | extern atomic_t nr_rotate_swap; |
67afa38e | 440 | extern bool has_usable_swap(void); |
ec8acf20 | 441 | |
81a0298b HY |
442 | static inline bool swap_use_vma_readahead(void) |
443 | { | |
444 | return READ_ONCE(swap_vma_readahead) && !atomic_read(&nr_rotate_swap); | |
445 | } | |
446 | ||
ec8acf20 SL |
447 | /* Swap 50% full? Release swapcache more aggressively.. */ |
448 | static inline bool vm_swap_full(void) | |
449 | { | |
450 | return atomic_long_read(&nr_swap_pages) * 2 < total_swap_pages; | |
451 | } | |
452 | ||
453 | static inline long get_nr_swap_pages(void) | |
454 | { | |
455 | return atomic_long_read(&nr_swap_pages); | |
456 | } | |
457 | ||
1da177e4 | 458 | extern void si_swapinfo(struct sysinfo *); |
38d8b4e6 | 459 | extern swp_entry_t get_swap_page(struct page *page); |
75f6d6d2 | 460 | extern void put_swap_page(struct page *page, swp_entry_t entry); |
910321ea | 461 | extern swp_entry_t get_swap_page_of_type(int); |
38d8b4e6 | 462 | extern int get_swap_pages(int n, bool cluster, swp_entry_t swp_entries[]); |
570a335b | 463 | extern int add_swap_count_continuation(swp_entry_t, gfp_t); |
aaa46865 | 464 | extern void swap_shmem_alloc(swp_entry_t); |
570a335b HD |
465 | extern int swap_duplicate(swp_entry_t); |
466 | extern int swapcache_prepare(swp_entry_t); | |
1da177e4 | 467 | extern void swap_free(swp_entry_t); |
7c00bafe | 468 | extern void swapcache_free_entries(swp_entry_t *entries, int n); |
2509ef26 | 469 | extern int free_swap_and_cache(swp_entry_t); |
7bf23687 | 470 | extern int swap_type_of(dev_t, sector_t, struct block_device **); |
f577eb30 | 471 | extern unsigned int count_swap_pages(int, int); |
d4906e1a | 472 | extern sector_t map_swap_page(struct page *, struct block_device **); |
3aef83e0 | 473 | extern sector_t swapdev_block(int, pgoff_t); |
bde05d1c | 474 | extern int page_swapcount(struct page *); |
aa8d22a1 | 475 | extern int __swap_count(struct swap_info_struct *si, swp_entry_t entry); |
e8c26ab6 | 476 | extern int __swp_swapcount(swp_entry_t entry); |
8334b962 | 477 | extern int swp_swapcount(swp_entry_t entry); |
f981c595 | 478 | extern struct swap_info_struct *page_swap_info(struct page *); |
0bcac06f | 479 | extern struct swap_info_struct *swp_swap_info(swp_entry_t entry); |
6d0a07ed | 480 | extern bool reuse_swap_page(struct page *, int *); |
a2c43eed | 481 | extern int try_to_free_swap(struct page *); |
1da177e4 | 482 | struct backing_dev_info; |
4b3ef9da HY |
483 | extern int init_swap_address_space(unsigned int type, unsigned long nr_pages); |
484 | extern void exit_swap_address_space(unsigned int type); | |
1da177e4 | 485 | |
1da177e4 LT |
486 | #else /* CONFIG_SWAP */ |
487 | ||
0bcac06f MK |
488 | static inline int swap_readpage(struct page *page, bool do_poll) |
489 | { | |
490 | return 0; | |
491 | } | |
492 | ||
493 | static inline struct swap_info_struct *swp_swap_info(swp_entry_t entry) | |
494 | { | |
495 | return NULL; | |
496 | } | |
497 | ||
d2cf5ad6 | 498 | #define swap_address_space(entry) (NULL) |
ec8acf20 | 499 | #define get_nr_swap_pages() 0L |
b962716b | 500 | #define total_swap_pages 0L |
33806f06 | 501 | #define total_swapcache_pages() 0UL |
ec8acf20 | 502 | #define vm_swap_full() 0 |
1da177e4 LT |
503 | |
504 | #define si_swapinfo(val) \ | |
505 | do { (val)->freeswap = (val)->totalswap = 0; } while (0) | |
9ae5b3c7 | 506 | /* only sparc can not include linux/pagemap.h in this file |
ea1754a0 | 507 | * so leave put_page and release_pages undeclared... */ |
1da177e4 | 508 | #define free_page_and_swap_cache(page) \ |
09cbfeaf | 509 | put_page(page) |
1da177e4 | 510 | #define free_pages_and_swap_cache(pages, nr) \ |
c6f92f9f | 511 | release_pages((pages), (nr)); |
1da177e4 | 512 | |
bd96b9eb CK |
513 | static inline void show_swap_cache_info(void) |
514 | { | |
515 | } | |
516 | ||
5042db43 JG |
517 | #define free_swap_and_cache(e) ({(is_migration_entry(e) || is_device_private_entry(e));}) |
518 | #define swapcache_prepare(e) ({(is_migration_entry(e) || is_device_private_entry(e));}) | |
bd96b9eb | 519 | |
570a335b | 520 | static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask) |
355cfa73 | 521 | { |
570a335b HD |
522 | return 0; |
523 | } | |
524 | ||
aaa46865 HD |
525 | static inline void swap_shmem_alloc(swp_entry_t swp) |
526 | { | |
527 | } | |
528 | ||
570a335b HD |
529 | static inline int swap_duplicate(swp_entry_t swp) |
530 | { | |
531 | return 0; | |
355cfa73 KH |
532 | } |
533 | ||
bd96b9eb CK |
534 | static inline void swap_free(swp_entry_t swp) |
535 | { | |
536 | } | |
537 | ||
75f6d6d2 | 538 | static inline void put_swap_page(struct page *page, swp_entry_t swp) |
cb4b86ba KH |
539 | { |
540 | } | |
541 | ||
02098fea | 542 | static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, |
bd96b9eb CK |
543 | struct vm_area_struct *vma, unsigned long addr) |
544 | { | |
545 | return NULL; | |
546 | } | |
547 | ||
ec560175 HY |
548 | static inline bool swap_use_vma_readahead(void) |
549 | { | |
550 | return false; | |
551 | } | |
552 | ||
553 | static inline struct page *swap_readahead_detect( | |
554 | struct vm_fault *vmf, struct vma_swap_readahead *swap_ra) | |
555 | { | |
556 | return NULL; | |
557 | } | |
558 | ||
559 | static inline struct page *do_swap_page_readahead( | |
560 | swp_entry_t fentry, gfp_t gfp_mask, | |
561 | struct vm_fault *vmf, struct vma_swap_readahead *swap_ra) | |
562 | { | |
563 | return NULL; | |
564 | } | |
565 | ||
9fab5619 HD |
566 | static inline int swap_writepage(struct page *p, struct writeback_control *wbc) |
567 | { | |
568 | return 0; | |
569 | } | |
570 | ||
ec560175 HY |
571 | static inline struct page *lookup_swap_cache(swp_entry_t swp, |
572 | struct vm_area_struct *vma, | |
573 | unsigned long addr) | |
bd96b9eb CK |
574 | { |
575 | return NULL; | |
576 | } | |
577 | ||
0f074658 | 578 | static inline int add_to_swap(struct page *page) |
60371d97 HD |
579 | { |
580 | return 0; | |
581 | } | |
582 | ||
73b1262f HD |
583 | static inline int add_to_swap_cache(struct page *page, swp_entry_t entry, |
584 | gfp_t gfp_mask) | |
bd96b9eb | 585 | { |
73b1262f | 586 | return -1; |
bd96b9eb CK |
587 | } |
588 | ||
589 | static inline void __delete_from_swap_cache(struct page *page) | |
590 | { | |
591 | } | |
592 | ||
593 | static inline void delete_from_swap_cache(struct page *page) | |
594 | { | |
595 | } | |
596 | ||
bde05d1c HD |
597 | static inline int page_swapcount(struct page *page) |
598 | { | |
599 | return 0; | |
600 | } | |
601 | ||
aa8d22a1 MK |
602 | static inline int __swap_count(struct swap_info_struct *si, swp_entry_t entry) |
603 | { | |
604 | return 0; | |
605 | } | |
606 | ||
e8c26ab6 TC |
607 | static inline int __swp_swapcount(swp_entry_t entry) |
608 | { | |
609 | return 0; | |
610 | } | |
611 | ||
8334b962 MK |
612 | static inline int swp_swapcount(swp_entry_t entry) |
613 | { | |
614 | return 0; | |
615 | } | |
616 | ||
ba3c4ce6 HY |
617 | #define reuse_swap_page(page, total_map_swapcount) \ |
618 | (page_trans_huge_mapcount(page, total_map_swapcount) == 1) | |
1da177e4 | 619 | |
a2c43eed | 620 | static inline int try_to_free_swap(struct page *page) |
68a22394 RR |
621 | { |
622 | return 0; | |
623 | } | |
624 | ||
38d8b4e6 | 625 | static inline swp_entry_t get_swap_page(struct page *page) |
1da177e4 LT |
626 | { |
627 | swp_entry_t entry; | |
628 | entry.val = 0; | |
629 | return entry; | |
630 | } | |
631 | ||
1da177e4 | 632 | #endif /* CONFIG_SWAP */ |
6f2cb2f1 | 633 | |
59807685 HY |
634 | #ifdef CONFIG_THP_SWAP |
635 | extern int split_swap_cluster(swp_entry_t entry); | |
636 | #else | |
637 | static inline int split_swap_cluster(swp_entry_t entry) | |
638 | { | |
639 | return 0; | |
640 | } | |
641 | #endif | |
642 | ||
6f2cb2f1 VD |
643 | #ifdef CONFIG_MEMCG |
644 | static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) | |
645 | { | |
4550c4e1 JW |
646 | /* Cgroup2 doesn't have per-cgroup swappiness */ |
647 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
648 | return vm_swappiness; | |
649 | ||
6f2cb2f1 VD |
650 | /* root ? */ |
651 | if (mem_cgroup_disabled() || !memcg->css.parent) | |
652 | return vm_swappiness; | |
653 | ||
654 | return memcg->swappiness; | |
655 | } | |
656 | ||
657 | #else | |
658 | static inline int mem_cgroup_swappiness(struct mem_cgroup *mem) | |
659 | { | |
660 | return vm_swappiness; | |
661 | } | |
662 | #endif | |
663 | ||
664 | #ifdef CONFIG_MEMCG_SWAP | |
665 | extern void mem_cgroup_swapout(struct page *page, swp_entry_t entry); | |
666 | extern int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry); | |
38d8b4e6 | 667 | extern void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages); |
d8b38438 | 668 | extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg); |
5ccc5aba | 669 | extern bool mem_cgroup_swap_full(struct page *page); |
6f2cb2f1 VD |
670 | #else |
671 | static inline void mem_cgroup_swapout(struct page *page, swp_entry_t entry) | |
672 | { | |
673 | } | |
674 | ||
675 | static inline int mem_cgroup_try_charge_swap(struct page *page, | |
676 | swp_entry_t entry) | |
677 | { | |
678 | return 0; | |
679 | } | |
680 | ||
38d8b4e6 HY |
681 | static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, |
682 | unsigned int nr_pages) | |
6f2cb2f1 VD |
683 | { |
684 | } | |
d8b38438 VD |
685 | |
686 | static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) | |
687 | { | |
688 | return get_nr_swap_pages(); | |
689 | } | |
5ccc5aba VD |
690 | |
691 | static inline bool mem_cgroup_swap_full(struct page *page) | |
692 | { | |
693 | return vm_swap_full(); | |
694 | } | |
6f2cb2f1 VD |
695 | #endif |
696 | ||
1da177e4 LT |
697 | #endif /* __KERNEL__*/ |
698 | #endif /* _LINUX_SWAP_H */ |