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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 | ||
64e3d12f KHY |
21 | struct pagevec; |
22 | ||
1da177e4 LT |
23 | #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */ |
24 | #define SWAP_FLAG_PRIO_MASK 0x7fff | |
25 | #define SWAP_FLAG_PRIO_SHIFT 0 | |
dcf6b7dd RA |
26 | #define SWAP_FLAG_DISCARD 0x10000 /* enable discard for swap */ |
27 | #define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */ | |
28 | #define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */ | |
1da177e4 | 29 | |
d15cab97 | 30 | #define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \ |
dcf6b7dd RA |
31 | SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \ |
32 | SWAP_FLAG_DISCARD_PAGES) | |
36005bae | 33 | #define SWAP_BATCH 64 |
d15cab97 | 34 | |
1da177e4 LT |
35 | static inline int current_is_kswapd(void) |
36 | { | |
37 | return current->flags & PF_KSWAPD; | |
38 | } | |
39 | ||
40 | /* | |
41 | * MAX_SWAPFILES defines the maximum number of swaptypes: things which can | |
42 | * be swapped to. The swap type and the offset into that swap type are | |
43 | * encoded into pte's and into pgoff_t's in the swapcache. Using five bits | |
44 | * for the type means that the maximum number of swapcache pages is 27 bits | |
45 | * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs | |
46 | * the type/offset into the pte as 5/27 as well. | |
47 | */ | |
48 | #define MAX_SWAPFILES_SHIFT 5 | |
a7420aa5 AK |
49 | |
50 | /* | |
51 | * Use some of the swap files numbers for other purposes. This | |
52 | * is a convenient way to hook into the VM to trigger special | |
53 | * actions on faults. | |
54 | */ | |
55 | ||
5042db43 JG |
56 | /* |
57 | * Unaddressable device memory support. See include/linux/hmm.h and | |
ad56b738 | 58 | * Documentation/vm/hmm.rst. Short description is we need struct pages for |
5042db43 JG |
59 | * device memory that is unaddressable (inaccessible) by CPU, so that we can |
60 | * migrate part of a process memory to device memory. | |
61 | * | |
62 | * When a page is migrated from CPU to device, we set the CPU page table entry | |
63 | * to a special SWP_DEVICE_* entry. | |
64 | */ | |
65 | #ifdef CONFIG_DEVICE_PRIVATE | |
66 | #define SWP_DEVICE_NUM 2 | |
67 | #define SWP_DEVICE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM) | |
68 | #define SWP_DEVICE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+1) | |
69 | #else | |
70 | #define SWP_DEVICE_NUM 0 | |
71 | #endif | |
72 | ||
a7420aa5 AK |
73 | /* |
74 | * NUMA node memory migration support | |
75 | */ | |
76 | #ifdef CONFIG_MIGRATION | |
77 | #define SWP_MIGRATION_NUM 2 | |
78 | #define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM) | |
79 | #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1) | |
0697212a | 80 | #else |
a7420aa5 | 81 | #define SWP_MIGRATION_NUM 0 |
0697212a | 82 | #endif |
1da177e4 | 83 | |
a7420aa5 AK |
84 | /* |
85 | * Handling of hardware poisoned pages with memory corruption. | |
86 | */ | |
87 | #ifdef CONFIG_MEMORY_FAILURE | |
88 | #define SWP_HWPOISON_NUM 1 | |
89 | #define SWP_HWPOISON MAX_SWAPFILES | |
90 | #else | |
91 | #define SWP_HWPOISON_NUM 0 | |
92 | #endif | |
93 | ||
94 | #define MAX_SWAPFILES \ | |
5042db43 JG |
95 | ((1 << MAX_SWAPFILES_SHIFT) - SWP_DEVICE_NUM - \ |
96 | SWP_MIGRATION_NUM - SWP_HWPOISON_NUM) | |
a7420aa5 | 97 | |
1da177e4 LT |
98 | /* |
99 | * Magic header for a swap area. The first part of the union is | |
100 | * what the swap magic looks like for the old (limited to 128MB) | |
101 | * swap area format, the second part of the union adds - in the | |
102 | * old reserved area - some extra information. Note that the first | |
103 | * kilobyte is reserved for boot loader or disk label stuff... | |
104 | * | |
105 | * Having the magic at the end of the PAGE_SIZE makes detecting swap | |
106 | * areas somewhat tricky on machines that support multiple page sizes. | |
107 | * For 2.5 we'll probably want to move the magic to just beyond the | |
108 | * bootbits... | |
109 | */ | |
110 | union swap_header { | |
111 | struct { | |
112 | char reserved[PAGE_SIZE - 10]; | |
113 | char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ | |
114 | } magic; | |
115 | struct { | |
e8f03d02 AD |
116 | char bootbits[1024]; /* Space for disklabel etc. */ |
117 | __u32 version; | |
118 | __u32 last_page; | |
119 | __u32 nr_badpages; | |
120 | unsigned char sws_uuid[16]; | |
121 | unsigned char sws_volume[16]; | |
122 | __u32 padding[117]; | |
123 | __u32 badpages[1]; | |
1da177e4 LT |
124 | } info; |
125 | }; | |
126 | ||
1da177e4 LT |
127 | /* |
128 | * current->reclaim_state points to one of these when a task is running | |
129 | * memory reclaim | |
130 | */ | |
131 | struct reclaim_state { | |
132 | unsigned long reclaimed_slab; | |
133 | }; | |
134 | ||
135 | #ifdef __KERNEL__ | |
136 | ||
137 | struct address_space; | |
138 | struct sysinfo; | |
139 | struct writeback_control; | |
140 | struct zone; | |
141 | ||
142 | /* | |
143 | * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of | |
144 | * disk blocks. A list of swap extents maps the entire swapfile. (Where the | |
145 | * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart | |
146 | * from setup, they're handled identically. | |
147 | * | |
148 | * We always assume that blocks are of size PAGE_SIZE. | |
149 | */ | |
150 | struct swap_extent { | |
4efaceb1 | 151 | struct rb_node rb_node; |
1da177e4 LT |
152 | pgoff_t start_page; |
153 | pgoff_t nr_pages; | |
154 | sector_t start_block; | |
155 | }; | |
156 | ||
157 | /* | |
158 | * Max bad pages in the new format.. | |
159 | */ | |
1da177e4 | 160 | #define MAX_SWAP_BADPAGES \ |
a4046c06 PHS |
161 | ((offsetof(union swap_header, magic.magic) - \ |
162 | offsetof(union swap_header, info.badpages)) / sizeof(int)) | |
1da177e4 LT |
163 | |
164 | enum { | |
165 | SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ | |
166 | SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ | |
dcf6b7dd | 167 | SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */ |
7992fde7 | 168 | SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */ |
20137a49 | 169 | SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ |
570a335b | 170 | SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */ |
b2725643 | 171 | SWP_BLKDEV = (1 << 6), /* its a block device */ |
bc4ae27d OS |
172 | SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */ |
173 | SWP_FS = (1 << 8), /* swap file goes through fs */ | |
174 | SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */ | |
175 | SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */ | |
176 | SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */ | |
177 | SWP_SYNCHRONOUS_IO = (1 << 12), /* synchronous IO is efficient */ | |
eb085574 | 178 | SWP_VALID = (1 << 13), /* swap is valid to be operated on? */ |
52b7efdb | 179 | /* add others here before... */ |
eb085574 | 180 | SWP_SCANNING = (1 << 14), /* refcount in scan_swap_map */ |
1da177e4 LT |
181 | }; |
182 | ||
d778df51 | 183 | #define SWAP_CLUSTER_MAX 32UL |
748446bb | 184 | #define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX |
1da177e4 | 185 | |
4b4bb6bb | 186 | /* Bit flag in swap_map */ |
570a335b | 187 | #define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */ |
4b4bb6bb WY |
188 | #define COUNT_CONTINUED 0x80 /* Flag swap_map continuation for full count */ |
189 | ||
190 | /* Special value in first swap_map */ | |
191 | #define SWAP_MAP_MAX 0x3e /* Max count */ | |
192 | #define SWAP_MAP_BAD 0x3f /* Note page is bad */ | |
193 | #define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs */ | |
194 | ||
195 | /* Special value in each swap_map continuation */ | |
196 | #define SWAP_CONT_MAX 0x7f /* Max count */ | |
253d553b | 197 | |
2a8f9449 SL |
198 | /* |
199 | * We use this to track usage of a cluster. A cluster is a block of swap disk | |
200 | * space with SWAPFILE_CLUSTER pages long and naturally aligns in disk. All | |
201 | * free clusters are organized into a list. We fetch an entry from the list to | |
202 | * get a free cluster. | |
203 | * | |
204 | * The data field stores next cluster if the cluster is free or cluster usage | |
205 | * counter otherwise. The flags field determines if a cluster is free. This is | |
206 | * protected by swap_info_struct.lock. | |
207 | */ | |
208 | struct swap_cluster_info { | |
235b6217 HY |
209 | spinlock_t lock; /* |
210 | * Protect swap_cluster_info fields | |
211 | * and swap_info_struct->swap_map | |
212 | * elements correspond to the swap | |
213 | * cluster | |
214 | */ | |
2a8f9449 SL |
215 | unsigned int data:24; |
216 | unsigned int flags:8; | |
217 | }; | |
218 | #define CLUSTER_FLAG_FREE 1 /* This cluster is free */ | |
219 | #define CLUSTER_FLAG_NEXT_NULL 2 /* This cluster has no next cluster */ | |
e0709829 | 220 | #define CLUSTER_FLAG_HUGE 4 /* This cluster is backing a transparent huge page */ |
2a8f9449 | 221 | |
ebc2a1a6 SL |
222 | /* |
223 | * We assign a cluster to each CPU, so each CPU can allocate swap entry from | |
224 | * its own cluster and swapout sequentially. The purpose is to optimize swapout | |
225 | * throughput. | |
226 | */ | |
227 | struct percpu_cluster { | |
228 | struct swap_cluster_info index; /* Current cluster index */ | |
229 | unsigned int next; /* Likely next allocation offset */ | |
230 | }; | |
231 | ||
6b534915 HY |
232 | struct swap_cluster_list { |
233 | struct swap_cluster_info head; | |
234 | struct swap_cluster_info tail; | |
235 | }; | |
236 | ||
1da177e4 LT |
237 | /* |
238 | * The in-memory structure used to track swap areas. | |
1da177e4 LT |
239 | */ |
240 | struct swap_info_struct { | |
efa90a98 HD |
241 | unsigned long flags; /* SWP_USED etc: see above */ |
242 | signed short prio; /* swap priority of this type */ | |
18ab4d4c | 243 | struct plist_node list; /* entry in swap_active_head */ |
efa90a98 | 244 | signed char type; /* strange name for an index */ |
7509765a HD |
245 | unsigned int max; /* extent of the swap_map */ |
246 | unsigned char *swap_map; /* vmalloc'ed array of usage counts */ | |
2a8f9449 | 247 | struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */ |
6b534915 | 248 | struct swap_cluster_list free_clusters; /* free clusters list */ |
7509765a HD |
249 | unsigned int lowest_bit; /* index of first free in swap_map */ |
250 | unsigned int highest_bit; /* index of last free in swap_map */ | |
251 | unsigned int pages; /* total of usable pages of swap */ | |
252 | unsigned int inuse_pages; /* number of those currently in use */ | |
253 | unsigned int cluster_next; /* likely index for next allocation */ | |
254 | unsigned int cluster_nr; /* countdown to next cluster search */ | |
49070588 | 255 | unsigned int __percpu *cluster_next_cpu; /*percpu index for next allocation */ |
ebc2a1a6 | 256 | struct percpu_cluster __percpu *percpu_cluster; /* per cpu's swap location */ |
4efaceb1 | 257 | struct rb_root swap_extent_root;/* root of the swap extent rbtree */ |
7509765a HD |
258 | struct block_device *bdev; /* swap device or bdev of swap file */ |
259 | struct file *swap_file; /* seldom referenced */ | |
260 | unsigned int old_block_size; /* seldom referenced */ | |
38b5faf4 DM |
261 | #ifdef CONFIG_FRONTSWAP |
262 | unsigned long *frontswap_map; /* frontswap in-use, one bit per page */ | |
263 | atomic_t frontswap_pages; /* frontswap pages in-use counter */ | |
264 | #endif | |
ec8acf20 SL |
265 | spinlock_t lock; /* |
266 | * protect map scan related fields like | |
267 | * swap_map, lowest_bit, highest_bit, | |
268 | * inuse_pages, cluster_next, | |
815c2c54 SL |
269 | * cluster_nr, lowest_alloc, |
270 | * highest_alloc, free/discard cluster | |
271 | * list. other fields are only changed | |
272 | * at swapon/swapoff, so are protected | |
273 | * by swap_lock. changing flags need | |
274 | * hold this lock and swap_lock. If | |
275 | * both locks need hold, hold swap_lock | |
276 | * first. | |
ec8acf20 | 277 | */ |
2628bd6f HY |
278 | spinlock_t cont_lock; /* |
279 | * protect swap count continuation page | |
280 | * list. | |
281 | */ | |
815c2c54 | 282 | struct work_struct discard_work; /* discard worker */ |
6b534915 | 283 | struct swap_cluster_list discard_clusters; /* discard clusters list */ |
16c3380f | 284 | struct plist_node avail_lists[]; /* |
66f71da9 AL |
285 | * entries in swap_avail_heads, one |
286 | * entry per node. | |
287 | * Must be last as the number of the | |
288 | * array is nr_node_ids, which is not | |
289 | * a fixed value so have to allocate | |
290 | * dynamically. | |
291 | * And it has to be an array so that | |
292 | * plist_for_each_* can work. | |
293 | */ | |
1da177e4 LT |
294 | }; |
295 | ||
ec560175 HY |
296 | #ifdef CONFIG_64BIT |
297 | #define SWAP_RA_ORDER_CEILING 5 | |
298 | #else | |
299 | /* Avoid stack overflow, because we need to save part of page table */ | |
300 | #define SWAP_RA_ORDER_CEILING 3 | |
301 | #define SWAP_RA_PTE_CACHE_SIZE (1 << SWAP_RA_ORDER_CEILING) | |
302 | #endif | |
303 | ||
304 | struct vma_swap_readahead { | |
305 | unsigned short win; | |
306 | unsigned short offset; | |
307 | unsigned short nr_pte; | |
308 | #ifdef CONFIG_64BIT | |
309 | pte_t *ptes; | |
310 | #else | |
311 | pte_t ptes[SWAP_RA_PTE_CACHE_SIZE]; | |
312 | #endif | |
313 | }; | |
314 | ||
a528910e | 315 | /* linux/mm/workingset.c */ |
31d8fcac | 316 | void workingset_age_nonresident(struct lruvec *lruvec, unsigned long nr_pages); |
b910718a | 317 | void *workingset_eviction(struct page *page, struct mem_cgroup *target_memcg); |
1899ad18 | 318 | void workingset_refault(struct page *page, void *shadow); |
a528910e | 319 | void workingset_activation(struct page *page); |
c7df8ad2 | 320 | |
74d60958 MW |
321 | /* Only track the nodes of mappings with shadow entries */ |
322 | void workingset_update_node(struct xa_node *node); | |
323 | #define mapping_set_update(xas, mapping) do { \ | |
324 | if (!dax_mapping(mapping) && !shmem_mapping(mapping)) \ | |
325 | xas_set_update(xas, workingset_update_node); \ | |
326 | } while (0) | |
a528910e | 327 | |
1da177e4 | 328 | /* linux/mm/page_alloc.c */ |
cb45b0e9 | 329 | extern unsigned long totalreserve_pages; |
ebec3862 | 330 | extern unsigned long nr_free_buffer_pages(void); |
1da177e4 | 331 | |
c41f012a MH |
332 | /* Definition of global_zone_page_state not available yet */ |
333 | #define nr_free_pages() global_zone_page_state(NR_FREE_PAGES) | |
96177299 CL |
334 | |
335 | ||
1da177e4 | 336 | /* linux/mm/swap.c */ |
96f8bf4f JW |
337 | extern void lru_note_cost(struct lruvec *lruvec, bool file, |
338 | unsigned int nr_pages); | |
339 | extern void lru_note_cost_page(struct page *); | |
c53954a0 | 340 | extern void lru_cache_add(struct page *); |
fa9add64 | 341 | extern void lru_add_page_tail(struct page *page, struct page *page_tail, |
5bc7b8ac | 342 | struct lruvec *lruvec, struct list_head *head); |
b3c97528 HH |
343 | extern void activate_page(struct page *); |
344 | extern void mark_page_accessed(struct page *); | |
1da177e4 | 345 | extern void lru_add_drain(void); |
f0cb3c76 | 346 | extern void lru_add_drain_cpu(int cpu); |
b01b2141 | 347 | extern void lru_add_drain_cpu_zone(struct zone *zone); |
5fbc4616 | 348 | extern void lru_add_drain_all(void); |
ac6aadb2 | 349 | extern void rotate_reclaimable_page(struct page *page); |
cc5993bd | 350 | extern void deactivate_file_page(struct page *page); |
9c276cc6 | 351 | extern void deactivate_page(struct page *page); |
f7ad2a6c | 352 | extern void mark_page_lazyfree(struct page *page); |
1da177e4 LT |
353 | extern void swap_setup(void); |
354 | ||
b518154e | 355 | extern void lru_cache_add_inactive_or_unevictable(struct page *page, |
00501b53 JW |
356 | struct vm_area_struct *vma); |
357 | ||
1da177e4 | 358 | /* linux/mm/vmscan.c */ |
5a1c84b4 | 359 | extern unsigned long zone_reclaimable_pages(struct zone *zone); |
dac1d27b | 360 | extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, |
327c0e96 | 361 | gfp_t gfp_mask, nodemask_t *mask); |
f3fd4a61 | 362 | extern int __isolate_lru_page(struct page *page, isolate_mode_t mode); |
b70a2a21 JW |
363 | extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, |
364 | unsigned long nr_pages, | |
365 | gfp_t gfp_mask, | |
366 | bool may_swap); | |
a9dd0a83 | 367 | extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem, |
185efc0f | 368 | gfp_t gfp_mask, bool noswap, |
ef8f2327 | 369 | pg_data_t *pgdat, |
185efc0f | 370 | unsigned long *nr_scanned); |
69e05944 | 371 | extern unsigned long shrink_all_memory(unsigned long nr_pages); |
1da177e4 | 372 | extern int vm_swappiness; |
b20a3503 CL |
373 | extern int remove_mapping(struct address_space *mapping, struct page *page); |
374 | ||
1a4e58cc | 375 | extern unsigned long reclaim_pages(struct list_head *page_list); |
9eeff239 | 376 | #ifdef CONFIG_NUMA |
a5f5f91d | 377 | extern int node_reclaim_mode; |
9614634f | 378 | extern int sysctl_min_unmapped_ratio; |
0ff38490 | 379 | extern int sysctl_min_slab_ratio; |
9eeff239 | 380 | #else |
a5f5f91d | 381 | #define node_reclaim_mode 0 |
9eeff239 CL |
382 | #endif |
383 | ||
64e3d12f | 384 | extern void check_move_unevictable_pages(struct pagevec *pvec); |
af936a16 | 385 | |
3218ae14 | 386 | extern int kswapd_run(int nid); |
8fe23e05 | 387 | extern void kswapd_stop(int nid); |
33398cf2 | 388 | |
1da177e4 | 389 | #ifdef CONFIG_SWAP |
be297968 CH |
390 | |
391 | #include <linux/blk_types.h> /* for bio_end_io_t */ | |
392 | ||
1da177e4 | 393 | /* linux/mm/page_io.c */ |
23955622 | 394 | extern int swap_readpage(struct page *page, bool do_poll); |
1da177e4 | 395 | extern int swap_writepage(struct page *page, struct writeback_control *wbc); |
4246a0b6 | 396 | extern void end_swap_bio_write(struct bio *bio); |
1eec6702 | 397 | extern int __swap_writepage(struct page *page, struct writeback_control *wbc, |
4246a0b6 | 398 | bio_end_io_t end_write_func); |
62c230bc | 399 | extern int swap_set_page_dirty(struct page *page); |
1da177e4 | 400 | |
a509bc1a MG |
401 | int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page, |
402 | unsigned long nr_pages, sector_t start_block); | |
403 | int generic_swapfile_activate(struct swap_info_struct *, struct file *, | |
404 | sector_t *); | |
405 | ||
1da177e4 | 406 | /* linux/mm/swap_state.c */ |
4b3ef9da HY |
407 | /* One swap address space for each 64M swap space */ |
408 | #define SWAP_ADDRESS_SPACE_SHIFT 14 | |
409 | #define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT) | |
410 | extern struct address_space *swapper_spaces[]; | |
411 | #define swap_address_space(entry) \ | |
412 | (&swapper_spaces[swp_type(entry)][swp_offset(entry) \ | |
413 | >> SWAP_ADDRESS_SPACE_SHIFT]) | |
33806f06 | 414 | extern unsigned long total_swapcache_pages(void); |
1da177e4 | 415 | extern void show_swap_cache_info(void); |
0f074658 | 416 | extern int add_to_swap(struct page *page); |
aae466b0 | 417 | extern void *get_shadow_from_swap_cache(swp_entry_t entry); |
3852f676 JK |
418 | extern int add_to_swap_cache(struct page *page, swp_entry_t entry, |
419 | gfp_t gfp, void **shadowp); | |
420 | extern void __delete_from_swap_cache(struct page *page, | |
421 | swp_entry_t entry, void *shadow); | |
1da177e4 | 422 | extern void delete_from_swap_cache(struct page *); |
3852f676 JK |
423 | extern void clear_shadow_from_swap_cache(int type, unsigned long begin, |
424 | unsigned long end); | |
1da177e4 LT |
425 | extern void free_page_and_swap_cache(struct page *); |
426 | extern void free_pages_and_swap_cache(struct page **, int); | |
ec560175 HY |
427 | extern struct page *lookup_swap_cache(swp_entry_t entry, |
428 | struct vm_area_struct *vma, | |
429 | unsigned long addr); | |
02098fea | 430 | extern struct page *read_swap_cache_async(swp_entry_t, gfp_t, |
23955622 SL |
431 | struct vm_area_struct *vma, unsigned long addr, |
432 | bool do_poll); | |
5b999aad DS |
433 | extern struct page *__read_swap_cache_async(swp_entry_t, gfp_t, |
434 | struct vm_area_struct *vma, unsigned long addr, | |
435 | bool *new_page_allocated); | |
e9e9b7ec MK |
436 | extern struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag, |
437 | struct vm_fault *vmf); | |
438 | extern struct page *swapin_readahead(swp_entry_t entry, gfp_t flag, | |
439 | struct vm_fault *vmf); | |
ec560175 | 440 | |
1da177e4 | 441 | /* linux/mm/swapfile.c */ |
ec8acf20 | 442 | extern atomic_long_t nr_swap_pages; |
1da177e4 | 443 | extern long total_swap_pages; |
81a0298b | 444 | extern atomic_t nr_rotate_swap; |
67afa38e | 445 | extern bool has_usable_swap(void); |
ec8acf20 SL |
446 | |
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); |
5d5e8f19 | 462 | extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size); |
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 *); |
eb085574 | 475 | extern int __swap_count(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); | |
eb085574 HY |
485 | extern struct swap_info_struct *get_swap_device(swp_entry_t entry); |
486 | ||
487 | static inline void put_swap_device(struct swap_info_struct *si) | |
488 | { | |
489 | rcu_read_unlock(); | |
490 | } | |
1da177e4 | 491 | |
1da177e4 LT |
492 | #else /* CONFIG_SWAP */ |
493 | ||
0bcac06f MK |
494 | static inline int swap_readpage(struct page *page, bool do_poll) |
495 | { | |
496 | return 0; | |
497 | } | |
498 | ||
499 | static inline struct swap_info_struct *swp_swap_info(swp_entry_t entry) | |
500 | { | |
501 | return NULL; | |
502 | } | |
503 | ||
d2cf5ad6 | 504 | #define swap_address_space(entry) (NULL) |
ec8acf20 | 505 | #define get_nr_swap_pages() 0L |
b962716b | 506 | #define total_swap_pages 0L |
33806f06 | 507 | #define total_swapcache_pages() 0UL |
ec8acf20 | 508 | #define vm_swap_full() 0 |
1da177e4 LT |
509 | |
510 | #define si_swapinfo(val) \ | |
511 | do { (val)->freeswap = (val)->totalswap = 0; } while (0) | |
9ae5b3c7 | 512 | /* only sparc can not include linux/pagemap.h in this file |
ea1754a0 | 513 | * so leave put_page and release_pages undeclared... */ |
1da177e4 | 514 | #define free_page_and_swap_cache(page) \ |
09cbfeaf | 515 | put_page(page) |
1da177e4 | 516 | #define free_pages_and_swap_cache(pages, nr) \ |
c6f92f9f | 517 | release_pages((pages), (nr)); |
1da177e4 | 518 | |
bd96b9eb CK |
519 | static inline void show_swap_cache_info(void) |
520 | { | |
521 | } | |
522 | ||
5042db43 JG |
523 | #define free_swap_and_cache(e) ({(is_migration_entry(e) || is_device_private_entry(e));}) |
524 | #define swapcache_prepare(e) ({(is_migration_entry(e) || is_device_private_entry(e));}) | |
bd96b9eb | 525 | |
570a335b | 526 | static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask) |
355cfa73 | 527 | { |
570a335b HD |
528 | return 0; |
529 | } | |
530 | ||
aaa46865 HD |
531 | static inline void swap_shmem_alloc(swp_entry_t swp) |
532 | { | |
533 | } | |
534 | ||
570a335b HD |
535 | static inline int swap_duplicate(swp_entry_t swp) |
536 | { | |
537 | return 0; | |
355cfa73 KH |
538 | } |
539 | ||
bd96b9eb CK |
540 | static inline void swap_free(swp_entry_t swp) |
541 | { | |
542 | } | |
543 | ||
75f6d6d2 | 544 | static inline void put_swap_page(struct page *page, swp_entry_t swp) |
cb4b86ba KH |
545 | { |
546 | } | |
547 | ||
e9e9b7ec MK |
548 | static inline struct page *swap_cluster_readahead(swp_entry_t entry, |
549 | gfp_t gfp_mask, struct vm_fault *vmf) | |
bd96b9eb CK |
550 | { |
551 | return NULL; | |
552 | } | |
553 | ||
e9e9b7ec MK |
554 | static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, |
555 | struct vm_fault *vmf) | |
ec560175 HY |
556 | { |
557 | return NULL; | |
558 | } | |
559 | ||
9fab5619 HD |
560 | static inline int swap_writepage(struct page *p, struct writeback_control *wbc) |
561 | { | |
562 | return 0; | |
563 | } | |
564 | ||
ec560175 HY |
565 | static inline struct page *lookup_swap_cache(swp_entry_t swp, |
566 | struct vm_area_struct *vma, | |
567 | unsigned long addr) | |
bd96b9eb CK |
568 | { |
569 | return NULL; | |
570 | } | |
571 | ||
0f074658 | 572 | static inline int add_to_swap(struct page *page) |
60371d97 HD |
573 | { |
574 | return 0; | |
575 | } | |
576 | ||
aae466b0 JK |
577 | static inline void *get_shadow_from_swap_cache(swp_entry_t entry) |
578 | { | |
579 | return NULL; | |
580 | } | |
581 | ||
73b1262f | 582 | static inline int add_to_swap_cache(struct page *page, swp_entry_t entry, |
3852f676 | 583 | gfp_t gfp_mask, void **shadowp) |
bd96b9eb | 584 | { |
73b1262f | 585 | return -1; |
bd96b9eb CK |
586 | } |
587 | ||
4e17ec25 | 588 | static inline void __delete_from_swap_cache(struct page *page, |
3852f676 | 589 | swp_entry_t entry, void *shadow) |
bd96b9eb CK |
590 | { |
591 | } | |
592 | ||
593 | static inline void delete_from_swap_cache(struct page *page) | |
594 | { | |
595 | } | |
596 | ||
3852f676 JK |
597 | static inline void clear_shadow_from_swap_cache(int type, unsigned long begin, |
598 | unsigned long end) | |
599 | { | |
600 | } | |
601 | ||
bde05d1c HD |
602 | static inline int page_swapcount(struct page *page) |
603 | { | |
604 | return 0; | |
605 | } | |
606 | ||
eb085574 | 607 | static inline int __swap_count(swp_entry_t entry) |
aa8d22a1 MK |
608 | { |
609 | return 0; | |
610 | } | |
611 | ||
e8c26ab6 TC |
612 | static inline int __swp_swapcount(swp_entry_t entry) |
613 | { | |
614 | return 0; | |
615 | } | |
616 | ||
8334b962 MK |
617 | static inline int swp_swapcount(swp_entry_t entry) |
618 | { | |
619 | return 0; | |
620 | } | |
621 | ||
ba3c4ce6 HY |
622 | #define reuse_swap_page(page, total_map_swapcount) \ |
623 | (page_trans_huge_mapcount(page, total_map_swapcount) == 1) | |
1da177e4 | 624 | |
a2c43eed | 625 | static inline int try_to_free_swap(struct page *page) |
68a22394 RR |
626 | { |
627 | return 0; | |
628 | } | |
629 | ||
38d8b4e6 | 630 | static inline swp_entry_t get_swap_page(struct page *page) |
1da177e4 LT |
631 | { |
632 | swp_entry_t entry; | |
633 | entry.val = 0; | |
634 | return entry; | |
635 | } | |
636 | ||
1da177e4 | 637 | #endif /* CONFIG_SWAP */ |
6f2cb2f1 | 638 | |
59807685 HY |
639 | #ifdef CONFIG_THP_SWAP |
640 | extern int split_swap_cluster(swp_entry_t entry); | |
641 | #else | |
642 | static inline int split_swap_cluster(swp_entry_t entry) | |
643 | { | |
644 | return 0; | |
645 | } | |
646 | #endif | |
647 | ||
6f2cb2f1 VD |
648 | #ifdef CONFIG_MEMCG |
649 | static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) | |
650 | { | |
4550c4e1 JW |
651 | /* Cgroup2 doesn't have per-cgroup swappiness */ |
652 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
653 | return vm_swappiness; | |
654 | ||
6f2cb2f1 | 655 | /* root ? */ |
59118c42 | 656 | if (mem_cgroup_disabled() || mem_cgroup_is_root(memcg)) |
6f2cb2f1 VD |
657 | return vm_swappiness; |
658 | ||
659 | return memcg->swappiness; | |
660 | } | |
6f2cb2f1 VD |
661 | #else |
662 | static inline int mem_cgroup_swappiness(struct mem_cgroup *mem) | |
663 | { | |
664 | return vm_swappiness; | |
665 | } | |
666 | #endif | |
667 | ||
2cf85583 | 668 | #if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP) |
6caa6a07 | 669 | extern void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask); |
2cf85583 | 670 | #else |
6caa6a07 | 671 | static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask) |
2cf85583 TH |
672 | { |
673 | } | |
674 | #endif | |
675 | ||
6f2cb2f1 VD |
676 | #ifdef CONFIG_MEMCG_SWAP |
677 | extern void mem_cgroup_swapout(struct page *page, swp_entry_t entry); | |
678 | extern int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry); | |
38d8b4e6 | 679 | extern void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages); |
d8b38438 | 680 | extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg); |
5ccc5aba | 681 | extern bool mem_cgroup_swap_full(struct page *page); |
6f2cb2f1 VD |
682 | #else |
683 | static inline void mem_cgroup_swapout(struct page *page, swp_entry_t entry) | |
684 | { | |
685 | } | |
686 | ||
687 | static inline int mem_cgroup_try_charge_swap(struct page *page, | |
688 | swp_entry_t entry) | |
689 | { | |
690 | return 0; | |
691 | } | |
692 | ||
38d8b4e6 HY |
693 | static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, |
694 | unsigned int nr_pages) | |
6f2cb2f1 VD |
695 | { |
696 | } | |
d8b38438 VD |
697 | |
698 | static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) | |
699 | { | |
700 | return get_nr_swap_pages(); | |
701 | } | |
5ccc5aba VD |
702 | |
703 | static inline bool mem_cgroup_swap_full(struct page *page) | |
704 | { | |
705 | return vm_swap_full(); | |
706 | } | |
6f2cb2f1 VD |
707 | #endif |
708 | ||
1da177e4 LT |
709 | #endif /* __KERNEL__*/ |
710 | #endif /* _LINUX_SWAP_H */ |