Commit | Line | Data |
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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 |
19 | struct notifier_block; |
20 | ||
ab954160 AM |
21 | struct bio; |
22 | ||
64e3d12f KHY |
23 | struct pagevec; |
24 | ||
1da177e4 LT |
25 | #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */ |
26 | #define SWAP_FLAG_PRIO_MASK 0x7fff | |
27 | #define SWAP_FLAG_PRIO_SHIFT 0 | |
dcf6b7dd RA |
28 | #define SWAP_FLAG_DISCARD 0x10000 /* enable discard for swap */ |
29 | #define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */ | |
30 | #define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */ | |
1da177e4 | 31 | |
d15cab97 | 32 | #define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \ |
dcf6b7dd RA |
33 | SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \ |
34 | SWAP_FLAG_DISCARD_PAGES) | |
36005bae | 35 | #define SWAP_BATCH 64 |
d15cab97 | 36 | |
1da177e4 LT |
37 | static inline int current_is_kswapd(void) |
38 | { | |
39 | return current->flags & PF_KSWAPD; | |
40 | } | |
41 | ||
42 | /* | |
43 | * MAX_SWAPFILES defines the maximum number of swaptypes: things which can | |
44 | * be swapped to. The swap type and the offset into that swap type are | |
45 | * encoded into pte's and into pgoff_t's in the swapcache. Using five bits | |
46 | * for the type means that the maximum number of swapcache pages is 27 bits | |
47 | * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs | |
48 | * the type/offset into the pte as 5/27 as well. | |
49 | */ | |
50 | #define MAX_SWAPFILES_SHIFT 5 | |
a7420aa5 AK |
51 | |
52 | /* | |
53 | * Use some of the swap files numbers for other purposes. This | |
54 | * is a convenient way to hook into the VM to trigger special | |
55 | * actions on faults. | |
56 | */ | |
57 | ||
5042db43 JG |
58 | /* |
59 | * Unaddressable device memory support. See include/linux/hmm.h and | |
ad56b738 | 60 | * Documentation/vm/hmm.rst. Short description is we need struct pages for |
5042db43 JG |
61 | * device memory that is unaddressable (inaccessible) by CPU, so that we can |
62 | * migrate part of a process memory to device memory. | |
63 | * | |
64 | * When a page is migrated from CPU to device, we set the CPU page table entry | |
b756a3b5 AP |
65 | * to a special SWP_DEVICE_{READ|WRITE} entry. |
66 | * | |
67 | * When a page is mapped by the device for exclusive access we set the CPU page | |
68 | * table entries to special SWP_DEVICE_EXCLUSIVE_* entries. | |
5042db43 JG |
69 | */ |
70 | #ifdef CONFIG_DEVICE_PRIVATE | |
b756a3b5 | 71 | #define SWP_DEVICE_NUM 4 |
5042db43 JG |
72 | #define SWP_DEVICE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM) |
73 | #define SWP_DEVICE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+1) | |
b756a3b5 AP |
74 | #define SWP_DEVICE_EXCLUSIVE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+2) |
75 | #define SWP_DEVICE_EXCLUSIVE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+3) | |
5042db43 JG |
76 | #else |
77 | #define SWP_DEVICE_NUM 0 | |
78 | #endif | |
79 | ||
a7420aa5 AK |
80 | /* |
81 | * NUMA node memory migration support | |
82 | */ | |
83 | #ifdef CONFIG_MIGRATION | |
84 | #define SWP_MIGRATION_NUM 2 | |
85 | #define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM) | |
86 | #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1) | |
0697212a | 87 | #else |
a7420aa5 | 88 | #define SWP_MIGRATION_NUM 0 |
0697212a | 89 | #endif |
1da177e4 | 90 | |
a7420aa5 AK |
91 | /* |
92 | * Handling of hardware poisoned pages with memory corruption. | |
93 | */ | |
94 | #ifdef CONFIG_MEMORY_FAILURE | |
95 | #define SWP_HWPOISON_NUM 1 | |
96 | #define SWP_HWPOISON MAX_SWAPFILES | |
97 | #else | |
98 | #define SWP_HWPOISON_NUM 0 | |
99 | #endif | |
100 | ||
101 | #define MAX_SWAPFILES \ | |
5042db43 JG |
102 | ((1 << MAX_SWAPFILES_SHIFT) - SWP_DEVICE_NUM - \ |
103 | SWP_MIGRATION_NUM - SWP_HWPOISON_NUM) | |
a7420aa5 | 104 | |
1da177e4 LT |
105 | /* |
106 | * Magic header for a swap area. The first part of the union is | |
107 | * what the swap magic looks like for the old (limited to 128MB) | |
108 | * swap area format, the second part of the union adds - in the | |
109 | * old reserved area - some extra information. Note that the first | |
110 | * kilobyte is reserved for boot loader or disk label stuff... | |
111 | * | |
112 | * Having the magic at the end of the PAGE_SIZE makes detecting swap | |
113 | * areas somewhat tricky on machines that support multiple page sizes. | |
114 | * For 2.5 we'll probably want to move the magic to just beyond the | |
115 | * bootbits... | |
116 | */ | |
117 | union swap_header { | |
118 | struct { | |
119 | char reserved[PAGE_SIZE - 10]; | |
120 | char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ | |
121 | } magic; | |
122 | struct { | |
e8f03d02 AD |
123 | char bootbits[1024]; /* Space for disklabel etc. */ |
124 | __u32 version; | |
125 | __u32 last_page; | |
126 | __u32 nr_badpages; | |
127 | unsigned char sws_uuid[16]; | |
128 | unsigned char sws_volume[16]; | |
129 | __u32 padding[117]; | |
130 | __u32 badpages[1]; | |
1da177e4 LT |
131 | } info; |
132 | }; | |
133 | ||
1da177e4 LT |
134 | /* |
135 | * current->reclaim_state points to one of these when a task is running | |
136 | * memory reclaim | |
137 | */ | |
138 | struct reclaim_state { | |
139 | unsigned long reclaimed_slab; | |
140 | }; | |
141 | ||
142 | #ifdef __KERNEL__ | |
143 | ||
144 | struct address_space; | |
145 | struct sysinfo; | |
146 | struct writeback_control; | |
147 | struct zone; | |
148 | ||
149 | /* | |
150 | * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of | |
151 | * disk blocks. A list of swap extents maps the entire swapfile. (Where the | |
152 | * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart | |
153 | * from setup, they're handled identically. | |
154 | * | |
155 | * We always assume that blocks are of size PAGE_SIZE. | |
156 | */ | |
157 | struct swap_extent { | |
4efaceb1 | 158 | struct rb_node rb_node; |
1da177e4 LT |
159 | pgoff_t start_page; |
160 | pgoff_t nr_pages; | |
161 | sector_t start_block; | |
162 | }; | |
163 | ||
164 | /* | |
165 | * Max bad pages in the new format.. | |
166 | */ | |
1da177e4 | 167 | #define MAX_SWAP_BADPAGES \ |
a4046c06 PHS |
168 | ((offsetof(union swap_header, magic.magic) - \ |
169 | offsetof(union swap_header, info.badpages)) / sizeof(int)) | |
1da177e4 LT |
170 | |
171 | enum { | |
172 | SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ | |
173 | SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ | |
dcf6b7dd | 174 | SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */ |
7992fde7 | 175 | SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */ |
20137a49 | 176 | SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ |
570a335b | 177 | SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */ |
b2725643 | 178 | SWP_BLKDEV = (1 << 6), /* its a block device */ |
bc4ae27d | 179 | SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */ |
32646315 | 180 | SWP_FS_OPS = (1 << 8), /* swapfile operations go through fs */ |
bc4ae27d OS |
181 | SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */ |
182 | SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */ | |
183 | SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */ | |
184 | SWP_SYNCHRONOUS_IO = (1 << 12), /* synchronous IO is efficient */ | |
52b7efdb | 185 | /* add others here before... */ |
eb085574 | 186 | SWP_SCANNING = (1 << 14), /* refcount in scan_swap_map */ |
1da177e4 LT |
187 | }; |
188 | ||
d778df51 | 189 | #define SWAP_CLUSTER_MAX 32UL |
748446bb | 190 | #define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX |
1da177e4 | 191 | |
4b4bb6bb | 192 | /* Bit flag in swap_map */ |
570a335b | 193 | #define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */ |
4b4bb6bb WY |
194 | #define COUNT_CONTINUED 0x80 /* Flag swap_map continuation for full count */ |
195 | ||
196 | /* Special value in first swap_map */ | |
197 | #define SWAP_MAP_MAX 0x3e /* Max count */ | |
198 | #define SWAP_MAP_BAD 0x3f /* Note page is bad */ | |
199 | #define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs */ | |
200 | ||
201 | /* Special value in each swap_map continuation */ | |
202 | #define SWAP_CONT_MAX 0x7f /* Max count */ | |
253d553b | 203 | |
2a8f9449 SL |
204 | /* |
205 | * We use this to track usage of a cluster. A cluster is a block of swap disk | |
206 | * space with SWAPFILE_CLUSTER pages long and naturally aligns in disk. All | |
207 | * free clusters are organized into a list. We fetch an entry from the list to | |
208 | * get a free cluster. | |
209 | * | |
210 | * The data field stores next cluster if the cluster is free or cluster usage | |
211 | * counter otherwise. The flags field determines if a cluster is free. This is | |
212 | * protected by swap_info_struct.lock. | |
213 | */ | |
214 | struct swap_cluster_info { | |
235b6217 HY |
215 | spinlock_t lock; /* |
216 | * Protect swap_cluster_info fields | |
217 | * and swap_info_struct->swap_map | |
218 | * elements correspond to the swap | |
219 | * cluster | |
220 | */ | |
2a8f9449 SL |
221 | unsigned int data:24; |
222 | unsigned int flags:8; | |
223 | }; | |
224 | #define CLUSTER_FLAG_FREE 1 /* This cluster is free */ | |
225 | #define CLUSTER_FLAG_NEXT_NULL 2 /* This cluster has no next cluster */ | |
e0709829 | 226 | #define CLUSTER_FLAG_HUGE 4 /* This cluster is backing a transparent huge page */ |
2a8f9449 | 227 | |
ebc2a1a6 SL |
228 | /* |
229 | * We assign a cluster to each CPU, so each CPU can allocate swap entry from | |
230 | * its own cluster and swapout sequentially. The purpose is to optimize swapout | |
231 | * throughput. | |
232 | */ | |
233 | struct percpu_cluster { | |
234 | struct swap_cluster_info index; /* Current cluster index */ | |
235 | unsigned int next; /* Likely next allocation offset */ | |
236 | }; | |
237 | ||
6b534915 HY |
238 | struct swap_cluster_list { |
239 | struct swap_cluster_info head; | |
240 | struct swap_cluster_info tail; | |
241 | }; | |
242 | ||
1da177e4 LT |
243 | /* |
244 | * The in-memory structure used to track swap areas. | |
1da177e4 LT |
245 | */ |
246 | struct swap_info_struct { | |
63d8620e | 247 | struct percpu_ref users; /* indicate and keep swap device valid. */ |
efa90a98 HD |
248 | unsigned long flags; /* SWP_USED etc: see above */ |
249 | signed short prio; /* swap priority of this type */ | |
18ab4d4c | 250 | struct plist_node list; /* entry in swap_active_head */ |
efa90a98 | 251 | signed char type; /* strange name for an index */ |
7509765a HD |
252 | unsigned int max; /* extent of the swap_map */ |
253 | unsigned char *swap_map; /* vmalloc'ed array of usage counts */ | |
2a8f9449 | 254 | struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */ |
6b534915 | 255 | struct swap_cluster_list free_clusters; /* free clusters list */ |
7509765a HD |
256 | unsigned int lowest_bit; /* index of first free in swap_map */ |
257 | unsigned int highest_bit; /* index of last free in swap_map */ | |
258 | unsigned int pages; /* total of usable pages of swap */ | |
259 | unsigned int inuse_pages; /* number of those currently in use */ | |
260 | unsigned int cluster_next; /* likely index for next allocation */ | |
261 | unsigned int cluster_nr; /* countdown to next cluster search */ | |
49070588 | 262 | unsigned int __percpu *cluster_next_cpu; /*percpu index for next allocation */ |
ebc2a1a6 | 263 | struct percpu_cluster __percpu *percpu_cluster; /* per cpu's swap location */ |
4efaceb1 | 264 | struct rb_root swap_extent_root;/* root of the swap extent rbtree */ |
7509765a HD |
265 | struct block_device *bdev; /* swap device or bdev of swap file */ |
266 | struct file *swap_file; /* seldom referenced */ | |
267 | unsigned int old_block_size; /* seldom referenced */ | |
63d8620e | 268 | struct completion comp; /* seldom referenced */ |
38b5faf4 DM |
269 | #ifdef CONFIG_FRONTSWAP |
270 | unsigned long *frontswap_map; /* frontswap in-use, one bit per page */ | |
271 | atomic_t frontswap_pages; /* frontswap pages in-use counter */ | |
272 | #endif | |
ec8acf20 SL |
273 | spinlock_t lock; /* |
274 | * protect map scan related fields like | |
275 | * swap_map, lowest_bit, highest_bit, | |
276 | * inuse_pages, cluster_next, | |
815c2c54 SL |
277 | * cluster_nr, lowest_alloc, |
278 | * highest_alloc, free/discard cluster | |
279 | * list. other fields are only changed | |
280 | * at swapon/swapoff, so are protected | |
281 | * by swap_lock. changing flags need | |
282 | * hold this lock and swap_lock. If | |
283 | * both locks need hold, hold swap_lock | |
284 | * first. | |
ec8acf20 | 285 | */ |
2628bd6f HY |
286 | spinlock_t cont_lock; /* |
287 | * protect swap count continuation page | |
288 | * list. | |
289 | */ | |
815c2c54 | 290 | struct work_struct discard_work; /* discard worker */ |
6b534915 | 291 | struct swap_cluster_list discard_clusters; /* discard clusters list */ |
16c3380f | 292 | struct plist_node avail_lists[]; /* |
66f71da9 AL |
293 | * entries in swap_avail_heads, one |
294 | * entry per node. | |
295 | * Must be last as the number of the | |
296 | * array is nr_node_ids, which is not | |
297 | * a fixed value so have to allocate | |
298 | * dynamically. | |
299 | * And it has to be an array so that | |
300 | * plist_for_each_* can work. | |
301 | */ | |
1da177e4 LT |
302 | }; |
303 | ||
ec560175 HY |
304 | #ifdef CONFIG_64BIT |
305 | #define SWAP_RA_ORDER_CEILING 5 | |
306 | #else | |
307 | /* Avoid stack overflow, because we need to save part of page table */ | |
308 | #define SWAP_RA_ORDER_CEILING 3 | |
309 | #define SWAP_RA_PTE_CACHE_SIZE (1 << SWAP_RA_ORDER_CEILING) | |
310 | #endif | |
311 | ||
312 | struct vma_swap_readahead { | |
313 | unsigned short win; | |
314 | unsigned short offset; | |
315 | unsigned short nr_pte; | |
316 | #ifdef CONFIG_64BIT | |
317 | pte_t *ptes; | |
318 | #else | |
319 | pte_t ptes[SWAP_RA_PTE_CACHE_SIZE]; | |
320 | #endif | |
321 | }; | |
322 | ||
2f52578f MWO |
323 | static inline swp_entry_t folio_swap_entry(struct folio *folio) |
324 | { | |
325 | swp_entry_t entry = { .val = page_private(&folio->page) }; | |
326 | return entry; | |
327 | } | |
328 | ||
a528910e | 329 | /* linux/mm/workingset.c */ |
31d8fcac | 330 | void workingset_age_nonresident(struct lruvec *lruvec, unsigned long nr_pages); |
b910718a | 331 | void *workingset_eviction(struct page *page, struct mem_cgroup *target_memcg); |
0995d7e5 | 332 | void workingset_refault(struct folio *folio, void *shadow); |
c5ce619a | 333 | void workingset_activation(struct folio *folio); |
c7df8ad2 | 334 | |
74d60958 MW |
335 | /* Only track the nodes of mappings with shadow entries */ |
336 | void workingset_update_node(struct xa_node *node); | |
337 | #define mapping_set_update(xas, mapping) do { \ | |
338 | if (!dax_mapping(mapping) && !shmem_mapping(mapping)) \ | |
339 | xas_set_update(xas, workingset_update_node); \ | |
340 | } while (0) | |
a528910e | 341 | |
1da177e4 | 342 | /* linux/mm/page_alloc.c */ |
cb45b0e9 | 343 | extern unsigned long totalreserve_pages; |
ebec3862 | 344 | extern unsigned long nr_free_buffer_pages(void); |
1da177e4 | 345 | |
c41f012a MH |
346 | /* Definition of global_zone_page_state not available yet */ |
347 | #define nr_free_pages() global_zone_page_state(NR_FREE_PAGES) | |
96177299 CL |
348 | |
349 | ||
1da177e4 | 350 | /* linux/mm/swap.c */ |
96f8bf4f JW |
351 | extern void lru_note_cost(struct lruvec *lruvec, bool file, |
352 | unsigned int nr_pages); | |
0995d7e5 | 353 | extern void lru_note_cost_folio(struct folio *); |
c53954a0 | 354 | extern void lru_cache_add(struct page *); |
76580b65 MWO |
355 | void mark_page_accessed(struct page *); |
356 | void folio_mark_accessed(struct folio *); | |
d479960e MK |
357 | |
358 | extern atomic_t lru_disable_count; | |
359 | ||
360 | static inline bool lru_cache_disabled(void) | |
361 | { | |
362 | return atomic_read(&lru_disable_count); | |
363 | } | |
364 | ||
365 | static inline void lru_cache_enable(void) | |
366 | { | |
367 | atomic_dec(&lru_disable_count); | |
368 | } | |
369 | ||
370 | extern void lru_cache_disable(void); | |
1da177e4 | 371 | extern void lru_add_drain(void); |
f0cb3c76 | 372 | extern void lru_add_drain_cpu(int cpu); |
b01b2141 | 373 | extern void lru_add_drain_cpu_zone(struct zone *zone); |
5fbc4616 | 374 | extern void lru_add_drain_all(void); |
cc5993bd | 375 | extern void deactivate_file_page(struct page *page); |
9c276cc6 | 376 | extern void deactivate_page(struct page *page); |
f7ad2a6c | 377 | extern void mark_page_lazyfree(struct page *page); |
1da177e4 LT |
378 | extern void swap_setup(void); |
379 | ||
b518154e | 380 | extern void lru_cache_add_inactive_or_unevictable(struct page *page, |
00501b53 JW |
381 | struct vm_area_struct *vma); |
382 | ||
1da177e4 | 383 | /* linux/mm/vmscan.c */ |
5a1c84b4 | 384 | extern unsigned long zone_reclaimable_pages(struct zone *zone); |
dac1d27b | 385 | extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, |
327c0e96 | 386 | gfp_t gfp_mask, nodemask_t *mask); |
c2135f7c | 387 | extern bool __isolate_lru_page_prepare(struct page *page, isolate_mode_t mode); |
b70a2a21 JW |
388 | extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, |
389 | unsigned long nr_pages, | |
390 | gfp_t gfp_mask, | |
391 | bool may_swap); | |
a9dd0a83 | 392 | extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem, |
185efc0f | 393 | gfp_t gfp_mask, bool noswap, |
ef8f2327 | 394 | pg_data_t *pgdat, |
185efc0f | 395 | unsigned long *nr_scanned); |
69e05944 | 396 | extern unsigned long shrink_all_memory(unsigned long nr_pages); |
1da177e4 | 397 | extern int vm_swappiness; |
b20a3503 CL |
398 | extern int remove_mapping(struct address_space *mapping, struct page *page); |
399 | ||
1a4e58cc | 400 | extern unsigned long reclaim_pages(struct list_head *page_list); |
9eeff239 | 401 | #ifdef CONFIG_NUMA |
a5f5f91d | 402 | extern int node_reclaim_mode; |
9614634f | 403 | extern int sysctl_min_unmapped_ratio; |
0ff38490 | 404 | extern int sysctl_min_slab_ratio; |
9eeff239 | 405 | #else |
a5f5f91d | 406 | #define node_reclaim_mode 0 |
9eeff239 CL |
407 | #endif |
408 | ||
202e35db DH |
409 | static inline bool node_reclaim_enabled(void) |
410 | { | |
411 | /* Is any node_reclaim_mode bit set? */ | |
412 | return node_reclaim_mode & (RECLAIM_ZONE|RECLAIM_WRITE|RECLAIM_UNMAP); | |
413 | } | |
414 | ||
64e3d12f | 415 | extern void check_move_unevictable_pages(struct pagevec *pvec); |
af936a16 | 416 | |
b87c517a | 417 | extern void kswapd_run(int nid); |
8fe23e05 | 418 | extern void kswapd_stop(int nid); |
33398cf2 | 419 | |
1da177e4 | 420 | #ifdef CONFIG_SWAP |
be297968 CH |
421 | |
422 | #include <linux/blk_types.h> /* for bio_end_io_t */ | |
423 | ||
1da177e4 | 424 | /* linux/mm/page_io.c */ |
23955622 | 425 | extern int swap_readpage(struct page *page, bool do_poll); |
1da177e4 | 426 | extern int swap_writepage(struct page *page, struct writeback_control *wbc); |
4246a0b6 | 427 | extern void end_swap_bio_write(struct bio *bio); |
1eec6702 | 428 | extern int __swap_writepage(struct page *page, struct writeback_control *wbc, |
4246a0b6 | 429 | bio_end_io_t end_write_func); |
62c230bc | 430 | extern int swap_set_page_dirty(struct page *page); |
1da177e4 | 431 | |
a509bc1a MG |
432 | int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page, |
433 | unsigned long nr_pages, sector_t start_block); | |
434 | int generic_swapfile_activate(struct swap_info_struct *, struct file *, | |
435 | sector_t *); | |
436 | ||
1da177e4 | 437 | /* linux/mm/swap_state.c */ |
4b3ef9da HY |
438 | /* One swap address space for each 64M swap space */ |
439 | #define SWAP_ADDRESS_SPACE_SHIFT 14 | |
440 | #define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT) | |
441 | extern struct address_space *swapper_spaces[]; | |
442 | #define swap_address_space(entry) \ | |
443 | (&swapper_spaces[swp_type(entry)][swp_offset(entry) \ | |
444 | >> SWAP_ADDRESS_SPACE_SHIFT]) | |
b6038942 SB |
445 | static inline unsigned long total_swapcache_pages(void) |
446 | { | |
447 | return global_node_page_state(NR_SWAPCACHE); | |
448 | } | |
449 | ||
1da177e4 | 450 | extern void show_swap_cache_info(void); |
0f074658 | 451 | extern int add_to_swap(struct page *page); |
aae466b0 | 452 | extern void *get_shadow_from_swap_cache(swp_entry_t entry); |
3852f676 JK |
453 | extern int add_to_swap_cache(struct page *page, swp_entry_t entry, |
454 | gfp_t gfp, void **shadowp); | |
455 | extern void __delete_from_swap_cache(struct page *page, | |
456 | swp_entry_t entry, void *shadow); | |
1da177e4 | 457 | extern void delete_from_swap_cache(struct page *); |
3852f676 JK |
458 | extern void clear_shadow_from_swap_cache(int type, unsigned long begin, |
459 | unsigned long end); | |
f4c4a3f4 | 460 | extern void free_swap_cache(struct page *); |
1da177e4 LT |
461 | extern void free_page_and_swap_cache(struct page *); |
462 | extern void free_pages_and_swap_cache(struct page **, int); | |
ec560175 HY |
463 | extern struct page *lookup_swap_cache(swp_entry_t entry, |
464 | struct vm_area_struct *vma, | |
465 | unsigned long addr); | |
61ef1865 | 466 | struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index); |
02098fea | 467 | extern struct page *read_swap_cache_async(swp_entry_t, gfp_t, |
23955622 SL |
468 | struct vm_area_struct *vma, unsigned long addr, |
469 | bool do_poll); | |
5b999aad DS |
470 | extern struct page *__read_swap_cache_async(swp_entry_t, gfp_t, |
471 | struct vm_area_struct *vma, unsigned long addr, | |
472 | bool *new_page_allocated); | |
e9e9b7ec MK |
473 | extern struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag, |
474 | struct vm_fault *vmf); | |
475 | extern struct page *swapin_readahead(swp_entry_t entry, gfp_t flag, | |
476 | struct vm_fault *vmf); | |
ec560175 | 477 | |
1da177e4 | 478 | /* linux/mm/swapfile.c */ |
ec8acf20 | 479 | extern atomic_long_t nr_swap_pages; |
1da177e4 | 480 | extern long total_swap_pages; |
81a0298b | 481 | extern atomic_t nr_rotate_swap; |
67afa38e | 482 | extern bool has_usable_swap(void); |
ec8acf20 SL |
483 | |
484 | /* Swap 50% full? Release swapcache more aggressively.. */ | |
485 | static inline bool vm_swap_full(void) | |
486 | { | |
487 | return atomic_long_read(&nr_swap_pages) * 2 < total_swap_pages; | |
488 | } | |
489 | ||
490 | static inline long get_nr_swap_pages(void) | |
491 | { | |
492 | return atomic_long_read(&nr_swap_pages); | |
493 | } | |
494 | ||
1da177e4 | 495 | extern void si_swapinfo(struct sysinfo *); |
38d8b4e6 | 496 | extern swp_entry_t get_swap_page(struct page *page); |
75f6d6d2 | 497 | extern void put_swap_page(struct page *page, swp_entry_t entry); |
910321ea | 498 | extern swp_entry_t get_swap_page_of_type(int); |
5d5e8f19 | 499 | extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size); |
570a335b | 500 | extern int add_swap_count_continuation(swp_entry_t, gfp_t); |
aaa46865 | 501 | extern void swap_shmem_alloc(swp_entry_t); |
570a335b HD |
502 | extern int swap_duplicate(swp_entry_t); |
503 | extern int swapcache_prepare(swp_entry_t); | |
1da177e4 | 504 | extern void swap_free(swp_entry_t); |
7c00bafe | 505 | extern void swapcache_free_entries(swp_entry_t *entries, int n); |
2509ef26 | 506 | extern int free_swap_and_cache(swp_entry_t); |
21bd9005 CH |
507 | int swap_type_of(dev_t device, sector_t offset); |
508 | int find_first_swap(dev_t *device); | |
f577eb30 | 509 | extern unsigned int count_swap_pages(int, int); |
3aef83e0 | 510 | extern sector_t swapdev_block(int, pgoff_t); |
bde05d1c | 511 | extern int page_swapcount(struct page *); |
eb085574 | 512 | extern int __swap_count(swp_entry_t entry); |
e8c26ab6 | 513 | extern int __swp_swapcount(swp_entry_t entry); |
8334b962 | 514 | extern int swp_swapcount(swp_entry_t entry); |
f981c595 | 515 | extern struct swap_info_struct *page_swap_info(struct page *); |
0bcac06f | 516 | extern struct swap_info_struct *swp_swap_info(swp_entry_t entry); |
6d0a07ed | 517 | extern bool reuse_swap_page(struct page *, int *); |
a2c43eed | 518 | extern int try_to_free_swap(struct page *); |
1da177e4 | 519 | struct backing_dev_info; |
4b3ef9da HY |
520 | extern int init_swap_address_space(unsigned int type, unsigned long nr_pages); |
521 | extern void exit_swap_address_space(unsigned int type); | |
eb085574 | 522 | extern struct swap_info_struct *get_swap_device(swp_entry_t entry); |
caf6912f | 523 | sector_t swap_page_sector(struct page *page); |
eb085574 HY |
524 | |
525 | static inline void put_swap_device(struct swap_info_struct *si) | |
526 | { | |
63d8620e | 527 | percpu_ref_put(&si->users); |
eb085574 | 528 | } |
1da177e4 | 529 | |
1da177e4 LT |
530 | #else /* CONFIG_SWAP */ |
531 | ||
0bcac06f MK |
532 | static inline int swap_readpage(struct page *page, bool do_poll) |
533 | { | |
534 | return 0; | |
535 | } | |
536 | ||
537 | static inline struct swap_info_struct *swp_swap_info(swp_entry_t entry) | |
538 | { | |
539 | return NULL; | |
540 | } | |
541 | ||
2799e775 ML |
542 | static inline struct swap_info_struct *get_swap_device(swp_entry_t entry) |
543 | { | |
544 | return NULL; | |
545 | } | |
546 | ||
547 | static inline void put_swap_device(struct swap_info_struct *si) | |
548 | { | |
549 | } | |
550 | ||
2bb6a033 MG |
551 | static inline struct address_space *swap_address_space(swp_entry_t entry) |
552 | { | |
553 | return NULL; | |
554 | } | |
555 | ||
ec8acf20 | 556 | #define get_nr_swap_pages() 0L |
b962716b | 557 | #define total_swap_pages 0L |
33806f06 | 558 | #define total_swapcache_pages() 0UL |
ec8acf20 | 559 | #define vm_swap_full() 0 |
1da177e4 LT |
560 | |
561 | #define si_swapinfo(val) \ | |
562 | do { (val)->freeswap = (val)->totalswap = 0; } while (0) | |
9ae5b3c7 | 563 | /* only sparc can not include linux/pagemap.h in this file |
ea1754a0 | 564 | * so leave put_page and release_pages undeclared... */ |
1da177e4 | 565 | #define free_page_and_swap_cache(page) \ |
09cbfeaf | 566 | put_page(page) |
1da177e4 | 567 | #define free_pages_and_swap_cache(pages, nr) \ |
c6f92f9f | 568 | release_pages((pages), (nr)); |
1da177e4 | 569 | |
f4c4a3f4 HY |
570 | static inline void free_swap_cache(struct page *page) |
571 | { | |
572 | } | |
573 | ||
bd96b9eb CK |
574 | static inline void show_swap_cache_info(void) |
575 | { | |
576 | } | |
577 | ||
af5cdaf8 AP |
578 | /* used to sanity check ptes in zap_pte_range when CONFIG_SWAP=0 */ |
579 | #define free_swap_and_cache(e) is_pfn_swap_entry(e) | |
bd96b9eb | 580 | |
570a335b | 581 | static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask) |
355cfa73 | 582 | { |
570a335b HD |
583 | return 0; |
584 | } | |
585 | ||
aaa46865 HD |
586 | static inline void swap_shmem_alloc(swp_entry_t swp) |
587 | { | |
588 | } | |
589 | ||
570a335b HD |
590 | static inline int swap_duplicate(swp_entry_t swp) |
591 | { | |
592 | return 0; | |
355cfa73 KH |
593 | } |
594 | ||
bd96b9eb CK |
595 | static inline void swap_free(swp_entry_t swp) |
596 | { | |
597 | } | |
598 | ||
75f6d6d2 | 599 | static inline void put_swap_page(struct page *page, swp_entry_t swp) |
cb4b86ba KH |
600 | { |
601 | } | |
602 | ||
e9e9b7ec MK |
603 | static inline struct page *swap_cluster_readahead(swp_entry_t entry, |
604 | gfp_t gfp_mask, struct vm_fault *vmf) | |
bd96b9eb CK |
605 | { |
606 | return NULL; | |
607 | } | |
608 | ||
e9e9b7ec MK |
609 | static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, |
610 | struct vm_fault *vmf) | |
ec560175 HY |
611 | { |
612 | return NULL; | |
613 | } | |
614 | ||
9fab5619 HD |
615 | static inline int swap_writepage(struct page *p, struct writeback_control *wbc) |
616 | { | |
617 | return 0; | |
618 | } | |
619 | ||
ec560175 HY |
620 | static inline struct page *lookup_swap_cache(swp_entry_t swp, |
621 | struct vm_area_struct *vma, | |
622 | unsigned long addr) | |
bd96b9eb CK |
623 | { |
624 | return NULL; | |
625 | } | |
626 | ||
61ef1865 MWO |
627 | static inline |
628 | struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index) | |
629 | { | |
630 | return find_get_page(mapping, index); | |
631 | } | |
632 | ||
0f074658 | 633 | static inline int add_to_swap(struct page *page) |
60371d97 HD |
634 | { |
635 | return 0; | |
636 | } | |
637 | ||
aae466b0 JK |
638 | static inline void *get_shadow_from_swap_cache(swp_entry_t entry) |
639 | { | |
640 | return NULL; | |
641 | } | |
642 | ||
73b1262f | 643 | static inline int add_to_swap_cache(struct page *page, swp_entry_t entry, |
3852f676 | 644 | gfp_t gfp_mask, void **shadowp) |
bd96b9eb | 645 | { |
73b1262f | 646 | return -1; |
bd96b9eb CK |
647 | } |
648 | ||
4e17ec25 | 649 | static inline void __delete_from_swap_cache(struct page *page, |
3852f676 | 650 | swp_entry_t entry, void *shadow) |
bd96b9eb CK |
651 | { |
652 | } | |
653 | ||
654 | static inline void delete_from_swap_cache(struct page *page) | |
655 | { | |
656 | } | |
657 | ||
3852f676 JK |
658 | static inline void clear_shadow_from_swap_cache(int type, unsigned long begin, |
659 | unsigned long end) | |
660 | { | |
661 | } | |
662 | ||
bde05d1c HD |
663 | static inline int page_swapcount(struct page *page) |
664 | { | |
665 | return 0; | |
666 | } | |
667 | ||
eb085574 | 668 | static inline int __swap_count(swp_entry_t entry) |
aa8d22a1 MK |
669 | { |
670 | return 0; | |
671 | } | |
672 | ||
e8c26ab6 TC |
673 | static inline int __swp_swapcount(swp_entry_t entry) |
674 | { | |
675 | return 0; | |
676 | } | |
677 | ||
8334b962 MK |
678 | static inline int swp_swapcount(swp_entry_t entry) |
679 | { | |
680 | return 0; | |
681 | } | |
682 | ||
ba3c4ce6 HY |
683 | #define reuse_swap_page(page, total_map_swapcount) \ |
684 | (page_trans_huge_mapcount(page, total_map_swapcount) == 1) | |
1da177e4 | 685 | |
a2c43eed | 686 | static inline int try_to_free_swap(struct page *page) |
68a22394 RR |
687 | { |
688 | return 0; | |
689 | } | |
690 | ||
38d8b4e6 | 691 | static inline swp_entry_t get_swap_page(struct page *page) |
1da177e4 LT |
692 | { |
693 | swp_entry_t entry; | |
694 | entry.val = 0; | |
695 | return entry; | |
696 | } | |
697 | ||
1da177e4 | 698 | #endif /* CONFIG_SWAP */ |
6f2cb2f1 | 699 | |
59807685 HY |
700 | #ifdef CONFIG_THP_SWAP |
701 | extern int split_swap_cluster(swp_entry_t entry); | |
702 | #else | |
703 | static inline int split_swap_cluster(swp_entry_t entry) | |
704 | { | |
705 | return 0; | |
706 | } | |
707 | #endif | |
708 | ||
6f2cb2f1 VD |
709 | #ifdef CONFIG_MEMCG |
710 | static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) | |
711 | { | |
4550c4e1 JW |
712 | /* Cgroup2 doesn't have per-cgroup swappiness */ |
713 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
714 | return vm_swappiness; | |
715 | ||
6f2cb2f1 | 716 | /* root ? */ |
59118c42 | 717 | if (mem_cgroup_disabled() || mem_cgroup_is_root(memcg)) |
6f2cb2f1 VD |
718 | return vm_swappiness; |
719 | ||
720 | return memcg->swappiness; | |
721 | } | |
6f2cb2f1 VD |
722 | #else |
723 | static inline int mem_cgroup_swappiness(struct mem_cgroup *mem) | |
724 | { | |
725 | return vm_swappiness; | |
726 | } | |
727 | #endif | |
728 | ||
2cf85583 | 729 | #if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP) |
01c4b28c SB |
730 | extern void __cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask); |
731 | static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask) | |
732 | { | |
733 | if (mem_cgroup_disabled()) | |
734 | return; | |
735 | __cgroup_throttle_swaprate(page, gfp_mask); | |
736 | } | |
2cf85583 | 737 | #else |
6caa6a07 | 738 | static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask) |
2cf85583 TH |
739 | { |
740 | } | |
741 | #endif | |
742 | ||
6f2cb2f1 VD |
743 | #ifdef CONFIG_MEMCG_SWAP |
744 | extern void mem_cgroup_swapout(struct page *page, swp_entry_t entry); | |
01c4b28c SB |
745 | extern int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry); |
746 | static inline int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) | |
747 | { | |
748 | if (mem_cgroup_disabled()) | |
749 | return 0; | |
750 | return __mem_cgroup_try_charge_swap(page, entry); | |
751 | } | |
752 | ||
753 | extern void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages); | |
754 | static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) | |
755 | { | |
756 | if (mem_cgroup_disabled()) | |
757 | return; | |
758 | __mem_cgroup_uncharge_swap(entry, nr_pages); | |
759 | } | |
760 | ||
d8b38438 | 761 | extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg); |
5ccc5aba | 762 | extern bool mem_cgroup_swap_full(struct page *page); |
6f2cb2f1 VD |
763 | #else |
764 | static inline void mem_cgroup_swapout(struct page *page, swp_entry_t entry) | |
765 | { | |
766 | } | |
767 | ||
768 | static inline int mem_cgroup_try_charge_swap(struct page *page, | |
769 | swp_entry_t entry) | |
770 | { | |
771 | return 0; | |
772 | } | |
773 | ||
38d8b4e6 HY |
774 | static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, |
775 | unsigned int nr_pages) | |
6f2cb2f1 VD |
776 | { |
777 | } | |
d8b38438 VD |
778 | |
779 | static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) | |
780 | { | |
781 | return get_nr_swap_pages(); | |
782 | } | |
5ccc5aba VD |
783 | |
784 | static inline bool mem_cgroup_swap_full(struct page *page) | |
785 | { | |
786 | return vm_swap_full(); | |
787 | } | |
6f2cb2f1 VD |
788 | #endif |
789 | ||
1da177e4 LT |
790 | #endif /* __KERNEL__*/ |
791 | #endif /* _LINUX_SWAP_H */ |