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