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1da177e4 LT |
1 | #ifndef _LINUX_SWAP_H |
2 | #define _LINUX_SWAP_H | |
3 | ||
1da177e4 LT |
4 | #include <linux/spinlock.h> |
5 | #include <linux/linkage.h> | |
6 | #include <linux/mmzone.h> | |
7 | #include <linux/list.h> | |
66e1707b | 8 | #include <linux/memcontrol.h> |
1da177e4 | 9 | #include <linux/sched.h> |
af936a16 | 10 | #include <linux/node.h> |
542d1c88 | 11 | |
1da177e4 LT |
12 | #include <asm/atomic.h> |
13 | #include <asm/page.h> | |
14 | ||
8bc719d3 MS |
15 | struct notifier_block; |
16 | ||
ab954160 AM |
17 | struct bio; |
18 | ||
1da177e4 LT |
19 | #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */ |
20 | #define SWAP_FLAG_PRIO_MASK 0x7fff | |
21 | #define SWAP_FLAG_PRIO_SHIFT 0 | |
22 | ||
23 | static inline int current_is_kswapd(void) | |
24 | { | |
25 | return current->flags & PF_KSWAPD; | |
26 | } | |
27 | ||
28 | /* | |
29 | * MAX_SWAPFILES defines the maximum number of swaptypes: things which can | |
30 | * be swapped to. The swap type and the offset into that swap type are | |
31 | * encoded into pte's and into pgoff_t's in the swapcache. Using five bits | |
32 | * for the type means that the maximum number of swapcache pages is 27 bits | |
33 | * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs | |
34 | * the type/offset into the pte as 5/27 as well. | |
35 | */ | |
36 | #define MAX_SWAPFILES_SHIFT 5 | |
0697212a | 37 | #ifndef CONFIG_MIGRATION |
1da177e4 | 38 | #define MAX_SWAPFILES (1 << MAX_SWAPFILES_SHIFT) |
0697212a CL |
39 | #else |
40 | /* Use last two entries for page migration swap entries */ | |
41 | #define MAX_SWAPFILES ((1 << MAX_SWAPFILES_SHIFT)-2) | |
42 | #define SWP_MIGRATION_READ MAX_SWAPFILES | |
43 | #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + 1) | |
44 | #endif | |
1da177e4 LT |
45 | |
46 | /* | |
47 | * Magic header for a swap area. The first part of the union is | |
48 | * what the swap magic looks like for the old (limited to 128MB) | |
49 | * swap area format, the second part of the union adds - in the | |
50 | * old reserved area - some extra information. Note that the first | |
51 | * kilobyte is reserved for boot loader or disk label stuff... | |
52 | * | |
53 | * Having the magic at the end of the PAGE_SIZE makes detecting swap | |
54 | * areas somewhat tricky on machines that support multiple page sizes. | |
55 | * For 2.5 we'll probably want to move the magic to just beyond the | |
56 | * bootbits... | |
57 | */ | |
58 | union swap_header { | |
59 | struct { | |
60 | char reserved[PAGE_SIZE - 10]; | |
61 | char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ | |
62 | } magic; | |
63 | struct { | |
e8f03d02 AD |
64 | char bootbits[1024]; /* Space for disklabel etc. */ |
65 | __u32 version; | |
66 | __u32 last_page; | |
67 | __u32 nr_badpages; | |
68 | unsigned char sws_uuid[16]; | |
69 | unsigned char sws_volume[16]; | |
70 | __u32 padding[117]; | |
71 | __u32 badpages[1]; | |
1da177e4 LT |
72 | } info; |
73 | }; | |
74 | ||
75 | /* A swap entry has to fit into a "unsigned long", as | |
76 | * the entry is hidden in the "index" field of the | |
77 | * swapper address space. | |
78 | */ | |
79 | typedef struct { | |
80 | unsigned long val; | |
81 | } swp_entry_t; | |
82 | ||
83 | /* | |
84 | * current->reclaim_state points to one of these when a task is running | |
85 | * memory reclaim | |
86 | */ | |
87 | struct reclaim_state { | |
88 | unsigned long reclaimed_slab; | |
89 | }; | |
90 | ||
91 | #ifdef __KERNEL__ | |
92 | ||
93 | struct address_space; | |
94 | struct sysinfo; | |
95 | struct writeback_control; | |
96 | struct zone; | |
97 | ||
98 | /* | |
99 | * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of | |
100 | * disk blocks. A list of swap extents maps the entire swapfile. (Where the | |
101 | * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart | |
102 | * from setup, they're handled identically. | |
103 | * | |
104 | * We always assume that blocks are of size PAGE_SIZE. | |
105 | */ | |
106 | struct swap_extent { | |
107 | struct list_head list; | |
108 | pgoff_t start_page; | |
109 | pgoff_t nr_pages; | |
110 | sector_t start_block; | |
111 | }; | |
112 | ||
113 | /* | |
114 | * Max bad pages in the new format.. | |
115 | */ | |
116 | #define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x) | |
117 | #define MAX_SWAP_BADPAGES \ | |
118 | ((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int)) | |
119 | ||
120 | enum { | |
121 | SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ | |
122 | SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ | |
6a6ba831 | 123 | SWP_DISCARDABLE = (1 << 2), /* blkdev supports discard */ |
7992fde7 | 124 | SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */ |
20137a49 | 125 | SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ |
52b7efdb HD |
126 | /* add others here before... */ |
127 | SWP_SCANNING = (1 << 8), /* refcount in scan_swap_map */ | |
1da177e4 LT |
128 | }; |
129 | ||
130 | #define SWAP_CLUSTER_MAX 32 | |
131 | ||
132 | #define SWAP_MAP_MAX 0x7fff | |
133 | #define SWAP_MAP_BAD 0x8000 | |
134 | ||
135 | /* | |
136 | * The in-memory structure used to track swap areas. | |
1da177e4 LT |
137 | */ |
138 | struct swap_info_struct { | |
ebebbbe9 | 139 | unsigned long flags; |
5d337b91 | 140 | int prio; /* swap priority */ |
ebebbbe9 | 141 | int next; /* next entry on swap list */ |
1da177e4 LT |
142 | struct file *swap_file; |
143 | struct block_device *bdev; | |
144 | struct list_head extent_list; | |
1da177e4 | 145 | struct swap_extent *curr_swap_extent; |
ebebbbe9 | 146 | unsigned short *swap_map; |
1da177e4 LT |
147 | unsigned int lowest_bit; |
148 | unsigned int highest_bit; | |
7992fde7 HD |
149 | unsigned int lowest_alloc; /* while preparing discard cluster */ |
150 | unsigned int highest_alloc; /* while preparing discard cluster */ | |
1da177e4 LT |
151 | unsigned int cluster_next; |
152 | unsigned int cluster_nr; | |
6eb396dc HD |
153 | unsigned int pages; |
154 | unsigned int max; | |
155 | unsigned int inuse_pages; | |
ebebbbe9 | 156 | unsigned int old_block_size; |
1da177e4 LT |
157 | }; |
158 | ||
159 | struct swap_list_t { | |
160 | int head; /* head of priority-ordered swapfile list */ | |
161 | int next; /* swapfile to be used next */ | |
162 | }; | |
163 | ||
164 | /* Swap 50% full? Release swapcache more aggressively.. */ | |
165 | #define vm_swap_full() (nr_swap_pages*2 < total_swap_pages) | |
166 | ||
1da177e4 LT |
167 | /* linux/mm/page_alloc.c */ |
168 | extern unsigned long totalram_pages; | |
cb45b0e9 | 169 | extern unsigned long totalreserve_pages; |
1da177e4 LT |
170 | extern unsigned int nr_free_buffer_pages(void); |
171 | extern unsigned int nr_free_pagecache_pages(void); | |
172 | ||
96177299 CL |
173 | /* Definition of global_page_state not available yet */ |
174 | #define nr_free_pages() global_page_state(NR_FREE_PAGES) | |
175 | ||
176 | ||
1da177e4 | 177 | /* linux/mm/swap.c */ |
f04e9ebb KM |
178 | extern void __lru_cache_add(struct page *, enum lru_list lru); |
179 | extern void lru_cache_add_lru(struct page *, enum lru_list lru); | |
b3c97528 HH |
180 | extern void activate_page(struct page *); |
181 | extern void mark_page_accessed(struct page *); | |
1da177e4 | 182 | extern void lru_add_drain(void); |
053837fc | 183 | extern int lru_add_drain_all(void); |
ac6aadb2 | 184 | extern void rotate_reclaimable_page(struct page *page); |
1da177e4 LT |
185 | extern void swap_setup(void); |
186 | ||
894bc310 LS |
187 | extern void add_page_to_unevictable_list(struct page *page); |
188 | ||
f04e9ebb KM |
189 | /** |
190 | * lru_cache_add: add a page to the page lists | |
191 | * @page: the page to add | |
192 | */ | |
4f98a2fe | 193 | static inline void lru_cache_add_anon(struct page *page) |
f04e9ebb | 194 | { |
4f98a2fe | 195 | __lru_cache_add(page, LRU_INACTIVE_ANON); |
f04e9ebb KM |
196 | } |
197 | ||
4f98a2fe | 198 | static inline void lru_cache_add_active_anon(struct page *page) |
f04e9ebb | 199 | { |
4f98a2fe RR |
200 | __lru_cache_add(page, LRU_ACTIVE_ANON); |
201 | } | |
202 | ||
203 | static inline void lru_cache_add_file(struct page *page) | |
204 | { | |
205 | __lru_cache_add(page, LRU_INACTIVE_FILE); | |
206 | } | |
207 | ||
208 | static inline void lru_cache_add_active_file(struct page *page) | |
209 | { | |
210 | __lru_cache_add(page, LRU_ACTIVE_FILE); | |
f04e9ebb KM |
211 | } |
212 | ||
1da177e4 | 213 | /* linux/mm/vmscan.c */ |
dac1d27b | 214 | extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, |
327c0e96 | 215 | gfp_t gfp_mask, nodemask_t *mask); |
e1a1cd59 | 216 | extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem, |
a7885eb8 KM |
217 | gfp_t gfp_mask, bool noswap, |
218 | unsigned int swappiness); | |
4f98a2fe | 219 | extern int __isolate_lru_page(struct page *page, int mode, int file); |
69e05944 | 220 | extern unsigned long shrink_all_memory(unsigned long nr_pages); |
1da177e4 | 221 | extern int vm_swappiness; |
b20a3503 | 222 | extern int remove_mapping(struct address_space *mapping, struct page *page); |
bd1e22b8 | 223 | extern long vm_total_pages; |
b20a3503 | 224 | |
9eeff239 CL |
225 | #ifdef CONFIG_NUMA |
226 | extern int zone_reclaim_mode; | |
9614634f | 227 | extern int sysctl_min_unmapped_ratio; |
0ff38490 | 228 | extern int sysctl_min_slab_ratio; |
9eeff239 CL |
229 | extern int zone_reclaim(struct zone *, gfp_t, unsigned int); |
230 | #else | |
231 | #define zone_reclaim_mode 0 | |
232 | static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order) | |
233 | { | |
234 | return 0; | |
235 | } | |
236 | #endif | |
237 | ||
894bc310 | 238 | extern int page_evictable(struct page *page, struct vm_area_struct *vma); |
89e004ea | 239 | extern void scan_mapping_unevictable_pages(struct address_space *); |
af936a16 LS |
240 | |
241 | extern unsigned long scan_unevictable_pages; | |
242 | extern int scan_unevictable_handler(struct ctl_table *, int, struct file *, | |
243 | void __user *, size_t *, loff_t *); | |
244 | extern int scan_unevictable_register_node(struct node *node); | |
245 | extern void scan_unevictable_unregister_node(struct node *node); | |
894bc310 | 246 | |
3218ae14 YG |
247 | extern int kswapd_run(int nid); |
248 | ||
1da177e4 LT |
249 | #ifdef CONFIG_MMU |
250 | /* linux/mm/shmem.c */ | |
251 | extern int shmem_unuse(swp_entry_t entry, struct page *page); | |
252 | #endif /* CONFIG_MMU */ | |
253 | ||
254 | extern void swap_unplug_io_fn(struct backing_dev_info *, struct page *); | |
255 | ||
256 | #ifdef CONFIG_SWAP | |
257 | /* linux/mm/page_io.c */ | |
258 | extern int swap_readpage(struct file *, struct page *); | |
259 | extern int swap_writepage(struct page *page, struct writeback_control *wbc); | |
6712ecf8 | 260 | extern void end_swap_bio_read(struct bio *bio, int err); |
1da177e4 LT |
261 | |
262 | /* linux/mm/swap_state.c */ | |
263 | extern struct address_space swapper_space; | |
264 | #define total_swapcache_pages swapper_space.nrpages | |
265 | extern void show_swap_cache_info(void); | |
ac47b003 | 266 | extern int add_to_swap(struct page *); |
73b1262f | 267 | extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t); |
1da177e4 LT |
268 | extern void __delete_from_swap_cache(struct page *); |
269 | extern void delete_from_swap_cache(struct page *); | |
1da177e4 LT |
270 | extern void free_page_and_swap_cache(struct page *); |
271 | extern void free_pages_and_swap_cache(struct page **, int); | |
46017e95 | 272 | extern struct page *lookup_swap_cache(swp_entry_t); |
02098fea | 273 | extern struct page *read_swap_cache_async(swp_entry_t, gfp_t, |
46017e95 | 274 | struct vm_area_struct *vma, unsigned long addr); |
02098fea | 275 | extern struct page *swapin_readahead(swp_entry_t, gfp_t, |
46017e95 HD |
276 | struct vm_area_struct *vma, unsigned long addr); |
277 | ||
1da177e4 | 278 | /* linux/mm/swapfile.c */ |
b962716b | 279 | extern long nr_swap_pages; |
1da177e4 | 280 | extern long total_swap_pages; |
1da177e4 LT |
281 | extern void si_swapinfo(struct sysinfo *); |
282 | extern swp_entry_t get_swap_page(void); | |
f577eb30 | 283 | extern swp_entry_t get_swap_page_of_type(int); |
1da177e4 LT |
284 | extern int swap_duplicate(swp_entry_t); |
285 | extern int valid_swaphandles(swp_entry_t, unsigned long *); | |
286 | extern void swap_free(swp_entry_t); | |
2509ef26 | 287 | extern int free_swap_and_cache(swp_entry_t); |
7bf23687 | 288 | extern int swap_type_of(dev_t, sector_t, struct block_device **); |
f577eb30 | 289 | extern unsigned int count_swap_pages(int, int); |
1da177e4 | 290 | extern sector_t map_swap_page(struct swap_info_struct *, pgoff_t); |
3aef83e0 | 291 | extern sector_t swapdev_block(int, pgoff_t); |
1da177e4 | 292 | extern struct swap_info_struct *get_swap_info_struct(unsigned); |
7b1fe597 | 293 | extern int reuse_swap_page(struct page *); |
a2c43eed | 294 | extern int try_to_free_swap(struct page *); |
1da177e4 LT |
295 | struct backing_dev_info; |
296 | ||
1da177e4 LT |
297 | /* linux/mm/thrash.c */ |
298 | extern struct mm_struct * swap_token_mm; | |
1da177e4 LT |
299 | extern void grab_swap_token(void); |
300 | extern void __put_swap_token(struct mm_struct *); | |
301 | ||
302 | static inline int has_swap_token(struct mm_struct *mm) | |
303 | { | |
304 | return (mm == swap_token_mm); | |
305 | } | |
306 | ||
307 | static inline void put_swap_token(struct mm_struct *mm) | |
308 | { | |
309 | if (has_swap_token(mm)) | |
310 | __put_swap_token(mm); | |
311 | } | |
312 | ||
f7b7fd8f RR |
313 | static inline void disable_swap_token(void) |
314 | { | |
315 | put_swap_token(swap_token_mm); | |
316 | } | |
317 | ||
d13d1443 | 318 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR |
8c7c6e34 | 319 | extern void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent); |
d13d1443 | 320 | #else |
8c7c6e34 KH |
321 | static inline void |
322 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent) | |
323 | { | |
324 | } | |
325 | #endif | |
326 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP | |
327 | extern void mem_cgroup_uncharge_swap(swp_entry_t ent); | |
328 | #else | |
329 | static inline void mem_cgroup_uncharge_swap(swp_entry_t ent) | |
d13d1443 KH |
330 | { |
331 | } | |
332 | #endif | |
333 | ||
1da177e4 LT |
334 | #else /* CONFIG_SWAP */ |
335 | ||
b962716b HD |
336 | #define nr_swap_pages 0L |
337 | #define total_swap_pages 0L | |
1da177e4 LT |
338 | #define total_swapcache_pages 0UL |
339 | ||
340 | #define si_swapinfo(val) \ | |
341 | do { (val)->freeswap = (val)->totalswap = 0; } while (0) | |
9ae5b3c7 OH |
342 | /* only sparc can not include linux/pagemap.h in this file |
343 | * so leave page_cache_release and release_pages undeclared... */ | |
1da177e4 LT |
344 | #define free_page_and_swap_cache(page) \ |
345 | page_cache_release(page) | |
346 | #define free_pages_and_swap_cache(pages, nr) \ | |
347 | release_pages((pages), (nr), 0); | |
348 | ||
bd96b9eb CK |
349 | static inline void show_swap_cache_info(void) |
350 | { | |
351 | } | |
352 | ||
2509ef26 HD |
353 | #define free_swap_and_cache(swp) is_migration_entry(swp) |
354 | #define swap_duplicate(swp) is_migration_entry(swp) | |
bd96b9eb CK |
355 | |
356 | static inline void swap_free(swp_entry_t swp) | |
357 | { | |
358 | } | |
359 | ||
02098fea | 360 | static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, |
bd96b9eb CK |
361 | struct vm_area_struct *vma, unsigned long addr) |
362 | { | |
363 | return NULL; | |
364 | } | |
365 | ||
9fab5619 HD |
366 | static inline int swap_writepage(struct page *p, struct writeback_control *wbc) |
367 | { | |
368 | return 0; | |
369 | } | |
370 | ||
bd96b9eb CK |
371 | static inline struct page *lookup_swap_cache(swp_entry_t swp) |
372 | { | |
373 | return NULL; | |
374 | } | |
375 | ||
60371d97 HD |
376 | static inline int add_to_swap(struct page *page) |
377 | { | |
378 | return 0; | |
379 | } | |
380 | ||
73b1262f HD |
381 | static inline int add_to_swap_cache(struct page *page, swp_entry_t entry, |
382 | gfp_t gfp_mask) | |
bd96b9eb | 383 | { |
73b1262f | 384 | return -1; |
bd96b9eb CK |
385 | } |
386 | ||
387 | static inline void __delete_from_swap_cache(struct page *page) | |
388 | { | |
389 | } | |
390 | ||
391 | static inline void delete_from_swap_cache(struct page *page) | |
392 | { | |
393 | } | |
394 | ||
7b1fe597 | 395 | #define reuse_swap_page(page) (page_mapcount(page) == 1) |
1da177e4 | 396 | |
a2c43eed | 397 | static inline int try_to_free_swap(struct page *page) |
68a22394 RR |
398 | { |
399 | return 0; | |
400 | } | |
401 | ||
1da177e4 LT |
402 | static inline swp_entry_t get_swap_page(void) |
403 | { | |
404 | swp_entry_t entry; | |
405 | entry.val = 0; | |
406 | return entry; | |
407 | } | |
408 | ||
409 | /* linux/mm/thrash.c */ | |
410 | #define put_swap_token(x) do { } while(0) | |
411 | #define grab_swap_token() do { } while(0) | |
412 | #define has_swap_token(x) 0 | |
f7b7fd8f | 413 | #define disable_swap_token() do { } while(0) |
1da177e4 | 414 | |
d13d1443 KH |
415 | static inline int mem_cgroup_cache_charge_swapin(struct page *page, |
416 | struct mm_struct *mm, gfp_t mask, bool locked) | |
417 | { | |
418 | return 0; | |
419 | } | |
420 | ||
e767e056 DN |
421 | static inline void |
422 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent) | |
423 | { | |
424 | } | |
425 | ||
1da177e4 LT |
426 | #endif /* CONFIG_SWAP */ |
427 | #endif /* __KERNEL__*/ | |
428 | #endif /* _LINUX_SWAP_H */ |