Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifndef _LINUX_SWAP_H |
| 2 | #define _LINUX_SWAP_H |
| 3 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | #include <linux/spinlock.h> |
| 5 | #include <linux/linkage.h> |
| 6 | #include <linux/mmzone.h> |
| 7 | #include <linux/list.h> |
| 8 | #include <linux/sched.h> |
Andrew Morton | 542d1c8 | 2005-07-12 13:58:31 -0700 | [diff] [blame] | 9 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | #include <asm/atomic.h> |
| 11 | #include <asm/page.h> |
| 12 | |
| 13 | #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */ |
| 14 | #define SWAP_FLAG_PRIO_MASK 0x7fff |
| 15 | #define SWAP_FLAG_PRIO_SHIFT 0 |
| 16 | |
| 17 | static inline int current_is_kswapd(void) |
| 18 | { |
| 19 | return current->flags & PF_KSWAPD; |
| 20 | } |
| 21 | |
| 22 | /* |
| 23 | * MAX_SWAPFILES defines the maximum number of swaptypes: things which can |
| 24 | * be swapped to. The swap type and the offset into that swap type are |
| 25 | * encoded into pte's and into pgoff_t's in the swapcache. Using five bits |
| 26 | * for the type means that the maximum number of swapcache pages is 27 bits |
| 27 | * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs |
| 28 | * the type/offset into the pte as 5/27 as well. |
| 29 | */ |
| 30 | #define MAX_SWAPFILES_SHIFT 5 |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 31 | #ifndef CONFIG_MIGRATION |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #define MAX_SWAPFILES (1 << MAX_SWAPFILES_SHIFT) |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 33 | #else |
| 34 | /* Use last two entries for page migration swap entries */ |
| 35 | #define MAX_SWAPFILES ((1 << MAX_SWAPFILES_SHIFT)-2) |
| 36 | #define SWP_MIGRATION_READ MAX_SWAPFILES |
| 37 | #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + 1) |
| 38 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | |
| 40 | /* |
| 41 | * Magic header for a swap area. The first part of the union is |
| 42 | * what the swap magic looks like for the old (limited to 128MB) |
| 43 | * swap area format, the second part of the union adds - in the |
| 44 | * old reserved area - some extra information. Note that the first |
| 45 | * kilobyte is reserved for boot loader or disk label stuff... |
| 46 | * |
| 47 | * Having the magic at the end of the PAGE_SIZE makes detecting swap |
| 48 | * areas somewhat tricky on machines that support multiple page sizes. |
| 49 | * For 2.5 we'll probably want to move the magic to just beyond the |
| 50 | * bootbits... |
| 51 | */ |
| 52 | union swap_header { |
| 53 | struct { |
| 54 | char reserved[PAGE_SIZE - 10]; |
| 55 | char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ |
| 56 | } magic; |
| 57 | struct { |
Andreas Dilger | e8f03d0 | 2006-06-23 02:03:14 -0700 | [diff] [blame] | 58 | char bootbits[1024]; /* Space for disklabel etc. */ |
| 59 | __u32 version; |
| 60 | __u32 last_page; |
| 61 | __u32 nr_badpages; |
| 62 | unsigned char sws_uuid[16]; |
| 63 | unsigned char sws_volume[16]; |
| 64 | __u32 padding[117]; |
| 65 | __u32 badpages[1]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | } info; |
| 67 | }; |
| 68 | |
| 69 | /* A swap entry has to fit into a "unsigned long", as |
| 70 | * the entry is hidden in the "index" field of the |
| 71 | * swapper address space. |
| 72 | */ |
| 73 | typedef struct { |
| 74 | unsigned long val; |
| 75 | } swp_entry_t; |
| 76 | |
| 77 | /* |
| 78 | * current->reclaim_state points to one of these when a task is running |
| 79 | * memory reclaim |
| 80 | */ |
| 81 | struct reclaim_state { |
| 82 | unsigned long reclaimed_slab; |
| 83 | }; |
| 84 | |
| 85 | #ifdef __KERNEL__ |
| 86 | |
| 87 | struct address_space; |
| 88 | struct sysinfo; |
| 89 | struct writeback_control; |
| 90 | struct zone; |
| 91 | |
| 92 | /* |
| 93 | * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of |
| 94 | * disk blocks. A list of swap extents maps the entire swapfile. (Where the |
| 95 | * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart |
| 96 | * from setup, they're handled identically. |
| 97 | * |
| 98 | * We always assume that blocks are of size PAGE_SIZE. |
| 99 | */ |
| 100 | struct swap_extent { |
| 101 | struct list_head list; |
| 102 | pgoff_t start_page; |
| 103 | pgoff_t nr_pages; |
| 104 | sector_t start_block; |
| 105 | }; |
| 106 | |
| 107 | /* |
| 108 | * Max bad pages in the new format.. |
| 109 | */ |
| 110 | #define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x) |
| 111 | #define MAX_SWAP_BADPAGES \ |
| 112 | ((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int)) |
| 113 | |
| 114 | enum { |
| 115 | SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ |
| 116 | SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ |
| 117 | SWP_ACTIVE = (SWP_USED | SWP_WRITEOK), |
Hugh Dickins | 52b7efdb | 2005-09-03 15:54:39 -0700 | [diff] [blame] | 118 | /* add others here before... */ |
| 119 | SWP_SCANNING = (1 << 8), /* refcount in scan_swap_map */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | }; |
| 121 | |
| 122 | #define SWAP_CLUSTER_MAX 32 |
| 123 | |
| 124 | #define SWAP_MAP_MAX 0x7fff |
| 125 | #define SWAP_MAP_BAD 0x8000 |
| 126 | |
| 127 | /* |
| 128 | * The in-memory structure used to track swap areas. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | */ |
| 130 | struct swap_info_struct { |
| 131 | unsigned int flags; |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 132 | int prio; /* swap priority */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | struct file *swap_file; |
| 134 | struct block_device *bdev; |
| 135 | struct list_head extent_list; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | struct swap_extent *curr_swap_extent; |
| 137 | unsigned old_block_size; |
| 138 | unsigned short * swap_map; |
| 139 | unsigned int lowest_bit; |
| 140 | unsigned int highest_bit; |
| 141 | unsigned int cluster_next; |
| 142 | unsigned int cluster_nr; |
Hugh Dickins | 6eb396d | 2005-09-03 15:54:35 -0700 | [diff] [blame] | 143 | unsigned int pages; |
| 144 | unsigned int max; |
| 145 | unsigned int inuse_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | int next; /* next entry on swap list */ |
| 147 | }; |
| 148 | |
| 149 | struct swap_list_t { |
| 150 | int head; /* head of priority-ordered swapfile list */ |
| 151 | int next; /* swapfile to be used next */ |
| 152 | }; |
| 153 | |
| 154 | /* Swap 50% full? Release swapcache more aggressively.. */ |
| 155 | #define vm_swap_full() (nr_swap_pages*2 < total_swap_pages) |
| 156 | |
| 157 | /* linux/mm/oom_kill.c */ |
Christoph Lameter | 9b0f8b0 | 2006-02-20 18:27:52 -0800 | [diff] [blame] | 158 | extern void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 159 | |
| 160 | /* linux/mm/memory.c */ |
| 161 | extern void swapin_readahead(swp_entry_t, unsigned long, struct vm_area_struct *); |
| 162 | |
| 163 | /* linux/mm/page_alloc.c */ |
| 164 | extern unsigned long totalram_pages; |
| 165 | extern unsigned long totalhigh_pages; |
Hideo AOKI | cb45b0e | 2006-04-10 22:52:59 -0700 | [diff] [blame] | 166 | extern unsigned long totalreserve_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | extern long nr_swap_pages; |
| 168 | extern unsigned int nr_free_pages(void); |
| 169 | extern unsigned int nr_free_pages_pgdat(pg_data_t *pgdat); |
| 170 | extern unsigned int nr_free_buffer_pages(void); |
| 171 | extern unsigned int nr_free_pagecache_pages(void); |
| 172 | |
| 173 | /* linux/mm/swap.c */ |
| 174 | extern void FASTCALL(lru_cache_add(struct page *)); |
| 175 | extern void FASTCALL(lru_cache_add_active(struct page *)); |
| 176 | extern void FASTCALL(activate_page(struct page *)); |
| 177 | extern void FASTCALL(mark_page_accessed(struct page *)); |
| 178 | extern void lru_add_drain(void); |
Nick Piggin | 053837f | 2006-01-18 17:42:27 -0800 | [diff] [blame] | 179 | extern int lru_add_drain_all(void); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | extern int rotate_reclaimable_page(struct page *page); |
| 181 | extern void swap_setup(void); |
| 182 | |
| 183 | /* linux/mm/vmscan.c */ |
Andrew Morton | 69e0594 | 2006-03-22 00:08:19 -0800 | [diff] [blame] | 184 | extern unsigned long try_to_free_pages(struct zone **, gfp_t); |
| 185 | extern unsigned long shrink_all_memory(unsigned long nr_pages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | extern int vm_swappiness; |
Christoph Lameter | b20a350 | 2006-03-22 00:09:12 -0800 | [diff] [blame] | 187 | extern int remove_mapping(struct address_space *mapping, struct page *page); |
Andrew Morton | bd1e22b | 2006-06-23 02:03:47 -0700 | [diff] [blame] | 188 | extern long vm_total_pages; |
Christoph Lameter | b20a350 | 2006-03-22 00:09:12 -0800 | [diff] [blame] | 189 | |
Christoph Lameter | 9eeff23 | 2006-01-18 17:42:31 -0800 | [diff] [blame] | 190 | #ifdef CONFIG_NUMA |
| 191 | extern int zone_reclaim_mode; |
| 192 | extern int zone_reclaim(struct zone *, gfp_t, unsigned int); |
| 193 | #else |
| 194 | #define zone_reclaim_mode 0 |
| 195 | static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order) |
| 196 | { |
| 197 | return 0; |
| 198 | } |
| 199 | #endif |
| 200 | |
Yasunori Goto | 3218ae1 | 2006-06-27 02:53:33 -0700 | [diff] [blame] | 201 | extern int kswapd_run(int nid); |
| 202 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | #ifdef CONFIG_MMU |
| 204 | /* linux/mm/shmem.c */ |
| 205 | extern int shmem_unuse(swp_entry_t entry, struct page *page); |
| 206 | #endif /* CONFIG_MMU */ |
| 207 | |
| 208 | extern void swap_unplug_io_fn(struct backing_dev_info *, struct page *); |
| 209 | |
| 210 | #ifdef CONFIG_SWAP |
| 211 | /* linux/mm/page_io.c */ |
| 212 | extern int swap_readpage(struct file *, struct page *); |
| 213 | extern int swap_writepage(struct page *page, struct writeback_control *wbc); |
| 214 | extern int rw_swap_page_sync(int, swp_entry_t, struct page *); |
| 215 | |
| 216 | /* linux/mm/swap_state.c */ |
| 217 | extern struct address_space swapper_space; |
| 218 | #define total_swapcache_pages swapper_space.nrpages |
| 219 | extern void show_swap_cache_info(void); |
Christoph Lameter | 1480a54 | 2006-01-08 01:00:53 -0800 | [diff] [blame] | 220 | extern int add_to_swap(struct page *, gfp_t); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | extern void __delete_from_swap_cache(struct page *); |
| 222 | extern void delete_from_swap_cache(struct page *); |
| 223 | extern int move_to_swap_cache(struct page *, swp_entry_t); |
| 224 | extern int move_from_swap_cache(struct page *, unsigned long, |
| 225 | struct address_space *); |
| 226 | extern void free_page_and_swap_cache(struct page *); |
| 227 | extern void free_pages_and_swap_cache(struct page **, int); |
| 228 | extern struct page * lookup_swap_cache(swp_entry_t); |
| 229 | extern struct page * read_swap_cache_async(swp_entry_t, struct vm_area_struct *vma, |
| 230 | unsigned long addr); |
| 231 | /* linux/mm/swapfile.c */ |
| 232 | extern long total_swap_pages; |
| 233 | extern unsigned int nr_swapfiles; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | extern void si_swapinfo(struct sysinfo *); |
| 235 | extern swp_entry_t get_swap_page(void); |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 236 | extern swp_entry_t get_swap_page_of_type(int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | extern int swap_duplicate(swp_entry_t); |
| 238 | extern int valid_swaphandles(swp_entry_t, unsigned long *); |
| 239 | extern void swap_free(swp_entry_t); |
| 240 | extern void free_swap_and_cache(swp_entry_t); |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 241 | extern int swap_type_of(dev_t); |
| 242 | extern unsigned int count_swap_pages(int, int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | extern sector_t map_swap_page(struct swap_info_struct *, pgoff_t); |
| 244 | extern struct swap_info_struct *get_swap_info_struct(unsigned); |
| 245 | extern int can_share_swap_page(struct page *); |
| 246 | extern int remove_exclusive_swap_page(struct page *); |
| 247 | struct backing_dev_info; |
| 248 | |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 249 | extern spinlock_t swap_lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 250 | |
| 251 | /* linux/mm/thrash.c */ |
| 252 | extern struct mm_struct * swap_token_mm; |
| 253 | extern unsigned long swap_token_default_timeout; |
| 254 | extern void grab_swap_token(void); |
| 255 | extern void __put_swap_token(struct mm_struct *); |
| 256 | |
| 257 | static inline int has_swap_token(struct mm_struct *mm) |
| 258 | { |
| 259 | return (mm == swap_token_mm); |
| 260 | } |
| 261 | |
| 262 | static inline void put_swap_token(struct mm_struct *mm) |
| 263 | { |
| 264 | if (has_swap_token(mm)) |
| 265 | __put_swap_token(mm); |
| 266 | } |
| 267 | |
Rik van Riel | f7b7fd8 | 2005-11-28 13:44:07 -0800 | [diff] [blame] | 268 | static inline void disable_swap_token(void) |
| 269 | { |
| 270 | put_swap_token(swap_token_mm); |
| 271 | } |
| 272 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | #else /* CONFIG_SWAP */ |
| 274 | |
| 275 | #define total_swap_pages 0 |
| 276 | #define total_swapcache_pages 0UL |
| 277 | |
| 278 | #define si_swapinfo(val) \ |
| 279 | do { (val)->freeswap = (val)->totalswap = 0; } while (0) |
Olaf Hering | 9ae5b3c | 2005-08-07 09:42:24 -0700 | [diff] [blame] | 280 | /* only sparc can not include linux/pagemap.h in this file |
| 281 | * so leave page_cache_release and release_pages undeclared... */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 282 | #define free_page_and_swap_cache(page) \ |
| 283 | page_cache_release(page) |
| 284 | #define free_pages_and_swap_cache(pages, nr) \ |
| 285 | release_pages((pages), (nr), 0); |
| 286 | |
Con Kolivas | bd96b9e | 2006-06-23 02:03:42 -0700 | [diff] [blame] | 287 | static inline void show_swap_cache_info(void) |
| 288 | { |
| 289 | } |
| 290 | |
| 291 | static inline void free_swap_and_cache(swp_entry_t swp) |
| 292 | { |
| 293 | } |
| 294 | |
| 295 | static inline int swap_duplicate(swp_entry_t swp) |
| 296 | { |
| 297 | return 0; |
| 298 | } |
| 299 | |
| 300 | static inline void swap_free(swp_entry_t swp) |
| 301 | { |
| 302 | } |
| 303 | |
| 304 | static inline struct page *read_swap_cache_async(swp_entry_t swp, |
| 305 | struct vm_area_struct *vma, unsigned long addr) |
| 306 | { |
| 307 | return NULL; |
| 308 | } |
| 309 | |
| 310 | static inline struct page *lookup_swap_cache(swp_entry_t swp) |
| 311 | { |
| 312 | return NULL; |
| 313 | } |
| 314 | |
| 315 | static inline int valid_swaphandles(swp_entry_t entry, unsigned long *offset) |
| 316 | { |
| 317 | return 0; |
| 318 | } |
| 319 | |
Hua Zhong | e6333fd | 2006-05-15 09:44:22 -0700 | [diff] [blame] | 320 | #define can_share_swap_page(p) (page_mapcount(p) == 1) |
Con Kolivas | bd96b9e | 2006-06-23 02:03:42 -0700 | [diff] [blame] | 321 | |
| 322 | static inline int move_to_swap_cache(struct page *page, swp_entry_t entry) |
| 323 | { |
| 324 | return 1; |
| 325 | } |
| 326 | |
| 327 | static inline int move_from_swap_cache(struct page *page, unsigned long index, |
| 328 | struct address_space *mapping) |
| 329 | { |
| 330 | return 1; |
| 331 | } |
| 332 | |
| 333 | static inline void __delete_from_swap_cache(struct page *page) |
| 334 | { |
| 335 | } |
| 336 | |
| 337 | static inline void delete_from_swap_cache(struct page *page) |
| 338 | { |
| 339 | } |
| 340 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | #define swap_token_default_timeout 0 |
| 342 | |
| 343 | static inline int remove_exclusive_swap_page(struct page *p) |
| 344 | { |
| 345 | return 0; |
| 346 | } |
| 347 | |
| 348 | static inline swp_entry_t get_swap_page(void) |
| 349 | { |
| 350 | swp_entry_t entry; |
| 351 | entry.val = 0; |
| 352 | return entry; |
| 353 | } |
| 354 | |
| 355 | /* linux/mm/thrash.c */ |
| 356 | #define put_swap_token(x) do { } while(0) |
| 357 | #define grab_swap_token() do { } while(0) |
| 358 | #define has_swap_token(x) 0 |
Rik van Riel | f7b7fd8 | 2005-11-28 13:44:07 -0800 | [diff] [blame] | 359 | #define disable_swap_token() do { } while(0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | |
| 361 | #endif /* CONFIG_SWAP */ |
| 362 | #endif /* __KERNEL__*/ |
| 363 | #endif /* _LINUX_SWAP_H */ |