| #ifndef _LINUX_SWAP_H |
| #define _LINUX_SWAP_H |
| |
| #include <linux/config.h> |
| #include <linux/spinlock.h> |
| #include <linux/linkage.h> |
| #include <linux/mmzone.h> |
| #include <linux/list.h> |
| #include <linux/sched.h> |
| |
| #include <asm/atomic.h> |
| #include <asm/page.h> |
| |
| #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */ |
| #define SWAP_FLAG_PRIO_MASK 0x7fff |
| #define SWAP_FLAG_PRIO_SHIFT 0 |
| |
| static inline int current_is_kswapd(void) |
| { |
| return current->flags & PF_KSWAPD; |
| } |
| |
| /* |
| * MAX_SWAPFILES defines the maximum number of swaptypes: things which can |
| * be swapped to. The swap type and the offset into that swap type are |
| * encoded into pte's and into pgoff_t's in the swapcache. Using five bits |
| * for the type means that the maximum number of swapcache pages is 27 bits |
| * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs |
| * the type/offset into the pte as 5/27 as well. |
| */ |
| #define MAX_SWAPFILES_SHIFT 5 |
| #define MAX_SWAPFILES (1 << MAX_SWAPFILES_SHIFT) |
| |
| /* |
| * Magic header for a swap area. The first part of the union is |
| * what the swap magic looks like for the old (limited to 128MB) |
| * swap area format, the second part of the union adds - in the |
| * old reserved area - some extra information. Note that the first |
| * kilobyte is reserved for boot loader or disk label stuff... |
| * |
| * Having the magic at the end of the PAGE_SIZE makes detecting swap |
| * areas somewhat tricky on machines that support multiple page sizes. |
| * For 2.5 we'll probably want to move the magic to just beyond the |
| * bootbits... |
| */ |
| union swap_header { |
| struct { |
| char reserved[PAGE_SIZE - 10]; |
| char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ |
| } magic; |
| struct { |
| char bootbits[1024]; /* Space for disklabel etc. */ |
| unsigned int version; |
| unsigned int last_page; |
| unsigned int nr_badpages; |
| unsigned int padding[125]; |
| unsigned int badpages[1]; |
| } info; |
| }; |
| |
| /* A swap entry has to fit into a "unsigned long", as |
| * the entry is hidden in the "index" field of the |
| * swapper address space. |
| */ |
| typedef struct { |
| unsigned long val; |
| } swp_entry_t; |
| |
| /* |
| * current->reclaim_state points to one of these when a task is running |
| * memory reclaim |
| */ |
| struct reclaim_state { |
| unsigned long reclaimed_slab; |
| }; |
| |
| #ifdef __KERNEL__ |
| |
| struct address_space; |
| struct sysinfo; |
| struct writeback_control; |
| struct zone; |
| |
| /* |
| * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of |
| * disk blocks. A list of swap extents maps the entire swapfile. (Where the |
| * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart |
| * from setup, they're handled identically. |
| * |
| * We always assume that blocks are of size PAGE_SIZE. |
| */ |
| struct swap_extent { |
| struct list_head list; |
| pgoff_t start_page; |
| pgoff_t nr_pages; |
| sector_t start_block; |
| }; |
| |
| /* |
| * Max bad pages in the new format.. |
| */ |
| #define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x) |
| #define MAX_SWAP_BADPAGES \ |
| ((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int)) |
| |
| enum { |
| SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ |
| SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ |
| SWP_ACTIVE = (SWP_USED | SWP_WRITEOK), |
| /* add others here before... */ |
| SWP_SCANNING = (1 << 8), /* refcount in scan_swap_map */ |
| }; |
| |
| #define SWAP_CLUSTER_MAX 32 |
| |
| #define SWAP_MAP_MAX 0x7fff |
| #define SWAP_MAP_BAD 0x8000 |
| |
| /* |
| * The in-memory structure used to track swap areas. |
| */ |
| struct swap_info_struct { |
| unsigned int flags; |
| int prio; /* swap priority */ |
| struct file *swap_file; |
| struct block_device *bdev; |
| struct list_head extent_list; |
| struct swap_extent *curr_swap_extent; |
| unsigned old_block_size; |
| unsigned short * swap_map; |
| unsigned int lowest_bit; |
| unsigned int highest_bit; |
| unsigned int cluster_next; |
| unsigned int cluster_nr; |
| unsigned int pages; |
| unsigned int max; |
| unsigned int inuse_pages; |
| int next; /* next entry on swap list */ |
| }; |
| |
| struct swap_list_t { |
| int head; /* head of priority-ordered swapfile list */ |
| int next; /* swapfile to be used next */ |
| }; |
| |
| /* Swap 50% full? Release swapcache more aggressively.. */ |
| #define vm_swap_full() (nr_swap_pages*2 < total_swap_pages) |
| |
| /* linux/mm/oom_kill.c */ |
| extern void out_of_memory(gfp_t gfp_mask, int order); |
| |
| /* linux/mm/memory.c */ |
| extern void swapin_readahead(swp_entry_t, unsigned long, struct vm_area_struct *); |
| |
| /* linux/mm/page_alloc.c */ |
| extern unsigned long totalram_pages; |
| extern unsigned long totalhigh_pages; |
| extern long nr_swap_pages; |
| extern unsigned int nr_free_pages(void); |
| extern unsigned int nr_free_pages_pgdat(pg_data_t *pgdat); |
| extern unsigned int nr_free_buffer_pages(void); |
| extern unsigned int nr_free_pagecache_pages(void); |
| |
| /* linux/mm/swap.c */ |
| extern void FASTCALL(lru_cache_add(struct page *)); |
| extern void FASTCALL(lru_cache_add_active(struct page *)); |
| extern void FASTCALL(activate_page(struct page *)); |
| extern void FASTCALL(mark_page_accessed(struct page *)); |
| extern void lru_add_drain(void); |
| extern int rotate_reclaimable_page(struct page *page); |
| extern void swap_setup(void); |
| |
| /* linux/mm/vmscan.c */ |
| extern int try_to_free_pages(struct zone **, gfp_t); |
| extern int shrink_all_memory(int); |
| extern int vm_swappiness; |
| |
| extern int isolate_lru_page(struct page *p); |
| extern int putback_lru_pages(struct list_head *l); |
| |
| #ifdef CONFIG_MIGRATION |
| extern int migrate_pages(struct list_head *l, struct list_head *t); |
| #endif |
| |
| #ifdef CONFIG_MMU |
| /* linux/mm/shmem.c */ |
| extern int shmem_unuse(swp_entry_t entry, struct page *page); |
| #endif /* CONFIG_MMU */ |
| |
| extern void swap_unplug_io_fn(struct backing_dev_info *, struct page *); |
| |
| #ifdef CONFIG_SWAP |
| /* linux/mm/page_io.c */ |
| extern int swap_readpage(struct file *, struct page *); |
| extern int swap_writepage(struct page *page, struct writeback_control *wbc); |
| extern int rw_swap_page_sync(int, swp_entry_t, struct page *); |
| |
| /* linux/mm/swap_state.c */ |
| extern struct address_space swapper_space; |
| #define total_swapcache_pages swapper_space.nrpages |
| extern void show_swap_cache_info(void); |
| extern int add_to_swap(struct page *); |
| extern void __delete_from_swap_cache(struct page *); |
| extern void delete_from_swap_cache(struct page *); |
| extern int move_to_swap_cache(struct page *, swp_entry_t); |
| extern int move_from_swap_cache(struct page *, unsigned long, |
| struct address_space *); |
| extern void free_page_and_swap_cache(struct page *); |
| extern void free_pages_and_swap_cache(struct page **, int); |
| extern struct page * lookup_swap_cache(swp_entry_t); |
| extern struct page * read_swap_cache_async(swp_entry_t, struct vm_area_struct *vma, |
| unsigned long addr); |
| /* linux/mm/swapfile.c */ |
| extern long total_swap_pages; |
| extern unsigned int nr_swapfiles; |
| extern struct swap_info_struct swap_info[]; |
| extern void si_swapinfo(struct sysinfo *); |
| extern swp_entry_t get_swap_page(void); |
| extern swp_entry_t get_swap_page_of_type(int type); |
| extern int swap_duplicate(swp_entry_t); |
| extern int valid_swaphandles(swp_entry_t, unsigned long *); |
| extern void swap_free(swp_entry_t); |
| extern void free_swap_and_cache(swp_entry_t); |
| extern sector_t map_swap_page(struct swap_info_struct *, pgoff_t); |
| extern struct swap_info_struct *get_swap_info_struct(unsigned); |
| extern int can_share_swap_page(struct page *); |
| extern int remove_exclusive_swap_page(struct page *); |
| struct backing_dev_info; |
| |
| extern spinlock_t swap_lock; |
| |
| /* linux/mm/thrash.c */ |
| extern struct mm_struct * swap_token_mm; |
| extern unsigned long swap_token_default_timeout; |
| extern void grab_swap_token(void); |
| extern void __put_swap_token(struct mm_struct *); |
| |
| static inline int has_swap_token(struct mm_struct *mm) |
| { |
| return (mm == swap_token_mm); |
| } |
| |
| static inline void put_swap_token(struct mm_struct *mm) |
| { |
| if (has_swap_token(mm)) |
| __put_swap_token(mm); |
| } |
| |
| static inline void disable_swap_token(void) |
| { |
| put_swap_token(swap_token_mm); |
| } |
| |
| #else /* CONFIG_SWAP */ |
| |
| #define total_swap_pages 0 |
| #define total_swapcache_pages 0UL |
| |
| #define si_swapinfo(val) \ |
| do { (val)->freeswap = (val)->totalswap = 0; } while (0) |
| /* only sparc can not include linux/pagemap.h in this file |
| * so leave page_cache_release and release_pages undeclared... */ |
| #define free_page_and_swap_cache(page) \ |
| page_cache_release(page) |
| #define free_pages_and_swap_cache(pages, nr) \ |
| release_pages((pages), (nr), 0); |
| |
| #define show_swap_cache_info() /*NOTHING*/ |
| #define free_swap_and_cache(swp) /*NOTHING*/ |
| #define swap_duplicate(swp) /*NOTHING*/ |
| #define swap_free(swp) /*NOTHING*/ |
| #define read_swap_cache_async(swp,vma,addr) NULL |
| #define lookup_swap_cache(swp) NULL |
| #define valid_swaphandles(swp, off) 0 |
| #define can_share_swap_page(p) 0 |
| #define move_to_swap_cache(p, swp) 1 |
| #define move_from_swap_cache(p, i, m) 1 |
| #define __delete_from_swap_cache(p) /*NOTHING*/ |
| #define delete_from_swap_cache(p) /*NOTHING*/ |
| #define swap_token_default_timeout 0 |
| |
| static inline int remove_exclusive_swap_page(struct page *p) |
| { |
| return 0; |
| } |
| |
| static inline swp_entry_t get_swap_page(void) |
| { |
| swp_entry_t entry; |
| entry.val = 0; |
| return entry; |
| } |
| |
| /* linux/mm/thrash.c */ |
| #define put_swap_token(x) do { } while(0) |
| #define grab_swap_token() do { } while(0) |
| #define has_swap_token(x) 0 |
| #define disable_swap_token() do { } while(0) |
| |
| #endif /* CONFIG_SWAP */ |
| #endif /* __KERNEL__*/ |
| #endif /* _LINUX_SWAP_H */ |