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#ifndef _LINUX_SWAP_H
#define _LINUX_SWAP_H
#include <linux/spinlock.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
#define MAX_SWAPFILES 32
/*
* 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;
};
#ifdef __KERNEL__
/*
* 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))
#include <asm/atomic.h>
#define SWP_USED 1
#define SWP_WRITEOK 3
#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;
kdev_t swap_device;
spinlock_t sdev_lock;
struct dentry * swap_file;
struct vfsmount *swap_vfsmnt;
unsigned short * swap_map;
unsigned int lowest_bit;
unsigned int highest_bit;
unsigned int cluster_next;
unsigned int cluster_nr;
int prio; /* swap priority */
int pages;
unsigned long max;
int next; /* next entry on swap list */
};
extern int nr_swap_pages;
/* Swap 50% full? Release swapcache more aggressively.. */
#define vm_swap_full() (nr_swap_pages*2 < total_swap_pages)
extern unsigned int nr_free_pages(void);
extern unsigned int nr_free_buffer_pages(void);
extern int nr_active_pages;
extern int nr_inactive_pages;
extern atomic_t nr_async_pages;
extern atomic_t page_cache_size;
extern atomic_t buffermem_pages;
extern spinlock_cacheline_t pagecache_lock_cacheline;
#define pagecache_lock (pagecache_lock_cacheline.lock)
extern void __remove_inode_page(struct page *);
/* Incomplete types for prototype declarations: */
struct task_struct;
struct vm_area_struct;
struct sysinfo;
struct zone_t;
/* linux/mm/swap.c */
extern void FASTCALL(lru_cache_add(struct page *));
extern void FASTCALL(__lru_cache_del(struct page *));
extern void FASTCALL(lru_cache_del(struct page *));
extern void FASTCALL(activate_page(struct page *));
extern void swap_setup(void);
/* linux/mm/vmscan.c */
extern wait_queue_head_t kswapd_wait;
extern int FASTCALL(try_to_free_pages(zone_t *, unsigned int, unsigned int));
/* linux/mm/page_io.c */
extern void rw_swap_page(int, struct page *);
extern void rw_swap_page_nolock(int, swp_entry_t, char *);
/* linux/mm/page_alloc.c */
/* linux/mm/swap_state.c */
#define SWAP_CACHE_INFO
#ifdef SWAP_CACHE_INFO
extern void show_swap_cache_info(void);
#endif
extern int add_to_swap_cache(struct page *, swp_entry_t);
extern void __delete_from_swap_cache(struct page *page);
extern void delete_from_swap_cache(struct page *page);
extern void free_page_and_swap_cache(struct page *page);
extern struct page * lookup_swap_cache(swp_entry_t);
extern struct page * read_swap_cache_async(swp_entry_t);
/* linux/mm/oom_kill.c */
extern void out_of_memory(void);
/* linux/mm/swapfile.c */
extern int total_swap_pages;
extern unsigned int nr_swapfiles;
extern struct swap_info_struct swap_info[];
extern int is_swap_partition(kdev_t);
extern void si_swapinfo(struct sysinfo *);
extern swp_entry_t get_swap_page(void);
extern void get_swaphandle_info(swp_entry_t, unsigned long *, kdev_t *,
struct inode **);
extern int swap_duplicate(swp_entry_t);
extern int swap_count(struct page *);
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);
struct swap_list_t {
int head; /* head of priority-ordered swapfile list */
int next; /* swapfile to be used next */
};
extern struct swap_list_t swap_list;
asmlinkage long sys_swapoff(const char *);
asmlinkage long sys_swapon(const char *, int);
extern spinlock_cacheline_t pagemap_lru_lock_cacheline;
#define pagemap_lru_lock pagemap_lru_lock_cacheline.lock
extern void FASTCALL(mark_page_accessed(struct page *));
/*
* List add/del helper macros. These must be called
* with the pagemap_lru_lock held!
*/
#define DEBUG_LRU_PAGE(page) \
do { \
if (!PageLRU(page)) \
BUG(); \
if (PageActive(page)) \
BUG(); \
} while (0)
#define add_page_to_active_list(page) \
do { \
DEBUG_LRU_PAGE(page); \
SetPageActive(page); \
list_add(&(page)->lru, &active_list); \
nr_active_pages++; \
} while (0)
#define add_page_to_inactive_list(page) \
do { \
DEBUG_LRU_PAGE(page); \
list_add(&(page)->lru, &inactive_list); \
nr_inactive_pages++; \
} while (0)
#define del_page_from_active_list(page) \
do { \
list_del(&(page)->lru); \
ClearPageActive(page); \
nr_active_pages--; \
} while (0)
#define del_page_from_inactive_list(page) \
do { \
list_del(&(page)->lru); \
nr_inactive_pages--; \
} while (0)
extern spinlock_t swaplock;
#define swap_list_lock() spin_lock(&swaplock)
#define swap_list_unlock() spin_unlock(&swaplock)
#define swap_device_lock(p) spin_lock(&p->sdev_lock)
#define swap_device_unlock(p) spin_unlock(&p->sdev_lock)
extern void shmem_unuse(swp_entry_t entry, struct page *page);
#endif /* __KERNEL__*/
#endif /* _LINUX_SWAP_H */
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