Include/linux/swap.h
17504 #ifndef _LINUX_SWAP_H 17505 #define _LINUX_SWAP_H 17506 17507 #include <asm/page.h> 17508 17509 /* set if swap priority specified */ 17510 #define SWAP_FLAG_PREFER 0x8000 17511 #define SWAP_FLAG_PRIO_MASK 0x7fff 17512 #define SWAP_FLAG_PRIO_SHIFT 0 17513 17514 #define MAX_SWAPFILES 8 17515 17516 union swap_header { 17517 struct 17518 { 17519 char reserved[PAGE_SIZE - 10]; 17520 char magic[10]; 17521 } magic; 17522 struct 17523 { 17524 char bootbits[1024]; /* Space for disklabel etc. */ 17525 unsigned int version; 17526 unsigned int last_page; 17527 unsigned int nr_badpages; 17528 unsigned int padding[125]; 17529 unsigned int badpages[1]; 17530 } info; 17531 }; 17532 17533 #ifdef __KERNEL__ 17534 17535 /* Max bad pages in the new format.. */ 17536 #define __swapoffset(x) \ 17537 ((unsigned long)&((union swap_header *)0)->x) 17538 #define MAX_SWAP_BADPAGES \ 17539 ((__swapoffset(magic.magic) - \ 17540 __swapoffset(info.badpages)) / sizeof(int)) 17541 17542 #undef DEBUG_SWAP 17543 17544 #include <asm/atomic.h> 17545 17546 #define SWP_USED 1 17547 #define SWP_WRITEOK 3 17548 17549 #define SWAP_CLUSTER_MAX 32 17550 17551 #define SWAP_MAP_MAX 0x7fff 17552 #define SWAP_MAP_BAD 0x8000 17553 17554 struct swap_info_struct { 17555 unsigned int flags; 17556 kdev_t swap_device; 17557 struct dentry * swap_file; 17558 unsigned short * swap_map; 17559 unsigned char * swap_lockmap; 17560 unsigned int lowest_bit; 17561 unsigned int highest_bit; 17562 unsigned int cluster_next; 17563 unsigned int cluster_nr; 17564 int prio; /* swap priority */ 17565 int pages; 17566 unsigned long max; 17567 int next; /* next entry on swap list */ 17568 }; 17569 17570 extern int nr_swap_pages; 17571 extern int nr_free_pages; 17572 extern atomic_t nr_async_pages; 17573 extern struct inode swapper_inode; 17574 extern unsigned long page_cache_size; 17575 extern int buffermem; 17576 17577 /* Incomplete types for prototype declarations: */ 17578 struct task_struct; 17579 struct vm_area_struct; 17580 struct sysinfo; 17581 17582 /* linux/ipc/shm.c */ 17583 extern int shm_swap (int, int); 17584 17585 /* linux/mm/swap.c */ 17586 extern void swap_setup (void); 17587 17588 /* linux/mm/vmscan.c */ 17589 extern int try_to_free_pages(unsigned int gfp_mask); 17590 17591 /* linux/mm/page_io.c */ 17592 extern void rw_swap_page(int, unsigned long, char *,int); 17593 extern void rw_swap_page_nocache(int, unsigned long, 17594 char *); 17595 extern void rw_swap_page_nolock(int, unsigned long, 17596 char *, int); 17597 extern void swap_after_unlock_page (unsigned long entry); 17598 17599 /* linux/mm/page_alloc.c */ 17600 extern void swap_in(struct task_struct *, 17601 struct vm_area_struct *, pte_t *, unsigned long, int); 17602 17603 17604 /* linux/mm/swap_state.c */ 17605 extern void show_swap_cache_info(void); 17606 extern int add_to_swap_cache(struct page *, 17607 unsigned long); 17608 extern int swap_duplicate(unsigned long); 17609 extern int swap_check_entry(unsigned long); 17610 struct page * lookup_swap_cache(unsigned long); 17611 extern struct page * read_swap_cache_async(unsigned long, 17612 int); 17613 #define read_swap_cache(entry) \ 17614 read_swap_cache_async(entry, 1); 17615 extern int FASTCALL(swap_count(unsigned long)); 17616 /* Make these inline later once they are working 17617 * properly. */ 17618 extern void delete_from_swap_cache(struct page *page); 17619 extern void free_page_and_swap_cache(unsigned long addr); 17620 17621 /* linux/mm/swapfile.c */ 17622 extern unsigned int nr_swapfiles; 17623 extern struct swap_info_struct swap_info[]; 17624 void si_swapinfo(struct sysinfo *); 17625 unsigned long get_swap_page(void); 17626 extern void FASTCALL(swap_free(unsigned long)); 17627 struct swap_list_t { 17628 int head; /* head of priority-ordered swapfile list */ 17629 int next; /* swapfile to be used next */ 17630 }; 17631 extern struct swap_list_t swap_list; 17632 asmlinkage int sys_swapoff(const char *); 17633 asmlinkage int sys_swapon(const char *, int); 17634 17635 /* vm_ops not present page codes for shared memory. 17636 * 17637 * Will go away eventually.. */ 17638 #define SHM_SWP_TYPE 0x20 17639 17640 /* swap cache stuff (in linux/mm/swap_state.c) */ 17641 17642 #define SWAP_CACHE_INFO 17643 17644 #ifdef SWAP_CACHE_INFO 17645 extern unsigned long swap_cache_add_total; 17646 extern unsigned long swap_cache_del_total; 17647 extern unsigned long swap_cache_find_total; 17648 extern unsigned long swap_cache_find_success; 17649 #endif 17650 17651 extern inline unsigned long 17652 in_swap_cache(struct page *page) 17653 { 17654 if (PageSwapCache(page)) 17655 return page->offset; 17656 return 0; 17657 } 17658 17659 /* Work out if there are any other processes sharing this 17660 * page, ignoring any page reference coming from the swap 17661 * cache, or from outstanding swap IO on this page. (The 17662 * page cache _does_ count as another valid reference to 17663 * the page, however.) */ 17664 static inline int is_page_shared(struct page *page) 17665 { 17666 unsigned int count; 17667 if (PageReserved(page)) 17668 return 1; 17669 count = atomic_read(&page->count); 17670 if (PageSwapCache(page)) 17671 count += swap_count(page->offset) - 2; 17672 if (PageFreeAfter(page)) 17673 count--; 17674 return count > 1; 17675 } 17676 17677 #endif /* __KERNEL__*/ 17678 17679 #endif /* _LINUX_SWAP_H */
