#ifndef _LINUX_FRONTSWAP_H #define _LINUX_FRONTSWAP_H #include <linux/swap.h> #include <linux/mm.h> #include <linux/bitops.h> struct frontswap_ops { void (*init)(unsigned); int (*store)(unsigned, pgoff_t, struct page *); int (*load)(unsigned, pgoff_t, struct page *); void (*invalidate_page)(unsigned, pgoff_t); void (*invalidate_area)(unsigned); }; extern bool frontswap_enabled; extern struct frontswap_ops frontswap_register_ops(struct frontswap_ops *ops); extern void frontswap_shrink(unsigned long); extern unsigned long frontswap_curr_pages(void); extern void frontswap_writethrough(bool); #define FRONTSWAP_HAS_EXCLUSIVE_GETS extern void frontswap_tmem_exclusive_gets(bool); extern void __frontswap_init(unsigned type); extern int __frontswap_store(struct page *page); extern int __frontswap_load(struct page *page); extern void __frontswap_invalidate_page(unsigned, pgoff_t); extern void __frontswap_invalidate_area(unsigned); #ifdef CONFIG_FRONTSWAP static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset) { bool ret = false; if (frontswap_enabled && sis->frontswap_map) ret = test_bit(offset, sis->frontswap_map); return ret; } static inline void frontswap_set(struct swap_info_struct *sis, pgoff_t offset) { if (frontswap_enabled && sis->frontswap_map) set_bit(offset, sis->frontswap_map); } static inline void frontswap_clear(struct swap_info_struct *sis, pgoff_t offset) { if (frontswap_enabled && sis->frontswap_map) clear_bit(offset, sis->frontswap_map); } static inline void frontswap_map_set(struct swap_info_struct *p, unsigned long *map) { p->frontswap_map = map; } static inline unsigned long *frontswap_map_get(struct swap_info_struct *p) { return p->frontswap_map; } #else /* all inline routines become no-ops and all externs are ignored */ #define frontswap_enabled (0) static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset) { return false; } static inline void frontswap_set(struct swap_info_struct *sis, pgoff_t offset) { } static inline void frontswap_clear(struct swap_info_struct *sis, pgoff_t offset) { } static inline void frontswap_map_set(struct swap_info_struct *p, unsigned long *map) { } static inline unsigned long *frontswap_map_get(struct swap_info_struct *p) { return NULL; } #endif static inline int frontswap_store(struct page *page) { int ret = -1; if (frontswap_enabled) ret = __frontswap_store(page); return ret; } static inline int frontswap_load(struct page *page) { int ret = -1; if (frontswap_enabled) ret = __frontswap_load(page); return ret; } static inline void frontswap_invalidate_page(unsigned type, pgoff_t offset) { if (frontswap_enabled) __frontswap_invalidate_page(type, offset); } static inline void frontswap_invalidate_area(unsigned type) { if (frontswap_enabled) __frontswap_invalidate_area(type); } static inline void frontswap_init(unsigned type) { if (frontswap_enabled) __frontswap_init(type); } #endif /* _LINUX_FRONTSWAP_H */