1#ifndef _LINUX_FRONTSWAP_H 2#define _LINUX_FRONTSWAP_H 3 4#include <linux/swap.h> 5#include <linux/mm.h> 6#include <linux/bitops.h> 7 8struct frontswap_ops { 9 void (*init)(unsigned); /* this swap type was just swapon'ed */ 10 int (*store)(unsigned, pgoff_t, struct page *); /* store a page */ 11 int (*load)(unsigned, pgoff_t, struct page *); /* load a page */ 12 void (*invalidate_page)(unsigned, pgoff_t); /* page no longer needed */ 13 void (*invalidate_area)(unsigned); /* swap type just swapoff'ed */ 14 struct frontswap_ops *next; /* private pointer to next ops */ 15}; 16 17extern bool frontswap_enabled; 18extern void frontswap_register_ops(struct frontswap_ops *ops); 19extern void frontswap_shrink(unsigned long); 20extern unsigned long frontswap_curr_pages(void); 21extern void frontswap_writethrough(bool); 22#define FRONTSWAP_HAS_EXCLUSIVE_GETS 23extern void frontswap_tmem_exclusive_gets(bool); 24 25extern bool __frontswap_test(struct swap_info_struct *, pgoff_t); 26extern void __frontswap_init(unsigned type, unsigned long *map); 27extern int __frontswap_store(struct page *page); 28extern int __frontswap_load(struct page *page); 29extern void __frontswap_invalidate_page(unsigned, pgoff_t); 30extern void __frontswap_invalidate_area(unsigned); 31 32#ifdef CONFIG_FRONTSWAP 33#define frontswap_enabled (1) 34 35static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset) 36{ 37 return __frontswap_test(sis, offset); 38} 39 40static inline void frontswap_map_set(struct swap_info_struct *p, 41 unsigned long *map) 42{ 43 p->frontswap_map = map; 44} 45 46static inline unsigned long *frontswap_map_get(struct swap_info_struct *p) 47{ 48 return p->frontswap_map; 49} 50#else 51/* all inline routines become no-ops and all externs are ignored */ 52 53#define frontswap_enabled (0) 54 55static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset) 56{ 57 return false; 58} 59 60static inline void frontswap_map_set(struct swap_info_struct *p, 61 unsigned long *map) 62{ 63} 64 65static inline unsigned long *frontswap_map_get(struct swap_info_struct *p) 66{ 67 return NULL; 68} 69#endif 70 71static inline int frontswap_store(struct page *page) 72{ 73 int ret = -1; 74 75 if (frontswap_enabled) 76 ret = __frontswap_store(page); 77 return ret; 78} 79 80static inline int frontswap_load(struct page *page) 81{ 82 int ret = -1; 83 84 if (frontswap_enabled) 85 ret = __frontswap_load(page); 86 return ret; 87} 88 89static inline void frontswap_invalidate_page(unsigned type, pgoff_t offset) 90{ 91 if (frontswap_enabled) 92 __frontswap_invalidate_page(type, offset); 93} 94 95static inline void frontswap_invalidate_area(unsigned type) 96{ 97 if (frontswap_enabled) 98 __frontswap_invalidate_area(type); 99} 100 101static inline void frontswap_init(unsigned type, unsigned long *map) 102{ 103 if (frontswap_enabled) 104 __frontswap_init(type, map); 105} 106 107#endif /* _LINUX_FRONTSWAP_H */ 108