LXR linux/include/linux/frontswap.h

   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);
  10        int (*store)(unsigned, pgoff_t, struct page *);
  11        int (*load)(unsigned, pgoff_t, struct page *);
  12        void (*invalidate_page)(unsigned, pgoff_t);
  13        void (*invalidate_area)(unsigned);
  14};
  15
  16extern bool frontswap_enabled;
  17extern struct frontswap_ops
  18        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
  23extern void __frontswap_init(unsigned type);
  24extern int __frontswap_store(struct page *page);
  25extern int __frontswap_load(struct page *page);
  26extern void __frontswap_invalidate_page(unsigned, pgoff_t);
  27extern void __frontswap_invalidate_area(unsigned);
  28
  29#ifdef CONFIG_FRONTSWAP
  30
  31static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
  32{
  33        bool ret = false;
  34
  35        if (frontswap_enabled && sis->frontswap_map)
  36                ret = test_bit(offset, sis->frontswap_map);
  37        return ret;
  38}
  39
  40static inline void frontswap_set(struct swap_info_struct *sis, pgoff_t offset)
  41{
  42        if (frontswap_enabled && sis->frontswap_map)
  43                set_bit(offset, sis->frontswap_map);
  44}
  45
  46static inline void frontswap_clear(struct swap_info_struct *sis, pgoff_t offset)
  47{
  48        if (frontswap_enabled && sis->frontswap_map)
  49                clear_bit(offset, sis->frontswap_map);
  50}
  51
  52static inline void frontswap_map_set(struct swap_info_struct *p,
  53                                     unsigned long *map)
  54{
  55        p->frontswap_map = map;
  56}
  57
  58static inline unsigned long *frontswap_map_get(struct swap_info_struct *p)
  59{
  60        return p->frontswap_map;
  61}
  62#else
  63/* all inline routines become no-ops and all externs are ignored */
  64
  65#define frontswap_enabled (0)
  66
  67static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
  68{
  69        return false;
  70}
  71
  72static inline void frontswap_set(struct swap_info_struct *sis, pgoff_t offset)
  73{
  74}
  75
  76static inline void frontswap_clear(struct swap_info_struct *sis, pgoff_t offset)
  77{
  78}
  79
  80static inline void frontswap_map_set(struct swap_info_struct *p,
  81                                     unsigned long *map)
  82{
  83}
  84
  85static inline unsigned long *frontswap_map_get(struct swap_info_struct *p)
  86{
  87        return NULL;
  88}
  89#endif
  90
  91static inline int frontswap_store(struct page *page)
  92{
  93        int ret = -1;
  94
  95        if (frontswap_enabled)
  96                ret = __frontswap_store(page);
  97        return ret;
  98}
  99
 100static inline int frontswap_load(struct page *page)
 101{
 102        int ret = -1;
 103
 104        if (frontswap_enabled)
 105                ret = __frontswap_load(page);
 106        return ret;
 107}
 108
 109static inline void frontswap_invalidate_page(unsigned type, pgoff_t offset)
 110{
 111        if (frontswap_enabled)
 112                __frontswap_invalidate_page(type, offset);
 113}
 114
 115static inline void frontswap_invalidate_area(unsigned type)
 116{
 117        if (frontswap_enabled)
 118                __frontswap_invalidate_area(type);
 119}
 120
 121static inline void frontswap_init(unsigned type)
 122{
 123        if (frontswap_enabled)
 124                __frontswap_init(type);
 125}
 126
 127#endif /* _LINUX_FRONTSWAP_H */
 128