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#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 (*put_page)(unsigned, pgoff_t, struct page *);
int (*get_page)(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);
extern void __frontswap_init(unsigned type);
extern int __frontswap_put_page(struct page *page);
extern int __frontswap_get_page(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_put_page(struct page *page)
{
int ret = -1;
if (frontswap_enabled)
ret = __frontswap_put_page(page);
return ret;
}
static inline int frontswap_get_page(struct page *page)
{
int ret = -1;
if (frontswap_enabled)
ret = __frontswap_get_page(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 */
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