123 lines
3.0 KiB
C
123 lines
3.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_FRONTSWAP_H
|
|
#define _LINUX_FRONTSWAP_H
|
|
|
|
#include <linux/swap.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/bitops.h>
|
|
#include <linux/jump_label.h>
|
|
|
|
/*
|
|
* Return code to denote that requested number of
|
|
* frontswap pages are unused(moved to page cache).
|
|
* Used in in shmem_unuse and try_to_unuse.
|
|
*/
|
|
#define FRONTSWAP_PAGES_UNUSED 2
|
|
|
|
struct frontswap_ops {
|
|
void (*init)(unsigned); /* this swap type was just swapon'ed */
|
|
int (*store)(unsigned, pgoff_t, struct page *); /* store a page */
|
|
int (*load)(unsigned, pgoff_t, struct page *); /* load a page */
|
|
void (*invalidate_page)(unsigned, pgoff_t); /* page no longer needed */
|
|
void (*invalidate_area)(unsigned); /* swap type just swapoff'ed */
|
|
struct frontswap_ops *next; /* private pointer to next ops */
|
|
};
|
|
|
|
extern void 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 bool __frontswap_test(struct swap_info_struct *, pgoff_t);
|
|
extern void __frontswap_init(unsigned type, unsigned long *map);
|
|
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
|
|
extern struct static_key_false frontswap_enabled_key;
|
|
|
|
static inline bool frontswap_enabled(void)
|
|
{
|
|
return static_branch_unlikely(&frontswap_enabled_key);
|
|
}
|
|
|
|
static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
|
|
{
|
|
return __frontswap_test(sis, offset);
|
|
}
|
|
|
|
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 */
|
|
|
|
static inline bool frontswap_enabled(void)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
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)
|
|
{
|
|
if (frontswap_enabled())
|
|
return __frontswap_store(page);
|
|
|
|
return -1;
|
|
}
|
|
|
|
static inline int frontswap_load(struct page *page)
|
|
{
|
|
if (frontswap_enabled())
|
|
return __frontswap_load(page);
|
|
|
|
return -1;
|
|
}
|
|
|
|
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, unsigned long *map)
|
|
{
|
|
#ifdef CONFIG_FRONTSWAP
|
|
__frontswap_init(type, map);
|
|
#endif
|
|
}
|
|
|
|
#endif /* _LINUX_FRONTSWAP_H */
|