linux-stable/include/linux/frontswap.h
Christoph Hellwig 1da0d94a3e frontswap: remove support for multiple ops
There is only a single instance of frontswap ops in the kernel, so
simplify the frontswap code by removing support for multiple operations.

Link: https://lkml.kernel.org/r/20211224062246.1258487-13-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-22 08:33:38 +02:00

91 lines
2.2 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>
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 */
};
int frontswap_register_ops(const struct frontswap_ops *ops);
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 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 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);
}
#endif /* _LINUX_FRONTSWAP_H */