forked from mirrors/linux
c82f16b52c
Drop the doubled word "in" in a comment. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Link: http://lkml.kernel.org/r/3af7ed91-ad62-8445-40a4-9e07a64b9523@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
122 lines
3 KiB
C
122 lines
3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_FRONTSWAP_H
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#define _LINUX_FRONTSWAP_H
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#include <linux/swap.h>
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#include <linux/mm.h>
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#include <linux/bitops.h>
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#include <linux/jump_label.h>
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/*
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* Return code to denote that requested number of
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* frontswap pages are unused(moved to page cache).
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* Used in shmem_unuse and try_to_unuse.
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*/
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#define FRONTSWAP_PAGES_UNUSED 2
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struct frontswap_ops {
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void (*init)(unsigned); /* this swap type was just swapon'ed */
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int (*store)(unsigned, pgoff_t, struct page *); /* store a page */
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int (*load)(unsigned, pgoff_t, struct page *); /* load a page */
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void (*invalidate_page)(unsigned, pgoff_t); /* page no longer needed */
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void (*invalidate_area)(unsigned); /* swap type just swapoff'ed */
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struct frontswap_ops *next; /* private pointer to next ops */
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};
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extern void frontswap_register_ops(struct frontswap_ops *ops);
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extern void frontswap_shrink(unsigned long);
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extern unsigned long frontswap_curr_pages(void);
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extern void frontswap_writethrough(bool);
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#define FRONTSWAP_HAS_EXCLUSIVE_GETS
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extern void frontswap_tmem_exclusive_gets(bool);
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extern bool __frontswap_test(struct swap_info_struct *, pgoff_t);
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extern void __frontswap_init(unsigned type, unsigned long *map);
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extern int __frontswap_store(struct page *page);
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extern int __frontswap_load(struct page *page);
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extern void __frontswap_invalidate_page(unsigned, pgoff_t);
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extern void __frontswap_invalidate_area(unsigned);
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#ifdef CONFIG_FRONTSWAP
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extern struct static_key_false frontswap_enabled_key;
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static inline bool frontswap_enabled(void)
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{
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return static_branch_unlikely(&frontswap_enabled_key);
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}
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static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
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{
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return __frontswap_test(sis, offset);
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}
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static inline void frontswap_map_set(struct swap_info_struct *p,
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unsigned long *map)
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{
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p->frontswap_map = map;
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}
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static inline unsigned long *frontswap_map_get(struct swap_info_struct *p)
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{
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return p->frontswap_map;
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}
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#else
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/* all inline routines become no-ops and all externs are ignored */
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static inline bool frontswap_enabled(void)
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{
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return false;
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}
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static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
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{
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return false;
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}
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static inline void frontswap_map_set(struct swap_info_struct *p,
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unsigned long *map)
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{
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}
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static inline unsigned long *frontswap_map_get(struct swap_info_struct *p)
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{
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return NULL;
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}
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#endif
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static inline int frontswap_store(struct page *page)
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{
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if (frontswap_enabled())
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return __frontswap_store(page);
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return -1;
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}
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static inline int frontswap_load(struct page *page)
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{
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if (frontswap_enabled())
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return __frontswap_load(page);
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return -1;
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}
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static inline void frontswap_invalidate_page(unsigned type, pgoff_t offset)
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{
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if (frontswap_enabled())
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__frontswap_invalidate_page(type, offset);
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}
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static inline void frontswap_invalidate_area(unsigned type)
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{
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if (frontswap_enabled())
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__frontswap_invalidate_area(type);
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}
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static inline void frontswap_init(unsigned type, unsigned long *map)
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{
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#ifdef CONFIG_FRONTSWAP
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__frontswap_init(type, map);
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#endif
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}
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#endif /* _LINUX_FRONTSWAP_H */
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