| /* 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 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 */ |