1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _MM_SWAP_H 3 #define _MM_SWAP_H 4 5 #ifdef CONFIG_SWAP 6 #include <linux/blk_types.h> /* for bio_end_io_t */ 7 8 /* linux/mm/page_io.c */ 9 int sio_pool_init(void); 10 struct swap_iocb; 11 int swap_readpage(struct page *page, bool do_poll, 12 struct swap_iocb **plug); 13 void __swap_read_unplug(struct swap_iocb *plug); 14 static inline void swap_read_unplug(struct swap_iocb *plug) 15 { 16 if (unlikely(plug)) 17 __swap_read_unplug(plug); 18 } 19 void swap_write_unplug(struct swap_iocb *sio); 20 int swap_writepage(struct page *page, struct writeback_control *wbc); 21 void end_swap_bio_write(struct bio *bio); 22 int __swap_writepage(struct page *page, struct writeback_control *wbc, 23 bio_end_io_t end_write_func); 24 25 /* linux/mm/swap_state.c */ 26 /* One swap address space for each 64M swap space */ 27 #define SWAP_ADDRESS_SPACE_SHIFT 14 28 #define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT) 29 extern struct address_space *swapper_spaces[]; 30 #define swap_address_space(entry) \ 31 (&swapper_spaces[swp_type(entry)][swp_offset(entry) \ 32 >> SWAP_ADDRESS_SPACE_SHIFT]) 33 34 void show_swap_cache_info(void); 35 bool add_to_swap(struct folio *folio); 36 void *get_shadow_from_swap_cache(swp_entry_t entry); 37 int add_to_swap_cache(struct page *page, swp_entry_t entry, 38 gfp_t gfp, void **shadowp); 39 void __delete_from_swap_cache(struct page *page, 40 swp_entry_t entry, void *shadow); 41 void delete_from_swap_cache(struct page *page); 42 void clear_shadow_from_swap_cache(int type, unsigned long begin, 43 unsigned long end); 44 void free_swap_cache(struct page *page); 45 struct page *lookup_swap_cache(swp_entry_t entry, 46 struct vm_area_struct *vma, 47 unsigned long addr); 48 struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index); 49 50 struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, 51 struct vm_area_struct *vma, 52 unsigned long addr, 53 bool do_poll, 54 struct swap_iocb **plug); 55 struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, 56 struct vm_area_struct *vma, 57 unsigned long addr, 58 bool *new_page_allocated); 59 struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag, 60 struct vm_fault *vmf); 61 struct page *swapin_readahead(swp_entry_t entry, gfp_t flag, 62 struct vm_fault *vmf); 63 64 static inline unsigned int page_swap_flags(struct page *page) 65 { 66 return page_swap_info(page)->flags; 67 } 68 #else /* CONFIG_SWAP */ 69 struct swap_iocb; 70 static inline int swap_readpage(struct page *page, bool do_poll, 71 struct swap_iocb **plug) 72 { 73 return 0; 74 } 75 static inline void swap_write_unplug(struct swap_iocb *sio) 76 { 77 } 78 79 static inline struct address_space *swap_address_space(swp_entry_t entry) 80 { 81 return NULL; 82 } 83 84 static inline void free_swap_cache(struct page *page) 85 { 86 } 87 88 static inline void show_swap_cache_info(void) 89 { 90 } 91 92 static inline struct page *swap_cluster_readahead(swp_entry_t entry, 93 gfp_t gfp_mask, struct vm_fault *vmf) 94 { 95 return NULL; 96 } 97 98 static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, 99 struct vm_fault *vmf) 100 { 101 return NULL; 102 } 103 104 static inline int swap_writepage(struct page *p, struct writeback_control *wbc) 105 { 106 return 0; 107 } 108 109 static inline struct page *lookup_swap_cache(swp_entry_t swp, 110 struct vm_area_struct *vma, 111 unsigned long addr) 112 { 113 return NULL; 114 } 115 116 static inline 117 struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index) 118 { 119 return find_get_page(mapping, index); 120 } 121 122 static inline bool add_to_swap(struct folio *folio) 123 { 124 return false; 125 } 126 127 static inline void *get_shadow_from_swap_cache(swp_entry_t entry) 128 { 129 return NULL; 130 } 131 132 static inline int add_to_swap_cache(struct page *page, swp_entry_t entry, 133 gfp_t gfp_mask, void **shadowp) 134 { 135 return -1; 136 } 137 138 static inline void __delete_from_swap_cache(struct page *page, 139 swp_entry_t entry, void *shadow) 140 { 141 } 142 143 static inline void delete_from_swap_cache(struct page *page) 144 { 145 } 146 147 static inline void clear_shadow_from_swap_cache(int type, unsigned long begin, 148 unsigned long end) 149 { 150 } 151 152 static inline unsigned int page_swap_flags(struct page *page) 153 { 154 return 0; 155 } 156 #endif /* CONFIG_SWAP */ 157 #endif /* _MM_SWAP_H */ 158