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 folio *folio, 40 swp_entry_t entry, void *shadow); 41 void delete_from_swap_cache(struct folio *folio); 42 void clear_shadow_from_swap_cache(int type, unsigned long begin, 43 unsigned long end); 44 struct page *lookup_swap_cache(swp_entry_t entry, 45 struct vm_area_struct *vma, 46 unsigned long addr); 47 struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index); 48 49 struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, 50 struct vm_area_struct *vma, 51 unsigned long addr, 52 bool do_poll, 53 struct swap_iocb **plug); 54 struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, 55 struct vm_area_struct *vma, 56 unsigned long addr, 57 bool *new_page_allocated); 58 struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag, 59 struct vm_fault *vmf); 60 struct page *swapin_readahead(swp_entry_t entry, gfp_t flag, 61 struct vm_fault *vmf); 62 63 static inline unsigned int folio_swap_flags(struct folio *folio) 64 { 65 return page_swap_info(&folio->page)->flags; 66 } 67 #else /* CONFIG_SWAP */ 68 struct swap_iocb; 69 static inline int swap_readpage(struct page *page, bool do_poll, 70 struct swap_iocb **plug) 71 { 72 return 0; 73 } 74 static inline void swap_write_unplug(struct swap_iocb *sio) 75 { 76 } 77 78 static inline struct address_space *swap_address_space(swp_entry_t entry) 79 { 80 return NULL; 81 } 82 83 static inline void show_swap_cache_info(void) 84 { 85 } 86 87 static inline struct page *swap_cluster_readahead(swp_entry_t entry, 88 gfp_t gfp_mask, struct vm_fault *vmf) 89 { 90 return NULL; 91 } 92 93 static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, 94 struct vm_fault *vmf) 95 { 96 return NULL; 97 } 98 99 static inline int swap_writepage(struct page *p, struct writeback_control *wbc) 100 { 101 return 0; 102 } 103 104 static inline struct page *lookup_swap_cache(swp_entry_t swp, 105 struct vm_area_struct *vma, 106 unsigned long addr) 107 { 108 return NULL; 109 } 110 111 static inline 112 struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index) 113 { 114 return find_get_page(mapping, index); 115 } 116 117 static inline bool add_to_swap(struct folio *folio) 118 { 119 return false; 120 } 121 122 static inline void *get_shadow_from_swap_cache(swp_entry_t entry) 123 { 124 return NULL; 125 } 126 127 static inline int add_to_swap_cache(struct page *page, swp_entry_t entry, 128 gfp_t gfp_mask, void **shadowp) 129 { 130 return -1; 131 } 132 133 static inline void __delete_from_swap_cache(struct folio *folio, 134 swp_entry_t entry, void *shadow) 135 { 136 } 137 138 static inline void delete_from_swap_cache(struct folio *folio) 139 { 140 } 141 142 static inline void clear_shadow_from_swap_cache(int type, unsigned long begin, 143 unsigned long end) 144 { 145 } 146 147 static inline unsigned int folio_swap_flags(struct folio *folio) 148 { 149 return 0; 150 } 151 #endif /* CONFIG_SWAP */ 152 #endif /* _MM_SWAP_H */ 153