1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _MM_SWAP_H 3 #define _MM_SWAP_H 4 5 struct mempolicy; 6 7 #ifdef CONFIG_SWAP 8 #include <linux/blk_types.h> /* for bio_end_io_t */ 9 10 /* linux/mm/page_io.c */ 11 int sio_pool_init(void); 12 struct swap_iocb; 13 void swap_read_folio(struct folio *folio, bool do_poll, 14 struct swap_iocb **plug); 15 void __swap_read_unplug(struct swap_iocb *plug); 16 static inline void swap_read_unplug(struct swap_iocb *plug) 17 { 18 if (unlikely(plug)) 19 __swap_read_unplug(plug); 20 } 21 void swap_write_unplug(struct swap_iocb *sio); 22 int swap_writepage(struct page *page, struct writeback_control *wbc); 23 void __swap_writepage(struct folio *folio, struct writeback_control *wbc); 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 folio *folio, 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 void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry); 45 struct folio *swap_cache_get_folio(swp_entry_t entry, 46 struct vm_area_struct *vma, unsigned long addr); 47 struct folio *filemap_get_incore_folio(struct address_space *mapping, 48 pgoff_t index); 49 50 struct folio *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, 51 struct vm_area_struct *vma, unsigned long addr, 52 struct swap_iocb **plug); 53 struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_flags, 54 struct mempolicy *mpol, pgoff_t ilx, bool *new_page_allocated, 55 bool skip_if_exists); 56 struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t flag, 57 struct mempolicy *mpol, pgoff_t ilx); 58 struct page *swapin_readahead(swp_entry_t entry, gfp_t flag, 59 struct vm_fault *vmf); 60 61 static inline unsigned int folio_swap_flags(struct folio *folio) 62 { 63 return swp_swap_info(folio->swap)->flags; 64 } 65 #else /* CONFIG_SWAP */ 66 struct swap_iocb; 67 static inline void swap_read_folio(struct folio *folio, bool do_poll, 68 struct swap_iocb **plug) 69 { 70 } 71 static inline void swap_write_unplug(struct swap_iocb *sio) 72 { 73 } 74 75 static inline struct address_space *swap_address_space(swp_entry_t entry) 76 { 77 return NULL; 78 } 79 80 static inline void show_swap_cache_info(void) 81 { 82 } 83 84 static inline struct folio *swap_cluster_readahead(swp_entry_t entry, 85 gfp_t gfp_mask, struct mempolicy *mpol, pgoff_t ilx) 86 { 87 return NULL; 88 } 89 90 static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, 91 struct vm_fault *vmf) 92 { 93 return NULL; 94 } 95 96 static inline int swap_writepage(struct page *p, struct writeback_control *wbc) 97 { 98 return 0; 99 } 100 101 static inline void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry) 102 { 103 } 104 105 static inline struct folio *swap_cache_get_folio(swp_entry_t entry, 106 struct vm_area_struct *vma, unsigned long addr) 107 { 108 return NULL; 109 } 110 111 static inline 112 struct folio *filemap_get_incore_folio(struct address_space *mapping, 113 pgoff_t index) 114 { 115 return filemap_get_folio(mapping, index); 116 } 117 118 static inline bool add_to_swap(struct folio *folio) 119 { 120 return false; 121 } 122 123 static inline void *get_shadow_from_swap_cache(swp_entry_t entry) 124 { 125 return NULL; 126 } 127 128 static inline int add_to_swap_cache(struct folio *folio, swp_entry_t entry, 129 gfp_t gfp_mask, void **shadowp) 130 { 131 return -1; 132 } 133 134 static inline void __delete_from_swap_cache(struct folio *folio, 135 swp_entry_t entry, void *shadow) 136 { 137 } 138 139 static inline void delete_from_swap_cache(struct folio *folio) 140 { 141 } 142 143 static inline void clear_shadow_from_swap_cache(int type, unsigned long begin, 144 unsigned long end) 145 { 146 } 147 148 static inline unsigned int folio_swap_flags(struct folio *folio) 149 { 150 return 0; 151 } 152 #endif /* CONFIG_SWAP */ 153 #endif /* _MM_SWAP_H */ 154