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