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 void swap_readpage(struct page *page, bool do_poll, struct swap_iocb **plug); 12 void __swap_read_unplug(struct swap_iocb *plug); 13 static inline void swap_read_unplug(struct swap_iocb *plug) 14 { 15 if (unlikely(plug)) 16 __swap_read_unplug(plug); 17 } 18 void swap_write_unplug(struct swap_iocb *sio); 19 int swap_writepage(struct page *page, struct writeback_control *wbc); 20 void __swap_writepage(struct page *page, struct writeback_control *wbc); 21 22 /* linux/mm/swap_state.c */ 23 /* One swap address space for each 64M swap space */ 24 #define SWAP_ADDRESS_SPACE_SHIFT 14 25 #define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT) 26 extern struct address_space *swapper_spaces[]; 27 #define swap_address_space(entry) \ 28 (&swapper_spaces[swp_type(entry)][swp_offset(entry) \ 29 >> SWAP_ADDRESS_SPACE_SHIFT]) 30 31 void show_swap_cache_info(void); 32 bool add_to_swap(struct folio *folio); 33 void *get_shadow_from_swap_cache(swp_entry_t entry); 34 int add_to_swap_cache(struct folio *folio, swp_entry_t entry, 35 gfp_t gfp, void **shadowp); 36 void __delete_from_swap_cache(struct folio *folio, 37 swp_entry_t entry, void *shadow); 38 void delete_from_swap_cache(struct folio *folio); 39 void clear_shadow_from_swap_cache(int type, unsigned long begin, 40 unsigned long end); 41 struct folio *swap_cache_get_folio(swp_entry_t entry, 42 struct vm_area_struct *vma, unsigned long addr); 43 struct folio *filemap_get_incore_folio(struct address_space *mapping, 44 pgoff_t index); 45 46 struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, 47 struct vm_area_struct *vma, 48 unsigned long addr, 49 bool do_poll, 50 struct swap_iocb **plug); 51 struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, 52 struct vm_area_struct *vma, 53 unsigned long addr, 54 bool *new_page_allocated); 55 struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag, 56 struct vm_fault *vmf); 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 page_swap_info(&folio->page)->flags; 63 } 64 #else /* CONFIG_SWAP */ 65 struct swap_iocb; 66 static inline void swap_readpage(struct page *page, 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 page *swap_cluster_readahead(swp_entry_t entry, 84 gfp_t gfp_mask, struct vm_fault *vmf) 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