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 int __swap_writepage(struct page *page, struct writeback_control *wbc); 22 23 /* linux/mm/swap_state.c */ 24 /* One swap address space for each 64M swap space */ 25 #define SWAP_ADDRESS_SPACE_SHIFT 14 26 #define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT) 27 extern struct address_space *swapper_spaces[]; 28 #define swap_address_space(entry) \ 29 (&swapper_spaces[swp_type(entry)][swp_offset(entry) \ 30 >> SWAP_ADDRESS_SPACE_SHIFT]) 31 32 void show_swap_cache_info(void); 33 bool add_to_swap(struct folio *folio); 34 void *get_shadow_from_swap_cache(swp_entry_t entry); 35 int add_to_swap_cache(struct folio *folio, swp_entry_t entry, 36 gfp_t gfp, void **shadowp); 37 void __delete_from_swap_cache(struct folio *folio, 38 swp_entry_t entry, void *shadow); 39 void delete_from_swap_cache(struct folio *folio); 40 void clear_shadow_from_swap_cache(int type, unsigned long begin, 41 unsigned long end); 42 struct folio *swap_cache_get_folio(swp_entry_t entry, 43 struct vm_area_struct *vma, unsigned long addr); 44 struct folio *filemap_get_incore_folio(struct address_space *mapping, 45 pgoff_t index); 46 47 struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, 48 struct vm_area_struct *vma, 49 unsigned long addr, 50 bool do_poll, 51 struct swap_iocb **plug); 52 struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, 53 struct vm_area_struct *vma, 54 unsigned long addr, 55 bool *new_page_allocated); 56 struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag, 57 struct vm_fault *vmf); 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 page_swap_info(&folio->page)->flags; 64 } 65 #else /* CONFIG_SWAP */ 66 struct swap_iocb; 67 static inline int swap_readpage(struct page *page, bool do_poll, 68 struct swap_iocb **plug) 69 { 70 return 0; 71 } 72 static inline void swap_write_unplug(struct swap_iocb *sio) 73 { 74 } 75 76 static inline struct address_space *swap_address_space(swp_entry_t entry) 77 { 78 return NULL; 79 } 80 81 static inline void show_swap_cache_info(void) 82 { 83 } 84 85 static inline struct page *swap_cluster_readahead(swp_entry_t entry, 86 gfp_t gfp_mask, struct vm_fault *vmf) 87 { 88 return NULL; 89 } 90 91 static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, 92 struct vm_fault *vmf) 93 { 94 return NULL; 95 } 96 97 static inline int swap_writepage(struct page *p, struct writeback_control *wbc) 98 { 99 return 0; 100 } 101 102 static inline struct folio *swap_cache_get_folio(swp_entry_t entry, 103 struct vm_area_struct *vma, unsigned long addr) 104 { 105 return NULL; 106 } 107 108 static inline 109 struct folio *filemap_get_incore_folio(struct address_space *mapping, 110 pgoff_t index) 111 { 112 return filemap_get_folio(mapping, index); 113 } 114 115 static inline bool add_to_swap(struct folio *folio) 116 { 117 return false; 118 } 119 120 static inline void *get_shadow_from_swap_cache(swp_entry_t entry) 121 { 122 return NULL; 123 } 124 125 static inline int add_to_swap_cache(struct folio *folio, swp_entry_t entry, 126 gfp_t gfp_mask, void **shadowp) 127 { 128 return -1; 129 } 130 131 static inline void __delete_from_swap_cache(struct folio *folio, 132 swp_entry_t entry, void *shadow) 133 { 134 } 135 136 static inline void delete_from_swap_cache(struct folio *folio) 137 { 138 } 139 140 static inline void clear_shadow_from_swap_cache(int type, unsigned long begin, 141 unsigned long end) 142 { 143 } 144 145 static inline unsigned int folio_swap_flags(struct folio *folio) 146 { 147 return 0; 148 } 149 #endif /* CONFIG_SWAP */ 150 #endif /* _MM_SWAP_H */ 151