1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef _MM_SWAP_H 3#define _MM_SWAP_H 4 5struct mempolicy; 6 7#ifdef CONFIG_SWAP 8#include <linux/blk_types.h> /* for bio_end_io_t */ 9 10/* linux/mm/page_io.c */ 11int sio_pool_init(void); 12struct swap_iocb; 13void swap_read_folio(struct folio *folio, bool do_poll, 14 struct swap_iocb **plug); 15void __swap_read_unplug(struct swap_iocb *plug); 16static inline void swap_read_unplug(struct swap_iocb *plug) 17{ 18 if (unlikely(plug)) 19 __swap_read_unplug(plug); 20} 21void swap_write_unplug(struct swap_iocb *sio); 22int swap_writepage(struct page *page, struct writeback_control *wbc); 23void __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) 29extern 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 34void show_swap_cache_info(void); 35bool add_to_swap(struct folio *folio); 36void *get_shadow_from_swap_cache(swp_entry_t entry); 37int add_to_swap_cache(struct folio *folio, swp_entry_t entry, 38 gfp_t gfp, void **shadowp); 39void __delete_from_swap_cache(struct folio *folio, 40 swp_entry_t entry, void *shadow); 41void delete_from_swap_cache(struct folio *folio); 42void clear_shadow_from_swap_cache(int type, unsigned long begin, 43 unsigned long end); 44void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry); 45struct folio *swap_cache_get_folio(swp_entry_t entry, 46 struct vm_area_struct *vma, unsigned long addr); 47struct folio *filemap_get_incore_folio(struct address_space *mapping, 48 pgoff_t index); 49 50struct 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); 53struct 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); 56struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t flag, 57 struct mempolicy *mpol, pgoff_t ilx); 58struct page *swapin_readahead(swp_entry_t entry, gfp_t flag, 59 struct vm_fault *vmf); 60 61static inline unsigned int folio_swap_flags(struct folio *folio) 62{ 63 return swp_swap_info(folio->swap)->flags; 64} 65#else /* CONFIG_SWAP */ 66struct swap_iocb; 67static inline void swap_read_folio(struct folio *folio, bool do_poll, 68 struct swap_iocb **plug) 69{ 70} 71static inline void swap_write_unplug(struct swap_iocb *sio) 72{ 73} 74 75static inline struct address_space *swap_address_space(swp_entry_t entry) 76{ 77 return NULL; 78} 79 80static inline void show_swap_cache_info(void) 81{ 82} 83 84static 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 90static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, 91 struct vm_fault *vmf) 92{ 93 return NULL; 94} 95 96static inline int swap_writepage(struct page *p, struct writeback_control *wbc) 97{ 98 return 0; 99} 100 101static inline void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry) 102{ 103} 104 105static 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 111static inline 112struct folio *filemap_get_incore_folio(struct address_space *mapping, 113 pgoff_t index) 114{ 115 return filemap_get_folio(mapping, index); 116} 117 118static inline bool add_to_swap(struct folio *folio) 119{ 120 return false; 121} 122 123static inline void *get_shadow_from_swap_cache(swp_entry_t entry) 124{ 125 return NULL; 126} 127 128static 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 134static inline void __delete_from_swap_cache(struct folio *folio, 135 swp_entry_t entry, void *shadow) 136{ 137} 138 139static inline void delete_from_swap_cache(struct folio *folio) 140{ 141} 142 143static inline void clear_shadow_from_swap_cache(int type, unsigned long begin, 144 unsigned long end) 145{ 146} 147 148static inline unsigned int folio_swap_flags(struct folio *folio) 149{ 150 return 0; 151} 152#endif /* CONFIG_SWAP */ 153#endif /* _MM_SWAP_H */ 154