| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef _LINUX_DAX_H |
| 3 | #define _LINUX_DAX_H |
| 4 | |
| 5 | #include <linux/fs.h> |
| 6 | #include <linux/mm.h> |
| 7 | #include <linux/radix-tree.h> |
| 8 | |
| 9 | typedef unsigned long dax_entry_t; |
| 10 | |
| 11 | struct dax_device; |
| 12 | struct gendisk; |
| 13 | struct iomap_ops; |
| 14 | struct iomap_iter; |
| 15 | struct iomap; |
| 16 | |
| 17 | struct dax_operations { |
| 18 | /* |
| 19 | * direct_access: translate a device-relative |
| 20 | * logical-page-offset into an absolute physical pfn. Return the |
| 21 | * number of pages available for DAX at that pfn. |
| 22 | */ |
| 23 | long (*direct_access)(struct dax_device *, pgoff_t, long, |
| 24 | void **, pfn_t *); |
| 25 | /* |
| 26 | * Validate whether this device is usable as an fsdax backing |
| 27 | * device. |
| 28 | */ |
| 29 | bool (*dax_supported)(struct dax_device *, struct block_device *, int, |
| 30 | sector_t, sector_t); |
| 31 | /* zero_page_range: required operation. Zero page range */ |
| 32 | int (*zero_page_range)(struct dax_device *, pgoff_t, size_t); |
| 33 | }; |
| 34 | |
| 35 | #if IS_ENABLED(CONFIG_DAX) |
| 36 | struct dax_device *alloc_dax(void *private, const struct dax_operations *ops); |
| 37 | void put_dax(struct dax_device *dax_dev); |
| 38 | void kill_dax(struct dax_device *dax_dev); |
| 39 | void dax_write_cache(struct dax_device *dax_dev, bool wc); |
| 40 | bool dax_write_cache_enabled(struct dax_device *dax_dev); |
| 41 | bool dax_synchronous(struct dax_device *dax_dev); |
| 42 | void set_dax_synchronous(struct dax_device *dax_dev); |
| 43 | /* |
| 44 | * Check if given mapping is supported by the file / underlying device. |
| 45 | */ |
| 46 | static inline bool daxdev_mapping_supported(struct vm_area_struct *vma, |
| 47 | struct dax_device *dax_dev) |
| 48 | { |
| 49 | if (!(vma->vm_flags & VM_SYNC)) |
| 50 | return true; |
| 51 | if (!IS_DAX(file_inode(vma->vm_file))) |
| 52 | return false; |
| 53 | return dax_synchronous(dax_dev); |
| 54 | } |
| 55 | #else |
| 56 | static inline struct dax_device *alloc_dax(void *private, |
| 57 | const struct dax_operations *ops) |
| 58 | { |
| 59 | /* |
| 60 | * Callers should check IS_ENABLED(CONFIG_DAX) to know if this |
| 61 | * NULL is an error or expected. |
| 62 | */ |
| 63 | return NULL; |
| 64 | } |
| 65 | static inline void put_dax(struct dax_device *dax_dev) |
| 66 | { |
| 67 | } |
| 68 | static inline void kill_dax(struct dax_device *dax_dev) |
| 69 | { |
| 70 | } |
| 71 | static inline void dax_write_cache(struct dax_device *dax_dev, bool wc) |
| 72 | { |
| 73 | } |
| 74 | static inline bool dax_write_cache_enabled(struct dax_device *dax_dev) |
| 75 | { |
| 76 | return false; |
| 77 | } |
| 78 | static inline bool dax_synchronous(struct dax_device *dax_dev) |
| 79 | { |
| 80 | return true; |
| 81 | } |
| 82 | static inline void set_dax_synchronous(struct dax_device *dax_dev) |
| 83 | { |
| 84 | } |
| 85 | static inline bool daxdev_mapping_supported(struct vm_area_struct *vma, |
| 86 | struct dax_device *dax_dev) |
| 87 | { |
| 88 | return !(vma->vm_flags & VM_SYNC); |
| 89 | } |
| 90 | #endif |
| 91 | |
| 92 | void set_dax_nocache(struct dax_device *dax_dev); |
| 93 | void set_dax_nomc(struct dax_device *dax_dev); |
| 94 | |
| 95 | struct writeback_control; |
| 96 | #if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX) |
| 97 | int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk); |
| 98 | void dax_remove_host(struct gendisk *disk); |
| 99 | struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev, |
| 100 | u64 *start_off); |
| 101 | static inline void fs_put_dax(struct dax_device *dax_dev) |
| 102 | { |
| 103 | put_dax(dax_dev); |
| 104 | } |
| 105 | #else |
| 106 | static inline int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk) |
| 107 | { |
| 108 | return 0; |
| 109 | } |
| 110 | static inline void dax_remove_host(struct gendisk *disk) |
| 111 | { |
| 112 | } |
| 113 | static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev, |
| 114 | u64 *start_off) |
| 115 | { |
| 116 | return NULL; |
| 117 | } |
| 118 | static inline void fs_put_dax(struct dax_device *dax_dev) |
| 119 | { |
| 120 | } |
| 121 | #endif /* CONFIG_BLOCK && CONFIG_FS_DAX */ |
| 122 | |
| 123 | #if IS_ENABLED(CONFIG_FS_DAX) |
| 124 | int dax_writeback_mapping_range(struct address_space *mapping, |
| 125 | struct dax_device *dax_dev, struct writeback_control *wbc); |
| 126 | |
| 127 | struct page *dax_layout_busy_page(struct address_space *mapping); |
| 128 | struct page *dax_layout_busy_page_range(struct address_space *mapping, loff_t start, loff_t end); |
| 129 | dax_entry_t dax_lock_page(struct page *page); |
| 130 | void dax_unlock_page(struct page *page, dax_entry_t cookie); |
| 131 | #else |
| 132 | static inline struct page *dax_layout_busy_page(struct address_space *mapping) |
| 133 | { |
| 134 | return NULL; |
| 135 | } |
| 136 | |
| 137 | static inline struct page *dax_layout_busy_page_range(struct address_space *mapping, pgoff_t start, pgoff_t nr_pages) |
| 138 | { |
| 139 | return NULL; |
| 140 | } |
| 141 | |
| 142 | static inline int dax_writeback_mapping_range(struct address_space *mapping, |
| 143 | struct dax_device *dax_dev, struct writeback_control *wbc) |
| 144 | { |
| 145 | return -EOPNOTSUPP; |
| 146 | } |
| 147 | |
| 148 | static inline dax_entry_t dax_lock_page(struct page *page) |
| 149 | { |
| 150 | if (IS_DAX(page->mapping->host)) |
| 151 | return ~0UL; |
| 152 | return 0; |
| 153 | } |
| 154 | |
| 155 | static inline void dax_unlock_page(struct page *page, dax_entry_t cookie) |
| 156 | { |
| 157 | } |
| 158 | #endif |
| 159 | |
| 160 | int dax_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero, |
| 161 | const struct iomap_ops *ops); |
| 162 | int dax_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, |
| 163 | const struct iomap_ops *ops); |
| 164 | |
| 165 | #if IS_ENABLED(CONFIG_DAX) |
| 166 | int dax_read_lock(void); |
| 167 | void dax_read_unlock(int id); |
| 168 | #else |
| 169 | static inline int dax_read_lock(void) |
| 170 | { |
| 171 | return 0; |
| 172 | } |
| 173 | |
| 174 | static inline void dax_read_unlock(int id) |
| 175 | { |
| 176 | } |
| 177 | #endif /* CONFIG_DAX */ |
| 178 | bool dax_alive(struct dax_device *dax_dev); |
| 179 | void *dax_get_private(struct dax_device *dax_dev); |
| 180 | long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, |
| 181 | void **kaddr, pfn_t *pfn); |
| 182 | size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, |
| 183 | size_t bytes, struct iov_iter *i); |
| 184 | size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, |
| 185 | size_t bytes, struct iov_iter *i); |
| 186 | int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, |
| 187 | size_t nr_pages); |
| 188 | void dax_flush(struct dax_device *dax_dev, void *addr, size_t size); |
| 189 | |
| 190 | ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, |
| 191 | const struct iomap_ops *ops); |
| 192 | vm_fault_t dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size, |
| 193 | pfn_t *pfnp, int *errp, const struct iomap_ops *ops); |
| 194 | vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf, |
| 195 | enum page_entry_size pe_size, pfn_t pfn); |
| 196 | int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index); |
| 197 | int dax_invalidate_mapping_entry_sync(struct address_space *mapping, |
| 198 | pgoff_t index); |
| 199 | static inline bool dax_mapping(struct address_space *mapping) |
| 200 | { |
| 201 | return mapping->host && IS_DAX(mapping->host); |
| 202 | } |
| 203 | |
| 204 | #ifdef CONFIG_DEV_DAX_HMEM_DEVICES |
| 205 | void hmem_register_device(int target_nid, struct resource *r); |
| 206 | #else |
| 207 | static inline void hmem_register_device(int target_nid, struct resource *r) |
| 208 | { |
| 209 | } |
| 210 | #endif |
| 211 | |
| 212 | #endif |