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 enum dax_access_mode { 18 DAX_ACCESS, 19 DAX_RECOVERY_WRITE, 20 }; 21 22 struct dax_operations { 23 /* 24 * direct_access: translate a device-relative 25 * logical-page-offset into an absolute physical pfn. Return the 26 * number of pages available for DAX at that pfn. 27 */ 28 long (*direct_access)(struct dax_device *, pgoff_t, long, 29 enum dax_access_mode, void **, pfn_t *); 30 /* 31 * Validate whether this device is usable as an fsdax backing 32 * device. 33 */ 34 bool (*dax_supported)(struct dax_device *, struct block_device *, int, 35 sector_t, sector_t); 36 /* zero_page_range: required operation. Zero page range */ 37 int (*zero_page_range)(struct dax_device *, pgoff_t, size_t); 38 /* 39 * recovery_write: recover a poisoned range by DAX device driver 40 * capable of clearing poison. 41 */ 42 size_t (*recovery_write)(struct dax_device *dax_dev, pgoff_t pgoff, 43 void *addr, size_t bytes, struct iov_iter *iter); 44 }; 45 46 struct dax_holder_operations { 47 /* 48 * notify_failure - notify memory failure into inner holder device 49 * @dax_dev: the dax device which contains the holder 50 * @offset: offset on this dax device where memory failure occurs 51 * @len: length of this memory failure event 52 * @flags: action flags for memory failure handler 53 */ 54 int (*notify_failure)(struct dax_device *dax_dev, u64 offset, 55 u64 len, int mf_flags); 56 }; 57 58 #if IS_ENABLED(CONFIG_DAX) 59 struct dax_device *alloc_dax(void *private, const struct dax_operations *ops); 60 void *dax_holder(struct dax_device *dax_dev); 61 void put_dax(struct dax_device *dax_dev); 62 void kill_dax(struct dax_device *dax_dev); 63 void dax_write_cache(struct dax_device *dax_dev, bool wc); 64 bool dax_write_cache_enabled(struct dax_device *dax_dev); 65 bool dax_synchronous(struct dax_device *dax_dev); 66 void set_dax_synchronous(struct dax_device *dax_dev); 67 size_t dax_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff, 68 void *addr, size_t bytes, struct iov_iter *i); 69 /* 70 * Check if given mapping is supported by the file / underlying device. 71 */ 72 static inline bool daxdev_mapping_supported(struct vm_area_struct *vma, 73 struct dax_device *dax_dev) 74 { 75 if (!(vma->vm_flags & VM_SYNC)) 76 return true; 77 if (!IS_DAX(file_inode(vma->vm_file))) 78 return false; 79 return dax_synchronous(dax_dev); 80 } 81 #else 82 static inline void *dax_holder(struct dax_device *dax_dev) 83 { 84 return NULL; 85 } 86 static inline struct dax_device *alloc_dax(void *private, 87 const struct dax_operations *ops) 88 { 89 /* 90 * Callers should check IS_ENABLED(CONFIG_DAX) to know if this 91 * NULL is an error or expected. 92 */ 93 return NULL; 94 } 95 static inline void put_dax(struct dax_device *dax_dev) 96 { 97 } 98 static inline void kill_dax(struct dax_device *dax_dev) 99 { 100 } 101 static inline void dax_write_cache(struct dax_device *dax_dev, bool wc) 102 { 103 } 104 static inline bool dax_write_cache_enabled(struct dax_device *dax_dev) 105 { 106 return false; 107 } 108 static inline bool dax_synchronous(struct dax_device *dax_dev) 109 { 110 return true; 111 } 112 static inline void set_dax_synchronous(struct dax_device *dax_dev) 113 { 114 } 115 static inline bool daxdev_mapping_supported(struct vm_area_struct *vma, 116 struct dax_device *dax_dev) 117 { 118 return !(vma->vm_flags & VM_SYNC); 119 } 120 static inline size_t dax_recovery_write(struct dax_device *dax_dev, 121 pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i) 122 { 123 return 0; 124 } 125 #endif 126 127 void set_dax_nocache(struct dax_device *dax_dev); 128 void set_dax_nomc(struct dax_device *dax_dev); 129 130 struct writeback_control; 131 #if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX) 132 int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk); 133 void dax_remove_host(struct gendisk *disk); 134 struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev, u64 *start_off, 135 void *holder, const struct dax_holder_operations *ops); 136 void fs_put_dax(struct dax_device *dax_dev, void *holder); 137 #else 138 static inline int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk) 139 { 140 return 0; 141 } 142 static inline void dax_remove_host(struct gendisk *disk) 143 { 144 } 145 static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev, 146 u64 *start_off, void *holder, 147 const struct dax_holder_operations *ops) 148 { 149 return NULL; 150 } 151 static inline void fs_put_dax(struct dax_device *dax_dev, void *holder) 152 { 153 } 154 #endif /* CONFIG_BLOCK && CONFIG_FS_DAX */ 155 156 #if IS_ENABLED(CONFIG_FS_DAX) 157 int dax_writeback_mapping_range(struct address_space *mapping, 158 struct dax_device *dax_dev, struct writeback_control *wbc); 159 160 struct page *dax_layout_busy_page(struct address_space *mapping); 161 struct page *dax_layout_busy_page_range(struct address_space *mapping, loff_t start, loff_t end); 162 dax_entry_t dax_lock_page(struct page *page); 163 void dax_unlock_page(struct page *page, dax_entry_t cookie); 164 dax_entry_t dax_lock_mapping_entry(struct address_space *mapping, 165 unsigned long index, struct page **page); 166 void dax_unlock_mapping_entry(struct address_space *mapping, 167 unsigned long index, dax_entry_t cookie); 168 #else 169 static inline struct page *dax_layout_busy_page(struct address_space *mapping) 170 { 171 return NULL; 172 } 173 174 static inline struct page *dax_layout_busy_page_range(struct address_space *mapping, pgoff_t start, pgoff_t nr_pages) 175 { 176 return NULL; 177 } 178 179 static inline int dax_writeback_mapping_range(struct address_space *mapping, 180 struct dax_device *dax_dev, struct writeback_control *wbc) 181 { 182 return -EOPNOTSUPP; 183 } 184 185 static inline dax_entry_t dax_lock_page(struct page *page) 186 { 187 if (IS_DAX(page->mapping->host)) 188 return ~0UL; 189 return 0; 190 } 191 192 static inline void dax_unlock_page(struct page *page, dax_entry_t cookie) 193 { 194 } 195 196 static inline dax_entry_t dax_lock_mapping_entry(struct address_space *mapping, 197 unsigned long index, struct page **page) 198 { 199 return 0; 200 } 201 202 static inline void dax_unlock_mapping_entry(struct address_space *mapping, 203 unsigned long index, dax_entry_t cookie) 204 { 205 } 206 #endif 207 208 int dax_file_unshare(struct inode *inode, loff_t pos, loff_t len, 209 const struct iomap_ops *ops); 210 int dax_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero, 211 const struct iomap_ops *ops); 212 int dax_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, 213 const struct iomap_ops *ops); 214 215 #if IS_ENABLED(CONFIG_DAX) 216 int dax_read_lock(void); 217 void dax_read_unlock(int id); 218 #else 219 static inline int dax_read_lock(void) 220 { 221 return 0; 222 } 223 224 static inline void dax_read_unlock(int id) 225 { 226 } 227 #endif /* CONFIG_DAX */ 228 bool dax_alive(struct dax_device *dax_dev); 229 void *dax_get_private(struct dax_device *dax_dev); 230 long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, 231 enum dax_access_mode mode, void **kaddr, pfn_t *pfn); 232 size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, 233 size_t bytes, struct iov_iter *i); 234 size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, 235 size_t bytes, struct iov_iter *i); 236 int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, 237 size_t nr_pages); 238 int dax_holder_notify_failure(struct dax_device *dax_dev, u64 off, u64 len, 239 int mf_flags); 240 void dax_flush(struct dax_device *dax_dev, void *addr, size_t size); 241 242 ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, 243 const struct iomap_ops *ops); 244 vm_fault_t dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size, 245 pfn_t *pfnp, int *errp, const struct iomap_ops *ops); 246 vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf, 247 enum page_entry_size pe_size, pfn_t pfn); 248 int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index); 249 int dax_invalidate_mapping_entry_sync(struct address_space *mapping, 250 pgoff_t index); 251 int dax_dedupe_file_range_compare(struct inode *src, loff_t srcoff, 252 struct inode *dest, loff_t destoff, 253 loff_t len, bool *is_same, 254 const struct iomap_ops *ops); 255 int dax_remap_file_range_prep(struct file *file_in, loff_t pos_in, 256 struct file *file_out, loff_t pos_out, 257 loff_t *len, unsigned int remap_flags, 258 const struct iomap_ops *ops); 259 static inline bool dax_mapping(struct address_space *mapping) 260 { 261 return mapping->host && IS_DAX(mapping->host); 262 } 263 264 #ifdef CONFIG_DEV_DAX_HMEM_DEVICES 265 void hmem_register_device(int target_nid, struct resource *r); 266 #else 267 static inline void hmem_register_device(int target_nid, struct resource *r) 268 { 269 } 270 #endif 271 272 #endif 273