1 /* SPDX-License-Identifier: GPL-2.0 */
7 #include <linux/radix-tree.h>
9 /* Flag for synchronous flush */
10 #define DAXDEV_F_SYNC (1UL << 0)
12 typedef unsigned long dax_entry_t;
17 struct dax_operations {
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.
23 long (*direct_access)(struct dax_device *, pgoff_t, long,
26 * Validate whether this device is usable as an fsdax backing
29 bool (*dax_supported)(struct dax_device *, struct block_device *, int,
31 /* copy_from_iter: required operation for fs-dax direct-i/o */
32 size_t (*copy_from_iter)(struct dax_device *, pgoff_t, void *, size_t,
34 /* copy_to_iter: required operation for fs-dax direct-i/o */
35 size_t (*copy_to_iter)(struct dax_device *, pgoff_t, void *, size_t,
37 /* zero_page_range: required operation. Zero page range */
38 int (*zero_page_range)(struct dax_device *, pgoff_t, size_t);
41 #if IS_ENABLED(CONFIG_DAX)
42 struct dax_device *alloc_dax(void *private, const char *host,
43 const struct dax_operations *ops, unsigned long flags);
44 void put_dax(struct dax_device *dax_dev);
45 void kill_dax(struct dax_device *dax_dev);
46 void dax_write_cache(struct dax_device *dax_dev, bool wc);
47 bool dax_write_cache_enabled(struct dax_device *dax_dev);
48 bool __dax_synchronous(struct dax_device *dax_dev);
49 static inline bool dax_synchronous(struct dax_device *dax_dev)
51 return __dax_synchronous(dax_dev);
53 void __set_dax_synchronous(struct dax_device *dax_dev);
54 static inline void set_dax_synchronous(struct dax_device *dax_dev)
56 __set_dax_synchronous(dax_dev);
59 * Check if given mapping is supported by the file / underlying device.
61 static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
62 struct dax_device *dax_dev)
64 if (!(vma->vm_flags & VM_SYNC))
66 if (!IS_DAX(file_inode(vma->vm_file)))
68 return dax_synchronous(dax_dev);
71 static inline struct dax_device *alloc_dax(void *private, const char *host,
72 const struct dax_operations *ops, unsigned long flags)
75 * Callers should check IS_ENABLED(CONFIG_DAX) to know if this
76 * NULL is an error or expected.
80 static inline void put_dax(struct dax_device *dax_dev)
83 static inline void kill_dax(struct dax_device *dax_dev)
86 static inline void dax_write_cache(struct dax_device *dax_dev, bool wc)
89 static inline bool dax_write_cache_enabled(struct dax_device *dax_dev)
93 static inline bool dax_synchronous(struct dax_device *dax_dev)
97 static inline void set_dax_synchronous(struct dax_device *dax_dev)
100 static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
101 struct dax_device *dax_dev)
103 return !(vma->vm_flags & VM_SYNC);
107 struct writeback_control;
108 int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff);
109 #if IS_ENABLED(CONFIG_FS_DAX)
110 bool generic_fsdax_supported(struct dax_device *dax_dev,
111 struct block_device *bdev, int blocksize, sector_t start,
114 bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,
115 int blocksize, sector_t start, sector_t len);
117 static inline void fs_put_dax(struct dax_device *dax_dev)
122 struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev);
123 int dax_writeback_mapping_range(struct address_space *mapping,
124 struct dax_device *dax_dev, struct writeback_control *wbc);
126 struct page *dax_layout_busy_page(struct address_space *mapping);
127 struct page *dax_layout_busy_page_range(struct address_space *mapping, loff_t start, loff_t end);
128 dax_entry_t dax_lock_page(struct page *page);
129 void dax_unlock_page(struct page *page, dax_entry_t cookie);
131 #define generic_fsdax_supported NULL
133 static inline bool dax_supported(struct dax_device *dax_dev,
134 struct block_device *bdev, int blocksize, sector_t start,
140 static inline void fs_put_dax(struct dax_device *dax_dev)
144 static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
149 static inline struct page *dax_layout_busy_page(struct address_space *mapping)
154 static inline struct page *dax_layout_busy_page_range(struct address_space *mapping, pgoff_t start, pgoff_t nr_pages)
159 static inline int dax_writeback_mapping_range(struct address_space *mapping,
160 struct dax_device *dax_dev, struct writeback_control *wbc)
165 static inline dax_entry_t dax_lock_page(struct page *page)
167 if (IS_DAX(page->mapping->host))
172 static inline void dax_unlock_page(struct page *page, dax_entry_t cookie)
177 #if IS_ENABLED(CONFIG_DAX)
178 int dax_read_lock(void);
179 void dax_read_unlock(int id);
181 static inline int dax_read_lock(void)
186 static inline void dax_read_unlock(int id)
189 #endif /* CONFIG_DAX */
190 bool dax_alive(struct dax_device *dax_dev);
191 void *dax_get_private(struct dax_device *dax_dev);
192 long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
193 void **kaddr, pfn_t *pfn);
194 size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
195 size_t bytes, struct iov_iter *i);
196 size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
197 size_t bytes, struct iov_iter *i);
198 int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
200 void dax_flush(struct dax_device *dax_dev, void *addr, size_t size);
202 ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
203 const struct iomap_ops *ops);
204 vm_fault_t dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
205 pfn_t *pfnp, int *errp, const struct iomap_ops *ops);
206 vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
207 enum page_entry_size pe_size, pfn_t pfn);
208 int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
209 int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
211 s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap);
212 static inline bool dax_mapping(struct address_space *mapping)
214 return mapping->host && IS_DAX(mapping->host);
217 #ifdef CONFIG_DEV_DAX_HMEM_DEVICES
218 void hmem_register_device(int target_nid, struct resource *r);
220 static inline void hmem_register_device(int target_nid, struct resource *r)