1 /* SPDX-License-Identifier: GPL-2.0 */
7 #include <linux/radix-tree.h>
8 #include <asm/pgtable.h>
10 typedef unsigned long dax_entry_t;
14 struct dax_operations {
16 * direct_access: translate a device-relative
17 * logical-page-offset into an absolute physical pfn. Return the
18 * number of pages available for DAX at that pfn.
20 long (*direct_access)(struct dax_device *, pgoff_t, long,
23 * Validate whether this device is usable as an fsdax backing
26 bool (*dax_supported)(struct dax_device *, struct block_device *, int,
28 /* copy_from_iter: required operation for fs-dax direct-i/o */
29 size_t (*copy_from_iter)(struct dax_device *, pgoff_t, void *, size_t,
31 /* copy_to_iter: required operation for fs-dax direct-i/o */
32 size_t (*copy_to_iter)(struct dax_device *, pgoff_t, void *, size_t,
36 extern struct attribute_group dax_attribute_group;
38 #if IS_ENABLED(CONFIG_DAX)
39 struct dax_device *dax_get_by_host(const char *host);
40 struct dax_device *alloc_dax(void *private, const char *host,
41 const struct dax_operations *ops);
42 void put_dax(struct dax_device *dax_dev);
43 void kill_dax(struct dax_device *dax_dev);
44 void dax_write_cache(struct dax_device *dax_dev, bool wc);
45 bool dax_write_cache_enabled(struct dax_device *dax_dev);
47 static inline struct dax_device *dax_get_by_host(const char *host)
51 static inline struct dax_device *alloc_dax(void *private, const char *host,
52 const struct dax_operations *ops)
55 * Callers should check IS_ENABLED(CONFIG_DAX) to know if this
56 * NULL is an error or expected.
60 static inline void put_dax(struct dax_device *dax_dev)
63 static inline void kill_dax(struct dax_device *dax_dev)
66 static inline void dax_write_cache(struct dax_device *dax_dev, bool wc)
69 static inline bool dax_write_cache_enabled(struct dax_device *dax_dev)
75 struct writeback_control;
76 int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff);
77 #if IS_ENABLED(CONFIG_FS_DAX)
78 bool __bdev_dax_supported(struct block_device *bdev, int blocksize);
79 static inline bool bdev_dax_supported(struct block_device *bdev, int blocksize)
81 return __bdev_dax_supported(bdev, blocksize);
84 bool __generic_fsdax_supported(struct dax_device *dax_dev,
85 struct block_device *bdev, int blocksize, sector_t start,
87 static inline bool generic_fsdax_supported(struct dax_device *dax_dev,
88 struct block_device *bdev, int blocksize, sector_t start,
91 return __generic_fsdax_supported(dax_dev, bdev, blocksize, start,
95 static inline struct dax_device *fs_dax_get_by_host(const char *host)
97 return dax_get_by_host(host);
100 static inline void fs_put_dax(struct dax_device *dax_dev)
105 struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev);
106 int dax_writeback_mapping_range(struct address_space *mapping,
107 struct block_device *bdev, struct writeback_control *wbc);
109 struct page *dax_layout_busy_page(struct address_space *mapping);
110 dax_entry_t dax_lock_page(struct page *page);
111 void dax_unlock_page(struct page *page, dax_entry_t cookie);
113 static inline bool bdev_dax_supported(struct block_device *bdev,
119 static inline bool generic_fsdax_supported(struct dax_device *dax_dev,
120 struct block_device *bdev, int blocksize, sector_t start,
126 static inline struct dax_device *fs_dax_get_by_host(const char *host)
131 static inline void fs_put_dax(struct dax_device *dax_dev)
135 static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
140 static inline struct page *dax_layout_busy_page(struct address_space *mapping)
145 static inline int dax_writeback_mapping_range(struct address_space *mapping,
146 struct block_device *bdev, struct writeback_control *wbc)
151 static inline dax_entry_t dax_lock_page(struct page *page)
153 if (IS_DAX(page->mapping->host))
158 static inline void dax_unlock_page(struct page *page, dax_entry_t cookie)
163 int dax_read_lock(void);
164 void dax_read_unlock(int id);
165 bool dax_alive(struct dax_device *dax_dev);
166 void *dax_get_private(struct dax_device *dax_dev);
167 long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
168 void **kaddr, pfn_t *pfn);
169 bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,
170 int blocksize, sector_t start, sector_t len);
171 size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
172 size_t bytes, struct iov_iter *i);
173 size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
174 size_t bytes, struct iov_iter *i);
175 void dax_flush(struct dax_device *dax_dev, void *addr, size_t size);
177 ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
178 const struct iomap_ops *ops);
179 vm_fault_t dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
180 pfn_t *pfnp, int *errp, const struct iomap_ops *ops);
181 vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
182 enum page_entry_size pe_size, pfn_t pfn);
183 int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
184 int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
188 int __dax_zero_page_range(struct block_device *bdev,
189 struct dax_device *dax_dev, sector_t sector,
190 unsigned int offset, unsigned int length);
192 static inline int __dax_zero_page_range(struct block_device *bdev,
193 struct dax_device *dax_dev, sector_t sector,
194 unsigned int offset, unsigned int length)
200 static inline bool dax_mapping(struct address_space *mapping)
202 return mapping->host && IS_DAX(mapping->host);