1 #ifndef _LINUX_DAX_H 2 #define _LINUX_DAX_H 3 4 #include <linux/fs.h> 5 #include <linux/mm.h> 6 #include <linux/radix-tree.h> 7 #include <asm/pgtable.h> 8 9 struct iomap_ops; 10 struct dax_device; 11 struct dax_operations { 12 /* 13 * direct_access: translate a device-relative 14 * logical-page-offset into an absolute physical pfn. Return the 15 * number of pages available for DAX at that pfn. 16 */ 17 long (*direct_access)(struct dax_device *, pgoff_t, long, 18 void **, pfn_t *); 19 /* copy_from_iter: required operation for fs-dax direct-i/o */ 20 size_t (*copy_from_iter)(struct dax_device *, pgoff_t, void *, size_t, 21 struct iov_iter *); 22 }; 23 24 extern struct attribute_group dax_attribute_group; 25 26 #if IS_ENABLED(CONFIG_DAX) 27 struct dax_device *dax_get_by_host(const char *host); 28 void put_dax(struct dax_device *dax_dev); 29 #else 30 static inline struct dax_device *dax_get_by_host(const char *host) 31 { 32 return NULL; 33 } 34 35 static inline void put_dax(struct dax_device *dax_dev) 36 { 37 } 38 #endif 39 40 int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff); 41 #if IS_ENABLED(CONFIG_FS_DAX) 42 int __bdev_dax_supported(struct super_block *sb, int blocksize); 43 static inline int bdev_dax_supported(struct super_block *sb, int blocksize) 44 { 45 return __bdev_dax_supported(sb, blocksize); 46 } 47 48 static inline struct dax_device *fs_dax_get_by_host(const char *host) 49 { 50 return dax_get_by_host(host); 51 } 52 53 static inline void fs_put_dax(struct dax_device *dax_dev) 54 { 55 put_dax(dax_dev); 56 } 57 58 struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev); 59 #else 60 static inline int bdev_dax_supported(struct super_block *sb, int blocksize) 61 { 62 return -EOPNOTSUPP; 63 } 64 65 static inline struct dax_device *fs_dax_get_by_host(const char *host) 66 { 67 return NULL; 68 } 69 70 static inline void fs_put_dax(struct dax_device *dax_dev) 71 { 72 } 73 74 static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) 75 { 76 return NULL; 77 } 78 #endif 79 80 int dax_read_lock(void); 81 void dax_read_unlock(int id); 82 struct dax_device *alloc_dax(void *private, const char *host, 83 const struct dax_operations *ops); 84 bool dax_alive(struct dax_device *dax_dev); 85 void kill_dax(struct dax_device *dax_dev); 86 void *dax_get_private(struct dax_device *dax_dev); 87 long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, 88 void **kaddr, pfn_t *pfn); 89 size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, 90 size_t bytes, struct iov_iter *i); 91 void dax_flush(struct dax_device *dax_dev, void *addr, size_t size); 92 void dax_write_cache(struct dax_device *dax_dev, bool wc); 93 bool dax_write_cache_enabled(struct dax_device *dax_dev); 94 95 ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, 96 const struct iomap_ops *ops); 97 int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size, 98 const struct iomap_ops *ops); 99 int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index); 100 int dax_invalidate_mapping_entry_sync(struct address_space *mapping, 101 pgoff_t index); 102 103 #ifdef CONFIG_FS_DAX 104 int __dax_zero_page_range(struct block_device *bdev, 105 struct dax_device *dax_dev, sector_t sector, 106 unsigned int offset, unsigned int length); 107 #else 108 static inline int __dax_zero_page_range(struct block_device *bdev, 109 struct dax_device *dax_dev, sector_t sector, 110 unsigned int offset, unsigned int length) 111 { 112 return -ENXIO; 113 } 114 #endif 115 116 static inline bool dax_mapping(struct address_space *mapping) 117 { 118 return mapping->host && IS_DAX(mapping->host); 119 } 120 121 struct writeback_control; 122 int dax_writeback_mapping_range(struct address_space *mapping, 123 struct block_device *bdev, struct writeback_control *wbc); 124 #endif 125