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 /* flush: optional driver-specific cache management after writes */ 23 void (*flush)(struct dax_device *, pgoff_t, void *, size_t); 24 }; 25 26 extern struct attribute_group dax_attribute_group; 27 28 #if IS_ENABLED(CONFIG_DAX) 29 struct dax_device *dax_get_by_host(const char *host); 30 void put_dax(struct dax_device *dax_dev); 31 #else 32 static inline struct dax_device *dax_get_by_host(const char *host) 33 { 34 return NULL; 35 } 36 37 static inline void put_dax(struct dax_device *dax_dev) 38 { 39 } 40 #endif 41 42 int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff); 43 #if IS_ENABLED(CONFIG_FS_DAX) 44 int __bdev_dax_supported(struct super_block *sb, int blocksize); 45 static inline int bdev_dax_supported(struct super_block *sb, int blocksize) 46 { 47 return __bdev_dax_supported(sb, blocksize); 48 } 49 50 static inline struct dax_device *fs_dax_get_by_host(const char *host) 51 { 52 return dax_get_by_host(host); 53 } 54 55 static inline void fs_put_dax(struct dax_device *dax_dev) 56 { 57 put_dax(dax_dev); 58 } 59 60 struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev); 61 #else 62 static inline int bdev_dax_supported(struct super_block *sb, int blocksize) 63 { 64 return -EOPNOTSUPP; 65 } 66 67 static inline struct dax_device *fs_dax_get_by_host(const char *host) 68 { 69 return NULL; 70 } 71 72 static inline void fs_put_dax(struct dax_device *dax_dev) 73 { 74 } 75 76 static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) 77 { 78 return NULL; 79 } 80 #endif 81 82 int dax_read_lock(void); 83 void dax_read_unlock(int id); 84 struct dax_device *alloc_dax(void *private, const char *host, 85 const struct dax_operations *ops); 86 bool dax_alive(struct dax_device *dax_dev); 87 void kill_dax(struct dax_device *dax_dev); 88 void *dax_get_private(struct dax_device *dax_dev); 89 long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, 90 void **kaddr, pfn_t *pfn); 91 size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, 92 size_t bytes, struct iov_iter *i); 93 void dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, 94 size_t size); 95 void dax_write_cache(struct dax_device *dax_dev, bool wc); 96 bool dax_write_cache_enabled(struct dax_device *dax_dev); 97 98 ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, 99 const struct iomap_ops *ops); 100 int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size, 101 const struct iomap_ops *ops); 102 int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index); 103 int dax_invalidate_mapping_entry_sync(struct address_space *mapping, 104 pgoff_t index); 105 106 #ifdef CONFIG_FS_DAX 107 int __dax_zero_page_range(struct block_device *bdev, 108 struct dax_device *dax_dev, sector_t sector, 109 unsigned int offset, unsigned int length); 110 #else 111 static inline int __dax_zero_page_range(struct block_device *bdev, 112 struct dax_device *dax_dev, sector_t sector, 113 unsigned int offset, unsigned int length) 114 { 115 return -ENXIO; 116 } 117 #endif 118 119 static inline bool dax_mapping(struct address_space *mapping) 120 { 121 return mapping->host && IS_DAX(mapping->host); 122 } 123 124 struct writeback_control; 125 int dax_writeback_mapping_range(struct address_space *mapping, 126 struct block_device *bdev, struct writeback_control *wbc); 127 #endif 128