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 #include <asm/pgtable.h> 9 10 struct iomap_ops; 11 struct dax_device; 12 struct dax_operations { 13 /* 14 * direct_access: translate a device-relative 15 * logical-page-offset into an absolute physical pfn. Return the 16 * number of pages available for DAX at that pfn. 17 */ 18 long (*direct_access)(struct dax_device *, pgoff_t, long, 19 void **, pfn_t *); 20 /* copy_from_iter: required operation for fs-dax direct-i/o */ 21 size_t (*copy_from_iter)(struct dax_device *, pgoff_t, void *, size_t, 22 struct iov_iter *); 23 }; 24 25 extern struct attribute_group dax_attribute_group; 26 27 #if IS_ENABLED(CONFIG_DAX) 28 struct dax_device *dax_get_by_host(const char *host); 29 void put_dax(struct dax_device *dax_dev); 30 #else 31 static inline struct dax_device *dax_get_by_host(const char *host) 32 { 33 return NULL; 34 } 35 36 static inline void put_dax(struct dax_device *dax_dev) 37 { 38 } 39 #endif 40 41 int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff); 42 #if IS_ENABLED(CONFIG_FS_DAX) 43 int __bdev_dax_supported(struct super_block *sb, int blocksize); 44 static inline int bdev_dax_supported(struct super_block *sb, int blocksize) 45 { 46 return __bdev_dax_supported(sb, blocksize); 47 } 48 49 static inline struct dax_device *fs_dax_get_by_host(const char *host) 50 { 51 return dax_get_by_host(host); 52 } 53 54 static inline void fs_put_dax(struct dax_device *dax_dev) 55 { 56 put_dax(dax_dev); 57 } 58 59 struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev); 60 #else 61 static inline int bdev_dax_supported(struct super_block *sb, int blocksize) 62 { 63 return -EOPNOTSUPP; 64 } 65 66 static inline struct dax_device *fs_dax_get_by_host(const char *host) 67 { 68 return NULL; 69 } 70 71 static inline void fs_put_dax(struct dax_device *dax_dev) 72 { 73 } 74 75 static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) 76 { 77 return NULL; 78 } 79 #endif 80 81 int dax_read_lock(void); 82 void dax_read_unlock(int id); 83 struct dax_device *alloc_dax(void *private, const char *host, 84 const struct dax_operations *ops); 85 bool dax_alive(struct dax_device *dax_dev); 86 void kill_dax(struct dax_device *dax_dev); 87 void *dax_get_private(struct dax_device *dax_dev); 88 long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, 89 void **kaddr, pfn_t *pfn); 90 size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, 91 size_t bytes, struct iov_iter *i); 92 void dax_flush(struct dax_device *dax_dev, void *addr, size_t size); 93 void dax_write_cache(struct dax_device *dax_dev, bool wc); 94 bool dax_write_cache_enabled(struct dax_device *dax_dev); 95 96 ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, 97 const struct iomap_ops *ops); 98 int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size, 99 pfn_t *pfnp, const struct iomap_ops *ops); 100 int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size, 101 pfn_t pfn); 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