Linux kernel mirror (for testing)
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linux
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
10struct iomap_ops;
11struct dax_device;
12struct 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
25extern struct attribute_group dax_attribute_group;
26
27#if IS_ENABLED(CONFIG_DAX)
28struct dax_device *dax_get_by_host(const char *host);
29void put_dax(struct dax_device *dax_dev);
30#else
31static inline struct dax_device *dax_get_by_host(const char *host)
32{
33 return NULL;
34}
35
36static inline void put_dax(struct dax_device *dax_dev)
37{
38}
39#endif
40
41int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff);
42#if IS_ENABLED(CONFIG_FS_DAX)
43int __bdev_dax_supported(struct super_block *sb, int blocksize);
44static inline int bdev_dax_supported(struct super_block *sb, int blocksize)
45{
46 return __bdev_dax_supported(sb, blocksize);
47}
48
49static inline struct dax_device *fs_dax_get_by_host(const char *host)
50{
51 return dax_get_by_host(host);
52}
53
54static inline void fs_put_dax(struct dax_device *dax_dev)
55{
56 put_dax(dax_dev);
57}
58
59struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev);
60#else
61static inline int bdev_dax_supported(struct super_block *sb, int blocksize)
62{
63 return -EOPNOTSUPP;
64}
65
66static inline struct dax_device *fs_dax_get_by_host(const char *host)
67{
68 return NULL;
69}
70
71static inline void fs_put_dax(struct dax_device *dax_dev)
72{
73}
74
75static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
76{
77 return NULL;
78}
79#endif
80
81int dax_read_lock(void);
82void dax_read_unlock(int id);
83struct dax_device *alloc_dax(void *private, const char *host,
84 const struct dax_operations *ops);
85bool dax_alive(struct dax_device *dax_dev);
86void kill_dax(struct dax_device *dax_dev);
87void *dax_get_private(struct dax_device *dax_dev);
88long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
89 void **kaddr, pfn_t *pfn);
90size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
91 size_t bytes, struct iov_iter *i);
92void dax_flush(struct dax_device *dax_dev, void *addr, size_t size);
93void dax_write_cache(struct dax_device *dax_dev, bool wc);
94bool dax_write_cache_enabled(struct dax_device *dax_dev);
95
96ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
97 const struct iomap_ops *ops);
98int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
99 pfn_t *pfnp, const struct iomap_ops *ops);
100int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
101 pfn_t pfn);
102int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
103int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
104 pgoff_t index);
105
106#ifdef CONFIG_FS_DAX
107int __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
111static 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
119static inline bool dax_mapping(struct address_space *mapping)
120{
121 return mapping->host && IS_DAX(mapping->host);
122}
123
124struct writeback_control;
125int dax_writeback_mapping_range(struct address_space *mapping,
126 struct block_device *bdev, struct writeback_control *wbc);
127#endif