Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
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linux
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
9struct iomap_ops;
10struct dax_device;
11struct 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
26extern struct attribute_group dax_attribute_group;
27
28#if IS_ENABLED(CONFIG_DAX)
29struct dax_device *dax_get_by_host(const char *host);
30void put_dax(struct dax_device *dax_dev);
31#else
32static inline struct dax_device *dax_get_by_host(const char *host)
33{
34 return NULL;
35}
36
37static inline void put_dax(struct dax_device *dax_dev)
38{
39}
40#endif
41
42int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff);
43#if IS_ENABLED(CONFIG_FS_DAX)
44int __bdev_dax_supported(struct super_block *sb, int blocksize);
45static inline int bdev_dax_supported(struct super_block *sb, int blocksize)
46{
47 return __bdev_dax_supported(sb, blocksize);
48}
49
50static inline struct dax_device *fs_dax_get_by_host(const char *host)
51{
52 return dax_get_by_host(host);
53}
54
55static inline void fs_put_dax(struct dax_device *dax_dev)
56{
57 put_dax(dax_dev);
58}
59
60struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev);
61#else
62static inline int bdev_dax_supported(struct super_block *sb, int blocksize)
63{
64 return -EOPNOTSUPP;
65}
66
67static inline struct dax_device *fs_dax_get_by_host(const char *host)
68{
69 return NULL;
70}
71
72static inline void fs_put_dax(struct dax_device *dax_dev)
73{
74}
75
76static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
77{
78 return NULL;
79}
80#endif
81
82int dax_read_lock(void);
83void dax_read_unlock(int id);
84struct dax_device *alloc_dax(void *private, const char *host,
85 const struct dax_operations *ops);
86bool dax_alive(struct dax_device *dax_dev);
87void kill_dax(struct dax_device *dax_dev);
88void *dax_get_private(struct dax_device *dax_dev);
89long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
90 void **kaddr, pfn_t *pfn);
91size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
92 size_t bytes, struct iov_iter *i);
93void dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
94 size_t size);
95void dax_write_cache(struct dax_device *dax_dev, bool wc);
96bool dax_write_cache_enabled(struct dax_device *dax_dev);
97
98ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
99 const struct iomap_ops *ops);
100int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
101 const struct iomap_ops *ops);
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