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