[linux-block.git] / include / linux / dax.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_DAX_H
#define _LINUX_DAX_H

#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/radix-tree.h>
#include <asm/pgtable.h>

struct iomap_ops;
struct dax_device;
struct dax_operations {
	/*
	 * direct_access: translate a device-relative
	 * logical-page-offset into an absolute physical pfn. Return the
	 * number of pages available for DAX at that pfn.
	 */
	long (*direct_access)(struct dax_device *, pgoff_t, long,
			void **, pfn_t *);
	/* copy_from_iter: required operation for fs-dax direct-i/o */
	size_t (*copy_from_iter)(struct dax_device *, pgoff_t, void *, size_t,
			struct iov_iter *);
};

extern struct attribute_group dax_attribute_group;

#if IS_ENABLED(CONFIG_DAX)
struct dax_device *dax_get_by_host(const char *host);
struct dax_device *alloc_dax(void *private, const char *host,
		const struct dax_operations *ops);
void put_dax(struct dax_device *dax_dev);
void kill_dax(struct dax_device *dax_dev);
void dax_write_cache(struct dax_device *dax_dev, bool wc);
bool dax_write_cache_enabled(struct dax_device *dax_dev);
#else
static inline struct dax_device *dax_get_by_host(const char *host)
{
	return NULL;
}
static inline struct dax_device *alloc_dax(void *private, const char *host,
		const struct dax_operations *ops)
{
	/*
	 * Callers should check IS_ENABLED(CONFIG_DAX) to know if this
	 * NULL is an error or expected.
	 */
	return NULL;
}
static inline void put_dax(struct dax_device *dax_dev)
{
}
static inline void kill_dax(struct dax_device *dax_dev)
{
}
static inline void dax_write_cache(struct dax_device *dax_dev, bool wc)
{
}
static inline bool dax_write_cache_enabled(struct dax_device *dax_dev)
{
	return false;
}
#endif

struct writeback_control;
int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff);
#if IS_ENABLED(CONFIG_FS_DAX)
bool __bdev_dax_supported(struct block_device *bdev, int blocksize);
static inline bool bdev_dax_supported(struct block_device *bdev, int blocksize)
{
	return __bdev_dax_supported(bdev, blocksize);
}

static inline struct dax_device *fs_dax_get_by_host(const char *host)
{
	return dax_get_by_host(host);
}

static inline void fs_put_dax(struct dax_device *dax_dev)
{
	put_dax(dax_dev);
}

struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev);
int dax_writeback_mapping_range(struct address_space *mapping,
		struct block_device *bdev, struct writeback_control *wbc);
#else
static inline bool bdev_dax_supported(struct block_device *bdev,
		int blocksize)
{
	return false;
}

static inline struct dax_device *fs_dax_get_by_host(const char *host)
{
	return NULL;
}

static inline void fs_put_dax(struct dax_device *dax_dev)
{
}

static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
{
	return NULL;
}

static inline int dax_writeback_mapping_range(struct address_space *mapping,
		struct block_device *bdev, struct writeback_control *wbc)
{
	return -EOPNOTSUPP;
}
#endif

int dax_read_lock(void);
void dax_read_unlock(int id);
bool dax_alive(struct dax_device *dax_dev);
void *dax_get_private(struct dax_device *dax_dev);
long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
		void **kaddr, pfn_t *pfn);
size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
		size_t bytes, struct iov_iter *i);
void dax_flush(struct dax_device *dax_dev, void *addr, size_t size);

ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
		const struct iomap_ops *ops);
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
		    pfn_t *pfnp, int *errp, const struct iomap_ops *ops);
int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
			  pfn_t pfn);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
				      pgoff_t index);

#ifdef CONFIG_FS_DAX
int __dax_zero_page_range(struct block_device *bdev,
		struct dax_device *dax_dev, sector_t sector,
		unsigned int offset, unsigned int length);
#else
static inline int __dax_zero_page_range(struct block_device *bdev,
		struct dax_device *dax_dev, sector_t sector,
		unsigned int offset, unsigned int length)
{
	return -ENXIO;
}
#endif

static inline bool dax_mapping(struct address_space *mapping)
{
	return mapping->host && IS_DAX(mapping->host);
}

#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
c94c2acf MW	2	#ifndef _LINUX_DAX_H
	3	#define _LINUX_DAX_H
	4
	5	#include <linux/fs.h>
	6	#include <linux/mm.h>
4f622938	7	#include <linux/radix-tree.h>
c94c2acf MW	8	#include <asm/pgtable.h>
c94c2acf MW	9
a254e568	10	struct iomap_ops;
6568b08b DW	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 );
5d61e43b	20	/* copy_from_iter: required operation for fs-dax direct-i/o */
0aed55af DW	21	size_t (copy_from_iter)(struct dax_device , pgoff_t, void *, size_t,
0aed55af DW	22	struct iov_iter *);
6568b08b	23	};
a254e568	24
6e0c90d6 DW	25	extern struct attribute_group dax_attribute_group;
6e0c90d6 DW	26
f5705aa8 DW	27	#if IS_ENABLED(CONFIG_DAX)
f5705aa8 DW	28	struct dax_device dax_get_by_host(const char host);
976431b0 DW	29	struct dax_device alloc_dax(void private, const char *host,
976431b0 DW	30	const struct dax_operations *ops);
f5705aa8	31	void put_dax(struct dax_device *dax_dev);
976431b0 DW	32	void kill_dax(struct dax_device *dax_dev);
	33	void dax_write_cache(struct dax_device *dax_dev, bool wc);
	34	bool dax_write_cache_enabled(struct dax_device *dax_dev);
f5705aa8 DW	35	#else
	36	static inline struct dax_device dax_get_by_host(const char host)
	37	{
	38	return NULL;
	39	}
976431b0 DW	40	static inline struct dax_device alloc_dax(void private, const char *host,
	41	const struct dax_operations *ops)
	42	{
	43	/*
	44	* Callers should check IS_ENABLED(CONFIG_DAX) to know if this
	45	* NULL is an error or expected.
	46	*/
	47	return NULL;
	48	}
f5705aa8 DW	49	static inline void put_dax(struct dax_device *dax_dev)
	50	{
	51	}
976431b0 DW	52	static inline void kill_dax(struct dax_device *dax_dev)
	53	{
	54	}
	55	static inline void dax_write_cache(struct dax_device *dax_dev, bool wc)
	56	{
	57	}
	58	static inline bool dax_write_cache_enabled(struct dax_device *dax_dev)
	59	{
	60	return false;
	61	}
f5705aa8 DW	62	#endif
f5705aa8 DW	63
f44c7763	64	struct writeback_control;
ef510424 DW	65	int bdev_dax_pgoff(struct block_device , sector_t, size_t, pgoff_t pgoff);
ef510424 DW	66	#if IS_ENABLED(CONFIG_FS_DAX)
80660f20 DJ	67	bool __bdev_dax_supported(struct block_device *bdev, int blocksize);
80660f20 DJ	68	static inline bool bdev_dax_supported(struct block_device *bdev, int blocksize)
ef510424	69	{
ba23cba9	70	return __bdev_dax_supported(bdev, blocksize);
ef510424	71	}
f5705aa8 DW	72
	73	static inline struct dax_device fs_dax_get_by_host(const char host)
	74	{
	75	return dax_get_by_host(host);
	76	}
	77
	78	static inline void fs_put_dax(struct dax_device *dax_dev)
	79	{
	80	put_dax(dax_dev);
	81	}
	82
78f35473	83	struct dax_device fs_dax_get_by_bdev(struct block_device bdev);
f44c7763 DW	84	int dax_writeback_mapping_range(struct address_space *mapping,
f44c7763 DW	85	struct block_device bdev, struct writeback_control wbc);
ef510424	86	#else
80660f20	87	static inline bool bdev_dax_supported(struct block_device *bdev,
ba23cba9	88	int blocksize)
ef510424	89	{
80660f20	90	return false;
ef510424	91	}
ef510424	92
f5705aa8	93	static inline struct dax_device fs_dax_get_by_host(const char host)
ef510424 DW	94	{
	95	return NULL;
	96	}
	97
f5705aa8	98	static inline void fs_put_dax(struct dax_device *dax_dev)
ef510424 DW	99	{
ef510424 DW	100	}
78f35473 DW	101
	102	static inline struct dax_device fs_dax_get_by_bdev(struct block_device bdev)
	103	{
	104	return NULL;
	105	}
f44c7763 DW	106
	107	static inline int dax_writeback_mapping_range(struct address_space *mapping,
	108	struct block_device bdev, struct writeback_control wbc)
	109	{
	110	return -EOPNOTSUPP;
	111	}
ef510424 DW	112	#endif
ef510424 DW	113
7b6be844 DW	114	int dax_read_lock(void);
7b6be844 DW	115	void dax_read_unlock(int id);
c1d6e828	116	bool dax_alive(struct dax_device *dax_dev);
c1d6e828	117	void dax_get_private(struct dax_device dax_dev);
b0686260 DW	118	long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
b0686260 DW	119	void *kaddr, pfn_t pfn);
7e026c8c DW	120	size_t dax_copy_from_iter(struct dax_device dax_dev, pgoff_t pgoff, void addr,
7e026c8c DW	121	size_t bytes, struct iov_iter *i);
c3ca015f	122	void dax_flush(struct dax_device dax_dev, void addr, size_t size);
7b6be844	123
11c59c92	124	ssize_t dax_iomap_rw(struct kiocb iocb, struct iov_iter iter,
8ff6daa1	125	const struct iomap_ops *ops);
c791ace1	126	int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
c0b24625	127	pfn_t pfnp, int errp, const struct iomap_ops *ops);
71eab6df JK	128	int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
71eab6df JK	129	pfn_t pfn);
ac401cc7	130	int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
c6dcf52c JK	131	int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
c6dcf52c JK	132	pgoff_t index);
d1a5f2b4 DW	133
d1a5f2b4 DW	134	#ifdef CONFIG_FS_DAX
cccbce67 DW	135	int __dax_zero_page_range(struct block_device *bdev,
cccbce67 DW	136	struct dax_device *dax_dev, sector_t sector,
679c8bd3	137	unsigned int offset, unsigned int length);
d1a5f2b4	138	#else
679c8bd3	139	static inline int __dax_zero_page_range(struct block_device *bdev,
cccbce67 DW	140	struct dax_device *dax_dev, sector_t sector,
cccbce67 DW	141	unsigned int offset, unsigned int length)
679c8bd3 CH	142	{
	143	return -ENXIO;
	144	}
d1a5f2b4 DW	145	#endif
d1a5f2b4 DW	146
f9fe48be RZ	147	static inline bool dax_mapping(struct address_space *mapping)
	148	{
	149	return mapping->host && IS_DAX(mapping->host);
	150	}
7f6d5b52	151
c94c2acf	152	#endif