[linux-2.6-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>

typedef unsigned long dax_entry_t;

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 *);
	/* copy_to_iter: required operation for fs-dax direct-i/o */
	size_t (*copy_to_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);

struct page *dax_layout_busy_page(struct address_space *mapping);
dax_entry_t dax_lock_page(struct page *page);
void dax_unlock_page(struct page *page, dax_entry_t cookie);
#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 struct page *dax_layout_busy_page(struct address_space *mapping)
{
	return NULL;
}

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

static inline dax_entry_t dax_lock_page(struct page *page)
{
	if (IS_DAX(page->mapping->host))
		return ~0UL;
	return 0;
}

static inline void dax_unlock_page(struct page *page, dax_entry_t cookie)
{
}
#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);
size_t dax_copy_to_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);
vm_fault_t dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
		    pfn_t *pfnp, int *errp, const struct iomap_ops *ops);
vm_fault_t 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
27359fd6 MW	10	typedef unsigned long dax_entry_t;
27359fd6 MW	11
a254e568	12	struct iomap_ops;
6568b08b DW	13	struct dax_device;
	14	struct dax_operations {
	15	/*
	16	* direct_access: translate a device-relative
	17	* logical-page-offset into an absolute physical pfn. Return the
	18	* number of pages available for DAX at that pfn.
	19	*/
	20	long (direct_access)(struct dax_device , pgoff_t, long,
	21	void *, pfn_t );
5d61e43b	22	/* copy_from_iter: required operation for fs-dax direct-i/o */
0aed55af DW	23	size_t (copy_from_iter)(struct dax_device , pgoff_t, void *, size_t,
0aed55af DW	24	struct iov_iter *);
b3a9a0c3 DW	25	/* copy_to_iter: required operation for fs-dax direct-i/o */
	26	size_t (copy_to_iter)(struct dax_device , pgoff_t, void *, size_t,
	27	struct iov_iter *);
6568b08b	28	};
a254e568	29
6e0c90d6 DW	30	extern struct attribute_group dax_attribute_group;
6e0c90d6 DW	31
f5705aa8 DW	32	#if IS_ENABLED(CONFIG_DAX)
f5705aa8 DW	33	struct dax_device dax_get_by_host(const char host);
976431b0 DW	34	struct dax_device alloc_dax(void private, const char *host,
976431b0 DW	35	const struct dax_operations *ops);
f5705aa8	36	void put_dax(struct dax_device *dax_dev);
976431b0 DW	37	void kill_dax(struct dax_device *dax_dev);
	38	void dax_write_cache(struct dax_device *dax_dev, bool wc);
	39	bool dax_write_cache_enabled(struct dax_device *dax_dev);
f5705aa8 DW	40	#else
	41	static inline struct dax_device dax_get_by_host(const char host)
	42	{
	43	return NULL;
	44	}
976431b0 DW	45	static inline struct dax_device alloc_dax(void private, const char *host,
	46	const struct dax_operations *ops)
	47	{
	48	/*
	49	* Callers should check IS_ENABLED(CONFIG_DAX) to know if this
	50	* NULL is an error or expected.
	51	*/
	52	return NULL;
	53	}
f5705aa8 DW	54	static inline void put_dax(struct dax_device *dax_dev)
	55	{
	56	}
976431b0 DW	57	static inline void kill_dax(struct dax_device *dax_dev)
	58	{
	59	}
	60	static inline void dax_write_cache(struct dax_device *dax_dev, bool wc)
	61	{
	62	}
	63	static inline bool dax_write_cache_enabled(struct dax_device *dax_dev)
	64	{
	65	return false;
	66	}
f5705aa8 DW	67	#endif
f5705aa8 DW	68
f44c7763	69	struct writeback_control;
ef510424 DW	70	int bdev_dax_pgoff(struct block_device , sector_t, size_t, pgoff_t pgoff);
ef510424 DW	71	#if IS_ENABLED(CONFIG_FS_DAX)
80660f20 DJ	72	bool __bdev_dax_supported(struct block_device *bdev, int blocksize);
80660f20 DJ	73	static inline bool bdev_dax_supported(struct block_device *bdev, int blocksize)
ef510424	74	{
ba23cba9	75	return __bdev_dax_supported(bdev, blocksize);
ef510424	76	}
f5705aa8 DW	77
	78	static inline struct dax_device fs_dax_get_by_host(const char host)
	79	{
	80	return dax_get_by_host(host);
	81	}
	82
	83	static inline void fs_put_dax(struct dax_device *dax_dev)
	84	{
	85	put_dax(dax_dev);
	86	}
	87
78f35473	88	struct dax_device fs_dax_get_by_bdev(struct block_device bdev);
f44c7763 DW	89	int dax_writeback_mapping_range(struct address_space *mapping,
f44c7763 DW	90	struct block_device bdev, struct writeback_control wbc);
5fac7408 DW	91
5fac7408 DW	92	struct page dax_layout_busy_page(struct address_space mapping);
27359fd6 MW	93	dax_entry_t dax_lock_page(struct page *page);
27359fd6 MW	94	void dax_unlock_page(struct page *page, dax_entry_t cookie);
ef510424	95	#else
80660f20	96	static inline bool bdev_dax_supported(struct block_device *bdev,
ba23cba9	97	int blocksize)
ef510424	98	{
80660f20	99	return false;
ef510424	100	}
ef510424	101
f5705aa8	102	static inline struct dax_device fs_dax_get_by_host(const char host)
ef510424 DW	103	{
	104	return NULL;
	105	}
	106
f5705aa8	107	static inline void fs_put_dax(struct dax_device *dax_dev)
ef510424 DW	108	{
ef510424 DW	109	}
78f35473 DW	110
	111	static inline struct dax_device fs_dax_get_by_bdev(struct block_device bdev)
	112	{
	113	return NULL;
	114	}
f44c7763	115
5fac7408 DW	116	static inline struct page dax_layout_busy_page(struct address_space mapping)
	117	{
	118	return NULL;
	119	}
	120
f44c7763 DW	121	static inline int dax_writeback_mapping_range(struct address_space *mapping,
	122	struct block_device bdev, struct writeback_control wbc)
	123	{
	124	return -EOPNOTSUPP;
	125	}
c2a7d2a1	126
27359fd6	127	static inline dax_entry_t dax_lock_page(struct page *page)
c2a7d2a1 DW	128	{
c2a7d2a1 DW	129	if (IS_DAX(page->mapping->host))
27359fd6 MW	130	return ~0UL;
27359fd6 MW	131	return 0;
c2a7d2a1 DW	132	}
c2a7d2a1 DW	133
27359fd6	134	static inline void dax_unlock_page(struct page *page, dax_entry_t cookie)
c2a7d2a1 DW	135	{
c2a7d2a1 DW	136	}
ef510424 DW	137	#endif
ef510424 DW	138
7b6be844 DW	139	int dax_read_lock(void);
7b6be844 DW	140	void dax_read_unlock(int id);
c1d6e828	141	bool dax_alive(struct dax_device *dax_dev);
c1d6e828	142	void dax_get_private(struct dax_device dax_dev);
b0686260 DW	143	long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
b0686260 DW	144	void *kaddr, pfn_t pfn);
7e026c8c DW	145	size_t dax_copy_from_iter(struct dax_device dax_dev, pgoff_t pgoff, void addr,
7e026c8c DW	146	size_t bytes, struct iov_iter *i);
b3a9a0c3 DW	147	size_t dax_copy_to_iter(struct dax_device dax_dev, pgoff_t pgoff, void addr,
b3a9a0c3 DW	148	size_t bytes, struct iov_iter *i);
c3ca015f	149	void dax_flush(struct dax_device dax_dev, void addr, size_t size);
7b6be844	150
11c59c92	151	ssize_t dax_iomap_rw(struct kiocb iocb, struct iov_iter iter,
8ff6daa1	152	const struct iomap_ops *ops);
f77bc3a8	153	vm_fault_t dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
c0b24625	154	pfn_t pfnp, int errp, const struct iomap_ops *ops);
ab77dab4 SJ	155	vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
ab77dab4 SJ	156	enum page_entry_size pe_size, pfn_t pfn);
ac401cc7	157	int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
c6dcf52c JK	158	int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
c6dcf52c JK	159	pgoff_t index);
d1a5f2b4 DW	160
d1a5f2b4 DW	161	#ifdef CONFIG_FS_DAX
cccbce67 DW	162	int __dax_zero_page_range(struct block_device *bdev,
cccbce67 DW	163	struct dax_device *dax_dev, sector_t sector,
679c8bd3	164	unsigned int offset, unsigned int length);
d1a5f2b4	165	#else
679c8bd3	166	static inline int __dax_zero_page_range(struct block_device *bdev,
cccbce67 DW	167	struct dax_device *dax_dev, sector_t sector,
cccbce67 DW	168	unsigned int offset, unsigned int length)
679c8bd3 CH	169	{
	170	return -ENXIO;
	171	}
d1a5f2b4 DW	172	#endif
d1a5f2b4 DW	173
f9fe48be RZ	174	static inline bool dax_mapping(struct address_space *mapping)
	175	{
	176	return mapping->host && IS_DAX(mapping->host);
	177	}
7f6d5b52	178
c94c2acf	179	#endif