[mirror_ubuntu-focal-kernel.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 *);
	/* 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);
bool dax_lock_mapping_entry(struct page *page);
void dax_unlock_mapping_entry(struct page *page);
#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 bool dax_lock_mapping_entry(struct page *page)
{
	if (IS_DAX(page->mapping->host))
		return true;
	return false;
}

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