[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>

/* Flag for synchronous flush */
#define DAXDEV_F_SYNC (1UL << 0)

typedef unsigned long dax_entry_t;

struct iomap_ops;
struct iomap;
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 *);
	/*
	 * Validate whether this device is usable as an fsdax backing
	 * device.
	 */
	bool (*dax_supported)(struct dax_device *, struct block_device *, int,
			sector_t, sector_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 *);
	/* zero_page_range: required operation. Zero page range   */
	int (*zero_page_range)(struct dax_device *, pgoff_t, size_t);
};

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, unsigned long flags);
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);
bool __dax_synchronous(struct dax_device *dax_dev);
static inline bool dax_synchronous(struct dax_device *dax_dev)
{
	return  __dax_synchronous(dax_dev);
}
void __set_dax_synchronous(struct dax_device *dax_dev);
static inline void set_dax_synchronous(struct dax_device *dax_dev)
{
	__set_dax_synchronous(dax_dev);
}
/*
 * Check if given mapping is supported by the file / underlying device.
 */
static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
					     struct dax_device *dax_dev)
{
	if (!(vma->vm_flags & VM_SYNC))
		return true;
	if (!IS_DAX(file_inode(vma->vm_file)))
		return false;
	return dax_synchronous(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, unsigned long flags)
{
	/*
	 * 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;
}
static inline bool dax_synchronous(struct dax_device *dax_dev)
{
	return true;
}
static inline void set_dax_synchronous(struct dax_device *dax_dev)
{
}
static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
				struct dax_device *dax_dev)
{
	return !(vma->vm_flags & VM_SYNC);
}
#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);
}

bool __generic_fsdax_supported(struct dax_device *dax_dev,
		struct block_device *bdev, int blocksize, sector_t start,
		sector_t sectors);
static inline bool generic_fsdax_supported(struct dax_device *dax_dev,
		struct block_device *bdev, int blocksize, sector_t start,
		sector_t sectors)
{
	return __generic_fsdax_supported(dax_dev, bdev, blocksize, start,
			sectors);
}

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 dax_device *dax_dev, 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 bool generic_fsdax_supported(struct dax_device *dax_dev,
		struct block_device *bdev, int blocksize, sector_t start,
		sector_t sectors)
{
	return false;
}

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 dax_device *dax_dev, 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);
bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,
		int blocksize, sector_t start, sector_t len);
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);
int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
			size_t nr_pages);
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);
int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
			struct iomap *iomap);
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	8
fefc1d97 PG	9	/* Flag for synchronous flush */
	10	#define DAXDEV_F_SYNC (1UL << 0)
	11
27359fd6 MW	12	typedef unsigned long dax_entry_t;
27359fd6 MW	13
a254e568	14	struct iomap_ops;
4f3b4f16	15	struct iomap;
6568b08b DW	16	struct dax_device;
	17	struct dax_operations {
	18	/*
	19	* direct_access: translate a device-relative
	20	* logical-page-offset into an absolute physical pfn. Return the
	21	* number of pages available for DAX at that pfn.
	22	*/
	23	long (direct_access)(struct dax_device , pgoff_t, long,
	24	void *, pfn_t );
7bf7eac8 DW	25	/*
	26	* Validate whether this device is usable as an fsdax backing
	27	* device.
	28	*/
	29	bool (dax_supported)(struct dax_device , struct block_device *, int,
	30	sector_t, sector_t);
5d61e43b	31	/* copy_from_iter: required operation for fs-dax direct-i/o */
0aed55af DW	32	size_t (copy_from_iter)(struct dax_device , pgoff_t, void *, size_t,
0aed55af DW	33	struct iov_iter *);
b3a9a0c3 DW	34	/* copy_to_iter: required operation for fs-dax direct-i/o */
	35	size_t (copy_to_iter)(struct dax_device , pgoff_t, void *, size_t,
	36	struct iov_iter *);
f605a263 VG	37	/* zero_page_range: required operation. Zero page range */
f605a263 VG	38	int (zero_page_range)(struct dax_device , pgoff_t, size_t);
6568b08b	39	};
a254e568	40
6e0c90d6 DW	41	extern struct attribute_group dax_attribute_group;
6e0c90d6 DW	42
f5705aa8 DW	43	#if IS_ENABLED(CONFIG_DAX)
f5705aa8 DW	44	struct dax_device dax_get_by_host(const char host);
976431b0	45	struct dax_device alloc_dax(void private, const char *host,
fefc1d97	46	const struct dax_operations *ops, unsigned long flags);
f5705aa8	47	void put_dax(struct dax_device *dax_dev);
976431b0 DW	48	void kill_dax(struct dax_device *dax_dev);
	49	void dax_write_cache(struct dax_device *dax_dev, bool wc);
	50	bool dax_write_cache_enabled(struct dax_device *dax_dev);
fefc1d97 PG	51	bool __dax_synchronous(struct dax_device *dax_dev);
	52	static inline bool dax_synchronous(struct dax_device *dax_dev)
	53	{
	54	return __dax_synchronous(dax_dev);
	55	}
	56	void __set_dax_synchronous(struct dax_device *dax_dev);
	57	static inline void set_dax_synchronous(struct dax_device *dax_dev)
	58	{
	59	__set_dax_synchronous(dax_dev);
	60	}
32de1484 PG	61	/*
	62	* Check if given mapping is supported by the file / underlying device.
	63	*/
	64	static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
	65	struct dax_device *dax_dev)
	66	{
	67	if (!(vma->vm_flags & VM_SYNC))
	68	return true;
	69	if (!IS_DAX(file_inode(vma->vm_file)))
	70	return false;
	71	return dax_synchronous(dax_dev);
	72	}
f5705aa8 DW	73	#else
	74	static inline struct dax_device dax_get_by_host(const char host)
	75	{
	76	return NULL;
	77	}
976431b0	78	static inline struct dax_device alloc_dax(void private, const char *host,
fefc1d97	79	const struct dax_operations *ops, unsigned long flags)
976431b0 DW	80	{
	81	/*
	82	* Callers should check IS_ENABLED(CONFIG_DAX) to know if this
	83	* NULL is an error or expected.
	84	*/
	85	return NULL;
	86	}
f5705aa8 DW	87	static inline void put_dax(struct dax_device *dax_dev)
	88	{
	89	}
976431b0 DW	90	static inline void kill_dax(struct dax_device *dax_dev)
	91	{
	92	}
	93	static inline void dax_write_cache(struct dax_device *dax_dev, bool wc)
	94	{
	95	}
	96	static inline bool dax_write_cache_enabled(struct dax_device *dax_dev)
	97	{
	98	return false;
	99	}
fefc1d97 PG	100	static inline bool dax_synchronous(struct dax_device *dax_dev)
	101	{
	102	return true;
	103	}
	104	static inline void set_dax_synchronous(struct dax_device *dax_dev)
	105	{
	106	}
32de1484 PG	107	static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
	108	struct dax_device *dax_dev)
	109	{
	110	return !(vma->vm_flags & VM_SYNC);
	111	}
f5705aa8 DW	112	#endif
f5705aa8 DW	113
f44c7763	114	struct writeback_control;
ef510424 DW	115	int bdev_dax_pgoff(struct block_device , sector_t, size_t, pgoff_t pgoff);
ef510424 DW	116	#if IS_ENABLED(CONFIG_FS_DAX)
80660f20 DJ	117	bool __bdev_dax_supported(struct block_device *bdev, int blocksize);
80660f20 DJ	118	static inline bool bdev_dax_supported(struct block_device *bdev, int blocksize)
ef510424	119	{
ba23cba9	120	return __bdev_dax_supported(bdev, blocksize);
ef510424	121	}
f5705aa8	122
7bf7eac8 DW	123	bool __generic_fsdax_supported(struct dax_device *dax_dev,
	124	struct block_device *bdev, int blocksize, sector_t start,
	125	sector_t sectors);
	126	static inline bool generic_fsdax_supported(struct dax_device *dax_dev,
	127	struct block_device *bdev, int blocksize, sector_t start,
	128	sector_t sectors)
	129	{
	130	return __generic_fsdax_supported(dax_dev, bdev, blocksize, start,
	131	sectors);
	132	}
	133
f5705aa8 DW	134	static inline void fs_put_dax(struct dax_device *dax_dev)
	135	{
	136	put_dax(dax_dev);
	137	}
	138
78f35473	139	struct dax_device fs_dax_get_by_bdev(struct block_device bdev);
f44c7763	140	int dax_writeback_mapping_range(struct address_space *mapping,
3f666c56	141	struct dax_device dax_dev, struct writeback_control wbc);
5fac7408 DW	142
5fac7408 DW	143	struct page dax_layout_busy_page(struct address_space mapping);
27359fd6 MW	144	dax_entry_t dax_lock_page(struct page *page);
27359fd6 MW	145	void dax_unlock_page(struct page *page, dax_entry_t cookie);
ef510424	146	#else
80660f20	147	static inline bool bdev_dax_supported(struct block_device *bdev,
ba23cba9	148	int blocksize)
ef510424	149	{
80660f20	150	return false;
ef510424	151	}
ef510424	152
7bf7eac8 DW	153	static inline bool generic_fsdax_supported(struct dax_device *dax_dev,
	154	struct block_device *bdev, int blocksize, sector_t start,
	155	sector_t sectors)
	156	{
	157	return false;
	158	}
	159
f5705aa8	160	static inline void fs_put_dax(struct dax_device *dax_dev)
ef510424 DW	161	{
ef510424 DW	162	}
78f35473 DW	163
	164	static inline struct dax_device fs_dax_get_by_bdev(struct block_device bdev)
	165	{
	166	return NULL;
	167	}
f44c7763	168
5fac7408 DW	169	static inline struct page dax_layout_busy_page(struct address_space mapping)
	170	{
	171	return NULL;
	172	}
	173
f44c7763	174	static inline int dax_writeback_mapping_range(struct address_space *mapping,
3f666c56	175	struct dax_device dax_dev, struct writeback_control wbc)
f44c7763 DW	176	{
	177	return -EOPNOTSUPP;
	178	}
c2a7d2a1	179
27359fd6	180	static inline dax_entry_t dax_lock_page(struct page *page)
c2a7d2a1 DW	181	{
c2a7d2a1 DW	182	if (IS_DAX(page->mapping->host))
27359fd6 MW	183	return ~0UL;
27359fd6 MW	184	return 0;
c2a7d2a1 DW	185	}
c2a7d2a1 DW	186
27359fd6	187	static inline void dax_unlock_page(struct page *page, dax_entry_t cookie)
c2a7d2a1 DW	188	{
c2a7d2a1 DW	189	}
ef510424 DW	190	#endif
ef510424 DW	191
7b6be844 DW	192	int dax_read_lock(void);
7b6be844 DW	193	void dax_read_unlock(int id);
c1d6e828	194	bool dax_alive(struct dax_device *dax_dev);
c1d6e828	195	void dax_get_private(struct dax_device dax_dev);
b0686260 DW	196	long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
b0686260 DW	197	void *kaddr, pfn_t pfn);
7bf7eac8 DW	198	bool dax_supported(struct dax_device dax_dev, struct block_device bdev,
7bf7eac8 DW	199	int blocksize, sector_t start, sector_t len);
7e026c8c DW	200	size_t dax_copy_from_iter(struct dax_device dax_dev, pgoff_t pgoff, void addr,
7e026c8c DW	201	size_t bytes, struct iov_iter *i);
b3a9a0c3 DW	202	size_t dax_copy_to_iter(struct dax_device dax_dev, pgoff_t pgoff, void addr,
b3a9a0c3 DW	203	size_t bytes, struct iov_iter *i);
f605a263 VG	204	int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
f605a263 VG	205	size_t nr_pages);
c3ca015f	206	void dax_flush(struct dax_device dax_dev, void addr, size_t size);
7b6be844	207
11c59c92	208	ssize_t dax_iomap_rw(struct kiocb iocb, struct iov_iter iter,
8ff6daa1	209	const struct iomap_ops *ops);
f77bc3a8	210	vm_fault_t dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
c0b24625	211	pfn_t pfnp, int errp, const struct iomap_ops *ops);
ab77dab4 SJ	212	vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
ab77dab4 SJ	213	enum page_entry_size pe_size, pfn_t pfn);
ac401cc7	214	int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
c6dcf52c JK	215	int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
c6dcf52c JK	216	pgoff_t index);
4f3b4f16 VG	217	int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
4f3b4f16 VG	218	struct iomap *iomap);
f9fe48be RZ	219	static inline bool dax_mapping(struct address_space *mapping)
	220	{
	221	return mapping->host && IS_DAX(mapping->host);
	222	}
7f6d5b52	223
c94c2acf	224	#endif