[mirror_ubuntu-jammy-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>

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

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 *);
	/*
	 * 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 *);
};

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 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 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 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);
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);
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
fefc1d97 PG	10	/* Flag for synchronous flush */
	11	#define DAXDEV_F_SYNC (1UL << 0)
	12
27359fd6 MW	13	typedef unsigned long dax_entry_t;
27359fd6 MW	14
a254e568	15	struct iomap_ops;
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 *);
6568b08b	37	};
a254e568	38
6e0c90d6 DW	39	extern struct attribute_group dax_attribute_group;
6e0c90d6 DW	40
f5705aa8 DW	41	#if IS_ENABLED(CONFIG_DAX)
f5705aa8 DW	42	struct dax_device dax_get_by_host(const char host);
976431b0	43	struct dax_device alloc_dax(void private, const char *host,
fefc1d97	44	const struct dax_operations *ops, unsigned long flags);
f5705aa8	45	void put_dax(struct dax_device *dax_dev);
976431b0 DW	46	void kill_dax(struct dax_device *dax_dev);
	47	void dax_write_cache(struct dax_device *dax_dev, bool wc);
	48	bool dax_write_cache_enabled(struct dax_device *dax_dev);
fefc1d97 PG	49	bool __dax_synchronous(struct dax_device *dax_dev);
	50	static inline bool dax_synchronous(struct dax_device *dax_dev)
	51	{
	52	return __dax_synchronous(dax_dev);
	53	}
	54	void __set_dax_synchronous(struct dax_device *dax_dev);
	55	static inline void set_dax_synchronous(struct dax_device *dax_dev)
	56	{
	57	__set_dax_synchronous(dax_dev);
	58	}
32de1484 PG	59	/*
	60	* Check if given mapping is supported by the file / underlying device.
	61	*/
	62	static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
	63	struct dax_device *dax_dev)
	64	{
	65	if (!(vma->vm_flags & VM_SYNC))
	66	return true;
	67	if (!IS_DAX(file_inode(vma->vm_file)))
	68	return false;
	69	return dax_synchronous(dax_dev);
	70	}
f5705aa8 DW	71	#else
	72	static inline struct dax_device dax_get_by_host(const char host)
	73	{
	74	return NULL;
	75	}
976431b0	76	static inline struct dax_device alloc_dax(void private, const char *host,
fefc1d97	77	const struct dax_operations *ops, unsigned long flags)
976431b0 DW	78	{
	79	/*
	80	* Callers should check IS_ENABLED(CONFIG_DAX) to know if this
	81	* NULL is an error or expected.
	82	*/
	83	return NULL;
	84	}
f5705aa8 DW	85	static inline void put_dax(struct dax_device *dax_dev)
	86	{
	87	}
976431b0 DW	88	static inline void kill_dax(struct dax_device *dax_dev)
	89	{
	90	}
	91	static inline void dax_write_cache(struct dax_device *dax_dev, bool wc)
	92	{
	93	}
	94	static inline bool dax_write_cache_enabled(struct dax_device *dax_dev)
	95	{
	96	return false;
	97	}
fefc1d97 PG	98	static inline bool dax_synchronous(struct dax_device *dax_dev)
	99	{
	100	return true;
	101	}
	102	static inline void set_dax_synchronous(struct dax_device *dax_dev)
	103	{
	104	}
32de1484 PG	105	static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
	106	struct dax_device *dax_dev)
	107	{
	108	return !(vma->vm_flags & VM_SYNC);
	109	}
f5705aa8 DW	110	#endif
f5705aa8 DW	111
f44c7763	112	struct writeback_control;
ef510424 DW	113	int bdev_dax_pgoff(struct block_device , sector_t, size_t, pgoff_t pgoff);
ef510424 DW	114	#if IS_ENABLED(CONFIG_FS_DAX)
80660f20 DJ	115	bool __bdev_dax_supported(struct block_device *bdev, int blocksize);
80660f20 DJ	116	static inline bool bdev_dax_supported(struct block_device *bdev, int blocksize)
ef510424	117	{
ba23cba9	118	return __bdev_dax_supported(bdev, blocksize);
ef510424	119	}
f5705aa8	120
7bf7eac8 DW	121	bool __generic_fsdax_supported(struct dax_device *dax_dev,
	122	struct block_device *bdev, int blocksize, sector_t start,
	123	sector_t sectors);
	124	static inline bool generic_fsdax_supported(struct dax_device *dax_dev,
	125	struct block_device *bdev, int blocksize, sector_t start,
	126	sector_t sectors)
	127	{
	128	return __generic_fsdax_supported(dax_dev, bdev, blocksize, start,
	129	sectors);
	130	}
	131
f5705aa8 DW	132	static inline struct dax_device fs_dax_get_by_host(const char host)
	133	{
	134	return dax_get_by_host(host);
	135	}
	136
	137	static inline void fs_put_dax(struct dax_device *dax_dev)
	138	{
	139	put_dax(dax_dev);
	140	}
	141
78f35473	142	struct dax_device fs_dax_get_by_bdev(struct block_device bdev);
f44c7763 DW	143	int dax_writeback_mapping_range(struct address_space *mapping,
f44c7763 DW	144	struct block_device bdev, struct writeback_control wbc);
5fac7408 DW	145
5fac7408 DW	146	struct page dax_layout_busy_page(struct address_space mapping);
27359fd6 MW	147	dax_entry_t dax_lock_page(struct page *page);
27359fd6 MW	148	void dax_unlock_page(struct page *page, dax_entry_t cookie);
ef510424	149	#else
80660f20	150	static inline bool bdev_dax_supported(struct block_device *bdev,
ba23cba9	151	int blocksize)
ef510424	152	{
80660f20	153	return false;
ef510424	154	}
ef510424	155
7bf7eac8 DW	156	static inline bool generic_fsdax_supported(struct dax_device *dax_dev,
	157	struct block_device *bdev, int blocksize, sector_t start,
	158	sector_t sectors)
	159	{
	160	return false;
	161	}
	162
f5705aa8	163	static inline struct dax_device fs_dax_get_by_host(const char host)
ef510424 DW	164	{
	165	return NULL;
	166	}
	167
f5705aa8	168	static inline void fs_put_dax(struct dax_device *dax_dev)
ef510424 DW	169	{
ef510424 DW	170	}
78f35473 DW	171
	172	static inline struct dax_device fs_dax_get_by_bdev(struct block_device bdev)
	173	{
	174	return NULL;
	175	}
f44c7763	176
5fac7408 DW	177	static inline struct page dax_layout_busy_page(struct address_space mapping)
	178	{
	179	return NULL;
	180	}
	181
f44c7763 DW	182	static inline int dax_writeback_mapping_range(struct address_space *mapping,
	183	struct block_device bdev, struct writeback_control wbc)
	184	{
	185	return -EOPNOTSUPP;
	186	}
c2a7d2a1	187
27359fd6	188	static inline dax_entry_t dax_lock_page(struct page *page)
c2a7d2a1 DW	189	{
c2a7d2a1 DW	190	if (IS_DAX(page->mapping->host))
27359fd6 MW	191	return ~0UL;
27359fd6 MW	192	return 0;
c2a7d2a1 DW	193	}
c2a7d2a1 DW	194
27359fd6	195	static inline void dax_unlock_page(struct page *page, dax_entry_t cookie)
c2a7d2a1 DW	196	{
c2a7d2a1 DW	197	}
ef510424 DW	198	#endif
ef510424 DW	199
7b6be844 DW	200	int dax_read_lock(void);
7b6be844 DW	201	void dax_read_unlock(int id);
c1d6e828	202	bool dax_alive(struct dax_device *dax_dev);
c1d6e828	203	void dax_get_private(struct dax_device dax_dev);
b0686260 DW	204	long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
b0686260 DW	205	void *kaddr, pfn_t pfn);
7bf7eac8 DW	206	bool dax_supported(struct dax_device dax_dev, struct block_device bdev,
7bf7eac8 DW	207	int blocksize, sector_t start, sector_t len);
7e026c8c DW	208	size_t dax_copy_from_iter(struct dax_device dax_dev, pgoff_t pgoff, void addr,
7e026c8c DW	209	size_t bytes, struct iov_iter *i);
b3a9a0c3 DW	210	size_t dax_copy_to_iter(struct dax_device dax_dev, pgoff_t pgoff, void addr,
b3a9a0c3 DW	211	size_t bytes, struct iov_iter *i);
c3ca015f	212	void dax_flush(struct dax_device dax_dev, void addr, size_t size);
7b6be844	213
11c59c92	214	ssize_t dax_iomap_rw(struct kiocb iocb, struct iov_iter iter,
8ff6daa1	215	const struct iomap_ops *ops);
f77bc3a8	216	vm_fault_t dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
c0b24625	217	pfn_t pfnp, int errp, const struct iomap_ops *ops);
ab77dab4 SJ	218	vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
ab77dab4 SJ	219	enum page_entry_size pe_size, pfn_t pfn);
ac401cc7	220	int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
c6dcf52c JK	221	int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
c6dcf52c JK	222	pgoff_t index);
d1a5f2b4 DW	223
d1a5f2b4 DW	224	#ifdef CONFIG_FS_DAX
cccbce67 DW	225	int __dax_zero_page_range(struct block_device *bdev,
cccbce67 DW	226	struct dax_device *dax_dev, sector_t sector,
679c8bd3	227	unsigned int offset, unsigned int length);
d1a5f2b4	228	#else
679c8bd3	229	static inline int __dax_zero_page_range(struct block_device *bdev,
cccbce67 DW	230	struct dax_device *dax_dev, sector_t sector,
cccbce67 DW	231	unsigned int offset, unsigned int length)
679c8bd3 CH	232	{
	233	return -ENXIO;
	234	}
d1a5f2b4 DW	235	#endif
d1a5f2b4 DW	236
f9fe48be RZ	237	static inline bool dax_mapping(struct address_space *mapping)
	238	{
	239	return mapping->host && IS_DAX(mapping->host);
	240	}
7f6d5b52	241
c94c2acf	242	#endif