[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>

typedef unsigned long dax_entry_t;

struct dax_device;
struct gendisk;
struct iomap_ops;
struct iomap_iter;
struct iomap;

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);
	/* zero_page_range: required operation. Zero page range   */
	int (*zero_page_range)(struct dax_device *, pgoff_t, size_t);
};

#if IS_ENABLED(CONFIG_DAX)
struct dax_device *alloc_dax(void *private, 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);
bool dax_synchronous(struct dax_device *dax_dev);
void set_dax_synchronous(struct dax_device *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 *alloc_dax(void *private,
		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;
}
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

void set_dax_nocache(struct dax_device *dax_dev);
void set_dax_nomc(struct dax_device *dax_dev);

struct writeback_control;
#if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX)
int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk);
void dax_remove_host(struct gendisk *disk);
struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev,
		u64 *start_off);
static inline void fs_put_dax(struct dax_device *dax_dev)
{
	put_dax(dax_dev);
}
#else
static inline int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk)
{
	return 0;
}
static inline void dax_remove_host(struct gendisk *disk)
{
}
static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev,
		u64 *start_off)
{
	return NULL;
}
static inline void fs_put_dax(struct dax_device *dax_dev)
{
}
#endif /* CONFIG_BLOCK && CONFIG_FS_DAX */

#if IS_ENABLED(CONFIG_FS_DAX)
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);
struct page *dax_layout_busy_page_range(struct address_space *mapping, loff_t start, loff_t end);
dax_entry_t dax_lock_page(struct page *page);
void dax_unlock_page(struct page *page, dax_entry_t cookie);
#else
static inline struct page *dax_layout_busy_page(struct address_space *mapping)
{
	return NULL;
}

static inline struct page *dax_layout_busy_page_range(struct address_space *mapping, pgoff_t start, pgoff_t nr_pages)
{
	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_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero,
		const struct iomap_ops *ops);
int dax_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
		const struct iomap_ops *ops);

#if IS_ENABLED(CONFIG_DAX)
int dax_read_lock(void);
void dax_read_unlock(int id);
#else
static inline int dax_read_lock(void)
{
	return 0;
}

static inline void dax_read_unlock(int id)
{
}
#endif /* CONFIG_DAX */
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);
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);
static inline bool dax_mapping(struct address_space *mapping)
{
	return mapping->host && IS_DAX(mapping->host);
}

#ifdef CONFIG_DEV_DAX_HMEM_DEVICES
void hmem_register_device(int target_nid, struct resource *r);
#else
static inline void hmem_register_device(int target_nid, struct resource *r)
{
}
#endif

#endif
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef _LINUX_DAX_H
	3	#define _LINUX_DAX_H
	4
	5	#include <linux/fs.h>
	6	#include <linux/mm.h>
	7	#include <linux/radix-tree.h>
	8
	9	typedef unsigned long dax_entry_t;
	10
	11	struct dax_device;
	12	struct gendisk;
	13	struct iomap_ops;
	14	struct iomap_iter;
	15	struct iomap;
	16
	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 );
	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);
	31	/* zero_page_range: required operation. Zero page range */
	32	int (zero_page_range)(struct dax_device , pgoff_t, size_t);
	33	};
	34
	35	#if IS_ENABLED(CONFIG_DAX)
	36	struct dax_device alloc_dax(void private, const struct dax_operations *ops);
	37	void put_dax(struct dax_device *dax_dev);
	38	void kill_dax(struct dax_device *dax_dev);
	39	void dax_write_cache(struct dax_device *dax_dev, bool wc);
	40	bool dax_write_cache_enabled(struct dax_device *dax_dev);
	41	bool dax_synchronous(struct dax_device *dax_dev);
	42	void set_dax_synchronous(struct dax_device *dax_dev);
	43	/*
	44	* Check if given mapping is supported by the file / underlying device.
	45	*/
	46	static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
	47	struct dax_device *dax_dev)
	48	{
	49	if (!(vma->vm_flags & VM_SYNC))
	50	return true;
	51	if (!IS_DAX(file_inode(vma->vm_file)))
	52	return false;
	53	return dax_synchronous(dax_dev);
	54	}
	55	#else
	56	static inline struct dax_device alloc_dax(void private,
	57	const struct dax_operations *ops)
	58	{
	59	/*
	60	* Callers should check IS_ENABLED(CONFIG_DAX) to know if this
	61	* NULL is an error or expected.
	62	*/
	63	return NULL;
	64	}
	65	static inline void put_dax(struct dax_device *dax_dev)
	66	{
	67	}
	68	static inline void kill_dax(struct dax_device *dax_dev)
	69	{
	70	}
	71	static inline void dax_write_cache(struct dax_device *dax_dev, bool wc)
	72	{
	73	}
	74	static inline bool dax_write_cache_enabled(struct dax_device *dax_dev)
	75	{
	76	return false;
	77	}
	78	static inline bool dax_synchronous(struct dax_device *dax_dev)
	79	{
	80	return true;
	81	}
	82	static inline void set_dax_synchronous(struct dax_device *dax_dev)
	83	{
	84	}
	85	static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
	86	struct dax_device *dax_dev)
	87	{
	88	return !(vma->vm_flags & VM_SYNC);
	89	}
	90	#endif
	91
	92	void set_dax_nocache(struct dax_device *dax_dev);
	93	void set_dax_nomc(struct dax_device *dax_dev);
	94
	95	struct writeback_control;
	96	#if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX)
	97	int dax_add_host(struct dax_device dax_dev, struct gendisk disk);
	98	void dax_remove_host(struct gendisk *disk);
	99	struct dax_device fs_dax_get_by_bdev(struct block_device bdev,
	100	u64 *start_off);
	101	static inline void fs_put_dax(struct dax_device *dax_dev)
	102	{
	103	put_dax(dax_dev);
	104	}
	105	#else
	106	static inline int dax_add_host(struct dax_device dax_dev, struct gendisk disk)
	107	{
	108	return 0;
	109	}
	110	static inline void dax_remove_host(struct gendisk *disk)
	111	{
	112	}
	113	static inline struct dax_device fs_dax_get_by_bdev(struct block_device bdev,
	114	u64 *start_off)
	115	{
	116	return NULL;
	117	}
	118	static inline void fs_put_dax(struct dax_device *dax_dev)
	119	{
	120	}
	121	#endif /* CONFIG_BLOCK && CONFIG_FS_DAX */
	122
	123	#if IS_ENABLED(CONFIG_FS_DAX)
	124	int dax_writeback_mapping_range(struct address_space *mapping,
	125	struct dax_device dax_dev, struct writeback_control wbc);
	126
	127	struct page dax_layout_busy_page(struct address_space mapping);
	128	struct page dax_layout_busy_page_range(struct address_space mapping, loff_t start, loff_t end);
	129	dax_entry_t dax_lock_page(struct page *page);
	130	void dax_unlock_page(struct page *page, dax_entry_t cookie);
	131	#else
	132	static inline struct page dax_layout_busy_page(struct address_space mapping)
	133	{
	134	return NULL;
	135	}
	136
	137	static inline struct page dax_layout_busy_page_range(struct address_space mapping, pgoff_t start, pgoff_t nr_pages)
	138	{
	139	return NULL;
	140	}
	141
	142	static inline int dax_writeback_mapping_range(struct address_space *mapping,
	143	struct dax_device dax_dev, struct writeback_control wbc)
	144	{
	145	return -EOPNOTSUPP;
	146	}
	147
	148	static inline dax_entry_t dax_lock_page(struct page *page)
	149	{
	150	if (IS_DAX(page->mapping->host))
	151	return ~0UL;
	152	return 0;
	153	}
	154
	155	static inline void dax_unlock_page(struct page *page, dax_entry_t cookie)
	156	{
	157	}
	158	#endif
	159
	160	int dax_zero_range(struct inode inode, loff_t pos, loff_t len, bool did_zero,
	161	const struct iomap_ops *ops);
	162	int dax_truncate_page(struct inode inode, loff_t pos, bool did_zero,
	163	const struct iomap_ops *ops);
	164
	165	#if IS_ENABLED(CONFIG_DAX)
	166	int dax_read_lock(void);
	167	void dax_read_unlock(int id);
	168	#else
	169	static inline int dax_read_lock(void)
	170	{
	171	return 0;
	172	}
	173
	174	static inline void dax_read_unlock(int id)
	175	{
	176	}
	177	#endif /* CONFIG_DAX */
	178	bool dax_alive(struct dax_device *dax_dev);
	179	void dax_get_private(struct dax_device dax_dev);
	180	long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
	181	void *kaddr, pfn_t pfn);
	182	size_t dax_copy_from_iter(struct dax_device dax_dev, pgoff_t pgoff, void addr,
	183	size_t bytes, struct iov_iter *i);
	184	size_t dax_copy_to_iter(struct dax_device dax_dev, pgoff_t pgoff, void addr,
	185	size_t bytes, struct iov_iter *i);
	186	int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
	187	size_t nr_pages);
	188	void dax_flush(struct dax_device dax_dev, void addr, size_t size);
	189
	190	ssize_t dax_iomap_rw(struct kiocb iocb, struct iov_iter iter,
	191	const struct iomap_ops *ops);
	192	vm_fault_t dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
	193	pfn_t pfnp, int errp, const struct iomap_ops *ops);
	194	vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
	195	enum page_entry_size pe_size, pfn_t pfn);
	196	int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
	197	int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
	198	pgoff_t index);
	199	static inline bool dax_mapping(struct address_space *mapping)
	200	{
	201	return mapping->host && IS_DAX(mapping->host);
	202	}
	203
	204	#ifdef CONFIG_DEV_DAX_HMEM_DEVICES
	205	void hmem_register_device(int target_nid, struct resource *r);
	206	#else
	207	static inline void hmem_register_device(int target_nid, struct resource *r)
	208	{
	209	}
	210	#endif
	211
	212	#endif