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- /* 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);
- }
- bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,
- int blocksize, sector_t start, sector_t len);
- /*
- * 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 dax_supported(struct dax_device *dax_dev,
- struct block_device *bdev, int blocksize, sector_t start,
- sector_t len)
- {
- return false;
- }
- 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);
- 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 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 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
- #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);
- s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap);
- 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
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