| /* 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 |