Line data Source code
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 : enum dax_access_mode {
18 : DAX_ACCESS,
19 : DAX_RECOVERY_WRITE,
20 : };
21 :
22 : struct dax_operations {
23 : /*
24 : * direct_access: translate a device-relative
25 : * logical-page-offset into an absolute physical pfn. Return the
26 : * number of pages available for DAX at that pfn.
27 : */
28 : long (*direct_access)(struct dax_device *, pgoff_t, long,
29 : enum dax_access_mode, void **, pfn_t *);
30 : /*
31 : * Validate whether this device is usable as an fsdax backing
32 : * device.
33 : */
34 : bool (*dax_supported)(struct dax_device *, struct block_device *, int,
35 : sector_t, sector_t);
36 : /* zero_page_range: required operation. Zero page range */
37 : int (*zero_page_range)(struct dax_device *, pgoff_t, size_t);
38 : /*
39 : * recovery_write: recover a poisoned range by DAX device driver
40 : * capable of clearing poison.
41 : */
42 : size_t (*recovery_write)(struct dax_device *dax_dev, pgoff_t pgoff,
43 : void *addr, size_t bytes, struct iov_iter *iter);
44 : };
45 :
46 : struct dax_holder_operations {
47 : /*
48 : * notify_failure - notify memory failure into inner holder device
49 : * @dax_dev: the dax device which contains the holder
50 : * @offset: offset on this dax device where memory failure occurs
51 : * @len: length of this memory failure event
52 : * @flags: action flags for memory failure handler
53 : */
54 : int (*notify_failure)(struct dax_device *dax_dev, u64 offset,
55 : u64 len, int mf_flags);
56 : };
57 :
58 : #if IS_ENABLED(CONFIG_DAX)
59 : struct dax_device *alloc_dax(void *private, const struct dax_operations *ops);
60 : void *dax_holder(struct dax_device *dax_dev);
61 : void put_dax(struct dax_device *dax_dev);
62 : void kill_dax(struct dax_device *dax_dev);
63 : void dax_write_cache(struct dax_device *dax_dev, bool wc);
64 : bool dax_write_cache_enabled(struct dax_device *dax_dev);
65 : bool dax_synchronous(struct dax_device *dax_dev);
66 : void set_dax_synchronous(struct dax_device *dax_dev);
67 : size_t dax_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff,
68 : void *addr, size_t bytes, struct iov_iter *i);
69 : /*
70 : * Check if given mapping is supported by the file / underlying device.
71 : */
72 12209529 : static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
73 : struct dax_device *dax_dev)
74 : {
75 12209529 : if (!(vma->vm_flags & VM_SYNC))
76 : return true;
77 0 : if (!IS_DAX(file_inode(vma->vm_file)))
78 : return false;
79 0 : return dax_synchronous(dax_dev);
80 : }
81 : #else
82 : static inline void *dax_holder(struct dax_device *dax_dev)
83 : {
84 : return NULL;
85 : }
86 : static inline struct dax_device *alloc_dax(void *private,
87 : const struct dax_operations *ops)
88 : {
89 : /*
90 : * Callers should check IS_ENABLED(CONFIG_DAX) to know if this
91 : * NULL is an error or expected.
92 : */
93 : return NULL;
94 : }
95 : static inline void put_dax(struct dax_device *dax_dev)
96 : {
97 : }
98 : static inline void kill_dax(struct dax_device *dax_dev)
99 : {
100 : }
101 : static inline void dax_write_cache(struct dax_device *dax_dev, bool wc)
102 : {
103 : }
104 : static inline bool dax_write_cache_enabled(struct dax_device *dax_dev)
105 : {
106 : return false;
107 : }
108 : static inline bool dax_synchronous(struct dax_device *dax_dev)
109 : {
110 : return true;
111 : }
112 : static inline void set_dax_synchronous(struct dax_device *dax_dev)
113 : {
114 : }
115 : static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
116 : struct dax_device *dax_dev)
117 : {
118 : return !(vma->vm_flags & VM_SYNC);
119 : }
120 : static inline size_t dax_recovery_write(struct dax_device *dax_dev,
121 : pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i)
122 : {
123 : return 0;
124 : }
125 : #endif
126 :
127 : void set_dax_nocache(struct dax_device *dax_dev);
128 : void set_dax_nomc(struct dax_device *dax_dev);
129 :
130 : struct writeback_control;
131 : #if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX)
132 : int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk);
133 : void dax_remove_host(struct gendisk *disk);
134 : struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev, u64 *start_off,
135 : void *holder, const struct dax_holder_operations *ops);
136 : void fs_put_dax(struct dax_device *dax_dev, void *holder);
137 : #else
138 : static inline int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk)
139 : {
140 : return 0;
141 : }
142 : static inline void dax_remove_host(struct gendisk *disk)
143 : {
144 : }
145 : static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev,
146 : u64 *start_off, void *holder,
147 : const struct dax_holder_operations *ops)
148 : {
149 : return NULL;
150 : }
151 : static inline void fs_put_dax(struct dax_device *dax_dev, void *holder)
152 : {
153 : }
154 : #endif /* CONFIG_BLOCK && CONFIG_FS_DAX */
155 :
156 : #if IS_ENABLED(CONFIG_FS_DAX)
157 : int dax_writeback_mapping_range(struct address_space *mapping,
158 : struct dax_device *dax_dev, struct writeback_control *wbc);
159 :
160 : struct page *dax_layout_busy_page(struct address_space *mapping);
161 : struct page *dax_layout_busy_page_range(struct address_space *mapping, loff_t start, loff_t end);
162 : dax_entry_t dax_lock_page(struct page *page);
163 : void dax_unlock_page(struct page *page, dax_entry_t cookie);
164 : dax_entry_t dax_lock_mapping_entry(struct address_space *mapping,
165 : unsigned long index, struct page **page);
166 : void dax_unlock_mapping_entry(struct address_space *mapping,
167 : unsigned long index, dax_entry_t cookie);
168 : #else
169 : static inline struct page *dax_layout_busy_page(struct address_space *mapping)
170 : {
171 : return NULL;
172 : }
173 :
174 : static inline struct page *dax_layout_busy_page_range(struct address_space *mapping, pgoff_t start, pgoff_t nr_pages)
175 : {
176 : return NULL;
177 : }
178 :
179 : static inline int dax_writeback_mapping_range(struct address_space *mapping,
180 : struct dax_device *dax_dev, struct writeback_control *wbc)
181 : {
182 : return -EOPNOTSUPP;
183 : }
184 :
185 : static inline dax_entry_t dax_lock_page(struct page *page)
186 : {
187 : if (IS_DAX(page->mapping->host))
188 : return ~0UL;
189 : return 0;
190 : }
191 :
192 : static inline void dax_unlock_page(struct page *page, dax_entry_t cookie)
193 : {
194 : }
195 :
196 : static inline dax_entry_t dax_lock_mapping_entry(struct address_space *mapping,
197 : unsigned long index, struct page **page)
198 : {
199 : return 0;
200 : }
201 :
202 : static inline void dax_unlock_mapping_entry(struct address_space *mapping,
203 : unsigned long index, dax_entry_t cookie)
204 : {
205 : }
206 : #endif
207 :
208 : int dax_file_unshare(struct inode *inode, loff_t pos, loff_t len,
209 : const struct iomap_ops *ops);
210 : int dax_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero,
211 : const struct iomap_ops *ops);
212 : int dax_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
213 : const struct iomap_ops *ops);
214 :
215 : #if IS_ENABLED(CONFIG_DAX)
216 : int dax_read_lock(void);
217 : void dax_read_unlock(int id);
218 : #else
219 : static inline int dax_read_lock(void)
220 : {
221 : return 0;
222 : }
223 :
224 : static inline void dax_read_unlock(int id)
225 : {
226 : }
227 : #endif /* CONFIG_DAX */
228 : bool dax_alive(struct dax_device *dax_dev);
229 : void *dax_get_private(struct dax_device *dax_dev);
230 : long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
231 : enum dax_access_mode mode, void **kaddr, pfn_t *pfn);
232 : size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
233 : size_t bytes, struct iov_iter *i);
234 : size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
235 : size_t bytes, struct iov_iter *i);
236 : int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
237 : size_t nr_pages);
238 : int dax_holder_notify_failure(struct dax_device *dax_dev, u64 off, u64 len,
239 : int mf_flags);
240 : void dax_flush(struct dax_device *dax_dev, void *addr, size_t size);
241 :
242 : ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
243 : const struct iomap_ops *ops);
244 : vm_fault_t dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
245 : pfn_t *pfnp, int *errp, const struct iomap_ops *ops);
246 : vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
247 : enum page_entry_size pe_size, pfn_t pfn);
248 : int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
249 : int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
250 : pgoff_t index);
251 : int dax_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
252 : struct inode *dest, loff_t destoff,
253 : loff_t len, bool *is_same,
254 : const struct iomap_ops *ops);
255 : int dax_remap_file_range_prep(struct file *file_in, loff_t pos_in,
256 : struct file *file_out, loff_t pos_out,
257 : loff_t *len, unsigned int remap_flags,
258 : const struct iomap_ops *ops);
259 : static inline bool dax_mapping(struct address_space *mapping)
260 : {
261 6182136582 : return mapping->host && IS_DAX(mapping->host);
262 : }
263 :
264 : /*
265 : * Due to dax's memory and block duo personalities, hwpoison reporting
266 : * takes into consideration which personality is presently visible.
267 : * When dax acts like a block device, such as in block IO, an encounter of
268 : * dax hwpoison is reported as -EIO.
269 : * When dax acts like memory, such as in page fault, a detection of hwpoison
270 : * is reported as -EHWPOISON which leads to VM_FAULT_HWPOISON.
271 : */
272 : static inline int dax_mem2blk_err(int err)
273 : {
274 0 : return (err == -EHWPOISON) ? -EIO : err;
275 : }
276 :
277 : #ifdef CONFIG_DEV_DAX_HMEM_DEVICES
278 : void hmem_register_resource(int target_nid, struct resource *r);
279 : #else
280 : static inline void hmem_register_resource(int target_nid, struct resource *r)
281 : {
282 : }
283 : #endif
284 :
285 : typedef int (*walk_hmem_fn)(struct device *dev, int target_nid,
286 : const struct resource *res);
287 : int walk_hmem_resources(struct device *dev, walk_hmem_fn fn);
288 : #endif
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