1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * debugfs.h - a tiny little debug file system
4 *
5 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
6 * Copyright (C) 2004 IBM Inc.
7 *
8 * debugfs is for people to use instead of /proc or /sys.
9 * See Documentation/filesystems/ for more details.
10 */
11
12 #ifndef _DEBUGFS_H_
13 #define _DEBUGFS_H_
14
15 #include <linux/fs.h>
16 #include <linux/seq_file.h>
17
18 #include <linux/types.h>
19 #include <linux/compiler.h>
20
21 struct device;
22 struct file_operations;
23
24 struct debugfs_blob_wrapper {
25 void *data;
26 unsigned long size;
27 };
28
29 struct debugfs_reg32 {
30 char *name;
31 unsigned long offset;
32 };
33
34 struct debugfs_regset32 {
35 const struct debugfs_reg32 *regs;
36 int nregs;
37 void __iomem *base;
38 struct device *dev; /* Optional device for Runtime PM */
39 };
40
41 struct debugfs_u32_array {
42 u32 *array;
43 u32 n_elements;
44 };
45
46 extern struct dentry *arch_debugfs_dir;
47
48 #define DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, __is_signed) \
49 static int __fops ## _open(struct inode *inode, struct file *file) \
50 { \
51 __simple_attr_check_format(__fmt, 0ull); \
52 return simple_attr_open(inode, file, __get, __set, __fmt); \
53 } \
54 static const struct file_operations __fops = { \
55 .owner = THIS_MODULE, \
56 .open = __fops ## _open, \
57 .release = simple_attr_release, \
58 .read = debugfs_attr_read, \
59 .write = (__is_signed) ? debugfs_attr_write_signed : debugfs_attr_write, \
60 .llseek = no_llseek, \
61 }
62
63 #define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \
64 DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, false)
65
66 #define DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(__fops, __get, __set, __fmt) \
67 DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, true)
68
69 typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *);
70
71 #if defined(CONFIG_DEBUG_FS)
72
73 struct dentry *debugfs_lookup(const char *name, struct dentry *parent);
74
75 struct dentry *debugfs_create_file(const char *name, umode_t mode,
76 struct dentry *parent, void *data,
77 const struct file_operations *fops);
78 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
79 struct dentry *parent, void *data,
80 const struct file_operations *fops);
81
82 void debugfs_create_file_size(const char *name, umode_t mode,
83 struct dentry *parent, void *data,
84 const struct file_operations *fops,
85 loff_t file_size);
86
87 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
88
89 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
90 const char *dest);
91
92 struct dentry *debugfs_create_automount(const char *name,
93 struct dentry *parent,
94 debugfs_automount_t f,
95 void *data);
96
97 void debugfs_remove(struct dentry *dentry);
98 #define debugfs_remove_recursive debugfs_remove
99
100 void debugfs_lookup_and_remove(const char *name, struct dentry *parent);
101
102 const struct file_operations *debugfs_real_fops(const struct file *filp);
103
104 int debugfs_file_get(struct dentry *dentry);
105 void debugfs_file_put(struct dentry *dentry);
106
107 ssize_t debugfs_attr_read(struct file *file, char __user *buf,
108 size_t len, loff_t *ppos);
109 ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
110 size_t len, loff_t *ppos);
111 ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf,
112 size_t len, loff_t *ppos);
113
114 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
115 struct dentry *new_dir, const char *new_name);
116
117 void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent,
118 u8 *value);
119 void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent,
120 u16 *value);
121 void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent,
122 u32 *value);
123 void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent,
124 u64 *value);
125 void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent,
126 unsigned long *value);
127 void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent,
128 u8 *value);
129 void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent,
130 u16 *value);
131 void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent,
132 u32 *value);
133 void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent,
134 u64 *value);
135 void debugfs_create_size_t(const char *name, umode_t mode,
136 struct dentry *parent, size_t *value);
137 void debugfs_create_atomic_t(const char *name, umode_t mode,
138 struct dentry *parent, atomic_t *value);
139 void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent,
140 bool *value);
141 void debugfs_create_str(const char *name, umode_t mode,
142 struct dentry *parent, char **value);
143
144 struct dentry *debugfs_create_blob(const char *name, umode_t mode,
145 struct dentry *parent,
146 struct debugfs_blob_wrapper *blob);
147
148 void debugfs_create_regset32(const char *name, umode_t mode,
149 struct dentry *parent,
150 struct debugfs_regset32 *regset);
151
152 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
153 int nregs, void __iomem *base, char *prefix);
154
155 void debugfs_create_u32_array(const char *name, umode_t mode,
156 struct dentry *parent,
157 struct debugfs_u32_array *array);
158
159 void debugfs_create_devm_seqfile(struct device *dev, const char *name,
160 struct dentry *parent,
161 int (*read_fn)(struct seq_file *s, void *data));
162
163 bool debugfs_initialized(void);
164
165 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
166 size_t count, loff_t *ppos);
167
168 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
169 size_t count, loff_t *ppos);
170
171 ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
172 size_t count, loff_t *ppos);
173
174 /**
175 * struct debugfs_cancellation - cancellation data
176 * @list: internal, for keeping track
177 * @cancel: callback to call
178 * @cancel_data: extra data for the callback to call
179 */
180 struct debugfs_cancellation {
181 struct list_head list;
182 void (*cancel)(struct dentry *, void *);
183 void *cancel_data;
184 };
185
186 void __acquires(cancellation)
187 debugfs_enter_cancellation(struct file *file,
188 struct debugfs_cancellation *cancellation);
189 void __releases(cancellation)
190 debugfs_leave_cancellation(struct file *file,
191 struct debugfs_cancellation *cancellation);
192
193 #else
194
195 #include <linux/err.h>
196
197 /*
198 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
199 * so users have a chance to detect if there was a real error or not. We don't
200 * want to duplicate the design decision mistakes of procfs and devfs again.
201 */
202
203 static inline struct dentry *debugfs_lookup(const char *name,
204 struct dentry *parent)
205 {
206 return ERR_PTR(-ENODEV);
207 }
208
209 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode,
210 struct dentry *parent, void *data,
211 const struct file_operations *fops)
212 {
213 return ERR_PTR(-ENODEV);
214 }
215
216 static inline struct dentry *debugfs_create_file_unsafe(const char *name,
217 umode_t mode, struct dentry *parent,
218 void *data,
219 const struct file_operations *fops)
220 {
221 return ERR_PTR(-ENODEV);
222 }
223
224 static inline void debugfs_create_file_size(const char *name, umode_t mode,
225 struct dentry *parent, void *data,
226 const struct file_operations *fops,
227 loff_t file_size)
228 { }
229
230 static inline struct dentry *debugfs_create_dir(const char *name,
231 struct dentry *parent)
232 {
233 return ERR_PTR(-ENODEV);
234 }
235
236 static inline struct dentry *debugfs_create_symlink(const char *name,
237 struct dentry *parent,
238 const char *dest)
239 {
240 return ERR_PTR(-ENODEV);
241 }
242
243 static inline struct dentry *debugfs_create_automount(const char *name,
244 struct dentry *parent,
245 debugfs_automount_t f,
246 void *data)
247 {
248 return ERR_PTR(-ENODEV);
249 }
250
251 static inline void debugfs_remove(struct dentry *dentry)
252 { }
253
254 static inline void debugfs_remove_recursive(struct dentry *dentry)
255 { }
256
257 static inline void debugfs_lookup_and_remove(const char *name,
258 struct dentry *parent)
259 { }
260
261 const struct file_operations *debugfs_real_fops(const struct file *filp);
262
263 static inline int debugfs_file_get(struct dentry *dentry)
264 {
265 return 0;
266 }
267
268 static inline void debugfs_file_put(struct dentry *dentry)
269 { }
270
271 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf,
272 size_t len, loff_t *ppos)
273 {
274 return -ENODEV;
275 }
276
277 static inline ssize_t debugfs_attr_write(struct file *file,
278 const char __user *buf,
279 size_t len, loff_t *ppos)
280 {
281 return -ENODEV;
282 }
283
284 static inline ssize_t debugfs_attr_write_signed(struct file *file,
285 const char __user *buf,
286 size_t len, loff_t *ppos)
287 {
288 return -ENODEV;
289 }
290
291 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
292 struct dentry *new_dir, char *new_name)
293 {
294 return ERR_PTR(-ENODEV);
295 }
296
297 static inline void debugfs_create_u8(const char *name, umode_t mode,
298 struct dentry *parent, u8 *value) { }
299
300 static inline void debugfs_create_u16(const char *name, umode_t mode,
301 struct dentry *parent, u16 *value) { }
302
303 static inline void debugfs_create_u32(const char *name, umode_t mode,
304 struct dentry *parent, u32 *value) { }
305
306 static inline void debugfs_create_u64(const char *name, umode_t mode,
307 struct dentry *parent, u64 *value) { }
308
309 static inline void debugfs_create_ulong(const char *name, umode_t mode,
310 struct dentry *parent,
311 unsigned long *value) { }
312
313 static inline void debugfs_create_x8(const char *name, umode_t mode,
314 struct dentry *parent, u8 *value) { }
315
316 static inline void debugfs_create_x16(const char *name, umode_t mode,
317 struct dentry *parent, u16 *value) { }
318
319 static inline void debugfs_create_x32(const char *name, umode_t mode,
320 struct dentry *parent, u32 *value) { }
321
322 static inline void debugfs_create_x64(const char *name, umode_t mode,
323 struct dentry *parent, u64 *value) { }
324
325 static inline void debugfs_create_size_t(const char *name, umode_t mode,
326 struct dentry *parent, size_t *value)
327 { }
328
329 static inline void debugfs_create_atomic_t(const char *name, umode_t mode,
330 struct dentry *parent,
331 atomic_t *value)
332 { }
333
334 static inline void debugfs_create_bool(const char *name, umode_t mode,
335 struct dentry *parent, bool *value) { }
336
337 static inline void debugfs_create_str(const char *name, umode_t mode,
338 struct dentry *parent,
339 char **value)
340 { }
341
342 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode,
343 struct dentry *parent,
344 struct debugfs_blob_wrapper *blob)
345 {
346 return ERR_PTR(-ENODEV);
347 }
348
349 static inline void debugfs_create_regset32(const char *name, umode_t mode,
350 struct dentry *parent,
351 struct debugfs_regset32 *regset)
352 {
353 }
354
355 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
356 int nregs, void __iomem *base, char *prefix)
357 {
358 }
359
360 static inline bool debugfs_initialized(void)
361 {
362 return false;
363 }
364
365 static inline void debugfs_create_u32_array(const char *name, umode_t mode,
366 struct dentry *parent,
367 struct debugfs_u32_array *array)
368 {
369 }
370
371 static inline void debugfs_create_devm_seqfile(struct device *dev,
372 const char *name,
373 struct dentry *parent,
374 int (*read_fn)(struct seq_file *s,
375 void *data))
376 {
377 }
378
379 static inline ssize_t debugfs_read_file_bool(struct file *file,
380 char __user *user_buf,
381 size_t count, loff_t *ppos)
382 {
383 return -ENODEV;
384 }
385
386 static inline ssize_t debugfs_write_file_bool(struct file *file,
387 const char __user *user_buf,
388 size_t count, loff_t *ppos)
389 {
390 return -ENODEV;
391 }
392
393 static inline ssize_t debugfs_read_file_str(struct file *file,
394 char __user *user_buf,
395 size_t count, loff_t *ppos)
396 {
397 return -ENODEV;
398 }
399
400 #endif
401
402 /**
403 * debugfs_create_xul - create a debugfs file that is used to read and write an
404 * unsigned long value, formatted in hexadecimal
405 * @name: a pointer to a string containing the name of the file to create.
406 * @mode: the permission that the file should have
407 * @parent: a pointer to the parent dentry for this file. This should be a
408 * directory dentry if set. If this parameter is %NULL, then the
409 * file will be created in the root of the debugfs filesystem.
410 * @value: a pointer to the variable that the file should read to and write
411 * from.
412 */
413 static inline void debugfs_create_xul(const char *name, umode_t mode,
414 struct dentry *parent,
415 unsigned long *value)
416 {
417 if (sizeof(*value) == sizeof(u32))
418 debugfs_create_x32(name, mode, parent, (u32 *)value);
419 else
420 debugfs_create_x64(name, mode, parent, (u64 *)value);
421 }
422
423 #endif
424
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