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 };
39
40 extern struct dentry *arch_debugfs_dir;
41
42 #define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \
43 static int __fops ## _open(struct inode *inode, struct file *file) \
44 { \
45 __simple_attr_check_format(__fmt, 0ull); \
46 return simple_attr_open(inode, file, __get, __set, __fmt); \
47 } \
48 static const struct file_operations __fops = { \
49 .owner = THIS_MODULE, \
50 .open = __fops ## _open, \
51 .release = simple_attr_release, \
52 .read = debugfs_attr_read, \
53 .write = debugfs_attr_write, \
54 .llseek = no_llseek, \
55 }
56
57 #if defined(CONFIG_DEBUG_FS)
58
59 struct dentry *debugfs_lookup(const char *name, struct dentry *parent);
60
61 struct dentry *debugfs_create_file(const char *name, umode_t mode,
62 struct dentry *parent, void *data,
63 const struct file_operations *fops);
64 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
65 struct dentry *parent, void *data,
66 const struct file_operations *fops);
67
68 struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
69 struct dentry *parent, void *data,
70 const struct file_operations *fops,
71 loff_t file_size);
72
73 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
74
75 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
76 const char *dest);
77
78 typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *);
79 struct dentry *debugfs_create_automount(const char *name,
80 struct dentry *parent,
81 debugfs_automount_t f,
82 void *data);
83
84 void debugfs_remove(struct dentry *dentry);
85 void debugfs_remove_recursive(struct dentry *dentry);
86
87 const struct file_operations *debugfs_real_fops(const struct file *filp);
88
89 int debugfs_file_get(struct dentry *dentry);
90 void debugfs_file_put(struct dentry *dentry);
91
92 ssize_t debugfs_attr_read(struct file *file, char __user *buf,
93 size_t len, loff_t *ppos);
94 ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
95 size_t len, loff_t *ppos);
96
97 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
98 struct dentry *new_dir, const char *new_name);
99
100 struct dentry *debugfs_create_u8(const char *name, umode_t mode,
101 struct dentry *parent, u8 *value);
102 struct dentry *debugfs_create_u16(const char *name, umode_t mode,
103 struct dentry *parent, u16 *value);
104 struct dentry *debugfs_create_u32(const char *name, umode_t mode,
105 struct dentry *parent, u32 *value);
106 struct dentry *debugfs_create_u64(const char *name, umode_t mode,
107 struct dentry *parent, u64 *value);
108 struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
109 struct dentry *parent, unsigned long *value);
110 struct dentry *debugfs_create_x8(const char *name, umode_t mode,
111 struct dentry *parent, u8 *value);
112 struct dentry *debugfs_create_x16(const char *name, umode_t mode,
113 struct dentry *parent, u16 *value);
114 struct dentry *debugfs_create_x32(const char *name, umode_t mode,
115 struct dentry *parent, u32 *value);
116 struct dentry *debugfs_create_x64(const char *name, umode_t mode,
117 struct dentry *parent, u64 *value);
118 struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
119 struct dentry *parent, size_t *value);
120 struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
121 struct dentry *parent, atomic_t *value);
122 struct dentry *debugfs_create_bool(const char *name, umode_t mode,
123 struct dentry *parent, bool *value);
124
125 struct dentry *debugfs_create_blob(const char *name, umode_t mode,
126 struct dentry *parent,
127 struct debugfs_blob_wrapper *blob);
128
129 struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
130 struct dentry *parent,
131 struct debugfs_regset32 *regset);
132
133 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
134 int nregs, void __iomem *base, char *prefix);
135
136 struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
137 struct dentry *parent,
138 u32 *array, u32 elements);
139
140 struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
141 struct dentry *parent,
142 int (*read_fn)(struct seq_file *s,
143 void *data));
144
145 bool debugfs_initialized(void);
146
147 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
148 size_t count, loff_t *ppos);
149
150 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
151 size_t count, loff_t *ppos);
152
153 #else
154
155 #include <linux/err.h>
156
157 /*
158 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
159 * so users have a chance to detect if there was a real error or not. We don't
160 * want to duplicate the design decision mistakes of procfs and devfs again.
161 */
162
163 static inline struct dentry *debugfs_lookup(const char *name,
164 struct dentry *parent)
165 {
166 return ERR_PTR(-ENODEV);
167 }
168
169 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode,
170 struct dentry *parent, void *data,
171 const struct file_operations *fops)
172 {
173 return ERR_PTR(-ENODEV);
174 }
175
176 static inline struct dentry *debugfs_create_file_unsafe(const char *name,
177 umode_t mode, struct dentry *parent,
178 void *data,
179 const struct file_operations *fops)
180 {
181 return ERR_PTR(-ENODEV);
182 }
183
184 static inline struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
185 struct dentry *parent, void *data,
186 const struct file_operations *fops,
187 loff_t file_size)
188 {
189 return ERR_PTR(-ENODEV);
190 }
191
192 static inline struct dentry *debugfs_create_dir(const char *name,
193 struct dentry *parent)
194 {
195 return ERR_PTR(-ENODEV);
196 }
197
198 static inline struct dentry *debugfs_create_symlink(const char *name,
199 struct dentry *parent,
200 const char *dest)
201 {
202 return ERR_PTR(-ENODEV);
203 }
204
205 static inline struct dentry *debugfs_create_automount(const char *name,
206 struct dentry *parent,
207 struct vfsmount *(*f)(void *),
208 void *data)
209 {
210 return ERR_PTR(-ENODEV);
211 }
212
213 static inline void debugfs_remove(struct dentry *dentry)
214 { }
215
216 static inline void debugfs_remove_recursive(struct dentry *dentry)
217 { }
218
219 const struct file_operations *debugfs_real_fops(const struct file *filp);
220
221 static inline int debugfs_file_get(struct dentry *dentry)
222 {
223 return 0;
224 }
225
226 static inline void debugfs_file_put(struct dentry *dentry)
227 { }
228
229 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf,
230 size_t len, loff_t *ppos)
231 {
232 return -ENODEV;
233 }
234
235 static inline ssize_t debugfs_attr_write(struct file *file,
236 const char __user *buf,
237 size_t len, loff_t *ppos)
238 {
239 return -ENODEV;
240 }
241
242 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
243 struct dentry *new_dir, char *new_name)
244 {
245 return ERR_PTR(-ENODEV);
246 }
247
248 static inline struct dentry *debugfs_create_u8(const char *name, umode_t mode,
249 struct dentry *parent,
250 u8 *value)
251 {
252 return ERR_PTR(-ENODEV);
253 }
254
255 static inline struct dentry *debugfs_create_u16(const char *name, umode_t mode,
256 struct dentry *parent,
257 u16 *value)
258 {
259 return ERR_PTR(-ENODEV);
260 }
261
262 static inline struct dentry *debugfs_create_u32(const char *name, umode_t mode,
263 struct dentry *parent,
264 u32 *value)
265 {
266 return ERR_PTR(-ENODEV);
267 }
268
269 static inline struct dentry *debugfs_create_u64(const char *name, umode_t mode,
270 struct dentry *parent,
271 u64 *value)
272 {
273 return ERR_PTR(-ENODEV);
274 }
275
276 static inline struct dentry *debugfs_create_ulong(const char *name,
277 umode_t mode,
278 struct dentry *parent,
279 unsigned long *value)
280 {
281 return ERR_PTR(-ENODEV);
282 }
283
284 static inline struct dentry *debugfs_create_x8(const char *name, umode_t mode,
285 struct dentry *parent,
286 u8 *value)
287 {
288 return ERR_PTR(-ENODEV);
289 }
290
291 static inline struct dentry *debugfs_create_x16(const char *name, umode_t mode,
292 struct dentry *parent,
293 u16 *value)
294 {
295 return ERR_PTR(-ENODEV);
296 }
297
298 static inline struct dentry *debugfs_create_x32(const char *name, umode_t mode,
299 struct dentry *parent,
300 u32 *value)
301 {
302 return ERR_PTR(-ENODEV);
303 }
304
305 static inline struct dentry *debugfs_create_x64(const char *name, umode_t mode,
306 struct dentry *parent,
307 u64 *value)
308 {
309 return ERR_PTR(-ENODEV);
310 }
311
312 static inline struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
313 struct dentry *parent,
314 size_t *value)
315 {
316 return ERR_PTR(-ENODEV);
317 }
318
319 static inline struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
320 struct dentry *parent, atomic_t *value)
321 {
322 return ERR_PTR(-ENODEV);
323 }
324
325 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode,
326 struct dentry *parent,
327 bool *value)
328 {
329 return ERR_PTR(-ENODEV);
330 }
331
332 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode,
333 struct dentry *parent,
334 struct debugfs_blob_wrapper *blob)
335 {
336 return ERR_PTR(-ENODEV);
337 }
338
339 static inline struct dentry *debugfs_create_regset32(const char *name,
340 umode_t mode, struct dentry *parent,
341 struct debugfs_regset32 *regset)
342 {
343 return ERR_PTR(-ENODEV);
344 }
345
346 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
347 int nregs, void __iomem *base, char *prefix)
348 {
349 }
350
351 static inline bool debugfs_initialized(void)
352 {
353 return false;
354 }
355
356 static inline struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
357 struct dentry *parent,
358 u32 *array, u32 elements)
359 {
360 return ERR_PTR(-ENODEV);
361 }
362
363 static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev,
364 const char *name,
365 struct dentry *parent,
366 int (*read_fn)(struct seq_file *s,
367 void *data))
368 {
369 return ERR_PTR(-ENODEV);
370 }
371
372 static inline ssize_t debugfs_read_file_bool(struct file *file,
373 char __user *user_buf,
374 size_t count, loff_t *ppos)
375 {
376 return -ENODEV;
377 }
378
379 static inline ssize_t debugfs_write_file_bool(struct file *file,
380 const char __user *user_buf,
381 size_t count, loff_t *ppos)
382 {
383 return -ENODEV;
384 }
385
386 #endif
387
388 #endif
389
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