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 #else
175
176 #include <linux/err.h>
177
178 /*
179 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
180 * so users have a chance to detect if there was a real error or not. We don't
181 * want to duplicate the design decision mistakes of procfs and devfs again.
182 */
183
184 static inline struct dentry *debugfs_lookup(const char *name,
185 struct dentry *parent)
186 {
187 return ERR_PTR(-ENODEV);
188 }
189
190 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode,
191 struct dentry *parent, void *data,
192 const struct file_operations *fops)
193 {
194 return ERR_PTR(-ENODEV);
195 }
196
197 static inline struct dentry *debugfs_create_file_unsafe(const char *name,
198 umode_t mode, struct dentry *parent,
199 void *data,
200 const struct file_operations *fops)
201 {
202 return ERR_PTR(-ENODEV);
203 }
204
205 static inline void debugfs_create_file_size(const char *name, umode_t mode,
206 struct dentry *parent, void *data,
207 const struct file_operations *fops,
208 loff_t file_size)
209 { }
210
211 static inline struct dentry *debugfs_create_dir(const char *name,
212 struct dentry *parent)
213 {
214 return ERR_PTR(-ENODEV);
215 }
216
217 static inline struct dentry *debugfs_create_symlink(const char *name,
218 struct dentry *parent,
219 const char *dest)
220 {
221 return ERR_PTR(-ENODEV);
222 }
223
224 static inline struct dentry *debugfs_create_automount(const char *name,
225 struct dentry *parent,
226 debugfs_automount_t f,
227 void *data)
228 {
229 return ERR_PTR(-ENODEV);
230 }
231
232 static inline void debugfs_remove(struct dentry *dentry)
233 { }
234
235 static inline void debugfs_remove_recursive(struct dentry *dentry)
236 { }
237
238 static inline void debugfs_lookup_and_remove(const char *name,
239 struct dentry *parent)
240 { }
241
242 const struct file_operations *debugfs_real_fops(const struct file *filp);
243
244 static inline int debugfs_file_get(struct dentry *dentry)
245 {
246 return 0;
247 }
248
249 static inline void debugfs_file_put(struct dentry *dentry)
250 { }
251
252 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf,
253 size_t len, loff_t *ppos)
254 {
255 return -ENODEV;
256 }
257
258 static inline ssize_t debugfs_attr_write(struct file *file,
259 const char __user *buf,
260 size_t len, loff_t *ppos)
261 {
262 return -ENODEV;
263 }
264
265 static inline ssize_t debugfs_attr_write_signed(struct file *file,
266 const char __user *buf,
267 size_t len, loff_t *ppos)
268 {
269 return -ENODEV;
270 }
271
272 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
273 struct dentry *new_dir, char *new_name)
274 {
275 return ERR_PTR(-ENODEV);
276 }
277
278 static inline void debugfs_create_u8(const char *name, umode_t mode,
279 struct dentry *parent, u8 *value) { }
280
281 static inline void debugfs_create_u16(const char *name, umode_t mode,
282 struct dentry *parent, u16 *value) { }
283
284 static inline void debugfs_create_u32(const char *name, umode_t mode,
285 struct dentry *parent, u32 *value) { }
286
287 static inline void debugfs_create_u64(const char *name, umode_t mode,
288 struct dentry *parent, u64 *value) { }
289
290 static inline void debugfs_create_ulong(const char *name, umode_t mode,
291 struct dentry *parent,
292 unsigned long *value) { }
293
294 static inline void debugfs_create_x8(const char *name, umode_t mode,
295 struct dentry *parent, u8 *value) { }
296
297 static inline void debugfs_create_x16(const char *name, umode_t mode,
298 struct dentry *parent, u16 *value) { }
299
300 static inline void debugfs_create_x32(const char *name, umode_t mode,
301 struct dentry *parent, u32 *value) { }
302
303 static inline void debugfs_create_x64(const char *name, umode_t mode,
304 struct dentry *parent, u64 *value) { }
305
306 static inline void debugfs_create_size_t(const char *name, umode_t mode,
307 struct dentry *parent, size_t *value)
308 { }
309
310 static inline void debugfs_create_atomic_t(const char *name, umode_t mode,
311 struct dentry *parent,
312 atomic_t *value)
313 { }
314
315 static inline void debugfs_create_bool(const char *name, umode_t mode,
316 struct dentry *parent, bool *value) { }
317
318 static inline void debugfs_create_str(const char *name, umode_t mode,
319 struct dentry *parent,
320 char **value)
321 { }
322
323 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode,
324 struct dentry *parent,
325 struct debugfs_blob_wrapper *blob)
326 {
327 return ERR_PTR(-ENODEV);
328 }
329
330 static inline void debugfs_create_regset32(const char *name, umode_t mode,
331 struct dentry *parent,
332 struct debugfs_regset32 *regset)
333 {
334 }
335
336 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
337 int nregs, void __iomem *base, char *prefix)
338 {
339 }
340
341 static inline bool debugfs_initialized(void)
342 {
343 return false;
344 }
345
346 static inline void debugfs_create_u32_array(const char *name, umode_t mode,
347 struct dentry *parent,
348 struct debugfs_u32_array *array)
349 {
350 }
351
352 static inline void debugfs_create_devm_seqfile(struct device *dev,
353 const char *name,
354 struct dentry *parent,
355 int (*read_fn)(struct seq_file *s,
356 void *data))
357 {
358 }
359
360 static inline ssize_t debugfs_read_file_bool(struct file *file,
361 char __user *user_buf,
362 size_t count, loff_t *ppos)
363 {
364 return -ENODEV;
365 }
366
367 static inline ssize_t debugfs_write_file_bool(struct file *file,
368 const char __user *user_buf,
369 size_t count, loff_t *ppos)
370 {
371 return -ENODEV;
372 }
373
374 static inline ssize_t debugfs_read_file_str(struct file *file,
375 char __user *user_buf,
376 size_t count, loff_t *ppos)
377 {
378 return -ENODEV;
379 }
380
381 #endif
382
383 /**
384 * debugfs_create_xul - create a debugfs file that is used to read and write an
385 * unsigned long value, formatted in hexadecimal
386 * @name: a pointer to a string containing the name of the file to create.
387 * @mode: the permission that the file should have
388 * @parent: a pointer to the parent dentry for this file. This should be a
389 * directory dentry if set. If this parameter is %NULL, then the
390 * file will be created in the root of the debugfs filesystem.
391 * @value: a pointer to the variable that the file should read to and write
392 * from.
393 */
debugfs_create_xul(const char * name,umode_t mode,struct dentry * parent,unsigned long * value)394 static inline void debugfs_create_xul(const char *name, umode_t mode,
395 struct dentry *parent,
396 unsigned long *value)
397 {
398 if (sizeof(*value) == sizeof(u32))
399 debugfs_create_x32(name, mode, parent, (u32 *)value);
400 else
401 debugfs_create_x64(name, mode, parent, (u64 *)value);
402 }
403
404 #endif
405