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(__fops, __get, __set, __fmt) \
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 = debugfs_attr_write, \
60 .llseek = no_llseek, \
61 }
62
63 typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *);
64
65 #if defined(CONFIG_DEBUG_FS)
66
67 struct dentry *debugfs_lookup(const char *name, struct dentry *parent);
68
69 struct dentry *debugfs_create_file(const char *name, umode_t mode,
70 struct dentry *parent, void *data,
71 const struct file_operations *fops);
72 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
73 struct dentry *parent, void *data,
74 const struct file_operations *fops);
75
76 void debugfs_create_file_size(const char *name, umode_t mode,
77 struct dentry *parent, void *data,
78 const struct file_operations *fops,
79 loff_t file_size);
80
81 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
82
83 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
84 const char *dest);
85
86 struct dentry *debugfs_create_automount(const char *name,
87 struct dentry *parent,
88 debugfs_automount_t f,
89 void *data);
90
91 void debugfs_remove(struct dentry *dentry);
92 #define debugfs_remove_recursive debugfs_remove
93
94 void debugfs_lookup_and_remove(const char *name, struct dentry *parent);
95
96 const struct file_operations *debugfs_real_fops(const struct file *filp);
97
98 int debugfs_file_get(struct dentry *dentry);
99 void debugfs_file_put(struct dentry *dentry);
100
101 ssize_t debugfs_attr_read(struct file *file, char __user *buf,
102 size_t len, loff_t *ppos);
103 ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
104 size_t len, loff_t *ppos);
105
106 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
107 struct dentry *new_dir, const char *new_name);
108
109 void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent,
110 u8 *value);
111 void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent,
112 u16 *value);
113 void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent,
114 u32 *value);
115 void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent,
116 u64 *value);
117 void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent,
118 unsigned long *value);
119 void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent,
120 u8 *value);
121 void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent,
122 u16 *value);
123 void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent,
124 u32 *value);
125 void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent,
126 u64 *value);
127 void debugfs_create_size_t(const char *name, umode_t mode,
128 struct dentry *parent, size_t *value);
129 void debugfs_create_atomic_t(const char *name, umode_t mode,
130 struct dentry *parent, atomic_t *value);
131 void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent,
132 bool *value);
133 void debugfs_create_str(const char *name, umode_t mode,
134 struct dentry *parent, char **value);
135
136 struct dentry *debugfs_create_blob(const char *name, umode_t mode,
137 struct dentry *parent,
138 struct debugfs_blob_wrapper *blob);
139
140 void debugfs_create_regset32(const char *name, umode_t mode,
141 struct dentry *parent,
142 struct debugfs_regset32 *regset);
143
144 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
145 int nregs, void __iomem *base, char *prefix);
146
147 void debugfs_create_u32_array(const char *name, umode_t mode,
148 struct dentry *parent,
149 struct debugfs_u32_array *array);
150
151 void debugfs_create_devm_seqfile(struct device *dev, const char *name,
152 struct dentry *parent,
153 int (*read_fn)(struct seq_file *s, void *data));
154
155 bool debugfs_initialized(void);
156
157 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
158 size_t count, loff_t *ppos);
159
160 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
161 size_t count, loff_t *ppos);
162
163 ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
164 size_t count, loff_t *ppos);
165
166 #else
167
168 #include <linux/err.h>
169
170 /*
171 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
172 * so users have a chance to detect if there was a real error or not. We don't
173 * want to duplicate the design decision mistakes of procfs and devfs again.
174 */
175
176 static inline struct dentry *debugfs_lookup(const char *name,
177 struct dentry *parent)
178 {
179 return ERR_PTR(-ENODEV);
180 }
181
182 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode,
183 struct dentry *parent, void *data,
184 const struct file_operations *fops)
185 {
186 return ERR_PTR(-ENODEV);
187 }
188
189 static inline struct dentry *debugfs_create_file_unsafe(const char *name,
190 umode_t mode, struct dentry *parent,
191 void *data,
192 const struct file_operations *fops)
193 {
194 return ERR_PTR(-ENODEV);
195 }
196
197 static inline void debugfs_create_file_size(const char *name, umode_t mode,
198 struct dentry *parent, void *data,
199 const struct file_operations *fops,
200 loff_t file_size)
201 { }
202
203 static inline struct dentry *debugfs_create_dir(const char *name,
204 struct dentry *parent)
205 {
206 return ERR_PTR(-ENODEV);
207 }
208
209 static inline struct dentry *debugfs_create_symlink(const char *name,
210 struct dentry *parent,
211 const char *dest)
212 {
213 return ERR_PTR(-ENODEV);
214 }
215
216 static inline struct dentry *debugfs_create_automount(const char *name,
217 struct dentry *parent,
218 debugfs_automount_t f,
219 void *data)
220 {
221 return ERR_PTR(-ENODEV);
222 }
223
224 static inline void debugfs_remove(struct dentry *dentry)
225 { }
226
227 static inline void debugfs_remove_recursive(struct dentry *dentry)
228 { }
229
230 static inline void debugfs_lookup_and_remove(const char *name,
231 struct dentry *parent)
232 { }
233
234 const struct file_operations *debugfs_real_fops(const struct file *filp);
235
236 static inline int debugfs_file_get(struct dentry *dentry)
237 {
238 return 0;
239 }
240
241 static inline void debugfs_file_put(struct dentry *dentry)
242 { }
243
244 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf,
245 size_t len, loff_t *ppos)
246 {
247 return -ENODEV;
248 }
249
250 static inline ssize_t debugfs_attr_write(struct file *file,
251 const char __user *buf,
252 size_t len, loff_t *ppos)
253 {
254 return -ENODEV;
255 }
256
257 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
258 struct dentry *new_dir, char *new_name)
259 {
260 return ERR_PTR(-ENODEV);
261 }
262
263 static inline void debugfs_create_u8(const char *name, umode_t mode,
264 struct dentry *parent, u8 *value) { }
265
266 static inline void debugfs_create_u16(const char *name, umode_t mode,
267 struct dentry *parent, u16 *value) { }
268
269 static inline void debugfs_create_u32(const char *name, umode_t mode,
270 struct dentry *parent, u32 *value) { }
271
272 static inline void debugfs_create_u64(const char *name, umode_t mode,
273 struct dentry *parent, u64 *value) { }
274
275 static inline void debugfs_create_ulong(const char *name, umode_t mode,
276 struct dentry *parent,
277 unsigned long *value) { }
278
279 static inline void debugfs_create_x8(const char *name, umode_t mode,
280 struct dentry *parent, u8 *value) { }
281
282 static inline void debugfs_create_x16(const char *name, umode_t mode,
283 struct dentry *parent, u16 *value) { }
284
285 static inline void debugfs_create_x32(const char *name, umode_t mode,
286 struct dentry *parent, u32 *value) { }
287
288 static inline void debugfs_create_x64(const char *name, umode_t mode,
289 struct dentry *parent, u64 *value) { }
290
291 static inline void debugfs_create_size_t(const char *name, umode_t mode,
292 struct dentry *parent, size_t *value)
293 { }
294
295 static inline void debugfs_create_atomic_t(const char *name, umode_t mode,
296 struct dentry *parent,
297 atomic_t *value)
298 { }
299
300 static inline void debugfs_create_bool(const char *name, umode_t mode,
301 struct dentry *parent, bool *value) { }
302
303 static inline void debugfs_create_str(const char *name, umode_t mode,
304 struct dentry *parent,
305 char **value)
306 { }
307
308 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode,
309 struct dentry *parent,
310 struct debugfs_blob_wrapper *blob)
311 {
312 return ERR_PTR(-ENODEV);
313 }
314
315 static inline void debugfs_create_regset32(const char *name, umode_t mode,
316 struct dentry *parent,
317 struct debugfs_regset32 *regset)
318 {
319 }
320
321 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
322 int nregs, void __iomem *base, char *prefix)
323 {
324 }
325
326 static inline bool debugfs_initialized(void)
327 {
328 return false;
329 }
330
331 static inline void debugfs_create_u32_array(const char *name, umode_t mode,
332 struct dentry *parent,
333 struct debugfs_u32_array *array)
334 {
335 }
336
337 static inline void debugfs_create_devm_seqfile(struct device *dev,
338 const char *name,
339 struct dentry *parent,
340 int (*read_fn)(struct seq_file *s,
341 void *data))
342 {
343 }
344
345 static inline ssize_t debugfs_read_file_bool(struct file *file,
346 char __user *user_buf,
347 size_t count, loff_t *ppos)
348 {
349 return -ENODEV;
350 }
351
352 static inline ssize_t debugfs_write_file_bool(struct file *file,
353 const char __user *user_buf,
354 size_t count, loff_t *ppos)
355 {
356 return -ENODEV;
357 }
358
359 static inline ssize_t debugfs_read_file_str(struct file *file,
360 char __user *user_buf,
361 size_t count, loff_t *ppos)
362 {
363 return -ENODEV;
364 }
365
366 #endif
367
368 /**
369 * debugfs_create_xul - create a debugfs file that is used to read and write an
370 * unsigned long value, formatted in hexadecimal
371 * @name: a pointer to a string containing the name of the file to create.
372 * @mode: the permission that the file should have
373 * @parent: a pointer to the parent dentry for this file. This should be a
374 * directory dentry if set. If this parameter is %NULL, then the
375 * file will be created in the root of the debugfs filesystem.
376 * @value: a pointer to the variable that the file should read to and write
377 * from.
378 */
debugfs_create_xul(const char * name,umode_t mode,struct dentry * parent,unsigned long * value)379 static inline void debugfs_create_xul(const char *name, umode_t mode,
380 struct dentry *parent,
381 unsigned long *value)
382 {
383 if (sizeof(*value) == sizeof(u32))
384 debugfs_create_x32(name, mode, parent, (u32 *)value);
385 else
386 debugfs_create_x64(name, mode, parent, (u64 *)value);
387 }
388
389 #endif
390
