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