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