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