1 // SPDX-License-Identifier: GPL-2.0
3 * debugfs.h - a tiny little debug file system
5 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
6 * Copyright (C) 2004 IBM Inc.
8 * debugfs is for people to use instead of /proc or /sys.
9 * See Documentation/filesystems/ for more details.
16 #include <linux/seq_file.h>
18 #include <linux/types.h>
19 #include <linux/compiler.h>
22 struct file_operations;
24 struct debugfs_blob_wrapper {
29 struct debugfs_reg32 {
34 struct debugfs_regset32 {
35 const struct debugfs_reg32 *regs;
40 extern struct dentry *arch_debugfs_dir;
42 #define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \
43 static int __fops ## _open(struct inode *inode, struct file *file) \
45 __simple_attr_check_format(__fmt, 0ull); \
46 return simple_attr_open(inode, file, __get, __set, __fmt); \
48 static const struct file_operations __fops = { \
49 .owner = THIS_MODULE, \
50 .open = __fops ## _open, \
51 .release = simple_attr_release, \
52 .read = debugfs_attr_read, \
53 .write = debugfs_attr_write, \
54 .llseek = no_llseek, \
57 typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *);
59 #if defined(CONFIG_DEBUG_FS)
61 struct dentry *debugfs_lookup(const char *name, struct dentry *parent);
63 struct dentry *debugfs_create_file(const char *name, umode_t mode,
64 struct dentry *parent, void *data,
65 const struct file_operations *fops);
66 struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
67 struct dentry *parent, void *data,
68 const struct file_operations *fops);
70 struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
71 struct dentry *parent, void *data,
72 const struct file_operations *fops,
75 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
77 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
80 struct dentry *debugfs_create_automount(const char *name,
81 struct dentry *parent,
82 debugfs_automount_t f,
85 void debugfs_remove(struct dentry *dentry);
86 #define debugfs_remove_recursive debugfs_remove
88 const struct file_operations *debugfs_real_fops(const struct file *filp);
90 int debugfs_file_get(struct dentry *dentry);
91 void debugfs_file_put(struct dentry *dentry);
93 ssize_t debugfs_attr_read(struct file *file, char __user *buf,
94 size_t len, loff_t *ppos);
95 ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
96 size_t len, loff_t *ppos);
98 struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
99 struct dentry *new_dir, const char *new_name);
101 void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent,
103 void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent,
105 struct dentry *debugfs_create_u32(const char *name, umode_t mode,
106 struct dentry *parent, u32 *value);
107 void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent,
109 struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
110 struct dentry *parent, unsigned long *value);
111 void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent,
113 void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent,
115 void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent,
117 void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent,
119 void debugfs_create_size_t(const char *name, umode_t mode,
120 struct dentry *parent, size_t *value);
121 void debugfs_create_atomic_t(const char *name, umode_t mode,
122 struct dentry *parent, atomic_t *value);
123 struct dentry *debugfs_create_bool(const char *name, umode_t mode,
124 struct dentry *parent, bool *value);
126 struct dentry *debugfs_create_blob(const char *name, umode_t mode,
127 struct dentry *parent,
128 struct debugfs_blob_wrapper *blob);
130 struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
131 struct dentry *parent,
132 struct debugfs_regset32 *regset);
134 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
135 int nregs, void __iomem *base, char *prefix);
137 void debugfs_create_u32_array(const char *name, umode_t mode,
138 struct dentry *parent, u32 *array, u32 elements);
140 struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
141 struct dentry *parent,
142 int (*read_fn)(struct seq_file *s,
145 bool debugfs_initialized(void);
147 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
148 size_t count, loff_t *ppos);
150 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
151 size_t count, loff_t *ppos);
155 #include <linux/err.h>
158 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
159 * so users have a chance to detect if there was a real error or not. We don't
160 * want to duplicate the design decision mistakes of procfs and devfs again.
163 static inline struct dentry *debugfs_lookup(const char *name,
164 struct dentry *parent)
166 return ERR_PTR(-ENODEV);
169 static inline struct dentry *debugfs_create_file(const char *name, umode_t mode,
170 struct dentry *parent, void *data,
171 const struct file_operations *fops)
173 return ERR_PTR(-ENODEV);
176 static inline struct dentry *debugfs_create_file_unsafe(const char *name,
177 umode_t mode, struct dentry *parent,
179 const struct file_operations *fops)
181 return ERR_PTR(-ENODEV);
184 static inline struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
185 struct dentry *parent, void *data,
186 const struct file_operations *fops,
189 return ERR_PTR(-ENODEV);
192 static inline struct dentry *debugfs_create_dir(const char *name,
193 struct dentry *parent)
195 return ERR_PTR(-ENODEV);
198 static inline struct dentry *debugfs_create_symlink(const char *name,
199 struct dentry *parent,
202 return ERR_PTR(-ENODEV);
205 static inline struct dentry *debugfs_create_automount(const char *name,
206 struct dentry *parent,
207 debugfs_automount_t f,
210 return ERR_PTR(-ENODEV);
213 static inline void debugfs_remove(struct dentry *dentry)
216 static inline void debugfs_remove_recursive(struct dentry *dentry)
219 const struct file_operations *debugfs_real_fops(const struct file *filp);
221 static inline int debugfs_file_get(struct dentry *dentry)
226 static inline void debugfs_file_put(struct dentry *dentry)
229 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf,
230 size_t len, loff_t *ppos)
235 static inline ssize_t debugfs_attr_write(struct file *file,
236 const char __user *buf,
237 size_t len, loff_t *ppos)
242 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
243 struct dentry *new_dir, char *new_name)
245 return ERR_PTR(-ENODEV);
248 static inline void debugfs_create_u8(const char *name, umode_t mode,
249 struct dentry *parent, u8 *value) { }
251 static inline void debugfs_create_u16(const char *name, umode_t mode,
252 struct dentry *parent, u16 *value) { }
254 static inline struct dentry *debugfs_create_u32(const char *name, umode_t mode,
255 struct dentry *parent,
258 return ERR_PTR(-ENODEV);
261 static inline void debugfs_create_u64(const char *name, umode_t mode,
262 struct dentry *parent, u64 *value) { }
264 static inline struct dentry *debugfs_create_ulong(const char *name,
266 struct dentry *parent,
267 unsigned long *value)
269 return ERR_PTR(-ENODEV);
272 static inline void debugfs_create_x8(const char *name, umode_t mode,
273 struct dentry *parent, u8 *value) { }
275 static inline void debugfs_create_x16(const char *name, umode_t mode,
276 struct dentry *parent, u16 *value) { }
278 static inline void debugfs_create_x32(const char *name, umode_t mode,
279 struct dentry *parent, u32 *value) { }
281 static inline void debugfs_create_x64(const char *name, umode_t mode,
282 struct dentry *parent, u64 *value) { }
284 static inline void debugfs_create_size_t(const char *name, umode_t mode,
285 struct dentry *parent, size_t *value)
288 static inline void debugfs_create_atomic_t(const char *name, umode_t mode,
289 struct dentry *parent,
293 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode,
294 struct dentry *parent,
297 return ERR_PTR(-ENODEV);
300 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode,
301 struct dentry *parent,
302 struct debugfs_blob_wrapper *blob)
304 return ERR_PTR(-ENODEV);
307 static inline struct dentry *debugfs_create_regset32(const char *name,
308 umode_t mode, struct dentry *parent,
309 struct debugfs_regset32 *regset)
311 return ERR_PTR(-ENODEV);
314 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
315 int nregs, void __iomem *base, char *prefix)
319 static inline bool debugfs_initialized(void)
324 static inline void debugfs_create_u32_array(const char *name, umode_t mode,
325 struct dentry *parent, u32 *array,
330 static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev,
332 struct dentry *parent,
333 int (*read_fn)(struct seq_file *s,
336 return ERR_PTR(-ENODEV);
339 static inline ssize_t debugfs_read_file_bool(struct file *file,
340 char __user *user_buf,
341 size_t count, loff_t *ppos)
346 static inline ssize_t debugfs_write_file_bool(struct file *file,
347 const char __user *user_buf,
348 size_t count, loff_t *ppos)
356 * debugfs_create_xul - create a debugfs file that is used to read and write an
357 * unsigned long value, formatted in hexadecimal
358 * @name: a pointer to a string containing the name of the file to create.
359 * @mode: the permission that the file should have
360 * @parent: a pointer to the parent dentry for this file. This should be a
361 * directory dentry if set. If this parameter is %NULL, then the
362 * file will be created in the root of the debugfs filesystem.
363 * @value: a pointer to the variable that the file should read to and write
366 static inline void debugfs_create_xul(const char *name, umode_t mode,
367 struct dentry *parent,
368 unsigned long *value)
370 if (sizeof(*value) == sizeof(u32))
371 debugfs_create_x32(name, mode, parent, (u32 *)value);
373 debugfs_create_x64(name, mode, parent, (u64 *)value);