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 void 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 void 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 void debugfs_create_file_size(const char *name, umode_t mode,
185 struct dentry *parent, void *data,
186 const struct file_operations *fops,
190 static inline struct dentry *debugfs_create_dir(const char *name,
191 struct dentry *parent)
193 return ERR_PTR(-ENODEV);
196 static inline struct dentry *debugfs_create_symlink(const char *name,
197 struct dentry *parent,
200 return ERR_PTR(-ENODEV);
203 static inline struct dentry *debugfs_create_automount(const char *name,
204 struct dentry *parent,
205 debugfs_automount_t f,
208 return ERR_PTR(-ENODEV);
211 static inline void debugfs_remove(struct dentry *dentry)
214 static inline void debugfs_remove_recursive(struct dentry *dentry)
217 const struct file_operations *debugfs_real_fops(const struct file *filp);
219 static inline int debugfs_file_get(struct dentry *dentry)
224 static inline void debugfs_file_put(struct dentry *dentry)
227 static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf,
228 size_t len, loff_t *ppos)
233 static inline ssize_t debugfs_attr_write(struct file *file,
234 const char __user *buf,
235 size_t len, loff_t *ppos)
240 static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
241 struct dentry *new_dir, char *new_name)
243 return ERR_PTR(-ENODEV);
246 static inline void debugfs_create_u8(const char *name, umode_t mode,
247 struct dentry *parent, u8 *value) { }
249 static inline void debugfs_create_u16(const char *name, umode_t mode,
250 struct dentry *parent, u16 *value) { }
252 static inline struct dentry *debugfs_create_u32(const char *name, umode_t mode,
253 struct dentry *parent,
256 return ERR_PTR(-ENODEV);
259 static inline void debugfs_create_u64(const char *name, umode_t mode,
260 struct dentry *parent, u64 *value) { }
262 static inline struct dentry *debugfs_create_ulong(const char *name,
264 struct dentry *parent,
265 unsigned long *value)
267 return ERR_PTR(-ENODEV);
270 static inline void debugfs_create_x8(const char *name, umode_t mode,
271 struct dentry *parent, u8 *value) { }
273 static inline void debugfs_create_x16(const char *name, umode_t mode,
274 struct dentry *parent, u16 *value) { }
276 static inline void debugfs_create_x32(const char *name, umode_t mode,
277 struct dentry *parent, u32 *value) { }
279 static inline void debugfs_create_x64(const char *name, umode_t mode,
280 struct dentry *parent, u64 *value) { }
282 static inline void debugfs_create_size_t(const char *name, umode_t mode,
283 struct dentry *parent, size_t *value)
286 static inline void debugfs_create_atomic_t(const char *name, umode_t mode,
287 struct dentry *parent,
291 static inline struct dentry *debugfs_create_bool(const char *name, umode_t mode,
292 struct dentry *parent,
295 return ERR_PTR(-ENODEV);
298 static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode,
299 struct dentry *parent,
300 struct debugfs_blob_wrapper *blob)
302 return ERR_PTR(-ENODEV);
305 static inline void debugfs_create_regset32(const char *name, umode_t mode,
306 struct dentry *parent,
307 struct debugfs_regset32 *regset)
311 static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
312 int nregs, void __iomem *base, char *prefix)
316 static inline bool debugfs_initialized(void)
321 static inline void debugfs_create_u32_array(const char *name, umode_t mode,
322 struct dentry *parent, u32 *array,
327 static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev,
329 struct dentry *parent,
330 int (*read_fn)(struct seq_file *s,
333 return ERR_PTR(-ENODEV);
336 static inline ssize_t debugfs_read_file_bool(struct file *file,
337 char __user *user_buf,
338 size_t count, loff_t *ppos)
343 static inline ssize_t debugfs_write_file_bool(struct file *file,
344 const char __user *user_buf,
345 size_t count, loff_t *ppos)
353 * debugfs_create_xul - create a debugfs file that is used to read and write an
354 * unsigned long value, formatted in hexadecimal
355 * @name: a pointer to a string containing the name of the file to create.
356 * @mode: the permission that the file should have
357 * @parent: a pointer to the parent dentry for this file. This should be a
358 * directory dentry if set. If this parameter is %NULL, then the
359 * file will be created in the root of the debugfs filesystem.
360 * @value: a pointer to the variable that the file should read to and write
363 static inline void debugfs_create_xul(const char *name, umode_t mode,
364 struct dentry *parent,
365 unsigned long *value)
367 if (sizeof(*value) == sizeof(u32))
368 debugfs_create_x32(name, mode, parent, (u32 *)value);
370 debugfs_create_x64(name, mode, parent, (u64 *)value);