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
21struct device;
22struct file_operations;
23
24struct debugfs_blob_wrapper {
25 void *data;
26 unsigned long size;
27};
28
29struct debugfs_reg32 {
30 char *name;
31 unsigned long offset;
32};
33
34struct 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
41struct debugfs_u32_array {
42 u32 *array;
43 u32 n_elements;
44};
45
46extern struct dentry *arch_debugfs_dir;
47
48#define DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, __is_signed) \
49static 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} \
54static 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
68typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *);
69
70struct debugfs_short_fops {
71 ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
72 ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
73 loff_t (*llseek) (struct file *, loff_t, int);
74};
75
76#if defined(CONFIG_DEBUG_FS)
77
78struct dentry *debugfs_lookup(const char *name, struct dentry *parent);
79
80struct dentry *debugfs_create_file_full(const char *name, umode_t mode,
81 struct dentry *parent, void *data,
82 const void *aux,
83 const struct file_operations *fops);
84struct dentry *debugfs_create_file_short(const char *name, umode_t mode,
85 struct dentry *parent, void *data,
86 const void *aux,
87 const struct debugfs_short_fops *fops);
88
89/**
90 * debugfs_create_file - create a file in the debugfs filesystem
91 * @name: a pointer to a string containing the name of the file to create.
92 * @mode: the permission that the file should have.
93 * @parent: a pointer to the parent dentry for this file. This should be a
94 * directory dentry if set. If this parameter is NULL, then the
95 * file will be created in the root of the debugfs filesystem.
96 * @data: a pointer to something that the caller will want to get to later
97 * on. The inode.i_private pointer will point to this value on
98 * the open() call.
99 * @fops: a pointer to a struct file_operations or struct debugfs_short_fops that
100 * should be used for this file.
101 *
102 * This is the basic "create a file" function for debugfs. It allows for a
103 * wide range of flexibility in creating a file, or a directory (if you want
104 * to create a directory, the debugfs_create_dir() function is
105 * recommended to be used instead.)
106 *
107 * This function will return a pointer to a dentry if it succeeds. This
108 * pointer must be passed to the debugfs_remove() function when the file is
109 * to be removed (no automatic cleanup happens if your module is unloaded,
110 * you are responsible here.) If an error occurs, ERR_PTR(-ERROR) will be
111 * returned.
112 *
113 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
114 * returned.
115 *
116 * If fops points to a struct debugfs_short_fops, then simple_open() will be
117 * used for the open, and only read/write/llseek are supported and are proxied,
118 * so no module reference or release are needed.
119 *
120 * NOTE: it's expected that most callers should _ignore_ the errors returned
121 * by this function. Other debugfs functions handle the fact that the "dentry"
122 * passed to them could be an error and they don't crash in that case.
123 * Drivers should generally work fine even if debugfs fails to init anyway.
124 */
125#define debugfs_create_file(name, mode, parent, data, fops) \
126 _Generic(fops, \
127 const struct file_operations *: debugfs_create_file_full, \
128 const struct debugfs_short_fops *: debugfs_create_file_short, \
129 struct file_operations *: debugfs_create_file_full, \
130 struct debugfs_short_fops *: debugfs_create_file_short) \
131 (name, mode, parent, data, NULL, fops)
132
133#define debugfs_create_file_aux(name, mode, parent, data, aux, fops) \
134 _Generic(fops, \
135 const struct file_operations *: debugfs_create_file_full, \
136 const struct debugfs_short_fops *: debugfs_create_file_short, \
137 struct file_operations *: debugfs_create_file_full, \
138 struct debugfs_short_fops *: debugfs_create_file_short) \
139 (name, mode, parent, data, aux, fops)
140
141struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
142 struct dentry *parent, void *data,
143 const struct file_operations *fops);
144
145void debugfs_create_file_size(const char *name, umode_t mode,
146 struct dentry *parent, void *data,
147 const struct file_operations *fops,
148 loff_t file_size);
149
150struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
151
152struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
153 const char *dest);
154
155struct dentry *debugfs_create_automount(const char *name,
156 struct dentry *parent,
157 debugfs_automount_t f,
158 void *data);
159
160void debugfs_remove(struct dentry *dentry);
161#define debugfs_remove_recursive debugfs_remove
162
163void debugfs_lookup_and_remove(const char *name, struct dentry *parent);
164
165const struct file_operations *debugfs_real_fops(const struct file *filp);
166const void *debugfs_get_aux(const struct file *file);
167
168int debugfs_file_get(struct dentry *dentry);
169void debugfs_file_put(struct dentry *dentry);
170
171ssize_t debugfs_attr_read(struct file *file, char __user *buf,
172 size_t len, loff_t *ppos);
173ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
174 size_t len, loff_t *ppos);
175ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf,
176 size_t len, loff_t *ppos);
177
178int debugfs_change_name(struct dentry *dentry, const char *fmt, ...) __printf(2, 3);
179
180void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent,
181 u8 *value);
182void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent,
183 u16 *value);
184void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent,
185 u32 *value);
186void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent,
187 u64 *value);
188void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent,
189 unsigned long *value);
190void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent,
191 u8 *value);
192void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent,
193 u16 *value);
194void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent,
195 u32 *value);
196void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent,
197 u64 *value);
198void debugfs_create_size_t(const char *name, umode_t mode,
199 struct dentry *parent, size_t *value);
200void debugfs_create_atomic_t(const char *name, umode_t mode,
201 struct dentry *parent, atomic_t *value);
202void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent,
203 bool *value);
204void debugfs_create_str(const char *name, umode_t mode,
205 struct dentry *parent, char **value);
206
207struct dentry *debugfs_create_blob(const char *name, umode_t mode,
208 struct dentry *parent,
209 struct debugfs_blob_wrapper *blob);
210
211void debugfs_create_regset32(const char *name, umode_t mode,
212 struct dentry *parent,
213 struct debugfs_regset32 *regset);
214
215void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
216 int nregs, void __iomem *base, char *prefix);
217
218void debugfs_create_u32_array(const char *name, umode_t mode,
219 struct dentry *parent,
220 struct debugfs_u32_array *array);
221
222void debugfs_create_devm_seqfile(struct device *dev, const char *name,
223 struct dentry *parent,
224 int (*read_fn)(struct seq_file *s, void *data));
225
226bool debugfs_initialized(void);
227
228ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
229 size_t count, loff_t *ppos);
230
231ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
232 size_t count, loff_t *ppos);
233
234ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
235 size_t count, loff_t *ppos);
236
237/**
238 * struct debugfs_cancellation - cancellation data
239 * @list: internal, for keeping track
240 * @cancel: callback to call
241 * @cancel_data: extra data for the callback to call
242 */
243struct debugfs_cancellation {
244 struct list_head list;
245 void (*cancel)(struct dentry *, void *);
246 void *cancel_data;
247};
248
249void __acquires(cancellation)
250debugfs_enter_cancellation(struct file *file,
251 struct debugfs_cancellation *cancellation);
252void __releases(cancellation)
253debugfs_leave_cancellation(struct file *file,
254 struct debugfs_cancellation *cancellation);
255
256#else
257
258#include <linux/err.h>
259
260/*
261 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
262 * so users have a chance to detect if there was a real error or not. We don't
263 * want to duplicate the design decision mistakes of procfs and devfs again.
264 */
265
266static inline struct dentry *debugfs_lookup(const char *name,
267 struct dentry *parent)
268{
269 return ERR_PTR(-ENODEV);
270}
271
272static inline struct dentry *debugfs_create_file_aux(const char *name,
273 umode_t mode, struct dentry *parent,
274 void *data, void *aux,
275 const void *fops)
276{
277 return ERR_PTR(-ENODEV);
278}
279
280static inline struct dentry *debugfs_create_file(const char *name, umode_t mode,
281 struct dentry *parent, void *data,
282 const void *fops)
283{
284 return ERR_PTR(-ENODEV);
285}
286
287static inline struct dentry *debugfs_create_file_unsafe(const char *name,
288 umode_t mode, struct dentry *parent,
289 void *data,
290 const struct file_operations *fops)
291{
292 return ERR_PTR(-ENODEV);
293}
294
295static inline void debugfs_create_file_size(const char *name, umode_t mode,
296 struct dentry *parent, void *data,
297 const struct file_operations *fops,
298 loff_t file_size)
299{ }
300
301static inline struct dentry *debugfs_create_dir(const char *name,
302 struct dentry *parent)
303{
304 return ERR_PTR(-ENODEV);
305}
306
307static inline struct dentry *debugfs_create_symlink(const char *name,
308 struct dentry *parent,
309 const char *dest)
310{
311 return ERR_PTR(-ENODEV);
312}
313
314static inline struct dentry *debugfs_create_automount(const char *name,
315 struct dentry *parent,
316 debugfs_automount_t f,
317 void *data)
318{
319 return ERR_PTR(-ENODEV);
320}
321
322static inline void debugfs_remove(struct dentry *dentry)
323{ }
324
325static inline void debugfs_remove_recursive(struct dentry *dentry)
326{ }
327
328static inline void debugfs_lookup_and_remove(const char *name,
329 struct dentry *parent)
330{ }
331
332const struct file_operations *debugfs_real_fops(const struct file *filp);
333void *debugfs_get_aux(const struct file *file);
334
335static inline int debugfs_file_get(struct dentry *dentry)
336{
337 return 0;
338}
339
340static inline void debugfs_file_put(struct dentry *dentry)
341{ }
342
343static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf,
344 size_t len, loff_t *ppos)
345{
346 return -ENODEV;
347}
348
349static inline ssize_t debugfs_attr_write(struct file *file,
350 const char __user *buf,
351 size_t len, loff_t *ppos)
352{
353 return -ENODEV;
354}
355
356static inline ssize_t debugfs_attr_write_signed(struct file *file,
357 const char __user *buf,
358 size_t len, loff_t *ppos)
359{
360 return -ENODEV;
361}
362
363static inline int __printf(2, 3) debugfs_change_name(struct dentry *dentry,
364 const char *fmt, ...)
365{
366 return -ENODEV;
367}
368
369static inline void debugfs_create_u8(const char *name, umode_t mode,
370 struct dentry *parent, u8 *value) { }
371
372static inline void debugfs_create_u16(const char *name, umode_t mode,
373 struct dentry *parent, u16 *value) { }
374
375static inline void debugfs_create_u32(const char *name, umode_t mode,
376 struct dentry *parent, u32 *value) { }
377
378static inline void debugfs_create_u64(const char *name, umode_t mode,
379 struct dentry *parent, u64 *value) { }
380
381static inline void debugfs_create_ulong(const char *name, umode_t mode,
382 struct dentry *parent,
383 unsigned long *value) { }
384
385static inline void debugfs_create_x8(const char *name, umode_t mode,
386 struct dentry *parent, u8 *value) { }
387
388static inline void debugfs_create_x16(const char *name, umode_t mode,
389 struct dentry *parent, u16 *value) { }
390
391static inline void debugfs_create_x32(const char *name, umode_t mode,
392 struct dentry *parent, u32 *value) { }
393
394static inline void debugfs_create_x64(const char *name, umode_t mode,
395 struct dentry *parent, u64 *value) { }
396
397static inline void debugfs_create_size_t(const char *name, umode_t mode,
398 struct dentry *parent, size_t *value)
399{ }
400
401static inline void debugfs_create_atomic_t(const char *name, umode_t mode,
402 struct dentry *parent,
403 atomic_t *value)
404{ }
405
406static inline void debugfs_create_bool(const char *name, umode_t mode,
407 struct dentry *parent, bool *value) { }
408
409static inline void debugfs_create_str(const char *name, umode_t mode,
410 struct dentry *parent,
411 char **value)
412{ }
413
414static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode,
415 struct dentry *parent,
416 struct debugfs_blob_wrapper *blob)
417{
418 return ERR_PTR(-ENODEV);
419}
420
421static inline void debugfs_create_regset32(const char *name, umode_t mode,
422 struct dentry *parent,
423 struct debugfs_regset32 *regset)
424{
425}
426
427static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
428 int nregs, void __iomem *base, char *prefix)
429{
430}
431
432static inline bool debugfs_initialized(void)
433{
434 return false;
435}
436
437static inline void debugfs_create_u32_array(const char *name, umode_t mode,
438 struct dentry *parent,
439 struct debugfs_u32_array *array)
440{
441}
442
443static inline void debugfs_create_devm_seqfile(struct device *dev,
444 const char *name,
445 struct dentry *parent,
446 int (*read_fn)(struct seq_file *s,
447 void *data))
448{
449}
450
451static inline ssize_t debugfs_read_file_bool(struct file *file,
452 char __user *user_buf,
453 size_t count, loff_t *ppos)
454{
455 return -ENODEV;
456}
457
458static inline ssize_t debugfs_write_file_bool(struct file *file,
459 const char __user *user_buf,
460 size_t count, loff_t *ppos)
461{
462 return -ENODEV;
463}
464
465static inline ssize_t debugfs_read_file_str(struct file *file,
466 char __user *user_buf,
467 size_t count, loff_t *ppos)
468{
469 return -ENODEV;
470}
471
472#endif
473
474#define debugfs_create_file_aux_num(name, mode, parent, data, n, fops) \
475 debugfs_create_file_aux(name, mode, parent, data, \
476 (void *)(unsigned long)n, fops)
477#define debugfs_get_aux_num(f) (unsigned long)debugfs_get_aux(f)
478
479/**
480 * debugfs_create_xul - create a debugfs file that is used to read and write an
481 * unsigned long value, formatted in hexadecimal
482 * @name: a pointer to a string containing the name of the file to create.
483 * @mode: the permission that the file should have
484 * @parent: a pointer to the parent dentry for this file. This should be a
485 * directory dentry if set. If this parameter is %NULL, then the
486 * file will be created in the root of the debugfs filesystem.
487 * @value: a pointer to the variable that the file should read to and write
488 * from.
489 */
490static inline void debugfs_create_xul(const char *name, umode_t mode,
491 struct dentry *parent,
492 unsigned long *value)
493{
494 if (sizeof(*value) == sizeof(u32))
495 debugfs_create_x32(name, mode, parent, value: (u32 *)value);
496 else
497 debugfs_create_x64(name, mode, parent, value: (u64 *)value);
498}
499
500#endif
501

source code of linux/include/linux/debugfs.h

Morty Proxy This is a proxified and sanitized view of the page, visit original site.