Linux kernel mirror (for testing)
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linux
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
165void *debugfs_get_aux(const struct file *file);
166
167int debugfs_file_get(struct dentry *dentry);
168void debugfs_file_put(struct dentry *dentry);
169
170ssize_t debugfs_attr_read(struct file *file, char __user *buf,
171 size_t len, loff_t *ppos);
172ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
173 size_t len, loff_t *ppos);
174ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf,
175 size_t len, loff_t *ppos);
176
177int debugfs_change_name(struct dentry *dentry, const char *fmt, ...) __printf(2, 3);
178
179void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent,
180 u8 *value);
181void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent,
182 u16 *value);
183void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent,
184 u32 *value);
185void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent,
186 u64 *value);
187void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent,
188 unsigned long *value);
189void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent,
190 u8 *value);
191void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent,
192 u16 *value);
193void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent,
194 u32 *value);
195void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent,
196 u64 *value);
197void debugfs_create_size_t(const char *name, umode_t mode,
198 struct dentry *parent, size_t *value);
199void debugfs_create_atomic_t(const char *name, umode_t mode,
200 struct dentry *parent, atomic_t *value);
201void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent,
202 bool *value);
203void debugfs_create_str(const char *name, umode_t mode,
204 struct dentry *parent, char **value);
205
206struct dentry *debugfs_create_blob(const char *name, umode_t mode,
207 struct dentry *parent,
208 struct debugfs_blob_wrapper *blob);
209
210void debugfs_create_regset32(const char *name, umode_t mode,
211 struct dentry *parent,
212 struct debugfs_regset32 *regset);
213
214void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
215 int nregs, void __iomem *base, char *prefix);
216
217void debugfs_create_u32_array(const char *name, umode_t mode,
218 struct dentry *parent,
219 struct debugfs_u32_array *array);
220
221void debugfs_create_devm_seqfile(struct device *dev, const char *name,
222 struct dentry *parent,
223 int (*read_fn)(struct seq_file *s, void *data));
224
225bool debugfs_initialized(void);
226
227ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
228 size_t count, loff_t *ppos);
229
230ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
231 size_t count, loff_t *ppos);
232
233ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
234 size_t count, loff_t *ppos);
235
236/**
237 * struct debugfs_cancellation - cancellation data
238 * @list: internal, for keeping track
239 * @cancel: callback to call
240 * @cancel_data: extra data for the callback to call
241 */
242context_lock_struct(debugfs_cancellation) {
243 struct list_head list;
244 void (*cancel)(struct dentry *, void *);
245 void *cancel_data;
246};
247
248void debugfs_enter_cancellation(struct file *file,
249 struct debugfs_cancellation *cancellation) __acquires(cancellation);
250void debugfs_leave_cancellation(struct file *file,
251 struct debugfs_cancellation *cancellation) __releases(cancellation);
252
253#else
254
255#include <linux/err.h>
256
257/*
258 * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
259 * so users have a chance to detect if there was a real error or not. We don't
260 * want to duplicate the design decision mistakes of procfs and devfs again.
261 */
262
263static inline struct dentry *debugfs_lookup(const char *name,
264 struct dentry *parent)
265{
266 return ERR_PTR(-ENODEV);
267}
268
269static inline struct dentry *debugfs_create_file_aux(const char *name,
270 umode_t mode, struct dentry *parent,
271 void *data, void *aux,
272 const void *fops)
273{
274 return ERR_PTR(-ENODEV);
275}
276
277static inline struct dentry *debugfs_create_file(const char *name, umode_t mode,
278 struct dentry *parent, void *data,
279 const void *fops)
280{
281 return ERR_PTR(-ENODEV);
282}
283
284static inline struct dentry *debugfs_create_file_unsafe(const char *name,
285 umode_t mode, struct dentry *parent,
286 void *data,
287 const struct file_operations *fops)
288{
289 return ERR_PTR(-ENODEV);
290}
291
292static inline void debugfs_create_file_size(const char *name, umode_t mode,
293 struct dentry *parent, void *data,
294 const struct file_operations *fops,
295 loff_t file_size)
296{ }
297
298static inline struct dentry *debugfs_create_dir(const char *name,
299 struct dentry *parent)
300{
301 return ERR_PTR(-ENODEV);
302}
303
304static inline struct dentry *debugfs_create_symlink(const char *name,
305 struct dentry *parent,
306 const char *dest)
307{
308 return ERR_PTR(-ENODEV);
309}
310
311static inline struct dentry *debugfs_create_automount(const char *name,
312 struct dentry *parent,
313 debugfs_automount_t f,
314 void *data)
315{
316 return ERR_PTR(-ENODEV);
317}
318
319static inline void debugfs_remove(struct dentry *dentry)
320{ }
321
322static inline void debugfs_remove_recursive(struct dentry *dentry)
323{ }
324
325static inline void debugfs_lookup_and_remove(const char *name,
326 struct dentry *parent)
327{ }
328
329void *debugfs_get_aux(const struct file *file);
330
331static inline int debugfs_file_get(struct dentry *dentry)
332{
333 return 0;
334}
335
336static inline void debugfs_file_put(struct dentry *dentry)
337{ }
338
339static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf,
340 size_t len, loff_t *ppos)
341{
342 return -ENODEV;
343}
344
345static inline ssize_t debugfs_attr_write(struct file *file,
346 const char __user *buf,
347 size_t len, loff_t *ppos)
348{
349 return -ENODEV;
350}
351
352static inline ssize_t debugfs_attr_write_signed(struct file *file,
353 const char __user *buf,
354 size_t len, loff_t *ppos)
355{
356 return -ENODEV;
357}
358
359static inline int __printf(2, 3) debugfs_change_name(struct dentry *dentry,
360 const char *fmt, ...)
361{
362 return -ENODEV;
363}
364
365static inline void debugfs_create_u8(const char *name, umode_t mode,
366 struct dentry *parent, u8 *value) { }
367
368static inline void debugfs_create_u16(const char *name, umode_t mode,
369 struct dentry *parent, u16 *value) { }
370
371static inline void debugfs_create_u32(const char *name, umode_t mode,
372 struct dentry *parent, u32 *value) { }
373
374static inline void debugfs_create_u64(const char *name, umode_t mode,
375 struct dentry *parent, u64 *value) { }
376
377static inline void debugfs_create_ulong(const char *name, umode_t mode,
378 struct dentry *parent,
379 unsigned long *value) { }
380
381static inline void debugfs_create_x8(const char *name, umode_t mode,
382 struct dentry *parent, u8 *value) { }
383
384static inline void debugfs_create_x16(const char *name, umode_t mode,
385 struct dentry *parent, u16 *value) { }
386
387static inline void debugfs_create_x32(const char *name, umode_t mode,
388 struct dentry *parent, u32 *value) { }
389
390static inline void debugfs_create_x64(const char *name, umode_t mode,
391 struct dentry *parent, u64 *value) { }
392
393static inline void debugfs_create_size_t(const char *name, umode_t mode,
394 struct dentry *parent, size_t *value)
395{ }
396
397static inline void debugfs_create_atomic_t(const char *name, umode_t mode,
398 struct dentry *parent,
399 atomic_t *value)
400{ }
401
402static inline void debugfs_create_bool(const char *name, umode_t mode,
403 struct dentry *parent, bool *value) { }
404
405static inline void debugfs_create_str(const char *name, umode_t mode,
406 struct dentry *parent,
407 char **value)
408{ }
409
410static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode,
411 struct dentry *parent,
412 struct debugfs_blob_wrapper *blob)
413{
414 return ERR_PTR(-ENODEV);
415}
416
417static inline void debugfs_create_regset32(const char *name, umode_t mode,
418 struct dentry *parent,
419 struct debugfs_regset32 *regset)
420{
421}
422
423static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
424 int nregs, void __iomem *base, char *prefix)
425{
426}
427
428static inline bool debugfs_initialized(void)
429{
430 return false;
431}
432
433static inline void debugfs_create_u32_array(const char *name, umode_t mode,
434 struct dentry *parent,
435 struct debugfs_u32_array *array)
436{
437}
438
439static inline void debugfs_create_devm_seqfile(struct device *dev,
440 const char *name,
441 struct dentry *parent,
442 int (*read_fn)(struct seq_file *s,
443 void *data))
444{
445}
446
447static inline ssize_t debugfs_read_file_bool(struct file *file,
448 char __user *user_buf,
449 size_t count, loff_t *ppos)
450{
451 return -ENODEV;
452}
453
454static inline ssize_t debugfs_write_file_bool(struct file *file,
455 const char __user *user_buf,
456 size_t count, loff_t *ppos)
457{
458 return -ENODEV;
459}
460
461static inline ssize_t debugfs_read_file_str(struct file *file,
462 char __user *user_buf,
463 size_t count, loff_t *ppos)
464{
465 return -ENODEV;
466}
467
468#endif
469
470#define debugfs_create_file_aux_num(name, mode, parent, data, n, fops) \
471 debugfs_create_file_aux(name, mode, parent, data, \
472 (void *)(unsigned long)n, fops)
473#define debugfs_get_aux_num(f) (unsigned long)debugfs_get_aux(f)
474
475/**
476 * debugfs_create_xul - create a debugfs file that is used to read and write an
477 * unsigned long value, formatted in hexadecimal
478 * @name: a pointer to a string containing the name of the file to create.
479 * @mode: the permission that the file should have
480 * @parent: a pointer to the parent dentry for this file. This should be a
481 * directory dentry if set. If this parameter is %NULL, then the
482 * file will be created in the root of the debugfs filesystem.
483 * @value: a pointer to the variable that the file should read to and write
484 * from.
485 */
486static inline void debugfs_create_xul(const char *name, umode_t mode,
487 struct dentry *parent,
488 unsigned long *value)
489{
490 if (sizeof(*value) == sizeof(u32))
491 debugfs_create_x32(name, mode, parent, (u32 *)value);
492 else
493 debugfs_create_x64(name, mode, parent, (u64 *)value);
494}
495
496#endif