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1/*
2 * file.c - part of debugfs, a tiny little debug file system
3 *
4 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
5 * Copyright (C) 2004 IBM Inc.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
10 *
11 * debugfs is for people to use instead of /proc or /sys.
12 * See Documentation/DocBook/filesystems for more details.
13 *
14 */
15
16#include <linux/module.h>
17#include <linux/fs.h>
18#include <linux/seq_file.h>
19#include <linux/pagemap.h>
20#include <linux/namei.h>
21#include <linux/debugfs.h>
22#include <linux/io.h>
23#include <linux/slab.h>
24#include <linux/atomic.h>
25
26static ssize_t default_read_file(struct file *file, char __user *buf,
27 size_t count, loff_t *ppos)
28{
29 return 0;
30}
31
32static ssize_t default_write_file(struct file *file, const char __user *buf,
33 size_t count, loff_t *ppos)
34{
35 return count;
36}
37
38const struct file_operations debugfs_file_operations = {
39 .read = default_read_file,
40 .write = default_write_file,
41 .open = simple_open,
42 .llseek = noop_llseek,
43};
44
45static void *debugfs_follow_link(struct dentry *dentry, struct nameidata *nd)
46{
47 nd_set_link(nd, dentry->d_inode->i_private);
48 return NULL;
49}
50
51const struct inode_operations debugfs_link_operations = {
52 .readlink = generic_readlink,
53 .follow_link = debugfs_follow_link,
54};
55
56static int debugfs_u8_set(void *data, u64 val)
57{
58 *(u8 *)data = val;
59 return 0;
60}
61static int debugfs_u8_get(void *data, u64 *val)
62{
63 *val = *(u8 *)data;
64 return 0;
65}
66DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
67DEFINE_SIMPLE_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
68DEFINE_SIMPLE_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
69
70/**
71 * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
72 * @name: a pointer to a string containing the name of the file to create.
73 * @mode: the permission that the file should have
74 * @parent: a pointer to the parent dentry for this file. This should be a
75 * directory dentry if set. If this parameter is %NULL, then the
76 * file will be created in the root of the debugfs filesystem.
77 * @value: a pointer to the variable that the file should read to and write
78 * from.
79 *
80 * This function creates a file in debugfs with the given name that
81 * contains the value of the variable @value. If the @mode variable is so
82 * set, it can be read from, and written to.
83 *
84 * This function will return a pointer to a dentry if it succeeds. This
85 * pointer must be passed to the debugfs_remove() function when the file is
86 * to be removed (no automatic cleanup happens if your module is unloaded,
87 * you are responsible here.) If an error occurs, %NULL will be returned.
88 *
89 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
90 * returned. It is not wise to check for this value, but rather, check for
91 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
92 * code.
93 */
94struct dentry *debugfs_create_u8(const char *name, umode_t mode,
95 struct dentry *parent, u8 *value)
96{
97 /* if there are no write bits set, make read only */
98 if (!(mode & S_IWUGO))
99 return debugfs_create_file(name, mode, parent, value, &fops_u8_ro);
100 /* if there are no read bits set, make write only */
101 if (!(mode & S_IRUGO))
102 return debugfs_create_file(name, mode, parent, value, &fops_u8_wo);
103
104 return debugfs_create_file(name, mode, parent, value, &fops_u8);
105}
106EXPORT_SYMBOL_GPL(debugfs_create_u8);
107
108static int debugfs_u16_set(void *data, u64 val)
109{
110 *(u16 *)data = val;
111 return 0;
112}
113static int debugfs_u16_get(void *data, u64 *val)
114{
115 *val = *(u16 *)data;
116 return 0;
117}
118DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
119DEFINE_SIMPLE_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
120DEFINE_SIMPLE_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
121
122/**
123 * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
124 * @name: a pointer to a string containing the name of the file to create.
125 * @mode: the permission that the file should have
126 * @parent: a pointer to the parent dentry for this file. This should be a
127 * directory dentry if set. If this parameter is %NULL, then the
128 * file will be created in the root of the debugfs filesystem.
129 * @value: a pointer to the variable that the file should read to and write
130 * from.
131 *
132 * This function creates a file in debugfs with the given name that
133 * contains the value of the variable @value. If the @mode variable is so
134 * set, it can be read from, and written to.
135 *
136 * This function will return a pointer to a dentry if it succeeds. This
137 * pointer must be passed to the debugfs_remove() function when the file is
138 * to be removed (no automatic cleanup happens if your module is unloaded,
139 * you are responsible here.) If an error occurs, %NULL will be returned.
140 *
141 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
142 * returned. It is not wise to check for this value, but rather, check for
143 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
144 * code.
145 */
146struct dentry *debugfs_create_u16(const char *name, umode_t mode,
147 struct dentry *parent, u16 *value)
148{
149 /* if there are no write bits set, make read only */
150 if (!(mode & S_IWUGO))
151 return debugfs_create_file(name, mode, parent, value, &fops_u16_ro);
152 /* if there are no read bits set, make write only */
153 if (!(mode & S_IRUGO))
154 return debugfs_create_file(name, mode, parent, value, &fops_u16_wo);
155
156 return debugfs_create_file(name, mode, parent, value, &fops_u16);
157}
158EXPORT_SYMBOL_GPL(debugfs_create_u16);
159
160static int debugfs_u32_set(void *data, u64 val)
161{
162 *(u32 *)data = val;
163 return 0;
164}
165static int debugfs_u32_get(void *data, u64 *val)
166{
167 *val = *(u32 *)data;
168 return 0;
169}
170DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
171DEFINE_SIMPLE_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
172DEFINE_SIMPLE_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
173
174/**
175 * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
176 * @name: a pointer to a string containing the name of the file to create.
177 * @mode: the permission that the file should have
178 * @parent: a pointer to the parent dentry for this file. This should be a
179 * directory dentry if set. If this parameter is %NULL, then the
180 * file will be created in the root of the debugfs filesystem.
181 * @value: a pointer to the variable that the file should read to and write
182 * from.
183 *
184 * This function creates a file in debugfs with the given name that
185 * contains the value of the variable @value. If the @mode variable is so
186 * set, it can be read from, and written to.
187 *
188 * This function will return a pointer to a dentry if it succeeds. This
189 * pointer must be passed to the debugfs_remove() function when the file is
190 * to be removed (no automatic cleanup happens if your module is unloaded,
191 * you are responsible here.) If an error occurs, %NULL will be returned.
192 *
193 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
194 * returned. It is not wise to check for this value, but rather, check for
195 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
196 * code.
197 */
198struct dentry *debugfs_create_u32(const char *name, umode_t mode,
199 struct dentry *parent, u32 *value)
200{
201 /* if there are no write bits set, make read only */
202 if (!(mode & S_IWUGO))
203 return debugfs_create_file(name, mode, parent, value, &fops_u32_ro);
204 /* if there are no read bits set, make write only */
205 if (!(mode & S_IRUGO))
206 return debugfs_create_file(name, mode, parent, value, &fops_u32_wo);
207
208 return debugfs_create_file(name, mode, parent, value, &fops_u32);
209}
210EXPORT_SYMBOL_GPL(debugfs_create_u32);
211
212static int debugfs_u64_set(void *data, u64 val)
213{
214 *(u64 *)data = val;
215 return 0;
216}
217
218static int debugfs_u64_get(void *data, u64 *val)
219{
220 *val = *(u64 *)data;
221 return 0;
222}
223DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
224DEFINE_SIMPLE_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
225DEFINE_SIMPLE_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
226
227/**
228 * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value
229 * @name: a pointer to a string containing the name of the file to create.
230 * @mode: the permission that the file should have
231 * @parent: a pointer to the parent dentry for this file. This should be a
232 * directory dentry if set. If this parameter is %NULL, then the
233 * file will be created in the root of the debugfs filesystem.
234 * @value: a pointer to the variable that the file should read to and write
235 * from.
236 *
237 * This function creates a file in debugfs with the given name that
238 * contains the value of the variable @value. If the @mode variable is so
239 * set, it can be read from, and written to.
240 *
241 * This function will return a pointer to a dentry if it succeeds. This
242 * pointer must be passed to the debugfs_remove() function when the file is
243 * to be removed (no automatic cleanup happens if your module is unloaded,
244 * you are responsible here.) If an error occurs, %NULL will be returned.
245 *
246 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
247 * returned. It is not wise to check for this value, but rather, check for
248 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
249 * code.
250 */
251struct dentry *debugfs_create_u64(const char *name, umode_t mode,
252 struct dentry *parent, u64 *value)
253{
254 /* if there are no write bits set, make read only */
255 if (!(mode & S_IWUGO))
256 return debugfs_create_file(name, mode, parent, value, &fops_u64_ro);
257 /* if there are no read bits set, make write only */
258 if (!(mode & S_IRUGO))
259 return debugfs_create_file(name, mode, parent, value, &fops_u64_wo);
260
261 return debugfs_create_file(name, mode, parent, value, &fops_u64);
262}
263EXPORT_SYMBOL_GPL(debugfs_create_u64);
264
265DEFINE_SIMPLE_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
266DEFINE_SIMPLE_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
267DEFINE_SIMPLE_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
268
269DEFINE_SIMPLE_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n");
270DEFINE_SIMPLE_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
271DEFINE_SIMPLE_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
272
273DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n");
274DEFINE_SIMPLE_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
275DEFINE_SIMPLE_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
276
277DEFINE_SIMPLE_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, "0x%016llx\n");
278
279/*
280 * debugfs_create_x{8,16,32,64} - create a debugfs file that is used to read and write an unsigned {8,16,32,64}-bit value
281 *
282 * These functions are exactly the same as the above functions (but use a hex
283 * output for the decimal challenged). For details look at the above unsigned
284 * decimal functions.
285 */
286
287/**
288 * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value
289 * @name: a pointer to a string containing the name of the file to create.
290 * @mode: the permission that the file should have
291 * @parent: a pointer to the parent dentry for this file. This should be a
292 * directory dentry if set. If this parameter is %NULL, then the
293 * file will be created in the root of the debugfs filesystem.
294 * @value: a pointer to the variable that the file should read to and write
295 * from.
296 */
297struct dentry *debugfs_create_x8(const char *name, umode_t mode,
298 struct dentry *parent, u8 *value)
299{
300 /* if there are no write bits set, make read only */
301 if (!(mode & S_IWUGO))
302 return debugfs_create_file(name, mode, parent, value, &fops_x8_ro);
303 /* if there are no read bits set, make write only */
304 if (!(mode & S_IRUGO))
305 return debugfs_create_file(name, mode, parent, value, &fops_x8_wo);
306
307 return debugfs_create_file(name, mode, parent, value, &fops_x8);
308}
309EXPORT_SYMBOL_GPL(debugfs_create_x8);
310
311/**
312 * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value
313 * @name: a pointer to a string containing the name of the file to create.
314 * @mode: the permission that the file should have
315 * @parent: a pointer to the parent dentry for this file. This should be a
316 * directory dentry if set. If this parameter is %NULL, then the
317 * file will be created in the root of the debugfs filesystem.
318 * @value: a pointer to the variable that the file should read to and write
319 * from.
320 */
321struct dentry *debugfs_create_x16(const char *name, umode_t mode,
322 struct dentry *parent, u16 *value)
323{
324 /* if there are no write bits set, make read only */
325 if (!(mode & S_IWUGO))
326 return debugfs_create_file(name, mode, parent, value, &fops_x16_ro);
327 /* if there are no read bits set, make write only */
328 if (!(mode & S_IRUGO))
329 return debugfs_create_file(name, mode, parent, value, &fops_x16_wo);
330
331 return debugfs_create_file(name, mode, parent, value, &fops_x16);
332}
333EXPORT_SYMBOL_GPL(debugfs_create_x16);
334
335/**
336 * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value
337 * @name: a pointer to a string containing the name of the file to create.
338 * @mode: the permission that the file should have
339 * @parent: a pointer to the parent dentry for this file. This should be a
340 * directory dentry if set. If this parameter is %NULL, then the
341 * file will be created in the root of the debugfs filesystem.
342 * @value: a pointer to the variable that the file should read to and write
343 * from.
344 */
345struct dentry *debugfs_create_x32(const char *name, umode_t mode,
346 struct dentry *parent, u32 *value)
347{
348 /* if there are no write bits set, make read only */
349 if (!(mode & S_IWUGO))
350 return debugfs_create_file(name, mode, parent, value, &fops_x32_ro);
351 /* if there are no read bits set, make write only */
352 if (!(mode & S_IRUGO))
353 return debugfs_create_file(name, mode, parent, value, &fops_x32_wo);
354
355 return debugfs_create_file(name, mode, parent, value, &fops_x32);
356}
357EXPORT_SYMBOL_GPL(debugfs_create_x32);
358
359/**
360 * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value
361 * @name: a pointer to a string containing the name of the file to create.
362 * @mode: the permission that the file should have
363 * @parent: a pointer to the parent dentry for this file. This should be a
364 * directory dentry if set. If this parameter is %NULL, then the
365 * file will be created in the root of the debugfs filesystem.
366 * @value: a pointer to the variable that the file should read to and write
367 * from.
368 */
369struct dentry *debugfs_create_x64(const char *name, umode_t mode,
370 struct dentry *parent, u64 *value)
371{
372 return debugfs_create_file(name, mode, parent, value, &fops_x64);
373}
374EXPORT_SYMBOL_GPL(debugfs_create_x64);
375
376
377static int debugfs_size_t_set(void *data, u64 val)
378{
379 *(size_t *)data = val;
380 return 0;
381}
382static int debugfs_size_t_get(void *data, u64 *val)
383{
384 *val = *(size_t *)data;
385 return 0;
386}
387DEFINE_SIMPLE_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
388 "%llu\n"); /* %llu and %zu are more or less the same */
389
390/**
391 * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value
392 * @name: a pointer to a string containing the name of the file to create.
393 * @mode: the permission that the file should have
394 * @parent: a pointer to the parent dentry for this file. This should be a
395 * directory dentry if set. If this parameter is %NULL, then the
396 * file will be created in the root of the debugfs filesystem.
397 * @value: a pointer to the variable that the file should read to and write
398 * from.
399 */
400struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
401 struct dentry *parent, size_t *value)
402{
403 return debugfs_create_file(name, mode, parent, value, &fops_size_t);
404}
405EXPORT_SYMBOL_GPL(debugfs_create_size_t);
406
407static int debugfs_atomic_t_set(void *data, u64 val)
408{
409 atomic_set((atomic_t *)data, val);
410 return 0;
411}
412static int debugfs_atomic_t_get(void *data, u64 *val)
413{
414 *val = atomic_read((atomic_t *)data);
415 return 0;
416}
417DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
418 debugfs_atomic_t_set, "%lld\n");
419DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%lld\n");
420DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%lld\n");
421
422/**
423 * debugfs_create_atomic_t - create a debugfs file that is used to read and
424 * write an atomic_t value
425 * @name: a pointer to a string containing the name of the file to create.
426 * @mode: the permission that the file should have
427 * @parent: a pointer to the parent dentry for this file. This should be a
428 * directory dentry if set. If this parameter is %NULL, then the
429 * file will be created in the root of the debugfs filesystem.
430 * @value: a pointer to the variable that the file should read to and write
431 * from.
432 */
433struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
434 struct dentry *parent, atomic_t *value)
435{
436 /* if there are no write bits set, make read only */
437 if (!(mode & S_IWUGO))
438 return debugfs_create_file(name, mode, parent, value,
439 &fops_atomic_t_ro);
440 /* if there are no read bits set, make write only */
441 if (!(mode & S_IRUGO))
442 return debugfs_create_file(name, mode, parent, value,
443 &fops_atomic_t_wo);
444
445 return debugfs_create_file(name, mode, parent, value, &fops_atomic_t);
446}
447EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
448
449static ssize_t read_file_bool(struct file *file, char __user *user_buf,
450 size_t count, loff_t *ppos)
451{
452 char buf[3];
453 u32 *val = file->private_data;
454
455 if (*val)
456 buf[0] = 'Y';
457 else
458 buf[0] = 'N';
459 buf[1] = '\n';
460 buf[2] = 0x00;
461 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
462}
463
464static ssize_t write_file_bool(struct file *file, const char __user *user_buf,
465 size_t count, loff_t *ppos)
466{
467 char buf[32];
468 size_t buf_size;
469 bool bv;
470 u32 *val = file->private_data;
471
472 buf_size = min(count, (sizeof(buf)-1));
473 if (copy_from_user(buf, user_buf, buf_size))
474 return -EFAULT;
475
476 buf[buf_size] = '\0';
477 if (strtobool(buf, &bv) == 0)
478 *val = bv;
479
480 return count;
481}
482
483static const struct file_operations fops_bool = {
484 .read = read_file_bool,
485 .write = write_file_bool,
486 .open = simple_open,
487 .llseek = default_llseek,
488};
489
490/**
491 * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value
492 * @name: a pointer to a string containing the name of the file to create.
493 * @mode: the permission that the file should have
494 * @parent: a pointer to the parent dentry for this file. This should be a
495 * directory dentry if set. If this parameter is %NULL, then the
496 * file will be created in the root of the debugfs filesystem.
497 * @value: a pointer to the variable that the file should read to and write
498 * from.
499 *
500 * This function creates a file in debugfs with the given name that
501 * contains the value of the variable @value. If the @mode variable is so
502 * set, it can be read from, and written to.
503 *
504 * This function will return a pointer to a dentry if it succeeds. This
505 * pointer must be passed to the debugfs_remove() function when the file is
506 * to be removed (no automatic cleanup happens if your module is unloaded,
507 * you are responsible here.) If an error occurs, %NULL will be returned.
508 *
509 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
510 * returned. It is not wise to check for this value, but rather, check for
511 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
512 * code.
513 */
514struct dentry *debugfs_create_bool(const char *name, umode_t mode,
515 struct dentry *parent, u32 *value)
516{
517 return debugfs_create_file(name, mode, parent, value, &fops_bool);
518}
519EXPORT_SYMBOL_GPL(debugfs_create_bool);
520
521static ssize_t read_file_blob(struct file *file, char __user *user_buf,
522 size_t count, loff_t *ppos)
523{
524 struct debugfs_blob_wrapper *blob = file->private_data;
525 return simple_read_from_buffer(user_buf, count, ppos, blob->data,
526 blob->size);
527}
528
529static const struct file_operations fops_blob = {
530 .read = read_file_blob,
531 .open = simple_open,
532 .llseek = default_llseek,
533};
534
535/**
536 * debugfs_create_blob - create a debugfs file that is used to read a binary blob
537 * @name: a pointer to a string containing the name of the file to create.
538 * @mode: the permission that the file should have
539 * @parent: a pointer to the parent dentry for this file. This should be a
540 * directory dentry if set. If this parameter is %NULL, then the
541 * file will be created in the root of the debugfs filesystem.
542 * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer
543 * to the blob data and the size of the data.
544 *
545 * This function creates a file in debugfs with the given name that exports
546 * @blob->data as a binary blob. If the @mode variable is so set it can be
547 * read from. Writing is not supported.
548 *
549 * This function will return a pointer to a dentry if it succeeds. This
550 * pointer must be passed to the debugfs_remove() function when the file is
551 * to be removed (no automatic cleanup happens if your module is unloaded,
552 * you are responsible here.) If an error occurs, %NULL will be returned.
553 *
554 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
555 * returned. It is not wise to check for this value, but rather, check for
556 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
557 * code.
558 */
559struct dentry *debugfs_create_blob(const char *name, umode_t mode,
560 struct dentry *parent,
561 struct debugfs_blob_wrapper *blob)
562{
563 return debugfs_create_file(name, mode, parent, blob, &fops_blob);
564}
565EXPORT_SYMBOL_GPL(debugfs_create_blob);
566
567struct array_data {
568 void *array;
569 u32 elements;
570};
571
572static size_t u32_format_array(char *buf, size_t bufsize,
573 u32 *array, int array_size)
574{
575 size_t ret = 0;
576
577 while (--array_size >= 0) {
578 size_t len;
579 char term = array_size ? ' ' : '\n';
580
581 len = snprintf(buf, bufsize, "%u%c", *array++, term);
582 ret += len;
583
584 buf += len;
585 bufsize -= len;
586 }
587 return ret;
588}
589
590static int u32_array_open(struct inode *inode, struct file *file)
591{
592 struct array_data *data = inode->i_private;
593 int size, elements = data->elements;
594 char *buf;
595
596 /*
597 * Max size:
598 * - 10 digits + ' '/'\n' = 11 bytes per number
599 * - terminating NUL character
600 */
601 size = elements*11;
602 buf = kmalloc(size+1, GFP_KERNEL);
603 if (!buf)
604 return -ENOMEM;
605 buf[size] = 0;
606
607 file->private_data = buf;
608 u32_format_array(buf, size, data->array, data->elements);
609
610 return nonseekable_open(inode, file);
611}
612
613static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
614 loff_t *ppos)
615{
616 size_t size = strlen(file->private_data);
617
618 return simple_read_from_buffer(buf, len, ppos,
619 file->private_data, size);
620}
621
622static int u32_array_release(struct inode *inode, struct file *file)
623{
624 kfree(file->private_data);
625
626 return 0;
627}
628
629static const struct file_operations u32_array_fops = {
630 .owner = THIS_MODULE,
631 .open = u32_array_open,
632 .release = u32_array_release,
633 .read = u32_array_read,
634 .llseek = no_llseek,
635};
636
637/**
638 * debugfs_create_u32_array - create a debugfs file that is used to read u32
639 * array.
640 * @name: a pointer to a string containing the name of the file to create.
641 * @mode: the permission that the file should have.
642 * @parent: a pointer to the parent dentry for this file. This should be a
643 * directory dentry if set. If this parameter is %NULL, then the
644 * file will be created in the root of the debugfs filesystem.
645 * @array: u32 array that provides data.
646 * @elements: total number of elements in the array.
647 *
648 * This function creates a file in debugfs with the given name that exports
649 * @array as data. If the @mode variable is so set it can be read from.
650 * Writing is not supported. Seek within the file is also not supported.
651 * Once array is created its size can not be changed.
652 *
653 * The function returns a pointer to dentry on success. If debugfs is not
654 * enabled in the kernel, the value -%ENODEV will be returned.
655 */
656struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
657 struct dentry *parent,
658 u32 *array, u32 elements)
659{
660 struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL);
661
662 if (data == NULL)
663 return NULL;
664
665 data->array = array;
666 data->elements = elements;
667
668 return debugfs_create_file(name, mode, parent, data, &u32_array_fops);
669}
670EXPORT_SYMBOL_GPL(debugfs_create_u32_array);
671
672#ifdef CONFIG_HAS_IOMEM
673
674/*
675 * The regset32 stuff is used to print 32-bit registers using the
676 * seq_file utilities. We offer printing a register set in an already-opened
677 * sequential file or create a debugfs file that only prints a regset32.
678 */
679
680/**
681 * debugfs_print_regs32 - use seq_print to describe a set of registers
682 * @s: the seq_file structure being used to generate output
683 * @regs: an array if struct debugfs_reg32 structures
684 * @nregs: the length of the above array
685 * @base: the base address to be used in reading the registers
686 * @prefix: a string to be prefixed to every output line
687 *
688 * This function outputs a text block describing the current values of
689 * some 32-bit hardware registers. It is meant to be used within debugfs
690 * files based on seq_file that need to show registers, intermixed with other
691 * information. The prefix argument may be used to specify a leading string,
692 * because some peripherals have several blocks of identical registers,
693 * for example configuration of dma channels
694 */
695int debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
696 int nregs, void __iomem *base, char *prefix)
697{
698 int i, ret = 0;
699
700 for (i = 0; i < nregs; i++, regs++) {
701 if (prefix)
702 ret += seq_printf(s, "%s", prefix);
703 ret += seq_printf(s, "%s = 0x%08x\n", regs->name,
704 readl(base + regs->offset));
705 }
706 return ret;
707}
708EXPORT_SYMBOL_GPL(debugfs_print_regs32);
709
710static int debugfs_show_regset32(struct seq_file *s, void *data)
711{
712 struct debugfs_regset32 *regset = s->private;
713
714 debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, "");
715 return 0;
716}
717
718static int debugfs_open_regset32(struct inode *inode, struct file *file)
719{
720 return single_open(file, debugfs_show_regset32, inode->i_private);
721}
722
723static const struct file_operations fops_regset32 = {
724 .open = debugfs_open_regset32,
725 .read = seq_read,
726 .llseek = seq_lseek,
727 .release = single_release,
728};
729
730/**
731 * debugfs_create_regset32 - create a debugfs file that returns register values
732 * @name: a pointer to a string containing the name of the file to create.
733 * @mode: the permission that the file should have
734 * @parent: a pointer to the parent dentry for this file. This should be a
735 * directory dentry if set. If this parameter is %NULL, then the
736 * file will be created in the root of the debugfs filesystem.
737 * @regset: a pointer to a struct debugfs_regset32, which contains a pointer
738 * to an array of register definitions, the array size and the base
739 * address where the register bank is to be found.
740 *
741 * This function creates a file in debugfs with the given name that reports
742 * the names and values of a set of 32-bit registers. If the @mode variable
743 * is so set it can be read from. Writing is not supported.
744 *
745 * This function will return a pointer to a dentry if it succeeds. This
746 * pointer must be passed to the debugfs_remove() function when the file is
747 * to be removed (no automatic cleanup happens if your module is unloaded,
748 * you are responsible here.) If an error occurs, %NULL will be returned.
749 *
750 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
751 * returned. It is not wise to check for this value, but rather, check for
752 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
753 * code.
754 */
755struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
756 struct dentry *parent,
757 struct debugfs_regset32 *regset)
758{
759 return debugfs_create_file(name, mode, parent, regset, &fops_regset32);
760}
761EXPORT_SYMBOL_GPL(debugfs_create_regset32);
762
763#endif /* CONFIG_HAS_IOMEM */
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * file.c - part of debugfs, 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#include <linux/module.h>
13#include <linux/fs.h>
14#include <linux/seq_file.h>
15#include <linux/pagemap.h>
16#include <linux/debugfs.h>
17#include <linux/io.h>
18#include <linux/slab.h>
19#include <linux/atomic.h>
20#include <linux/device.h>
21#include <linux/poll.h>
22#include <linux/security.h>
23
24#include "internal.h"
25
26struct poll_table_struct;
27
28static ssize_t default_read_file(struct file *file, char __user *buf,
29 size_t count, loff_t *ppos)
30{
31 return 0;
32}
33
34static ssize_t default_write_file(struct file *file, const char __user *buf,
35 size_t count, loff_t *ppos)
36{
37 return count;
38}
39
40const struct file_operations debugfs_noop_file_operations = {
41 .read = default_read_file,
42 .write = default_write_file,
43 .open = simple_open,
44 .llseek = noop_llseek,
45};
46
47#define F_DENTRY(filp) ((filp)->f_path.dentry)
48
49const struct file_operations *debugfs_real_fops(const struct file *filp)
50{
51 struct debugfs_fsdata *fsd = F_DENTRY(filp)->d_fsdata;
52
53 if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) {
54 /*
55 * Urgh, we've been called w/o a protecting
56 * debugfs_file_get().
57 */
58 WARN_ON(1);
59 return NULL;
60 }
61
62 return fsd->real_fops;
63}
64EXPORT_SYMBOL_GPL(debugfs_real_fops);
65
66/**
67 * debugfs_file_get - mark the beginning of file data access
68 * @dentry: the dentry object whose data is being accessed.
69 *
70 * Up to a matching call to debugfs_file_put(), any successive call
71 * into the file removing functions debugfs_remove() and
72 * debugfs_remove_recursive() will block. Since associated private
73 * file data may only get freed after a successful return of any of
74 * the removal functions, you may safely access it after a successful
75 * call to debugfs_file_get() without worrying about lifetime issues.
76 *
77 * If -%EIO is returned, the file has already been removed and thus,
78 * it is not safe to access any of its data. If, on the other hand,
79 * it is allowed to access the file data, zero is returned.
80 */
81int debugfs_file_get(struct dentry *dentry)
82{
83 struct debugfs_fsdata *fsd;
84 void *d_fsd;
85
86 d_fsd = READ_ONCE(dentry->d_fsdata);
87 if (!((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) {
88 fsd = d_fsd;
89 } else {
90 fsd = kmalloc(sizeof(*fsd), GFP_KERNEL);
91 if (!fsd)
92 return -ENOMEM;
93
94 fsd->real_fops = (void *)((unsigned long)d_fsd &
95 ~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT);
96 refcount_set(&fsd->active_users, 1);
97 init_completion(&fsd->active_users_drained);
98 if (cmpxchg(&dentry->d_fsdata, d_fsd, fsd) != d_fsd) {
99 kfree(fsd);
100 fsd = READ_ONCE(dentry->d_fsdata);
101 }
102 }
103
104 /*
105 * In case of a successful cmpxchg() above, this check is
106 * strictly necessary and must follow it, see the comment in
107 * __debugfs_remove_file().
108 * OTOH, if the cmpxchg() hasn't been executed or wasn't
109 * successful, this serves the purpose of not starving
110 * removers.
111 */
112 if (d_unlinked(dentry))
113 return -EIO;
114
115 if (!refcount_inc_not_zero(&fsd->active_users))
116 return -EIO;
117
118 return 0;
119}
120EXPORT_SYMBOL_GPL(debugfs_file_get);
121
122/**
123 * debugfs_file_put - mark the end of file data access
124 * @dentry: the dentry object formerly passed to
125 * debugfs_file_get().
126 *
127 * Allow any ongoing concurrent call into debugfs_remove() or
128 * debugfs_remove_recursive() blocked by a former call to
129 * debugfs_file_get() to proceed and return to its caller.
130 */
131void debugfs_file_put(struct dentry *dentry)
132{
133 struct debugfs_fsdata *fsd = READ_ONCE(dentry->d_fsdata);
134
135 if (refcount_dec_and_test(&fsd->active_users))
136 complete(&fsd->active_users_drained);
137}
138EXPORT_SYMBOL_GPL(debugfs_file_put);
139
140/*
141 * Only permit access to world-readable files when the kernel is locked down.
142 * We also need to exclude any file that has ways to write or alter it as root
143 * can bypass the permissions check.
144 */
145static bool debugfs_is_locked_down(struct inode *inode,
146 struct file *filp,
147 const struct file_operations *real_fops)
148{
149 if ((inode->i_mode & 07777) == 0444 &&
150 !(filp->f_mode & FMODE_WRITE) &&
151 !real_fops->unlocked_ioctl &&
152 !real_fops->compat_ioctl &&
153 !real_fops->mmap)
154 return false;
155
156 return security_locked_down(LOCKDOWN_DEBUGFS);
157}
158
159static int open_proxy_open(struct inode *inode, struct file *filp)
160{
161 struct dentry *dentry = F_DENTRY(filp);
162 const struct file_operations *real_fops = NULL;
163 int r;
164
165 r = debugfs_file_get(dentry);
166 if (r)
167 return r == -EIO ? -ENOENT : r;
168
169 real_fops = debugfs_real_fops(filp);
170
171 r = debugfs_is_locked_down(inode, filp, real_fops);
172 if (r)
173 goto out;
174
175 real_fops = fops_get(real_fops);
176 if (!real_fops) {
177 /* Huh? Module did not clean up after itself at exit? */
178 WARN(1, "debugfs file owner did not clean up at exit: %pd",
179 dentry);
180 r = -ENXIO;
181 goto out;
182 }
183 replace_fops(filp, real_fops);
184
185 if (real_fops->open)
186 r = real_fops->open(inode, filp);
187
188out:
189 debugfs_file_put(dentry);
190 return r;
191}
192
193const struct file_operations debugfs_open_proxy_file_operations = {
194 .open = open_proxy_open,
195};
196
197#define PROTO(args...) args
198#define ARGS(args...) args
199
200#define FULL_PROXY_FUNC(name, ret_type, filp, proto, args) \
201static ret_type full_proxy_ ## name(proto) \
202{ \
203 struct dentry *dentry = F_DENTRY(filp); \
204 const struct file_operations *real_fops; \
205 ret_type r; \
206 \
207 r = debugfs_file_get(dentry); \
208 if (unlikely(r)) \
209 return r; \
210 real_fops = debugfs_real_fops(filp); \
211 r = real_fops->name(args); \
212 debugfs_file_put(dentry); \
213 return r; \
214}
215
216FULL_PROXY_FUNC(llseek, loff_t, filp,
217 PROTO(struct file *filp, loff_t offset, int whence),
218 ARGS(filp, offset, whence));
219
220FULL_PROXY_FUNC(read, ssize_t, filp,
221 PROTO(struct file *filp, char __user *buf, size_t size,
222 loff_t *ppos),
223 ARGS(filp, buf, size, ppos));
224
225FULL_PROXY_FUNC(write, ssize_t, filp,
226 PROTO(struct file *filp, const char __user *buf, size_t size,
227 loff_t *ppos),
228 ARGS(filp, buf, size, ppos));
229
230FULL_PROXY_FUNC(unlocked_ioctl, long, filp,
231 PROTO(struct file *filp, unsigned int cmd, unsigned long arg),
232 ARGS(filp, cmd, arg));
233
234static __poll_t full_proxy_poll(struct file *filp,
235 struct poll_table_struct *wait)
236{
237 struct dentry *dentry = F_DENTRY(filp);
238 __poll_t r = 0;
239 const struct file_operations *real_fops;
240
241 if (debugfs_file_get(dentry))
242 return EPOLLHUP;
243
244 real_fops = debugfs_real_fops(filp);
245 r = real_fops->poll(filp, wait);
246 debugfs_file_put(dentry);
247 return r;
248}
249
250static int full_proxy_release(struct inode *inode, struct file *filp)
251{
252 const struct dentry *dentry = F_DENTRY(filp);
253 const struct file_operations *real_fops = debugfs_real_fops(filp);
254 const struct file_operations *proxy_fops = filp->f_op;
255 int r = 0;
256
257 /*
258 * We must not protect this against removal races here: the
259 * original releaser should be called unconditionally in order
260 * not to leak any resources. Releasers must not assume that
261 * ->i_private is still being meaningful here.
262 */
263 if (real_fops->release)
264 r = real_fops->release(inode, filp);
265
266 replace_fops(filp, d_inode(dentry)->i_fop);
267 kfree((void *)proxy_fops);
268 fops_put(real_fops);
269 return r;
270}
271
272static void __full_proxy_fops_init(struct file_operations *proxy_fops,
273 const struct file_operations *real_fops)
274{
275 proxy_fops->release = full_proxy_release;
276 if (real_fops->llseek)
277 proxy_fops->llseek = full_proxy_llseek;
278 if (real_fops->read)
279 proxy_fops->read = full_proxy_read;
280 if (real_fops->write)
281 proxy_fops->write = full_proxy_write;
282 if (real_fops->poll)
283 proxy_fops->poll = full_proxy_poll;
284 if (real_fops->unlocked_ioctl)
285 proxy_fops->unlocked_ioctl = full_proxy_unlocked_ioctl;
286}
287
288static int full_proxy_open(struct inode *inode, struct file *filp)
289{
290 struct dentry *dentry = F_DENTRY(filp);
291 const struct file_operations *real_fops = NULL;
292 struct file_operations *proxy_fops = NULL;
293 int r;
294
295 r = debugfs_file_get(dentry);
296 if (r)
297 return r == -EIO ? -ENOENT : r;
298
299 real_fops = debugfs_real_fops(filp);
300
301 r = debugfs_is_locked_down(inode, filp, real_fops);
302 if (r)
303 goto out;
304
305 real_fops = fops_get(real_fops);
306 if (!real_fops) {
307 /* Huh? Module did not cleanup after itself at exit? */
308 WARN(1, "debugfs file owner did not clean up at exit: %pd",
309 dentry);
310 r = -ENXIO;
311 goto out;
312 }
313
314 proxy_fops = kzalloc(sizeof(*proxy_fops), GFP_KERNEL);
315 if (!proxy_fops) {
316 r = -ENOMEM;
317 goto free_proxy;
318 }
319 __full_proxy_fops_init(proxy_fops, real_fops);
320 replace_fops(filp, proxy_fops);
321
322 if (real_fops->open) {
323 r = real_fops->open(inode, filp);
324 if (r) {
325 replace_fops(filp, d_inode(dentry)->i_fop);
326 goto free_proxy;
327 } else if (filp->f_op != proxy_fops) {
328 /* No protection against file removal anymore. */
329 WARN(1, "debugfs file owner replaced proxy fops: %pd",
330 dentry);
331 goto free_proxy;
332 }
333 }
334
335 goto out;
336free_proxy:
337 kfree(proxy_fops);
338 fops_put(real_fops);
339out:
340 debugfs_file_put(dentry);
341 return r;
342}
343
344const struct file_operations debugfs_full_proxy_file_operations = {
345 .open = full_proxy_open,
346};
347
348ssize_t debugfs_attr_read(struct file *file, char __user *buf,
349 size_t len, loff_t *ppos)
350{
351 struct dentry *dentry = F_DENTRY(file);
352 ssize_t ret;
353
354 ret = debugfs_file_get(dentry);
355 if (unlikely(ret))
356 return ret;
357 ret = simple_attr_read(file, buf, len, ppos);
358 debugfs_file_put(dentry);
359 return ret;
360}
361EXPORT_SYMBOL_GPL(debugfs_attr_read);
362
363ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
364 size_t len, loff_t *ppos)
365{
366 struct dentry *dentry = F_DENTRY(file);
367 ssize_t ret;
368
369 ret = debugfs_file_get(dentry);
370 if (unlikely(ret))
371 return ret;
372 ret = simple_attr_write(file, buf, len, ppos);
373 debugfs_file_put(dentry);
374 return ret;
375}
376EXPORT_SYMBOL_GPL(debugfs_attr_write);
377
378static struct dentry *debugfs_create_mode_unsafe(const char *name, umode_t mode,
379 struct dentry *parent, void *value,
380 const struct file_operations *fops,
381 const struct file_operations *fops_ro,
382 const struct file_operations *fops_wo)
383{
384 /* if there are no write bits set, make read only */
385 if (!(mode & S_IWUGO))
386 return debugfs_create_file_unsafe(name, mode, parent, value,
387 fops_ro);
388 /* if there are no read bits set, make write only */
389 if (!(mode & S_IRUGO))
390 return debugfs_create_file_unsafe(name, mode, parent, value,
391 fops_wo);
392
393 return debugfs_create_file_unsafe(name, mode, parent, value, fops);
394}
395
396static int debugfs_u8_set(void *data, u64 val)
397{
398 *(u8 *)data = val;
399 return 0;
400}
401static int debugfs_u8_get(void *data, u64 *val)
402{
403 *val = *(u8 *)data;
404 return 0;
405}
406DEFINE_DEBUGFS_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
407DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
408DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
409
410/**
411 * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
412 * @name: a pointer to a string containing the name of the file to create.
413 * @mode: the permission that the file should have
414 * @parent: a pointer to the parent dentry for this file. This should be a
415 * directory dentry if set. If this parameter is %NULL, then the
416 * file will be created in the root of the debugfs filesystem.
417 * @value: a pointer to the variable that the file should read to and write
418 * from.
419 *
420 * This function creates a file in debugfs with the given name that
421 * contains the value of the variable @value. If the @mode variable is so
422 * set, it can be read from, and written to.
423 *
424 * This function will return a pointer to a dentry if it succeeds. This
425 * pointer must be passed to the debugfs_remove() function when the file is
426 * to be removed (no automatic cleanup happens if your module is unloaded,
427 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
428 * returned.
429 *
430 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
431 * be returned.
432 */
433struct dentry *debugfs_create_u8(const char *name, umode_t mode,
434 struct dentry *parent, u8 *value)
435{
436 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8,
437 &fops_u8_ro, &fops_u8_wo);
438}
439EXPORT_SYMBOL_GPL(debugfs_create_u8);
440
441static int debugfs_u16_set(void *data, u64 val)
442{
443 *(u16 *)data = val;
444 return 0;
445}
446static int debugfs_u16_get(void *data, u64 *val)
447{
448 *val = *(u16 *)data;
449 return 0;
450}
451DEFINE_DEBUGFS_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
452DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
453DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
454
455/**
456 * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
457 * @name: a pointer to a string containing the name of the file to create.
458 * @mode: the permission that the file should have
459 * @parent: a pointer to the parent dentry for this file. This should be a
460 * directory dentry if set. If this parameter is %NULL, then the
461 * file will be created in the root of the debugfs filesystem.
462 * @value: a pointer to the variable that the file should read to and write
463 * from.
464 *
465 * This function creates a file in debugfs with the given name that
466 * contains the value of the variable @value. If the @mode variable is so
467 * set, it can be read from, and written to.
468 *
469 * This function will return a pointer to a dentry if it succeeds. This
470 * pointer must be passed to the debugfs_remove() function when the file is
471 * to be removed (no automatic cleanup happens if your module is unloaded,
472 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
473 * returned.
474 *
475 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
476 * be returned.
477 */
478struct dentry *debugfs_create_u16(const char *name, umode_t mode,
479 struct dentry *parent, u16 *value)
480{
481 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16,
482 &fops_u16_ro, &fops_u16_wo);
483}
484EXPORT_SYMBOL_GPL(debugfs_create_u16);
485
486static int debugfs_u32_set(void *data, u64 val)
487{
488 *(u32 *)data = val;
489 return 0;
490}
491static int debugfs_u32_get(void *data, u64 *val)
492{
493 *val = *(u32 *)data;
494 return 0;
495}
496DEFINE_DEBUGFS_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
497DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
498DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
499
500/**
501 * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
502 * @name: a pointer to a string containing the name of the file to create.
503 * @mode: the permission that the file should have
504 * @parent: a pointer to the parent dentry for this file. This should be a
505 * directory dentry if set. If this parameter is %NULL, then the
506 * file will be created in the root of the debugfs filesystem.
507 * @value: a pointer to the variable that the file should read to and write
508 * from.
509 *
510 * This function creates a file in debugfs with the given name that
511 * contains the value of the variable @value. If the @mode variable is so
512 * set, it can be read from, and written to.
513 *
514 * This function will return a pointer to a dentry if it succeeds. This
515 * pointer must be passed to the debugfs_remove() function when the file is
516 * to be removed (no automatic cleanup happens if your module is unloaded,
517 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
518 * returned.
519 *
520 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
521 * be returned.
522 */
523struct dentry *debugfs_create_u32(const char *name, umode_t mode,
524 struct dentry *parent, u32 *value)
525{
526 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u32,
527 &fops_u32_ro, &fops_u32_wo);
528}
529EXPORT_SYMBOL_GPL(debugfs_create_u32);
530
531static int debugfs_u64_set(void *data, u64 val)
532{
533 *(u64 *)data = val;
534 return 0;
535}
536
537static int debugfs_u64_get(void *data, u64 *val)
538{
539 *val = *(u64 *)data;
540 return 0;
541}
542DEFINE_DEBUGFS_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
543DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
544DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
545
546/**
547 * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value
548 * @name: a pointer to a string containing the name of the file to create.
549 * @mode: the permission that the file should have
550 * @parent: a pointer to the parent dentry for this file. This should be a
551 * directory dentry if set. If this parameter is %NULL, then the
552 * file will be created in the root of the debugfs filesystem.
553 * @value: a pointer to the variable that the file should read to and write
554 * from.
555 *
556 * This function creates a file in debugfs with the given name that
557 * contains the value of the variable @value. If the @mode variable is so
558 * set, it can be read from, and written to.
559 *
560 * This function will return a pointer to a dentry if it succeeds. This
561 * pointer must be passed to the debugfs_remove() function when the file is
562 * to be removed (no automatic cleanup happens if your module is unloaded,
563 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
564 * returned.
565 *
566 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
567 * be returned.
568 */
569struct dentry *debugfs_create_u64(const char *name, umode_t mode,
570 struct dentry *parent, u64 *value)
571{
572 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u64,
573 &fops_u64_ro, &fops_u64_wo);
574}
575EXPORT_SYMBOL_GPL(debugfs_create_u64);
576
577static int debugfs_ulong_set(void *data, u64 val)
578{
579 *(unsigned long *)data = val;
580 return 0;
581}
582
583static int debugfs_ulong_get(void *data, u64 *val)
584{
585 *val = *(unsigned long *)data;
586 return 0;
587}
588DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set,
589 "%llu\n");
590DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n");
591DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n");
592
593/**
594 * debugfs_create_ulong - create a debugfs file that is used to read and write
595 * an unsigned long value.
596 * @name: a pointer to a string containing the name of the file to create.
597 * @mode: the permission that the file should have
598 * @parent: a pointer to the parent dentry for this file. This should be a
599 * directory dentry if set. If this parameter is %NULL, then the
600 * file will be created in the root of the debugfs filesystem.
601 * @value: a pointer to the variable that the file should read to and write
602 * from.
603 *
604 * This function creates a file in debugfs with the given name that
605 * contains the value of the variable @value. If the @mode variable is so
606 * set, it can be read from, and written to.
607 *
608 * This function will return a pointer to a dentry if it succeeds. This
609 * pointer must be passed to the debugfs_remove() function when the file is
610 * to be removed (no automatic cleanup happens if your module is unloaded,
611 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
612 * returned.
613 *
614 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
615 * be returned.
616 */
617struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
618 struct dentry *parent, unsigned long *value)
619{
620 return debugfs_create_mode_unsafe(name, mode, parent, value,
621 &fops_ulong, &fops_ulong_ro,
622 &fops_ulong_wo);
623}
624EXPORT_SYMBOL_GPL(debugfs_create_ulong);
625
626DEFINE_DEBUGFS_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
627DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
628DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
629
630DEFINE_DEBUGFS_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set,
631 "0x%04llx\n");
632DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
633DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
634
635DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set,
636 "0x%08llx\n");
637DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
638DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
639
640DEFINE_DEBUGFS_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set,
641 "0x%016llx\n");
642DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_ro, debugfs_u64_get, NULL, "0x%016llx\n");
643DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n");
644
645/*
646 * debugfs_create_x{8,16,32,64} - create a debugfs file that is used to read and write an unsigned {8,16,32,64}-bit value
647 *
648 * These functions are exactly the same as the above functions (but use a hex
649 * output for the decimal challenged). For details look at the above unsigned
650 * decimal functions.
651 */
652
653/**
654 * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value
655 * @name: a pointer to a string containing the name of the file to create.
656 * @mode: the permission that the file should have
657 * @parent: a pointer to the parent dentry for this file. This should be a
658 * directory dentry if set. If this parameter is %NULL, then the
659 * file will be created in the root of the debugfs filesystem.
660 * @value: a pointer to the variable that the file should read to and write
661 * from.
662 */
663struct dentry *debugfs_create_x8(const char *name, umode_t mode,
664 struct dentry *parent, u8 *value)
665{
666 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8,
667 &fops_x8_ro, &fops_x8_wo);
668}
669EXPORT_SYMBOL_GPL(debugfs_create_x8);
670
671/**
672 * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value
673 * @name: a pointer to a string containing the name of the file to create.
674 * @mode: the permission that the file should have
675 * @parent: a pointer to the parent dentry for this file. This should be a
676 * directory dentry if set. If this parameter is %NULL, then the
677 * file will be created in the root of the debugfs filesystem.
678 * @value: a pointer to the variable that the file should read to and write
679 * from.
680 */
681struct dentry *debugfs_create_x16(const char *name, umode_t mode,
682 struct dentry *parent, u16 *value)
683{
684 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x16,
685 &fops_x16_ro, &fops_x16_wo);
686}
687EXPORT_SYMBOL_GPL(debugfs_create_x16);
688
689/**
690 * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value
691 * @name: a pointer to a string containing the name of the file to create.
692 * @mode: the permission that the file should have
693 * @parent: a pointer to the parent dentry for this file. This should be a
694 * directory dentry if set. If this parameter is %NULL, then the
695 * file will be created in the root of the debugfs filesystem.
696 * @value: a pointer to the variable that the file should read to and write
697 * from.
698 */
699struct dentry *debugfs_create_x32(const char *name, umode_t mode,
700 struct dentry *parent, u32 *value)
701{
702 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x32,
703 &fops_x32_ro, &fops_x32_wo);
704}
705EXPORT_SYMBOL_GPL(debugfs_create_x32);
706
707/**
708 * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value
709 * @name: a pointer to a string containing the name of the file to create.
710 * @mode: the permission that the file should have
711 * @parent: a pointer to the parent dentry for this file. This should be a
712 * directory dentry if set. If this parameter is %NULL, then the
713 * file will be created in the root of the debugfs filesystem.
714 * @value: a pointer to the variable that the file should read to and write
715 * from.
716 */
717struct dentry *debugfs_create_x64(const char *name, umode_t mode,
718 struct dentry *parent, u64 *value)
719{
720 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x64,
721 &fops_x64_ro, &fops_x64_wo);
722}
723EXPORT_SYMBOL_GPL(debugfs_create_x64);
724
725
726static int debugfs_size_t_set(void *data, u64 val)
727{
728 *(size_t *)data = val;
729 return 0;
730}
731static int debugfs_size_t_get(void *data, u64 *val)
732{
733 *val = *(size_t *)data;
734 return 0;
735}
736DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
737 "%llu\n"); /* %llu and %zu are more or less the same */
738DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_ro, debugfs_size_t_get, NULL, "%llu\n");
739DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n");
740
741/**
742 * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value
743 * @name: a pointer to a string containing the name of the file to create.
744 * @mode: the permission that the file should have
745 * @parent: a pointer to the parent dentry for this file. This should be a
746 * directory dentry if set. If this parameter is %NULL, then the
747 * file will be created in the root of the debugfs filesystem.
748 * @value: a pointer to the variable that the file should read to and write
749 * from.
750 */
751struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
752 struct dentry *parent, size_t *value)
753{
754 return debugfs_create_mode_unsafe(name, mode, parent, value,
755 &fops_size_t, &fops_size_t_ro,
756 &fops_size_t_wo);
757}
758EXPORT_SYMBOL_GPL(debugfs_create_size_t);
759
760static int debugfs_atomic_t_set(void *data, u64 val)
761{
762 atomic_set((atomic_t *)data, val);
763 return 0;
764}
765static int debugfs_atomic_t_get(void *data, u64 *val)
766{
767 *val = atomic_read((atomic_t *)data);
768 return 0;
769}
770DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
771 debugfs_atomic_t_set, "%lld\n");
772DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL,
773 "%lld\n");
774DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set,
775 "%lld\n");
776
777/**
778 * debugfs_create_atomic_t - create a debugfs file that is used to read and
779 * write an atomic_t value
780 * @name: a pointer to a string containing the name of the file to create.
781 * @mode: the permission that the file should have
782 * @parent: a pointer to the parent dentry for this file. This should be a
783 * directory dentry if set. If this parameter is %NULL, then the
784 * file will be created in the root of the debugfs filesystem.
785 * @value: a pointer to the variable that the file should read to and write
786 * from.
787 */
788struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
789 struct dentry *parent, atomic_t *value)
790{
791 return debugfs_create_mode_unsafe(name, mode, parent, value,
792 &fops_atomic_t, &fops_atomic_t_ro,
793 &fops_atomic_t_wo);
794}
795EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
796
797ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
798 size_t count, loff_t *ppos)
799{
800 char buf[3];
801 bool val;
802 int r;
803 struct dentry *dentry = F_DENTRY(file);
804
805 r = debugfs_file_get(dentry);
806 if (unlikely(r))
807 return r;
808 val = *(bool *)file->private_data;
809 debugfs_file_put(dentry);
810
811 if (val)
812 buf[0] = 'Y';
813 else
814 buf[0] = 'N';
815 buf[1] = '\n';
816 buf[2] = 0x00;
817 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
818}
819EXPORT_SYMBOL_GPL(debugfs_read_file_bool);
820
821ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
822 size_t count, loff_t *ppos)
823{
824 bool bv;
825 int r;
826 bool *val = file->private_data;
827 struct dentry *dentry = F_DENTRY(file);
828
829 r = kstrtobool_from_user(user_buf, count, &bv);
830 if (!r) {
831 r = debugfs_file_get(dentry);
832 if (unlikely(r))
833 return r;
834 *val = bv;
835 debugfs_file_put(dentry);
836 }
837
838 return count;
839}
840EXPORT_SYMBOL_GPL(debugfs_write_file_bool);
841
842static const struct file_operations fops_bool = {
843 .read = debugfs_read_file_bool,
844 .write = debugfs_write_file_bool,
845 .open = simple_open,
846 .llseek = default_llseek,
847};
848
849static const struct file_operations fops_bool_ro = {
850 .read = debugfs_read_file_bool,
851 .open = simple_open,
852 .llseek = default_llseek,
853};
854
855static const struct file_operations fops_bool_wo = {
856 .write = debugfs_write_file_bool,
857 .open = simple_open,
858 .llseek = default_llseek,
859};
860
861/**
862 * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value
863 * @name: a pointer to a string containing the name of the file to create.
864 * @mode: the permission that the file should have
865 * @parent: a pointer to the parent dentry for this file. This should be a
866 * directory dentry if set. If this parameter is %NULL, then the
867 * file will be created in the root of the debugfs filesystem.
868 * @value: a pointer to the variable that the file should read to and write
869 * from.
870 *
871 * This function creates a file in debugfs with the given name that
872 * contains the value of the variable @value. If the @mode variable is so
873 * set, it can be read from, and written to.
874 *
875 * This function will return a pointer to a dentry if it succeeds. This
876 * pointer must be passed to the debugfs_remove() function when the file is
877 * to be removed (no automatic cleanup happens if your module is unloaded,
878 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
879 * returned.
880 *
881 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
882 * be returned.
883 */
884struct dentry *debugfs_create_bool(const char *name, umode_t mode,
885 struct dentry *parent, bool *value)
886{
887 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_bool,
888 &fops_bool_ro, &fops_bool_wo);
889}
890EXPORT_SYMBOL_GPL(debugfs_create_bool);
891
892static ssize_t read_file_blob(struct file *file, char __user *user_buf,
893 size_t count, loff_t *ppos)
894{
895 struct debugfs_blob_wrapper *blob = file->private_data;
896 struct dentry *dentry = F_DENTRY(file);
897 ssize_t r;
898
899 r = debugfs_file_get(dentry);
900 if (unlikely(r))
901 return r;
902 r = simple_read_from_buffer(user_buf, count, ppos, blob->data,
903 blob->size);
904 debugfs_file_put(dentry);
905 return r;
906}
907
908static const struct file_operations fops_blob = {
909 .read = read_file_blob,
910 .open = simple_open,
911 .llseek = default_llseek,
912};
913
914/**
915 * debugfs_create_blob - create a debugfs file that is used to read a binary blob
916 * @name: a pointer to a string containing the name of the file to create.
917 * @mode: the permission that the file should have
918 * @parent: a pointer to the parent dentry for this file. This should be a
919 * directory dentry if set. If this parameter is %NULL, then the
920 * file will be created in the root of the debugfs filesystem.
921 * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer
922 * to the blob data and the size of the data.
923 *
924 * This function creates a file in debugfs with the given name that exports
925 * @blob->data as a binary blob. If the @mode variable is so set it can be
926 * read from. Writing is not supported.
927 *
928 * This function will return a pointer to a dentry if it succeeds. This
929 * pointer must be passed to the debugfs_remove() function when the file is
930 * to be removed (no automatic cleanup happens if your module is unloaded,
931 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
932 * returned.
933 *
934 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
935 * be returned.
936 */
937struct dentry *debugfs_create_blob(const char *name, umode_t mode,
938 struct dentry *parent,
939 struct debugfs_blob_wrapper *blob)
940{
941 return debugfs_create_file_unsafe(name, mode, parent, blob, &fops_blob);
942}
943EXPORT_SYMBOL_GPL(debugfs_create_blob);
944
945struct array_data {
946 void *array;
947 u32 elements;
948};
949
950static size_t u32_format_array(char *buf, size_t bufsize,
951 u32 *array, int array_size)
952{
953 size_t ret = 0;
954
955 while (--array_size >= 0) {
956 size_t len;
957 char term = array_size ? ' ' : '\n';
958
959 len = snprintf(buf, bufsize, "%u%c", *array++, term);
960 ret += len;
961
962 buf += len;
963 bufsize -= len;
964 }
965 return ret;
966}
967
968static int u32_array_open(struct inode *inode, struct file *file)
969{
970 struct array_data *data = inode->i_private;
971 int size, elements = data->elements;
972 char *buf;
973
974 /*
975 * Max size:
976 * - 10 digits + ' '/'\n' = 11 bytes per number
977 * - terminating NUL character
978 */
979 size = elements*11;
980 buf = kmalloc(size+1, GFP_KERNEL);
981 if (!buf)
982 return -ENOMEM;
983 buf[size] = 0;
984
985 file->private_data = buf;
986 u32_format_array(buf, size, data->array, data->elements);
987
988 return nonseekable_open(inode, file);
989}
990
991static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
992 loff_t *ppos)
993{
994 size_t size = strlen(file->private_data);
995
996 return simple_read_from_buffer(buf, len, ppos,
997 file->private_data, size);
998}
999
1000static int u32_array_release(struct inode *inode, struct file *file)
1001{
1002 kfree(file->private_data);
1003
1004 return 0;
1005}
1006
1007static const struct file_operations u32_array_fops = {
1008 .owner = THIS_MODULE,
1009 .open = u32_array_open,
1010 .release = u32_array_release,
1011 .read = u32_array_read,
1012 .llseek = no_llseek,
1013};
1014
1015/**
1016 * debugfs_create_u32_array - create a debugfs file that is used to read u32
1017 * array.
1018 * @name: a pointer to a string containing the name of the file to create.
1019 * @mode: the permission that the file should have.
1020 * @parent: a pointer to the parent dentry for this file. This should be a
1021 * directory dentry if set. If this parameter is %NULL, then the
1022 * file will be created in the root of the debugfs filesystem.
1023 * @array: u32 array that provides data.
1024 * @elements: total number of elements in the array.
1025 *
1026 * This function creates a file in debugfs with the given name that exports
1027 * @array as data. If the @mode variable is so set it can be read from.
1028 * Writing is not supported. Seek within the file is also not supported.
1029 * Once array is created its size can not be changed.
1030 */
1031void debugfs_create_u32_array(const char *name, umode_t mode,
1032 struct dentry *parent, u32 *array, u32 elements)
1033{
1034 struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL);
1035
1036 if (data == NULL)
1037 return;
1038
1039 data->array = array;
1040 data->elements = elements;
1041
1042 debugfs_create_file_unsafe(name, mode, parent, data, &u32_array_fops);
1043}
1044EXPORT_SYMBOL_GPL(debugfs_create_u32_array);
1045
1046#ifdef CONFIG_HAS_IOMEM
1047
1048/*
1049 * The regset32 stuff is used to print 32-bit registers using the
1050 * seq_file utilities. We offer printing a register set in an already-opened
1051 * sequential file or create a debugfs file that only prints a regset32.
1052 */
1053
1054/**
1055 * debugfs_print_regs32 - use seq_print to describe a set of registers
1056 * @s: the seq_file structure being used to generate output
1057 * @regs: an array if struct debugfs_reg32 structures
1058 * @nregs: the length of the above array
1059 * @base: the base address to be used in reading the registers
1060 * @prefix: a string to be prefixed to every output line
1061 *
1062 * This function outputs a text block describing the current values of
1063 * some 32-bit hardware registers. It is meant to be used within debugfs
1064 * files based on seq_file that need to show registers, intermixed with other
1065 * information. The prefix argument may be used to specify a leading string,
1066 * because some peripherals have several blocks of identical registers,
1067 * for example configuration of dma channels
1068 */
1069void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
1070 int nregs, void __iomem *base, char *prefix)
1071{
1072 int i;
1073
1074 for (i = 0; i < nregs; i++, regs++) {
1075 if (prefix)
1076 seq_printf(s, "%s", prefix);
1077 seq_printf(s, "%s = 0x%08x\n", regs->name,
1078 readl(base + regs->offset));
1079 if (seq_has_overflowed(s))
1080 break;
1081 }
1082}
1083EXPORT_SYMBOL_GPL(debugfs_print_regs32);
1084
1085static int debugfs_show_regset32(struct seq_file *s, void *data)
1086{
1087 struct debugfs_regset32 *regset = s->private;
1088
1089 debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, "");
1090 return 0;
1091}
1092
1093static int debugfs_open_regset32(struct inode *inode, struct file *file)
1094{
1095 return single_open(file, debugfs_show_regset32, inode->i_private);
1096}
1097
1098static const struct file_operations fops_regset32 = {
1099 .open = debugfs_open_regset32,
1100 .read = seq_read,
1101 .llseek = seq_lseek,
1102 .release = single_release,
1103};
1104
1105/**
1106 * debugfs_create_regset32 - create a debugfs file that returns register values
1107 * @name: a pointer to a string containing the name of the file to create.
1108 * @mode: the permission that the file should have
1109 * @parent: a pointer to the parent dentry for this file. This should be a
1110 * directory dentry if set. If this parameter is %NULL, then the
1111 * file will be created in the root of the debugfs filesystem.
1112 * @regset: a pointer to a struct debugfs_regset32, which contains a pointer
1113 * to an array of register definitions, the array size and the base
1114 * address where the register bank is to be found.
1115 *
1116 * This function creates a file in debugfs with the given name that reports
1117 * the names and values of a set of 32-bit registers. If the @mode variable
1118 * is so set it can be read from. Writing is not supported.
1119 *
1120 * This function will return a pointer to a dentry if it succeeds. This
1121 * pointer must be passed to the debugfs_remove() function when the file is
1122 * to be removed (no automatic cleanup happens if your module is unloaded,
1123 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
1124 * returned.
1125 *
1126 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
1127 * be returned.
1128 */
1129struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
1130 struct dentry *parent,
1131 struct debugfs_regset32 *regset)
1132{
1133 return debugfs_create_file(name, mode, parent, regset, &fops_regset32);
1134}
1135EXPORT_SYMBOL_GPL(debugfs_create_regset32);
1136
1137#endif /* CONFIG_HAS_IOMEM */
1138
1139struct debugfs_devm_entry {
1140 int (*read)(struct seq_file *seq, void *data);
1141 struct device *dev;
1142};
1143
1144static int debugfs_devm_entry_open(struct inode *inode, struct file *f)
1145{
1146 struct debugfs_devm_entry *entry = inode->i_private;
1147
1148 return single_open(f, entry->read, entry->dev);
1149}
1150
1151static const struct file_operations debugfs_devm_entry_ops = {
1152 .owner = THIS_MODULE,
1153 .open = debugfs_devm_entry_open,
1154 .release = single_release,
1155 .read = seq_read,
1156 .llseek = seq_lseek
1157};
1158
1159/**
1160 * debugfs_create_devm_seqfile - create a debugfs file that is bound to device.
1161 *
1162 * @dev: device related to this debugfs file.
1163 * @name: name of the debugfs file.
1164 * @parent: a pointer to the parent dentry for this file. This should be a
1165 * directory dentry if set. If this parameter is %NULL, then the
1166 * file will be created in the root of the debugfs filesystem.
1167 * @read_fn: function pointer called to print the seq_file content.
1168 */
1169struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
1170 struct dentry *parent,
1171 int (*read_fn)(struct seq_file *s,
1172 void *data))
1173{
1174 struct debugfs_devm_entry *entry;
1175
1176 if (IS_ERR(parent))
1177 return ERR_PTR(-ENOENT);
1178
1179 entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL);
1180 if (!entry)
1181 return ERR_PTR(-ENOMEM);
1182
1183 entry->read = read_fn;
1184 entry->dev = dev;
1185
1186 return debugfs_create_file(name, S_IRUGO, parent, entry,
1187 &debugfs_devm_entry_ops);
1188}
1189EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile);
1190