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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/*
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/pagemap.h>
19#include <linux/namei.h>
20#include <linux/debugfs.h>
21
22static ssize_t default_read_file(struct file *file, char __user *buf,
23 size_t count, loff_t *ppos)
24{
25 return 0;
26}
27
28static ssize_t default_write_file(struct file *file, const char __user *buf,
29 size_t count, loff_t *ppos)
30{
31 return count;
32}
33
34static int default_open(struct inode *inode, struct file *file)
35{
36 if (inode->i_private)
37 file->private_data = inode->i_private;
38
39 return 0;
40}
41
42const struct file_operations debugfs_file_operations = {
43 .read = default_read_file,
44 .write = default_write_file,
45 .open = default_open,
46 .llseek = noop_llseek,
47};
48
49static void *debugfs_follow_link(struct dentry *dentry, struct nameidata *nd)
50{
51 nd_set_link(nd, dentry->d_inode->i_private);
52 return NULL;
53}
54
55const struct inode_operations debugfs_link_operations = {
56 .readlink = generic_readlink,
57 .follow_link = debugfs_follow_link,
58};
59
60static int debugfs_u8_set(void *data, u64 val)
61{
62 *(u8 *)data = val;
63 return 0;
64}
65static int debugfs_u8_get(void *data, u64 *val)
66{
67 *val = *(u8 *)data;
68 return 0;
69}
70DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
71DEFINE_SIMPLE_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
72DEFINE_SIMPLE_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
73
74/**
75 * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
76 * @name: a pointer to a string containing the name of the file to create.
77 * @mode: the permission that the file should have
78 * @parent: a pointer to the parent dentry for this file. This should be a
79 * directory dentry if set. If this parameter is %NULL, then the
80 * file will be created in the root of the debugfs filesystem.
81 * @value: a pointer to the variable that the file should read to and write
82 * from.
83 *
84 * This function creates a file in debugfs with the given name that
85 * contains the value of the variable @value. If the @mode variable is so
86 * set, it can be read from, and written to.
87 *
88 * This function will return a pointer to a dentry if it succeeds. This
89 * pointer must be passed to the debugfs_remove() function when the file is
90 * to be removed (no automatic cleanup happens if your module is unloaded,
91 * you are responsible here.) If an error occurs, %NULL will be returned.
92 *
93 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
94 * returned. It is not wise to check for this value, but rather, check for
95 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
96 * code.
97 */
98struct dentry *debugfs_create_u8(const char *name, mode_t mode,
99 struct dentry *parent, u8 *value)
100{
101 /* if there are no write bits set, make read only */
102 if (!(mode & S_IWUGO))
103 return debugfs_create_file(name, mode, parent, value, &fops_u8_ro);
104 /* if there are no read bits set, make write only */
105 if (!(mode & S_IRUGO))
106 return debugfs_create_file(name, mode, parent, value, &fops_u8_wo);
107
108 return debugfs_create_file(name, mode, parent, value, &fops_u8);
109}
110EXPORT_SYMBOL_GPL(debugfs_create_u8);
111
112static int debugfs_u16_set(void *data, u64 val)
113{
114 *(u16 *)data = val;
115 return 0;
116}
117static int debugfs_u16_get(void *data, u64 *val)
118{
119 *val = *(u16 *)data;
120 return 0;
121}
122DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
123DEFINE_SIMPLE_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
124DEFINE_SIMPLE_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
125
126/**
127 * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
128 * @name: a pointer to a string containing the name of the file to create.
129 * @mode: the permission that the file should have
130 * @parent: a pointer to the parent dentry for this file. This should be a
131 * directory dentry if set. If this parameter is %NULL, then the
132 * file will be created in the root of the debugfs filesystem.
133 * @value: a pointer to the variable that the file should read to and write
134 * from.
135 *
136 * This function creates a file in debugfs with the given name that
137 * contains the value of the variable @value. If the @mode variable is so
138 * set, it can be read from, and written to.
139 *
140 * This function will return a pointer to a dentry if it succeeds. This
141 * pointer must be passed to the debugfs_remove() function when the file is
142 * to be removed (no automatic cleanup happens if your module is unloaded,
143 * you are responsible here.) If an error occurs, %NULL will be returned.
144 *
145 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
146 * returned. It is not wise to check for this value, but rather, check for
147 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
148 * code.
149 */
150struct dentry *debugfs_create_u16(const char *name, mode_t mode,
151 struct dentry *parent, u16 *value)
152{
153 /* if there are no write bits set, make read only */
154 if (!(mode & S_IWUGO))
155 return debugfs_create_file(name, mode, parent, value, &fops_u16_ro);
156 /* if there are no read bits set, make write only */
157 if (!(mode & S_IRUGO))
158 return debugfs_create_file(name, mode, parent, value, &fops_u16_wo);
159
160 return debugfs_create_file(name, mode, parent, value, &fops_u16);
161}
162EXPORT_SYMBOL_GPL(debugfs_create_u16);
163
164static int debugfs_u32_set(void *data, u64 val)
165{
166 *(u32 *)data = val;
167 return 0;
168}
169static int debugfs_u32_get(void *data, u64 *val)
170{
171 *val = *(u32 *)data;
172 return 0;
173}
174DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
175DEFINE_SIMPLE_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
176DEFINE_SIMPLE_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
177
178/**
179 * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
180 * @name: a pointer to a string containing the name of the file to create.
181 * @mode: the permission that the file should have
182 * @parent: a pointer to the parent dentry for this file. This should be a
183 * directory dentry if set. If this parameter is %NULL, then the
184 * file will be created in the root of the debugfs filesystem.
185 * @value: a pointer to the variable that the file should read to and write
186 * from.
187 *
188 * This function creates a file in debugfs with the given name that
189 * contains the value of the variable @value. If the @mode variable is so
190 * set, it can be read from, and written to.
191 *
192 * This function will return a pointer to a dentry if it succeeds. This
193 * pointer must be passed to the debugfs_remove() function when the file is
194 * to be removed (no automatic cleanup happens if your module is unloaded,
195 * you are responsible here.) If an error occurs, %NULL will be returned.
196 *
197 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
198 * returned. It is not wise to check for this value, but rather, check for
199 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
200 * code.
201 */
202struct dentry *debugfs_create_u32(const char *name, mode_t mode,
203 struct dentry *parent, u32 *value)
204{
205 /* if there are no write bits set, make read only */
206 if (!(mode & S_IWUGO))
207 return debugfs_create_file(name, mode, parent, value, &fops_u32_ro);
208 /* if there are no read bits set, make write only */
209 if (!(mode & S_IRUGO))
210 return debugfs_create_file(name, mode, parent, value, &fops_u32_wo);
211
212 return debugfs_create_file(name, mode, parent, value, &fops_u32);
213}
214EXPORT_SYMBOL_GPL(debugfs_create_u32);
215
216static int debugfs_u64_set(void *data, u64 val)
217{
218 *(u64 *)data = val;
219 return 0;
220}
221
222static int debugfs_u64_get(void *data, u64 *val)
223{
224 *val = *(u64 *)data;
225 return 0;
226}
227DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
228DEFINE_SIMPLE_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
229DEFINE_SIMPLE_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
230
231/**
232 * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value
233 * @name: a pointer to a string containing the name of the file to create.
234 * @mode: the permission that the file should have
235 * @parent: a pointer to the parent dentry for this file. This should be a
236 * directory dentry if set. If this parameter is %NULL, then the
237 * file will be created in the root of the debugfs filesystem.
238 * @value: a pointer to the variable that the file should read to and write
239 * from.
240 *
241 * This function creates a file in debugfs with the given name that
242 * contains the value of the variable @value. If the @mode variable is so
243 * set, it can be read from, and written to.
244 *
245 * This function will return a pointer to a dentry if it succeeds. This
246 * pointer must be passed to the debugfs_remove() function when the file is
247 * to be removed (no automatic cleanup happens if your module is unloaded,
248 * you are responsible here.) If an error occurs, %NULL will be returned.
249 *
250 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
251 * returned. It is not wise to check for this value, but rather, check for
252 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
253 * code.
254 */
255struct dentry *debugfs_create_u64(const char *name, mode_t mode,
256 struct dentry *parent, u64 *value)
257{
258 /* if there are no write bits set, make read only */
259 if (!(mode & S_IWUGO))
260 return debugfs_create_file(name, mode, parent, value, &fops_u64_ro);
261 /* if there are no read bits set, make write only */
262 if (!(mode & S_IRUGO))
263 return debugfs_create_file(name, mode, parent, value, &fops_u64_wo);
264
265 return debugfs_create_file(name, mode, parent, value, &fops_u64);
266}
267EXPORT_SYMBOL_GPL(debugfs_create_u64);
268
269DEFINE_SIMPLE_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
270DEFINE_SIMPLE_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
271DEFINE_SIMPLE_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
272
273DEFINE_SIMPLE_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n");
274DEFINE_SIMPLE_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
275DEFINE_SIMPLE_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
276
277DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n");
278DEFINE_SIMPLE_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
279DEFINE_SIMPLE_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
280
281DEFINE_SIMPLE_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, "0x%016llx\n");
282
283/*
284 * 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
285 *
286 * These functions are exactly the same as the above functions (but use a hex
287 * output for the decimal challenged). For details look at the above unsigned
288 * decimal functions.
289 */
290
291/**
292 * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value
293 * @name: a pointer to a string containing the name of the file to create.
294 * @mode: the permission that the file should have
295 * @parent: a pointer to the parent dentry for this file. This should be a
296 * directory dentry if set. If this parameter is %NULL, then the
297 * file will be created in the root of the debugfs filesystem.
298 * @value: a pointer to the variable that the file should read to and write
299 * from.
300 */
301struct dentry *debugfs_create_x8(const char *name, mode_t mode,
302 struct dentry *parent, u8 *value)
303{
304 /* if there are no write bits set, make read only */
305 if (!(mode & S_IWUGO))
306 return debugfs_create_file(name, mode, parent, value, &fops_x8_ro);
307 /* if there are no read bits set, make write only */
308 if (!(mode & S_IRUGO))
309 return debugfs_create_file(name, mode, parent, value, &fops_x8_wo);
310
311 return debugfs_create_file(name, mode, parent, value, &fops_x8);
312}
313EXPORT_SYMBOL_GPL(debugfs_create_x8);
314
315/**
316 * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value
317 * @name: a pointer to a string containing the name of the file to create.
318 * @mode: the permission that the file should have
319 * @parent: a pointer to the parent dentry for this file. This should be a
320 * directory dentry if set. If this parameter is %NULL, then the
321 * file will be created in the root of the debugfs filesystem.
322 * @value: a pointer to the variable that the file should read to and write
323 * from.
324 */
325struct dentry *debugfs_create_x16(const char *name, mode_t mode,
326 struct dentry *parent, u16 *value)
327{
328 /* if there are no write bits set, make read only */
329 if (!(mode & S_IWUGO))
330 return debugfs_create_file(name, mode, parent, value, &fops_x16_ro);
331 /* if there are no read bits set, make write only */
332 if (!(mode & S_IRUGO))
333 return debugfs_create_file(name, mode, parent, value, &fops_x16_wo);
334
335 return debugfs_create_file(name, mode, parent, value, &fops_x16);
336}
337EXPORT_SYMBOL_GPL(debugfs_create_x16);
338
339/**
340 * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value
341 * @name: a pointer to a string containing the name of the file to create.
342 * @mode: the permission that the file should have
343 * @parent: a pointer to the parent dentry for this file. This should be a
344 * directory dentry if set. If this parameter is %NULL, then the
345 * file will be created in the root of the debugfs filesystem.
346 * @value: a pointer to the variable that the file should read to and write
347 * from.
348 */
349struct dentry *debugfs_create_x32(const char *name, mode_t mode,
350 struct dentry *parent, u32 *value)
351{
352 /* if there are no write bits set, make read only */
353 if (!(mode & S_IWUGO))
354 return debugfs_create_file(name, mode, parent, value, &fops_x32_ro);
355 /* if there are no read bits set, make write only */
356 if (!(mode & S_IRUGO))
357 return debugfs_create_file(name, mode, parent, value, &fops_x32_wo);
358
359 return debugfs_create_file(name, mode, parent, value, &fops_x32);
360}
361EXPORT_SYMBOL_GPL(debugfs_create_x32);
362
363/**
364 * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value
365 * @name: a pointer to a string containing the name of the file to create.
366 * @mode: the permission that the file should have
367 * @parent: a pointer to the parent dentry for this file. This should be a
368 * directory dentry if set. If this parameter is %NULL, then the
369 * file will be created in the root of the debugfs filesystem.
370 * @value: a pointer to the variable that the file should read to and write
371 * from.
372 */
373struct dentry *debugfs_create_x64(const char *name, mode_t mode,
374 struct dentry *parent, u64 *value)
375{
376 return debugfs_create_file(name, mode, parent, value, &fops_x64);
377}
378EXPORT_SYMBOL_GPL(debugfs_create_x64);
379
380
381static int debugfs_size_t_set(void *data, u64 val)
382{
383 *(size_t *)data = val;
384 return 0;
385}
386static int debugfs_size_t_get(void *data, u64 *val)
387{
388 *val = *(size_t *)data;
389 return 0;
390}
391DEFINE_SIMPLE_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
392 "%llu\n"); /* %llu and %zu are more or less the same */
393
394/**
395 * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value
396 * @name: a pointer to a string containing the name of the file to create.
397 * @mode: the permission that the file should have
398 * @parent: a pointer to the parent dentry for this file. This should be a
399 * directory dentry if set. If this parameter is %NULL, then the
400 * file will be created in the root of the debugfs filesystem.
401 * @value: a pointer to the variable that the file should read to and write
402 * from.
403 */
404struct dentry *debugfs_create_size_t(const char *name, mode_t mode,
405 struct dentry *parent, size_t *value)
406{
407 return debugfs_create_file(name, mode, parent, value, &fops_size_t);
408}
409EXPORT_SYMBOL_GPL(debugfs_create_size_t);
410
411
412static ssize_t read_file_bool(struct file *file, char __user *user_buf,
413 size_t count, loff_t *ppos)
414{
415 char buf[3];
416 u32 *val = file->private_data;
417
418 if (*val)
419 buf[0] = 'Y';
420 else
421 buf[0] = 'N';
422 buf[1] = '\n';
423 buf[2] = 0x00;
424 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
425}
426
427static ssize_t write_file_bool(struct file *file, const char __user *user_buf,
428 size_t count, loff_t *ppos)
429{
430 char buf[32];
431 size_t buf_size;
432 bool bv;
433 u32 *val = file->private_data;
434
435 buf_size = min(count, (sizeof(buf)-1));
436 if (copy_from_user(buf, user_buf, buf_size))
437 return -EFAULT;
438
439 if (strtobool(buf, &bv) == 0)
440 *val = bv;
441
442 return count;
443}
444
445static const struct file_operations fops_bool = {
446 .read = read_file_bool,
447 .write = write_file_bool,
448 .open = default_open,
449 .llseek = default_llseek,
450};
451
452/**
453 * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value
454 * @name: a pointer to a string containing the name of the file to create.
455 * @mode: the permission that the file should have
456 * @parent: a pointer to the parent dentry for this file. This should be a
457 * directory dentry if set. If this parameter is %NULL, then the
458 * file will be created in the root of the debugfs filesystem.
459 * @value: a pointer to the variable that the file should read to and write
460 * from.
461 *
462 * This function creates a file in debugfs with the given name that
463 * contains the value of the variable @value. If the @mode variable is so
464 * set, it can be read from, and written to.
465 *
466 * This function will return a pointer to a dentry if it succeeds. This
467 * pointer must be passed to the debugfs_remove() function when the file is
468 * to be removed (no automatic cleanup happens if your module is unloaded,
469 * you are responsible here.) If an error occurs, %NULL will be returned.
470 *
471 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
472 * returned. It is not wise to check for this value, but rather, check for
473 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
474 * code.
475 */
476struct dentry *debugfs_create_bool(const char *name, mode_t mode,
477 struct dentry *parent, u32 *value)
478{
479 return debugfs_create_file(name, mode, parent, value, &fops_bool);
480}
481EXPORT_SYMBOL_GPL(debugfs_create_bool);
482
483static ssize_t read_file_blob(struct file *file, char __user *user_buf,
484 size_t count, loff_t *ppos)
485{
486 struct debugfs_blob_wrapper *blob = file->private_data;
487 return simple_read_from_buffer(user_buf, count, ppos, blob->data,
488 blob->size);
489}
490
491static const struct file_operations fops_blob = {
492 .read = read_file_blob,
493 .open = default_open,
494 .llseek = default_llseek,
495};
496
497/**
498 * debugfs_create_blob - create a debugfs file that is used to read a binary blob
499 * @name: a pointer to a string containing the name of the file to create.
500 * @mode: the permission that the file should have
501 * @parent: a pointer to the parent dentry for this file. This should be a
502 * directory dentry if set. If this parameter is %NULL, then the
503 * file will be created in the root of the debugfs filesystem.
504 * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer
505 * to the blob data and the size of the data.
506 *
507 * This function creates a file in debugfs with the given name that exports
508 * @blob->data as a binary blob. If the @mode variable is so set it can be
509 * read from. Writing is not supported.
510 *
511 * This function will return a pointer to a dentry if it succeeds. This
512 * pointer must be passed to the debugfs_remove() function when the file is
513 * to be removed (no automatic cleanup happens if your module is unloaded,
514 * you are responsible here.) If an error occurs, %NULL will be returned.
515 *
516 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
517 * returned. It is not wise to check for this value, but rather, check for
518 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
519 * code.
520 */
521struct dentry *debugfs_create_blob(const char *name, mode_t mode,
522 struct dentry *parent,
523 struct debugfs_blob_wrapper *blob)
524{
525 return debugfs_create_file(name, mode, parent, blob, &fops_blob);
526}
527EXPORT_SYMBOL_GPL(debugfs_create_blob);