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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/pagemap.h> | |
19 | #include <linux/namei.h> | |
20 | #include <linux/debugfs.h> | |
21 | ||
22 | static ssize_t default_read_file(struct file *file, char __user *buf, | |
23 | size_t count, loff_t *ppos) | |
24 | { | |
25 | return 0; | |
26 | } | |
27 | ||
28 | static 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 | ||
34 | static 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 | ||
42 | const 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 | ||
49 | static 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 | ||
55 | const struct inode_operations debugfs_link_operations = { | |
56 | .readlink = generic_readlink, | |
57 | .follow_link = debugfs_follow_link, | |
58 | }; | |
59 | ||
60 | static int debugfs_u8_set(void *data, u64 val) | |
61 | { | |
62 | *(u8 *)data = val; | |
63 | return 0; | |
64 | } | |
65 | static int debugfs_u8_get(void *data, u64 *val) | |
66 | { | |
67 | *val = *(u8 *)data; | |
68 | return 0; | |
69 | } | |
70 | DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n"); | |
71 | DEFINE_SIMPLE_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n"); | |
72 | DEFINE_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 | */ | |
98 | struct 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 | } | |
110 | EXPORT_SYMBOL_GPL(debugfs_create_u8); | |
111 | ||
112 | static int debugfs_u16_set(void *data, u64 val) | |
113 | { | |
114 | *(u16 *)data = val; | |
115 | return 0; | |
116 | } | |
117 | static int debugfs_u16_get(void *data, u64 *val) | |
118 | { | |
119 | *val = *(u16 *)data; | |
120 | return 0; | |
121 | } | |
122 | DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n"); | |
123 | DEFINE_SIMPLE_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n"); | |
124 | DEFINE_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 | */ | |
150 | struct 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 | } | |
162 | EXPORT_SYMBOL_GPL(debugfs_create_u16); | |
163 | ||
164 | static int debugfs_u32_set(void *data, u64 val) | |
165 | { | |
166 | *(u32 *)data = val; | |
167 | return 0; | |
168 | } | |
169 | static int debugfs_u32_get(void *data, u64 *val) | |
170 | { | |
171 | *val = *(u32 *)data; | |
172 | return 0; | |
173 | } | |
174 | DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n"); | |
175 | DEFINE_SIMPLE_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n"); | |
176 | DEFINE_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 | */ | |
202 | struct 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 | } | |
214 | EXPORT_SYMBOL_GPL(debugfs_create_u32); | |
215 | ||
216 | static int debugfs_u64_set(void *data, u64 val) | |
217 | { | |
218 | *(u64 *)data = val; | |
219 | return 0; | |
220 | } | |
221 | ||
222 | static int debugfs_u64_get(void *data, u64 *val) | |
223 | { | |
224 | *val = *(u64 *)data; | |
225 | return 0; | |
226 | } | |
227 | DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n"); | |
228 | DEFINE_SIMPLE_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n"); | |
229 | DEFINE_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 | */ | |
255 | struct 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 | } | |
267 | EXPORT_SYMBOL_GPL(debugfs_create_u64); | |
268 | ||
269 | DEFINE_SIMPLE_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n"); | |
270 | DEFINE_SIMPLE_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n"); | |
271 | DEFINE_SIMPLE_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n"); | |
272 | ||
273 | DEFINE_SIMPLE_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n"); | |
274 | DEFINE_SIMPLE_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n"); | |
275 | DEFINE_SIMPLE_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n"); | |
276 | ||
277 | DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n"); | |
278 | DEFINE_SIMPLE_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n"); | |
279 | DEFINE_SIMPLE_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n"); | |
280 | ||
281 | DEFINE_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 | */ | |
301 | struct 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 | } | |
313 | EXPORT_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 | */ | |
325 | struct 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 | } | |
337 | EXPORT_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 | */ | |
349 | struct 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 | } | |
361 | EXPORT_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 | */ | |
373 | struct 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 | } | |
378 | EXPORT_SYMBOL_GPL(debugfs_create_x64); | |
379 | ||
380 | ||
381 | static int debugfs_size_t_set(void *data, u64 val) | |
382 | { | |
383 | *(size_t *)data = val; | |
384 | return 0; | |
385 | } | |
386 | static int debugfs_size_t_get(void *data, u64 *val) | |
387 | { | |
388 | *val = *(size_t *)data; | |
389 | return 0; | |
390 | } | |
391 | DEFINE_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 | */ | |
404 | struct 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 | } | |
409 | EXPORT_SYMBOL_GPL(debugfs_create_size_t); | |
410 | ||
411 | ||
412 | static 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 | ||
427 | static 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 | int buf_size; | |
432 | u32 *val = file->private_data; | |
433 | ||
434 | buf_size = min(count, (sizeof(buf)-1)); | |
435 | if (copy_from_user(buf, user_buf, buf_size)) | |
436 | return -EFAULT; | |
437 | ||
438 | switch (buf[0]) { | |
439 | case 'y': | |
440 | case 'Y': | |
441 | case '1': | |
442 | *val = 1; | |
443 | break; | |
444 | case 'n': | |
445 | case 'N': | |
446 | case '0': | |
447 | *val = 0; | |
448 | break; | |
449 | } | |
450 | ||
451 | return count; | |
452 | } | |
453 | ||
454 | static const struct file_operations fops_bool = { | |
455 | .read = read_file_bool, | |
456 | .write = write_file_bool, | |
457 | .open = default_open, | |
458 | .llseek = default_llseek, | |
459 | }; | |
460 | ||
461 | /** | |
462 | * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value | |
463 | * @name: a pointer to a string containing the name of the file to create. | |
464 | * @mode: the permission that the file should have | |
465 | * @parent: a pointer to the parent dentry for this file. This should be a | |
466 | * directory dentry if set. If this parameter is %NULL, then the | |
467 | * file will be created in the root of the debugfs filesystem. | |
468 | * @value: a pointer to the variable that the file should read to and write | |
469 | * from. | |
470 | * | |
471 | * This function creates a file in debugfs with the given name that | |
472 | * contains the value of the variable @value. If the @mode variable is so | |
473 | * set, it can be read from, and written to. | |
474 | * | |
475 | * This function will return a pointer to a dentry if it succeeds. This | |
476 | * pointer must be passed to the debugfs_remove() function when the file is | |
477 | * to be removed (no automatic cleanup happens if your module is unloaded, | |
478 | * you are responsible here.) If an error occurs, %NULL will be returned. | |
479 | * | |
480 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be | |
481 | * returned. It is not wise to check for this value, but rather, check for | |
482 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling | |
483 | * code. | |
484 | */ | |
485 | struct dentry *debugfs_create_bool(const char *name, mode_t mode, | |
486 | struct dentry *parent, u32 *value) | |
487 | { | |
488 | return debugfs_create_file(name, mode, parent, value, &fops_bool); | |
489 | } | |
490 | EXPORT_SYMBOL_GPL(debugfs_create_bool); | |
491 | ||
492 | static ssize_t read_file_blob(struct file *file, char __user *user_buf, | |
493 | size_t count, loff_t *ppos) | |
494 | { | |
495 | struct debugfs_blob_wrapper *blob = file->private_data; | |
496 | return simple_read_from_buffer(user_buf, count, ppos, blob->data, | |
497 | blob->size); | |
498 | } | |
499 | ||
500 | static const struct file_operations fops_blob = { | |
501 | .read = read_file_blob, | |
502 | .open = default_open, | |
503 | .llseek = default_llseek, | |
504 | }; | |
505 | ||
506 | /** | |
507 | * debugfs_create_blob - create a debugfs file that is used to read a binary blob | |
508 | * @name: a pointer to a string containing the name of the file to create. | |
509 | * @mode: the permission that the file should have | |
510 | * @parent: a pointer to the parent dentry for this file. This should be a | |
511 | * directory dentry if set. If this parameter is %NULL, then the | |
512 | * file will be created in the root of the debugfs filesystem. | |
513 | * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer | |
514 | * to the blob data and the size of the data. | |
515 | * | |
516 | * This function creates a file in debugfs with the given name that exports | |
517 | * @blob->data as a binary blob. If the @mode variable is so set it can be | |
518 | * read from. Writing is not supported. | |
519 | * | |
520 | * This function will return a pointer to a dentry if it succeeds. This | |
521 | * pointer must be passed to the debugfs_remove() function when the file is | |
522 | * to be removed (no automatic cleanup happens if your module is unloaded, | |
523 | * you are responsible here.) If an error occurs, %NULL will be returned. | |
524 | * | |
525 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be | |
526 | * returned. It is not wise to check for this value, but rather, check for | |
527 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling | |
528 | * code. | |
529 | */ | |
530 | struct dentry *debugfs_create_blob(const char *name, mode_t mode, | |
531 | struct dentry *parent, | |
532 | struct debugfs_blob_wrapper *blob) | |
533 | { | |
534 | return debugfs_create_file(name, mode, parent, blob, &fops_blob); | |
535 | } | |
536 | EXPORT_SYMBOL_GPL(debugfs_create_blob); |