TTY: fix UV serial console regression
[zen-stable.git] / fs / debugfs / file.c
blobf65d4455c5e521dbde1a41407f740a2371848046
1 /*
2 * file.c - part of debugfs, a tiny little debug file system
4 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
5 * Copyright (C) 2004 IBM Inc.
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.
11 * debugfs is for people to use instead of /proc or /sys.
12 * See Documentation/DocBook/filesystems for more details.
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>
24 static ssize_t default_read_file(struct file *file, char __user *buf,
25 size_t count, loff_t *ppos)
27 return 0;
30 static ssize_t default_write_file(struct file *file, const char __user *buf,
31 size_t count, loff_t *ppos)
33 return count;
36 static int default_open(struct inode *inode, struct file *file)
38 if (inode->i_private)
39 file->private_data = inode->i_private;
41 return 0;
44 const struct file_operations debugfs_file_operations = {
45 .read = default_read_file,
46 .write = default_write_file,
47 .open = default_open,
48 .llseek = noop_llseek,
51 static void *debugfs_follow_link(struct dentry *dentry, struct nameidata *nd)
53 nd_set_link(nd, dentry->d_inode->i_private);
54 return NULL;
57 const struct inode_operations debugfs_link_operations = {
58 .readlink = generic_readlink,
59 .follow_link = debugfs_follow_link,
62 static int debugfs_u8_set(void *data, u64 val)
64 *(u8 *)data = val;
65 return 0;
67 static int debugfs_u8_get(void *data, u64 *val)
69 *val = *(u8 *)data;
70 return 0;
72 DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
73 DEFINE_SIMPLE_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
74 DEFINE_SIMPLE_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
76 /**
77 * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
78 * @name: a pointer to a string containing the name of the file to create.
79 * @mode: the permission that the file should have
80 * @parent: a pointer to the parent dentry for this file. This should be a
81 * directory dentry if set. If this parameter is %NULL, then the
82 * file will be created in the root of the debugfs filesystem.
83 * @value: a pointer to the variable that the file should read to and write
84 * from.
86 * This function creates a file in debugfs with the given name that
87 * contains the value of the variable @value. If the @mode variable is so
88 * set, it can be read from, and written to.
90 * This function will return a pointer to a dentry if it succeeds. This
91 * pointer must be passed to the debugfs_remove() function when the file is
92 * to be removed (no automatic cleanup happens if your module is unloaded,
93 * you are responsible here.) If an error occurs, %NULL will be returned.
95 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
96 * returned. It is not wise to check for this value, but rather, check for
97 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
98 * code.
100 struct dentry *debugfs_create_u8(const char *name, umode_t mode,
101 struct dentry *parent, u8 *value)
103 /* if there are no write bits set, make read only */
104 if (!(mode & S_IWUGO))
105 return debugfs_create_file(name, mode, parent, value, &fops_u8_ro);
106 /* if there are no read bits set, make write only */
107 if (!(mode & S_IRUGO))
108 return debugfs_create_file(name, mode, parent, value, &fops_u8_wo);
110 return debugfs_create_file(name, mode, parent, value, &fops_u8);
112 EXPORT_SYMBOL_GPL(debugfs_create_u8);
114 static int debugfs_u16_set(void *data, u64 val)
116 *(u16 *)data = val;
117 return 0;
119 static int debugfs_u16_get(void *data, u64 *val)
121 *val = *(u16 *)data;
122 return 0;
124 DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
125 DEFINE_SIMPLE_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
126 DEFINE_SIMPLE_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
129 * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
130 * @name: a pointer to a string containing the name of the file to create.
131 * @mode: the permission that the file should have
132 * @parent: a pointer to the parent dentry for this file. This should be a
133 * directory dentry if set. If this parameter is %NULL, then the
134 * file will be created in the root of the debugfs filesystem.
135 * @value: a pointer to the variable that the file should read to and write
136 * from.
138 * This function creates a file in debugfs with the given name that
139 * contains the value of the variable @value. If the @mode variable is so
140 * set, it can be read from, and written to.
142 * This function will return a pointer to a dentry if it succeeds. This
143 * pointer must be passed to the debugfs_remove() function when the file is
144 * to be removed (no automatic cleanup happens if your module is unloaded,
145 * you are responsible here.) If an error occurs, %NULL will be returned.
147 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
148 * returned. It is not wise to check for this value, but rather, check for
149 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
150 * code.
152 struct dentry *debugfs_create_u16(const char *name, umode_t mode,
153 struct dentry *parent, u16 *value)
155 /* if there are no write bits set, make read only */
156 if (!(mode & S_IWUGO))
157 return debugfs_create_file(name, mode, parent, value, &fops_u16_ro);
158 /* if there are no read bits set, make write only */
159 if (!(mode & S_IRUGO))
160 return debugfs_create_file(name, mode, parent, value, &fops_u16_wo);
162 return debugfs_create_file(name, mode, parent, value, &fops_u16);
164 EXPORT_SYMBOL_GPL(debugfs_create_u16);
166 static int debugfs_u32_set(void *data, u64 val)
168 *(u32 *)data = val;
169 return 0;
171 static int debugfs_u32_get(void *data, u64 *val)
173 *val = *(u32 *)data;
174 return 0;
176 DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
177 DEFINE_SIMPLE_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
178 DEFINE_SIMPLE_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
181 * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
182 * @name: a pointer to a string containing the name of the file to create.
183 * @mode: the permission that the file should have
184 * @parent: a pointer to the parent dentry for this file. This should be a
185 * directory dentry if set. If this parameter is %NULL, then the
186 * file will be created in the root of the debugfs filesystem.
187 * @value: a pointer to the variable that the file should read to and write
188 * from.
190 * This function creates a file in debugfs with the given name that
191 * contains the value of the variable @value. If the @mode variable is so
192 * set, it can be read from, and written to.
194 * This function will return a pointer to a dentry if it succeeds. This
195 * pointer must be passed to the debugfs_remove() function when the file is
196 * to be removed (no automatic cleanup happens if your module is unloaded,
197 * you are responsible here.) If an error occurs, %NULL will be returned.
199 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
200 * returned. It is not wise to check for this value, but rather, check for
201 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
202 * code.
204 struct dentry *debugfs_create_u32(const char *name, umode_t mode,
205 struct dentry *parent, u32 *value)
207 /* if there are no write bits set, make read only */
208 if (!(mode & S_IWUGO))
209 return debugfs_create_file(name, mode, parent, value, &fops_u32_ro);
210 /* if there are no read bits set, make write only */
211 if (!(mode & S_IRUGO))
212 return debugfs_create_file(name, mode, parent, value, &fops_u32_wo);
214 return debugfs_create_file(name, mode, parent, value, &fops_u32);
216 EXPORT_SYMBOL_GPL(debugfs_create_u32);
218 static int debugfs_u64_set(void *data, u64 val)
220 *(u64 *)data = val;
221 return 0;
224 static int debugfs_u64_get(void *data, u64 *val)
226 *val = *(u64 *)data;
227 return 0;
229 DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
230 DEFINE_SIMPLE_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
231 DEFINE_SIMPLE_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
234 * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value
235 * @name: a pointer to a string containing the name of the file to create.
236 * @mode: the permission that the file should have
237 * @parent: a pointer to the parent dentry for this file. This should be a
238 * directory dentry if set. If this parameter is %NULL, then the
239 * file will be created in the root of the debugfs filesystem.
240 * @value: a pointer to the variable that the file should read to and write
241 * from.
243 * This function creates a file in debugfs with the given name that
244 * contains the value of the variable @value. If the @mode variable is so
245 * set, it can be read from, and written to.
247 * This function will return a pointer to a dentry if it succeeds. This
248 * pointer must be passed to the debugfs_remove() function when the file is
249 * to be removed (no automatic cleanup happens if your module is unloaded,
250 * you are responsible here.) If an error occurs, %NULL will be returned.
252 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
253 * returned. It is not wise to check for this value, but rather, check for
254 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
255 * code.
257 struct dentry *debugfs_create_u64(const char *name, umode_t mode,
258 struct dentry *parent, u64 *value)
260 /* if there are no write bits set, make read only */
261 if (!(mode & S_IWUGO))
262 return debugfs_create_file(name, mode, parent, value, &fops_u64_ro);
263 /* if there are no read bits set, make write only */
264 if (!(mode & S_IRUGO))
265 return debugfs_create_file(name, mode, parent, value, &fops_u64_wo);
267 return debugfs_create_file(name, mode, parent, value, &fops_u64);
269 EXPORT_SYMBOL_GPL(debugfs_create_u64);
271 DEFINE_SIMPLE_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
272 DEFINE_SIMPLE_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
273 DEFINE_SIMPLE_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
275 DEFINE_SIMPLE_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n");
276 DEFINE_SIMPLE_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
277 DEFINE_SIMPLE_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
279 DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n");
280 DEFINE_SIMPLE_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
281 DEFINE_SIMPLE_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
283 DEFINE_SIMPLE_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, "0x%016llx\n");
286 * 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
288 * These functions are exactly the same as the above functions (but use a hex
289 * output for the decimal challenged). For details look at the above unsigned
290 * decimal functions.
294 * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value
295 * @name: a pointer to a string containing the name of the file to create.
296 * @mode: the permission that the file should have
297 * @parent: a pointer to the parent dentry for this file. This should be a
298 * directory dentry if set. If this parameter is %NULL, then the
299 * file will be created in the root of the debugfs filesystem.
300 * @value: a pointer to the variable that the file should read to and write
301 * from.
303 struct dentry *debugfs_create_x8(const char *name, umode_t mode,
304 struct dentry *parent, u8 *value)
306 /* if there are no write bits set, make read only */
307 if (!(mode & S_IWUGO))
308 return debugfs_create_file(name, mode, parent, value, &fops_x8_ro);
309 /* if there are no read bits set, make write only */
310 if (!(mode & S_IRUGO))
311 return debugfs_create_file(name, mode, parent, value, &fops_x8_wo);
313 return debugfs_create_file(name, mode, parent, value, &fops_x8);
315 EXPORT_SYMBOL_GPL(debugfs_create_x8);
318 * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value
319 * @name: a pointer to a string containing the name of the file to create.
320 * @mode: the permission that the file should have
321 * @parent: a pointer to the parent dentry for this file. This should be a
322 * directory dentry if set. If this parameter is %NULL, then the
323 * file will be created in the root of the debugfs filesystem.
324 * @value: a pointer to the variable that the file should read to and write
325 * from.
327 struct dentry *debugfs_create_x16(const char *name, umode_t mode,
328 struct dentry *parent, u16 *value)
330 /* if there are no write bits set, make read only */
331 if (!(mode & S_IWUGO))
332 return debugfs_create_file(name, mode, parent, value, &fops_x16_ro);
333 /* if there are no read bits set, make write only */
334 if (!(mode & S_IRUGO))
335 return debugfs_create_file(name, mode, parent, value, &fops_x16_wo);
337 return debugfs_create_file(name, mode, parent, value, &fops_x16);
339 EXPORT_SYMBOL_GPL(debugfs_create_x16);
342 * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value
343 * @name: a pointer to a string containing the name of the file to create.
344 * @mode: the permission that the file should have
345 * @parent: a pointer to the parent dentry for this file. This should be a
346 * directory dentry if set. If this parameter is %NULL, then the
347 * file will be created in the root of the debugfs filesystem.
348 * @value: a pointer to the variable that the file should read to and write
349 * from.
351 struct dentry *debugfs_create_x32(const char *name, umode_t mode,
352 struct dentry *parent, u32 *value)
354 /* if there are no write bits set, make read only */
355 if (!(mode & S_IWUGO))
356 return debugfs_create_file(name, mode, parent, value, &fops_x32_ro);
357 /* if there are no read bits set, make write only */
358 if (!(mode & S_IRUGO))
359 return debugfs_create_file(name, mode, parent, value, &fops_x32_wo);
361 return debugfs_create_file(name, mode, parent, value, &fops_x32);
363 EXPORT_SYMBOL_GPL(debugfs_create_x32);
366 * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value
367 * @name: a pointer to a string containing the name of the file to create.
368 * @mode: the permission that the file should have
369 * @parent: a pointer to the parent dentry for this file. This should be a
370 * directory dentry if set. If this parameter is %NULL, then the
371 * file will be created in the root of the debugfs filesystem.
372 * @value: a pointer to the variable that the file should read to and write
373 * from.
375 struct dentry *debugfs_create_x64(const char *name, umode_t mode,
376 struct dentry *parent, u64 *value)
378 return debugfs_create_file(name, mode, parent, value, &fops_x64);
380 EXPORT_SYMBOL_GPL(debugfs_create_x64);
383 static int debugfs_size_t_set(void *data, u64 val)
385 *(size_t *)data = val;
386 return 0;
388 static int debugfs_size_t_get(void *data, u64 *val)
390 *val = *(size_t *)data;
391 return 0;
393 DEFINE_SIMPLE_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
394 "%llu\n"); /* %llu and %zu are more or less the same */
397 * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value
398 * @name: a pointer to a string containing the name of the file to create.
399 * @mode: the permission that the file should have
400 * @parent: a pointer to the parent dentry for this file. This should be a
401 * directory dentry if set. If this parameter is %NULL, then the
402 * file will be created in the root of the debugfs filesystem.
403 * @value: a pointer to the variable that the file should read to and write
404 * from.
406 struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
407 struct dentry *parent, size_t *value)
409 return debugfs_create_file(name, mode, parent, value, &fops_size_t);
411 EXPORT_SYMBOL_GPL(debugfs_create_size_t);
414 static ssize_t read_file_bool(struct file *file, char __user *user_buf,
415 size_t count, loff_t *ppos)
417 char buf[3];
418 u32 *val = file->private_data;
420 if (*val)
421 buf[0] = 'Y';
422 else
423 buf[0] = 'N';
424 buf[1] = '\n';
425 buf[2] = 0x00;
426 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
429 static ssize_t write_file_bool(struct file *file, const char __user *user_buf,
430 size_t count, loff_t *ppos)
432 char buf[32];
433 size_t buf_size;
434 bool bv;
435 u32 *val = file->private_data;
437 buf_size = min(count, (sizeof(buf)-1));
438 if (copy_from_user(buf, user_buf, buf_size))
439 return -EFAULT;
441 if (strtobool(buf, &bv) == 0)
442 *val = bv;
444 return count;
447 static const struct file_operations fops_bool = {
448 .read = read_file_bool,
449 .write = write_file_bool,
450 .open = default_open,
451 .llseek = default_llseek,
455 * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value
456 * @name: a pointer to a string containing the name of the file to create.
457 * @mode: the permission that the file should have
458 * @parent: a pointer to the parent dentry for this file. This should be a
459 * directory dentry if set. If this parameter is %NULL, then the
460 * file will be created in the root of the debugfs filesystem.
461 * @value: a pointer to the variable that the file should read to and write
462 * from.
464 * This function creates a file in debugfs with the given name that
465 * contains the value of the variable @value. If the @mode variable is so
466 * set, it can be read from, and written to.
468 * This function will return a pointer to a dentry if it succeeds. This
469 * pointer must be passed to the debugfs_remove() function when the file is
470 * to be removed (no automatic cleanup happens if your module is unloaded,
471 * you are responsible here.) If an error occurs, %NULL will be returned.
473 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
474 * returned. It is not wise to check for this value, but rather, check for
475 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
476 * code.
478 struct dentry *debugfs_create_bool(const char *name, umode_t mode,
479 struct dentry *parent, u32 *value)
481 return debugfs_create_file(name, mode, parent, value, &fops_bool);
483 EXPORT_SYMBOL_GPL(debugfs_create_bool);
485 static ssize_t read_file_blob(struct file *file, char __user *user_buf,
486 size_t count, loff_t *ppos)
488 struct debugfs_blob_wrapper *blob = file->private_data;
489 return simple_read_from_buffer(user_buf, count, ppos, blob->data,
490 blob->size);
493 static const struct file_operations fops_blob = {
494 .read = read_file_blob,
495 .open = default_open,
496 .llseek = default_llseek,
500 * debugfs_create_blob - create a debugfs file that is used to read a binary blob
501 * @name: a pointer to a string containing the name of the file to create.
502 * @mode: the permission that the file should have
503 * @parent: a pointer to the parent dentry for this file. This should be a
504 * directory dentry if set. If this parameter is %NULL, then the
505 * file will be created in the root of the debugfs filesystem.
506 * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer
507 * to the blob data and the size of the data.
509 * This function creates a file in debugfs with the given name that exports
510 * @blob->data as a binary blob. If the @mode variable is so set it can be
511 * read from. Writing is not supported.
513 * This function will return a pointer to a dentry if it succeeds. This
514 * pointer must be passed to the debugfs_remove() function when the file is
515 * to be removed (no automatic cleanup happens if your module is unloaded,
516 * you are responsible here.) If an error occurs, %NULL will be returned.
518 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
519 * returned. It is not wise to check for this value, but rather, check for
520 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
521 * code.
523 struct dentry *debugfs_create_blob(const char *name, umode_t mode,
524 struct dentry *parent,
525 struct debugfs_blob_wrapper *blob)
527 return debugfs_create_file(name, mode, parent, blob, &fops_blob);
529 EXPORT_SYMBOL_GPL(debugfs_create_blob);
531 #ifdef CONFIG_HAS_IOMEM
534 * The regset32 stuff is used to print 32-bit registers using the
535 * seq_file utilities. We offer printing a register set in an already-opened
536 * sequential file or create a debugfs file that only prints a regset32.
540 * debugfs_print_regs32 - use seq_print to describe a set of registers
541 * @s: the seq_file structure being used to generate output
542 * @regs: an array if struct debugfs_reg32 structures
543 * @mregs: the length of the above array
544 * @base: the base address to be used in reading the registers
545 * @prefix: a string to be prefixed to every output line
547 * This function outputs a text block describing the current values of
548 * some 32-bit hardware registers. It is meant to be used within debugfs
549 * files based on seq_file that need to show registers, intermixed with other
550 * information. The prefix argument may be used to specify a leading string,
551 * because some peripherals have several blocks of identical registers,
552 * for example configuration of dma channels
554 int debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
555 int nregs, void __iomem *base, char *prefix)
557 int i, ret = 0;
559 for (i = 0; i < nregs; i++, regs++) {
560 if (prefix)
561 ret += seq_printf(s, "%s", prefix);
562 ret += seq_printf(s, "%s = 0x%08x\n", regs->name,
563 readl(base + regs->offset));
565 return ret;
567 EXPORT_SYMBOL_GPL(debugfs_print_regs32);
569 static int debugfs_show_regset32(struct seq_file *s, void *data)
571 struct debugfs_regset32 *regset = s->private;
573 debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, "");
574 return 0;
577 static int debugfs_open_regset32(struct inode *inode, struct file *file)
579 return single_open(file, debugfs_show_regset32, inode->i_private);
582 static const struct file_operations fops_regset32 = {
583 .open = debugfs_open_regset32,
584 .read = seq_read,
585 .llseek = seq_lseek,
586 .release = single_release,
590 * debugfs_create_regset32 - create a debugfs file that returns register values
591 * @name: a pointer to a string containing the name of the file to create.
592 * @mode: the permission that the file should have
593 * @parent: a pointer to the parent dentry for this file. This should be a
594 * directory dentry if set. If this parameter is %NULL, then the
595 * file will be created in the root of the debugfs filesystem.
596 * @regset: a pointer to a struct debugfs_regset32, which contains a pointer
597 * to an array of register definitions, the array size and the base
598 * address where the register bank is to be found.
600 * This function creates a file in debugfs with the given name that reports
601 * the names and values of a set of 32-bit registers. If the @mode variable
602 * is so set it can be read from. Writing is not supported.
604 * This function will return a pointer to a dentry if it succeeds. This
605 * pointer must be passed to the debugfs_remove() function when the file is
606 * to be removed (no automatic cleanup happens if your module is unloaded,
607 * you are responsible here.) If an error occurs, %NULL will be returned.
609 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
610 * returned. It is not wise to check for this value, but rather, check for
611 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
612 * code.
614 struct dentry *debugfs_create_regset32(const char *name, mode_t mode,
615 struct dentry *parent,
616 struct debugfs_regset32 *regset)
618 return debugfs_create_file(name, mode, parent, regset, &fops_regset32);
620 EXPORT_SYMBOL_GPL(debugfs_create_regset32);
622 #endif /* CONFIG_HAS_IOMEM */