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