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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/pm_runtime.h>
22#include <linux/poll.h>
23#include <linux/security.h>
24
25#include "internal.h"
26
27struct poll_table_struct;
28
29static ssize_t default_read_file(struct file *file, char __user *buf,
30 size_t count, loff_t *ppos)
31{
32 return 0;
33}
34
35static ssize_t default_write_file(struct file *file, const char __user *buf,
36 size_t count, loff_t *ppos)
37{
38 return count;
39}
40
41const struct file_operations debugfs_noop_file_operations = {
42 .read = default_read_file,
43 .write = default_write_file,
44 .open = simple_open,
45 .llseek = noop_llseek,
46};
47
48#define F_DENTRY(filp) ((filp)->f_path.dentry)
49
50const struct file_operations *debugfs_real_fops(const struct file *filp)
51{
52 struct debugfs_fsdata *fsd = F_DENTRY(filp)->d_fsdata;
53
54 if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) {
55 /*
56 * Urgh, we've been called w/o a protecting
57 * debugfs_file_get().
58 */
59 WARN_ON(1);
60 return NULL;
61 }
62
63 return fsd->real_fops;
64}
65EXPORT_SYMBOL_GPL(debugfs_real_fops);
66
67enum dbgfs_get_mode {
68 DBGFS_GET_ALREADY,
69 DBGFS_GET_REGULAR,
70 DBGFS_GET_SHORT,
71};
72
73static int __debugfs_file_get(struct dentry *dentry, enum dbgfs_get_mode mode)
74{
75 struct debugfs_fsdata *fsd;
76 void *d_fsd;
77
78 /*
79 * This could only happen if some debugfs user erroneously calls
80 * debugfs_file_get() on a dentry that isn't even a file, let
81 * them know about it.
82 */
83 if (WARN_ON(!d_is_reg(dentry)))
84 return -EINVAL;
85
86 d_fsd = READ_ONCE(dentry->d_fsdata);
87 if (!((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) {
88 fsd = d_fsd;
89 } else {
90 if (WARN_ON(mode == DBGFS_GET_ALREADY))
91 return -EINVAL;
92
93 fsd = kmalloc(sizeof(*fsd), GFP_KERNEL);
94 if (!fsd)
95 return -ENOMEM;
96
97 if (mode == DBGFS_GET_SHORT) {
98 fsd->real_fops = NULL;
99 fsd->short_fops = (void *)((unsigned long)d_fsd &
100 ~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT);
101 } else {
102 fsd->real_fops = (void *)((unsigned long)d_fsd &
103 ~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT);
104 fsd->short_fops = NULL;
105 }
106 refcount_set(&fsd->active_users, 1);
107 init_completion(&fsd->active_users_drained);
108 INIT_LIST_HEAD(&fsd->cancellations);
109 mutex_init(&fsd->cancellations_mtx);
110
111 if (cmpxchg(&dentry->d_fsdata, d_fsd, fsd) != d_fsd) {
112 mutex_destroy(&fsd->cancellations_mtx);
113 kfree(fsd);
114 fsd = READ_ONCE(dentry->d_fsdata);
115 }
116 }
117
118 /*
119 * In case of a successful cmpxchg() above, this check is
120 * strictly necessary and must follow it, see the comment in
121 * __debugfs_remove_file().
122 * OTOH, if the cmpxchg() hasn't been executed or wasn't
123 * successful, this serves the purpose of not starving
124 * removers.
125 */
126 if (d_unlinked(dentry))
127 return -EIO;
128
129 if (!refcount_inc_not_zero(&fsd->active_users))
130 return -EIO;
131
132 return 0;
133}
134
135/**
136 * debugfs_file_get - mark the beginning of file data access
137 * @dentry: the dentry object whose data is being accessed.
138 *
139 * Up to a matching call to debugfs_file_put(), any successive call
140 * into the file removing functions debugfs_remove() and
141 * debugfs_remove_recursive() will block. Since associated private
142 * file data may only get freed after a successful return of any of
143 * the removal functions, you may safely access it after a successful
144 * call to debugfs_file_get() without worrying about lifetime issues.
145 *
146 * If -%EIO is returned, the file has already been removed and thus,
147 * it is not safe to access any of its data. If, on the other hand,
148 * it is allowed to access the file data, zero is returned.
149 */
150int debugfs_file_get(struct dentry *dentry)
151{
152 return __debugfs_file_get(dentry, DBGFS_GET_ALREADY);
153}
154EXPORT_SYMBOL_GPL(debugfs_file_get);
155
156/**
157 * debugfs_file_put - mark the end of file data access
158 * @dentry: the dentry object formerly passed to
159 * debugfs_file_get().
160 *
161 * Allow any ongoing concurrent call into debugfs_remove() or
162 * debugfs_remove_recursive() blocked by a former call to
163 * debugfs_file_get() to proceed and return to its caller.
164 */
165void debugfs_file_put(struct dentry *dentry)
166{
167 struct debugfs_fsdata *fsd = READ_ONCE(dentry->d_fsdata);
168
169 if (refcount_dec_and_test(&fsd->active_users))
170 complete(&fsd->active_users_drained);
171}
172EXPORT_SYMBOL_GPL(debugfs_file_put);
173
174/**
175 * debugfs_enter_cancellation - enter a debugfs cancellation
176 * @file: the file being accessed
177 * @cancellation: the cancellation object, the cancel callback
178 * inside of it must be initialized
179 *
180 * When a debugfs file is removed it needs to wait for all active
181 * operations to complete. However, the operation itself may need
182 * to wait for hardware or completion of some asynchronous process
183 * or similar. As such, it may need to be cancelled to avoid long
184 * waits or even deadlocks.
185 *
186 * This function can be used inside a debugfs handler that may
187 * need to be cancelled. As soon as this function is called, the
188 * cancellation's 'cancel' callback may be called, at which point
189 * the caller should proceed to call debugfs_leave_cancellation()
190 * and leave the debugfs handler function as soon as possible.
191 * Note that the 'cancel' callback is only ever called in the
192 * context of some kind of debugfs_remove().
193 *
194 * This function must be paired with debugfs_leave_cancellation().
195 */
196void debugfs_enter_cancellation(struct file *file,
197 struct debugfs_cancellation *cancellation)
198{
199 struct debugfs_fsdata *fsd;
200 struct dentry *dentry = F_DENTRY(file);
201
202 INIT_LIST_HEAD(&cancellation->list);
203
204 if (WARN_ON(!d_is_reg(dentry)))
205 return;
206
207 if (WARN_ON(!cancellation->cancel))
208 return;
209
210 fsd = READ_ONCE(dentry->d_fsdata);
211 if (WARN_ON(!fsd ||
212 ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)))
213 return;
214
215 mutex_lock(&fsd->cancellations_mtx);
216 list_add(&cancellation->list, &fsd->cancellations);
217 mutex_unlock(&fsd->cancellations_mtx);
218
219 /* if we're already removing wake it up to cancel */
220 if (d_unlinked(dentry))
221 complete(&fsd->active_users_drained);
222}
223EXPORT_SYMBOL_GPL(debugfs_enter_cancellation);
224
225/**
226 * debugfs_leave_cancellation - leave cancellation section
227 * @file: the file being accessed
228 * @cancellation: the cancellation previously registered with
229 * debugfs_enter_cancellation()
230 *
231 * See the documentation of debugfs_enter_cancellation().
232 */
233void debugfs_leave_cancellation(struct file *file,
234 struct debugfs_cancellation *cancellation)
235{
236 struct debugfs_fsdata *fsd;
237 struct dentry *dentry = F_DENTRY(file);
238
239 if (WARN_ON(!d_is_reg(dentry)))
240 return;
241
242 fsd = READ_ONCE(dentry->d_fsdata);
243 if (WARN_ON(!fsd ||
244 ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)))
245 return;
246
247 mutex_lock(&fsd->cancellations_mtx);
248 if (!list_empty(&cancellation->list))
249 list_del(&cancellation->list);
250 mutex_unlock(&fsd->cancellations_mtx);
251}
252EXPORT_SYMBOL_GPL(debugfs_leave_cancellation);
253
254/*
255 * Only permit access to world-readable files when the kernel is locked down.
256 * We also need to exclude any file that has ways to write or alter it as root
257 * can bypass the permissions check.
258 */
259static int debugfs_locked_down(struct inode *inode,
260 struct file *filp,
261 const struct file_operations *real_fops)
262{
263 if ((inode->i_mode & 07777 & ~0444) == 0 &&
264 !(filp->f_mode & FMODE_WRITE) &&
265 (!real_fops ||
266 (!real_fops->unlocked_ioctl &&
267 !real_fops->compat_ioctl &&
268 !real_fops->mmap)))
269 return 0;
270
271 if (security_locked_down(LOCKDOWN_DEBUGFS))
272 return -EPERM;
273
274 return 0;
275}
276
277static int open_proxy_open(struct inode *inode, struct file *filp)
278{
279 struct dentry *dentry = F_DENTRY(filp);
280 const struct file_operations *real_fops = NULL;
281 int r;
282
283 r = __debugfs_file_get(dentry, DBGFS_GET_REGULAR);
284 if (r)
285 return r == -EIO ? -ENOENT : r;
286
287 real_fops = debugfs_real_fops(filp);
288
289 r = debugfs_locked_down(inode, filp, real_fops);
290 if (r)
291 goto out;
292
293 if (!fops_get(real_fops)) {
294#ifdef CONFIG_MODULES
295 if (real_fops->owner &&
296 real_fops->owner->state == MODULE_STATE_GOING) {
297 r = -ENXIO;
298 goto out;
299 }
300#endif
301
302 /* Huh? Module did not clean up after itself at exit? */
303 WARN(1, "debugfs file owner did not clean up at exit: %pd",
304 dentry);
305 r = -ENXIO;
306 goto out;
307 }
308 replace_fops(filp, real_fops);
309
310 if (real_fops->open)
311 r = real_fops->open(inode, filp);
312
313out:
314 debugfs_file_put(dentry);
315 return r;
316}
317
318const struct file_operations debugfs_open_proxy_file_operations = {
319 .open = open_proxy_open,
320};
321
322#define PROTO(args...) args
323#define ARGS(args...) args
324
325#define FULL_PROXY_FUNC(name, ret_type, filp, proto, args) \
326static ret_type full_proxy_ ## name(proto) \
327{ \
328 struct dentry *dentry = F_DENTRY(filp); \
329 const struct file_operations *real_fops; \
330 ret_type r; \
331 \
332 r = debugfs_file_get(dentry); \
333 if (unlikely(r)) \
334 return r; \
335 real_fops = debugfs_real_fops(filp); \
336 r = real_fops->name(args); \
337 debugfs_file_put(dentry); \
338 return r; \
339}
340
341#define FULL_PROXY_FUNC_BOTH(name, ret_type, filp, proto, args) \
342static ret_type full_proxy_ ## name(proto) \
343{ \
344 struct dentry *dentry = F_DENTRY(filp); \
345 struct debugfs_fsdata *fsd; \
346 ret_type r; \
347 \
348 r = debugfs_file_get(dentry); \
349 if (unlikely(r)) \
350 return r; \
351 fsd = dentry->d_fsdata; \
352 if (fsd->real_fops) \
353 r = fsd->real_fops->name(args); \
354 else \
355 r = fsd->short_fops->name(args); \
356 debugfs_file_put(dentry); \
357 return r; \
358}
359
360FULL_PROXY_FUNC_BOTH(llseek, loff_t, filp,
361 PROTO(struct file *filp, loff_t offset, int whence),
362 ARGS(filp, offset, whence));
363
364FULL_PROXY_FUNC_BOTH(read, ssize_t, filp,
365 PROTO(struct file *filp, char __user *buf, size_t size,
366 loff_t *ppos),
367 ARGS(filp, buf, size, ppos));
368
369FULL_PROXY_FUNC_BOTH(write, ssize_t, filp,
370 PROTO(struct file *filp, const char __user *buf,
371 size_t size, loff_t *ppos),
372 ARGS(filp, buf, size, ppos));
373
374FULL_PROXY_FUNC(unlocked_ioctl, long, filp,
375 PROTO(struct file *filp, unsigned int cmd, unsigned long arg),
376 ARGS(filp, cmd, arg));
377
378static __poll_t full_proxy_poll(struct file *filp,
379 struct poll_table_struct *wait)
380{
381 struct dentry *dentry = F_DENTRY(filp);
382 __poll_t r = 0;
383 const struct file_operations *real_fops;
384
385 if (debugfs_file_get(dentry))
386 return EPOLLHUP;
387
388 real_fops = debugfs_real_fops(filp);
389 r = real_fops->poll(filp, wait);
390 debugfs_file_put(dentry);
391 return r;
392}
393
394static int full_proxy_release(struct inode *inode, struct file *filp)
395{
396 const struct dentry *dentry = F_DENTRY(filp);
397 const struct file_operations *real_fops = debugfs_real_fops(filp);
398 const struct file_operations *proxy_fops = filp->f_op;
399 int r = 0;
400
401 /*
402 * We must not protect this against removal races here: the
403 * original releaser should be called unconditionally in order
404 * not to leak any resources. Releasers must not assume that
405 * ->i_private is still being meaningful here.
406 */
407 if (real_fops && real_fops->release)
408 r = real_fops->release(inode, filp);
409
410 replace_fops(filp, d_inode(dentry)->i_fop);
411 kfree(proxy_fops);
412 fops_put(real_fops);
413 return r;
414}
415
416static void __full_proxy_fops_init(struct file_operations *proxy_fops,
417 struct debugfs_fsdata *fsd)
418{
419 proxy_fops->release = full_proxy_release;
420
421 if ((fsd->real_fops && fsd->real_fops->llseek) ||
422 (fsd->short_fops && fsd->short_fops->llseek))
423 proxy_fops->llseek = full_proxy_llseek;
424
425 if ((fsd->real_fops && fsd->real_fops->read) ||
426 (fsd->short_fops && fsd->short_fops->read))
427 proxy_fops->read = full_proxy_read;
428
429 if ((fsd->real_fops && fsd->real_fops->write) ||
430 (fsd->short_fops && fsd->short_fops->write))
431 proxy_fops->write = full_proxy_write;
432
433 if (fsd->real_fops && fsd->real_fops->poll)
434 proxy_fops->poll = full_proxy_poll;
435
436 if (fsd->real_fops && fsd->real_fops->unlocked_ioctl)
437 proxy_fops->unlocked_ioctl = full_proxy_unlocked_ioctl;
438}
439
440static int full_proxy_open(struct inode *inode, struct file *filp,
441 enum dbgfs_get_mode mode)
442{
443 struct dentry *dentry = F_DENTRY(filp);
444 const struct file_operations *real_fops;
445 struct file_operations *proxy_fops = NULL;
446 struct debugfs_fsdata *fsd;
447 int r;
448
449 r = __debugfs_file_get(dentry, mode);
450 if (r)
451 return r == -EIO ? -ENOENT : r;
452
453 fsd = dentry->d_fsdata;
454 real_fops = fsd->real_fops;
455 r = debugfs_locked_down(inode, filp, real_fops);
456 if (r)
457 goto out;
458
459 if (real_fops && !fops_get(real_fops)) {
460#ifdef CONFIG_MODULES
461 if (real_fops->owner &&
462 real_fops->owner->state == MODULE_STATE_GOING) {
463 r = -ENXIO;
464 goto out;
465 }
466#endif
467
468 /* Huh? Module did not cleanup after itself at exit? */
469 WARN(1, "debugfs file owner did not clean up at exit: %pd",
470 dentry);
471 r = -ENXIO;
472 goto out;
473 }
474
475 proxy_fops = kzalloc(sizeof(*proxy_fops), GFP_KERNEL);
476 if (!proxy_fops) {
477 r = -ENOMEM;
478 goto free_proxy;
479 }
480 __full_proxy_fops_init(proxy_fops, fsd);
481 replace_fops(filp, proxy_fops);
482
483 if (!real_fops || real_fops->open) {
484 if (real_fops)
485 r = real_fops->open(inode, filp);
486 else
487 r = simple_open(inode, filp);
488 if (r) {
489 replace_fops(filp, d_inode(dentry)->i_fop);
490 goto free_proxy;
491 } else if (filp->f_op != proxy_fops) {
492 /* No protection against file removal anymore. */
493 WARN(1, "debugfs file owner replaced proxy fops: %pd",
494 dentry);
495 goto free_proxy;
496 }
497 }
498
499 goto out;
500free_proxy:
501 kfree(proxy_fops);
502 fops_put(real_fops);
503out:
504 debugfs_file_put(dentry);
505 return r;
506}
507
508static int full_proxy_open_regular(struct inode *inode, struct file *filp)
509{
510 return full_proxy_open(inode, filp, DBGFS_GET_REGULAR);
511}
512
513const struct file_operations debugfs_full_proxy_file_operations = {
514 .open = full_proxy_open_regular,
515};
516
517static int full_proxy_open_short(struct inode *inode, struct file *filp)
518{
519 return full_proxy_open(inode, filp, DBGFS_GET_SHORT);
520}
521
522const struct file_operations debugfs_full_short_proxy_file_operations = {
523 .open = full_proxy_open_short,
524};
525
526ssize_t debugfs_attr_read(struct file *file, char __user *buf,
527 size_t len, loff_t *ppos)
528{
529 struct dentry *dentry = F_DENTRY(file);
530 ssize_t ret;
531
532 ret = debugfs_file_get(dentry);
533 if (unlikely(ret))
534 return ret;
535 ret = simple_attr_read(file, buf, len, ppos);
536 debugfs_file_put(dentry);
537 return ret;
538}
539EXPORT_SYMBOL_GPL(debugfs_attr_read);
540
541static ssize_t debugfs_attr_write_xsigned(struct file *file, const char __user *buf,
542 size_t len, loff_t *ppos, bool is_signed)
543{
544 struct dentry *dentry = F_DENTRY(file);
545 ssize_t ret;
546
547 ret = debugfs_file_get(dentry);
548 if (unlikely(ret))
549 return ret;
550 if (is_signed)
551 ret = simple_attr_write_signed(file, buf, len, ppos);
552 else
553 ret = simple_attr_write(file, buf, len, ppos);
554 debugfs_file_put(dentry);
555 return ret;
556}
557
558ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
559 size_t len, loff_t *ppos)
560{
561 return debugfs_attr_write_xsigned(file, buf, len, ppos, false);
562}
563EXPORT_SYMBOL_GPL(debugfs_attr_write);
564
565ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf,
566 size_t len, loff_t *ppos)
567{
568 return debugfs_attr_write_xsigned(file, buf, len, ppos, true);
569}
570EXPORT_SYMBOL_GPL(debugfs_attr_write_signed);
571
572static struct dentry *debugfs_create_mode_unsafe(const char *name, umode_t mode,
573 struct dentry *parent, void *value,
574 const struct file_operations *fops,
575 const struct file_operations *fops_ro,
576 const struct file_operations *fops_wo)
577{
578 /* if there are no write bits set, make read only */
579 if (!(mode & S_IWUGO))
580 return debugfs_create_file_unsafe(name, mode, parent, value,
581 fops_ro);
582 /* if there are no read bits set, make write only */
583 if (!(mode & S_IRUGO))
584 return debugfs_create_file_unsafe(name, mode, parent, value,
585 fops_wo);
586
587 return debugfs_create_file_unsafe(name, mode, parent, value, fops);
588}
589
590static int debugfs_u8_set(void *data, u64 val)
591{
592 *(u8 *)data = val;
593 return 0;
594}
595static int debugfs_u8_get(void *data, u64 *val)
596{
597 *val = *(u8 *)data;
598 return 0;
599}
600DEFINE_DEBUGFS_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
601DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
602DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
603
604/**
605 * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
606 * @name: a pointer to a string containing the name of the file to create.
607 * @mode: the permission that the file should have
608 * @parent: a pointer to the parent dentry for this file. This should be a
609 * directory dentry if set. If this parameter is %NULL, then the
610 * file will be created in the root of the debugfs filesystem.
611 * @value: a pointer to the variable that the file should read to and write
612 * from.
613 *
614 * This function creates a file in debugfs with the given name that
615 * contains the value of the variable @value. If the @mode variable is so
616 * set, it can be read from, and written to.
617 */
618void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent,
619 u8 *value)
620{
621 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8,
622 &fops_u8_ro, &fops_u8_wo);
623}
624EXPORT_SYMBOL_GPL(debugfs_create_u8);
625
626static int debugfs_u16_set(void *data, u64 val)
627{
628 *(u16 *)data = val;
629 return 0;
630}
631static int debugfs_u16_get(void *data, u64 *val)
632{
633 *val = *(u16 *)data;
634 return 0;
635}
636DEFINE_DEBUGFS_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
637DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
638DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
639
640/**
641 * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
642 * @name: a pointer to a string containing the name of the file to create.
643 * @mode: the permission that the file should have
644 * @parent: a pointer to the parent dentry for this file. This should be a
645 * directory dentry if set. If this parameter is %NULL, then the
646 * file will be created in the root of the debugfs filesystem.
647 * @value: a pointer to the variable that the file should read to and write
648 * from.
649 *
650 * This function creates a file in debugfs with the given name that
651 * contains the value of the variable @value. If the @mode variable is so
652 * set, it can be read from, and written to.
653 */
654void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent,
655 u16 *value)
656{
657 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16,
658 &fops_u16_ro, &fops_u16_wo);
659}
660EXPORT_SYMBOL_GPL(debugfs_create_u16);
661
662static int debugfs_u32_set(void *data, u64 val)
663{
664 *(u32 *)data = val;
665 return 0;
666}
667static int debugfs_u32_get(void *data, u64 *val)
668{
669 *val = *(u32 *)data;
670 return 0;
671}
672DEFINE_DEBUGFS_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
673DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
674DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
675
676/**
677 * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
678 * @name: a pointer to a string containing the name of the file to create.
679 * @mode: the permission that the file should have
680 * @parent: a pointer to the parent dentry for this file. This should be a
681 * directory dentry if set. If this parameter is %NULL, then the
682 * file will be created in the root of the debugfs filesystem.
683 * @value: a pointer to the variable that the file should read to and write
684 * from.
685 *
686 * This function creates a file in debugfs with the given name that
687 * contains the value of the variable @value. If the @mode variable is so
688 * set, it can be read from, and written to.
689 */
690void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent,
691 u32 *value)
692{
693 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u32,
694 &fops_u32_ro, &fops_u32_wo);
695}
696EXPORT_SYMBOL_GPL(debugfs_create_u32);
697
698static int debugfs_u64_set(void *data, u64 val)
699{
700 *(u64 *)data = val;
701 return 0;
702}
703
704static int debugfs_u64_get(void *data, u64 *val)
705{
706 *val = *(u64 *)data;
707 return 0;
708}
709DEFINE_DEBUGFS_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
710DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
711DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
712
713/**
714 * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value
715 * @name: a pointer to a string containing the name of the file to create.
716 * @mode: the permission that the file should have
717 * @parent: a pointer to the parent dentry for this file. This should be a
718 * directory dentry if set. If this parameter is %NULL, then the
719 * file will be created in the root of the debugfs filesystem.
720 * @value: a pointer to the variable that the file should read to and write
721 * from.
722 *
723 * This function creates a file in debugfs with the given name that
724 * contains the value of the variable @value. If the @mode variable is so
725 * set, it can be read from, and written to.
726 */
727void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent,
728 u64 *value)
729{
730 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u64,
731 &fops_u64_ro, &fops_u64_wo);
732}
733EXPORT_SYMBOL_GPL(debugfs_create_u64);
734
735static int debugfs_ulong_set(void *data, u64 val)
736{
737 *(unsigned long *)data = val;
738 return 0;
739}
740
741static int debugfs_ulong_get(void *data, u64 *val)
742{
743 *val = *(unsigned long *)data;
744 return 0;
745}
746DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set,
747 "%llu\n");
748DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n");
749DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n");
750
751/**
752 * debugfs_create_ulong - create a debugfs file that is used to read and write
753 * an unsigned long value.
754 * @name: a pointer to a string containing the name of the file to create.
755 * @mode: the permission that the file should have
756 * @parent: a pointer to the parent dentry for this file. This should be a
757 * directory dentry if set. If this parameter is %NULL, then the
758 * file will be created in the root of the debugfs filesystem.
759 * @value: a pointer to the variable that the file should read to and write
760 * from.
761 *
762 * This function creates a file in debugfs with the given name that
763 * contains the value of the variable @value. If the @mode variable is so
764 * set, it can be read from, and written to.
765 */
766void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent,
767 unsigned long *value)
768{
769 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_ulong,
770 &fops_ulong_ro, &fops_ulong_wo);
771}
772EXPORT_SYMBOL_GPL(debugfs_create_ulong);
773
774DEFINE_DEBUGFS_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
775DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
776DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
777
778DEFINE_DEBUGFS_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set,
779 "0x%04llx\n");
780DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
781DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
782
783DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set,
784 "0x%08llx\n");
785DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
786DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
787
788DEFINE_DEBUGFS_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set,
789 "0x%016llx\n");
790DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_ro, debugfs_u64_get, NULL, "0x%016llx\n");
791DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n");
792
793/*
794 * 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
795 *
796 * These functions are exactly the same as the above functions (but use a hex
797 * output for the decimal challenged). For details look at the above unsigned
798 * decimal functions.
799 */
800
801/**
802 * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value
803 * @name: a pointer to a string containing the name of the file to create.
804 * @mode: the permission that the file should have
805 * @parent: a pointer to the parent dentry for this file. This should be a
806 * directory dentry if set. If this parameter is %NULL, then the
807 * file will be created in the root of the debugfs filesystem.
808 * @value: a pointer to the variable that the file should read to and write
809 * from.
810 */
811void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent,
812 u8 *value)
813{
814 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8,
815 &fops_x8_ro, &fops_x8_wo);
816}
817EXPORT_SYMBOL_GPL(debugfs_create_x8);
818
819/**
820 * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value
821 * @name: a pointer to a string containing the name of the file to create.
822 * @mode: the permission that the file should have
823 * @parent: a pointer to the parent dentry for this file. This should be a
824 * directory dentry if set. If this parameter is %NULL, then the
825 * file will be created in the root of the debugfs filesystem.
826 * @value: a pointer to the variable that the file should read to and write
827 * from.
828 */
829void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent,
830 u16 *value)
831{
832 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x16,
833 &fops_x16_ro, &fops_x16_wo);
834}
835EXPORT_SYMBOL_GPL(debugfs_create_x16);
836
837/**
838 * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value
839 * @name: a pointer to a string containing the name of the file to create.
840 * @mode: the permission that the file should have
841 * @parent: a pointer to the parent dentry for this file. This should be a
842 * directory dentry if set. If this parameter is %NULL, then the
843 * file will be created in the root of the debugfs filesystem.
844 * @value: a pointer to the variable that the file should read to and write
845 * from.
846 */
847void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent,
848 u32 *value)
849{
850 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x32,
851 &fops_x32_ro, &fops_x32_wo);
852}
853EXPORT_SYMBOL_GPL(debugfs_create_x32);
854
855/**
856 * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value
857 * @name: a pointer to a string containing the name of the file to create.
858 * @mode: the permission that the file should have
859 * @parent: a pointer to the parent dentry for this file. This should be a
860 * directory dentry if set. If this parameter is %NULL, then the
861 * file will be created in the root of the debugfs filesystem.
862 * @value: a pointer to the variable that the file should read to and write
863 * from.
864 */
865void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent,
866 u64 *value)
867{
868 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x64,
869 &fops_x64_ro, &fops_x64_wo);
870}
871EXPORT_SYMBOL_GPL(debugfs_create_x64);
872
873
874static int debugfs_size_t_set(void *data, u64 val)
875{
876 *(size_t *)data = val;
877 return 0;
878}
879static int debugfs_size_t_get(void *data, u64 *val)
880{
881 *val = *(size_t *)data;
882 return 0;
883}
884DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
885 "%llu\n"); /* %llu and %zu are more or less the same */
886DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_ro, debugfs_size_t_get, NULL, "%llu\n");
887DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n");
888
889/**
890 * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value
891 * @name: a pointer to a string containing the name of the file to create.
892 * @mode: the permission that the file should have
893 * @parent: a pointer to the parent dentry for this file. This should be a
894 * directory dentry if set. If this parameter is %NULL, then the
895 * file will be created in the root of the debugfs filesystem.
896 * @value: a pointer to the variable that the file should read to and write
897 * from.
898 */
899void debugfs_create_size_t(const char *name, umode_t mode,
900 struct dentry *parent, size_t *value)
901{
902 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_size_t,
903 &fops_size_t_ro, &fops_size_t_wo);
904}
905EXPORT_SYMBOL_GPL(debugfs_create_size_t);
906
907static int debugfs_atomic_t_set(void *data, u64 val)
908{
909 atomic_set((atomic_t *)data, val);
910 return 0;
911}
912static int debugfs_atomic_t_get(void *data, u64 *val)
913{
914 *val = atomic_read((atomic_t *)data);
915 return 0;
916}
917DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t, debugfs_atomic_t_get,
918 debugfs_atomic_t_set, "%lld\n");
919DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_ro, debugfs_atomic_t_get, NULL,
920 "%lld\n");
921DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_wo, NULL, debugfs_atomic_t_set,
922 "%lld\n");
923
924/**
925 * debugfs_create_atomic_t - create a debugfs file that is used to read and
926 * write an atomic_t value
927 * @name: a pointer to a string containing the name of the file to create.
928 * @mode: the permission that the file should have
929 * @parent: a pointer to the parent dentry for this file. This should be a
930 * directory dentry if set. If this parameter is %NULL, then the
931 * file will be created in the root of the debugfs filesystem.
932 * @value: a pointer to the variable that the file should read to and write
933 * from.
934 */
935void debugfs_create_atomic_t(const char *name, umode_t mode,
936 struct dentry *parent, atomic_t *value)
937{
938 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_atomic_t,
939 &fops_atomic_t_ro, &fops_atomic_t_wo);
940}
941EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
942
943ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
944 size_t count, loff_t *ppos)
945{
946 char buf[2];
947 bool val;
948 int r;
949 struct dentry *dentry = F_DENTRY(file);
950
951 r = debugfs_file_get(dentry);
952 if (unlikely(r))
953 return r;
954 val = *(bool *)file->private_data;
955 debugfs_file_put(dentry);
956
957 if (val)
958 buf[0] = 'Y';
959 else
960 buf[0] = 'N';
961 buf[1] = '\n';
962 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
963}
964EXPORT_SYMBOL_GPL(debugfs_read_file_bool);
965
966ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
967 size_t count, loff_t *ppos)
968{
969 bool bv;
970 int r;
971 bool *val = file->private_data;
972 struct dentry *dentry = F_DENTRY(file);
973
974 r = kstrtobool_from_user(user_buf, count, &bv);
975 if (!r) {
976 r = debugfs_file_get(dentry);
977 if (unlikely(r))
978 return r;
979 *val = bv;
980 debugfs_file_put(dentry);
981 }
982
983 return count;
984}
985EXPORT_SYMBOL_GPL(debugfs_write_file_bool);
986
987static const struct file_operations fops_bool = {
988 .read = debugfs_read_file_bool,
989 .write = debugfs_write_file_bool,
990 .open = simple_open,
991 .llseek = default_llseek,
992};
993
994static const struct file_operations fops_bool_ro = {
995 .read = debugfs_read_file_bool,
996 .open = simple_open,
997 .llseek = default_llseek,
998};
999
1000static const struct file_operations fops_bool_wo = {
1001 .write = debugfs_write_file_bool,
1002 .open = simple_open,
1003 .llseek = default_llseek,
1004};
1005
1006/**
1007 * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value
1008 * @name: a pointer to a string containing the name of the file to create.
1009 * @mode: the permission that the file should have
1010 * @parent: a pointer to the parent dentry for this file. This should be a
1011 * directory dentry if set. If this parameter is %NULL, then the
1012 * file will be created in the root of the debugfs filesystem.
1013 * @value: a pointer to the variable that the file should read to and write
1014 * from.
1015 *
1016 * This function creates a file in debugfs with the given name that
1017 * contains the value of the variable @value. If the @mode variable is so
1018 * set, it can be read from, and written to.
1019 */
1020void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent,
1021 bool *value)
1022{
1023 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_bool,
1024 &fops_bool_ro, &fops_bool_wo);
1025}
1026EXPORT_SYMBOL_GPL(debugfs_create_bool);
1027
1028ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
1029 size_t count, loff_t *ppos)
1030{
1031 struct dentry *dentry = F_DENTRY(file);
1032 char *str, *copy = NULL;
1033 int copy_len, len;
1034 ssize_t ret;
1035
1036 ret = debugfs_file_get(dentry);
1037 if (unlikely(ret))
1038 return ret;
1039
1040 str = *(char **)file->private_data;
1041 len = strlen(str) + 1;
1042 copy = kmalloc(len, GFP_KERNEL);
1043 if (!copy) {
1044 debugfs_file_put(dentry);
1045 return -ENOMEM;
1046 }
1047
1048 copy_len = strscpy(copy, str, len);
1049 debugfs_file_put(dentry);
1050 if (copy_len < 0) {
1051 kfree(copy);
1052 return copy_len;
1053 }
1054
1055 copy[copy_len] = '\n';
1056
1057 ret = simple_read_from_buffer(user_buf, count, ppos, copy, len);
1058 kfree(copy);
1059
1060 return ret;
1061}
1062EXPORT_SYMBOL_GPL(debugfs_create_str);
1063
1064static ssize_t debugfs_write_file_str(struct file *file, const char __user *user_buf,
1065 size_t count, loff_t *ppos)
1066{
1067 struct dentry *dentry = F_DENTRY(file);
1068 char *old, *new = NULL;
1069 int pos = *ppos;
1070 int r;
1071
1072 r = debugfs_file_get(dentry);
1073 if (unlikely(r))
1074 return r;
1075
1076 old = *(char **)file->private_data;
1077
1078 /* only allow strict concatenation */
1079 r = -EINVAL;
1080 if (pos && pos != strlen(old))
1081 goto error;
1082
1083 r = -E2BIG;
1084 if (pos + count + 1 > PAGE_SIZE)
1085 goto error;
1086
1087 r = -ENOMEM;
1088 new = kmalloc(pos + count + 1, GFP_KERNEL);
1089 if (!new)
1090 goto error;
1091
1092 if (pos)
1093 memcpy(new, old, pos);
1094
1095 r = -EFAULT;
1096 if (copy_from_user(new + pos, user_buf, count))
1097 goto error;
1098
1099 new[pos + count] = '\0';
1100 strim(new);
1101
1102 rcu_assign_pointer(*(char __rcu **)file->private_data, new);
1103 synchronize_rcu();
1104 kfree(old);
1105
1106 debugfs_file_put(dentry);
1107 return count;
1108
1109error:
1110 kfree(new);
1111 debugfs_file_put(dentry);
1112 return r;
1113}
1114
1115static const struct file_operations fops_str = {
1116 .read = debugfs_read_file_str,
1117 .write = debugfs_write_file_str,
1118 .open = simple_open,
1119 .llseek = default_llseek,
1120};
1121
1122static const struct file_operations fops_str_ro = {
1123 .read = debugfs_read_file_str,
1124 .open = simple_open,
1125 .llseek = default_llseek,
1126};
1127
1128static const struct file_operations fops_str_wo = {
1129 .write = debugfs_write_file_str,
1130 .open = simple_open,
1131 .llseek = default_llseek,
1132};
1133
1134/**
1135 * debugfs_create_str - create a debugfs file that is used to read and write a string value
1136 * @name: a pointer to a string containing the name of the file to create.
1137 * @mode: the permission that the file should have
1138 * @parent: a pointer to the parent dentry for this file. This should be a
1139 * directory dentry if set. If this parameter is %NULL, then the
1140 * file will be created in the root of the debugfs filesystem.
1141 * @value: a pointer to the variable that the file should read to and write
1142 * from.
1143 *
1144 * This function creates a file in debugfs with the given name that
1145 * contains the value of the variable @value. If the @mode variable is so
1146 * set, it can be read from, and written to.
1147 */
1148void debugfs_create_str(const char *name, umode_t mode,
1149 struct dentry *parent, char **value)
1150{
1151 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_str,
1152 &fops_str_ro, &fops_str_wo);
1153}
1154
1155static ssize_t read_file_blob(struct file *file, char __user *user_buf,
1156 size_t count, loff_t *ppos)
1157{
1158 struct debugfs_blob_wrapper *blob = file->private_data;
1159 struct dentry *dentry = F_DENTRY(file);
1160 ssize_t r;
1161
1162 r = debugfs_file_get(dentry);
1163 if (unlikely(r))
1164 return r;
1165 r = simple_read_from_buffer(user_buf, count, ppos, blob->data,
1166 blob->size);
1167 debugfs_file_put(dentry);
1168 return r;
1169}
1170
1171static ssize_t write_file_blob(struct file *file, const char __user *user_buf,
1172 size_t count, loff_t *ppos)
1173{
1174 struct debugfs_blob_wrapper *blob = file->private_data;
1175 struct dentry *dentry = F_DENTRY(file);
1176 ssize_t r;
1177
1178 r = debugfs_file_get(dentry);
1179 if (unlikely(r))
1180 return r;
1181 r = simple_write_to_buffer(blob->data, blob->size, ppos, user_buf,
1182 count);
1183
1184 debugfs_file_put(dentry);
1185 return r;
1186}
1187
1188static const struct file_operations fops_blob = {
1189 .read = read_file_blob,
1190 .write = write_file_blob,
1191 .open = simple_open,
1192 .llseek = default_llseek,
1193};
1194
1195/**
1196 * debugfs_create_blob - create a debugfs file that is used to read and write
1197 * a binary blob
1198 * @name: a pointer to a string containing the name of the file to create.
1199 * @mode: the permission that the file should have
1200 * @parent: a pointer to the parent dentry for this file. This should be a
1201 * directory dentry if set. If this parameter is %NULL, then the
1202 * file will be created in the root of the debugfs filesystem.
1203 * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer
1204 * to the blob data and the size of the data.
1205 *
1206 * This function creates a file in debugfs with the given name that exports
1207 * @blob->data as a binary blob. If the @mode variable is so set it can be
1208 * read from and written to.
1209 *
1210 * This function will return a pointer to a dentry if it succeeds. This
1211 * pointer must be passed to the debugfs_remove() function when the file is
1212 * to be removed (no automatic cleanup happens if your module is unloaded,
1213 * you are responsible here.) If an error occurs, ERR_PTR(-ERROR) will be
1214 * returned.
1215 *
1216 * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will
1217 * be returned.
1218 */
1219struct dentry *debugfs_create_blob(const char *name, umode_t mode,
1220 struct dentry *parent,
1221 struct debugfs_blob_wrapper *blob)
1222{
1223 return debugfs_create_file_unsafe(name, mode & 0644, parent, blob, &fops_blob);
1224}
1225EXPORT_SYMBOL_GPL(debugfs_create_blob);
1226
1227static size_t u32_format_array(char *buf, size_t bufsize,
1228 u32 *array, int array_size)
1229{
1230 size_t ret = 0;
1231
1232 while (--array_size >= 0) {
1233 size_t len;
1234 char term = array_size ? ' ' : '\n';
1235
1236 len = snprintf(buf, bufsize, "%u%c", *array++, term);
1237 ret += len;
1238
1239 buf += len;
1240 bufsize -= len;
1241 }
1242 return ret;
1243}
1244
1245static int u32_array_open(struct inode *inode, struct file *file)
1246{
1247 struct debugfs_u32_array *data = inode->i_private;
1248 int size, elements = data->n_elements;
1249 char *buf;
1250
1251 /*
1252 * Max size:
1253 * - 10 digits + ' '/'\n' = 11 bytes per number
1254 * - terminating NUL character
1255 */
1256 size = elements*11;
1257 buf = kmalloc(size+1, GFP_KERNEL);
1258 if (!buf)
1259 return -ENOMEM;
1260 buf[size] = 0;
1261
1262 file->private_data = buf;
1263 u32_format_array(buf, size, data->array, data->n_elements);
1264
1265 return nonseekable_open(inode, file);
1266}
1267
1268static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
1269 loff_t *ppos)
1270{
1271 size_t size = strlen(file->private_data);
1272
1273 return simple_read_from_buffer(buf, len, ppos,
1274 file->private_data, size);
1275}
1276
1277static int u32_array_release(struct inode *inode, struct file *file)
1278{
1279 kfree(file->private_data);
1280
1281 return 0;
1282}
1283
1284static const struct file_operations u32_array_fops = {
1285 .owner = THIS_MODULE,
1286 .open = u32_array_open,
1287 .release = u32_array_release,
1288 .read = u32_array_read,
1289};
1290
1291/**
1292 * debugfs_create_u32_array - create a debugfs file that is used to read u32
1293 * array.
1294 * @name: a pointer to a string containing the name of the file to create.
1295 * @mode: the permission that the file should have.
1296 * @parent: a pointer to the parent dentry for this file. This should be a
1297 * directory dentry if set. If this parameter is %NULL, then the
1298 * file will be created in the root of the debugfs filesystem.
1299 * @array: wrapper struct containing data pointer and size of the array.
1300 *
1301 * This function creates a file in debugfs with the given name that exports
1302 * @array as data. If the @mode variable is so set it can be read from.
1303 * Writing is not supported. Seek within the file is also not supported.
1304 * Once array is created its size can not be changed.
1305 */
1306void debugfs_create_u32_array(const char *name, umode_t mode,
1307 struct dentry *parent,
1308 struct debugfs_u32_array *array)
1309{
1310 debugfs_create_file_unsafe(name, mode, parent, array, &u32_array_fops);
1311}
1312EXPORT_SYMBOL_GPL(debugfs_create_u32_array);
1313
1314#ifdef CONFIG_HAS_IOMEM
1315
1316/*
1317 * The regset32 stuff is used to print 32-bit registers using the
1318 * seq_file utilities. We offer printing a register set in an already-opened
1319 * sequential file or create a debugfs file that only prints a regset32.
1320 */
1321
1322/**
1323 * debugfs_print_regs32 - use seq_print to describe a set of registers
1324 * @s: the seq_file structure being used to generate output
1325 * @regs: an array if struct debugfs_reg32 structures
1326 * @nregs: the length of the above array
1327 * @base: the base address to be used in reading the registers
1328 * @prefix: a string to be prefixed to every output line
1329 *
1330 * This function outputs a text block describing the current values of
1331 * some 32-bit hardware registers. It is meant to be used within debugfs
1332 * files based on seq_file that need to show registers, intermixed with other
1333 * information. The prefix argument may be used to specify a leading string,
1334 * because some peripherals have several blocks of identical registers,
1335 * for example configuration of dma channels
1336 */
1337void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
1338 int nregs, void __iomem *base, char *prefix)
1339{
1340 int i;
1341
1342 for (i = 0; i < nregs; i++, regs++) {
1343 if (prefix)
1344 seq_printf(s, "%s", prefix);
1345 seq_printf(s, "%s = 0x%08x\n", regs->name,
1346 readl(base + regs->offset));
1347 if (seq_has_overflowed(s))
1348 break;
1349 }
1350}
1351EXPORT_SYMBOL_GPL(debugfs_print_regs32);
1352
1353static int debugfs_regset32_show(struct seq_file *s, void *data)
1354{
1355 struct debugfs_regset32 *regset = s->private;
1356
1357 if (regset->dev)
1358 pm_runtime_get_sync(regset->dev);
1359
1360 debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, "");
1361
1362 if (regset->dev)
1363 pm_runtime_put(regset->dev);
1364
1365 return 0;
1366}
1367
1368DEFINE_SHOW_ATTRIBUTE(debugfs_regset32);
1369
1370/**
1371 * debugfs_create_regset32 - create a debugfs file that returns register values
1372 * @name: a pointer to a string containing the name of the file to create.
1373 * @mode: the permission that the file should have
1374 * @parent: a pointer to the parent dentry for this file. This should be a
1375 * directory dentry if set. If this parameter is %NULL, then the
1376 * file will be created in the root of the debugfs filesystem.
1377 * @regset: a pointer to a struct debugfs_regset32, which contains a pointer
1378 * to an array of register definitions, the array size and the base
1379 * address where the register bank is to be found.
1380 *
1381 * This function creates a file in debugfs with the given name that reports
1382 * the names and values of a set of 32-bit registers. If the @mode variable
1383 * is so set it can be read from. Writing is not supported.
1384 */
1385void debugfs_create_regset32(const char *name, umode_t mode,
1386 struct dentry *parent,
1387 struct debugfs_regset32 *regset)
1388{
1389 debugfs_create_file(name, mode, parent, regset, &debugfs_regset32_fops);
1390}
1391EXPORT_SYMBOL_GPL(debugfs_create_regset32);
1392
1393#endif /* CONFIG_HAS_IOMEM */
1394
1395struct debugfs_devm_entry {
1396 int (*read)(struct seq_file *seq, void *data);
1397 struct device *dev;
1398};
1399
1400static int debugfs_devm_entry_open(struct inode *inode, struct file *f)
1401{
1402 struct debugfs_devm_entry *entry = inode->i_private;
1403
1404 return single_open(f, entry->read, entry->dev);
1405}
1406
1407static const struct file_operations debugfs_devm_entry_ops = {
1408 .owner = THIS_MODULE,
1409 .open = debugfs_devm_entry_open,
1410 .release = single_release,
1411 .read = seq_read,
1412 .llseek = seq_lseek
1413};
1414
1415/**
1416 * debugfs_create_devm_seqfile - create a debugfs file that is bound to device.
1417 *
1418 * @dev: device related to this debugfs file.
1419 * @name: name of the debugfs file.
1420 * @parent: a pointer to the parent dentry for this file. This should be a
1421 * directory dentry if set. If this parameter is %NULL, then the
1422 * file will be created in the root of the debugfs filesystem.
1423 * @read_fn: function pointer called to print the seq_file content.
1424 */
1425void debugfs_create_devm_seqfile(struct device *dev, const char *name,
1426 struct dentry *parent,
1427 int (*read_fn)(struct seq_file *s, void *data))
1428{
1429 struct debugfs_devm_entry *entry;
1430
1431 if (IS_ERR(parent))
1432 return;
1433
1434 entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL);
1435 if (!entry)
1436 return;
1437
1438 entry->read = read_fn;
1439 entry->dev = dev;
1440
1441 debugfs_create_file(name, S_IRUGO, parent, entry,
1442 &debugfs_devm_entry_ops);
1443}
1444EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile);
1/*
2 * file.c - part of debugfs, a tiny little debug file system
3 *
4 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
5 * Copyright (C) 2004 IBM Inc.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
10 *
11 * debugfs is for people to use instead of /proc or /sys.
12 * See Documentation/DocBook/filesystems for more details.
13 *
14 */
15
16#include <linux/module.h>
17#include <linux/fs.h>
18#include <linux/seq_file.h>
19#include <linux/pagemap.h>
20#include <linux/namei.h>
21#include <linux/debugfs.h>
22#include <linux/io.h>
23#include <linux/slab.h>
24#include <linux/atomic.h>
25
26static ssize_t default_read_file(struct file *file, char __user *buf,
27 size_t count, loff_t *ppos)
28{
29 return 0;
30}
31
32static ssize_t default_write_file(struct file *file, const char __user *buf,
33 size_t count, loff_t *ppos)
34{
35 return count;
36}
37
38const struct file_operations debugfs_file_operations = {
39 .read = default_read_file,
40 .write = default_write_file,
41 .open = simple_open,
42 .llseek = noop_llseek,
43};
44
45static void *debugfs_follow_link(struct dentry *dentry, struct nameidata *nd)
46{
47 nd_set_link(nd, dentry->d_inode->i_private);
48 return NULL;
49}
50
51const struct inode_operations debugfs_link_operations = {
52 .readlink = generic_readlink,
53 .follow_link = debugfs_follow_link,
54};
55
56static int debugfs_u8_set(void *data, u64 val)
57{
58 *(u8 *)data = val;
59 return 0;
60}
61static int debugfs_u8_get(void *data, u64 *val)
62{
63 *val = *(u8 *)data;
64 return 0;
65}
66DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
67DEFINE_SIMPLE_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
68DEFINE_SIMPLE_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
69
70/**
71 * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
72 * @name: a pointer to a string containing the name of the file to create.
73 * @mode: the permission that the file should have
74 * @parent: a pointer to the parent dentry for this file. This should be a
75 * directory dentry if set. If this parameter is %NULL, then the
76 * file will be created in the root of the debugfs filesystem.
77 * @value: a pointer to the variable that the file should read to and write
78 * from.
79 *
80 * This function creates a file in debugfs with the given name that
81 * contains the value of the variable @value. If the @mode variable is so
82 * set, it can be read from, and written to.
83 *
84 * This function will return a pointer to a dentry if it succeeds. This
85 * pointer must be passed to the debugfs_remove() function when the file is
86 * to be removed (no automatic cleanup happens if your module is unloaded,
87 * you are responsible here.) If an error occurs, %NULL will be returned.
88 *
89 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
90 * returned. It is not wise to check for this value, but rather, check for
91 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
92 * code.
93 */
94struct dentry *debugfs_create_u8(const char *name, umode_t mode,
95 struct dentry *parent, u8 *value)
96{
97 /* if there are no write bits set, make read only */
98 if (!(mode & S_IWUGO))
99 return debugfs_create_file(name, mode, parent, value, &fops_u8_ro);
100 /* if there are no read bits set, make write only */
101 if (!(mode & S_IRUGO))
102 return debugfs_create_file(name, mode, parent, value, &fops_u8_wo);
103
104 return debugfs_create_file(name, mode, parent, value, &fops_u8);
105}
106EXPORT_SYMBOL_GPL(debugfs_create_u8);
107
108static int debugfs_u16_set(void *data, u64 val)
109{
110 *(u16 *)data = val;
111 return 0;
112}
113static int debugfs_u16_get(void *data, u64 *val)
114{
115 *val = *(u16 *)data;
116 return 0;
117}
118DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
119DEFINE_SIMPLE_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
120DEFINE_SIMPLE_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
121
122/**
123 * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
124 * @name: a pointer to a string containing the name of the file to create.
125 * @mode: the permission that the file should have
126 * @parent: a pointer to the parent dentry for this file. This should be a
127 * directory dentry if set. If this parameter is %NULL, then the
128 * file will be created in the root of the debugfs filesystem.
129 * @value: a pointer to the variable that the file should read to and write
130 * from.
131 *
132 * This function creates a file in debugfs with the given name that
133 * contains the value of the variable @value. If the @mode variable is so
134 * set, it can be read from, and written to.
135 *
136 * This function will return a pointer to a dentry if it succeeds. This
137 * pointer must be passed to the debugfs_remove() function when the file is
138 * to be removed (no automatic cleanup happens if your module is unloaded,
139 * you are responsible here.) If an error occurs, %NULL will be returned.
140 *
141 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
142 * returned. It is not wise to check for this value, but rather, check for
143 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
144 * code.
145 */
146struct dentry *debugfs_create_u16(const char *name, umode_t mode,
147 struct dentry *parent, u16 *value)
148{
149 /* if there are no write bits set, make read only */
150 if (!(mode & S_IWUGO))
151 return debugfs_create_file(name, mode, parent, value, &fops_u16_ro);
152 /* if there are no read bits set, make write only */
153 if (!(mode & S_IRUGO))
154 return debugfs_create_file(name, mode, parent, value, &fops_u16_wo);
155
156 return debugfs_create_file(name, mode, parent, value, &fops_u16);
157}
158EXPORT_SYMBOL_GPL(debugfs_create_u16);
159
160static int debugfs_u32_set(void *data, u64 val)
161{
162 *(u32 *)data = val;
163 return 0;
164}
165static int debugfs_u32_get(void *data, u64 *val)
166{
167 *val = *(u32 *)data;
168 return 0;
169}
170DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
171DEFINE_SIMPLE_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
172DEFINE_SIMPLE_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
173
174/**
175 * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
176 * @name: a pointer to a string containing the name of the file to create.
177 * @mode: the permission that the file should have
178 * @parent: a pointer to the parent dentry for this file. This should be a
179 * directory dentry if set. If this parameter is %NULL, then the
180 * file will be created in the root of the debugfs filesystem.
181 * @value: a pointer to the variable that the file should read to and write
182 * from.
183 *
184 * This function creates a file in debugfs with the given name that
185 * contains the value of the variable @value. If the @mode variable is so
186 * set, it can be read from, and written to.
187 *
188 * This function will return a pointer to a dentry if it succeeds. This
189 * pointer must be passed to the debugfs_remove() function when the file is
190 * to be removed (no automatic cleanup happens if your module is unloaded,
191 * you are responsible here.) If an error occurs, %NULL will be returned.
192 *
193 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
194 * returned. It is not wise to check for this value, but rather, check for
195 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
196 * code.
197 */
198struct dentry *debugfs_create_u32(const char *name, umode_t mode,
199 struct dentry *parent, u32 *value)
200{
201 /* if there are no write bits set, make read only */
202 if (!(mode & S_IWUGO))
203 return debugfs_create_file(name, mode, parent, value, &fops_u32_ro);
204 /* if there are no read bits set, make write only */
205 if (!(mode & S_IRUGO))
206 return debugfs_create_file(name, mode, parent, value, &fops_u32_wo);
207
208 return debugfs_create_file(name, mode, parent, value, &fops_u32);
209}
210EXPORT_SYMBOL_GPL(debugfs_create_u32);
211
212static int debugfs_u64_set(void *data, u64 val)
213{
214 *(u64 *)data = val;
215 return 0;
216}
217
218static int debugfs_u64_get(void *data, u64 *val)
219{
220 *val = *(u64 *)data;
221 return 0;
222}
223DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
224DEFINE_SIMPLE_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
225DEFINE_SIMPLE_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
226
227/**
228 * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value
229 * @name: a pointer to a string containing the name of the file to create.
230 * @mode: the permission that the file should have
231 * @parent: a pointer to the parent dentry for this file. This should be a
232 * directory dentry if set. If this parameter is %NULL, then the
233 * file will be created in the root of the debugfs filesystem.
234 * @value: a pointer to the variable that the file should read to and write
235 * from.
236 *
237 * This function creates a file in debugfs with the given name that
238 * contains the value of the variable @value. If the @mode variable is so
239 * set, it can be read from, and written to.
240 *
241 * This function will return a pointer to a dentry if it succeeds. This
242 * pointer must be passed to the debugfs_remove() function when the file is
243 * to be removed (no automatic cleanup happens if your module is unloaded,
244 * you are responsible here.) If an error occurs, %NULL will be returned.
245 *
246 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
247 * returned. It is not wise to check for this value, but rather, check for
248 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
249 * code.
250 */
251struct dentry *debugfs_create_u64(const char *name, umode_t mode,
252 struct dentry *parent, u64 *value)
253{
254 /* if there are no write bits set, make read only */
255 if (!(mode & S_IWUGO))
256 return debugfs_create_file(name, mode, parent, value, &fops_u64_ro);
257 /* if there are no read bits set, make write only */
258 if (!(mode & S_IRUGO))
259 return debugfs_create_file(name, mode, parent, value, &fops_u64_wo);
260
261 return debugfs_create_file(name, mode, parent, value, &fops_u64);
262}
263EXPORT_SYMBOL_GPL(debugfs_create_u64);
264
265DEFINE_SIMPLE_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
266DEFINE_SIMPLE_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
267DEFINE_SIMPLE_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
268
269DEFINE_SIMPLE_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n");
270DEFINE_SIMPLE_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
271DEFINE_SIMPLE_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
272
273DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n");
274DEFINE_SIMPLE_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
275DEFINE_SIMPLE_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
276
277DEFINE_SIMPLE_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, "0x%016llx\n");
278
279/*
280 * debugfs_create_x{8,16,32,64} - create a debugfs file that is used to read and write an unsigned {8,16,32,64}-bit value
281 *
282 * These functions are exactly the same as the above functions (but use a hex
283 * output for the decimal challenged). For details look at the above unsigned
284 * decimal functions.
285 */
286
287/**
288 * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value
289 * @name: a pointer to a string containing the name of the file to create.
290 * @mode: the permission that the file should have
291 * @parent: a pointer to the parent dentry for this file. This should be a
292 * directory dentry if set. If this parameter is %NULL, then the
293 * file will be created in the root of the debugfs filesystem.
294 * @value: a pointer to the variable that the file should read to and write
295 * from.
296 */
297struct dentry *debugfs_create_x8(const char *name, umode_t mode,
298 struct dentry *parent, u8 *value)
299{
300 /* if there are no write bits set, make read only */
301 if (!(mode & S_IWUGO))
302 return debugfs_create_file(name, mode, parent, value, &fops_x8_ro);
303 /* if there are no read bits set, make write only */
304 if (!(mode & S_IRUGO))
305 return debugfs_create_file(name, mode, parent, value, &fops_x8_wo);
306
307 return debugfs_create_file(name, mode, parent, value, &fops_x8);
308}
309EXPORT_SYMBOL_GPL(debugfs_create_x8);
310
311/**
312 * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value
313 * @name: a pointer to a string containing the name of the file to create.
314 * @mode: the permission that the file should have
315 * @parent: a pointer to the parent dentry for this file. This should be a
316 * directory dentry if set. If this parameter is %NULL, then the
317 * file will be created in the root of the debugfs filesystem.
318 * @value: a pointer to the variable that the file should read to and write
319 * from.
320 */
321struct dentry *debugfs_create_x16(const char *name, umode_t mode,
322 struct dentry *parent, u16 *value)
323{
324 /* if there are no write bits set, make read only */
325 if (!(mode & S_IWUGO))
326 return debugfs_create_file(name, mode, parent, value, &fops_x16_ro);
327 /* if there are no read bits set, make write only */
328 if (!(mode & S_IRUGO))
329 return debugfs_create_file(name, mode, parent, value, &fops_x16_wo);
330
331 return debugfs_create_file(name, mode, parent, value, &fops_x16);
332}
333EXPORT_SYMBOL_GPL(debugfs_create_x16);
334
335/**
336 * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value
337 * @name: a pointer to a string containing the name of the file to create.
338 * @mode: the permission that the file should have
339 * @parent: a pointer to the parent dentry for this file. This should be a
340 * directory dentry if set. If this parameter is %NULL, then the
341 * file will be created in the root of the debugfs filesystem.
342 * @value: a pointer to the variable that the file should read to and write
343 * from.
344 */
345struct dentry *debugfs_create_x32(const char *name, umode_t mode,
346 struct dentry *parent, u32 *value)
347{
348 /* if there are no write bits set, make read only */
349 if (!(mode & S_IWUGO))
350 return debugfs_create_file(name, mode, parent, value, &fops_x32_ro);
351 /* if there are no read bits set, make write only */
352 if (!(mode & S_IRUGO))
353 return debugfs_create_file(name, mode, parent, value, &fops_x32_wo);
354
355 return debugfs_create_file(name, mode, parent, value, &fops_x32);
356}
357EXPORT_SYMBOL_GPL(debugfs_create_x32);
358
359/**
360 * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value
361 * @name: a pointer to a string containing the name of the file to create.
362 * @mode: the permission that the file should have
363 * @parent: a pointer to the parent dentry for this file. This should be a
364 * directory dentry if set. If this parameter is %NULL, then the
365 * file will be created in the root of the debugfs filesystem.
366 * @value: a pointer to the variable that the file should read to and write
367 * from.
368 */
369struct dentry *debugfs_create_x64(const char *name, umode_t mode,
370 struct dentry *parent, u64 *value)
371{
372 return debugfs_create_file(name, mode, parent, value, &fops_x64);
373}
374EXPORT_SYMBOL_GPL(debugfs_create_x64);
375
376
377static int debugfs_size_t_set(void *data, u64 val)
378{
379 *(size_t *)data = val;
380 return 0;
381}
382static int debugfs_size_t_get(void *data, u64 *val)
383{
384 *val = *(size_t *)data;
385 return 0;
386}
387DEFINE_SIMPLE_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
388 "%llu\n"); /* %llu and %zu are more or less the same */
389
390/**
391 * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value
392 * @name: a pointer to a string containing the name of the file to create.
393 * @mode: the permission that the file should have
394 * @parent: a pointer to the parent dentry for this file. This should be a
395 * directory dentry if set. If this parameter is %NULL, then the
396 * file will be created in the root of the debugfs filesystem.
397 * @value: a pointer to the variable that the file should read to and write
398 * from.
399 */
400struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
401 struct dentry *parent, size_t *value)
402{
403 return debugfs_create_file(name, mode, parent, value, &fops_size_t);
404}
405EXPORT_SYMBOL_GPL(debugfs_create_size_t);
406
407static int debugfs_atomic_t_set(void *data, u64 val)
408{
409 atomic_set((atomic_t *)data, val);
410 return 0;
411}
412static int debugfs_atomic_t_get(void *data, u64 *val)
413{
414 *val = atomic_read((atomic_t *)data);
415 return 0;
416}
417DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
418 debugfs_atomic_t_set, "%lld\n");
419DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%lld\n");
420DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%lld\n");
421
422/**
423 * debugfs_create_atomic_t - create a debugfs file that is used to read and
424 * write an atomic_t value
425 * @name: a pointer to a string containing the name of the file to create.
426 * @mode: the permission that the file should have
427 * @parent: a pointer to the parent dentry for this file. This should be a
428 * directory dentry if set. If this parameter is %NULL, then the
429 * file will be created in the root of the debugfs filesystem.
430 * @value: a pointer to the variable that the file should read to and write
431 * from.
432 */
433struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
434 struct dentry *parent, atomic_t *value)
435{
436 /* if there are no write bits set, make read only */
437 if (!(mode & S_IWUGO))
438 return debugfs_create_file(name, mode, parent, value,
439 &fops_atomic_t_ro);
440 /* if there are no read bits set, make write only */
441 if (!(mode & S_IRUGO))
442 return debugfs_create_file(name, mode, parent, value,
443 &fops_atomic_t_wo);
444
445 return debugfs_create_file(name, mode, parent, value, &fops_atomic_t);
446}
447EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
448
449static ssize_t read_file_bool(struct file *file, char __user *user_buf,
450 size_t count, loff_t *ppos)
451{
452 char buf[3];
453 u32 *val = file->private_data;
454
455 if (*val)
456 buf[0] = 'Y';
457 else
458 buf[0] = 'N';
459 buf[1] = '\n';
460 buf[2] = 0x00;
461 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
462}
463
464static ssize_t write_file_bool(struct file *file, const char __user *user_buf,
465 size_t count, loff_t *ppos)
466{
467 char buf[32];
468 size_t buf_size;
469 bool bv;
470 u32 *val = file->private_data;
471
472 buf_size = min(count, (sizeof(buf)-1));
473 if (copy_from_user(buf, user_buf, buf_size))
474 return -EFAULT;
475
476 buf[buf_size] = '\0';
477 if (strtobool(buf, &bv) == 0)
478 *val = bv;
479
480 return count;
481}
482
483static const struct file_operations fops_bool = {
484 .read = read_file_bool,
485 .write = write_file_bool,
486 .open = simple_open,
487 .llseek = default_llseek,
488};
489
490/**
491 * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value
492 * @name: a pointer to a string containing the name of the file to create.
493 * @mode: the permission that the file should have
494 * @parent: a pointer to the parent dentry for this file. This should be a
495 * directory dentry if set. If this parameter is %NULL, then the
496 * file will be created in the root of the debugfs filesystem.
497 * @value: a pointer to the variable that the file should read to and write
498 * from.
499 *
500 * This function creates a file in debugfs with the given name that
501 * contains the value of the variable @value. If the @mode variable is so
502 * set, it can be read from, and written to.
503 *
504 * This function will return a pointer to a dentry if it succeeds. This
505 * pointer must be passed to the debugfs_remove() function when the file is
506 * to be removed (no automatic cleanup happens if your module is unloaded,
507 * you are responsible here.) If an error occurs, %NULL will be returned.
508 *
509 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
510 * returned. It is not wise to check for this value, but rather, check for
511 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
512 * code.
513 */
514struct dentry *debugfs_create_bool(const char *name, umode_t mode,
515 struct dentry *parent, u32 *value)
516{
517 return debugfs_create_file(name, mode, parent, value, &fops_bool);
518}
519EXPORT_SYMBOL_GPL(debugfs_create_bool);
520
521static ssize_t read_file_blob(struct file *file, char __user *user_buf,
522 size_t count, loff_t *ppos)
523{
524 struct debugfs_blob_wrapper *blob = file->private_data;
525 return simple_read_from_buffer(user_buf, count, ppos, blob->data,
526 blob->size);
527}
528
529static const struct file_operations fops_blob = {
530 .read = read_file_blob,
531 .open = simple_open,
532 .llseek = default_llseek,
533};
534
535/**
536 * debugfs_create_blob - create a debugfs file that is used to read a binary blob
537 * @name: a pointer to a string containing the name of the file to create.
538 * @mode: the permission that the file should have
539 * @parent: a pointer to the parent dentry for this file. This should be a
540 * directory dentry if set. If this parameter is %NULL, then the
541 * file will be created in the root of the debugfs filesystem.
542 * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer
543 * to the blob data and the size of the data.
544 *
545 * This function creates a file in debugfs with the given name that exports
546 * @blob->data as a binary blob. If the @mode variable is so set it can be
547 * read from. Writing is not supported.
548 *
549 * This function will return a pointer to a dentry if it succeeds. This
550 * pointer must be passed to the debugfs_remove() function when the file is
551 * to be removed (no automatic cleanup happens if your module is unloaded,
552 * you are responsible here.) If an error occurs, %NULL will be returned.
553 *
554 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
555 * returned. It is not wise to check for this value, but rather, check for
556 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
557 * code.
558 */
559struct dentry *debugfs_create_blob(const char *name, umode_t mode,
560 struct dentry *parent,
561 struct debugfs_blob_wrapper *blob)
562{
563 return debugfs_create_file(name, mode, parent, blob, &fops_blob);
564}
565EXPORT_SYMBOL_GPL(debugfs_create_blob);
566
567struct array_data {
568 void *array;
569 u32 elements;
570};
571
572static size_t u32_format_array(char *buf, size_t bufsize,
573 u32 *array, int array_size)
574{
575 size_t ret = 0;
576
577 while (--array_size >= 0) {
578 size_t len;
579 char term = array_size ? ' ' : '\n';
580
581 len = snprintf(buf, bufsize, "%u%c", *array++, term);
582 ret += len;
583
584 buf += len;
585 bufsize -= len;
586 }
587 return ret;
588}
589
590static int u32_array_open(struct inode *inode, struct file *file)
591{
592 struct array_data *data = inode->i_private;
593 int size, elements = data->elements;
594 char *buf;
595
596 /*
597 * Max size:
598 * - 10 digits + ' '/'\n' = 11 bytes per number
599 * - terminating NUL character
600 */
601 size = elements*11;
602 buf = kmalloc(size+1, GFP_KERNEL);
603 if (!buf)
604 return -ENOMEM;
605 buf[size] = 0;
606
607 file->private_data = buf;
608 u32_format_array(buf, size, data->array, data->elements);
609
610 return nonseekable_open(inode, file);
611}
612
613static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
614 loff_t *ppos)
615{
616 size_t size = strlen(file->private_data);
617
618 return simple_read_from_buffer(buf, len, ppos,
619 file->private_data, size);
620}
621
622static int u32_array_release(struct inode *inode, struct file *file)
623{
624 kfree(file->private_data);
625
626 return 0;
627}
628
629static const struct file_operations u32_array_fops = {
630 .owner = THIS_MODULE,
631 .open = u32_array_open,
632 .release = u32_array_release,
633 .read = u32_array_read,
634 .llseek = no_llseek,
635};
636
637/**
638 * debugfs_create_u32_array - create a debugfs file that is used to read u32
639 * array.
640 * @name: a pointer to a string containing the name of the file to create.
641 * @mode: the permission that the file should have.
642 * @parent: a pointer to the parent dentry for this file. This should be a
643 * directory dentry if set. If this parameter is %NULL, then the
644 * file will be created in the root of the debugfs filesystem.
645 * @array: u32 array that provides data.
646 * @elements: total number of elements in the array.
647 *
648 * This function creates a file in debugfs with the given name that exports
649 * @array as data. If the @mode variable is so set it can be read from.
650 * Writing is not supported. Seek within the file is also not supported.
651 * Once array is created its size can not be changed.
652 *
653 * The function returns a pointer to dentry on success. If debugfs is not
654 * enabled in the kernel, the value -%ENODEV will be returned.
655 */
656struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
657 struct dentry *parent,
658 u32 *array, u32 elements)
659{
660 struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL);
661
662 if (data == NULL)
663 return NULL;
664
665 data->array = array;
666 data->elements = elements;
667
668 return debugfs_create_file(name, mode, parent, data, &u32_array_fops);
669}
670EXPORT_SYMBOL_GPL(debugfs_create_u32_array);
671
672#ifdef CONFIG_HAS_IOMEM
673
674/*
675 * The regset32 stuff is used to print 32-bit registers using the
676 * seq_file utilities. We offer printing a register set in an already-opened
677 * sequential file or create a debugfs file that only prints a regset32.
678 */
679
680/**
681 * debugfs_print_regs32 - use seq_print to describe a set of registers
682 * @s: the seq_file structure being used to generate output
683 * @regs: an array if struct debugfs_reg32 structures
684 * @nregs: the length of the above array
685 * @base: the base address to be used in reading the registers
686 * @prefix: a string to be prefixed to every output line
687 *
688 * This function outputs a text block describing the current values of
689 * some 32-bit hardware registers. It is meant to be used within debugfs
690 * files based on seq_file that need to show registers, intermixed with other
691 * information. The prefix argument may be used to specify a leading string,
692 * because some peripherals have several blocks of identical registers,
693 * for example configuration of dma channels
694 */
695int debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
696 int nregs, void __iomem *base, char *prefix)
697{
698 int i, ret = 0;
699
700 for (i = 0; i < nregs; i++, regs++) {
701 if (prefix)
702 ret += seq_printf(s, "%s", prefix);
703 ret += seq_printf(s, "%s = 0x%08x\n", regs->name,
704 readl(base + regs->offset));
705 }
706 return ret;
707}
708EXPORT_SYMBOL_GPL(debugfs_print_regs32);
709
710static int debugfs_show_regset32(struct seq_file *s, void *data)
711{
712 struct debugfs_regset32 *regset = s->private;
713
714 debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, "");
715 return 0;
716}
717
718static int debugfs_open_regset32(struct inode *inode, struct file *file)
719{
720 return single_open(file, debugfs_show_regset32, inode->i_private);
721}
722
723static const struct file_operations fops_regset32 = {
724 .open = debugfs_open_regset32,
725 .read = seq_read,
726 .llseek = seq_lseek,
727 .release = single_release,
728};
729
730/**
731 * debugfs_create_regset32 - create a debugfs file that returns register values
732 * @name: a pointer to a string containing the name of the file to create.
733 * @mode: the permission that the file should have
734 * @parent: a pointer to the parent dentry for this file. This should be a
735 * directory dentry if set. If this parameter is %NULL, then the
736 * file will be created in the root of the debugfs filesystem.
737 * @regset: a pointer to a struct debugfs_regset32, which contains a pointer
738 * to an array of register definitions, the array size and the base
739 * address where the register bank is to be found.
740 *
741 * This function creates a file in debugfs with the given name that reports
742 * the names and values of a set of 32-bit registers. If the @mode variable
743 * is so set it can be read from. Writing is not supported.
744 *
745 * This function will return a pointer to a dentry if it succeeds. This
746 * pointer must be passed to the debugfs_remove() function when the file is
747 * to be removed (no automatic cleanup happens if your module is unloaded,
748 * you are responsible here.) If an error occurs, %NULL will be returned.
749 *
750 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
751 * returned. It is not wise to check for this value, but rather, check for
752 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
753 * code.
754 */
755struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
756 struct dentry *parent,
757 struct debugfs_regset32 *regset)
758{
759 return debugfs_create_file(name, mode, parent, regset, &fops_regset32);
760}
761EXPORT_SYMBOL_GPL(debugfs_create_regset32);
762
763#endif /* CONFIG_HAS_IOMEM */