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