projects/linux·blob v4.13 · refs

1143 lines · 38.2 KiB

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