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1/*
2 * Routines for driver control interface
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 *
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22#include <linux/threads.h>
23#include <linux/interrupt.h>
24#include <linux/module.h>
25#include <linux/slab.h>
26#include <linux/vmalloc.h>
27#include <linux/time.h>
28#include <sound/core.h>
29#include <sound/minors.h>
30#include <sound/info.h>
31#include <sound/control.h>
32
33/* max number of user-defined controls */
34#define MAX_USER_CONTROLS 32
35#define MAX_CONTROL_COUNT 1028
36
37struct snd_kctl_ioctl {
38 struct list_head list; /* list of all ioctls */
39 snd_kctl_ioctl_func_t fioctl;
40};
41
42static DECLARE_RWSEM(snd_ioctl_rwsem);
43static LIST_HEAD(snd_control_ioctls);
44#ifdef CONFIG_COMPAT
45static LIST_HEAD(snd_control_compat_ioctls);
46#endif
47
48static int snd_ctl_open(struct inode *inode, struct file *file)
49{
50 unsigned long flags;
51 struct snd_card *card;
52 struct snd_ctl_file *ctl;
53 int i, err;
54
55 err = nonseekable_open(inode, file);
56 if (err < 0)
57 return err;
58
59 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
60 if (!card) {
61 err = -ENODEV;
62 goto __error1;
63 }
64 err = snd_card_file_add(card, file);
65 if (err < 0) {
66 err = -ENODEV;
67 goto __error1;
68 }
69 if (!try_module_get(card->module)) {
70 err = -EFAULT;
71 goto __error2;
72 }
73 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
74 if (ctl == NULL) {
75 err = -ENOMEM;
76 goto __error;
77 }
78 INIT_LIST_HEAD(&ctl->events);
79 init_waitqueue_head(&ctl->change_sleep);
80 spin_lock_init(&ctl->read_lock);
81 ctl->card = card;
82 for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
83 ctl->preferred_subdevice[i] = -1;
84 ctl->pid = get_pid(task_pid(current));
85 file->private_data = ctl;
86 write_lock_irqsave(&card->ctl_files_rwlock, flags);
87 list_add_tail(&ctl->list, &card->ctl_files);
88 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
89 snd_card_unref(card);
90 return 0;
91
92 __error:
93 module_put(card->module);
94 __error2:
95 snd_card_file_remove(card, file);
96 __error1:
97 if (card)
98 snd_card_unref(card);
99 return err;
100}
101
102static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
103{
104 unsigned long flags;
105 struct snd_kctl_event *cread;
106
107 spin_lock_irqsave(&ctl->read_lock, flags);
108 while (!list_empty(&ctl->events)) {
109 cread = snd_kctl_event(ctl->events.next);
110 list_del(&cread->list);
111 kfree(cread);
112 }
113 spin_unlock_irqrestore(&ctl->read_lock, flags);
114}
115
116static int snd_ctl_release(struct inode *inode, struct file *file)
117{
118 unsigned long flags;
119 struct snd_card *card;
120 struct snd_ctl_file *ctl;
121 struct snd_kcontrol *control;
122 unsigned int idx;
123
124 ctl = file->private_data;
125 file->private_data = NULL;
126 card = ctl->card;
127 write_lock_irqsave(&card->ctl_files_rwlock, flags);
128 list_del(&ctl->list);
129 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
130 down_write(&card->controls_rwsem);
131 list_for_each_entry(control, &card->controls, list)
132 for (idx = 0; idx < control->count; idx++)
133 if (control->vd[idx].owner == ctl)
134 control->vd[idx].owner = NULL;
135 up_write(&card->controls_rwsem);
136 snd_ctl_empty_read_queue(ctl);
137 put_pid(ctl->pid);
138 kfree(ctl);
139 module_put(card->module);
140 snd_card_file_remove(card, file);
141 return 0;
142}
143
144/**
145 * snd_ctl_notify - Send notification to user-space for a control change
146 * @card: the card to send notification
147 * @mask: the event mask, SNDRV_CTL_EVENT_*
148 * @id: the ctl element id to send notification
149 *
150 * This function adds an event record with the given id and mask, appends
151 * to the list and wakes up the user-space for notification. This can be
152 * called in the atomic context.
153 */
154void snd_ctl_notify(struct snd_card *card, unsigned int mask,
155 struct snd_ctl_elem_id *id)
156{
157 unsigned long flags;
158 struct snd_ctl_file *ctl;
159 struct snd_kctl_event *ev;
160
161 if (snd_BUG_ON(!card || !id))
162 return;
163 read_lock(&card->ctl_files_rwlock);
164#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
165 card->mixer_oss_change_count++;
166#endif
167 list_for_each_entry(ctl, &card->ctl_files, list) {
168 if (!ctl->subscribed)
169 continue;
170 spin_lock_irqsave(&ctl->read_lock, flags);
171 list_for_each_entry(ev, &ctl->events, list) {
172 if (ev->id.numid == id->numid) {
173 ev->mask |= mask;
174 goto _found;
175 }
176 }
177 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
178 if (ev) {
179 ev->id = *id;
180 ev->mask = mask;
181 list_add_tail(&ev->list, &ctl->events);
182 } else {
183 dev_err(card->dev, "No memory available to allocate event\n");
184 }
185 _found:
186 wake_up(&ctl->change_sleep);
187 spin_unlock_irqrestore(&ctl->read_lock, flags);
188 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
189 }
190 read_unlock(&card->ctl_files_rwlock);
191}
192EXPORT_SYMBOL(snd_ctl_notify);
193
194/**
195 * snd_ctl_new - create a new control instance with some elements
196 * @kctl: the pointer to store new control instance
197 * @count: the number of elements in this control
198 * @access: the default access flags for elements in this control
199 * @file: given when locking these elements
200 *
201 * Allocates a memory object for a new control instance. The instance has
202 * elements as many as the given number (@count). Each element has given
203 * access permissions (@access). Each element is locked when @file is given.
204 *
205 * Return: 0 on success, error code on failure
206 */
207static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
208 unsigned int access, struct snd_ctl_file *file)
209{
210 unsigned int size;
211 unsigned int idx;
212
213 if (count == 0 || count > MAX_CONTROL_COUNT)
214 return -EINVAL;
215
216 size = sizeof(struct snd_kcontrol);
217 size += sizeof(struct snd_kcontrol_volatile) * count;
218
219 *kctl = kzalloc(size, GFP_KERNEL);
220 if (!*kctl)
221 return -ENOMEM;
222
223 for (idx = 0; idx < count; idx++) {
224 (*kctl)->vd[idx].access = access;
225 (*kctl)->vd[idx].owner = file;
226 }
227 (*kctl)->count = count;
228
229 return 0;
230}
231
232/**
233 * snd_ctl_new1 - create a control instance from the template
234 * @ncontrol: the initialization record
235 * @private_data: the private data to set
236 *
237 * Allocates a new struct snd_kcontrol instance and initialize from the given
238 * template. When the access field of ncontrol is 0, it's assumed as
239 * READWRITE access. When the count field is 0, it's assumes as one.
240 *
241 * Return: The pointer of the newly generated instance, or %NULL on failure.
242 */
243struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
244 void *private_data)
245{
246 struct snd_kcontrol *kctl;
247 unsigned int count;
248 unsigned int access;
249 int err;
250
251 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
252 return NULL;
253
254 count = ncontrol->count;
255 if (count == 0)
256 count = 1;
257
258 access = ncontrol->access;
259 if (access == 0)
260 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
261 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
262 SNDRV_CTL_ELEM_ACCESS_VOLATILE |
263 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
264 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
265 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
266 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);
267
268 err = snd_ctl_new(&kctl, count, access, NULL);
269 if (err < 0)
270 return NULL;
271
272 /* The 'numid' member is decided when calling snd_ctl_add(). */
273 kctl->id.iface = ncontrol->iface;
274 kctl->id.device = ncontrol->device;
275 kctl->id.subdevice = ncontrol->subdevice;
276 if (ncontrol->name) {
277 strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
278 if (strcmp(ncontrol->name, kctl->id.name) != 0)
279 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
280 ncontrol->name, kctl->id.name);
281 }
282 kctl->id.index = ncontrol->index;
283
284 kctl->info = ncontrol->info;
285 kctl->get = ncontrol->get;
286 kctl->put = ncontrol->put;
287 kctl->tlv.p = ncontrol->tlv.p;
288
289 kctl->private_value = ncontrol->private_value;
290 kctl->private_data = private_data;
291
292 return kctl;
293}
294EXPORT_SYMBOL(snd_ctl_new1);
295
296/**
297 * snd_ctl_free_one - release the control instance
298 * @kcontrol: the control instance
299 *
300 * Releases the control instance created via snd_ctl_new()
301 * or snd_ctl_new1().
302 * Don't call this after the control was added to the card.
303 */
304void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
305{
306 if (kcontrol) {
307 if (kcontrol->private_free)
308 kcontrol->private_free(kcontrol);
309 kfree(kcontrol);
310 }
311}
312EXPORT_SYMBOL(snd_ctl_free_one);
313
314static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
315 unsigned int count)
316{
317 struct snd_kcontrol *kctl;
318
319 /* Make sure that the ids assigned to the control do not wrap around */
320 if (card->last_numid >= UINT_MAX - count)
321 card->last_numid = 0;
322
323 list_for_each_entry(kctl, &card->controls, list) {
324 if (kctl->id.numid < card->last_numid + 1 + count &&
325 kctl->id.numid + kctl->count > card->last_numid + 1) {
326 card->last_numid = kctl->id.numid + kctl->count - 1;
327 return true;
328 }
329 }
330 return false;
331}
332
333static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
334{
335 unsigned int iter = 100000;
336
337 while (snd_ctl_remove_numid_conflict(card, count)) {
338 if (--iter == 0) {
339 /* this situation is very unlikely */
340 dev_err(card->dev, "unable to allocate new control numid\n");
341 return -ENOMEM;
342 }
343 }
344 return 0;
345}
346
347/**
348 * snd_ctl_add - add the control instance to the card
349 * @card: the card instance
350 * @kcontrol: the control instance to add
351 *
352 * Adds the control instance created via snd_ctl_new() or
353 * snd_ctl_new1() to the given card. Assigns also an unique
354 * numid used for fast search.
355 *
356 * It frees automatically the control which cannot be added.
357 *
358 * Return: Zero if successful, or a negative error code on failure.
359 *
360 */
361int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
362{
363 struct snd_ctl_elem_id id;
364 unsigned int idx;
365 unsigned int count;
366 int err = -EINVAL;
367
368 if (! kcontrol)
369 return err;
370 if (snd_BUG_ON(!card || !kcontrol->info))
371 goto error;
372 id = kcontrol->id;
373 if (id.index > UINT_MAX - kcontrol->count)
374 goto error;
375
376 down_write(&card->controls_rwsem);
377 if (snd_ctl_find_id(card, &id)) {
378 up_write(&card->controls_rwsem);
379 dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
380 id.iface,
381 id.device,
382 id.subdevice,
383 id.name,
384 id.index);
385 err = -EBUSY;
386 goto error;
387 }
388 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
389 up_write(&card->controls_rwsem);
390 err = -ENOMEM;
391 goto error;
392 }
393 list_add_tail(&kcontrol->list, &card->controls);
394 card->controls_count += kcontrol->count;
395 kcontrol->id.numid = card->last_numid + 1;
396 card->last_numid += kcontrol->count;
397 id = kcontrol->id;
398 count = kcontrol->count;
399 up_write(&card->controls_rwsem);
400 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
401 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
402 return 0;
403
404 error:
405 snd_ctl_free_one(kcontrol);
406 return err;
407}
408EXPORT_SYMBOL(snd_ctl_add);
409
410/**
411 * snd_ctl_replace - replace the control instance of the card
412 * @card: the card instance
413 * @kcontrol: the control instance to replace
414 * @add_on_replace: add the control if not already added
415 *
416 * Replaces the given control. If the given control does not exist
417 * and the add_on_replace flag is set, the control is added. If the
418 * control exists, it is destroyed first.
419 *
420 * It frees automatically the control which cannot be added or replaced.
421 *
422 * Return: Zero if successful, or a negative error code on failure.
423 */
424int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
425 bool add_on_replace)
426{
427 struct snd_ctl_elem_id id;
428 unsigned int count;
429 unsigned int idx;
430 struct snd_kcontrol *old;
431 int ret;
432
433 if (!kcontrol)
434 return -EINVAL;
435 if (snd_BUG_ON(!card || !kcontrol->info)) {
436 ret = -EINVAL;
437 goto error;
438 }
439 id = kcontrol->id;
440 down_write(&card->controls_rwsem);
441 old = snd_ctl_find_id(card, &id);
442 if (!old) {
443 if (add_on_replace)
444 goto add;
445 up_write(&card->controls_rwsem);
446 ret = -EINVAL;
447 goto error;
448 }
449 ret = snd_ctl_remove(card, old);
450 if (ret < 0) {
451 up_write(&card->controls_rwsem);
452 goto error;
453 }
454add:
455 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
456 up_write(&card->controls_rwsem);
457 ret = -ENOMEM;
458 goto error;
459 }
460 list_add_tail(&kcontrol->list, &card->controls);
461 card->controls_count += kcontrol->count;
462 kcontrol->id.numid = card->last_numid + 1;
463 card->last_numid += kcontrol->count;
464 id = kcontrol->id;
465 count = kcontrol->count;
466 up_write(&card->controls_rwsem);
467 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
468 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
469 return 0;
470
471error:
472 snd_ctl_free_one(kcontrol);
473 return ret;
474}
475EXPORT_SYMBOL(snd_ctl_replace);
476
477/**
478 * snd_ctl_remove - remove the control from the card and release it
479 * @card: the card instance
480 * @kcontrol: the control instance to remove
481 *
482 * Removes the control from the card and then releases the instance.
483 * You don't need to call snd_ctl_free_one(). You must be in
484 * the write lock - down_write(&card->controls_rwsem).
485 *
486 * Return: 0 if successful, or a negative error code on failure.
487 */
488int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
489{
490 struct snd_ctl_elem_id id;
491 unsigned int idx;
492
493 if (snd_BUG_ON(!card || !kcontrol))
494 return -EINVAL;
495 list_del(&kcontrol->list);
496 card->controls_count -= kcontrol->count;
497 id = kcontrol->id;
498 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
499 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
500 snd_ctl_free_one(kcontrol);
501 return 0;
502}
503EXPORT_SYMBOL(snd_ctl_remove);
504
505/**
506 * snd_ctl_remove_id - remove the control of the given id and release it
507 * @card: the card instance
508 * @id: the control id to remove
509 *
510 * Finds the control instance with the given id, removes it from the
511 * card list and releases it.
512 *
513 * Return: 0 if successful, or a negative error code on failure.
514 */
515int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
516{
517 struct snd_kcontrol *kctl;
518 int ret;
519
520 down_write(&card->controls_rwsem);
521 kctl = snd_ctl_find_id(card, id);
522 if (kctl == NULL) {
523 up_write(&card->controls_rwsem);
524 return -ENOENT;
525 }
526 ret = snd_ctl_remove(card, kctl);
527 up_write(&card->controls_rwsem);
528 return ret;
529}
530EXPORT_SYMBOL(snd_ctl_remove_id);
531
532/**
533 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
534 * @file: active control handle
535 * @id: the control id to remove
536 *
537 * Finds the control instance with the given id, removes it from the
538 * card list and releases it.
539 *
540 * Return: 0 if successful, or a negative error code on failure.
541 */
542static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
543 struct snd_ctl_elem_id *id)
544{
545 struct snd_card *card = file->card;
546 struct snd_kcontrol *kctl;
547 int idx, ret;
548
549 down_write(&card->controls_rwsem);
550 kctl = snd_ctl_find_id(card, id);
551 if (kctl == NULL) {
552 ret = -ENOENT;
553 goto error;
554 }
555 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
556 ret = -EINVAL;
557 goto error;
558 }
559 for (idx = 0; idx < kctl->count; idx++)
560 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
561 ret = -EBUSY;
562 goto error;
563 }
564 ret = snd_ctl_remove(card, kctl);
565 if (ret < 0)
566 goto error;
567 card->user_ctl_count--;
568error:
569 up_write(&card->controls_rwsem);
570 return ret;
571}
572
573/**
574 * snd_ctl_activate_id - activate/inactivate the control of the given id
575 * @card: the card instance
576 * @id: the control id to activate/inactivate
577 * @active: non-zero to activate
578 *
579 * Finds the control instance with the given id, and activate or
580 * inactivate the control together with notification, if changed.
581 * The given ID data is filled with full information.
582 *
583 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
584 */
585int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
586 int active)
587{
588 struct snd_kcontrol *kctl;
589 struct snd_kcontrol_volatile *vd;
590 unsigned int index_offset;
591 int ret;
592
593 down_write(&card->controls_rwsem);
594 kctl = snd_ctl_find_id(card, id);
595 if (kctl == NULL) {
596 ret = -ENOENT;
597 goto unlock;
598 }
599 index_offset = snd_ctl_get_ioff(kctl, id);
600 vd = &kctl->vd[index_offset];
601 ret = 0;
602 if (active) {
603 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
604 goto unlock;
605 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
606 } else {
607 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
608 goto unlock;
609 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
610 }
611 snd_ctl_build_ioff(id, kctl, index_offset);
612 ret = 1;
613 unlock:
614 up_write(&card->controls_rwsem);
615 if (ret > 0)
616 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
617 return ret;
618}
619EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
620
621/**
622 * snd_ctl_rename_id - replace the id of a control on the card
623 * @card: the card instance
624 * @src_id: the old id
625 * @dst_id: the new id
626 *
627 * Finds the control with the old id from the card, and replaces the
628 * id with the new one.
629 *
630 * Return: Zero if successful, or a negative error code on failure.
631 */
632int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
633 struct snd_ctl_elem_id *dst_id)
634{
635 struct snd_kcontrol *kctl;
636
637 down_write(&card->controls_rwsem);
638 kctl = snd_ctl_find_id(card, src_id);
639 if (kctl == NULL) {
640 up_write(&card->controls_rwsem);
641 return -ENOENT;
642 }
643 kctl->id = *dst_id;
644 kctl->id.numid = card->last_numid + 1;
645 card->last_numid += kctl->count;
646 up_write(&card->controls_rwsem);
647 return 0;
648}
649EXPORT_SYMBOL(snd_ctl_rename_id);
650
651/**
652 * snd_ctl_find_numid - find the control instance with the given number-id
653 * @card: the card instance
654 * @numid: the number-id to search
655 *
656 * Finds the control instance with the given number-id from the card.
657 *
658 * The caller must down card->controls_rwsem before calling this function
659 * (if the race condition can happen).
660 *
661 * Return: The pointer of the instance if found, or %NULL if not.
662 *
663 */
664struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
665{
666 struct snd_kcontrol *kctl;
667
668 if (snd_BUG_ON(!card || !numid))
669 return NULL;
670 list_for_each_entry(kctl, &card->controls, list) {
671 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
672 return kctl;
673 }
674 return NULL;
675}
676EXPORT_SYMBOL(snd_ctl_find_numid);
677
678/**
679 * snd_ctl_find_id - find the control instance with the given id
680 * @card: the card instance
681 * @id: the id to search
682 *
683 * Finds the control instance with the given id from the card.
684 *
685 * The caller must down card->controls_rwsem before calling this function
686 * (if the race condition can happen).
687 *
688 * Return: The pointer of the instance if found, or %NULL if not.
689 *
690 */
691struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
692 struct snd_ctl_elem_id *id)
693{
694 struct snd_kcontrol *kctl;
695
696 if (snd_BUG_ON(!card || !id))
697 return NULL;
698 if (id->numid != 0)
699 return snd_ctl_find_numid(card, id->numid);
700 list_for_each_entry(kctl, &card->controls, list) {
701 if (kctl->id.iface != id->iface)
702 continue;
703 if (kctl->id.device != id->device)
704 continue;
705 if (kctl->id.subdevice != id->subdevice)
706 continue;
707 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
708 continue;
709 if (kctl->id.index > id->index)
710 continue;
711 if (kctl->id.index + kctl->count <= id->index)
712 continue;
713 return kctl;
714 }
715 return NULL;
716}
717EXPORT_SYMBOL(snd_ctl_find_id);
718
719static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
720 unsigned int cmd, void __user *arg)
721{
722 struct snd_ctl_card_info *info;
723
724 info = kzalloc(sizeof(*info), GFP_KERNEL);
725 if (! info)
726 return -ENOMEM;
727 down_read(&snd_ioctl_rwsem);
728 info->card = card->number;
729 strlcpy(info->id, card->id, sizeof(info->id));
730 strlcpy(info->driver, card->driver, sizeof(info->driver));
731 strlcpy(info->name, card->shortname, sizeof(info->name));
732 strlcpy(info->longname, card->longname, sizeof(info->longname));
733 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
734 strlcpy(info->components, card->components, sizeof(info->components));
735 up_read(&snd_ioctl_rwsem);
736 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
737 kfree(info);
738 return -EFAULT;
739 }
740 kfree(info);
741 return 0;
742}
743
744static int snd_ctl_elem_list(struct snd_card *card,
745 struct snd_ctl_elem_list __user *_list)
746{
747 struct list_head *plist;
748 struct snd_ctl_elem_list list;
749 struct snd_kcontrol *kctl;
750 struct snd_ctl_elem_id *dst, *id;
751 unsigned int offset, space, jidx;
752
753 if (copy_from_user(&list, _list, sizeof(list)))
754 return -EFAULT;
755 offset = list.offset;
756 space = list.space;
757 /* try limit maximum space */
758 if (space > 16384)
759 return -ENOMEM;
760 if (space > 0) {
761 /* allocate temporary buffer for atomic operation */
762 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
763 if (dst == NULL)
764 return -ENOMEM;
765 down_read(&card->controls_rwsem);
766 list.count = card->controls_count;
767 plist = card->controls.next;
768 while (plist != &card->controls) {
769 if (offset == 0)
770 break;
771 kctl = snd_kcontrol(plist);
772 if (offset < kctl->count)
773 break;
774 offset -= kctl->count;
775 plist = plist->next;
776 }
777 list.used = 0;
778 id = dst;
779 while (space > 0 && plist != &card->controls) {
780 kctl = snd_kcontrol(plist);
781 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
782 snd_ctl_build_ioff(id, kctl, jidx);
783 id++;
784 space--;
785 list.used++;
786 }
787 plist = plist->next;
788 offset = 0;
789 }
790 up_read(&card->controls_rwsem);
791 if (list.used > 0 &&
792 copy_to_user(list.pids, dst,
793 list.used * sizeof(struct snd_ctl_elem_id))) {
794 vfree(dst);
795 return -EFAULT;
796 }
797 vfree(dst);
798 } else {
799 down_read(&card->controls_rwsem);
800 list.count = card->controls_count;
801 up_read(&card->controls_rwsem);
802 }
803 if (copy_to_user(_list, &list, sizeof(list)))
804 return -EFAULT;
805 return 0;
806}
807
808static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
809 struct snd_ctl_elem_info *info)
810{
811 struct snd_card *card = ctl->card;
812 struct snd_kcontrol *kctl;
813 struct snd_kcontrol_volatile *vd;
814 unsigned int index_offset;
815 int result;
816
817 down_read(&card->controls_rwsem);
818 kctl = snd_ctl_find_id(card, &info->id);
819 if (kctl == NULL) {
820 up_read(&card->controls_rwsem);
821 return -ENOENT;
822 }
823#ifdef CONFIG_SND_DEBUG
824 info->access = 0;
825#endif
826 result = kctl->info(kctl, info);
827 if (result >= 0) {
828 snd_BUG_ON(info->access);
829 index_offset = snd_ctl_get_ioff(kctl, &info->id);
830 vd = &kctl->vd[index_offset];
831 snd_ctl_build_ioff(&info->id, kctl, index_offset);
832 info->access = vd->access;
833 if (vd->owner) {
834 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
835 if (vd->owner == ctl)
836 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
837 info->owner = pid_vnr(vd->owner->pid);
838 } else {
839 info->owner = -1;
840 }
841 }
842 up_read(&card->controls_rwsem);
843 return result;
844}
845
846static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
847 struct snd_ctl_elem_info __user *_info)
848{
849 struct snd_ctl_elem_info info;
850 int result;
851
852 if (copy_from_user(&info, _info, sizeof(info)))
853 return -EFAULT;
854 snd_power_lock(ctl->card);
855 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
856 if (result >= 0)
857 result = snd_ctl_elem_info(ctl, &info);
858 snd_power_unlock(ctl->card);
859 if (result >= 0)
860 if (copy_to_user(_info, &info, sizeof(info)))
861 return -EFAULT;
862 return result;
863}
864
865static int snd_ctl_elem_read(struct snd_card *card,
866 struct snd_ctl_elem_value *control)
867{
868 struct snd_kcontrol *kctl;
869 struct snd_kcontrol_volatile *vd;
870 unsigned int index_offset;
871 int result;
872
873 down_read(&card->controls_rwsem);
874 kctl = snd_ctl_find_id(card, &control->id);
875 if (kctl == NULL) {
876 result = -ENOENT;
877 } else {
878 index_offset = snd_ctl_get_ioff(kctl, &control->id);
879 vd = &kctl->vd[index_offset];
880 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
881 kctl->get != NULL) {
882 snd_ctl_build_ioff(&control->id, kctl, index_offset);
883 result = kctl->get(kctl, control);
884 } else
885 result = -EPERM;
886 }
887 up_read(&card->controls_rwsem);
888 return result;
889}
890
891static int snd_ctl_elem_read_user(struct snd_card *card,
892 struct snd_ctl_elem_value __user *_control)
893{
894 struct snd_ctl_elem_value *control;
895 int result;
896
897 control = memdup_user(_control, sizeof(*control));
898 if (IS_ERR(control))
899 return PTR_ERR(control);
900
901 snd_power_lock(card);
902 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
903 if (result >= 0)
904 result = snd_ctl_elem_read(card, control);
905 snd_power_unlock(card);
906 if (result >= 0)
907 if (copy_to_user(_control, control, sizeof(*control)))
908 result = -EFAULT;
909 kfree(control);
910 return result;
911}
912
913static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
914 struct snd_ctl_elem_value *control)
915{
916 struct snd_kcontrol *kctl;
917 struct snd_kcontrol_volatile *vd;
918 unsigned int index_offset;
919 int result;
920
921 down_read(&card->controls_rwsem);
922 kctl = snd_ctl_find_id(card, &control->id);
923 if (kctl == NULL) {
924 result = -ENOENT;
925 } else {
926 index_offset = snd_ctl_get_ioff(kctl, &control->id);
927 vd = &kctl->vd[index_offset];
928 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
929 kctl->put == NULL ||
930 (file && vd->owner && vd->owner != file)) {
931 result = -EPERM;
932 } else {
933 snd_ctl_build_ioff(&control->id, kctl, index_offset);
934 result = kctl->put(kctl, control);
935 }
936 if (result > 0) {
937 struct snd_ctl_elem_id id = control->id;
938 up_read(&card->controls_rwsem);
939 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
940 return 0;
941 }
942 }
943 up_read(&card->controls_rwsem);
944 return result;
945}
946
947static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
948 struct snd_ctl_elem_value __user *_control)
949{
950 struct snd_ctl_elem_value *control;
951 struct snd_card *card;
952 int result;
953
954 control = memdup_user(_control, sizeof(*control));
955 if (IS_ERR(control))
956 return PTR_ERR(control);
957
958 card = file->card;
959 snd_power_lock(card);
960 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
961 if (result >= 0)
962 result = snd_ctl_elem_write(card, file, control);
963 snd_power_unlock(card);
964 if (result >= 0)
965 if (copy_to_user(_control, control, sizeof(*control)))
966 result = -EFAULT;
967 kfree(control);
968 return result;
969}
970
971static int snd_ctl_elem_lock(struct snd_ctl_file *file,
972 struct snd_ctl_elem_id __user *_id)
973{
974 struct snd_card *card = file->card;
975 struct snd_ctl_elem_id id;
976 struct snd_kcontrol *kctl;
977 struct snd_kcontrol_volatile *vd;
978 int result;
979
980 if (copy_from_user(&id, _id, sizeof(id)))
981 return -EFAULT;
982 down_write(&card->controls_rwsem);
983 kctl = snd_ctl_find_id(card, &id);
984 if (kctl == NULL) {
985 result = -ENOENT;
986 } else {
987 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
988 if (vd->owner != NULL)
989 result = -EBUSY;
990 else {
991 vd->owner = file;
992 result = 0;
993 }
994 }
995 up_write(&card->controls_rwsem);
996 return result;
997}
998
999static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1000 struct snd_ctl_elem_id __user *_id)
1001{
1002 struct snd_card *card = file->card;
1003 struct snd_ctl_elem_id id;
1004 struct snd_kcontrol *kctl;
1005 struct snd_kcontrol_volatile *vd;
1006 int result;
1007
1008 if (copy_from_user(&id, _id, sizeof(id)))
1009 return -EFAULT;
1010 down_write(&card->controls_rwsem);
1011 kctl = snd_ctl_find_id(card, &id);
1012 if (kctl == NULL) {
1013 result = -ENOENT;
1014 } else {
1015 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1016 if (vd->owner == NULL)
1017 result = -EINVAL;
1018 else if (vd->owner != file)
1019 result = -EPERM;
1020 else {
1021 vd->owner = NULL;
1022 result = 0;
1023 }
1024 }
1025 up_write(&card->controls_rwsem);
1026 return result;
1027}
1028
1029struct user_element {
1030 struct snd_ctl_elem_info info;
1031 struct snd_card *card;
1032 char *elem_data; /* element data */
1033 unsigned long elem_data_size; /* size of element data in bytes */
1034 void *tlv_data; /* TLV data */
1035 unsigned long tlv_data_size; /* TLV data size */
1036 void *priv_data; /* private data (like strings for enumerated type) */
1037};
1038
1039static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1040 struct snd_ctl_elem_info *uinfo)
1041{
1042 struct user_element *ue = kcontrol->private_data;
1043 unsigned int offset;
1044
1045 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1046 *uinfo = ue->info;
1047 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1048
1049 return 0;
1050}
1051
1052static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1053 struct snd_ctl_elem_info *uinfo)
1054{
1055 struct user_element *ue = kcontrol->private_data;
1056 const char *names;
1057 unsigned int item;
1058 unsigned int offset;
1059
1060 item = uinfo->value.enumerated.item;
1061
1062 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1063 *uinfo = ue->info;
1064 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1065
1066 item = min(item, uinfo->value.enumerated.items - 1);
1067 uinfo->value.enumerated.item = item;
1068
1069 names = ue->priv_data;
1070 for (; item > 0; --item)
1071 names += strlen(names) + 1;
1072 strcpy(uinfo->value.enumerated.name, names);
1073
1074 return 0;
1075}
1076
1077static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1078 struct snd_ctl_elem_value *ucontrol)
1079{
1080 struct user_element *ue = kcontrol->private_data;
1081 unsigned int size = ue->elem_data_size;
1082 char *src = ue->elem_data +
1083 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1084
1085 mutex_lock(&ue->card->user_ctl_lock);
1086 memcpy(&ucontrol->value, src, size);
1087 mutex_unlock(&ue->card->user_ctl_lock);
1088 return 0;
1089}
1090
1091static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1092 struct snd_ctl_elem_value *ucontrol)
1093{
1094 int change;
1095 struct user_element *ue = kcontrol->private_data;
1096 unsigned int size = ue->elem_data_size;
1097 char *dst = ue->elem_data +
1098 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1099
1100 mutex_lock(&ue->card->user_ctl_lock);
1101 change = memcmp(&ucontrol->value, dst, size) != 0;
1102 if (change)
1103 memcpy(dst, &ucontrol->value, size);
1104 mutex_unlock(&ue->card->user_ctl_lock);
1105 return change;
1106}
1107
1108static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1109 int op_flag,
1110 unsigned int size,
1111 unsigned int __user *tlv)
1112{
1113 struct user_element *ue = kcontrol->private_data;
1114 int change = 0;
1115 void *new_data;
1116
1117 if (op_flag == SNDRV_CTL_TLV_OP_WRITE) {
1118 if (size > 1024 * 128) /* sane value */
1119 return -EINVAL;
1120
1121 new_data = memdup_user(tlv, size);
1122 if (IS_ERR(new_data))
1123 return PTR_ERR(new_data);
1124 mutex_lock(&ue->card->user_ctl_lock);
1125 change = ue->tlv_data_size != size;
1126 if (!change)
1127 change = memcmp(ue->tlv_data, new_data, size);
1128 kfree(ue->tlv_data);
1129 ue->tlv_data = new_data;
1130 ue->tlv_data_size = size;
1131 mutex_unlock(&ue->card->user_ctl_lock);
1132 } else {
1133 int ret = 0;
1134
1135 mutex_lock(&ue->card->user_ctl_lock);
1136 if (!ue->tlv_data_size || !ue->tlv_data) {
1137 ret = -ENXIO;
1138 goto err_unlock;
1139 }
1140 if (size < ue->tlv_data_size) {
1141 ret = -ENOSPC;
1142 goto err_unlock;
1143 }
1144 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1145 ret = -EFAULT;
1146err_unlock:
1147 mutex_unlock(&ue->card->user_ctl_lock);
1148 if (ret)
1149 return ret;
1150 }
1151 return change;
1152}
1153
1154static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1155{
1156 char *names, *p;
1157 size_t buf_len, name_len;
1158 unsigned int i;
1159 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1160
1161 if (ue->info.value.enumerated.names_length > 64 * 1024)
1162 return -EINVAL;
1163
1164 names = memdup_user((const void __user *)user_ptrval,
1165 ue->info.value.enumerated.names_length);
1166 if (IS_ERR(names))
1167 return PTR_ERR(names);
1168
1169 /* check that there are enough valid names */
1170 buf_len = ue->info.value.enumerated.names_length;
1171 p = names;
1172 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1173 name_len = strnlen(p, buf_len);
1174 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1175 kfree(names);
1176 return -EINVAL;
1177 }
1178 p += name_len + 1;
1179 buf_len -= name_len + 1;
1180 }
1181
1182 ue->priv_data = names;
1183 ue->info.value.enumerated.names_ptr = 0;
1184
1185 return 0;
1186}
1187
1188static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1189{
1190 struct user_element *ue = kcontrol->private_data;
1191
1192 kfree(ue->tlv_data);
1193 kfree(ue->priv_data);
1194 kfree(ue);
1195}
1196
1197static int snd_ctl_elem_add(struct snd_ctl_file *file,
1198 struct snd_ctl_elem_info *info, int replace)
1199{
1200 /* The capacity of struct snd_ctl_elem_value.value.*/
1201 static const unsigned int value_sizes[] = {
1202 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long),
1203 [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long),
1204 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
1205 [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char),
1206 [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958),
1207 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
1208 };
1209 static const unsigned int max_value_counts[] = {
1210 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128,
1211 [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128,
1212 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
1213 [SNDRV_CTL_ELEM_TYPE_BYTES] = 512,
1214 [SNDRV_CTL_ELEM_TYPE_IEC958] = 1,
1215 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
1216 };
1217 struct snd_card *card = file->card;
1218 struct snd_kcontrol *kctl;
1219 unsigned int count;
1220 unsigned int access;
1221 long private_size;
1222 struct user_element *ue;
1223 unsigned int offset;
1224 int err;
1225
1226 if (!*info->id.name)
1227 return -EINVAL;
1228 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1229 return -EINVAL;
1230
1231 /* Delete a control to replace them if needed. */
1232 if (replace) {
1233 info->id.numid = 0;
1234 err = snd_ctl_remove_user_ctl(file, &info->id);
1235 if (err)
1236 return err;
1237 }
1238
1239 /*
1240 * The number of userspace controls are counted control by control,
1241 * not element by element.
1242 */
1243 if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1244 return -ENOMEM;
1245
1246 /* Check the number of elements for this userspace control. */
1247 count = info->owner;
1248 if (count == 0)
1249 count = 1;
1250
1251 /* Arrange access permissions if needed. */
1252 access = info->access;
1253 if (access == 0)
1254 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1255 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1256 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1257 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE);
1258 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
1259 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1260 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1261
1262 /*
1263 * Check information and calculate the size of data specific to
1264 * this userspace control.
1265 */
1266 if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
1267 info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
1268 return -EINVAL;
1269 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
1270 info->value.enumerated.items == 0)
1271 return -EINVAL;
1272 if (info->count < 1 ||
1273 info->count > max_value_counts[info->type])
1274 return -EINVAL;
1275 private_size = value_sizes[info->type] * info->count;
1276
1277 /*
1278 * Keep memory object for this userspace control. After passing this
1279 * code block, the instance should be freed by snd_ctl_free_one().
1280 *
1281 * Note that these elements in this control are locked.
1282 */
1283 err = snd_ctl_new(&kctl, count, access, file);
1284 if (err < 0)
1285 return err;
1286 memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1287 kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1288 GFP_KERNEL);
1289 if (kctl->private_data == NULL) {
1290 kfree(kctl);
1291 return -ENOMEM;
1292 }
1293 kctl->private_free = snd_ctl_elem_user_free;
1294
1295 /* Set private data for this userspace control. */
1296 ue = (struct user_element *)kctl->private_data;
1297 ue->card = card;
1298 ue->info = *info;
1299 ue->info.access = 0;
1300 ue->elem_data = (char *)ue + sizeof(*ue);
1301 ue->elem_data_size = private_size;
1302 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1303 err = snd_ctl_elem_init_enum_names(ue);
1304 if (err < 0) {
1305 snd_ctl_free_one(kctl);
1306 return err;
1307 }
1308 }
1309
1310 /* Set callback functions. */
1311 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1312 kctl->info = snd_ctl_elem_user_enum_info;
1313 else
1314 kctl->info = snd_ctl_elem_user_info;
1315 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1316 kctl->get = snd_ctl_elem_user_get;
1317 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1318 kctl->put = snd_ctl_elem_user_put;
1319 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
1320 kctl->tlv.c = snd_ctl_elem_user_tlv;
1321
1322 /* This function manage to free the instance on failure. */
1323 err = snd_ctl_add(card, kctl);
1324 if (err < 0)
1325 return err;
1326 offset = snd_ctl_get_ioff(kctl, &info->id);
1327 snd_ctl_build_ioff(&info->id, kctl, offset);
1328 /*
1329 * Here we cannot fill any field for the number of elements added by
1330 * this operation because there're no specific fields. The usage of
1331 * 'owner' field for this purpose may cause any bugs to userspace
1332 * applications because the field originally means PID of a process
1333 * which locks the element.
1334 */
1335
1336 down_write(&card->controls_rwsem);
1337 card->user_ctl_count++;
1338 up_write(&card->controls_rwsem);
1339
1340 return 0;
1341}
1342
1343static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1344 struct snd_ctl_elem_info __user *_info, int replace)
1345{
1346 struct snd_ctl_elem_info info;
1347 int err;
1348
1349 if (copy_from_user(&info, _info, sizeof(info)))
1350 return -EFAULT;
1351 err = snd_ctl_elem_add(file, &info, replace);
1352 if (err < 0)
1353 return err;
1354 if (copy_to_user(_info, &info, sizeof(info))) {
1355 snd_ctl_remove_user_ctl(file, &info.id);
1356 return -EFAULT;
1357 }
1358
1359 return 0;
1360}
1361
1362static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1363 struct snd_ctl_elem_id __user *_id)
1364{
1365 struct snd_ctl_elem_id id;
1366
1367 if (copy_from_user(&id, _id, sizeof(id)))
1368 return -EFAULT;
1369 return snd_ctl_remove_user_ctl(file, &id);
1370}
1371
1372static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1373{
1374 int subscribe;
1375 if (get_user(subscribe, ptr))
1376 return -EFAULT;
1377 if (subscribe < 0) {
1378 subscribe = file->subscribed;
1379 if (put_user(subscribe, ptr))
1380 return -EFAULT;
1381 return 0;
1382 }
1383 if (subscribe) {
1384 file->subscribed = 1;
1385 return 0;
1386 } else if (file->subscribed) {
1387 snd_ctl_empty_read_queue(file);
1388 file->subscribed = 0;
1389 }
1390 return 0;
1391}
1392
1393static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1394 struct snd_ctl_tlv __user *_tlv,
1395 int op_flag)
1396{
1397 struct snd_card *card = file->card;
1398 struct snd_ctl_tlv tlv;
1399 struct snd_kcontrol *kctl;
1400 struct snd_kcontrol_volatile *vd;
1401 unsigned int len;
1402 int err = 0;
1403
1404 if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1405 return -EFAULT;
1406 if (tlv.length < sizeof(unsigned int) * 2)
1407 return -EINVAL;
1408 if (!tlv.numid)
1409 return -EINVAL;
1410 down_read(&card->controls_rwsem);
1411 kctl = snd_ctl_find_numid(card, tlv.numid);
1412 if (kctl == NULL) {
1413 err = -ENOENT;
1414 goto __kctl_end;
1415 }
1416 if (kctl->tlv.p == NULL) {
1417 err = -ENXIO;
1418 goto __kctl_end;
1419 }
1420 vd = &kctl->vd[tlv.numid - kctl->id.numid];
1421 if ((op_flag == SNDRV_CTL_TLV_OP_READ &&
1422 (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1423 (op_flag == SNDRV_CTL_TLV_OP_WRITE &&
1424 (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1425 (op_flag == SNDRV_CTL_TLV_OP_CMD &&
1426 (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1427 err = -ENXIO;
1428 goto __kctl_end;
1429 }
1430 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1431 if (vd->owner != NULL && vd->owner != file) {
1432 err = -EPERM;
1433 goto __kctl_end;
1434 }
1435 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1436 if (err > 0) {
1437 struct snd_ctl_elem_id id = kctl->id;
1438 up_read(&card->controls_rwsem);
1439 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1440 return 0;
1441 }
1442 } else {
1443 if (op_flag != SNDRV_CTL_TLV_OP_READ) {
1444 err = -ENXIO;
1445 goto __kctl_end;
1446 }
1447 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1448 if (tlv.length < len) {
1449 err = -ENOMEM;
1450 goto __kctl_end;
1451 }
1452 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1453 err = -EFAULT;
1454 }
1455 __kctl_end:
1456 up_read(&card->controls_rwsem);
1457 return err;
1458}
1459
1460static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1461{
1462 struct snd_ctl_file *ctl;
1463 struct snd_card *card;
1464 struct snd_kctl_ioctl *p;
1465 void __user *argp = (void __user *)arg;
1466 int __user *ip = argp;
1467 int err;
1468
1469 ctl = file->private_data;
1470 card = ctl->card;
1471 if (snd_BUG_ON(!card))
1472 return -ENXIO;
1473 switch (cmd) {
1474 case SNDRV_CTL_IOCTL_PVERSION:
1475 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1476 case SNDRV_CTL_IOCTL_CARD_INFO:
1477 return snd_ctl_card_info(card, ctl, cmd, argp);
1478 case SNDRV_CTL_IOCTL_ELEM_LIST:
1479 return snd_ctl_elem_list(card, argp);
1480 case SNDRV_CTL_IOCTL_ELEM_INFO:
1481 return snd_ctl_elem_info_user(ctl, argp);
1482 case SNDRV_CTL_IOCTL_ELEM_READ:
1483 return snd_ctl_elem_read_user(card, argp);
1484 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1485 return snd_ctl_elem_write_user(ctl, argp);
1486 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1487 return snd_ctl_elem_lock(ctl, argp);
1488 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1489 return snd_ctl_elem_unlock(ctl, argp);
1490 case SNDRV_CTL_IOCTL_ELEM_ADD:
1491 return snd_ctl_elem_add_user(ctl, argp, 0);
1492 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1493 return snd_ctl_elem_add_user(ctl, argp, 1);
1494 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1495 return snd_ctl_elem_remove(ctl, argp);
1496 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1497 return snd_ctl_subscribe_events(ctl, ip);
1498 case SNDRV_CTL_IOCTL_TLV_READ:
1499 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1500 case SNDRV_CTL_IOCTL_TLV_WRITE:
1501 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1502 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1503 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1504 case SNDRV_CTL_IOCTL_POWER:
1505 return -ENOPROTOOPT;
1506 case SNDRV_CTL_IOCTL_POWER_STATE:
1507#ifdef CONFIG_PM
1508 return put_user(card->power_state, ip) ? -EFAULT : 0;
1509#else
1510 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1511#endif
1512 }
1513 down_read(&snd_ioctl_rwsem);
1514 list_for_each_entry(p, &snd_control_ioctls, list) {
1515 err = p->fioctl(card, ctl, cmd, arg);
1516 if (err != -ENOIOCTLCMD) {
1517 up_read(&snd_ioctl_rwsem);
1518 return err;
1519 }
1520 }
1521 up_read(&snd_ioctl_rwsem);
1522 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1523 return -ENOTTY;
1524}
1525
1526static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1527 size_t count, loff_t * offset)
1528{
1529 struct snd_ctl_file *ctl;
1530 int err = 0;
1531 ssize_t result = 0;
1532
1533 ctl = file->private_data;
1534 if (snd_BUG_ON(!ctl || !ctl->card))
1535 return -ENXIO;
1536 if (!ctl->subscribed)
1537 return -EBADFD;
1538 if (count < sizeof(struct snd_ctl_event))
1539 return -EINVAL;
1540 spin_lock_irq(&ctl->read_lock);
1541 while (count >= sizeof(struct snd_ctl_event)) {
1542 struct snd_ctl_event ev;
1543 struct snd_kctl_event *kev;
1544 while (list_empty(&ctl->events)) {
1545 wait_queue_t wait;
1546 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1547 err = -EAGAIN;
1548 goto __end_lock;
1549 }
1550 init_waitqueue_entry(&wait, current);
1551 add_wait_queue(&ctl->change_sleep, &wait);
1552 set_current_state(TASK_INTERRUPTIBLE);
1553 spin_unlock_irq(&ctl->read_lock);
1554 schedule();
1555 remove_wait_queue(&ctl->change_sleep, &wait);
1556 if (ctl->card->shutdown)
1557 return -ENODEV;
1558 if (signal_pending(current))
1559 return -ERESTARTSYS;
1560 spin_lock_irq(&ctl->read_lock);
1561 }
1562 kev = snd_kctl_event(ctl->events.next);
1563 ev.type = SNDRV_CTL_EVENT_ELEM;
1564 ev.data.elem.mask = kev->mask;
1565 ev.data.elem.id = kev->id;
1566 list_del(&kev->list);
1567 spin_unlock_irq(&ctl->read_lock);
1568 kfree(kev);
1569 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1570 err = -EFAULT;
1571 goto __end;
1572 }
1573 spin_lock_irq(&ctl->read_lock);
1574 buffer += sizeof(struct snd_ctl_event);
1575 count -= sizeof(struct snd_ctl_event);
1576 result += sizeof(struct snd_ctl_event);
1577 }
1578 __end_lock:
1579 spin_unlock_irq(&ctl->read_lock);
1580 __end:
1581 return result > 0 ? result : err;
1582}
1583
1584static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1585{
1586 unsigned int mask;
1587 struct snd_ctl_file *ctl;
1588
1589 ctl = file->private_data;
1590 if (!ctl->subscribed)
1591 return 0;
1592 poll_wait(file, &ctl->change_sleep, wait);
1593
1594 mask = 0;
1595 if (!list_empty(&ctl->events))
1596 mask |= POLLIN | POLLRDNORM;
1597
1598 return mask;
1599}
1600
1601/*
1602 * register the device-specific control-ioctls.
1603 * called from each device manager like pcm.c, hwdep.c, etc.
1604 */
1605static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1606{
1607 struct snd_kctl_ioctl *pn;
1608
1609 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1610 if (pn == NULL)
1611 return -ENOMEM;
1612 pn->fioctl = fcn;
1613 down_write(&snd_ioctl_rwsem);
1614 list_add_tail(&pn->list, lists);
1615 up_write(&snd_ioctl_rwsem);
1616 return 0;
1617}
1618
1619/**
1620 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1621 * @fcn: ioctl callback function
1622 *
1623 * called from each device manager like pcm.c, hwdep.c, etc.
1624 */
1625int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1626{
1627 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1628}
1629EXPORT_SYMBOL(snd_ctl_register_ioctl);
1630
1631#ifdef CONFIG_COMPAT
1632/**
1633 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1634 * control-ioctls
1635 * @fcn: ioctl callback function
1636 */
1637int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1638{
1639 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1640}
1641EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1642#endif
1643
1644/*
1645 * de-register the device-specific control-ioctls.
1646 */
1647static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1648 struct list_head *lists)
1649{
1650 struct snd_kctl_ioctl *p;
1651
1652 if (snd_BUG_ON(!fcn))
1653 return -EINVAL;
1654 down_write(&snd_ioctl_rwsem);
1655 list_for_each_entry(p, lists, list) {
1656 if (p->fioctl == fcn) {
1657 list_del(&p->list);
1658 up_write(&snd_ioctl_rwsem);
1659 kfree(p);
1660 return 0;
1661 }
1662 }
1663 up_write(&snd_ioctl_rwsem);
1664 snd_BUG();
1665 return -EINVAL;
1666}
1667
1668/**
1669 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1670 * @fcn: ioctl callback function to unregister
1671 */
1672int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1673{
1674 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1675}
1676EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1677
1678#ifdef CONFIG_COMPAT
1679/**
1680 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
1681 * control-ioctls
1682 * @fcn: ioctl callback function to unregister
1683 */
1684int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1685{
1686 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1687}
1688EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1689#endif
1690
1691static int snd_ctl_fasync(int fd, struct file * file, int on)
1692{
1693 struct snd_ctl_file *ctl;
1694
1695 ctl = file->private_data;
1696 return fasync_helper(fd, file, on, &ctl->fasync);
1697}
1698
1699/* return the preferred subdevice number if already assigned;
1700 * otherwise return -1
1701 */
1702int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
1703{
1704 struct snd_ctl_file *kctl;
1705 int subdevice = -1;
1706
1707 read_lock(&card->ctl_files_rwlock);
1708 list_for_each_entry(kctl, &card->ctl_files, list) {
1709 if (kctl->pid == task_pid(current)) {
1710 subdevice = kctl->preferred_subdevice[type];
1711 if (subdevice != -1)
1712 break;
1713 }
1714 }
1715 read_unlock(&card->ctl_files_rwlock);
1716 return subdevice;
1717}
1718EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
1719
1720/*
1721 * ioctl32 compat
1722 */
1723#ifdef CONFIG_COMPAT
1724#include "control_compat.c"
1725#else
1726#define snd_ctl_ioctl_compat NULL
1727#endif
1728
1729/*
1730 * INIT PART
1731 */
1732
1733static const struct file_operations snd_ctl_f_ops =
1734{
1735 .owner = THIS_MODULE,
1736 .read = snd_ctl_read,
1737 .open = snd_ctl_open,
1738 .release = snd_ctl_release,
1739 .llseek = no_llseek,
1740 .poll = snd_ctl_poll,
1741 .unlocked_ioctl = snd_ctl_ioctl,
1742 .compat_ioctl = snd_ctl_ioctl_compat,
1743 .fasync = snd_ctl_fasync,
1744};
1745
1746/*
1747 * registration of the control device
1748 */
1749static int snd_ctl_dev_register(struct snd_device *device)
1750{
1751 struct snd_card *card = device->device_data;
1752
1753 return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1754 &snd_ctl_f_ops, card, &card->ctl_dev);
1755}
1756
1757/*
1758 * disconnection of the control device
1759 */
1760static int snd_ctl_dev_disconnect(struct snd_device *device)
1761{
1762 struct snd_card *card = device->device_data;
1763 struct snd_ctl_file *ctl;
1764
1765 read_lock(&card->ctl_files_rwlock);
1766 list_for_each_entry(ctl, &card->ctl_files, list) {
1767 wake_up(&ctl->change_sleep);
1768 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1769 }
1770 read_unlock(&card->ctl_files_rwlock);
1771
1772 return snd_unregister_device(&card->ctl_dev);
1773}
1774
1775/*
1776 * free all controls
1777 */
1778static int snd_ctl_dev_free(struct snd_device *device)
1779{
1780 struct snd_card *card = device->device_data;
1781 struct snd_kcontrol *control;
1782
1783 down_write(&card->controls_rwsem);
1784 while (!list_empty(&card->controls)) {
1785 control = snd_kcontrol(card->controls.next);
1786 snd_ctl_remove(card, control);
1787 }
1788 up_write(&card->controls_rwsem);
1789 put_device(&card->ctl_dev);
1790 return 0;
1791}
1792
1793/*
1794 * create control core:
1795 * called from init.c
1796 */
1797int snd_ctl_create(struct snd_card *card)
1798{
1799 static struct snd_device_ops ops = {
1800 .dev_free = snd_ctl_dev_free,
1801 .dev_register = snd_ctl_dev_register,
1802 .dev_disconnect = snd_ctl_dev_disconnect,
1803 };
1804 int err;
1805
1806 if (snd_BUG_ON(!card))
1807 return -ENXIO;
1808 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
1809 return -ENXIO;
1810
1811 snd_device_initialize(&card->ctl_dev, card);
1812 dev_set_name(&card->ctl_dev, "controlC%d", card->number);
1813
1814 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1815 if (err < 0)
1816 put_device(&card->ctl_dev);
1817 return err;
1818}
1819
1820/*
1821 * Frequently used control callbacks/helpers
1822 */
1823
1824/**
1825 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
1826 * callback with a mono channel
1827 * @kcontrol: the kcontrol instance
1828 * @uinfo: info to store
1829 *
1830 * This is a function that can be used as info callback for a standard
1831 * boolean control with a single mono channel.
1832 */
1833int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1834 struct snd_ctl_elem_info *uinfo)
1835{
1836 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1837 uinfo->count = 1;
1838 uinfo->value.integer.min = 0;
1839 uinfo->value.integer.max = 1;
1840 return 0;
1841}
1842EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1843
1844/**
1845 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
1846 * callback with stereo two channels
1847 * @kcontrol: the kcontrol instance
1848 * @uinfo: info to store
1849 *
1850 * This is a function that can be used as info callback for a standard
1851 * boolean control with stereo two channels.
1852 */
1853int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1854 struct snd_ctl_elem_info *uinfo)
1855{
1856 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1857 uinfo->count = 2;
1858 uinfo->value.integer.min = 0;
1859 uinfo->value.integer.max = 1;
1860 return 0;
1861}
1862EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1863
1864/**
1865 * snd_ctl_enum_info - fills the info structure for an enumerated control
1866 * @info: the structure to be filled
1867 * @channels: the number of the control's channels; often one
1868 * @items: the number of control values; also the size of @names
1869 * @names: an array containing the names of all control values
1870 *
1871 * Sets all required fields in @info to their appropriate values.
1872 * If the control's accessibility is not the default (readable and writable),
1873 * the caller has to fill @info->access.
1874 *
1875 * Return: Zero.
1876 */
1877int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1878 unsigned int items, const char *const names[])
1879{
1880 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1881 info->count = channels;
1882 info->value.enumerated.items = items;
1883 if (!items)
1884 return 0;
1885 if (info->value.enumerated.item >= items)
1886 info->value.enumerated.item = items - 1;
1887 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
1888 "ALSA: too long item name '%s'\n",
1889 names[info->value.enumerated.item]);
1890 strlcpy(info->value.enumerated.name,
1891 names[info->value.enumerated.item],
1892 sizeof(info->value.enumerated.name));
1893 return 0;
1894}
1895EXPORT_SYMBOL(snd_ctl_enum_info);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Routines for driver control interface
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/threads.h>
8#include <linux/interrupt.h>
9#include <linux/module.h>
10#include <linux/moduleparam.h>
11#include <linux/slab.h>
12#include <linux/vmalloc.h>
13#include <linux/time.h>
14#include <linux/mm.h>
15#include <linux/math64.h>
16#include <linux/sched/signal.h>
17#include <sound/core.h>
18#include <sound/minors.h>
19#include <sound/info.h>
20#include <sound/control.h>
21
22// Max allocation size for user controls.
23static int max_user_ctl_alloc_size = 8 * 1024 * 1024;
24module_param_named(max_user_ctl_alloc_size, max_user_ctl_alloc_size, int, 0444);
25MODULE_PARM_DESC(max_user_ctl_alloc_size, "Max allocation size for user controls");
26
27#define MAX_CONTROL_COUNT 1028
28
29struct snd_kctl_ioctl {
30 struct list_head list; /* list of all ioctls */
31 snd_kctl_ioctl_func_t fioctl;
32};
33
34static DECLARE_RWSEM(snd_ioctl_rwsem);
35static DECLARE_RWSEM(snd_ctl_layer_rwsem);
36static LIST_HEAD(snd_control_ioctls);
37#ifdef CONFIG_COMPAT
38static LIST_HEAD(snd_control_compat_ioctls);
39#endif
40static struct snd_ctl_layer_ops *snd_ctl_layer;
41
42static int snd_ctl_open(struct inode *inode, struct file *file)
43{
44 unsigned long flags;
45 struct snd_card *card;
46 struct snd_ctl_file *ctl;
47 int i, err;
48
49 err = stream_open(inode, file);
50 if (err < 0)
51 return err;
52
53 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
54 if (!card) {
55 err = -ENODEV;
56 goto __error1;
57 }
58 err = snd_card_file_add(card, file);
59 if (err < 0) {
60 err = -ENODEV;
61 goto __error1;
62 }
63 if (!try_module_get(card->module)) {
64 err = -EFAULT;
65 goto __error2;
66 }
67 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
68 if (ctl == NULL) {
69 err = -ENOMEM;
70 goto __error;
71 }
72 INIT_LIST_HEAD(&ctl->events);
73 init_waitqueue_head(&ctl->change_sleep);
74 spin_lock_init(&ctl->read_lock);
75 ctl->card = card;
76 for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
77 ctl->preferred_subdevice[i] = -1;
78 ctl->pid = get_pid(task_pid(current));
79 file->private_data = ctl;
80 write_lock_irqsave(&card->ctl_files_rwlock, flags);
81 list_add_tail(&ctl->list, &card->ctl_files);
82 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
83 snd_card_unref(card);
84 return 0;
85
86 __error:
87 module_put(card->module);
88 __error2:
89 snd_card_file_remove(card, file);
90 __error1:
91 if (card)
92 snd_card_unref(card);
93 return err;
94}
95
96static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
97{
98 unsigned long flags;
99 struct snd_kctl_event *cread;
100
101 spin_lock_irqsave(&ctl->read_lock, flags);
102 while (!list_empty(&ctl->events)) {
103 cread = snd_kctl_event(ctl->events.next);
104 list_del(&cread->list);
105 kfree(cread);
106 }
107 spin_unlock_irqrestore(&ctl->read_lock, flags);
108}
109
110static int snd_ctl_release(struct inode *inode, struct file *file)
111{
112 unsigned long flags;
113 struct snd_card *card;
114 struct snd_ctl_file *ctl;
115 struct snd_kcontrol *control;
116 unsigned int idx;
117
118 ctl = file->private_data;
119 file->private_data = NULL;
120 card = ctl->card;
121 write_lock_irqsave(&card->ctl_files_rwlock, flags);
122 list_del(&ctl->list);
123 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
124 down_write(&card->controls_rwsem);
125 list_for_each_entry(control, &card->controls, list)
126 for (idx = 0; idx < control->count; idx++)
127 if (control->vd[idx].owner == ctl)
128 control->vd[idx].owner = NULL;
129 up_write(&card->controls_rwsem);
130 snd_fasync_free(ctl->fasync);
131 snd_ctl_empty_read_queue(ctl);
132 put_pid(ctl->pid);
133 kfree(ctl);
134 module_put(card->module);
135 snd_card_file_remove(card, file);
136 return 0;
137}
138
139/**
140 * snd_ctl_notify - Send notification to user-space for a control change
141 * @card: the card to send notification
142 * @mask: the event mask, SNDRV_CTL_EVENT_*
143 * @id: the ctl element id to send notification
144 *
145 * This function adds an event record with the given id and mask, appends
146 * to the list and wakes up the user-space for notification. This can be
147 * called in the atomic context.
148 */
149void snd_ctl_notify(struct snd_card *card, unsigned int mask,
150 struct snd_ctl_elem_id *id)
151{
152 unsigned long flags;
153 struct snd_ctl_file *ctl;
154 struct snd_kctl_event *ev;
155
156 if (snd_BUG_ON(!card || !id))
157 return;
158 if (card->shutdown)
159 return;
160 read_lock_irqsave(&card->ctl_files_rwlock, flags);
161#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
162 card->mixer_oss_change_count++;
163#endif
164 list_for_each_entry(ctl, &card->ctl_files, list) {
165 if (!ctl->subscribed)
166 continue;
167 spin_lock(&ctl->read_lock);
168 list_for_each_entry(ev, &ctl->events, list) {
169 if (ev->id.numid == id->numid) {
170 ev->mask |= mask;
171 goto _found;
172 }
173 }
174 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
175 if (ev) {
176 ev->id = *id;
177 ev->mask = mask;
178 list_add_tail(&ev->list, &ctl->events);
179 } else {
180 dev_err(card->dev, "No memory available to allocate event\n");
181 }
182 _found:
183 wake_up(&ctl->change_sleep);
184 spin_unlock(&ctl->read_lock);
185 snd_kill_fasync(ctl->fasync, SIGIO, POLL_IN);
186 }
187 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
188}
189EXPORT_SYMBOL(snd_ctl_notify);
190
191/**
192 * snd_ctl_notify_one - Send notification to user-space for a control change
193 * @card: the card to send notification
194 * @mask: the event mask, SNDRV_CTL_EVENT_*
195 * @kctl: the pointer with the control instance
196 * @ioff: the additional offset to the control index
197 *
198 * This function calls snd_ctl_notify() and does additional jobs
199 * like LED state changes.
200 */
201void snd_ctl_notify_one(struct snd_card *card, unsigned int mask,
202 struct snd_kcontrol *kctl, unsigned int ioff)
203{
204 struct snd_ctl_elem_id id = kctl->id;
205 struct snd_ctl_layer_ops *lops;
206
207 id.index += ioff;
208 id.numid += ioff;
209 snd_ctl_notify(card, mask, &id);
210 down_read(&snd_ctl_layer_rwsem);
211 for (lops = snd_ctl_layer; lops; lops = lops->next)
212 lops->lnotify(card, mask, kctl, ioff);
213 up_read(&snd_ctl_layer_rwsem);
214}
215EXPORT_SYMBOL(snd_ctl_notify_one);
216
217/**
218 * snd_ctl_new - create a new control instance with some elements
219 * @kctl: the pointer to store new control instance
220 * @count: the number of elements in this control
221 * @access: the default access flags for elements in this control
222 * @file: given when locking these elements
223 *
224 * Allocates a memory object for a new control instance. The instance has
225 * elements as many as the given number (@count). Each element has given
226 * access permissions (@access). Each element is locked when @file is given.
227 *
228 * Return: 0 on success, error code on failure
229 */
230static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
231 unsigned int access, struct snd_ctl_file *file)
232{
233 unsigned int idx;
234
235 if (count == 0 || count > MAX_CONTROL_COUNT)
236 return -EINVAL;
237
238 *kctl = kzalloc(struct_size(*kctl, vd, count), GFP_KERNEL);
239 if (!*kctl)
240 return -ENOMEM;
241
242 for (idx = 0; idx < count; idx++) {
243 (*kctl)->vd[idx].access = access;
244 (*kctl)->vd[idx].owner = file;
245 }
246 (*kctl)->count = count;
247
248 return 0;
249}
250
251/**
252 * snd_ctl_new1 - create a control instance from the template
253 * @ncontrol: the initialization record
254 * @private_data: the private data to set
255 *
256 * Allocates a new struct snd_kcontrol instance and initialize from the given
257 * template. When the access field of ncontrol is 0, it's assumed as
258 * READWRITE access. When the count field is 0, it's assumes as one.
259 *
260 * Return: The pointer of the newly generated instance, or %NULL on failure.
261 */
262struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
263 void *private_data)
264{
265 struct snd_kcontrol *kctl;
266 unsigned int count;
267 unsigned int access;
268 int err;
269
270 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
271 return NULL;
272
273 count = ncontrol->count;
274 if (count == 0)
275 count = 1;
276
277 access = ncontrol->access;
278 if (access == 0)
279 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
280 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
281 SNDRV_CTL_ELEM_ACCESS_VOLATILE |
282 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
283 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
284 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
285 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK |
286 SNDRV_CTL_ELEM_ACCESS_LED_MASK |
287 SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK);
288
289 err = snd_ctl_new(&kctl, count, access, NULL);
290 if (err < 0)
291 return NULL;
292
293 /* The 'numid' member is decided when calling snd_ctl_add(). */
294 kctl->id.iface = ncontrol->iface;
295 kctl->id.device = ncontrol->device;
296 kctl->id.subdevice = ncontrol->subdevice;
297 if (ncontrol->name) {
298 strscpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
299 if (strcmp(ncontrol->name, kctl->id.name) != 0)
300 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
301 ncontrol->name, kctl->id.name);
302 }
303 kctl->id.index = ncontrol->index;
304
305 kctl->info = ncontrol->info;
306 kctl->get = ncontrol->get;
307 kctl->put = ncontrol->put;
308 kctl->tlv.p = ncontrol->tlv.p;
309
310 kctl->private_value = ncontrol->private_value;
311 kctl->private_data = private_data;
312
313 return kctl;
314}
315EXPORT_SYMBOL(snd_ctl_new1);
316
317/**
318 * snd_ctl_free_one - release the control instance
319 * @kcontrol: the control instance
320 *
321 * Releases the control instance created via snd_ctl_new()
322 * or snd_ctl_new1().
323 * Don't call this after the control was added to the card.
324 */
325void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
326{
327 if (kcontrol) {
328 if (kcontrol->private_free)
329 kcontrol->private_free(kcontrol);
330 kfree(kcontrol);
331 }
332}
333EXPORT_SYMBOL(snd_ctl_free_one);
334
335static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
336 unsigned int count)
337{
338 struct snd_kcontrol *kctl;
339
340 /* Make sure that the ids assigned to the control do not wrap around */
341 if (card->last_numid >= UINT_MAX - count)
342 card->last_numid = 0;
343
344 list_for_each_entry(kctl, &card->controls, list) {
345 if (kctl->id.numid < card->last_numid + 1 + count &&
346 kctl->id.numid + kctl->count > card->last_numid + 1) {
347 card->last_numid = kctl->id.numid + kctl->count - 1;
348 return true;
349 }
350 }
351 return false;
352}
353
354static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
355{
356 unsigned int iter = 100000;
357
358 while (snd_ctl_remove_numid_conflict(card, count)) {
359 if (--iter == 0) {
360 /* this situation is very unlikely */
361 dev_err(card->dev, "unable to allocate new control numid\n");
362 return -ENOMEM;
363 }
364 }
365 return 0;
366}
367
368/* check whether the given id is contained in the given kctl */
369static bool elem_id_matches(const struct snd_kcontrol *kctl,
370 const struct snd_ctl_elem_id *id)
371{
372 return kctl->id.iface == id->iface &&
373 kctl->id.device == id->device &&
374 kctl->id.subdevice == id->subdevice &&
375 !strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)) &&
376 kctl->id.index <= id->index &&
377 kctl->id.index + kctl->count > id->index;
378}
379
380#ifdef CONFIG_SND_CTL_FAST_LOOKUP
381/* Compute a hash key for the corresponding ctl id
382 * It's for the name lookup, hence the numid is excluded.
383 * The hash key is bound in LONG_MAX to be used for Xarray key.
384 */
385#define MULTIPLIER 37
386static unsigned long get_ctl_id_hash(const struct snd_ctl_elem_id *id)
387{
388 int i;
389 unsigned long h;
390
391 h = id->iface;
392 h = MULTIPLIER * h + id->device;
393 h = MULTIPLIER * h + id->subdevice;
394 for (i = 0; i < SNDRV_CTL_ELEM_ID_NAME_MAXLEN && id->name[i]; i++)
395 h = MULTIPLIER * h + id->name[i];
396 h = MULTIPLIER * h + id->index;
397 h &= LONG_MAX;
398 return h;
399}
400
401/* add hash entries to numid and ctl xarray tables */
402static void add_hash_entries(struct snd_card *card,
403 struct snd_kcontrol *kcontrol)
404{
405 struct snd_ctl_elem_id id = kcontrol->id;
406 int i;
407
408 xa_store_range(&card->ctl_numids, kcontrol->id.numid,
409 kcontrol->id.numid + kcontrol->count - 1,
410 kcontrol, GFP_KERNEL);
411
412 for (i = 0; i < kcontrol->count; i++) {
413 id.index = kcontrol->id.index + i;
414 if (xa_insert(&card->ctl_hash, get_ctl_id_hash(&id),
415 kcontrol, GFP_KERNEL)) {
416 /* skip hash for this entry, noting we had collision */
417 card->ctl_hash_collision = true;
418 dev_dbg(card->dev, "ctl_hash collision %d:%s:%d\n",
419 id.iface, id.name, id.index);
420 }
421 }
422}
423
424/* remove hash entries that have been added */
425static void remove_hash_entries(struct snd_card *card,
426 struct snd_kcontrol *kcontrol)
427{
428 struct snd_ctl_elem_id id = kcontrol->id;
429 struct snd_kcontrol *matched;
430 unsigned long h;
431 int i;
432
433 for (i = 0; i < kcontrol->count; i++) {
434 xa_erase(&card->ctl_numids, id.numid);
435 h = get_ctl_id_hash(&id);
436 matched = xa_load(&card->ctl_hash, h);
437 if (matched && (matched == kcontrol ||
438 elem_id_matches(matched, &id)))
439 xa_erase(&card->ctl_hash, h);
440 id.index++;
441 id.numid++;
442 }
443}
444#else /* CONFIG_SND_CTL_FAST_LOOKUP */
445static inline void add_hash_entries(struct snd_card *card,
446 struct snd_kcontrol *kcontrol)
447{
448}
449static inline void remove_hash_entries(struct snd_card *card,
450 struct snd_kcontrol *kcontrol)
451{
452}
453#endif /* CONFIG_SND_CTL_FAST_LOOKUP */
454
455enum snd_ctl_add_mode {
456 CTL_ADD_EXCLUSIVE, CTL_REPLACE, CTL_ADD_ON_REPLACE,
457};
458
459/* add/replace a new kcontrol object; call with card->controls_rwsem locked */
460static int __snd_ctl_add_replace(struct snd_card *card,
461 struct snd_kcontrol *kcontrol,
462 enum snd_ctl_add_mode mode)
463{
464 struct snd_ctl_elem_id id;
465 unsigned int idx;
466 struct snd_kcontrol *old;
467 int err;
468
469 id = kcontrol->id;
470 if (id.index > UINT_MAX - kcontrol->count)
471 return -EINVAL;
472
473 old = snd_ctl_find_id(card, &id);
474 if (!old) {
475 if (mode == CTL_REPLACE)
476 return -EINVAL;
477 } else {
478 if (mode == CTL_ADD_EXCLUSIVE) {
479 dev_err(card->dev,
480 "control %i:%i:%i:%s:%i is already present\n",
481 id.iface, id.device, id.subdevice, id.name,
482 id.index);
483 return -EBUSY;
484 }
485
486 err = snd_ctl_remove(card, old);
487 if (err < 0)
488 return err;
489 }
490
491 if (snd_ctl_find_hole(card, kcontrol->count) < 0)
492 return -ENOMEM;
493
494 list_add_tail(&kcontrol->list, &card->controls);
495 card->controls_count += kcontrol->count;
496 kcontrol->id.numid = card->last_numid + 1;
497 card->last_numid += kcontrol->count;
498
499 add_hash_entries(card, kcontrol);
500
501 for (idx = 0; idx < kcontrol->count; idx++)
502 snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_ADD, kcontrol, idx);
503
504 return 0;
505}
506
507static int snd_ctl_add_replace(struct snd_card *card,
508 struct snd_kcontrol *kcontrol,
509 enum snd_ctl_add_mode mode)
510{
511 int err = -EINVAL;
512
513 if (! kcontrol)
514 return err;
515 if (snd_BUG_ON(!card || !kcontrol->info))
516 goto error;
517
518 down_write(&card->controls_rwsem);
519 err = __snd_ctl_add_replace(card, kcontrol, mode);
520 up_write(&card->controls_rwsem);
521 if (err < 0)
522 goto error;
523 return 0;
524
525 error:
526 snd_ctl_free_one(kcontrol);
527 return err;
528}
529
530/**
531 * snd_ctl_add - add the control instance to the card
532 * @card: the card instance
533 * @kcontrol: the control instance to add
534 *
535 * Adds the control instance created via snd_ctl_new() or
536 * snd_ctl_new1() to the given card. Assigns also an unique
537 * numid used for fast search.
538 *
539 * It frees automatically the control which cannot be added.
540 *
541 * Return: Zero if successful, or a negative error code on failure.
542 *
543 */
544int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
545{
546 return snd_ctl_add_replace(card, kcontrol, CTL_ADD_EXCLUSIVE);
547}
548EXPORT_SYMBOL(snd_ctl_add);
549
550/**
551 * snd_ctl_replace - replace the control instance of the card
552 * @card: the card instance
553 * @kcontrol: the control instance to replace
554 * @add_on_replace: add the control if not already added
555 *
556 * Replaces the given control. If the given control does not exist
557 * and the add_on_replace flag is set, the control is added. If the
558 * control exists, it is destroyed first.
559 *
560 * It frees automatically the control which cannot be added or replaced.
561 *
562 * Return: Zero if successful, or a negative error code on failure.
563 */
564int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
565 bool add_on_replace)
566{
567 return snd_ctl_add_replace(card, kcontrol,
568 add_on_replace ? CTL_ADD_ON_REPLACE : CTL_REPLACE);
569}
570EXPORT_SYMBOL(snd_ctl_replace);
571
572static int __snd_ctl_remove(struct snd_card *card,
573 struct snd_kcontrol *kcontrol,
574 bool remove_hash)
575{
576 unsigned int idx;
577
578 if (snd_BUG_ON(!card || !kcontrol))
579 return -EINVAL;
580 list_del(&kcontrol->list);
581
582 if (remove_hash)
583 remove_hash_entries(card, kcontrol);
584
585 card->controls_count -= kcontrol->count;
586 for (idx = 0; idx < kcontrol->count; idx++)
587 snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_REMOVE, kcontrol, idx);
588 snd_ctl_free_one(kcontrol);
589 return 0;
590}
591
592/**
593 * snd_ctl_remove - remove the control from the card and release it
594 * @card: the card instance
595 * @kcontrol: the control instance to remove
596 *
597 * Removes the control from the card and then releases the instance.
598 * You don't need to call snd_ctl_free_one(). You must be in
599 * the write lock - down_write(&card->controls_rwsem).
600 *
601 * Return: 0 if successful, or a negative error code on failure.
602 */
603int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
604{
605 return __snd_ctl_remove(card, kcontrol, true);
606}
607EXPORT_SYMBOL(snd_ctl_remove);
608
609/**
610 * snd_ctl_remove_id - remove the control of the given id and release it
611 * @card: the card instance
612 * @id: the control id to remove
613 *
614 * Finds the control instance with the given id, removes it from the
615 * card list and releases it.
616 *
617 * Return: 0 if successful, or a negative error code on failure.
618 */
619int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
620{
621 struct snd_kcontrol *kctl;
622 int ret;
623
624 down_write(&card->controls_rwsem);
625 kctl = snd_ctl_find_id(card, id);
626 if (kctl == NULL) {
627 up_write(&card->controls_rwsem);
628 return -ENOENT;
629 }
630 ret = snd_ctl_remove(card, kctl);
631 up_write(&card->controls_rwsem);
632 return ret;
633}
634EXPORT_SYMBOL(snd_ctl_remove_id);
635
636/**
637 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
638 * @file: active control handle
639 * @id: the control id to remove
640 *
641 * Finds the control instance with the given id, removes it from the
642 * card list and releases it.
643 *
644 * Return: 0 if successful, or a negative error code on failure.
645 */
646static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
647 struct snd_ctl_elem_id *id)
648{
649 struct snd_card *card = file->card;
650 struct snd_kcontrol *kctl;
651 int idx, ret;
652
653 down_write(&card->controls_rwsem);
654 kctl = snd_ctl_find_id(card, id);
655 if (kctl == NULL) {
656 ret = -ENOENT;
657 goto error;
658 }
659 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
660 ret = -EINVAL;
661 goto error;
662 }
663 for (idx = 0; idx < kctl->count; idx++)
664 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
665 ret = -EBUSY;
666 goto error;
667 }
668 ret = snd_ctl_remove(card, kctl);
669error:
670 up_write(&card->controls_rwsem);
671 return ret;
672}
673
674/**
675 * snd_ctl_activate_id - activate/inactivate the control of the given id
676 * @card: the card instance
677 * @id: the control id to activate/inactivate
678 * @active: non-zero to activate
679 *
680 * Finds the control instance with the given id, and activate or
681 * inactivate the control together with notification, if changed.
682 * The given ID data is filled with full information.
683 *
684 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
685 */
686int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
687 int active)
688{
689 struct snd_kcontrol *kctl;
690 struct snd_kcontrol_volatile *vd;
691 unsigned int index_offset;
692 int ret;
693
694 down_write(&card->controls_rwsem);
695 kctl = snd_ctl_find_id(card, id);
696 if (kctl == NULL) {
697 ret = -ENOENT;
698 goto unlock;
699 }
700 index_offset = snd_ctl_get_ioff(kctl, id);
701 vd = &kctl->vd[index_offset];
702 ret = 0;
703 if (active) {
704 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
705 goto unlock;
706 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
707 } else {
708 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
709 goto unlock;
710 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
711 }
712 snd_ctl_build_ioff(id, kctl, index_offset);
713 downgrade_write(&card->controls_rwsem);
714 snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_INFO, kctl, index_offset);
715 up_read(&card->controls_rwsem);
716 return 1;
717
718 unlock:
719 up_write(&card->controls_rwsem);
720 return ret;
721}
722EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
723
724/**
725 * snd_ctl_rename_id - replace the id of a control on the card
726 * @card: the card instance
727 * @src_id: the old id
728 * @dst_id: the new id
729 *
730 * Finds the control with the old id from the card, and replaces the
731 * id with the new one.
732 *
733 * Return: Zero if successful, or a negative error code on failure.
734 */
735int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
736 struct snd_ctl_elem_id *dst_id)
737{
738 struct snd_kcontrol *kctl;
739
740 down_write(&card->controls_rwsem);
741 kctl = snd_ctl_find_id(card, src_id);
742 if (kctl == NULL) {
743 up_write(&card->controls_rwsem);
744 return -ENOENT;
745 }
746 remove_hash_entries(card, kctl);
747 kctl->id = *dst_id;
748 kctl->id.numid = card->last_numid + 1;
749 card->last_numid += kctl->count;
750 add_hash_entries(card, kctl);
751 up_write(&card->controls_rwsem);
752 return 0;
753}
754EXPORT_SYMBOL(snd_ctl_rename_id);
755
756/**
757 * snd_ctl_rename - rename the control on the card
758 * @card: the card instance
759 * @kctl: the control to rename
760 * @name: the new name
761 *
762 * Renames the specified control on the card to the new name.
763 *
764 * Make sure to take the control write lock - down_write(&card->controls_rwsem).
765 */
766void snd_ctl_rename(struct snd_card *card, struct snd_kcontrol *kctl,
767 const char *name)
768{
769 remove_hash_entries(card, kctl);
770
771 if (strscpy(kctl->id.name, name, sizeof(kctl->id.name)) < 0)
772 pr_warn("ALSA: Renamed control new name '%s' truncated to '%s'\n",
773 name, kctl->id.name);
774
775 add_hash_entries(card, kctl);
776}
777EXPORT_SYMBOL(snd_ctl_rename);
778
779#ifndef CONFIG_SND_CTL_FAST_LOOKUP
780static struct snd_kcontrol *
781snd_ctl_find_numid_slow(struct snd_card *card, unsigned int numid)
782{
783 struct snd_kcontrol *kctl;
784
785 list_for_each_entry(kctl, &card->controls, list) {
786 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
787 return kctl;
788 }
789 return NULL;
790}
791#endif /* !CONFIG_SND_CTL_FAST_LOOKUP */
792
793/**
794 * snd_ctl_find_numid - find the control instance with the given number-id
795 * @card: the card instance
796 * @numid: the number-id to search
797 *
798 * Finds the control instance with the given number-id from the card.
799 *
800 * The caller must down card->controls_rwsem before calling this function
801 * (if the race condition can happen).
802 *
803 * Return: The pointer of the instance if found, or %NULL if not.
804 *
805 */
806struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
807{
808 if (snd_BUG_ON(!card || !numid))
809 return NULL;
810#ifdef CONFIG_SND_CTL_FAST_LOOKUP
811 return xa_load(&card->ctl_numids, numid);
812#else
813 return snd_ctl_find_numid_slow(card, numid);
814#endif
815}
816EXPORT_SYMBOL(snd_ctl_find_numid);
817
818/**
819 * snd_ctl_find_id - find the control instance with the given id
820 * @card: the card instance
821 * @id: the id to search
822 *
823 * Finds the control instance with the given id from the card.
824 *
825 * The caller must down card->controls_rwsem before calling this function
826 * (if the race condition can happen).
827 *
828 * Return: The pointer of the instance if found, or %NULL if not.
829 *
830 */
831struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
832 struct snd_ctl_elem_id *id)
833{
834 struct snd_kcontrol *kctl;
835
836 if (snd_BUG_ON(!card || !id))
837 return NULL;
838 if (id->numid != 0)
839 return snd_ctl_find_numid(card, id->numid);
840#ifdef CONFIG_SND_CTL_FAST_LOOKUP
841 kctl = xa_load(&card->ctl_hash, get_ctl_id_hash(id));
842 if (kctl && elem_id_matches(kctl, id))
843 return kctl;
844 if (!card->ctl_hash_collision)
845 return NULL; /* we can rely on only hash table */
846#endif
847 /* no matching in hash table - try all as the last resort */
848 list_for_each_entry(kctl, &card->controls, list)
849 if (elem_id_matches(kctl, id))
850 return kctl;
851
852 return NULL;
853}
854EXPORT_SYMBOL(snd_ctl_find_id);
855
856static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
857 unsigned int cmd, void __user *arg)
858{
859 struct snd_ctl_card_info *info;
860
861 info = kzalloc(sizeof(*info), GFP_KERNEL);
862 if (! info)
863 return -ENOMEM;
864 down_read(&snd_ioctl_rwsem);
865 info->card = card->number;
866 strscpy(info->id, card->id, sizeof(info->id));
867 strscpy(info->driver, card->driver, sizeof(info->driver));
868 strscpy(info->name, card->shortname, sizeof(info->name));
869 strscpy(info->longname, card->longname, sizeof(info->longname));
870 strscpy(info->mixername, card->mixername, sizeof(info->mixername));
871 strscpy(info->components, card->components, sizeof(info->components));
872 up_read(&snd_ioctl_rwsem);
873 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
874 kfree(info);
875 return -EFAULT;
876 }
877 kfree(info);
878 return 0;
879}
880
881static int snd_ctl_elem_list(struct snd_card *card,
882 struct snd_ctl_elem_list *list)
883{
884 struct snd_kcontrol *kctl;
885 struct snd_ctl_elem_id id;
886 unsigned int offset, space, jidx;
887 int err = 0;
888
889 offset = list->offset;
890 space = list->space;
891
892 down_read(&card->controls_rwsem);
893 list->count = card->controls_count;
894 list->used = 0;
895 if (space > 0) {
896 list_for_each_entry(kctl, &card->controls, list) {
897 if (offset >= kctl->count) {
898 offset -= kctl->count;
899 continue;
900 }
901 for (jidx = offset; jidx < kctl->count; jidx++) {
902 snd_ctl_build_ioff(&id, kctl, jidx);
903 if (copy_to_user(list->pids + list->used, &id,
904 sizeof(id))) {
905 err = -EFAULT;
906 goto out;
907 }
908 list->used++;
909 if (!--space)
910 goto out;
911 }
912 offset = 0;
913 }
914 }
915 out:
916 up_read(&card->controls_rwsem);
917 return err;
918}
919
920static int snd_ctl_elem_list_user(struct snd_card *card,
921 struct snd_ctl_elem_list __user *_list)
922{
923 struct snd_ctl_elem_list list;
924 int err;
925
926 if (copy_from_user(&list, _list, sizeof(list)))
927 return -EFAULT;
928 err = snd_ctl_elem_list(card, &list);
929 if (err)
930 return err;
931 if (copy_to_user(_list, &list, sizeof(list)))
932 return -EFAULT;
933
934 return 0;
935}
936
937/* Check whether the given kctl info is valid */
938static int snd_ctl_check_elem_info(struct snd_card *card,
939 const struct snd_ctl_elem_info *info)
940{
941 static const unsigned int max_value_counts[] = {
942 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128,
943 [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128,
944 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
945 [SNDRV_CTL_ELEM_TYPE_BYTES] = 512,
946 [SNDRV_CTL_ELEM_TYPE_IEC958] = 1,
947 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
948 };
949
950 if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
951 info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64) {
952 if (card)
953 dev_err(card->dev,
954 "control %i:%i:%i:%s:%i: invalid type %d\n",
955 info->id.iface, info->id.device,
956 info->id.subdevice, info->id.name,
957 info->id.index, info->type);
958 return -EINVAL;
959 }
960 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
961 info->value.enumerated.items == 0) {
962 if (card)
963 dev_err(card->dev,
964 "control %i:%i:%i:%s:%i: zero enum items\n",
965 info->id.iface, info->id.device,
966 info->id.subdevice, info->id.name,
967 info->id.index);
968 return -EINVAL;
969 }
970 if (info->count > max_value_counts[info->type]) {
971 if (card)
972 dev_err(card->dev,
973 "control %i:%i:%i:%s:%i: invalid count %d\n",
974 info->id.iface, info->id.device,
975 info->id.subdevice, info->id.name,
976 info->id.index, info->count);
977 return -EINVAL;
978 }
979
980 return 0;
981}
982
983/* The capacity of struct snd_ctl_elem_value.value.*/
984static const unsigned int value_sizes[] = {
985 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long),
986 [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long),
987 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
988 [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char),
989 [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958),
990 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
991};
992
993/* fill the remaining snd_ctl_elem_value data with the given pattern */
994static void fill_remaining_elem_value(struct snd_ctl_elem_value *control,
995 struct snd_ctl_elem_info *info,
996 u32 pattern)
997{
998 size_t offset = value_sizes[info->type] * info->count;
999
1000 offset = DIV_ROUND_UP(offset, sizeof(u32));
1001 memset32((u32 *)control->value.bytes.data + offset, pattern,
1002 sizeof(control->value) / sizeof(u32) - offset);
1003}
1004
1005/* check whether the given integer ctl value is valid */
1006static int sanity_check_int_value(struct snd_card *card,
1007 const struct snd_ctl_elem_value *control,
1008 const struct snd_ctl_elem_info *info,
1009 int i, bool print_error)
1010{
1011 long long lval, lmin, lmax, lstep;
1012 u64 rem;
1013
1014 switch (info->type) {
1015 default:
1016 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1017 lval = control->value.integer.value[i];
1018 lmin = 0;
1019 lmax = 1;
1020 lstep = 0;
1021 break;
1022 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1023 lval = control->value.integer.value[i];
1024 lmin = info->value.integer.min;
1025 lmax = info->value.integer.max;
1026 lstep = info->value.integer.step;
1027 break;
1028 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1029 lval = control->value.integer64.value[i];
1030 lmin = info->value.integer64.min;
1031 lmax = info->value.integer64.max;
1032 lstep = info->value.integer64.step;
1033 break;
1034 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1035 lval = control->value.enumerated.item[i];
1036 lmin = 0;
1037 lmax = info->value.enumerated.items - 1;
1038 lstep = 0;
1039 break;
1040 }
1041
1042 if (lval < lmin || lval > lmax) {
1043 if (print_error)
1044 dev_err(card->dev,
1045 "control %i:%i:%i:%s:%i: value out of range %lld (%lld/%lld) at count %i\n",
1046 control->id.iface, control->id.device,
1047 control->id.subdevice, control->id.name,
1048 control->id.index, lval, lmin, lmax, i);
1049 return -EINVAL;
1050 }
1051 if (lstep) {
1052 div64_u64_rem(lval, lstep, &rem);
1053 if (rem) {
1054 if (print_error)
1055 dev_err(card->dev,
1056 "control %i:%i:%i:%s:%i: unaligned value %lld (step %lld) at count %i\n",
1057 control->id.iface, control->id.device,
1058 control->id.subdevice, control->id.name,
1059 control->id.index, lval, lstep, i);
1060 return -EINVAL;
1061 }
1062 }
1063
1064 return 0;
1065}
1066
1067/* check whether the all input values are valid for the given elem value */
1068static int sanity_check_input_values(struct snd_card *card,
1069 const struct snd_ctl_elem_value *control,
1070 const struct snd_ctl_elem_info *info,
1071 bool print_error)
1072{
1073 int i, ret;
1074
1075 switch (info->type) {
1076 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1077 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1078 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1079 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1080 for (i = 0; i < info->count; i++) {
1081 ret = sanity_check_int_value(card, control, info, i,
1082 print_error);
1083 if (ret < 0)
1084 return ret;
1085 }
1086 break;
1087 default:
1088 break;
1089 }
1090
1091 return 0;
1092}
1093
1094/* perform sanity checks to the given snd_ctl_elem_value object */
1095static int sanity_check_elem_value(struct snd_card *card,
1096 const struct snd_ctl_elem_value *control,
1097 const struct snd_ctl_elem_info *info,
1098 u32 pattern)
1099{
1100 size_t offset;
1101 int ret;
1102 u32 *p;
1103
1104 ret = sanity_check_input_values(card, control, info, true);
1105 if (ret < 0)
1106 return ret;
1107
1108 /* check whether the remaining area kept untouched */
1109 offset = value_sizes[info->type] * info->count;
1110 offset = DIV_ROUND_UP(offset, sizeof(u32));
1111 p = (u32 *)control->value.bytes.data + offset;
1112 for (; offset < sizeof(control->value) / sizeof(u32); offset++, p++) {
1113 if (*p != pattern) {
1114 ret = -EINVAL;
1115 break;
1116 }
1117 *p = 0; /* clear the checked area */
1118 }
1119
1120 return ret;
1121}
1122
1123static int __snd_ctl_elem_info(struct snd_card *card,
1124 struct snd_kcontrol *kctl,
1125 struct snd_ctl_elem_info *info,
1126 struct snd_ctl_file *ctl)
1127{
1128 struct snd_kcontrol_volatile *vd;
1129 unsigned int index_offset;
1130 int result;
1131
1132#ifdef CONFIG_SND_DEBUG
1133 info->access = 0;
1134#endif
1135 result = snd_power_ref_and_wait(card);
1136 if (!result)
1137 result = kctl->info(kctl, info);
1138 snd_power_unref(card);
1139 if (result >= 0) {
1140 snd_BUG_ON(info->access);
1141 index_offset = snd_ctl_get_ioff(kctl, &info->id);
1142 vd = &kctl->vd[index_offset];
1143 snd_ctl_build_ioff(&info->id, kctl, index_offset);
1144 info->access = vd->access;
1145 if (vd->owner) {
1146 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
1147 if (vd->owner == ctl)
1148 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
1149 info->owner = pid_vnr(vd->owner->pid);
1150 } else {
1151 info->owner = -1;
1152 }
1153 if (!snd_ctl_skip_validation(info) &&
1154 snd_ctl_check_elem_info(card, info) < 0)
1155 result = -EINVAL;
1156 }
1157 return result;
1158}
1159
1160static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
1161 struct snd_ctl_elem_info *info)
1162{
1163 struct snd_card *card = ctl->card;
1164 struct snd_kcontrol *kctl;
1165 int result;
1166
1167 down_read(&card->controls_rwsem);
1168 kctl = snd_ctl_find_id(card, &info->id);
1169 if (kctl == NULL)
1170 result = -ENOENT;
1171 else
1172 result = __snd_ctl_elem_info(card, kctl, info, ctl);
1173 up_read(&card->controls_rwsem);
1174 return result;
1175}
1176
1177static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
1178 struct snd_ctl_elem_info __user *_info)
1179{
1180 struct snd_ctl_elem_info info;
1181 int result;
1182
1183 if (copy_from_user(&info, _info, sizeof(info)))
1184 return -EFAULT;
1185 result = snd_ctl_elem_info(ctl, &info);
1186 if (result < 0)
1187 return result;
1188 /* drop internal access flags */
1189 info.access &= ~(SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK|
1190 SNDRV_CTL_ELEM_ACCESS_LED_MASK);
1191 if (copy_to_user(_info, &info, sizeof(info)))
1192 return -EFAULT;
1193 return result;
1194}
1195
1196static int snd_ctl_elem_read(struct snd_card *card,
1197 struct snd_ctl_elem_value *control)
1198{
1199 struct snd_kcontrol *kctl;
1200 struct snd_kcontrol_volatile *vd;
1201 unsigned int index_offset;
1202 struct snd_ctl_elem_info info;
1203 const u32 pattern = 0xdeadbeef;
1204 int ret;
1205
1206 down_read(&card->controls_rwsem);
1207 kctl = snd_ctl_find_id(card, &control->id);
1208 if (kctl == NULL) {
1209 ret = -ENOENT;
1210 goto unlock;
1211 }
1212
1213 index_offset = snd_ctl_get_ioff(kctl, &control->id);
1214 vd = &kctl->vd[index_offset];
1215 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) || kctl->get == NULL) {
1216 ret = -EPERM;
1217 goto unlock;
1218 }
1219
1220 snd_ctl_build_ioff(&control->id, kctl, index_offset);
1221
1222#ifdef CONFIG_SND_CTL_DEBUG
1223 /* info is needed only for validation */
1224 memset(&info, 0, sizeof(info));
1225 info.id = control->id;
1226 ret = __snd_ctl_elem_info(card, kctl, &info, NULL);
1227 if (ret < 0)
1228 goto unlock;
1229#endif
1230
1231 if (!snd_ctl_skip_validation(&info))
1232 fill_remaining_elem_value(control, &info, pattern);
1233 ret = snd_power_ref_and_wait(card);
1234 if (!ret)
1235 ret = kctl->get(kctl, control);
1236 snd_power_unref(card);
1237 if (ret < 0)
1238 goto unlock;
1239 if (!snd_ctl_skip_validation(&info) &&
1240 sanity_check_elem_value(card, control, &info, pattern) < 0) {
1241 dev_err(card->dev,
1242 "control %i:%i:%i:%s:%i: access overflow\n",
1243 control->id.iface, control->id.device,
1244 control->id.subdevice, control->id.name,
1245 control->id.index);
1246 ret = -EINVAL;
1247 goto unlock;
1248 }
1249unlock:
1250 up_read(&card->controls_rwsem);
1251 return ret;
1252}
1253
1254static int snd_ctl_elem_read_user(struct snd_card *card,
1255 struct snd_ctl_elem_value __user *_control)
1256{
1257 struct snd_ctl_elem_value *control;
1258 int result;
1259
1260 control = memdup_user(_control, sizeof(*control));
1261 if (IS_ERR(control))
1262 return PTR_ERR(control);
1263
1264 result = snd_ctl_elem_read(card, control);
1265 if (result < 0)
1266 goto error;
1267
1268 if (copy_to_user(_control, control, sizeof(*control)))
1269 result = -EFAULT;
1270 error:
1271 kfree(control);
1272 return result;
1273}
1274
1275static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
1276 struct snd_ctl_elem_value *control)
1277{
1278 struct snd_kcontrol *kctl;
1279 struct snd_kcontrol_volatile *vd;
1280 unsigned int index_offset;
1281 int result;
1282
1283 down_write(&card->controls_rwsem);
1284 kctl = snd_ctl_find_id(card, &control->id);
1285 if (kctl == NULL) {
1286 up_write(&card->controls_rwsem);
1287 return -ENOENT;
1288 }
1289
1290 index_offset = snd_ctl_get_ioff(kctl, &control->id);
1291 vd = &kctl->vd[index_offset];
1292 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
1293 (file && vd->owner && vd->owner != file)) {
1294 up_write(&card->controls_rwsem);
1295 return -EPERM;
1296 }
1297
1298 snd_ctl_build_ioff(&control->id, kctl, index_offset);
1299 result = snd_power_ref_and_wait(card);
1300 /* validate input values */
1301 if (IS_ENABLED(CONFIG_SND_CTL_INPUT_VALIDATION) && !result) {
1302 struct snd_ctl_elem_info info;
1303
1304 memset(&info, 0, sizeof(info));
1305 info.id = control->id;
1306 result = __snd_ctl_elem_info(card, kctl, &info, NULL);
1307 if (!result)
1308 result = sanity_check_input_values(card, control, &info,
1309 false);
1310 }
1311 if (!result)
1312 result = kctl->put(kctl, control);
1313 snd_power_unref(card);
1314 if (result < 0) {
1315 up_write(&card->controls_rwsem);
1316 return result;
1317 }
1318
1319 if (result > 0) {
1320 downgrade_write(&card->controls_rwsem);
1321 snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, index_offset);
1322 up_read(&card->controls_rwsem);
1323 } else {
1324 up_write(&card->controls_rwsem);
1325 }
1326
1327 return 0;
1328}
1329
1330static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
1331 struct snd_ctl_elem_value __user *_control)
1332{
1333 struct snd_ctl_elem_value *control;
1334 struct snd_card *card;
1335 int result;
1336
1337 control = memdup_user(_control, sizeof(*control));
1338 if (IS_ERR(control))
1339 return PTR_ERR(control);
1340
1341 card = file->card;
1342 result = snd_ctl_elem_write(card, file, control);
1343 if (result < 0)
1344 goto error;
1345
1346 if (copy_to_user(_control, control, sizeof(*control)))
1347 result = -EFAULT;
1348 error:
1349 kfree(control);
1350 return result;
1351}
1352
1353static int snd_ctl_elem_lock(struct snd_ctl_file *file,
1354 struct snd_ctl_elem_id __user *_id)
1355{
1356 struct snd_card *card = file->card;
1357 struct snd_ctl_elem_id id;
1358 struct snd_kcontrol *kctl;
1359 struct snd_kcontrol_volatile *vd;
1360 int result;
1361
1362 if (copy_from_user(&id, _id, sizeof(id)))
1363 return -EFAULT;
1364 down_write(&card->controls_rwsem);
1365 kctl = snd_ctl_find_id(card, &id);
1366 if (kctl == NULL) {
1367 result = -ENOENT;
1368 } else {
1369 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1370 if (vd->owner != NULL)
1371 result = -EBUSY;
1372 else {
1373 vd->owner = file;
1374 result = 0;
1375 }
1376 }
1377 up_write(&card->controls_rwsem);
1378 return result;
1379}
1380
1381static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1382 struct snd_ctl_elem_id __user *_id)
1383{
1384 struct snd_card *card = file->card;
1385 struct snd_ctl_elem_id id;
1386 struct snd_kcontrol *kctl;
1387 struct snd_kcontrol_volatile *vd;
1388 int result;
1389
1390 if (copy_from_user(&id, _id, sizeof(id)))
1391 return -EFAULT;
1392 down_write(&card->controls_rwsem);
1393 kctl = snd_ctl_find_id(card, &id);
1394 if (kctl == NULL) {
1395 result = -ENOENT;
1396 } else {
1397 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1398 if (vd->owner == NULL)
1399 result = -EINVAL;
1400 else if (vd->owner != file)
1401 result = -EPERM;
1402 else {
1403 vd->owner = NULL;
1404 result = 0;
1405 }
1406 }
1407 up_write(&card->controls_rwsem);
1408 return result;
1409}
1410
1411struct user_element {
1412 struct snd_ctl_elem_info info;
1413 struct snd_card *card;
1414 char *elem_data; /* element data */
1415 unsigned long elem_data_size; /* size of element data in bytes */
1416 void *tlv_data; /* TLV data */
1417 unsigned long tlv_data_size; /* TLV data size */
1418 void *priv_data; /* private data (like strings for enumerated type) */
1419};
1420
1421// check whether the addition (in bytes) of user ctl element may overflow the limit.
1422static bool check_user_elem_overflow(struct snd_card *card, ssize_t add)
1423{
1424 return (ssize_t)card->user_ctl_alloc_size + add > max_user_ctl_alloc_size;
1425}
1426
1427static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1428 struct snd_ctl_elem_info *uinfo)
1429{
1430 struct user_element *ue = kcontrol->private_data;
1431 unsigned int offset;
1432
1433 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1434 *uinfo = ue->info;
1435 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1436
1437 return 0;
1438}
1439
1440static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1441 struct snd_ctl_elem_info *uinfo)
1442{
1443 struct user_element *ue = kcontrol->private_data;
1444 const char *names;
1445 unsigned int item;
1446 unsigned int offset;
1447
1448 item = uinfo->value.enumerated.item;
1449
1450 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1451 *uinfo = ue->info;
1452 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1453
1454 item = min(item, uinfo->value.enumerated.items - 1);
1455 uinfo->value.enumerated.item = item;
1456
1457 names = ue->priv_data;
1458 for (; item > 0; --item)
1459 names += strlen(names) + 1;
1460 strcpy(uinfo->value.enumerated.name, names);
1461
1462 return 0;
1463}
1464
1465static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1466 struct snd_ctl_elem_value *ucontrol)
1467{
1468 struct user_element *ue = kcontrol->private_data;
1469 unsigned int size = ue->elem_data_size;
1470 char *src = ue->elem_data +
1471 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1472
1473 memcpy(&ucontrol->value, src, size);
1474 return 0;
1475}
1476
1477static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1478 struct snd_ctl_elem_value *ucontrol)
1479{
1480 int change;
1481 struct user_element *ue = kcontrol->private_data;
1482 unsigned int size = ue->elem_data_size;
1483 char *dst = ue->elem_data +
1484 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1485
1486 change = memcmp(&ucontrol->value, dst, size) != 0;
1487 if (change)
1488 memcpy(dst, &ucontrol->value, size);
1489 return change;
1490}
1491
1492/* called in controls_rwsem write lock */
1493static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1494 unsigned int size)
1495{
1496 struct user_element *ue = kctl->private_data;
1497 unsigned int *container;
1498 unsigned int mask = 0;
1499 int i;
1500 int change;
1501
1502 if (size > 1024 * 128) /* sane value */
1503 return -EINVAL;
1504
1505 // does the TLV size change cause overflow?
1506 if (check_user_elem_overflow(ue->card, (ssize_t)(size - ue->tlv_data_size)))
1507 return -ENOMEM;
1508
1509 container = vmemdup_user(buf, size);
1510 if (IS_ERR(container))
1511 return PTR_ERR(container);
1512
1513 change = ue->tlv_data_size != size;
1514 if (!change)
1515 change = memcmp(ue->tlv_data, container, size) != 0;
1516 if (!change) {
1517 kvfree(container);
1518 return 0;
1519 }
1520
1521 if (ue->tlv_data == NULL) {
1522 /* Now TLV data is available. */
1523 for (i = 0; i < kctl->count; ++i)
1524 kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
1525 mask = SNDRV_CTL_EVENT_MASK_INFO;
1526 } else {
1527 ue->card->user_ctl_alloc_size -= ue->tlv_data_size;
1528 ue->tlv_data_size = 0;
1529 kvfree(ue->tlv_data);
1530 }
1531
1532 ue->tlv_data = container;
1533 ue->tlv_data_size = size;
1534 // decremented at private_free.
1535 ue->card->user_ctl_alloc_size += size;
1536
1537 mask |= SNDRV_CTL_EVENT_MASK_TLV;
1538 for (i = 0; i < kctl->count; ++i)
1539 snd_ctl_notify_one(ue->card, mask, kctl, i);
1540
1541 return change;
1542}
1543
1544static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1545 unsigned int size)
1546{
1547 struct user_element *ue = kctl->private_data;
1548
1549 if (ue->tlv_data_size == 0 || ue->tlv_data == NULL)
1550 return -ENXIO;
1551
1552 if (size < ue->tlv_data_size)
1553 return -ENOSPC;
1554
1555 if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size))
1556 return -EFAULT;
1557
1558 return 0;
1559}
1560
1561static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag,
1562 unsigned int size, unsigned int __user *buf)
1563{
1564 if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
1565 return replace_user_tlv(kctl, buf, size);
1566 else
1567 return read_user_tlv(kctl, buf, size);
1568}
1569
1570/* called in controls_rwsem write lock */
1571static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1572{
1573 char *names, *p;
1574 size_t buf_len, name_len;
1575 unsigned int i;
1576 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1577
1578 buf_len = ue->info.value.enumerated.names_length;
1579 if (buf_len > 64 * 1024)
1580 return -EINVAL;
1581
1582 if (check_user_elem_overflow(ue->card, buf_len))
1583 return -ENOMEM;
1584 names = vmemdup_user((const void __user *)user_ptrval, buf_len);
1585 if (IS_ERR(names))
1586 return PTR_ERR(names);
1587
1588 /* check that there are enough valid names */
1589 p = names;
1590 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1591 name_len = strnlen(p, buf_len);
1592 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1593 kvfree(names);
1594 return -EINVAL;
1595 }
1596 p += name_len + 1;
1597 buf_len -= name_len + 1;
1598 }
1599
1600 ue->priv_data = names;
1601 ue->info.value.enumerated.names_ptr = 0;
1602 // increment the allocation size; decremented again at private_free.
1603 ue->card->user_ctl_alloc_size += ue->info.value.enumerated.names_length;
1604
1605 return 0;
1606}
1607
1608static size_t compute_user_elem_size(size_t size, unsigned int count)
1609{
1610 return sizeof(struct user_element) + size * count;
1611}
1612
1613static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1614{
1615 struct user_element *ue = kcontrol->private_data;
1616
1617 // decrement the allocation size.
1618 ue->card->user_ctl_alloc_size -= compute_user_elem_size(ue->elem_data_size, kcontrol->count);
1619 ue->card->user_ctl_alloc_size -= ue->tlv_data_size;
1620 if (ue->priv_data)
1621 ue->card->user_ctl_alloc_size -= ue->info.value.enumerated.names_length;
1622
1623 kvfree(ue->tlv_data);
1624 kvfree(ue->priv_data);
1625 kfree(ue);
1626}
1627
1628static int snd_ctl_elem_add(struct snd_ctl_file *file,
1629 struct snd_ctl_elem_info *info, int replace)
1630{
1631 struct snd_card *card = file->card;
1632 struct snd_kcontrol *kctl;
1633 unsigned int count;
1634 unsigned int access;
1635 long private_size;
1636 size_t alloc_size;
1637 struct user_element *ue;
1638 unsigned int offset;
1639 int err;
1640
1641 if (!*info->id.name)
1642 return -EINVAL;
1643 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1644 return -EINVAL;
1645
1646 /* Delete a control to replace them if needed. */
1647 if (replace) {
1648 info->id.numid = 0;
1649 err = snd_ctl_remove_user_ctl(file, &info->id);
1650 if (err)
1651 return err;
1652 }
1653
1654 /* Check the number of elements for this userspace control. */
1655 count = info->owner;
1656 if (count == 0)
1657 count = 1;
1658
1659 /* Arrange access permissions if needed. */
1660 access = info->access;
1661 if (access == 0)
1662 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1663 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1664 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1665 SNDRV_CTL_ELEM_ACCESS_TLV_WRITE);
1666
1667 /* In initial state, nothing is available as TLV container. */
1668 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1669 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1670 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1671
1672 /*
1673 * Check information and calculate the size of data specific to
1674 * this userspace control.
1675 */
1676 /* pass NULL to card for suppressing error messages */
1677 err = snd_ctl_check_elem_info(NULL, info);
1678 if (err < 0)
1679 return err;
1680 /* user-space control doesn't allow zero-size data */
1681 if (info->count < 1)
1682 return -EINVAL;
1683 private_size = value_sizes[info->type] * info->count;
1684 alloc_size = compute_user_elem_size(private_size, count);
1685
1686 down_write(&card->controls_rwsem);
1687 if (check_user_elem_overflow(card, alloc_size)) {
1688 err = -ENOMEM;
1689 goto unlock;
1690 }
1691
1692 /*
1693 * Keep memory object for this userspace control. After passing this
1694 * code block, the instance should be freed by snd_ctl_free_one().
1695 *
1696 * Note that these elements in this control are locked.
1697 */
1698 err = snd_ctl_new(&kctl, count, access, file);
1699 if (err < 0)
1700 goto unlock;
1701 memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1702 ue = kzalloc(alloc_size, GFP_KERNEL);
1703 if (!ue) {
1704 kfree(kctl);
1705 err = -ENOMEM;
1706 goto unlock;
1707 }
1708 kctl->private_data = ue;
1709 kctl->private_free = snd_ctl_elem_user_free;
1710
1711 // increment the allocated size; decremented again at private_free.
1712 card->user_ctl_alloc_size += alloc_size;
1713
1714 /* Set private data for this userspace control. */
1715 ue->card = card;
1716 ue->info = *info;
1717 ue->info.access = 0;
1718 ue->elem_data = (char *)ue + sizeof(*ue);
1719 ue->elem_data_size = private_size;
1720 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1721 err = snd_ctl_elem_init_enum_names(ue);
1722 if (err < 0) {
1723 snd_ctl_free_one(kctl);
1724 goto unlock;
1725 }
1726 }
1727
1728 /* Set callback functions. */
1729 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1730 kctl->info = snd_ctl_elem_user_enum_info;
1731 else
1732 kctl->info = snd_ctl_elem_user_info;
1733 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1734 kctl->get = snd_ctl_elem_user_get;
1735 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1736 kctl->put = snd_ctl_elem_user_put;
1737 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1738 kctl->tlv.c = snd_ctl_elem_user_tlv;
1739
1740 /* This function manage to free the instance on failure. */
1741 err = __snd_ctl_add_replace(card, kctl, CTL_ADD_EXCLUSIVE);
1742 if (err < 0) {
1743 snd_ctl_free_one(kctl);
1744 goto unlock;
1745 }
1746 offset = snd_ctl_get_ioff(kctl, &info->id);
1747 snd_ctl_build_ioff(&info->id, kctl, offset);
1748 /*
1749 * Here we cannot fill any field for the number of elements added by
1750 * this operation because there're no specific fields. The usage of
1751 * 'owner' field for this purpose may cause any bugs to userspace
1752 * applications because the field originally means PID of a process
1753 * which locks the element.
1754 */
1755 unlock:
1756 up_write(&card->controls_rwsem);
1757 return err;
1758}
1759
1760static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1761 struct snd_ctl_elem_info __user *_info, int replace)
1762{
1763 struct snd_ctl_elem_info info;
1764 int err;
1765
1766 if (copy_from_user(&info, _info, sizeof(info)))
1767 return -EFAULT;
1768 err = snd_ctl_elem_add(file, &info, replace);
1769 if (err < 0)
1770 return err;
1771 if (copy_to_user(_info, &info, sizeof(info))) {
1772 snd_ctl_remove_user_ctl(file, &info.id);
1773 return -EFAULT;
1774 }
1775
1776 return 0;
1777}
1778
1779static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1780 struct snd_ctl_elem_id __user *_id)
1781{
1782 struct snd_ctl_elem_id id;
1783
1784 if (copy_from_user(&id, _id, sizeof(id)))
1785 return -EFAULT;
1786 return snd_ctl_remove_user_ctl(file, &id);
1787}
1788
1789static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1790{
1791 int subscribe;
1792 if (get_user(subscribe, ptr))
1793 return -EFAULT;
1794 if (subscribe < 0) {
1795 subscribe = file->subscribed;
1796 if (put_user(subscribe, ptr))
1797 return -EFAULT;
1798 return 0;
1799 }
1800 if (subscribe) {
1801 file->subscribed = 1;
1802 return 0;
1803 } else if (file->subscribed) {
1804 snd_ctl_empty_read_queue(file);
1805 file->subscribed = 0;
1806 }
1807 return 0;
1808}
1809
1810static int call_tlv_handler(struct snd_ctl_file *file, int op_flag,
1811 struct snd_kcontrol *kctl,
1812 struct snd_ctl_elem_id *id,
1813 unsigned int __user *buf, unsigned int size)
1814{
1815 static const struct {
1816 int op;
1817 int perm;
1818 } pairs[] = {
1819 {SNDRV_CTL_TLV_OP_READ, SNDRV_CTL_ELEM_ACCESS_TLV_READ},
1820 {SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE},
1821 {SNDRV_CTL_TLV_OP_CMD, SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND},
1822 };
1823 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1824 int i, ret;
1825
1826 /* Check support of the request for this element. */
1827 for (i = 0; i < ARRAY_SIZE(pairs); ++i) {
1828 if (op_flag == pairs[i].op && (vd->access & pairs[i].perm))
1829 break;
1830 }
1831 if (i == ARRAY_SIZE(pairs))
1832 return -ENXIO;
1833
1834 if (kctl->tlv.c == NULL)
1835 return -ENXIO;
1836
1837 /* Write and command operations are not allowed for locked element. */
1838 if (op_flag != SNDRV_CTL_TLV_OP_READ &&
1839 vd->owner != NULL && vd->owner != file)
1840 return -EPERM;
1841
1842 ret = snd_power_ref_and_wait(file->card);
1843 if (!ret)
1844 ret = kctl->tlv.c(kctl, op_flag, size, buf);
1845 snd_power_unref(file->card);
1846 return ret;
1847}
1848
1849static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id,
1850 unsigned int __user *buf, unsigned int size)
1851{
1852 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1853 unsigned int len;
1854
1855 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ))
1856 return -ENXIO;
1857
1858 if (kctl->tlv.p == NULL)
1859 return -ENXIO;
1860
1861 len = sizeof(unsigned int) * 2 + kctl->tlv.p[1];
1862 if (size < len)
1863 return -ENOMEM;
1864
1865 if (copy_to_user(buf, kctl->tlv.p, len))
1866 return -EFAULT;
1867
1868 return 0;
1869}
1870
1871static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1872 struct snd_ctl_tlv __user *buf,
1873 int op_flag)
1874{
1875 struct snd_ctl_tlv header;
1876 unsigned int __user *container;
1877 unsigned int container_size;
1878 struct snd_kcontrol *kctl;
1879 struct snd_ctl_elem_id id;
1880 struct snd_kcontrol_volatile *vd;
1881
1882 if (copy_from_user(&header, buf, sizeof(header)))
1883 return -EFAULT;
1884
1885 /* In design of control core, numerical ID starts at 1. */
1886 if (header.numid == 0)
1887 return -EINVAL;
1888
1889 /* At least, container should include type and length fields. */
1890 if (header.length < sizeof(unsigned int) * 2)
1891 return -EINVAL;
1892 container_size = header.length;
1893 container = buf->tlv;
1894
1895 kctl = snd_ctl_find_numid(file->card, header.numid);
1896 if (kctl == NULL)
1897 return -ENOENT;
1898
1899 /* Calculate index of the element in this set. */
1900 id = kctl->id;
1901 snd_ctl_build_ioff(&id, kctl, header.numid - id.numid);
1902 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1903
1904 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1905 return call_tlv_handler(file, op_flag, kctl, &id, container,
1906 container_size);
1907 } else {
1908 if (op_flag == SNDRV_CTL_TLV_OP_READ) {
1909 return read_tlv_buf(kctl, &id, container,
1910 container_size);
1911 }
1912 }
1913
1914 /* Not supported. */
1915 return -ENXIO;
1916}
1917
1918static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1919{
1920 struct snd_ctl_file *ctl;
1921 struct snd_card *card;
1922 struct snd_kctl_ioctl *p;
1923 void __user *argp = (void __user *)arg;
1924 int __user *ip = argp;
1925 int err;
1926
1927 ctl = file->private_data;
1928 card = ctl->card;
1929 if (snd_BUG_ON(!card))
1930 return -ENXIO;
1931 switch (cmd) {
1932 case SNDRV_CTL_IOCTL_PVERSION:
1933 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1934 case SNDRV_CTL_IOCTL_CARD_INFO:
1935 return snd_ctl_card_info(card, ctl, cmd, argp);
1936 case SNDRV_CTL_IOCTL_ELEM_LIST:
1937 return snd_ctl_elem_list_user(card, argp);
1938 case SNDRV_CTL_IOCTL_ELEM_INFO:
1939 return snd_ctl_elem_info_user(ctl, argp);
1940 case SNDRV_CTL_IOCTL_ELEM_READ:
1941 return snd_ctl_elem_read_user(card, argp);
1942 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1943 return snd_ctl_elem_write_user(ctl, argp);
1944 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1945 return snd_ctl_elem_lock(ctl, argp);
1946 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1947 return snd_ctl_elem_unlock(ctl, argp);
1948 case SNDRV_CTL_IOCTL_ELEM_ADD:
1949 return snd_ctl_elem_add_user(ctl, argp, 0);
1950 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1951 return snd_ctl_elem_add_user(ctl, argp, 1);
1952 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1953 return snd_ctl_elem_remove(ctl, argp);
1954 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1955 return snd_ctl_subscribe_events(ctl, ip);
1956 case SNDRV_CTL_IOCTL_TLV_READ:
1957 down_read(&ctl->card->controls_rwsem);
1958 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1959 up_read(&ctl->card->controls_rwsem);
1960 return err;
1961 case SNDRV_CTL_IOCTL_TLV_WRITE:
1962 down_write(&ctl->card->controls_rwsem);
1963 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1964 up_write(&ctl->card->controls_rwsem);
1965 return err;
1966 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1967 down_write(&ctl->card->controls_rwsem);
1968 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1969 up_write(&ctl->card->controls_rwsem);
1970 return err;
1971 case SNDRV_CTL_IOCTL_POWER:
1972 return -ENOPROTOOPT;
1973 case SNDRV_CTL_IOCTL_POWER_STATE:
1974 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1975 }
1976 down_read(&snd_ioctl_rwsem);
1977 list_for_each_entry(p, &snd_control_ioctls, list) {
1978 err = p->fioctl(card, ctl, cmd, arg);
1979 if (err != -ENOIOCTLCMD) {
1980 up_read(&snd_ioctl_rwsem);
1981 return err;
1982 }
1983 }
1984 up_read(&snd_ioctl_rwsem);
1985 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1986 return -ENOTTY;
1987}
1988
1989static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1990 size_t count, loff_t * offset)
1991{
1992 struct snd_ctl_file *ctl;
1993 int err = 0;
1994 ssize_t result = 0;
1995
1996 ctl = file->private_data;
1997 if (snd_BUG_ON(!ctl || !ctl->card))
1998 return -ENXIO;
1999 if (!ctl->subscribed)
2000 return -EBADFD;
2001 if (count < sizeof(struct snd_ctl_event))
2002 return -EINVAL;
2003 spin_lock_irq(&ctl->read_lock);
2004 while (count >= sizeof(struct snd_ctl_event)) {
2005 struct snd_ctl_event ev;
2006 struct snd_kctl_event *kev;
2007 while (list_empty(&ctl->events)) {
2008 wait_queue_entry_t wait;
2009 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
2010 err = -EAGAIN;
2011 goto __end_lock;
2012 }
2013 init_waitqueue_entry(&wait, current);
2014 add_wait_queue(&ctl->change_sleep, &wait);
2015 set_current_state(TASK_INTERRUPTIBLE);
2016 spin_unlock_irq(&ctl->read_lock);
2017 schedule();
2018 remove_wait_queue(&ctl->change_sleep, &wait);
2019 if (ctl->card->shutdown)
2020 return -ENODEV;
2021 if (signal_pending(current))
2022 return -ERESTARTSYS;
2023 spin_lock_irq(&ctl->read_lock);
2024 }
2025 kev = snd_kctl_event(ctl->events.next);
2026 ev.type = SNDRV_CTL_EVENT_ELEM;
2027 ev.data.elem.mask = kev->mask;
2028 ev.data.elem.id = kev->id;
2029 list_del(&kev->list);
2030 spin_unlock_irq(&ctl->read_lock);
2031 kfree(kev);
2032 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
2033 err = -EFAULT;
2034 goto __end;
2035 }
2036 spin_lock_irq(&ctl->read_lock);
2037 buffer += sizeof(struct snd_ctl_event);
2038 count -= sizeof(struct snd_ctl_event);
2039 result += sizeof(struct snd_ctl_event);
2040 }
2041 __end_lock:
2042 spin_unlock_irq(&ctl->read_lock);
2043 __end:
2044 return result > 0 ? result : err;
2045}
2046
2047static __poll_t snd_ctl_poll(struct file *file, poll_table * wait)
2048{
2049 __poll_t mask;
2050 struct snd_ctl_file *ctl;
2051
2052 ctl = file->private_data;
2053 if (!ctl->subscribed)
2054 return 0;
2055 poll_wait(file, &ctl->change_sleep, wait);
2056
2057 mask = 0;
2058 if (!list_empty(&ctl->events))
2059 mask |= EPOLLIN | EPOLLRDNORM;
2060
2061 return mask;
2062}
2063
2064/*
2065 * register the device-specific control-ioctls.
2066 * called from each device manager like pcm.c, hwdep.c, etc.
2067 */
2068static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
2069{
2070 struct snd_kctl_ioctl *pn;
2071
2072 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
2073 if (pn == NULL)
2074 return -ENOMEM;
2075 pn->fioctl = fcn;
2076 down_write(&snd_ioctl_rwsem);
2077 list_add_tail(&pn->list, lists);
2078 up_write(&snd_ioctl_rwsem);
2079 return 0;
2080}
2081
2082/**
2083 * snd_ctl_register_ioctl - register the device-specific control-ioctls
2084 * @fcn: ioctl callback function
2085 *
2086 * called from each device manager like pcm.c, hwdep.c, etc.
2087 *
2088 * Return: zero if successful, or a negative error code
2089 */
2090int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
2091{
2092 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
2093}
2094EXPORT_SYMBOL(snd_ctl_register_ioctl);
2095
2096#ifdef CONFIG_COMPAT
2097/**
2098 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
2099 * control-ioctls
2100 * @fcn: ioctl callback function
2101 *
2102 * Return: zero if successful, or a negative error code
2103 */
2104int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
2105{
2106 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
2107}
2108EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
2109#endif
2110
2111/*
2112 * de-register the device-specific control-ioctls.
2113 */
2114static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
2115 struct list_head *lists)
2116{
2117 struct snd_kctl_ioctl *p;
2118
2119 if (snd_BUG_ON(!fcn))
2120 return -EINVAL;
2121 down_write(&snd_ioctl_rwsem);
2122 list_for_each_entry(p, lists, list) {
2123 if (p->fioctl == fcn) {
2124 list_del(&p->list);
2125 up_write(&snd_ioctl_rwsem);
2126 kfree(p);
2127 return 0;
2128 }
2129 }
2130 up_write(&snd_ioctl_rwsem);
2131 snd_BUG();
2132 return -EINVAL;
2133}
2134
2135/**
2136 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
2137 * @fcn: ioctl callback function to unregister
2138 *
2139 * Return: zero if successful, or a negative error code
2140 */
2141int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
2142{
2143 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
2144}
2145EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
2146
2147#ifdef CONFIG_COMPAT
2148/**
2149 * snd_ctl_unregister_ioctl_compat - de-register the device-specific compat
2150 * 32bit control-ioctls
2151 * @fcn: ioctl callback function to unregister
2152 *
2153 * Return: zero if successful, or a negative error code
2154 */
2155int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
2156{
2157 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
2158}
2159EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
2160#endif
2161
2162static int snd_ctl_fasync(int fd, struct file * file, int on)
2163{
2164 struct snd_ctl_file *ctl;
2165
2166 ctl = file->private_data;
2167 return snd_fasync_helper(fd, file, on, &ctl->fasync);
2168}
2169
2170/* return the preferred subdevice number if already assigned;
2171 * otherwise return -1
2172 */
2173int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
2174{
2175 struct snd_ctl_file *kctl;
2176 int subdevice = -1;
2177 unsigned long flags;
2178
2179 read_lock_irqsave(&card->ctl_files_rwlock, flags);
2180 list_for_each_entry(kctl, &card->ctl_files, list) {
2181 if (kctl->pid == task_pid(current)) {
2182 subdevice = kctl->preferred_subdevice[type];
2183 if (subdevice != -1)
2184 break;
2185 }
2186 }
2187 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
2188 return subdevice;
2189}
2190EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
2191
2192/*
2193 * ioctl32 compat
2194 */
2195#ifdef CONFIG_COMPAT
2196#include "control_compat.c"
2197#else
2198#define snd_ctl_ioctl_compat NULL
2199#endif
2200
2201/*
2202 * control layers (audio LED etc.)
2203 */
2204
2205/**
2206 * snd_ctl_request_layer - request to use the layer
2207 * @module_name: Name of the kernel module (NULL == build-in)
2208 *
2209 * Return: zero if successful, or an error code when the module cannot be loaded
2210 */
2211int snd_ctl_request_layer(const char *module_name)
2212{
2213 struct snd_ctl_layer_ops *lops;
2214
2215 if (module_name == NULL)
2216 return 0;
2217 down_read(&snd_ctl_layer_rwsem);
2218 for (lops = snd_ctl_layer; lops; lops = lops->next)
2219 if (strcmp(lops->module_name, module_name) == 0)
2220 break;
2221 up_read(&snd_ctl_layer_rwsem);
2222 if (lops)
2223 return 0;
2224 return request_module(module_name);
2225}
2226EXPORT_SYMBOL_GPL(snd_ctl_request_layer);
2227
2228/**
2229 * snd_ctl_register_layer - register new control layer
2230 * @lops: operation structure
2231 *
2232 * The new layer can track all control elements and do additional
2233 * operations on top (like audio LED handling).
2234 */
2235void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops)
2236{
2237 struct snd_card *card;
2238 int card_number;
2239
2240 down_write(&snd_ctl_layer_rwsem);
2241 lops->next = snd_ctl_layer;
2242 snd_ctl_layer = lops;
2243 up_write(&snd_ctl_layer_rwsem);
2244 for (card_number = 0; card_number < SNDRV_CARDS; card_number++) {
2245 card = snd_card_ref(card_number);
2246 if (card) {
2247 down_read(&card->controls_rwsem);
2248 lops->lregister(card);
2249 up_read(&card->controls_rwsem);
2250 snd_card_unref(card);
2251 }
2252 }
2253}
2254EXPORT_SYMBOL_GPL(snd_ctl_register_layer);
2255
2256/**
2257 * snd_ctl_disconnect_layer - disconnect control layer
2258 * @lops: operation structure
2259 *
2260 * It is expected that the information about tracked cards
2261 * is freed before this call (the disconnect callback is
2262 * not called here).
2263 */
2264void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops)
2265{
2266 struct snd_ctl_layer_ops *lops2, *prev_lops2;
2267
2268 down_write(&snd_ctl_layer_rwsem);
2269 for (lops2 = snd_ctl_layer, prev_lops2 = NULL; lops2; lops2 = lops2->next) {
2270 if (lops2 == lops) {
2271 if (!prev_lops2)
2272 snd_ctl_layer = lops->next;
2273 else
2274 prev_lops2->next = lops->next;
2275 break;
2276 }
2277 prev_lops2 = lops2;
2278 }
2279 up_write(&snd_ctl_layer_rwsem);
2280}
2281EXPORT_SYMBOL_GPL(snd_ctl_disconnect_layer);
2282
2283/*
2284 * INIT PART
2285 */
2286
2287static const struct file_operations snd_ctl_f_ops =
2288{
2289 .owner = THIS_MODULE,
2290 .read = snd_ctl_read,
2291 .open = snd_ctl_open,
2292 .release = snd_ctl_release,
2293 .llseek = no_llseek,
2294 .poll = snd_ctl_poll,
2295 .unlocked_ioctl = snd_ctl_ioctl,
2296 .compat_ioctl = snd_ctl_ioctl_compat,
2297 .fasync = snd_ctl_fasync,
2298};
2299
2300/*
2301 * registration of the control device
2302 */
2303static int snd_ctl_dev_register(struct snd_device *device)
2304{
2305 struct snd_card *card = device->device_data;
2306 struct snd_ctl_layer_ops *lops;
2307 int err;
2308
2309 err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
2310 &snd_ctl_f_ops, card, &card->ctl_dev);
2311 if (err < 0)
2312 return err;
2313 down_read(&card->controls_rwsem);
2314 down_read(&snd_ctl_layer_rwsem);
2315 for (lops = snd_ctl_layer; lops; lops = lops->next)
2316 lops->lregister(card);
2317 up_read(&snd_ctl_layer_rwsem);
2318 up_read(&card->controls_rwsem);
2319 return 0;
2320}
2321
2322/*
2323 * disconnection of the control device
2324 */
2325static int snd_ctl_dev_disconnect(struct snd_device *device)
2326{
2327 struct snd_card *card = device->device_data;
2328 struct snd_ctl_file *ctl;
2329 struct snd_ctl_layer_ops *lops;
2330 unsigned long flags;
2331
2332 read_lock_irqsave(&card->ctl_files_rwlock, flags);
2333 list_for_each_entry(ctl, &card->ctl_files, list) {
2334 wake_up(&ctl->change_sleep);
2335 snd_kill_fasync(ctl->fasync, SIGIO, POLL_ERR);
2336 }
2337 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
2338
2339 down_read(&card->controls_rwsem);
2340 down_read(&snd_ctl_layer_rwsem);
2341 for (lops = snd_ctl_layer; lops; lops = lops->next)
2342 lops->ldisconnect(card);
2343 up_read(&snd_ctl_layer_rwsem);
2344 up_read(&card->controls_rwsem);
2345
2346 return snd_unregister_device(&card->ctl_dev);
2347}
2348
2349/*
2350 * free all controls
2351 */
2352static int snd_ctl_dev_free(struct snd_device *device)
2353{
2354 struct snd_card *card = device->device_data;
2355 struct snd_kcontrol *control;
2356
2357 down_write(&card->controls_rwsem);
2358 while (!list_empty(&card->controls)) {
2359 control = snd_kcontrol(card->controls.next);
2360 __snd_ctl_remove(card, control, false);
2361 }
2362
2363#ifdef CONFIG_SND_CTL_FAST_LOOKUP
2364 xa_destroy(&card->ctl_numids);
2365 xa_destroy(&card->ctl_hash);
2366#endif
2367 up_write(&card->controls_rwsem);
2368 put_device(&card->ctl_dev);
2369 return 0;
2370}
2371
2372/*
2373 * create control core:
2374 * called from init.c
2375 */
2376int snd_ctl_create(struct snd_card *card)
2377{
2378 static const struct snd_device_ops ops = {
2379 .dev_free = snd_ctl_dev_free,
2380 .dev_register = snd_ctl_dev_register,
2381 .dev_disconnect = snd_ctl_dev_disconnect,
2382 };
2383 int err;
2384
2385 if (snd_BUG_ON(!card))
2386 return -ENXIO;
2387 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
2388 return -ENXIO;
2389
2390 snd_device_initialize(&card->ctl_dev, card);
2391 dev_set_name(&card->ctl_dev, "controlC%d", card->number);
2392
2393 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
2394 if (err < 0)
2395 put_device(&card->ctl_dev);
2396 return err;
2397}
2398
2399/*
2400 * Frequently used control callbacks/helpers
2401 */
2402
2403/**
2404 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
2405 * callback with a mono channel
2406 * @kcontrol: the kcontrol instance
2407 * @uinfo: info to store
2408 *
2409 * This is a function that can be used as info callback for a standard
2410 * boolean control with a single mono channel.
2411 *
2412 * Return: Zero (always successful)
2413 */
2414int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
2415 struct snd_ctl_elem_info *uinfo)
2416{
2417 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
2418 uinfo->count = 1;
2419 uinfo->value.integer.min = 0;
2420 uinfo->value.integer.max = 1;
2421 return 0;
2422}
2423EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
2424
2425/**
2426 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
2427 * callback with stereo two channels
2428 * @kcontrol: the kcontrol instance
2429 * @uinfo: info to store
2430 *
2431 * This is a function that can be used as info callback for a standard
2432 * boolean control with stereo two channels.
2433 *
2434 * Return: Zero (always successful)
2435 */
2436int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
2437 struct snd_ctl_elem_info *uinfo)
2438{
2439 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
2440 uinfo->count = 2;
2441 uinfo->value.integer.min = 0;
2442 uinfo->value.integer.max = 1;
2443 return 0;
2444}
2445EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
2446
2447/**
2448 * snd_ctl_enum_info - fills the info structure for an enumerated control
2449 * @info: the structure to be filled
2450 * @channels: the number of the control's channels; often one
2451 * @items: the number of control values; also the size of @names
2452 * @names: an array containing the names of all control values
2453 *
2454 * Sets all required fields in @info to their appropriate values.
2455 * If the control's accessibility is not the default (readable and writable),
2456 * the caller has to fill @info->access.
2457 *
2458 * Return: Zero (always successful)
2459 */
2460int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
2461 unsigned int items, const char *const names[])
2462{
2463 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
2464 info->count = channels;
2465 info->value.enumerated.items = items;
2466 if (!items)
2467 return 0;
2468 if (info->value.enumerated.item >= items)
2469 info->value.enumerated.item = items - 1;
2470 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
2471 "ALSA: too long item name '%s'\n",
2472 names[info->value.enumerated.item]);
2473 strscpy(info->value.enumerated.name,
2474 names[info->value.enumerated.item],
2475 sizeof(info->value.enumerated.name));
2476 return 0;
2477}
2478EXPORT_SYMBOL(snd_ctl_enum_info);