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TOMOYO Linux Cross Reference
Linux/sound/core/control.c

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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 
 37 struct snd_kctl_ioctl {
 38         struct list_head list;          /* list of all ioctls */
 39         snd_kctl_ioctl_func_t fioctl;
 40 };
 41 
 42 static DECLARE_RWSEM(snd_ioctl_rwsem);
 43 static LIST_HEAD(snd_control_ioctls);
 44 #ifdef CONFIG_COMPAT
 45 static LIST_HEAD(snd_control_compat_ioctls);
 46 #endif
 47 
 48 static 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 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         ctl->prefer_pcm_subdevice = -1;
 83         ctl->prefer_rawmidi_subdevice = -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 
102 static 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 
116 static 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 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
145                     struct snd_ctl_elem_id *id)
146 {
147         unsigned long flags;
148         struct snd_ctl_file *ctl;
149         struct snd_kctl_event *ev;
150         
151         if (snd_BUG_ON(!card || !id))
152                 return;
153         if (card->shutdown)
154                 return;
155         read_lock(&card->ctl_files_rwlock);
156 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
157         card->mixer_oss_change_count++;
158 #endif
159         list_for_each_entry(ctl, &card->ctl_files, list) {
160                 if (!ctl->subscribed)
161                         continue;
162                 spin_lock_irqsave(&ctl->read_lock, flags);
163                 list_for_each_entry(ev, &ctl->events, list) {
164                         if (ev->id.numid == id->numid) {
165                                 ev->mask |= mask;
166                                 goto _found;
167                         }
168                 }
169                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
170                 if (ev) {
171                         ev->id = *id;
172                         ev->mask = mask;
173                         list_add_tail(&ev->list, &ctl->events);
174                 } else {
175                         snd_printk(KERN_ERR "No memory available to allocate event\n");
176                 }
177         _found:
178                 wake_up(&ctl->change_sleep);
179                 spin_unlock_irqrestore(&ctl->read_lock, flags);
180                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
181         }
182         read_unlock(&card->ctl_files_rwlock);
183 }
184 
185 EXPORT_SYMBOL(snd_ctl_notify);
186 
187 /**
188  * snd_ctl_new - create a control instance from the template
189  * @control: the control template
190  * @access: the default control access
191  *
192  * Allocates a new struct snd_kcontrol instance and copies the given template 
193  * to the new instance. It does not copy volatile data (access).
194  *
195  * Return: The pointer of the new instance, or %NULL on failure.
196  */
197 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
198                                         unsigned int access)
199 {
200         struct snd_kcontrol *kctl;
201         unsigned int idx;
202         
203         if (snd_BUG_ON(!control || !control->count))
204                 return NULL;
205 
206         if (control->count > MAX_CONTROL_COUNT)
207                 return NULL;
208 
209         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
210         if (kctl == NULL) {
211                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
212                 return NULL;
213         }
214         *kctl = *control;
215         for (idx = 0; idx < kctl->count; idx++)
216                 kctl->vd[idx].access = access;
217         return kctl;
218 }
219 
220 /**
221  * snd_ctl_new1 - create a control instance from the template
222  * @ncontrol: the initialization record
223  * @private_data: the private data to set
224  *
225  * Allocates a new struct snd_kcontrol instance and initialize from the given 
226  * template.  When the access field of ncontrol is 0, it's assumed as
227  * READWRITE access. When the count field is 0, it's assumes as one.
228  *
229  * Return: The pointer of the newly generated instance, or %NULL on failure.
230  */
231 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
232                                   void *private_data)
233 {
234         struct snd_kcontrol kctl;
235         unsigned int access;
236         
237         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
238                 return NULL;
239         memset(&kctl, 0, sizeof(kctl));
240         kctl.id.iface = ncontrol->iface;
241         kctl.id.device = ncontrol->device;
242         kctl.id.subdevice = ncontrol->subdevice;
243         if (ncontrol->name) {
244                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
245                 if (strcmp(ncontrol->name, kctl.id.name) != 0)
246                         snd_printk(KERN_WARNING
247                                    "Control name '%s' truncated to '%s'\n",
248                                    ncontrol->name, kctl.id.name);
249         }
250         kctl.id.index = ncontrol->index;
251         kctl.count = ncontrol->count ? ncontrol->count : 1;
252         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
253                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
254                                       SNDRV_CTL_ELEM_ACCESS_VOLATILE|
255                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
256                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
257                                       SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
258                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
259         kctl.info = ncontrol->info;
260         kctl.get = ncontrol->get;
261         kctl.put = ncontrol->put;
262         kctl.tlv.p = ncontrol->tlv.p;
263         kctl.private_value = ncontrol->private_value;
264         kctl.private_data = private_data;
265         return snd_ctl_new(&kctl, access);
266 }
267 
268 EXPORT_SYMBOL(snd_ctl_new1);
269 
270 /**
271  * snd_ctl_free_one - release the control instance
272  * @kcontrol: the control instance
273  *
274  * Releases the control instance created via snd_ctl_new()
275  * or snd_ctl_new1().
276  * Don't call this after the control was added to the card.
277  */
278 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
279 {
280         if (kcontrol) {
281                 if (kcontrol->private_free)
282                         kcontrol->private_free(kcontrol);
283                 kfree(kcontrol);
284         }
285 }
286 
287 EXPORT_SYMBOL(snd_ctl_free_one);
288 
289 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
290                                           unsigned int count)
291 {
292         struct snd_kcontrol *kctl;
293 
294         /* Make sure that the ids assigned to the control do not wrap around */
295         if (card->last_numid >= UINT_MAX - count)
296                 card->last_numid = 0;
297 
298         list_for_each_entry(kctl, &card->controls, list) {
299                 if (kctl->id.numid < card->last_numid + 1 + count &&
300                     kctl->id.numid + kctl->count > card->last_numid + 1) {
301                         card->last_numid = kctl->id.numid + kctl->count - 1;
302                         return true;
303                 }
304         }
305         return false;
306 }
307 
308 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
309 {
310         unsigned int iter = 100000;
311 
312         while (snd_ctl_remove_numid_conflict(card, count)) {
313                 if (--iter == 0) {
314                         /* this situation is very unlikely */
315                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
316                         return -ENOMEM;
317                 }
318         }
319         return 0;
320 }
321 
322 /**
323  * snd_ctl_add - add the control instance to the card
324  * @card: the card instance
325  * @kcontrol: the control instance to add
326  *
327  * Adds the control instance created via snd_ctl_new() or
328  * snd_ctl_new1() to the given card. Assigns also an unique
329  * numid used for fast search.
330  *
331  * It frees automatically the control which cannot be added.
332  *
333  * Return: Zero if successful, or a negative error code on failure.
334  *
335  */
336 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
337 {
338         struct snd_ctl_elem_id id;
339         unsigned int idx;
340         unsigned int count;
341         int err = -EINVAL;
342 
343         if (! kcontrol)
344                 return err;
345         if (snd_BUG_ON(!card || !kcontrol->info))
346                 goto error;
347         id = kcontrol->id;
348         if (id.index > UINT_MAX - kcontrol->count)
349                 goto error;
350 
351         down_write(&card->controls_rwsem);
352         if (snd_ctl_find_id(card, &id)) {
353                 up_write(&card->controls_rwsem);
354                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
355                                         id.iface,
356                                         id.device,
357                                         id.subdevice,
358                                         id.name,
359                                         id.index);
360                 err = -EBUSY;
361                 goto error;
362         }
363         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
364                 up_write(&card->controls_rwsem);
365                 err = -ENOMEM;
366                 goto error;
367         }
368         list_add_tail(&kcontrol->list, &card->controls);
369         card->controls_count += kcontrol->count;
370         kcontrol->id.numid = card->last_numid + 1;
371         card->last_numid += kcontrol->count;
372         count = kcontrol->count;
373         up_write(&card->controls_rwsem);
374         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
375                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
376         return 0;
377 
378  error:
379         snd_ctl_free_one(kcontrol);
380         return err;
381 }
382 
383 EXPORT_SYMBOL(snd_ctl_add);
384 
385 /**
386  * snd_ctl_replace - replace the control instance of the card
387  * @card: the card instance
388  * @kcontrol: the control instance to replace
389  * @add_on_replace: add the control if not already added
390  *
391  * Replaces the given control.  If the given control does not exist
392  * and the add_on_replace flag is set, the control is added.  If the
393  * control exists, it is destroyed first.
394  *
395  * It frees automatically the control which cannot be added or replaced.
396  *
397  * Return: Zero if successful, or a negative error code on failure.
398  */
399 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
400                     bool add_on_replace)
401 {
402         struct snd_ctl_elem_id id;
403         unsigned int count;
404         unsigned int idx;
405         struct snd_kcontrol *old;
406         int ret;
407 
408         if (!kcontrol)
409                 return -EINVAL;
410         if (snd_BUG_ON(!card || !kcontrol->info)) {
411                 ret = -EINVAL;
412                 goto error;
413         }
414         id = kcontrol->id;
415         down_write(&card->controls_rwsem);
416         old = snd_ctl_find_id(card, &id);
417         if (!old) {
418                 if (add_on_replace)
419                         goto add;
420                 up_write(&card->controls_rwsem);
421                 ret = -EINVAL;
422                 goto error;
423         }
424         ret = snd_ctl_remove(card, old);
425         if (ret < 0) {
426                 up_write(&card->controls_rwsem);
427                 goto error;
428         }
429 add:
430         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
431                 up_write(&card->controls_rwsem);
432                 ret = -ENOMEM;
433                 goto error;
434         }
435         list_add_tail(&kcontrol->list, &card->controls);
436         card->controls_count += kcontrol->count;
437         kcontrol->id.numid = card->last_numid + 1;
438         card->last_numid += kcontrol->count;
439         count = kcontrol->count;
440         up_write(&card->controls_rwsem);
441         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
442                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
443         return 0;
444 
445 error:
446         snd_ctl_free_one(kcontrol);
447         return ret;
448 }
449 EXPORT_SYMBOL(snd_ctl_replace);
450 
451 /**
452  * snd_ctl_remove - remove the control from the card and release it
453  * @card: the card instance
454  * @kcontrol: the control instance to remove
455  *
456  * Removes the control from the card and then releases the instance.
457  * You don't need to call snd_ctl_free_one(). You must be in
458  * the write lock - down_write(&card->controls_rwsem).
459  *
460  * Return: 0 if successful, or a negative error code on failure.
461  */
462 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
463 {
464         struct snd_ctl_elem_id id;
465         unsigned int idx;
466 
467         if (snd_BUG_ON(!card || !kcontrol))
468                 return -EINVAL;
469         list_del(&kcontrol->list);
470         card->controls_count -= kcontrol->count;
471         id = kcontrol->id;
472         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
473                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
474         snd_ctl_free_one(kcontrol);
475         return 0;
476 }
477 
478 EXPORT_SYMBOL(snd_ctl_remove);
479 
480 /**
481  * snd_ctl_remove_id - remove the control of the given id and release it
482  * @card: the card instance
483  * @id: the control id to remove
484  *
485  * Finds the control instance with the given id, removes it from the
486  * card list and releases it.
487  *
488  * Return: 0 if successful, or a negative error code on failure.
489  */
490 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
491 {
492         struct snd_kcontrol *kctl;
493         int ret;
494 
495         down_write(&card->controls_rwsem);
496         kctl = snd_ctl_find_id(card, id);
497         if (kctl == NULL) {
498                 up_write(&card->controls_rwsem);
499                 return -ENOENT;
500         }
501         ret = snd_ctl_remove(card, kctl);
502         up_write(&card->controls_rwsem);
503         return ret;
504 }
505 
506 EXPORT_SYMBOL(snd_ctl_remove_id);
507 
508 /**
509  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
510  * @file: active control handle
511  * @id: the control id to remove
512  *
513  * Finds the control instance with the given id, removes it from the
514  * card list and releases it.
515  *
516  * Return: 0 if successful, or a negative error code on failure.
517  */
518 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
519                                    struct snd_ctl_elem_id *id)
520 {
521         struct snd_card *card = file->card;
522         struct snd_kcontrol *kctl;
523         int idx, ret;
524 
525         down_write(&card->controls_rwsem);
526         kctl = snd_ctl_find_id(card, id);
527         if (kctl == NULL) {
528                 ret = -ENOENT;
529                 goto error;
530         }
531         if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
532                 ret = -EINVAL;
533                 goto error;
534         }
535         for (idx = 0; idx < kctl->count; idx++)
536                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
537                         ret = -EBUSY;
538                         goto error;
539                 }
540         ret = snd_ctl_remove(card, kctl);
541         if (ret < 0)
542                 goto error;
543         card->user_ctl_count--;
544 error:
545         up_write(&card->controls_rwsem);
546         return ret;
547 }
548 
549 /**
550  * snd_ctl_activate_id - activate/inactivate the control of the given id
551  * @card: the card instance
552  * @id: the control id to activate/inactivate
553  * @active: non-zero to activate
554  *
555  * Finds the control instance with the given id, and activate or
556  * inactivate the control together with notification, if changed.
557  *
558  * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
559  */
560 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
561                         int active)
562 {
563         struct snd_kcontrol *kctl;
564         struct snd_kcontrol_volatile *vd;
565         unsigned int index_offset;
566         int ret;
567 
568         down_write(&card->controls_rwsem);
569         kctl = snd_ctl_find_id(card, id);
570         if (kctl == NULL) {
571                 ret = -ENOENT;
572                 goto unlock;
573         }
574         index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
575         vd = &kctl->vd[index_offset];
576         ret = 0;
577         if (active) {
578                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
579                         goto unlock;
580                 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
581         } else {
582                 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
583                         goto unlock;
584                 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
585         }
586         ret = 1;
587  unlock:
588         up_write(&card->controls_rwsem);
589         if (ret > 0)
590                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
591         return ret;
592 }
593 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
594 
595 /**
596  * snd_ctl_rename_id - replace the id of a control on the card
597  * @card: the card instance
598  * @src_id: the old id
599  * @dst_id: the new id
600  *
601  * Finds the control with the old id from the card, and replaces the
602  * id with the new one.
603  *
604  * Return: Zero if successful, or a negative error code on failure.
605  */
606 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
607                       struct snd_ctl_elem_id *dst_id)
608 {
609         struct snd_kcontrol *kctl;
610 
611         down_write(&card->controls_rwsem);
612         kctl = snd_ctl_find_id(card, src_id);
613         if (kctl == NULL) {
614                 up_write(&card->controls_rwsem);
615                 return -ENOENT;
616         }
617         kctl->id = *dst_id;
618         kctl->id.numid = card->last_numid + 1;
619         card->last_numid += kctl->count;
620         up_write(&card->controls_rwsem);
621         return 0;
622 }
623 
624 EXPORT_SYMBOL(snd_ctl_rename_id);
625 
626 /**
627  * snd_ctl_find_numid - find the control instance with the given number-id
628  * @card: the card instance
629  * @numid: the number-id to search
630  *
631  * Finds the control instance with the given number-id from the card.
632  *
633  * The caller must down card->controls_rwsem before calling this function
634  * (if the race condition can happen).
635  *
636  * Return: The pointer of the instance if found, or %NULL if not.
637  *
638  */
639 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
640 {
641         struct snd_kcontrol *kctl;
642 
643         if (snd_BUG_ON(!card || !numid))
644                 return NULL;
645         list_for_each_entry(kctl, &card->controls, list) {
646                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
647                         return kctl;
648         }
649         return NULL;
650 }
651 
652 EXPORT_SYMBOL(snd_ctl_find_numid);
653 
654 /**
655  * snd_ctl_find_id - find the control instance with the given id
656  * @card: the card instance
657  * @id: the id to search
658  *
659  * Finds the control instance with the given id from the card.
660  *
661  * The caller must down card->controls_rwsem before calling this function
662  * (if the race condition can happen).
663  *
664  * Return: The pointer of the instance if found, or %NULL if not.
665  *
666  */
667 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
668                                      struct snd_ctl_elem_id *id)
669 {
670         struct snd_kcontrol *kctl;
671 
672         if (snd_BUG_ON(!card || !id))
673                 return NULL;
674         if (id->numid != 0)
675                 return snd_ctl_find_numid(card, id->numid);
676         list_for_each_entry(kctl, &card->controls, list) {
677                 if (kctl->id.iface != id->iface)
678                         continue;
679                 if (kctl->id.device != id->device)
680                         continue;
681                 if (kctl->id.subdevice != id->subdevice)
682                         continue;
683                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
684                         continue;
685                 if (kctl->id.index > id->index)
686                         continue;
687                 if (kctl->id.index + kctl->count <= id->index)
688                         continue;
689                 return kctl;
690         }
691         return NULL;
692 }
693 
694 EXPORT_SYMBOL(snd_ctl_find_id);
695 
696 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
697                              unsigned int cmd, void __user *arg)
698 {
699         struct snd_ctl_card_info *info;
700 
701         info = kzalloc(sizeof(*info), GFP_KERNEL);
702         if (! info)
703                 return -ENOMEM;
704         down_read(&snd_ioctl_rwsem);
705         info->card = card->number;
706         strlcpy(info->id, card->id, sizeof(info->id));
707         strlcpy(info->driver, card->driver, sizeof(info->driver));
708         strlcpy(info->name, card->shortname, sizeof(info->name));
709         strlcpy(info->longname, card->longname, sizeof(info->longname));
710         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
711         strlcpy(info->components, card->components, sizeof(info->components));
712         up_read(&snd_ioctl_rwsem);
713         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
714                 kfree(info);
715                 return -EFAULT;
716         }
717         kfree(info);
718         return 0;
719 }
720 
721 static int snd_ctl_elem_list(struct snd_card *card,
722                              struct snd_ctl_elem_list __user *_list)
723 {
724         struct list_head *plist;
725         struct snd_ctl_elem_list list;
726         struct snd_kcontrol *kctl;
727         struct snd_ctl_elem_id *dst, *id;
728         unsigned int offset, space, jidx;
729         
730         if (copy_from_user(&list, _list, sizeof(list)))
731                 return -EFAULT;
732         offset = list.offset;
733         space = list.space;
734         /* try limit maximum space */
735         if (space > 16384)
736                 return -ENOMEM;
737         if (space > 0) {
738                 /* allocate temporary buffer for atomic operation */
739                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
740                 if (dst == NULL)
741                         return -ENOMEM;
742                 down_read(&card->controls_rwsem);
743                 list.count = card->controls_count;
744                 plist = card->controls.next;
745                 while (plist != &card->controls) {
746                         if (offset == 0)
747                                 break;
748                         kctl = snd_kcontrol(plist);
749                         if (offset < kctl->count)
750                                 break;
751                         offset -= kctl->count;
752                         plist = plist->next;
753                 }
754                 list.used = 0;
755                 id = dst;
756                 while (space > 0 && plist != &card->controls) {
757                         kctl = snd_kcontrol(plist);
758                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
759                                 snd_ctl_build_ioff(id, kctl, jidx);
760                                 id++;
761                                 space--;
762                                 list.used++;
763                         }
764                         plist = plist->next;
765                         offset = 0;
766                 }
767                 up_read(&card->controls_rwsem);
768                 if (list.used > 0 &&
769                     copy_to_user(list.pids, dst,
770                                  list.used * sizeof(struct snd_ctl_elem_id))) {
771                         vfree(dst);
772                         return -EFAULT;
773                 }
774                 vfree(dst);
775         } else {
776                 down_read(&card->controls_rwsem);
777                 list.count = card->controls_count;
778                 up_read(&card->controls_rwsem);
779         }
780         if (copy_to_user(_list, &list, sizeof(list)))
781                 return -EFAULT;
782         return 0;
783 }
784 
785 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
786                              struct snd_ctl_elem_info *info)
787 {
788         struct snd_card *card = ctl->card;
789         struct snd_kcontrol *kctl;
790         struct snd_kcontrol_volatile *vd;
791         unsigned int index_offset;
792         int result;
793         
794         down_read(&card->controls_rwsem);
795         kctl = snd_ctl_find_id(card, &info->id);
796         if (kctl == NULL) {
797                 up_read(&card->controls_rwsem);
798                 return -ENOENT;
799         }
800 #ifdef CONFIG_SND_DEBUG
801         info->access = 0;
802 #endif
803         result = kctl->info(kctl, info);
804         if (result >= 0) {
805                 snd_BUG_ON(info->access);
806                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
807                 vd = &kctl->vd[index_offset];
808                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
809                 info->access = vd->access;
810                 if (vd->owner) {
811                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
812                         if (vd->owner == ctl)
813                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
814                         info->owner = pid_vnr(vd->owner->pid);
815                 } else {
816                         info->owner = -1;
817                 }
818         }
819         up_read(&card->controls_rwsem);
820         return result;
821 }
822 
823 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
824                                   struct snd_ctl_elem_info __user *_info)
825 {
826         struct snd_ctl_elem_info info;
827         int result;
828 
829         if (copy_from_user(&info, _info, sizeof(info)))
830                 return -EFAULT;
831         snd_power_lock(ctl->card);
832         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
833         if (result >= 0)
834                 result = snd_ctl_elem_info(ctl, &info);
835         snd_power_unlock(ctl->card);
836         if (result >= 0)
837                 if (copy_to_user(_info, &info, sizeof(info)))
838                         return -EFAULT;
839         return result;
840 }
841 
842 static int snd_ctl_elem_read(struct snd_card *card,
843                              struct snd_ctl_elem_value *control)
844 {
845         struct snd_kcontrol *kctl;
846         struct snd_kcontrol_volatile *vd;
847         unsigned int index_offset;
848         int result;
849 
850         down_read(&card->controls_rwsem);
851         kctl = snd_ctl_find_id(card, &control->id);
852         if (kctl == NULL) {
853                 result = -ENOENT;
854         } else {
855                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
856                 vd = &kctl->vd[index_offset];
857                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
858                     kctl->get != NULL) {
859                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
860                         result = kctl->get(kctl, control);
861                 } else
862                         result = -EPERM;
863         }
864         up_read(&card->controls_rwsem);
865         return result;
866 }
867 
868 static int snd_ctl_elem_read_user(struct snd_card *card,
869                                   struct snd_ctl_elem_value __user *_control)
870 {
871         struct snd_ctl_elem_value *control;
872         int result;
873 
874         control = memdup_user(_control, sizeof(*control));
875         if (IS_ERR(control))
876                 return PTR_ERR(control);
877 
878         snd_power_lock(card);
879         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
880         if (result >= 0)
881                 result = snd_ctl_elem_read(card, control);
882         snd_power_unlock(card);
883         if (result >= 0)
884                 if (copy_to_user(_control, control, sizeof(*control)))
885                         result = -EFAULT;
886         kfree(control);
887         return result;
888 }
889 
890 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
891                               struct snd_ctl_elem_value *control)
892 {
893         struct snd_kcontrol *kctl;
894         struct snd_kcontrol_volatile *vd;
895         unsigned int index_offset;
896         int result;
897 
898         down_read(&card->controls_rwsem);
899         kctl = snd_ctl_find_id(card, &control->id);
900         if (kctl == NULL) {
901                 result = -ENOENT;
902         } else {
903                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
904                 vd = &kctl->vd[index_offset];
905                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
906                     kctl->put == NULL ||
907                     (file && vd->owner && vd->owner != file)) {
908                         result = -EPERM;
909                 } else {
910                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
911                         result = kctl->put(kctl, control);
912                 }
913                 if (result > 0) {
914                         struct snd_ctl_elem_id id = control->id;
915                         up_read(&card->controls_rwsem);
916                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
917                         return 0;
918                 }
919         }
920         up_read(&card->controls_rwsem);
921         return result;
922 }
923 
924 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
925                                    struct snd_ctl_elem_value __user *_control)
926 {
927         struct snd_ctl_elem_value *control;
928         struct snd_card *card;
929         int result;
930 
931         control = memdup_user(_control, sizeof(*control));
932         if (IS_ERR(control))
933                 return PTR_ERR(control);
934 
935         card = file->card;
936         snd_power_lock(card);
937         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
938         if (result >= 0)
939                 result = snd_ctl_elem_write(card, file, control);
940         snd_power_unlock(card);
941         if (result >= 0)
942                 if (copy_to_user(_control, control, sizeof(*control)))
943                         result = -EFAULT;
944         kfree(control);
945         return result;
946 }
947 
948 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
949                              struct snd_ctl_elem_id __user *_id)
950 {
951         struct snd_card *card = file->card;
952         struct snd_ctl_elem_id id;
953         struct snd_kcontrol *kctl;
954         struct snd_kcontrol_volatile *vd;
955         int result;
956         
957         if (copy_from_user(&id, _id, sizeof(id)))
958                 return -EFAULT;
959         down_write(&card->controls_rwsem);
960         kctl = snd_ctl_find_id(card, &id);
961         if (kctl == NULL) {
962                 result = -ENOENT;
963         } else {
964                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
965                 if (vd->owner != NULL)
966                         result = -EBUSY;
967                 else {
968                         vd->owner = file;
969                         result = 0;
970                 }
971         }
972         up_write(&card->controls_rwsem);
973         return result;
974 }
975 
976 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
977                                struct snd_ctl_elem_id __user *_id)
978 {
979         struct snd_card *card = file->card;
980         struct snd_ctl_elem_id id;
981         struct snd_kcontrol *kctl;
982         struct snd_kcontrol_volatile *vd;
983         int result;
984         
985         if (copy_from_user(&id, _id, sizeof(id)))
986                 return -EFAULT;
987         down_write(&card->controls_rwsem);
988         kctl = snd_ctl_find_id(card, &id);
989         if (kctl == NULL) {
990                 result = -ENOENT;
991         } else {
992                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
993                 if (vd->owner == NULL)
994                         result = -EINVAL;
995                 else if (vd->owner != file)
996                         result = -EPERM;
997                 else {
998                         vd->owner = NULL;
999                         result = 0;
1000                 }
1001         }
1002         up_write(&card->controls_rwsem);
1003         return result;
1004 }
1005 
1006 struct user_element {
1007         struct snd_ctl_elem_info info;
1008         struct snd_card *card;
1009         void *elem_data;                /* element data */
1010         unsigned long elem_data_size;   /* size of element data in bytes */
1011         void *tlv_data;                 /* TLV data */
1012         unsigned long tlv_data_size;    /* TLV data size */
1013         void *priv_data;                /* private data (like strings for enumerated type) */
1014 };
1015 
1016 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1017                                   struct snd_ctl_elem_info *uinfo)
1018 {
1019         struct user_element *ue = kcontrol->private_data;
1020 
1021         *uinfo = ue->info;
1022         return 0;
1023 }
1024 
1025 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1026                                        struct snd_ctl_elem_info *uinfo)
1027 {
1028         struct user_element *ue = kcontrol->private_data;
1029         const char *names;
1030         unsigned int item;
1031 
1032         item = uinfo->value.enumerated.item;
1033 
1034         *uinfo = ue->info;
1035 
1036         item = min(item, uinfo->value.enumerated.items - 1);
1037         uinfo->value.enumerated.item = item;
1038 
1039         names = ue->priv_data;
1040         for (; item > 0; --item)
1041                 names += strlen(names) + 1;
1042         strcpy(uinfo->value.enumerated.name, names);
1043 
1044         return 0;
1045 }
1046 
1047 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1048                                  struct snd_ctl_elem_value *ucontrol)
1049 {
1050         struct user_element *ue = kcontrol->private_data;
1051 
1052         mutex_lock(&ue->card->user_ctl_lock);
1053         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1054         mutex_unlock(&ue->card->user_ctl_lock);
1055         return 0;
1056 }
1057 
1058 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1059                                  struct snd_ctl_elem_value *ucontrol)
1060 {
1061         int change;
1062         struct user_element *ue = kcontrol->private_data;
1063 
1064         mutex_lock(&ue->card->user_ctl_lock);
1065         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1066         if (change)
1067                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1068         mutex_unlock(&ue->card->user_ctl_lock);
1069         return change;
1070 }
1071 
1072 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1073                                  int op_flag,
1074                                  unsigned int size,
1075                                  unsigned int __user *tlv)
1076 {
1077         struct user_element *ue = kcontrol->private_data;
1078         int change = 0;
1079         void *new_data;
1080 
1081         if (op_flag > 0) {
1082                 if (size > 1024 * 128)  /* sane value */
1083                         return -EINVAL;
1084 
1085                 new_data = memdup_user(tlv, size);
1086                 if (IS_ERR(new_data))
1087                         return PTR_ERR(new_data);
1088                 mutex_lock(&ue->card->user_ctl_lock);
1089                 change = ue->tlv_data_size != size;
1090                 if (!change)
1091                         change = memcmp(ue->tlv_data, new_data, size);
1092                 kfree(ue->tlv_data);
1093                 ue->tlv_data = new_data;
1094                 ue->tlv_data_size = size;
1095                 mutex_unlock(&ue->card->user_ctl_lock);
1096         } else {
1097                 int ret = 0;
1098 
1099                 mutex_lock(&ue->card->user_ctl_lock);
1100                 if (!ue->tlv_data_size || !ue->tlv_data) {
1101                         ret = -ENXIO;
1102                         goto err_unlock;
1103                 }
1104                 if (size < ue->tlv_data_size) {
1105                         ret = -ENOSPC;
1106                         goto err_unlock;
1107                 }
1108                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1109                         ret = -EFAULT;
1110 err_unlock:
1111                 mutex_unlock(&ue->card->user_ctl_lock);
1112                 if (ret)
1113                         return ret;
1114         }
1115         return change;
1116 }
1117 
1118 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1119 {
1120         char *names, *p;
1121         size_t buf_len, name_len;
1122         unsigned int i;
1123         const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1124 
1125         if (ue->info.value.enumerated.names_length > 64 * 1024)
1126                 return -EINVAL;
1127 
1128         names = memdup_user((const void __user *)user_ptrval,
1129                 ue->info.value.enumerated.names_length);
1130         if (IS_ERR(names))
1131                 return PTR_ERR(names);
1132 
1133         /* check that there are enough valid names */
1134         buf_len = ue->info.value.enumerated.names_length;
1135         p = names;
1136         for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1137                 name_len = strnlen(p, buf_len);
1138                 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1139                         kfree(names);
1140                         return -EINVAL;
1141                 }
1142                 p += name_len + 1;
1143                 buf_len -= name_len + 1;
1144         }
1145 
1146         ue->priv_data = names;
1147         ue->info.value.enumerated.names_ptr = 0;
1148 
1149         return 0;
1150 }
1151 
1152 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1153 {
1154         struct user_element *ue = kcontrol->private_data;
1155 
1156         kfree(ue->tlv_data);
1157         kfree(ue->priv_data);
1158         kfree(ue);
1159 }
1160 
1161 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1162                             struct snd_ctl_elem_info *info, int replace)
1163 {
1164         struct snd_card *card = file->card;
1165         struct snd_kcontrol kctl, *_kctl;
1166         unsigned int access;
1167         long private_size;
1168         struct user_element *ue;
1169         int idx, err;
1170 
1171         if (info->count < 1)
1172                 return -EINVAL;
1173         if (!*info->id.name)
1174                 return -EINVAL;
1175         if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1176                 return -EINVAL;
1177         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1178                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1179                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1180                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1181         info->id.numid = 0;
1182         memset(&kctl, 0, sizeof(kctl));
1183 
1184         if (replace) {
1185                 err = snd_ctl_remove_user_ctl(file, &info->id);
1186                 if (err)
1187                         return err;
1188         }
1189 
1190         if (card->user_ctl_count >= MAX_USER_CONTROLS)
1191                 return -ENOMEM;
1192 
1193         memcpy(&kctl.id, &info->id, sizeof(info->id));
1194         kctl.count = info->owner ? info->owner : 1;
1195         access |= SNDRV_CTL_ELEM_ACCESS_USER;
1196         if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1197                 kctl.info = snd_ctl_elem_user_enum_info;
1198         else
1199                 kctl.info = snd_ctl_elem_user_info;
1200         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1201                 kctl.get = snd_ctl_elem_user_get;
1202         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1203                 kctl.put = snd_ctl_elem_user_put;
1204         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1205                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1206                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1207         }
1208         switch (info->type) {
1209         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1210         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1211                 private_size = sizeof(long);
1212                 if (info->count > 128)
1213                         return -EINVAL;
1214                 break;
1215         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1216                 private_size = sizeof(long long);
1217                 if (info->count > 64)
1218                         return -EINVAL;
1219                 break;
1220         case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1221                 private_size = sizeof(unsigned int);
1222                 if (info->count > 128 || info->value.enumerated.items == 0)
1223                         return -EINVAL;
1224                 break;
1225         case SNDRV_CTL_ELEM_TYPE_BYTES:
1226                 private_size = sizeof(unsigned char);
1227                 if (info->count > 512)
1228                         return -EINVAL;
1229                 break;
1230         case SNDRV_CTL_ELEM_TYPE_IEC958:
1231                 private_size = sizeof(struct snd_aes_iec958);
1232                 if (info->count != 1)
1233                         return -EINVAL;
1234                 break;
1235         default:
1236                 return -EINVAL;
1237         }
1238         private_size *= info->count;
1239         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1240         if (ue == NULL)
1241                 return -ENOMEM;
1242         ue->card = card;
1243         ue->info = *info;
1244         ue->info.access = 0;
1245         ue->elem_data = (char *)ue + sizeof(*ue);
1246         ue->elem_data_size = private_size;
1247         if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1248                 err = snd_ctl_elem_init_enum_names(ue);
1249                 if (err < 0) {
1250                         kfree(ue);
1251                         return err;
1252                 }
1253         }
1254         kctl.private_free = snd_ctl_elem_user_free;
1255         _kctl = snd_ctl_new(&kctl, access);
1256         if (_kctl == NULL) {
1257                 kfree(ue->priv_data);
1258                 kfree(ue);
1259                 return -ENOMEM;
1260         }
1261         _kctl->private_data = ue;
1262         for (idx = 0; idx < _kctl->count; idx++)
1263                 _kctl->vd[idx].owner = file;
1264         err = snd_ctl_add(card, _kctl);
1265         if (err < 0)
1266                 return err;
1267 
1268         down_write(&card->controls_rwsem);
1269         card->user_ctl_count++;
1270         up_write(&card->controls_rwsem);
1271 
1272         return 0;
1273 }
1274 
1275 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1276                                  struct snd_ctl_elem_info __user *_info, int replace)
1277 {
1278         struct snd_ctl_elem_info info;
1279         if (copy_from_user(&info, _info, sizeof(info)))
1280                 return -EFAULT;
1281         return snd_ctl_elem_add(file, &info, replace);
1282 }
1283 
1284 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1285                                struct snd_ctl_elem_id __user *_id)
1286 {
1287         struct snd_ctl_elem_id id;
1288 
1289         if (copy_from_user(&id, _id, sizeof(id)))
1290                 return -EFAULT;
1291         return snd_ctl_remove_user_ctl(file, &id);
1292 }
1293 
1294 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1295 {
1296         int subscribe;
1297         if (get_user(subscribe, ptr))
1298                 return -EFAULT;
1299         if (subscribe < 0) {
1300                 subscribe = file->subscribed;
1301                 if (put_user(subscribe, ptr))
1302                         return -EFAULT;
1303                 return 0;
1304         }
1305         if (subscribe) {
1306                 file->subscribed = 1;
1307                 return 0;
1308         } else if (file->subscribed) {
1309                 snd_ctl_empty_read_queue(file);
1310                 file->subscribed = 0;
1311         }
1312         return 0;
1313 }
1314 
1315 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1316                              struct snd_ctl_tlv __user *_tlv,
1317                              int op_flag)
1318 {
1319         struct snd_card *card = file->card;
1320         struct snd_ctl_tlv tlv;
1321         struct snd_kcontrol *kctl;
1322         struct snd_kcontrol_volatile *vd;
1323         unsigned int len;
1324         int err = 0;
1325 
1326         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1327                 return -EFAULT;
1328         if (tlv.length < sizeof(unsigned int) * 2)
1329                 return -EINVAL;
1330         if (!tlv.numid)
1331                 return -EINVAL;
1332         down_read(&card->controls_rwsem);
1333         kctl = snd_ctl_find_numid(card, tlv.numid);
1334         if (kctl == NULL) {
1335                 err = -ENOENT;
1336                 goto __kctl_end;
1337         }
1338         if (kctl->tlv.p == NULL) {
1339                 err = -ENXIO;
1340                 goto __kctl_end;
1341         }
1342         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1343         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1344             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1345             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1346                 err = -ENXIO;
1347                 goto __kctl_end;
1348         }
1349         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1350                 if (vd->owner != NULL && vd->owner != file) {
1351                         err = -EPERM;
1352                         goto __kctl_end;
1353                 }
1354                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1355                 if (err > 0) {
1356                         struct snd_ctl_elem_id id = kctl->id;
1357                         up_read(&card->controls_rwsem);
1358                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1359                         return 0;
1360                 }
1361         } else {
1362                 if (op_flag) {
1363                         err = -ENXIO;
1364                         goto __kctl_end;
1365                 }
1366                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1367                 if (tlv.length < len) {
1368                         err = -ENOMEM;
1369                         goto __kctl_end;
1370                 }
1371                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1372                         err = -EFAULT;
1373         }
1374       __kctl_end:
1375         up_read(&card->controls_rwsem);
1376         return err;
1377 }
1378 
1379 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1380 {
1381         struct snd_ctl_file *ctl;
1382         struct snd_card *card;
1383         struct snd_kctl_ioctl *p;
1384         void __user *argp = (void __user *)arg;
1385         int __user *ip = argp;
1386         int err;
1387 
1388         ctl = file->private_data;
1389         card = ctl->card;
1390         if (snd_BUG_ON(!card))
1391                 return -ENXIO;
1392         switch (cmd) {
1393         case SNDRV_CTL_IOCTL_PVERSION:
1394                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1395         case SNDRV_CTL_IOCTL_CARD_INFO:
1396                 return snd_ctl_card_info(card, ctl, cmd, argp);
1397         case SNDRV_CTL_IOCTL_ELEM_LIST:
1398                 return snd_ctl_elem_list(card, argp);
1399         case SNDRV_CTL_IOCTL_ELEM_INFO:
1400                 return snd_ctl_elem_info_user(ctl, argp);
1401         case SNDRV_CTL_IOCTL_ELEM_READ:
1402                 return snd_ctl_elem_read_user(card, argp);
1403         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1404                 return snd_ctl_elem_write_user(ctl, argp);
1405         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1406                 return snd_ctl_elem_lock(ctl, argp);
1407         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1408                 return snd_ctl_elem_unlock(ctl, argp);
1409         case SNDRV_CTL_IOCTL_ELEM_ADD:
1410                 return snd_ctl_elem_add_user(ctl, argp, 0);
1411         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1412                 return snd_ctl_elem_add_user(ctl, argp, 1);
1413         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1414                 return snd_ctl_elem_remove(ctl, argp);
1415         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1416                 return snd_ctl_subscribe_events(ctl, ip);
1417         case SNDRV_CTL_IOCTL_TLV_READ:
1418                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1419         case SNDRV_CTL_IOCTL_TLV_WRITE:
1420                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1421         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1422                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1423         case SNDRV_CTL_IOCTL_POWER:
1424                 return -ENOPROTOOPT;
1425         case SNDRV_CTL_IOCTL_POWER_STATE:
1426 #ifdef CONFIG_PM
1427                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1428 #else
1429                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1430 #endif
1431         }
1432         down_read(&snd_ioctl_rwsem);
1433         list_for_each_entry(p, &snd_control_ioctls, list) {
1434                 err = p->fioctl(card, ctl, cmd, arg);
1435                 if (err != -ENOIOCTLCMD) {
1436                         up_read(&snd_ioctl_rwsem);
1437                         return err;
1438                 }
1439         }
1440         up_read(&snd_ioctl_rwsem);
1441         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1442         return -ENOTTY;
1443 }
1444 
1445 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1446                             size_t count, loff_t * offset)
1447 {
1448         struct snd_ctl_file *ctl;
1449         int err = 0;
1450         ssize_t result = 0;
1451 
1452         ctl = file->private_data;
1453         if (snd_BUG_ON(!ctl || !ctl->card))
1454                 return -ENXIO;
1455         if (!ctl->subscribed)
1456                 return -EBADFD;
1457         if (count < sizeof(struct snd_ctl_event))
1458                 return -EINVAL;
1459         spin_lock_irq(&ctl->read_lock);
1460         while (count >= sizeof(struct snd_ctl_event)) {
1461                 struct snd_ctl_event ev;
1462                 struct snd_kctl_event *kev;
1463                 while (list_empty(&ctl->events)) {
1464                         wait_queue_t wait;
1465                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1466                                 err = -EAGAIN;
1467                                 goto __end_lock;
1468                         }
1469                         init_waitqueue_entry(&wait, current);
1470                         add_wait_queue(&ctl->change_sleep, &wait);
1471                         set_current_state(TASK_INTERRUPTIBLE);
1472                         spin_unlock_irq(&ctl->read_lock);
1473                         schedule();
1474                         remove_wait_queue(&ctl->change_sleep, &wait);
1475                         if (ctl->card->shutdown)
1476                                 return -ENODEV;
1477                         if (signal_pending(current))
1478                                 return -ERESTARTSYS;
1479                         spin_lock_irq(&ctl->read_lock);
1480                 }
1481                 kev = snd_kctl_event(ctl->events.next);
1482                 ev.type = SNDRV_CTL_EVENT_ELEM;
1483                 ev.data.elem.mask = kev->mask;
1484                 ev.data.elem.id = kev->id;
1485                 list_del(&kev->list);
1486                 spin_unlock_irq(&ctl->read_lock);
1487                 kfree(kev);
1488                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1489                         err = -EFAULT;
1490                         goto __end;
1491                 }
1492                 spin_lock_irq(&ctl->read_lock);
1493                 buffer += sizeof(struct snd_ctl_event);
1494                 count -= sizeof(struct snd_ctl_event);
1495                 result += sizeof(struct snd_ctl_event);
1496         }
1497       __end_lock:
1498         spin_unlock_irq(&ctl->read_lock);
1499       __end:
1500         return result > 0 ? result : err;
1501 }
1502 
1503 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1504 {
1505         unsigned int mask;
1506         struct snd_ctl_file *ctl;
1507 
1508         ctl = file->private_data;
1509         if (!ctl->subscribed)
1510                 return 0;
1511         poll_wait(file, &ctl->change_sleep, wait);
1512 
1513         mask = 0;
1514         if (!list_empty(&ctl->events))
1515                 mask |= POLLIN | POLLRDNORM;
1516 
1517         return mask;
1518 }
1519 
1520 /*
1521  * register the device-specific control-ioctls.
1522  * called from each device manager like pcm.c, hwdep.c, etc.
1523  */
1524 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1525 {
1526         struct snd_kctl_ioctl *pn;
1527 
1528         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1529         if (pn == NULL)
1530                 return -ENOMEM;
1531         pn->fioctl = fcn;
1532         down_write(&snd_ioctl_rwsem);
1533         list_add_tail(&pn->list, lists);
1534         up_write(&snd_ioctl_rwsem);
1535         return 0;
1536 }
1537 
1538 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1539 {
1540         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1541 }
1542 
1543 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1544 
1545 #ifdef CONFIG_COMPAT
1546 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1547 {
1548         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1549 }
1550 
1551 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1552 #endif
1553 
1554 /*
1555  * de-register the device-specific control-ioctls.
1556  */
1557 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1558                                      struct list_head *lists)
1559 {
1560         struct snd_kctl_ioctl *p;
1561 
1562         if (snd_BUG_ON(!fcn))
1563                 return -EINVAL;
1564         down_write(&snd_ioctl_rwsem);
1565         list_for_each_entry(p, lists, list) {
1566                 if (p->fioctl == fcn) {
1567                         list_del(&p->list);
1568                         up_write(&snd_ioctl_rwsem);
1569                         kfree(p);
1570                         return 0;
1571                 }
1572         }
1573         up_write(&snd_ioctl_rwsem);
1574         snd_BUG();
1575         return -EINVAL;
1576 }
1577 
1578 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1579 {
1580         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1581 }
1582 
1583 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1584 
1585 #ifdef CONFIG_COMPAT
1586 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1587 {
1588         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1589 }
1590 
1591 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1592 #endif
1593 
1594 static int snd_ctl_fasync(int fd, struct file * file, int on)
1595 {
1596         struct snd_ctl_file *ctl;
1597 
1598         ctl = file->private_data;
1599         return fasync_helper(fd, file, on, &ctl->fasync);
1600 }
1601 
1602 /*
1603  * ioctl32 compat
1604  */
1605 #ifdef CONFIG_COMPAT
1606 #include "control_compat.c"
1607 #else
1608 #define snd_ctl_ioctl_compat    NULL
1609 #endif
1610 
1611 /*
1612  *  INIT PART
1613  */
1614 
1615 static const struct file_operations snd_ctl_f_ops =
1616 {
1617         .owner =        THIS_MODULE,
1618         .read =         snd_ctl_read,
1619         .open =         snd_ctl_open,
1620         .release =      snd_ctl_release,
1621         .llseek =       no_llseek,
1622         .poll =         snd_ctl_poll,
1623         .unlocked_ioctl =       snd_ctl_ioctl,
1624         .compat_ioctl = snd_ctl_ioctl_compat,
1625         .fasync =       snd_ctl_fasync,
1626 };
1627 
1628 /*
1629  * registration of the control device
1630  */
1631 static int snd_ctl_dev_register(struct snd_device *device)
1632 {
1633         struct snd_card *card = device->device_data;
1634         int err, cardnum;
1635         char name[16];
1636 
1637         if (snd_BUG_ON(!card))
1638                 return -ENXIO;
1639         cardnum = card->number;
1640         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1641                 return -ENXIO;
1642         sprintf(name, "controlC%i", cardnum);
1643         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1644                                        &snd_ctl_f_ops, card, name)) < 0)
1645                 return err;
1646         return 0;
1647 }
1648 
1649 /*
1650  * disconnection of the control device
1651  */
1652 static int snd_ctl_dev_disconnect(struct snd_device *device)
1653 {
1654         struct snd_card *card = device->device_data;
1655         struct snd_ctl_file *ctl;
1656         int err, cardnum;
1657 
1658         if (snd_BUG_ON(!card))
1659                 return -ENXIO;
1660         cardnum = card->number;
1661         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1662                 return -ENXIO;
1663 
1664         read_lock(&card->ctl_files_rwlock);
1665         list_for_each_entry(ctl, &card->ctl_files, list) {
1666                 wake_up(&ctl->change_sleep);
1667                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1668         }
1669         read_unlock(&card->ctl_files_rwlock);
1670 
1671         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1672                                          card, -1)) < 0)
1673                 return err;
1674         return 0;
1675 }
1676 
1677 /*
1678  * free all controls
1679  */
1680 static int snd_ctl_dev_free(struct snd_device *device)
1681 {
1682         struct snd_card *card = device->device_data;
1683         struct snd_kcontrol *control;
1684 
1685         down_write(&card->controls_rwsem);
1686         while (!list_empty(&card->controls)) {
1687                 control = snd_kcontrol(card->controls.next);
1688                 snd_ctl_remove(card, control);
1689         }
1690         up_write(&card->controls_rwsem);
1691         return 0;
1692 }
1693 
1694 /*
1695  * create control core:
1696  * called from init.c
1697  */
1698 int snd_ctl_create(struct snd_card *card)
1699 {
1700         static struct snd_device_ops ops = {
1701                 .dev_free = snd_ctl_dev_free,
1702                 .dev_register = snd_ctl_dev_register,
1703                 .dev_disconnect = snd_ctl_dev_disconnect,
1704         };
1705 
1706         if (snd_BUG_ON(!card))
1707                 return -ENXIO;
1708         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1709 }
1710 
1711 /*
1712  * Frequently used control callbacks/helpers
1713  */
1714 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1715                               struct snd_ctl_elem_info *uinfo)
1716 {
1717         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1718         uinfo->count = 1;
1719         uinfo->value.integer.min = 0;
1720         uinfo->value.integer.max = 1;
1721         return 0;
1722 }
1723 
1724 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1725 
1726 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1727                                 struct snd_ctl_elem_info *uinfo)
1728 {
1729         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1730         uinfo->count = 2;
1731         uinfo->value.integer.min = 0;
1732         uinfo->value.integer.max = 1;
1733         return 0;
1734 }
1735 
1736 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1737 
1738 /**
1739  * snd_ctl_enum_info - fills the info structure for an enumerated control
1740  * @info: the structure to be filled
1741  * @channels: the number of the control's channels; often one
1742  * @items: the number of control values; also the size of @names
1743  * @names: an array containing the names of all control values
1744  *
1745  * Sets all required fields in @info to their appropriate values.
1746  * If the control's accessibility is not the default (readable and writable),
1747  * the caller has to fill @info->access.
1748  *
1749  * Return: Zero.
1750  */
1751 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1752                       unsigned int items, const char *const names[])
1753 {
1754         info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1755         info->count = channels;
1756         info->value.enumerated.items = items;
1757         if (info->value.enumerated.item >= items)
1758                 info->value.enumerated.item = items - 1;
1759         strlcpy(info->value.enumerated.name,
1760                 names[info->value.enumerated.item],
1761                 sizeof(info->value.enumerated.name));
1762         return 0;
1763 }
1764 EXPORT_SYMBOL(snd_ctl_enum_info);
1765 

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