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