1/*
   2 *  Routines for driver control interface
   3 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4 *
   5 *
   6 *   This program is free software; you can redistribute it and/or modify
   7 *   it under the terms of the GNU General Public License as published by
   8 *   the Free Software Foundation; either version 2 of the License, or
   9 *   (at your option) any later version.
  10 *
  11 *   This program is distributed in the hope that it will be useful,
  12 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *   GNU General Public License for more details.
  15 *
  16 *   You should have received a copy of the GNU General Public License
  17 *   along with this program; if not, write to the Free Software
  18 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19 *
  20 */
  21
  22#include <linux/threads.h>
  23#include <linux/interrupt.h>
  24#include <linux/module.h>
  25#include <linux/slab.h>
  26#include <linux/vmalloc.h>
  27#include <linux/time.h>
  28#include <sound/core.h>
  29#include <sound/minors.h>
  30#include <sound/info.h>
  31#include <sound/control.h>
  32
  33/* max number of user-defined controls */
  34#define MAX_USER_CONTROLS	32
  35#define MAX_CONTROL_COUNT	1028
  36
  37struct snd_kctl_ioctl {
  38	struct list_head list;		/* list of all ioctls */
  39	snd_kctl_ioctl_func_t fioctl;
  40};
  41
  42static DECLARE_RWSEM(snd_ioctl_rwsem);
  43static LIST_HEAD(snd_control_ioctls);
  44#ifdef CONFIG_COMPAT
  45static LIST_HEAD(snd_control_compat_ioctls);
  46#endif
  47
  48static int snd_ctl_open(struct inode *inode, struct file *file)
  49{
  50	unsigned long flags;
  51	struct snd_card *card;
  52	struct snd_ctl_file *ctl;
  53	int i, err;
  54
  55	err = nonseekable_open(inode, file);
  56	if (err < 0)
  57		return err;
  58
  59	card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
  60	if (!card) {
  61		err = -ENODEV;
  62		goto __error1;
  63	}
  64	err = snd_card_file_add(card, file);
  65	if (err < 0) {
  66		err = -ENODEV;
  67		goto __error1;
  68	}
  69	if (!try_module_get(card->module)) {
  70		err = -EFAULT;
  71		goto __error2;
  72	}
  73	ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
  74	if (ctl == NULL) {
  75		err = -ENOMEM;
  76		goto __error;
  77	}
  78	INIT_LIST_HEAD(&ctl->events);
  79	init_waitqueue_head(&ctl->change_sleep);
  80	spin_lock_init(&ctl->read_lock);
  81	ctl->card = card;
  82	for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
  83		ctl->preferred_subdevice[i] = -1;
  84	ctl->pid = get_pid(task_pid(current));
  85	file->private_data = ctl;
  86	write_lock_irqsave(&card->ctl_files_rwlock, flags);
  87	list_add_tail(&ctl->list, &card->ctl_files);
  88	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
  89	snd_card_unref(card);
  90	return 0;
  91
  92      __error:
  93	module_put(card->module);
  94      __error2:
  95	snd_card_file_remove(card, file);
  96      __error1:
  97	if (card)
  98		snd_card_unref(card);
  99      	return err;
 100}
 101
 102static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
 103{
 104	unsigned long flags;
 105	struct snd_kctl_event *cread;
 106	
 107	spin_lock_irqsave(&ctl->read_lock, flags);
 108	while (!list_empty(&ctl->events)) {
 109		cread = snd_kctl_event(ctl->events.next);
 110		list_del(&cread->list);
 111		kfree(cread);
 112	}
 113	spin_unlock_irqrestore(&ctl->read_lock, flags);
 114}
 115
 116static int snd_ctl_release(struct inode *inode, struct file *file)
 117{
 118	unsigned long flags;
 119	struct snd_card *card;
 120	struct snd_ctl_file *ctl;
 121	struct snd_kcontrol *control;
 122	unsigned int idx;
 123
 124	ctl = file->private_data;
 125	file->private_data = NULL;
 126	card = ctl->card;
 127	write_lock_irqsave(&card->ctl_files_rwlock, flags);
 128	list_del(&ctl->list);
 129	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 130	down_write(&card->controls_rwsem);
 131	list_for_each_entry(control, &card->controls, list)
 132		for (idx = 0; idx < control->count; idx++)
 133			if (control->vd[idx].owner == ctl)
 134				control->vd[idx].owner = NULL;
 135	up_write(&card->controls_rwsem);
 136	snd_ctl_empty_read_queue(ctl);
 137	put_pid(ctl->pid);
 138	kfree(ctl);
 139	module_put(card->module);
 140	snd_card_file_remove(card, file);
 141	return 0;
 142}
 143
 144/**
 145 * snd_ctl_notify - Send notification to user-space for a control change
 146 * @card: the card to send notification
 147 * @mask: the event mask, SNDRV_CTL_EVENT_*
 148 * @id: the ctl element id to send notification
 149 *
 150 * This function adds an event record with the given id and mask, appends
 151 * to the list and wakes up the user-space for notification.  This can be
 152 * called in the atomic context.
 153 */
 154void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 155		    struct snd_ctl_elem_id *id)
 156{
 157	unsigned long flags;
 158	struct snd_ctl_file *ctl;
 159	struct snd_kctl_event *ev;
 160	
 161	if (snd_BUG_ON(!card || !id))
 162		return;
 
 
 163	read_lock(&card->ctl_files_rwlock);
 164#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
 165	card->mixer_oss_change_count++;
 166#endif
 167	list_for_each_entry(ctl, &card->ctl_files, list) {
 168		if (!ctl->subscribed)
 169			continue;
 170		spin_lock_irqsave(&ctl->read_lock, flags);
 171		list_for_each_entry(ev, &ctl->events, list) {
 172			if (ev->id.numid == id->numid) {
 173				ev->mask |= mask;
 174				goto _found;
 175			}
 176		}
 177		ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 178		if (ev) {
 179			ev->id = *id;
 180			ev->mask = mask;
 181			list_add_tail(&ev->list, &ctl->events);
 182		} else {
 183			dev_err(card->dev, "No memory available to allocate event\n");
 184		}
 185	_found:
 186		wake_up(&ctl->change_sleep);
 187		spin_unlock_irqrestore(&ctl->read_lock, flags);
 188		kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 189	}
 190	read_unlock(&card->ctl_files_rwlock);
 191}
 192EXPORT_SYMBOL(snd_ctl_notify);
 193
 194/**
 195 * snd_ctl_new - create a new control instance with some elements
 196 * @kctl: the pointer to store new control instance
 197 * @count: the number of elements in this control
 198 * @access: the default access flags for elements in this control
 199 * @file: given when locking these elements
 200 *
 201 * Allocates a memory object for a new control instance. The instance has
 202 * elements as many as the given number (@count). Each element has given
 203 * access permissions (@access). Each element is locked when @file is given.
 204 *
 205 * Return: 0 on success, error code on failure
 206 */
 207static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
 208		       unsigned int access, struct snd_ctl_file *file)
 209{
 210	unsigned int size;
 211	unsigned int idx;
 212	
 213	if (count == 0 || count > MAX_CONTROL_COUNT)
 214		return -EINVAL;
 215
 216	size  = sizeof(struct snd_kcontrol);
 217	size += sizeof(struct snd_kcontrol_volatile) * count;
 218
 219	*kctl = kzalloc(size, GFP_KERNEL);
 220	if (!*kctl)
 221		return -ENOMEM;
 222
 223	for (idx = 0; idx < count; idx++) {
 224		(*kctl)->vd[idx].access = access;
 225		(*kctl)->vd[idx].owner = file;
 226	}
 227	(*kctl)->count = count;
 228
 229	return 0;
 230}
 231
 232/**
 233 * snd_ctl_new1 - create a control instance from the template
 234 * @ncontrol: the initialization record
 235 * @private_data: the private data to set
 236 *
 237 * Allocates a new struct snd_kcontrol instance and initialize from the given 
 238 * template.  When the access field of ncontrol is 0, it's assumed as
 239 * READWRITE access. When the count field is 0, it's assumes as one.
 240 *
 241 * Return: The pointer of the newly generated instance, or %NULL on failure.
 242 */
 243struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 244				  void *private_data)
 245{
 246	struct snd_kcontrol *kctl;
 247	unsigned int count;
 248	unsigned int access;
 249	int err;
 250	
 251	if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 252		return NULL;
 253
 254	count = ncontrol->count;
 255	if (count == 0)
 256		count = 1;
 257
 258	access = ncontrol->access;
 259	if (access == 0)
 260		access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
 261	access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
 262		   SNDRV_CTL_ELEM_ACCESS_VOLATILE |
 263		   SNDRV_CTL_ELEM_ACCESS_INACTIVE |
 264		   SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
 265		   SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
 266		   SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);
 267
 268	err = snd_ctl_new(&kctl, count, access, NULL);
 269	if (err < 0)
 270		return NULL;
 271
 272	/* The 'numid' member is decided when calling snd_ctl_add(). */
 273	kctl->id.iface = ncontrol->iface;
 274	kctl->id.device = ncontrol->device;
 275	kctl->id.subdevice = ncontrol->subdevice;
 276	if (ncontrol->name) {
 277		strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
 278		if (strcmp(ncontrol->name, kctl->id.name) != 0)
 279			pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
 280				ncontrol->name, kctl->id.name);
 281	}
 282	kctl->id.index = ncontrol->index;
 283
 284	kctl->info = ncontrol->info;
 285	kctl->get = ncontrol->get;
 286	kctl->put = ncontrol->put;
 287	kctl->tlv.p = ncontrol->tlv.p;
 288
 289	kctl->private_value = ncontrol->private_value;
 290	kctl->private_data = private_data;
 291
 292	return kctl;
 293}
 294EXPORT_SYMBOL(snd_ctl_new1);
 295
 296/**
 297 * snd_ctl_free_one - release the control instance
 298 * @kcontrol: the control instance
 299 *
 300 * Releases the control instance created via snd_ctl_new()
 301 * or snd_ctl_new1().
 302 * Don't call this after the control was added to the card.
 303 */
 304void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 305{
 306	if (kcontrol) {
 307		if (kcontrol->private_free)
 308			kcontrol->private_free(kcontrol);
 309		kfree(kcontrol);
 310	}
 311}
 312EXPORT_SYMBOL(snd_ctl_free_one);
 313
 314static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
 315					  unsigned int count)
 316{
 317	struct snd_kcontrol *kctl;
 318
 319	/* Make sure that the ids assigned to the control do not wrap around */
 320	if (card->last_numid >= UINT_MAX - count)
 321		card->last_numid = 0;
 322
 323	list_for_each_entry(kctl, &card->controls, list) {
 324		if (kctl->id.numid < card->last_numid + 1 + count &&
 325		    kctl->id.numid + kctl->count > card->last_numid + 1) {
 326		    	card->last_numid = kctl->id.numid + kctl->count - 1;
 327			return true;
 328		}
 329	}
 330	return false;
 331}
 332
 333static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 334{
 335	unsigned int iter = 100000;
 336
 337	while (snd_ctl_remove_numid_conflict(card, count)) {
 338		if (--iter == 0) {
 339			/* this situation is very unlikely */
 340			dev_err(card->dev, "unable to allocate new control numid\n");
 341			return -ENOMEM;
 342		}
 343	}
 344	return 0;
 345}
 346
 347/**
 348 * snd_ctl_add - add the control instance to the card
 349 * @card: the card instance
 350 * @kcontrol: the control instance to add
 351 *
 352 * Adds the control instance created via snd_ctl_new() or
 353 * snd_ctl_new1() to the given card. Assigns also an unique
 354 * numid used for fast search.
 355 *
 356 * It frees automatically the control which cannot be added.
 357 *
 358 * Return: Zero if successful, or a negative error code on failure.
 359 *
 360 */
 361int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 362{
 363	struct snd_ctl_elem_id id;
 364	unsigned int idx;
 365	unsigned int count;
 366	int err = -EINVAL;
 367
 368	if (! kcontrol)
 369		return err;
 370	if (snd_BUG_ON(!card || !kcontrol->info))
 371		goto error;
 372	id = kcontrol->id;
 373	if (id.index > UINT_MAX - kcontrol->count)
 374		goto error;
 375
 376	down_write(&card->controls_rwsem);
 377	if (snd_ctl_find_id(card, &id)) {
 378		up_write(&card->controls_rwsem);
 379		dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
 380					id.iface,
 381					id.device,
 382					id.subdevice,
 383					id.name,
 384					id.index);
 385		err = -EBUSY;
 386		goto error;
 387	}
 388	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 389		up_write(&card->controls_rwsem);
 390		err = -ENOMEM;
 391		goto error;
 392	}
 393	list_add_tail(&kcontrol->list, &card->controls);
 394	card->controls_count += kcontrol->count;
 395	kcontrol->id.numid = card->last_numid + 1;
 396	card->last_numid += kcontrol->count;
 397	id = kcontrol->id;
 398	count = kcontrol->count;
 399	up_write(&card->controls_rwsem);
 400	for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 401		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 402	return 0;
 403
 404 error:
 405	snd_ctl_free_one(kcontrol);
 406	return err;
 407}
 408EXPORT_SYMBOL(snd_ctl_add);
 409
 410/**
 411 * snd_ctl_replace - replace the control instance of the card
 412 * @card: the card instance
 413 * @kcontrol: the control instance to replace
 414 * @add_on_replace: add the control if not already added
 415 *
 416 * Replaces the given control.  If the given control does not exist
 417 * and the add_on_replace flag is set, the control is added.  If the
 418 * control exists, it is destroyed first.
 419 *
 420 * It frees automatically the control which cannot be added or replaced.
 421 *
 422 * Return: Zero if successful, or a negative error code on failure.
 423 */
 424int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 425		    bool add_on_replace)
 426{
 427	struct snd_ctl_elem_id id;
 428	unsigned int count;
 429	unsigned int idx;
 430	struct snd_kcontrol *old;
 431	int ret;
 432
 433	if (!kcontrol)
 434		return -EINVAL;
 435	if (snd_BUG_ON(!card || !kcontrol->info)) {
 436		ret = -EINVAL;
 437		goto error;
 438	}
 439	id = kcontrol->id;
 440	down_write(&card->controls_rwsem);
 441	old = snd_ctl_find_id(card, &id);
 442	if (!old) {
 443		if (add_on_replace)
 444			goto add;
 445		up_write(&card->controls_rwsem);
 446		ret = -EINVAL;
 447		goto error;
 448	}
 449	ret = snd_ctl_remove(card, old);
 450	if (ret < 0) {
 451		up_write(&card->controls_rwsem);
 452		goto error;
 453	}
 454add:
 455	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 456		up_write(&card->controls_rwsem);
 457		ret = -ENOMEM;
 458		goto error;
 459	}
 460	list_add_tail(&kcontrol->list, &card->controls);
 461	card->controls_count += kcontrol->count;
 462	kcontrol->id.numid = card->last_numid + 1;
 463	card->last_numid += kcontrol->count;
 464	id = kcontrol->id;
 465	count = kcontrol->count;
 466	up_write(&card->controls_rwsem);
 467	for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 468		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 469	return 0;
 470
 471error:
 472	snd_ctl_free_one(kcontrol);
 473	return ret;
 474}
 475EXPORT_SYMBOL(snd_ctl_replace);
 476
 477/**
 478 * snd_ctl_remove - remove the control from the card and release it
 479 * @card: the card instance
 480 * @kcontrol: the control instance to remove
 481 *
 482 * Removes the control from the card and then releases the instance.
 483 * You don't need to call snd_ctl_free_one(). You must be in
 484 * the write lock - down_write(&card->controls_rwsem).
 485 *
 486 * Return: 0 if successful, or a negative error code on failure.
 487 */
 488int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 489{
 490	struct snd_ctl_elem_id id;
 491	unsigned int idx;
 492
 493	if (snd_BUG_ON(!card || !kcontrol))
 494		return -EINVAL;
 495	list_del(&kcontrol->list);
 496	card->controls_count -= kcontrol->count;
 497	id = kcontrol->id;
 498	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 499		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 500	snd_ctl_free_one(kcontrol);
 501	return 0;
 502}
 503EXPORT_SYMBOL(snd_ctl_remove);
 504
 505/**
 506 * snd_ctl_remove_id - remove the control of the given id and release it
 507 * @card: the card instance
 508 * @id: the control id to remove
 509 *
 510 * Finds the control instance with the given id, removes it from the
 511 * card list and releases it.
 512 *
 513 * Return: 0 if successful, or a negative error code on failure.
 514 */
 515int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 516{
 517	struct snd_kcontrol *kctl;
 518	int ret;
 519
 520	down_write(&card->controls_rwsem);
 521	kctl = snd_ctl_find_id(card, id);
 522	if (kctl == NULL) {
 523		up_write(&card->controls_rwsem);
 524		return -ENOENT;
 525	}
 526	ret = snd_ctl_remove(card, kctl);
 527	up_write(&card->controls_rwsem);
 528	return ret;
 529}
 530EXPORT_SYMBOL(snd_ctl_remove_id);
 531
 532/**
 533 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 534 * @file: active control handle
 535 * @id: the control id to remove
 536 *
 537 * Finds the control instance with the given id, removes it from the
 538 * card list and releases it.
 539 *
 540 * Return: 0 if successful, or a negative error code on failure.
 541 */
 542static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 543				   struct snd_ctl_elem_id *id)
 544{
 545	struct snd_card *card = file->card;
 546	struct snd_kcontrol *kctl;
 547	int idx, ret;
 548
 549	down_write(&card->controls_rwsem);
 550	kctl = snd_ctl_find_id(card, id);
 551	if (kctl == NULL) {
 552		ret = -ENOENT;
 553		goto error;
 554	}
 555	if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 556		ret = -EINVAL;
 557		goto error;
 558	}
 559	for (idx = 0; idx < kctl->count; idx++)
 560		if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 561			ret = -EBUSY;
 562			goto error;
 563		}
 564	ret = snd_ctl_remove(card, kctl);
 565	if (ret < 0)
 566		goto error;
 567	card->user_ctl_count--;
 568error:
 569	up_write(&card->controls_rwsem);
 570	return ret;
 571}
 572
 573/**
 574 * snd_ctl_activate_id - activate/inactivate the control of the given id
 575 * @card: the card instance
 576 * @id: the control id to activate/inactivate
 577 * @active: non-zero to activate
 578 *
 579 * Finds the control instance with the given id, and activate or
 580 * inactivate the control together with notification, if changed.
 581 * The given ID data is filled with full information.
 582 *
 583 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
 584 */
 585int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 586			int active)
 587{
 588	struct snd_kcontrol *kctl;
 589	struct snd_kcontrol_volatile *vd;
 590	unsigned int index_offset;
 591	int ret;
 592
 593	down_write(&card->controls_rwsem);
 594	kctl = snd_ctl_find_id(card, id);
 595	if (kctl == NULL) {
 596		ret = -ENOENT;
 597		goto unlock;
 598	}
 599	index_offset = snd_ctl_get_ioff(kctl, id);
 600	vd = &kctl->vd[index_offset];
 601	ret = 0;
 602	if (active) {
 603		if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
 604			goto unlock;
 605		vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 606	} else {
 607		if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
 608			goto unlock;
 609		vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 610	}
 611	snd_ctl_build_ioff(id, kctl, index_offset);
 612	ret = 1;
 613 unlock:
 614	up_write(&card->controls_rwsem);
 615	if (ret > 0)
 616		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 617	return ret;
 618}
 619EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
 620
 621/**
 622 * snd_ctl_rename_id - replace the id of a control on the card
 623 * @card: the card instance
 624 * @src_id: the old id
 625 * @dst_id: the new id
 626 *
 627 * Finds the control with the old id from the card, and replaces the
 628 * id with the new one.
 629 *
 630 * Return: Zero if successful, or a negative error code on failure.
 631 */
 632int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 633		      struct snd_ctl_elem_id *dst_id)
 634{
 635	struct snd_kcontrol *kctl;
 636
 637	down_write(&card->controls_rwsem);
 638	kctl = snd_ctl_find_id(card, src_id);
 639	if (kctl == NULL) {
 640		up_write(&card->controls_rwsem);
 641		return -ENOENT;
 642	}
 643	kctl->id = *dst_id;
 644	kctl->id.numid = card->last_numid + 1;
 645	card->last_numid += kctl->count;
 646	up_write(&card->controls_rwsem);
 647	return 0;
 648}
 649EXPORT_SYMBOL(snd_ctl_rename_id);
 650
 651/**
 652 * snd_ctl_find_numid - find the control instance with the given number-id
 653 * @card: the card instance
 654 * @numid: the number-id to search
 655 *
 656 * Finds the control instance with the given number-id from the card.
 657 *
 658 * The caller must down card->controls_rwsem before calling this function
 659 * (if the race condition can happen).
 660 *
 661 * Return: The pointer of the instance if found, or %NULL if not.
 662 *
 663 */
 664struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 665{
 666	struct snd_kcontrol *kctl;
 667
 668	if (snd_BUG_ON(!card || !numid))
 669		return NULL;
 670	list_for_each_entry(kctl, &card->controls, list) {
 671		if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 672			return kctl;
 673	}
 674	return NULL;
 675}
 676EXPORT_SYMBOL(snd_ctl_find_numid);
 677
 678/**
 679 * snd_ctl_find_id - find the control instance with the given id
 680 * @card: the card instance
 681 * @id: the id to search
 682 *
 683 * Finds the control instance with the given id from the card.
 684 *
 685 * The caller must down card->controls_rwsem before calling this function
 686 * (if the race condition can happen).
 687 *
 688 * Return: The pointer of the instance if found, or %NULL if not.
 689 *
 690 */
 691struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 692				     struct snd_ctl_elem_id *id)
 693{
 694	struct snd_kcontrol *kctl;
 695
 696	if (snd_BUG_ON(!card || !id))
 697		return NULL;
 698	if (id->numid != 0)
 699		return snd_ctl_find_numid(card, id->numid);
 700	list_for_each_entry(kctl, &card->controls, list) {
 701		if (kctl->id.iface != id->iface)
 702			continue;
 703		if (kctl->id.device != id->device)
 704			continue;
 705		if (kctl->id.subdevice != id->subdevice)
 706			continue;
 707		if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 708			continue;
 709		if (kctl->id.index > id->index)
 710			continue;
 711		if (kctl->id.index + kctl->count <= id->index)
 712			continue;
 713		return kctl;
 714	}
 715	return NULL;
 716}
 717EXPORT_SYMBOL(snd_ctl_find_id);
 718
 719static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 720			     unsigned int cmd, void __user *arg)
 721{
 722	struct snd_ctl_card_info *info;
 723
 724	info = kzalloc(sizeof(*info), GFP_KERNEL);
 725	if (! info)
 726		return -ENOMEM;
 727	down_read(&snd_ioctl_rwsem);
 728	info->card = card->number;
 729	strlcpy(info->id, card->id, sizeof(info->id));
 730	strlcpy(info->driver, card->driver, sizeof(info->driver));
 731	strlcpy(info->name, card->shortname, sizeof(info->name));
 732	strlcpy(info->longname, card->longname, sizeof(info->longname));
 733	strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 734	strlcpy(info->components, card->components, sizeof(info->components));
 735	up_read(&snd_ioctl_rwsem);
 736	if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 737		kfree(info);
 738		return -EFAULT;
 739	}
 740	kfree(info);
 741	return 0;
 742}
 743
 744static int snd_ctl_elem_list(struct snd_card *card,
 745			     struct snd_ctl_elem_list __user *_list)
 746{
 747	struct list_head *plist;
 748	struct snd_ctl_elem_list list;
 749	struct snd_kcontrol *kctl;
 750	struct snd_ctl_elem_id *dst, *id;
 751	unsigned int offset, space, jidx;
 752	
 753	if (copy_from_user(&list, _list, sizeof(list)))
 754		return -EFAULT;
 755	offset = list.offset;
 756	space = list.space;
 757	/* try limit maximum space */
 758	if (space > 16384)
 759		return -ENOMEM;
 760	if (space > 0) {
 761		/* allocate temporary buffer for atomic operation */
 762		dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 763		if (dst == NULL)
 764			return -ENOMEM;
 765		down_read(&card->controls_rwsem);
 766		list.count = card->controls_count;
 767		plist = card->controls.next;
 768		while (plist != &card->controls) {
 769			if (offset == 0)
 770				break;
 771			kctl = snd_kcontrol(plist);
 772			if (offset < kctl->count)
 773				break;
 774			offset -= kctl->count;
 775			plist = plist->next;
 776		}
 777		list.used = 0;
 778		id = dst;
 779		while (space > 0 && plist != &card->controls) {
 780			kctl = snd_kcontrol(plist);
 781			for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 782				snd_ctl_build_ioff(id, kctl, jidx);
 783				id++;
 784				space--;
 785				list.used++;
 786			}
 787			plist = plist->next;
 788			offset = 0;
 789		}
 790		up_read(&card->controls_rwsem);
 791		if (list.used > 0 &&
 792		    copy_to_user(list.pids, dst,
 793				 list.used * sizeof(struct snd_ctl_elem_id))) {
 794			vfree(dst);
 795			return -EFAULT;
 796		}
 797		vfree(dst);
 798	} else {
 799		down_read(&card->controls_rwsem);
 800		list.count = card->controls_count;
 801		up_read(&card->controls_rwsem);
 802	}
 803	if (copy_to_user(_list, &list, sizeof(list)))
 804		return -EFAULT;
 805	return 0;
 806}
 807
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 808static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 809			     struct snd_ctl_elem_info *info)
 810{
 811	struct snd_card *card = ctl->card;
 812	struct snd_kcontrol *kctl;
 813	struct snd_kcontrol_volatile *vd;
 814	unsigned int index_offset;
 815	int result;
 816	
 817	down_read(&card->controls_rwsem);
 818	kctl = snd_ctl_find_id(card, &info->id);
 819	if (kctl == NULL) {
 820		up_read(&card->controls_rwsem);
 821		return -ENOENT;
 822	}
 823#ifdef CONFIG_SND_DEBUG
 824	info->access = 0;
 825#endif
 826	result = kctl->info(kctl, info);
 827	if (result >= 0) {
 828		snd_BUG_ON(info->access);
 829		index_offset = snd_ctl_get_ioff(kctl, &info->id);
 830		vd = &kctl->vd[index_offset];
 831		snd_ctl_build_ioff(&info->id, kctl, index_offset);
 832		info->access = vd->access;
 833		if (vd->owner) {
 834			info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 835			if (vd->owner == ctl)
 836				info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 837			info->owner = pid_vnr(vd->owner->pid);
 838		} else {
 839			info->owner = -1;
 840		}
 841	}
 842	up_read(&card->controls_rwsem);
 843	return result;
 844}
 845
 846static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 847				  struct snd_ctl_elem_info __user *_info)
 848{
 849	struct snd_ctl_elem_info info;
 850	int result;
 851
 852	if (copy_from_user(&info, _info, sizeof(info)))
 853		return -EFAULT;
 854	snd_power_lock(ctl->card);
 855	result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 856	if (result >= 0)
 857		result = snd_ctl_elem_info(ctl, &info);
 858	snd_power_unlock(ctl->card);
 859	if (result >= 0)
 860		if (copy_to_user(_info, &info, sizeof(info)))
 861			return -EFAULT;
 862	return result;
 863}
 864
 865static int snd_ctl_elem_read(struct snd_card *card,
 866			     struct snd_ctl_elem_value *control)
 867{
 868	struct snd_kcontrol *kctl;
 869	struct snd_kcontrol_volatile *vd;
 870	unsigned int index_offset;
 871	int result;
 872
 873	down_read(&card->controls_rwsem);
 874	kctl = snd_ctl_find_id(card, &control->id);
 875	if (kctl == NULL) {
 876		result = -ENOENT;
 877	} else {
 878		index_offset = snd_ctl_get_ioff(kctl, &control->id);
 879		vd = &kctl->vd[index_offset];
 880		if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 881		    kctl->get != NULL) {
 882			snd_ctl_build_ioff(&control->id, kctl, index_offset);
 883			result = kctl->get(kctl, control);
 884		} else
 885			result = -EPERM;
 886	}
 887	up_read(&card->controls_rwsem);
 888	return result;
 889}
 890
 891static int snd_ctl_elem_read_user(struct snd_card *card,
 892				  struct snd_ctl_elem_value __user *_control)
 893{
 894	struct snd_ctl_elem_value *control;
 895	int result;
 896
 897	control = memdup_user(_control, sizeof(*control));
 898	if (IS_ERR(control))
 899		return PTR_ERR(control);
 900
 901	snd_power_lock(card);
 902	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 903	if (result >= 0)
 904		result = snd_ctl_elem_read(card, control);
 905	snd_power_unlock(card);
 906	if (result >= 0)
 907		if (copy_to_user(_control, control, sizeof(*control)))
 908			result = -EFAULT;
 909	kfree(control);
 910	return result;
 911}
 912
 913static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 914			      struct snd_ctl_elem_value *control)
 915{
 916	struct snd_kcontrol *kctl;
 917	struct snd_kcontrol_volatile *vd;
 918	unsigned int index_offset;
 919	int result;
 920
 921	down_read(&card->controls_rwsem);
 922	kctl = snd_ctl_find_id(card, &control->id);
 923	if (kctl == NULL) {
 924		result = -ENOENT;
 925	} else {
 926		index_offset = snd_ctl_get_ioff(kctl, &control->id);
 927		vd = &kctl->vd[index_offset];
 928		if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 929		    kctl->put == NULL ||
 930		    (file && vd->owner && vd->owner != file)) {
 931			result = -EPERM;
 932		} else {
 933			snd_ctl_build_ioff(&control->id, kctl, index_offset);
 934			result = kctl->put(kctl, control);
 935		}
 936		if (result > 0) {
 937			struct snd_ctl_elem_id id = control->id;
 938			up_read(&card->controls_rwsem);
 939			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
 940			return 0;
 941		}
 942	}
 943	up_read(&card->controls_rwsem);
 944	return result;
 945}
 946
 947static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 948				   struct snd_ctl_elem_value __user *_control)
 949{
 950	struct snd_ctl_elem_value *control;
 951	struct snd_card *card;
 952	int result;
 953
 954	control = memdup_user(_control, sizeof(*control));
 955	if (IS_ERR(control))
 956		return PTR_ERR(control);
 957
 958	card = file->card;
 959	snd_power_lock(card);
 960	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 961	if (result >= 0)
 962		result = snd_ctl_elem_write(card, file, control);
 963	snd_power_unlock(card);
 964	if (result >= 0)
 965		if (copy_to_user(_control, control, sizeof(*control)))
 966			result = -EFAULT;
 967	kfree(control);
 968	return result;
 969}
 970
 971static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 972			     struct snd_ctl_elem_id __user *_id)
 973{
 974	struct snd_card *card = file->card;
 975	struct snd_ctl_elem_id id;
 976	struct snd_kcontrol *kctl;
 977	struct snd_kcontrol_volatile *vd;
 978	int result;
 979	
 980	if (copy_from_user(&id, _id, sizeof(id)))
 981		return -EFAULT;
 982	down_write(&card->controls_rwsem);
 983	kctl = snd_ctl_find_id(card, &id);
 984	if (kctl == NULL) {
 985		result = -ENOENT;
 986	} else {
 987		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 988		if (vd->owner != NULL)
 989			result = -EBUSY;
 990		else {
 991			vd->owner = file;
 992			result = 0;
 993		}
 994	}
 995	up_write(&card->controls_rwsem);
 996	return result;
 997}
 998
 999static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1000			       struct snd_ctl_elem_id __user *_id)
1001{
1002	struct snd_card *card = file->card;
1003	struct snd_ctl_elem_id id;
1004	struct snd_kcontrol *kctl;
1005	struct snd_kcontrol_volatile *vd;
1006	int result;
1007	
1008	if (copy_from_user(&id, _id, sizeof(id)))
1009		return -EFAULT;
1010	down_write(&card->controls_rwsem);
1011	kctl = snd_ctl_find_id(card, &id);
1012	if (kctl == NULL) {
1013		result = -ENOENT;
1014	} else {
1015		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1016		if (vd->owner == NULL)
1017			result = -EINVAL;
1018		else if (vd->owner != file)
1019			result = -EPERM;
1020		else {
1021			vd->owner = NULL;
1022			result = 0;
1023		}
1024	}
1025	up_write(&card->controls_rwsem);
1026	return result;
1027}
1028
1029struct user_element {
1030	struct snd_ctl_elem_info info;
1031	struct snd_card *card;
1032	char *elem_data;		/* element data */
1033	unsigned long elem_data_size;	/* size of element data in bytes */
1034	void *tlv_data;			/* TLV data */
1035	unsigned long tlv_data_size;	/* TLV data size */
1036	void *priv_data;		/* private data (like strings for enumerated type) */
1037};
1038
1039static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1040				  struct snd_ctl_elem_info *uinfo)
1041{
1042	struct user_element *ue = kcontrol->private_data;
1043	unsigned int offset;
1044
1045	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1046	*uinfo = ue->info;
1047	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1048
1049	return 0;
1050}
1051
1052static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1053				       struct snd_ctl_elem_info *uinfo)
1054{
1055	struct user_element *ue = kcontrol->private_data;
1056	const char *names;
1057	unsigned int item;
1058	unsigned int offset;
1059
1060	item = uinfo->value.enumerated.item;
1061
1062	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1063	*uinfo = ue->info;
1064	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1065
1066	item = min(item, uinfo->value.enumerated.items - 1);
1067	uinfo->value.enumerated.item = item;
1068
1069	names = ue->priv_data;
1070	for (; item > 0; --item)
1071		names += strlen(names) + 1;
1072	strcpy(uinfo->value.enumerated.name, names);
1073
1074	return 0;
1075}
1076
1077static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1078				 struct snd_ctl_elem_value *ucontrol)
1079{
1080	struct user_element *ue = kcontrol->private_data;
1081	unsigned int size = ue->elem_data_size;
1082	char *src = ue->elem_data +
1083			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1084
1085	mutex_lock(&ue->card->user_ctl_lock);
1086	memcpy(&ucontrol->value, src, size);
1087	mutex_unlock(&ue->card->user_ctl_lock);
1088	return 0;
1089}
1090
1091static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1092				 struct snd_ctl_elem_value *ucontrol)
1093{
1094	int change;
1095	struct user_element *ue = kcontrol->private_data;
1096	unsigned int size = ue->elem_data_size;
1097	char *dst = ue->elem_data +
1098			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1099
1100	mutex_lock(&ue->card->user_ctl_lock);
1101	change = memcmp(&ucontrol->value, dst, size) != 0;
1102	if (change)
1103		memcpy(dst, &ucontrol->value, size);
1104	mutex_unlock(&ue->card->user_ctl_lock);
1105	return change;
1106}
1107
1108static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1109				 int op_flag,
1110				 unsigned int size,
1111				 unsigned int __user *tlv)
1112{
1113	struct user_element *ue = kcontrol->private_data;
1114	int change = 0;
1115	void *new_data;
1116
1117	if (op_flag == SNDRV_CTL_TLV_OP_WRITE) {
1118		if (size > 1024 * 128)	/* sane value */
1119			return -EINVAL;
1120
1121		new_data = memdup_user(tlv, size);
1122		if (IS_ERR(new_data))
1123			return PTR_ERR(new_data);
1124		mutex_lock(&ue->card->user_ctl_lock);
1125		change = ue->tlv_data_size != size;
1126		if (!change)
1127			change = memcmp(ue->tlv_data, new_data, size);
1128		kfree(ue->tlv_data);
1129		ue->tlv_data = new_data;
1130		ue->tlv_data_size = size;
1131		mutex_unlock(&ue->card->user_ctl_lock);
1132	} else {
1133		int ret = 0;
1134
1135		mutex_lock(&ue->card->user_ctl_lock);
1136		if (!ue->tlv_data_size || !ue->tlv_data) {
1137			ret = -ENXIO;
1138			goto err_unlock;
1139		}
1140		if (size < ue->tlv_data_size) {
1141			ret = -ENOSPC;
1142			goto err_unlock;
1143		}
1144		if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1145			ret = -EFAULT;
1146err_unlock:
1147		mutex_unlock(&ue->card->user_ctl_lock);
1148		if (ret)
1149			return ret;
1150	}
1151	return change;
1152}
1153
1154static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1155{
1156	char *names, *p;
1157	size_t buf_len, name_len;
1158	unsigned int i;
1159	const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1160
1161	if (ue->info.value.enumerated.names_length > 64 * 1024)
1162		return -EINVAL;
1163
1164	names = memdup_user((const void __user *)user_ptrval,
1165		ue->info.value.enumerated.names_length);
1166	if (IS_ERR(names))
1167		return PTR_ERR(names);
1168
1169	/* check that there are enough valid names */
1170	buf_len = ue->info.value.enumerated.names_length;
1171	p = names;
1172	for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1173		name_len = strnlen(p, buf_len);
1174		if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1175			kfree(names);
1176			return -EINVAL;
1177		}
1178		p += name_len + 1;
1179		buf_len -= name_len + 1;
1180	}
1181
1182	ue->priv_data = names;
1183	ue->info.value.enumerated.names_ptr = 0;
1184
1185	return 0;
1186}
1187
1188static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1189{
1190	struct user_element *ue = kcontrol->private_data;
1191
1192	kfree(ue->tlv_data);
1193	kfree(ue->priv_data);
1194	kfree(ue);
1195}
1196
1197static int snd_ctl_elem_add(struct snd_ctl_file *file,
1198			    struct snd_ctl_elem_info *info, int replace)
1199{
1200	/* The capacity of struct snd_ctl_elem_value.value.*/
1201	static const unsigned int value_sizes[] = {
1202		[SNDRV_CTL_ELEM_TYPE_BOOLEAN]	= sizeof(long),
1203		[SNDRV_CTL_ELEM_TYPE_INTEGER]	= sizeof(long),
1204		[SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
1205		[SNDRV_CTL_ELEM_TYPE_BYTES]	= sizeof(unsigned char),
1206		[SNDRV_CTL_ELEM_TYPE_IEC958]	= sizeof(struct snd_aes_iec958),
1207		[SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
1208	};
1209	static const unsigned int max_value_counts[] = {
1210		[SNDRV_CTL_ELEM_TYPE_BOOLEAN]	= 128,
1211		[SNDRV_CTL_ELEM_TYPE_INTEGER]	= 128,
1212		[SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
1213		[SNDRV_CTL_ELEM_TYPE_BYTES]	= 512,
1214		[SNDRV_CTL_ELEM_TYPE_IEC958]	= 1,
1215		[SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
1216	};
1217	struct snd_card *card = file->card;
1218	struct snd_kcontrol *kctl;
1219	unsigned int count;
1220	unsigned int access;
1221	long private_size;
1222	struct user_element *ue;
1223	unsigned int offset;
1224	int err;
1225
1226	if (!*info->id.name)
1227		return -EINVAL;
1228	if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1229		return -EINVAL;
1230
1231	/* Delete a control to replace them if needed. */
1232	if (replace) {
1233		info->id.numid = 0;
1234		err = snd_ctl_remove_user_ctl(file, &info->id);
1235		if (err)
1236			return err;
1237	}
1238
1239	/*
1240	 * The number of userspace controls are counted control by control,
1241	 * not element by element.
1242	 */
1243	if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1244		return -ENOMEM;
1245
1246	/* Check the number of elements for this userspace control. */
1247	count = info->owner;
1248	if (count == 0)
1249		count = 1;
1250
1251	/* Arrange access permissions if needed. */
1252	access = info->access;
1253	if (access == 0)
1254		access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1255	access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1256		   SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1257		   SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE);
1258	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
1259		access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1260	access |= SNDRV_CTL_ELEM_ACCESS_USER;
1261
1262	/*
1263	 * Check information and calculate the size of data specific to
1264	 * this userspace control.
1265	 */
1266	if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
1267	    info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
1268		return -EINVAL;
1269	if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
1270	    info->value.enumerated.items == 0)
1271		return -EINVAL;
1272	if (info->count < 1 ||
1273	    info->count > max_value_counts[info->type])
 
 
1274		return -EINVAL;
1275	private_size = value_sizes[info->type] * info->count;
1276
1277	/*
1278	 * Keep memory object for this userspace control. After passing this
1279	 * code block, the instance should be freed by snd_ctl_free_one().
1280	 *
1281	 * Note that these elements in this control are locked.
1282	 */
1283	err = snd_ctl_new(&kctl, count, access, file);
1284	if (err < 0)
1285		return err;
1286	memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1287	kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1288				     GFP_KERNEL);
1289	if (kctl->private_data == NULL) {
1290		kfree(kctl);
1291		return -ENOMEM;
1292	}
1293	kctl->private_free = snd_ctl_elem_user_free;
1294
1295	/* Set private data for this userspace control. */
1296	ue = (struct user_element *)kctl->private_data;
1297	ue->card = card;
1298	ue->info = *info;
1299	ue->info.access = 0;
1300	ue->elem_data = (char *)ue + sizeof(*ue);
1301	ue->elem_data_size = private_size;
1302	if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1303		err = snd_ctl_elem_init_enum_names(ue);
1304		if (err < 0) {
1305			snd_ctl_free_one(kctl);
1306			return err;
1307		}
1308	}
1309
1310	/* Set callback functions. */
1311	if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1312		kctl->info = snd_ctl_elem_user_enum_info;
1313	else
1314		kctl->info = snd_ctl_elem_user_info;
1315	if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1316		kctl->get = snd_ctl_elem_user_get;
1317	if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1318		kctl->put = snd_ctl_elem_user_put;
1319	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
1320		kctl->tlv.c = snd_ctl_elem_user_tlv;
1321
1322	/* This function manage to free the instance on failure. */
1323	err = snd_ctl_add(card, kctl);
1324	if (err < 0)
1325		return err;
1326	offset = snd_ctl_get_ioff(kctl, &info->id);
1327	snd_ctl_build_ioff(&info->id, kctl, offset);
1328	/*
1329	 * Here we cannot fill any field for the number of elements added by
1330	 * this operation because there're no specific fields. The usage of
1331	 * 'owner' field for this purpose may cause any bugs to userspace
1332	 * applications because the field originally means PID of a process
1333	 * which locks the element.
1334	 */
1335
1336	down_write(&card->controls_rwsem);
1337	card->user_ctl_count++;
1338	up_write(&card->controls_rwsem);
1339
1340	return 0;
1341}
1342
1343static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1344				 struct snd_ctl_elem_info __user *_info, int replace)
1345{
1346	struct snd_ctl_elem_info info;
1347	int err;
1348
1349	if (copy_from_user(&info, _info, sizeof(info)))
1350		return -EFAULT;
1351	err = snd_ctl_elem_add(file, &info, replace);
1352	if (err < 0)
1353		return err;
1354	if (copy_to_user(_info, &info, sizeof(info))) {
1355		snd_ctl_remove_user_ctl(file, &info.id);
1356		return -EFAULT;
1357	}
1358
1359	return 0;
1360}
1361
1362static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1363			       struct snd_ctl_elem_id __user *_id)
1364{
1365	struct snd_ctl_elem_id id;
1366
1367	if (copy_from_user(&id, _id, sizeof(id)))
1368		return -EFAULT;
1369	return snd_ctl_remove_user_ctl(file, &id);
1370}
1371
1372static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1373{
1374	int subscribe;
1375	if (get_user(subscribe, ptr))
1376		return -EFAULT;
1377	if (subscribe < 0) {
1378		subscribe = file->subscribed;
1379		if (put_user(subscribe, ptr))
1380			return -EFAULT;
1381		return 0;
1382	}
1383	if (subscribe) {
1384		file->subscribed = 1;
1385		return 0;
1386	} else if (file->subscribed) {
1387		snd_ctl_empty_read_queue(file);
1388		file->subscribed = 0;
1389	}
1390	return 0;
1391}
1392
1393static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1394                             struct snd_ctl_tlv __user *_tlv,
1395                             int op_flag)
1396{
1397	struct snd_card *card = file->card;
1398	struct snd_ctl_tlv tlv;
1399	struct snd_kcontrol *kctl;
1400	struct snd_kcontrol_volatile *vd;
1401	unsigned int len;
1402	int err = 0;
1403
1404	if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1405		return -EFAULT;
1406	if (tlv.length < sizeof(unsigned int) * 2)
1407		return -EINVAL;
1408	if (!tlv.numid)
1409		return -EINVAL;
1410	down_read(&card->controls_rwsem);
1411	kctl = snd_ctl_find_numid(card, tlv.numid);
1412	if (kctl == NULL) {
1413		err = -ENOENT;
1414		goto __kctl_end;
1415	}
1416	if (kctl->tlv.p == NULL) {
1417		err = -ENXIO;
1418		goto __kctl_end;
1419	}
1420	vd = &kctl->vd[tlv.numid - kctl->id.numid];
1421	if ((op_flag == SNDRV_CTL_TLV_OP_READ &&
1422	     (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1423	    (op_flag == SNDRV_CTL_TLV_OP_WRITE &&
1424	     (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1425	    (op_flag == SNDRV_CTL_TLV_OP_CMD &&
1426	     (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1427	    	err = -ENXIO;
1428	    	goto __kctl_end;
1429	}
1430	if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1431		if (vd->owner != NULL && vd->owner != file) {
1432			err = -EPERM;
1433			goto __kctl_end;
1434		}
1435		err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1436		if (err > 0) {
1437			struct snd_ctl_elem_id id = kctl->id;
1438			up_read(&card->controls_rwsem);
1439			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1440			return 0;
1441		}
1442	} else {
1443		if (op_flag != SNDRV_CTL_TLV_OP_READ) {
1444			err = -ENXIO;
1445			goto __kctl_end;
1446		}
1447		len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1448		if (tlv.length < len) {
1449			err = -ENOMEM;
1450			goto __kctl_end;
1451		}
1452		if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1453			err = -EFAULT;
1454	}
1455      __kctl_end:
1456	up_read(&card->controls_rwsem);
1457	return err;
1458}
1459
1460static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1461{
1462	struct snd_ctl_file *ctl;
1463	struct snd_card *card;
1464	struct snd_kctl_ioctl *p;
1465	void __user *argp = (void __user *)arg;
1466	int __user *ip = argp;
1467	int err;
1468
1469	ctl = file->private_data;
1470	card = ctl->card;
1471	if (snd_BUG_ON(!card))
1472		return -ENXIO;
1473	switch (cmd) {
1474	case SNDRV_CTL_IOCTL_PVERSION:
1475		return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1476	case SNDRV_CTL_IOCTL_CARD_INFO:
1477		return snd_ctl_card_info(card, ctl, cmd, argp);
1478	case SNDRV_CTL_IOCTL_ELEM_LIST:
1479		return snd_ctl_elem_list(card, argp);
1480	case SNDRV_CTL_IOCTL_ELEM_INFO:
1481		return snd_ctl_elem_info_user(ctl, argp);
1482	case SNDRV_CTL_IOCTL_ELEM_READ:
1483		return snd_ctl_elem_read_user(card, argp);
1484	case SNDRV_CTL_IOCTL_ELEM_WRITE:
1485		return snd_ctl_elem_write_user(ctl, argp);
1486	case SNDRV_CTL_IOCTL_ELEM_LOCK:
1487		return snd_ctl_elem_lock(ctl, argp);
1488	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1489		return snd_ctl_elem_unlock(ctl, argp);
1490	case SNDRV_CTL_IOCTL_ELEM_ADD:
1491		return snd_ctl_elem_add_user(ctl, argp, 0);
1492	case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1493		return snd_ctl_elem_add_user(ctl, argp, 1);
1494	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1495		return snd_ctl_elem_remove(ctl, argp);
1496	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1497		return snd_ctl_subscribe_events(ctl, ip);
1498	case SNDRV_CTL_IOCTL_TLV_READ:
1499		return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1500	case SNDRV_CTL_IOCTL_TLV_WRITE:
1501		return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1502	case SNDRV_CTL_IOCTL_TLV_COMMAND:
1503		return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1504	case SNDRV_CTL_IOCTL_POWER:
1505		return -ENOPROTOOPT;
1506	case SNDRV_CTL_IOCTL_POWER_STATE:
1507#ifdef CONFIG_PM
1508		return put_user(card->power_state, ip) ? -EFAULT : 0;
1509#else
1510		return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1511#endif
1512	}
1513	down_read(&snd_ioctl_rwsem);
1514	list_for_each_entry(p, &snd_control_ioctls, list) {
1515		err = p->fioctl(card, ctl, cmd, arg);
1516		if (err != -ENOIOCTLCMD) {
1517			up_read(&snd_ioctl_rwsem);
1518			return err;
1519		}
1520	}
1521	up_read(&snd_ioctl_rwsem);
1522	dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1523	return -ENOTTY;
1524}
1525
1526static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1527			    size_t count, loff_t * offset)
1528{
1529	struct snd_ctl_file *ctl;
1530	int err = 0;
1531	ssize_t result = 0;
1532
1533	ctl = file->private_data;
1534	if (snd_BUG_ON(!ctl || !ctl->card))
1535		return -ENXIO;
1536	if (!ctl->subscribed)
1537		return -EBADFD;
1538	if (count < sizeof(struct snd_ctl_event))
1539		return -EINVAL;
1540	spin_lock_irq(&ctl->read_lock);
1541	while (count >= sizeof(struct snd_ctl_event)) {
1542		struct snd_ctl_event ev;
1543		struct snd_kctl_event *kev;
1544		while (list_empty(&ctl->events)) {
1545			wait_queue_t wait;
1546			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1547				err = -EAGAIN;
1548				goto __end_lock;
1549			}
1550			init_waitqueue_entry(&wait, current);
1551			add_wait_queue(&ctl->change_sleep, &wait);
1552			set_current_state(TASK_INTERRUPTIBLE);
1553			spin_unlock_irq(&ctl->read_lock);
1554			schedule();
1555			remove_wait_queue(&ctl->change_sleep, &wait);
1556			if (ctl->card->shutdown)
1557				return -ENODEV;
1558			if (signal_pending(current))
1559				return -ERESTARTSYS;
1560			spin_lock_irq(&ctl->read_lock);
1561		}
1562		kev = snd_kctl_event(ctl->events.next);
1563		ev.type = SNDRV_CTL_EVENT_ELEM;
1564		ev.data.elem.mask = kev->mask;
1565		ev.data.elem.id = kev->id;
1566		list_del(&kev->list);
1567		spin_unlock_irq(&ctl->read_lock);
1568		kfree(kev);
1569		if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1570			err = -EFAULT;
1571			goto __end;
1572		}
1573		spin_lock_irq(&ctl->read_lock);
1574		buffer += sizeof(struct snd_ctl_event);
1575		count -= sizeof(struct snd_ctl_event);
1576		result += sizeof(struct snd_ctl_event);
1577	}
1578      __end_lock:
1579	spin_unlock_irq(&ctl->read_lock);
1580      __end:
1581      	return result > 0 ? result : err;
1582}
1583
1584static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1585{
1586	unsigned int mask;
1587	struct snd_ctl_file *ctl;
1588
1589	ctl = file->private_data;
1590	if (!ctl->subscribed)
1591		return 0;
1592	poll_wait(file, &ctl->change_sleep, wait);
1593
1594	mask = 0;
1595	if (!list_empty(&ctl->events))
1596		mask |= POLLIN | POLLRDNORM;
1597
1598	return mask;
1599}
1600
1601/*
1602 * register the device-specific control-ioctls.
1603 * called from each device manager like pcm.c, hwdep.c, etc.
1604 */
1605static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1606{
1607	struct snd_kctl_ioctl *pn;
1608
1609	pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1610	if (pn == NULL)
1611		return -ENOMEM;
1612	pn->fioctl = fcn;
1613	down_write(&snd_ioctl_rwsem);
1614	list_add_tail(&pn->list, lists);
1615	up_write(&snd_ioctl_rwsem);
1616	return 0;
1617}
1618
1619/**
1620 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1621 * @fcn: ioctl callback function
1622 *
1623 * called from each device manager like pcm.c, hwdep.c, etc.
1624 */
1625int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1626{
1627	return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1628}
1629EXPORT_SYMBOL(snd_ctl_register_ioctl);
1630
1631#ifdef CONFIG_COMPAT
1632/**
1633 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1634 * control-ioctls
1635 * @fcn: ioctl callback function
1636 */
1637int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1638{
1639	return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1640}
1641EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1642#endif
1643
1644/*
1645 * de-register the device-specific control-ioctls.
1646 */
1647static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1648				     struct list_head *lists)
1649{
1650	struct snd_kctl_ioctl *p;
1651
1652	if (snd_BUG_ON(!fcn))
1653		return -EINVAL;
1654	down_write(&snd_ioctl_rwsem);
1655	list_for_each_entry(p, lists, list) {
1656		if (p->fioctl == fcn) {
1657			list_del(&p->list);
1658			up_write(&snd_ioctl_rwsem);
1659			kfree(p);
1660			return 0;
1661		}
1662	}
1663	up_write(&snd_ioctl_rwsem);
1664	snd_BUG();
1665	return -EINVAL;
1666}
1667
1668/**
1669 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1670 * @fcn: ioctl callback function to unregister
1671 */
1672int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1673{
1674	return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1675}
1676EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1677
1678#ifdef CONFIG_COMPAT
1679/**
1680 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
1681 * control-ioctls
1682 * @fcn: ioctl callback function to unregister
1683 */
1684int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1685{
1686	return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1687}
1688EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1689#endif
1690
1691static int snd_ctl_fasync(int fd, struct file * file, int on)
1692{
1693	struct snd_ctl_file *ctl;
1694
1695	ctl = file->private_data;
1696	return fasync_helper(fd, file, on, &ctl->fasync);
1697}
1698
1699/* return the preferred subdevice number if already assigned;
1700 * otherwise return -1
1701 */
1702int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
1703{
1704	struct snd_ctl_file *kctl;
1705	int subdevice = -1;
1706
1707	read_lock(&card->ctl_files_rwlock);
1708	list_for_each_entry(kctl, &card->ctl_files, list) {
1709		if (kctl->pid == task_pid(current)) {
1710			subdevice = kctl->preferred_subdevice[type];
1711			if (subdevice != -1)
1712				break;
1713		}
1714	}
1715	read_unlock(&card->ctl_files_rwlock);
1716	return subdevice;
1717}
1718EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
1719
1720/*
1721 * ioctl32 compat
1722 */
1723#ifdef CONFIG_COMPAT
1724#include "control_compat.c"
1725#else
1726#define snd_ctl_ioctl_compat	NULL
1727#endif
1728
1729/*
1730 *  INIT PART
1731 */
1732
1733static const struct file_operations snd_ctl_f_ops =
1734{
1735	.owner =	THIS_MODULE,
1736	.read =		snd_ctl_read,
1737	.open =		snd_ctl_open,
1738	.release =	snd_ctl_release,
1739	.llseek =	no_llseek,
1740	.poll =		snd_ctl_poll,
1741	.unlocked_ioctl =	snd_ctl_ioctl,
1742	.compat_ioctl =	snd_ctl_ioctl_compat,
1743	.fasync =	snd_ctl_fasync,
1744};
1745
1746/*
1747 * registration of the control device
1748 */
1749static int snd_ctl_dev_register(struct snd_device *device)
1750{
1751	struct snd_card *card = device->device_data;
1752
1753	return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1754				   &snd_ctl_f_ops, card, &card->ctl_dev);
1755}
1756
1757/*
1758 * disconnection of the control device
1759 */
1760static int snd_ctl_dev_disconnect(struct snd_device *device)
1761{
1762	struct snd_card *card = device->device_data;
1763	struct snd_ctl_file *ctl;
1764
1765	read_lock(&card->ctl_files_rwlock);
1766	list_for_each_entry(ctl, &card->ctl_files, list) {
1767		wake_up(&ctl->change_sleep);
1768		kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1769	}
1770	read_unlock(&card->ctl_files_rwlock);
1771
1772	return snd_unregister_device(&card->ctl_dev);
1773}
1774
1775/*
1776 * free all controls
1777 */
1778static int snd_ctl_dev_free(struct snd_device *device)
1779{
1780	struct snd_card *card = device->device_data;
1781	struct snd_kcontrol *control;
1782
1783	down_write(&card->controls_rwsem);
1784	while (!list_empty(&card->controls)) {
1785		control = snd_kcontrol(card->controls.next);
1786		snd_ctl_remove(card, control);
1787	}
1788	up_write(&card->controls_rwsem);
1789	put_device(&card->ctl_dev);
1790	return 0;
1791}
1792
1793/*
1794 * create control core:
1795 * called from init.c
1796 */
1797int snd_ctl_create(struct snd_card *card)
1798{
1799	static struct snd_device_ops ops = {
1800		.dev_free = snd_ctl_dev_free,
1801		.dev_register =	snd_ctl_dev_register,
1802		.dev_disconnect = snd_ctl_dev_disconnect,
1803	};
1804	int err;
1805
1806	if (snd_BUG_ON(!card))
1807		return -ENXIO;
1808	if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
1809		return -ENXIO;
1810
1811	snd_device_initialize(&card->ctl_dev, card);
1812	dev_set_name(&card->ctl_dev, "controlC%d", card->number);
1813
1814	err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1815	if (err < 0)
1816		put_device(&card->ctl_dev);
1817	return err;
1818}
1819
1820/*
1821 * Frequently used control callbacks/helpers
1822 */
1823
1824/**
1825 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
1826 * callback with a mono channel
1827 * @kcontrol: the kcontrol instance
1828 * @uinfo: info to store
1829 *
1830 * This is a function that can be used as info callback for a standard
1831 * boolean control with a single mono channel.
1832 */
1833int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1834			      struct snd_ctl_elem_info *uinfo)
1835{
1836	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1837	uinfo->count = 1;
1838	uinfo->value.integer.min = 0;
1839	uinfo->value.integer.max = 1;
1840	return 0;
1841}
1842EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1843
1844/**
1845 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
1846 * callback with stereo two channels
1847 * @kcontrol: the kcontrol instance
1848 * @uinfo: info to store
1849 *
1850 * This is a function that can be used as info callback for a standard
1851 * boolean control with stereo two channels.
1852 */
1853int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1854				struct snd_ctl_elem_info *uinfo)
1855{
1856	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1857	uinfo->count = 2;
1858	uinfo->value.integer.min = 0;
1859	uinfo->value.integer.max = 1;
1860	return 0;
1861}
1862EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1863
1864/**
1865 * snd_ctl_enum_info - fills the info structure for an enumerated control
1866 * @info: the structure to be filled
1867 * @channels: the number of the control's channels; often one
1868 * @items: the number of control values; also the size of @names
1869 * @names: an array containing the names of all control values
1870 *
1871 * Sets all required fields in @info to their appropriate values.
1872 * If the control's accessibility is not the default (readable and writable),
1873 * the caller has to fill @info->access.
1874 *
1875 * Return: Zero.
1876 */
1877int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1878		      unsigned int items, const char *const names[])
1879{
1880	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1881	info->count = channels;
1882	info->value.enumerated.items = items;
1883	if (!items)
1884		return 0;
1885	if (info->value.enumerated.item >= items)
1886		info->value.enumerated.item = items - 1;
1887	WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
1888	     "ALSA: too long item name '%s'\n",
1889	     names[info->value.enumerated.item]);
1890	strlcpy(info->value.enumerated.name,
1891		names[info->value.enumerated.item],
1892		sizeof(info->value.enumerated.name));
1893	return 0;
1894}
1895EXPORT_SYMBOL(snd_ctl_enum_info);