control.c 51.1 KB
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/*
 *  Routines for driver control interface
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 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
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 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/threads.h>
#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/time.h>
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#include <linux/mm.h>
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#include <linux/sched/signal.h>
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#include <sound/core.h>
#include <sound/minors.h>
#include <sound/info.h>
#include <sound/control.h>

/* max number of user-defined controls */
#define MAX_USER_CONTROLS	32
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#define MAX_CONTROL_COUNT	1028
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struct snd_kctl_ioctl {
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	struct list_head list;		/* list of all ioctls */
	snd_kctl_ioctl_func_t fioctl;
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};
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static DECLARE_RWSEM(snd_ioctl_rwsem);
static LIST_HEAD(snd_control_ioctls);
#ifdef CONFIG_COMPAT
static LIST_HEAD(snd_control_compat_ioctls);
#endif

static int snd_ctl_open(struct inode *inode, struct file *file)
{
	unsigned long flags;
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	struct snd_card *card;
	struct snd_ctl_file *ctl;
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	int i, err;
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	err = nonseekable_open(inode, file);
	if (err < 0)
		return err;

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	card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
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	if (!card) {
		err = -ENODEV;
		goto __error1;
	}
	err = snd_card_file_add(card, file);
	if (err < 0) {
		err = -ENODEV;
		goto __error1;
	}
	if (!try_module_get(card->module)) {
		err = -EFAULT;
		goto __error2;
	}
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	ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
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	if (ctl == NULL) {
		err = -ENOMEM;
		goto __error;
	}
	INIT_LIST_HEAD(&ctl->events);
	init_waitqueue_head(&ctl->change_sleep);
	spin_lock_init(&ctl->read_lock);
	ctl->card = card;
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	for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
		ctl->preferred_subdevice[i] = -1;
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	ctl->pid = get_pid(task_pid(current));
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	file->private_data = ctl;
	write_lock_irqsave(&card->ctl_files_rwlock, flags);
	list_add_tail(&ctl->list, &card->ctl_files);
	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
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	snd_card_unref(card);
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	return 0;

      __error:
	module_put(card->module);
      __error2:
	snd_card_file_remove(card, file);
      __error1:
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	if (card)
		snd_card_unref(card);
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      	return err;
}

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static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
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{
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	unsigned long flags;
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	struct snd_kctl_event *cread;
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	spin_lock_irqsave(&ctl->read_lock, flags);
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	while (!list_empty(&ctl->events)) {
		cread = snd_kctl_event(ctl->events.next);
		list_del(&cread->list);
		kfree(cread);
	}
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	spin_unlock_irqrestore(&ctl->read_lock, flags);
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}

static int snd_ctl_release(struct inode *inode, struct file *file)
{
	unsigned long flags;
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	struct snd_card *card;
	struct snd_ctl_file *ctl;
	struct snd_kcontrol *control;
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	unsigned int idx;

	ctl = file->private_data;
	file->private_data = NULL;
	card = ctl->card;
	write_lock_irqsave(&card->ctl_files_rwlock, flags);
	list_del(&ctl->list);
	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
	down_write(&card->controls_rwsem);
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	list_for_each_entry(control, &card->controls, list)
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		for (idx = 0; idx < control->count; idx++)
			if (control->vd[idx].owner == ctl)
				control->vd[idx].owner = NULL;
	up_write(&card->controls_rwsem);
	snd_ctl_empty_read_queue(ctl);
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	put_pid(ctl->pid);
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	kfree(ctl);
	module_put(card->module);
	snd_card_file_remove(card, file);
	return 0;
}

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/**
 * snd_ctl_notify - Send notification to user-space for a control change
 * @card: the card to send notification
 * @mask: the event mask, SNDRV_CTL_EVENT_*
 * @id: the ctl element id to send notification
 *
 * This function adds an event record with the given id and mask, appends
 * to the list and wakes up the user-space for notification.  This can be
 * called in the atomic context.
 */
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void snd_ctl_notify(struct snd_card *card, unsigned int mask,
		    struct snd_ctl_elem_id *id)
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{
	unsigned long flags;
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	struct snd_ctl_file *ctl;
	struct snd_kctl_event *ev;
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	if (snd_BUG_ON(!card || !id))
		return;
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	if (card->shutdown)
		return;
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	read_lock(&card->ctl_files_rwlock);
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#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
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	card->mixer_oss_change_count++;
#endif
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	list_for_each_entry(ctl, &card->ctl_files, list) {
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		if (!ctl->subscribed)
			continue;
		spin_lock_irqsave(&ctl->read_lock, flags);
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		list_for_each_entry(ev, &ctl->events, list) {
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			if (ev->id.numid == id->numid) {
				ev->mask |= mask;
				goto _found;
			}
		}
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		ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
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		if (ev) {
			ev->id = *id;
			ev->mask = mask;
			list_add_tail(&ev->list, &ctl->events);
		} else {
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			dev_err(card->dev, "No memory available to allocate event\n");
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		}
	_found:
		wake_up(&ctl->change_sleep);
		spin_unlock_irqrestore(&ctl->read_lock, flags);
		kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
	}
	read_unlock(&card->ctl_files_rwlock);
}
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EXPORT_SYMBOL(snd_ctl_notify);

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/**
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 * snd_ctl_new - create a new control instance with some elements
 * @kctl: the pointer to store new control instance
 * @count: the number of elements in this control
 * @access: the default access flags for elements in this control
 * @file: given when locking these elements
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 *
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 * Allocates a memory object for a new control instance. The instance has
 * elements as many as the given number (@count). Each element has given
 * access permissions (@access). Each element is locked when @file is given.
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 *
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 * Return: 0 on success, error code on failure
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 */
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static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
		       unsigned int access, struct snd_ctl_file *file)
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{
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	unsigned int size;
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	unsigned int idx;
	
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	if (count == 0 || count > MAX_CONTROL_COUNT)
		return -EINVAL;
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	size  = sizeof(struct snd_kcontrol);
	size += sizeof(struct snd_kcontrol_volatile) * count;
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	*kctl = kzalloc(size, GFP_KERNEL);
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	if (!*kctl)
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		return -ENOMEM;

	for (idx = 0; idx < count; idx++) {
		(*kctl)->vd[idx].access = access;
		(*kctl)->vd[idx].owner = file;
	}
	(*kctl)->count = count;

	return 0;
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}

/**
 * snd_ctl_new1 - create a control instance from the template
 * @ncontrol: the initialization record
 * @private_data: the private data to set
 *
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 * Allocates a new struct snd_kcontrol instance and initialize from the given 
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 * template.  When the access field of ncontrol is 0, it's assumed as
 * READWRITE access. When the count field is 0, it's assumes as one.
 *
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 * Return: The pointer of the newly generated instance, or %NULL on failure.
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 */
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struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
				  void *private_data)
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{
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	struct snd_kcontrol *kctl;
	unsigned int count;
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	unsigned int access;
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	int err;
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	if (snd_BUG_ON(!ncontrol || !ncontrol->info))
		return NULL;
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	count = ncontrol->count;
	if (count == 0)
		count = 1;

	access = ncontrol->access;
	if (access == 0)
		access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
	access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
		   SNDRV_CTL_ELEM_ACCESS_VOLATILE |
		   SNDRV_CTL_ELEM_ACCESS_INACTIVE |
		   SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
		   SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
		   SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);

	err = snd_ctl_new(&kctl, count, access, NULL);
	if (err < 0)
		return NULL;

	/* The 'numid' member is decided when calling snd_ctl_add(). */
	kctl->id.iface = ncontrol->iface;
	kctl->id.device = ncontrol->device;
	kctl->id.subdevice = ncontrol->subdevice;
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	if (ncontrol->name) {
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		strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
		if (strcmp(ncontrol->name, kctl->id.name) != 0)
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			pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
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				ncontrol->name, kctl->id.name);
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	}
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	kctl->id.index = ncontrol->index;

	kctl->info = ncontrol->info;
	kctl->get = ncontrol->get;
	kctl->put = ncontrol->put;
	kctl->tlv.p = ncontrol->tlv.p;

	kctl->private_value = ncontrol->private_value;
	kctl->private_data = private_data;

	return kctl;
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}
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EXPORT_SYMBOL(snd_ctl_new1);

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/**
 * snd_ctl_free_one - release the control instance
 * @kcontrol: the control instance
 *
 * Releases the control instance created via snd_ctl_new()
 * or snd_ctl_new1().
 * Don't call this after the control was added to the card.
 */
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void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
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{
	if (kcontrol) {
		if (kcontrol->private_free)
			kcontrol->private_free(kcontrol);
		kfree(kcontrol);
	}
}
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EXPORT_SYMBOL(snd_ctl_free_one);

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static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
					  unsigned int count)
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{
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	struct snd_kcontrol *kctl;
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	/* Make sure that the ids assigned to the control do not wrap around */
	if (card->last_numid >= UINT_MAX - count)
		card->last_numid = 0;

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	list_for_each_entry(kctl, &card->controls, list) {
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		if (kctl->id.numid < card->last_numid + 1 + count &&
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		    kctl->id.numid + kctl->count > card->last_numid + 1) {
		    	card->last_numid = kctl->id.numid + kctl->count - 1;
			return true;
		}
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	}
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	return false;
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}

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static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
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{
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	unsigned int iter = 100000;
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	while (snd_ctl_remove_numid_conflict(card, count)) {
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		if (--iter == 0) {
			/* this situation is very unlikely */
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			dev_err(card->dev, "unable to allocate new control numid\n");
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			return -ENOMEM;
		}
	}
	return 0;
}

/**
 * snd_ctl_add - add the control instance to the card
 * @card: the card instance
 * @kcontrol: the control instance to add
 *
 * Adds the control instance created via snd_ctl_new() or
 * snd_ctl_new1() to the given card. Assigns also an unique
 * numid used for fast search.
 *
 * It frees automatically the control which cannot be added.
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 *
 * Return: Zero if successful, or a negative error code on failure.
 *
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 */
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int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
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{
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	struct snd_ctl_elem_id id;
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	unsigned int idx;
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	unsigned int count;
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	int err = -EINVAL;
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	if (! kcontrol)
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		return err;
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	if (snd_BUG_ON(!card || !kcontrol->info))
		goto error;
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	id = kcontrol->id;
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	if (id.index > UINT_MAX - kcontrol->count)
		goto error;

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	down_write(&card->controls_rwsem);
	if (snd_ctl_find_id(card, &id)) {
		up_write(&card->controls_rwsem);
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		dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
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					id.iface,
					id.device,
					id.subdevice,
					id.name,
					id.index);
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		err = -EBUSY;
		goto error;
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	}
	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
		up_write(&card->controls_rwsem);
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		err = -ENOMEM;
		goto error;
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	}
	list_add_tail(&kcontrol->list, &card->controls);
	card->controls_count += kcontrol->count;
	kcontrol->id.numid = card->last_numid + 1;
	card->last_numid += kcontrol->count;
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	id = kcontrol->id;
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	count = kcontrol->count;
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	up_write(&card->controls_rwsem);
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	for (idx = 0; idx < count; idx++, id.index++, id.numid++)
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		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
	return 0;
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 error:
	snd_ctl_free_one(kcontrol);
	return err;
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}
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EXPORT_SYMBOL(snd_ctl_add);

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/**
 * snd_ctl_replace - replace the control instance of the card
 * @card: the card instance
 * @kcontrol: the control instance to replace
 * @add_on_replace: add the control if not already added
 *
 * Replaces the given control.  If the given control does not exist
 * and the add_on_replace flag is set, the control is added.  If the
 * control exists, it is destroyed first.
 *
 * It frees automatically the control which cannot be added or replaced.
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 *
 * Return: Zero if successful, or a negative error code on failure.
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 */
int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
		    bool add_on_replace)
{
	struct snd_ctl_elem_id id;
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	unsigned int count;
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	unsigned int idx;
	struct snd_kcontrol *old;
	int ret;

	if (!kcontrol)
		return -EINVAL;
	if (snd_BUG_ON(!card || !kcontrol->info)) {
		ret = -EINVAL;
		goto error;
	}
	id = kcontrol->id;
	down_write(&card->controls_rwsem);
	old = snd_ctl_find_id(card, &id);
	if (!old) {
		if (add_on_replace)
			goto add;
		up_write(&card->controls_rwsem);
		ret = -EINVAL;
		goto error;
	}
	ret = snd_ctl_remove(card, old);
	if (ret < 0) {
		up_write(&card->controls_rwsem);
		goto error;
	}
add:
	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
		up_write(&card->controls_rwsem);
		ret = -ENOMEM;
		goto error;
	}
	list_add_tail(&kcontrol->list, &card->controls);
	card->controls_count += kcontrol->count;
	kcontrol->id.numid = card->last_numid + 1;
	card->last_numid += kcontrol->count;
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	id = kcontrol->id;
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	count = kcontrol->count;
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	up_write(&card->controls_rwsem);
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	for (idx = 0; idx < count; idx++, id.index++, id.numid++)
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		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
	return 0;

error:
	snd_ctl_free_one(kcontrol);
	return ret;
}
EXPORT_SYMBOL(snd_ctl_replace);

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/**
 * snd_ctl_remove - remove the control from the card and release it
 * @card: the card instance
 * @kcontrol: the control instance to remove
 *
 * Removes the control from the card and then releases the instance.
 * You don't need to call snd_ctl_free_one(). You must be in
 * the write lock - down_write(&card->controls_rwsem).
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 *
 * Return: 0 if successful, or a negative error code on failure.
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 */
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int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
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{
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	struct snd_ctl_elem_id id;
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	unsigned int idx;

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	if (snd_BUG_ON(!card || !kcontrol))
		return -EINVAL;
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	list_del(&kcontrol->list);
	card->controls_count -= kcontrol->count;
	id = kcontrol->id;
	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
	snd_ctl_free_one(kcontrol);
	return 0;
}
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EXPORT_SYMBOL(snd_ctl_remove);

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/**
 * snd_ctl_remove_id - remove the control of the given id and release it
 * @card: the card instance
 * @id: the control id to remove
 *
 * Finds the control instance with the given id, removes it from the
 * card list and releases it.
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 *
 * Return: 0 if successful, or a negative error code on failure.
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 */
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int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
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{
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	struct snd_kcontrol *kctl;
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	int ret;

	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, id);
	if (kctl == NULL) {
		up_write(&card->controls_rwsem);
		return -ENOENT;
	}
	ret = snd_ctl_remove(card, kctl);
	up_write(&card->controls_rwsem);
	return ret;
}
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EXPORT_SYMBOL(snd_ctl_remove_id);

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/**
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 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
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 * @file: active control handle
 * @id: the control id to remove
 *
 * Finds the control instance with the given id, removes it from the
 * card list and releases it.
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 *
 * Return: 0 if successful, or a negative error code on failure.
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 */
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static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
				   struct snd_ctl_elem_id *id)
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{
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	struct snd_card *card = file->card;
	struct snd_kcontrol *kctl;
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	int idx, ret;

	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, id);
	if (kctl == NULL) {
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		ret = -ENOENT;
		goto error;
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	}
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	if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
		ret = -EINVAL;
		goto error;
	}
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	for (idx = 0; idx < kctl->count; idx++)
		if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
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			ret = -EBUSY;
			goto error;
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		}
	ret = snd_ctl_remove(card, kctl);
569 570 571
	if (ret < 0)
		goto error;
	card->user_ctl_count--;
572
error:
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	up_write(&card->controls_rwsem);
	return ret;
}

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/**
 * snd_ctl_activate_id - activate/inactivate the control of the given id
 * @card: the card instance
 * @id: the control id to activate/inactivate
 * @active: non-zero to activate
 *
 * Finds the control instance with the given id, and activate or
 * inactivate the control together with notification, if changed.
585
 * The given ID data is filled with full information.
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 *
587
 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
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 */
int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
			int active)
{
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
	unsigned int index_offset;
	int ret;

	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, id);
	if (kctl == NULL) {
		ret = -ENOENT;
		goto unlock;
	}
603
	index_offset = snd_ctl_get_ioff(kctl, id);
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	vd = &kctl->vd[index_offset];
	ret = 0;
	if (active) {
		if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
			goto unlock;
		vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
	} else {
		if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
			goto unlock;
		vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
	}
615
	snd_ctl_build_ioff(id, kctl, index_offset);
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	ret = 1;
 unlock:
	up_write(&card->controls_rwsem);
	if (ret > 0)
		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
	return ret;
}
EXPORT_SYMBOL_GPL(snd_ctl_activate_id);

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/**
 * snd_ctl_rename_id - replace the id of a control on the card
 * @card: the card instance
 * @src_id: the old id
 * @dst_id: the new id
 *
 * Finds the control with the old id from the card, and replaces the
 * id with the new one.
 *
634
 * Return: Zero if successful, or a negative error code on failure.
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 */
636 637
int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
		      struct snd_ctl_elem_id *dst_id)
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{
639
	struct snd_kcontrol *kctl;
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	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, src_id);
	if (kctl == NULL) {
		up_write(&card->controls_rwsem);
		return -ENOENT;
	}
	kctl->id = *dst_id;
	kctl->id.numid = card->last_numid + 1;
	card->last_numid += kctl->count;
	up_write(&card->controls_rwsem);
	return 0;
}
653 654
EXPORT_SYMBOL(snd_ctl_rename_id);

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/**
 * snd_ctl_find_numid - find the control instance with the given number-id
 * @card: the card instance
 * @numid: the number-id to search
 *
 * Finds the control instance with the given number-id from the card.
 *
 * The caller must down card->controls_rwsem before calling this function
 * (if the race condition can happen).
664 665 666
 *
 * Return: The pointer of the instance if found, or %NULL if not.
 *
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 */
668
struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
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{
670
	struct snd_kcontrol *kctl;
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	if (snd_BUG_ON(!card || !numid))
		return NULL;
674
	list_for_each_entry(kctl, &card->controls, list) {
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		if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
			return kctl;
	}
	return NULL;
}
680 681
EXPORT_SYMBOL(snd_ctl_find_numid);

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/**
 * snd_ctl_find_id - find the control instance with the given id
 * @card: the card instance
 * @id: the id to search
 *
 * Finds the control instance with the given id from the card.
 *
 * The caller must down card->controls_rwsem before calling this function
 * (if the race condition can happen).
691 692 693
 *
 * Return: The pointer of the instance if found, or %NULL if not.
 *
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 */
695 696
struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
				     struct snd_ctl_elem_id *id)
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{
698
	struct snd_kcontrol *kctl;
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700 701
	if (snd_BUG_ON(!card || !id))
		return NULL;
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	if (id->numid != 0)
		return snd_ctl_find_numid(card, id->numid);
704
	list_for_each_entry(kctl, &card->controls, list) {
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		if (kctl->id.iface != id->iface)
			continue;
		if (kctl->id.device != id->device)
			continue;
		if (kctl->id.subdevice != id->subdevice)
			continue;
		if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
			continue;
		if (kctl->id.index > id->index)
			continue;
		if (kctl->id.index + kctl->count <= id->index)
			continue;
		return kctl;
	}
	return NULL;
}
721 722
EXPORT_SYMBOL(snd_ctl_find_id);

723
static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
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			     unsigned int cmd, void __user *arg)
{
726
	struct snd_ctl_card_info *info;
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728
	info = kzalloc(sizeof(*info), GFP_KERNEL);
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	if (! info)
		return -ENOMEM;
	down_read(&snd_ioctl_rwsem);
	info->card = card->number;
	strlcpy(info->id, card->id, sizeof(info->id));
	strlcpy(info->driver, card->driver, sizeof(info->driver));
	strlcpy(info->name, card->shortname, sizeof(info->name));
	strlcpy(info->longname, card->longname, sizeof(info->longname));
	strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
	strlcpy(info->components, card->components, sizeof(info->components));
	up_read(&snd_ioctl_rwsem);
740
	if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
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		kfree(info);
		return -EFAULT;
	}
	kfree(info);
	return 0;
}

748 749
static int snd_ctl_elem_list(struct snd_card *card,
			     struct snd_ctl_elem_list __user *_list)
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{
751 752
	struct snd_ctl_elem_list list;
	struct snd_kcontrol *kctl;
753
	struct snd_ctl_elem_id id;
754
	unsigned int offset, space, jidx;
755
	int err = 0;
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	if (copy_from_user(&list, _list, sizeof(list)))
		return -EFAULT;
	offset = list.offset;
	space = list.space;
761

762 763 764
	down_read(&card->controls_rwsem);
	list.count = card->controls_count;
	list.used = 0;
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	if (space > 0) {
766 767 768 769 770 771 772 773 774 775 776 777
		list_for_each_entry(kctl, &card->controls, list) {
			if (offset >= kctl->count) {
				offset -= kctl->count;
				continue;
			}
			for (jidx = offset; jidx < kctl->count; jidx++) {
				snd_ctl_build_ioff(&id, kctl, jidx);
				if (copy_to_user(list.pids + list.used, &id,
						 sizeof(id))) {
					err = -EFAULT;
					goto out;
				}
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				list.used++;
779 780
				if (!--space)
					goto out;
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			}
			offset = 0;
		}
	}
785 786 787 788 789
 out:
	up_read(&card->controls_rwsem);
	if (!err && copy_to_user(_list, &list, sizeof(list)))
		err = -EFAULT;
	return err;
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}

792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821
static bool validate_element_member_dimension(struct snd_ctl_elem_info *info)
{
	unsigned int members;
	unsigned int i;

	if (info->dimen.d[0] == 0)
		return true;

	members = 1;
	for (i = 0; i < ARRAY_SIZE(info->dimen.d); ++i) {
		if (info->dimen.d[i] == 0)
			break;
		members *= info->dimen.d[i];

		/*
		 * info->count should be validated in advance, to guarantee
		 * calculation soundness.
		 */
		if (members > info->count)
			return false;
	}

	for (++i; i < ARRAY_SIZE(info->dimen.d); ++i) {
		if (info->dimen.d[i] > 0)
			return false;
	}

	return members == info->count;
}

822 823
static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
			     struct snd_ctl_elem_info *info)
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{
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	struct snd_card *card = ctl->card;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
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	unsigned int index_offset;
	int result;
	
	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &info->id);
	if (kctl == NULL) {
		up_read(&card->controls_rwsem);
		return -ENOENT;
	}
#ifdef CONFIG_SND_DEBUG
	info->access = 0;
#endif
	result = kctl->info(kctl, info);
	if (result >= 0) {
842
		snd_BUG_ON(info->access);
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		index_offset = snd_ctl_get_ioff(kctl, &info->id);
		vd = &kctl->vd[index_offset];
		snd_ctl_build_ioff(&info->id, kctl, index_offset);
		info->access = vd->access;
		if (vd->owner) {
			info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
			if (vd->owner == ctl)
				info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
851
			info->owner = pid_vnr(vd->owner->pid);
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		} else {
			info->owner = -1;
		}
	}
	up_read(&card->controls_rwsem);
	return result;
}

860 861
static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
				  struct snd_ctl_elem_info __user *_info)
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{
863
	struct snd_ctl_elem_info info;
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	int result;

	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
868
	result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
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	if (result < 0)
		return result;
	result = snd_ctl_elem_info(ctl, &info);
	if (result < 0)
		return result;
	if (copy_to_user(_info, &info, sizeof(info)))
		return -EFAULT;
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	return result;
}

879 880
static int snd_ctl_elem_read(struct snd_card *card,
			     struct snd_ctl_elem_value *control)
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{
882 883
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
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	unsigned int index_offset;

	kctl = snd_ctl_find_id(card, &control->id);
887 888 889 890 891 892 893 894 895 896
	if (kctl == NULL)
		return -ENOENT;

	index_offset = snd_ctl_get_ioff(kctl, &control->id);
	vd = &kctl->vd[index_offset];
	if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get == NULL)
		return -EPERM;

	snd_ctl_build_ioff(&control->id, kctl, index_offset);
	return kctl->get(kctl, control);
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}

899 900
static int snd_ctl_elem_read_user(struct snd_card *card,
				  struct snd_ctl_elem_value __user *_control)
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{
902
	struct snd_ctl_elem_value *control;
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	int result;
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	control = memdup_user(_control, sizeof(*control));
	if (IS_ERR(control))
		return PTR_ERR(control);

909
	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
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	if (result < 0)
		goto error;

	down_read(&card->controls_rwsem);
	result = snd_ctl_elem_read(card, control);
	up_read(&card->controls_rwsem);
	if (result < 0)
		goto error;

	if (copy_to_user(_control, control, sizeof(*control)))
		result = -EFAULT;
 error:
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	kfree(control);
	return result;
}

926 927
static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
			      struct snd_ctl_elem_value *control)
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{
929 930
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
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	unsigned int index_offset;
932
	int result;
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	kctl = snd_ctl_find_id(card, &control->id);
935 936 937 938 939 940 941 942
	if (kctl == NULL)
		return -ENOENT;

	index_offset = snd_ctl_get_ioff(kctl, &control->id);
	vd = &kctl->vd[index_offset];
	if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
	    (file && vd->owner && vd->owner != file)) {
		return -EPERM;
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	}
944 945 946 947 948 949 950 951 952 953 954 955

	snd_ctl_build_ioff(&control->id, kctl, index_offset);
	result = kctl->put(kctl, control);
	if (result < 0)
		return result;

	if (result > 0) {
		struct snd_ctl_elem_id id = control->id;
		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
	}

	return 0;
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}

958 959
static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
				   struct snd_ctl_elem_value __user *_control)
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{
961
	struct snd_ctl_elem_value *control;
962
	struct snd_card *card;
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	int result;

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	control = memdup_user(_control, sizeof(*control));
	if (IS_ERR(control))
		return PTR_ERR(control);

969
	card = file->card;
970
	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
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	if (result < 0)
		goto error;

	down_write(&card->controls_rwsem);
	result = snd_ctl_elem_write(card, file, control);
	up_write(&card->controls_rwsem);
	if (result < 0)
		goto error;

	if (copy_to_user(_control, control, sizeof(*control)))
		result = -EFAULT;
 error:
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	kfree(control);
	return result;
}

987 988
static int snd_ctl_elem_lock(struct snd_ctl_file *file,
			     struct snd_ctl_elem_id __user *_id)
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{
990 991 992 993
	struct snd_card *card = file->card;
	struct snd_ctl_elem_id id;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
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	int result;
	
	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
		if (vd->owner != NULL)
			result = -EBUSY;
		else {
			vd->owner = file;
			result = 0;
		}
	}
	up_write(&card->controls_rwsem);
	return result;
}

1015 1016
static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
			       struct snd_ctl_elem_id __user *_id)
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{
1018 1019 1020 1021
	struct snd_card *card = file->card;
	struct snd_ctl_elem_id id;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
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	int result;
	
	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
		if (vd->owner == NULL)
			result = -EINVAL;
		else if (vd->owner != file)
			result = -EPERM;
		else {
			vd->owner = NULL;
			result = 0;
		}
	}
	up_write(&card->controls_rwsem);
	return result;
}

struct user_element {
1046
	struct snd_ctl_elem_info info;
1047
	struct snd_card *card;
1048
	char *elem_data;		/* element data */
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	unsigned long elem_data_size;	/* size of element data in bytes */
1050 1051
	void *tlv_data;			/* TLV data */
	unsigned long tlv_data_size;	/* TLV data size */
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	void *priv_data;		/* private data (like strings for enumerated type) */
};

1055 1056
static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
				  struct snd_ctl_elem_info *uinfo)
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{
	struct user_element *ue = kcontrol->private_data;
1059
	unsigned int offset;
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1061
	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
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	*uinfo = ue->info;
1063 1064
	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);

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	return 0;
}

1068 1069 1070 1071 1072 1073
static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
				       struct snd_ctl_elem_info *uinfo)
{
	struct user_element *ue = kcontrol->private_data;
	const char *names;
	unsigned int item;
1074
	unsigned int offset;
1075 1076 1077

	item = uinfo->value.enumerated.item;

1078
	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1079
	*uinfo = ue->info;
1080
	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092

	item = min(item, uinfo->value.enumerated.items - 1);
	uinfo->value.enumerated.item = item;

	names = ue->priv_data;
	for (; item > 0; --item)
		names += strlen(names) + 1;
	strcpy(uinfo->value.enumerated.name, names);

	return 0;
}

1093 1094
static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
				 struct snd_ctl_elem_value *ucontrol)
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{
	struct user_element *ue = kcontrol->private_data;
1097 1098 1099
	unsigned int size = ue->elem_data_size;
	char *src = ue->elem_data +
			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
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1101
	memcpy(&ucontrol->value, src, size);
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	return 0;
}

1105 1106
static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
				 struct snd_ctl_elem_value *ucontrol)
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{
	int change;
	struct user_element *ue = kcontrol->private_data;
1110 1111 1112
	unsigned int size = ue->elem_data_size;
	char *dst = ue->elem_data +
			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1113

1114
	change = memcmp(&ucontrol->value, dst, size) != 0;
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	if (change)
1116
		memcpy(dst, &ucontrol->value, size);
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1117 1118 1119
	return change;
}

1120 1121
static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
			    unsigned int size)
1122
{
1123 1124
	struct user_element *ue = kctl->private_data;
	unsigned int *container;
1125
	struct snd_ctl_elem_id id;
1126
	unsigned int mask = 0;
1127
	int i;
1128
	int change;
1129

1130 1131
	if (size > 1024 * 128)	/* sane value */
		return -EINVAL;
1132

1133
	container = vmemdup_user(buf, size);
1134 1135
	if (IS_ERR(container))
		return PTR_ERR(container);
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1136

1137 1138
	change = ue->tlv_data_size != size;
	if (!change)
1139
		change = memcmp(ue->tlv_data, container, size) != 0;
1140
	if (!change) {
1141
		kvfree(container);
1142 1143
		return 0;
	}
1144

1145 1146 1147 1148 1149 1150 1151
	if (ue->tlv_data == NULL) {
		/* Now TLV data is available. */
		for (i = 0; i < kctl->count; ++i)
			kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
		mask = SNDRV_CTL_EVENT_MASK_INFO;
	}

1152
	kvfree(ue->tlv_data);
1153 1154
	ue->tlv_data = container;
	ue->tlv_data_size = size;
1155

1156
	mask |= SNDRV_CTL_EVENT_MASK_TLV;
1157 1158
	for (i = 0; i < kctl->count; ++i) {
		snd_ctl_build_ioff(&id, kctl, i);
1159
		snd_ctl_notify(ue->card, mask, &id);
1160
	}
1161

1162 1163
	return change;
}
1164

1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188
static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
			 unsigned int size)
{
	struct user_element *ue = kctl->private_data;

	if (ue->tlv_data_size == 0 || ue->tlv_data == NULL)
		return -ENXIO;

	if (size < ue->tlv_data_size)
		return -ENOSPC;

	if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size))
		return -EFAULT;

	return 0;
}

static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag,
				 unsigned int size, unsigned int __user *buf)
{
	if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
		return replace_user_tlv(kctl, buf, size);
	else
		return read_user_tlv(kctl, buf, size);
1189 1190
}

1191 1192 1193 1194 1195
static int snd_ctl_elem_init_enum_names(struct user_element *ue)
{
	char *names, *p;
	size_t buf_len, name_len;
	unsigned int i;
1196
	const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1197 1198 1199 1200

	if (ue->info.value.enumerated.names_length > 64 * 1024)
		return -EINVAL;

1201
	names = memdup_user((const void __user *)user_ptrval,
1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224
		ue->info.value.enumerated.names_length);
	if (IS_ERR(names))
		return PTR_ERR(names);

	/* check that there are enough valid names */
	buf_len = ue->info.value.enumerated.names_length;
	p = names;
	for (i = 0; i < ue->info.value.enumerated.items; ++i) {
		name_len = strnlen(p, buf_len);
		if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
			kfree(names);
			return -EINVAL;
		}
		p += name_len + 1;
		buf_len -= name_len + 1;
	}

	ue->priv_data = names;
	ue->info.value.enumerated.names_ptr = 0;

	return 0;
}

1225
static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
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1226
{
1227
	struct user_element *ue = kcontrol->private_data;
1228

1229
	kvfree(ue->tlv_data);
1230
	kfree(ue->priv_data);
1231
	kfree(ue);
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1232 1233
}

1234 1235
static int snd_ctl_elem_add(struct snd_ctl_file *file,
			    struct snd_ctl_elem_info *info, int replace)
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1236
{
1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253
	/* The capacity of struct snd_ctl_elem_value.value.*/
	static const unsigned int value_sizes[] = {
		[SNDRV_CTL_ELEM_TYPE_BOOLEAN]	= sizeof(long),
		[SNDRV_CTL_ELEM_TYPE_INTEGER]	= sizeof(long),
		[SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
		[SNDRV_CTL_ELEM_TYPE_BYTES]	= sizeof(unsigned char),
		[SNDRV_CTL_ELEM_TYPE_IEC958]	= sizeof(struct snd_aes_iec958),
		[SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
	};
	static const unsigned int max_value_counts[] = {
		[SNDRV_CTL_ELEM_TYPE_BOOLEAN]	= 128,
		[SNDRV_CTL_ELEM_TYPE_INTEGER]	= 128,
		[SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
		[SNDRV_CTL_ELEM_TYPE_BYTES]	= 512,
		[SNDRV_CTL_ELEM_TYPE_IEC958]	= 1,
		[SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
	};
1254
	struct snd_card *card = file->card;
1255 1256
	struct snd_kcontrol *kctl;
	unsigned int count;
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1257 1258 1259
	unsigned int access;
	long private_size;
	struct user_element *ue;
1260
	unsigned int offset;
1261
	int err;
1262

1263 1264 1265 1266
	if (!*info->id.name)
		return -EINVAL;
	if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
		return -EINVAL;
1267

1268
	/* Delete a control to replace them if needed. */
1269
	if (replace) {
1270
		info->id.numid = 0;
1271 1272 1273
		err = snd_ctl_remove_user_ctl(file, &info->id);
		if (err)
			return err;
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	}
1275

1276 1277 1278 1279 1280
	/*
	 * The number of userspace controls are counted control by control,
	 * not element by element.
	 */
	if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1281 1282
		return -ENOMEM;

1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293
	/* Check the number of elements for this userspace control. */
	count = info->owner;
	if (count == 0)
		count = 1;

	/* Arrange access permissions if needed. */
	access = info->access;
	if (access == 0)
		access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
	access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
		   SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1294 1295 1296 1297
		   SNDRV_CTL_ELEM_ACCESS_TLV_WRITE);

	/* In initial state, nothing is available as TLV container. */
	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1298
		access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1299
	access |= SNDRV_CTL_ELEM_ACCESS_USER;
1300

1301 1302 1303 1304
	/*
	 * Check information and calculate the size of data specific to
	 * this userspace control.
	 */
1305 1306
	if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
	    info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
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		return -EINVAL;
1308 1309 1310 1311 1312 1313
	if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
	    info->value.enumerated.items == 0)
		return -EINVAL;
	if (info->count < 1 ||
	    info->count > max_value_counts[info->type])
		return -EINVAL;
1314 1315
	if (!validate_element_member_dimension(info))
		return -EINVAL;
1316
	private_size = value_sizes[info->type] * info->count;
1317 1318 1319 1320 1321 1322 1323 1324 1325 1326

	/*
	 * Keep memory object for this userspace control. After passing this
	 * code block, the instance should be freed by snd_ctl_free_one().
	 *
	 * Note that these elements in this control are locked.
	 */
	err = snd_ctl_new(&kctl, count, access, file);
	if (err < 0)
		return err;
1327
	memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1328
	kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1329 1330 1331
				     GFP_KERNEL);
	if (kctl->private_data == NULL) {
		kfree(kctl);
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		return -ENOMEM;
1333 1334 1335 1336 1337
	}
	kctl->private_free = snd_ctl_elem_user_free;

	/* Set private data for this userspace control. */
	ue = (struct user_element *)kctl->private_data;
1338
	ue->card = card;
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1339
	ue->info = *info;
1340
	ue->info.access = 0;
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1341 1342
	ue->elem_data = (char *)ue + sizeof(*ue);
	ue->elem_data_size = private_size;
1343 1344 1345
	if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
		err = snd_ctl_elem_init_enum_names(ue);
		if (err < 0) {
1346
			snd_ctl_free_one(kctl);
1347 1348 1349
			return err;
		}
	}
1350 1351 1352 1353 1354 1355 1356 1357 1358 1359

	/* Set callback functions. */
	if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
		kctl->info = snd_ctl_elem_user_enum_info;
	else
		kctl->info = snd_ctl_elem_user_info;
	if (access & SNDRV_CTL_ELEM_ACCESS_READ)
		kctl->get = snd_ctl_elem_user_get;
	if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
		kctl->put = snd_ctl_elem_user_put;
1360
	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1361 1362 1363 1364
		kctl->tlv.c = snd_ctl_elem_user_tlv;

	/* This function manage to free the instance on failure. */
	err = snd_ctl_add(card, kctl);
1365
	if (err < 0)
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		return err;
1367 1368 1369 1370 1371 1372 1373 1374 1375
	offset = snd_ctl_get_ioff(kctl, &info->id);
	snd_ctl_build_ioff(&info->id, kctl, offset);
	/*
	 * Here we cannot fill any field for the number of elements added by
	 * this operation because there're no specific fields. The usage of
	 * 'owner' field for this purpose may cause any bugs to userspace
	 * applications because the field originally means PID of a process
	 * which locks the element.
	 */
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1376 1377 1378 1379 1380 1381 1382 1383

	down_write(&card->controls_rwsem);
	card->user_ctl_count++;
	up_write(&card->controls_rwsem);

	return 0;
}

1384 1385
static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
				 struct snd_ctl_elem_info __user *_info, int replace)
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1386
{
1387
	struct snd_ctl_elem_info info;
1388 1389
	int err;

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1390 1391
	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
1392 1393 1394 1395 1396 1397 1398 1399 1400
	err = snd_ctl_elem_add(file, &info, replace);
	if (err < 0)
		return err;
	if (copy_to_user(_info, &info, sizeof(info))) {
		snd_ctl_remove_user_ctl(file, &info.id);
		return -EFAULT;
	}

	return 0;
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1401 1402
}

1403 1404
static int snd_ctl_elem_remove(struct snd_ctl_file *file,
			       struct snd_ctl_elem_id __user *_id)
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1405
{
1406
	struct snd_ctl_elem_id id;
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1407 1408 1409

	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
1410
	return snd_ctl_remove_user_ctl(file, &id);
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1411 1412
}

1413
static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
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1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433
{
	int subscribe;
	if (get_user(subscribe, ptr))
		return -EFAULT;
	if (subscribe < 0) {
		subscribe = file->subscribed;
		if (put_user(subscribe, ptr))
			return -EFAULT;
		return 0;
	}
	if (subscribe) {
		file->subscribed = 1;
		return 0;
	} else if (file->subscribed) {
		snd_ctl_empty_read_queue(file);
		file->subscribed = 0;
	}
	return 0;
}

1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464
static int call_tlv_handler(struct snd_ctl_file *file, int op_flag,
			    struct snd_kcontrol *kctl,
			    struct snd_ctl_elem_id *id,
			    unsigned int __user *buf, unsigned int size)
{
	static const struct {
		int op;
		int perm;
	} pairs[] = {
		{SNDRV_CTL_TLV_OP_READ,  SNDRV_CTL_ELEM_ACCESS_TLV_READ},
		{SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE},
		{SNDRV_CTL_TLV_OP_CMD,   SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND},
	};
	struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
	int i;

	/* Check support of the request for this element. */
	for (i = 0; i < ARRAY_SIZE(pairs); ++i) {
		if (op_flag == pairs[i].op && (vd->access & pairs[i].perm))
			break;
	}
	if (i == ARRAY_SIZE(pairs))
		return -ENXIO;

	if (kctl->tlv.c == NULL)
		return -ENXIO;

	/* When locked, this is unavailable. */
	if (vd->owner != NULL && vd->owner != file)
		return -EPERM;

1465
	return kctl->tlv.c(kctl, op_flag, size, buf);
1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489
}

static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id,
			unsigned int __user *buf, unsigned int size)
{
	struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
	unsigned int len;

	if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ))
		return -ENXIO;

	if (kctl->tlv.p == NULL)
		return -ENXIO;

	len = sizeof(unsigned int) * 2 + kctl->tlv.p[1];
	if (size < len)
		return -ENOMEM;

	if (copy_to_user(buf, kctl->tlv.p, len))
		return -EFAULT;

	return 0;
}

1490
static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1491
			     struct snd_ctl_tlv __user *buf,
1492
                             int op_flag)
1493
{
1494 1495 1496
	struct snd_ctl_tlv header;
	unsigned int *container;
	unsigned int container_size;
1497
	struct snd_kcontrol *kctl;
1498
	struct snd_ctl_elem_id id;
1499
	struct snd_kcontrol_volatile *vd;
1500

1501
	if (copy_from_user(&header, buf, sizeof(header)))
1502
		return -EFAULT;
1503 1504 1505

	/* In design of control core, numerical ID starts at 1. */
	if (header.numid == 0)
1506
		return -EINVAL;
1507 1508 1509

	/* At least, container should include type and length fields.  */
	if (header.length < sizeof(unsigned int) * 2)
1510
		return -EINVAL;
1511 1512
	container_size = header.length;
	container = buf->tlv;
1513

1514
	kctl = snd_ctl_find_numid(file->card, header.numid);
1515 1516 1517
	if (kctl == NULL)
		return -ENOENT;

1518 1519 1520 1521
	/* Calculate index of the element in this set. */
	id = kctl->id;
	snd_ctl_build_ioff(&id, kctl, header.numid - id.numid);
	vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1522

1523
	if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1524 1525
		return call_tlv_handler(file, op_flag, kctl, &id, container,
					container_size);
1526
	} else {
1527 1528 1529 1530
		if (op_flag == SNDRV_CTL_TLV_OP_READ) {
			return read_tlv_buf(kctl, &id, container,
					    container_size);
		}
1531
	}
1532

1533 1534
	/* Not supported. */
	return -ENXIO;
1535 1536
}

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1537 1538
static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
1539 1540 1541
	struct snd_ctl_file *ctl;
	struct snd_card *card;
	struct snd_kctl_ioctl *p;
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1542 1543 1544 1545 1546 1547
	void __user *argp = (void __user *)arg;
	int __user *ip = argp;
	int err;

	ctl = file->private_data;
	card = ctl->card;
1548 1549
	if (snd_BUG_ON(!card))
		return -ENXIO;
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1550 1551 1552 1553 1554 1555
	switch (cmd) {
	case SNDRV_CTL_IOCTL_PVERSION:
		return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
	case SNDRV_CTL_IOCTL_CARD_INFO:
		return snd_ctl_card_info(card, ctl, cmd, argp);
	case SNDRV_CTL_IOCTL_ELEM_LIST:
1556
		return snd_ctl_elem_list(card, argp);
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1557 1558 1559
	case SNDRV_CTL_IOCTL_ELEM_INFO:
		return snd_ctl_elem_info_user(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_READ:
1560
		return snd_ctl_elem_read_user(card, argp);
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	case SNDRV_CTL_IOCTL_ELEM_WRITE:
		return snd_ctl_elem_write_user(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_LOCK:
		return snd_ctl_elem_lock(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
		return snd_ctl_elem_unlock(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_ADD:
		return snd_ctl_elem_add_user(ctl, argp, 0);
	case SNDRV_CTL_IOCTL_ELEM_REPLACE:
		return snd_ctl_elem_add_user(ctl, argp, 1);
	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
		return snd_ctl_elem_remove(ctl, argp);
	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
		return snd_ctl_subscribe_events(ctl, ip);
1575
	case SNDRV_CTL_IOCTL_TLV_READ:
1576 1577 1578 1579
		down_read(&ctl->card->controls_rwsem);
		err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
		up_read(&ctl->card->controls_rwsem);
		return err;
1580
	case SNDRV_CTL_IOCTL_TLV_WRITE:
1581 1582 1583 1584
		down_write(&ctl->card->controls_rwsem);
		err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
		up_write(&ctl->card->controls_rwsem);
		return err;
1585
	case SNDRV_CTL_IOCTL_TLV_COMMAND:
1586 1587 1588 1589
		down_write(&ctl->card->controls_rwsem);
		err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
		up_write(&ctl->card->controls_rwsem);
		return err;
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	case SNDRV_CTL_IOCTL_POWER:
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		return -ENOPROTOOPT;
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1592 1593 1594 1595 1596 1597 1598 1599
	case SNDRV_CTL_IOCTL_POWER_STATE:
#ifdef CONFIG_PM
		return put_user(card->power_state, ip) ? -EFAULT : 0;
#else
		return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
#endif
	}
	down_read(&snd_ioctl_rwsem);
1600
	list_for_each_entry(p, &snd_control_ioctls, list) {
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		err = p->fioctl(card, ctl, cmd, arg);
		if (err != -ENOIOCTLCMD) {
			up_read(&snd_ioctl_rwsem);
			return err;
		}
	}
	up_read(&snd_ioctl_rwsem);
1608
	dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
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1609 1610 1611
	return -ENOTTY;
}

1612 1613
static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
			    size_t count, loff_t * offset)
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{
1615
	struct snd_ctl_file *ctl;
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1616 1617 1618 1619
	int err = 0;
	ssize_t result = 0;

	ctl = file->private_data;
1620 1621
	if (snd_BUG_ON(!ctl || !ctl->card))
		return -ENXIO;
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1622 1623
	if (!ctl->subscribed)
		return -EBADFD;
1624
	if (count < sizeof(struct snd_ctl_event))
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1625 1626
		return -EINVAL;
	spin_lock_irq(&ctl->read_lock);
1627 1628 1629
	while (count >= sizeof(struct snd_ctl_event)) {
		struct snd_ctl_event ev;
		struct snd_kctl_event *kev;
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1630
		while (list_empty(&ctl->events)) {
1631
			wait_queue_entry_t wait;
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			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
				err = -EAGAIN;
				goto __end_lock;
			}
			init_waitqueue_entry(&wait, current);
			add_wait_queue(&ctl->change_sleep, &wait);
			set_current_state(TASK_INTERRUPTIBLE);
			spin_unlock_irq(&ctl->read_lock);
			schedule();
			remove_wait_queue(&ctl->change_sleep, &wait);
1642 1643
			if (ctl->card->shutdown)
				return -ENODEV;
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			if (signal_pending(current))
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				return -ERESTARTSYS;
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			spin_lock_irq(&ctl->read_lock);
		}
		kev = snd_kctl_event(ctl->events.next);
		ev.type = SNDRV_CTL_EVENT_ELEM;
		ev.data.elem.mask = kev->mask;
		ev.data.elem.id = kev->id;
		list_del(&kev->list);
		spin_unlock_irq(&ctl->read_lock);
		kfree(kev);
1655
		if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
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			err = -EFAULT;
			goto __end;
		}
		spin_lock_irq(&ctl->read_lock);
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		buffer += sizeof(struct snd_ctl_event);
		count -= sizeof(struct snd_ctl_event);
		result += sizeof(struct snd_ctl_event);
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	}
      __end_lock:
	spin_unlock_irq(&ctl->read_lock);
      __end:
      	return result > 0 ? result : err;
}

static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
{
	unsigned int mask;
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	struct snd_ctl_file *ctl;
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	ctl = file->private_data;
	if (!ctl->subscribed)
		return 0;
	poll_wait(file, &ctl->change_sleep, wait);

	mask = 0;
	if (!list_empty(&ctl->events))
		mask |= POLLIN | POLLRDNORM;

	return mask;
}

/*
 * register the device-specific control-ioctls.
 * called from each device manager like pcm.c, hwdep.c, etc.
 */
static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
{
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	struct snd_kctl_ioctl *pn;
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	pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
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	if (pn == NULL)
		return -ENOMEM;
	pn->fioctl = fcn;
	down_write(&snd_ioctl_rwsem);
	list_add_tail(&pn->list, lists);
	up_write(&snd_ioctl_rwsem);
	return 0;
}

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/**
 * snd_ctl_register_ioctl - register the device-specific control-ioctls
 * @fcn: ioctl callback function
 *
 * called from each device manager like pcm.c, hwdep.c, etc.
 */
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int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
}
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EXPORT_SYMBOL(snd_ctl_register_ioctl);

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#ifdef CONFIG_COMPAT
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/**
 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
 * control-ioctls
 * @fcn: ioctl callback function
 */
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int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
}
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EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
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#endif

/*
 * de-register the device-specific control-ioctls.
 */
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static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
				     struct list_head *lists)
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{
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	struct snd_kctl_ioctl *p;
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	if (snd_BUG_ON(!fcn))
		return -EINVAL;
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	down_write(&snd_ioctl_rwsem);
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	list_for_each_entry(p, lists, list) {
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		if (p->fioctl == fcn) {
			list_del(&p->list);
			up_write(&snd_ioctl_rwsem);
			kfree(p);
			return 0;
		}
	}
	up_write(&snd_ioctl_rwsem);
	snd_BUG();
	return -EINVAL;
}

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/**
 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
 * @fcn: ioctl callback function to unregister
 */
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int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
}
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EXPORT_SYMBOL(snd_ctl_unregister_ioctl);

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#ifdef CONFIG_COMPAT
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/**
 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
 * control-ioctls
 * @fcn: ioctl callback function to unregister
 */
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int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
}
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EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
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#endif

static int snd_ctl_fasync(int fd, struct file * file, int on)
{
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	struct snd_ctl_file *ctl;
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	ctl = file->private_data;
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	return fasync_helper(fd, file, on, &ctl->fasync);
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}

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/* return the preferred subdevice number if already assigned;
 * otherwise return -1
 */
int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
{
	struct snd_ctl_file *kctl;
	int subdevice = -1;

	read_lock(&card->ctl_files_rwlock);
	list_for_each_entry(kctl, &card->ctl_files, list) {
		if (kctl->pid == task_pid(current)) {
			subdevice = kctl->preferred_subdevice[type];
			if (subdevice != -1)
				break;
		}
	}
	read_unlock(&card->ctl_files_rwlock);
	return subdevice;
}
EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);

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/*
 * ioctl32 compat
 */
#ifdef CONFIG_COMPAT
#include "control_compat.c"
#else
#define snd_ctl_ioctl_compat	NULL
#endif

/*
 *  INIT PART
 */

1819
static const struct file_operations snd_ctl_f_ops =
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{
	.owner =	THIS_MODULE,
	.read =		snd_ctl_read,
	.open =		snd_ctl_open,
	.release =	snd_ctl_release,
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	.llseek =	no_llseek,
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	.poll =		snd_ctl_poll,
	.unlocked_ioctl =	snd_ctl_ioctl,
	.compat_ioctl =	snd_ctl_ioctl_compat,
	.fasync =	snd_ctl_fasync,
};

/*
 * registration of the control device
 */
1835
static int snd_ctl_dev_register(struct snd_device *device)
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{
1837
	struct snd_card *card = device->device_data;
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	return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
				   &snd_ctl_f_ops, card, &card->ctl_dev);
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}

/*
 * disconnection of the control device
 */
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static int snd_ctl_dev_disconnect(struct snd_device *device)
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{
1848 1849
	struct snd_card *card = device->device_data;
	struct snd_ctl_file *ctl;
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1851
	read_lock(&card->ctl_files_rwlock);
1852
	list_for_each_entry(ctl, &card->ctl_files, list) {
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		wake_up(&ctl->change_sleep);
		kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
	}
1856
	read_unlock(&card->ctl_files_rwlock);
1857

1858
	return snd_unregister_device(&card->ctl_dev);
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}

/*
 * free all controls
 */
1864
static int snd_ctl_dev_free(struct snd_device *device)
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{
1866 1867
	struct snd_card *card = device->device_data;
	struct snd_kcontrol *control;
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	down_write(&card->controls_rwsem);
	while (!list_empty(&card->controls)) {
		control = snd_kcontrol(card->controls.next);
		snd_ctl_remove(card, control);
	}
	up_write(&card->controls_rwsem);
1875
	put_device(&card->ctl_dev);
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	return 0;
}

/*
 * create control core:
 * called from init.c
 */
1883
int snd_ctl_create(struct snd_card *card)
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{
1885
	static struct snd_device_ops ops = {
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		.dev_free = snd_ctl_dev_free,
		.dev_register =	snd_ctl_dev_register,
		.dev_disconnect = snd_ctl_dev_disconnect,
	};
1890
	int err;
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1892 1893
	if (snd_BUG_ON(!card))
		return -ENXIO;
1894 1895 1896 1897 1898 1899 1900 1901 1902 1903
	if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
		return -ENXIO;

	snd_device_initialize(&card->ctl_dev, card);
	dev_set_name(&card->ctl_dev, "controlC%d", card->number);

	err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
	if (err < 0)
		put_device(&card->ctl_dev);
	return err;
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}
1905 1906

/*
1907
 * Frequently used control callbacks/helpers
1908
 */
1909 1910 1911 1912 1913 1914 1915 1916 1917 1918

/**
 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
 * callback with a mono channel
 * @kcontrol: the kcontrol instance
 * @uinfo: info to store
 *
 * This is a function that can be used as info callback for a standard
 * boolean control with a single mono channel.
 */
1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929
int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
			      struct snd_ctl_elem_info *uinfo)
{
	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
	uinfo->count = 1;
	uinfo->value.integer.min = 0;
	uinfo->value.integer.max = 1;
	return 0;
}
EXPORT_SYMBOL(snd_ctl_boolean_mono_info);

1930 1931 1932 1933 1934 1935 1936 1937 1938
/**
 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
 * callback with stereo two channels
 * @kcontrol: the kcontrol instance
 * @uinfo: info to store
 *
 * This is a function that can be used as info callback for a standard
 * boolean control with stereo two channels.
 */
1939 1940 1941 1942 1943 1944 1945 1946 1947 1948
int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
				struct snd_ctl_elem_info *uinfo)
{
	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
	uinfo->count = 2;
	uinfo->value.integer.min = 0;
	uinfo->value.integer.max = 1;
	return 0;
}
EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959

/**
 * snd_ctl_enum_info - fills the info structure for an enumerated control
 * @info: the structure to be filled
 * @channels: the number of the control's channels; often one
 * @items: the number of control values; also the size of @names
 * @names: an array containing the names of all control values
 *
 * Sets all required fields in @info to their appropriate values.
 * If the control's accessibility is not the default (readable and writable),
 * the caller has to fill @info->access.
1960 1961
 *
 * Return: Zero.
1962 1963 1964 1965 1966 1967 1968
 */
int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
		      unsigned int items, const char *const names[])
{
	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
	info->count = channels;
	info->value.enumerated.items = items;
1969 1970
	if (!items)
		return 0;
1971 1972
	if (info->value.enumerated.item >= items)
		info->value.enumerated.item = items - 1;
1973 1974 1975
	WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
	     "ALSA: too long item name '%s'\n",
	     names[info->value.enumerated.item]);
1976 1977 1978 1979 1980 1981
	strlcpy(info->value.enumerated.name,
		names[info->value.enumerated.item],
		sizeof(info->value.enumerated.name));
	return 0;
}
EXPORT_SYMBOL(snd_ctl_enum_info);