control.c 50.9 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/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) {
564 565
			ret = -EBUSY;
			goto error;
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		}
	ret = snd_ctl_remove(card, kctl);
568 569 570
	if (ret < 0)
		goto error;
	card->user_ctl_count--;
571
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.
584
 * The given ID data is filled with full information.
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 *
586
 * 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;
	}
602
	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;
	}
614
	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.
 *
633
 * Return: Zero if successful, or a negative error code on failure.
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 */
635 636
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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{
638
	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;
}
652 653
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).
663 664 665
 *
 * Return: The pointer of the instance if found, or %NULL if not.
 *
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 */
667
struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
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{
669
	struct snd_kcontrol *kctl;
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671 672
	if (snd_BUG_ON(!card || !numid))
		return NULL;
673
	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;
}
679 680
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).
690 691 692
 *
 * Return: The pointer of the instance if found, or %NULL if not.
 *
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 */
694 695
struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
				     struct snd_ctl_elem_id *id)
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{
697
	struct snd_kcontrol *kctl;
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699 700
	if (snd_BUG_ON(!card || !id))
		return NULL;
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	if (id->numid != 0)
		return snd_ctl_find_numid(card, id->numid);
703
	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;
}
720 721
EXPORT_SYMBOL(snd_ctl_find_id);

722
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)
{
725
	struct snd_ctl_card_info *info;
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727
	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);
739
	if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
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		kfree(info);
		return -EFAULT;
	}
	kfree(info);
	return 0;
}

747 748
static int snd_ctl_elem_list(struct snd_card *card,
			     struct snd_ctl_elem_list __user *_list)
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{
750 751
	struct snd_ctl_elem_list list;
	struct snd_kcontrol *kctl;
752
	struct snd_ctl_elem_id id;
753
	unsigned int offset, space, jidx;
754
	int err = 0;
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	if (copy_from_user(&list, _list, sizeof(list)))
		return -EFAULT;
	offset = list.offset;
	space = list.space;
760

761 762 763
	down_read(&card->controls_rwsem);
	list.count = card->controls_count;
	list.used = 0;
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	if (space > 0) {
765 766 767 768 769 770 771 772 773 774 775 776
		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++;
778 779
				if (!--space)
					goto out;
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			}
			offset = 0;
		}
	}
784 785 786 787 788
 out:
	up_read(&card->controls_rwsem);
	if (!err && copy_to_user(_list, &list, sizeof(list)))
		err = -EFAULT;
	return err;
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}

791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820
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;
}

821 822
static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
			     struct snd_ctl_elem_info *info)
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{
824 825 826
	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) {
841
		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;
850
			info->owner = pid_vnr(vd->owner->pid);
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		} else {
			info->owner = -1;
		}
	}
	up_read(&card->controls_rwsem);
	return result;
}

859 860
static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
				  struct snd_ctl_elem_info __user *_info)
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{
862
	struct snd_ctl_elem_info info;
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	int result;

	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
867
	snd_power_lock(ctl->card);
868
	result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
869 870 871
	if (result >= 0)
		result = snd_ctl_elem_info(ctl, &info);
	snd_power_unlock(ctl->card);
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	if (result >= 0)
		if (copy_to_user(_info, &info, sizeof(info)))
			return -EFAULT;
	return result;
}

878 879
static int snd_ctl_elem_read(struct snd_card *card,
			     struct snd_ctl_elem_value *control)
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{
881 882
	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);
886 887 888 889 890 891 892 893 894 895
	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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}

898 899
static int snd_ctl_elem_read_user(struct snd_card *card,
				  struct snd_ctl_elem_value __user *_control)
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{
901
	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);

908
	snd_power_lock(card);
909
	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
910 911
	if (result >= 0) {
		down_read(&card->controls_rwsem);
912
		result = snd_ctl_elem_read(card, control);
913 914
		up_read(&card->controls_rwsem);
	}
915
	snd_power_unlock(card);
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	if (result >= 0)
		if (copy_to_user(_control, control, sizeof(*control)))
			result = -EFAULT;
	kfree(control);
	return result;
}

923 924
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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{
926 927
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
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	unsigned int index_offset;
929
	int result;
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	kctl = snd_ctl_find_id(card, &control->id);
932 933 934 935 936 937 938 939
	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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	}
941 942 943 944 945 946 947 948 949 950 951 952

	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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}

955 956
static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
				   struct snd_ctl_elem_value __user *_control)
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{
958
	struct snd_ctl_elem_value *control;
959
	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);

966 967
	card = file->card;
	snd_power_lock(card);
968
	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
969
	if (result >= 0) {
970
		down_write(&card->controls_rwsem);
971
		result = snd_ctl_elem_write(card, file, control);
972
		up_write(&card->controls_rwsem);
973
	}
974
	snd_power_unlock(card);
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	if (result >= 0)
		if (copy_to_user(_control, control, sizeof(*control)))
			result = -EFAULT;
	kfree(control);
	return result;
}

982 983
static int snd_ctl_elem_lock(struct snd_ctl_file *file,
			     struct snd_ctl_elem_id __user *_id)
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{
985 986 987 988
	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;
}

1010 1011
static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
			       struct snd_ctl_elem_id __user *_id)
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{
1013 1014 1015 1016
	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 {
1041
	struct snd_ctl_elem_info info;
1042
	struct snd_card *card;
1043
	char *elem_data;		/* element data */
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	unsigned long elem_data_size;	/* size of element data in bytes */
1045 1046
	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) */
};

1050 1051
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;
1054
	unsigned int offset;
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1056
	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
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	*uinfo = ue->info;
1058 1059
	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);

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	return 0;
}

1063 1064 1065 1066 1067 1068
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;
1069
	unsigned int offset;
1070 1071 1072

	item = uinfo->value.enumerated.item;

1073
	offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1074
	*uinfo = ue->info;
1075
	snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087

	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;
}

1088 1089
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;
1092 1093 1094
	unsigned int size = ue->elem_data_size;
	char *src = ue->elem_data +
			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
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1096
	memcpy(&ucontrol->value, src, size);
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	return 0;
}

1100 1101
static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
				 struct snd_ctl_elem_value *ucontrol)
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1102 1103 1104
{
	int change;
	struct user_element *ue = kcontrol->private_data;
1105 1106 1107
	unsigned int size = ue->elem_data_size;
	char *dst = ue->elem_data +
			snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1108

1109
	change = memcmp(&ucontrol->value, dst, size) != 0;
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	if (change)
1111
		memcpy(dst, &ucontrol->value, size);
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1112 1113 1114
	return change;
}

1115 1116
static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
			    unsigned int size)
1117
{
1118 1119
	struct user_element *ue = kctl->private_data;
	unsigned int *container;
1120 1121
	struct snd_ctl_elem_id id;
	int i;
1122
	int change;
1123

1124 1125
	if (size > 1024 * 128)	/* sane value */
		return -EINVAL;
1126

1127 1128 1129
	container = memdup_user(buf, size);
	if (IS_ERR(container))
		return PTR_ERR(container);
L
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1130

1131 1132
	change = ue->tlv_data_size != size;
	if (!change)
1133
		change = memcmp(ue->tlv_data, container, size) != 0;
1134 1135 1136 1137
	if (!change) {
		kfree(container);
		return 0;
	}
1138

1139 1140 1141
	kfree(ue->tlv_data);
	ue->tlv_data = container;
	ue->tlv_data_size = size;
1142

1143 1144 1145 1146
	for (i = 0; i < kctl->count; ++i) {
		snd_ctl_build_ioff(&id, kctl, i);
		snd_ctl_notify(ue->card, SNDRV_CTL_EVENT_MASK_TLV, &id);
	}
1147

1148 1149
	return change;
}
1150

1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174
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);
1175 1176
}

1177 1178 1179 1180 1181
static int snd_ctl_elem_init_enum_names(struct user_element *ue)
{
	char *names, *p;
	size_t buf_len, name_len;
	unsigned int i;
1182
	const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1183 1184 1185 1186

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

1187
	names = memdup_user((const void __user *)user_ptrval,
1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210
		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;
}

1211
static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
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1212
{
1213
	struct user_element *ue = kcontrol->private_data;
1214 1215 1216

	kfree(ue->tlv_data);
	kfree(ue->priv_data);
1217
	kfree(ue);
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1218 1219
}

1220 1221
static int snd_ctl_elem_add(struct snd_ctl_file *file,
			    struct snd_ctl_elem_info *info, int replace)
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1222
{
1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239
	/* 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,
	};
1240
	struct snd_card *card = file->card;
1241 1242
	struct snd_kcontrol *kctl;
	unsigned int count;
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1243 1244 1245
	unsigned int access;
	long private_size;
	struct user_element *ue;
1246
	unsigned int offset;
1247
	int err;
1248

1249 1250 1251 1252
	if (!*info->id.name)
		return -EINVAL;
	if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
		return -EINVAL;
1253

1254
	/* Delete a control to replace them if needed. */
1255
	if (replace) {
1256
		info->id.numid = 0;
1257 1258 1259
		err = snd_ctl_remove_user_ctl(file, &info->id);
		if (err)
			return err;
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1260
	}
1261

1262 1263 1264 1265 1266
	/*
	 * The number of userspace controls are counted control by control,
	 * not element by element.
	 */
	if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1267 1268
		return -ENOMEM;

1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281
	/* 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 |
		   SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE);
	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
1282
		access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1283
	access |= SNDRV_CTL_ELEM_ACCESS_USER;
1284

1285 1286 1287 1288
	/*
	 * Check information and calculate the size of data specific to
	 * this userspace control.
	 */
1289 1290
	if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
	    info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
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		return -EINVAL;
1292 1293 1294 1295 1296 1297
	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;
1298 1299
	if (!validate_element_member_dimension(info))
		return -EINVAL;
1300
	private_size = value_sizes[info->type] * info->count;
1301 1302 1303 1304 1305 1306 1307 1308 1309 1310

	/*
	 * 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;
1311
	memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1312
	kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1313 1314 1315
				     GFP_KERNEL);
	if (kctl->private_data == NULL) {
		kfree(kctl);
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		return -ENOMEM;
1317 1318 1319 1320 1321
	}
	kctl->private_free = snd_ctl_elem_user_free;

	/* Set private data for this userspace control. */
	ue = (struct user_element *)kctl->private_data;
1322
	ue->card = card;
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1323
	ue->info = *info;
1324
	ue->info.access = 0;
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	ue->elem_data = (char *)ue + sizeof(*ue);
	ue->elem_data_size = private_size;
1327 1328 1329
	if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
		err = snd_ctl_elem_init_enum_names(ue);
		if (err < 0) {
1330
			snd_ctl_free_one(kctl);
1331 1332 1333
			return err;
		}
	}
1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348

	/* 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;
	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
		kctl->tlv.c = snd_ctl_elem_user_tlv;

	/* This function manage to free the instance on failure. */
	err = snd_ctl_add(card, kctl);
1349
	if (err < 0)
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		return err;
1351 1352 1353 1354 1355 1356 1357 1358 1359
	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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1360 1361 1362 1363 1364 1365 1366 1367

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

	return 0;
}

1368 1369
static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
				 struct snd_ctl_elem_info __user *_info, int replace)
L
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1370
{
1371
	struct snd_ctl_elem_info info;
1372 1373
	int err;

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1374 1375
	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
1376 1377 1378 1379 1380 1381 1382 1383 1384
	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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1385 1386
}

1387 1388
static int snd_ctl_elem_remove(struct snd_ctl_file *file,
			       struct snd_ctl_elem_id __user *_id)
L
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1389
{
1390
	struct snd_ctl_elem_id id;
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1391 1392 1393

	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
1394
	return snd_ctl_remove_user_ctl(file, &id);
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1395 1396
}

1397
static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
L
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1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417
{
	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;
}

1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448
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;

1449
	return kctl->tlv.c(kctl, op_flag, size, buf);
1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473
}

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;
}

1474
static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1475
			     struct snd_ctl_tlv __user *buf,
1476
                             int op_flag)
1477
{
1478 1479 1480
	struct snd_ctl_tlv header;
	unsigned int *container;
	unsigned int container_size;
1481
	struct snd_kcontrol *kctl;
1482
	struct snd_ctl_elem_id id;
1483
	struct snd_kcontrol_volatile *vd;
1484

1485
	if (copy_from_user(&header, buf, sizeof(header)))
1486
		return -EFAULT;
1487 1488 1489

	/* In design of control core, numerical ID starts at 1. */
	if (header.numid == 0)
1490
		return -EINVAL;
1491 1492 1493

	/* At least, container should include type and length fields.  */
	if (header.length < sizeof(unsigned int) * 2)
1494
		return -EINVAL;
1495 1496
	container_size = header.length;
	container = buf->tlv;
1497

1498
	kctl = snd_ctl_find_numid(file->card, header.numid);
1499 1500 1501
	if (kctl == NULL)
		return -ENOENT;

1502 1503 1504 1505
	/* 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)];
1506

1507
	if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1508 1509
		return call_tlv_handler(file, op_flag, kctl, &id, container,
					container_size);
1510
	} else {
1511 1512 1513 1514
		if (op_flag == SNDRV_CTL_TLV_OP_READ) {
			return read_tlv_buf(kctl, &id, container,
					    container_size);
		}
1515
	}
1516

1517 1518
	/* Not supported. */
	return -ENXIO;
1519 1520
}

L
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1521 1522
static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
1523 1524 1525
	struct snd_ctl_file *ctl;
	struct snd_card *card;
	struct snd_kctl_ioctl *p;
L
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1526 1527 1528 1529 1530 1531
	void __user *argp = (void __user *)arg;
	int __user *ip = argp;
	int err;

	ctl = file->private_data;
	card = ctl->card;
1532 1533
	if (snd_BUG_ON(!card))
		return -ENXIO;
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1534 1535 1536 1537 1538 1539
	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:
1540
		return snd_ctl_elem_list(card, argp);
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1541 1542 1543
	case SNDRV_CTL_IOCTL_ELEM_INFO:
		return snd_ctl_elem_info_user(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_READ:
1544
		return snd_ctl_elem_read_user(card, argp);
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1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558
	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);
1559
	case SNDRV_CTL_IOCTL_TLV_READ:
1560 1561 1562 1563
		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;
1564
	case SNDRV_CTL_IOCTL_TLV_WRITE:
1565 1566 1567 1568
		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;
1569
	case SNDRV_CTL_IOCTL_TLV_COMMAND:
1570 1571 1572 1573
		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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1574
	case SNDRV_CTL_IOCTL_POWER:
T
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1575
		return -ENOPROTOOPT;
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1576 1577 1578 1579 1580 1581 1582 1583
	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);
1584
	list_for_each_entry(p, &snd_control_ioctls, list) {
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1585 1586 1587 1588 1589 1590 1591
		err = p->fioctl(card, ctl, cmd, arg);
		if (err != -ENOIOCTLCMD) {
			up_read(&snd_ioctl_rwsem);
			return err;
		}
	}
	up_read(&snd_ioctl_rwsem);
1592
	dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
L
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1593 1594 1595
	return -ENOTTY;
}

1596 1597
static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
			    size_t count, loff_t * offset)
L
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1598
{
1599
	struct snd_ctl_file *ctl;
L
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1600 1601 1602 1603
	int err = 0;
	ssize_t result = 0;

	ctl = file->private_data;
1604 1605
	if (snd_BUG_ON(!ctl || !ctl->card))
		return -ENXIO;
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1606 1607
	if (!ctl->subscribed)
		return -EBADFD;
1608
	if (count < sizeof(struct snd_ctl_event))
L
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1609 1610
		return -EINVAL;
	spin_lock_irq(&ctl->read_lock);
1611 1612 1613
	while (count >= sizeof(struct snd_ctl_event)) {
		struct snd_ctl_event ev;
		struct snd_kctl_event *kev;
L
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1614
		while (list_empty(&ctl->events)) {
1615
			wait_queue_entry_t wait;
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1616 1617 1618 1619 1620 1621 1622 1623 1624 1625
			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);
1626 1627
			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);
1639
		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;
}

1689 1690 1691 1692 1693 1694
/**
 * 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
 */

1803
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
 */
1819
static int snd_ctl_dev_register(struct snd_device *device)
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{
1821
	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
 */
1830
static int snd_ctl_dev_disconnect(struct snd_device *device)
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{
1832 1833
	struct snd_card *card = device->device_data;
	struct snd_ctl_file *ctl;
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1835
	read_lock(&card->ctl_files_rwlock);
1836
	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);
	}
1840
	read_unlock(&card->ctl_files_rwlock);
1841

1842
	return snd_unregister_device(&card->ctl_dev);
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}

/*
 * free all controls
 */
1848
static int snd_ctl_dev_free(struct snd_device *device)
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{
1850 1851
	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);
1859
	put_device(&card->ctl_dev);
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	return 0;
}

/*
 * create control core:
 * called from init.c
 */
1867
int snd_ctl_create(struct snd_card *card)
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{
1869
	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,
	};
1874
	int err;
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1876 1877
	if (snd_BUG_ON(!card))
		return -ENXIO;
1878 1879 1880 1881 1882 1883 1884 1885 1886 1887
	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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}
1889 1890

/*
1891
 * Frequently used control callbacks/helpers
1892
 */
1893 1894 1895 1896 1897 1898 1899 1900 1901 1902

/**
 * 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.
 */
1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913
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);

1914 1915 1916 1917 1918 1919 1920 1921 1922
/**
 * 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.
 */
1923 1924 1925 1926 1927 1928 1929 1930 1931 1932
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);
1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943

/**
 * 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.
1944 1945
 *
 * Return: Zero.
1946 1947 1948 1949 1950 1951 1952
 */
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;
1953 1954
	if (!items)
		return 0;
1955 1956
	if (info->value.enumerated.item >= items)
		info->value.enumerated.item = items - 1;
1957 1958 1959
	WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
	     "ALSA: too long item name '%s'\n",
	     names[info->value.enumerated.item]);
1960 1961 1962 1963 1964 1965
	strlcpy(info->value.enumerated.name,
		names[info->value.enumerated.item],
		sizeof(info->value.enumerated.name));
	return 0;
}
EXPORT_SYMBOL(snd_ctl_enum_info);