linux/sound/core/control.c
Takashi Iwai 7d8e829201 ALSA: Get rid of card power_lock
Currently we're taking power_lock at each card component for assuring
the power-up sequence, but it doesn't help anything in the
implementation at the moment: it just serializes unnecessarily the
callers, but it doesn't protect about the power state change itself.
It used to have some usefulness in the early days where we managed the
PM manually.  But now the suspend/resume core procedure is beyond our
hands, and power_lock lost its meaning.

This patch drops the power_lock from allover the places.
There shouldn't be any issues by this change, as it's no helper
regarding the power state change.  Rather we'll get better performance
by removing the serialization; which is the only slight concern of any
behavior change, but it can't be a showstopper, after all.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-08-30 20:44:29 +02:00

1981 lines
51 KiB
C

/*
* Routines for driver control interface
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*
*
* 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>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/time.h>
#include <linux/sched/signal.h>
#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
#define MAX_CONTROL_COUNT 1028
struct snd_kctl_ioctl {
struct list_head list; /* list of all ioctls */
snd_kctl_ioctl_func_t fioctl;
};
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;
struct snd_card *card;
struct snd_ctl_file *ctl;
int i, err;
err = nonseekable_open(inode, file);
if (err < 0)
return err;
card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
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;
}
ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
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;
for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
ctl->preferred_subdevice[i] = -1;
ctl->pid = get_pid(task_pid(current));
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);
snd_card_unref(card);
return 0;
__error:
module_put(card->module);
__error2:
snd_card_file_remove(card, file);
__error1:
if (card)
snd_card_unref(card);
return err;
}
static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
{
unsigned long flags;
struct snd_kctl_event *cread;
spin_lock_irqsave(&ctl->read_lock, flags);
while (!list_empty(&ctl->events)) {
cread = snd_kctl_event(ctl->events.next);
list_del(&cread->list);
kfree(cread);
}
spin_unlock_irqrestore(&ctl->read_lock, flags);
}
static int snd_ctl_release(struct inode *inode, struct file *file)
{
unsigned long flags;
struct snd_card *card;
struct snd_ctl_file *ctl;
struct snd_kcontrol *control;
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);
list_for_each_entry(control, &card->controls, list)
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);
put_pid(ctl->pid);
kfree(ctl);
module_put(card->module);
snd_card_file_remove(card, file);
return 0;
}
/**
* 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.
*/
void snd_ctl_notify(struct snd_card *card, unsigned int mask,
struct snd_ctl_elem_id *id)
{
unsigned long flags;
struct snd_ctl_file *ctl;
struct snd_kctl_event *ev;
if (snd_BUG_ON(!card || !id))
return;
if (card->shutdown)
return;
read_lock(&card->ctl_files_rwlock);
#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
card->mixer_oss_change_count++;
#endif
list_for_each_entry(ctl, &card->ctl_files, list) {
if (!ctl->subscribed)
continue;
spin_lock_irqsave(&ctl->read_lock, flags);
list_for_each_entry(ev, &ctl->events, list) {
if (ev->id.numid == id->numid) {
ev->mask |= mask;
goto _found;
}
}
ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
if (ev) {
ev->id = *id;
ev->mask = mask;
list_add_tail(&ev->list, &ctl->events);
} else {
dev_err(card->dev, "No memory available to allocate event\n");
}
_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);
}
EXPORT_SYMBOL(snd_ctl_notify);
/**
* 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
*
* 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.
*
* Return: 0 on success, error code on failure
*/
static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
unsigned int access, struct snd_ctl_file *file)
{
unsigned int size;
unsigned int idx;
if (count == 0 || count > MAX_CONTROL_COUNT)
return -EINVAL;
size = sizeof(struct snd_kcontrol);
size += sizeof(struct snd_kcontrol_volatile) * count;
*kctl = kzalloc(size, GFP_KERNEL);
if (!*kctl)
return -ENOMEM;
for (idx = 0; idx < count; idx++) {
(*kctl)->vd[idx].access = access;
(*kctl)->vd[idx].owner = file;
}
(*kctl)->count = count;
return 0;
}
/**
* snd_ctl_new1 - create a control instance from the template
* @ncontrol: the initialization record
* @private_data: the private data to set
*
* Allocates a new struct snd_kcontrol instance and initialize from the given
* 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.
*
* Return: The pointer of the newly generated instance, or %NULL on failure.
*/
struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
void *private_data)
{
struct snd_kcontrol *kctl;
unsigned int count;
unsigned int access;
int err;
if (snd_BUG_ON(!ncontrol || !ncontrol->info))
return NULL;
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;
if (ncontrol->name) {
strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
if (strcmp(ncontrol->name, kctl->id.name) != 0)
pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
ncontrol->name, kctl->id.name);
}
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;
}
EXPORT_SYMBOL(snd_ctl_new1);
/**
* 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.
*/
void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
{
if (kcontrol) {
if (kcontrol->private_free)
kcontrol->private_free(kcontrol);
kfree(kcontrol);
}
}
EXPORT_SYMBOL(snd_ctl_free_one);
static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
unsigned int count)
{
struct snd_kcontrol *kctl;
/* Make sure that the ids assigned to the control do not wrap around */
if (card->last_numid >= UINT_MAX - count)
card->last_numid = 0;
list_for_each_entry(kctl, &card->controls, list) {
if (kctl->id.numid < card->last_numid + 1 + count &&
kctl->id.numid + kctl->count > card->last_numid + 1) {
card->last_numid = kctl->id.numid + kctl->count - 1;
return true;
}
}
return false;
}
static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
{
unsigned int iter = 100000;
while (snd_ctl_remove_numid_conflict(card, count)) {
if (--iter == 0) {
/* this situation is very unlikely */
dev_err(card->dev, "unable to allocate new control numid\n");
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.
*
* Return: Zero if successful, or a negative error code on failure.
*
*/
int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
{
struct snd_ctl_elem_id id;
unsigned int idx;
unsigned int count;
int err = -EINVAL;
if (! kcontrol)
return err;
if (snd_BUG_ON(!card || !kcontrol->info))
goto error;
id = kcontrol->id;
if (id.index > UINT_MAX - kcontrol->count)
goto error;
down_write(&card->controls_rwsem);
if (snd_ctl_find_id(card, &id)) {
up_write(&card->controls_rwsem);
dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
id.iface,
id.device,
id.subdevice,
id.name,
id.index);
err = -EBUSY;
goto error;
}
if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
up_write(&card->controls_rwsem);
err = -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;
id = kcontrol->id;
count = kcontrol->count;
up_write(&card->controls_rwsem);
for (idx = 0; idx < count; idx++, id.index++, id.numid++)
snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
return 0;
error:
snd_ctl_free_one(kcontrol);
return err;
}
EXPORT_SYMBOL(snd_ctl_add);
/**
* 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.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
bool add_on_replace)
{
struct snd_ctl_elem_id id;
unsigned int count;
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;
id = kcontrol->id;
count = kcontrol->count;
up_write(&card->controls_rwsem);
for (idx = 0; idx < count; idx++, id.index++, id.numid++)
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);
/**
* 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).
*
* Return: 0 if successful, or a negative error code on failure.
*/
int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
{
struct snd_ctl_elem_id id;
unsigned int idx;
if (snd_BUG_ON(!card || !kcontrol))
return -EINVAL;
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;
}
EXPORT_SYMBOL(snd_ctl_remove);
/**
* 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.
*
* Return: 0 if successful, or a negative error code on failure.
*/
int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
{
struct snd_kcontrol *kctl;
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;
}
EXPORT_SYMBOL(snd_ctl_remove_id);
/**
* snd_ctl_remove_user_ctl - remove and release the unlocked user control
* @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.
*
* Return: 0 if successful, or a negative error code on failure.
*/
static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
struct snd_ctl_elem_id *id)
{
struct snd_card *card = file->card;
struct snd_kcontrol *kctl;
int idx, ret;
down_write(&card->controls_rwsem);
kctl = snd_ctl_find_id(card, id);
if (kctl == NULL) {
ret = -ENOENT;
goto error;
}
if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
ret = -EINVAL;
goto error;
}
for (idx = 0; idx < kctl->count; idx++)
if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
ret = -EBUSY;
goto error;
}
ret = snd_ctl_remove(card, kctl);
if (ret < 0)
goto error;
card->user_ctl_count--;
error:
up_write(&card->controls_rwsem);
return ret;
}
/**
* 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.
* The given ID data is filled with full information.
*
* Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
*/
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;
}
index_offset = snd_ctl_get_ioff(kctl, id);
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;
}
snd_ctl_build_ioff(id, kctl, index_offset);
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);
/**
* 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.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
struct snd_ctl_elem_id *dst_id)
{
struct snd_kcontrol *kctl;
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;
}
EXPORT_SYMBOL(snd_ctl_rename_id);
/**
* 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).
*
* Return: The pointer of the instance if found, or %NULL if not.
*
*/
struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
{
struct snd_kcontrol *kctl;
if (snd_BUG_ON(!card || !numid))
return NULL;
list_for_each_entry(kctl, &card->controls, list) {
if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
return kctl;
}
return NULL;
}
EXPORT_SYMBOL(snd_ctl_find_numid);
/**
* 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).
*
* Return: The pointer of the instance if found, or %NULL if not.
*
*/
struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
struct snd_ctl_elem_id *id)
{
struct snd_kcontrol *kctl;
if (snd_BUG_ON(!card || !id))
return NULL;
if (id->numid != 0)
return snd_ctl_find_numid(card, id->numid);
list_for_each_entry(kctl, &card->controls, list) {
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;
}
EXPORT_SYMBOL(snd_ctl_find_id);
static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
unsigned int cmd, void __user *arg)
{
struct snd_ctl_card_info *info;
info = kzalloc(sizeof(*info), GFP_KERNEL);
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);
if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
kfree(info);
return -EFAULT;
}
kfree(info);
return 0;
}
static int snd_ctl_elem_list(struct snd_card *card,
struct snd_ctl_elem_list __user *_list)
{
struct snd_ctl_elem_list list;
struct snd_kcontrol *kctl;
struct snd_ctl_elem_id id;
unsigned int offset, space, jidx;
int err = 0;
if (copy_from_user(&list, _list, sizeof(list)))
return -EFAULT;
offset = list.offset;
space = list.space;
down_read(&card->controls_rwsem);
list.count = card->controls_count;
list.used = 0;
if (space > 0) {
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;
}
list.used++;
if (!--space)
goto out;
}
offset = 0;
}
}
out:
up_read(&card->controls_rwsem);
if (!err && copy_to_user(_list, &list, sizeof(list)))
err = -EFAULT;
return err;
}
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;
}
static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
struct snd_ctl_elem_info *info)
{
struct snd_card *card = ctl->card;
struct snd_kcontrol *kctl;
struct snd_kcontrol_volatile *vd;
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) {
snd_BUG_ON(info->access);
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;
info->owner = pid_vnr(vd->owner->pid);
} else {
info->owner = -1;
}
}
up_read(&card->controls_rwsem);
return result;
}
static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
struct snd_ctl_elem_info __user *_info)
{
struct snd_ctl_elem_info info;
int result;
if (copy_from_user(&info, _info, sizeof(info)))
return -EFAULT;
result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
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;
return result;
}
static int snd_ctl_elem_read(struct snd_card *card,
struct snd_ctl_elem_value *control)
{
struct snd_kcontrol *kctl;
struct snd_kcontrol_volatile *vd;
unsigned int index_offset;
kctl = snd_ctl_find_id(card, &control->id);
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);
}
static int snd_ctl_elem_read_user(struct snd_card *card,
struct snd_ctl_elem_value __user *_control)
{
struct snd_ctl_elem_value *control;
int result;
control = memdup_user(_control, sizeof(*control));
if (IS_ERR(control))
return PTR_ERR(control);
result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
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:
kfree(control);
return result;
}
static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
struct snd_ctl_elem_value *control)
{
struct snd_kcontrol *kctl;
struct snd_kcontrol_volatile *vd;
unsigned int index_offset;
int result;
kctl = snd_ctl_find_id(card, &control->id);
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;
}
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;
}
static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
struct snd_ctl_elem_value __user *_control)
{
struct snd_ctl_elem_value *control;
struct snd_card *card;
int result;
control = memdup_user(_control, sizeof(*control));
if (IS_ERR(control))
return PTR_ERR(control);
card = file->card;
result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
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:
kfree(control);
return result;
}
static int snd_ctl_elem_lock(struct snd_ctl_file *file,
struct snd_ctl_elem_id __user *_id)
{
struct snd_card *card = file->card;
struct snd_ctl_elem_id id;
struct snd_kcontrol *kctl;
struct snd_kcontrol_volatile *vd;
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;
}
static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
struct snd_ctl_elem_id __user *_id)
{
struct snd_card *card = file->card;
struct snd_ctl_elem_id id;
struct snd_kcontrol *kctl;
struct snd_kcontrol_volatile *vd;
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 {
struct snd_ctl_elem_info info;
struct snd_card *card;
char *elem_data; /* element data */
unsigned long elem_data_size; /* size of element data in bytes */
void *tlv_data; /* TLV data */
unsigned long tlv_data_size; /* TLV data size */
void *priv_data; /* private data (like strings for enumerated type) */
};
static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo)
{
struct user_element *ue = kcontrol->private_data;
unsigned int offset;
offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
*uinfo = ue->info;
snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
return 0;
}
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;
unsigned int offset;
item = uinfo->value.enumerated.item;
offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
*uinfo = ue->info;
snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
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;
}
static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
struct user_element *ue = kcontrol->private_data;
unsigned int size = ue->elem_data_size;
char *src = ue->elem_data +
snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
memcpy(&ucontrol->value, src, size);
return 0;
}
static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
int change;
struct user_element *ue = kcontrol->private_data;
unsigned int size = ue->elem_data_size;
char *dst = ue->elem_data +
snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
change = memcmp(&ucontrol->value, dst, size) != 0;
if (change)
memcpy(dst, &ucontrol->value, size);
return change;
}
static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
unsigned int size)
{
struct user_element *ue = kctl->private_data;
unsigned int *container;
struct snd_ctl_elem_id id;
unsigned int mask = 0;
int i;
int change;
if (size > 1024 * 128) /* sane value */
return -EINVAL;
container = memdup_user(buf, size);
if (IS_ERR(container))
return PTR_ERR(container);
change = ue->tlv_data_size != size;
if (!change)
change = memcmp(ue->tlv_data, container, size) != 0;
if (!change) {
kfree(container);
return 0;
}
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;
}
kfree(ue->tlv_data);
ue->tlv_data = container;
ue->tlv_data_size = size;
mask |= SNDRV_CTL_EVENT_MASK_TLV;
for (i = 0; i < kctl->count; ++i) {
snd_ctl_build_ioff(&id, kctl, i);
snd_ctl_notify(ue->card, mask, &id);
}
return change;
}
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);
}
static int snd_ctl_elem_init_enum_names(struct user_element *ue)
{
char *names, *p;
size_t buf_len, name_len;
unsigned int i;
const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
if (ue->info.value.enumerated.names_length > 64 * 1024)
return -EINVAL;
names = memdup_user((const void __user *)user_ptrval,
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;
}
static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
{
struct user_element *ue = kcontrol->private_data;
kfree(ue->tlv_data);
kfree(ue->priv_data);
kfree(ue);
}
static int snd_ctl_elem_add(struct snd_ctl_file *file,
struct snd_ctl_elem_info *info, int replace)
{
/* 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,
};
struct snd_card *card = file->card;
struct snd_kcontrol *kctl;
unsigned int count;
unsigned int access;
long private_size;
struct user_element *ue;
unsigned int offset;
int err;
if (!*info->id.name)
return -EINVAL;
if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
return -EINVAL;
/* Delete a control to replace them if needed. */
if (replace) {
info->id.numid = 0;
err = snd_ctl_remove_user_ctl(file, &info->id);
if (err)
return err;
}
/*
* The number of userspace controls are counted control by control,
* not element by element.
*/
if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
return -ENOMEM;
/* 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_WRITE);
/* In initial state, nothing is available as TLV container. */
if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
access |= SNDRV_CTL_ELEM_ACCESS_USER;
/*
* Check information and calculate the size of data specific to
* this userspace control.
*/
if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
return -EINVAL;
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;
if (!validate_element_member_dimension(info))
return -EINVAL;
private_size = value_sizes[info->type] * info->count;
/*
* 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;
memcpy(&kctl->id, &info->id, sizeof(kctl->id));
kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
GFP_KERNEL);
if (kctl->private_data == NULL) {
kfree(kctl);
return -ENOMEM;
}
kctl->private_free = snd_ctl_elem_user_free;
/* Set private data for this userspace control. */
ue = (struct user_element *)kctl->private_data;
ue->card = card;
ue->info = *info;
ue->info.access = 0;
ue->elem_data = (char *)ue + sizeof(*ue);
ue->elem_data_size = private_size;
if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
err = snd_ctl_elem_init_enum_names(ue);
if (err < 0) {
snd_ctl_free_one(kctl);
return err;
}
}
/* 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_WRITE)
kctl->tlv.c = snd_ctl_elem_user_tlv;
/* This function manage to free the instance on failure. */
err = snd_ctl_add(card, kctl);
if (err < 0)
return err;
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.
*/
down_write(&card->controls_rwsem);
card->user_ctl_count++;
up_write(&card->controls_rwsem);
return 0;
}
static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
struct snd_ctl_elem_info __user *_info, int replace)
{
struct snd_ctl_elem_info info;
int err;
if (copy_from_user(&info, _info, sizeof(info)))
return -EFAULT;
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;
}
static int snd_ctl_elem_remove(struct snd_ctl_file *file,
struct snd_ctl_elem_id __user *_id)
{
struct snd_ctl_elem_id id;
if (copy_from_user(&id, _id, sizeof(id)))
return -EFAULT;
return snd_ctl_remove_user_ctl(file, &id);
}
static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
{
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;
}
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;
return kctl->tlv.c(kctl, op_flag, size, buf);
}
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;
}
static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
struct snd_ctl_tlv __user *buf,
int op_flag)
{
struct snd_ctl_tlv header;
unsigned int *container;
unsigned int container_size;
struct snd_kcontrol *kctl;
struct snd_ctl_elem_id id;
struct snd_kcontrol_volatile *vd;
if (copy_from_user(&header, buf, sizeof(header)))
return -EFAULT;
/* In design of control core, numerical ID starts at 1. */
if (header.numid == 0)
return -EINVAL;
/* At least, container should include type and length fields. */
if (header.length < sizeof(unsigned int) * 2)
return -EINVAL;
container_size = header.length;
container = buf->tlv;
kctl = snd_ctl_find_numid(file->card, header.numid);
if (kctl == NULL)
return -ENOENT;
/* 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)];
if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
return call_tlv_handler(file, op_flag, kctl, &id, container,
container_size);
} else {
if (op_flag == SNDRV_CTL_TLV_OP_READ) {
return read_tlv_buf(kctl, &id, container,
container_size);
}
}
/* Not supported. */
return -ENXIO;
}
static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct snd_ctl_file *ctl;
struct snd_card *card;
struct snd_kctl_ioctl *p;
void __user *argp = (void __user *)arg;
int __user *ip = argp;
int err;
ctl = file->private_data;
card = ctl->card;
if (snd_BUG_ON(!card))
return -ENXIO;
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:
return snd_ctl_elem_list(card, argp);
case SNDRV_CTL_IOCTL_ELEM_INFO:
return snd_ctl_elem_info_user(ctl, argp);
case SNDRV_CTL_IOCTL_ELEM_READ:
return snd_ctl_elem_read_user(card, argp);
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);
case SNDRV_CTL_IOCTL_TLV_READ:
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;
case SNDRV_CTL_IOCTL_TLV_WRITE:
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;
case SNDRV_CTL_IOCTL_TLV_COMMAND:
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;
case SNDRV_CTL_IOCTL_POWER:
return -ENOPROTOOPT;
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);
list_for_each_entry(p, &snd_control_ioctls, list) {
err = p->fioctl(card, ctl, cmd, arg);
if (err != -ENOIOCTLCMD) {
up_read(&snd_ioctl_rwsem);
return err;
}
}
up_read(&snd_ioctl_rwsem);
dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
return -ENOTTY;
}
static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
size_t count, loff_t * offset)
{
struct snd_ctl_file *ctl;
int err = 0;
ssize_t result = 0;
ctl = file->private_data;
if (snd_BUG_ON(!ctl || !ctl->card))
return -ENXIO;
if (!ctl->subscribed)
return -EBADFD;
if (count < sizeof(struct snd_ctl_event))
return -EINVAL;
spin_lock_irq(&ctl->read_lock);
while (count >= sizeof(struct snd_ctl_event)) {
struct snd_ctl_event ev;
struct snd_kctl_event *kev;
while (list_empty(&ctl->events)) {
wait_queue_entry_t wait;
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);
if (ctl->card->shutdown)
return -ENODEV;
if (signal_pending(current))
return -ERESTARTSYS;
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);
if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
err = -EFAULT;
goto __end;
}
spin_lock_irq(&ctl->read_lock);
buffer += sizeof(struct snd_ctl_event);
count -= sizeof(struct snd_ctl_event);
result += sizeof(struct snd_ctl_event);
}
__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;
struct snd_ctl_file *ctl;
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)
{
struct snd_kctl_ioctl *pn;
pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
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;
}
/**
* 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.
*/
int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
{
return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
}
EXPORT_SYMBOL(snd_ctl_register_ioctl);
#ifdef CONFIG_COMPAT
/**
* snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
* control-ioctls
* @fcn: ioctl callback function
*/
int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
{
return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
}
EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
#endif
/*
* de-register the device-specific control-ioctls.
*/
static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
struct list_head *lists)
{
struct snd_kctl_ioctl *p;
if (snd_BUG_ON(!fcn))
return -EINVAL;
down_write(&snd_ioctl_rwsem);
list_for_each_entry(p, lists, list) {
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;
}
/**
* snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
* @fcn: ioctl callback function to unregister
*/
int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
{
return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
}
EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
#ifdef CONFIG_COMPAT
/**
* snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
* control-ioctls
* @fcn: ioctl callback function to unregister
*/
int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
{
return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
}
EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
#endif
static int snd_ctl_fasync(int fd, struct file * file, int on)
{
struct snd_ctl_file *ctl;
ctl = file->private_data;
return fasync_helper(fd, file, on, &ctl->fasync);
}
/* 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);
/*
* ioctl32 compat
*/
#ifdef CONFIG_COMPAT
#include "control_compat.c"
#else
#define snd_ctl_ioctl_compat NULL
#endif
/*
* INIT PART
*/
static const struct file_operations snd_ctl_f_ops =
{
.owner = THIS_MODULE,
.read = snd_ctl_read,
.open = snd_ctl_open,
.release = snd_ctl_release,
.llseek = no_llseek,
.poll = snd_ctl_poll,
.unlocked_ioctl = snd_ctl_ioctl,
.compat_ioctl = snd_ctl_ioctl_compat,
.fasync = snd_ctl_fasync,
};
/*
* registration of the control device
*/
static int snd_ctl_dev_register(struct snd_device *device)
{
struct snd_card *card = device->device_data;
return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
&snd_ctl_f_ops, card, &card->ctl_dev);
}
/*
* disconnection of the control device
*/
static int snd_ctl_dev_disconnect(struct snd_device *device)
{
struct snd_card *card = device->device_data;
struct snd_ctl_file *ctl;
read_lock(&card->ctl_files_rwlock);
list_for_each_entry(ctl, &card->ctl_files, list) {
wake_up(&ctl->change_sleep);
kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
}
read_unlock(&card->ctl_files_rwlock);
return snd_unregister_device(&card->ctl_dev);
}
/*
* free all controls
*/
static int snd_ctl_dev_free(struct snd_device *device)
{
struct snd_card *card = device->device_data;
struct snd_kcontrol *control;
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);
put_device(&card->ctl_dev);
return 0;
}
/*
* create control core:
* called from init.c
*/
int snd_ctl_create(struct snd_card *card)
{
static struct snd_device_ops ops = {
.dev_free = snd_ctl_dev_free,
.dev_register = snd_ctl_dev_register,
.dev_disconnect = snd_ctl_dev_disconnect,
};
int err;
if (snd_BUG_ON(!card))
return -ENXIO;
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;
}
/*
* Frequently used control callbacks/helpers
*/
/**
* 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.
*/
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);
/**
* 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.
*/
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);
/**
* 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.
*
* Return: Zero.
*/
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;
if (!items)
return 0;
if (info->value.enumerated.item >= items)
info->value.enumerated.item = items - 1;
WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
"ALSA: too long item name '%s'\n",
names[info->value.enumerated.item]);
strlcpy(info->value.enumerated.name,
names[info->value.enumerated.item],
sizeof(info->value.enumerated.name));
return 0;
}
EXPORT_SYMBOL(snd_ctl_enum_info);