// SPDX-License-Identifier: GPL-2.0+
/*
* virtio-snd: Virtio sound device
* Copyright (C) 2021 OpenSynergy GmbH
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/virtio_config.h>
#include <sound/initval.h>
#include <uapi/linux/virtio_ids.h>
#include "virtio_card.h"
u32 virtsnd_msg_timeout_ms = MSEC_PER_SEC;
module_param_named(msg_timeout_ms, virtsnd_msg_timeout_ms, uint, 0644);
MODULE_PARM_DESC(msg_timeout_ms, "Message completion timeout in milliseconds");
static void virtsnd_remove(struct virtio_device *vdev);
/**
* virtsnd_event_send() - Add an event to the event queue.
* @vqueue: Underlying event virtqueue.
* @event: Event.
* @notify: Indicates whether or not to send a notification to the device.
* @gfp: Kernel flags for memory allocation.
*
* Context: Any context.
*/
static void virtsnd_event_send(struct virtqueue *vqueue,
struct virtio_snd_event *event, bool notify,
gfp_t gfp)
{
struct scatterlist sg;
struct scatterlist *psgs[1] = { &sg };
/* reset event content */
memset(event, 0, sizeof(*event));
sg_init_one(&sg, event, sizeof(*event));
if (virtqueue_add_sgs(vqueue, psgs, 0, 1, event, gfp) || !notify)
return;
if (virtqueue_kick_prepare(vqueue))
virtqueue_notify(vqueue);
}
/**
* virtsnd_event_dispatch() - Dispatch an event from the device side.
* @snd: VirtIO sound device.
* @event: VirtIO sound event.
*
* Context: Any context.
*/
static void virtsnd_event_dispatch(struct virtio_snd *snd,
struct virtio_snd_event *event)
{
switch (le32_to_cpu(event->hdr.code)) {
case VIRTIO_SND_EVT_JACK_CONNECTED:
case VIRTIO_SND_EVT_JACK_DISCONNECTED:
virtsnd_jack_event(snd, event);
break;
case VIRTIO_SND_EVT_PCM_PERIOD_ELAPSED:
case VIRTIO_SND_EVT_PCM_XRUN:
virtsnd_pcm_event(snd, event);
break;
case VIRTIO_SND_EVT_CTL_NOTIFY:
virtsnd_kctl_event(snd, event);
break;
}
}
/**
* virtsnd_event_notify_cb() - Dispatch all reported events from the event queue.
* @vqueue: Underlying event virtqueue.
*
* This callback function is called upon a vring interrupt request from the
* device.
*
* Context: Interrupt context.
*/
static void virtsnd_event_notify_cb(struct virtqueue *vqueue)
{
struct virtio_snd *snd = vqueue->vdev->priv;
struct virtio_snd_queue *queue = virtsnd_event_queue(snd);
struct virtio_snd_event *event;
u32 length;
unsigned long flags;
spin_lock_irqsave(&queue->lock, flags);
do {
virtqueue_disable_cb(vqueue);
while ((event = virtqueue_get_buf(vqueue, &length))) {
virtsnd_event_dispatch(snd, event);
virtsnd_event_send(vqueue, event, true, GFP_ATOMIC);
}
} while (!virtqueue_enable_cb(vqueue));
spin_unlock_irqrestore(&queue->lock, flags);
}
/**
* virtsnd_find_vqs() - Enumerate and initialize all virtqueues.
* @snd: VirtIO sound device.
*
* After calling this function, the event queue is disabled.
*
* Context: Any context.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_find_vqs(struct virtio_snd *snd)
{
struct virtio_device *vdev = snd->vdev;
struct virtqueue_info vqs_info[VIRTIO_SND_VQ_MAX] = {
[VIRTIO_SND_VQ_CONTROL] = { "virtsnd-ctl",
virtsnd_ctl_notify_cb },
[VIRTIO_SND_VQ_EVENT] = { "virtsnd-event",
virtsnd_event_notify_cb },
[VIRTIO_SND_VQ_TX] = { "virtsnd-tx",
virtsnd_pcm_tx_notify_cb },
[VIRTIO_SND_VQ_RX] = { "virtsnd-rx",
virtsnd_pcm_rx_notify_cb },
};
struct virtqueue *vqs[VIRTIO_SND_VQ_MAX] = { 0 };
unsigned int i;
unsigned int n;
int rc;
rc = virtio_find_vqs(vdev, VIRTIO_SND_VQ_MAX, vqs, vqs_info, NULL);
if (rc) {
dev_err(&vdev->dev, "failed to initialize virtqueues\n");
return rc;
}
for (i = 0; i < VIRTIO_SND_VQ_MAX; ++i)
snd->queues[i].vqueue = vqs[i];
/* Allocate events and populate the event queue */
virtqueue_disable_cb(vqs[VIRTIO_SND_VQ_EVENT]);
n = virtqueue_get_vring_size(vqs[VIRTIO_SND_VQ_EVENT]);
snd->event_msgs = kmalloc_array(n, sizeof(*snd->event_msgs),
GFP_KERNEL);
if (!snd->event_msgs)
return -ENOMEM;
for (i = 0; i < n; ++i)
virtsnd_event_send(vqs[VIRTIO_SND_VQ_EVENT],
&snd->event_msgs[i], false, GFP_KERNEL);
return 0;
}
/**
* virtsnd_enable_event_vq() - Enable the event virtqueue.
* @snd: VirtIO sound device.
*
* Context: Any context.
*/
static void virtsnd_enable_event_vq(struct virtio_snd *snd)
{
struct virtio_snd_queue *queue = virtsnd_event_queue(snd);
if (!virtqueue_enable_cb(queue->vqueue))
virtsnd_event_notify_cb(queue->vqueue);
}
/**
* virtsnd_disable_event_vq() - Disable the event virtqueue.
* @snd: VirtIO sound device.
*
* Context: Any context.
*/
static void virtsnd_disable_event_vq(struct virtio_snd *snd)
{
struct virtio_snd_queue *queue = virtsnd_event_queue(snd);
struct virtio_snd_event *event;
u32 length;
unsigned long flags;
if (queue->vqueue) {
spin_lock_irqsave(&queue->lock, flags);
virtqueue_disable_cb(queue->vqueue);
while ((event = virtqueue_get_buf(queue->vqueue, &length)))
virtsnd_event_dispatch(snd, event);
spin_unlock_irqrestore(&queue->lock, flags);
}
}
/**
* virtsnd_build_devs() - Read configuration and build ALSA devices.
* @snd: VirtIO sound device.
*
* Context: Any context that permits to sleep.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_build_devs(struct virtio_snd *snd)
{
struct virtio_device *vdev = snd->vdev;
struct device *dev = &vdev->dev;
int rc;
rc = snd_card_new(dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
THIS_MODULE, 0, &snd->card);
if (rc < 0)
return rc;
snd->card->private_data = snd;
strscpy(snd->card->driver, VIRTIO_SND_CARD_DRIVER,
sizeof(snd->card->driver));
strscpy(snd->card->shortname, VIRTIO_SND_CARD_NAME,
sizeof(snd->card->shortname));
if (dev->parent->bus)
snprintf(snd->card->longname, sizeof(snd->card->longname),
VIRTIO_SND_CARD_NAME " at %s/%s/%s",
dev->parent->bus->name, dev_name(dev->parent),
dev_name(dev));
else
snprintf(snd->card->longname, sizeof(snd->card->longname),
VIRTIO_SND_CARD_NAME " at %s/%s",
dev_name(dev->parent), dev_name(dev));
rc = virtsnd_jack_parse_cfg(snd);
if (rc)
return rc;
rc = virtsnd_pcm_parse_cfg(snd);
if (rc)
return rc;
rc = virtsnd_chmap_parse_cfg(snd);
if (rc)
return rc;
if (virtio_has_feature(vdev, VIRTIO_SND_F_CTLS)) {
rc = virtsnd_kctl_parse_cfg(snd);
if (rc)
return rc;
}
if (snd->njacks) {
rc = virtsnd_jack_build_devs(snd);
if (rc)
return rc;
}
if (snd->nsubstreams) {
rc = virtsnd_pcm_build_devs(snd);
if (rc)
return rc;
}
if (snd->nchmaps) {
rc = virtsnd_chmap_build_devs(snd);
if (rc)
return rc;
}
if (snd->nkctls) {
rc = virtsnd_kctl_build_devs(snd);
if (rc)
return rc;
}
return snd_card_register(snd->card);
}
/**
* virtsnd_validate() - Validate if the device can be started.
* @vdev: VirtIO parent device.
*
* Context: Any context.
* Return: 0 on success, -EINVAL on failure.
*/
static int virtsnd_validate(struct virtio_device *vdev)
{
if (!vdev->config->get) {
dev_err(&vdev->dev, "configuration access disabled\n");
return -EINVAL;
}
if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
dev_err(&vdev->dev,
"device does not comply with spec version 1.x\n");
return -EINVAL;
}
if (!virtsnd_msg_timeout_ms) {
dev_err(&vdev->dev, "msg_timeout_ms value cannot be zero\n");
return -EINVAL;
}
if (virtsnd_pcm_validate(vdev))
return -EINVAL;
return 0;
}
/**
* virtsnd_probe() - Create and initialize the device.
* @vdev: VirtIO parent device.
*
* Context: Any context that permits to sleep.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_probe(struct virtio_device *vdev)
{
struct virtio_snd *snd;
unsigned int i;
int rc;
snd = devm_kzalloc(&vdev->dev, sizeof(*snd), GFP_KERNEL);
if (!snd)
return -ENOMEM;
snd->vdev = vdev;
INIT_LIST_HEAD(&snd->ctl_msgs);
INIT_LIST_HEAD(&snd->pcm_list);
vdev->priv = snd;
for (i = 0; i < VIRTIO_SND_VQ_MAX; ++i)
spin_lock_init(&snd->queues[i].lock);
rc = virtsnd_find_vqs(snd);
if (rc)
goto on_exit;
virtio_device_ready(vdev);
rc = virtsnd_build_devs(snd);
if (rc)
goto on_exit;
virtsnd_enable_event_vq(snd);
on_exit:
if (rc)
virtsnd_remove(vdev);
return rc;
}
/**
* virtsnd_remove() - Remove VirtIO and ALSA devices.
* @vdev: VirtIO parent device.
*
* Context: Any context that permits to sleep.
*/
static void virtsnd_remove(struct virtio_device *vdev)
{
struct virtio_snd *snd = vdev->priv;
unsigned int i;
virtsnd_disable_event_vq(snd);
virtsnd_ctl_msg_cancel_all(snd);
if (snd->card)
snd_card_free(snd->card);
vdev->config->del_vqs(vdev);
virtio_reset_device(vdev);
for (i = 0; snd->substreams && i < snd->nsubstreams; ++i) {
struct virtio_pcm_substream *vss = &snd->substreams[i];
cancel_work_sync(&vss->elapsed_period);
virtsnd_pcm_msg_free(vss);
}
kfree(snd->event_msgs);
}
#ifdef CONFIG_PM_SLEEP
/**
* virtsnd_freeze() - Suspend device.
* @vdev: VirtIO parent device.
*
* Context: Any context.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_freeze(struct virtio_device *vdev)
{
struct virtio_snd *snd = vdev->priv;
unsigned int i;
virtsnd_disable_event_vq(snd);
virtsnd_ctl_msg_cancel_all(snd);
vdev->config->del_vqs(vdev);
virtio_reset_device(vdev);
for (i = 0; i < snd->nsubstreams; ++i)
cancel_work_sync(&snd->substreams[i].elapsed_period);
kfree(snd->event_msgs);
snd->event_msgs = NULL;
return 0;
}
/**
* virtsnd_restore() - Resume device.
* @vdev: VirtIO parent device.
*
* Context: Any context.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_restore(struct virtio_device *vdev)
{
struct virtio_snd *snd = vdev->priv;
int rc;
rc = virtsnd_find_vqs(snd);
if (rc)
return rc;
virtio_device_ready(vdev);
virtsnd_enable_event_vq(snd);
return 0;
}
#endif /* CONFIG_PM_SLEEP */
static const struct virtio_device_id id_table[] = {
{ VIRTIO_ID_SOUND, VIRTIO_DEV_ANY_ID },
{ 0 },
};
static unsigned int features[] = {
VIRTIO_SND_F_CTLS
};
static struct virtio_driver virtsnd_driver = {
.driver.name = KBUILD_MODNAME,
.id_table = id_table,
.feature_table = features,
.feature_table_size = ARRAY_SIZE(features),
.validate = virtsnd_validate,
.probe = virtsnd_probe,
.remove = virtsnd_remove,
#ifdef CONFIG_PM_SLEEP
.freeze = virtsnd_freeze,
.restore = virtsnd_restore,
#endif
};
module_virtio_driver(virtsnd_driver);
MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_DESCRIPTION("Virtio sound card driver");
MODULE_LICENSE("GPL");
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