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-rw-r--r--sound/virtio/Kconfig10
-rw-r--r--sound/virtio/Makefile7
-rw-r--r--sound/virtio/virtio_card.c324
-rw-r--r--sound/virtio/virtio_card.h65
4 files changed, 406 insertions, 0 deletions
diff --git a/sound/virtio/Kconfig b/sound/virtio/Kconfig
new file mode 100644
index 000000000000..094cba24ee5b
--- /dev/null
+++ b/sound/virtio/Kconfig
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Sound card driver for virtio
+
+config SND_VIRTIO
+ tristate "Virtio sound driver"
+ depends on VIRTIO
+ select SND_PCM
+ select SND_JACK
+ help
+ This is the virtual sound driver for virtio. Say Y or M.
diff --git a/sound/virtio/Makefile b/sound/virtio/Makefile
new file mode 100644
index 000000000000..8c87ebb9982b
--- /dev/null
+++ b/sound/virtio/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0+
+
+obj-$(CONFIG_SND_VIRTIO) += virtio_snd.o
+
+virtio_snd-objs := \
+ virtio_card.o
+
diff --git a/sound/virtio/virtio_card.c b/sound/virtio/virtio_card.c
new file mode 100644
index 000000000000..5a37056858e9
--- /dev/null
+++ b/sound/virtio/virtio_card.c
@@ -0,0 +1,324 @@
+// 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"
+
+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)
+{
+}
+
+/**
+ * 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);
+ }
+ if (unlikely(virtqueue_is_broken(vqueue)))
+ break;
+ } 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;
+ static vq_callback_t *callbacks[VIRTIO_SND_VQ_MAX] = {
+ [VIRTIO_SND_VQ_EVENT] = virtsnd_event_notify_cb
+ };
+ static const char *names[VIRTIO_SND_VQ_MAX] = {
+ [VIRTIO_SND_VQ_EVENT] = "virtsnd-event"
+ };
+ 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, callbacks, names,
+ 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));
+
+ 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;
+ }
+
+ 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;
+
+ 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;
+
+ virtsnd_disable_event_vq(snd);
+
+ if (snd->card)
+ snd_card_free(snd->card);
+
+ vdev->config->del_vqs(vdev);
+ vdev->config->reset(vdev);
+
+ kfree(snd->event_msgs);
+}
+
+static const struct virtio_device_id id_table[] = {
+ { VIRTIO_ID_SOUND, VIRTIO_DEV_ANY_ID },
+ { 0 },
+};
+
+static struct virtio_driver virtsnd_driver = {
+ .driver.name = KBUILD_MODNAME,
+ .driver.owner = THIS_MODULE,
+ .id_table = id_table,
+ .validate = virtsnd_validate,
+ .probe = virtsnd_probe,
+ .remove = virtsnd_remove,
+};
+
+static int __init init(void)
+{
+ return register_virtio_driver(&virtsnd_driver);
+}
+module_init(init);
+
+static void __exit fini(void)
+{
+ unregister_virtio_driver(&virtsnd_driver);
+}
+module_exit(fini);
+
+MODULE_DEVICE_TABLE(virtio, id_table);
+MODULE_DESCRIPTION("Virtio sound card driver");
+MODULE_LICENSE("GPL");
diff --git a/sound/virtio/virtio_card.h b/sound/virtio/virtio_card.h
new file mode 100644
index 000000000000..b903b1b12e90
--- /dev/null
+++ b/sound/virtio/virtio_card.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#ifndef VIRTIO_SND_CARD_H
+#define VIRTIO_SND_CARD_H
+
+#include <linux/slab.h>
+#include <linux/virtio.h>
+#include <sound/core.h>
+#include <uapi/linux/virtio_snd.h>
+
+#define VIRTIO_SND_CARD_DRIVER "virtio-snd"
+#define VIRTIO_SND_CARD_NAME "VirtIO SoundCard"
+
+/**
+ * struct virtio_snd_queue - Virtqueue wrapper structure.
+ * @lock: Used to synchronize access to a virtqueue.
+ * @vqueue: Underlying virtqueue.
+ */
+struct virtio_snd_queue {
+ spinlock_t lock;
+ struct virtqueue *vqueue;
+};
+
+/**
+ * struct virtio_snd - VirtIO sound card device.
+ * @vdev: Underlying virtio device.
+ * @queues: Virtqueue wrappers.
+ * @card: ALSA sound card.
+ * @event_msgs: Device events.
+ */
+struct virtio_snd {
+ struct virtio_device *vdev;
+ struct virtio_snd_queue queues[VIRTIO_SND_VQ_MAX];
+ struct snd_card *card;
+ struct virtio_snd_event *event_msgs;
+};
+
+static inline struct virtio_snd_queue *
+virtsnd_control_queue(struct virtio_snd *snd)
+{
+ return &snd->queues[VIRTIO_SND_VQ_CONTROL];
+}
+
+static inline struct virtio_snd_queue *
+virtsnd_event_queue(struct virtio_snd *snd)
+{
+ return &snd->queues[VIRTIO_SND_VQ_EVENT];
+}
+
+static inline struct virtio_snd_queue *
+virtsnd_tx_queue(struct virtio_snd *snd)
+{
+ return &snd->queues[VIRTIO_SND_VQ_TX];
+}
+
+static inline struct virtio_snd_queue *
+virtsnd_rx_queue(struct virtio_snd *snd)
+{
+ return &snd->queues[VIRTIO_SND_VQ_RX];
+}
+
+#endif /* VIRTIO_SND_CARD_H */
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-29 05:40:41 +0000