diff options
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/Kconfig | 2 | ||||
| -rw-r--r-- | sound/Makefile | 3 | ||||
| -rw-r--r-- | sound/virtio/Kconfig | 10 | ||||
| -rw-r--r-- | sound/virtio/Makefile | 7 | ||||
| -rw-r--r-- | sound/virtio/virtio_card.c | 324 | ||||
| -rw-r--r-- | sound/virtio/virtio_card.h | 65 |
6 files changed, 410 insertions, 1 deletions
diff --git a/sound/Kconfig b/sound/Kconfig index 36785410fbe1..e56d96d2b11c 100644 --- a/sound/Kconfig +++ b/sound/Kconfig @@ -99,6 +99,8 @@ source "sound/synth/Kconfig" source "sound/xen/Kconfig" +source "sound/virtio/Kconfig" + endif # SND endif # !UML diff --git a/sound/Makefile b/sound/Makefile index 797ecdcd35e2..04ef04b1168f 100644 --- a/sound/Makefile +++ b/sound/Makefile @@ -5,7 +5,8 @@ obj-$(CONFIG_SOUND) += soundcore.o obj-$(CONFIG_DMASOUND) += oss/dmasound/ obj-$(CONFIG_SND) += core/ i2c/ drivers/ isa/ pci/ ppc/ arm/ sh/ synth/ usb/ \ - firewire/ sparc/ spi/ parisc/ pcmcia/ mips/ soc/ atmel/ hda/ x86/ xen/ + firewire/ sparc/ spi/ parisc/ pcmcia/ mips/ soc/ atmel/ hda/ x86/ xen/ \ + virtio/ obj-$(CONFIG_SND_AOA) += aoa/ # This one must be compilable even if sound is configured out 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 */ |