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linux-7.2.3/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.

linux-7.2.3/sound/virtio/Makefile

@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0+
+
+obj-$(CONFIG_SND_VIRTIO) += virtio_snd.o
+
+virtio_snd-y := \
+	virtio_card.o \
+	virtio_chmap.o \
+	virtio_ctl_msg.o \
+	virtio_jack.o \
+	virtio_kctl.o \
+	virtio_pcm.o \
+	virtio_pcm_msg.o \
+	virtio_pcm_ops.o
+

linux-7.2.3/sound/virtio/virtio_card.c

@@ -0,0 +1,449 @@
+// 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;
+
+	guard(spinlock_irqsave)(&queue->lock);
+	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));
+}
+
+/**
+ * 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_objs(*snd->event_msgs, n);
+	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;
+
+	if (queue->vqueue) {
+		guard(spinlock_irqsave)(&queue->lock);
+		virtqueue_disable_cb(queue->vqueue);
+		while ((event = virtqueue_get_buf(queue->vqueue, &length)))
+			virtsnd_event_dispatch(snd, event);
+	}
+}
+
+/**
+ * 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");

linux-7.2.3/sound/virtio/virtio_card.h

@@ -0,0 +1,133 @@
+/* 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>
+
+#include "virtio_ctl_msg.h"
+#include "virtio_pcm.h"
+
+#define VIRTIO_SND_CARD_DRIVER	"virtio-snd"
+#define VIRTIO_SND_CARD_NAME	"VirtIO SoundCard"
+#define VIRTIO_SND_PCM_NAME	"VirtIO PCM"
+
+struct virtio_jack;
+struct virtio_pcm_substream;
+
+/**
+ * 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_kctl - VirtIO control element.
+ * @kctl: ALSA control element.
+ * @items: Items for the ENUMERATED element type.
+ */
+struct virtio_kctl {
+	struct snd_kcontrol *kctl;
+	struct virtio_snd_ctl_enum_item *items;
+};
+
+/**
+ * struct virtio_snd - VirtIO sound card device.
+ * @vdev: Underlying virtio device.
+ * @queues: Virtqueue wrappers.
+ * @card: ALSA sound card.
+ * @ctl_msgs: Pending control request list.
+ * @event_msgs: Device events.
+ * @pcm_list: VirtIO PCM device list.
+ * @jacks: VirtIO jacks.
+ * @njacks: Number of jacks.
+ * @substreams: VirtIO PCM substreams.
+ * @nsubstreams: Number of PCM substreams.
+ * @chmaps: VirtIO channel maps.
+ * @nchmaps: Number of channel maps.
+ * @kctl_infos: VirtIO control element information.
+ * @kctls: VirtIO control elements.
+ * @nkctls: Number of control elements.
+ */
+struct virtio_snd {
+	struct virtio_device *vdev;
+	struct virtio_snd_queue queues[VIRTIO_SND_VQ_MAX];
+	struct snd_card *card;
+	struct list_head ctl_msgs;
+	struct virtio_snd_event *event_msgs;
+	struct list_head pcm_list;
+	struct virtio_jack *jacks;
+	u32 njacks;
+	struct virtio_pcm_substream *substreams;
+	u32 nsubstreams;
+	struct virtio_snd_chmap_info *chmaps;
+	u32 nchmaps;
+	struct virtio_snd_ctl_info *kctl_infos;
+	struct virtio_kctl *kctls;
+	u32 nkctls;
+};
+
+/* Message completion timeout in milliseconds (module parameter). */
+extern u32 virtsnd_msg_timeout_ms;
+
+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];
+}
+
+static inline struct virtio_snd_queue *
+virtsnd_pcm_queue(struct virtio_pcm_substream *vss)
+{
+	if (vss->direction == SNDRV_PCM_STREAM_PLAYBACK)
+		return virtsnd_tx_queue(vss->snd);
+	else
+		return virtsnd_rx_queue(vss->snd);
+}
+
+int virtsnd_jack_parse_cfg(struct virtio_snd *snd);
+
+int virtsnd_jack_build_devs(struct virtio_snd *snd);
+
+void virtsnd_jack_event(struct virtio_snd *snd,
+			struct virtio_snd_event *event);
+
+int virtsnd_chmap_parse_cfg(struct virtio_snd *snd);
+
+int virtsnd_chmap_build_devs(struct virtio_snd *snd);
+
+int virtsnd_kctl_parse_cfg(struct virtio_snd *snd);
+
+int virtsnd_kctl_build_devs(struct virtio_snd *snd);
+
+void virtsnd_kctl_event(struct virtio_snd *snd, struct virtio_snd_event *event);
+
+#endif /* VIRTIO_SND_CARD_H */

linux-7.2.3/sound/virtio/virtio_chmap.c

@@ -0,0 +1,219 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#include <linux/virtio_config.h>
+
+#include "virtio_card.h"
+
+/* VirtIO->ALSA channel position map */
+static const u8 g_v2a_position_map[] = {
+	[VIRTIO_SND_CHMAP_NONE] = SNDRV_CHMAP_UNKNOWN,
+	[VIRTIO_SND_CHMAP_NA] = SNDRV_CHMAP_NA,
+	[VIRTIO_SND_CHMAP_MONO] = SNDRV_CHMAP_MONO,
+	[VIRTIO_SND_CHMAP_FL] = SNDRV_CHMAP_FL,
+	[VIRTIO_SND_CHMAP_FR] = SNDRV_CHMAP_FR,
+	[VIRTIO_SND_CHMAP_RL] = SNDRV_CHMAP_RL,
+	[VIRTIO_SND_CHMAP_RR] = SNDRV_CHMAP_RR,
+	[VIRTIO_SND_CHMAP_FC] = SNDRV_CHMAP_FC,
+	[VIRTIO_SND_CHMAP_LFE] = SNDRV_CHMAP_LFE,
+	[VIRTIO_SND_CHMAP_SL] = SNDRV_CHMAP_SL,
+	[VIRTIO_SND_CHMAP_SR] = SNDRV_CHMAP_SR,
+	[VIRTIO_SND_CHMAP_RC] = SNDRV_CHMAP_RC,
+	[VIRTIO_SND_CHMAP_FLC] = SNDRV_CHMAP_FLC,
+	[VIRTIO_SND_CHMAP_FRC] = SNDRV_CHMAP_FRC,
+	[VIRTIO_SND_CHMAP_RLC] = SNDRV_CHMAP_RLC,
+	[VIRTIO_SND_CHMAP_RRC] = SNDRV_CHMAP_RRC,
+	[VIRTIO_SND_CHMAP_FLW] = SNDRV_CHMAP_FLW,
+	[VIRTIO_SND_CHMAP_FRW] = SNDRV_CHMAP_FRW,
+	[VIRTIO_SND_CHMAP_FLH] = SNDRV_CHMAP_FLH,
+	[VIRTIO_SND_CHMAP_FCH] = SNDRV_CHMAP_FCH,
+	[VIRTIO_SND_CHMAP_FRH] = SNDRV_CHMAP_FRH,
+	[VIRTIO_SND_CHMAP_TC] = SNDRV_CHMAP_TC,
+	[VIRTIO_SND_CHMAP_TFL] = SNDRV_CHMAP_TFL,
+	[VIRTIO_SND_CHMAP_TFR] = SNDRV_CHMAP_TFR,
+	[VIRTIO_SND_CHMAP_TFC] = SNDRV_CHMAP_TFC,
+	[VIRTIO_SND_CHMAP_TRL] = SNDRV_CHMAP_TRL,
+	[VIRTIO_SND_CHMAP_TRR] = SNDRV_CHMAP_TRR,
+	[VIRTIO_SND_CHMAP_TRC] = SNDRV_CHMAP_TRC,
+	[VIRTIO_SND_CHMAP_TFLC] = SNDRV_CHMAP_TFLC,
+	[VIRTIO_SND_CHMAP_TFRC] = SNDRV_CHMAP_TFRC,
+	[VIRTIO_SND_CHMAP_TSL] = SNDRV_CHMAP_TSL,
+	[VIRTIO_SND_CHMAP_TSR] = SNDRV_CHMAP_TSR,
+	[VIRTIO_SND_CHMAP_LLFE] = SNDRV_CHMAP_LLFE,
+	[VIRTIO_SND_CHMAP_RLFE] = SNDRV_CHMAP_RLFE,
+	[VIRTIO_SND_CHMAP_BC] = SNDRV_CHMAP_BC,
+	[VIRTIO_SND_CHMAP_BLC] = SNDRV_CHMAP_BLC,
+	[VIRTIO_SND_CHMAP_BRC] = SNDRV_CHMAP_BRC
+};
+
+/**
+ * virtsnd_chmap_parse_cfg() - Parse the channel map configuration.
+ * @snd: VirtIO sound device.
+ *
+ * This function is called during initial device initialization.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_chmap_parse_cfg(struct virtio_snd *snd)
+{
+	struct virtio_device *vdev = snd->vdev;
+	u32 i;
+	int rc;
+
+	virtio_cread_le(vdev, struct virtio_snd_config, chmaps, &snd->nchmaps);
+	if (!snd->nchmaps)
+		return 0;
+
+	snd->chmaps = devm_kcalloc(&vdev->dev, snd->nchmaps,
+				   sizeof(*snd->chmaps), GFP_KERNEL);
+	if (!snd->chmaps)
+		return -ENOMEM;
+
+	rc = virtsnd_ctl_query_info(snd, VIRTIO_SND_R_CHMAP_INFO, 0,
+				    snd->nchmaps, sizeof(*snd->chmaps),
+				    snd->chmaps);
+	if (rc)
+		return rc;
+
+	/* Count the number of channel maps per each PCM device/stream. */
+	for (i = 0; i < snd->nchmaps; ++i) {
+		struct virtio_snd_chmap_info *info = &snd->chmaps[i];
+		u32 nid = le32_to_cpu(info->hdr.hda_fn_nid);
+		struct virtio_pcm *vpcm;
+		struct virtio_pcm_stream *vs;
+
+		vpcm = virtsnd_pcm_find_or_create(snd, nid);
+		if (IS_ERR(vpcm))
+			return PTR_ERR(vpcm);
+
+		switch (info->direction) {
+		case VIRTIO_SND_D_OUTPUT:
+			vs = &vpcm->streams[SNDRV_PCM_STREAM_PLAYBACK];
+			break;
+		case VIRTIO_SND_D_INPUT:
+			vs = &vpcm->streams[SNDRV_PCM_STREAM_CAPTURE];
+			break;
+		default:
+			dev_err(&vdev->dev,
+				"chmap #%u: unknown direction (%u)\n", i,
+				info->direction);
+			return -EINVAL;
+		}
+
+		vs->nchmaps++;
+	}
+
+	return 0;
+}
+
+/**
+ * virtsnd_chmap_add_ctls() - Create an ALSA control for channel maps.
+ * @pcm: ALSA PCM device.
+ * @direction: PCM stream direction (SNDRV_PCM_STREAM_XXX).
+ * @vs: VirtIO PCM stream.
+ *
+ * Context: Any context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_chmap_add_ctls(struct snd_pcm *pcm, int direction,
+				  struct virtio_pcm_stream *vs)
+{
+	u32 i;
+	int max_channels = 0;
+
+	for (i = 0; i < vs->nchmaps; i++)
+		if (max_channels < vs->chmaps[i].channels)
+			max_channels = vs->chmaps[i].channels;
+
+	return snd_pcm_add_chmap_ctls(pcm, direction, vs->chmaps, max_channels,
+				      0, NULL);
+}
+
+/**
+ * virtsnd_chmap_build_devs() - Build ALSA controls for channel maps.
+ * @snd: VirtIO sound device.
+ *
+ * Context: Any context.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_chmap_build_devs(struct virtio_snd *snd)
+{
+	struct virtio_device *vdev = snd->vdev;
+	struct virtio_pcm *vpcm;
+	struct virtio_pcm_stream *vs;
+	u32 i;
+	int rc;
+
+	/* Allocate channel map elements per each PCM device/stream. */
+	list_for_each_entry(vpcm, &snd->pcm_list, list) {
+		for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) {
+			vs = &vpcm->streams[i];
+
+			if (!vs->nchmaps)
+				continue;
+
+			vs->chmaps = devm_kcalloc(&vdev->dev, vs->nchmaps + 1,
+						  sizeof(*vs->chmaps),
+						  GFP_KERNEL);
+			if (!vs->chmaps)
+				return -ENOMEM;
+
+			vs->nchmaps = 0;
+		}
+	}
+
+	/* Initialize channel maps per each PCM device/stream. */
+	for (i = 0; i < snd->nchmaps; ++i) {
+		struct virtio_snd_chmap_info *info = &snd->chmaps[i];
+		unsigned int channels = info->channels;
+		unsigned int ch;
+		struct snd_pcm_chmap_elem *chmap;
+
+		vpcm = virtsnd_pcm_find(snd, le32_to_cpu(info->hdr.hda_fn_nid));
+		if (IS_ERR(vpcm))
+			return PTR_ERR(vpcm);
+
+		if (info->direction == VIRTIO_SND_D_OUTPUT)
+			vs = &vpcm->streams[SNDRV_PCM_STREAM_PLAYBACK];
+		else
+			vs = &vpcm->streams[SNDRV_PCM_STREAM_CAPTURE];
+
+		chmap = &vs->chmaps[vs->nchmaps++];
+
+		if (channels > ARRAY_SIZE(chmap->map))
+			channels = ARRAY_SIZE(chmap->map);
+
+		chmap->channels = channels;
+
+		for (ch = 0; ch < channels; ++ch) {
+			u8 position = info->positions[ch];
+
+			if (position >= ARRAY_SIZE(g_v2a_position_map))
+				return -EINVAL;
+
+			chmap->map[ch] = g_v2a_position_map[position];
+		}
+	}
+
+	/* Create an ALSA control per each PCM device/stream. */
+	list_for_each_entry(vpcm, &snd->pcm_list, list) {
+		if (!vpcm->pcm)
+			continue;
+
+		for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) {
+			vs = &vpcm->streams[i];
+
+			if (!vs->nchmaps)
+				continue;
+
+			rc = virtsnd_chmap_add_ctls(vpcm->pcm, i, vs);
+			if (rc)
+				return rc;
+		}
+	}
+
+	return 0;
+}

linux-7.2.3/sound/virtio/virtio_ctl_msg.c

@@ -0,0 +1,303 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#include <linux/moduleparam.h>
+#include <linux/virtio_config.h>
+
+#include "virtio_card.h"
+
+/**
+ * struct virtio_snd_msg - Control message.
+ * @sg_request: Scattergather list containing a device request (header).
+ * @sg_response: Scattergather list containing a device response (status).
+ * @list: Pending message list entry.
+ * @notify: Request completed notification.
+ * @ref_count: Reference count used to manage a message lifetime.
+ */
+struct virtio_snd_msg {
+	struct scatterlist sg_request;
+	struct scatterlist sg_response;
+	struct list_head list;
+	struct completion notify;
+	refcount_t ref_count;
+};
+
+/**
+ * virtsnd_ctl_msg_ref() - Increment reference counter for the message.
+ * @msg: Control message.
+ *
+ * Context: Any context.
+ */
+void virtsnd_ctl_msg_ref(struct virtio_snd_msg *msg)
+{
+	refcount_inc(&msg->ref_count);
+}
+
+/**
+ * virtsnd_ctl_msg_unref() - Decrement reference counter for the message.
+ * @msg: Control message.
+ *
+ * The message will be freed when the ref_count value is 0.
+ *
+ * Context: Any context.
+ */
+void virtsnd_ctl_msg_unref(struct virtio_snd_msg *msg)
+{
+	if (refcount_dec_and_test(&msg->ref_count))
+		kfree(msg);
+}
+
+/**
+ * virtsnd_ctl_msg_request() - Get a pointer to the request header.
+ * @msg: Control message.
+ *
+ * Context: Any context.
+ */
+void *virtsnd_ctl_msg_request(struct virtio_snd_msg *msg)
+{
+	return sg_virt(&msg->sg_request);
+}
+
+/**
+ * virtsnd_ctl_msg_response() - Get a pointer to the response header.
+ * @msg: Control message.
+ *
+ * Context: Any context.
+ */
+void *virtsnd_ctl_msg_response(struct virtio_snd_msg *msg)
+{
+	return sg_virt(&msg->sg_response);
+}
+
+/**
+ * virtsnd_ctl_msg_alloc() - Allocate and initialize a control message.
+ * @request_size: Size of request header.
+ * @response_size: Size of response header.
+ * @gfp: Kernel flags for memory allocation.
+ *
+ * The message will be automatically freed when the ref_count value is 0.
+ *
+ * Context: Any context. May sleep if @gfp flags permit.
+ * Return: Allocated message on success, NULL on failure.
+ */
+struct virtio_snd_msg *virtsnd_ctl_msg_alloc(size_t request_size,
+					     size_t response_size, gfp_t gfp)
+{
+	struct virtio_snd_msg *msg;
+
+	if (!request_size || !response_size)
+		return NULL;
+
+	msg = kzalloc(sizeof(*msg) + request_size + response_size, gfp);
+	if (!msg)
+		return NULL;
+
+	sg_init_one(&msg->sg_request, (u8 *)msg + sizeof(*msg), request_size);
+	sg_init_one(&msg->sg_response, (u8 *)msg + sizeof(*msg) + request_size,
+		    response_size);
+
+	INIT_LIST_HEAD(&msg->list);
+	init_completion(&msg->notify);
+	/* This reference is dropped in virtsnd_ctl_msg_complete(). */
+	refcount_set(&msg->ref_count, 1);
+
+	return msg;
+}
+
+/**
+ * virtsnd_ctl_msg_send() - Send a control message.
+ * @snd: VirtIO sound device.
+ * @msg: Control message.
+ * @out_sgs: Additional sg-list to attach to the request header (may be NULL).
+ * @in_sgs: Additional sg-list to attach to the response header (may be NULL).
+ * @nowait: Flag indicating whether to wait for completion.
+ *
+ * Context: Any context. Takes and releases the control queue spinlock.
+ *          May sleep if @nowait is false.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_ctl_msg_send(struct virtio_snd *snd, struct virtio_snd_msg *msg,
+			 struct scatterlist *out_sgs,
+			 struct scatterlist *in_sgs, bool nowait)
+{
+	struct virtio_device *vdev = snd->vdev;
+	struct virtio_snd_queue *queue = virtsnd_control_queue(snd);
+	unsigned int js = msecs_to_jiffies(virtsnd_msg_timeout_ms);
+	struct virtio_snd_hdr *request = virtsnd_ctl_msg_request(msg);
+	struct virtio_snd_hdr *response = virtsnd_ctl_msg_response(msg);
+	unsigned int nouts = 0;
+	unsigned int nins = 0;
+	struct scatterlist *psgs[4];
+	bool notify = false;
+	int rc;
+
+	virtsnd_ctl_msg_ref(msg);
+
+	/* Set the default status in case the message was canceled. */
+	response->code = cpu_to_le32(VIRTIO_SND_S_IO_ERR);
+
+	psgs[nouts++] = &msg->sg_request;
+	if (out_sgs)
+		psgs[nouts++] = out_sgs;
+
+	psgs[nouts + nins++] = &msg->sg_response;
+	if (in_sgs)
+		psgs[nouts + nins++] = in_sgs;
+
+	scoped_guard(spinlock_irqsave, &queue->lock) {
+		rc = virtqueue_add_sgs(queue->vqueue, psgs, nouts, nins, msg,
+				       GFP_ATOMIC);
+		if (!rc) {
+			notify = virtqueue_kick_prepare(queue->vqueue);
+
+			list_add_tail(&msg->list, &snd->ctl_msgs);
+		}
+	}
+
+	if (rc) {
+		dev_err(&vdev->dev, "failed to send control message (0x%08x)\n",
+			le32_to_cpu(request->code));
+
+		/*
+		 * Since in this case virtsnd_ctl_msg_complete() will not be
+		 * called, it is necessary to decrement the reference count.
+		 */
+		virtsnd_ctl_msg_unref(msg);
+
+		goto on_exit;
+	}
+
+	if (notify)
+		virtqueue_notify(queue->vqueue);
+
+	if (nowait)
+		goto on_exit;
+
+	rc = wait_for_completion_interruptible_timeout(&msg->notify, js);
+	if (rc <= 0) {
+		if (!rc) {
+			dev_err(&vdev->dev,
+				"control message (0x%08x) timeout\n",
+				le32_to_cpu(request->code));
+			rc = -ETIMEDOUT;
+		}
+
+		goto on_exit;
+	}
+
+	switch (le32_to_cpu(response->code)) {
+	case VIRTIO_SND_S_OK:
+		rc = 0;
+		break;
+	case VIRTIO_SND_S_NOT_SUPP:
+		rc = -EOPNOTSUPP;
+		break;
+	case VIRTIO_SND_S_IO_ERR:
+		rc = -EIO;
+		break;
+	default:
+		rc = -EINVAL;
+		break;
+	}
+
+on_exit:
+	virtsnd_ctl_msg_unref(msg);
+
+	return rc;
+}
+
+/**
+ * virtsnd_ctl_msg_complete() - Complete a control message.
+ * @msg: Control message.
+ *
+ * Context: Any context. Expects the control queue spinlock to be held by
+ *          caller.
+ */
+void virtsnd_ctl_msg_complete(struct virtio_snd_msg *msg)
+{
+	list_del(&msg->list);
+	complete(&msg->notify);
+
+	virtsnd_ctl_msg_unref(msg);
+}
+
+/**
+ * virtsnd_ctl_msg_cancel_all() - Cancel all pending control messages.
+ * @snd: VirtIO sound device.
+ *
+ * Context: Any context.
+ */
+void virtsnd_ctl_msg_cancel_all(struct virtio_snd *snd)
+{
+	struct virtio_snd_queue *queue = virtsnd_control_queue(snd);
+
+	guard(spinlock_irqsave)(&queue->lock);
+	while (!list_empty(&snd->ctl_msgs)) {
+		struct virtio_snd_msg *msg =
+			list_first_entry(&snd->ctl_msgs, struct virtio_snd_msg,
+					 list);
+
+		virtsnd_ctl_msg_complete(msg);
+	}
+}
+
+/**
+ * virtsnd_ctl_query_info() - Query the item configuration from the device.
+ * @snd: VirtIO sound device.
+ * @command: Control request code (VIRTIO_SND_R_XXX_INFO).
+ * @start_id: Item start identifier.
+ * @count: Item count to query.
+ * @size: Item information size in bytes.
+ * @info: Buffer for storing item information.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_ctl_query_info(struct virtio_snd *snd, int command, int start_id,
+			   int count, size_t size, void *info)
+{
+	struct virtio_snd_msg *msg;
+	struct virtio_snd_query_info *query;
+	struct scatterlist sg;
+
+	msg = virtsnd_ctl_msg_alloc(sizeof(*query),
+				    sizeof(struct virtio_snd_hdr), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	query = virtsnd_ctl_msg_request(msg);
+	query->hdr.code = cpu_to_le32(command);
+	query->start_id = cpu_to_le32(start_id);
+	query->count = cpu_to_le32(count);
+	query->size = cpu_to_le32(size);
+
+	sg_init_one(&sg, info, count * size);
+
+	return virtsnd_ctl_msg_send(snd, msg, NULL, &sg, false);
+}
+
+/**
+ * virtsnd_ctl_notify_cb() - Process all completed control messages.
+ * @vqueue: Underlying control virtqueue.
+ *
+ * This callback function is called upon a vring interrupt request from the
+ * device.
+ *
+ * Context: Interrupt context. Takes and releases the control queue spinlock.
+ */
+void virtsnd_ctl_notify_cb(struct virtqueue *vqueue)
+{
+	struct virtio_snd *snd = vqueue->vdev->priv;
+	struct virtio_snd_queue *queue = virtsnd_control_queue(snd);
+	struct virtio_snd_msg *msg;
+	u32 length;
+
+	guard(spinlock_irqsave)(&queue->lock);
+	do {
+		virtqueue_disable_cb(vqueue);
+		while ((msg = virtqueue_get_buf(vqueue, &length)))
+			virtsnd_ctl_msg_complete(msg);
+	} while (!virtqueue_enable_cb(vqueue));
+}

linux-7.2.3/sound/virtio/virtio_ctl_msg.h

@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#ifndef VIRTIO_SND_MSG_H
+#define VIRTIO_SND_MSG_H
+
+#include <linux/atomic.h>
+#include <linux/virtio.h>
+
+struct virtio_snd;
+struct virtio_snd_msg;
+
+void virtsnd_ctl_msg_ref(struct virtio_snd_msg *msg);
+
+void virtsnd_ctl_msg_unref(struct virtio_snd_msg *msg);
+
+void *virtsnd_ctl_msg_request(struct virtio_snd_msg *msg);
+
+void *virtsnd_ctl_msg_response(struct virtio_snd_msg *msg);
+
+struct virtio_snd_msg *virtsnd_ctl_msg_alloc(size_t request_size,
+					     size_t response_size, gfp_t gfp);
+
+int virtsnd_ctl_msg_send(struct virtio_snd *snd, struct virtio_snd_msg *msg,
+			 struct scatterlist *out_sgs,
+			 struct scatterlist *in_sgs, bool nowait);
+
+/**
+ * virtsnd_ctl_msg_send_sync() - Simplified sending of synchronous message.
+ * @snd: VirtIO sound device.
+ * @msg: Control message.
+ *
+ * After returning from this function, the message will be deleted. If message
+ * content is still needed, the caller must additionally to
+ * virtsnd_ctl_msg_ref/unref() it.
+ *
+ * The msg_timeout_ms module parameter defines the message completion timeout.
+ * If the message is not completed within this time, the function will return an
+ * error.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ *
+ * The return value is a message status code (VIRTIO_SND_S_XXX) converted to an
+ * appropriate -errno value.
+ */
+static inline int virtsnd_ctl_msg_send_sync(struct virtio_snd *snd,
+					    struct virtio_snd_msg *msg)
+{
+	return virtsnd_ctl_msg_send(snd, msg, NULL, NULL, false);
+}
+
+/**
+ * virtsnd_ctl_msg_send_async() - Simplified sending of asynchronous message.
+ * @snd: VirtIO sound device.
+ * @msg: Control message.
+ *
+ * Context: Any context.
+ * Return: 0 on success, -errno on failure.
+ */
+static inline int virtsnd_ctl_msg_send_async(struct virtio_snd *snd,
+					     struct virtio_snd_msg *msg)
+{
+	return virtsnd_ctl_msg_send(snd, msg, NULL, NULL, true);
+}
+
+void virtsnd_ctl_msg_cancel_all(struct virtio_snd *snd);
+
+void virtsnd_ctl_msg_complete(struct virtio_snd_msg *msg);
+
+int virtsnd_ctl_query_info(struct virtio_snd *snd, int command, int start_id,
+			   int count, size_t size, void *info);
+
+void virtsnd_ctl_notify_cb(struct virtqueue *vqueue);
+
+#endif /* VIRTIO_SND_MSG_H */

linux-7.2.3/sound/virtio/virtio_jack.c

@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#include <linux/virtio_config.h>
+#include <sound/jack.h>
+#include <sound/hda_verbs.h>
+
+#include "virtio_card.h"
+
+/**
+ * DOC: Implementation Status
+ *
+ * At the moment jacks have a simple implementation and can only be used to
+ * receive notifications about a plugged in/out device.
+ *
+ * VIRTIO_SND_R_JACK_REMAP
+ *   is not supported
+ */
+
+/**
+ * struct virtio_jack - VirtIO jack.
+ * @jack: Kernel jack control.
+ * @nid: Functional group node identifier.
+ * @features: Jack virtio feature bit map (1 << VIRTIO_SND_JACK_F_XXX).
+ * @defconf: Pin default configuration value.
+ * @caps: Pin capabilities value.
+ * @connected: Current jack connection status.
+ * @type: Kernel jack type (SND_JACK_XXX).
+ */
+struct virtio_jack {
+	struct snd_jack *jack;
+	u32 nid;
+	u32 features;
+	u32 defconf;
+	u32 caps;
+	bool connected;
+	int type;
+};
+
+/**
+ * virtsnd_jack_get_label() - Get the name string for the jack.
+ * @vjack: VirtIO jack.
+ *
+ * Returns the jack name based on the default pin configuration value (see HDA
+ * specification).
+ *
+ * Context: Any context.
+ * Return: Name string.
+ */
+static const char *virtsnd_jack_get_label(struct virtio_jack *vjack)
+{
+	unsigned int defconf = vjack->defconf;
+	unsigned int device =
+		(defconf & AC_DEFCFG_DEVICE) >> AC_DEFCFG_DEVICE_SHIFT;
+	unsigned int location =
+		(defconf & AC_DEFCFG_LOCATION) >> AC_DEFCFG_LOCATION_SHIFT;
+
+	switch (device) {
+	case AC_JACK_LINE_OUT:
+		return "Line Out";
+	case AC_JACK_SPEAKER:
+		return "Speaker";
+	case AC_JACK_HP_OUT:
+		return "Headphone";
+	case AC_JACK_CD:
+		return "CD";
+	case AC_JACK_SPDIF_OUT:
+	case AC_JACK_DIG_OTHER_OUT:
+		if (location == AC_JACK_LOC_HDMI)
+			return "HDMI Out";
+		else
+			return "SPDIF Out";
+	case AC_JACK_LINE_IN:
+		return "Line";
+	case AC_JACK_AUX:
+		return "Aux";
+	case AC_JACK_MIC_IN:
+		return "Mic";
+	case AC_JACK_SPDIF_IN:
+		return "SPDIF In";
+	case AC_JACK_DIG_OTHER_IN:
+		return "Digital In";
+	default:
+		return "Misc";
+	}
+}
+
+/**
+ * virtsnd_jack_get_type() - Get the type for the jack.
+ * @vjack: VirtIO jack.
+ *
+ * Returns the jack type based on the default pin configuration value (see HDA
+ * specification).
+ *
+ * Context: Any context.
+ * Return: SND_JACK_XXX value.
+ */
+static int virtsnd_jack_get_type(struct virtio_jack *vjack)
+{
+	unsigned int defconf = vjack->defconf;
+	unsigned int device =
+		(defconf & AC_DEFCFG_DEVICE) >> AC_DEFCFG_DEVICE_SHIFT;
+
+	switch (device) {
+	case AC_JACK_LINE_OUT:
+	case AC_JACK_SPEAKER:
+		return SND_JACK_LINEOUT;
+	case AC_JACK_HP_OUT:
+		return SND_JACK_HEADPHONE;
+	case AC_JACK_SPDIF_OUT:
+	case AC_JACK_DIG_OTHER_OUT:
+		return SND_JACK_AVOUT;
+	case AC_JACK_MIC_IN:
+		return SND_JACK_MICROPHONE;
+	default:
+		return SND_JACK_LINEIN;
+	}
+}
+
+/**
+ * virtsnd_jack_parse_cfg() - Parse the jack configuration.
+ * @snd: VirtIO sound device.
+ *
+ * This function is called during initial device initialization.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_jack_parse_cfg(struct virtio_snd *snd)
+{
+	struct virtio_device *vdev = snd->vdev;
+	struct virtio_snd_jack_info *info;
+	u32 i;
+	int rc;
+
+	virtio_cread_le(vdev, struct virtio_snd_config, jacks, &snd->njacks);
+	if (!snd->njacks)
+		return 0;
+
+	snd->jacks = devm_kcalloc(&vdev->dev, snd->njacks, sizeof(*snd->jacks),
+				  GFP_KERNEL);
+	if (!snd->jacks)
+		return -ENOMEM;
+
+	info = kzalloc_objs(*info, snd->njacks);
+	if (!info)
+		return -ENOMEM;
+
+	rc = virtsnd_ctl_query_info(snd, VIRTIO_SND_R_JACK_INFO, 0, snd->njacks,
+				    sizeof(*info), info);
+	if (rc)
+		goto on_exit;
+
+	for (i = 0; i < snd->njacks; ++i) {
+		struct virtio_jack *vjack = &snd->jacks[i];
+
+		vjack->nid = le32_to_cpu(info[i].hdr.hda_fn_nid);
+		vjack->features = le32_to_cpu(info[i].features);
+		vjack->defconf = le32_to_cpu(info[i].hda_reg_defconf);
+		vjack->caps = le32_to_cpu(info[i].hda_reg_caps);
+		vjack->connected = info[i].connected;
+	}
+
+on_exit:
+	kfree(info);
+
+	return rc;
+}
+
+/**
+ * virtsnd_jack_build_devs() - Build ALSA controls for jacks.
+ * @snd: VirtIO sound device.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_jack_build_devs(struct virtio_snd *snd)
+{
+	u32 i;
+	int rc;
+
+	for (i = 0; i < snd->njacks; ++i) {
+		struct virtio_jack *vjack = &snd->jacks[i];
+
+		vjack->type = virtsnd_jack_get_type(vjack);
+
+		rc = snd_jack_new(snd->card, virtsnd_jack_get_label(vjack),
+				  vjack->type, &vjack->jack, true, true);
+		if (rc)
+			return rc;
+
+		if (vjack->jack)
+			vjack->jack->private_data = vjack;
+
+		snd_jack_report(vjack->jack,
+				vjack->connected ? vjack->type : 0);
+	}
+
+	return 0;
+}
+
+/**
+ * virtsnd_jack_event() - Handle the jack event notification.
+ * @snd: VirtIO sound device.
+ * @event: VirtIO sound event.
+ *
+ * Context: Interrupt context.
+ */
+void virtsnd_jack_event(struct virtio_snd *snd, struct virtio_snd_event *event)
+{
+	u32 jack_id = le32_to_cpu(event->data);
+	struct virtio_jack *vjack;
+
+	if (jack_id >= snd->njacks)
+		return;
+
+	vjack = &snd->jacks[jack_id];
+
+	switch (le32_to_cpu(event->hdr.code)) {
+	case VIRTIO_SND_EVT_JACK_CONNECTED:
+		vjack->connected = true;
+		break;
+	case VIRTIO_SND_EVT_JACK_DISCONNECTED:
+		vjack->connected = false;
+		break;
+	default:
+		return;
+	}
+
+	snd_jack_report(vjack->jack, vjack->connected ? vjack->type : 0);
+}

linux-7.2.3/sound/virtio/virtio_kctl.c

@@ -0,0 +1,527 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2022 OpenSynergy GmbH
+ */
+#include <sound/control.h>
+#include <linux/virtio_config.h>
+
+#include "virtio_card.h"
+
+/* Map for converting VirtIO types to ALSA types. */
+static const snd_ctl_elem_type_t g_v2a_type_map[] = {
+	[VIRTIO_SND_CTL_TYPE_BOOLEAN] = SNDRV_CTL_ELEM_TYPE_BOOLEAN,
+	[VIRTIO_SND_CTL_TYPE_INTEGER] = SNDRV_CTL_ELEM_TYPE_INTEGER,
+	[VIRTIO_SND_CTL_TYPE_INTEGER64] = SNDRV_CTL_ELEM_TYPE_INTEGER64,
+	[VIRTIO_SND_CTL_TYPE_ENUMERATED] = SNDRV_CTL_ELEM_TYPE_ENUMERATED,
+	[VIRTIO_SND_CTL_TYPE_BYTES] = SNDRV_CTL_ELEM_TYPE_BYTES,
+	[VIRTIO_SND_CTL_TYPE_IEC958] = SNDRV_CTL_ELEM_TYPE_IEC958
+};
+
+/* Map for converting VirtIO types to maximum value counts. */
+static const unsigned int g_v2a_count_map[] = {
+	[VIRTIO_SND_CTL_TYPE_BOOLEAN] =
+		ARRAY_SIZE(((struct virtio_snd_ctl_value *)0)->value.integer),
+	[VIRTIO_SND_CTL_TYPE_INTEGER] =
+		ARRAY_SIZE(((struct virtio_snd_ctl_value *)0)->value.integer),
+	[VIRTIO_SND_CTL_TYPE_INTEGER64] =
+		ARRAY_SIZE(((struct virtio_snd_ctl_value *)0)->value.integer64),
+	[VIRTIO_SND_CTL_TYPE_ENUMERATED] =
+		ARRAY_SIZE(((struct virtio_snd_ctl_value *)0)->value.enumerated),
+	[VIRTIO_SND_CTL_TYPE_BYTES] =
+		ARRAY_SIZE(((struct virtio_snd_ctl_value *)0)->value.bytes),
+	[VIRTIO_SND_CTL_TYPE_IEC958] = 1
+};
+
+/* Map for converting VirtIO access rights to ALSA access rights. */
+static const unsigned int g_v2a_access_map[] = {
+	[VIRTIO_SND_CTL_ACCESS_READ] = SNDRV_CTL_ELEM_ACCESS_READ,
+	[VIRTIO_SND_CTL_ACCESS_WRITE] = SNDRV_CTL_ELEM_ACCESS_WRITE,
+	[VIRTIO_SND_CTL_ACCESS_VOLATILE] = SNDRV_CTL_ELEM_ACCESS_VOLATILE,
+	[VIRTIO_SND_CTL_ACCESS_INACTIVE] = SNDRV_CTL_ELEM_ACCESS_INACTIVE,
+	[VIRTIO_SND_CTL_ACCESS_TLV_READ] = SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+	[VIRTIO_SND_CTL_ACCESS_TLV_WRITE] = SNDRV_CTL_ELEM_ACCESS_TLV_WRITE,
+	[VIRTIO_SND_CTL_ACCESS_TLV_COMMAND] = SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND
+};
+
+/* Map for converting VirtIO event masks to ALSA event masks. */
+static const unsigned int g_v2a_mask_map[] = {
+	[VIRTIO_SND_CTL_EVT_MASK_VALUE] = SNDRV_CTL_EVENT_MASK_VALUE,
+	[VIRTIO_SND_CTL_EVT_MASK_INFO] = SNDRV_CTL_EVENT_MASK_INFO,
+	[VIRTIO_SND_CTL_EVT_MASK_TLV] = SNDRV_CTL_EVENT_MASK_TLV
+};
+
+static int virtsnd_kctl_validate_info(struct virtio_snd *snd, u32 cid,
+				      struct virtio_snd_ctl_info *kinfo)
+{
+	struct virtio_device *vdev = snd->vdev;
+	unsigned int type = le32_to_cpu(kinfo->type);
+	unsigned int count = le32_to_cpu(kinfo->count);
+
+	if (type >= ARRAY_SIZE(g_v2a_type_map)) {
+		dev_err(&vdev->dev, "control #%u: unknown type %u\n",
+			cid, type);
+		return -EINVAL;
+	}
+
+	if (count > g_v2a_count_map[type] ||
+	    (type == VIRTIO_SND_CTL_TYPE_IEC958 && count != 1)) {
+		dev_err(&vdev->dev, "control #%u: invalid count %u for type %u\n",
+			cid, count, type);
+		return -EINVAL;
+	}
+
+	if (type == VIRTIO_SND_CTL_TYPE_ENUMERATED &&
+	    !le32_to_cpu(kinfo->value.enumerated.items)) {
+		dev_err(&vdev->dev,
+			"control #%u: no items for enumerated control\n",
+			cid);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * virtsnd_kctl_info() - Returns information about the control.
+ * @kcontrol: ALSA control element.
+ * @uinfo: Element information.
+ *
+ * Context: Process context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_kctl_info(struct snd_kcontrol *kcontrol,
+			     struct snd_ctl_elem_info *uinfo)
+{
+	struct virtio_snd *snd = snd_kcontrol_chip(kcontrol);
+	struct virtio_kctl *kctl = &snd->kctls[kcontrol->private_value];
+	struct virtio_snd_ctl_info *kinfo =
+		&snd->kctl_infos[kcontrol->private_value];
+	unsigned int i;
+
+	uinfo->type = g_v2a_type_map[le32_to_cpu(kinfo->type)];
+	uinfo->count = le32_to_cpu(kinfo->count);
+
+	switch (uinfo->type) {
+	case SNDRV_CTL_ELEM_TYPE_INTEGER:
+		uinfo->value.integer.min =
+			le32_to_cpu(kinfo->value.integer.min);
+		uinfo->value.integer.max =
+			le32_to_cpu(kinfo->value.integer.max);
+		uinfo->value.integer.step =
+			le32_to_cpu(kinfo->value.integer.step);
+
+		break;
+	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
+		uinfo->value.integer64.min =
+			le64_to_cpu(kinfo->value.integer64.min);
+		uinfo->value.integer64.max =
+			le64_to_cpu(kinfo->value.integer64.max);
+		uinfo->value.integer64.step =
+			le64_to_cpu(kinfo->value.integer64.step);
+
+		break;
+	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
+		uinfo->value.enumerated.items =
+			le32_to_cpu(kinfo->value.enumerated.items);
+		i = uinfo->value.enumerated.item;
+		if (i >= uinfo->value.enumerated.items)
+			return -EINVAL;
+
+		strscpy(uinfo->value.enumerated.name, kctl->items[i].item,
+			sizeof(uinfo->value.enumerated.name));
+
+		break;
+	}
+
+	return 0;
+}
+
+/**
+ * virtsnd_kctl_get() - Read the value from the control.
+ * @kcontrol: ALSA control element.
+ * @uvalue: Element value.
+ *
+ * Context: Process context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_kctl_get(struct snd_kcontrol *kcontrol,
+			    struct snd_ctl_elem_value *uvalue)
+{
+	struct virtio_snd *snd = snd_kcontrol_chip(kcontrol);
+	struct virtio_snd_ctl_info *kinfo =
+		&snd->kctl_infos[kcontrol->private_value];
+	unsigned int type = le32_to_cpu(kinfo->type);
+	unsigned int count = le32_to_cpu(kinfo->count);
+	struct virtio_snd_msg *msg;
+	struct virtio_snd_ctl_hdr *hdr;
+	struct virtio_snd_ctl_value *kvalue;
+	size_t request_size = sizeof(*hdr);
+	size_t response_size = sizeof(struct virtio_snd_hdr) + sizeof(*kvalue);
+	unsigned int i;
+	int rc;
+
+	msg = virtsnd_ctl_msg_alloc(request_size, response_size, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	virtsnd_ctl_msg_ref(msg);
+
+	hdr = virtsnd_ctl_msg_request(msg);
+	hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_READ);
+	hdr->control_id = cpu_to_le32(kcontrol->private_value);
+
+	rc = virtsnd_ctl_msg_send_sync(snd, msg);
+	if (rc)
+		goto on_failure;
+
+	kvalue = (void *)((u8 *)virtsnd_ctl_msg_response(msg) +
+			  sizeof(struct virtio_snd_hdr));
+
+	switch (type) {
+	case VIRTIO_SND_CTL_TYPE_BOOLEAN:
+	case VIRTIO_SND_CTL_TYPE_INTEGER:
+		for (i = 0; i < count; ++i)
+			uvalue->value.integer.value[i] =
+				le32_to_cpu(kvalue->value.integer[i]);
+		break;
+	case VIRTIO_SND_CTL_TYPE_INTEGER64:
+		for (i = 0; i < count; ++i)
+			uvalue->value.integer64.value[i] =
+				le64_to_cpu(kvalue->value.integer64[i]);
+		break;
+	case VIRTIO_SND_CTL_TYPE_ENUMERATED:
+		for (i = 0; i < count; ++i)
+			uvalue->value.enumerated.item[i] =
+				le32_to_cpu(kvalue->value.enumerated[i]);
+		break;
+	case VIRTIO_SND_CTL_TYPE_BYTES:
+		memcpy(uvalue->value.bytes.data, kvalue->value.bytes, count);
+		break;
+	case VIRTIO_SND_CTL_TYPE_IEC958:
+		memcpy(&uvalue->value.iec958, &kvalue->value.iec958,
+		       sizeof(uvalue->value.iec958));
+		break;
+	}
+
+on_failure:
+	virtsnd_ctl_msg_unref(msg);
+
+	return rc;
+}
+
+/**
+ * virtsnd_kctl_put() - Write the value to the control.
+ * @kcontrol: ALSA control element.
+ * @uvalue: Element value.
+ *
+ * Context: Process context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_kctl_put(struct snd_kcontrol *kcontrol,
+			    struct snd_ctl_elem_value *uvalue)
+{
+	struct virtio_snd *snd = snd_kcontrol_chip(kcontrol);
+	struct virtio_snd_ctl_info *kinfo =
+		&snd->kctl_infos[kcontrol->private_value];
+	unsigned int type = le32_to_cpu(kinfo->type);
+	unsigned int count = le32_to_cpu(kinfo->count);
+	struct virtio_snd_msg *msg;
+	struct virtio_snd_ctl_hdr *hdr;
+	struct virtio_snd_ctl_value *kvalue;
+	size_t request_size = sizeof(*hdr) + sizeof(*kvalue);
+	size_t response_size = sizeof(struct virtio_snd_hdr);
+	unsigned int i;
+
+	msg = virtsnd_ctl_msg_alloc(request_size, response_size, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	hdr = virtsnd_ctl_msg_request(msg);
+	hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_WRITE);
+	hdr->control_id = cpu_to_le32(kcontrol->private_value);
+
+	kvalue = (void *)((u8 *)hdr + sizeof(*hdr));
+
+	switch (type) {
+	case VIRTIO_SND_CTL_TYPE_BOOLEAN:
+	case VIRTIO_SND_CTL_TYPE_INTEGER:
+		for (i = 0; i < count; ++i)
+			kvalue->value.integer[i] =
+				cpu_to_le32(uvalue->value.integer.value[i]);
+		break;
+	case VIRTIO_SND_CTL_TYPE_INTEGER64:
+		for (i = 0; i < count; ++i)
+			kvalue->value.integer64[i] =
+				cpu_to_le64(uvalue->value.integer64.value[i]);
+		break;
+	case VIRTIO_SND_CTL_TYPE_ENUMERATED:
+		for (i = 0; i < count; ++i)
+			kvalue->value.enumerated[i] =
+				cpu_to_le32(uvalue->value.enumerated.item[i]);
+		break;
+	case VIRTIO_SND_CTL_TYPE_BYTES:
+		memcpy(kvalue->value.bytes, uvalue->value.bytes.data, count);
+		break;
+	case VIRTIO_SND_CTL_TYPE_IEC958:
+		memcpy(&kvalue->value.iec958, &uvalue->value.iec958,
+		       sizeof(kvalue->value.iec958));
+		break;
+	}
+
+	return virtsnd_ctl_msg_send_sync(snd, msg);
+}
+
+/**
+ * virtsnd_kctl_tlv_op() - Perform an operation on the control's metadata.
+ * @kcontrol: ALSA control element.
+ * @op_flag: Operation code (SNDRV_CTL_TLV_OP_XXX).
+ * @size: Size of the TLV data in bytes.
+ * @utlv: TLV data.
+ *
+ * Context: Process context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_kctl_tlv_op(struct snd_kcontrol *kcontrol, int op_flag,
+			       unsigned int size, unsigned int __user *utlv)
+{
+	struct virtio_snd *snd = snd_kcontrol_chip(kcontrol);
+	struct virtio_snd_msg *msg;
+	struct virtio_snd_ctl_hdr *hdr;
+	unsigned int *tlv;
+	struct scatterlist sg;
+	int rc;
+
+	msg = virtsnd_ctl_msg_alloc(sizeof(*hdr), sizeof(struct virtio_snd_hdr),
+				    GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	tlv = kzalloc(size, GFP_KERNEL);
+	if (!tlv) {
+		rc = -ENOMEM;
+		goto on_msg_unref;
+	}
+
+	sg_init_one(&sg, tlv, size);
+
+	hdr = virtsnd_ctl_msg_request(msg);
+	hdr->control_id = cpu_to_le32(kcontrol->private_value);
+
+	switch (op_flag) {
+	case SNDRV_CTL_TLV_OP_READ:
+		hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_TLV_READ);
+
+		rc = virtsnd_ctl_msg_send(snd, msg, NULL, &sg, false);
+		if (!rc) {
+			if (copy_to_user(utlv, tlv, size))
+				rc = -EFAULT;
+		}
+
+		break;
+	case SNDRV_CTL_TLV_OP_WRITE:
+	case SNDRV_CTL_TLV_OP_CMD:
+		if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
+			hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_TLV_WRITE);
+		else
+			hdr->hdr.code =
+				cpu_to_le32(VIRTIO_SND_R_CTL_TLV_COMMAND);
+
+		if (copy_from_user(tlv, utlv, size)) {
+			rc = -EFAULT;
+			goto on_msg_unref;
+		} else {
+			rc = virtsnd_ctl_msg_send(snd, msg, &sg, NULL, false);
+		}
+
+		break;
+	default:
+		rc = -EINVAL;
+		/* We never get here - we listed all values for op_flag */
+		WARN_ON(1);
+		goto on_msg_unref;
+	}
+	kfree(tlv);
+	return rc;
+
+on_msg_unref:
+	virtsnd_ctl_msg_unref(msg);
+	kfree(tlv);
+
+	return rc;
+}
+
+/**
+ * virtsnd_kctl_get_enum_items() - Query items for the ENUMERATED element type.
+ * @snd: VirtIO sound device.
+ * @cid: Control element ID.
+ *
+ * This function is called during initial device initialization.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_kctl_get_enum_items(struct virtio_snd *snd, unsigned int cid)
+{
+	struct virtio_device *vdev = snd->vdev;
+	struct virtio_snd_ctl_info *kinfo = &snd->kctl_infos[cid];
+	struct virtio_kctl *kctl = &snd->kctls[cid];
+	struct virtio_snd_msg *msg;
+	struct virtio_snd_ctl_hdr *hdr;
+	unsigned int n = le32_to_cpu(kinfo->value.enumerated.items);
+	struct scatterlist sg;
+
+	msg = virtsnd_ctl_msg_alloc(sizeof(*hdr),
+				    sizeof(struct virtio_snd_hdr), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	kctl->items = devm_kcalloc(&vdev->dev, n, sizeof(*kctl->items),
+				   GFP_KERNEL);
+	if (!kctl->items) {
+		virtsnd_ctl_msg_unref(msg);
+		return -ENOMEM;
+	}
+
+	sg_init_one(&sg, kctl->items, n * sizeof(*kctl->items));
+
+	hdr = virtsnd_ctl_msg_request(msg);
+	hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_ENUM_ITEMS);
+	hdr->control_id = cpu_to_le32(cid);
+
+	return virtsnd_ctl_msg_send(snd, msg, NULL, &sg, false);
+}
+
+/**
+ * virtsnd_kctl_parse_cfg() - Parse the control element configuration.
+ * @snd: VirtIO sound device.
+ *
+ * This function is called during initial device initialization.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_kctl_parse_cfg(struct virtio_snd *snd)
+{
+	struct virtio_device *vdev = snd->vdev;
+	u32 i;
+	int rc;
+
+	virtio_cread_le(vdev, struct virtio_snd_config, controls,
+			&snd->nkctls);
+	if (!snd->nkctls)
+		return 0;
+
+	snd->kctl_infos = devm_kcalloc(&vdev->dev, snd->nkctls,
+				       sizeof(*snd->kctl_infos), GFP_KERNEL);
+	if (!snd->kctl_infos)
+		return -ENOMEM;
+
+	snd->kctls = devm_kcalloc(&vdev->dev, snd->nkctls, sizeof(*snd->kctls),
+				  GFP_KERNEL);
+	if (!snd->kctls)
+		return -ENOMEM;
+
+	rc = virtsnd_ctl_query_info(snd, VIRTIO_SND_R_CTL_INFO, 0, snd->nkctls,
+				    sizeof(*snd->kctl_infos), snd->kctl_infos);
+	if (rc)
+		return rc;
+
+	for (i = 0; i < snd->nkctls; ++i) {
+		struct virtio_snd_ctl_info *kinfo = &snd->kctl_infos[i];
+		unsigned int type = le32_to_cpu(kinfo->type);
+
+		rc = virtsnd_kctl_validate_info(snd, i, kinfo);
+		if (rc)
+			return rc;
+
+		if (type == VIRTIO_SND_CTL_TYPE_ENUMERATED) {
+			rc = virtsnd_kctl_get_enum_items(snd, i);
+			if (rc)
+				return rc;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * virtsnd_kctl_build_devs() - Build ALSA control elements.
+ * @snd: VirtIO sound device.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_kctl_build_devs(struct virtio_snd *snd)
+{
+	unsigned int cid;
+
+	for (cid = 0; cid < snd->nkctls; ++cid) {
+		struct virtio_snd_ctl_info *kinfo = &snd->kctl_infos[cid];
+		struct virtio_kctl *kctl = &snd->kctls[cid];
+		struct snd_kcontrol_new kctl_new;
+		unsigned int i;
+		int rc;
+
+		memset(&kctl_new, 0, sizeof(kctl_new));
+
+		kctl_new.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+		kctl_new.name = kinfo->name;
+		kctl_new.index = le32_to_cpu(kinfo->index);
+
+		for (i = 0; i < ARRAY_SIZE(g_v2a_access_map); ++i)
+			if (le32_to_cpu(kinfo->access) & (1 << i))
+				kctl_new.access |= g_v2a_access_map[i];
+
+		if (kctl_new.access & (SNDRV_CTL_ELEM_ACCESS_TLV_READ |
+				       SNDRV_CTL_ELEM_ACCESS_TLV_WRITE |
+				       SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND)) {
+			kctl_new.access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
+			kctl_new.tlv.c = virtsnd_kctl_tlv_op;
+		}
+
+		kctl_new.info = virtsnd_kctl_info;
+		kctl_new.get = virtsnd_kctl_get;
+		kctl_new.put = virtsnd_kctl_put;
+		kctl_new.private_value = cid;
+
+		kctl->kctl = snd_ctl_new1(&kctl_new, snd);
+		if (!kctl->kctl)
+			return -ENOMEM;
+
+		rc = snd_ctl_add(snd->card, kctl->kctl);
+		if (rc)
+			return rc;
+	}
+
+	return 0;
+}
+
+/**
+ * virtsnd_kctl_event() - Handle the control element event notification.
+ * @snd: VirtIO sound device.
+ * @event: VirtIO sound event.
+ *
+ * Context: Interrupt context.
+ */
+void virtsnd_kctl_event(struct virtio_snd *snd, struct virtio_snd_event *event)
+{
+	struct virtio_snd_ctl_event *kevent =
+		(struct virtio_snd_ctl_event *)event;
+	struct virtio_kctl *kctl;
+	unsigned int cid = le16_to_cpu(kevent->control_id);
+	unsigned int mask = 0;
+	unsigned int i;
+
+	if (cid >= snd->nkctls)
+		return;
+
+	for (i = 0; i < ARRAY_SIZE(g_v2a_mask_map); ++i)
+		if (le16_to_cpu(kevent->mask) & (1 << i))
+			mask |= g_v2a_mask_map[i];
+
+
+	kctl = &snd->kctls[cid];
+
+	snd_ctl_notify(snd->card, mask, &kctl->kctl->id);
+}

linux-7.2.3/sound/virtio/virtio_pcm.c

@@ -0,0 +1,525 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#include <linux/moduleparam.h>
+#include <linux/virtio_config.h>
+
+#include "virtio_card.h"
+
+static u32 pcm_buffer_ms = 160;
+module_param(pcm_buffer_ms, uint, 0644);
+MODULE_PARM_DESC(pcm_buffer_ms, "PCM substream buffer time in milliseconds");
+
+static u32 pcm_periods_min = 2;
+module_param(pcm_periods_min, uint, 0644);
+MODULE_PARM_DESC(pcm_periods_min, "Minimum number of PCM periods");
+
+static u32 pcm_periods_max = 16;
+module_param(pcm_periods_max, uint, 0644);
+MODULE_PARM_DESC(pcm_periods_max, "Maximum number of PCM periods");
+
+static u32 pcm_period_ms_min = 10;
+module_param(pcm_period_ms_min, uint, 0644);
+MODULE_PARM_DESC(pcm_period_ms_min, "Minimum PCM period time in milliseconds");
+
+static u32 pcm_period_ms_max = 80;
+module_param(pcm_period_ms_max, uint, 0644);
+MODULE_PARM_DESC(pcm_period_ms_max, "Maximum PCM period time in milliseconds");
+
+/* Map for converting VirtIO format to ALSA format. */
+static const snd_pcm_format_t g_v2a_format_map[] = {
+	[VIRTIO_SND_PCM_FMT_IMA_ADPCM] = SNDRV_PCM_FORMAT_IMA_ADPCM,
+	[VIRTIO_SND_PCM_FMT_MU_LAW] = SNDRV_PCM_FORMAT_MU_LAW,
+	[VIRTIO_SND_PCM_FMT_A_LAW] = SNDRV_PCM_FORMAT_A_LAW,
+	[VIRTIO_SND_PCM_FMT_S8] = SNDRV_PCM_FORMAT_S8,
+	[VIRTIO_SND_PCM_FMT_U8] = SNDRV_PCM_FORMAT_U8,
+	[VIRTIO_SND_PCM_FMT_S16] = SNDRV_PCM_FORMAT_S16_LE,
+	[VIRTIO_SND_PCM_FMT_U16] = SNDRV_PCM_FORMAT_U16_LE,
+	[VIRTIO_SND_PCM_FMT_S18_3] = SNDRV_PCM_FORMAT_S18_3LE,
+	[VIRTIO_SND_PCM_FMT_U18_3] = SNDRV_PCM_FORMAT_U18_3LE,
+	[VIRTIO_SND_PCM_FMT_S20_3] = SNDRV_PCM_FORMAT_S20_3LE,
+	[VIRTIO_SND_PCM_FMT_U20_3] = SNDRV_PCM_FORMAT_U20_3LE,
+	[VIRTIO_SND_PCM_FMT_S24_3] = SNDRV_PCM_FORMAT_S24_3LE,
+	[VIRTIO_SND_PCM_FMT_U24_3] = SNDRV_PCM_FORMAT_U24_3LE,
+	[VIRTIO_SND_PCM_FMT_S20] = SNDRV_PCM_FORMAT_S20_LE,
+	[VIRTIO_SND_PCM_FMT_U20] = SNDRV_PCM_FORMAT_U20_LE,
+	[VIRTIO_SND_PCM_FMT_S24] = SNDRV_PCM_FORMAT_S24_LE,
+	[VIRTIO_SND_PCM_FMT_U24] = SNDRV_PCM_FORMAT_U24_LE,
+	[VIRTIO_SND_PCM_FMT_S32] = SNDRV_PCM_FORMAT_S32_LE,
+	[VIRTIO_SND_PCM_FMT_U32] = SNDRV_PCM_FORMAT_U32_LE,
+	[VIRTIO_SND_PCM_FMT_FLOAT] = SNDRV_PCM_FORMAT_FLOAT_LE,
+	[VIRTIO_SND_PCM_FMT_FLOAT64] = SNDRV_PCM_FORMAT_FLOAT64_LE,
+	[VIRTIO_SND_PCM_FMT_DSD_U8] = SNDRV_PCM_FORMAT_DSD_U8,
+	[VIRTIO_SND_PCM_FMT_DSD_U16] = SNDRV_PCM_FORMAT_DSD_U16_LE,
+	[VIRTIO_SND_PCM_FMT_DSD_U32] = SNDRV_PCM_FORMAT_DSD_U32_LE,
+	[VIRTIO_SND_PCM_FMT_IEC958_SUBFRAME] =
+		SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE
+};
+
+/* Map for converting VirtIO frame rate to ALSA frame rate. */
+struct virtsnd_v2a_rate {
+	unsigned int alsa_bit;
+	unsigned int rate;
+};
+
+static const struct virtsnd_v2a_rate g_v2a_rate_map[] = {
+	[VIRTIO_SND_PCM_RATE_5512] = { SNDRV_PCM_RATE_5512, 5512 },
+	[VIRTIO_SND_PCM_RATE_8000] = { SNDRV_PCM_RATE_8000, 8000 },
+	[VIRTIO_SND_PCM_RATE_11025] = { SNDRV_PCM_RATE_11025, 11025 },
+	[VIRTIO_SND_PCM_RATE_16000] = { SNDRV_PCM_RATE_16000, 16000 },
+	[VIRTIO_SND_PCM_RATE_22050] = { SNDRV_PCM_RATE_22050, 22050 },
+	[VIRTIO_SND_PCM_RATE_32000] = { SNDRV_PCM_RATE_32000, 32000 },
+	[VIRTIO_SND_PCM_RATE_44100] = { SNDRV_PCM_RATE_44100, 44100 },
+	[VIRTIO_SND_PCM_RATE_48000] = { SNDRV_PCM_RATE_48000, 48000 },
+	[VIRTIO_SND_PCM_RATE_64000] = { SNDRV_PCM_RATE_64000, 64000 },
+	[VIRTIO_SND_PCM_RATE_88200] = { SNDRV_PCM_RATE_88200, 88200 },
+	[VIRTIO_SND_PCM_RATE_96000] = { SNDRV_PCM_RATE_96000, 96000 },
+	[VIRTIO_SND_PCM_RATE_176400] = { SNDRV_PCM_RATE_176400, 176400 },
+	[VIRTIO_SND_PCM_RATE_192000] = { SNDRV_PCM_RATE_192000, 192000 },
+	[VIRTIO_SND_PCM_RATE_384000] = { SNDRV_PCM_RATE_384000, 384000 }
+};
+
+/**
+ * virtsnd_pcm_build_hw() - Parse substream config and build HW descriptor.
+ * @vss: VirtIO substream.
+ * @info: VirtIO substream information entry.
+ *
+ * Context: Any context.
+ * Return: 0 on success, -EINVAL if configuration is invalid.
+ */
+static int virtsnd_pcm_build_hw(struct virtio_pcm_substream *vss,
+				struct virtio_snd_pcm_info *info)
+{
+	struct virtio_device *vdev = vss->snd->vdev;
+	unsigned int i;
+	u64 values;
+	size_t sample_max = 0;
+	size_t sample_min = 0;
+
+	vss->features = le32_to_cpu(info->features);
+
+	/*
+	 * TODO: set SNDRV_PCM_INFO_{BATCH,BLOCK_TRANSFER} if device supports
+	 * only message-based transport.
+	 */
+	vss->hw.info =
+		SNDRV_PCM_INFO_MMAP |
+		SNDRV_PCM_INFO_MMAP_VALID |
+		SNDRV_PCM_INFO_BATCH |
+		SNDRV_PCM_INFO_BLOCK_TRANSFER |
+		SNDRV_PCM_INFO_INTERLEAVED |
+		SNDRV_PCM_INFO_PAUSE |
+		SNDRV_PCM_INFO_NO_REWINDS |
+		SNDRV_PCM_INFO_SYNC_APPLPTR;
+
+	if (!info->channels_min || info->channels_min > info->channels_max) {
+		dev_err(&vdev->dev,
+			"SID %u: invalid channel range [%u %u]\n",
+			vss->sid, info->channels_min, info->channels_max);
+		return -EINVAL;
+	}
+
+	vss->hw.channels_min = info->channels_min;
+	vss->hw.channels_max = info->channels_max;
+
+	values = le64_to_cpu(info->formats);
+
+	vss->hw.formats = 0;
+
+	for (i = 0; i < ARRAY_SIZE(g_v2a_format_map); ++i)
+		if (values & (1ULL << i)) {
+			snd_pcm_format_t alsa_fmt = g_v2a_format_map[i];
+			int bytes = snd_pcm_format_physical_width(alsa_fmt) / 8;
+
+			if (!sample_min || sample_min > bytes)
+				sample_min = bytes;
+
+			if (sample_max < bytes)
+				sample_max = bytes;
+
+			vss->hw.formats |= pcm_format_to_bits(alsa_fmt);
+		}
+
+	if (!vss->hw.formats) {
+		dev_err(&vdev->dev,
+			"SID %u: no supported PCM sample formats found\n",
+			vss->sid);
+		return -EINVAL;
+	}
+
+	values = le64_to_cpu(info->rates);
+
+	vss->hw.rates = 0;
+
+	for (i = 0; i < ARRAY_SIZE(g_v2a_rate_map); ++i)
+		if (values & (1ULL << i)) {
+			if (!vss->hw.rate_min ||
+			    vss->hw.rate_min > g_v2a_rate_map[i].rate)
+				vss->hw.rate_min = g_v2a_rate_map[i].rate;
+
+			if (vss->hw.rate_max < g_v2a_rate_map[i].rate)
+				vss->hw.rate_max = g_v2a_rate_map[i].rate;
+
+			vss->hw.rates |= g_v2a_rate_map[i].alsa_bit;
+		}
+
+	if (!vss->hw.rates) {
+		dev_err(&vdev->dev,
+			"SID %u: no supported PCM frame rates found\n",
+			vss->sid);
+		return -EINVAL;
+	}
+
+	vss->hw.periods_min = pcm_periods_min;
+	vss->hw.periods_max = pcm_periods_max;
+
+	/*
+	 * We must ensure that there is enough space in the buffer to store
+	 * pcm_buffer_ms ms for the combination (Cmax, Smax, Rmax), where:
+	 *   Cmax = maximum supported number of channels,
+	 *   Smax = maximum supported sample size in bytes,
+	 *   Rmax = maximum supported frame rate.
+	 */
+	vss->hw.buffer_bytes_max =
+		PAGE_ALIGN(sample_max * vss->hw.channels_max * pcm_buffer_ms *
+			   (vss->hw.rate_max / MSEC_PER_SEC));
+
+	/*
+	 * We must ensure that the minimum period size is enough to store
+	 * pcm_period_ms_min ms for the combination (Cmin, Smin, Rmin), where:
+	 *   Cmin = minimum supported number of channels,
+	 *   Smin = minimum supported sample size in bytes,
+	 *   Rmin = minimum supported frame rate.
+	 */
+	vss->hw.period_bytes_min =
+		sample_min * vss->hw.channels_min * pcm_period_ms_min *
+		(vss->hw.rate_min / MSEC_PER_SEC);
+
+	/*
+	 * We must ensure that the maximum period size is enough to store
+	 * pcm_period_ms_max ms for the combination (Cmax, Smax, Rmax).
+	 */
+	vss->hw.period_bytes_max =
+		sample_max * vss->hw.channels_max * pcm_period_ms_max *
+		(vss->hw.rate_max / MSEC_PER_SEC);
+
+	return 0;
+}
+
+/**
+ * virtsnd_pcm_find() - Find the PCM device for the specified node ID.
+ * @snd: VirtIO sound device.
+ * @nid: Function node ID.
+ *
+ * Context: Any context.
+ * Return: a pointer to the PCM device or ERR_PTR(-ENOENT).
+ */
+struct virtio_pcm *virtsnd_pcm_find(struct virtio_snd *snd, u32 nid)
+{
+	struct virtio_pcm *vpcm;
+
+	list_for_each_entry(vpcm, &snd->pcm_list, list)
+		if (vpcm->nid == nid)
+			return vpcm;
+
+	return ERR_PTR(-ENOENT);
+}
+
+/**
+ * virtsnd_pcm_find_or_create() - Find or create the PCM device for the
+ *                                specified node ID.
+ * @snd: VirtIO sound device.
+ * @nid: Function node ID.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: a pointer to the PCM device or ERR_PTR(-errno).
+ */
+struct virtio_pcm *virtsnd_pcm_find_or_create(struct virtio_snd *snd, u32 nid)
+{
+	struct virtio_device *vdev = snd->vdev;
+	struct virtio_pcm *vpcm;
+
+	vpcm = virtsnd_pcm_find(snd, nid);
+	if (!IS_ERR(vpcm))
+		return vpcm;
+
+	vpcm = devm_kzalloc(&vdev->dev, sizeof(*vpcm), GFP_KERNEL);
+	if (!vpcm)
+		return ERR_PTR(-ENOMEM);
+
+	vpcm->nid = nid;
+	list_add_tail(&vpcm->list, &snd->pcm_list);
+
+	return vpcm;
+}
+
+/**
+ * virtsnd_pcm_validate() - Validate if the device can be started.
+ * @vdev: VirtIO parent device.
+ *
+ * Context: Any context.
+ * Return: 0 on success, -EINVAL on failure.
+ */
+int virtsnd_pcm_validate(struct virtio_device *vdev)
+{
+	if (pcm_periods_min < 2 || pcm_periods_min > pcm_periods_max) {
+		dev_err(&vdev->dev,
+			"invalid range [%u %u] of the number of PCM periods\n",
+			pcm_periods_min, pcm_periods_max);
+		return -EINVAL;
+	}
+
+	if (!pcm_period_ms_min || pcm_period_ms_min > pcm_period_ms_max) {
+		dev_err(&vdev->dev,
+			"invalid range [%u %u] of the size of the PCM period\n",
+			pcm_period_ms_min, pcm_period_ms_max);
+		return -EINVAL;
+	}
+
+	if (pcm_buffer_ms < pcm_periods_min * pcm_period_ms_min) {
+		dev_err(&vdev->dev,
+			"pcm_buffer_ms(=%u) value cannot be < %u ms\n",
+			pcm_buffer_ms, pcm_periods_min * pcm_period_ms_min);
+		return -EINVAL;
+	}
+
+	if (pcm_period_ms_max > pcm_buffer_ms / 2) {
+		dev_err(&vdev->dev,
+			"pcm_period_ms_max(=%u) value cannot be > %u ms\n",
+			pcm_period_ms_max, pcm_buffer_ms / 2);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * virtsnd_pcm_period_elapsed() - Kernel work function to handle the elapsed
+ *                                period state.
+ * @work: Elapsed period work.
+ *
+ * The main purpose of this function is to call snd_pcm_period_elapsed() in
+ * a process context, not in an interrupt context. This is necessary because PCM
+ * devices operate in non-atomic mode.
+ *
+ * Context: Process context.
+ */
+static void virtsnd_pcm_period_elapsed(struct work_struct *work)
+{
+	struct virtio_pcm_substream *vss =
+		container_of(work, struct virtio_pcm_substream, elapsed_period);
+
+	snd_pcm_period_elapsed(vss->substream);
+}
+
+/**
+ * virtsnd_pcm_parse_cfg() - Parse the stream configuration.
+ * @snd: VirtIO sound device.
+ *
+ * This function is called during initial device initialization.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_pcm_parse_cfg(struct virtio_snd *snd)
+{
+	struct virtio_device *vdev = snd->vdev;
+	struct virtio_snd_pcm_info *info;
+	u32 i;
+	int rc;
+
+	virtio_cread_le(vdev, struct virtio_snd_config, streams,
+			&snd->nsubstreams);
+	if (!snd->nsubstreams)
+		return 0;
+
+	snd->substreams = devm_kcalloc(&vdev->dev, snd->nsubstreams,
+				       sizeof(*snd->substreams), GFP_KERNEL);
+	if (!snd->substreams)
+		return -ENOMEM;
+
+	/*
+	 * Initialize critical substream fields early in case we hit an
+	 * error path and end up trying to clean up uninitialized structures
+	 * elsewhere.
+	 */
+	for (i = 0; i < snd->nsubstreams; ++i) {
+		struct virtio_pcm_substream *vss = &snd->substreams[i];
+
+		vss->snd = snd;
+		vss->sid = i;
+		INIT_WORK(&vss->elapsed_period, virtsnd_pcm_period_elapsed);
+		init_waitqueue_head(&vss->msg_empty);
+		spin_lock_init(&vss->lock);
+	}
+
+	info = kzalloc_objs(*info, snd->nsubstreams);
+	if (!info)
+		return -ENOMEM;
+
+	rc = virtsnd_ctl_query_info(snd, VIRTIO_SND_R_PCM_INFO, 0,
+				    snd->nsubstreams, sizeof(*info), info);
+	if (rc)
+		goto on_exit;
+
+	for (i = 0; i < snd->nsubstreams; ++i) {
+		struct virtio_pcm_substream *vss = &snd->substreams[i];
+		struct virtio_pcm *vpcm;
+
+		rc = virtsnd_pcm_build_hw(vss, &info[i]);
+		if (rc)
+			goto on_exit;
+
+		vss->nid = le32_to_cpu(info[i].hdr.hda_fn_nid);
+
+		vpcm = virtsnd_pcm_find_or_create(snd, vss->nid);
+		if (IS_ERR(vpcm)) {
+			rc = PTR_ERR(vpcm);
+			goto on_exit;
+		}
+
+		switch (info[i].direction) {
+		case VIRTIO_SND_D_OUTPUT:
+			vss->direction = SNDRV_PCM_STREAM_PLAYBACK;
+			break;
+		case VIRTIO_SND_D_INPUT:
+			vss->direction = SNDRV_PCM_STREAM_CAPTURE;
+			break;
+		default:
+			dev_err(&vdev->dev, "SID %u: unknown direction (%u)\n",
+				vss->sid, info[i].direction);
+			rc = -EINVAL;
+			goto on_exit;
+		}
+
+		vpcm->streams[vss->direction].nsubstreams++;
+	}
+
+on_exit:
+	kfree(info);
+
+	return rc;
+}
+
+/**
+ * virtsnd_pcm_build_devs() - Build ALSA PCM devices.
+ * @snd: VirtIO sound device.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_pcm_build_devs(struct virtio_snd *snd)
+{
+	struct virtio_device *vdev = snd->vdev;
+	struct virtio_pcm *vpcm;
+	u32 i;
+	int rc;
+
+	list_for_each_entry(vpcm, &snd->pcm_list, list) {
+		unsigned int npbs =
+			vpcm->streams[SNDRV_PCM_STREAM_PLAYBACK].nsubstreams;
+		unsigned int ncps =
+			vpcm->streams[SNDRV_PCM_STREAM_CAPTURE].nsubstreams;
+
+		if (!npbs && !ncps)
+			continue;
+
+		rc = snd_pcm_new(snd->card, VIRTIO_SND_CARD_DRIVER, vpcm->nid,
+				 npbs, ncps, &vpcm->pcm);
+		if (rc) {
+			dev_err(&vdev->dev, "snd_pcm_new[%u] failed: %d\n",
+				vpcm->nid, rc);
+			return rc;
+		}
+
+		vpcm->pcm->info_flags = 0;
+		vpcm->pcm->dev_class = SNDRV_PCM_CLASS_GENERIC;
+		vpcm->pcm->dev_subclass = SNDRV_PCM_SUBCLASS_GENERIC_MIX;
+		snprintf(vpcm->pcm->name, sizeof(vpcm->pcm->name),
+			 VIRTIO_SND_PCM_NAME " %u", vpcm->pcm->device);
+		vpcm->pcm->private_data = vpcm;
+		vpcm->pcm->nonatomic = true;
+
+		for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) {
+			struct virtio_pcm_stream *stream = &vpcm->streams[i];
+
+			if (!stream->nsubstreams)
+				continue;
+
+			stream->substreams =
+				devm_kcalloc(&vdev->dev, stream->nsubstreams,
+					     sizeof(*stream->substreams),
+					     GFP_KERNEL);
+			if (!stream->substreams)
+				return -ENOMEM;
+
+			stream->nsubstreams = 0;
+		}
+	}
+
+	for (i = 0; i < snd->nsubstreams; ++i) {
+		struct virtio_pcm_stream *vs;
+		struct virtio_pcm_substream *vss = &snd->substreams[i];
+
+		vpcm = virtsnd_pcm_find(snd, vss->nid);
+		if (IS_ERR(vpcm))
+			return PTR_ERR(vpcm);
+
+		vs = &vpcm->streams[vss->direction];
+		vs->substreams[vs->nsubstreams++] = vss;
+	}
+
+	list_for_each_entry(vpcm, &snd->pcm_list, list) {
+		for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) {
+			struct virtio_pcm_stream *vs = &vpcm->streams[i];
+			struct snd_pcm_str *ks = &vpcm->pcm->streams[i];
+			struct snd_pcm_substream *kss;
+
+			if (!vs->nsubstreams)
+				continue;
+
+			for (kss = ks->substream; kss; kss = kss->next)
+				vs->substreams[kss->number]->substream = kss;
+
+			snd_pcm_set_ops(vpcm->pcm, i, &virtsnd_pcm_ops[i]);
+		}
+
+		snd_pcm_set_managed_buffer_all(vpcm->pcm,
+					       SNDRV_DMA_TYPE_VMALLOC, NULL,
+					       0, 0);
+	}
+
+	return 0;
+}
+
+/**
+ * virtsnd_pcm_event() - Handle the PCM device event notification.
+ * @snd: VirtIO sound device.
+ * @event: VirtIO sound event.
+ *
+ * Context: Interrupt context.
+ */
+void virtsnd_pcm_event(struct virtio_snd *snd, struct virtio_snd_event *event)
+{
+	struct virtio_pcm_substream *vss;
+	u32 sid = le32_to_cpu(event->data);
+
+	if (sid >= snd->nsubstreams)
+		return;
+
+	vss = &snd->substreams[sid];
+
+	switch (le32_to_cpu(event->hdr.code)) {
+	case VIRTIO_SND_EVT_PCM_PERIOD_ELAPSED:
+		/* TODO: deal with shmem elapsed period */
+		break;
+	case VIRTIO_SND_EVT_PCM_XRUN:
+		scoped_guard(spinlock, &vss->lock) {
+			if (vss->xfer_enabled)
+				vss->xfer_xrun = true;
+		}
+		break;
+	}
+}

linux-7.2.3/sound/virtio/virtio_pcm.h

@@ -0,0 +1,126 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#ifndef VIRTIO_SND_PCM_H
+#define VIRTIO_SND_PCM_H
+
+#include <linux/atomic.h>
+#include <linux/virtio_config.h>
+#include <sound/pcm.h>
+#include <sound/pcm-indirect.h>
+
+struct virtio_pcm;
+struct virtio_pcm_msg;
+
+/**
+ * struct virtio_pcm_substream - VirtIO PCM substream.
+ * @snd: VirtIO sound device.
+ * @nid: Function group node identifier.
+ * @sid: Stream identifier.
+ * @direction: Stream data flow direction (SNDRV_PCM_STREAM_XXX).
+ * @features: Stream VirtIO feature bit map (1 << VIRTIO_SND_PCM_F_XXX).
+ * @substream: Kernel ALSA substream.
+ * @pcm_indirect: Kernel indirect pcm structure.
+ * @hw: Kernel ALSA substream hardware descriptor.
+ * @elapsed_period: Kernel work to handle the elapsed period state.
+ * @lock: Spinlock that protects fields shared by interrupt handlers and
+ *        substream operators.
+ * @buffer_bytes: Current buffer size in bytes.
+ * @hw_ptr: Substream hardware pointer value in bytes [0 ... buffer_bytes).
+ * @xfer_enabled: Data transfer state (0 - off, 1 - on).
+ * @xfer_xrun: Data underflow/overflow state (0 - no xrun, 1 - xrun).
+ * @stopped: True if the substream is stopped and must be released on the device
+ *           side.
+ * @suspended: True if the substream is suspended and must be reconfigured on
+ *             the device side at resume.
+ * @msgs: Allocated I/O messages.
+ * @nmsgs: Number of allocated I/O messages.
+ * @msg_count: Number of pending I/O messages in the virtqueue.
+ * @msg_empty: Notify when msg_count is zero.
+ */
+struct virtio_pcm_substream {
+	struct virtio_snd *snd;
+	u32 nid;
+	u32 sid;
+	u32 direction;
+	u32 features;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_indirect pcm_indirect;
+	struct snd_pcm_hardware hw;
+	struct work_struct elapsed_period;
+	spinlock_t lock;
+	size_t buffer_bytes;
+	size_t hw_ptr;
+	bool xfer_enabled;
+	bool xfer_xrun;
+	bool stopped;
+	bool suspended;
+	struct virtio_pcm_msg **msgs;
+	unsigned int nmsgs;
+	unsigned int msg_count;
+	wait_queue_head_t msg_empty;
+};
+
+/**
+ * struct virtio_pcm_stream - VirtIO PCM stream.
+ * @substreams: VirtIO substreams belonging to the stream.
+ * @nsubstreams: Number of substreams.
+ * @chmaps: Kernel channel maps belonging to the stream.
+ * @nchmaps: Number of channel maps.
+ */
+struct virtio_pcm_stream {
+	struct virtio_pcm_substream **substreams;
+	u32 nsubstreams;
+	struct snd_pcm_chmap_elem *chmaps;
+	u32 nchmaps;
+};
+
+/**
+ * struct virtio_pcm - VirtIO PCM device.
+ * @list: VirtIO PCM list entry.
+ * @nid: Function group node identifier.
+ * @pcm: Kernel PCM device.
+ * @streams: VirtIO PCM streams (playback and capture).
+ */
+struct virtio_pcm {
+	struct list_head list;
+	u32 nid;
+	struct snd_pcm *pcm;
+	struct virtio_pcm_stream streams[SNDRV_PCM_STREAM_LAST + 1];
+};
+
+extern const struct snd_pcm_ops virtsnd_pcm_ops[];
+
+int virtsnd_pcm_validate(struct virtio_device *vdev);
+
+int virtsnd_pcm_parse_cfg(struct virtio_snd *snd);
+
+int virtsnd_pcm_build_devs(struct virtio_snd *snd);
+
+void virtsnd_pcm_event(struct virtio_snd *snd, struct virtio_snd_event *event);
+
+void virtsnd_pcm_tx_notify_cb(struct virtqueue *vqueue);
+
+void virtsnd_pcm_rx_notify_cb(struct virtqueue *vqueue);
+
+struct virtio_pcm *virtsnd_pcm_find(struct virtio_snd *snd, u32 nid);
+
+struct virtio_pcm *virtsnd_pcm_find_or_create(struct virtio_snd *snd, u32 nid);
+
+struct virtio_snd_msg *
+virtsnd_pcm_ctl_msg_alloc(struct virtio_pcm_substream *vss,
+			  unsigned int command, gfp_t gfp);
+
+int virtsnd_pcm_msg_alloc(struct virtio_pcm_substream *vss,
+			  unsigned int periods, unsigned int period_bytes);
+
+void virtsnd_pcm_msg_free(struct virtio_pcm_substream *vss);
+
+int virtsnd_pcm_msg_send(struct virtio_pcm_substream *vss, unsigned long offset,
+			 unsigned long bytes);
+
+unsigned int virtsnd_pcm_msg_pending_num(struct virtio_pcm_substream *vss);
+
+#endif /* VIRTIO_SND_PCM_H */

linux-7.2.3/sound/virtio/virtio_pcm_msg.c

@@ -0,0 +1,415 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#include <sound/pcm_params.h>
+
+#include "virtio_card.h"
+
+/**
+ * struct virtio_pcm_msg - VirtIO I/O message.
+ * @substream: VirtIO PCM substream.
+ * @xfer: Request header payload.
+ * @status: Response header payload.
+ * @length: Data length in bytes.
+ * @sgs: Payload scatter-gather table.
+ */
+struct virtio_pcm_msg {
+	struct virtio_pcm_substream *substream;
+	struct virtio_snd_pcm_xfer xfer;
+	struct virtio_snd_pcm_status status;
+	size_t length;
+	struct scatterlist sgs[];
+};
+
+/**
+ * enum pcm_msg_sg_index - Index values for the virtio_pcm_msg->sgs field in
+ *                         an I/O message.
+ * @PCM_MSG_SG_XFER: Element containing a virtio_snd_pcm_xfer structure.
+ * @PCM_MSG_SG_STATUS: Element containing a virtio_snd_pcm_status structure.
+ * @PCM_MSG_SG_DATA: The first element containing a data buffer.
+ */
+enum pcm_msg_sg_index {
+	PCM_MSG_SG_XFER = 0,
+	PCM_MSG_SG_STATUS,
+	PCM_MSG_SG_DATA
+};
+
+/**
+ * virtsnd_pcm_sg_num() - Count the number of sg-elements required to represent
+ *                        vmalloc'ed buffer.
+ * @data: Pointer to vmalloc'ed buffer.
+ * @length: Buffer size.
+ *
+ * Context: Any context.
+ * Return: Number of physically contiguous parts in the @data.
+ */
+static int virtsnd_pcm_sg_num(u8 *data, unsigned int length)
+{
+	phys_addr_t sg_address;
+	unsigned int sg_length;
+	int num = 0;
+
+	while (length) {
+		struct page *pg = vmalloc_to_page(data);
+		phys_addr_t pg_address = page_to_phys(pg);
+		size_t pg_length;
+
+		pg_length = PAGE_SIZE - offset_in_page(data);
+		if (pg_length > length)
+			pg_length = length;
+
+		if (!num || sg_address + sg_length != pg_address) {
+			sg_address = pg_address;
+			sg_length = pg_length;
+			num++;
+		} else {
+			sg_length += pg_length;
+		}
+
+		data += pg_length;
+		length -= pg_length;
+	}
+
+	return num;
+}
+
+/**
+ * virtsnd_pcm_sg_from() - Build sg-list from vmalloc'ed buffer.
+ * @sgs: Preallocated sg-list to populate.
+ * @nsgs: The maximum number of elements in the @sgs.
+ * @data: Pointer to vmalloc'ed buffer.
+ * @length: Buffer size.
+ *
+ * Splits the buffer into physically contiguous parts and makes an sg-list of
+ * such parts.
+ *
+ * Context: Any context.
+ */
+static void virtsnd_pcm_sg_from(struct scatterlist *sgs, int nsgs, u8 *data,
+				unsigned int length)
+{
+	int idx = -1;
+
+	while (length) {
+		struct page *pg = vmalloc_to_page(data);
+		size_t pg_length;
+
+		pg_length = PAGE_SIZE - offset_in_page(data);
+		if (pg_length > length)
+			pg_length = length;
+
+		if (idx == -1 ||
+		    sg_phys(&sgs[idx]) + sgs[idx].length != page_to_phys(pg)) {
+			if (idx + 1 == nsgs)
+				break;
+			sg_set_page(&sgs[++idx], pg, pg_length,
+				    offset_in_page(data));
+		} else {
+			sgs[idx].length += pg_length;
+		}
+
+		data += pg_length;
+		length -= pg_length;
+	}
+
+	sg_mark_end(&sgs[idx]);
+}
+
+/**
+ * virtsnd_pcm_msg_alloc() - Allocate I/O messages.
+ * @vss: VirtIO PCM substream.
+ * @periods: Current number of periods.
+ * @period_bytes: Current period size in bytes.
+ *
+ * The function slices the buffer into @periods parts (each with the size of
+ * @period_bytes), and creates @periods corresponding I/O messages.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -ENOMEM on failure.
+ */
+int virtsnd_pcm_msg_alloc(struct virtio_pcm_substream *vss,
+			  unsigned int periods, unsigned int period_bytes)
+{
+	struct snd_pcm_runtime *runtime = vss->substream->runtime;
+	unsigned int i;
+
+	vss->msgs = kzalloc_objs(*vss->msgs, periods);
+	if (!vss->msgs)
+		return -ENOMEM;
+
+	vss->nmsgs = periods;
+
+	for (i = 0; i < periods; ++i) {
+		u8 *data = runtime->dma_area + period_bytes * i;
+		int sg_num = virtsnd_pcm_sg_num(data, period_bytes);
+		struct virtio_pcm_msg *msg;
+
+		msg = kzalloc_flex(*msg, sgs, sg_num + 2);
+		if (!msg)
+			return -ENOMEM;
+
+		msg->substream = vss;
+		sg_init_one(&msg->sgs[PCM_MSG_SG_XFER], &msg->xfer,
+			    sizeof(msg->xfer));
+		sg_init_one(&msg->sgs[PCM_MSG_SG_STATUS], &msg->status,
+			    sizeof(msg->status));
+		virtsnd_pcm_sg_from(&msg->sgs[PCM_MSG_SG_DATA], sg_num, data,
+				    period_bytes);
+
+		vss->msgs[i] = msg;
+	}
+
+	return 0;
+}
+
+/**
+ * virtsnd_pcm_msg_free() - Free all allocated I/O messages.
+ * @vss: VirtIO PCM substream.
+ *
+ * Context: Any context.
+ */
+void virtsnd_pcm_msg_free(struct virtio_pcm_substream *vss)
+{
+	unsigned int i;
+
+	for (i = 0; vss->msgs && i < vss->nmsgs; ++i)
+		kfree(vss->msgs[i]);
+	kfree(vss->msgs);
+
+	vss->msgs = NULL;
+	vss->nmsgs = 0;
+}
+
+/**
+ * virtsnd_pcm_msg_send() - Send asynchronous I/O messages.
+ * @vss: VirtIO PCM substream.
+ * @offset: starting position that has been updated
+ * @bytes: number of bytes that has been updated
+ *
+ * All messages are organized in an ordered circular list. Each time the
+ * function is called, all currently non-enqueued messages are added to the
+ * virtqueue. For this, the function uses offset and bytes to calculate the
+ * messages that need to be added.
+ *
+ * Context: Any context. Expects the tx/rx queue and the VirtIO substream
+ *          spinlocks to be held by caller.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_pcm_msg_send(struct virtio_pcm_substream *vss, unsigned long offset,
+			 unsigned long bytes)
+{
+	struct virtio_snd *snd = vss->snd;
+	struct virtio_device *vdev = snd->vdev;
+	struct virtqueue *vqueue = virtsnd_pcm_queue(vss)->vqueue;
+	unsigned long period_bytes = snd_pcm_lib_period_bytes(vss->substream);
+	unsigned long start, end, i;
+	unsigned int msg_count = vss->msg_count;
+	bool notify = false;
+	int rc;
+
+	start = offset / period_bytes;
+	end = (offset + bytes - 1) / period_bytes;
+
+	for (i = start; i <= end; i++) {
+		struct virtio_pcm_msg *msg = vss->msgs[i];
+		struct scatterlist *psgs[] = {
+			&msg->sgs[PCM_MSG_SG_XFER],
+			&msg->sgs[PCM_MSG_SG_DATA],
+			&msg->sgs[PCM_MSG_SG_STATUS]
+		};
+		unsigned long n;
+
+		n = period_bytes - (offset % period_bytes);
+		if (n > bytes)
+			n = bytes;
+
+		msg->length += n;
+		if (msg->length == period_bytes) {
+			msg->xfer.stream_id = cpu_to_le32(vss->sid);
+			memset(&msg->status, 0, sizeof(msg->status));
+
+			if (vss->direction == SNDRV_PCM_STREAM_PLAYBACK)
+				rc = virtqueue_add_sgs(vqueue, psgs, 2, 1, msg,
+						       GFP_ATOMIC);
+			else
+				rc = virtqueue_add_sgs(vqueue, psgs, 1, 2, msg,
+						       GFP_ATOMIC);
+
+			if (rc) {
+				dev_err(&vdev->dev,
+					"SID %u: failed to send I/O message\n",
+					vss->sid);
+				return rc;
+			}
+
+			vss->msg_count++;
+		}
+
+		offset = 0;
+		bytes -= n;
+	}
+
+	if (msg_count == vss->msg_count)
+		return 0;
+
+	if (!(vss->features & (1U << VIRTIO_SND_PCM_F_MSG_POLLING)))
+		notify = virtqueue_kick_prepare(vqueue);
+
+	if (notify)
+		virtqueue_notify(vqueue);
+
+	return 0;
+}
+
+/**
+ * virtsnd_pcm_msg_pending_num() - Returns the number of pending I/O messages.
+ * @vss: VirtIO substream.
+ *
+ * Context: Any context.
+ * Return: Number of messages.
+ */
+unsigned int virtsnd_pcm_msg_pending_num(struct virtio_pcm_substream *vss)
+{
+	guard(spinlock_irqsave)(&vss->lock);
+	return vss->msg_count;
+}
+
+/**
+ * virtsnd_pcm_msg_complete() - Complete an I/O message.
+ * @msg: I/O message.
+ * @written_bytes: Number of bytes written to the message.
+ *
+ * Completion of the message means the elapsed period. If transmission is
+ * allowed, then each completed message is immediately placed back at the end
+ * of the queue.
+ *
+ * For the playback substream, @written_bytes is equal to sizeof(msg->status).
+ *
+ * For the capture substream, @written_bytes is equal to sizeof(msg->status)
+ * plus the number of captured bytes.
+ *
+ * Context: Interrupt context. Takes and releases the VirtIO substream spinlock.
+ */
+static void virtsnd_pcm_msg_complete(struct virtio_pcm_msg *msg,
+				     size_t written_bytes)
+{
+	struct virtio_pcm_substream *vss = msg->substream;
+
+	/*
+	 * hw_ptr always indicates the buffer position of the first I/O message
+	 * in the virtqueue. Therefore, on each completion of an I/O message,
+	 * the hw_ptr value is unconditionally advanced.
+	 */
+	guard(spinlock)(&vss->lock);
+	/*
+	 * If the capture substream returned an incorrect status, then just
+	 * increase the hw_ptr by the message size.
+	 */
+	if (vss->direction == SNDRV_PCM_STREAM_PLAYBACK ||
+	    written_bytes <= sizeof(msg->status))
+		vss->hw_ptr += msg->length;
+	else
+		vss->hw_ptr += written_bytes - sizeof(msg->status);
+
+	if (vss->hw_ptr >= vss->buffer_bytes)
+		vss->hw_ptr -= vss->buffer_bytes;
+
+	msg->length = 0;
+
+	vss->xfer_xrun = false;
+	vss->msg_count--;
+
+	if (vss->xfer_enabled) {
+		struct snd_pcm_runtime *runtime = vss->substream->runtime;
+
+		runtime->delay =
+			bytes_to_frames(runtime,
+					le32_to_cpu(msg->status.latency_bytes));
+
+		schedule_work(&vss->elapsed_period);
+	} else if (!vss->msg_count) {
+		wake_up_all(&vss->msg_empty);
+	}
+}
+
+/**
+ * virtsnd_pcm_notify_cb() - Process all completed I/O messages.
+ * @queue: Underlying tx/rx virtqueue.
+ *
+ * Context: Interrupt context. Takes and releases the tx/rx queue spinlock.
+ */
+static inline void virtsnd_pcm_notify_cb(struct virtio_snd_queue *queue)
+{
+	struct virtio_pcm_msg *msg;
+	u32 written_bytes;
+
+	guard(spinlock_irqsave)(&queue->lock);
+	do {
+		virtqueue_disable_cb(queue->vqueue);
+		while ((msg = virtqueue_get_buf(queue->vqueue, &written_bytes)))
+			virtsnd_pcm_msg_complete(msg, written_bytes);
+	} while (!virtqueue_enable_cb(queue->vqueue));
+}
+
+/**
+ * virtsnd_pcm_tx_notify_cb() - Process all completed TX messages.
+ * @vqueue: Underlying tx virtqueue.
+ *
+ * Context: Interrupt context.
+ */
+void virtsnd_pcm_tx_notify_cb(struct virtqueue *vqueue)
+{
+	struct virtio_snd *snd = vqueue->vdev->priv;
+
+	virtsnd_pcm_notify_cb(virtsnd_tx_queue(snd));
+}
+
+/**
+ * virtsnd_pcm_rx_notify_cb() - Process all completed RX messages.
+ * @vqueue: Underlying rx virtqueue.
+ *
+ * Context: Interrupt context.
+ */
+void virtsnd_pcm_rx_notify_cb(struct virtqueue *vqueue)
+{
+	struct virtio_snd *snd = vqueue->vdev->priv;
+
+	virtsnd_pcm_notify_cb(virtsnd_rx_queue(snd));
+}
+
+/**
+ * virtsnd_pcm_ctl_msg_alloc() - Allocate and initialize the PCM device control
+ *                               message for the specified substream.
+ * @vss: VirtIO PCM substream.
+ * @command: Control request code (VIRTIO_SND_R_PCM_XXX).
+ * @gfp: Kernel flags for memory allocation.
+ *
+ * Context: Any context. May sleep if @gfp flags permit.
+ * Return: Allocated message on success, NULL on failure.
+ */
+struct virtio_snd_msg *
+virtsnd_pcm_ctl_msg_alloc(struct virtio_pcm_substream *vss,
+			  unsigned int command, gfp_t gfp)
+{
+	size_t request_size = sizeof(struct virtio_snd_pcm_hdr);
+	size_t response_size = sizeof(struct virtio_snd_hdr);
+	struct virtio_snd_msg *msg;
+
+	switch (command) {
+	case VIRTIO_SND_R_PCM_SET_PARAMS:
+		request_size = sizeof(struct virtio_snd_pcm_set_params);
+		break;
+	}
+
+	msg = virtsnd_ctl_msg_alloc(request_size, response_size, gfp);
+	if (msg) {
+		struct virtio_snd_pcm_hdr *hdr = virtsnd_ctl_msg_request(msg);
+
+		hdr->hdr.code = cpu_to_le32(command);
+		hdr->stream_id = cpu_to_le32(vss->sid);
+	}
+
+	return msg;
+}

linux-7.2.3/sound/virtio/virtio_pcm_ops.c

@@ -0,0 +1,526 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#include <sound/pcm_params.h>
+
+#include "virtio_card.h"
+
+/*
+ * I/O messages lifetime
+ * ---------------------
+ *
+ * Allocation:
+ *   Messages are initially allocated in the ops->hw_params() after the size and
+ *   number of periods have been successfully negotiated.
+ *
+ * Freeing:
+ *   Messages can be safely freed after the queue has been successfully flushed
+ *   (RELEASE command in the ops->sync_stop()) and the ops->hw_free() has been
+ *   called.
+ *
+ *   When the substream stops, the ops->sync_stop() waits until the device has
+ *   completed all pending messages. This wait can be interrupted either by a
+ *   signal or due to a timeout. In this case, the device can still access
+ *   messages even after calling ops->hw_free(). It can also issue an interrupt,
+ *   and the interrupt handler will also try to access message structures.
+ *
+ *   Therefore, freeing of already allocated messages occurs:
+ *
+ *   - in ops->hw_params(), if this operator was called several times in a row,
+ *     or if ops->hw_free() failed to free messages previously;
+ *
+ *   - in ops->hw_free(), if the queue has been successfully flushed;
+ *
+ *   - in dev->release().
+ */
+
+/* Map for converting ALSA format to VirtIO format. */
+struct virtsnd_a2v_format {
+	snd_pcm_format_t alsa_bit;
+	unsigned int vio_bit;
+};
+
+static const struct virtsnd_a2v_format g_a2v_format_map[] = {
+	{ SNDRV_PCM_FORMAT_IMA_ADPCM, VIRTIO_SND_PCM_FMT_IMA_ADPCM },
+	{ SNDRV_PCM_FORMAT_MU_LAW, VIRTIO_SND_PCM_FMT_MU_LAW },
+	{ SNDRV_PCM_FORMAT_A_LAW, VIRTIO_SND_PCM_FMT_A_LAW },
+	{ SNDRV_PCM_FORMAT_S8, VIRTIO_SND_PCM_FMT_S8 },
+	{ SNDRV_PCM_FORMAT_U8, VIRTIO_SND_PCM_FMT_U8 },
+	{ SNDRV_PCM_FORMAT_S16_LE, VIRTIO_SND_PCM_FMT_S16 },
+	{ SNDRV_PCM_FORMAT_U16_LE, VIRTIO_SND_PCM_FMT_U16 },
+	{ SNDRV_PCM_FORMAT_S18_3LE, VIRTIO_SND_PCM_FMT_S18_3 },
+	{ SNDRV_PCM_FORMAT_U18_3LE, VIRTIO_SND_PCM_FMT_U18_3 },
+	{ SNDRV_PCM_FORMAT_S20_3LE, VIRTIO_SND_PCM_FMT_S20_3 },
+	{ SNDRV_PCM_FORMAT_U20_3LE, VIRTIO_SND_PCM_FMT_U20_3 },
+	{ SNDRV_PCM_FORMAT_S24_3LE, VIRTIO_SND_PCM_FMT_S24_3 },
+	{ SNDRV_PCM_FORMAT_U24_3LE, VIRTIO_SND_PCM_FMT_U24_3 },
+	{ SNDRV_PCM_FORMAT_S20_LE, VIRTIO_SND_PCM_FMT_S20 },
+	{ SNDRV_PCM_FORMAT_U20_LE, VIRTIO_SND_PCM_FMT_U20 },
+	{ SNDRV_PCM_FORMAT_S24_LE, VIRTIO_SND_PCM_FMT_S24 },
+	{ SNDRV_PCM_FORMAT_U24_LE, VIRTIO_SND_PCM_FMT_U24 },
+	{ SNDRV_PCM_FORMAT_S32_LE, VIRTIO_SND_PCM_FMT_S32 },
+	{ SNDRV_PCM_FORMAT_U32_LE, VIRTIO_SND_PCM_FMT_U32 },
+	{ SNDRV_PCM_FORMAT_FLOAT_LE, VIRTIO_SND_PCM_FMT_FLOAT },
+	{ SNDRV_PCM_FORMAT_FLOAT64_LE, VIRTIO_SND_PCM_FMT_FLOAT64 },
+	{ SNDRV_PCM_FORMAT_DSD_U8, VIRTIO_SND_PCM_FMT_DSD_U8 },
+	{ SNDRV_PCM_FORMAT_DSD_U16_LE, VIRTIO_SND_PCM_FMT_DSD_U16 },
+	{ SNDRV_PCM_FORMAT_DSD_U32_LE, VIRTIO_SND_PCM_FMT_DSD_U32 },
+	{ SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE,
+	  VIRTIO_SND_PCM_FMT_IEC958_SUBFRAME }
+};
+
+/* Map for converting ALSA frame rate to VirtIO frame rate. */
+struct virtsnd_a2v_rate {
+	unsigned int rate;
+	unsigned int vio_bit;
+};
+
+static const struct virtsnd_a2v_rate g_a2v_rate_map[] = {
+	{ 5512, VIRTIO_SND_PCM_RATE_5512 },
+	{ 8000, VIRTIO_SND_PCM_RATE_8000 },
+	{ 11025, VIRTIO_SND_PCM_RATE_11025 },
+	{ 16000, VIRTIO_SND_PCM_RATE_16000 },
+	{ 22050, VIRTIO_SND_PCM_RATE_22050 },
+	{ 32000, VIRTIO_SND_PCM_RATE_32000 },
+	{ 44100, VIRTIO_SND_PCM_RATE_44100 },
+	{ 48000, VIRTIO_SND_PCM_RATE_48000 },
+	{ 64000, VIRTIO_SND_PCM_RATE_64000 },
+	{ 88200, VIRTIO_SND_PCM_RATE_88200 },
+	{ 96000, VIRTIO_SND_PCM_RATE_96000 },
+	{ 176400, VIRTIO_SND_PCM_RATE_176400 },
+	{ 192000, VIRTIO_SND_PCM_RATE_192000 },
+	{ 384000, VIRTIO_SND_PCM_RATE_384000 }
+};
+
+static int virtsnd_pcm_sync_stop(struct snd_pcm_substream *substream);
+
+/**
+ * virtsnd_pcm_open() - Open the PCM substream.
+ * @substream: Kernel ALSA substream.
+ *
+ * Context: Process context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct virtio_pcm *vpcm = snd_pcm_substream_chip(substream);
+	struct virtio_pcm_stream *vs = &vpcm->streams[substream->stream];
+	struct virtio_pcm_substream *vss = vs->substreams[substream->number];
+
+	substream->runtime->hw = vss->hw;
+	substream->private_data = vss;
+
+	snd_pcm_hw_constraint_integer(substream->runtime,
+				      SNDRV_PCM_HW_PARAM_PERIODS);
+
+	vss->stopped = !!virtsnd_pcm_msg_pending_num(vss);
+	vss->suspended = false;
+
+	/*
+	 * If the substream has already been used, then the I/O queue may be in
+	 * an invalid state. Just in case, we do a check and try to return the
+	 * queue to its original state, if necessary.
+	 */
+	return virtsnd_pcm_sync_stop(substream);
+}
+
+/**
+ * virtsnd_pcm_close() - Close the PCM substream.
+ * @substream: Kernel ALSA substream.
+ *
+ * Context: Process context.
+ * Return: 0.
+ */
+static int virtsnd_pcm_close(struct snd_pcm_substream *substream)
+{
+	return 0;
+}
+
+/**
+ * virtsnd_pcm_dev_set_params() - Set the parameters of the PCM substream on
+ *                                the device side.
+ * @vss: VirtIO PCM substream.
+ * @buffer_bytes: Size of the hardware buffer.
+ * @period_bytes: Size of the hardware period.
+ * @channels: Selected number of channels.
+ * @format: Selected sample format (SNDRV_PCM_FORMAT_XXX).
+ * @rate: Selected frame rate.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_pcm_dev_set_params(struct virtio_pcm_substream *vss,
+				      unsigned int buffer_bytes,
+				      unsigned int period_bytes,
+				      unsigned int channels,
+				      snd_pcm_format_t format,
+				      unsigned int rate)
+{
+	struct virtio_snd_msg *msg;
+	struct virtio_snd_pcm_set_params *request;
+	unsigned int i;
+	int vformat = -1;
+	int vrate = -1;
+
+	for (i = 0; i < ARRAY_SIZE(g_a2v_format_map); ++i)
+		if (g_a2v_format_map[i].alsa_bit == format) {
+			vformat = g_a2v_format_map[i].vio_bit;
+
+			break;
+		}
+
+	for (i = 0; i < ARRAY_SIZE(g_a2v_rate_map); ++i)
+		if (g_a2v_rate_map[i].rate == rate) {
+			vrate = g_a2v_rate_map[i].vio_bit;
+
+			break;
+		}
+
+	if (vformat == -1 || vrate == -1)
+		return -EINVAL;
+
+	msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_SET_PARAMS,
+					GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	request = virtsnd_ctl_msg_request(msg);
+	request->buffer_bytes = cpu_to_le32(buffer_bytes);
+	request->period_bytes = cpu_to_le32(period_bytes);
+	request->channels = channels;
+	request->format = vformat;
+	request->rate = vrate;
+
+	if (vss->features & (1U << VIRTIO_SND_PCM_F_MSG_POLLING))
+		request->features |=
+			cpu_to_le32(1U << VIRTIO_SND_PCM_F_MSG_POLLING);
+
+	if (vss->features & (1U << VIRTIO_SND_PCM_F_EVT_XRUNS))
+		request->features |=
+			cpu_to_le32(1U << VIRTIO_SND_PCM_F_EVT_XRUNS);
+
+	return virtsnd_ctl_msg_send_sync(vss->snd, msg);
+}
+
+/**
+ * virtsnd_pcm_hw_params() - Set the parameters of the PCM substream.
+ * @substream: Kernel ALSA substream.
+ * @hw_params: Hardware parameters.
+ *
+ * Context: Process context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_pcm_hw_params(struct snd_pcm_substream *substream,
+				 struct snd_pcm_hw_params *hw_params)
+{
+	struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
+	struct virtio_device *vdev = vss->snd->vdev;
+	int rc;
+
+	if (virtsnd_pcm_msg_pending_num(vss)) {
+		dev_err(&vdev->dev, "SID %u: invalid I/O queue state\n",
+			vss->sid);
+		return -EBADFD;
+	}
+
+	rc = virtsnd_pcm_dev_set_params(vss, params_buffer_bytes(hw_params),
+					params_period_bytes(hw_params),
+					params_channels(hw_params),
+					params_format(hw_params),
+					params_rate(hw_params));
+	if (rc)
+		return rc;
+
+	/*
+	 * Free previously allocated messages if ops->hw_params() is called
+	 * several times in a row, or if ops->hw_free() failed to free messages.
+	 */
+	virtsnd_pcm_msg_free(vss);
+
+	return virtsnd_pcm_msg_alloc(vss, params_periods(hw_params),
+				     params_period_bytes(hw_params));
+}
+
+/**
+ * virtsnd_pcm_hw_free() - Reset the parameters of the PCM substream.
+ * @substream: Kernel ALSA substream.
+ *
+ * Context: Process context.
+ * Return: 0
+ */
+static int virtsnd_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
+
+	/* If the queue is flushed, we can safely free the messages here. */
+	if (!virtsnd_pcm_msg_pending_num(vss))
+		virtsnd_pcm_msg_free(vss);
+
+	return 0;
+}
+
+/**
+ * virtsnd_pcm_prepare() - Prepare the PCM substream.
+ * @substream: Kernel ALSA substream.
+ *
+ * Context: Process context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_pcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
+	struct virtio_device *vdev = vss->snd->vdev;
+	struct virtio_snd_msg *msg;
+
+	if (!vss->suspended) {
+		if (virtsnd_pcm_msg_pending_num(vss)) {
+			dev_err(&vdev->dev, "SID %u: invalid I/O queue state\n",
+				vss->sid);
+			return -EBADFD;
+		}
+
+		vss->buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
+		vss->hw_ptr = 0;
+	} else {
+		struct snd_pcm_runtime *runtime = substream->runtime;
+		unsigned int buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
+		unsigned int period_bytes = snd_pcm_lib_period_bytes(substream);
+		int rc;
+
+		rc = virtsnd_pcm_dev_set_params(vss, buffer_bytes, period_bytes,
+						runtime->channels,
+						runtime->format, runtime->rate);
+		if (rc)
+			return rc;
+	}
+
+	vss->xfer_xrun = false;
+	vss->suspended = false;
+	vss->msg_count = 0;
+
+	memset(&vss->pcm_indirect, 0, sizeof(vss->pcm_indirect));
+	vss->pcm_indirect.sw_buffer_size =
+		vss->pcm_indirect.hw_buffer_size =
+		snd_pcm_lib_buffer_bytes(substream);
+
+	msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_PREPARE,
+					GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	return virtsnd_ctl_msg_send_sync(vss->snd, msg);
+}
+
+/**
+ * virtsnd_pcm_trigger() - Process command for the PCM substream.
+ * @substream: Kernel ALSA substream.
+ * @command: Substream command (SNDRV_PCM_TRIGGER_XXX).
+ *
+ * Context: Any context. Takes and releases the VirtIO substream spinlock.
+ *          May take and release the tx/rx queue spinlock.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_pcm_trigger(struct snd_pcm_substream *substream, int command)
+{
+	struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
+	struct virtio_snd *snd = vss->snd;
+	struct virtio_snd_queue *queue;
+	struct virtio_snd_msg *msg;
+	int rc = 0;
+
+	switch (command) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		queue = virtsnd_pcm_queue(vss);
+
+		scoped_guard(spinlock_irqsave, &queue->lock) {
+			guard(spinlock)(&vss->lock);
+			if (vss->direction == SNDRV_PCM_STREAM_CAPTURE)
+				rc = virtsnd_pcm_msg_send(vss, 0, vss->buffer_bytes);
+			if (rc)
+				return rc;
+			vss->xfer_enabled = true;
+		}
+
+		msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_START,
+						GFP_KERNEL);
+		if (!msg) {
+			guard(spinlock_irqsave)(&vss->lock);
+			vss->xfer_enabled = false;
+
+			return -ENOMEM;
+		}
+
+		return virtsnd_ctl_msg_send_sync(snd, msg);
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+		vss->suspended = true;
+		fallthrough;
+	case SNDRV_PCM_TRIGGER_STOP:
+		vss->stopped = true;
+		fallthrough;
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		scoped_guard(spinlock_irqsave, &vss->lock) {
+			vss->xfer_enabled = false;
+		}
+
+		msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_STOP,
+						GFP_KERNEL);
+		if (!msg)
+			return -ENOMEM;
+
+		return virtsnd_ctl_msg_send_sync(snd, msg);
+	default:
+		return -EINVAL;
+	}
+}
+
+/**
+ * virtsnd_pcm_sync_stop() - Synchronous PCM substream stop.
+ * @substream: Kernel ALSA substream.
+ *
+ * The function can be called both from the upper level or from the driver
+ * itself.
+ *
+ * Context: Process context. Takes and releases the VirtIO substream spinlock.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_pcm_sync_stop(struct snd_pcm_substream *substream)
+{
+	struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
+	struct virtio_snd *snd = vss->snd;
+	struct virtio_snd_msg *msg;
+	unsigned int js = msecs_to_jiffies(virtsnd_msg_timeout_ms);
+	int rc;
+
+	cancel_work_sync(&vss->elapsed_period);
+
+	if (!vss->stopped)
+		return 0;
+
+	msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_RELEASE,
+					GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	rc = virtsnd_ctl_msg_send_sync(snd, msg);
+	if (rc)
+		return rc;
+
+	/*
+	 * The spec states that upon receipt of the RELEASE command "the device
+	 * MUST complete all pending I/O messages for the specified stream ID".
+	 * Thus, we consider the absence of I/O messages in the queue as an
+	 * indication that the substream has been released.
+	 */
+	rc = wait_event_interruptible_timeout(vss->msg_empty,
+					      !virtsnd_pcm_msg_pending_num(vss),
+					      js);
+	if (rc <= 0) {
+		dev_warn(&snd->vdev->dev, "SID %u: failed to flush I/O queue\n",
+			 vss->sid);
+
+		return !rc ? -ETIMEDOUT : rc;
+	}
+
+	vss->stopped = false;
+
+	return 0;
+}
+
+/**
+ * virtsnd_pcm_pb_pointer() - Get the current hardware position for the PCM
+ *                         substream for playback.
+ * @substream: Kernel ALSA substream.
+ *
+ * Context: Any context.
+ * Return: Hardware position in frames inside [0 ... buffer_size) range.
+ */
+static snd_pcm_uframes_t
+virtsnd_pcm_pb_pointer(struct snd_pcm_substream *substream)
+{
+	struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
+
+	return snd_pcm_indirect_playback_pointer(substream,
+		&vss->pcm_indirect,
+		vss->hw_ptr);
+}
+
+/**
+ * virtsnd_pcm_cp_pointer() - Get the current hardware position for the PCM
+ *                         substream for capture.
+ * @substream: Kernel ALSA substream.
+ *
+ * Context: Any context.
+ * Return: Hardware position in frames inside [0 ... buffer_size) range.
+ */
+static snd_pcm_uframes_t
+virtsnd_pcm_cp_pointer(struct snd_pcm_substream *substream)
+{
+	struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
+
+	return snd_pcm_indirect_capture_pointer(substream,
+		&vss->pcm_indirect,
+		vss->hw_ptr);
+}
+
+static void virtsnd_pcm_trans_copy(struct snd_pcm_substream *substream,
+				   struct snd_pcm_indirect *rec, size_t bytes)
+{
+	struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
+
+	virtsnd_pcm_msg_send(vss, rec->sw_data, bytes);
+}
+
+static int virtsnd_pcm_pb_ack(struct snd_pcm_substream *substream)
+{
+	struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
+	struct virtio_snd_queue *queue = virtsnd_pcm_queue(vss);
+
+	guard(spinlock_irqsave)(&queue->lock);
+	guard(spinlock)(&vss->lock);
+
+	return snd_pcm_indirect_playback_transfer(substream, &vss->pcm_indirect,
+						  virtsnd_pcm_trans_copy);
+}
+
+static int virtsnd_pcm_cp_ack(struct snd_pcm_substream *substream)
+{
+	struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
+	struct virtio_snd_queue *queue = virtsnd_pcm_queue(vss);
+
+	guard(spinlock_irqsave)(&queue->lock);
+	guard(spinlock)(&vss->lock);
+
+	return snd_pcm_indirect_capture_transfer(substream, &vss->pcm_indirect,
+						 virtsnd_pcm_trans_copy);
+}
+
+/* PCM substream operators map. */
+const struct snd_pcm_ops virtsnd_pcm_ops[] = {
+	{
+		.open = virtsnd_pcm_open,
+		.close = virtsnd_pcm_close,
+		.ioctl = snd_pcm_lib_ioctl,
+		.hw_params = virtsnd_pcm_hw_params,
+		.hw_free = virtsnd_pcm_hw_free,
+		.prepare = virtsnd_pcm_prepare,
+		.trigger = virtsnd_pcm_trigger,
+		.sync_stop = virtsnd_pcm_sync_stop,
+		.pointer = virtsnd_pcm_pb_pointer,
+		.ack = virtsnd_pcm_pb_ack,
+	},
+	{
+		.open = virtsnd_pcm_open,
+		.close = virtsnd_pcm_close,
+		.ioctl = snd_pcm_lib_ioctl,
+		.hw_params = virtsnd_pcm_hw_params,
+		.hw_free = virtsnd_pcm_hw_free,
+		.prepare = virtsnd_pcm_prepare,
+		.trigger = virtsnd_pcm_trigger,
+		.sync_stop = virtsnd_pcm_sync_stop,
+		.pointer = virtsnd_pcm_cp_pointer,
+		.ack = virtsnd_pcm_cp_ack,
+	},
+};