1 files changed, 530 insertions, 0 deletions
diff --git a/meta-egvirt/dynamic-layers/rcar-gen3/recipes-kernel/linux/linux-common/0002-ALSA-virtio-handling-control-messages.patch b/meta-egvirt/dynamic-layers/rcar-gen3/recipes-kernel/linux/linux-common/0002-ALSA-virtio-handling-control-messages.patch
new file mode 100644
index 00000000..a5e8a65d
--- /dev/null
+++ b/meta-egvirt/dynamic-layers/rcar-gen3/recipes-kernel/linux/linux-common/0002-ALSA-virtio-handling-control-messages.patch
@@ -0,0 +1,530 @@
+From de4d20acac58f2aa04539a611540e3f1589f1d3a Mon Sep 17 00:00:00 2001
+From: Anton Yakovlev <anton.yakovlev@opensynergy.com>
+Date: Tue, 2 Mar 2021 17:47:03 +0100
+Subject: [PATCH 2/9] ALSA: virtio: handling control messages
+
+The control queue can be used by different parts of the driver to send
+commands to the device. Control messages can be either synchronous or
+asynchronous. The lifetime of a message is controlled by a reference
+count.
+
+Introduce a module parameter to set the message completion timeout:
+  msg_timeout_ms [=1000]
+
+Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
+Link: https://lore.kernel.org/r/20210302164709.3142702-4-anton.yakovlev@opensynergy.com
+Signed-off-by: Takashi Iwai <tiwai@suse.de>
+---
+ sound/virtio/Makefile         |   3 +-
+ sound/virtio/virtio_card.c    |  13 ++
+ sound/virtio/virtio_card.h    |   7 +
+ sound/virtio/virtio_ctl_msg.c | 310 ++++++++++++++++++++++++++++++++++
+ sound/virtio/virtio_ctl_msg.h |  78 +++++++++
+ 5 files changed, 410 insertions(+), 1 deletion(-)
+ create mode 100644 sound/virtio/virtio_ctl_msg.c
+ create mode 100644 sound/virtio/virtio_ctl_msg.h
+
+diff --git a/sound/virtio/Makefile b/sound/virtio/Makefile
+index 8c87ebb9982b..dc551e637441 100644
+--- a/sound/virtio/Makefile
++++ b/sound/virtio/Makefile
+@@ -3,5 +3,6 @@
+ obj-$(CONFIG_SND_VIRTIO) += virtio_snd.o
+ 
+ virtio_snd-objs := \
+-	virtio_card.o
++	virtio_card.o \
++	virtio_ctl_msg.o
+ 
+diff --git a/sound/virtio/virtio_card.c b/sound/virtio/virtio_card.c
+index 5a37056858e9..b757b2444078 100644
+--- a/sound/virtio/virtio_card.c
++++ b/sound/virtio/virtio_card.c
+@@ -11,6 +11,10 @@
+ 
+ #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);
+ 
+ /**
+@@ -96,9 +100,11 @@ static int virtsnd_find_vqs(struct virtio_snd *snd)
+ {
+ 	struct virtio_device *vdev = snd->vdev;
+ 	static vq_callback_t *callbacks[VIRTIO_SND_VQ_MAX] = {
++		[VIRTIO_SND_VQ_CONTROL] = virtsnd_ctl_notify_cb,
+ 		[VIRTIO_SND_VQ_EVENT] = virtsnd_event_notify_cb
+ 	};
+ 	static const char *names[VIRTIO_SND_VQ_MAX] = {
++		[VIRTIO_SND_VQ_CONTROL] = "virtsnd-ctl",
+ 		[VIRTIO_SND_VQ_EVENT] = "virtsnd-event"
+ 	};
+ 	struct virtqueue *vqs[VIRTIO_SND_VQ_MAX] = { 0 };
+@@ -226,6 +232,11 @@ static int virtsnd_validate(struct virtio_device *vdev)
+ 		return -EINVAL;
+ 	}
+ 
++	if (!virtsnd_msg_timeout_ms) {
++		dev_err(&vdev->dev, "msg_timeout_ms value cannot be zero\n");
++		return -EINVAL;
++	}
++
+ 	return 0;
+ }
+ 
+@@ -247,6 +258,7 @@ static int virtsnd_probe(struct virtio_device *vdev)
+ 		return -ENOMEM;
+ 
+ 	snd->vdev = vdev;
++	INIT_LIST_HEAD(&snd->ctl_msgs);
+ 
+ 	vdev->priv = snd;
+ 
+@@ -283,6 +295,7 @@ static void virtsnd_remove(struct virtio_device *vdev)
+ 	struct virtio_snd *snd = vdev->priv;
+ 
+ 	virtsnd_disable_event_vq(snd);
++	virtsnd_ctl_msg_cancel_all(snd);
+ 
+ 	if (snd->card)
+ 		snd_card_free(snd->card);
+diff --git a/sound/virtio/virtio_card.h b/sound/virtio/virtio_card.h
+index b903b1b12e90..1e76eeff160f 100644
+--- a/sound/virtio/virtio_card.h
++++ b/sound/virtio/virtio_card.h
+@@ -11,6 +11,8 @@
+ #include <sound/core.h>
+ #include <uapi/linux/virtio_snd.h>
+ 
++#include "virtio_ctl_msg.h"
++
+ #define VIRTIO_SND_CARD_DRIVER	"virtio-snd"
+ #define VIRTIO_SND_CARD_NAME	"VirtIO SoundCard"
+ 
+@@ -29,15 +31,20 @@ struct virtio_snd_queue {
+  * @vdev: Underlying virtio device.
+  * @queues: Virtqueue wrappers.
+  * @card: ALSA sound card.
++ * @ctl_msgs: Pending control request list.
+  * @event_msgs: Device events.
+  */
+ struct virtio_snd {
+ 	struct virtio_device *vdev;
+ 	struct virtio_snd_queue queues[VIRTIO_SND_VQ_MAX];
+ 	struct snd_card *card;
++	struct list_head ctl_msgs;
+ 	struct virtio_snd_event *event_msgs;
+ };
+ 
++/* 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)
+ {
+diff --git a/sound/virtio/virtio_ctl_msg.c b/sound/virtio/virtio_ctl_msg.c
+new file mode 100644
+index 000000000000..26ff7e7cc041
+--- /dev/null
++++ b/sound/virtio/virtio_ctl_msg.c
+@@ -0,0 +1,310 @@
++// 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_request() - 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;
++	unsigned long flags;
++	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;
++
++	spin_lock_irqsave(&queue->lock, flags);
++	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);
++	}
++	spin_unlock_irqrestore(&queue->lock, flags);
++
++	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);
++	unsigned long flags;
++
++	spin_lock_irqsave(&queue->lock, flags);
++	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);
++	}
++	spin_unlock_irqrestore(&queue->lock, flags);
++}
++
++/**
++ * 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;
++	unsigned long flags;
++
++	spin_lock_irqsave(&queue->lock, flags);
++	do {
++		virtqueue_disable_cb(vqueue);
++		while ((msg = virtqueue_get_buf(vqueue, &length)))
++			virtsnd_ctl_msg_complete(msg);
++		if (unlikely(virtqueue_is_broken(vqueue)))
++			break;
++	} while (!virtqueue_enable_cb(vqueue));
++	spin_unlock_irqrestore(&queue->lock, flags);
++}
+diff --git a/sound/virtio/virtio_ctl_msg.h b/sound/virtio/virtio_ctl_msg.h
+new file mode 100644
+index 000000000000..7f4db044f28e
+--- /dev/null
++++ b/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 */
+-- 
+2.34.1
+