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 <[email protected]> --- sound/virtio/Makefile | 3 +- sound/virtio/virtio_card.c | 20 +++ sound/virtio/virtio_card.h | 7 + sound/virtio/virtio_ctl_msg.c | 293 ++++++++++++++++++++++++++++++++++ sound/virtio/virtio_ctl_msg.h | 122 ++++++++++++++ 5 files changed, 444 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 532d823fdf6f..955eadc2d858 100644 --- a/sound/virtio/virtio_card.c +++ b/sound/virtio/virtio_card.c @@ -24,6 +24,10 @@ #include "virtio_card.h" +int msg_timeout_ms = MSEC_PER_SEC; +module_param(msg_timeout_ms, int, 0644); +MODULE_PARM_DESC(msg_timeout_ms, "Message completion timeout in milliseconds"); + static void virtsnd_remove(struct virtio_device *vdev); /** @@ -125,6 +129,7 @@ static int virtsnd_find_vqs(struct virtio_snd *snd) unsigned int n = 0; int rc; + callbacks[VIRTIO_SND_VQ_CONTROL] = virtsnd_ctl_notify_cb; callbacks[VIRTIO_SND_VQ_EVENT] = virtsnd_event_notify_cb; rc = virtio_find_vqs(vdev, VIRTIO_SND_VQ_MAX, vqs, callbacks, names, @@ -193,6 +198,15 @@ static void virtsnd_disable_vqs(struct virtio_snd *snd) if (queue->vqueue) virtqueue_disable_cb(queue->vqueue); queue->vqueue = NULL; + /* Cancel all pending requests for the control queue */ + if (i == VIRTIO_SND_VQ_CONTROL) { + struct virtio_snd_msg *msg; + struct virtio_snd_msg *next; + + list_for_each_entry_safe(msg, next, &snd->ctl_msgs, + list) + virtsnd_ctl_msg_complete(snd, msg); + } spin_unlock_irqrestore(&queue->lock, flags); } @@ -283,6 +297,11 @@ static int virtsnd_validate(struct virtio_device *vdev) return -EINVAL; } + if (!msg_timeout_ms) { + dev_err(&vdev->dev, "msg_timeout_ms value cannot be zero\n"); + return -EINVAL; + } + return 0; } @@ -305,6 +324,7 @@ static int virtsnd_probe(struct virtio_device *vdev) snd->vdev = vdev; INIT_WORK(&snd->reset_work, virtsnd_reset_fn); + INIT_LIST_HEAD(&snd->ctl_msgs); vdev->priv = snd; diff --git a/sound/virtio/virtio_card.h b/sound/virtio/virtio_card.h index 10084abaaf18..37b734a92134 100644 --- a/sound/virtio/virtio_card.h +++ b/sound/virtio/virtio_card.h @@ -23,6 +23,8 @@ #include <sound/core.h> #include <uapi/linux/virtio_snd.h> +#include "virtio_ctl_msg.h" + /** * struct virtio_snd_queue - Virtqueue wrapper structure. * @lock: Used to synchronize access to a virtqueue. @@ -39,6 +41,7 @@ struct virtio_snd_queue { * @queues: Virtqueue wrappers. * @reset_work: Reset device work. * @card: ALSA sound card. + * @ctl_msgs: Pending control request list. * @event_msgs: Device events. */ struct virtio_snd { @@ -46,9 +49,13 @@ struct virtio_snd { struct virtio_snd_queue queues[VIRTIO_SND_VQ_MAX]; struct work_struct reset_work; struct snd_card *card; + struct list_head ctl_msgs; struct virtio_snd_event *event_msgs; }; +/* Message completion timeout in milliseconds (module parameter). */ +extern int 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..c1701756bc32 --- /dev/null +++ b/sound/virtio/virtio_ctl_msg.c @@ -0,0 +1,293 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Sound card driver for virtio + * Copyright (C) 2020 OpenSynergy GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ +#include <linux/moduleparam.h> +#include <linux/virtio_config.h> + +#include "virtio_card.h" +#include "virtio_ctl_msg.h" + +/** + * virtsnd_ctl_msg_alloc_ext() - Allocate and initialize a control message. + * @vdev: VirtIO parent device. + * @request_size: Size of request header (pointed to by sg_request field). + * @response_size: Size of response header (pointed to by sg_response field). + * @sgs: Additional data to attach to the message (may be NULL). + * @out_sgs: Number of scattergather elements to attach to the request header. + * @in_sgs: Number of scattergather elements to attach to the 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, ERR_PTR(-errno) on failure. + */ +struct virtio_snd_msg *virtsnd_ctl_msg_alloc_ext(struct virtio_device *vdev, + size_t request_size, + size_t response_size, + struct scatterlist *sgs, + unsigned int out_sgs, + unsigned int in_sgs, gfp_t gfp) +{ + struct virtio_snd_msg *msg; + size_t msg_size = + sizeof(*msg) + (1 + out_sgs + 1 + in_sgs) * sizeof(*msg->sgs); + unsigned int i; + + msg = devm_kzalloc(&vdev->dev, msg_size + request_size + response_size, + gfp); + if (!msg) + return ERR_PTR(-ENOMEM); + + sg_init_one(&msg->sg_request, (u8 *)msg + msg_size, request_size); + sg_init_one(&msg->sg_response, (u8 *)msg + msg_size + request_size, + response_size); + + INIT_LIST_HEAD(&msg->list); + init_completion(&msg->notify); + atomic_set(&msg->ref_count, 1); + + msg->sgs[msg->out_sgs++] = &msg->sg_request; + if (sgs) + for (i = 0; i < out_sgs; ++i) + msg->sgs[msg->out_sgs++] = &sgs[i]; + + msg->sgs[msg->out_sgs + msg->in_sgs++] = &msg->sg_response; + if (sgs) + for (i = out_sgs; i < out_sgs + in_sgs; ++i) + msg->sgs[msg->out_sgs + msg->in_sgs++] = &sgs[i]; + + return msg; +} + +/** + * virtsnd_ctl_msg_send() - Send an (asynchronous) control message. + * @snd: VirtIO sound device. + * @msg: Control message. + * + * If a message is failed to be enqueued, it will be deleted. If message content + * is still needed, the caller must additionally to virtsnd_ctl_msg_ref/unref() + * it. + * + * Context: Any context. Takes and releases the control queue spinlock. + * Return: 0 on success, -errno on failure. + */ +int virtsnd_ctl_msg_send(struct virtio_snd *snd, struct virtio_snd_msg *msg) +{ + struct virtio_device *vdev = snd->vdev; + struct virtio_snd_queue *queue = virtsnd_control_queue(snd); + struct virtio_snd_hdr *response = sg_virt(&msg->sg_response); + bool notify = false; + unsigned long flags; + int rc = -EIO; + + /* Set the default status in case the message was not sent or was + * canceled. + */ + response->code = cpu_to_virtio32(vdev, VIRTIO_SND_S_IO_ERR); + + spin_lock_irqsave(&queue->lock, flags); + if (queue->vqueue) { + rc = virtqueue_add_sgs(queue->vqueue, msg->sgs, msg->out_sgs, + msg->in_sgs, 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) { + if (!notify || virtqueue_notify(queue->vqueue)) + return 0; + + spin_lock_irqsave(&queue->lock, flags); + list_del(&msg->list); + spin_unlock_irqrestore(&queue->lock, flags); + } + + virtsnd_ctl_msg_unref(snd->vdev, msg); + + return -EIO; +} + +/** + * virtsnd_ctl_msg_send_sync() - Send a (synchronous) control 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. Takes and releases the control queue spinlock. + * 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. + */ +int virtsnd_ctl_msg_send_sync(struct virtio_snd *snd, + struct virtio_snd_msg *msg) +{ + struct virtio_device *vdev = snd->vdev; + unsigned int js = msecs_to_jiffies(msg_timeout_ms); + struct virtio_snd_hdr *response; + int rc; + + virtsnd_ctl_msg_ref(vdev, msg); + + rc = virtsnd_ctl_msg_send(snd, msg); + if (rc) + goto on_failure; + + rc = wait_for_completion_interruptible_timeout(&msg->notify, js); + if (rc <= 0) { + if (!rc) { + struct virtio_snd_hdr *request = + sg_virt(&msg->sg_request); + + dev_err(&vdev->dev, + "control message (0x%08x) timeout\n", + le32_to_cpu(request->code)); + rc = -EIO; + } + + goto on_failure; + } + + response = sg_virt(&msg->sg_response); + + switch (le32_to_cpu(response->code)) { + case VIRTIO_SND_S_OK: + rc = 0; + break; + case VIRTIO_SND_S_BAD_MSG: + rc = -EINVAL; + break; + case VIRTIO_SND_S_NOT_SUPP: + rc = -EOPNOTSUPP; + break; + case VIRTIO_SND_S_IO_ERR: + rc = -EIO; + break; + default: + rc = -EPERM; + break; + } + +on_failure: + virtsnd_ctl_msg_unref(vdev, msg); + + return rc; +} + +/** + * virtsnd_ctl_msg_complete() - Complete a control message. + * @snd: VirtIO sound device. + * @msg: Control message. + * + * Context: Any context. + */ +void virtsnd_ctl_msg_complete(struct virtio_snd *snd, + struct virtio_snd_msg *msg) +{ + list_del(&msg->list); + complete(&msg->notify); + + virtsnd_ctl_msg_unref(snd->vdev, 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_device *vdev = snd->vdev; + struct virtio_snd_msg *msg; + struct virtio_snd_query_info *query; + struct scatterlist sg; + + sg_init_one(&sg, info, count * size); + + msg = virtsnd_ctl_msg_alloc_ext(vdev, sizeof(*query), + sizeof(struct virtio_snd_hdr), &sg, 0, + 1, GFP_KERNEL); + if (IS_ERR(msg)) + return PTR_ERR(msg); + + query = sg_virt(&msg->sg_request); + query->hdr.code = cpu_to_virtio32(vdev, command); + query->start_id = cpu_to_virtio32(vdev, start_id); + query->count = cpu_to_virtio32(vdev, count); + query->size = cpu_to_virtio32(vdev, size); + + return virtsnd_ctl_msg_send_sync(snd, msg); +} + +/** + * 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); + unsigned long flags; + + spin_lock_irqsave(&queue->lock, flags); + while (queue->vqueue) { + virtqueue_disable_cb(queue->vqueue); + + for (;;) { + struct virtio_snd_msg *msg; + u32 length; + + msg = virtqueue_get_buf(queue->vqueue, &length); + if (!msg) + break; + + virtsnd_ctl_msg_complete(snd, msg); + } + + if (unlikely(virtqueue_is_broken(queue->vqueue))) + break; + + if (virtqueue_enable_cb(queue->vqueue)) + break; + } + 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..0f8de8f2fd2d --- /dev/null +++ b/sound/virtio/virtio_ctl_msg.h @@ -0,0 +1,122 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Sound card driver for virtio + * Copyright (C) 2020 OpenSynergy GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ +#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 - Control message. + * @sg_request: Scattergather element containing a device request (header). + * @sg_response: Scattergather element containing a device response (status). + * @list: Pending message list entry. + * @notify: Request completed notification. + * @ref_count: Reference count used to manage a message lifetime. + * @out_sgs: Number of read-only sg elements in the sgs array. + * @in_sgs: Number of write-only sg elements in the sgs array. + * @sgs: Array of sg elements to add to the control virtqueue. + */ +struct virtio_snd_msg { +/* public: */ + struct scatterlist sg_request; + struct scatterlist sg_response; +/* private: internal use only */ + struct list_head list; + struct completion notify; + atomic_t ref_count; + unsigned int out_sgs; + unsigned int in_sgs; + struct scatterlist *sgs[0]; +}; + +/** + * virtsnd_ctl_msg_ref() - Increment reference counter for the message. + * @vdev: VirtIO parent device. + * @msg: Control message. + * + * Context: Any context. + */ +static inline void virtsnd_ctl_msg_ref(struct virtio_device *vdev, + struct virtio_snd_msg *msg) +{ + atomic_inc(&msg->ref_count); +} + +/** + * virtsnd_ctl_msg_unref() - Decrement reference counter for the message. + * @vdev: VirtIO parent device. + * @msg: Control message. + * + * The message will be freed when the ref_count value is 0. + * + * Context: Any context. + */ +static inline void virtsnd_ctl_msg_unref(struct virtio_device *vdev, + struct virtio_snd_msg *msg) +{ + if (!atomic_dec_return(&msg->ref_count)) + devm_kfree(&vdev->dev, msg); +} + +struct virtio_snd_msg *virtsnd_ctl_msg_alloc_ext(struct virtio_device *vdev, + size_t request_size, + size_t response_size, + struct scatterlist *sgs, + unsigned int out_sgs, + unsigned int in_sgs, + gfp_t gfp); + +/** + * virtsnd_ctl_msg_alloc() - Simplified control message allocation. + * @vdev: VirtIO parent device. + * @request_size: Size of request header (pointed to by sg_request field). + * @response_size: Size of response header (pointed to by sg_response field). + * @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, ERR_PTR(-errno) on failure. + */ +static inline +struct virtio_snd_msg *virtsnd_ctl_msg_alloc(struct virtio_device *vdev, + size_t request_size, + size_t response_size, gfp_t gfp) +{ + return virtsnd_ctl_msg_alloc_ext(vdev, request_size, response_size, + NULL, 0, 0, gfp); +} + +int virtsnd_ctl_msg_send(struct virtio_snd *snd, struct virtio_snd_msg *msg); + +int virtsnd_ctl_msg_send_sync(struct virtio_snd *snd, + struct virtio_snd_msg *msg); + +void virtsnd_ctl_msg_complete(struct virtio_snd *snd, + 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 */ -- 2.30.0
