Re: [PATCH v12 06/40] virtio_ring: introduce virtqueue_init()

[Jason Wang <jasowang@xxxxxxxxxx>]

在 2022/7/20 11:04, Xuan Zhuo 写道:
> Separate the logic of virtqueue initialization. This logic is irrelevant
> to ring layout.
>
> This logic can be called independently when implementing resize/reset
> later.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>


Acked-by: Jason Wang <jasowang@xxxxxxxxxx>


> ---
>   drivers/virtio/virtio_ring.c | 61 ++++++++++++++++++------------------
>   1 file changed, 31 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index 1bc5794e9739..87ce17562b29 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -368,6 +368,34 @@ static int vring_mapping_error(const struct vring_virtqueue *vq,
>   	return dma_mapping_error(vring_dma_dev(vq), addr);
>   }
>   
> +static void virtqueue_init(struct vring_virtqueue *vq, u32 num)
> +{
> +	struct virtio_device *vdev;
> +
> +	vdev = vq->vq.vdev;
> +
> +	vq->vq.num_free = num;
> +	if (vq->packed_ring)
> +		vq->last_used_idx = 0 | (1 << VRING_PACKED_EVENT_F_WRAP_CTR);
> +	else
> +		vq->last_used_idx = 0;
> +	vq->event_triggered = false;
> +	vq->num_added = 0;
> +	vq->use_dma_api = vring_use_dma_api(vdev);
> +#ifdef DEBUG
> +	vq->in_use = false;
> +	vq->last_add_time_valid = false;
> +#endif
> +
> +	vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
> +
> +	if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))
> +		vq->weak_barriers = false;
> +
> +	/* Put everything in free lists. */
> +	vq->free_head = 0;
> +}
> +
>   
>   /*
>    * Split ring specific functions - *_split().
> @@ -1706,7 +1734,6 @@ static struct virtqueue *vring_create_virtqueue_packed(
>   	vq->vq.callback = callback;
>   	vq->vq.vdev = vdev;
>   	vq->vq.name = name;
> -	vq->vq.num_free = num;
>   	vq->vq.index = index;
>   	vq->we_own_ring = true;
>   	vq->notify = notify;
> @@ -1716,22 +1743,10 @@ static struct virtqueue *vring_create_virtqueue_packed(
>   #else
>   	vq->broken = false;
>   #endif
> -	vq->last_used_idx = 0 | (1 << VRING_PACKED_EVENT_F_WRAP_CTR);
> -	vq->event_triggered = false;
> -	vq->num_added = 0;
>   	vq->packed_ring = true;
> -	vq->use_dma_api = vring_use_dma_api(vdev);
> -#ifdef DEBUG
> -	vq->in_use = false;
> -	vq->last_add_time_valid = false;
> -#endif
>   
>   	vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
>   		!context;
> -	vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
> -
> -	if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))
> -		vq->weak_barriers = false;
>   
>   	vq->packed.ring_dma_addr = ring_dma_addr;
>   	vq->packed.driver_event_dma_addr = driver_event_dma_addr;
> @@ -1759,8 +1774,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
>   	memset(vq->packed.desc_state, 0,
>   		num * sizeof(struct vring_desc_state_packed));
>   
> -	/* Put everything in free lists. */
> -	vq->free_head = 0;
> +	virtqueue_init(vq, num);
>   
>   	vq->packed.desc_extra = vring_alloc_desc_extra(num);
>   	if (!vq->packed.desc_extra)
> @@ -2205,7 +2219,6 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
>   	vq->vq.callback = callback;
>   	vq->vq.vdev = vdev;
>   	vq->vq.name = name;
> -	vq->vq.num_free = vring.num;
>   	vq->vq.index = index;
>   	vq->we_own_ring = false;
>   	vq->notify = notify;
> @@ -2215,21 +2228,9 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
>   #else
>   	vq->broken = false;
>   #endif
> -	vq->last_used_idx = 0;
> -	vq->event_triggered = false;
> -	vq->num_added = 0;
> -	vq->use_dma_api = vring_use_dma_api(vdev);
> -#ifdef DEBUG
> -	vq->in_use = false;
> -	vq->last_add_time_valid = false;
> -#endif
>   
>   	vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
>   		!context;
> -	vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
> -
> -	if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))
> -		vq->weak_barriers = false;
>   
>   	vq->split.queue_dma_addr = 0;
>   	vq->split.queue_size_in_bytes = 0;
> @@ -2255,11 +2256,11 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
>   	if (!vq->split.desc_extra)
>   		goto err_extra;
>   
> -	/* Put everything in free lists. */
> -	vq->free_head = 0;
>   	memset(vq->split.desc_state, 0, vring.num *
>   			sizeof(struct vring_desc_state_split));
>   
> +	virtqueue_init(vq, vq->split.vring.num);
> +
>   	spin_lock(&vdev->vqs_list_lock);
>   	list_add_tail(&vq->vq.list, &vdev->vqs);
>   	spin_unlock(&vdev->vqs_list_lock);