在 2022/3/8 下午8:34, Xuan Zhuo 写道:
Separate the logic of split to create vring queue. For the convenience of passing parameters, add a structure vring_split. This feature is required for subsequent virtuqueue reset vring. Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> --- drivers/virtio/virtio_ring.c | 74 +++++++++++++++++++++++++----------- 1 file changed, 51 insertions(+), 23 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index b87130c8f312..d32793615451 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -85,6 +85,13 @@ struct vring_desc_extra { u16 next; /* The next desc state in a list. */ };+struct vring_split {+ void *queue; + dma_addr_t dma_addr; + size_t queue_size_in_bytes; + struct vring vring; +};
So this structure will be only used in vring_create_vring_split() which seems not that useful.
More see below.
+ struct vring_virtqueue { struct virtqueue vq;@@ -915,28 +922,21 @@ static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq)return NULL; }-static struct virtqueue *vring_create_virtqueue_split(- unsigned int index, - unsigned int num, - unsigned int vring_align, - struct virtio_device *vdev, - bool weak_barriers, - bool may_reduce_num, - bool context, - bool (*notify)(struct virtqueue *), - void (*callback)(struct virtqueue *), - const char *name) +static int vring_create_vring_split(struct vring_split *vring, + struct virtio_device *vdev, + unsigned int vring_align, + bool weak_barriers, + bool may_reduce_num, + u32 num)
I'd rename this as vring_alloc_queue_split() and let it simply return the address of queue like vring_alloc_queue().
And let it simple accept dma_addr_t *dma_adder instead of vring_split.
{ - struct virtqueue *vq; void *queue = NULL; dma_addr_t dma_addr; size_t queue_size_in_bytes; - struct vring vring;/* We assume num is a power of 2. */if (num & (num - 1)) { dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num); - return NULL; + return -EINVAL; }/* TODO: allocate each queue chunk individually */@@ -947,11 +947,11 @@ static struct virtqueue *vring_create_virtqueue_split( if (queue) break; if (!may_reduce_num) - return NULL; + return -ENOMEM; }if (!num)- return NULL; + return -ENOMEM;if (!queue) {/* Try to get a single page. You are my only hope! */ @@ -959,21 +959,49 @@ static struct virtqueue *vring_create_virtqueue_split( &dma_addr, GFP_KERNEL|__GFP_ZERO); } if (!queue) - return NULL; + return -ENOMEM;queue_size_in_bytes = vring_size(num, vring_align);- vring_init(&vring, num, queue, vring_align); + vring_init(&vring->vring, num, queue, vring_align);
It's better to move this to its caller (vring_create_virtqueue_split), so we have rather simple logic below:
+
+ vring->dma_addr = dma_addr;
+ vring->queue = queue;
+ vring->queue_size_in_bytes = queue_size_in_bytes;
+
+ return 0;
+}
+
+static struct virtqueue *vring_create_virtqueue_split(
+ unsigned int index,
+ unsigned int num,
+ unsigned int vring_align,
+ struct virtio_device *vdev,
+ bool weak_barriers,
+ bool may_reduce_num,
+ bool context,
+ bool (*notify)(struct virtqueue *),
+ void (*callback)(struct virtqueue *),
+ const char *name)
+{
+ struct vring_split vring;
+ struct virtqueue *vq;
+ int err;
+
+ err = vring_create_vring_split(&vring, vdev, vring_align, weak_barriers,
+ may_reduce_num, num);
+ if (err)
+ return NULL;
queue = vring_alloc_queue_split(vdev, &dma_addr, ...); if (!queue) return -ENOMEM; vring_init(); ... Thanks
- vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,+ vq = __vring_new_virtqueue(index, vring.vring, vdev, weak_barriers, context, notify, callback, name); if (!vq) { - vring_free_queue(vdev, queue_size_in_bytes, queue, - dma_addr); + vring_free_queue(vdev, vring.queue_size_in_bytes, vring.queue, + vring.dma_addr); return NULL; }- to_vvq(vq)->split.queue_dma_addr = dma_addr;- to_vvq(vq)->split.queue_size_in_bytes = queue_size_in_bytes; + to_vvq(vq)->split.queue_dma_addr = vring.dma_addr; + to_vvq(vq)->split.queue_size_in_bytes = vring.queue_size_in_bytes; to_vvq(vq)->we_own_ring = true;return vq;
