[PATCH v13 14/42] virtio_ring: split: introduce virtqueue_reinit_split()

[Xuan Zhuo <xuanzhuo@linux.alibaba.com>]

Introduce a function to initialize vq without allocating new ring,
desc_state, desc_extra.

Subsequent patches will call this function after reset vq to
reinitialize vq.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 drivers/virtio/virtio_ring.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 2067818f7047..aa5dda96824e 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -967,6 +967,25 @@ static void virtqueue_vring_init_split(struct vring_virtqueue_split *vring_split
 	}
 }
 
+static void virtqueue_reinit_split(struct vring_virtqueue *vq)
+{
+	int size, i;
+
+	memset(vq->split.vring.desc, 0, vq->split.queue_size_in_bytes);
+
+	size = sizeof(struct vring_desc_state_split) * vq->split.vring.num;
+	memset(vq->split.desc_state, 0, size);
+
+	size = sizeof(struct vring_desc_extra) * vq->split.vring.num;
+	memset(vq->split.desc_extra, 0, size);
+
+	for (i = 0; i < vq->split.vring.num - 1; i++)
+		vq->split.desc_extra[i].next = i + 1;
+
+	virtqueue_init(vq, vq->split.vring.num);
+	virtqueue_vring_init_split(&vq->split, vq);
+}
+
 static void virtqueue_vring_attach_split(struct vring_virtqueue *vq,
 					 struct vring_virtqueue_split *vring_split)
 {
-- 
2.31.0