[PATCH v11 11/40] virtio_ring: split: extract the logic of vring init

Xuan Zhuo
2022-06-29T06:57:46Z

Separate the logic of initializing vring, and subsequent patches will
call it separately.

This function completes the variable initialization of split vring. It
together with the logic of atatch constitutes the initialization of
vring.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 30 +++++++++++++++++++-----------
1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 9025bd373d3b..35540daaa1e7 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -940,6 +940,24 @@ static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq)
return NULL;
}

+static void virtqueue_vring_init_split(struct vring_virtqueue *vq)
+{
+ struct virtio_device *vdev;
+
+ vdev = vq->vq.vdev;
+
+ vq->split.avail_flags_shadow = 0;
+ vq->split.avail_idx_shadow = 0;
+
+ /* No callback? Tell other side not to bother us. */
+ if (!vq->vq.callback) {
+ vq->split.avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
+ if (!vq->event)
+ vq->split.vring.avail->flags = cpu_to_virtio16(vdev,
+ vq->split.avail_flags_shadow);
+ }
+}
+
static void virtqueue_vring_attach_split(struct vring_virtqueue *vq,
struct vring_virtqueue_split *vring)
{
@@ -2299,17 +2317,6 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
!context;

- vq->split.avail_flags_shadow = 0;
- vq->split.avail_idx_shadow = 0;
-
- /* No callback? Tell other side not to bother us. */
- if (!callback) {
- vq->split.avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
- if (!vq->event)
- vq->split.vring.avail->flags = cpu_to_virtio16(vdev,
- vq->split.avail_flags_shadow);
- }
-
vring.vring = _vring;

err = vring_alloc_state_extra_split(&vring);
@@ -2320,6 +2327,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,

virtqueue_init(vq, vring.vring.num);
virtqueue_vring_attach_split(vq, &vring);
+ virtqueue_vring_init_split(vq);

spin_lock(&vdev->vqs_list_lock);
list_add_tail(&vq->vq.list, &vdev->vqs);
--
2.31.0