[PATCH v14 20/42] virtio_ring: packed: extract the logic of vring init

[Xuan Zhuo]

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

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

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
Acked-by: Jason Wang <jasowang at redhat.com>
---
 drivers/virtio/virtio_ring.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 533af061d009..a6f90e6e621b 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1932,6 +1932,22 @@ static int vring_alloc_state_extra_packed(struct vring_virtqueue_packed *vring_p
 	return -ENOMEM;
 }
 
+static void virtqueue_vring_init_packed(struct vring_virtqueue_packed *vring_packed,
+					bool callback)
+{
+	vring_packed->next_avail_idx = 0;
+	vring_packed->avail_wrap_counter = 1;
+	vring_packed->event_flags_shadow = 0;
+	vring_packed->avail_used_flags = 1 << VRING_PACKED_DESC_F_AVAIL;
+
+	/* No callback?  Tell other side not to bother us. */
+	if (!callback) {
+		vring_packed->event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE;
+		vring_packed->vring.driver->flags =
+			cpu_to_le16(vring_packed->event_flags_shadow);
+	}
+}
+
 static struct virtqueue *vring_create_virtqueue_packed(
 	unsigned int index,
 	unsigned int num,
@@ -1986,11 +2002,6 @@ static struct virtqueue *vring_create_virtqueue_packed(
 
 	vq->packed.vring = vring_packed.vring;
 
-	vq->packed.next_avail_idx = 0;
-	vq->packed.avail_wrap_counter = 1;
-	vq->packed.event_flags_shadow = 0;
-	vq->packed.avail_used_flags = 1 << VRING_PACKED_DESC_F_AVAIL;
-
 	err = vring_alloc_state_extra_packed(&vring_packed);
 	if (err)
 		goto err_state_extra;
@@ -2001,12 +2012,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	vq->packed.desc_state = vring_packed.desc_state;
 	vq->packed.desc_extra = vring_packed.desc_extra;
 
-	/* No callback?  Tell other side not to bother us. */
-	if (!callback) {
-		vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE;
-		vq->packed.vring.driver->flags =
-			cpu_to_le16(vq->packed.event_flags_shadow);
-	}
+	virtqueue_vring_init_packed(&vring_packed, !!callback);
 
 	virtqueue_init(vq, num);
 
-- 
2.31.0