[PATCH v9 15/32] virtio_ring: packed: extract the logic of vq init

[Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>]

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

The characteristic of this part of the logic is that it does not depend
on the information passed by the upper layer, and can be called
repeatedly.

Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
 drivers/virtio/virtio_ring.c | 71 ++++++++++++++++++++----------------
 1 file changed, 39 insertions(+), 32 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 80d446fa8d16..c783eb272468 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1933,6 +1933,44 @@ static void vring_virtqueue_attach_packed(struct vring_virtqueue *vq,
 	vq->packed.desc_extra = extra;
 }
 
+static void vring_virtqueue_init_packed(struct vring_virtqueue *vq,
+					struct virtio_device *vdev)
+{
+	vq->vq.num_free = vq->packed.vring.num;
+	vq->we_own_ring = true;
+	vq->broken = false;
+	vq->last_used_idx = 0;
+	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->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.next_avail_idx = 0;
+	vq->packed.avail_wrap_counter = 1;
+	vq->packed.used_wrap_counter = 1;
+	vq->packed.event_flags_shadow = 0;
+	vq->packed.avail_used_flags = 1 << VRING_PACKED_DESC_F_AVAIL;
+
+	/* Put everything in free lists. */
+	vq->free_head = 0;
+
+	/* No callback?  Tell other side not to bother us. */
+	if (!vq->vq.callback) {
+		vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE;
+		vq->packed.vring.driver->flags =
+			cpu_to_le16(vq->packed.event_flags_shadow);
+	}
+}
+
 static struct virtqueue *vring_create_virtqueue_packed(
 	unsigned int index,
 	unsigned int num,
@@ -1968,34 +2006,12 @@ 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;
 	vq->weak_barriers = weak_barriers;
-	vq->broken = false;
-	vq->last_used_idx = 0;
-	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.next_avail_idx = 0;
-	vq->packed.avail_wrap_counter = 1;
-	vq->packed.used_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(num, &state, &extra);
 	if (err)
@@ -2005,16 +2021,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
 				      ring_dma_addr, driver_event_dma_addr,
 				      device_event_dma_addr, ring_size_in_bytes,
 				      event_size_in_bytes, state, extra);
-
-	/* Put everything in free lists. */
-	vq->free_head = 0;
-
-	/* 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);
-	}
+	vring_virtqueue_init_packed(vq, vdev);
 
 	spin_lock(&vdev->vqs_list_lock);
 	list_add_tail(&vq->vq.list, &vdev->vqs);
-- 
2.31.0