[PATCH] virtio_ring: share __vring_new_virtqueue with packed ring

[PATCH] virtio_ring: share __vring_new_virtqueue with packed ring

[Liang Chen]

Packed ring allocation and initialization was explicitly done in
vring_create_virtqueue_packed, which resulted in much of the logic
implemented in __vring_new_virtqueue to be duplicated there. With some
adjustment to __vring_new_virtqueue, it can now be used for packed ring
creation as well.

Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
---
 drivers/virtio/virtio_ring.c | 83 +++++++++++-------------------------
 1 file changed, 25 insertions(+), 58 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 2e7689bb933b..991af334ac6a 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -213,7 +213,7 @@ struct vring_virtqueue {
 };
 
 static struct virtqueue *__vring_new_virtqueue(unsigned int index,
-					       struct vring_virtqueue_split *vring_split,
+					       void *vring,
 					       struct virtio_device *vdev,
 					       bool weak_barriers,
 					       bool context,
@@ -1990,57 +1990,20 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	const char *name)
 {
 	struct vring_virtqueue_packed vring_packed = {};
-	struct vring_virtqueue *vq;
-	int err;
+	struct virtqueue *vq;
 
 	if (vring_alloc_queue_packed(&vring_packed, vdev, num))
 		goto err_ring;
 
-	vq = kmalloc(sizeof(*vq), GFP_KERNEL);
-	if (!vq)
-		goto err_vq;
-
-	vq->vq.callback = callback;
-	vq->vq.vdev = vdev;
-	vq->vq.name = name;
-	vq->vq.index = index;
-	vq->vq.reset = false;
-	vq->we_own_ring = true;
-	vq->notify = notify;
-	vq->weak_barriers = weak_barriers;
-#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
-	vq->broken = true;
-#else
-	vq->broken = false;
-#endif
-	vq->packed_ring = true;
-	vq->use_dma_api = vring_use_dma_api(vdev);
-
-	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;
-
-	err = vring_alloc_state_extra_packed(&vring_packed);
-	if (err)
-		goto err_state_extra;
-
-	virtqueue_vring_init_packed(&vring_packed, !!callback);
-
-	virtqueue_init(vq, num);
-	virtqueue_vring_attach_packed(vq, &vring_packed);
+	vq = __vring_new_virtqueue(index, &vring_packed, vdev, weak_barriers,
+				   context, notify, callback, name);
+	if (!vq) {
+		vring_free_packed(&vring_packed, vdev);
+		return NULL;
+	}
 
-	spin_lock(&vdev->vqs_list_lock);
-	list_add_tail(&vq->vq.list, &vdev->vqs);
-	spin_unlock(&vdev->vqs_list_lock);
-	return &vq->vq;
+	return vq;
 
-err_state_extra:
-	kfree(vq);
-err_vq:
-	vring_free_packed(&vring_packed, vdev);
 err_ring:
 	return NULL;
 }
@@ -2473,9 +2436,8 @@ irqreturn_t vring_interrupt(int irq, void *_vq)
 }
 EXPORT_SYMBOL_GPL(vring_interrupt);
 
-/* Only available for split ring */
 static struct virtqueue *__vring_new_virtqueue(unsigned int index,
-					       struct vring_virtqueue_split *vring_split,
+					       void *vring,
 					       struct virtio_device *vdev,
 					       bool weak_barriers,
 					       bool context,
@@ -2486,20 +2448,17 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
 	struct vring_virtqueue *vq;
 	int err;
 
-	if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
-		return NULL;
-
 	vq = kmalloc(sizeof(*vq), GFP_KERNEL);
 	if (!vq)
 		return NULL;
 
-	vq->packed_ring = false;
+	vq->packed_ring = virtio_has_feature(vdev, VIRTIO_F_RING_PACKED);
 	vq->vq.callback = callback;
 	vq->vq.vdev = vdev;
 	vq->vq.name = name;
 	vq->vq.index = index;
 	vq->vq.reset = false;
-	vq->we_own_ring = false;
+	vq->we_own_ring = vq->packed_ring;
 	vq->notify = notify;
 	vq->weak_barriers = weak_barriers;
 #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
@@ -2516,16 +2475,24 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
 	if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))
 		vq->weak_barriers = false;
 
-	err = vring_alloc_state_extra_split(vring_split);
+	if (vq->packed_ring)
+		err = vring_alloc_state_extra_packed(vring);
+	else
+		err = vring_alloc_state_extra_split(vring);
 	if (err) {
 		kfree(vq);
 		return NULL;
 	}
 
-	virtqueue_vring_init_split(vring_split, vq);
-
-	virtqueue_init(vq, vring_split->vring.num);
-	virtqueue_vring_attach_split(vq, vring_split);
+	if (vq->packed_ring) {
+		virtqueue_vring_init_packed(vring, !!callback);
+		virtqueue_init(vq, ((struct vring_virtqueue_packed *)vring)->vring.num);
+		virtqueue_vring_attach_packed(vq, vring);
+	} else {
+		virtqueue_vring_init_split(vring, vq);
+		virtqueue_init(vq, ((struct vring_virtqueue_split *)vring)->vring.num);
+		virtqueue_vring_attach_split(vq, vring);
+	}
 
 	spin_lock(&vdev->vqs_list_lock);
 	list_add_tail(&vq->vq.list, &vdev->vqs);
-- 
2.32.0