virtio_ring: packed: extract the logic of alloc queue

Separate the logic of packed to create vring queue.

This feature is required for subsequent virtuqueue reset vring.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-19-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/virtio/virtio_ring.c

@@ -1854,19 +1854,10 @@ static void vring_free_packed(struct vring_virtqueue_packed *vring_packed,
 	kfree(vring_packed->desc_extra);
 }
 
-static struct virtqueue *vring_create_virtqueue_packed(
-	unsigned int index,
-	unsigned int num,
-	unsigned int vring_align,
-	struct virtio_device *vdev,
-	bool weak_barriers,
-	bool may_reduce_num,
-	bool context,
-	bool (*notify)(struct virtqueue *),
-	void (*callback)(struct virtqueue *),
-	const char *name)
+static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed,
+				    struct virtio_device *vdev,
+				    u32 num)
 {
-	struct vring_virtqueue *vq;
 	struct vring_packed_desc *ring;
 	struct vring_packed_desc_event *driver, *device;
 	dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr;
@@ -1878,21 +1869,59 @@ static struct virtqueue *vring_create_virtqueue_packed(
 				 &ring_dma_addr,
 				 GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
 	if (!ring)
-		goto err_ring;
+		goto err;
+
+	vring_packed->vring.desc         = ring;
+	vring_packed->ring_dma_addr      = ring_dma_addr;
+	vring_packed->ring_size_in_bytes = ring_size_in_bytes;
 
 	event_size_in_bytes = sizeof(struct vring_packed_desc_event);
 
 	driver = vring_alloc_queue(vdev, event_size_in_bytes,
 				   &driver_event_dma_addr,
 				   GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
 	if (!driver)
-		goto err_driver;
+		goto err;
+
+	vring_packed->vring.driver          = driver;
+	vring_packed->event_size_in_bytes   = event_size_in_bytes;
+	vring_packed->driver_event_dma_addr = driver_event_dma_addr;
 
 	device = vring_alloc_queue(vdev, event_size_in_bytes,
 				   &device_event_dma_addr,
 				   GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
 	if (!device)
-		goto err_device;
+		goto err;
+
+	vring_packed->vring.device          = device;
+	vring_packed->device_event_dma_addr = device_event_dma_addr;
+
+	vring_packed->vring.num = num;
+
+	return 0;
+
+err:
+	vring_free_packed(vring_packed, vdev);
+	return -ENOMEM;
+}
+
+static struct virtqueue *vring_create_virtqueue_packed(
+	unsigned int index,
+	unsigned int num,
+	unsigned int vring_align,
+	struct virtio_device *vdev,
+	bool weak_barriers,
+	bool may_reduce_num,
+	bool context,
+	bool (*notify)(struct virtqueue *),
+	void (*callback)(struct virtqueue *),
+	const char *name)
+{
+	struct vring_virtqueue_packed vring_packed = {};
+	struct vring_virtqueue *vq;
+
+	if (vring_alloc_queue_packed(&vring_packed, vdev, num))
+		goto err_ring;
 
 	vq = kmalloc(sizeof(*vq), GFP_KERNEL);
 	if (!vq)
@@ -1920,17 +1949,14 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))
 		vq->weak_barriers = false;
 
-	vq->packed.ring_dma_addr = ring_dma_addr;
-	vq->packed.driver_event_dma_addr = driver_event_dma_addr;
-	vq->packed.device_event_dma_addr = device_event_dma_addr;
+	vq->packed.ring_dma_addr = vring_packed.ring_dma_addr;
+	vq->packed.driver_event_dma_addr = vring_packed.driver_event_dma_addr;
+	vq->packed.device_event_dma_addr = vring_packed.device_event_dma_addr;
 
-	vq->packed.ring_size_in_bytes = ring_size_in_bytes;
-	vq->packed.event_size_in_bytes = event_size_in_bytes;
+	vq->packed.ring_size_in_bytes = vring_packed.ring_size_in_bytes;
+	vq->packed.event_size_in_bytes = vring_packed.event_size_in_bytes;
 
-	vq->packed.vring.num = num;
-	vq->packed.vring.desc = ring;
-	vq->packed.vring.driver = driver;
-	vq->packed.vring.device = device;
+	vq->packed.vring = vring_packed.vring;
 
 	vq->packed.next_avail_idx = 0;
 	vq->packed.avail_wrap_counter = 1;
@@ -1972,11 +1998,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
 err_desc_state:
 	kfree(vq);
 err_vq:
-	vring_free_queue(vdev, event_size_in_bytes, device, device_event_dma_addr);
-err_device:
-	vring_free_queue(vdev, event_size_in_bytes, driver, driver_event_dma_addr);
-err_driver:
-	vring_free_queue(vdev, ring_size_in_bytes, ring, ring_dma_addr);
+	vring_free_packed(&vring_packed, vdev);
 err_ring:
 	return NULL;
 }