[PATCH v9 12/32] virtio_ring: packed: extract the logic of alloc queue

[Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>]

Separate the logic of packed to create vring queue.

For the convenience of passing parameters, add a structure
vring_packed.

This feature is required for subsequent virtuqueue reset vring.

Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
 drivers/virtio/virtio_ring.c | 70 ++++++++++++++++++++++++++++--------
 1 file changed, 56 insertions(+), 14 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 33864134a744..ea451ae2aaef 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1817,19 +1817,17 @@ static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num)
 	return 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 virtio_device *vdev,
+				    u32 num,
+				    struct vring_packed_desc **_ring,
+				    struct vring_packed_desc_event **_driver,
+				    struct vring_packed_desc_event **_device,
+				    dma_addr_t *_ring_dma_addr,
+				    dma_addr_t *_driver_event_dma_addr,
+				    dma_addr_t *_device_event_dma_addr,
+				    size_t *_ring_size_in_bytes,
+				    size_t *_event_size_in_bytes)
 {
-	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;
@@ -1857,6 +1855,52 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	if (!device)
 		goto err_device;
 
+	*_ring                   = ring;
+	*_driver                 = driver;
+	*_device                 = device;
+	*_ring_dma_addr          = ring_dma_addr;
+	*_driver_event_dma_addr  = driver_event_dma_addr;
+	*_device_event_dma_addr  = device_event_dma_addr;
+	*_ring_size_in_bytes     = ring_size_in_bytes;
+	*_event_size_in_bytes    = event_size_in_bytes;
+
+	return 0;
+
+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);
+
+err_ring:
+	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)
+{
+	dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr;
+	struct vring_packed_desc_event *driver, *device;
+	size_t ring_size_in_bytes, event_size_in_bytes;
+	struct vring_packed_desc *ring;
+	struct vring_virtqueue *vq;
+
+	if (vring_alloc_queue_packed(vdev, num, &ring, &driver, &device,
+				     &ring_dma_addr, &driver_event_dma_addr,
+				     &device_event_dma_addr,
+				     &ring_size_in_bytes,
+				     &event_size_in_bytes))
+		goto err_ring;
+
 	vq = kmalloc(sizeof(*vq), GFP_KERNEL);
 	if (!vq)
 		goto err_vq;
@@ -1939,9 +1983,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	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);
 err_ring:
 	return NULL;
-- 
2.31.0