[PATCH v9 07/32] virtio_ring: split: extract the logic of alloc state and extra

[Xuan Zhuo <xuanzhuo@linux.alibaba.com>]

Separate the logic of creating desc_state, desc_extra, and subsequent
patches will call it independently.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 53 ++++++++++++++++++++++++++----------
 1 file changed, 38 insertions(+), 15 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 72d5ae063fa0..6de67439cb57 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -198,6 +198,7 @@ struct vring_virtqueue {
 #endif
 };
 
+static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num);
 
 /*
  * Helpers.
@@ -915,6 +916,33 @@ static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq)
 	return NULL;
 }
 
+static int vring_alloc_state_extra_split(u32 num,
+					 struct vring_desc_state_split **desc_state,
+					 struct vring_desc_extra **desc_extra)
+{
+	struct vring_desc_state_split *state;
+	struct vring_desc_extra *extra;
+
+	state = kmalloc_array(num, sizeof(struct vring_desc_state_split), GFP_KERNEL);
+	if (!state)
+		goto err_state;
+
+	extra = vring_alloc_desc_extra(num);
+	if (!extra)
+		goto err_extra;
+
+	memset(state, 0, num * sizeof(struct vring_desc_state_split));
+
+	*desc_state = state;
+	*desc_extra = extra;
+	return 0;
+
+err_extra:
+	kfree(state);
+err_state:
+	return -ENOMEM;
+}
+
 static void *vring_alloc_queue_split(struct virtio_device *vdev,
 				     dma_addr_t *dma_addr,
 				     u32 *n,
@@ -2196,7 +2224,10 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
 					void (*callback)(struct virtqueue *),
 					const char *name)
 {
+	struct vring_desc_state_split *state;
+	struct vring_desc_extra *extra;
 	struct vring_virtqueue *vq;
+	int err;
 
 	if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
 		return NULL;
@@ -2246,30 +2277,22 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
 					vq->split.avail_flags_shadow);
 	}
 
-	vq->split.desc_state = kmalloc_array(vring.num,
-			sizeof(struct vring_desc_state_split), GFP_KERNEL);
-	if (!vq->split.desc_state)
-		goto err_state;
+	err = vring_alloc_state_extra_split(vring.num, &state, &extra);
+	if (err) {
+		kfree(vq);
+		return NULL;
+	}
 
-	vq->split.desc_extra = vring_alloc_desc_extra(vring.num);
-	if (!vq->split.desc_extra)
-		goto err_extra;
+	vq->split.desc_state = state;
+	vq->split.desc_extra = extra;
 
 	/* Put everything in free lists. */
 	vq->free_head = 0;
-	memset(vq->split.desc_state, 0, vring.num *
-			sizeof(struct vring_desc_state_split));
 
 	spin_lock(&vdev->vqs_list_lock);
 	list_add_tail(&vq->vq.list, &vdev->vqs);
 	spin_unlock(&vdev->vqs_list_lock);
 	return &vq->vq;
-
-err_extra:
-	kfree(vq->split.desc_state);
-err_state:
-	kfree(vq);
-	return NULL;
 }
 EXPORT_SYMBOL_GPL(__vring_new_virtqueue);
 
-- 
2.31.0