[PATCH 12/14] virtio_net: unify the code for recycling the xmit ptr

[Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>]

There are two completely similar and independent implementations. This
is inconvenient for the subsequent addition of new types. So extract a
function from this piece of code and call this function uniformly to
recover old xmit ptr.

Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
---
 drivers/net/virtio_net.c | 66 +++++++++++++++++-----------------------
 1 file changed, 28 insertions(+), 38 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 660459b4c3e3..b56f8617700f 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -348,6 +348,30 @@ static struct xdp_frame *ptr_to_xdp(void *ptr)
 	return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
 }
 
+static void __free_old_xmit(struct send_queue *sq, bool in_napi,
+			    u64 *bytes, u64 *packets)
+{
+	unsigned int len;
+	void *ptr;
+
+	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
+		if (!is_xdp_frame(ptr)) {
+			struct sk_buff *skb = ptr;
+
+			pr_debug("Sent skb %p\n", skb);
+
+			*bytes += skb->len;
+			napi_consume_skb(skb, in_napi);
+		} else {
+			struct xdp_frame *frame = ptr_to_xdp(ptr);
+
+			*bytes += xdp_get_frame_len(frame);
+			xdp_return_frame(frame);
+		}
+		(*packets)++;
+	}
+}
+
 /* Converting between virtqueue no. and kernel tx/rx queue no.
  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
  */
@@ -740,27 +764,9 @@ static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)
 
 static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi)
 {
-	unsigned int len;
-	unsigned int packets = 0;
-	unsigned int bytes = 0;
-	void *ptr;
-
-	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
-		if (likely(!is_xdp_frame(ptr))) {
-			struct sk_buff *skb = ptr;
-
-			pr_debug("Sent skb %p\n", skb);
+	u64 bytes = 0, packets = 0;
 
-			bytes += skb->len;
-			napi_consume_skb(skb, in_napi);
-		} else {
-			struct xdp_frame *frame = ptr_to_xdp(ptr);
-
-			bytes += xdp_get_frame_len(frame);
-			xdp_return_frame(frame);
-		}
-		packets++;
-	}
+	__free_old_xmit(sq, in_napi, &bytes, &packets);
 
 	/* Avoid overhead when no packets have been processed
 	 * happens when called speculatively from start_xmit.
@@ -910,14 +916,11 @@ static int virtnet_xdp_xmit(struct net_device *dev,
 {
 	struct virtnet_info *vi = netdev_priv(dev);
 	struct receive_queue *rq = vi->rq;
+	u64 bytes = 0, packets = 0;
 	struct bpf_prog *xdp_prog;
 	struct send_queue *sq;
-	unsigned int len;
-	int packets = 0;
-	int bytes = 0;
 	int nxmit = 0;
 	int kicks = 0;
-	void *ptr;
 	int ret;
 	int i;
 
@@ -936,20 +939,7 @@ static int virtnet_xdp_xmit(struct net_device *dev,
 	}
 
 	/* Free up any pending old buffers before queueing new ones. */
-	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
-		if (likely(is_xdp_frame(ptr))) {
-			struct xdp_frame *frame = ptr_to_xdp(ptr);
-
-			bytes += xdp_get_frame_len(frame);
-			xdp_return_frame(frame);
-		} else {
-			struct sk_buff *skb = ptr;
-
-			bytes += skb->len;
-			napi_consume_skb(skb, false);
-		}
-		packets++;
-	}
+	__free_old_xmit(sq, false, &bytes, &packets);
 
 	for (i = 0; i < n; i++) {
 		struct xdp_frame *xdpf = frames[i];
-- 
2.32.0.3.g01195cf9f