virtio_net: separate virtnet_tx_resize()

This patch separates two sub-functions from virtnet_tx_resize():

* virtnet_tx_pause
* virtnet_tx_resume

Then the subsequent virtnet_tx_reset() can share these two functions.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://patch.msgid.link/20240708112537.96291-4-xuanzhuo@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: fengidri

drivers/net/virtio_net.c

@@ -2703,12 +2703,11 @@ static int virtnet_rx_resize(struct virtnet_info *vi,
 	return err;
 }
 
-static int virtnet_tx_resize(struct virtnet_info *vi,
-			     struct send_queue *sq, u32 ring_num)
+static void virtnet_tx_pause(struct virtnet_info *vi, struct send_queue *sq)
 {
 	bool running = netif_running(vi->dev);
 	struct netdev_queue *txq;
-	int err, qindex;
+	int qindex;
 
 	qindex = sq - vi->sq;
 
@@ -2729,10 +2728,17 @@ static int virtnet_tx_resize(struct virtnet_info *vi,
 	netif_stop_subqueue(vi->dev, qindex);
 
 	__netif_tx_unlock_bh(txq);
+}
 
-	err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf);
-	if (err)
-		netdev_err(vi->dev, "resize tx fail: tx queue index: %d err: %d\n", qindex, err);
+static void virtnet_tx_resume(struct virtnet_info *vi, struct send_queue *sq)
+{
+	bool running = netif_running(vi->dev);
+	struct netdev_queue *txq;
+	int qindex;
+
+	qindex = sq - vi->sq;
+
+	txq = netdev_get_tx_queue(vi->dev, qindex);
 
 	__netif_tx_lock_bh(txq);
 	sq->reset = false;
@@ -2741,6 +2747,23 @@ static int virtnet_tx_resize(struct virtnet_info *vi,
 
 	if (running)
 		virtnet_napi_tx_enable(vi, sq->vq, &sq->napi);
+}
+
+static int virtnet_tx_resize(struct virtnet_info *vi, struct send_queue *sq,
+			     u32 ring_num)
+{
+	int qindex, err;
+
+	qindex = sq - vi->sq;
+
+	virtnet_tx_pause(vi, sq);
+
+	err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf);
+	if (err)
+		netdev_err(vi->dev, "resize tx fail: tx queue index: %d err: %d\n", qindex, err);
+
+	virtnet_tx_resume(vi, sq);
+
 	return err;
 }