[PATCH net-next RFC 1/2] virtio-net: factor out logic for stopping TX

[Jason Wang <jasowang@redhat.com>]

This patch factors out the logic of checking and stopping TX into a
dedicated helper. This will be used by following patch.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/net/virtio_net.c | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 7646ddd9bef7..2f6c3dc68ba0 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1088,11 +1088,10 @@ static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
 		return false;
 }
 
-static void check_sq_full_and_disable(struct virtnet_info *vi,
-				      struct net_device *dev,
-				      struct send_queue *sq)
+static bool tx_may_stop(struct virtnet_info *vi,
+			struct net_device *dev,
+			struct send_queue *sq)
 {
-	bool use_napi = sq->napi.weight;
 	int qnum;
 
 	qnum = sq - vi->sq;
@@ -1114,6 +1113,25 @@ static void check_sq_full_and_disable(struct virtnet_info *vi,
 		u64_stats_update_begin(&sq->stats.syncp);
 		u64_stats_inc(&sq->stats.stop);
 		u64_stats_update_end(&sq->stats.syncp);
+
+		return true;
+	}
+
+	return false;
+}
+
+static void check_sq_full_and_disable(struct virtnet_info *vi,
+				      struct net_device *dev,
+				      struct send_queue *sq)
+{
+	bool use_napi = sq->napi.weight;
+	int qnum;
+
+	qnum = sq - vi->sq;
+
+	if (tx_may_stop(vi, dev, sq)) {
+		struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
+
 		if (use_napi) {
 			if (unlikely(!virtqueue_enable_cb_delayed(sq->vq)))
 				virtqueue_napi_schedule(&sq->napi, sq->vq);
-- 
2.34.1