[13/33] virtio_net: virtnet_poll_tx support rescheduled

Commit Message

Xuan Zhuo Feb. 2, 2023, 11 a.m. UTC

virtnet_poll_tx() support to return budget when busy to be rescheduled.

When retval < budget, napi_poll() in dev.c will exit directly. And
virtqueue_napi_complete() will be called to close napi.

When retval == budget, the napi_poll() in dev.c will re-add napi to the
queue.

The purpose of this patch is to support xsk xmit in virtio_poll_tx() for
subsequent patch.

Signed-off-by: Xuan Zhuo <[e-mail]>
---
 drivers/net/virtio_net.c | 6 ++++++
 1 file changed, 6 insertions(+)

Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 058ec6ca7cfc..eb7f00194b5c 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1848,6 +1848,7 @@  static int virtnet_poll_tx(struct napi_struct *napi, int budget)
 	struct virtnet_info *vi = sq->vq->vdev->priv;
 	unsigned int index = vq2txq(sq->vq);
 	struct netdev_queue *txq;
+	int busy = 0;
 	int opaque;
 	bool done;
 
@@ -1865,6 +1866,11 @@  static int virtnet_poll_tx(struct napi_struct *napi, int budget)
 	if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
 		netif_tx_wake_queue(txq);
 
+	if (busy) {
+		__netif_tx_unlock(txq);
+		return budget;
+	}
+
 	opaque = virtqueue_enable_cb_prepare(sq->vq);
 
 	done = napi_complete_done(napi, 0);