diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 156d76fee164..4452306d5328 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -44,6 +44,7 @@ struct virtnet_info /* The skb we couldn't send because buffers were full. */ struct sk_buff *last_xmit_skb; + /* If we need to free in a timer, this is it. */ struct timer_list xmit_free_timer; /* Number of input buffers, and max we've ever had. */ @@ -51,6 +52,7 @@ struct virtnet_info /* For cleaning up after transmission. */ struct tasklet_struct tasklet; + bool free_in_tasklet; /* Receive & send queues. */ struct sk_buff_head recv; @@ -74,7 +76,7 @@ static void skb_xmit_done(struct virtqueue *svq) /* Suppress further interrupts. */ svq->vq_ops->disable_cb(svq); - /* We were waiting for more output buffers. */ + /* We were probably waiting for more output buffers. */ netif_wake_queue(vi->dev); /* Make sure we re-xmit last_xmit_skb: if there are no more packets @@ -242,6 +244,8 @@ static void free_old_xmit_skbs(struct virtnet_info *vi) } } +/* If the virtio transport doesn't always notify us when all in-flight packets + * are consumed, we fall back to using this function on a timer to free them. */ static void xmit_free(unsigned long data) { struct virtnet_info *vi = (void *)data; @@ -302,7 +306,7 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1; err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb); - if (!err) + if (!err && !vi->free_in_tasklet) mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10)); return err; @@ -317,6 +321,8 @@ static void xmit_tasklet(unsigned long data) vi->svq->vq_ops->kick(vi->svq); vi->last_xmit_skb = NULL; } + if (vi->free_in_tasklet) + free_old_xmit_skbs(vi); netif_tx_unlock_bh(vi->dev); } @@ -457,6 +463,10 @@ static int virtnet_probe(struct virtio_device *vdev) vi->vdev = vdev; vdev->priv = vi; + /* If they give us a callback when all buffers are done, we don't need + * the timer. */ + vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY); + /* We expect two virtqueues, receive then send. */ vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done); if (IS_ERR(vi->rvq)) { @@ -476,7 +486,8 @@ static int virtnet_probe(struct virtio_device *vdev) tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi); - setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi); + if (!vi->free_in_tasklet) + setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi); err = register_netdev(dev); if (err) { @@ -515,7 +526,8 @@ static void virtnet_remove(struct virtio_device *vdev) /* Stop all the virtqueues. */ vdev->config->reset(vdev); - del_timer_sync(&vi->xmit_free_timer); + if (!vi->free_in_tasklet) + del_timer_sync(&vi->xmit_free_timer); /* Free our skbs in send and recv queues, if any. */ while ((skb = __skb_dequeue(&vi->recv)) != NULL) { @@ -540,7 +552,7 @@ static struct virtio_device_id id_table[] = { static unsigned int features[] = { VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, - VIRTIO_NET_F_HOST_ECN, + VIRTIO_NET_F_HOST_ECN, VIRTIO_F_NOTIFY_ON_EMPTY, }; static struct virtio_driver virtio_net = {