Merge branch 'linus' into x86/i8259

[linux-2.6] / drivers / net / virtio_net.c

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 156d76fee1646de6f3260d176f300218734dc246..4452306d53286cbcaf9bac4e092b51e95d9cdc15 100644 (file)
--- 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 = {