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path: root/drivers/net/virtio_net.c
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Diffstat (limited to 'drivers/net/virtio_net.c')
-rw-r--r--drivers/net/virtio_net.c91
1 files changed, 77 insertions, 14 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index f926b5a..4452306 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -44,9 +44,16 @@ 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. */
unsigned int num, max;
+ /* For cleaning up after transmission. */
+ struct tasklet_struct tasklet;
+ bool free_in_tasklet;
+
/* Receive & send queues. */
struct sk_buff_head recv;
struct sk_buff_head send;
@@ -68,8 +75,13 @@ 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
+ * queued, start_xmit won't be called. */
+ tasklet_schedule(&vi->tasklet);
}
static void receive_skb(struct net_device *dev, struct sk_buff *skb,
@@ -86,9 +98,7 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb,
BUG_ON(len > MAX_PACKET_LEN);
skb_trim(skb, len);
- skb->protocol = eth_type_trans(skb, dev);
- pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
- ntohs(skb->protocol), skb->len, skb->pkt_type);
+
dev->stats.rx_bytes += skb->len;
dev->stats.rx_packets++;
@@ -98,6 +108,10 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb,
goto frame_err;
}
+ skb->protocol = eth_type_trans(skb, dev);
+ pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
+ ntohs(skb->protocol), skb->len, skb->pkt_type);
+
if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
pr_debug("GSO!\n");
switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
@@ -230,9 +244,25 @@ 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;
+
+ netif_tx_lock(vi->dev);
+
+ free_old_xmit_skbs(vi);
+
+ if (!skb_queue_empty(&vi->send))
+ mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
+
+ netif_tx_unlock(vi->dev);
+}
+
static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
{
- int num;
+ int num, err;
struct scatterlist sg[2+MAX_SKB_FRAGS];
struct virtio_net_hdr *hdr;
const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
@@ -275,7 +305,25 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
vnet_hdr_to_sg(sg, skb);
num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
- return vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
+ err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
+ if (!err && !vi->free_in_tasklet)
+ mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
+
+ return err;
+}
+
+static void xmit_tasklet(unsigned long data)
+{
+ struct virtnet_info *vi = (void *)data;
+
+ netif_tx_lock_bh(vi->dev);
+ if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) {
+ 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);
}
static int start_xmit(struct sk_buff *skb, struct net_device *dev)
@@ -287,21 +335,25 @@ again:
free_old_xmit_skbs(vi);
/* If we has a buffer left over from last time, send it now. */
- if (vi->last_xmit_skb) {
+ if (unlikely(vi->last_xmit_skb)) {
if (xmit_skb(vi, vi->last_xmit_skb) != 0) {
/* Drop this skb: we only queue one. */
vi->dev->stats.tx_dropped++;
kfree_skb(skb);
+ skb = NULL;
goto stop_queue;
}
vi->last_xmit_skb = NULL;
}
/* Put new one in send queue and do transmit */
- __skb_queue_head(&vi->send, skb);
- if (xmit_skb(vi, skb) != 0) {
- vi->last_xmit_skb = skb;
- goto stop_queue;
+ if (likely(skb)) {
+ __skb_queue_head(&vi->send, skb);
+ if (xmit_skb(vi, skb) != 0) {
+ vi->last_xmit_skb = skb;
+ skb = NULL;
+ goto stop_queue;
+ }
}
done:
vi->svq->vq_ops->kick(vi->svq);
@@ -411,6 +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)) {
@@ -428,6 +484,11 @@ static int virtnet_probe(struct virtio_device *vdev)
skb_queue_head_init(&vi->recv);
skb_queue_head_init(&vi->send);
+ tasklet_init(&vi->tasklet, xmit_tasklet, (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) {
pr_debug("virtio_net: registering device failed\n");
@@ -465,13 +526,15 @@ static void virtnet_remove(struct virtio_device *vdev)
/* Stop all the virtqueues. */
vdev->config->reset(vdev);
+ 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) {
kfree_skb(skb);
vi->num--;
}
- while ((skb = __skb_dequeue(&vi->send)) != NULL)
- kfree_skb(skb);
+ __skb_queue_purge(&vi->send);
BUG_ON(vi->num != 0);
@@ -489,7 +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 = {