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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 f926b5ab3d09..4452306d5328 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -44,9 +44,16 @@ struct virtnet_info
44 /* The skb we couldn't send because buffers were full. */ 44 /* The skb we couldn't send because buffers were full. */
45 struct sk_buff *last_xmit_skb; 45 struct sk_buff *last_xmit_skb;
46 46
47 /* If we need to free in a timer, this is it. */
48 struct timer_list xmit_free_timer;
49
47 /* Number of input buffers, and max we've ever had. */ 50 /* Number of input buffers, and max we've ever had. */
48 unsigned int num, max; 51 unsigned int num, max;
49 52
53 /* For cleaning up after transmission. */
54 struct tasklet_struct tasklet;
55 bool free_in_tasklet;
56
50 /* Receive & send queues. */ 57 /* Receive & send queues. */
51 struct sk_buff_head recv; 58 struct sk_buff_head recv;
52 struct sk_buff_head send; 59 struct sk_buff_head send;
@@ -68,8 +75,13 @@ static void skb_xmit_done(struct virtqueue *svq)
68 75
69 /* Suppress further interrupts. */ 76 /* Suppress further interrupts. */
70 svq->vq_ops->disable_cb(svq); 77 svq->vq_ops->disable_cb(svq);
71 /* We were waiting for more output buffers. */ 78
79 /* We were probably waiting for more output buffers. */
72 netif_wake_queue(vi->dev); 80 netif_wake_queue(vi->dev);
81
82 /* Make sure we re-xmit last_xmit_skb: if there are no more packets
83 * queued, start_xmit won't be called. */
84 tasklet_schedule(&vi->tasklet);
73} 85}
74 86
75static void receive_skb(struct net_device *dev, struct sk_buff *skb, 87static 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,
86 BUG_ON(len > MAX_PACKET_LEN); 98 BUG_ON(len > MAX_PACKET_LEN);
87 99
88 skb_trim(skb, len); 100 skb_trim(skb, len);
89 skb->protocol = eth_type_trans(skb, dev); 101
90 pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
91 ntohs(skb->protocol), skb->len, skb->pkt_type);
92 dev->stats.rx_bytes += skb->len; 102 dev->stats.rx_bytes += skb->len;
93 dev->stats.rx_packets++; 103 dev->stats.rx_packets++;
94 104
@@ -98,6 +108,10 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb,
98 goto frame_err; 108 goto frame_err;
99 } 109 }
100 110
111 skb->protocol = eth_type_trans(skb, dev);
112 pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
113 ntohs(skb->protocol), skb->len, skb->pkt_type);
114
101 if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { 115 if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
102 pr_debug("GSO!\n"); 116 pr_debug("GSO!\n");
103 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 117 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
@@ -230,9 +244,25 @@ static void free_old_xmit_skbs(struct virtnet_info *vi)
230 } 244 }
231} 245}
232 246
247/* If the virtio transport doesn't always notify us when all in-flight packets
248 * are consumed, we fall back to using this function on a timer to free them. */
249static void xmit_free(unsigned long data)
250{
251 struct virtnet_info *vi = (void *)data;
252
253 netif_tx_lock(vi->dev);
254
255 free_old_xmit_skbs(vi);
256
257 if (!skb_queue_empty(&vi->send))
258 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
259
260 netif_tx_unlock(vi->dev);
261}
262
233static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) 263static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
234{ 264{
235 int num; 265 int num, err;
236 struct scatterlist sg[2+MAX_SKB_FRAGS]; 266 struct scatterlist sg[2+MAX_SKB_FRAGS];
237 struct virtio_net_hdr *hdr; 267 struct virtio_net_hdr *hdr;
238 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 268 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)
275 vnet_hdr_to_sg(sg, skb); 305 vnet_hdr_to_sg(sg, skb);
276 num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1; 306 num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
277 307
278 return vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb); 308 err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
309 if (!err && !vi->free_in_tasklet)
310 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
311
312 return err;
313}
314
315static void xmit_tasklet(unsigned long data)
316{
317 struct virtnet_info *vi = (void *)data;
318
319 netif_tx_lock_bh(vi->dev);
320 if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) {
321 vi->svq->vq_ops->kick(vi->svq);
322 vi->last_xmit_skb = NULL;
323 }
324 if (vi->free_in_tasklet)
325 free_old_xmit_skbs(vi);
326 netif_tx_unlock_bh(vi->dev);
279} 327}
280 328
281static int start_xmit(struct sk_buff *skb, struct net_device *dev) 329static int start_xmit(struct sk_buff *skb, struct net_device *dev)
@@ -287,21 +335,25 @@ again:
287 free_old_xmit_skbs(vi); 335 free_old_xmit_skbs(vi);
288 336
289 /* If we has a buffer left over from last time, send it now. */ 337 /* If we has a buffer left over from last time, send it now. */
290 if (vi->last_xmit_skb) { 338 if (unlikely(vi->last_xmit_skb)) {
291 if (xmit_skb(vi, vi->last_xmit_skb) != 0) { 339 if (xmit_skb(vi, vi->last_xmit_skb) != 0) {
292 /* Drop this skb: we only queue one. */ 340 /* Drop this skb: we only queue one. */
293 vi->dev->stats.tx_dropped++; 341 vi->dev->stats.tx_dropped++;
294 kfree_skb(skb); 342 kfree_skb(skb);
343 skb = NULL;
295 goto stop_queue; 344 goto stop_queue;
296 } 345 }
297 vi->last_xmit_skb = NULL; 346 vi->last_xmit_skb = NULL;
298 } 347 }
299 348
300 /* Put new one in send queue and do transmit */ 349 /* Put new one in send queue and do transmit */
301 __skb_queue_head(&vi->send, skb); 350 if (likely(skb)) {
302 if (xmit_skb(vi, skb) != 0) { 351 __skb_queue_head(&vi->send, skb);
303 vi->last_xmit_skb = skb; 352 if (xmit_skb(vi, skb) != 0) {
304 goto stop_queue; 353 vi->last_xmit_skb = skb;
354 skb = NULL;
355 goto stop_queue;
356 }
305 } 357 }
306done: 358done:
307 vi->svq->vq_ops->kick(vi->svq); 359 vi->svq->vq_ops->kick(vi->svq);
@@ -411,6 +463,10 @@ static int virtnet_probe(struct virtio_device *vdev)
411 vi->vdev = vdev; 463 vi->vdev = vdev;
412 vdev->priv = vi; 464 vdev->priv = vi;
413 465
466 /* If they give us a callback when all buffers are done, we don't need
467 * the timer. */
468 vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY);
469
414 /* We expect two virtqueues, receive then send. */ 470 /* We expect two virtqueues, receive then send. */
415 vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done); 471 vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done);
416 if (IS_ERR(vi->rvq)) { 472 if (IS_ERR(vi->rvq)) {
@@ -428,6 +484,11 @@ static int virtnet_probe(struct virtio_device *vdev)
428 skb_queue_head_init(&vi->recv); 484 skb_queue_head_init(&vi->recv);
429 skb_queue_head_init(&vi->send); 485 skb_queue_head_init(&vi->send);
430 486
487 tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi);
488
489 if (!vi->free_in_tasklet)
490 setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi);
491
431 err = register_netdev(dev); 492 err = register_netdev(dev);
432 if (err) { 493 if (err) {
433 pr_debug("virtio_net: registering device failed\n"); 494 pr_debug("virtio_net: registering device failed\n");
@@ -465,13 +526,15 @@ static void virtnet_remove(struct virtio_device *vdev)
465 /* Stop all the virtqueues. */ 526 /* Stop all the virtqueues. */
466 vdev->config->reset(vdev); 527 vdev->config->reset(vdev);
467 528
529 if (!vi->free_in_tasklet)
530 del_timer_sync(&vi->xmit_free_timer);
531
468 /* Free our skbs in send and recv queues, if any. */ 532 /* Free our skbs in send and recv queues, if any. */
469 while ((skb = __skb_dequeue(&vi->recv)) != NULL) { 533 while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
470 kfree_skb(skb); 534 kfree_skb(skb);
471 vi->num--; 535 vi->num--;
472 } 536 }
473 while ((skb = __skb_dequeue(&vi->send)) != NULL) 537 __skb_queue_purge(&vi->send);
474 kfree_skb(skb);
475 538
476 BUG_ON(vi->num != 0); 539 BUG_ON(vi->num != 0);
477 540
@@ -489,7 +552,7 @@ static struct virtio_device_id id_table[] = {
489static unsigned int features[] = { 552static unsigned int features[] = {
490 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 553 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
491 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 554 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
492 VIRTIO_NET_F_HOST_ECN, 555 VIRTIO_NET_F_HOST_ECN, VIRTIO_F_NOTIFY_ON_EMPTY,
493}; 556};
494 557
495static struct virtio_driver virtio_net = { 558static struct virtio_driver virtio_net = {