netdev: convert pseudo drivers to netdev_tx_t
[linux-2.6.git] / drivers / net / virtio_net.c
1 /* A simple network driver using virtio.
2  *
3  * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  */
19 //#define DEBUG
20 #include <linux/netdevice.h>
21 #include <linux/etherdevice.h>
22 #include <linux/ethtool.h>
23 #include <linux/module.h>
24 #include <linux/virtio.h>
25 #include <linux/virtio_net.h>
26 #include <linux/scatterlist.h>
27 #include <linux/if_vlan.h>
28
29 static int napi_weight = 128;
30 module_param(napi_weight, int, 0444);
31
32 static int csum = 1, gso = 1;
33 module_param(csum, bool, 0444);
34 module_param(gso, bool, 0444);
35
36 /* FIXME: MTU in config. */
37 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
38 #define GOOD_COPY_LEN   128
39
40 #define VIRTNET_SEND_COMMAND_SG_MAX    2
41
42 struct virtnet_info
43 {
44         struct virtio_device *vdev;
45         struct virtqueue *rvq, *svq, *cvq;
46         struct net_device *dev;
47         struct napi_struct napi;
48         unsigned int status;
49
50         /* The skb we couldn't send because buffers were full. */
51         struct sk_buff *last_xmit_skb;
52
53         /* If we need to free in a timer, this is it. */
54         struct timer_list xmit_free_timer;
55
56         /* Number of input buffers, and max we've ever had. */
57         unsigned int num, max;
58
59         /* For cleaning up after transmission. */
60         struct tasklet_struct tasklet;
61         bool free_in_tasklet;
62
63         /* I like... big packets and I cannot lie! */
64         bool big_packets;
65
66         /* Host will merge rx buffers for big packets (shake it! shake it!) */
67         bool mergeable_rx_bufs;
68
69         /* Receive & send queues. */
70         struct sk_buff_head recv;
71         struct sk_buff_head send;
72
73         /* Chain pages by the private ptr. */
74         struct page *pages;
75 };
76
77 static inline void *skb_vnet_hdr(struct sk_buff *skb)
78 {
79         return (struct virtio_net_hdr *)skb->cb;
80 }
81
82 static void give_a_page(struct virtnet_info *vi, struct page *page)
83 {
84         page->private = (unsigned long)vi->pages;
85         vi->pages = page;
86 }
87
88 static void trim_pages(struct virtnet_info *vi, struct sk_buff *skb)
89 {
90         unsigned int i;
91
92         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
93                 give_a_page(vi, skb_shinfo(skb)->frags[i].page);
94         skb_shinfo(skb)->nr_frags = 0;
95         skb->data_len = 0;
96 }
97
98 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
99 {
100         struct page *p = vi->pages;
101
102         if (p)
103                 vi->pages = (struct page *)p->private;
104         else
105                 p = alloc_page(gfp_mask);
106         return p;
107 }
108
109 static void skb_xmit_done(struct virtqueue *svq)
110 {
111         struct virtnet_info *vi = svq->vdev->priv;
112
113         /* Suppress further interrupts. */
114         svq->vq_ops->disable_cb(svq);
115
116         /* We were probably waiting for more output buffers. */
117         netif_wake_queue(vi->dev);
118
119         /* Make sure we re-xmit last_xmit_skb: if there are no more packets
120          * queued, start_xmit won't be called. */
121         tasklet_schedule(&vi->tasklet);
122 }
123
124 static void receive_skb(struct net_device *dev, struct sk_buff *skb,
125                         unsigned len)
126 {
127         struct virtnet_info *vi = netdev_priv(dev);
128         struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
129         int err;
130         int i;
131
132         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
133                 pr_debug("%s: short packet %i\n", dev->name, len);
134                 dev->stats.rx_length_errors++;
135                 goto drop;
136         }
137
138         if (vi->mergeable_rx_bufs) {
139                 struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb);
140                 unsigned int copy;
141                 char *p = page_address(skb_shinfo(skb)->frags[0].page);
142
143                 if (len > PAGE_SIZE)
144                         len = PAGE_SIZE;
145                 len -= sizeof(struct virtio_net_hdr_mrg_rxbuf);
146
147                 memcpy(hdr, p, sizeof(*mhdr));
148                 p += sizeof(*mhdr);
149
150                 copy = len;
151                 if (copy > skb_tailroom(skb))
152                         copy = skb_tailroom(skb);
153
154                 memcpy(skb_put(skb, copy), p, copy);
155
156                 len -= copy;
157
158                 if (!len) {
159                         give_a_page(vi, skb_shinfo(skb)->frags[0].page);
160                         skb_shinfo(skb)->nr_frags--;
161                 } else {
162                         skb_shinfo(skb)->frags[0].page_offset +=
163                                 sizeof(*mhdr) + copy;
164                         skb_shinfo(skb)->frags[0].size = len;
165                         skb->data_len += len;
166                         skb->len += len;
167                 }
168
169                 while (--mhdr->num_buffers) {
170                         struct sk_buff *nskb;
171
172                         i = skb_shinfo(skb)->nr_frags;
173                         if (i >= MAX_SKB_FRAGS) {
174                                 pr_debug("%s: packet too long %d\n", dev->name,
175                                          len);
176                                 dev->stats.rx_length_errors++;
177                                 goto drop;
178                         }
179
180                         nskb = vi->rvq->vq_ops->get_buf(vi->rvq, &len);
181                         if (!nskb) {
182                                 pr_debug("%s: rx error: %d buffers missing\n",
183                                          dev->name, mhdr->num_buffers);
184                                 dev->stats.rx_length_errors++;
185                                 goto drop;
186                         }
187
188                         __skb_unlink(nskb, &vi->recv);
189                         vi->num--;
190
191                         skb_shinfo(skb)->frags[i] = skb_shinfo(nskb)->frags[0];
192                         skb_shinfo(nskb)->nr_frags = 0;
193                         kfree_skb(nskb);
194
195                         if (len > PAGE_SIZE)
196                                 len = PAGE_SIZE;
197
198                         skb_shinfo(skb)->frags[i].size = len;
199                         skb_shinfo(skb)->nr_frags++;
200                         skb->data_len += len;
201                         skb->len += len;
202                 }
203         } else {
204                 len -= sizeof(struct virtio_net_hdr);
205
206                 if (len <= MAX_PACKET_LEN)
207                         trim_pages(vi, skb);
208
209                 err = pskb_trim(skb, len);
210                 if (err) {
211                         pr_debug("%s: pskb_trim failed %i %d\n", dev->name,
212                                  len, err);
213                         dev->stats.rx_dropped++;
214                         goto drop;
215                 }
216         }
217
218         skb->truesize += skb->data_len;
219         dev->stats.rx_bytes += skb->len;
220         dev->stats.rx_packets++;
221
222         if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
223                 pr_debug("Needs csum!\n");
224                 if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
225                         goto frame_err;
226         }
227
228         skb->protocol = eth_type_trans(skb, dev);
229         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
230                  ntohs(skb->protocol), skb->len, skb->pkt_type);
231
232         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
233                 pr_debug("GSO!\n");
234                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
235                 case VIRTIO_NET_HDR_GSO_TCPV4:
236                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
237                         break;
238                 case VIRTIO_NET_HDR_GSO_UDP:
239                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
240                         break;
241                 case VIRTIO_NET_HDR_GSO_TCPV6:
242                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
243                         break;
244                 default:
245                         if (net_ratelimit())
246                                 printk(KERN_WARNING "%s: bad gso type %u.\n",
247                                        dev->name, hdr->gso_type);
248                         goto frame_err;
249                 }
250
251                 if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
252                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
253
254                 skb_shinfo(skb)->gso_size = hdr->gso_size;
255                 if (skb_shinfo(skb)->gso_size == 0) {
256                         if (net_ratelimit())
257                                 printk(KERN_WARNING "%s: zero gso size.\n",
258                                        dev->name);
259                         goto frame_err;
260                 }
261
262                 /* Header must be checked, and gso_segs computed. */
263                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
264                 skb_shinfo(skb)->gso_segs = 0;
265         }
266
267         netif_receive_skb(skb);
268         return;
269
270 frame_err:
271         dev->stats.rx_frame_errors++;
272 drop:
273         dev_kfree_skb(skb);
274 }
275
276 static void try_fill_recv_maxbufs(struct virtnet_info *vi)
277 {
278         struct sk_buff *skb;
279         struct scatterlist sg[2+MAX_SKB_FRAGS];
280         int num, err, i;
281
282         sg_init_table(sg, 2+MAX_SKB_FRAGS);
283         for (;;) {
284                 struct virtio_net_hdr *hdr;
285
286                 skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN + NET_IP_ALIGN);
287                 if (unlikely(!skb))
288                         break;
289
290                 skb_reserve(skb, NET_IP_ALIGN);
291                 skb_put(skb, MAX_PACKET_LEN);
292
293                 hdr = skb_vnet_hdr(skb);
294                 sg_set_buf(sg, hdr, sizeof(*hdr));
295
296                 if (vi->big_packets) {
297                         for (i = 0; i < MAX_SKB_FRAGS; i++) {
298                                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
299                                 f->page = get_a_page(vi, GFP_ATOMIC);
300                                 if (!f->page)
301                                         break;
302
303                                 f->page_offset = 0;
304                                 f->size = PAGE_SIZE;
305
306                                 skb->data_len += PAGE_SIZE;
307                                 skb->len += PAGE_SIZE;
308
309                                 skb_shinfo(skb)->nr_frags++;
310                         }
311                 }
312
313                 num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
314                 skb_queue_head(&vi->recv, skb);
315
316                 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
317                 if (err) {
318                         skb_unlink(skb, &vi->recv);
319                         trim_pages(vi, skb);
320                         kfree_skb(skb);
321                         break;
322                 }
323                 vi->num++;
324         }
325         if (unlikely(vi->num > vi->max))
326                 vi->max = vi->num;
327         vi->rvq->vq_ops->kick(vi->rvq);
328 }
329
330 static void try_fill_recv(struct virtnet_info *vi)
331 {
332         struct sk_buff *skb;
333         struct scatterlist sg[1];
334         int err;
335
336         if (!vi->mergeable_rx_bufs) {
337                 try_fill_recv_maxbufs(vi);
338                 return;
339         }
340
341         for (;;) {
342                 skb_frag_t *f;
343
344                 skb = netdev_alloc_skb(vi->dev, GOOD_COPY_LEN + NET_IP_ALIGN);
345                 if (unlikely(!skb))
346                         break;
347
348                 skb_reserve(skb, NET_IP_ALIGN);
349
350                 f = &skb_shinfo(skb)->frags[0];
351                 f->page = get_a_page(vi, GFP_ATOMIC);
352                 if (!f->page) {
353                         kfree_skb(skb);
354                         break;
355                 }
356
357                 f->page_offset = 0;
358                 f->size = PAGE_SIZE;
359
360                 skb_shinfo(skb)->nr_frags++;
361
362                 sg_init_one(sg, page_address(f->page), PAGE_SIZE);
363                 skb_queue_head(&vi->recv, skb);
364
365                 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 1, skb);
366                 if (err) {
367                         skb_unlink(skb, &vi->recv);
368                         kfree_skb(skb);
369                         break;
370                 }
371                 vi->num++;
372         }
373         if (unlikely(vi->num > vi->max))
374                 vi->max = vi->num;
375         vi->rvq->vq_ops->kick(vi->rvq);
376 }
377
378 static void skb_recv_done(struct virtqueue *rvq)
379 {
380         struct virtnet_info *vi = rvq->vdev->priv;
381         /* Schedule NAPI, Suppress further interrupts if successful. */
382         if (napi_schedule_prep(&vi->napi)) {
383                 rvq->vq_ops->disable_cb(rvq);
384                 __napi_schedule(&vi->napi);
385         }
386 }
387
388 static int virtnet_poll(struct napi_struct *napi, int budget)
389 {
390         struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
391         struct sk_buff *skb = NULL;
392         unsigned int len, received = 0;
393
394 again:
395         while (received < budget &&
396                (skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
397                 __skb_unlink(skb, &vi->recv);
398                 receive_skb(vi->dev, skb, len);
399                 vi->num--;
400                 received++;
401         }
402
403         /* FIXME: If we oom and completely run out of inbufs, we need
404          * to start a timer trying to fill more. */
405         if (vi->num < vi->max / 2)
406                 try_fill_recv(vi);
407
408         /* Out of packets? */
409         if (received < budget) {
410                 napi_complete(napi);
411                 if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
412                     && napi_schedule_prep(napi)) {
413                         vi->rvq->vq_ops->disable_cb(vi->rvq);
414                         __napi_schedule(napi);
415                         goto again;
416                 }
417         }
418
419         return received;
420 }
421
422 static void free_old_xmit_skbs(struct virtnet_info *vi)
423 {
424         struct sk_buff *skb;
425         unsigned int len;
426
427         while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
428                 pr_debug("Sent skb %p\n", skb);
429                 __skb_unlink(skb, &vi->send);
430                 vi->dev->stats.tx_bytes += skb->len;
431                 vi->dev->stats.tx_packets++;
432                 kfree_skb(skb);
433         }
434 }
435
436 /* If the virtio transport doesn't always notify us when all in-flight packets
437  * are consumed, we fall back to using this function on a timer to free them. */
438 static void xmit_free(unsigned long data)
439 {
440         struct virtnet_info *vi = (void *)data;
441
442         netif_tx_lock(vi->dev);
443
444         free_old_xmit_skbs(vi);
445
446         if (!skb_queue_empty(&vi->send))
447                 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
448
449         netif_tx_unlock(vi->dev);
450 }
451
452 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
453 {
454         int num, err;
455         struct scatterlist sg[2+MAX_SKB_FRAGS];
456         struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb);
457         struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
458         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
459
460         sg_init_table(sg, 2+MAX_SKB_FRAGS);
461
462         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
463
464         if (skb->ip_summed == CHECKSUM_PARTIAL) {
465                 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
466                 hdr->csum_start = skb->csum_start - skb_headroom(skb);
467                 hdr->csum_offset = skb->csum_offset;
468         } else {
469                 hdr->flags = 0;
470                 hdr->csum_offset = hdr->csum_start = 0;
471         }
472
473         if (skb_is_gso(skb)) {
474                 hdr->hdr_len = skb_headlen(skb);
475                 hdr->gso_size = skb_shinfo(skb)->gso_size;
476                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
477                         hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
478                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
479                         hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
480                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
481                         hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
482                 else
483                         BUG();
484                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
485                         hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
486         } else {
487                 hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
488                 hdr->gso_size = hdr->hdr_len = 0;
489         }
490
491         mhdr->num_buffers = 0;
492
493         /* Encode metadata header at front. */
494         if (vi->mergeable_rx_bufs)
495                 sg_set_buf(sg, mhdr, sizeof(*mhdr));
496         else
497                 sg_set_buf(sg, hdr, sizeof(*hdr));
498
499         num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
500
501         err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
502         if (!err && !vi->free_in_tasklet)
503                 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
504
505         return err;
506 }
507
508 static void xmit_tasklet(unsigned long data)
509 {
510         struct virtnet_info *vi = (void *)data;
511
512         netif_tx_lock_bh(vi->dev);
513         if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) {
514                 vi->svq->vq_ops->kick(vi->svq);
515                 vi->last_xmit_skb = NULL;
516         }
517         if (vi->free_in_tasklet)
518                 free_old_xmit_skbs(vi);
519         netif_tx_unlock_bh(vi->dev);
520 }
521
522 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
523 {
524         struct virtnet_info *vi = netdev_priv(dev);
525
526 again:
527         /* Free up any pending old buffers before queueing new ones. */
528         free_old_xmit_skbs(vi);
529
530         /* If we has a buffer left over from last time, send it now. */
531         if (unlikely(vi->last_xmit_skb) &&
532             xmit_skb(vi, vi->last_xmit_skb) != 0)
533                 goto stop_queue;
534
535         vi->last_xmit_skb = NULL;
536
537         /* Put new one in send queue and do transmit */
538         if (likely(skb)) {
539                 __skb_queue_head(&vi->send, skb);
540                 if (xmit_skb(vi, skb) != 0) {
541                         vi->last_xmit_skb = skb;
542                         skb = NULL;
543                         goto stop_queue;
544                 }
545         }
546 done:
547         vi->svq->vq_ops->kick(vi->svq);
548         return NETDEV_TX_OK;
549
550 stop_queue:
551         pr_debug("%s: virtio not prepared to send\n", dev->name);
552         netif_stop_queue(dev);
553
554         /* Activate callback for using skbs: if this returns false it
555          * means some were used in the meantime. */
556         if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
557                 vi->svq->vq_ops->disable_cb(vi->svq);
558                 netif_start_queue(dev);
559                 goto again;
560         }
561         if (skb) {
562                 /* Drop this skb: we only queue one. */
563                 vi->dev->stats.tx_dropped++;
564                 kfree_skb(skb);
565         }
566         goto done;
567 }
568
569 static int virtnet_set_mac_address(struct net_device *dev, void *p)
570 {
571         struct virtnet_info *vi = netdev_priv(dev);
572         struct virtio_device *vdev = vi->vdev;
573         int ret;
574
575         ret = eth_mac_addr(dev, p);
576         if (ret)
577                 return ret;
578
579         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
580                 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
581                                   dev->dev_addr, dev->addr_len);
582
583         return 0;
584 }
585
586 #ifdef CONFIG_NET_POLL_CONTROLLER
587 static void virtnet_netpoll(struct net_device *dev)
588 {
589         struct virtnet_info *vi = netdev_priv(dev);
590
591         napi_schedule(&vi->napi);
592 }
593 #endif
594
595 static int virtnet_open(struct net_device *dev)
596 {
597         struct virtnet_info *vi = netdev_priv(dev);
598
599         napi_enable(&vi->napi);
600
601         /* If all buffers were filled by other side before we napi_enabled, we
602          * won't get another interrupt, so process any outstanding packets
603          * now.  virtnet_poll wants re-enable the queue, so we disable here.
604          * We synchronize against interrupts via NAPI_STATE_SCHED */
605         if (napi_schedule_prep(&vi->napi)) {
606                 vi->rvq->vq_ops->disable_cb(vi->rvq);
607                 __napi_schedule(&vi->napi);
608         }
609         return 0;
610 }
611
612 /*
613  * Send command via the control virtqueue and check status.  Commands
614  * supported by the hypervisor, as indicated by feature bits, should
615  * never fail unless improperly formated.
616  */
617 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
618                                  struct scatterlist *data, int out, int in)
619 {
620         struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
621         struct virtio_net_ctrl_hdr ctrl;
622         virtio_net_ctrl_ack status = ~0;
623         unsigned int tmp;
624         int i;
625
626         /* Caller should know better */
627         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
628                 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
629
630         out++; /* Add header */
631         in++; /* Add return status */
632
633         ctrl.class = class;
634         ctrl.cmd = cmd;
635
636         sg_init_table(sg, out + in);
637
638         sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
639         for_each_sg(data, s, out + in - 2, i)
640                 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
641         sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
642
643         BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi));
644
645         vi->cvq->vq_ops->kick(vi->cvq);
646
647         /*
648          * Spin for a response, the kick causes an ioport write, trapping
649          * into the hypervisor, so the request should be handled immediately.
650          */
651         while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp))
652                 cpu_relax();
653
654         return status == VIRTIO_NET_OK;
655 }
656
657 static int virtnet_close(struct net_device *dev)
658 {
659         struct virtnet_info *vi = netdev_priv(dev);
660
661         napi_disable(&vi->napi);
662
663         return 0;
664 }
665
666 static int virtnet_set_tx_csum(struct net_device *dev, u32 data)
667 {
668         struct virtnet_info *vi = netdev_priv(dev);
669         struct virtio_device *vdev = vi->vdev;
670
671         if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM))
672                 return -ENOSYS;
673
674         return ethtool_op_set_tx_hw_csum(dev, data);
675 }
676
677 static void virtnet_set_rx_mode(struct net_device *dev)
678 {
679         struct virtnet_info *vi = netdev_priv(dev);
680         struct scatterlist sg[2];
681         u8 promisc, allmulti;
682         struct virtio_net_ctrl_mac *mac_data;
683         struct dev_addr_list *addr;
684         struct netdev_hw_addr *ha;
685         void *buf;
686         int i;
687
688         /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
689         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
690                 return;
691
692         promisc = ((dev->flags & IFF_PROMISC) != 0);
693         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
694
695         sg_init_one(sg, &promisc, sizeof(promisc));
696
697         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
698                                   VIRTIO_NET_CTRL_RX_PROMISC,
699                                   sg, 1, 0))
700                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
701                          promisc ? "en" : "dis");
702
703         sg_init_one(sg, &allmulti, sizeof(allmulti));
704
705         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
706                                   VIRTIO_NET_CTRL_RX_ALLMULTI,
707                                   sg, 1, 0))
708                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
709                          allmulti ? "en" : "dis");
710
711         /* MAC filter - use one buffer for both lists */
712         mac_data = buf = kzalloc(((dev->uc.count + dev->mc_count) * ETH_ALEN) +
713                                  (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
714         if (!buf) {
715                 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
716                 return;
717         }
718
719         sg_init_table(sg, 2);
720
721         /* Store the unicast list and count in the front of the buffer */
722         mac_data->entries = dev->uc.count;
723         i = 0;
724         list_for_each_entry(ha, &dev->uc.list, list)
725                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
726
727         sg_set_buf(&sg[0], mac_data,
728                    sizeof(mac_data->entries) + (dev->uc.count * ETH_ALEN));
729
730         /* multicast list and count fill the end */
731         mac_data = (void *)&mac_data->macs[dev->uc.count][0];
732
733         mac_data->entries = dev->mc_count;
734         addr = dev->mc_list;
735         for (i = 0; i < dev->mc_count; i++, addr = addr->next)
736                 memcpy(&mac_data->macs[i][0], addr->da_addr, ETH_ALEN);
737
738         sg_set_buf(&sg[1], mac_data,
739                    sizeof(mac_data->entries) + (dev->mc_count * ETH_ALEN));
740
741         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
742                                   VIRTIO_NET_CTRL_MAC_TABLE_SET,
743                                   sg, 2, 0))
744                 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
745
746         kfree(buf);
747 }
748
749 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
750 {
751         struct virtnet_info *vi = netdev_priv(dev);
752         struct scatterlist sg;
753
754         sg_init_one(&sg, &vid, sizeof(vid));
755
756         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
757                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
758                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
759 }
760
761 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
762 {
763         struct virtnet_info *vi = netdev_priv(dev);
764         struct scatterlist sg;
765
766         sg_init_one(&sg, &vid, sizeof(vid));
767
768         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
769                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
770                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
771 }
772
773 static struct ethtool_ops virtnet_ethtool_ops = {
774         .set_tx_csum = virtnet_set_tx_csum,
775         .set_sg = ethtool_op_set_sg,
776         .set_tso = ethtool_op_set_tso,
777         .set_ufo = ethtool_op_set_ufo,
778         .get_link = ethtool_op_get_link,
779 };
780
781 #define MIN_MTU 68
782 #define MAX_MTU 65535
783
784 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
785 {
786         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
787                 return -EINVAL;
788         dev->mtu = new_mtu;
789         return 0;
790 }
791
792 static const struct net_device_ops virtnet_netdev = {
793         .ndo_open            = virtnet_open,
794         .ndo_stop            = virtnet_close,
795         .ndo_start_xmit      = start_xmit,
796         .ndo_validate_addr   = eth_validate_addr,
797         .ndo_set_mac_address = virtnet_set_mac_address,
798         .ndo_set_rx_mode     = virtnet_set_rx_mode,
799         .ndo_change_mtu      = virtnet_change_mtu,
800         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
801         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
802 #ifdef CONFIG_NET_POLL_CONTROLLER
803         .ndo_poll_controller = virtnet_netpoll,
804 #endif
805 };
806
807 static void virtnet_update_status(struct virtnet_info *vi)
808 {
809         u16 v;
810
811         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS))
812                 return;
813
814         vi->vdev->config->get(vi->vdev,
815                               offsetof(struct virtio_net_config, status),
816                               &v, sizeof(v));
817
818         /* Ignore unknown (future) status bits */
819         v &= VIRTIO_NET_S_LINK_UP;
820
821         if (vi->status == v)
822                 return;
823
824         vi->status = v;
825
826         if (vi->status & VIRTIO_NET_S_LINK_UP) {
827                 netif_carrier_on(vi->dev);
828                 netif_wake_queue(vi->dev);
829         } else {
830                 netif_carrier_off(vi->dev);
831                 netif_stop_queue(vi->dev);
832         }
833 }
834
835 static void virtnet_config_changed(struct virtio_device *vdev)
836 {
837         struct virtnet_info *vi = vdev->priv;
838
839         virtnet_update_status(vi);
840 }
841
842 static int virtnet_probe(struct virtio_device *vdev)
843 {
844         int err;
845         struct net_device *dev;
846         struct virtnet_info *vi;
847         struct virtqueue *vqs[3];
848         vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
849         const char *names[] = { "input", "output", "control" };
850         int nvqs;
851
852         /* Allocate ourselves a network device with room for our info */
853         dev = alloc_etherdev(sizeof(struct virtnet_info));
854         if (!dev)
855                 return -ENOMEM;
856
857         /* Set up network device as normal. */
858         dev->netdev_ops = &virtnet_netdev;
859         dev->features = NETIF_F_HIGHDMA;
860         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
861         SET_NETDEV_DEV(dev, &vdev->dev);
862
863         /* Do we support "hardware" checksums? */
864         if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
865                 /* This opens up the world of extra features. */
866                 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
867                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
868                         dev->features |= NETIF_F_TSO | NETIF_F_UFO
869                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
870                 }
871                 /* Individual feature bits: what can host handle? */
872                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
873                         dev->features |= NETIF_F_TSO;
874                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
875                         dev->features |= NETIF_F_TSO6;
876                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
877                         dev->features |= NETIF_F_TSO_ECN;
878                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
879                         dev->features |= NETIF_F_UFO;
880         }
881
882         /* Configuration may specify what MAC to use.  Otherwise random. */
883         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
884                 vdev->config->get(vdev,
885                                   offsetof(struct virtio_net_config, mac),
886                                   dev->dev_addr, dev->addr_len);
887         } else
888                 random_ether_addr(dev->dev_addr);
889
890         /* Set up our device-specific information */
891         vi = netdev_priv(dev);
892         netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
893         vi->dev = dev;
894         vi->vdev = vdev;
895         vdev->priv = vi;
896         vi->pages = NULL;
897
898         /* If they give us a callback when all buffers are done, we don't need
899          * the timer. */
900         vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY);
901
902         /* If we can receive ANY GSO packets, we must allocate large ones. */
903         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4)
904             || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6)
905             || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
906                 vi->big_packets = true;
907
908         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
909                 vi->mergeable_rx_bufs = true;
910
911         /* We expect two virtqueues, receive then send,
912          * and optionally control. */
913         nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
914
915         err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names);
916         if (err)
917                 goto free;
918
919         vi->rvq = vqs[0];
920         vi->svq = vqs[1];
921
922         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
923                 vi->cvq = vqs[2];
924
925                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
926                         dev->features |= NETIF_F_HW_VLAN_FILTER;
927         }
928
929         /* Initialize our empty receive and send queues. */
930         skb_queue_head_init(&vi->recv);
931         skb_queue_head_init(&vi->send);
932
933         tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi);
934
935         if (!vi->free_in_tasklet)
936                 setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi);
937
938         err = register_netdev(dev);
939         if (err) {
940                 pr_debug("virtio_net: registering device failed\n");
941                 goto free_vqs;
942         }
943
944         /* Last of all, set up some receive buffers. */
945         try_fill_recv(vi);
946
947         /* If we didn't even get one input buffer, we're useless. */
948         if (vi->num == 0) {
949                 err = -ENOMEM;
950                 goto unregister;
951         }
952
953         vi->status = VIRTIO_NET_S_LINK_UP;
954         virtnet_update_status(vi);
955         netif_carrier_on(dev);
956
957         pr_debug("virtnet: registered device %s\n", dev->name);
958         return 0;
959
960 unregister:
961         unregister_netdev(dev);
962 free_vqs:
963         vdev->config->del_vqs(vdev);
964 free:
965         free_netdev(dev);
966         return err;
967 }
968
969 static void virtnet_remove(struct virtio_device *vdev)
970 {
971         struct virtnet_info *vi = vdev->priv;
972         struct sk_buff *skb;
973
974         /* Stop all the virtqueues. */
975         vdev->config->reset(vdev);
976
977         if (!vi->free_in_tasklet)
978                 del_timer_sync(&vi->xmit_free_timer);
979
980         /* Free our skbs in send and recv queues, if any. */
981         while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
982                 kfree_skb(skb);
983                 vi->num--;
984         }
985         __skb_queue_purge(&vi->send);
986
987         BUG_ON(vi->num != 0);
988
989         unregister_netdev(vi->dev);
990
991         vdev->config->del_vqs(vi->vdev);
992
993         while (vi->pages)
994                 __free_pages(get_a_page(vi, GFP_KERNEL), 0);
995
996         free_netdev(vi->dev);
997 }
998
999 static struct virtio_device_id id_table[] = {
1000         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1001         { 0 },
1002 };
1003
1004 static unsigned int features[] = {
1005         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1006         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1007         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1008         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1009         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1010         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1011         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1012         VIRTIO_F_NOTIFY_ON_EMPTY,
1013 };
1014
1015 static struct virtio_driver virtio_net = {
1016         .feature_table = features,
1017         .feature_table_size = ARRAY_SIZE(features),
1018         .driver.name =  KBUILD_MODNAME,
1019         .driver.owner = THIS_MODULE,
1020         .id_table =     id_table,
1021         .probe =        virtnet_probe,
1022         .remove =       __devexit_p(virtnet_remove),
1023         .config_changed = virtnet_config_changed,
1024 };
1025
1026 static int __init init(void)
1027 {
1028         return register_virtio_driver(&virtio_net);
1029 }
1030
1031 static void __exit fini(void)
1032 {
1033         unregister_virtio_driver(&virtio_net);
1034 }
1035 module_init(init);
1036 module_exit(fini);
1037
1038 MODULE_DEVICE_TABLE(virtio, id_table);
1039 MODULE_DESCRIPTION("Virtio network driver");
1040 MODULE_LICENSE("GPL");