net: convert multicast list to list_head
[linux-2.6.git] / drivers / net / virtio_net.c
1 /* A 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         /* Number of input buffers, and max we've ever had. */
51         unsigned int num, max;
52
53         /* I like... big packets and I cannot lie! */
54         bool big_packets;
55
56         /* Host will merge rx buffers for big packets (shake it! shake it!) */
57         bool mergeable_rx_bufs;
58
59         /* Work struct for refilling if we run low on memory. */
60         struct delayed_work refill;
61
62         /* Chain pages by the private ptr. */
63         struct page *pages;
64 };
65
66 struct skb_vnet_hdr {
67         union {
68                 struct virtio_net_hdr hdr;
69                 struct virtio_net_hdr_mrg_rxbuf mhdr;
70         };
71         unsigned int num_sg;
72 };
73
74 struct padded_vnet_hdr {
75         struct virtio_net_hdr hdr;
76         /*
77          * virtio_net_hdr should be in a separated sg buffer because of a
78          * QEMU bug, and data sg buffer shares same page with this header sg.
79          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
80          */
81         char padding[6];
82 };
83
84 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
85 {
86         return (struct skb_vnet_hdr *)skb->cb;
87 }
88
89 /*
90  * private is used to chain pages for big packets, put the whole
91  * most recent used list in the beginning for reuse
92  */
93 static void give_pages(struct virtnet_info *vi, struct page *page)
94 {
95         struct page *end;
96
97         /* Find end of list, sew whole thing into vi->pages. */
98         for (end = page; end->private; end = (struct page *)end->private);
99         end->private = (unsigned long)vi->pages;
100         vi->pages = page;
101 }
102
103 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
104 {
105         struct page *p = vi->pages;
106
107         if (p) {
108                 vi->pages = (struct page *)p->private;
109                 /* clear private here, it is used to chain pages */
110                 p->private = 0;
111         } else
112                 p = alloc_page(gfp_mask);
113         return p;
114 }
115
116 static void skb_xmit_done(struct virtqueue *svq)
117 {
118         struct virtnet_info *vi = svq->vdev->priv;
119
120         /* Suppress further interrupts. */
121         svq->vq_ops->disable_cb(svq);
122
123         /* We were probably waiting for more output buffers. */
124         netif_wake_queue(vi->dev);
125 }
126
127 static void set_skb_frag(struct sk_buff *skb, struct page *page,
128                          unsigned int offset, unsigned int *len)
129 {
130         int i = skb_shinfo(skb)->nr_frags;
131         skb_frag_t *f;
132
133         f = &skb_shinfo(skb)->frags[i];
134         f->size = min((unsigned)PAGE_SIZE - offset, *len);
135         f->page_offset = offset;
136         f->page = page;
137
138         skb->data_len += f->size;
139         skb->len += f->size;
140         skb_shinfo(skb)->nr_frags++;
141         *len -= f->size;
142 }
143
144 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
145                                    struct page *page, unsigned int len)
146 {
147         struct sk_buff *skb;
148         struct skb_vnet_hdr *hdr;
149         unsigned int copy, hdr_len, offset;
150         char *p;
151
152         p = page_address(page);
153
154         /* copy small packet so we can reuse these pages for small data */
155         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
156         if (unlikely(!skb))
157                 return NULL;
158
159         hdr = skb_vnet_hdr(skb);
160
161         if (vi->mergeable_rx_bufs) {
162                 hdr_len = sizeof hdr->mhdr;
163                 offset = hdr_len;
164         } else {
165                 hdr_len = sizeof hdr->hdr;
166                 offset = sizeof(struct padded_vnet_hdr);
167         }
168
169         memcpy(hdr, p, hdr_len);
170
171         len -= hdr_len;
172         p += offset;
173
174         copy = len;
175         if (copy > skb_tailroom(skb))
176                 copy = skb_tailroom(skb);
177         memcpy(skb_put(skb, copy), p, copy);
178
179         len -= copy;
180         offset += copy;
181
182         while (len) {
183                 set_skb_frag(skb, page, offset, &len);
184                 page = (struct page *)page->private;
185                 offset = 0;
186         }
187
188         if (page)
189                 give_pages(vi, page);
190
191         return skb;
192 }
193
194 static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
195 {
196         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
197         struct page *page;
198         int num_buf, i, len;
199
200         num_buf = hdr->mhdr.num_buffers;
201         while (--num_buf) {
202                 i = skb_shinfo(skb)->nr_frags;
203                 if (i >= MAX_SKB_FRAGS) {
204                         pr_debug("%s: packet too long\n", skb->dev->name);
205                         skb->dev->stats.rx_length_errors++;
206                         return -EINVAL;
207                 }
208
209                 page = vi->rvq->vq_ops->get_buf(vi->rvq, &len);
210                 if (!page) {
211                         pr_debug("%s: rx error: %d buffers missing\n",
212                                  skb->dev->name, hdr->mhdr.num_buffers);
213                         skb->dev->stats.rx_length_errors++;
214                         return -EINVAL;
215                 }
216                 if (len > PAGE_SIZE)
217                         len = PAGE_SIZE;
218
219                 set_skb_frag(skb, page, 0, &len);
220
221                 --vi->num;
222         }
223         return 0;
224 }
225
226 static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
227 {
228         struct virtnet_info *vi = netdev_priv(dev);
229         struct sk_buff *skb;
230         struct page *page;
231         struct skb_vnet_hdr *hdr;
232
233         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
234                 pr_debug("%s: short packet %i\n", dev->name, len);
235                 dev->stats.rx_length_errors++;
236                 if (vi->mergeable_rx_bufs || vi->big_packets)
237                         give_pages(vi, buf);
238                 else
239                         dev_kfree_skb(buf);
240                 return;
241         }
242
243         if (!vi->mergeable_rx_bufs && !vi->big_packets) {
244                 skb = buf;
245                 len -= sizeof(struct virtio_net_hdr);
246                 skb_trim(skb, len);
247         } else {
248                 page = buf;
249                 skb = page_to_skb(vi, page, len);
250                 if (unlikely(!skb)) {
251                         dev->stats.rx_dropped++;
252                         give_pages(vi, page);
253                         return;
254                 }
255                 if (vi->mergeable_rx_bufs)
256                         if (receive_mergeable(vi, skb)) {
257                                 dev_kfree_skb(skb);
258                                 return;
259                         }
260         }
261
262         hdr = skb_vnet_hdr(skb);
263         skb->truesize += skb->data_len;
264         dev->stats.rx_bytes += skb->len;
265         dev->stats.rx_packets++;
266
267         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
268                 pr_debug("Needs csum!\n");
269                 if (!skb_partial_csum_set(skb,
270                                           hdr->hdr.csum_start,
271                                           hdr->hdr.csum_offset))
272                         goto frame_err;
273         }
274
275         skb->protocol = eth_type_trans(skb, dev);
276         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
277                  ntohs(skb->protocol), skb->len, skb->pkt_type);
278
279         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
280                 pr_debug("GSO!\n");
281                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
282                 case VIRTIO_NET_HDR_GSO_TCPV4:
283                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
284                         break;
285                 case VIRTIO_NET_HDR_GSO_UDP:
286                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
287                         break;
288                 case VIRTIO_NET_HDR_GSO_TCPV6:
289                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
290                         break;
291                 default:
292                         if (net_ratelimit())
293                                 printk(KERN_WARNING "%s: bad gso type %u.\n",
294                                        dev->name, hdr->hdr.gso_type);
295                         goto frame_err;
296                 }
297
298                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
299                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
300
301                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
302                 if (skb_shinfo(skb)->gso_size == 0) {
303                         if (net_ratelimit())
304                                 printk(KERN_WARNING "%s: zero gso size.\n",
305                                        dev->name);
306                         goto frame_err;
307                 }
308
309                 /* Header must be checked, and gso_segs computed. */
310                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
311                 skb_shinfo(skb)->gso_segs = 0;
312         }
313
314         netif_receive_skb(skb);
315         return;
316
317 frame_err:
318         dev->stats.rx_frame_errors++;
319         dev_kfree_skb(skb);
320 }
321
322 static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp)
323 {
324         struct sk_buff *skb;
325         struct skb_vnet_hdr *hdr;
326         struct scatterlist sg[2];
327         int err;
328
329         sg_init_table(sg, 2);
330         skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN);
331         if (unlikely(!skb))
332                 return -ENOMEM;
333
334         skb_put(skb, MAX_PACKET_LEN);
335
336         hdr = skb_vnet_hdr(skb);
337         sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr);
338
339         skb_to_sgvec(skb, sg + 1, 0, skb->len);
340
341         err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 2, skb);
342         if (err < 0)
343                 dev_kfree_skb(skb);
344
345         return err;
346 }
347
348 static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp)
349 {
350         struct scatterlist sg[MAX_SKB_FRAGS + 2];
351         struct page *first, *list = NULL;
352         char *p;
353         int i, err, offset;
354
355         sg_init_table(sg, MAX_SKB_FRAGS + 2);
356         /* page in sg[MAX_SKB_FRAGS + 1] is list tail */
357         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
358                 first = get_a_page(vi, gfp);
359                 if (!first) {
360                         if (list)
361                                 give_pages(vi, list);
362                         return -ENOMEM;
363                 }
364                 sg_set_buf(&sg[i], page_address(first), PAGE_SIZE);
365
366                 /* chain new page in list head to match sg */
367                 first->private = (unsigned long)list;
368                 list = first;
369         }
370
371         first = get_a_page(vi, gfp);
372         if (!first) {
373                 give_pages(vi, list);
374                 return -ENOMEM;
375         }
376         p = page_address(first);
377
378         /* sg[0], sg[1] share the same page */
379         /* a separated sg[0] for  virtio_net_hdr only during to QEMU bug*/
380         sg_set_buf(&sg[0], p, sizeof(struct virtio_net_hdr));
381
382         /* sg[1] for data packet, from offset */
383         offset = sizeof(struct padded_vnet_hdr);
384         sg_set_buf(&sg[1], p + offset, PAGE_SIZE - offset);
385
386         /* chain first in list head */
387         first->private = (unsigned long)list;
388         err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, MAX_SKB_FRAGS + 2,
389                                        first);
390         if (err < 0)
391                 give_pages(vi, first);
392
393         return err;
394 }
395
396 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp)
397 {
398         struct page *page;
399         struct scatterlist sg;
400         int err;
401
402         page = get_a_page(vi, gfp);
403         if (!page)
404                 return -ENOMEM;
405
406         sg_init_one(&sg, page_address(page), PAGE_SIZE);
407
408         err = vi->rvq->vq_ops->add_buf(vi->rvq, &sg, 0, 1, page);
409         if (err < 0)
410                 give_pages(vi, page);
411
412         return err;
413 }
414
415 /* Returns false if we couldn't fill entirely (OOM). */
416 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
417 {
418         int err;
419         bool oom = false;
420
421         do {
422                 if (vi->mergeable_rx_bufs)
423                         err = add_recvbuf_mergeable(vi, gfp);
424                 else if (vi->big_packets)
425                         err = add_recvbuf_big(vi, gfp);
426                 else
427                         err = add_recvbuf_small(vi, gfp);
428
429                 if (err < 0) {
430                         oom = true;
431                         break;
432                 }
433                 ++vi->num;
434         } while (err > 0);
435         if (unlikely(vi->num > vi->max))
436                 vi->max = vi->num;
437         vi->rvq->vq_ops->kick(vi->rvq);
438         return !oom;
439 }
440
441 static void skb_recv_done(struct virtqueue *rvq)
442 {
443         struct virtnet_info *vi = rvq->vdev->priv;
444         /* Schedule NAPI, Suppress further interrupts if successful. */
445         if (napi_schedule_prep(&vi->napi)) {
446                 rvq->vq_ops->disable_cb(rvq);
447                 __napi_schedule(&vi->napi);
448         }
449 }
450
451 static void refill_work(struct work_struct *work)
452 {
453         struct virtnet_info *vi;
454         bool still_empty;
455
456         vi = container_of(work, struct virtnet_info, refill.work);
457         napi_disable(&vi->napi);
458         still_empty = !try_fill_recv(vi, GFP_KERNEL);
459         napi_enable(&vi->napi);
460
461         /* In theory, this can happen: if we don't get any buffers in
462          * we will *never* try to fill again. */
463         if (still_empty)
464                 schedule_delayed_work(&vi->refill, HZ/2);
465 }
466
467 static int virtnet_poll(struct napi_struct *napi, int budget)
468 {
469         struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
470         void *buf;
471         unsigned int len, received = 0;
472
473 again:
474         while (received < budget &&
475                (buf = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
476                 receive_buf(vi->dev, buf, len);
477                 --vi->num;
478                 received++;
479         }
480
481         if (vi->num < vi->max / 2) {
482                 if (!try_fill_recv(vi, GFP_ATOMIC))
483                         schedule_delayed_work(&vi->refill, 0);
484         }
485
486         /* Out of packets? */
487         if (received < budget) {
488                 napi_complete(napi);
489                 if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq)) &&
490                     napi_schedule_prep(napi)) {
491                         vi->rvq->vq_ops->disable_cb(vi->rvq);
492                         __napi_schedule(napi);
493                         goto again;
494                 }
495         }
496
497         return received;
498 }
499
500 static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
501 {
502         struct sk_buff *skb;
503         unsigned int len, tot_sgs = 0;
504
505         while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
506                 pr_debug("Sent skb %p\n", skb);
507                 vi->dev->stats.tx_bytes += skb->len;
508                 vi->dev->stats.tx_packets++;
509                 tot_sgs += skb_vnet_hdr(skb)->num_sg;
510                 dev_kfree_skb_any(skb);
511         }
512         return tot_sgs;
513 }
514
515 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
516 {
517         struct scatterlist sg[2+MAX_SKB_FRAGS];
518         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
519         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
520
521         sg_init_table(sg, 2+MAX_SKB_FRAGS);
522
523         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
524
525         if (skb->ip_summed == CHECKSUM_PARTIAL) {
526                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
527                 hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb);
528                 hdr->hdr.csum_offset = skb->csum_offset;
529         } else {
530                 hdr->hdr.flags = 0;
531                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
532         }
533
534         if (skb_is_gso(skb)) {
535                 hdr->hdr.hdr_len = skb_headlen(skb);
536                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
537                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
538                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
539                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
540                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
541                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
542                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
543                 else
544                         BUG();
545                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
546                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
547         } else {
548                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
549                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
550         }
551
552         hdr->mhdr.num_buffers = 0;
553
554         /* Encode metadata header at front. */
555         if (vi->mergeable_rx_bufs)
556                 sg_set_buf(sg, &hdr->mhdr, sizeof hdr->mhdr);
557         else
558                 sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr);
559
560         hdr->num_sg = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
561         return vi->svq->vq_ops->add_buf(vi->svq, sg, hdr->num_sg, 0, skb);
562 }
563
564 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
565 {
566         struct virtnet_info *vi = netdev_priv(dev);
567         int capacity;
568
569 again:
570         /* Free up any pending old buffers before queueing new ones. */
571         free_old_xmit_skbs(vi);
572
573         /* Try to transmit */
574         capacity = xmit_skb(vi, skb);
575
576         /* This can happen with OOM and indirect buffers. */
577         if (unlikely(capacity < 0)) {
578                 netif_stop_queue(dev);
579                 dev_warn(&dev->dev, "Unexpected full queue\n");
580                 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
581                         vi->svq->vq_ops->disable_cb(vi->svq);
582                         netif_start_queue(dev);
583                         goto again;
584                 }
585                 return NETDEV_TX_BUSY;
586         }
587         vi->svq->vq_ops->kick(vi->svq);
588
589         /* Don't wait up for transmitted skbs to be freed. */
590         skb_orphan(skb);
591         nf_reset(skb);
592
593         /* Apparently nice girls don't return TX_BUSY; stop the queue
594          * before it gets out of hand.  Naturally, this wastes entries. */
595         if (capacity < 2+MAX_SKB_FRAGS) {
596                 netif_stop_queue(dev);
597                 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
598                         /* More just got used, free them then recheck. */
599                         capacity += free_old_xmit_skbs(vi);
600                         if (capacity >= 2+MAX_SKB_FRAGS) {
601                                 netif_start_queue(dev);
602                                 vi->svq->vq_ops->disable_cb(vi->svq);
603                         }
604                 }
605         }
606
607         return NETDEV_TX_OK;
608 }
609
610 static int virtnet_set_mac_address(struct net_device *dev, void *p)
611 {
612         struct virtnet_info *vi = netdev_priv(dev);
613         struct virtio_device *vdev = vi->vdev;
614         int ret;
615
616         ret = eth_mac_addr(dev, p);
617         if (ret)
618                 return ret;
619
620         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
621                 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
622                                   dev->dev_addr, dev->addr_len);
623
624         return 0;
625 }
626
627 #ifdef CONFIG_NET_POLL_CONTROLLER
628 static void virtnet_netpoll(struct net_device *dev)
629 {
630         struct virtnet_info *vi = netdev_priv(dev);
631
632         napi_schedule(&vi->napi);
633 }
634 #endif
635
636 static int virtnet_open(struct net_device *dev)
637 {
638         struct virtnet_info *vi = netdev_priv(dev);
639
640         napi_enable(&vi->napi);
641
642         /* If all buffers were filled by other side before we napi_enabled, we
643          * won't get another interrupt, so process any outstanding packets
644          * now.  virtnet_poll wants re-enable the queue, so we disable here.
645          * We synchronize against interrupts via NAPI_STATE_SCHED */
646         if (napi_schedule_prep(&vi->napi)) {
647                 vi->rvq->vq_ops->disable_cb(vi->rvq);
648                 __napi_schedule(&vi->napi);
649         }
650         return 0;
651 }
652
653 /*
654  * Send command via the control virtqueue and check status.  Commands
655  * supported by the hypervisor, as indicated by feature bits, should
656  * never fail unless improperly formated.
657  */
658 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
659                                  struct scatterlist *data, int out, int in)
660 {
661         struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
662         struct virtio_net_ctrl_hdr ctrl;
663         virtio_net_ctrl_ack status = ~0;
664         unsigned int tmp;
665         int i;
666
667         /* Caller should know better */
668         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
669                 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
670
671         out++; /* Add header */
672         in++; /* Add return status */
673
674         ctrl.class = class;
675         ctrl.cmd = cmd;
676
677         sg_init_table(sg, out + in);
678
679         sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
680         for_each_sg(data, s, out + in - 2, i)
681                 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
682         sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
683
684         BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi) < 0);
685
686         vi->cvq->vq_ops->kick(vi->cvq);
687
688         /*
689          * Spin for a response, the kick causes an ioport write, trapping
690          * into the hypervisor, so the request should be handled immediately.
691          */
692         while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp))
693                 cpu_relax();
694
695         return status == VIRTIO_NET_OK;
696 }
697
698 static int virtnet_close(struct net_device *dev)
699 {
700         struct virtnet_info *vi = netdev_priv(dev);
701
702         napi_disable(&vi->napi);
703
704         return 0;
705 }
706
707 static int virtnet_set_tx_csum(struct net_device *dev, u32 data)
708 {
709         struct virtnet_info *vi = netdev_priv(dev);
710         struct virtio_device *vdev = vi->vdev;
711
712         if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM))
713                 return -ENOSYS;
714
715         return ethtool_op_set_tx_hw_csum(dev, data);
716 }
717
718 static void virtnet_set_rx_mode(struct net_device *dev)
719 {
720         struct virtnet_info *vi = netdev_priv(dev);
721         struct scatterlist sg[2];
722         u8 promisc, allmulti;
723         struct virtio_net_ctrl_mac *mac_data;
724         struct netdev_hw_addr *ha;
725         int uc_count;
726         int mc_count;
727         void *buf;
728         int i;
729
730         /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
731         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
732                 return;
733
734         promisc = ((dev->flags & IFF_PROMISC) != 0);
735         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
736
737         sg_init_one(sg, &promisc, sizeof(promisc));
738
739         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
740                                   VIRTIO_NET_CTRL_RX_PROMISC,
741                                   sg, 1, 0))
742                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
743                          promisc ? "en" : "dis");
744
745         sg_init_one(sg, &allmulti, sizeof(allmulti));
746
747         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
748                                   VIRTIO_NET_CTRL_RX_ALLMULTI,
749                                   sg, 1, 0))
750                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
751                          allmulti ? "en" : "dis");
752
753         uc_count = netdev_uc_count(dev);
754         mc_count = netdev_mc_count(dev);
755         /* MAC filter - use one buffer for both lists */
756         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
757                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
758         mac_data = buf;
759         if (!buf) {
760                 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
761                 return;
762         }
763
764         sg_init_table(sg, 2);
765
766         /* Store the unicast list and count in the front of the buffer */
767         mac_data->entries = uc_count;
768         i = 0;
769         netdev_for_each_uc_addr(ha, dev)
770                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
771
772         sg_set_buf(&sg[0], mac_data,
773                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
774
775         /* multicast list and count fill the end */
776         mac_data = (void *)&mac_data->macs[uc_count][0];
777
778         mac_data->entries = mc_count;
779         i = 0;
780         netdev_for_each_mc_addr(ha, dev)
781                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
782
783         sg_set_buf(&sg[1], mac_data,
784                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
785
786         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
787                                   VIRTIO_NET_CTRL_MAC_TABLE_SET,
788                                   sg, 2, 0))
789                 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
790
791         kfree(buf);
792 }
793
794 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
795 {
796         struct virtnet_info *vi = netdev_priv(dev);
797         struct scatterlist sg;
798
799         sg_init_one(&sg, &vid, sizeof(vid));
800
801         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
802                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
803                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
804 }
805
806 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
807 {
808         struct virtnet_info *vi = netdev_priv(dev);
809         struct scatterlist sg;
810
811         sg_init_one(&sg, &vid, sizeof(vid));
812
813         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
814                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
815                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
816 }
817
818 static const struct ethtool_ops virtnet_ethtool_ops = {
819         .set_tx_csum = virtnet_set_tx_csum,
820         .set_sg = ethtool_op_set_sg,
821         .set_tso = ethtool_op_set_tso,
822         .set_ufo = ethtool_op_set_ufo,
823         .get_link = ethtool_op_get_link,
824 };
825
826 #define MIN_MTU 68
827 #define MAX_MTU 65535
828
829 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
830 {
831         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
832                 return -EINVAL;
833         dev->mtu = new_mtu;
834         return 0;
835 }
836
837 static const struct net_device_ops virtnet_netdev = {
838         .ndo_open            = virtnet_open,
839         .ndo_stop            = virtnet_close,
840         .ndo_start_xmit      = start_xmit,
841         .ndo_validate_addr   = eth_validate_addr,
842         .ndo_set_mac_address = virtnet_set_mac_address,
843         .ndo_set_rx_mode     = virtnet_set_rx_mode,
844         .ndo_change_mtu      = virtnet_change_mtu,
845         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
846         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
847 #ifdef CONFIG_NET_POLL_CONTROLLER
848         .ndo_poll_controller = virtnet_netpoll,
849 #endif
850 };
851
852 static void virtnet_update_status(struct virtnet_info *vi)
853 {
854         u16 v;
855
856         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS))
857                 return;
858
859         vi->vdev->config->get(vi->vdev,
860                               offsetof(struct virtio_net_config, status),
861                               &v, sizeof(v));
862
863         /* Ignore unknown (future) status bits */
864         v &= VIRTIO_NET_S_LINK_UP;
865
866         if (vi->status == v)
867                 return;
868
869         vi->status = v;
870
871         if (vi->status & VIRTIO_NET_S_LINK_UP) {
872                 netif_carrier_on(vi->dev);
873                 netif_wake_queue(vi->dev);
874         } else {
875                 netif_carrier_off(vi->dev);
876                 netif_stop_queue(vi->dev);
877         }
878 }
879
880 static void virtnet_config_changed(struct virtio_device *vdev)
881 {
882         struct virtnet_info *vi = vdev->priv;
883
884         virtnet_update_status(vi);
885 }
886
887 static int virtnet_probe(struct virtio_device *vdev)
888 {
889         int err;
890         struct net_device *dev;
891         struct virtnet_info *vi;
892         struct virtqueue *vqs[3];
893         vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
894         const char *names[] = { "input", "output", "control" };
895         int nvqs;
896
897         /* Allocate ourselves a network device with room for our info */
898         dev = alloc_etherdev(sizeof(struct virtnet_info));
899         if (!dev)
900                 return -ENOMEM;
901
902         /* Set up network device as normal. */
903         dev->netdev_ops = &virtnet_netdev;
904         dev->features = NETIF_F_HIGHDMA;
905         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
906         SET_NETDEV_DEV(dev, &vdev->dev);
907
908         /* Do we support "hardware" checksums? */
909         if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
910                 /* This opens up the world of extra features. */
911                 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
912                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
913                         dev->features |= NETIF_F_TSO | NETIF_F_UFO
914                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
915                 }
916                 /* Individual feature bits: what can host handle? */
917                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
918                         dev->features |= NETIF_F_TSO;
919                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
920                         dev->features |= NETIF_F_TSO6;
921                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
922                         dev->features |= NETIF_F_TSO_ECN;
923                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
924                         dev->features |= NETIF_F_UFO;
925         }
926
927         /* Configuration may specify what MAC to use.  Otherwise random. */
928         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
929                 vdev->config->get(vdev,
930                                   offsetof(struct virtio_net_config, mac),
931                                   dev->dev_addr, dev->addr_len);
932         } else
933                 random_ether_addr(dev->dev_addr);
934
935         /* Set up our device-specific information */
936         vi = netdev_priv(dev);
937         netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
938         vi->dev = dev;
939         vi->vdev = vdev;
940         vdev->priv = vi;
941         vi->pages = NULL;
942         INIT_DELAYED_WORK(&vi->refill, refill_work);
943
944         /* If we can receive ANY GSO packets, we must allocate large ones. */
945         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
946             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
947             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
948                 vi->big_packets = true;
949
950         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
951                 vi->mergeable_rx_bufs = true;
952
953         /* We expect two virtqueues, receive then send,
954          * and optionally control. */
955         nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
956
957         err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names);
958         if (err)
959                 goto free;
960
961         vi->rvq = vqs[0];
962         vi->svq = vqs[1];
963
964         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
965                 vi->cvq = vqs[2];
966
967                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
968                         dev->features |= NETIF_F_HW_VLAN_FILTER;
969         }
970
971         err = register_netdev(dev);
972         if (err) {
973                 pr_debug("virtio_net: registering device failed\n");
974                 goto free_vqs;
975         }
976
977         /* Last of all, set up some receive buffers. */
978         try_fill_recv(vi, GFP_KERNEL);
979
980         /* If we didn't even get one input buffer, we're useless. */
981         if (vi->num == 0) {
982                 err = -ENOMEM;
983                 goto unregister;
984         }
985
986         vi->status = VIRTIO_NET_S_LINK_UP;
987         virtnet_update_status(vi);
988         netif_carrier_on(dev);
989
990         pr_debug("virtnet: registered device %s\n", dev->name);
991         return 0;
992
993 unregister:
994         unregister_netdev(dev);
995         cancel_delayed_work_sync(&vi->refill);
996 free_vqs:
997         vdev->config->del_vqs(vdev);
998 free:
999         free_netdev(dev);
1000         return err;
1001 }
1002
1003 static void free_unused_bufs(struct virtnet_info *vi)
1004 {
1005         void *buf;
1006         while (1) {
1007                 buf = vi->svq->vq_ops->detach_unused_buf(vi->svq);
1008                 if (!buf)
1009                         break;
1010                 dev_kfree_skb(buf);
1011         }
1012         while (1) {
1013                 buf = vi->rvq->vq_ops->detach_unused_buf(vi->rvq);
1014                 if (!buf)
1015                         break;
1016                 if (vi->mergeable_rx_bufs || vi->big_packets)
1017                         give_pages(vi, buf);
1018                 else
1019                         dev_kfree_skb(buf);
1020                 --vi->num;
1021         }
1022         BUG_ON(vi->num != 0);
1023 }
1024
1025 static void __devexit virtnet_remove(struct virtio_device *vdev)
1026 {
1027         struct virtnet_info *vi = vdev->priv;
1028
1029         /* Stop all the virtqueues. */
1030         vdev->config->reset(vdev);
1031
1032
1033         unregister_netdev(vi->dev);
1034         cancel_delayed_work_sync(&vi->refill);
1035
1036         /* Free unused buffers in both send and recv, if any. */
1037         free_unused_bufs(vi);
1038
1039         vdev->config->del_vqs(vi->vdev);
1040
1041         while (vi->pages)
1042                 __free_pages(get_a_page(vi, GFP_KERNEL), 0);
1043
1044         free_netdev(vi->dev);
1045 }
1046
1047 static struct virtio_device_id id_table[] = {
1048         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1049         { 0 },
1050 };
1051
1052 static unsigned int features[] = {
1053         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1054         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1055         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1056         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1057         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1058         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1059         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1060 };
1061
1062 static struct virtio_driver virtio_net_driver = {
1063         .feature_table = features,
1064         .feature_table_size = ARRAY_SIZE(features),
1065         .driver.name =  KBUILD_MODNAME,
1066         .driver.owner = THIS_MODULE,
1067         .id_table =     id_table,
1068         .probe =        virtnet_probe,
1069         .remove =       __devexit_p(virtnet_remove),
1070         .config_changed = virtnet_config_changed,
1071 };
1072
1073 static int __init init(void)
1074 {
1075         return register_virtio_driver(&virtio_net_driver);
1076 }
1077
1078 static void __exit fini(void)
1079 {
1080         unregister_virtio_driver(&virtio_net_driver);
1081 }
1082 module_init(init);
1083 module_exit(fini);
1084
1085 MODULE_DEVICE_TABLE(virtio, id_table);
1086 MODULE_DESCRIPTION("Virtio network driver");
1087 MODULE_LICENSE("GPL");