Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[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 #include <linux/slab.h>
29
30 static int napi_weight = 128;
31 module_param(napi_weight, int, 0444);
32
33 static int csum = 1, gso = 1;
34 module_param(csum, bool, 0444);
35 module_param(gso, bool, 0444);
36
37 /* FIXME: MTU in config. */
38 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
39 #define GOOD_COPY_LEN   128
40
41 #define VIRTNET_SEND_COMMAND_SG_MAX    2
42
43 struct virtnet_info {
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         /* fragments + linear part + virtio header */
66         struct scatterlist rx_sg[MAX_SKB_FRAGS + 2];
67         struct scatterlist tx_sg[MAX_SKB_FRAGS + 2];
68 };
69
70 struct skb_vnet_hdr {
71         union {
72                 struct virtio_net_hdr hdr;
73                 struct virtio_net_hdr_mrg_rxbuf mhdr;
74         };
75         unsigned int num_sg;
76 };
77
78 struct padded_vnet_hdr {
79         struct virtio_net_hdr hdr;
80         /*
81          * virtio_net_hdr should be in a separated sg buffer because of a
82          * QEMU bug, and data sg buffer shares same page with this header sg.
83          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
84          */
85         char padding[6];
86 };
87
88 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
89 {
90         return (struct skb_vnet_hdr *)skb->cb;
91 }
92
93 /*
94  * private is used to chain pages for big packets, put the whole
95  * most recent used list in the beginning for reuse
96  */
97 static void give_pages(struct virtnet_info *vi, struct page *page)
98 {
99         struct page *end;
100
101         /* Find end of list, sew whole thing into vi->pages. */
102         for (end = page; end->private; end = (struct page *)end->private);
103         end->private = (unsigned long)vi->pages;
104         vi->pages = page;
105 }
106
107 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
108 {
109         struct page *p = vi->pages;
110
111         if (p) {
112                 vi->pages = (struct page *)p->private;
113                 /* clear private here, it is used to chain pages */
114                 p->private = 0;
115         } else
116                 p = alloc_page(gfp_mask);
117         return p;
118 }
119
120 static void skb_xmit_done(struct virtqueue *svq)
121 {
122         struct virtnet_info *vi = svq->vdev->priv;
123
124         /* Suppress further interrupts. */
125         svq->vq_ops->disable_cb(svq);
126
127         /* We were probably waiting for more output buffers. */
128         netif_wake_queue(vi->dev);
129 }
130
131 static void set_skb_frag(struct sk_buff *skb, struct page *page,
132                          unsigned int offset, unsigned int *len)
133 {
134         int i = skb_shinfo(skb)->nr_frags;
135         skb_frag_t *f;
136
137         f = &skb_shinfo(skb)->frags[i];
138         f->size = min((unsigned)PAGE_SIZE - offset, *len);
139         f->page_offset = offset;
140         f->page = page;
141
142         skb->data_len += f->size;
143         skb->len += f->size;
144         skb_shinfo(skb)->nr_frags++;
145         *len -= f->size;
146 }
147
148 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
149                                    struct page *page, unsigned int len)
150 {
151         struct sk_buff *skb;
152         struct skb_vnet_hdr *hdr;
153         unsigned int copy, hdr_len, offset;
154         char *p;
155
156         p = page_address(page);
157
158         /* copy small packet so we can reuse these pages for small data */
159         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
160         if (unlikely(!skb))
161                 return NULL;
162
163         hdr = skb_vnet_hdr(skb);
164
165         if (vi->mergeable_rx_bufs) {
166                 hdr_len = sizeof hdr->mhdr;
167                 offset = hdr_len;
168         } else {
169                 hdr_len = sizeof hdr->hdr;
170                 offset = sizeof(struct padded_vnet_hdr);
171         }
172
173         memcpy(hdr, p, hdr_len);
174
175         len -= hdr_len;
176         p += offset;
177
178         copy = len;
179         if (copy > skb_tailroom(skb))
180                 copy = skb_tailroom(skb);
181         memcpy(skb_put(skb, copy), p, copy);
182
183         len -= copy;
184         offset += copy;
185
186         while (len) {
187                 set_skb_frag(skb, page, offset, &len);
188                 page = (struct page *)page->private;
189                 offset = 0;
190         }
191
192         if (page)
193                 give_pages(vi, page);
194
195         return skb;
196 }
197
198 static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
199 {
200         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
201         struct page *page;
202         int num_buf, i, len;
203
204         num_buf = hdr->mhdr.num_buffers;
205         while (--num_buf) {
206                 i = skb_shinfo(skb)->nr_frags;
207                 if (i >= MAX_SKB_FRAGS) {
208                         pr_debug("%s: packet too long\n", skb->dev->name);
209                         skb->dev->stats.rx_length_errors++;
210                         return -EINVAL;
211                 }
212
213                 page = vi->rvq->vq_ops->get_buf(vi->rvq, &len);
214                 if (!page) {
215                         pr_debug("%s: rx error: %d buffers missing\n",
216                                  skb->dev->name, hdr->mhdr.num_buffers);
217                         skb->dev->stats.rx_length_errors++;
218                         return -EINVAL;
219                 }
220                 if (len > PAGE_SIZE)
221                         len = PAGE_SIZE;
222
223                 set_skb_frag(skb, page, 0, &len);
224
225                 --vi->num;
226         }
227         return 0;
228 }
229
230 static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
231 {
232         struct virtnet_info *vi = netdev_priv(dev);
233         struct sk_buff *skb;
234         struct page *page;
235         struct skb_vnet_hdr *hdr;
236
237         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
238                 pr_debug("%s: short packet %i\n", dev->name, len);
239                 dev->stats.rx_length_errors++;
240                 if (vi->mergeable_rx_bufs || vi->big_packets)
241                         give_pages(vi, buf);
242                 else
243                         dev_kfree_skb(buf);
244                 return;
245         }
246
247         if (!vi->mergeable_rx_bufs && !vi->big_packets) {
248                 skb = buf;
249                 len -= sizeof(struct virtio_net_hdr);
250                 skb_trim(skb, len);
251         } else {
252                 page = buf;
253                 skb = page_to_skb(vi, page, len);
254                 if (unlikely(!skb)) {
255                         dev->stats.rx_dropped++;
256                         give_pages(vi, page);
257                         return;
258                 }
259                 if (vi->mergeable_rx_bufs)
260                         if (receive_mergeable(vi, skb)) {
261                                 dev_kfree_skb(skb);
262                                 return;
263                         }
264         }
265
266         hdr = skb_vnet_hdr(skb);
267         skb->truesize += skb->data_len;
268         dev->stats.rx_bytes += skb->len;
269         dev->stats.rx_packets++;
270
271         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
272                 pr_debug("Needs csum!\n");
273                 if (!skb_partial_csum_set(skb,
274                                           hdr->hdr.csum_start,
275                                           hdr->hdr.csum_offset))
276                         goto frame_err;
277         }
278
279         skb->protocol = eth_type_trans(skb, dev);
280         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
281                  ntohs(skb->protocol), skb->len, skb->pkt_type);
282
283         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
284                 pr_debug("GSO!\n");
285                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
286                 case VIRTIO_NET_HDR_GSO_TCPV4:
287                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
288                         break;
289                 case VIRTIO_NET_HDR_GSO_UDP:
290                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
291                         break;
292                 case VIRTIO_NET_HDR_GSO_TCPV6:
293                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
294                         break;
295                 default:
296                         if (net_ratelimit())
297                                 printk(KERN_WARNING "%s: bad gso type %u.\n",
298                                        dev->name, hdr->hdr.gso_type);
299                         goto frame_err;
300                 }
301
302                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
303                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
304
305                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
306                 if (skb_shinfo(skb)->gso_size == 0) {
307                         if (net_ratelimit())
308                                 printk(KERN_WARNING "%s: zero gso size.\n",
309                                        dev->name);
310                         goto frame_err;
311                 }
312
313                 /* Header must be checked, and gso_segs computed. */
314                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
315                 skb_shinfo(skb)->gso_segs = 0;
316         }
317
318         netif_receive_skb(skb);
319         return;
320
321 frame_err:
322         dev->stats.rx_frame_errors++;
323         dev_kfree_skb(skb);
324 }
325
326 static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp)
327 {
328         struct sk_buff *skb;
329         struct skb_vnet_hdr *hdr;
330         int err;
331
332         sg_init_table(sg, 2);
333         skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN);
334         if (unlikely(!skb))
335                 return -ENOMEM;
336
337         skb_put(skb, MAX_PACKET_LEN);
338
339         hdr = skb_vnet_hdr(skb);
340         sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr);
341
342         skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len);
343
344         err = vi->rvq->vq_ops->add_buf(vi->rvq, vi->rx_sg, 0, 2, skb);
345         if (err < 0)
346                 dev_kfree_skb(skb);
347
348         return err;
349 }
350
351 static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp)
352 {
353         struct page *first, *list = NULL;
354         char *p;
355         int i, err, offset;
356
357         /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */
358         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
359                 first = get_a_page(vi, gfp);
360                 if (!first) {
361                         if (list)
362                                 give_pages(vi, list);
363                         return -ENOMEM;
364                 }
365                 sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE);
366
367                 /* chain new page in list head to match sg */
368                 first->private = (unsigned long)list;
369                 list = first;
370         }
371
372         first = get_a_page(vi, gfp);
373         if (!first) {
374                 give_pages(vi, list);
375                 return -ENOMEM;
376         }
377         p = page_address(first);
378
379         /* vi->rx_sg[0], vi->rx_sg[1] share the same page */
380         /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */
381         sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr));
382
383         /* vi->rx_sg[1] for data packet, from offset */
384         offset = sizeof(struct padded_vnet_hdr);
385         sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset);
386
387         /* chain first in list head */
388         first->private = (unsigned long)list;
389         err = vi->rvq->vq_ops->add_buf(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2,
390                                        first);
391         if (err < 0)
392                 give_pages(vi, first);
393
394         return err;
395 }
396
397 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp)
398 {
399         struct page *page;
400         int err;
401
402         page = get_a_page(vi, gfp);
403         if (!page)
404                 return -ENOMEM;
405
406         sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE);
407
408         err = vi->rvq->vq_ops->add_buf(vi->rvq, vi->rx_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 skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
518         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
519
520         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
521
522         if (skb->ip_summed == CHECKSUM_PARTIAL) {
523                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
524                 hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb);
525                 hdr->hdr.csum_offset = skb->csum_offset;
526         } else {
527                 hdr->hdr.flags = 0;
528                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
529         }
530
531         if (skb_is_gso(skb)) {
532                 hdr->hdr.hdr_len = skb_headlen(skb);
533                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
534                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
535                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
536                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
537                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
538                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
539                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
540                 else
541                         BUG();
542                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
543                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
544         } else {
545                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
546                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
547         }
548
549         hdr->mhdr.num_buffers = 0;
550
551         /* Encode metadata header at front. */
552         if (vi->mergeable_rx_bufs)
553                 sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr);
554         else
555                 sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr);
556
557         hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1;
558         return vi->svq->vq_ops->add_buf(vi->svq, vi->tx_sg, hdr->num_sg,
559                                         0, skb);
560 }
561
562 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
563 {
564         struct virtnet_info *vi = netdev_priv(dev);
565         int capacity;
566
567 again:
568         /* Free up any pending old buffers before queueing new ones. */
569         free_old_xmit_skbs(vi);
570
571         /* Try to transmit */
572         capacity = xmit_skb(vi, skb);
573
574         /* This can happen with OOM and indirect buffers. */
575         if (unlikely(capacity < 0)) {
576                 netif_stop_queue(dev);
577                 dev_warn(&dev->dev, "Unexpected full queue\n");
578                 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
579                         vi->svq->vq_ops->disable_cb(vi->svq);
580                         netif_start_queue(dev);
581                         goto again;
582                 }
583                 return NETDEV_TX_BUSY;
584         }
585         vi->svq->vq_ops->kick(vi->svq);
586
587         /* Don't wait up for transmitted skbs to be freed. */
588         skb_orphan(skb);
589         nf_reset(skb);
590
591         /* Apparently nice girls don't return TX_BUSY; stop the queue
592          * before it gets out of hand.  Naturally, this wastes entries. */
593         if (capacity < 2+MAX_SKB_FRAGS) {
594                 netif_stop_queue(dev);
595                 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
596                         /* More just got used, free them then recheck. */
597                         capacity += free_old_xmit_skbs(vi);
598                         if (capacity >= 2+MAX_SKB_FRAGS) {
599                                 netif_start_queue(dev);
600                                 vi->svq->vq_ops->disable_cb(vi->svq);
601                         }
602                 }
603         }
604
605         return NETDEV_TX_OK;
606 }
607
608 static int virtnet_set_mac_address(struct net_device *dev, void *p)
609 {
610         struct virtnet_info *vi = netdev_priv(dev);
611         struct virtio_device *vdev = vi->vdev;
612         int ret;
613
614         ret = eth_mac_addr(dev, p);
615         if (ret)
616                 return ret;
617
618         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
619                 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
620                                   dev->dev_addr, dev->addr_len);
621
622         return 0;
623 }
624
625 #ifdef CONFIG_NET_POLL_CONTROLLER
626 static void virtnet_netpoll(struct net_device *dev)
627 {
628         struct virtnet_info *vi = netdev_priv(dev);
629
630         napi_schedule(&vi->napi);
631 }
632 #endif
633
634 static int virtnet_open(struct net_device *dev)
635 {
636         struct virtnet_info *vi = netdev_priv(dev);
637
638         napi_enable(&vi->napi);
639
640         /* If all buffers were filled by other side before we napi_enabled, we
641          * won't get another interrupt, so process any outstanding packets
642          * now.  virtnet_poll wants re-enable the queue, so we disable here.
643          * We synchronize against interrupts via NAPI_STATE_SCHED */
644         if (napi_schedule_prep(&vi->napi)) {
645                 vi->rvq->vq_ops->disable_cb(vi->rvq);
646                 __napi_schedule(&vi->napi);
647         }
648         return 0;
649 }
650
651 /*
652  * Send command via the control virtqueue and check status.  Commands
653  * supported by the hypervisor, as indicated by feature bits, should
654  * never fail unless improperly formated.
655  */
656 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
657                                  struct scatterlist *data, int out, int in)
658 {
659         struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
660         struct virtio_net_ctrl_hdr ctrl;
661         virtio_net_ctrl_ack status = ~0;
662         unsigned int tmp;
663         int i;
664
665         /* Caller should know better */
666         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
667                 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
668
669         out++; /* Add header */
670         in++; /* Add return status */
671
672         ctrl.class = class;
673         ctrl.cmd = cmd;
674
675         sg_init_table(sg, out + in);
676
677         sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
678         for_each_sg(data, s, out + in - 2, i)
679                 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
680         sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
681
682         BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi) < 0);
683
684         vi->cvq->vq_ops->kick(vi->cvq);
685
686         /*
687          * Spin for a response, the kick causes an ioport write, trapping
688          * into the hypervisor, so the request should be handled immediately.
689          */
690         while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp))
691                 cpu_relax();
692
693         return status == VIRTIO_NET_OK;
694 }
695
696 static int virtnet_close(struct net_device *dev)
697 {
698         struct virtnet_info *vi = netdev_priv(dev);
699
700         napi_disable(&vi->napi);
701
702         return 0;
703 }
704
705 static int virtnet_set_tx_csum(struct net_device *dev, u32 data)
706 {
707         struct virtnet_info *vi = netdev_priv(dev);
708         struct virtio_device *vdev = vi->vdev;
709
710         if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM))
711                 return -ENOSYS;
712
713         return ethtool_op_set_tx_hw_csum(dev, data);
714 }
715
716 static void virtnet_set_rx_mode(struct net_device *dev)
717 {
718         struct virtnet_info *vi = netdev_priv(dev);
719         struct scatterlist sg[2];
720         u8 promisc, allmulti;
721         struct virtio_net_ctrl_mac *mac_data;
722         struct netdev_hw_addr *ha;
723         int uc_count;
724         int mc_count;
725         void *buf;
726         int i;
727
728         /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
729         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
730                 return;
731
732         promisc = ((dev->flags & IFF_PROMISC) != 0);
733         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
734
735         sg_init_one(sg, &promisc, sizeof(promisc));
736
737         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
738                                   VIRTIO_NET_CTRL_RX_PROMISC,
739                                   sg, 1, 0))
740                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
741                          promisc ? "en" : "dis");
742
743         sg_init_one(sg, &allmulti, sizeof(allmulti));
744
745         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
746                                   VIRTIO_NET_CTRL_RX_ALLMULTI,
747                                   sg, 1, 0))
748                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
749                          allmulti ? "en" : "dis");
750
751         uc_count = netdev_uc_count(dev);
752         mc_count = netdev_mc_count(dev);
753         /* MAC filter - use one buffer for both lists */
754         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
755                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
756         mac_data = buf;
757         if (!buf) {
758                 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
759                 return;
760         }
761
762         sg_init_table(sg, 2);
763
764         /* Store the unicast list and count in the front of the buffer */
765         mac_data->entries = uc_count;
766         i = 0;
767         netdev_for_each_uc_addr(ha, dev)
768                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
769
770         sg_set_buf(&sg[0], mac_data,
771                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
772
773         /* multicast list and count fill the end */
774         mac_data = (void *)&mac_data->macs[uc_count][0];
775
776         mac_data->entries = mc_count;
777         i = 0;
778         netdev_for_each_mc_addr(ha, dev)
779                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
780
781         sg_set_buf(&sg[1], mac_data,
782                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
783
784         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
785                                   VIRTIO_NET_CTRL_MAC_TABLE_SET,
786                                   sg, 2, 0))
787                 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
788
789         kfree(buf);
790 }
791
792 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
793 {
794         struct virtnet_info *vi = netdev_priv(dev);
795         struct scatterlist sg;
796
797         sg_init_one(&sg, &vid, sizeof(vid));
798
799         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
800                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
801                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
802 }
803
804 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
805 {
806         struct virtnet_info *vi = netdev_priv(dev);
807         struct scatterlist sg;
808
809         sg_init_one(&sg, &vid, sizeof(vid));
810
811         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
812                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
813                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
814 }
815
816 static const struct ethtool_ops virtnet_ethtool_ops = {
817         .set_tx_csum = virtnet_set_tx_csum,
818         .set_sg = ethtool_op_set_sg,
819         .set_tso = ethtool_op_set_tso,
820         .set_ufo = ethtool_op_set_ufo,
821         .get_link = ethtool_op_get_link,
822 };
823
824 #define MIN_MTU 68
825 #define MAX_MTU 65535
826
827 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
828 {
829         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
830                 return -EINVAL;
831         dev->mtu = new_mtu;
832         return 0;
833 }
834
835 static const struct net_device_ops virtnet_netdev = {
836         .ndo_open            = virtnet_open,
837         .ndo_stop            = virtnet_close,
838         .ndo_start_xmit      = start_xmit,
839         .ndo_validate_addr   = eth_validate_addr,
840         .ndo_set_mac_address = virtnet_set_mac_address,
841         .ndo_set_rx_mode     = virtnet_set_rx_mode,
842         .ndo_change_mtu      = virtnet_change_mtu,
843         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
844         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
845 #ifdef CONFIG_NET_POLL_CONTROLLER
846         .ndo_poll_controller = virtnet_netpoll,
847 #endif
848 };
849
850 static void virtnet_update_status(struct virtnet_info *vi)
851 {
852         u16 v;
853
854         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS))
855                 return;
856
857         vi->vdev->config->get(vi->vdev,
858                               offsetof(struct virtio_net_config, status),
859                               &v, sizeof(v));
860
861         /* Ignore unknown (future) status bits */
862         v &= VIRTIO_NET_S_LINK_UP;
863
864         if (vi->status == v)
865                 return;
866
867         vi->status = v;
868
869         if (vi->status & VIRTIO_NET_S_LINK_UP) {
870                 netif_carrier_on(vi->dev);
871                 netif_wake_queue(vi->dev);
872         } else {
873                 netif_carrier_off(vi->dev);
874                 netif_stop_queue(vi->dev);
875         }
876 }
877
878 static void virtnet_config_changed(struct virtio_device *vdev)
879 {
880         struct virtnet_info *vi = vdev->priv;
881
882         virtnet_update_status(vi);
883 }
884
885 static int virtnet_probe(struct virtio_device *vdev)
886 {
887         int err;
888         struct net_device *dev;
889         struct virtnet_info *vi;
890         struct virtqueue *vqs[3];
891         vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
892         const char *names[] = { "input", "output", "control" };
893         int nvqs;
894
895         /* Allocate ourselves a network device with room for our info */
896         dev = alloc_etherdev(sizeof(struct virtnet_info));
897         if (!dev)
898                 return -ENOMEM;
899
900         /* Set up network device as normal. */
901         dev->netdev_ops = &virtnet_netdev;
902         dev->features = NETIF_F_HIGHDMA;
903         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
904         SET_NETDEV_DEV(dev, &vdev->dev);
905
906         /* Do we support "hardware" checksums? */
907         if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
908                 /* This opens up the world of extra features. */
909                 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
910                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
911                         dev->features |= NETIF_F_TSO | NETIF_F_UFO
912                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
913                 }
914                 /* Individual feature bits: what can host handle? */
915                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
916                         dev->features |= NETIF_F_TSO;
917                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
918                         dev->features |= NETIF_F_TSO6;
919                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
920                         dev->features |= NETIF_F_TSO_ECN;
921                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
922                         dev->features |= NETIF_F_UFO;
923         }
924
925         /* Configuration may specify what MAC to use.  Otherwise random. */
926         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
927                 vdev->config->get(vdev,
928                                   offsetof(struct virtio_net_config, mac),
929                                   dev->dev_addr, dev->addr_len);
930         } else
931                 random_ether_addr(dev->dev_addr);
932
933         /* Set up our device-specific information */
934         vi = netdev_priv(dev);
935         netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
936         vi->dev = dev;
937         vi->vdev = vdev;
938         vdev->priv = vi;
939         vi->pages = NULL;
940         INIT_DELAYED_WORK(&vi->refill, refill_work);
941         sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg));
942         sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg));
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");