include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[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 {
45         struct virtio_device *vdev;
46         struct virtqueue *rvq, *svq, *cvq;
47         struct net_device *dev;
48         struct napi_struct napi;
49         unsigned int status;
50
51         /* Number of input buffers, and max we've ever had. */
52         unsigned int num, max;
53
54         /* I like... big packets and I cannot lie! */
55         bool big_packets;
56
57         /* Host will merge rx buffers for big packets (shake it! shake it!) */
58         bool mergeable_rx_bufs;
59
60         /* Work struct for refilling if we run low on memory. */
61         struct delayed_work refill;
62
63         /* Chain pages by the private ptr. */
64         struct page *pages;
65 };
66
67 struct skb_vnet_hdr {
68         union {
69                 struct virtio_net_hdr hdr;
70                 struct virtio_net_hdr_mrg_rxbuf mhdr;
71         };
72         unsigned int num_sg;
73 };
74
75 struct padded_vnet_hdr {
76         struct virtio_net_hdr hdr;
77         /*
78          * virtio_net_hdr should be in a separated sg buffer because of a
79          * QEMU bug, and data sg buffer shares same page with this header sg.
80          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
81          */
82         char padding[6];
83 };
84
85 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
86 {
87         return (struct skb_vnet_hdr *)skb->cb;
88 }
89
90 /*
91  * private is used to chain pages for big packets, put the whole
92  * most recent used list in the beginning for reuse
93  */
94 static void give_pages(struct virtnet_info *vi, struct page *page)
95 {
96         struct page *end;
97
98         /* Find end of list, sew whole thing into vi->pages. */
99         for (end = page; end->private; end = (struct page *)end->private);
100         end->private = (unsigned long)vi->pages;
101         vi->pages = page;
102 }
103
104 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
105 {
106         struct page *p = vi->pages;
107
108         if (p) {
109                 vi->pages = (struct page *)p->private;
110                 /* clear private here, it is used to chain pages */
111                 p->private = 0;
112         } else
113                 p = alloc_page(gfp_mask);
114         return p;
115 }
116
117 static void skb_xmit_done(struct virtqueue *svq)
118 {
119         struct virtnet_info *vi = svq->vdev->priv;
120
121         /* Suppress further interrupts. */
122         svq->vq_ops->disable_cb(svq);
123
124         /* We were probably waiting for more output buffers. */
125         netif_wake_queue(vi->dev);
126 }
127
128 static void set_skb_frag(struct sk_buff *skb, struct page *page,
129                          unsigned int offset, unsigned int *len)
130 {
131         int i = skb_shinfo(skb)->nr_frags;
132         skb_frag_t *f;
133
134         f = &skb_shinfo(skb)->frags[i];
135         f->size = min((unsigned)PAGE_SIZE - offset, *len);
136         f->page_offset = offset;
137         f->page = page;
138
139         skb->data_len += f->size;
140         skb->len += f->size;
141         skb_shinfo(skb)->nr_frags++;
142         *len -= f->size;
143 }
144
145 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
146                                    struct page *page, unsigned int len)
147 {
148         struct sk_buff *skb;
149         struct skb_vnet_hdr *hdr;
150         unsigned int copy, hdr_len, offset;
151         char *p;
152
153         p = page_address(page);
154
155         /* copy small packet so we can reuse these pages for small data */
156         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
157         if (unlikely(!skb))
158                 return NULL;
159
160         hdr = skb_vnet_hdr(skb);
161
162         if (vi->mergeable_rx_bufs) {
163                 hdr_len = sizeof hdr->mhdr;
164                 offset = hdr_len;
165         } else {
166                 hdr_len = sizeof hdr->hdr;
167                 offset = sizeof(struct padded_vnet_hdr);
168         }
169
170         memcpy(hdr, p, hdr_len);
171
172         len -= hdr_len;
173         p += offset;
174
175         copy = len;
176         if (copy > skb_tailroom(skb))
177                 copy = skb_tailroom(skb);
178         memcpy(skb_put(skb, copy), p, copy);
179
180         len -= copy;
181         offset += copy;
182
183         while (len) {
184                 set_skb_frag(skb, page, offset, &len);
185                 page = (struct page *)page->private;
186                 offset = 0;
187         }
188
189         if (page)
190                 give_pages(vi, page);
191
192         return skb;
193 }
194
195 static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
196 {
197         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
198         struct page *page;
199         int num_buf, i, len;
200
201         num_buf = hdr->mhdr.num_buffers;
202         while (--num_buf) {
203                 i = skb_shinfo(skb)->nr_frags;
204                 if (i >= MAX_SKB_FRAGS) {
205                         pr_debug("%s: packet too long\n", skb->dev->name);
206                         skb->dev->stats.rx_length_errors++;
207                         return -EINVAL;
208                 }
209
210                 page = vi->rvq->vq_ops->get_buf(vi->rvq, &len);
211                 if (!page) {
212                         pr_debug("%s: rx error: %d buffers missing\n",
213                                  skb->dev->name, hdr->mhdr.num_buffers);
214                         skb->dev->stats.rx_length_errors++;
215                         return -EINVAL;
216                 }
217                 if (len > PAGE_SIZE)
218                         len = PAGE_SIZE;
219
220                 set_skb_frag(skb, page, 0, &len);
221
222                 --vi->num;
223         }
224         return 0;
225 }
226
227 static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
228 {
229         struct virtnet_info *vi = netdev_priv(dev);
230         struct sk_buff *skb;
231         struct page *page;
232         struct skb_vnet_hdr *hdr;
233
234         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
235                 pr_debug("%s: short packet %i\n", dev->name, len);
236                 dev->stats.rx_length_errors++;
237                 if (vi->mergeable_rx_bufs || vi->big_packets)
238                         give_pages(vi, buf);
239                 else
240                         dev_kfree_skb(buf);
241                 return;
242         }
243
244         if (!vi->mergeable_rx_bufs && !vi->big_packets) {
245                 skb = buf;
246                 len -= sizeof(struct virtio_net_hdr);
247                 skb_trim(skb, len);
248         } else {
249                 page = buf;
250                 skb = page_to_skb(vi, page, len);
251                 if (unlikely(!skb)) {
252                         dev->stats.rx_dropped++;
253                         give_pages(vi, page);
254                         return;
255                 }
256                 if (vi->mergeable_rx_bufs)
257                         if (receive_mergeable(vi, skb)) {
258                                 dev_kfree_skb(skb);
259                                 return;
260                         }
261         }
262
263         hdr = skb_vnet_hdr(skb);
264         skb->truesize += skb->data_len;
265         dev->stats.rx_bytes += skb->len;
266         dev->stats.rx_packets++;
267
268         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
269                 pr_debug("Needs csum!\n");
270                 if (!skb_partial_csum_set(skb,
271                                           hdr->hdr.csum_start,
272                                           hdr->hdr.csum_offset))
273                         goto frame_err;
274         }
275
276         skb->protocol = eth_type_trans(skb, dev);
277         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
278                  ntohs(skb->protocol), skb->len, skb->pkt_type);
279
280         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
281                 pr_debug("GSO!\n");
282                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
283                 case VIRTIO_NET_HDR_GSO_TCPV4:
284                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
285                         break;
286                 case VIRTIO_NET_HDR_GSO_UDP:
287                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
288                         break;
289                 case VIRTIO_NET_HDR_GSO_TCPV6:
290                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
291                         break;
292                 default:
293                         if (net_ratelimit())
294                                 printk(KERN_WARNING "%s: bad gso type %u.\n",
295                                        dev->name, hdr->hdr.gso_type);
296                         goto frame_err;
297                 }
298
299                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
300                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
301
302                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
303                 if (skb_shinfo(skb)->gso_size == 0) {
304                         if (net_ratelimit())
305                                 printk(KERN_WARNING "%s: zero gso size.\n",
306                                        dev->name);
307                         goto frame_err;
308                 }
309
310                 /* Header must be checked, and gso_segs computed. */
311                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
312                 skb_shinfo(skb)->gso_segs = 0;
313         }
314
315         netif_receive_skb(skb);
316         return;
317
318 frame_err:
319         dev->stats.rx_frame_errors++;
320         dev_kfree_skb(skb);
321 }
322
323 static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp)
324 {
325         struct sk_buff *skb;
326         struct skb_vnet_hdr *hdr;
327         struct scatterlist sg[2];
328         int err;
329
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         /* page in sg[MAX_SKB_FRAGS + 1] is list tail */
356         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
357                 first = get_a_page(vi, gfp);
358                 if (!first) {
359                         if (list)
360                                 give_pages(vi, list);
361                         return -ENOMEM;
362                 }
363                 sg_set_buf(&sg[i], page_address(first), PAGE_SIZE);
364
365                 /* chain new page in list head to match sg */
366                 first->private = (unsigned long)list;
367                 list = first;
368         }
369
370         first = get_a_page(vi, gfp);
371         if (!first) {
372                 give_pages(vi, list);
373                 return -ENOMEM;
374         }
375         p = page_address(first);
376
377         /* sg[0], sg[1] share the same page */
378         /* a separated sg[0] for  virtio_net_hdr only during to QEMU bug*/
379         sg_set_buf(&sg[0], p, sizeof(struct virtio_net_hdr));
380
381         /* sg[1] for data packet, from offset */
382         offset = sizeof(struct padded_vnet_hdr);
383         sg_set_buf(&sg[1], p + offset, PAGE_SIZE - offset);
384
385         /* chain first in list head */
386         first->private = (unsigned long)list;
387         err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, MAX_SKB_FRAGS + 2,
388                                        first);
389         if (err < 0)
390                 give_pages(vi, first);
391
392         return err;
393 }
394
395 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp)
396 {
397         struct page *page;
398         struct scatterlist sg;
399         int err;
400
401         page = get_a_page(vi, gfp);
402         if (!page)
403                 return -ENOMEM;
404
405         sg_init_one(&sg, page_address(page), PAGE_SIZE);
406
407         err = vi->rvq->vq_ops->add_buf(vi->rvq, &sg, 0, 1, page);
408         if (err < 0)
409                 give_pages(vi, page);
410
411         return err;
412 }
413
414 /* Returns false if we couldn't fill entirely (OOM). */
415 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
416 {
417         int err;
418         bool oom = false;
419
420         do {
421                 if (vi->mergeable_rx_bufs)
422                         err = add_recvbuf_mergeable(vi, gfp);
423                 else if (vi->big_packets)
424                         err = add_recvbuf_big(vi, gfp);
425                 else
426                         err = add_recvbuf_small(vi, gfp);
427
428                 if (err < 0) {
429                         oom = true;
430                         break;
431                 }
432                 ++vi->num;
433         } while (err > 0);
434         if (unlikely(vi->num > vi->max))
435                 vi->max = vi->num;
436         vi->rvq->vq_ops->kick(vi->rvq);
437         return !oom;
438 }
439
440 static void skb_recv_done(struct virtqueue *rvq)
441 {
442         struct virtnet_info *vi = rvq->vdev->priv;
443         /* Schedule NAPI, Suppress further interrupts if successful. */
444         if (napi_schedule_prep(&vi->napi)) {
445                 rvq->vq_ops->disable_cb(rvq);
446                 __napi_schedule(&vi->napi);
447         }
448 }
449
450 static void refill_work(struct work_struct *work)
451 {
452         struct virtnet_info *vi;
453         bool still_empty;
454
455         vi = container_of(work, struct virtnet_info, refill.work);
456         napi_disable(&vi->napi);
457         still_empty = !try_fill_recv(vi, GFP_KERNEL);
458         napi_enable(&vi->napi);
459
460         /* In theory, this can happen: if we don't get any buffers in
461          * we will *never* try to fill again. */
462         if (still_empty)
463                 schedule_delayed_work(&vi->refill, HZ/2);
464 }
465
466 static int virtnet_poll(struct napi_struct *napi, int budget)
467 {
468         struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
469         void *buf;
470         unsigned int len, received = 0;
471
472 again:
473         while (received < budget &&
474                (buf = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
475                 receive_buf(vi->dev, buf, len);
476                 --vi->num;
477                 received++;
478         }
479
480         if (vi->num < vi->max / 2) {
481                 if (!try_fill_recv(vi, GFP_ATOMIC))
482                         schedule_delayed_work(&vi->refill, 0);
483         }
484
485         /* Out of packets? */
486         if (received < budget) {
487                 napi_complete(napi);
488                 if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq)) &&
489                     napi_schedule_prep(napi)) {
490                         vi->rvq->vq_ops->disable_cb(vi->rvq);
491                         __napi_schedule(napi);
492                         goto again;
493                 }
494         }
495
496         return received;
497 }
498
499 static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
500 {
501         struct sk_buff *skb;
502         unsigned int len, tot_sgs = 0;
503
504         while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
505                 pr_debug("Sent skb %p\n", skb);
506                 vi->dev->stats.tx_bytes += skb->len;
507                 vi->dev->stats.tx_packets++;
508                 tot_sgs += skb_vnet_hdr(skb)->num_sg;
509                 dev_kfree_skb_any(skb);
510         }
511         return tot_sgs;
512 }
513
514 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
515 {
516         struct scatterlist sg[2+MAX_SKB_FRAGS];
517         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
518         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
519
520         sg_init_table(sg, 2+MAX_SKB_FRAGS);
521
522         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
523
524         if (skb->ip_summed == CHECKSUM_PARTIAL) {
525                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
526                 hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb);
527                 hdr->hdr.csum_offset = skb->csum_offset;
528         } else {
529                 hdr->hdr.flags = 0;
530                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
531         }
532
533         if (skb_is_gso(skb)) {
534                 hdr->hdr.hdr_len = skb_headlen(skb);
535                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
536                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
537                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
538                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
539                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
540                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
541                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
542                 else
543                         BUG();
544                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
545                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
546         } else {
547                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
548                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
549         }
550
551         hdr->mhdr.num_buffers = 0;
552
553         /* Encode metadata header at front. */
554         if (vi->mergeable_rx_bufs)
555                 sg_set_buf(sg, &hdr->mhdr, sizeof hdr->mhdr);
556         else
557                 sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr);
558
559         hdr->num_sg = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
560         return vi->svq->vq_ops->add_buf(vi->svq, sg, hdr->num_sg, 0, skb);
561 }
562
563 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
564 {
565         struct virtnet_info *vi = netdev_priv(dev);
566         int capacity;
567
568 again:
569         /* Free up any pending old buffers before queueing new ones. */
570         free_old_xmit_skbs(vi);
571
572         /* Try to transmit */
573         capacity = xmit_skb(vi, skb);
574
575         /* This can happen with OOM and indirect buffers. */
576         if (unlikely(capacity < 0)) {
577                 netif_stop_queue(dev);
578                 dev_warn(&dev->dev, "Unexpected full queue\n");
579                 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
580                         vi->svq->vq_ops->disable_cb(vi->svq);
581                         netif_start_queue(dev);
582                         goto again;
583                 }
584                 return NETDEV_TX_BUSY;
585         }
586         vi->svq->vq_ops->kick(vi->svq);
587
588         /* Don't wait up for transmitted skbs to be freed. */
589         skb_orphan(skb);
590         nf_reset(skb);
591
592         /* Apparently nice girls don't return TX_BUSY; stop the queue
593          * before it gets out of hand.  Naturally, this wastes entries. */
594         if (capacity < 2+MAX_SKB_FRAGS) {
595                 netif_stop_queue(dev);
596                 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
597                         /* More just got used, free them then recheck. */
598                         capacity += free_old_xmit_skbs(vi);
599                         if (capacity >= 2+MAX_SKB_FRAGS) {
600                                 netif_start_queue(dev);
601                                 vi->svq->vq_ops->disable_cb(vi->svq);
602                         }
603                 }
604         }
605
606         return NETDEV_TX_OK;
607 }
608
609 static int virtnet_set_mac_address(struct net_device *dev, void *p)
610 {
611         struct virtnet_info *vi = netdev_priv(dev);
612         struct virtio_device *vdev = vi->vdev;
613         int ret;
614
615         ret = eth_mac_addr(dev, p);
616         if (ret)
617                 return ret;
618
619         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
620                 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
621                                   dev->dev_addr, dev->addr_len);
622
623         return 0;
624 }
625
626 #ifdef CONFIG_NET_POLL_CONTROLLER
627 static void virtnet_netpoll(struct net_device *dev)
628 {
629         struct virtnet_info *vi = netdev_priv(dev);
630
631         napi_schedule(&vi->napi);
632 }
633 #endif
634
635 static int virtnet_open(struct net_device *dev)
636 {
637         struct virtnet_info *vi = netdev_priv(dev);
638
639         napi_enable(&vi->napi);
640
641         /* If all buffers were filled by other side before we napi_enabled, we
642          * won't get another interrupt, so process any outstanding packets
643          * now.  virtnet_poll wants re-enable the queue, so we disable here.
644          * We synchronize against interrupts via NAPI_STATE_SCHED */
645         if (napi_schedule_prep(&vi->napi)) {
646                 vi->rvq->vq_ops->disable_cb(vi->rvq);
647                 __napi_schedule(&vi->napi);
648         }
649         return 0;
650 }
651
652 /*
653  * Send command via the control virtqueue and check status.  Commands
654  * supported by the hypervisor, as indicated by feature bits, should
655  * never fail unless improperly formated.
656  */
657 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
658                                  struct scatterlist *data, int out, int in)
659 {
660         struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
661         struct virtio_net_ctrl_hdr ctrl;
662         virtio_net_ctrl_ack status = ~0;
663         unsigned int tmp;
664         int i;
665
666         /* Caller should know better */
667         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
668                 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
669
670         out++; /* Add header */
671         in++; /* Add return status */
672
673         ctrl.class = class;
674         ctrl.cmd = cmd;
675
676         sg_init_table(sg, out + in);
677
678         sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
679         for_each_sg(data, s, out + in - 2, i)
680                 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
681         sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
682
683         BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi) < 0);
684
685         vi->cvq->vq_ops->kick(vi->cvq);
686
687         /*
688          * Spin for a response, the kick causes an ioport write, trapping
689          * into the hypervisor, so the request should be handled immediately.
690          */
691         while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp))
692                 cpu_relax();
693
694         return status == VIRTIO_NET_OK;
695 }
696
697 static int virtnet_close(struct net_device *dev)
698 {
699         struct virtnet_info *vi = netdev_priv(dev);
700
701         napi_disable(&vi->napi);
702
703         return 0;
704 }
705
706 static int virtnet_set_tx_csum(struct net_device *dev, u32 data)
707 {
708         struct virtnet_info *vi = netdev_priv(dev);
709         struct virtio_device *vdev = vi->vdev;
710
711         if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM))
712                 return -ENOSYS;
713
714         return ethtool_op_set_tx_hw_csum(dev, data);
715 }
716
717 static void virtnet_set_rx_mode(struct net_device *dev)
718 {
719         struct virtnet_info *vi = netdev_priv(dev);
720         struct scatterlist sg[2];
721         u8 promisc, allmulti;
722         struct virtio_net_ctrl_mac *mac_data;
723         struct dev_addr_list *addr;
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(addr, dev)
781                 memcpy(&mac_data->macs[i++][0], addr->da_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");