cris: add arch/cris/include/asm/serial.h
[linux-2.6/next.git] / drivers / net / virtio_net.c
blob0c7321c35ad408ab7ec4ce62383cc2afdf90b541
1 /* A network driver using virtio.
3 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
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.
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.
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
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>
30 static int napi_weight = 128;
31 module_param(napi_weight, int, 0444);
33 static int csum = 1, gso = 1;
34 module_param(csum, bool, 0444);
35 module_param(gso, bool, 0444);
37 /* FIXME: MTU in config. */
38 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
39 #define GOOD_COPY_LEN 128
41 #define VIRTNET_SEND_COMMAND_SG_MAX 2
43 struct virtnet_stats {
44 struct u64_stats_sync syncp;
45 u64 tx_bytes;
46 u64 tx_packets;
48 u64 rx_bytes;
49 u64 rx_packets;
52 struct virtnet_info {
53 struct virtio_device *vdev;
54 struct virtqueue *rvq, *svq, *cvq;
55 struct net_device *dev;
56 struct napi_struct napi;
57 unsigned int status;
59 /* Number of input buffers, and max we've ever had. */
60 unsigned int num, max;
62 /* I like... big packets and I cannot lie! */
63 bool big_packets;
65 /* Host will merge rx buffers for big packets (shake it! shake it!) */
66 bool mergeable_rx_bufs;
68 /* Active statistics */
69 struct virtnet_stats __percpu *stats;
71 /* Work struct for refilling if we run low on memory. */
72 struct delayed_work refill;
74 /* Chain pages by the private ptr. */
75 struct page *pages;
77 /* fragments + linear part + virtio header */
78 struct scatterlist rx_sg[MAX_SKB_FRAGS + 2];
79 struct scatterlist tx_sg[MAX_SKB_FRAGS + 2];
82 struct skb_vnet_hdr {
83 union {
84 struct virtio_net_hdr hdr;
85 struct virtio_net_hdr_mrg_rxbuf mhdr;
87 unsigned int num_sg;
90 struct padded_vnet_hdr {
91 struct virtio_net_hdr hdr;
93 * virtio_net_hdr should be in a separated sg buffer because of a
94 * QEMU bug, and data sg buffer shares same page with this header sg.
95 * This padding makes next sg 16 byte aligned after virtio_net_hdr.
97 char padding[6];
100 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
102 return (struct skb_vnet_hdr *)skb->cb;
106 * private is used to chain pages for big packets, put the whole
107 * most recent used list in the beginning for reuse
109 static void give_pages(struct virtnet_info *vi, struct page *page)
111 struct page *end;
113 /* Find end of list, sew whole thing into vi->pages. */
114 for (end = page; end->private; end = (struct page *)end->private);
115 end->private = (unsigned long)vi->pages;
116 vi->pages = page;
119 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
121 struct page *p = vi->pages;
123 if (p) {
124 vi->pages = (struct page *)p->private;
125 /* clear private here, it is used to chain pages */
126 p->private = 0;
127 } else
128 p = alloc_page(gfp_mask);
129 return p;
132 static void skb_xmit_done(struct virtqueue *svq)
134 struct virtnet_info *vi = svq->vdev->priv;
136 /* Suppress further interrupts. */
137 virtqueue_disable_cb(svq);
139 /* We were probably waiting for more output buffers. */
140 netif_wake_queue(vi->dev);
143 static void set_skb_frag(struct sk_buff *skb, struct page *page,
144 unsigned int offset, unsigned int *len)
146 int i = skb_shinfo(skb)->nr_frags;
147 skb_frag_t *f;
149 f = &skb_shinfo(skb)->frags[i];
150 f->size = min((unsigned)PAGE_SIZE - offset, *len);
151 f->page_offset = offset;
152 f->page = page;
154 skb->data_len += f->size;
155 skb->len += f->size;
156 skb_shinfo(skb)->nr_frags++;
157 *len -= f->size;
160 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
161 struct page *page, unsigned int len)
163 struct sk_buff *skb;
164 struct skb_vnet_hdr *hdr;
165 unsigned int copy, hdr_len, offset;
166 char *p;
168 p = page_address(page);
170 /* copy small packet so we can reuse these pages for small data */
171 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
172 if (unlikely(!skb))
173 return NULL;
175 hdr = skb_vnet_hdr(skb);
177 if (vi->mergeable_rx_bufs) {
178 hdr_len = sizeof hdr->mhdr;
179 offset = hdr_len;
180 } else {
181 hdr_len = sizeof hdr->hdr;
182 offset = sizeof(struct padded_vnet_hdr);
185 memcpy(hdr, p, hdr_len);
187 len -= hdr_len;
188 p += offset;
190 copy = len;
191 if (copy > skb_tailroom(skb))
192 copy = skb_tailroom(skb);
193 memcpy(skb_put(skb, copy), p, copy);
195 len -= copy;
196 offset += copy;
198 while (len) {
199 set_skb_frag(skb, page, offset, &len);
200 page = (struct page *)page->private;
201 offset = 0;
204 if (page)
205 give_pages(vi, page);
207 return skb;
210 static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
212 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
213 struct page *page;
214 int num_buf, i, len;
216 num_buf = hdr->mhdr.num_buffers;
217 while (--num_buf) {
218 i = skb_shinfo(skb)->nr_frags;
219 if (i >= MAX_SKB_FRAGS) {
220 pr_debug("%s: packet too long\n", skb->dev->name);
221 skb->dev->stats.rx_length_errors++;
222 return -EINVAL;
224 page = virtqueue_get_buf(vi->rvq, &len);
225 if (!page) {
226 pr_debug("%s: rx error: %d buffers missing\n",
227 skb->dev->name, hdr->mhdr.num_buffers);
228 skb->dev->stats.rx_length_errors++;
229 return -EINVAL;
232 if (len > PAGE_SIZE)
233 len = PAGE_SIZE;
235 set_skb_frag(skb, page, 0, &len);
237 --vi->num;
239 return 0;
242 static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
244 struct virtnet_info *vi = netdev_priv(dev);
245 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats);
246 struct sk_buff *skb;
247 struct page *page;
248 struct skb_vnet_hdr *hdr;
250 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
251 pr_debug("%s: short packet %i\n", dev->name, len);
252 dev->stats.rx_length_errors++;
253 if (vi->mergeable_rx_bufs || vi->big_packets)
254 give_pages(vi, buf);
255 else
256 dev_kfree_skb(buf);
257 return;
260 if (!vi->mergeable_rx_bufs && !vi->big_packets) {
261 skb = buf;
262 len -= sizeof(struct virtio_net_hdr);
263 skb_trim(skb, len);
264 } else {
265 page = buf;
266 skb = page_to_skb(vi, page, len);
267 if (unlikely(!skb)) {
268 dev->stats.rx_dropped++;
269 give_pages(vi, page);
270 return;
272 if (vi->mergeable_rx_bufs)
273 if (receive_mergeable(vi, skb)) {
274 dev_kfree_skb(skb);
275 return;
279 hdr = skb_vnet_hdr(skb);
280 skb->truesize += skb->data_len;
282 u64_stats_update_begin(&stats->syncp);
283 stats->rx_bytes += skb->len;
284 stats->rx_packets++;
285 u64_stats_update_end(&stats->syncp);
287 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
288 pr_debug("Needs csum!\n");
289 if (!skb_partial_csum_set(skb,
290 hdr->hdr.csum_start,
291 hdr->hdr.csum_offset))
292 goto frame_err;
293 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
294 skb->ip_summed = CHECKSUM_UNNECESSARY;
297 skb->protocol = eth_type_trans(skb, dev);
298 pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
299 ntohs(skb->protocol), skb->len, skb->pkt_type);
301 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
302 pr_debug("GSO!\n");
303 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
304 case VIRTIO_NET_HDR_GSO_TCPV4:
305 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
306 break;
307 case VIRTIO_NET_HDR_GSO_UDP:
308 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
309 break;
310 case VIRTIO_NET_HDR_GSO_TCPV6:
311 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
312 break;
313 default:
314 if (net_ratelimit())
315 printk(KERN_WARNING "%s: bad gso type %u.\n",
316 dev->name, hdr->hdr.gso_type);
317 goto frame_err;
320 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
321 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
323 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
324 if (skb_shinfo(skb)->gso_size == 0) {
325 if (net_ratelimit())
326 printk(KERN_WARNING "%s: zero gso size.\n",
327 dev->name);
328 goto frame_err;
331 /* Header must be checked, and gso_segs computed. */
332 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
333 skb_shinfo(skb)->gso_segs = 0;
336 netif_receive_skb(skb);
337 return;
339 frame_err:
340 dev->stats.rx_frame_errors++;
341 dev_kfree_skb(skb);
344 static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp)
346 struct sk_buff *skb;
347 struct skb_vnet_hdr *hdr;
348 int err;
350 skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN);
351 if (unlikely(!skb))
352 return -ENOMEM;
354 skb_put(skb, MAX_PACKET_LEN);
356 hdr = skb_vnet_hdr(skb);
357 sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr);
359 skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len);
361 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 2, skb, gfp);
362 if (err < 0)
363 dev_kfree_skb(skb);
365 return err;
368 static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp)
370 struct page *first, *list = NULL;
371 char *p;
372 int i, err, offset;
374 /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */
375 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
376 first = get_a_page(vi, gfp);
377 if (!first) {
378 if (list)
379 give_pages(vi, list);
380 return -ENOMEM;
382 sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE);
384 /* chain new page in list head to match sg */
385 first->private = (unsigned long)list;
386 list = first;
389 first = get_a_page(vi, gfp);
390 if (!first) {
391 give_pages(vi, list);
392 return -ENOMEM;
394 p = page_address(first);
396 /* vi->rx_sg[0], vi->rx_sg[1] share the same page */
397 /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */
398 sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr));
400 /* vi->rx_sg[1] for data packet, from offset */
401 offset = sizeof(struct padded_vnet_hdr);
402 sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset);
404 /* chain first in list head */
405 first->private = (unsigned long)list;
406 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2,
407 first, gfp);
408 if (err < 0)
409 give_pages(vi, first);
411 return err;
414 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp)
416 struct page *page;
417 int err;
419 page = get_a_page(vi, gfp);
420 if (!page)
421 return -ENOMEM;
423 sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE);
425 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 1, page, gfp);
426 if (err < 0)
427 give_pages(vi, page);
429 return err;
432 /* Returns false if we couldn't fill entirely (OOM). */
433 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
435 int err;
436 bool oom;
438 do {
439 if (vi->mergeable_rx_bufs)
440 err = add_recvbuf_mergeable(vi, gfp);
441 else if (vi->big_packets)
442 err = add_recvbuf_big(vi, gfp);
443 else
444 err = add_recvbuf_small(vi, gfp);
446 oom = err == -ENOMEM;
447 if (err < 0)
448 break;
449 ++vi->num;
450 } while (err > 0);
451 if (unlikely(vi->num > vi->max))
452 vi->max = vi->num;
453 virtqueue_kick(vi->rvq);
454 return !oom;
457 static void skb_recv_done(struct virtqueue *rvq)
459 struct virtnet_info *vi = rvq->vdev->priv;
460 /* Schedule NAPI, Suppress further interrupts if successful. */
461 if (napi_schedule_prep(&vi->napi)) {
462 virtqueue_disable_cb(rvq);
463 __napi_schedule(&vi->napi);
467 static void virtnet_napi_enable(struct virtnet_info *vi)
469 napi_enable(&vi->napi);
471 /* If all buffers were filled by other side before we napi_enabled, we
472 * won't get another interrupt, so process any outstanding packets
473 * now. virtnet_poll wants re-enable the queue, so we disable here.
474 * We synchronize against interrupts via NAPI_STATE_SCHED */
475 if (napi_schedule_prep(&vi->napi)) {
476 virtqueue_disable_cb(vi->rvq);
477 __napi_schedule(&vi->napi);
481 static void refill_work(struct work_struct *work)
483 struct virtnet_info *vi;
484 bool still_empty;
486 vi = container_of(work, struct virtnet_info, refill.work);
487 napi_disable(&vi->napi);
488 still_empty = !try_fill_recv(vi, GFP_KERNEL);
489 virtnet_napi_enable(vi);
491 /* In theory, this can happen: if we don't get any buffers in
492 * we will *never* try to fill again. */
493 if (still_empty)
494 schedule_delayed_work(&vi->refill, HZ/2);
497 static int virtnet_poll(struct napi_struct *napi, int budget)
499 struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
500 void *buf;
501 unsigned int len, received = 0;
503 again:
504 while (received < budget &&
505 (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) {
506 receive_buf(vi->dev, buf, len);
507 --vi->num;
508 received++;
511 if (vi->num < vi->max / 2) {
512 if (!try_fill_recv(vi, GFP_ATOMIC))
513 schedule_delayed_work(&vi->refill, 0);
516 /* Out of packets? */
517 if (received < budget) {
518 napi_complete(napi);
519 if (unlikely(!virtqueue_enable_cb(vi->rvq)) &&
520 napi_schedule_prep(napi)) {
521 virtqueue_disable_cb(vi->rvq);
522 __napi_schedule(napi);
523 goto again;
527 return received;
530 static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
532 struct sk_buff *skb;
533 unsigned int len, tot_sgs = 0;
534 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats);
536 while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) {
537 pr_debug("Sent skb %p\n", skb);
539 u64_stats_update_begin(&stats->syncp);
540 stats->tx_bytes += skb->len;
541 stats->tx_packets++;
542 u64_stats_update_end(&stats->syncp);
544 tot_sgs += skb_vnet_hdr(skb)->num_sg;
545 dev_kfree_skb_any(skb);
547 return tot_sgs;
550 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
552 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
553 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
555 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
557 if (skb->ip_summed == CHECKSUM_PARTIAL) {
558 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
559 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
560 hdr->hdr.csum_offset = skb->csum_offset;
561 } else {
562 hdr->hdr.flags = 0;
563 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
566 if (skb_is_gso(skb)) {
567 hdr->hdr.hdr_len = skb_headlen(skb);
568 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
569 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
570 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
571 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
572 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
573 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
574 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
575 else
576 BUG();
577 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
578 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
579 } else {
580 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
581 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
584 hdr->mhdr.num_buffers = 0;
586 /* Encode metadata header at front. */
587 if (vi->mergeable_rx_bufs)
588 sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr);
589 else
590 sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr);
592 hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1;
593 return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg,
594 0, skb);
597 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
599 struct virtnet_info *vi = netdev_priv(dev);
600 int capacity;
602 /* Free up any pending old buffers before queueing new ones. */
603 free_old_xmit_skbs(vi);
605 /* Try to transmit */
606 capacity = xmit_skb(vi, skb);
608 /* This can happen with OOM and indirect buffers. */
609 if (unlikely(capacity < 0)) {
610 if (net_ratelimit()) {
611 if (likely(capacity == -ENOMEM)) {
612 dev_warn(&dev->dev,
613 "TX queue failure: out of memory\n");
614 } else {
615 dev->stats.tx_fifo_errors++;
616 dev_warn(&dev->dev,
617 "Unexpected TX queue failure: %d\n",
618 capacity);
621 dev->stats.tx_dropped++;
622 kfree_skb(skb);
623 return NETDEV_TX_OK;
625 virtqueue_kick(vi->svq);
627 /* Don't wait up for transmitted skbs to be freed. */
628 skb_orphan(skb);
629 nf_reset(skb);
631 /* Apparently nice girls don't return TX_BUSY; stop the queue
632 * before it gets out of hand. Naturally, this wastes entries. */
633 if (capacity < 2+MAX_SKB_FRAGS) {
634 netif_stop_queue(dev);
635 if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) {
636 /* More just got used, free them then recheck. */
637 capacity += free_old_xmit_skbs(vi);
638 if (capacity >= 2+MAX_SKB_FRAGS) {
639 netif_start_queue(dev);
640 virtqueue_disable_cb(vi->svq);
645 return NETDEV_TX_OK;
648 static int virtnet_set_mac_address(struct net_device *dev, void *p)
650 struct virtnet_info *vi = netdev_priv(dev);
651 struct virtio_device *vdev = vi->vdev;
652 int ret;
654 ret = eth_mac_addr(dev, p);
655 if (ret)
656 return ret;
658 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
659 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
660 dev->dev_addr, dev->addr_len);
662 return 0;
665 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
666 struct rtnl_link_stats64 *tot)
668 struct virtnet_info *vi = netdev_priv(dev);
669 int cpu;
670 unsigned int start;
672 for_each_possible_cpu(cpu) {
673 struct virtnet_stats __percpu *stats
674 = per_cpu_ptr(vi->stats, cpu);
675 u64 tpackets, tbytes, rpackets, rbytes;
677 do {
678 start = u64_stats_fetch_begin(&stats->syncp);
679 tpackets = stats->tx_packets;
680 tbytes = stats->tx_bytes;
681 rpackets = stats->rx_packets;
682 rbytes = stats->rx_bytes;
683 } while (u64_stats_fetch_retry(&stats->syncp, start));
685 tot->rx_packets += rpackets;
686 tot->tx_packets += tpackets;
687 tot->rx_bytes += rbytes;
688 tot->tx_bytes += tbytes;
691 tot->tx_dropped = dev->stats.tx_dropped;
692 tot->rx_dropped = dev->stats.rx_dropped;
693 tot->rx_length_errors = dev->stats.rx_length_errors;
694 tot->rx_frame_errors = dev->stats.rx_frame_errors;
696 return tot;
699 #ifdef CONFIG_NET_POLL_CONTROLLER
700 static void virtnet_netpoll(struct net_device *dev)
702 struct virtnet_info *vi = netdev_priv(dev);
704 napi_schedule(&vi->napi);
706 #endif
708 static int virtnet_open(struct net_device *dev)
710 struct virtnet_info *vi = netdev_priv(dev);
712 virtnet_napi_enable(vi);
713 return 0;
717 * Send command via the control virtqueue and check status. Commands
718 * supported by the hypervisor, as indicated by feature bits, should
719 * never fail unless improperly formated.
721 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
722 struct scatterlist *data, int out, int in)
724 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
725 struct virtio_net_ctrl_hdr ctrl;
726 virtio_net_ctrl_ack status = ~0;
727 unsigned int tmp;
728 int i;
730 /* Caller should know better */
731 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
732 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
734 out++; /* Add header */
735 in++; /* Add return status */
737 ctrl.class = class;
738 ctrl.cmd = cmd;
740 sg_init_table(sg, out + in);
742 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
743 for_each_sg(data, s, out + in - 2, i)
744 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
745 sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
747 BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi) < 0);
749 virtqueue_kick(vi->cvq);
752 * Spin for a response, the kick causes an ioport write, trapping
753 * into the hypervisor, so the request should be handled immediately.
755 while (!virtqueue_get_buf(vi->cvq, &tmp))
756 cpu_relax();
758 return status == VIRTIO_NET_OK;
761 static int virtnet_close(struct net_device *dev)
763 struct virtnet_info *vi = netdev_priv(dev);
765 napi_disable(&vi->napi);
767 return 0;
770 static void virtnet_set_rx_mode(struct net_device *dev)
772 struct virtnet_info *vi = netdev_priv(dev);
773 struct scatterlist sg[2];
774 u8 promisc, allmulti;
775 struct virtio_net_ctrl_mac *mac_data;
776 struct netdev_hw_addr *ha;
777 int uc_count;
778 int mc_count;
779 void *buf;
780 int i;
782 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
783 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
784 return;
786 promisc = ((dev->flags & IFF_PROMISC) != 0);
787 allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
789 sg_init_one(sg, &promisc, sizeof(promisc));
791 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
792 VIRTIO_NET_CTRL_RX_PROMISC,
793 sg, 1, 0))
794 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
795 promisc ? "en" : "dis");
797 sg_init_one(sg, &allmulti, sizeof(allmulti));
799 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
800 VIRTIO_NET_CTRL_RX_ALLMULTI,
801 sg, 1, 0))
802 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
803 allmulti ? "en" : "dis");
805 uc_count = netdev_uc_count(dev);
806 mc_count = netdev_mc_count(dev);
807 /* MAC filter - use one buffer for both lists */
808 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
809 (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
810 mac_data = buf;
811 if (!buf) {
812 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
813 return;
816 sg_init_table(sg, 2);
818 /* Store the unicast list and count in the front of the buffer */
819 mac_data->entries = uc_count;
820 i = 0;
821 netdev_for_each_uc_addr(ha, dev)
822 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
824 sg_set_buf(&sg[0], mac_data,
825 sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
827 /* multicast list and count fill the end */
828 mac_data = (void *)&mac_data->macs[uc_count][0];
830 mac_data->entries = mc_count;
831 i = 0;
832 netdev_for_each_mc_addr(ha, dev)
833 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
835 sg_set_buf(&sg[1], mac_data,
836 sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
838 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
839 VIRTIO_NET_CTRL_MAC_TABLE_SET,
840 sg, 2, 0))
841 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
843 kfree(buf);
846 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
848 struct virtnet_info *vi = netdev_priv(dev);
849 struct scatterlist sg;
851 sg_init_one(&sg, &vid, sizeof(vid));
853 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
854 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
855 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
858 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
860 struct virtnet_info *vi = netdev_priv(dev);
861 struct scatterlist sg;
863 sg_init_one(&sg, &vid, sizeof(vid));
865 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
866 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
867 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
870 static const struct ethtool_ops virtnet_ethtool_ops = {
871 .get_link = ethtool_op_get_link,
874 #define MIN_MTU 68
875 #define MAX_MTU 65535
877 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
879 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
880 return -EINVAL;
881 dev->mtu = new_mtu;
882 return 0;
885 static const struct net_device_ops virtnet_netdev = {
886 .ndo_open = virtnet_open,
887 .ndo_stop = virtnet_close,
888 .ndo_start_xmit = start_xmit,
889 .ndo_validate_addr = eth_validate_addr,
890 .ndo_set_mac_address = virtnet_set_mac_address,
891 .ndo_set_rx_mode = virtnet_set_rx_mode,
892 .ndo_change_mtu = virtnet_change_mtu,
893 .ndo_get_stats64 = virtnet_stats,
894 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
895 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
896 #ifdef CONFIG_NET_POLL_CONTROLLER
897 .ndo_poll_controller = virtnet_netpoll,
898 #endif
901 static void virtnet_update_status(struct virtnet_info *vi)
903 u16 v;
905 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS))
906 return;
908 vi->vdev->config->get(vi->vdev,
909 offsetof(struct virtio_net_config, status),
910 &v, sizeof(v));
912 /* Ignore unknown (future) status bits */
913 v &= VIRTIO_NET_S_LINK_UP;
915 if (vi->status == v)
916 return;
918 vi->status = v;
920 if (vi->status & VIRTIO_NET_S_LINK_UP) {
921 netif_carrier_on(vi->dev);
922 netif_wake_queue(vi->dev);
923 } else {
924 netif_carrier_off(vi->dev);
925 netif_stop_queue(vi->dev);
929 static void virtnet_config_changed(struct virtio_device *vdev)
931 struct virtnet_info *vi = vdev->priv;
933 virtnet_update_status(vi);
936 static int virtnet_probe(struct virtio_device *vdev)
938 int err;
939 struct net_device *dev;
940 struct virtnet_info *vi;
941 struct virtqueue *vqs[3];
942 vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
943 const char *names[] = { "input", "output", "control" };
944 int nvqs;
946 /* Allocate ourselves a network device with room for our info */
947 dev = alloc_etherdev(sizeof(struct virtnet_info));
948 if (!dev)
949 return -ENOMEM;
951 /* Set up network device as normal. */
952 dev->netdev_ops = &virtnet_netdev;
953 dev->features = NETIF_F_HIGHDMA;
955 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
956 SET_NETDEV_DEV(dev, &vdev->dev);
958 /* Do we support "hardware" checksums? */
959 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
960 /* This opens up the world of extra features. */
961 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
962 if (csum)
963 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
965 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
966 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
967 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
969 /* Individual feature bits: what can host handle? */
970 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
971 dev->hw_features |= NETIF_F_TSO;
972 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
973 dev->hw_features |= NETIF_F_TSO6;
974 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
975 dev->hw_features |= NETIF_F_TSO_ECN;
976 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
977 dev->hw_features |= NETIF_F_UFO;
979 if (gso)
980 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
981 /* (!csum && gso) case will be fixed by register_netdev() */
984 /* Configuration may specify what MAC to use. Otherwise random. */
985 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
986 vdev->config->get(vdev,
987 offsetof(struct virtio_net_config, mac),
988 dev->dev_addr, dev->addr_len);
989 } else
990 random_ether_addr(dev->dev_addr);
992 /* Set up our device-specific information */
993 vi = netdev_priv(dev);
994 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
995 vi->dev = dev;
996 vi->vdev = vdev;
997 vdev->priv = vi;
998 vi->pages = NULL;
999 vi->stats = alloc_percpu(struct virtnet_stats);
1000 err = -ENOMEM;
1001 if (vi->stats == NULL)
1002 goto free;
1004 INIT_DELAYED_WORK(&vi->refill, refill_work);
1005 sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg));
1006 sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg));
1008 /* If we can receive ANY GSO packets, we must allocate large ones. */
1009 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1010 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1011 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1012 vi->big_packets = true;
1014 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1015 vi->mergeable_rx_bufs = true;
1017 /* We expect two virtqueues, receive then send,
1018 * and optionally control. */
1019 nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
1021 err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names);
1022 if (err)
1023 goto free_stats;
1025 vi->rvq = vqs[0];
1026 vi->svq = vqs[1];
1028 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
1029 vi->cvq = vqs[2];
1031 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1032 dev->features |= NETIF_F_HW_VLAN_FILTER;
1035 err = register_netdev(dev);
1036 if (err) {
1037 pr_debug("virtio_net: registering device failed\n");
1038 goto free_vqs;
1041 /* Last of all, set up some receive buffers. */
1042 try_fill_recv(vi, GFP_KERNEL);
1044 /* If we didn't even get one input buffer, we're useless. */
1045 if (vi->num == 0) {
1046 err = -ENOMEM;
1047 goto unregister;
1050 /* Assume link up if device can't report link status,
1051 otherwise get link status from config. */
1052 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1053 netif_carrier_off(dev);
1054 virtnet_update_status(vi);
1055 } else {
1056 vi->status = VIRTIO_NET_S_LINK_UP;
1057 netif_carrier_on(dev);
1060 pr_debug("virtnet: registered device %s\n", dev->name);
1061 return 0;
1063 unregister:
1064 unregister_netdev(dev);
1065 cancel_delayed_work_sync(&vi->refill);
1066 free_vqs:
1067 vdev->config->del_vqs(vdev);
1068 free_stats:
1069 free_percpu(vi->stats);
1070 free:
1071 free_netdev(dev);
1072 return err;
1075 static void free_unused_bufs(struct virtnet_info *vi)
1077 void *buf;
1078 while (1) {
1079 buf = virtqueue_detach_unused_buf(vi->svq);
1080 if (!buf)
1081 break;
1082 dev_kfree_skb(buf);
1084 while (1) {
1085 buf = virtqueue_detach_unused_buf(vi->rvq);
1086 if (!buf)
1087 break;
1088 if (vi->mergeable_rx_bufs || vi->big_packets)
1089 give_pages(vi, buf);
1090 else
1091 dev_kfree_skb(buf);
1092 --vi->num;
1094 BUG_ON(vi->num != 0);
1097 static void __devexit virtnet_remove(struct virtio_device *vdev)
1099 struct virtnet_info *vi = vdev->priv;
1101 /* Stop all the virtqueues. */
1102 vdev->config->reset(vdev);
1105 unregister_netdev(vi->dev);
1106 cancel_delayed_work_sync(&vi->refill);
1108 /* Free unused buffers in both send and recv, if any. */
1109 free_unused_bufs(vi);
1111 vdev->config->del_vqs(vi->vdev);
1113 while (vi->pages)
1114 __free_pages(get_a_page(vi, GFP_KERNEL), 0);
1116 free_percpu(vi->stats);
1117 free_netdev(vi->dev);
1120 static struct virtio_device_id id_table[] = {
1121 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1122 { 0 },
1125 static unsigned int features[] = {
1126 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1127 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1128 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1129 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1130 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1131 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1132 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1135 static struct virtio_driver virtio_net_driver = {
1136 .feature_table = features,
1137 .feature_table_size = ARRAY_SIZE(features),
1138 .driver.name = KBUILD_MODNAME,
1139 .driver.owner = THIS_MODULE,
1140 .id_table = id_table,
1141 .probe = virtnet_probe,
1142 .remove = __devexit_p(virtnet_remove),
1143 .config_changed = virtnet_config_changed,
1146 static int __init init(void)
1148 return register_virtio_driver(&virtio_net_driver);
1151 static void __exit fini(void)
1153 unregister_virtio_driver(&virtio_net_driver);
1155 module_init(init);
1156 module_exit(fini);
1158 MODULE_DEVICE_TABLE(virtio, id_table);
1159 MODULE_DESCRIPTION("Virtio network driver");
1160 MODULE_LICENSE("GPL");