OMAPDSS: VENC: fix NULL pointer dereference in DSS2 VENC sysfs debug attr on OMAP4
[zen-stable.git] / drivers / net / virtio_net.c
blob4880aa8b4c28b4662446e8e56b2acc98958645e4
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 bool csum = true, gso = true;
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
42 #define VIRTNET_DRIVER_VERSION "1.0.0"
44 struct virtnet_stats {
45 struct u64_stats_sync syncp;
46 u64 tx_bytes;
47 u64 tx_packets;
49 u64 rx_bytes;
50 u64 rx_packets;
53 struct virtnet_info {
54 struct virtio_device *vdev;
55 struct virtqueue *rvq, *svq, *cvq;
56 struct net_device *dev;
57 struct napi_struct napi;
58 unsigned int status;
60 /* Number of input buffers, and max we've ever had. */
61 unsigned int num, max;
63 /* I like... big packets and I cannot lie! */
64 bool big_packets;
66 /* Host will merge rx buffers for big packets (shake it! shake it!) */
67 bool mergeable_rx_bufs;
69 /* Active statistics */
70 struct virtnet_stats __percpu *stats;
72 /* Work struct for refilling if we run low on memory. */
73 struct delayed_work refill;
75 /* Chain pages by the private ptr. */
76 struct page *pages;
78 /* fragments + linear part + virtio header */
79 struct scatterlist rx_sg[MAX_SKB_FRAGS + 2];
80 struct scatterlist tx_sg[MAX_SKB_FRAGS + 2];
83 struct skb_vnet_hdr {
84 union {
85 struct virtio_net_hdr hdr;
86 struct virtio_net_hdr_mrg_rxbuf mhdr;
88 unsigned int num_sg;
91 struct padded_vnet_hdr {
92 struct virtio_net_hdr hdr;
94 * virtio_net_hdr should be in a separated sg buffer because of a
95 * QEMU bug, and data sg buffer shares same page with this header sg.
96 * This padding makes next sg 16 byte aligned after virtio_net_hdr.
98 char padding[6];
101 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
103 return (struct skb_vnet_hdr *)skb->cb;
107 * private is used to chain pages for big packets, put the whole
108 * most recent used list in the beginning for reuse
110 static void give_pages(struct virtnet_info *vi, struct page *page)
112 struct page *end;
114 /* Find end of list, sew whole thing into vi->pages. */
115 for (end = page; end->private; end = (struct page *)end->private);
116 end->private = (unsigned long)vi->pages;
117 vi->pages = page;
120 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
122 struct page *p = vi->pages;
124 if (p) {
125 vi->pages = (struct page *)p->private;
126 /* clear private here, it is used to chain pages */
127 p->private = 0;
128 } else
129 p = alloc_page(gfp_mask);
130 return p;
133 static void skb_xmit_done(struct virtqueue *svq)
135 struct virtnet_info *vi = svq->vdev->priv;
137 /* Suppress further interrupts. */
138 virtqueue_disable_cb(svq);
140 /* We were probably waiting for more output buffers. */
141 netif_wake_queue(vi->dev);
144 static void set_skb_frag(struct sk_buff *skb, struct page *page,
145 unsigned int offset, unsigned int *len)
147 int size = min((unsigned)PAGE_SIZE - offset, *len);
148 int i = skb_shinfo(skb)->nr_frags;
150 __skb_fill_page_desc(skb, i, page, offset, size);
152 skb->data_len += size;
153 skb->len += size;
154 skb->truesize += PAGE_SIZE;
155 skb_shinfo(skb)->nr_frags++;
156 *len -= size;
159 /* Called from bottom half context */
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;
199 * Verify that we can indeed put this data into a skb.
200 * This is here to handle cases when the device erroneously
201 * tries to receive more than is possible. This is usually
202 * the case of a broken device.
204 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
205 if (net_ratelimit())
206 pr_debug("%s: too much data\n", skb->dev->name);
207 dev_kfree_skb(skb);
208 return NULL;
211 while (len) {
212 set_skb_frag(skb, page, offset, &len);
213 page = (struct page *)page->private;
214 offset = 0;
217 if (page)
218 give_pages(vi, page);
220 return skb;
223 static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
225 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
226 struct page *page;
227 int num_buf, i, len;
229 num_buf = hdr->mhdr.num_buffers;
230 while (--num_buf) {
231 i = skb_shinfo(skb)->nr_frags;
232 if (i >= MAX_SKB_FRAGS) {
233 pr_debug("%s: packet too long\n", skb->dev->name);
234 skb->dev->stats.rx_length_errors++;
235 return -EINVAL;
237 page = virtqueue_get_buf(vi->rvq, &len);
238 if (!page) {
239 pr_debug("%s: rx error: %d buffers missing\n",
240 skb->dev->name, hdr->mhdr.num_buffers);
241 skb->dev->stats.rx_length_errors++;
242 return -EINVAL;
245 if (len > PAGE_SIZE)
246 len = PAGE_SIZE;
248 set_skb_frag(skb, page, 0, &len);
250 --vi->num;
252 return 0;
255 static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
257 struct virtnet_info *vi = netdev_priv(dev);
258 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats);
259 struct sk_buff *skb;
260 struct page *page;
261 struct skb_vnet_hdr *hdr;
263 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
264 pr_debug("%s: short packet %i\n", dev->name, len);
265 dev->stats.rx_length_errors++;
266 if (vi->mergeable_rx_bufs || vi->big_packets)
267 give_pages(vi, buf);
268 else
269 dev_kfree_skb(buf);
270 return;
273 if (!vi->mergeable_rx_bufs && !vi->big_packets) {
274 skb = buf;
275 len -= sizeof(struct virtio_net_hdr);
276 skb_trim(skb, len);
277 } else {
278 page = buf;
279 skb = page_to_skb(vi, page, len);
280 if (unlikely(!skb)) {
281 dev->stats.rx_dropped++;
282 give_pages(vi, page);
283 return;
285 if (vi->mergeable_rx_bufs)
286 if (receive_mergeable(vi, skb)) {
287 dev_kfree_skb(skb);
288 return;
292 hdr = skb_vnet_hdr(skb);
294 u64_stats_update_begin(&stats->syncp);
295 stats->rx_bytes += skb->len;
296 stats->rx_packets++;
297 u64_stats_update_end(&stats->syncp);
299 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
300 pr_debug("Needs csum!\n");
301 if (!skb_partial_csum_set(skb,
302 hdr->hdr.csum_start,
303 hdr->hdr.csum_offset))
304 goto frame_err;
305 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
306 skb->ip_summed = CHECKSUM_UNNECESSARY;
309 skb->protocol = eth_type_trans(skb, dev);
310 pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
311 ntohs(skb->protocol), skb->len, skb->pkt_type);
313 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
314 pr_debug("GSO!\n");
315 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
316 case VIRTIO_NET_HDR_GSO_TCPV4:
317 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
318 break;
319 case VIRTIO_NET_HDR_GSO_UDP:
320 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
321 break;
322 case VIRTIO_NET_HDR_GSO_TCPV6:
323 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
324 break;
325 default:
326 if (net_ratelimit())
327 printk(KERN_WARNING "%s: bad gso type %u.\n",
328 dev->name, hdr->hdr.gso_type);
329 goto frame_err;
332 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
333 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
335 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
336 if (skb_shinfo(skb)->gso_size == 0) {
337 if (net_ratelimit())
338 printk(KERN_WARNING "%s: zero gso size.\n",
339 dev->name);
340 goto frame_err;
343 /* Header must be checked, and gso_segs computed. */
344 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
345 skb_shinfo(skb)->gso_segs = 0;
348 netif_receive_skb(skb);
349 return;
351 frame_err:
352 dev->stats.rx_frame_errors++;
353 dev_kfree_skb(skb);
356 static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp)
358 struct sk_buff *skb;
359 struct skb_vnet_hdr *hdr;
360 int err;
362 skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp);
363 if (unlikely(!skb))
364 return -ENOMEM;
366 skb_put(skb, MAX_PACKET_LEN);
368 hdr = skb_vnet_hdr(skb);
369 sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr);
371 skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len);
373 err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 2, skb, gfp);
374 if (err < 0)
375 dev_kfree_skb(skb);
377 return err;
380 static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp)
382 struct page *first, *list = NULL;
383 char *p;
384 int i, err, offset;
386 /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */
387 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
388 first = get_a_page(vi, gfp);
389 if (!first) {
390 if (list)
391 give_pages(vi, list);
392 return -ENOMEM;
394 sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE);
396 /* chain new page in list head to match sg */
397 first->private = (unsigned long)list;
398 list = first;
401 first = get_a_page(vi, gfp);
402 if (!first) {
403 give_pages(vi, list);
404 return -ENOMEM;
406 p = page_address(first);
408 /* vi->rx_sg[0], vi->rx_sg[1] share the same page */
409 /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */
410 sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr));
412 /* vi->rx_sg[1] for data packet, from offset */
413 offset = sizeof(struct padded_vnet_hdr);
414 sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset);
416 /* chain first in list head */
417 first->private = (unsigned long)list;
418 err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2,
419 first, gfp);
420 if (err < 0)
421 give_pages(vi, first);
423 return err;
426 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp)
428 struct page *page;
429 int err;
431 page = get_a_page(vi, gfp);
432 if (!page)
433 return -ENOMEM;
435 sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE);
437 err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 1, page, gfp);
438 if (err < 0)
439 give_pages(vi, page);
441 return err;
445 * Returns false if we couldn't fill entirely (OOM).
447 * Normally run in the receive path, but can also be run from ndo_open
448 * before we're receiving packets, or from refill_work which is
449 * careful to disable receiving (using napi_disable).
451 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
453 int err;
454 bool oom;
456 do {
457 if (vi->mergeable_rx_bufs)
458 err = add_recvbuf_mergeable(vi, gfp);
459 else if (vi->big_packets)
460 err = add_recvbuf_big(vi, gfp);
461 else
462 err = add_recvbuf_small(vi, gfp);
464 oom = err == -ENOMEM;
465 if (err < 0)
466 break;
467 ++vi->num;
468 } while (err > 0);
469 if (unlikely(vi->num > vi->max))
470 vi->max = vi->num;
471 virtqueue_kick(vi->rvq);
472 return !oom;
475 static void skb_recv_done(struct virtqueue *rvq)
477 struct virtnet_info *vi = rvq->vdev->priv;
478 /* Schedule NAPI, Suppress further interrupts if successful. */
479 if (napi_schedule_prep(&vi->napi)) {
480 virtqueue_disable_cb(rvq);
481 __napi_schedule(&vi->napi);
485 static void virtnet_napi_enable(struct virtnet_info *vi)
487 napi_enable(&vi->napi);
489 /* If all buffers were filled by other side before we napi_enabled, we
490 * won't get another interrupt, so process any outstanding packets
491 * now. virtnet_poll wants re-enable the queue, so we disable here.
492 * We synchronize against interrupts via NAPI_STATE_SCHED */
493 if (napi_schedule_prep(&vi->napi)) {
494 virtqueue_disable_cb(vi->rvq);
495 __napi_schedule(&vi->napi);
499 static void refill_work(struct work_struct *work)
501 struct virtnet_info *vi;
502 bool still_empty;
504 vi = container_of(work, struct virtnet_info, refill.work);
505 napi_disable(&vi->napi);
506 still_empty = !try_fill_recv(vi, GFP_KERNEL);
507 virtnet_napi_enable(vi);
509 /* In theory, this can happen: if we don't get any buffers in
510 * we will *never* try to fill again. */
511 if (still_empty)
512 queue_delayed_work(system_nrt_wq, &vi->refill, HZ/2);
515 static int virtnet_poll(struct napi_struct *napi, int budget)
517 struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
518 void *buf;
519 unsigned int len, received = 0;
521 again:
522 while (received < budget &&
523 (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) {
524 receive_buf(vi->dev, buf, len);
525 --vi->num;
526 received++;
529 if (vi->num < vi->max / 2) {
530 if (!try_fill_recv(vi, GFP_ATOMIC))
531 queue_delayed_work(system_nrt_wq, &vi->refill, 0);
534 /* Out of packets? */
535 if (received < budget) {
536 napi_complete(napi);
537 if (unlikely(!virtqueue_enable_cb(vi->rvq)) &&
538 napi_schedule_prep(napi)) {
539 virtqueue_disable_cb(vi->rvq);
540 __napi_schedule(napi);
541 goto again;
545 return received;
548 static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
550 struct sk_buff *skb;
551 unsigned int len, tot_sgs = 0;
552 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats);
554 while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) {
555 pr_debug("Sent skb %p\n", skb);
557 u64_stats_update_begin(&stats->syncp);
558 stats->tx_bytes += skb->len;
559 stats->tx_packets++;
560 u64_stats_update_end(&stats->syncp);
562 tot_sgs += skb_vnet_hdr(skb)->num_sg;
563 dev_kfree_skb_any(skb);
565 return tot_sgs;
568 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
570 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
571 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
573 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
575 if (skb->ip_summed == CHECKSUM_PARTIAL) {
576 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
577 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
578 hdr->hdr.csum_offset = skb->csum_offset;
579 } else {
580 hdr->hdr.flags = 0;
581 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
584 if (skb_is_gso(skb)) {
585 hdr->hdr.hdr_len = skb_headlen(skb);
586 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
587 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
588 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
589 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
590 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
591 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
592 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
593 else
594 BUG();
595 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
596 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
597 } else {
598 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
599 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
602 hdr->mhdr.num_buffers = 0;
604 /* Encode metadata header at front. */
605 if (vi->mergeable_rx_bufs)
606 sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr);
607 else
608 sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr);
610 hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1;
611 return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg,
612 0, skb, GFP_ATOMIC);
615 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
617 struct virtnet_info *vi = netdev_priv(dev);
618 int capacity;
620 /* Free up any pending old buffers before queueing new ones. */
621 free_old_xmit_skbs(vi);
623 /* Try to transmit */
624 capacity = xmit_skb(vi, skb);
626 /* This can happen with OOM and indirect buffers. */
627 if (unlikely(capacity < 0)) {
628 if (net_ratelimit()) {
629 if (likely(capacity == -ENOMEM)) {
630 dev_warn(&dev->dev,
631 "TX queue failure: out of memory\n");
632 } else {
633 dev->stats.tx_fifo_errors++;
634 dev_warn(&dev->dev,
635 "Unexpected TX queue failure: %d\n",
636 capacity);
639 dev->stats.tx_dropped++;
640 kfree_skb(skb);
641 return NETDEV_TX_OK;
643 virtqueue_kick(vi->svq);
645 /* Don't wait up for transmitted skbs to be freed. */
646 skb_orphan(skb);
647 nf_reset(skb);
649 /* Apparently nice girls don't return TX_BUSY; stop the queue
650 * before it gets out of hand. Naturally, this wastes entries. */
651 if (capacity < 2+MAX_SKB_FRAGS) {
652 netif_stop_queue(dev);
653 if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) {
654 /* More just got used, free them then recheck. */
655 capacity += free_old_xmit_skbs(vi);
656 if (capacity >= 2+MAX_SKB_FRAGS) {
657 netif_start_queue(dev);
658 virtqueue_disable_cb(vi->svq);
663 return NETDEV_TX_OK;
666 static int virtnet_set_mac_address(struct net_device *dev, void *p)
668 struct virtnet_info *vi = netdev_priv(dev);
669 struct virtio_device *vdev = vi->vdev;
670 int ret;
672 ret = eth_mac_addr(dev, p);
673 if (ret)
674 return ret;
676 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
677 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
678 dev->dev_addr, dev->addr_len);
680 return 0;
683 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
684 struct rtnl_link_stats64 *tot)
686 struct virtnet_info *vi = netdev_priv(dev);
687 int cpu;
688 unsigned int start;
690 for_each_possible_cpu(cpu) {
691 struct virtnet_stats __percpu *stats
692 = per_cpu_ptr(vi->stats, cpu);
693 u64 tpackets, tbytes, rpackets, rbytes;
695 do {
696 start = u64_stats_fetch_begin(&stats->syncp);
697 tpackets = stats->tx_packets;
698 tbytes = stats->tx_bytes;
699 rpackets = stats->rx_packets;
700 rbytes = stats->rx_bytes;
701 } while (u64_stats_fetch_retry(&stats->syncp, start));
703 tot->rx_packets += rpackets;
704 tot->tx_packets += tpackets;
705 tot->rx_bytes += rbytes;
706 tot->tx_bytes += tbytes;
709 tot->tx_dropped = dev->stats.tx_dropped;
710 tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
711 tot->rx_dropped = dev->stats.rx_dropped;
712 tot->rx_length_errors = dev->stats.rx_length_errors;
713 tot->rx_frame_errors = dev->stats.rx_frame_errors;
715 return tot;
718 #ifdef CONFIG_NET_POLL_CONTROLLER
719 static void virtnet_netpoll(struct net_device *dev)
721 struct virtnet_info *vi = netdev_priv(dev);
723 napi_schedule(&vi->napi);
725 #endif
727 static int virtnet_open(struct net_device *dev)
729 struct virtnet_info *vi = netdev_priv(dev);
731 /* Make sure we have some buffers: if oom use wq. */
732 if (!try_fill_recv(vi, GFP_KERNEL))
733 queue_delayed_work(system_nrt_wq, &vi->refill, 0);
735 virtnet_napi_enable(vi);
736 return 0;
740 * Send command via the control virtqueue and check status. Commands
741 * supported by the hypervisor, as indicated by feature bits, should
742 * never fail unless improperly formated.
744 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
745 struct scatterlist *data, int out, int in)
747 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
748 struct virtio_net_ctrl_hdr ctrl;
749 virtio_net_ctrl_ack status = ~0;
750 unsigned int tmp;
751 int i;
753 /* Caller should know better */
754 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
755 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
757 out++; /* Add header */
758 in++; /* Add return status */
760 ctrl.class = class;
761 ctrl.cmd = cmd;
763 sg_init_table(sg, out + in);
765 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
766 for_each_sg(data, s, out + in - 2, i)
767 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
768 sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
770 BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0);
772 virtqueue_kick(vi->cvq);
775 * Spin for a response, the kick causes an ioport write, trapping
776 * into the hypervisor, so the request should be handled immediately.
778 while (!virtqueue_get_buf(vi->cvq, &tmp))
779 cpu_relax();
781 return status == VIRTIO_NET_OK;
784 static int virtnet_close(struct net_device *dev)
786 struct virtnet_info *vi = netdev_priv(dev);
788 /* Make sure refill_work doesn't re-enable napi! */
789 cancel_delayed_work_sync(&vi->refill);
790 napi_disable(&vi->napi);
792 return 0;
795 static void virtnet_set_rx_mode(struct net_device *dev)
797 struct virtnet_info *vi = netdev_priv(dev);
798 struct scatterlist sg[2];
799 u8 promisc, allmulti;
800 struct virtio_net_ctrl_mac *mac_data;
801 struct netdev_hw_addr *ha;
802 int uc_count;
803 int mc_count;
804 void *buf;
805 int i;
807 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
808 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
809 return;
811 promisc = ((dev->flags & IFF_PROMISC) != 0);
812 allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
814 sg_init_one(sg, &promisc, sizeof(promisc));
816 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
817 VIRTIO_NET_CTRL_RX_PROMISC,
818 sg, 1, 0))
819 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
820 promisc ? "en" : "dis");
822 sg_init_one(sg, &allmulti, sizeof(allmulti));
824 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
825 VIRTIO_NET_CTRL_RX_ALLMULTI,
826 sg, 1, 0))
827 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
828 allmulti ? "en" : "dis");
830 uc_count = netdev_uc_count(dev);
831 mc_count = netdev_mc_count(dev);
832 /* MAC filter - use one buffer for both lists */
833 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
834 (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
835 mac_data = buf;
836 if (!buf) {
837 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
838 return;
841 sg_init_table(sg, 2);
843 /* Store the unicast list and count in the front of the buffer */
844 mac_data->entries = uc_count;
845 i = 0;
846 netdev_for_each_uc_addr(ha, dev)
847 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
849 sg_set_buf(&sg[0], mac_data,
850 sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
852 /* multicast list and count fill the end */
853 mac_data = (void *)&mac_data->macs[uc_count][0];
855 mac_data->entries = mc_count;
856 i = 0;
857 netdev_for_each_mc_addr(ha, dev)
858 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
860 sg_set_buf(&sg[1], mac_data,
861 sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
863 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
864 VIRTIO_NET_CTRL_MAC_TABLE_SET,
865 sg, 2, 0))
866 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
868 kfree(buf);
871 static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
873 struct virtnet_info *vi = netdev_priv(dev);
874 struct scatterlist sg;
876 sg_init_one(&sg, &vid, sizeof(vid));
878 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
879 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
880 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
881 return 0;
884 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
886 struct virtnet_info *vi = netdev_priv(dev);
887 struct scatterlist sg;
889 sg_init_one(&sg, &vid, sizeof(vid));
891 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
892 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
893 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
894 return 0;
897 static void virtnet_get_ringparam(struct net_device *dev,
898 struct ethtool_ringparam *ring)
900 struct virtnet_info *vi = netdev_priv(dev);
902 ring->rx_max_pending = virtqueue_get_vring_size(vi->rvq);
903 ring->tx_max_pending = virtqueue_get_vring_size(vi->svq);
904 ring->rx_pending = ring->rx_max_pending;
905 ring->tx_pending = ring->tx_max_pending;
910 static void virtnet_get_drvinfo(struct net_device *dev,
911 struct ethtool_drvinfo *info)
913 struct virtnet_info *vi = netdev_priv(dev);
914 struct virtio_device *vdev = vi->vdev;
916 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
917 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
918 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
922 static const struct ethtool_ops virtnet_ethtool_ops = {
923 .get_drvinfo = virtnet_get_drvinfo,
924 .get_link = ethtool_op_get_link,
925 .get_ringparam = virtnet_get_ringparam,
928 #define MIN_MTU 68
929 #define MAX_MTU 65535
931 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
933 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
934 return -EINVAL;
935 dev->mtu = new_mtu;
936 return 0;
939 static const struct net_device_ops virtnet_netdev = {
940 .ndo_open = virtnet_open,
941 .ndo_stop = virtnet_close,
942 .ndo_start_xmit = start_xmit,
943 .ndo_validate_addr = eth_validate_addr,
944 .ndo_set_mac_address = virtnet_set_mac_address,
945 .ndo_set_rx_mode = virtnet_set_rx_mode,
946 .ndo_change_mtu = virtnet_change_mtu,
947 .ndo_get_stats64 = virtnet_stats,
948 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
949 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
950 #ifdef CONFIG_NET_POLL_CONTROLLER
951 .ndo_poll_controller = virtnet_netpoll,
952 #endif
955 static void virtnet_update_status(struct virtnet_info *vi)
957 u16 v;
959 if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
960 offsetof(struct virtio_net_config, status),
961 &v) < 0)
962 return;
964 /* Ignore unknown (future) status bits */
965 v &= VIRTIO_NET_S_LINK_UP;
967 if (vi->status == v)
968 return;
970 vi->status = v;
972 if (vi->status & VIRTIO_NET_S_LINK_UP) {
973 netif_carrier_on(vi->dev);
974 netif_wake_queue(vi->dev);
975 } else {
976 netif_carrier_off(vi->dev);
977 netif_stop_queue(vi->dev);
981 static void virtnet_config_changed(struct virtio_device *vdev)
983 struct virtnet_info *vi = vdev->priv;
985 virtnet_update_status(vi);
988 static int init_vqs(struct virtnet_info *vi)
990 struct virtqueue *vqs[3];
991 vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
992 const char *names[] = { "input", "output", "control" };
993 int nvqs, err;
995 /* We expect two virtqueues, receive then send,
996 * and optionally control. */
997 nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
999 err = vi->vdev->config->find_vqs(vi->vdev, nvqs, vqs, callbacks, names);
1000 if (err)
1001 return err;
1003 vi->rvq = vqs[0];
1004 vi->svq = vqs[1];
1006 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
1007 vi->cvq = vqs[2];
1009 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1010 vi->dev->features |= NETIF_F_HW_VLAN_FILTER;
1012 return 0;
1015 static int virtnet_probe(struct virtio_device *vdev)
1017 int err;
1018 struct net_device *dev;
1019 struct virtnet_info *vi;
1021 /* Allocate ourselves a network device with room for our info */
1022 dev = alloc_etherdev(sizeof(struct virtnet_info));
1023 if (!dev)
1024 return -ENOMEM;
1026 /* Set up network device as normal. */
1027 dev->priv_flags |= IFF_UNICAST_FLT;
1028 dev->netdev_ops = &virtnet_netdev;
1029 dev->features = NETIF_F_HIGHDMA;
1031 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
1032 SET_NETDEV_DEV(dev, &vdev->dev);
1034 /* Do we support "hardware" checksums? */
1035 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1036 /* This opens up the world of extra features. */
1037 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1038 if (csum)
1039 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1041 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1042 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1043 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1045 /* Individual feature bits: what can host handle? */
1046 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1047 dev->hw_features |= NETIF_F_TSO;
1048 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1049 dev->hw_features |= NETIF_F_TSO6;
1050 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1051 dev->hw_features |= NETIF_F_TSO_ECN;
1052 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1053 dev->hw_features |= NETIF_F_UFO;
1055 if (gso)
1056 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1057 /* (!csum && gso) case will be fixed by register_netdev() */
1060 /* Configuration may specify what MAC to use. Otherwise random. */
1061 if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
1062 offsetof(struct virtio_net_config, mac),
1063 dev->dev_addr, dev->addr_len) < 0)
1064 random_ether_addr(dev->dev_addr);
1066 /* Set up our device-specific information */
1067 vi = netdev_priv(dev);
1068 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
1069 vi->dev = dev;
1070 vi->vdev = vdev;
1071 vdev->priv = vi;
1072 vi->pages = NULL;
1073 vi->stats = alloc_percpu(struct virtnet_stats);
1074 err = -ENOMEM;
1075 if (vi->stats == NULL)
1076 goto free;
1078 INIT_DELAYED_WORK(&vi->refill, refill_work);
1079 sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg));
1080 sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg));
1082 /* If we can receive ANY GSO packets, we must allocate large ones. */
1083 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1084 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1085 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1086 vi->big_packets = true;
1088 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1089 vi->mergeable_rx_bufs = true;
1091 err = init_vqs(vi);
1092 if (err)
1093 goto free_stats;
1095 err = register_netdev(dev);
1096 if (err) {
1097 pr_debug("virtio_net: registering device failed\n");
1098 goto free_vqs;
1101 /* Last of all, set up some receive buffers. */
1102 try_fill_recv(vi, GFP_KERNEL);
1104 /* If we didn't even get one input buffer, we're useless. */
1105 if (vi->num == 0) {
1106 err = -ENOMEM;
1107 goto unregister;
1110 /* Assume link up if device can't report link status,
1111 otherwise get link status from config. */
1112 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1113 netif_carrier_off(dev);
1114 virtnet_update_status(vi);
1115 } else {
1116 vi->status = VIRTIO_NET_S_LINK_UP;
1117 netif_carrier_on(dev);
1120 pr_debug("virtnet: registered device %s\n", dev->name);
1121 return 0;
1123 unregister:
1124 unregister_netdev(dev);
1125 free_vqs:
1126 vdev->config->del_vqs(vdev);
1127 free_stats:
1128 free_percpu(vi->stats);
1129 free:
1130 free_netdev(dev);
1131 return err;
1134 static void free_unused_bufs(struct virtnet_info *vi)
1136 void *buf;
1137 while (1) {
1138 buf = virtqueue_detach_unused_buf(vi->svq);
1139 if (!buf)
1140 break;
1141 dev_kfree_skb(buf);
1143 while (1) {
1144 buf = virtqueue_detach_unused_buf(vi->rvq);
1145 if (!buf)
1146 break;
1147 if (vi->mergeable_rx_bufs || vi->big_packets)
1148 give_pages(vi, buf);
1149 else
1150 dev_kfree_skb(buf);
1151 --vi->num;
1153 BUG_ON(vi->num != 0);
1156 static void remove_vq_common(struct virtnet_info *vi)
1158 vi->vdev->config->reset(vi->vdev);
1160 /* Free unused buffers in both send and recv, if any. */
1161 free_unused_bufs(vi);
1163 vi->vdev->config->del_vqs(vi->vdev);
1165 while (vi->pages)
1166 __free_pages(get_a_page(vi, GFP_KERNEL), 0);
1169 static void __devexit virtnet_remove(struct virtio_device *vdev)
1171 struct virtnet_info *vi = vdev->priv;
1173 unregister_netdev(vi->dev);
1175 remove_vq_common(vi);
1177 free_percpu(vi->stats);
1178 free_netdev(vi->dev);
1181 #ifdef CONFIG_PM
1182 static int virtnet_freeze(struct virtio_device *vdev)
1184 struct virtnet_info *vi = vdev->priv;
1186 virtqueue_disable_cb(vi->rvq);
1187 virtqueue_disable_cb(vi->svq);
1188 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ))
1189 virtqueue_disable_cb(vi->cvq);
1191 netif_device_detach(vi->dev);
1192 cancel_delayed_work_sync(&vi->refill);
1194 if (netif_running(vi->dev))
1195 napi_disable(&vi->napi);
1197 remove_vq_common(vi);
1199 return 0;
1202 static int virtnet_restore(struct virtio_device *vdev)
1204 struct virtnet_info *vi = vdev->priv;
1205 int err;
1207 err = init_vqs(vi);
1208 if (err)
1209 return err;
1211 if (netif_running(vi->dev))
1212 virtnet_napi_enable(vi);
1214 netif_device_attach(vi->dev);
1216 if (!try_fill_recv(vi, GFP_KERNEL))
1217 queue_delayed_work(system_nrt_wq, &vi->refill, 0);
1219 return 0;
1221 #endif
1223 static struct virtio_device_id id_table[] = {
1224 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1225 { 0 },
1228 static unsigned int features[] = {
1229 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1230 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1231 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1232 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1233 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1234 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1235 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1238 static struct virtio_driver virtio_net_driver = {
1239 .feature_table = features,
1240 .feature_table_size = ARRAY_SIZE(features),
1241 .driver.name = KBUILD_MODNAME,
1242 .driver.owner = THIS_MODULE,
1243 .id_table = id_table,
1244 .probe = virtnet_probe,
1245 .remove = __devexit_p(virtnet_remove),
1246 .config_changed = virtnet_config_changed,
1247 #ifdef CONFIG_PM
1248 .freeze = virtnet_freeze,
1249 .restore = virtnet_restore,
1250 #endif
1253 static int __init init(void)
1255 return register_virtio_driver(&virtio_net_driver);
1258 static void __exit fini(void)
1260 unregister_virtio_driver(&virtio_net_driver);
1262 module_init(init);
1263 module_exit(fini);
1265 MODULE_DEVICE_TABLE(virtio, id_table);
1266 MODULE_DESCRIPTION("Virtio network driver");
1267 MODULE_LICENSE("GPL");