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Linux 4.4.145
[linux/fpc-iii.git] / drivers / net / virtio_net.c
blob2759d386ade79d83b6f5d3836eac66ca951fc2b3
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, see <http://www.gnu.org/licenses/>.
17 */
18 //#define DEBUG
19 #include <linux/netdevice.h>
20 #include <linux/etherdevice.h>
21 #include <linux/ethtool.h>
22 #include <linux/module.h>
23 #include <linux/virtio.h>
24 #include <linux/virtio_net.h>
25 #include <linux/scatterlist.h>
26 #include <linux/if_vlan.h>
27 #include <linux/slab.h>
28 #include <linux/cpu.h>
29 #include <linux/average.h>
30 #include <net/busy_poll.h>
31
32 static int napi_weight = NAPI_POLL_WEIGHT;
33 module_param(napi_weight, int, 0444);
34
35 static bool csum = true, gso = true;
36 module_param(csum, bool, 0444);
37 module_param(gso, bool, 0444);
38
39 /* FIXME: MTU in config. */
40 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
41 #define GOOD_COPY_LEN 128
42
43 /* RX packet size EWMA. The average packet size is used to determine the packet
44 * buffer size when refilling RX rings. As the entire RX ring may be refilled
45 * at once, the weight is chosen so that the EWMA will be insensitive to short-
46 * term, transient changes in packet size.
47 */
48 DECLARE_EWMA(pkt_len, 1, 64)
49
50 /* With mergeable buffers we align buffer address and use the low bits to
51 * encode its true size. Buffer size is up to 1 page so we need to align to
52 * square root of page size to ensure we reserve enough bits to encode the true
53 * size.
54 */
55 #define MERGEABLE_BUFFER_MIN_ALIGN_SHIFT ((PAGE_SHIFT + 1) / 2)
56
57 /* Minimum alignment for mergeable packet buffers. */
58 #define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, \
59 1 << MERGEABLE_BUFFER_MIN_ALIGN_SHIFT)
60
61 #define VIRTNET_DRIVER_VERSION "1.0.0"
62
63 struct virtnet_stats {
64 struct u64_stats_sync tx_syncp;
65 struct u64_stats_sync rx_syncp;
66 u64 tx_bytes;
67 u64 tx_packets;
68
69 u64 rx_bytes;
70 u64 rx_packets;
71 };
72
73 /* Internal representation of a send virtqueue */
74 struct send_queue {
75 /* Virtqueue associated with this send _queue */
76 struct virtqueue *vq;
77
78 /* TX: fragments + linear part + virtio header */
79 struct scatterlist sg[MAX_SKB_FRAGS + 2];
80
81 /* Name of the send queue: output.$index */
82 char name[40];
83 };
84
85 /* Internal representation of a receive virtqueue */
86 struct receive_queue {
87 /* Virtqueue associated with this receive_queue */
88 struct virtqueue *vq;
89
90 struct napi_struct napi;
91
92 /* Chain pages by the private ptr. */
93 struct page *pages;
94
95 /* Average packet length for mergeable receive buffers. */
96 struct ewma_pkt_len mrg_avg_pkt_len;
97
98 /* Page frag for packet buffer allocation. */
99 struct page_frag alloc_frag;
100
101 /* RX: fragments + linear part + virtio header */
102 struct scatterlist sg[MAX_SKB_FRAGS + 2];
103
104 /* Name of this receive queue: input.$index */
105 char name[40];
106 };
107
108 struct virtnet_info {
109 struct virtio_device *vdev;
110 struct virtqueue *cvq;
111 struct net_device *dev;
112 struct send_queue *sq;
113 struct receive_queue *rq;
114 unsigned int status;
115
116 /* Max # of queue pairs supported by the device */
117 u16 max_queue_pairs;
118
119 /* # of queue pairs currently used by the driver */
120 u16 curr_queue_pairs;
121
122 /* I like... big packets and I cannot lie! */
123 bool big_packets;
124
125 /* Host will merge rx buffers for big packets (shake it! shake it!) */
126 bool mergeable_rx_bufs;
127
128 /* Has control virtqueue */
129 bool has_cvq;
130
131 /* Host can handle any s/g split between our header and packet data */
132 bool any_header_sg;
133
134 /* Packet virtio header size */
135 u8 hdr_len;
136
137 /* Active statistics */
138 struct virtnet_stats __percpu *stats;
139
140 /* Work struct for refilling if we run low on memory. */
141 struct delayed_work refill;
142
143 /* Work struct for config space updates */
144 struct work_struct config_work;
145
146 /* Does the affinity hint is set for virtqueues? */
147 bool affinity_hint_set;
148
149 /* CPU hot plug notifier */
150 struct notifier_block nb;
151
152 /* Control VQ buffers: protected by the rtnl lock */
153 struct virtio_net_ctrl_hdr ctrl_hdr;
154 virtio_net_ctrl_ack ctrl_status;
155 u8 ctrl_promisc;
156 u8 ctrl_allmulti;
157 };
158
159 struct padded_vnet_hdr {
160 struct virtio_net_hdr_mrg_rxbuf hdr;
161 /*
162 * hdr is in a separate sg buffer, and data sg buffer shares same page
163 * with this header sg. This padding makes next sg 16 byte aligned
164 * after the header.
165 */
166 char padding[4];
167 };
168
169 /* Converting between virtqueue no. and kernel tx/rx queue no.
170 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
171 */
172 static int vq2txq(struct virtqueue *vq)
173 {
174 return (vq->index - 1) / 2;
175 }
176
177 static int txq2vq(int txq)
178 {
179 return txq * 2 + 1;
180 }
181
182 static int vq2rxq(struct virtqueue *vq)
183 {
184 return vq->index / 2;
185 }
186
187 static int rxq2vq(int rxq)
188 {
189 return rxq * 2;
190 }
191
192 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
193 {
194 return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
195 }
196
197 /*
198 * private is used to chain pages for big packets, put the whole
199 * most recent used list in the beginning for reuse
200 */
201 static void give_pages(struct receive_queue *rq, struct page *page)
202 {
203 struct page *end;
204
205 /* Find end of list, sew whole thing into vi->rq.pages. */
206 for (end = page; end->private; end = (struct page *)end->private);
207 end->private = (unsigned long)rq->pages;
208 rq->pages = page;
209 }
210
211 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
212 {
213 struct page *p = rq->pages;
214
215 if (p) {
216 rq->pages = (struct page *)p->private;
217 /* clear private here, it is used to chain pages */
218 p->private = 0;
219 } else
220 p = alloc_page(gfp_mask);
221 return p;
222 }
223
224 static void skb_xmit_done(struct virtqueue *vq)
225 {
226 struct virtnet_info *vi = vq->vdev->priv;
227
228 /* Suppress further interrupts. */
229 virtqueue_disable_cb(vq);
230
231 /* We were probably waiting for more output buffers. */
232 netif_wake_subqueue(vi->dev, vq2txq(vq));
233 }
234
235 static unsigned int mergeable_ctx_to_buf_truesize(unsigned long mrg_ctx)
236 {
237 unsigned int truesize = mrg_ctx & (MERGEABLE_BUFFER_ALIGN - 1);
238 return (truesize + 1) * MERGEABLE_BUFFER_ALIGN;
239 }
240
241 static void *mergeable_ctx_to_buf_address(unsigned long mrg_ctx)
242 {
243 return (void *)(mrg_ctx & -MERGEABLE_BUFFER_ALIGN);
244
245 }
246
247 static unsigned long mergeable_buf_to_ctx(void *buf, unsigned int truesize)
248 {
249 unsigned int size = truesize / MERGEABLE_BUFFER_ALIGN;
250 return (unsigned long)buf | (size - 1);
251 }
252
253 /* Called from bottom half context */
254 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
255 struct receive_queue *rq,
256 struct page *page, unsigned int offset,
257 unsigned int len, unsigned int truesize)
258 {
259 struct sk_buff *skb;
260 struct virtio_net_hdr_mrg_rxbuf *hdr;
261 unsigned int copy, hdr_len, hdr_padded_len;
262 char *p;
263
264 p = page_address(page) + offset;
265
266 /* copy small packet so we can reuse these pages for small data */
267 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
268 if (unlikely(!skb))
269 return NULL;
270
271 hdr = skb_vnet_hdr(skb);
272
273 hdr_len = vi->hdr_len;
274 if (vi->mergeable_rx_bufs)
275 hdr_padded_len = sizeof *hdr;
276 else
277 hdr_padded_len = sizeof(struct padded_vnet_hdr);
278
279 memcpy(hdr, p, hdr_len);
280
281 len -= hdr_len;
282 offset += hdr_padded_len;
283 p += hdr_padded_len;
284
285 copy = len;
286 if (copy > skb_tailroom(skb))
287 copy = skb_tailroom(skb);
288 memcpy(skb_put(skb, copy), p, copy);
289
290 len -= copy;
291 offset += copy;
292
293 if (vi->mergeable_rx_bufs) {
294 if (len)
295 skb_add_rx_frag(skb, 0, page, offset, len, truesize);
296 else
297 put_page(page);
298 return skb;
299 }
300
301 /*
302 * Verify that we can indeed put this data into a skb.
303 * This is here to handle cases when the device erroneously
304 * tries to receive more than is possible. This is usually
305 * the case of a broken device.
306 */
307 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
308 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
309 dev_kfree_skb(skb);
310 return NULL;
311 }
312 BUG_ON(offset >= PAGE_SIZE);
313 while (len) {
314 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
315 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
316 frag_size, truesize);
317 len -= frag_size;
318 page = (struct page *)page->private;
319 offset = 0;
320 }
321
322 if (page)
323 give_pages(rq, page);
324
325 return skb;
326 }
327
328 static struct sk_buff *receive_small(struct virtnet_info *vi, void *buf, unsigned int len)
329 {
330 struct sk_buff * skb = buf;
331
332 len -= vi->hdr_len;
333 skb_trim(skb, len);
334
335 return skb;
336 }
337
338 static struct sk_buff *receive_big(struct net_device *dev,
339 struct virtnet_info *vi,
340 struct receive_queue *rq,
341 void *buf,
342 unsigned int len)
343 {
344 struct page *page = buf;
345 struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
346
347 if (unlikely(!skb))
348 goto err;
349
350 return skb;
351
352 err:
353 dev->stats.rx_dropped++;
354 give_pages(rq, page);
355 return NULL;
356 }
357
358 static struct sk_buff *receive_mergeable(struct net_device *dev,
359 struct virtnet_info *vi,
360 struct receive_queue *rq,
361 unsigned long ctx,
362 unsigned int len)
363 {
364 void *buf = mergeable_ctx_to_buf_address(ctx);
365 struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
366 u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
367 struct page *page = virt_to_head_page(buf);
368 int offset = buf - page_address(page);
369 unsigned int truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
370
371 struct sk_buff *head_skb = page_to_skb(vi, rq, page, offset, len,
372 truesize);
373 struct sk_buff *curr_skb = head_skb;
374
375 if (unlikely(!curr_skb))
376 goto err_skb;
377 while (--num_buf) {
378 int num_skb_frags;
379
380 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
381 if (unlikely(!ctx)) {
382 pr_debug("%s: rx error: %d buffers out of %d missing\n",
383 dev->name, num_buf,
384 virtio16_to_cpu(vi->vdev,
385 hdr->num_buffers));
386 dev->stats.rx_length_errors++;
387 goto err_buf;
388 }
389
390 buf = mergeable_ctx_to_buf_address(ctx);
391 page = virt_to_head_page(buf);
392
393 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
394 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
395 struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
396
397 if (unlikely(!nskb))
398 goto err_skb;
399 if (curr_skb == head_skb)
400 skb_shinfo(curr_skb)->frag_list = nskb;
401 else
402 curr_skb->next = nskb;
403 curr_skb = nskb;
404 head_skb->truesize += nskb->truesize;
405 num_skb_frags = 0;
406 }
407 truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
408 if (curr_skb != head_skb) {
409 head_skb->data_len += len;
410 head_skb->len += len;
411 head_skb->truesize += truesize;
412 }
413 offset = buf - page_address(page);
414 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
415 put_page(page);
416 skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
417 len, truesize);
418 } else {
419 skb_add_rx_frag(curr_skb, num_skb_frags, page,
420 offset, len, truesize);
421 }
422 }
423
424 ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
425 return head_skb;
426
427 err_skb:
428 put_page(page);
429 while (--num_buf) {
430 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
431 if (unlikely(!ctx)) {
432 pr_debug("%s: rx error: %d buffers missing\n",
433 dev->name, num_buf);
434 dev->stats.rx_length_errors++;
435 break;
436 }
437 page = virt_to_head_page(mergeable_ctx_to_buf_address(ctx));
438 put_page(page);
439 }
440 err_buf:
441 dev->stats.rx_dropped++;
442 dev_kfree_skb(head_skb);
443 return NULL;
444 }
445
446 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
447 void *buf, unsigned int len)
448 {
449 struct net_device *dev = vi->dev;
450 struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
451 struct sk_buff *skb;
452 struct virtio_net_hdr_mrg_rxbuf *hdr;
453
454 if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
455 pr_debug("%s: short packet %i\n", dev->name, len);
456 dev->stats.rx_length_errors++;
457 if (vi->mergeable_rx_bufs) {
458 unsigned long ctx = (unsigned long)buf;
459 void *base = mergeable_ctx_to_buf_address(ctx);
460 put_page(virt_to_head_page(base));
461 } else if (vi->big_packets) {
462 give_pages(rq, buf);
463 } else {
464 dev_kfree_skb(buf);
465 }
466 return;
467 }
468
469 if (vi->mergeable_rx_bufs)
470 skb = receive_mergeable(dev, vi, rq, (unsigned long)buf, len);
471 else if (vi->big_packets)
472 skb = receive_big(dev, vi, rq, buf, len);
473 else
474 skb = receive_small(vi, buf, len);
475
476 if (unlikely(!skb))
477 return;
478
479 hdr = skb_vnet_hdr(skb);
480
481 u64_stats_update_begin(&stats->rx_syncp);
482 stats->rx_bytes += skb->len;
483 stats->rx_packets++;
484 u64_stats_update_end(&stats->rx_syncp);
485
486 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
487 pr_debug("Needs csum!\n");
488 if (!skb_partial_csum_set(skb,
489 virtio16_to_cpu(vi->vdev, hdr->hdr.csum_start),
490 virtio16_to_cpu(vi->vdev, hdr->hdr.csum_offset)))
491 goto frame_err;
492 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
493 skb->ip_summed = CHECKSUM_UNNECESSARY;
494 }
495
496 skb->protocol = eth_type_trans(skb, dev);
497 pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
498 ntohs(skb->protocol), skb->len, skb->pkt_type);
499
500 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
501 pr_debug("GSO!\n");
502 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
503 case VIRTIO_NET_HDR_GSO_TCPV4:
504 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
505 break;
506 case VIRTIO_NET_HDR_GSO_UDP:
507 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
508 break;
509 case VIRTIO_NET_HDR_GSO_TCPV6:
510 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
511 break;
512 default:
513 net_warn_ratelimited("%s: bad gso type %u.\n",
514 dev->name, hdr->hdr.gso_type);
515 goto frame_err;
516 }
517
518 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
519 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
520
521 skb_shinfo(skb)->gso_size = virtio16_to_cpu(vi->vdev,
522 hdr->hdr.gso_size);
523 if (skb_shinfo(skb)->gso_size == 0) {
524 net_warn_ratelimited("%s: zero gso size.\n", dev->name);
525 goto frame_err;
526 }
527
528 /* Header must be checked, and gso_segs computed. */
529 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
530 skb_shinfo(skb)->gso_segs = 0;
531 }
532
533 skb_mark_napi_id(skb, &rq->napi);
534
535 napi_gro_receive(&rq->napi, skb);
536 return;
537
538 frame_err:
539 dev->stats.rx_frame_errors++;
540 dev_kfree_skb(skb);
541 }
542
543 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
544 gfp_t gfp)
545 {
546 struct sk_buff *skb;
547 struct virtio_net_hdr_mrg_rxbuf *hdr;
548 int err;
549
550 skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp);
551 if (unlikely(!skb))
552 return -ENOMEM;
553
554 skb_put(skb, GOOD_PACKET_LEN);
555
556 hdr = skb_vnet_hdr(skb);
557 sg_init_table(rq->sg, 2);
558 sg_set_buf(rq->sg, hdr, vi->hdr_len);
559
560 err = skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
561 if (unlikely(err < 0)) {
562 dev_kfree_skb(skb);
563 return err;
564 }
565
566 err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
567 if (err < 0)
568 dev_kfree_skb(skb);
569
570 return err;
571 }
572
573 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
574 gfp_t gfp)
575 {
576 struct page *first, *list = NULL;
577 char *p;
578 int i, err, offset;
579
580 sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
581
582 /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
583 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
584 first = get_a_page(rq, gfp);
585 if (!first) {
586 if (list)
587 give_pages(rq, list);
588 return -ENOMEM;
589 }
590 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
591
592 /* chain new page in list head to match sg */
593 first->private = (unsigned long)list;
594 list = first;
595 }
596
597 first = get_a_page(rq, gfp);
598 if (!first) {
599 give_pages(rq, list);
600 return -ENOMEM;
601 }
602 p = page_address(first);
603
604 /* rq->sg[0], rq->sg[1] share the same page */
605 /* a separated rq->sg[0] for header - required in case !any_header_sg */
606 sg_set_buf(&rq->sg[0], p, vi->hdr_len);
607
608 /* rq->sg[1] for data packet, from offset */
609 offset = sizeof(struct padded_vnet_hdr);
610 sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
611
612 /* chain first in list head */
613 first->private = (unsigned long)list;
614 err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
615 first, gfp);
616 if (err < 0)
617 give_pages(rq, first);
618
619 return err;
620 }
621
622 static unsigned int get_mergeable_buf_len(struct ewma_pkt_len *avg_pkt_len)
623 {
624 const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
625 unsigned int len;
626
627 len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
628 GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
629 return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
630 }
631
632 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
633 {
634 struct page_frag *alloc_frag = &rq->alloc_frag;
635 char *buf;
636 unsigned long ctx;
637 int err;
638 unsigned int len, hole;
639
640 len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len);
641 if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
642 return -ENOMEM;
643
644 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
645 ctx = mergeable_buf_to_ctx(buf, len);
646 get_page(alloc_frag->page);
647 alloc_frag->offset += len;
648 hole = alloc_frag->size - alloc_frag->offset;
649 if (hole < len) {
650 /* To avoid internal fragmentation, if there is very likely not
651 * enough space for another buffer, add the remaining space to
652 * the current buffer. This extra space is not included in
653 * the truesize stored in ctx.
654 */
655 len += hole;
656 alloc_frag->offset += hole;
657 }
658
659 sg_init_one(rq->sg, buf, len);
660 err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, (void *)ctx, gfp);
661 if (err < 0)
662 put_page(virt_to_head_page(buf));
663
664 return err;
665 }
666
667 /*
668 * Returns false if we couldn't fill entirely (OOM).
669 *
670 * Normally run in the receive path, but can also be run from ndo_open
671 * before we're receiving packets, or from refill_work which is
672 * careful to disable receiving (using napi_disable).
673 */
674 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
675 gfp_t gfp)
676 {
677 int err;
678 bool oom;
679
680 gfp |= __GFP_COLD;
681 do {
682 if (vi->mergeable_rx_bufs)
683 err = add_recvbuf_mergeable(rq, gfp);
684 else if (vi->big_packets)
685 err = add_recvbuf_big(vi, rq, gfp);
686 else
687 err = add_recvbuf_small(vi, rq, gfp);
688
689 oom = err == -ENOMEM;
690 if (err)
691 break;
692 } while (rq->vq->num_free);
693 virtqueue_kick(rq->vq);
694 return !oom;
695 }
696
697 static void skb_recv_done(struct virtqueue *rvq)
698 {
699 struct virtnet_info *vi = rvq->vdev->priv;
700 struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
701
702 /* Schedule NAPI, Suppress further interrupts if successful. */
703 if (napi_schedule_prep(&rq->napi)) {
704 virtqueue_disable_cb(rvq);
705 __napi_schedule(&rq->napi);
706 }
707 }
708
709 static void virtnet_napi_enable(struct receive_queue *rq)
710 {
711 napi_enable(&rq->napi);
712
713 /* If all buffers were filled by other side before we napi_enabled, we
714 * won't get another interrupt, so process any outstanding packets
715 * now. virtnet_poll wants re-enable the queue, so we disable here.
716 * We synchronize against interrupts via NAPI_STATE_SCHED */
717 if (napi_schedule_prep(&rq->napi)) {
718 virtqueue_disable_cb(rq->vq);
719 local_bh_disable();
720 __napi_schedule(&rq->napi);
721 local_bh_enable();
722 }
723 }
724
725 static void refill_work(struct work_struct *work)
726 {
727 struct virtnet_info *vi =
728 container_of(work, struct virtnet_info, refill.work);
729 bool still_empty;
730 int i;
731
732 for (i = 0; i < vi->curr_queue_pairs; i++) {
733 struct receive_queue *rq = &vi->rq[i];
734
735 napi_disable(&rq->napi);
736 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
737 virtnet_napi_enable(rq);
738
739 /* In theory, this can happen: if we don't get any buffers in
740 * we will *never* try to fill again.
741 */
742 if (still_empty)
743 schedule_delayed_work(&vi->refill, HZ/2);
744 }
745 }
746
747 static int virtnet_receive(struct receive_queue *rq, int budget)
748 {
749 struct virtnet_info *vi = rq->vq->vdev->priv;
750 unsigned int len, received = 0;
751 void *buf;
752
753 while (received < budget &&
754 (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
755 receive_buf(vi, rq, buf, len);
756 received++;
757 }
758
759 if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
760 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
761 schedule_delayed_work(&vi->refill, 0);
762 }
763
764 return received;
765 }
766
767 static int virtnet_poll(struct napi_struct *napi, int budget)
768 {
769 struct receive_queue *rq =
770 container_of(napi, struct receive_queue, napi);
771 unsigned int r, received;
772
773 received = virtnet_receive(rq, budget);
774
775 /* Out of packets? */
776 if (received < budget) {
777 r = virtqueue_enable_cb_prepare(rq->vq);
778 napi_complete_done(napi, received);
779 if (unlikely(virtqueue_poll(rq->vq, r)) &&
780 napi_schedule_prep(napi)) {
781 virtqueue_disable_cb(rq->vq);
782 __napi_schedule(napi);
783 }
784 }
785
786 return received;
787 }
788
789 #ifdef CONFIG_NET_RX_BUSY_POLL
790 /* must be called with local_bh_disable()d */
791 static int virtnet_busy_poll(struct napi_struct *napi)
792 {
793 struct receive_queue *rq =
794 container_of(napi, struct receive_queue, napi);
795 struct virtnet_info *vi = rq->vq->vdev->priv;
796 int r, received = 0, budget = 4;
797
798 if (!(vi->status & VIRTIO_NET_S_LINK_UP))
799 return LL_FLUSH_FAILED;
800
801 if (!napi_schedule_prep(napi))
802 return LL_FLUSH_BUSY;
803
804 virtqueue_disable_cb(rq->vq);
805
806 again:
807 received += virtnet_receive(rq, budget);
808
809 r = virtqueue_enable_cb_prepare(rq->vq);
810 clear_bit(NAPI_STATE_SCHED, &napi->state);
811 if (unlikely(virtqueue_poll(rq->vq, r)) &&
812 napi_schedule_prep(napi)) {
813 virtqueue_disable_cb(rq->vq);
814 if (received < budget) {
815 budget -= received;
816 goto again;
817 } else {
818 __napi_schedule(napi);
819 }
820 }
821
822 return received;
823 }
824 #endif /* CONFIG_NET_RX_BUSY_POLL */
825
826 static int virtnet_open(struct net_device *dev)
827 {
828 struct virtnet_info *vi = netdev_priv(dev);
829 int i;
830
831 for (i = 0; i < vi->max_queue_pairs; i++) {
832 if (i < vi->curr_queue_pairs)
833 /* Make sure we have some buffers: if oom use wq. */
834 if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
835 schedule_delayed_work(&vi->refill, 0);
836 virtnet_napi_enable(&vi->rq[i]);
837 }
838
839 return 0;
840 }
841
842 static void free_old_xmit_skbs(struct send_queue *sq)
843 {
844 struct sk_buff *skb;
845 unsigned int len;
846 struct virtnet_info *vi = sq->vq->vdev->priv;
847 struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
848
849 while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
850 pr_debug("Sent skb %p\n", skb);
851
852 u64_stats_update_begin(&stats->tx_syncp);
853 stats->tx_bytes += skb->len;
854 stats->tx_packets++;
855 u64_stats_update_end(&stats->tx_syncp);
856
857 dev_kfree_skb_any(skb);
858 }
859 }
860
861 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
862 {
863 struct virtio_net_hdr_mrg_rxbuf *hdr;
864 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
865 struct virtnet_info *vi = sq->vq->vdev->priv;
866 int num_sg;
867 unsigned hdr_len = vi->hdr_len;
868 bool can_push;
869
870 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
871
872 can_push = vi->any_header_sg &&
873 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
874 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
875 /* Even if we can, don't push here yet as this would skew
876 * csum_start offset below. */
877 if (can_push)
878 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
879 else
880 hdr = skb_vnet_hdr(skb);
881
882 if (skb->ip_summed == CHECKSUM_PARTIAL) {
883 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
884 hdr->hdr.csum_start = cpu_to_virtio16(vi->vdev,
885 skb_checksum_start_offset(skb));
886 hdr->hdr.csum_offset = cpu_to_virtio16(vi->vdev,
887 skb->csum_offset);
888 } else {
889 hdr->hdr.flags = 0;
890 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
891 }
892
893 if (skb_is_gso(skb)) {
894 hdr->hdr.hdr_len = cpu_to_virtio16(vi->vdev, skb_headlen(skb));
895 hdr->hdr.gso_size = cpu_to_virtio16(vi->vdev,
896 skb_shinfo(skb)->gso_size);
897 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
898 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
899 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
900 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
901 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
902 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
903 else
904 BUG();
905 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
906 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
907 } else {
908 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
909 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
910 }
911
912 if (vi->mergeable_rx_bufs)
913 hdr->num_buffers = 0;
914
915 sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
916 if (can_push) {
917 __skb_push(skb, hdr_len);
918 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
919 if (unlikely(num_sg < 0))
920 return num_sg;
921 /* Pull header back to avoid skew in tx bytes calculations. */
922 __skb_pull(skb, hdr_len);
923 } else {
924 sg_set_buf(sq->sg, hdr, hdr_len);
925 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
926 if (unlikely(num_sg < 0))
927 return num_sg;
928 num_sg++;
929 }
930 return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
931 }
932
933 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
934 {
935 struct virtnet_info *vi = netdev_priv(dev);
936 int qnum = skb_get_queue_mapping(skb);
937 struct send_queue *sq = &vi->sq[qnum];
938 int err;
939 struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
940 bool kick = !skb->xmit_more;
941
942 /* Free up any pending old buffers before queueing new ones. */
943 free_old_xmit_skbs(sq);
944
945 /* timestamp packet in software */
946 skb_tx_timestamp(skb);
947
948 /* Try to transmit */
949 err = xmit_skb(sq, skb);
950
951 /* This should not happen! */
952 if (unlikely(err)) {
953 dev->stats.tx_fifo_errors++;
954 if (net_ratelimit())
955 dev_warn(&dev->dev,
956 "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
957 dev->stats.tx_dropped++;
958 dev_kfree_skb_any(skb);
959 return NETDEV_TX_OK;
960 }
961
962 /* Don't wait up for transmitted skbs to be freed. */
963 skb_orphan(skb);
964 nf_reset(skb);
965
966 /* If running out of space, stop queue to avoid getting packets that we
967 * are then unable to transmit.
968 * An alternative would be to force queuing layer to requeue the skb by
969 * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
970 * returned in a normal path of operation: it means that driver is not
971 * maintaining the TX queue stop/start state properly, and causes
972 * the stack to do a non-trivial amount of useless work.
973 * Since most packets only take 1 or 2 ring slots, stopping the queue
974 * early means 16 slots are typically wasted.
975 */
976 if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
977 netif_stop_subqueue(dev, qnum);
978 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
979 /* More just got used, free them then recheck. */
980 free_old_xmit_skbs(sq);
981 if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
982 netif_start_subqueue(dev, qnum);
983 virtqueue_disable_cb(sq->vq);
984 }
985 }
986 }
987
988 if (kick || netif_xmit_stopped(txq))
989 virtqueue_kick(sq->vq);
990
991 return NETDEV_TX_OK;
992 }
993
994 /*
995 * Send command via the control virtqueue and check status. Commands
996 * supported by the hypervisor, as indicated by feature bits, should
997 * never fail unless improperly formatted.
998 */
999 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
1000 struct scatterlist *out)
1001 {
1002 struct scatterlist *sgs[4], hdr, stat;
1003 unsigned out_num = 0, tmp;
1004
1005 /* Caller should know better */
1006 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
1007
1008 vi->ctrl_status = ~0;
1009 vi->ctrl_hdr.class = class;
1010 vi->ctrl_hdr.cmd = cmd;
1011 /* Add header */
1012 sg_init_one(&hdr, &vi->ctrl_hdr, sizeof(vi->ctrl_hdr));
1013 sgs[out_num++] = &hdr;
1014
1015 if (out)
1016 sgs[out_num++] = out;
1017
1018 /* Add return status. */
1019 sg_init_one(&stat, &vi->ctrl_status, sizeof(vi->ctrl_status));
1020 sgs[out_num] = &stat;
1021
1022 BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1023 virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
1024
1025 if (unlikely(!virtqueue_kick(vi->cvq)))
1026 return vi->ctrl_status == VIRTIO_NET_OK;
1027
1028 /* Spin for a response, the kick causes an ioport write, trapping
1029 * into the hypervisor, so the request should be handled immediately.
1030 */
1031 while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1032 !virtqueue_is_broken(vi->cvq))
1033 cpu_relax();
1034
1035 return vi->ctrl_status == VIRTIO_NET_OK;
1036 }
1037
1038 static int virtnet_set_mac_address(struct net_device *dev, void *p)
1039 {
1040 struct virtnet_info *vi = netdev_priv(dev);
1041 struct virtio_device *vdev = vi->vdev;
1042 int ret;
1043 struct sockaddr *addr = p;
1044 struct scatterlist sg;
1045
1046 ret = eth_prepare_mac_addr_change(dev, p);
1047 if (ret)
1048 return ret;
1049
1050 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1051 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1052 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1053 VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1054 dev_warn(&vdev->dev,
1055 "Failed to set mac address by vq command.\n");
1056 return -EINVAL;
1057 }
1058 } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
1059 !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1060 unsigned int i;
1061
1062 /* Naturally, this has an atomicity problem. */
1063 for (i = 0; i < dev->addr_len; i++)
1064 virtio_cwrite8(vdev,
1065 offsetof(struct virtio_net_config, mac) +
1066 i, addr->sa_data[i]);
1067 }
1068
1069 eth_commit_mac_addr_change(dev, p);
1070
1071 return 0;
1072 }
1073
1074 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
1075 struct rtnl_link_stats64 *tot)
1076 {
1077 struct virtnet_info *vi = netdev_priv(dev);
1078 int cpu;
1079 unsigned int start;
1080
1081 for_each_possible_cpu(cpu) {
1082 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
1083 u64 tpackets, tbytes, rpackets, rbytes;
1084
1085 do {
1086 start = u64_stats_fetch_begin_irq(&stats->tx_syncp);
1087 tpackets = stats->tx_packets;
1088 tbytes = stats->tx_bytes;
1089 } while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start));
1090
1091 do {
1092 start = u64_stats_fetch_begin_irq(&stats->rx_syncp);
1093 rpackets = stats->rx_packets;
1094 rbytes = stats->rx_bytes;
1095 } while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start));
1096
1097 tot->rx_packets += rpackets;
1098 tot->tx_packets += tpackets;
1099 tot->rx_bytes += rbytes;
1100 tot->tx_bytes += tbytes;
1101 }
1102
1103 tot->tx_dropped = dev->stats.tx_dropped;
1104 tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1105 tot->rx_dropped = dev->stats.rx_dropped;
1106 tot->rx_length_errors = dev->stats.rx_length_errors;
1107 tot->rx_frame_errors = dev->stats.rx_frame_errors;
1108
1109 return tot;
1110 }
1111
1112 #ifdef CONFIG_NET_POLL_CONTROLLER
1113 static void virtnet_netpoll(struct net_device *dev)
1114 {
1115 struct virtnet_info *vi = netdev_priv(dev);
1116 int i;
1117
1118 for (i = 0; i < vi->curr_queue_pairs; i++)
1119 napi_schedule(&vi->rq[i].napi);
1120 }
1121 #endif
1122
1123 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1124 {
1125 rtnl_lock();
1126 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1127 VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1128 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1129 rtnl_unlock();
1130 }
1131
1132 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1133 {
1134 struct scatterlist sg;
1135 struct virtio_net_ctrl_mq s;
1136 struct net_device *dev = vi->dev;
1137
1138 if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1139 return 0;
1140
1141 s.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1142 sg_init_one(&sg, &s, sizeof(s));
1143
1144 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1145 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1146 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1147 queue_pairs);
1148 return -EINVAL;
1149 } else {
1150 vi->curr_queue_pairs = queue_pairs;
1151 /* virtnet_open() will refill when device is going to up. */
1152 if (dev->flags & IFF_UP)
1153 schedule_delayed_work(&vi->refill, 0);
1154 }
1155
1156 return 0;
1157 }
1158
1159 static int virtnet_close(struct net_device *dev)
1160 {
1161 struct virtnet_info *vi = netdev_priv(dev);
1162 int i;
1163
1164 /* Make sure refill_work doesn't re-enable napi! */
1165 cancel_delayed_work_sync(&vi->refill);
1166
1167 for (i = 0; i < vi->max_queue_pairs; i++)
1168 napi_disable(&vi->rq[i].napi);
1169
1170 return 0;
1171 }
1172
1173 static void virtnet_set_rx_mode(struct net_device *dev)
1174 {
1175 struct virtnet_info *vi = netdev_priv(dev);
1176 struct scatterlist sg[2];
1177 struct virtio_net_ctrl_mac *mac_data;
1178 struct netdev_hw_addr *ha;
1179 int uc_count;
1180 int mc_count;
1181 void *buf;
1182 int i;
1183
1184 /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1185 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1186 return;
1187
1188 vi->ctrl_promisc = ((dev->flags & IFF_PROMISC) != 0);
1189 vi->ctrl_allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1190
1191 sg_init_one(sg, &vi->ctrl_promisc, sizeof(vi->ctrl_promisc));
1192
1193 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1194 VIRTIO_NET_CTRL_RX_PROMISC, sg))
1195 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1196 vi->ctrl_promisc ? "en" : "dis");
1197
1198 sg_init_one(sg, &vi->ctrl_allmulti, sizeof(vi->ctrl_allmulti));
1199
1200 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1201 VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1202 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1203 vi->ctrl_allmulti ? "en" : "dis");
1204
1205 uc_count = netdev_uc_count(dev);
1206 mc_count = netdev_mc_count(dev);
1207 /* MAC filter - use one buffer for both lists */
1208 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1209 (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1210 mac_data = buf;
1211 if (!buf)
1212 return;
1213
1214 sg_init_table(sg, 2);
1215
1216 /* Store the unicast list and count in the front of the buffer */
1217 mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1218 i = 0;
1219 netdev_for_each_uc_addr(ha, dev)
1220 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1221
1222 sg_set_buf(&sg[0], mac_data,
1223 sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1224
1225 /* multicast list and count fill the end */
1226 mac_data = (void *)&mac_data->macs[uc_count][0];
1227
1228 mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1229 i = 0;
1230 netdev_for_each_mc_addr(ha, dev)
1231 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1232
1233 sg_set_buf(&sg[1], mac_data,
1234 sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1235
1236 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1237 VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1238 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1239
1240 kfree(buf);
1241 }
1242
1243 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1244 __be16 proto, u16 vid)
1245 {
1246 struct virtnet_info *vi = netdev_priv(dev);
1247 struct scatterlist sg;
1248
1249 sg_init_one(&sg, &vid, sizeof(vid));
1250
1251 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1252 VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1253 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1254 return 0;
1255 }
1256
1257 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1258 __be16 proto, u16 vid)
1259 {
1260 struct virtnet_info *vi = netdev_priv(dev);
1261 struct scatterlist sg;
1262
1263 sg_init_one(&sg, &vid, sizeof(vid));
1264
1265 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1266 VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1267 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1268 return 0;
1269 }
1270
1271 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1272 {
1273 int i;
1274
1275 if (vi->affinity_hint_set) {
1276 for (i = 0; i < vi->max_queue_pairs; i++) {
1277 virtqueue_set_affinity(vi->rq[i].vq, -1);
1278 virtqueue_set_affinity(vi->sq[i].vq, -1);
1279 }
1280
1281 vi->affinity_hint_set = false;
1282 }
1283 }
1284
1285 static void virtnet_set_affinity(struct virtnet_info *vi)
1286 {
1287 int i;
1288 int cpu;
1289
1290 /* In multiqueue mode, when the number of cpu is equal to the number of
1291 * queue pairs, we let the queue pairs to be private to one cpu by
1292 * setting the affinity hint to eliminate the contention.
1293 */
1294 if (vi->curr_queue_pairs == 1 ||
1295 vi->max_queue_pairs != num_online_cpus()) {
1296 virtnet_clean_affinity(vi, -1);
1297 return;
1298 }
1299
1300 i = 0;
1301 for_each_online_cpu(cpu) {
1302 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1303 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1304 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1305 i++;
1306 }
1307
1308 vi->affinity_hint_set = true;
1309 }
1310
1311 static int virtnet_cpu_callback(struct notifier_block *nfb,
1312 unsigned long action, void *hcpu)
1313 {
1314 struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb);
1315
1316 switch(action & ~CPU_TASKS_FROZEN) {
1317 case CPU_ONLINE:
1318 case CPU_DOWN_FAILED:
1319 case CPU_DEAD:
1320 virtnet_set_affinity(vi);
1321 break;
1322 case CPU_DOWN_PREPARE:
1323 virtnet_clean_affinity(vi, (long)hcpu);
1324 break;
1325 default:
1326 break;
1327 }
1328
1329 return NOTIFY_OK;
1330 }
1331
1332 static void virtnet_get_ringparam(struct net_device *dev,
1333 struct ethtool_ringparam *ring)
1334 {
1335 struct virtnet_info *vi = netdev_priv(dev);
1336
1337 ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1338 ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1339 ring->rx_pending = ring->rx_max_pending;
1340 ring->tx_pending = ring->tx_max_pending;
1341 }
1342
1343
1344 static void virtnet_get_drvinfo(struct net_device *dev,
1345 struct ethtool_drvinfo *info)
1346 {
1347 struct virtnet_info *vi = netdev_priv(dev);
1348 struct virtio_device *vdev = vi->vdev;
1349
1350 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1351 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1352 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1353
1354 }
1355
1356 /* TODO: Eliminate OOO packets during switching */
1357 static int virtnet_set_channels(struct net_device *dev,
1358 struct ethtool_channels *channels)
1359 {
1360 struct virtnet_info *vi = netdev_priv(dev);
1361 u16 queue_pairs = channels->combined_count;
1362 int err;
1363
1364 /* We don't support separate rx/tx channels.
1365 * We don't allow setting 'other' channels.
1366 */
1367 if (channels->rx_count || channels->tx_count || channels->other_count)
1368 return -EINVAL;
1369
1370 if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1371 return -EINVAL;
1372
1373 get_online_cpus();
1374 err = virtnet_set_queues(vi, queue_pairs);
1375 if (!err) {
1376 netif_set_real_num_tx_queues(dev, queue_pairs);
1377 netif_set_real_num_rx_queues(dev, queue_pairs);
1378
1379 virtnet_set_affinity(vi);
1380 }
1381 put_online_cpus();
1382
1383 return err;
1384 }
1385
1386 static void virtnet_get_channels(struct net_device *dev,
1387 struct ethtool_channels *channels)
1388 {
1389 struct virtnet_info *vi = netdev_priv(dev);
1390
1391 channels->combined_count = vi->curr_queue_pairs;
1392 channels->max_combined = vi->max_queue_pairs;
1393 channels->max_other = 0;
1394 channels->rx_count = 0;
1395 channels->tx_count = 0;
1396 channels->other_count = 0;
1397 }
1398
1399 static const struct ethtool_ops virtnet_ethtool_ops = {
1400 .get_drvinfo = virtnet_get_drvinfo,
1401 .get_link = ethtool_op_get_link,
1402 .get_ringparam = virtnet_get_ringparam,
1403 .set_channels = virtnet_set_channels,
1404 .get_channels = virtnet_get_channels,
1405 .get_ts_info = ethtool_op_get_ts_info,
1406 };
1407
1408 #define MIN_MTU 68
1409 #define MAX_MTU 65535
1410
1411 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1412 {
1413 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1414 return -EINVAL;
1415 dev->mtu = new_mtu;
1416 return 0;
1417 }
1418
1419 static const struct net_device_ops virtnet_netdev = {
1420 .ndo_open = virtnet_open,
1421 .ndo_stop = virtnet_close,
1422 .ndo_start_xmit = start_xmit,
1423 .ndo_validate_addr = eth_validate_addr,
1424 .ndo_set_mac_address = virtnet_set_mac_address,
1425 .ndo_set_rx_mode = virtnet_set_rx_mode,
1426 .ndo_change_mtu = virtnet_change_mtu,
1427 .ndo_get_stats64 = virtnet_stats,
1428 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1429 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1430 #ifdef CONFIG_NET_POLL_CONTROLLER
1431 .ndo_poll_controller = virtnet_netpoll,
1432 #endif
1433 #ifdef CONFIG_NET_RX_BUSY_POLL
1434 .ndo_busy_poll = virtnet_busy_poll,
1435 #endif
1436 .ndo_features_check = passthru_features_check,
1437 };
1438
1439 static void virtnet_config_changed_work(struct work_struct *work)
1440 {
1441 struct virtnet_info *vi =
1442 container_of(work, struct virtnet_info, config_work);
1443 u16 v;
1444
1445 if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
1446 struct virtio_net_config, status, &v) < 0)
1447 return;
1448
1449 if (v & VIRTIO_NET_S_ANNOUNCE) {
1450 netdev_notify_peers(vi->dev);
1451 virtnet_ack_link_announce(vi);
1452 }
1453
1454 /* Ignore unknown (future) status bits */
1455 v &= VIRTIO_NET_S_LINK_UP;
1456
1457 if (vi->status == v)
1458 return;
1459
1460 vi->status = v;
1461
1462 if (vi->status & VIRTIO_NET_S_LINK_UP) {
1463 netif_carrier_on(vi->dev);
1464 netif_tx_wake_all_queues(vi->dev);
1465 } else {
1466 netif_carrier_off(vi->dev);
1467 netif_tx_stop_all_queues(vi->dev);
1468 }
1469 }
1470
1471 static void virtnet_config_changed(struct virtio_device *vdev)
1472 {
1473 struct virtnet_info *vi = vdev->priv;
1474
1475 schedule_work(&vi->config_work);
1476 }
1477
1478 static void virtnet_free_queues(struct virtnet_info *vi)
1479 {
1480 int i;
1481
1482 for (i = 0; i < vi->max_queue_pairs; i++) {
1483 napi_hash_del(&vi->rq[i].napi);
1484 netif_napi_del(&vi->rq[i].napi);
1485 }
1486
1487 /* We called napi_hash_del() before netif_napi_del(),
1488 * we need to respect an RCU grace period before freeing vi->rq
1489 */
1490 synchronize_net();
1491
1492 kfree(vi->rq);
1493 kfree(vi->sq);
1494 }
1495
1496 static void free_receive_bufs(struct virtnet_info *vi)
1497 {
1498 int i;
1499
1500 for (i = 0; i < vi->max_queue_pairs; i++) {
1501 while (vi->rq[i].pages)
1502 __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1503 }
1504 }
1505
1506 static void free_receive_page_frags(struct virtnet_info *vi)
1507 {
1508 int i;
1509 for (i = 0; i < vi->max_queue_pairs; i++)
1510 if (vi->rq[i].alloc_frag.page)
1511 put_page(vi->rq[i].alloc_frag.page);
1512 }
1513
1514 static void free_unused_bufs(struct virtnet_info *vi)
1515 {
1516 void *buf;
1517 int i;
1518
1519 for (i = 0; i < vi->max_queue_pairs; i++) {
1520 struct virtqueue *vq = vi->sq[i].vq;
1521 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1522 dev_kfree_skb(buf);
1523 }
1524
1525 for (i = 0; i < vi->max_queue_pairs; i++) {
1526 struct virtqueue *vq = vi->rq[i].vq;
1527
1528 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1529 if (vi->mergeable_rx_bufs) {
1530 unsigned long ctx = (unsigned long)buf;
1531 void *base = mergeable_ctx_to_buf_address(ctx);
1532 put_page(virt_to_head_page(base));
1533 } else if (vi->big_packets) {
1534 give_pages(&vi->rq[i], buf);
1535 } else {
1536 dev_kfree_skb(buf);
1537 }
1538 }
1539 }
1540 }
1541
1542 static void virtnet_del_vqs(struct virtnet_info *vi)
1543 {
1544 struct virtio_device *vdev = vi->vdev;
1545
1546 virtnet_clean_affinity(vi, -1);
1547
1548 vdev->config->del_vqs(vdev);
1549
1550 virtnet_free_queues(vi);
1551 }
1552
1553 static int virtnet_find_vqs(struct virtnet_info *vi)
1554 {
1555 vq_callback_t **callbacks;
1556 struct virtqueue **vqs;
1557 int ret = -ENOMEM;
1558 int i, total_vqs;
1559 const char **names;
1560
1561 /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1562 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1563 * possible control vq.
1564 */
1565 total_vqs = vi->max_queue_pairs * 2 +
1566 virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1567
1568 /* Allocate space for find_vqs parameters */
1569 vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1570 if (!vqs)
1571 goto err_vq;
1572 callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1573 if (!callbacks)
1574 goto err_callback;
1575 names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1576 if (!names)
1577 goto err_names;
1578
1579 /* Parameters for control virtqueue, if any */
1580 if (vi->has_cvq) {
1581 callbacks[total_vqs - 1] = NULL;
1582 names[total_vqs - 1] = "control";
1583 }
1584
1585 /* Allocate/initialize parameters for send/receive virtqueues */
1586 for (i = 0; i < vi->max_queue_pairs; i++) {
1587 callbacks[rxq2vq(i)] = skb_recv_done;
1588 callbacks[txq2vq(i)] = skb_xmit_done;
1589 sprintf(vi->rq[i].name, "input.%d", i);
1590 sprintf(vi->sq[i].name, "output.%d", i);
1591 names[rxq2vq(i)] = vi->rq[i].name;
1592 names[txq2vq(i)] = vi->sq[i].name;
1593 }
1594
1595 ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1596 names);
1597 if (ret)
1598 goto err_find;
1599
1600 if (vi->has_cvq) {
1601 vi->cvq = vqs[total_vqs - 1];
1602 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1603 vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1604 }
1605
1606 for (i = 0; i < vi->max_queue_pairs; i++) {
1607 vi->rq[i].vq = vqs[rxq2vq(i)];
1608 vi->sq[i].vq = vqs[txq2vq(i)];
1609 }
1610
1611 kfree(names);
1612 kfree(callbacks);
1613 kfree(vqs);
1614
1615 return 0;
1616
1617 err_find:
1618 kfree(names);
1619 err_names:
1620 kfree(callbacks);
1621 err_callback:
1622 kfree(vqs);
1623 err_vq:
1624 return ret;
1625 }
1626
1627 static int virtnet_alloc_queues(struct virtnet_info *vi)
1628 {
1629 int i;
1630
1631 vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1632 if (!vi->sq)
1633 goto err_sq;
1634 vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1635 if (!vi->rq)
1636 goto err_rq;
1637
1638 INIT_DELAYED_WORK(&vi->refill, refill_work);
1639 for (i = 0; i < vi->max_queue_pairs; i++) {
1640 vi->rq[i].pages = NULL;
1641 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1642 napi_weight);
1643 napi_hash_add(&vi->rq[i].napi);
1644
1645 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1646 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
1647 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1648 }
1649
1650 return 0;
1651
1652 err_rq:
1653 kfree(vi->sq);
1654 err_sq:
1655 return -ENOMEM;
1656 }
1657
1658 static int init_vqs(struct virtnet_info *vi)
1659 {
1660 int ret;
1661
1662 /* Allocate send & receive queues */
1663 ret = virtnet_alloc_queues(vi);
1664 if (ret)
1665 goto err;
1666
1667 ret = virtnet_find_vqs(vi);
1668 if (ret)
1669 goto err_free;
1670
1671 get_online_cpus();
1672 virtnet_set_affinity(vi);
1673 put_online_cpus();
1674
1675 return 0;
1676
1677 err_free:
1678 virtnet_free_queues(vi);
1679 err:
1680 return ret;
1681 }
1682
1683 #ifdef CONFIG_SYSFS
1684 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
1685 struct rx_queue_attribute *attribute, char *buf)
1686 {
1687 struct virtnet_info *vi = netdev_priv(queue->dev);
1688 unsigned int queue_index = get_netdev_rx_queue_index(queue);
1689 struct ewma_pkt_len *avg;
1690
1691 BUG_ON(queue_index >= vi->max_queue_pairs);
1692 avg = &vi->rq[queue_index].mrg_avg_pkt_len;
1693 return sprintf(buf, "%u\n", get_mergeable_buf_len(avg));
1694 }
1695
1696 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
1697 __ATTR_RO(mergeable_rx_buffer_size);
1698
1699 static struct attribute *virtio_net_mrg_rx_attrs[] = {
1700 &mergeable_rx_buffer_size_attribute.attr,
1701 NULL
1702 };
1703
1704 static const struct attribute_group virtio_net_mrg_rx_group = {
1705 .name = "virtio_net",
1706 .attrs = virtio_net_mrg_rx_attrs
1707 };
1708 #endif
1709
1710 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
1711 unsigned int fbit,
1712 const char *fname, const char *dname)
1713 {
1714 if (!virtio_has_feature(vdev, fbit))
1715 return false;
1716
1717 dev_err(&vdev->dev, "device advertises feature %s but not %s",
1718 fname, dname);
1719
1720 return true;
1721 }
1722
1723 #define VIRTNET_FAIL_ON(vdev, fbit, dbit) \
1724 virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
1725
1726 static bool virtnet_validate_features(struct virtio_device *vdev)
1727 {
1728 if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
1729 (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
1730 "VIRTIO_NET_F_CTRL_VQ") ||
1731 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
1732 "VIRTIO_NET_F_CTRL_VQ") ||
1733 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
1734 "VIRTIO_NET_F_CTRL_VQ") ||
1735 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
1736 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
1737 "VIRTIO_NET_F_CTRL_VQ"))) {
1738 return false;
1739 }
1740
1741 return true;
1742 }
1743
1744 static int virtnet_probe(struct virtio_device *vdev)
1745 {
1746 int i, err;
1747 struct net_device *dev;
1748 struct virtnet_info *vi;
1749 u16 max_queue_pairs;
1750
1751 if (!vdev->config->get) {
1752 dev_err(&vdev->dev, "%s failure: config access disabled\n",
1753 __func__);
1754 return -EINVAL;
1755 }
1756
1757 if (!virtnet_validate_features(vdev))
1758 return -EINVAL;
1759
1760 /* Find if host supports multiqueue virtio_net device */
1761 err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
1762 struct virtio_net_config,
1763 max_virtqueue_pairs, &max_queue_pairs);
1764
1765 /* We need at least 2 queue's */
1766 if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1767 max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1768 !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1769 max_queue_pairs = 1;
1770
1771 /* Allocate ourselves a network device with room for our info */
1772 dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1773 if (!dev)
1774 return -ENOMEM;
1775
1776 /* Set up network device as normal. */
1777 dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1778 dev->netdev_ops = &virtnet_netdev;
1779 dev->features = NETIF_F_HIGHDMA;
1780
1781 dev->ethtool_ops = &virtnet_ethtool_ops;
1782 SET_NETDEV_DEV(dev, &vdev->dev);
1783
1784 /* Do we support "hardware" checksums? */
1785 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1786 /* This opens up the world of extra features. */
1787 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
1788 if (csum)
1789 dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
1790
1791 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1792 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1793 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1794 }
1795 /* Individual feature bits: what can host handle? */
1796 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1797 dev->hw_features |= NETIF_F_TSO;
1798 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1799 dev->hw_features |= NETIF_F_TSO6;
1800 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1801 dev->hw_features |= NETIF_F_TSO_ECN;
1802 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1803 dev->hw_features |= NETIF_F_UFO;
1804
1805 dev->features |= NETIF_F_GSO_ROBUST;
1806
1807 if (gso)
1808 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1809 /* (!csum && gso) case will be fixed by register_netdev() */
1810 }
1811 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
1812 dev->features |= NETIF_F_RXCSUM;
1813
1814 dev->vlan_features = dev->features;
1815
1816 /* Configuration may specify what MAC to use. Otherwise random. */
1817 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
1818 virtio_cread_bytes(vdev,
1819 offsetof(struct virtio_net_config, mac),
1820 dev->dev_addr, dev->addr_len);
1821 else
1822 eth_hw_addr_random(dev);
1823
1824 /* Set up our device-specific information */
1825 vi = netdev_priv(dev);
1826 vi->dev = dev;
1827 vi->vdev = vdev;
1828 vdev->priv = vi;
1829 vi->stats = alloc_percpu(struct virtnet_stats);
1830 err = -ENOMEM;
1831 if (vi->stats == NULL)
1832 goto free;
1833
1834 for_each_possible_cpu(i) {
1835 struct virtnet_stats *virtnet_stats;
1836 virtnet_stats = per_cpu_ptr(vi->stats, i);
1837 u64_stats_init(&virtnet_stats->tx_syncp);
1838 u64_stats_init(&virtnet_stats->rx_syncp);
1839 }
1840
1841 INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1842
1843 /* If we can receive ANY GSO packets, we must allocate large ones. */
1844 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1845 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1846 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
1847 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
1848 vi->big_packets = true;
1849
1850 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1851 vi->mergeable_rx_bufs = true;
1852
1853 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
1854 virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
1855 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1856 else
1857 vi->hdr_len = sizeof(struct virtio_net_hdr);
1858
1859 if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
1860 virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
1861 vi->any_header_sg = true;
1862
1863 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1864 vi->has_cvq = true;
1865
1866 if (vi->any_header_sg)
1867 dev->needed_headroom = vi->hdr_len;
1868
1869 /* Use single tx/rx queue pair as default */
1870 vi->curr_queue_pairs = 1;
1871 vi->max_queue_pairs = max_queue_pairs;
1872
1873 /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1874 err = init_vqs(vi);
1875 if (err)
1876 goto free_stats;
1877
1878 #ifdef CONFIG_SYSFS
1879 if (vi->mergeable_rx_bufs)
1880 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
1881 #endif
1882 netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
1883 netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
1884
1885 err = register_netdev(dev);
1886 if (err) {
1887 pr_debug("virtio_net: registering device failed\n");
1888 goto free_vqs;
1889 }
1890
1891 virtio_device_ready(vdev);
1892
1893 /* Last of all, set up some receive buffers. */
1894 for (i = 0; i < vi->curr_queue_pairs; i++) {
1895 try_fill_recv(vi, &vi->rq[i], GFP_KERNEL);
1896
1897 /* If we didn't even get one input buffer, we're useless. */
1898 if (vi->rq[i].vq->num_free ==
1899 virtqueue_get_vring_size(vi->rq[i].vq)) {
1900 free_unused_bufs(vi);
1901 err = -ENOMEM;
1902 goto free_recv_bufs;
1903 }
1904 }
1905
1906 vi->nb.notifier_call = &virtnet_cpu_callback;
1907 err = register_hotcpu_notifier(&vi->nb);
1908 if (err) {
1909 pr_debug("virtio_net: registering cpu notifier failed\n");
1910 goto free_recv_bufs;
1911 }
1912
1913 /* Assume link up if device can't report link status,
1914 otherwise get link status from config. */
1915 netif_carrier_off(dev);
1916 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1917 schedule_work(&vi->config_work);
1918 } else {
1919 vi->status = VIRTIO_NET_S_LINK_UP;
1920 netif_carrier_on(dev);
1921 }
1922
1923 pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1924 dev->name, max_queue_pairs);
1925
1926 return 0;
1927
1928 free_recv_bufs:
1929 vi->vdev->config->reset(vdev);
1930
1931 free_receive_bufs(vi);
1932 unregister_netdev(dev);
1933 free_vqs:
1934 cancel_delayed_work_sync(&vi->refill);
1935 free_receive_page_frags(vi);
1936 virtnet_del_vqs(vi);
1937 free_stats:
1938 free_percpu(vi->stats);
1939 free:
1940 free_netdev(dev);
1941 return err;
1942 }
1943
1944 static void remove_vq_common(struct virtnet_info *vi)
1945 {
1946 vi->vdev->config->reset(vi->vdev);
1947
1948 /* Free unused buffers in both send and recv, if any. */
1949 free_unused_bufs(vi);
1950
1951 free_receive_bufs(vi);
1952
1953 free_receive_page_frags(vi);
1954
1955 virtnet_del_vqs(vi);
1956 }
1957
1958 static void virtnet_remove(struct virtio_device *vdev)
1959 {
1960 struct virtnet_info *vi = vdev->priv;
1961
1962 unregister_hotcpu_notifier(&vi->nb);
1963
1964 /* Make sure no work handler is accessing the device. */
1965 flush_work(&vi->config_work);
1966
1967 unregister_netdev(vi->dev);
1968
1969 remove_vq_common(vi);
1970
1971 free_percpu(vi->stats);
1972 free_netdev(vi->dev);
1973 }
1974
1975 #ifdef CONFIG_PM_SLEEP
1976 static int virtnet_freeze(struct virtio_device *vdev)
1977 {
1978 struct virtnet_info *vi = vdev->priv;
1979 int i;
1980
1981 unregister_hotcpu_notifier(&vi->nb);
1982
1983 /* Make sure no work handler is accessing the device */
1984 flush_work(&vi->config_work);
1985
1986 netif_device_detach(vi->dev);
1987 cancel_delayed_work_sync(&vi->refill);
1988
1989 if (netif_running(vi->dev)) {
1990 for (i = 0; i < vi->max_queue_pairs; i++)
1991 napi_disable(&vi->rq[i].napi);
1992 }
1993
1994 remove_vq_common(vi);
1995
1996 return 0;
1997 }
1998
1999 static int virtnet_restore(struct virtio_device *vdev)
2000 {
2001 struct virtnet_info *vi = vdev->priv;
2002 int err, i;
2003
2004 err = init_vqs(vi);
2005 if (err)
2006 return err;
2007
2008 virtio_device_ready(vdev);
2009
2010 if (netif_running(vi->dev)) {
2011 for (i = 0; i < vi->curr_queue_pairs; i++)
2012 if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
2013 schedule_delayed_work(&vi->refill, 0);
2014
2015 for (i = 0; i < vi->max_queue_pairs; i++)
2016 virtnet_napi_enable(&vi->rq[i]);
2017 }
2018
2019 netif_device_attach(vi->dev);
2020
2021 rtnl_lock();
2022 virtnet_set_queues(vi, vi->curr_queue_pairs);
2023 rtnl_unlock();
2024
2025 err = register_hotcpu_notifier(&vi->nb);
2026 if (err)
2027 return err;
2028
2029 return 0;
2030 }
2031 #endif
2032
2033 static struct virtio_device_id id_table[] = {
2034 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
2035 { 0 },
2036 };
2037
2038 static unsigned int features[] = {
2039 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
2040 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
2041 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
2042 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
2043 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
2044 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
2045 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
2046 VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
2047 VIRTIO_NET_F_CTRL_MAC_ADDR,
2048 VIRTIO_F_ANY_LAYOUT,
2049 };
2050
2051 static struct virtio_driver virtio_net_driver = {
2052 .feature_table = features,
2053 .feature_table_size = ARRAY_SIZE(features),
2054 .driver.name = KBUILD_MODNAME,
2055 .driver.owner = THIS_MODULE,
2056 .id_table = id_table,
2057 .probe = virtnet_probe,
2058 .remove = virtnet_remove,
2059 .config_changed = virtnet_config_changed,
2060 #ifdef CONFIG_PM_SLEEP
2061 .freeze = virtnet_freeze,
2062 .restore = virtnet_restore,
2063 #endif
2064 };
2065
2066 module_virtio_driver(virtio_net_driver);
2067
2068 MODULE_DEVICE_TABLE(virtio, id_table);
2069 MODULE_DESCRIPTION("Virtio network driver");
2070 MODULE_LICENSE("GPL");
Linux with added FPC-III support