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