xref: /linux/drivers/net/hyperv/netvsc_drv.c (revision 037fc3368be46dc1a2a90f6e50c8cbce49d75fd6)
1 /*
2  * Copyright (c) 2009, Microsoft Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, see <http://www.gnu.org/licenses/>.
15  *
16  * Authors:
17  *   Haiyang Zhang <haiyangz@microsoft.com>
18  *   Hank Janssen  <hjanssen@microsoft.com>
19  */
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 
22 #include <linux/init.h>
23 #include <linux/atomic.h>
24 #include <linux/module.h>
25 #include <linux/highmem.h>
26 #include <linux/device.h>
27 #include <linux/io.h>
28 #include <linux/delay.h>
29 #include <linux/netdevice.h>
30 #include <linux/inetdevice.h>
31 #include <linux/etherdevice.h>
32 #include <linux/pci.h>
33 #include <linux/skbuff.h>
34 #include <linux/if_vlan.h>
35 #include <linux/in.h>
36 #include <linux/slab.h>
37 #include <linux/rtnetlink.h>
38 #include <linux/netpoll.h>
39 
40 #include <net/arp.h>
41 #include <net/route.h>
42 #include <net/sock.h>
43 #include <net/pkt_sched.h>
44 #include <net/checksum.h>
45 #include <net/ip6_checksum.h>
46 
47 #include "hyperv_net.h"
48 
49 #define RING_SIZE_MIN	64
50 #define RETRY_US_LO	5000
51 #define RETRY_US_HI	10000
52 #define RETRY_MAX	2000	/* >10 sec */
53 
54 #define LINKCHANGE_INT (2 * HZ)
55 #define VF_TAKEOVER_INT (HZ / 10)
56 
57 static unsigned int ring_size __ro_after_init = 128;
58 module_param(ring_size, uint, 0444);
59 MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
60 unsigned int netvsc_ring_bytes __ro_after_init;
61 
62 static const u32 default_msg = NETIF_MSG_DRV | NETIF_MSG_PROBE |
63 				NETIF_MSG_LINK | NETIF_MSG_IFUP |
64 				NETIF_MSG_IFDOWN | NETIF_MSG_RX_ERR |
65 				NETIF_MSG_TX_ERR;
66 
67 static int debug = -1;
68 module_param(debug, int, 0444);
69 MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");
70 
71 static LIST_HEAD(netvsc_dev_list);
72 
73 static void netvsc_change_rx_flags(struct net_device *net, int change)
74 {
75 	struct net_device_context *ndev_ctx = netdev_priv(net);
76 	struct net_device *vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
77 	int inc;
78 
79 	if (!vf_netdev)
80 		return;
81 
82 	if (change & IFF_PROMISC) {
83 		inc = (net->flags & IFF_PROMISC) ? 1 : -1;
84 		dev_set_promiscuity(vf_netdev, inc);
85 	}
86 
87 	if (change & IFF_ALLMULTI) {
88 		inc = (net->flags & IFF_ALLMULTI) ? 1 : -1;
89 		dev_set_allmulti(vf_netdev, inc);
90 	}
91 }
92 
93 static void netvsc_set_rx_mode(struct net_device *net)
94 {
95 	struct net_device_context *ndev_ctx = netdev_priv(net);
96 	struct net_device *vf_netdev;
97 	struct netvsc_device *nvdev;
98 
99 	rcu_read_lock();
100 	vf_netdev = rcu_dereference(ndev_ctx->vf_netdev);
101 	if (vf_netdev) {
102 		dev_uc_sync(vf_netdev, net);
103 		dev_mc_sync(vf_netdev, net);
104 	}
105 
106 	nvdev = rcu_dereference(ndev_ctx->nvdev);
107 	if (nvdev)
108 		rndis_filter_update(nvdev);
109 	rcu_read_unlock();
110 }
111 
112 static int netvsc_open(struct net_device *net)
113 {
114 	struct net_device_context *ndev_ctx = netdev_priv(net);
115 	struct net_device *vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
116 	struct netvsc_device *nvdev = rtnl_dereference(ndev_ctx->nvdev);
117 	struct rndis_device *rdev;
118 	int ret = 0;
119 
120 	netif_carrier_off(net);
121 
122 	/* Open up the device */
123 	ret = rndis_filter_open(nvdev);
124 	if (ret != 0) {
125 		netdev_err(net, "unable to open device (ret %d).\n", ret);
126 		return ret;
127 	}
128 
129 	rdev = nvdev->extension;
130 	if (!rdev->link_state) {
131 		netif_carrier_on(net);
132 		netif_tx_wake_all_queues(net);
133 	}
134 
135 	if (vf_netdev) {
136 		/* Setting synthetic device up transparently sets
137 		 * slave as up. If open fails, then slave will be
138 		 * still be offline (and not used).
139 		 */
140 		ret = dev_open(vf_netdev, NULL);
141 		if (ret)
142 			netdev_warn(net,
143 				    "unable to open slave: %s: %d\n",
144 				    vf_netdev->name, ret);
145 	}
146 	return 0;
147 }
148 
149 static int netvsc_wait_until_empty(struct netvsc_device *nvdev)
150 {
151 	unsigned int retry = 0;
152 	int i;
153 
154 	/* Ensure pending bytes in ring are read */
155 	for (;;) {
156 		u32 aread = 0;
157 
158 		for (i = 0; i < nvdev->num_chn; i++) {
159 			struct vmbus_channel *chn
160 				= nvdev->chan_table[i].channel;
161 
162 			if (!chn)
163 				continue;
164 
165 			/* make sure receive not running now */
166 			napi_synchronize(&nvdev->chan_table[i].napi);
167 
168 			aread = hv_get_bytes_to_read(&chn->inbound);
169 			if (aread)
170 				break;
171 
172 			aread = hv_get_bytes_to_read(&chn->outbound);
173 			if (aread)
174 				break;
175 		}
176 
177 		if (aread == 0)
178 			return 0;
179 
180 		if (++retry > RETRY_MAX)
181 			return -ETIMEDOUT;
182 
183 		usleep_range(RETRY_US_LO, RETRY_US_HI);
184 	}
185 }
186 
187 static int netvsc_close(struct net_device *net)
188 {
189 	struct net_device_context *net_device_ctx = netdev_priv(net);
190 	struct net_device *vf_netdev
191 		= rtnl_dereference(net_device_ctx->vf_netdev);
192 	struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
193 	int ret;
194 
195 	netif_tx_disable(net);
196 
197 	/* No need to close rndis filter if it is removed already */
198 	if (!nvdev)
199 		return 0;
200 
201 	ret = rndis_filter_close(nvdev);
202 	if (ret != 0) {
203 		netdev_err(net, "unable to close device (ret %d).\n", ret);
204 		return ret;
205 	}
206 
207 	ret = netvsc_wait_until_empty(nvdev);
208 	if (ret)
209 		netdev_err(net, "Ring buffer not empty after closing rndis\n");
210 
211 	if (vf_netdev)
212 		dev_close(vf_netdev);
213 
214 	return ret;
215 }
216 
217 static inline void *init_ppi_data(struct rndis_message *msg,
218 				  u32 ppi_size, u32 pkt_type)
219 {
220 	struct rndis_packet *rndis_pkt = &msg->msg.pkt;
221 	struct rndis_per_packet_info *ppi;
222 
223 	rndis_pkt->data_offset += ppi_size;
224 	ppi = (void *)rndis_pkt + rndis_pkt->per_pkt_info_offset
225 		+ rndis_pkt->per_pkt_info_len;
226 
227 	ppi->size = ppi_size;
228 	ppi->type = pkt_type;
229 	ppi->internal = 0;
230 	ppi->ppi_offset = sizeof(struct rndis_per_packet_info);
231 
232 	rndis_pkt->per_pkt_info_len += ppi_size;
233 
234 	return ppi + 1;
235 }
236 
237 /* Azure hosts don't support non-TCP port numbers in hashing for fragmented
238  * packets. We can use ethtool to change UDP hash level when necessary.
239  */
240 static inline u32 netvsc_get_hash(
241 	struct sk_buff *skb,
242 	const struct net_device_context *ndc)
243 {
244 	struct flow_keys flow;
245 	u32 hash, pkt_proto = 0;
246 	static u32 hashrnd __read_mostly;
247 
248 	net_get_random_once(&hashrnd, sizeof(hashrnd));
249 
250 	if (!skb_flow_dissect_flow_keys(skb, &flow, 0))
251 		return 0;
252 
253 	switch (flow.basic.ip_proto) {
254 	case IPPROTO_TCP:
255 		if (flow.basic.n_proto == htons(ETH_P_IP))
256 			pkt_proto = HV_TCP4_L4HASH;
257 		else if (flow.basic.n_proto == htons(ETH_P_IPV6))
258 			pkt_proto = HV_TCP6_L4HASH;
259 
260 		break;
261 
262 	case IPPROTO_UDP:
263 		if (flow.basic.n_proto == htons(ETH_P_IP))
264 			pkt_proto = HV_UDP4_L4HASH;
265 		else if (flow.basic.n_proto == htons(ETH_P_IPV6))
266 			pkt_proto = HV_UDP6_L4HASH;
267 
268 		break;
269 	}
270 
271 	if (pkt_proto & ndc->l4_hash) {
272 		return skb_get_hash(skb);
273 	} else {
274 		if (flow.basic.n_proto == htons(ETH_P_IP))
275 			hash = jhash2((u32 *)&flow.addrs.v4addrs, 2, hashrnd);
276 		else if (flow.basic.n_proto == htons(ETH_P_IPV6))
277 			hash = jhash2((u32 *)&flow.addrs.v6addrs, 8, hashrnd);
278 		else
279 			hash = 0;
280 
281 		skb_set_hash(skb, hash, PKT_HASH_TYPE_L3);
282 	}
283 
284 	return hash;
285 }
286 
287 static inline int netvsc_get_tx_queue(struct net_device *ndev,
288 				      struct sk_buff *skb, int old_idx)
289 {
290 	const struct net_device_context *ndc = netdev_priv(ndev);
291 	struct sock *sk = skb->sk;
292 	int q_idx;
293 
294 	q_idx = ndc->tx_table[netvsc_get_hash(skb, ndc) &
295 			      (VRSS_SEND_TAB_SIZE - 1)];
296 
297 	/* If queue index changed record the new value */
298 	if (q_idx != old_idx &&
299 	    sk && sk_fullsock(sk) && rcu_access_pointer(sk->sk_dst_cache))
300 		sk_tx_queue_set(sk, q_idx);
301 
302 	return q_idx;
303 }
304 
305 /*
306  * Select queue for transmit.
307  *
308  * If a valid queue has already been assigned, then use that.
309  * Otherwise compute tx queue based on hash and the send table.
310  *
311  * This is basically similar to default (__netdev_pick_tx) with the added step
312  * of using the host send_table when no other queue has been assigned.
313  *
314  * TODO support XPS - but get_xps_queue not exported
315  */
316 static u16 netvsc_pick_tx(struct net_device *ndev, struct sk_buff *skb)
317 {
318 	int q_idx = sk_tx_queue_get(skb->sk);
319 
320 	if (q_idx < 0 || skb->ooo_okay || q_idx >= ndev->real_num_tx_queues) {
321 		/* If forwarding a packet, we use the recorded queue when
322 		 * available for better cache locality.
323 		 */
324 		if (skb_rx_queue_recorded(skb))
325 			q_idx = skb_get_rx_queue(skb);
326 		else
327 			q_idx = netvsc_get_tx_queue(ndev, skb, q_idx);
328 	}
329 
330 	return q_idx;
331 }
332 
333 static u16 netvsc_select_queue(struct net_device *ndev, struct sk_buff *skb,
334 			       struct net_device *sb_dev,
335 			       select_queue_fallback_t fallback)
336 {
337 	struct net_device_context *ndc = netdev_priv(ndev);
338 	struct net_device *vf_netdev;
339 	u16 txq;
340 
341 	rcu_read_lock();
342 	vf_netdev = rcu_dereference(ndc->vf_netdev);
343 	if (vf_netdev) {
344 		const struct net_device_ops *vf_ops = vf_netdev->netdev_ops;
345 
346 		if (vf_ops->ndo_select_queue)
347 			txq = vf_ops->ndo_select_queue(vf_netdev, skb,
348 						       sb_dev, fallback);
349 		else
350 			txq = fallback(vf_netdev, skb, NULL);
351 
352 		/* Record the queue selected by VF so that it can be
353 		 * used for common case where VF has more queues than
354 		 * the synthetic device.
355 		 */
356 		qdisc_skb_cb(skb)->slave_dev_queue_mapping = txq;
357 	} else {
358 		txq = netvsc_pick_tx(ndev, skb);
359 	}
360 	rcu_read_unlock();
361 
362 	while (unlikely(txq >= ndev->real_num_tx_queues))
363 		txq -= ndev->real_num_tx_queues;
364 
365 	return txq;
366 }
367 
368 static u32 fill_pg_buf(struct page *page, u32 offset, u32 len,
369 		       struct hv_page_buffer *pb)
370 {
371 	int j = 0;
372 
373 	/* Deal with compound pages by ignoring unused part
374 	 * of the page.
375 	 */
376 	page += (offset >> PAGE_SHIFT);
377 	offset &= ~PAGE_MASK;
378 
379 	while (len > 0) {
380 		unsigned long bytes;
381 
382 		bytes = PAGE_SIZE - offset;
383 		if (bytes > len)
384 			bytes = len;
385 		pb[j].pfn = page_to_pfn(page);
386 		pb[j].offset = offset;
387 		pb[j].len = bytes;
388 
389 		offset += bytes;
390 		len -= bytes;
391 
392 		if (offset == PAGE_SIZE && len) {
393 			page++;
394 			offset = 0;
395 			j++;
396 		}
397 	}
398 
399 	return j + 1;
400 }
401 
402 static u32 init_page_array(void *hdr, u32 len, struct sk_buff *skb,
403 			   struct hv_netvsc_packet *packet,
404 			   struct hv_page_buffer *pb)
405 {
406 	u32 slots_used = 0;
407 	char *data = skb->data;
408 	int frags = skb_shinfo(skb)->nr_frags;
409 	int i;
410 
411 	/* The packet is laid out thus:
412 	 * 1. hdr: RNDIS header and PPI
413 	 * 2. skb linear data
414 	 * 3. skb fragment data
415 	 */
416 	slots_used += fill_pg_buf(virt_to_page(hdr),
417 				  offset_in_page(hdr),
418 				  len, &pb[slots_used]);
419 
420 	packet->rmsg_size = len;
421 	packet->rmsg_pgcnt = slots_used;
422 
423 	slots_used += fill_pg_buf(virt_to_page(data),
424 				offset_in_page(data),
425 				skb_headlen(skb), &pb[slots_used]);
426 
427 	for (i = 0; i < frags; i++) {
428 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
429 
430 		slots_used += fill_pg_buf(skb_frag_page(frag),
431 					frag->page_offset,
432 					skb_frag_size(frag), &pb[slots_used]);
433 	}
434 	return slots_used;
435 }
436 
437 static int count_skb_frag_slots(struct sk_buff *skb)
438 {
439 	int i, frags = skb_shinfo(skb)->nr_frags;
440 	int pages = 0;
441 
442 	for (i = 0; i < frags; i++) {
443 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
444 		unsigned long size = skb_frag_size(frag);
445 		unsigned long offset = frag->page_offset;
446 
447 		/* Skip unused frames from start of page */
448 		offset &= ~PAGE_MASK;
449 		pages += PFN_UP(offset + size);
450 	}
451 	return pages;
452 }
453 
454 static int netvsc_get_slots(struct sk_buff *skb)
455 {
456 	char *data = skb->data;
457 	unsigned int offset = offset_in_page(data);
458 	unsigned int len = skb_headlen(skb);
459 	int slots;
460 	int frag_slots;
461 
462 	slots = DIV_ROUND_UP(offset + len, PAGE_SIZE);
463 	frag_slots = count_skb_frag_slots(skb);
464 	return slots + frag_slots;
465 }
466 
467 static u32 net_checksum_info(struct sk_buff *skb)
468 {
469 	if (skb->protocol == htons(ETH_P_IP)) {
470 		struct iphdr *ip = ip_hdr(skb);
471 
472 		if (ip->protocol == IPPROTO_TCP)
473 			return TRANSPORT_INFO_IPV4_TCP;
474 		else if (ip->protocol == IPPROTO_UDP)
475 			return TRANSPORT_INFO_IPV4_UDP;
476 	} else {
477 		struct ipv6hdr *ip6 = ipv6_hdr(skb);
478 
479 		if (ip6->nexthdr == IPPROTO_TCP)
480 			return TRANSPORT_INFO_IPV6_TCP;
481 		else if (ip6->nexthdr == IPPROTO_UDP)
482 			return TRANSPORT_INFO_IPV6_UDP;
483 	}
484 
485 	return TRANSPORT_INFO_NOT_IP;
486 }
487 
488 /* Send skb on the slave VF device. */
489 static int netvsc_vf_xmit(struct net_device *net, struct net_device *vf_netdev,
490 			  struct sk_buff *skb)
491 {
492 	struct net_device_context *ndev_ctx = netdev_priv(net);
493 	unsigned int len = skb->len;
494 	int rc;
495 
496 	skb->dev = vf_netdev;
497 	skb->queue_mapping = qdisc_skb_cb(skb)->slave_dev_queue_mapping;
498 
499 	rc = dev_queue_xmit(skb);
500 	if (likely(rc == NET_XMIT_SUCCESS || rc == NET_XMIT_CN)) {
501 		struct netvsc_vf_pcpu_stats *pcpu_stats
502 			= this_cpu_ptr(ndev_ctx->vf_stats);
503 
504 		u64_stats_update_begin(&pcpu_stats->syncp);
505 		pcpu_stats->tx_packets++;
506 		pcpu_stats->tx_bytes += len;
507 		u64_stats_update_end(&pcpu_stats->syncp);
508 	} else {
509 		this_cpu_inc(ndev_ctx->vf_stats->tx_dropped);
510 	}
511 
512 	return rc;
513 }
514 
515 static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
516 {
517 	struct net_device_context *net_device_ctx = netdev_priv(net);
518 	struct hv_netvsc_packet *packet = NULL;
519 	int ret;
520 	unsigned int num_data_pgs;
521 	struct rndis_message *rndis_msg;
522 	struct net_device *vf_netdev;
523 	u32 rndis_msg_size;
524 	u32 hash;
525 	struct hv_page_buffer pb[MAX_PAGE_BUFFER_COUNT];
526 
527 	/* if VF is present and up then redirect packets
528 	 * already called with rcu_read_lock_bh
529 	 */
530 	vf_netdev = rcu_dereference_bh(net_device_ctx->vf_netdev);
531 	if (vf_netdev && netif_running(vf_netdev) &&
532 	    !netpoll_tx_running(net))
533 		return netvsc_vf_xmit(net, vf_netdev, skb);
534 
535 	/* We will atmost need two pages to describe the rndis
536 	 * header. We can only transmit MAX_PAGE_BUFFER_COUNT number
537 	 * of pages in a single packet. If skb is scattered around
538 	 * more pages we try linearizing it.
539 	 */
540 
541 	num_data_pgs = netvsc_get_slots(skb) + 2;
542 
543 	if (unlikely(num_data_pgs > MAX_PAGE_BUFFER_COUNT)) {
544 		++net_device_ctx->eth_stats.tx_scattered;
545 
546 		if (skb_linearize(skb))
547 			goto no_memory;
548 
549 		num_data_pgs = netvsc_get_slots(skb) + 2;
550 		if (num_data_pgs > MAX_PAGE_BUFFER_COUNT) {
551 			++net_device_ctx->eth_stats.tx_too_big;
552 			goto drop;
553 		}
554 	}
555 
556 	/*
557 	 * Place the rndis header in the skb head room and
558 	 * the skb->cb will be used for hv_netvsc_packet
559 	 * structure.
560 	 */
561 	ret = skb_cow_head(skb, RNDIS_AND_PPI_SIZE);
562 	if (ret)
563 		goto no_memory;
564 
565 	/* Use the skb control buffer for building up the packet */
566 	BUILD_BUG_ON(sizeof(struct hv_netvsc_packet) >
567 			FIELD_SIZEOF(struct sk_buff, cb));
568 	packet = (struct hv_netvsc_packet *)skb->cb;
569 
570 	packet->q_idx = skb_get_queue_mapping(skb);
571 
572 	packet->total_data_buflen = skb->len;
573 	packet->total_bytes = skb->len;
574 	packet->total_packets = 1;
575 
576 	rndis_msg = (struct rndis_message *)skb->head;
577 
578 	/* Add the rndis header */
579 	rndis_msg->ndis_msg_type = RNDIS_MSG_PACKET;
580 	rndis_msg->msg_len = packet->total_data_buflen;
581 
582 	rndis_msg->msg.pkt = (struct rndis_packet) {
583 		.data_offset = sizeof(struct rndis_packet),
584 		.data_len = packet->total_data_buflen,
585 		.per_pkt_info_offset = sizeof(struct rndis_packet),
586 	};
587 
588 	rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
589 
590 	hash = skb_get_hash_raw(skb);
591 	if (hash != 0 && net->real_num_tx_queues > 1) {
592 		u32 *hash_info;
593 
594 		rndis_msg_size += NDIS_HASH_PPI_SIZE;
595 		hash_info = init_ppi_data(rndis_msg, NDIS_HASH_PPI_SIZE,
596 					  NBL_HASH_VALUE);
597 		*hash_info = hash;
598 	}
599 
600 	if (skb_vlan_tag_present(skb)) {
601 		struct ndis_pkt_8021q_info *vlan;
602 
603 		rndis_msg_size += NDIS_VLAN_PPI_SIZE;
604 		vlan = init_ppi_data(rndis_msg, NDIS_VLAN_PPI_SIZE,
605 				     IEEE_8021Q_INFO);
606 
607 		vlan->value = 0;
608 		vlan->vlanid = skb_vlan_tag_get_id(skb);
609 		vlan->cfi = skb_vlan_tag_get_cfi(skb);
610 		vlan->pri = skb_vlan_tag_get_prio(skb);
611 	}
612 
613 	if (skb_is_gso(skb)) {
614 		struct ndis_tcp_lso_info *lso_info;
615 
616 		rndis_msg_size += NDIS_LSO_PPI_SIZE;
617 		lso_info = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
618 					 TCP_LARGESEND_PKTINFO);
619 
620 		lso_info->value = 0;
621 		lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
622 		if (skb->protocol == htons(ETH_P_IP)) {
623 			lso_info->lso_v2_transmit.ip_version =
624 				NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
625 			ip_hdr(skb)->tot_len = 0;
626 			ip_hdr(skb)->check = 0;
627 			tcp_hdr(skb)->check =
628 				~csum_tcpudp_magic(ip_hdr(skb)->saddr,
629 						   ip_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
630 		} else {
631 			lso_info->lso_v2_transmit.ip_version =
632 				NDIS_TCP_LARGE_SEND_OFFLOAD_IPV6;
633 			ipv6_hdr(skb)->payload_len = 0;
634 			tcp_hdr(skb)->check =
635 				~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
636 						 &ipv6_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
637 		}
638 		lso_info->lso_v2_transmit.tcp_header_offset = skb_transport_offset(skb);
639 		lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
640 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
641 		if (net_checksum_info(skb) & net_device_ctx->tx_checksum_mask) {
642 			struct ndis_tcp_ip_checksum_info *csum_info;
643 
644 			rndis_msg_size += NDIS_CSUM_PPI_SIZE;
645 			csum_info = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
646 						  TCPIP_CHKSUM_PKTINFO);
647 
648 			csum_info->value = 0;
649 			csum_info->transmit.tcp_header_offset = skb_transport_offset(skb);
650 
651 			if (skb->protocol == htons(ETH_P_IP)) {
652 				csum_info->transmit.is_ipv4 = 1;
653 
654 				if (ip_hdr(skb)->protocol == IPPROTO_TCP)
655 					csum_info->transmit.tcp_checksum = 1;
656 				else
657 					csum_info->transmit.udp_checksum = 1;
658 			} else {
659 				csum_info->transmit.is_ipv6 = 1;
660 
661 				if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
662 					csum_info->transmit.tcp_checksum = 1;
663 				else
664 					csum_info->transmit.udp_checksum = 1;
665 			}
666 		} else {
667 			/* Can't do offload of this type of checksum */
668 			if (skb_checksum_help(skb))
669 				goto drop;
670 		}
671 	}
672 
673 	/* Start filling in the page buffers with the rndis hdr */
674 	rndis_msg->msg_len += rndis_msg_size;
675 	packet->total_data_buflen = rndis_msg->msg_len;
676 	packet->page_buf_cnt = init_page_array(rndis_msg, rndis_msg_size,
677 					       skb, packet, pb);
678 
679 	/* timestamp packet in software */
680 	skb_tx_timestamp(skb);
681 
682 	ret = netvsc_send(net, packet, rndis_msg, pb, skb);
683 	if (likely(ret == 0))
684 		return NETDEV_TX_OK;
685 
686 	if (ret == -EAGAIN) {
687 		++net_device_ctx->eth_stats.tx_busy;
688 		return NETDEV_TX_BUSY;
689 	}
690 
691 	if (ret == -ENOSPC)
692 		++net_device_ctx->eth_stats.tx_no_space;
693 
694 drop:
695 	dev_kfree_skb_any(skb);
696 	net->stats.tx_dropped++;
697 
698 	return NETDEV_TX_OK;
699 
700 no_memory:
701 	++net_device_ctx->eth_stats.tx_no_memory;
702 	goto drop;
703 }
704 
705 /*
706  * netvsc_linkstatus_callback - Link up/down notification
707  */
708 void netvsc_linkstatus_callback(struct net_device *net,
709 				struct rndis_message *resp)
710 {
711 	struct rndis_indicate_status *indicate = &resp->msg.indicate_status;
712 	struct net_device_context *ndev_ctx = netdev_priv(net);
713 	struct netvsc_reconfig *event;
714 	unsigned long flags;
715 
716 	/* Update the physical link speed when changing to another vSwitch */
717 	if (indicate->status == RNDIS_STATUS_LINK_SPEED_CHANGE) {
718 		u32 speed;
719 
720 		speed = *(u32 *)((void *)indicate
721 				 + indicate->status_buf_offset) / 10000;
722 		ndev_ctx->speed = speed;
723 		return;
724 	}
725 
726 	/* Handle these link change statuses below */
727 	if (indicate->status != RNDIS_STATUS_NETWORK_CHANGE &&
728 	    indicate->status != RNDIS_STATUS_MEDIA_CONNECT &&
729 	    indicate->status != RNDIS_STATUS_MEDIA_DISCONNECT)
730 		return;
731 
732 	if (net->reg_state != NETREG_REGISTERED)
733 		return;
734 
735 	event = kzalloc(sizeof(*event), GFP_ATOMIC);
736 	if (!event)
737 		return;
738 	event->event = indicate->status;
739 
740 	spin_lock_irqsave(&ndev_ctx->lock, flags);
741 	list_add_tail(&event->list, &ndev_ctx->reconfig_events);
742 	spin_unlock_irqrestore(&ndev_ctx->lock, flags);
743 
744 	schedule_delayed_work(&ndev_ctx->dwork, 0);
745 }
746 
747 static void netvsc_comp_ipcsum(struct sk_buff *skb)
748 {
749 	struct iphdr *iph = (struct iphdr *)skb->data;
750 
751 	iph->check = 0;
752 	iph->check = ip_fast_csum(iph, iph->ihl);
753 }
754 
755 static struct sk_buff *netvsc_alloc_recv_skb(struct net_device *net,
756 					     struct netvsc_channel *nvchan)
757 {
758 	struct napi_struct *napi = &nvchan->napi;
759 	const struct ndis_pkt_8021q_info *vlan = nvchan->rsc.vlan;
760 	const struct ndis_tcp_ip_checksum_info *csum_info =
761 						nvchan->rsc.csum_info;
762 	struct sk_buff *skb;
763 	int i;
764 
765 	skb = napi_alloc_skb(napi, nvchan->rsc.pktlen);
766 	if (!skb)
767 		return skb;
768 
769 	/*
770 	 * Copy to skb. This copy is needed here since the memory pointed by
771 	 * hv_netvsc_packet cannot be deallocated
772 	 */
773 	for (i = 0; i < nvchan->rsc.cnt; i++)
774 		skb_put_data(skb, nvchan->rsc.data[i], nvchan->rsc.len[i]);
775 
776 	skb->protocol = eth_type_trans(skb, net);
777 
778 	/* skb is already created with CHECKSUM_NONE */
779 	skb_checksum_none_assert(skb);
780 
781 	/* Incoming packets may have IP header checksum verified by the host.
782 	 * They may not have IP header checksum computed after coalescing.
783 	 * We compute it here if the flags are set, because on Linux, the IP
784 	 * checksum is always checked.
785 	 */
786 	if (csum_info && csum_info->receive.ip_checksum_value_invalid &&
787 	    csum_info->receive.ip_checksum_succeeded &&
788 	    skb->protocol == htons(ETH_P_IP))
789 		netvsc_comp_ipcsum(skb);
790 
791 	/* Do L4 checksum offload if enabled and present.
792 	 */
793 	if (csum_info && (net->features & NETIF_F_RXCSUM)) {
794 		if (csum_info->receive.tcp_checksum_succeeded ||
795 		    csum_info->receive.udp_checksum_succeeded)
796 			skb->ip_summed = CHECKSUM_UNNECESSARY;
797 	}
798 
799 	if (vlan) {
800 		u16 vlan_tci = vlan->vlanid | (vlan->pri << VLAN_PRIO_SHIFT) |
801 			(vlan->cfi ? VLAN_CFI_MASK : 0);
802 
803 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
804 				       vlan_tci);
805 	}
806 
807 	return skb;
808 }
809 
810 /*
811  * netvsc_recv_callback -  Callback when we receive a packet from the
812  * "wire" on the specified device.
813  */
814 int netvsc_recv_callback(struct net_device *net,
815 			 struct netvsc_device *net_device,
816 			 struct netvsc_channel *nvchan)
817 {
818 	struct net_device_context *net_device_ctx = netdev_priv(net);
819 	struct vmbus_channel *channel = nvchan->channel;
820 	u16 q_idx = channel->offermsg.offer.sub_channel_index;
821 	struct sk_buff *skb;
822 	struct netvsc_stats *rx_stats;
823 
824 	if (net->reg_state != NETREG_REGISTERED)
825 		return NVSP_STAT_FAIL;
826 
827 	/* Allocate a skb - TODO direct I/O to pages? */
828 	skb = netvsc_alloc_recv_skb(net, nvchan);
829 
830 	if (unlikely(!skb)) {
831 		++net_device_ctx->eth_stats.rx_no_memory;
832 		rcu_read_unlock();
833 		return NVSP_STAT_FAIL;
834 	}
835 
836 	skb_record_rx_queue(skb, q_idx);
837 
838 	/*
839 	 * Even if injecting the packet, record the statistics
840 	 * on the synthetic device because modifying the VF device
841 	 * statistics will not work correctly.
842 	 */
843 	rx_stats = &nvchan->rx_stats;
844 	u64_stats_update_begin(&rx_stats->syncp);
845 	rx_stats->packets++;
846 	rx_stats->bytes += nvchan->rsc.pktlen;
847 
848 	if (skb->pkt_type == PACKET_BROADCAST)
849 		++rx_stats->broadcast;
850 	else if (skb->pkt_type == PACKET_MULTICAST)
851 		++rx_stats->multicast;
852 	u64_stats_update_end(&rx_stats->syncp);
853 
854 	napi_gro_receive(&nvchan->napi, skb);
855 	return NVSP_STAT_SUCCESS;
856 }
857 
858 static void netvsc_get_drvinfo(struct net_device *net,
859 			       struct ethtool_drvinfo *info)
860 {
861 	strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
862 	strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
863 }
864 
865 static void netvsc_get_channels(struct net_device *net,
866 				struct ethtool_channels *channel)
867 {
868 	struct net_device_context *net_device_ctx = netdev_priv(net);
869 	struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
870 
871 	if (nvdev) {
872 		channel->max_combined	= nvdev->max_chn;
873 		channel->combined_count = nvdev->num_chn;
874 	}
875 }
876 
877 /* Alloc struct netvsc_device_info, and initialize it from either existing
878  * struct netvsc_device, or from default values.
879  */
880 static struct netvsc_device_info *netvsc_devinfo_get
881 			(struct netvsc_device *nvdev)
882 {
883 	struct netvsc_device_info *dev_info;
884 
885 	dev_info = kzalloc(sizeof(*dev_info), GFP_ATOMIC);
886 
887 	if (!dev_info)
888 		return NULL;
889 
890 	if (nvdev) {
891 		dev_info->num_chn = nvdev->num_chn;
892 		dev_info->send_sections = nvdev->send_section_cnt;
893 		dev_info->send_section_size = nvdev->send_section_size;
894 		dev_info->recv_sections = nvdev->recv_section_cnt;
895 		dev_info->recv_section_size = nvdev->recv_section_size;
896 
897 		memcpy(dev_info->rss_key, nvdev->extension->rss_key,
898 		       NETVSC_HASH_KEYLEN);
899 	} else {
900 		dev_info->num_chn = VRSS_CHANNEL_DEFAULT;
901 		dev_info->send_sections = NETVSC_DEFAULT_TX;
902 		dev_info->send_section_size = NETVSC_SEND_SECTION_SIZE;
903 		dev_info->recv_sections = NETVSC_DEFAULT_RX;
904 		dev_info->recv_section_size = NETVSC_RECV_SECTION_SIZE;
905 	}
906 
907 	return dev_info;
908 }
909 
910 static int netvsc_detach(struct net_device *ndev,
911 			 struct netvsc_device *nvdev)
912 {
913 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
914 	struct hv_device *hdev = ndev_ctx->device_ctx;
915 	int ret;
916 
917 	/* Don't try continuing to try and setup sub channels */
918 	if (cancel_work_sync(&nvdev->subchan_work))
919 		nvdev->num_chn = 1;
920 
921 	/* If device was up (receiving) then shutdown */
922 	if (netif_running(ndev)) {
923 		netif_tx_disable(ndev);
924 
925 		ret = rndis_filter_close(nvdev);
926 		if (ret) {
927 			netdev_err(ndev,
928 				   "unable to close device (ret %d).\n", ret);
929 			return ret;
930 		}
931 
932 		ret = netvsc_wait_until_empty(nvdev);
933 		if (ret) {
934 			netdev_err(ndev,
935 				   "Ring buffer not empty after closing rndis\n");
936 			return ret;
937 		}
938 	}
939 
940 	netif_device_detach(ndev);
941 
942 	rndis_filter_device_remove(hdev, nvdev);
943 
944 	return 0;
945 }
946 
947 static int netvsc_attach(struct net_device *ndev,
948 			 struct netvsc_device_info *dev_info)
949 {
950 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
951 	struct hv_device *hdev = ndev_ctx->device_ctx;
952 	struct netvsc_device *nvdev;
953 	struct rndis_device *rdev;
954 	int ret;
955 
956 	nvdev = rndis_filter_device_add(hdev, dev_info);
957 	if (IS_ERR(nvdev))
958 		return PTR_ERR(nvdev);
959 
960 	if (nvdev->num_chn > 1) {
961 		ret = rndis_set_subchannel(ndev, nvdev, dev_info);
962 
963 		/* if unavailable, just proceed with one queue */
964 		if (ret) {
965 			nvdev->max_chn = 1;
966 			nvdev->num_chn = 1;
967 		}
968 	}
969 
970 	/* In any case device is now ready */
971 	netif_device_attach(ndev);
972 
973 	/* Note: enable and attach happen when sub-channels setup */
974 	netif_carrier_off(ndev);
975 
976 	if (netif_running(ndev)) {
977 		ret = rndis_filter_open(nvdev);
978 		if (ret)
979 			return ret;
980 
981 		rdev = nvdev->extension;
982 		if (!rdev->link_state)
983 			netif_carrier_on(ndev);
984 	}
985 
986 	return 0;
987 }
988 
989 static int netvsc_set_channels(struct net_device *net,
990 			       struct ethtool_channels *channels)
991 {
992 	struct net_device_context *net_device_ctx = netdev_priv(net);
993 	struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
994 	unsigned int orig, count = channels->combined_count;
995 	struct netvsc_device_info *device_info;
996 	int ret;
997 
998 	/* We do not support separate count for rx, tx, or other */
999 	if (count == 0 ||
1000 	    channels->rx_count || channels->tx_count || channels->other_count)
1001 		return -EINVAL;
1002 
1003 	if (!nvdev || nvdev->destroy)
1004 		return -ENODEV;
1005 
1006 	if (nvdev->nvsp_version < NVSP_PROTOCOL_VERSION_5)
1007 		return -EINVAL;
1008 
1009 	if (count > nvdev->max_chn)
1010 		return -EINVAL;
1011 
1012 	orig = nvdev->num_chn;
1013 
1014 	device_info = netvsc_devinfo_get(nvdev);
1015 
1016 	if (!device_info)
1017 		return -ENOMEM;
1018 
1019 	device_info->num_chn = count;
1020 
1021 	ret = netvsc_detach(net, nvdev);
1022 	if (ret)
1023 		goto out;
1024 
1025 	ret = netvsc_attach(net, device_info);
1026 	if (ret) {
1027 		device_info->num_chn = orig;
1028 		if (netvsc_attach(net, device_info))
1029 			netdev_err(net, "restoring channel setting failed\n");
1030 	}
1031 
1032 out:
1033 	kfree(device_info);
1034 	return ret;
1035 }
1036 
1037 static bool
1038 netvsc_validate_ethtool_ss_cmd(const struct ethtool_link_ksettings *cmd)
1039 {
1040 	struct ethtool_link_ksettings diff1 = *cmd;
1041 	struct ethtool_link_ksettings diff2 = {};
1042 
1043 	diff1.base.speed = 0;
1044 	diff1.base.duplex = 0;
1045 	/* advertising and cmd are usually set */
1046 	ethtool_link_ksettings_zero_link_mode(&diff1, advertising);
1047 	diff1.base.cmd = 0;
1048 	/* We set port to PORT_OTHER */
1049 	diff2.base.port = PORT_OTHER;
1050 
1051 	return !memcmp(&diff1, &diff2, sizeof(diff1));
1052 }
1053 
1054 static void netvsc_init_settings(struct net_device *dev)
1055 {
1056 	struct net_device_context *ndc = netdev_priv(dev);
1057 
1058 	ndc->l4_hash = HV_DEFAULT_L4HASH;
1059 
1060 	ndc->speed = SPEED_UNKNOWN;
1061 	ndc->duplex = DUPLEX_FULL;
1062 
1063 	dev->features = NETIF_F_LRO;
1064 }
1065 
1066 static int netvsc_get_link_ksettings(struct net_device *dev,
1067 				     struct ethtool_link_ksettings *cmd)
1068 {
1069 	struct net_device_context *ndc = netdev_priv(dev);
1070 
1071 	cmd->base.speed = ndc->speed;
1072 	cmd->base.duplex = ndc->duplex;
1073 	cmd->base.port = PORT_OTHER;
1074 
1075 	return 0;
1076 }
1077 
1078 static int netvsc_set_link_ksettings(struct net_device *dev,
1079 				     const struct ethtool_link_ksettings *cmd)
1080 {
1081 	struct net_device_context *ndc = netdev_priv(dev);
1082 	u32 speed;
1083 
1084 	speed = cmd->base.speed;
1085 	if (!ethtool_validate_speed(speed) ||
1086 	    !ethtool_validate_duplex(cmd->base.duplex) ||
1087 	    !netvsc_validate_ethtool_ss_cmd(cmd))
1088 		return -EINVAL;
1089 
1090 	ndc->speed = speed;
1091 	ndc->duplex = cmd->base.duplex;
1092 
1093 	return 0;
1094 }
1095 
1096 static int netvsc_change_mtu(struct net_device *ndev, int mtu)
1097 {
1098 	struct net_device_context *ndevctx = netdev_priv(ndev);
1099 	struct net_device *vf_netdev = rtnl_dereference(ndevctx->vf_netdev);
1100 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1101 	int orig_mtu = ndev->mtu;
1102 	struct netvsc_device_info *device_info;
1103 	int ret = 0;
1104 
1105 	if (!nvdev || nvdev->destroy)
1106 		return -ENODEV;
1107 
1108 	device_info = netvsc_devinfo_get(nvdev);
1109 
1110 	if (!device_info)
1111 		return -ENOMEM;
1112 
1113 	/* Change MTU of underlying VF netdev first. */
1114 	if (vf_netdev) {
1115 		ret = dev_set_mtu(vf_netdev, mtu);
1116 		if (ret)
1117 			goto out;
1118 	}
1119 
1120 	ret = netvsc_detach(ndev, nvdev);
1121 	if (ret)
1122 		goto rollback_vf;
1123 
1124 	ndev->mtu = mtu;
1125 
1126 	ret = netvsc_attach(ndev, device_info);
1127 	if (!ret)
1128 		goto out;
1129 
1130 	/* Attempt rollback to original MTU */
1131 	ndev->mtu = orig_mtu;
1132 
1133 	if (netvsc_attach(ndev, device_info))
1134 		netdev_err(ndev, "restoring mtu failed\n");
1135 rollback_vf:
1136 	if (vf_netdev)
1137 		dev_set_mtu(vf_netdev, orig_mtu);
1138 
1139 out:
1140 	kfree(device_info);
1141 	return ret;
1142 }
1143 
1144 static void netvsc_get_vf_stats(struct net_device *net,
1145 				struct netvsc_vf_pcpu_stats *tot)
1146 {
1147 	struct net_device_context *ndev_ctx = netdev_priv(net);
1148 	int i;
1149 
1150 	memset(tot, 0, sizeof(*tot));
1151 
1152 	for_each_possible_cpu(i) {
1153 		const struct netvsc_vf_pcpu_stats *stats
1154 			= per_cpu_ptr(ndev_ctx->vf_stats, i);
1155 		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1156 		unsigned int start;
1157 
1158 		do {
1159 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1160 			rx_packets = stats->rx_packets;
1161 			tx_packets = stats->tx_packets;
1162 			rx_bytes = stats->rx_bytes;
1163 			tx_bytes = stats->tx_bytes;
1164 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1165 
1166 		tot->rx_packets += rx_packets;
1167 		tot->tx_packets += tx_packets;
1168 		tot->rx_bytes   += rx_bytes;
1169 		tot->tx_bytes   += tx_bytes;
1170 		tot->tx_dropped += stats->tx_dropped;
1171 	}
1172 }
1173 
1174 static void netvsc_get_pcpu_stats(struct net_device *net,
1175 				  struct netvsc_ethtool_pcpu_stats *pcpu_tot)
1176 {
1177 	struct net_device_context *ndev_ctx = netdev_priv(net);
1178 	struct netvsc_device *nvdev = rcu_dereference_rtnl(ndev_ctx->nvdev);
1179 	int i;
1180 
1181 	/* fetch percpu stats of vf */
1182 	for_each_possible_cpu(i) {
1183 		const struct netvsc_vf_pcpu_stats *stats =
1184 			per_cpu_ptr(ndev_ctx->vf_stats, i);
1185 		struct netvsc_ethtool_pcpu_stats *this_tot = &pcpu_tot[i];
1186 		unsigned int start;
1187 
1188 		do {
1189 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1190 			this_tot->vf_rx_packets = stats->rx_packets;
1191 			this_tot->vf_tx_packets = stats->tx_packets;
1192 			this_tot->vf_rx_bytes = stats->rx_bytes;
1193 			this_tot->vf_tx_bytes = stats->tx_bytes;
1194 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1195 		this_tot->rx_packets = this_tot->vf_rx_packets;
1196 		this_tot->tx_packets = this_tot->vf_tx_packets;
1197 		this_tot->rx_bytes   = this_tot->vf_rx_bytes;
1198 		this_tot->tx_bytes   = this_tot->vf_tx_bytes;
1199 	}
1200 
1201 	/* fetch percpu stats of netvsc */
1202 	for (i = 0; i < nvdev->num_chn; i++) {
1203 		const struct netvsc_channel *nvchan = &nvdev->chan_table[i];
1204 		const struct netvsc_stats *stats;
1205 		struct netvsc_ethtool_pcpu_stats *this_tot =
1206 			&pcpu_tot[nvchan->channel->target_cpu];
1207 		u64 packets, bytes;
1208 		unsigned int start;
1209 
1210 		stats = &nvchan->tx_stats;
1211 		do {
1212 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1213 			packets = stats->packets;
1214 			bytes = stats->bytes;
1215 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1216 
1217 		this_tot->tx_bytes	+= bytes;
1218 		this_tot->tx_packets	+= packets;
1219 
1220 		stats = &nvchan->rx_stats;
1221 		do {
1222 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1223 			packets = stats->packets;
1224 			bytes = stats->bytes;
1225 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1226 
1227 		this_tot->rx_bytes	+= bytes;
1228 		this_tot->rx_packets	+= packets;
1229 	}
1230 }
1231 
1232 static void netvsc_get_stats64(struct net_device *net,
1233 			       struct rtnl_link_stats64 *t)
1234 {
1235 	struct net_device_context *ndev_ctx = netdev_priv(net);
1236 	struct netvsc_device *nvdev = rcu_dereference_rtnl(ndev_ctx->nvdev);
1237 	struct netvsc_vf_pcpu_stats vf_tot;
1238 	int i;
1239 
1240 	if (!nvdev)
1241 		return;
1242 
1243 	netdev_stats_to_stats64(t, &net->stats);
1244 
1245 	netvsc_get_vf_stats(net, &vf_tot);
1246 	t->rx_packets += vf_tot.rx_packets;
1247 	t->tx_packets += vf_tot.tx_packets;
1248 	t->rx_bytes   += vf_tot.rx_bytes;
1249 	t->tx_bytes   += vf_tot.tx_bytes;
1250 	t->tx_dropped += vf_tot.tx_dropped;
1251 
1252 	for (i = 0; i < nvdev->num_chn; i++) {
1253 		const struct netvsc_channel *nvchan = &nvdev->chan_table[i];
1254 		const struct netvsc_stats *stats;
1255 		u64 packets, bytes, multicast;
1256 		unsigned int start;
1257 
1258 		stats = &nvchan->tx_stats;
1259 		do {
1260 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1261 			packets = stats->packets;
1262 			bytes = stats->bytes;
1263 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1264 
1265 		t->tx_bytes	+= bytes;
1266 		t->tx_packets	+= packets;
1267 
1268 		stats = &nvchan->rx_stats;
1269 		do {
1270 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1271 			packets = stats->packets;
1272 			bytes = stats->bytes;
1273 			multicast = stats->multicast + stats->broadcast;
1274 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1275 
1276 		t->rx_bytes	+= bytes;
1277 		t->rx_packets	+= packets;
1278 		t->multicast	+= multicast;
1279 	}
1280 }
1281 
1282 static int netvsc_set_mac_addr(struct net_device *ndev, void *p)
1283 {
1284 	struct net_device_context *ndc = netdev_priv(ndev);
1285 	struct net_device *vf_netdev = rtnl_dereference(ndc->vf_netdev);
1286 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1287 	struct sockaddr *addr = p;
1288 	int err;
1289 
1290 	err = eth_prepare_mac_addr_change(ndev, p);
1291 	if (err)
1292 		return err;
1293 
1294 	if (!nvdev)
1295 		return -ENODEV;
1296 
1297 	if (vf_netdev) {
1298 		err = dev_set_mac_address(vf_netdev, addr, NULL);
1299 		if (err)
1300 			return err;
1301 	}
1302 
1303 	err = rndis_filter_set_device_mac(nvdev, addr->sa_data);
1304 	if (!err) {
1305 		eth_commit_mac_addr_change(ndev, p);
1306 	} else if (vf_netdev) {
1307 		/* rollback change on VF */
1308 		memcpy(addr->sa_data, ndev->dev_addr, ETH_ALEN);
1309 		dev_set_mac_address(vf_netdev, addr, NULL);
1310 	}
1311 
1312 	return err;
1313 }
1314 
1315 static const struct {
1316 	char name[ETH_GSTRING_LEN];
1317 	u16 offset;
1318 } netvsc_stats[] = {
1319 	{ "tx_scattered", offsetof(struct netvsc_ethtool_stats, tx_scattered) },
1320 	{ "tx_no_memory", offsetof(struct netvsc_ethtool_stats, tx_no_memory) },
1321 	{ "tx_no_space",  offsetof(struct netvsc_ethtool_stats, tx_no_space) },
1322 	{ "tx_too_big",	  offsetof(struct netvsc_ethtool_stats, tx_too_big) },
1323 	{ "tx_busy",	  offsetof(struct netvsc_ethtool_stats, tx_busy) },
1324 	{ "tx_send_full", offsetof(struct netvsc_ethtool_stats, tx_send_full) },
1325 	{ "rx_comp_busy", offsetof(struct netvsc_ethtool_stats, rx_comp_busy) },
1326 	{ "rx_no_memory", offsetof(struct netvsc_ethtool_stats, rx_no_memory) },
1327 	{ "stop_queue", offsetof(struct netvsc_ethtool_stats, stop_queue) },
1328 	{ "wake_queue", offsetof(struct netvsc_ethtool_stats, wake_queue) },
1329 }, pcpu_stats[] = {
1330 	{ "cpu%u_rx_packets",
1331 		offsetof(struct netvsc_ethtool_pcpu_stats, rx_packets) },
1332 	{ "cpu%u_rx_bytes",
1333 		offsetof(struct netvsc_ethtool_pcpu_stats, rx_bytes) },
1334 	{ "cpu%u_tx_packets",
1335 		offsetof(struct netvsc_ethtool_pcpu_stats, tx_packets) },
1336 	{ "cpu%u_tx_bytes",
1337 		offsetof(struct netvsc_ethtool_pcpu_stats, tx_bytes) },
1338 	{ "cpu%u_vf_rx_packets",
1339 		offsetof(struct netvsc_ethtool_pcpu_stats, vf_rx_packets) },
1340 	{ "cpu%u_vf_rx_bytes",
1341 		offsetof(struct netvsc_ethtool_pcpu_stats, vf_rx_bytes) },
1342 	{ "cpu%u_vf_tx_packets",
1343 		offsetof(struct netvsc_ethtool_pcpu_stats, vf_tx_packets) },
1344 	{ "cpu%u_vf_tx_bytes",
1345 		offsetof(struct netvsc_ethtool_pcpu_stats, vf_tx_bytes) },
1346 }, vf_stats[] = {
1347 	{ "vf_rx_packets", offsetof(struct netvsc_vf_pcpu_stats, rx_packets) },
1348 	{ "vf_rx_bytes",   offsetof(struct netvsc_vf_pcpu_stats, rx_bytes) },
1349 	{ "vf_tx_packets", offsetof(struct netvsc_vf_pcpu_stats, tx_packets) },
1350 	{ "vf_tx_bytes",   offsetof(struct netvsc_vf_pcpu_stats, tx_bytes) },
1351 	{ "vf_tx_dropped", offsetof(struct netvsc_vf_pcpu_stats, tx_dropped) },
1352 };
1353 
1354 #define NETVSC_GLOBAL_STATS_LEN	ARRAY_SIZE(netvsc_stats)
1355 #define NETVSC_VF_STATS_LEN	ARRAY_SIZE(vf_stats)
1356 
1357 /* statistics per queue (rx/tx packets/bytes) */
1358 #define NETVSC_PCPU_STATS_LEN (num_present_cpus() * ARRAY_SIZE(pcpu_stats))
1359 
1360 /* 4 statistics per queue (rx/tx packets/bytes) */
1361 #define NETVSC_QUEUE_STATS_LEN(dev) ((dev)->num_chn * 4)
1362 
1363 static int netvsc_get_sset_count(struct net_device *dev, int string_set)
1364 {
1365 	struct net_device_context *ndc = netdev_priv(dev);
1366 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1367 
1368 	if (!nvdev)
1369 		return -ENODEV;
1370 
1371 	switch (string_set) {
1372 	case ETH_SS_STATS:
1373 		return NETVSC_GLOBAL_STATS_LEN
1374 			+ NETVSC_VF_STATS_LEN
1375 			+ NETVSC_QUEUE_STATS_LEN(nvdev)
1376 			+ NETVSC_PCPU_STATS_LEN;
1377 	default:
1378 		return -EINVAL;
1379 	}
1380 }
1381 
1382 static void netvsc_get_ethtool_stats(struct net_device *dev,
1383 				     struct ethtool_stats *stats, u64 *data)
1384 {
1385 	struct net_device_context *ndc = netdev_priv(dev);
1386 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1387 	const void *nds = &ndc->eth_stats;
1388 	const struct netvsc_stats *qstats;
1389 	struct netvsc_vf_pcpu_stats sum;
1390 	struct netvsc_ethtool_pcpu_stats *pcpu_sum;
1391 	unsigned int start;
1392 	u64 packets, bytes;
1393 	int i, j, cpu;
1394 
1395 	if (!nvdev)
1396 		return;
1397 
1398 	for (i = 0; i < NETVSC_GLOBAL_STATS_LEN; i++)
1399 		data[i] = *(unsigned long *)(nds + netvsc_stats[i].offset);
1400 
1401 	netvsc_get_vf_stats(dev, &sum);
1402 	for (j = 0; j < NETVSC_VF_STATS_LEN; j++)
1403 		data[i++] = *(u64 *)((void *)&sum + vf_stats[j].offset);
1404 
1405 	for (j = 0; j < nvdev->num_chn; j++) {
1406 		qstats = &nvdev->chan_table[j].tx_stats;
1407 
1408 		do {
1409 			start = u64_stats_fetch_begin_irq(&qstats->syncp);
1410 			packets = qstats->packets;
1411 			bytes = qstats->bytes;
1412 		} while (u64_stats_fetch_retry_irq(&qstats->syncp, start));
1413 		data[i++] = packets;
1414 		data[i++] = bytes;
1415 
1416 		qstats = &nvdev->chan_table[j].rx_stats;
1417 		do {
1418 			start = u64_stats_fetch_begin_irq(&qstats->syncp);
1419 			packets = qstats->packets;
1420 			bytes = qstats->bytes;
1421 		} while (u64_stats_fetch_retry_irq(&qstats->syncp, start));
1422 		data[i++] = packets;
1423 		data[i++] = bytes;
1424 	}
1425 
1426 	pcpu_sum = kvmalloc_array(num_possible_cpus(),
1427 				  sizeof(struct netvsc_ethtool_pcpu_stats),
1428 				  GFP_KERNEL);
1429 	netvsc_get_pcpu_stats(dev, pcpu_sum);
1430 	for_each_present_cpu(cpu) {
1431 		struct netvsc_ethtool_pcpu_stats *this_sum = &pcpu_sum[cpu];
1432 
1433 		for (j = 0; j < ARRAY_SIZE(pcpu_stats); j++)
1434 			data[i++] = *(u64 *)((void *)this_sum
1435 					     + pcpu_stats[j].offset);
1436 	}
1437 	kvfree(pcpu_sum);
1438 }
1439 
1440 static void netvsc_get_strings(struct net_device *dev, u32 stringset, u8 *data)
1441 {
1442 	struct net_device_context *ndc = netdev_priv(dev);
1443 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1444 	u8 *p = data;
1445 	int i, cpu;
1446 
1447 	if (!nvdev)
1448 		return;
1449 
1450 	switch (stringset) {
1451 	case ETH_SS_STATS:
1452 		for (i = 0; i < ARRAY_SIZE(netvsc_stats); i++) {
1453 			memcpy(p, netvsc_stats[i].name, ETH_GSTRING_LEN);
1454 			p += ETH_GSTRING_LEN;
1455 		}
1456 
1457 		for (i = 0; i < ARRAY_SIZE(vf_stats); i++) {
1458 			memcpy(p, vf_stats[i].name, ETH_GSTRING_LEN);
1459 			p += ETH_GSTRING_LEN;
1460 		}
1461 
1462 		for (i = 0; i < nvdev->num_chn; i++) {
1463 			sprintf(p, "tx_queue_%u_packets", i);
1464 			p += ETH_GSTRING_LEN;
1465 			sprintf(p, "tx_queue_%u_bytes", i);
1466 			p += ETH_GSTRING_LEN;
1467 			sprintf(p, "rx_queue_%u_packets", i);
1468 			p += ETH_GSTRING_LEN;
1469 			sprintf(p, "rx_queue_%u_bytes", i);
1470 			p += ETH_GSTRING_LEN;
1471 		}
1472 
1473 		for_each_present_cpu(cpu) {
1474 			for (i = 0; i < ARRAY_SIZE(pcpu_stats); i++) {
1475 				sprintf(p, pcpu_stats[i].name, cpu);
1476 				p += ETH_GSTRING_LEN;
1477 			}
1478 		}
1479 
1480 		break;
1481 	}
1482 }
1483 
1484 static int
1485 netvsc_get_rss_hash_opts(struct net_device_context *ndc,
1486 			 struct ethtool_rxnfc *info)
1487 {
1488 	const u32 l4_flag = RXH_L4_B_0_1 | RXH_L4_B_2_3;
1489 
1490 	info->data = RXH_IP_SRC | RXH_IP_DST;
1491 
1492 	switch (info->flow_type) {
1493 	case TCP_V4_FLOW:
1494 		if (ndc->l4_hash & HV_TCP4_L4HASH)
1495 			info->data |= l4_flag;
1496 
1497 		break;
1498 
1499 	case TCP_V6_FLOW:
1500 		if (ndc->l4_hash & HV_TCP6_L4HASH)
1501 			info->data |= l4_flag;
1502 
1503 		break;
1504 
1505 	case UDP_V4_FLOW:
1506 		if (ndc->l4_hash & HV_UDP4_L4HASH)
1507 			info->data |= l4_flag;
1508 
1509 		break;
1510 
1511 	case UDP_V6_FLOW:
1512 		if (ndc->l4_hash & HV_UDP6_L4HASH)
1513 			info->data |= l4_flag;
1514 
1515 		break;
1516 
1517 	case IPV4_FLOW:
1518 	case IPV6_FLOW:
1519 		break;
1520 	default:
1521 		info->data = 0;
1522 		break;
1523 	}
1524 
1525 	return 0;
1526 }
1527 
1528 static int
1529 netvsc_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info,
1530 		 u32 *rules)
1531 {
1532 	struct net_device_context *ndc = netdev_priv(dev);
1533 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1534 
1535 	if (!nvdev)
1536 		return -ENODEV;
1537 
1538 	switch (info->cmd) {
1539 	case ETHTOOL_GRXRINGS:
1540 		info->data = nvdev->num_chn;
1541 		return 0;
1542 
1543 	case ETHTOOL_GRXFH:
1544 		return netvsc_get_rss_hash_opts(ndc, info);
1545 	}
1546 	return -EOPNOTSUPP;
1547 }
1548 
1549 static int netvsc_set_rss_hash_opts(struct net_device_context *ndc,
1550 				    struct ethtool_rxnfc *info)
1551 {
1552 	if (info->data == (RXH_IP_SRC | RXH_IP_DST |
1553 			   RXH_L4_B_0_1 | RXH_L4_B_2_3)) {
1554 		switch (info->flow_type) {
1555 		case TCP_V4_FLOW:
1556 			ndc->l4_hash |= HV_TCP4_L4HASH;
1557 			break;
1558 
1559 		case TCP_V6_FLOW:
1560 			ndc->l4_hash |= HV_TCP6_L4HASH;
1561 			break;
1562 
1563 		case UDP_V4_FLOW:
1564 			ndc->l4_hash |= HV_UDP4_L4HASH;
1565 			break;
1566 
1567 		case UDP_V6_FLOW:
1568 			ndc->l4_hash |= HV_UDP6_L4HASH;
1569 			break;
1570 
1571 		default:
1572 			return -EOPNOTSUPP;
1573 		}
1574 
1575 		return 0;
1576 	}
1577 
1578 	if (info->data == (RXH_IP_SRC | RXH_IP_DST)) {
1579 		switch (info->flow_type) {
1580 		case TCP_V4_FLOW:
1581 			ndc->l4_hash &= ~HV_TCP4_L4HASH;
1582 			break;
1583 
1584 		case TCP_V6_FLOW:
1585 			ndc->l4_hash &= ~HV_TCP6_L4HASH;
1586 			break;
1587 
1588 		case UDP_V4_FLOW:
1589 			ndc->l4_hash &= ~HV_UDP4_L4HASH;
1590 			break;
1591 
1592 		case UDP_V6_FLOW:
1593 			ndc->l4_hash &= ~HV_UDP6_L4HASH;
1594 			break;
1595 
1596 		default:
1597 			return -EOPNOTSUPP;
1598 		}
1599 
1600 		return 0;
1601 	}
1602 
1603 	return -EOPNOTSUPP;
1604 }
1605 
1606 static int
1607 netvsc_set_rxnfc(struct net_device *ndev, struct ethtool_rxnfc *info)
1608 {
1609 	struct net_device_context *ndc = netdev_priv(ndev);
1610 
1611 	if (info->cmd == ETHTOOL_SRXFH)
1612 		return netvsc_set_rss_hash_opts(ndc, info);
1613 
1614 	return -EOPNOTSUPP;
1615 }
1616 
1617 static u32 netvsc_get_rxfh_key_size(struct net_device *dev)
1618 {
1619 	return NETVSC_HASH_KEYLEN;
1620 }
1621 
1622 static u32 netvsc_rss_indir_size(struct net_device *dev)
1623 {
1624 	return ITAB_NUM;
1625 }
1626 
1627 static int netvsc_get_rxfh(struct net_device *dev, u32 *indir, u8 *key,
1628 			   u8 *hfunc)
1629 {
1630 	struct net_device_context *ndc = netdev_priv(dev);
1631 	struct netvsc_device *ndev = rtnl_dereference(ndc->nvdev);
1632 	struct rndis_device *rndis_dev;
1633 	int i;
1634 
1635 	if (!ndev)
1636 		return -ENODEV;
1637 
1638 	if (hfunc)
1639 		*hfunc = ETH_RSS_HASH_TOP;	/* Toeplitz */
1640 
1641 	rndis_dev = ndev->extension;
1642 	if (indir) {
1643 		for (i = 0; i < ITAB_NUM; i++)
1644 			indir[i] = rndis_dev->rx_table[i];
1645 	}
1646 
1647 	if (key)
1648 		memcpy(key, rndis_dev->rss_key, NETVSC_HASH_KEYLEN);
1649 
1650 	return 0;
1651 }
1652 
1653 static int netvsc_set_rxfh(struct net_device *dev, const u32 *indir,
1654 			   const u8 *key, const u8 hfunc)
1655 {
1656 	struct net_device_context *ndc = netdev_priv(dev);
1657 	struct netvsc_device *ndev = rtnl_dereference(ndc->nvdev);
1658 	struct rndis_device *rndis_dev;
1659 	int i;
1660 
1661 	if (!ndev)
1662 		return -ENODEV;
1663 
1664 	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
1665 		return -EOPNOTSUPP;
1666 
1667 	rndis_dev = ndev->extension;
1668 	if (indir) {
1669 		for (i = 0; i < ITAB_NUM; i++)
1670 			if (indir[i] >= ndev->num_chn)
1671 				return -EINVAL;
1672 
1673 		for (i = 0; i < ITAB_NUM; i++)
1674 			rndis_dev->rx_table[i] = indir[i];
1675 	}
1676 
1677 	if (!key) {
1678 		if (!indir)
1679 			return 0;
1680 
1681 		key = rndis_dev->rss_key;
1682 	}
1683 
1684 	return rndis_filter_set_rss_param(rndis_dev, key);
1685 }
1686 
1687 /* Hyper-V RNDIS protocol does not have ring in the HW sense.
1688  * It does have pre-allocated receive area which is divided into sections.
1689  */
1690 static void __netvsc_get_ringparam(struct netvsc_device *nvdev,
1691 				   struct ethtool_ringparam *ring)
1692 {
1693 	u32 max_buf_size;
1694 
1695 	ring->rx_pending = nvdev->recv_section_cnt;
1696 	ring->tx_pending = nvdev->send_section_cnt;
1697 
1698 	if (nvdev->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
1699 		max_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
1700 	else
1701 		max_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
1702 
1703 	ring->rx_max_pending = max_buf_size / nvdev->recv_section_size;
1704 	ring->tx_max_pending = NETVSC_SEND_BUFFER_SIZE
1705 		/ nvdev->send_section_size;
1706 }
1707 
1708 static void netvsc_get_ringparam(struct net_device *ndev,
1709 				 struct ethtool_ringparam *ring)
1710 {
1711 	struct net_device_context *ndevctx = netdev_priv(ndev);
1712 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1713 
1714 	if (!nvdev)
1715 		return;
1716 
1717 	__netvsc_get_ringparam(nvdev, ring);
1718 }
1719 
1720 static int netvsc_set_ringparam(struct net_device *ndev,
1721 				struct ethtool_ringparam *ring)
1722 {
1723 	struct net_device_context *ndevctx = netdev_priv(ndev);
1724 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1725 	struct netvsc_device_info *device_info;
1726 	struct ethtool_ringparam orig;
1727 	u32 new_tx, new_rx;
1728 	int ret = 0;
1729 
1730 	if (!nvdev || nvdev->destroy)
1731 		return -ENODEV;
1732 
1733 	memset(&orig, 0, sizeof(orig));
1734 	__netvsc_get_ringparam(nvdev, &orig);
1735 
1736 	new_tx = clamp_t(u32, ring->tx_pending,
1737 			 NETVSC_MIN_TX_SECTIONS, orig.tx_max_pending);
1738 	new_rx = clamp_t(u32, ring->rx_pending,
1739 			 NETVSC_MIN_RX_SECTIONS, orig.rx_max_pending);
1740 
1741 	if (new_tx == orig.tx_pending &&
1742 	    new_rx == orig.rx_pending)
1743 		return 0;	 /* no change */
1744 
1745 	device_info = netvsc_devinfo_get(nvdev);
1746 
1747 	if (!device_info)
1748 		return -ENOMEM;
1749 
1750 	device_info->send_sections = new_tx;
1751 	device_info->recv_sections = new_rx;
1752 
1753 	ret = netvsc_detach(ndev, nvdev);
1754 	if (ret)
1755 		goto out;
1756 
1757 	ret = netvsc_attach(ndev, device_info);
1758 	if (ret) {
1759 		device_info->send_sections = orig.tx_pending;
1760 		device_info->recv_sections = orig.rx_pending;
1761 
1762 		if (netvsc_attach(ndev, device_info))
1763 			netdev_err(ndev, "restoring ringparam failed");
1764 	}
1765 
1766 out:
1767 	kfree(device_info);
1768 	return ret;
1769 }
1770 
1771 static int netvsc_set_features(struct net_device *ndev,
1772 			       netdev_features_t features)
1773 {
1774 	netdev_features_t change = features ^ ndev->features;
1775 	struct net_device_context *ndevctx = netdev_priv(ndev);
1776 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1777 	struct ndis_offload_params offloads;
1778 
1779 	if (!nvdev || nvdev->destroy)
1780 		return -ENODEV;
1781 
1782 	if (!(change & NETIF_F_LRO))
1783 		return 0;
1784 
1785 	memset(&offloads, 0, sizeof(struct ndis_offload_params));
1786 
1787 	if (features & NETIF_F_LRO) {
1788 		offloads.rsc_ip_v4 = NDIS_OFFLOAD_PARAMETERS_RSC_ENABLED;
1789 		offloads.rsc_ip_v6 = NDIS_OFFLOAD_PARAMETERS_RSC_ENABLED;
1790 	} else {
1791 		offloads.rsc_ip_v4 = NDIS_OFFLOAD_PARAMETERS_RSC_DISABLED;
1792 		offloads.rsc_ip_v6 = NDIS_OFFLOAD_PARAMETERS_RSC_DISABLED;
1793 	}
1794 
1795 	return rndis_filter_set_offload_params(ndev, nvdev, &offloads);
1796 }
1797 
1798 static u32 netvsc_get_msglevel(struct net_device *ndev)
1799 {
1800 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1801 
1802 	return ndev_ctx->msg_enable;
1803 }
1804 
1805 static void netvsc_set_msglevel(struct net_device *ndev, u32 val)
1806 {
1807 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1808 
1809 	ndev_ctx->msg_enable = val;
1810 }
1811 
1812 static const struct ethtool_ops ethtool_ops = {
1813 	.get_drvinfo	= netvsc_get_drvinfo,
1814 	.get_msglevel	= netvsc_get_msglevel,
1815 	.set_msglevel	= netvsc_set_msglevel,
1816 	.get_link	= ethtool_op_get_link,
1817 	.get_ethtool_stats = netvsc_get_ethtool_stats,
1818 	.get_sset_count = netvsc_get_sset_count,
1819 	.get_strings	= netvsc_get_strings,
1820 	.get_channels   = netvsc_get_channels,
1821 	.set_channels   = netvsc_set_channels,
1822 	.get_ts_info	= ethtool_op_get_ts_info,
1823 	.get_rxnfc	= netvsc_get_rxnfc,
1824 	.set_rxnfc	= netvsc_set_rxnfc,
1825 	.get_rxfh_key_size = netvsc_get_rxfh_key_size,
1826 	.get_rxfh_indir_size = netvsc_rss_indir_size,
1827 	.get_rxfh	= netvsc_get_rxfh,
1828 	.set_rxfh	= netvsc_set_rxfh,
1829 	.get_link_ksettings = netvsc_get_link_ksettings,
1830 	.set_link_ksettings = netvsc_set_link_ksettings,
1831 	.get_ringparam	= netvsc_get_ringparam,
1832 	.set_ringparam	= netvsc_set_ringparam,
1833 };
1834 
1835 static const struct net_device_ops device_ops = {
1836 	.ndo_open =			netvsc_open,
1837 	.ndo_stop =			netvsc_close,
1838 	.ndo_start_xmit =		netvsc_start_xmit,
1839 	.ndo_change_rx_flags =		netvsc_change_rx_flags,
1840 	.ndo_set_rx_mode =		netvsc_set_rx_mode,
1841 	.ndo_set_features =		netvsc_set_features,
1842 	.ndo_change_mtu =		netvsc_change_mtu,
1843 	.ndo_validate_addr =		eth_validate_addr,
1844 	.ndo_set_mac_address =		netvsc_set_mac_addr,
1845 	.ndo_select_queue =		netvsc_select_queue,
1846 	.ndo_get_stats64 =		netvsc_get_stats64,
1847 };
1848 
1849 /*
1850  * Handle link status changes. For RNDIS_STATUS_NETWORK_CHANGE emulate link
1851  * down/up sequence. In case of RNDIS_STATUS_MEDIA_CONNECT when carrier is
1852  * present send GARP packet to network peers with netif_notify_peers().
1853  */
1854 static void netvsc_link_change(struct work_struct *w)
1855 {
1856 	struct net_device_context *ndev_ctx =
1857 		container_of(w, struct net_device_context, dwork.work);
1858 	struct hv_device *device_obj = ndev_ctx->device_ctx;
1859 	struct net_device *net = hv_get_drvdata(device_obj);
1860 	struct netvsc_device *net_device;
1861 	struct rndis_device *rdev;
1862 	struct netvsc_reconfig *event = NULL;
1863 	bool notify = false, reschedule = false;
1864 	unsigned long flags, next_reconfig, delay;
1865 
1866 	/* if changes are happening, comeback later */
1867 	if (!rtnl_trylock()) {
1868 		schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT);
1869 		return;
1870 	}
1871 
1872 	net_device = rtnl_dereference(ndev_ctx->nvdev);
1873 	if (!net_device)
1874 		goto out_unlock;
1875 
1876 	rdev = net_device->extension;
1877 
1878 	next_reconfig = ndev_ctx->last_reconfig + LINKCHANGE_INT;
1879 	if (time_is_after_jiffies(next_reconfig)) {
1880 		/* link_watch only sends one notification with current state
1881 		 * per second, avoid doing reconfig more frequently. Handle
1882 		 * wrap around.
1883 		 */
1884 		delay = next_reconfig - jiffies;
1885 		delay = delay < LINKCHANGE_INT ? delay : LINKCHANGE_INT;
1886 		schedule_delayed_work(&ndev_ctx->dwork, delay);
1887 		goto out_unlock;
1888 	}
1889 	ndev_ctx->last_reconfig = jiffies;
1890 
1891 	spin_lock_irqsave(&ndev_ctx->lock, flags);
1892 	if (!list_empty(&ndev_ctx->reconfig_events)) {
1893 		event = list_first_entry(&ndev_ctx->reconfig_events,
1894 					 struct netvsc_reconfig, list);
1895 		list_del(&event->list);
1896 		reschedule = !list_empty(&ndev_ctx->reconfig_events);
1897 	}
1898 	spin_unlock_irqrestore(&ndev_ctx->lock, flags);
1899 
1900 	if (!event)
1901 		goto out_unlock;
1902 
1903 	switch (event->event) {
1904 		/* Only the following events are possible due to the check in
1905 		 * netvsc_linkstatus_callback()
1906 		 */
1907 	case RNDIS_STATUS_MEDIA_CONNECT:
1908 		if (rdev->link_state) {
1909 			rdev->link_state = false;
1910 			netif_carrier_on(net);
1911 			netif_tx_wake_all_queues(net);
1912 		} else {
1913 			notify = true;
1914 		}
1915 		kfree(event);
1916 		break;
1917 	case RNDIS_STATUS_MEDIA_DISCONNECT:
1918 		if (!rdev->link_state) {
1919 			rdev->link_state = true;
1920 			netif_carrier_off(net);
1921 			netif_tx_stop_all_queues(net);
1922 		}
1923 		kfree(event);
1924 		break;
1925 	case RNDIS_STATUS_NETWORK_CHANGE:
1926 		/* Only makes sense if carrier is present */
1927 		if (!rdev->link_state) {
1928 			rdev->link_state = true;
1929 			netif_carrier_off(net);
1930 			netif_tx_stop_all_queues(net);
1931 			event->event = RNDIS_STATUS_MEDIA_CONNECT;
1932 			spin_lock_irqsave(&ndev_ctx->lock, flags);
1933 			list_add(&event->list, &ndev_ctx->reconfig_events);
1934 			spin_unlock_irqrestore(&ndev_ctx->lock, flags);
1935 			reschedule = true;
1936 		}
1937 		break;
1938 	}
1939 
1940 	rtnl_unlock();
1941 
1942 	if (notify)
1943 		netdev_notify_peers(net);
1944 
1945 	/* link_watch only sends one notification with current state per
1946 	 * second, handle next reconfig event in 2 seconds.
1947 	 */
1948 	if (reschedule)
1949 		schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT);
1950 
1951 	return;
1952 
1953 out_unlock:
1954 	rtnl_unlock();
1955 }
1956 
1957 static struct net_device *get_netvsc_byref(struct net_device *vf_netdev)
1958 {
1959 	struct net_device_context *net_device_ctx;
1960 	struct net_device *dev;
1961 
1962 	dev = netdev_master_upper_dev_get(vf_netdev);
1963 	if (!dev || dev->netdev_ops != &device_ops)
1964 		return NULL;	/* not a netvsc device */
1965 
1966 	net_device_ctx = netdev_priv(dev);
1967 	if (!rtnl_dereference(net_device_ctx->nvdev))
1968 		return NULL;	/* device is removed */
1969 
1970 	return dev;
1971 }
1972 
1973 /* Called when VF is injecting data into network stack.
1974  * Change the associated network device from VF to netvsc.
1975  * note: already called with rcu_read_lock
1976  */
1977 static rx_handler_result_t netvsc_vf_handle_frame(struct sk_buff **pskb)
1978 {
1979 	struct sk_buff *skb = *pskb;
1980 	struct net_device *ndev = rcu_dereference(skb->dev->rx_handler_data);
1981 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1982 	struct netvsc_vf_pcpu_stats *pcpu_stats
1983 		 = this_cpu_ptr(ndev_ctx->vf_stats);
1984 
1985 	skb->dev = ndev;
1986 
1987 	u64_stats_update_begin(&pcpu_stats->syncp);
1988 	pcpu_stats->rx_packets++;
1989 	pcpu_stats->rx_bytes += skb->len;
1990 	u64_stats_update_end(&pcpu_stats->syncp);
1991 
1992 	return RX_HANDLER_ANOTHER;
1993 }
1994 
1995 static int netvsc_vf_join(struct net_device *vf_netdev,
1996 			  struct net_device *ndev)
1997 {
1998 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1999 	int ret;
2000 
2001 	ret = netdev_rx_handler_register(vf_netdev,
2002 					 netvsc_vf_handle_frame, ndev);
2003 	if (ret != 0) {
2004 		netdev_err(vf_netdev,
2005 			   "can not register netvsc VF receive handler (err = %d)\n",
2006 			   ret);
2007 		goto rx_handler_failed;
2008 	}
2009 
2010 	ret = netdev_master_upper_dev_link(vf_netdev, ndev,
2011 					   NULL, NULL, NULL);
2012 	if (ret != 0) {
2013 		netdev_err(vf_netdev,
2014 			   "can not set master device %s (err = %d)\n",
2015 			   ndev->name, ret);
2016 		goto upper_link_failed;
2017 	}
2018 
2019 	/* set slave flag before open to prevent IPv6 addrconf */
2020 	vf_netdev->flags |= IFF_SLAVE;
2021 
2022 	schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);
2023 
2024 	call_netdevice_notifiers(NETDEV_JOIN, vf_netdev);
2025 
2026 	netdev_info(vf_netdev, "joined to %s\n", ndev->name);
2027 	return 0;
2028 
2029 upper_link_failed:
2030 	netdev_rx_handler_unregister(vf_netdev);
2031 rx_handler_failed:
2032 	return ret;
2033 }
2034 
2035 static void __netvsc_vf_setup(struct net_device *ndev,
2036 			      struct net_device *vf_netdev)
2037 {
2038 	int ret;
2039 
2040 	/* Align MTU of VF with master */
2041 	ret = dev_set_mtu(vf_netdev, ndev->mtu);
2042 	if (ret)
2043 		netdev_warn(vf_netdev,
2044 			    "unable to change mtu to %u\n", ndev->mtu);
2045 
2046 	/* set multicast etc flags on VF */
2047 	dev_change_flags(vf_netdev, ndev->flags | IFF_SLAVE, NULL);
2048 
2049 	/* sync address list from ndev to VF */
2050 	netif_addr_lock_bh(ndev);
2051 	dev_uc_sync(vf_netdev, ndev);
2052 	dev_mc_sync(vf_netdev, ndev);
2053 	netif_addr_unlock_bh(ndev);
2054 
2055 	if (netif_running(ndev)) {
2056 		ret = dev_open(vf_netdev, NULL);
2057 		if (ret)
2058 			netdev_warn(vf_netdev,
2059 				    "unable to open: %d\n", ret);
2060 	}
2061 }
2062 
2063 /* Setup VF as slave of the synthetic device.
2064  * Runs in workqueue to avoid recursion in netlink callbacks.
2065  */
2066 static void netvsc_vf_setup(struct work_struct *w)
2067 {
2068 	struct net_device_context *ndev_ctx
2069 		= container_of(w, struct net_device_context, vf_takeover.work);
2070 	struct net_device *ndev = hv_get_drvdata(ndev_ctx->device_ctx);
2071 	struct net_device *vf_netdev;
2072 
2073 	if (!rtnl_trylock()) {
2074 		schedule_delayed_work(&ndev_ctx->vf_takeover, 0);
2075 		return;
2076 	}
2077 
2078 	vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
2079 	if (vf_netdev)
2080 		__netvsc_vf_setup(ndev, vf_netdev);
2081 
2082 	rtnl_unlock();
2083 }
2084 
2085 /* Find netvsc by VF serial number.
2086  * The PCI hyperv controller records the serial number as the slot kobj name.
2087  */
2088 static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
2089 {
2090 	struct device *parent = vf_netdev->dev.parent;
2091 	struct net_device_context *ndev_ctx;
2092 	struct pci_dev *pdev;
2093 	u32 serial;
2094 
2095 	if (!parent || !dev_is_pci(parent))
2096 		return NULL; /* not a PCI device */
2097 
2098 	pdev = to_pci_dev(parent);
2099 	if (!pdev->slot) {
2100 		netdev_notice(vf_netdev, "no PCI slot information\n");
2101 		return NULL;
2102 	}
2103 
2104 	if (kstrtou32(pci_slot_name(pdev->slot), 10, &serial)) {
2105 		netdev_notice(vf_netdev, "Invalid vf serial:%s\n",
2106 			      pci_slot_name(pdev->slot));
2107 		return NULL;
2108 	}
2109 
2110 	list_for_each_entry(ndev_ctx, &netvsc_dev_list, list) {
2111 		if (!ndev_ctx->vf_alloc)
2112 			continue;
2113 
2114 		if (ndev_ctx->vf_serial == serial)
2115 			return hv_get_drvdata(ndev_ctx->device_ctx);
2116 	}
2117 
2118 	netdev_notice(vf_netdev,
2119 		      "no netdev found for vf serial:%u\n", serial);
2120 	return NULL;
2121 }
2122 
2123 static int netvsc_register_vf(struct net_device *vf_netdev)
2124 {
2125 	struct net_device_context *net_device_ctx;
2126 	struct netvsc_device *netvsc_dev;
2127 	struct net_device *ndev;
2128 	int ret;
2129 
2130 	if (vf_netdev->addr_len != ETH_ALEN)
2131 		return NOTIFY_DONE;
2132 
2133 	ndev = get_netvsc_byslot(vf_netdev);
2134 	if (!ndev)
2135 		return NOTIFY_DONE;
2136 
2137 	net_device_ctx = netdev_priv(ndev);
2138 	netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
2139 	if (!netvsc_dev || rtnl_dereference(net_device_ctx->vf_netdev))
2140 		return NOTIFY_DONE;
2141 
2142 	/* if synthetic interface is a different namespace,
2143 	 * then move the VF to that namespace; join will be
2144 	 * done again in that context.
2145 	 */
2146 	if (!net_eq(dev_net(ndev), dev_net(vf_netdev))) {
2147 		ret = dev_change_net_namespace(vf_netdev,
2148 					       dev_net(ndev), "eth%d");
2149 		if (ret)
2150 			netdev_err(vf_netdev,
2151 				   "could not move to same namespace as %s: %d\n",
2152 				   ndev->name, ret);
2153 		else
2154 			netdev_info(vf_netdev,
2155 				    "VF moved to namespace with: %s\n",
2156 				    ndev->name);
2157 		return NOTIFY_DONE;
2158 	}
2159 
2160 	netdev_info(ndev, "VF registering: %s\n", vf_netdev->name);
2161 
2162 	if (netvsc_vf_join(vf_netdev, ndev) != 0)
2163 		return NOTIFY_DONE;
2164 
2165 	dev_hold(vf_netdev);
2166 	rcu_assign_pointer(net_device_ctx->vf_netdev, vf_netdev);
2167 	return NOTIFY_OK;
2168 }
2169 
2170 /* VF up/down change detected, schedule to change data path */
2171 static int netvsc_vf_changed(struct net_device *vf_netdev)
2172 {
2173 	struct net_device_context *net_device_ctx;
2174 	struct netvsc_device *netvsc_dev;
2175 	struct net_device *ndev;
2176 	bool vf_is_up = netif_running(vf_netdev);
2177 
2178 	ndev = get_netvsc_byref(vf_netdev);
2179 	if (!ndev)
2180 		return NOTIFY_DONE;
2181 
2182 	net_device_ctx = netdev_priv(ndev);
2183 	netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
2184 	if (!netvsc_dev)
2185 		return NOTIFY_DONE;
2186 
2187 	netvsc_switch_datapath(ndev, vf_is_up);
2188 	netdev_info(ndev, "Data path switched %s VF: %s\n",
2189 		    vf_is_up ? "to" : "from", vf_netdev->name);
2190 
2191 	return NOTIFY_OK;
2192 }
2193 
2194 static int netvsc_unregister_vf(struct net_device *vf_netdev)
2195 {
2196 	struct net_device *ndev;
2197 	struct net_device_context *net_device_ctx;
2198 
2199 	ndev = get_netvsc_byref(vf_netdev);
2200 	if (!ndev)
2201 		return NOTIFY_DONE;
2202 
2203 	net_device_ctx = netdev_priv(ndev);
2204 	cancel_delayed_work_sync(&net_device_ctx->vf_takeover);
2205 
2206 	netdev_info(ndev, "VF unregistering: %s\n", vf_netdev->name);
2207 
2208 	netdev_rx_handler_unregister(vf_netdev);
2209 	netdev_upper_dev_unlink(vf_netdev, ndev);
2210 	RCU_INIT_POINTER(net_device_ctx->vf_netdev, NULL);
2211 	dev_put(vf_netdev);
2212 
2213 	return NOTIFY_OK;
2214 }
2215 
2216 static int netvsc_probe(struct hv_device *dev,
2217 			const struct hv_vmbus_device_id *dev_id)
2218 {
2219 	struct net_device *net = NULL;
2220 	struct net_device_context *net_device_ctx;
2221 	struct netvsc_device_info *device_info = NULL;
2222 	struct netvsc_device *nvdev;
2223 	int ret = -ENOMEM;
2224 
2225 	net = alloc_etherdev_mq(sizeof(struct net_device_context),
2226 				VRSS_CHANNEL_MAX);
2227 	if (!net)
2228 		goto no_net;
2229 
2230 	netif_carrier_off(net);
2231 
2232 	netvsc_init_settings(net);
2233 
2234 	net_device_ctx = netdev_priv(net);
2235 	net_device_ctx->device_ctx = dev;
2236 	net_device_ctx->msg_enable = netif_msg_init(debug, default_msg);
2237 	if (netif_msg_probe(net_device_ctx))
2238 		netdev_dbg(net, "netvsc msg_enable: %d\n",
2239 			   net_device_ctx->msg_enable);
2240 
2241 	hv_set_drvdata(dev, net);
2242 
2243 	INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change);
2244 
2245 	spin_lock_init(&net_device_ctx->lock);
2246 	INIT_LIST_HEAD(&net_device_ctx->reconfig_events);
2247 	INIT_DELAYED_WORK(&net_device_ctx->vf_takeover, netvsc_vf_setup);
2248 
2249 	net_device_ctx->vf_stats
2250 		= netdev_alloc_pcpu_stats(struct netvsc_vf_pcpu_stats);
2251 	if (!net_device_ctx->vf_stats)
2252 		goto no_stats;
2253 
2254 	net->netdev_ops = &device_ops;
2255 	net->ethtool_ops = &ethtool_ops;
2256 	SET_NETDEV_DEV(net, &dev->device);
2257 
2258 	/* We always need headroom for rndis header */
2259 	net->needed_headroom = RNDIS_AND_PPI_SIZE;
2260 
2261 	/* Initialize the number of queues to be 1, we may change it if more
2262 	 * channels are offered later.
2263 	 */
2264 	netif_set_real_num_tx_queues(net, 1);
2265 	netif_set_real_num_rx_queues(net, 1);
2266 
2267 	/* Notify the netvsc driver of the new device */
2268 	device_info = netvsc_devinfo_get(NULL);
2269 
2270 	if (!device_info) {
2271 		ret = -ENOMEM;
2272 		goto devinfo_failed;
2273 	}
2274 
2275 	nvdev = rndis_filter_device_add(dev, device_info);
2276 	if (IS_ERR(nvdev)) {
2277 		ret = PTR_ERR(nvdev);
2278 		netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
2279 		goto rndis_failed;
2280 	}
2281 
2282 	memcpy(net->dev_addr, device_info->mac_adr, ETH_ALEN);
2283 
2284 	/* We must get rtnl lock before scheduling nvdev->subchan_work,
2285 	 * otherwise netvsc_subchan_work() can get rtnl lock first and wait
2286 	 * all subchannels to show up, but that may not happen because
2287 	 * netvsc_probe() can't get rtnl lock and as a result vmbus_onoffer()
2288 	 * -> ... -> device_add() -> ... -> __device_attach() can't get
2289 	 * the device lock, so all the subchannels can't be processed --
2290 	 * finally netvsc_subchan_work() hangs forever.
2291 	 */
2292 	rtnl_lock();
2293 
2294 	if (nvdev->num_chn > 1)
2295 		schedule_work(&nvdev->subchan_work);
2296 
2297 	/* hw_features computed in rndis_netdev_set_hwcaps() */
2298 	net->features = net->hw_features |
2299 		NETIF_F_HIGHDMA | NETIF_F_SG |
2300 		NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX;
2301 	net->vlan_features = net->features;
2302 
2303 	netdev_lockdep_set_classes(net);
2304 
2305 	/* MTU range: 68 - 1500 or 65521 */
2306 	net->min_mtu = NETVSC_MTU_MIN;
2307 	if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
2308 		net->max_mtu = NETVSC_MTU - ETH_HLEN;
2309 	else
2310 		net->max_mtu = ETH_DATA_LEN;
2311 
2312 	ret = register_netdevice(net);
2313 	if (ret != 0) {
2314 		pr_err("Unable to register netdev.\n");
2315 		goto register_failed;
2316 	}
2317 
2318 	list_add(&net_device_ctx->list, &netvsc_dev_list);
2319 	rtnl_unlock();
2320 
2321 	kfree(device_info);
2322 	return 0;
2323 
2324 register_failed:
2325 	rtnl_unlock();
2326 	rndis_filter_device_remove(dev, nvdev);
2327 rndis_failed:
2328 	kfree(device_info);
2329 devinfo_failed:
2330 	free_percpu(net_device_ctx->vf_stats);
2331 no_stats:
2332 	hv_set_drvdata(dev, NULL);
2333 	free_netdev(net);
2334 no_net:
2335 	return ret;
2336 }
2337 
2338 static int netvsc_remove(struct hv_device *dev)
2339 {
2340 	struct net_device_context *ndev_ctx;
2341 	struct net_device *vf_netdev, *net;
2342 	struct netvsc_device *nvdev;
2343 
2344 	net = hv_get_drvdata(dev);
2345 	if (net == NULL) {
2346 		dev_err(&dev->device, "No net device to remove\n");
2347 		return 0;
2348 	}
2349 
2350 	ndev_ctx = netdev_priv(net);
2351 
2352 	cancel_delayed_work_sync(&ndev_ctx->dwork);
2353 
2354 	rtnl_lock();
2355 	nvdev = rtnl_dereference(ndev_ctx->nvdev);
2356 	if (nvdev)
2357 		cancel_work_sync(&nvdev->subchan_work);
2358 
2359 	/*
2360 	 * Call to the vsc driver to let it know that the device is being
2361 	 * removed. Also blocks mtu and channel changes.
2362 	 */
2363 	vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
2364 	if (vf_netdev)
2365 		netvsc_unregister_vf(vf_netdev);
2366 
2367 	if (nvdev)
2368 		rndis_filter_device_remove(dev, nvdev);
2369 
2370 	unregister_netdevice(net);
2371 	list_del(&ndev_ctx->list);
2372 
2373 	rtnl_unlock();
2374 
2375 	hv_set_drvdata(dev, NULL);
2376 
2377 	free_percpu(ndev_ctx->vf_stats);
2378 	free_netdev(net);
2379 	return 0;
2380 }
2381 
2382 static const struct hv_vmbus_device_id id_table[] = {
2383 	/* Network guid */
2384 	{ HV_NIC_GUID, },
2385 	{ },
2386 };
2387 
2388 MODULE_DEVICE_TABLE(vmbus, id_table);
2389 
2390 /* The one and only one */
2391 static struct  hv_driver netvsc_drv = {
2392 	.name = KBUILD_MODNAME,
2393 	.id_table = id_table,
2394 	.probe = netvsc_probe,
2395 	.remove = netvsc_remove,
2396 	.driver = {
2397 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
2398 	},
2399 };
2400 
2401 /*
2402  * On Hyper-V, every VF interface is matched with a corresponding
2403  * synthetic interface. The synthetic interface is presented first
2404  * to the guest. When the corresponding VF instance is registered,
2405  * we will take care of switching the data path.
2406  */
2407 static int netvsc_netdev_event(struct notifier_block *this,
2408 			       unsigned long event, void *ptr)
2409 {
2410 	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2411 
2412 	/* Skip our own events */
2413 	if (event_dev->netdev_ops == &device_ops)
2414 		return NOTIFY_DONE;
2415 
2416 	/* Avoid non-Ethernet type devices */
2417 	if (event_dev->type != ARPHRD_ETHER)
2418 		return NOTIFY_DONE;
2419 
2420 	/* Avoid Vlan dev with same MAC registering as VF */
2421 	if (is_vlan_dev(event_dev))
2422 		return NOTIFY_DONE;
2423 
2424 	/* Avoid Bonding master dev with same MAC registering as VF */
2425 	if ((event_dev->priv_flags & IFF_BONDING) &&
2426 	    (event_dev->flags & IFF_MASTER))
2427 		return NOTIFY_DONE;
2428 
2429 	switch (event) {
2430 	case NETDEV_REGISTER:
2431 		return netvsc_register_vf(event_dev);
2432 	case NETDEV_UNREGISTER:
2433 		return netvsc_unregister_vf(event_dev);
2434 	case NETDEV_UP:
2435 	case NETDEV_DOWN:
2436 		return netvsc_vf_changed(event_dev);
2437 	default:
2438 		return NOTIFY_DONE;
2439 	}
2440 }
2441 
2442 static struct notifier_block netvsc_netdev_notifier = {
2443 	.notifier_call = netvsc_netdev_event,
2444 };
2445 
2446 static void __exit netvsc_drv_exit(void)
2447 {
2448 	unregister_netdevice_notifier(&netvsc_netdev_notifier);
2449 	vmbus_driver_unregister(&netvsc_drv);
2450 }
2451 
2452 static int __init netvsc_drv_init(void)
2453 {
2454 	int ret;
2455 
2456 	if (ring_size < RING_SIZE_MIN) {
2457 		ring_size = RING_SIZE_MIN;
2458 		pr_info("Increased ring_size to %u (min allowed)\n",
2459 			ring_size);
2460 	}
2461 	netvsc_ring_bytes = ring_size * PAGE_SIZE;
2462 
2463 	ret = vmbus_driver_register(&netvsc_drv);
2464 	if (ret)
2465 		return ret;
2466 
2467 	register_netdevice_notifier(&netvsc_netdev_notifier);
2468 	return 0;
2469 }
2470 
2471 MODULE_LICENSE("GPL");
2472 MODULE_DESCRIPTION("Microsoft Hyper-V network driver");
2473 
2474 module_init(netvsc_drv_init);
2475 module_exit(netvsc_drv_exit);
2476