xref: /linux/drivers/net/hyperv/netvsc_drv.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2009, Microsoft Corporation.
4  *
5  * Authors:
6  *   Haiyang Zhang <haiyangz@microsoft.com>
7  *   Hank Janssen  <hjanssen@microsoft.com>
8  */
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 
11 #include <linux/init.h>
12 #include <linux/atomic.h>
13 #include <linux/module.h>
14 #include <linux/highmem.h>
15 #include <linux/device.h>
16 #include <linux/io.h>
17 #include <linux/delay.h>
18 #include <linux/netdevice.h>
19 #include <linux/inetdevice.h>
20 #include <linux/etherdevice.h>
21 #include <linux/pci.h>
22 #include <linux/skbuff.h>
23 #include <linux/if_vlan.h>
24 #include <linux/in.h>
25 #include <linux/slab.h>
26 #include <linux/rtnetlink.h>
27 #include <linux/netpoll.h>
28 
29 #include <net/arp.h>
30 #include <net/route.h>
31 #include <net/sock.h>
32 #include <net/pkt_sched.h>
33 #include <net/checksum.h>
34 #include <net/ip6_checksum.h>
35 
36 #include "hyperv_net.h"
37 
38 #define RING_SIZE_MIN	64
39 #define RETRY_US_LO	5000
40 #define RETRY_US_HI	10000
41 #define RETRY_MAX	2000	/* >10 sec */
42 
43 #define LINKCHANGE_INT (2 * HZ)
44 #define VF_TAKEOVER_INT (HZ / 10)
45 
46 static unsigned int ring_size __ro_after_init = 128;
47 module_param(ring_size, uint, 0444);
48 MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
49 unsigned int netvsc_ring_bytes __ro_after_init;
50 
51 static const u32 default_msg = NETIF_MSG_DRV | NETIF_MSG_PROBE |
52 				NETIF_MSG_LINK | NETIF_MSG_IFUP |
53 				NETIF_MSG_IFDOWN | NETIF_MSG_RX_ERR |
54 				NETIF_MSG_TX_ERR;
55 
56 static int debug = -1;
57 module_param(debug, int, 0444);
58 MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");
59 
60 static LIST_HEAD(netvsc_dev_list);
61 
62 static void netvsc_change_rx_flags(struct net_device *net, int change)
63 {
64 	struct net_device_context *ndev_ctx = netdev_priv(net);
65 	struct net_device *vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
66 	int inc;
67 
68 	if (!vf_netdev)
69 		return;
70 
71 	if (change & IFF_PROMISC) {
72 		inc = (net->flags & IFF_PROMISC) ? 1 : -1;
73 		dev_set_promiscuity(vf_netdev, inc);
74 	}
75 
76 	if (change & IFF_ALLMULTI) {
77 		inc = (net->flags & IFF_ALLMULTI) ? 1 : -1;
78 		dev_set_allmulti(vf_netdev, inc);
79 	}
80 }
81 
82 static void netvsc_set_rx_mode(struct net_device *net)
83 {
84 	struct net_device_context *ndev_ctx = netdev_priv(net);
85 	struct net_device *vf_netdev;
86 	struct netvsc_device *nvdev;
87 
88 	rcu_read_lock();
89 	vf_netdev = rcu_dereference(ndev_ctx->vf_netdev);
90 	if (vf_netdev) {
91 		dev_uc_sync(vf_netdev, net);
92 		dev_mc_sync(vf_netdev, net);
93 	}
94 
95 	nvdev = rcu_dereference(ndev_ctx->nvdev);
96 	if (nvdev)
97 		rndis_filter_update(nvdev);
98 	rcu_read_unlock();
99 }
100 
101 static void netvsc_tx_enable(struct netvsc_device *nvscdev,
102 			     struct net_device *ndev)
103 {
104 	nvscdev->tx_disable = false;
105 	virt_wmb(); /* ensure queue wake up mechanism is on */
106 
107 	netif_tx_wake_all_queues(ndev);
108 }
109 
110 static int netvsc_open(struct net_device *net)
111 {
112 	struct net_device_context *ndev_ctx = netdev_priv(net);
113 	struct net_device *vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
114 	struct netvsc_device *nvdev = rtnl_dereference(ndev_ctx->nvdev);
115 	struct rndis_device *rdev;
116 	int ret = 0;
117 
118 	netif_carrier_off(net);
119 
120 	/* Open up the device */
121 	ret = rndis_filter_open(nvdev);
122 	if (ret != 0) {
123 		netdev_err(net, "unable to open device (ret %d).\n", ret);
124 		return ret;
125 	}
126 
127 	rdev = nvdev->extension;
128 	if (!rdev->link_state) {
129 		netif_carrier_on(net);
130 		netvsc_tx_enable(nvdev, net);
131 	}
132 
133 	if (vf_netdev) {
134 		/* Setting synthetic device up transparently sets
135 		 * slave as up. If open fails, then slave will be
136 		 * still be offline (and not used).
137 		 */
138 		ret = dev_open(vf_netdev, NULL);
139 		if (ret)
140 			netdev_warn(net,
141 				    "unable to open slave: %s: %d\n",
142 				    vf_netdev->name, ret);
143 	}
144 	return 0;
145 }
146 
147 static int netvsc_wait_until_empty(struct netvsc_device *nvdev)
148 {
149 	unsigned int retry = 0;
150 	int i;
151 
152 	/* Ensure pending bytes in ring are read */
153 	for (;;) {
154 		u32 aread = 0;
155 
156 		for (i = 0; i < nvdev->num_chn; i++) {
157 			struct vmbus_channel *chn
158 				= nvdev->chan_table[i].channel;
159 
160 			if (!chn)
161 				continue;
162 
163 			/* make sure receive not running now */
164 			napi_synchronize(&nvdev->chan_table[i].napi);
165 
166 			aread = hv_get_bytes_to_read(&chn->inbound);
167 			if (aread)
168 				break;
169 
170 			aread = hv_get_bytes_to_read(&chn->outbound);
171 			if (aread)
172 				break;
173 		}
174 
175 		if (aread == 0)
176 			return 0;
177 
178 		if (++retry > RETRY_MAX)
179 			return -ETIMEDOUT;
180 
181 		usleep_range(RETRY_US_LO, RETRY_US_HI);
182 	}
183 }
184 
185 static void netvsc_tx_disable(struct netvsc_device *nvscdev,
186 			      struct net_device *ndev)
187 {
188 	if (nvscdev) {
189 		nvscdev->tx_disable = true;
190 		virt_wmb(); /* ensure txq will not wake up after stop */
191 	}
192 
193 	netif_tx_disable(ndev);
194 }
195 
196 static int netvsc_close(struct net_device *net)
197 {
198 	struct net_device_context *net_device_ctx = netdev_priv(net);
199 	struct net_device *vf_netdev
200 		= rtnl_dereference(net_device_ctx->vf_netdev);
201 	struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
202 	int ret;
203 
204 	netvsc_tx_disable(nvdev, net);
205 
206 	/* No need to close rndis filter if it is removed already */
207 	if (!nvdev)
208 		return 0;
209 
210 	ret = rndis_filter_close(nvdev);
211 	if (ret != 0) {
212 		netdev_err(net, "unable to close device (ret %d).\n", ret);
213 		return ret;
214 	}
215 
216 	ret = netvsc_wait_until_empty(nvdev);
217 	if (ret)
218 		netdev_err(net, "Ring buffer not empty after closing rndis\n");
219 
220 	if (vf_netdev)
221 		dev_close(vf_netdev);
222 
223 	return ret;
224 }
225 
226 static inline void *init_ppi_data(struct rndis_message *msg,
227 				  u32 ppi_size, u32 pkt_type)
228 {
229 	struct rndis_packet *rndis_pkt = &msg->msg.pkt;
230 	struct rndis_per_packet_info *ppi;
231 
232 	rndis_pkt->data_offset += ppi_size;
233 	ppi = (void *)rndis_pkt + rndis_pkt->per_pkt_info_offset
234 		+ rndis_pkt->per_pkt_info_len;
235 
236 	ppi->size = ppi_size;
237 	ppi->type = pkt_type;
238 	ppi->internal = 0;
239 	ppi->ppi_offset = sizeof(struct rndis_per_packet_info);
240 
241 	rndis_pkt->per_pkt_info_len += ppi_size;
242 
243 	return ppi + 1;
244 }
245 
246 /* Azure hosts don't support non-TCP port numbers in hashing for fragmented
247  * packets. We can use ethtool to change UDP hash level when necessary.
248  */
249 static inline u32 netvsc_get_hash(
250 	struct sk_buff *skb,
251 	const struct net_device_context *ndc)
252 {
253 	struct flow_keys flow;
254 	u32 hash, pkt_proto = 0;
255 	static u32 hashrnd __read_mostly;
256 
257 	net_get_random_once(&hashrnd, sizeof(hashrnd));
258 
259 	if (!skb_flow_dissect_flow_keys(skb, &flow, 0))
260 		return 0;
261 
262 	switch (flow.basic.ip_proto) {
263 	case IPPROTO_TCP:
264 		if (flow.basic.n_proto == htons(ETH_P_IP))
265 			pkt_proto = HV_TCP4_L4HASH;
266 		else if (flow.basic.n_proto == htons(ETH_P_IPV6))
267 			pkt_proto = HV_TCP6_L4HASH;
268 
269 		break;
270 
271 	case IPPROTO_UDP:
272 		if (flow.basic.n_proto == htons(ETH_P_IP))
273 			pkt_proto = HV_UDP4_L4HASH;
274 		else if (flow.basic.n_proto == htons(ETH_P_IPV6))
275 			pkt_proto = HV_UDP6_L4HASH;
276 
277 		break;
278 	}
279 
280 	if (pkt_proto & ndc->l4_hash) {
281 		return skb_get_hash(skb);
282 	} else {
283 		if (flow.basic.n_proto == htons(ETH_P_IP))
284 			hash = jhash2((u32 *)&flow.addrs.v4addrs, 2, hashrnd);
285 		else if (flow.basic.n_proto == htons(ETH_P_IPV6))
286 			hash = jhash2((u32 *)&flow.addrs.v6addrs, 8, hashrnd);
287 		else
288 			hash = 0;
289 
290 		skb_set_hash(skb, hash, PKT_HASH_TYPE_L3);
291 	}
292 
293 	return hash;
294 }
295 
296 static inline int netvsc_get_tx_queue(struct net_device *ndev,
297 				      struct sk_buff *skb, int old_idx)
298 {
299 	const struct net_device_context *ndc = netdev_priv(ndev);
300 	struct sock *sk = skb->sk;
301 	int q_idx;
302 
303 	q_idx = ndc->tx_table[netvsc_get_hash(skb, ndc) &
304 			      (VRSS_SEND_TAB_SIZE - 1)];
305 
306 	/* If queue index changed record the new value */
307 	if (q_idx != old_idx &&
308 	    sk && sk_fullsock(sk) && rcu_access_pointer(sk->sk_dst_cache))
309 		sk_tx_queue_set(sk, q_idx);
310 
311 	return q_idx;
312 }
313 
314 /*
315  * Select queue for transmit.
316  *
317  * If a valid queue has already been assigned, then use that.
318  * Otherwise compute tx queue based on hash and the send table.
319  *
320  * This is basically similar to default (netdev_pick_tx) with the added step
321  * of using the host send_table when no other queue has been assigned.
322  *
323  * TODO support XPS - but get_xps_queue not exported
324  */
325 static u16 netvsc_pick_tx(struct net_device *ndev, struct sk_buff *skb)
326 {
327 	int q_idx = sk_tx_queue_get(skb->sk);
328 
329 	if (q_idx < 0 || skb->ooo_okay || q_idx >= ndev->real_num_tx_queues) {
330 		/* If forwarding a packet, we use the recorded queue when
331 		 * available for better cache locality.
332 		 */
333 		if (skb_rx_queue_recorded(skb))
334 			q_idx = skb_get_rx_queue(skb);
335 		else
336 			q_idx = netvsc_get_tx_queue(ndev, skb, q_idx);
337 	}
338 
339 	return q_idx;
340 }
341 
342 static u16 netvsc_select_queue(struct net_device *ndev, struct sk_buff *skb,
343 			       struct net_device *sb_dev)
344 {
345 	struct net_device_context *ndc = netdev_priv(ndev);
346 	struct net_device *vf_netdev;
347 	u16 txq;
348 
349 	rcu_read_lock();
350 	vf_netdev = rcu_dereference(ndc->vf_netdev);
351 	if (vf_netdev) {
352 		const struct net_device_ops *vf_ops = vf_netdev->netdev_ops;
353 
354 		if (vf_ops->ndo_select_queue)
355 			txq = vf_ops->ndo_select_queue(vf_netdev, skb, sb_dev);
356 		else
357 			txq = netdev_pick_tx(vf_netdev, skb, NULL);
358 
359 		/* Record the queue selected by VF so that it can be
360 		 * used for common case where VF has more queues than
361 		 * the synthetic device.
362 		 */
363 		qdisc_skb_cb(skb)->slave_dev_queue_mapping = txq;
364 	} else {
365 		txq = netvsc_pick_tx(ndev, skb);
366 	}
367 	rcu_read_unlock();
368 
369 	while (unlikely(txq >= ndev->real_num_tx_queues))
370 		txq -= ndev->real_num_tx_queues;
371 
372 	return txq;
373 }
374 
375 static u32 fill_pg_buf(struct page *page, u32 offset, u32 len,
376 		       struct hv_page_buffer *pb)
377 {
378 	int j = 0;
379 
380 	/* Deal with compound pages by ignoring unused part
381 	 * of the page.
382 	 */
383 	page += (offset >> PAGE_SHIFT);
384 	offset &= ~PAGE_MASK;
385 
386 	while (len > 0) {
387 		unsigned long bytes;
388 
389 		bytes = PAGE_SIZE - offset;
390 		if (bytes > len)
391 			bytes = len;
392 		pb[j].pfn = page_to_pfn(page);
393 		pb[j].offset = offset;
394 		pb[j].len = bytes;
395 
396 		offset += bytes;
397 		len -= bytes;
398 
399 		if (offset == PAGE_SIZE && len) {
400 			page++;
401 			offset = 0;
402 			j++;
403 		}
404 	}
405 
406 	return j + 1;
407 }
408 
409 static u32 init_page_array(void *hdr, u32 len, struct sk_buff *skb,
410 			   struct hv_netvsc_packet *packet,
411 			   struct hv_page_buffer *pb)
412 {
413 	u32 slots_used = 0;
414 	char *data = skb->data;
415 	int frags = skb_shinfo(skb)->nr_frags;
416 	int i;
417 
418 	/* The packet is laid out thus:
419 	 * 1. hdr: RNDIS header and PPI
420 	 * 2. skb linear data
421 	 * 3. skb fragment data
422 	 */
423 	slots_used += fill_pg_buf(virt_to_page(hdr),
424 				  offset_in_page(hdr),
425 				  len, &pb[slots_used]);
426 
427 	packet->rmsg_size = len;
428 	packet->rmsg_pgcnt = slots_used;
429 
430 	slots_used += fill_pg_buf(virt_to_page(data),
431 				offset_in_page(data),
432 				skb_headlen(skb), &pb[slots_used]);
433 
434 	for (i = 0; i < frags; i++) {
435 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
436 
437 		slots_used += fill_pg_buf(skb_frag_page(frag),
438 					frag->page_offset,
439 					skb_frag_size(frag), &pb[slots_used]);
440 	}
441 	return slots_used;
442 }
443 
444 static int count_skb_frag_slots(struct sk_buff *skb)
445 {
446 	int i, frags = skb_shinfo(skb)->nr_frags;
447 	int pages = 0;
448 
449 	for (i = 0; i < frags; i++) {
450 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
451 		unsigned long size = skb_frag_size(frag);
452 		unsigned long offset = frag->page_offset;
453 
454 		/* Skip unused frames from start of page */
455 		offset &= ~PAGE_MASK;
456 		pages += PFN_UP(offset + size);
457 	}
458 	return pages;
459 }
460 
461 static int netvsc_get_slots(struct sk_buff *skb)
462 {
463 	char *data = skb->data;
464 	unsigned int offset = offset_in_page(data);
465 	unsigned int len = skb_headlen(skb);
466 	int slots;
467 	int frag_slots;
468 
469 	slots = DIV_ROUND_UP(offset + len, PAGE_SIZE);
470 	frag_slots = count_skb_frag_slots(skb);
471 	return slots + frag_slots;
472 }
473 
474 static u32 net_checksum_info(struct sk_buff *skb)
475 {
476 	if (skb->protocol == htons(ETH_P_IP)) {
477 		struct iphdr *ip = ip_hdr(skb);
478 
479 		if (ip->protocol == IPPROTO_TCP)
480 			return TRANSPORT_INFO_IPV4_TCP;
481 		else if (ip->protocol == IPPROTO_UDP)
482 			return TRANSPORT_INFO_IPV4_UDP;
483 	} else {
484 		struct ipv6hdr *ip6 = ipv6_hdr(skb);
485 
486 		if (ip6->nexthdr == IPPROTO_TCP)
487 			return TRANSPORT_INFO_IPV6_TCP;
488 		else if (ip6->nexthdr == IPPROTO_UDP)
489 			return TRANSPORT_INFO_IPV6_UDP;
490 	}
491 
492 	return TRANSPORT_INFO_NOT_IP;
493 }
494 
495 /* Send skb on the slave VF device. */
496 static int netvsc_vf_xmit(struct net_device *net, struct net_device *vf_netdev,
497 			  struct sk_buff *skb)
498 {
499 	struct net_device_context *ndev_ctx = netdev_priv(net);
500 	unsigned int len = skb->len;
501 	int rc;
502 
503 	skb->dev = vf_netdev;
504 	skb->queue_mapping = qdisc_skb_cb(skb)->slave_dev_queue_mapping;
505 
506 	rc = dev_queue_xmit(skb);
507 	if (likely(rc == NET_XMIT_SUCCESS || rc == NET_XMIT_CN)) {
508 		struct netvsc_vf_pcpu_stats *pcpu_stats
509 			= this_cpu_ptr(ndev_ctx->vf_stats);
510 
511 		u64_stats_update_begin(&pcpu_stats->syncp);
512 		pcpu_stats->tx_packets++;
513 		pcpu_stats->tx_bytes += len;
514 		u64_stats_update_end(&pcpu_stats->syncp);
515 	} else {
516 		this_cpu_inc(ndev_ctx->vf_stats->tx_dropped);
517 	}
518 
519 	return rc;
520 }
521 
522 static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
523 {
524 	struct net_device_context *net_device_ctx = netdev_priv(net);
525 	struct hv_netvsc_packet *packet = NULL;
526 	int ret;
527 	unsigned int num_data_pgs;
528 	struct rndis_message *rndis_msg;
529 	struct net_device *vf_netdev;
530 	u32 rndis_msg_size;
531 	u32 hash;
532 	struct hv_page_buffer pb[MAX_PAGE_BUFFER_COUNT];
533 
534 	/* if VF is present and up then redirect packets
535 	 * already called with rcu_read_lock_bh
536 	 */
537 	vf_netdev = rcu_dereference_bh(net_device_ctx->vf_netdev);
538 	if (vf_netdev && netif_running(vf_netdev) &&
539 	    !netpoll_tx_running(net))
540 		return netvsc_vf_xmit(net, vf_netdev, skb);
541 
542 	/* We will atmost need two pages to describe the rndis
543 	 * header. We can only transmit MAX_PAGE_BUFFER_COUNT number
544 	 * of pages in a single packet. If skb is scattered around
545 	 * more pages we try linearizing it.
546 	 */
547 
548 	num_data_pgs = netvsc_get_slots(skb) + 2;
549 
550 	if (unlikely(num_data_pgs > MAX_PAGE_BUFFER_COUNT)) {
551 		++net_device_ctx->eth_stats.tx_scattered;
552 
553 		if (skb_linearize(skb))
554 			goto no_memory;
555 
556 		num_data_pgs = netvsc_get_slots(skb) + 2;
557 		if (num_data_pgs > MAX_PAGE_BUFFER_COUNT) {
558 			++net_device_ctx->eth_stats.tx_too_big;
559 			goto drop;
560 		}
561 	}
562 
563 	/*
564 	 * Place the rndis header in the skb head room and
565 	 * the skb->cb will be used for hv_netvsc_packet
566 	 * structure.
567 	 */
568 	ret = skb_cow_head(skb, RNDIS_AND_PPI_SIZE);
569 	if (ret)
570 		goto no_memory;
571 
572 	/* Use the skb control buffer for building up the packet */
573 	BUILD_BUG_ON(sizeof(struct hv_netvsc_packet) >
574 			FIELD_SIZEOF(struct sk_buff, cb));
575 	packet = (struct hv_netvsc_packet *)skb->cb;
576 
577 	packet->q_idx = skb_get_queue_mapping(skb);
578 
579 	packet->total_data_buflen = skb->len;
580 	packet->total_bytes = skb->len;
581 	packet->total_packets = 1;
582 
583 	rndis_msg = (struct rndis_message *)skb->head;
584 
585 	/* Add the rndis header */
586 	rndis_msg->ndis_msg_type = RNDIS_MSG_PACKET;
587 	rndis_msg->msg_len = packet->total_data_buflen;
588 
589 	rndis_msg->msg.pkt = (struct rndis_packet) {
590 		.data_offset = sizeof(struct rndis_packet),
591 		.data_len = packet->total_data_buflen,
592 		.per_pkt_info_offset = sizeof(struct rndis_packet),
593 	};
594 
595 	rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
596 
597 	hash = skb_get_hash_raw(skb);
598 	if (hash != 0 && net->real_num_tx_queues > 1) {
599 		u32 *hash_info;
600 
601 		rndis_msg_size += NDIS_HASH_PPI_SIZE;
602 		hash_info = init_ppi_data(rndis_msg, NDIS_HASH_PPI_SIZE,
603 					  NBL_HASH_VALUE);
604 		*hash_info = hash;
605 	}
606 
607 	if (skb_vlan_tag_present(skb)) {
608 		struct ndis_pkt_8021q_info *vlan;
609 
610 		rndis_msg_size += NDIS_VLAN_PPI_SIZE;
611 		vlan = init_ppi_data(rndis_msg, NDIS_VLAN_PPI_SIZE,
612 				     IEEE_8021Q_INFO);
613 
614 		vlan->value = 0;
615 		vlan->vlanid = skb_vlan_tag_get_id(skb);
616 		vlan->cfi = skb_vlan_tag_get_cfi(skb);
617 		vlan->pri = skb_vlan_tag_get_prio(skb);
618 	}
619 
620 	if (skb_is_gso(skb)) {
621 		struct ndis_tcp_lso_info *lso_info;
622 
623 		rndis_msg_size += NDIS_LSO_PPI_SIZE;
624 		lso_info = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
625 					 TCP_LARGESEND_PKTINFO);
626 
627 		lso_info->value = 0;
628 		lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
629 		if (skb->protocol == htons(ETH_P_IP)) {
630 			lso_info->lso_v2_transmit.ip_version =
631 				NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
632 			ip_hdr(skb)->tot_len = 0;
633 			ip_hdr(skb)->check = 0;
634 			tcp_hdr(skb)->check =
635 				~csum_tcpudp_magic(ip_hdr(skb)->saddr,
636 						   ip_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
637 		} else {
638 			lso_info->lso_v2_transmit.ip_version =
639 				NDIS_TCP_LARGE_SEND_OFFLOAD_IPV6;
640 			ipv6_hdr(skb)->payload_len = 0;
641 			tcp_hdr(skb)->check =
642 				~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
643 						 &ipv6_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
644 		}
645 		lso_info->lso_v2_transmit.tcp_header_offset = skb_transport_offset(skb);
646 		lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
647 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
648 		if (net_checksum_info(skb) & net_device_ctx->tx_checksum_mask) {
649 			struct ndis_tcp_ip_checksum_info *csum_info;
650 
651 			rndis_msg_size += NDIS_CSUM_PPI_SIZE;
652 			csum_info = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
653 						  TCPIP_CHKSUM_PKTINFO);
654 
655 			csum_info->value = 0;
656 			csum_info->transmit.tcp_header_offset = skb_transport_offset(skb);
657 
658 			if (skb->protocol == htons(ETH_P_IP)) {
659 				csum_info->transmit.is_ipv4 = 1;
660 
661 				if (ip_hdr(skb)->protocol == IPPROTO_TCP)
662 					csum_info->transmit.tcp_checksum = 1;
663 				else
664 					csum_info->transmit.udp_checksum = 1;
665 			} else {
666 				csum_info->transmit.is_ipv6 = 1;
667 
668 				if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
669 					csum_info->transmit.tcp_checksum = 1;
670 				else
671 					csum_info->transmit.udp_checksum = 1;
672 			}
673 		} else {
674 			/* Can't do offload of this type of checksum */
675 			if (skb_checksum_help(skb))
676 				goto drop;
677 		}
678 	}
679 
680 	/* Start filling in the page buffers with the rndis hdr */
681 	rndis_msg->msg_len += rndis_msg_size;
682 	packet->total_data_buflen = rndis_msg->msg_len;
683 	packet->page_buf_cnt = init_page_array(rndis_msg, rndis_msg_size,
684 					       skb, packet, pb);
685 
686 	/* timestamp packet in software */
687 	skb_tx_timestamp(skb);
688 
689 	ret = netvsc_send(net, packet, rndis_msg, pb, skb);
690 	if (likely(ret == 0))
691 		return NETDEV_TX_OK;
692 
693 	if (ret == -EAGAIN) {
694 		++net_device_ctx->eth_stats.tx_busy;
695 		return NETDEV_TX_BUSY;
696 	}
697 
698 	if (ret == -ENOSPC)
699 		++net_device_ctx->eth_stats.tx_no_space;
700 
701 drop:
702 	dev_kfree_skb_any(skb);
703 	net->stats.tx_dropped++;
704 
705 	return NETDEV_TX_OK;
706 
707 no_memory:
708 	++net_device_ctx->eth_stats.tx_no_memory;
709 	goto drop;
710 }
711 
712 /*
713  * netvsc_linkstatus_callback - Link up/down notification
714  */
715 void netvsc_linkstatus_callback(struct net_device *net,
716 				struct rndis_message *resp)
717 {
718 	struct rndis_indicate_status *indicate = &resp->msg.indicate_status;
719 	struct net_device_context *ndev_ctx = netdev_priv(net);
720 	struct netvsc_reconfig *event;
721 	unsigned long flags;
722 
723 	/* Update the physical link speed when changing to another vSwitch */
724 	if (indicate->status == RNDIS_STATUS_LINK_SPEED_CHANGE) {
725 		u32 speed;
726 
727 		speed = *(u32 *)((void *)indicate
728 				 + indicate->status_buf_offset) / 10000;
729 		ndev_ctx->speed = speed;
730 		return;
731 	}
732 
733 	/* Handle these link change statuses below */
734 	if (indicate->status != RNDIS_STATUS_NETWORK_CHANGE &&
735 	    indicate->status != RNDIS_STATUS_MEDIA_CONNECT &&
736 	    indicate->status != RNDIS_STATUS_MEDIA_DISCONNECT)
737 		return;
738 
739 	if (net->reg_state != NETREG_REGISTERED)
740 		return;
741 
742 	event = kzalloc(sizeof(*event), GFP_ATOMIC);
743 	if (!event)
744 		return;
745 	event->event = indicate->status;
746 
747 	spin_lock_irqsave(&ndev_ctx->lock, flags);
748 	list_add_tail(&event->list, &ndev_ctx->reconfig_events);
749 	spin_unlock_irqrestore(&ndev_ctx->lock, flags);
750 
751 	schedule_delayed_work(&ndev_ctx->dwork, 0);
752 }
753 
754 static void netvsc_comp_ipcsum(struct sk_buff *skb)
755 {
756 	struct iphdr *iph = (struct iphdr *)skb->data;
757 
758 	iph->check = 0;
759 	iph->check = ip_fast_csum(iph, iph->ihl);
760 }
761 
762 static struct sk_buff *netvsc_alloc_recv_skb(struct net_device *net,
763 					     struct netvsc_channel *nvchan)
764 {
765 	struct napi_struct *napi = &nvchan->napi;
766 	const struct ndis_pkt_8021q_info *vlan = nvchan->rsc.vlan;
767 	const struct ndis_tcp_ip_checksum_info *csum_info =
768 						nvchan->rsc.csum_info;
769 	struct sk_buff *skb;
770 	int i;
771 
772 	skb = napi_alloc_skb(napi, nvchan->rsc.pktlen);
773 	if (!skb)
774 		return skb;
775 
776 	/*
777 	 * Copy to skb. This copy is needed here since the memory pointed by
778 	 * hv_netvsc_packet cannot be deallocated
779 	 */
780 	for (i = 0; i < nvchan->rsc.cnt; i++)
781 		skb_put_data(skb, nvchan->rsc.data[i], nvchan->rsc.len[i]);
782 
783 	skb->protocol = eth_type_trans(skb, net);
784 
785 	/* skb is already created with CHECKSUM_NONE */
786 	skb_checksum_none_assert(skb);
787 
788 	/* Incoming packets may have IP header checksum verified by the host.
789 	 * They may not have IP header checksum computed after coalescing.
790 	 * We compute it here if the flags are set, because on Linux, the IP
791 	 * checksum is always checked.
792 	 */
793 	if (csum_info && csum_info->receive.ip_checksum_value_invalid &&
794 	    csum_info->receive.ip_checksum_succeeded &&
795 	    skb->protocol == htons(ETH_P_IP))
796 		netvsc_comp_ipcsum(skb);
797 
798 	/* Do L4 checksum offload if enabled and present.
799 	 */
800 	if (csum_info && (net->features & NETIF_F_RXCSUM)) {
801 		if (csum_info->receive.tcp_checksum_succeeded ||
802 		    csum_info->receive.udp_checksum_succeeded)
803 			skb->ip_summed = CHECKSUM_UNNECESSARY;
804 	}
805 
806 	if (vlan) {
807 		u16 vlan_tci = vlan->vlanid | (vlan->pri << VLAN_PRIO_SHIFT) |
808 			(vlan->cfi ? VLAN_CFI_MASK : 0);
809 
810 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
811 				       vlan_tci);
812 	}
813 
814 	return skb;
815 }
816 
817 /*
818  * netvsc_recv_callback -  Callback when we receive a packet from the
819  * "wire" on the specified device.
820  */
821 int netvsc_recv_callback(struct net_device *net,
822 			 struct netvsc_device *net_device,
823 			 struct netvsc_channel *nvchan)
824 {
825 	struct net_device_context *net_device_ctx = netdev_priv(net);
826 	struct vmbus_channel *channel = nvchan->channel;
827 	u16 q_idx = channel->offermsg.offer.sub_channel_index;
828 	struct sk_buff *skb;
829 	struct netvsc_stats *rx_stats;
830 
831 	if (net->reg_state != NETREG_REGISTERED)
832 		return NVSP_STAT_FAIL;
833 
834 	/* Allocate a skb - TODO direct I/O to pages? */
835 	skb = netvsc_alloc_recv_skb(net, nvchan);
836 
837 	if (unlikely(!skb)) {
838 		++net_device_ctx->eth_stats.rx_no_memory;
839 		rcu_read_unlock();
840 		return NVSP_STAT_FAIL;
841 	}
842 
843 	skb_record_rx_queue(skb, q_idx);
844 
845 	/*
846 	 * Even if injecting the packet, record the statistics
847 	 * on the synthetic device because modifying the VF device
848 	 * statistics will not work correctly.
849 	 */
850 	rx_stats = &nvchan->rx_stats;
851 	u64_stats_update_begin(&rx_stats->syncp);
852 	rx_stats->packets++;
853 	rx_stats->bytes += nvchan->rsc.pktlen;
854 
855 	if (skb->pkt_type == PACKET_BROADCAST)
856 		++rx_stats->broadcast;
857 	else if (skb->pkt_type == PACKET_MULTICAST)
858 		++rx_stats->multicast;
859 	u64_stats_update_end(&rx_stats->syncp);
860 
861 	napi_gro_receive(&nvchan->napi, skb);
862 	return NVSP_STAT_SUCCESS;
863 }
864 
865 static void netvsc_get_drvinfo(struct net_device *net,
866 			       struct ethtool_drvinfo *info)
867 {
868 	strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
869 	strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
870 }
871 
872 static void netvsc_get_channels(struct net_device *net,
873 				struct ethtool_channels *channel)
874 {
875 	struct net_device_context *net_device_ctx = netdev_priv(net);
876 	struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
877 
878 	if (nvdev) {
879 		channel->max_combined	= nvdev->max_chn;
880 		channel->combined_count = nvdev->num_chn;
881 	}
882 }
883 
884 /* Alloc struct netvsc_device_info, and initialize it from either existing
885  * struct netvsc_device, or from default values.
886  */
887 static struct netvsc_device_info *netvsc_devinfo_get
888 			(struct netvsc_device *nvdev)
889 {
890 	struct netvsc_device_info *dev_info;
891 
892 	dev_info = kzalloc(sizeof(*dev_info), GFP_ATOMIC);
893 
894 	if (!dev_info)
895 		return NULL;
896 
897 	if (nvdev) {
898 		dev_info->num_chn = nvdev->num_chn;
899 		dev_info->send_sections = nvdev->send_section_cnt;
900 		dev_info->send_section_size = nvdev->send_section_size;
901 		dev_info->recv_sections = nvdev->recv_section_cnt;
902 		dev_info->recv_section_size = nvdev->recv_section_size;
903 
904 		memcpy(dev_info->rss_key, nvdev->extension->rss_key,
905 		       NETVSC_HASH_KEYLEN);
906 	} else {
907 		dev_info->num_chn = VRSS_CHANNEL_DEFAULT;
908 		dev_info->send_sections = NETVSC_DEFAULT_TX;
909 		dev_info->send_section_size = NETVSC_SEND_SECTION_SIZE;
910 		dev_info->recv_sections = NETVSC_DEFAULT_RX;
911 		dev_info->recv_section_size = NETVSC_RECV_SECTION_SIZE;
912 	}
913 
914 	return dev_info;
915 }
916 
917 static int netvsc_detach(struct net_device *ndev,
918 			 struct netvsc_device *nvdev)
919 {
920 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
921 	struct hv_device *hdev = ndev_ctx->device_ctx;
922 	int ret;
923 
924 	/* Don't try continuing to try and setup sub channels */
925 	if (cancel_work_sync(&nvdev->subchan_work))
926 		nvdev->num_chn = 1;
927 
928 	/* If device was up (receiving) then shutdown */
929 	if (netif_running(ndev)) {
930 		netvsc_tx_disable(nvdev, ndev);
931 
932 		ret = rndis_filter_close(nvdev);
933 		if (ret) {
934 			netdev_err(ndev,
935 				   "unable to close device (ret %d).\n", ret);
936 			return ret;
937 		}
938 
939 		ret = netvsc_wait_until_empty(nvdev);
940 		if (ret) {
941 			netdev_err(ndev,
942 				   "Ring buffer not empty after closing rndis\n");
943 			return ret;
944 		}
945 	}
946 
947 	netif_device_detach(ndev);
948 
949 	rndis_filter_device_remove(hdev, nvdev);
950 
951 	return 0;
952 }
953 
954 static int netvsc_attach(struct net_device *ndev,
955 			 struct netvsc_device_info *dev_info)
956 {
957 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
958 	struct hv_device *hdev = ndev_ctx->device_ctx;
959 	struct netvsc_device *nvdev;
960 	struct rndis_device *rdev;
961 	int ret;
962 
963 	nvdev = rndis_filter_device_add(hdev, dev_info);
964 	if (IS_ERR(nvdev))
965 		return PTR_ERR(nvdev);
966 
967 	if (nvdev->num_chn > 1) {
968 		ret = rndis_set_subchannel(ndev, nvdev, dev_info);
969 
970 		/* if unavailable, just proceed with one queue */
971 		if (ret) {
972 			nvdev->max_chn = 1;
973 			nvdev->num_chn = 1;
974 		}
975 	}
976 
977 	/* In any case device is now ready */
978 	netif_device_attach(ndev);
979 
980 	/* Note: enable and attach happen when sub-channels setup */
981 	netif_carrier_off(ndev);
982 
983 	if (netif_running(ndev)) {
984 		ret = rndis_filter_open(nvdev);
985 		if (ret)
986 			return ret;
987 
988 		rdev = nvdev->extension;
989 		if (!rdev->link_state)
990 			netif_carrier_on(ndev);
991 	}
992 
993 	return 0;
994 }
995 
996 static int netvsc_set_channels(struct net_device *net,
997 			       struct ethtool_channels *channels)
998 {
999 	struct net_device_context *net_device_ctx = netdev_priv(net);
1000 	struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
1001 	unsigned int orig, count = channels->combined_count;
1002 	struct netvsc_device_info *device_info;
1003 	int ret;
1004 
1005 	/* We do not support separate count for rx, tx, or other */
1006 	if (count == 0 ||
1007 	    channels->rx_count || channels->tx_count || channels->other_count)
1008 		return -EINVAL;
1009 
1010 	if (!nvdev || nvdev->destroy)
1011 		return -ENODEV;
1012 
1013 	if (nvdev->nvsp_version < NVSP_PROTOCOL_VERSION_5)
1014 		return -EINVAL;
1015 
1016 	if (count > nvdev->max_chn)
1017 		return -EINVAL;
1018 
1019 	orig = nvdev->num_chn;
1020 
1021 	device_info = netvsc_devinfo_get(nvdev);
1022 
1023 	if (!device_info)
1024 		return -ENOMEM;
1025 
1026 	device_info->num_chn = count;
1027 
1028 	ret = netvsc_detach(net, nvdev);
1029 	if (ret)
1030 		goto out;
1031 
1032 	ret = netvsc_attach(net, device_info);
1033 	if (ret) {
1034 		device_info->num_chn = orig;
1035 		if (netvsc_attach(net, device_info))
1036 			netdev_err(net, "restoring channel setting failed\n");
1037 	}
1038 
1039 out:
1040 	kfree(device_info);
1041 	return ret;
1042 }
1043 
1044 static bool
1045 netvsc_validate_ethtool_ss_cmd(const struct ethtool_link_ksettings *cmd)
1046 {
1047 	struct ethtool_link_ksettings diff1 = *cmd;
1048 	struct ethtool_link_ksettings diff2 = {};
1049 
1050 	diff1.base.speed = 0;
1051 	diff1.base.duplex = 0;
1052 	/* advertising and cmd are usually set */
1053 	ethtool_link_ksettings_zero_link_mode(&diff1, advertising);
1054 	diff1.base.cmd = 0;
1055 	/* We set port to PORT_OTHER */
1056 	diff2.base.port = PORT_OTHER;
1057 
1058 	return !memcmp(&diff1, &diff2, sizeof(diff1));
1059 }
1060 
1061 static void netvsc_init_settings(struct net_device *dev)
1062 {
1063 	struct net_device_context *ndc = netdev_priv(dev);
1064 
1065 	ndc->l4_hash = HV_DEFAULT_L4HASH;
1066 
1067 	ndc->speed = SPEED_UNKNOWN;
1068 	ndc->duplex = DUPLEX_FULL;
1069 
1070 	dev->features = NETIF_F_LRO;
1071 }
1072 
1073 static int netvsc_get_link_ksettings(struct net_device *dev,
1074 				     struct ethtool_link_ksettings *cmd)
1075 {
1076 	struct net_device_context *ndc = netdev_priv(dev);
1077 
1078 	cmd->base.speed = ndc->speed;
1079 	cmd->base.duplex = ndc->duplex;
1080 	cmd->base.port = PORT_OTHER;
1081 
1082 	return 0;
1083 }
1084 
1085 static int netvsc_set_link_ksettings(struct net_device *dev,
1086 				     const struct ethtool_link_ksettings *cmd)
1087 {
1088 	struct net_device_context *ndc = netdev_priv(dev);
1089 	u32 speed;
1090 
1091 	speed = cmd->base.speed;
1092 	if (!ethtool_validate_speed(speed) ||
1093 	    !ethtool_validate_duplex(cmd->base.duplex) ||
1094 	    !netvsc_validate_ethtool_ss_cmd(cmd))
1095 		return -EINVAL;
1096 
1097 	ndc->speed = speed;
1098 	ndc->duplex = cmd->base.duplex;
1099 
1100 	return 0;
1101 }
1102 
1103 static int netvsc_change_mtu(struct net_device *ndev, int mtu)
1104 {
1105 	struct net_device_context *ndevctx = netdev_priv(ndev);
1106 	struct net_device *vf_netdev = rtnl_dereference(ndevctx->vf_netdev);
1107 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1108 	int orig_mtu = ndev->mtu;
1109 	struct netvsc_device_info *device_info;
1110 	int ret = 0;
1111 
1112 	if (!nvdev || nvdev->destroy)
1113 		return -ENODEV;
1114 
1115 	device_info = netvsc_devinfo_get(nvdev);
1116 
1117 	if (!device_info)
1118 		return -ENOMEM;
1119 
1120 	/* Change MTU of underlying VF netdev first. */
1121 	if (vf_netdev) {
1122 		ret = dev_set_mtu(vf_netdev, mtu);
1123 		if (ret)
1124 			goto out;
1125 	}
1126 
1127 	ret = netvsc_detach(ndev, nvdev);
1128 	if (ret)
1129 		goto rollback_vf;
1130 
1131 	ndev->mtu = mtu;
1132 
1133 	ret = netvsc_attach(ndev, device_info);
1134 	if (!ret)
1135 		goto out;
1136 
1137 	/* Attempt rollback to original MTU */
1138 	ndev->mtu = orig_mtu;
1139 
1140 	if (netvsc_attach(ndev, device_info))
1141 		netdev_err(ndev, "restoring mtu failed\n");
1142 rollback_vf:
1143 	if (vf_netdev)
1144 		dev_set_mtu(vf_netdev, orig_mtu);
1145 
1146 out:
1147 	kfree(device_info);
1148 	return ret;
1149 }
1150 
1151 static void netvsc_get_vf_stats(struct net_device *net,
1152 				struct netvsc_vf_pcpu_stats *tot)
1153 {
1154 	struct net_device_context *ndev_ctx = netdev_priv(net);
1155 	int i;
1156 
1157 	memset(tot, 0, sizeof(*tot));
1158 
1159 	for_each_possible_cpu(i) {
1160 		const struct netvsc_vf_pcpu_stats *stats
1161 			= per_cpu_ptr(ndev_ctx->vf_stats, i);
1162 		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1163 		unsigned int start;
1164 
1165 		do {
1166 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1167 			rx_packets = stats->rx_packets;
1168 			tx_packets = stats->tx_packets;
1169 			rx_bytes = stats->rx_bytes;
1170 			tx_bytes = stats->tx_bytes;
1171 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1172 
1173 		tot->rx_packets += rx_packets;
1174 		tot->tx_packets += tx_packets;
1175 		tot->rx_bytes   += rx_bytes;
1176 		tot->tx_bytes   += tx_bytes;
1177 		tot->tx_dropped += stats->tx_dropped;
1178 	}
1179 }
1180 
1181 static void netvsc_get_pcpu_stats(struct net_device *net,
1182 				  struct netvsc_ethtool_pcpu_stats *pcpu_tot)
1183 {
1184 	struct net_device_context *ndev_ctx = netdev_priv(net);
1185 	struct netvsc_device *nvdev = rcu_dereference_rtnl(ndev_ctx->nvdev);
1186 	int i;
1187 
1188 	/* fetch percpu stats of vf */
1189 	for_each_possible_cpu(i) {
1190 		const struct netvsc_vf_pcpu_stats *stats =
1191 			per_cpu_ptr(ndev_ctx->vf_stats, i);
1192 		struct netvsc_ethtool_pcpu_stats *this_tot = &pcpu_tot[i];
1193 		unsigned int start;
1194 
1195 		do {
1196 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1197 			this_tot->vf_rx_packets = stats->rx_packets;
1198 			this_tot->vf_tx_packets = stats->tx_packets;
1199 			this_tot->vf_rx_bytes = stats->rx_bytes;
1200 			this_tot->vf_tx_bytes = stats->tx_bytes;
1201 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1202 		this_tot->rx_packets = this_tot->vf_rx_packets;
1203 		this_tot->tx_packets = this_tot->vf_tx_packets;
1204 		this_tot->rx_bytes   = this_tot->vf_rx_bytes;
1205 		this_tot->tx_bytes   = this_tot->vf_tx_bytes;
1206 	}
1207 
1208 	/* fetch percpu stats of netvsc */
1209 	for (i = 0; i < nvdev->num_chn; i++) {
1210 		const struct netvsc_channel *nvchan = &nvdev->chan_table[i];
1211 		const struct netvsc_stats *stats;
1212 		struct netvsc_ethtool_pcpu_stats *this_tot =
1213 			&pcpu_tot[nvchan->channel->target_cpu];
1214 		u64 packets, bytes;
1215 		unsigned int start;
1216 
1217 		stats = &nvchan->tx_stats;
1218 		do {
1219 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1220 			packets = stats->packets;
1221 			bytes = stats->bytes;
1222 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1223 
1224 		this_tot->tx_bytes	+= bytes;
1225 		this_tot->tx_packets	+= packets;
1226 
1227 		stats = &nvchan->rx_stats;
1228 		do {
1229 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1230 			packets = stats->packets;
1231 			bytes = stats->bytes;
1232 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1233 
1234 		this_tot->rx_bytes	+= bytes;
1235 		this_tot->rx_packets	+= packets;
1236 	}
1237 }
1238 
1239 static void netvsc_get_stats64(struct net_device *net,
1240 			       struct rtnl_link_stats64 *t)
1241 {
1242 	struct net_device_context *ndev_ctx = netdev_priv(net);
1243 	struct netvsc_device *nvdev = rcu_dereference_rtnl(ndev_ctx->nvdev);
1244 	struct netvsc_vf_pcpu_stats vf_tot;
1245 	int i;
1246 
1247 	if (!nvdev)
1248 		return;
1249 
1250 	netdev_stats_to_stats64(t, &net->stats);
1251 
1252 	netvsc_get_vf_stats(net, &vf_tot);
1253 	t->rx_packets += vf_tot.rx_packets;
1254 	t->tx_packets += vf_tot.tx_packets;
1255 	t->rx_bytes   += vf_tot.rx_bytes;
1256 	t->tx_bytes   += vf_tot.tx_bytes;
1257 	t->tx_dropped += vf_tot.tx_dropped;
1258 
1259 	for (i = 0; i < nvdev->num_chn; i++) {
1260 		const struct netvsc_channel *nvchan = &nvdev->chan_table[i];
1261 		const struct netvsc_stats *stats;
1262 		u64 packets, bytes, multicast;
1263 		unsigned int start;
1264 
1265 		stats = &nvchan->tx_stats;
1266 		do {
1267 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1268 			packets = stats->packets;
1269 			bytes = stats->bytes;
1270 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1271 
1272 		t->tx_bytes	+= bytes;
1273 		t->tx_packets	+= packets;
1274 
1275 		stats = &nvchan->rx_stats;
1276 		do {
1277 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1278 			packets = stats->packets;
1279 			bytes = stats->bytes;
1280 			multicast = stats->multicast + stats->broadcast;
1281 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1282 
1283 		t->rx_bytes	+= bytes;
1284 		t->rx_packets	+= packets;
1285 		t->multicast	+= multicast;
1286 	}
1287 }
1288 
1289 static int netvsc_set_mac_addr(struct net_device *ndev, void *p)
1290 {
1291 	struct net_device_context *ndc = netdev_priv(ndev);
1292 	struct net_device *vf_netdev = rtnl_dereference(ndc->vf_netdev);
1293 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1294 	struct sockaddr *addr = p;
1295 	int err;
1296 
1297 	err = eth_prepare_mac_addr_change(ndev, p);
1298 	if (err)
1299 		return err;
1300 
1301 	if (!nvdev)
1302 		return -ENODEV;
1303 
1304 	if (vf_netdev) {
1305 		err = dev_set_mac_address(vf_netdev, addr, NULL);
1306 		if (err)
1307 			return err;
1308 	}
1309 
1310 	err = rndis_filter_set_device_mac(nvdev, addr->sa_data);
1311 	if (!err) {
1312 		eth_commit_mac_addr_change(ndev, p);
1313 	} else if (vf_netdev) {
1314 		/* rollback change on VF */
1315 		memcpy(addr->sa_data, ndev->dev_addr, ETH_ALEN);
1316 		dev_set_mac_address(vf_netdev, addr, NULL);
1317 	}
1318 
1319 	return err;
1320 }
1321 
1322 static const struct {
1323 	char name[ETH_GSTRING_LEN];
1324 	u16 offset;
1325 } netvsc_stats[] = {
1326 	{ "tx_scattered", offsetof(struct netvsc_ethtool_stats, tx_scattered) },
1327 	{ "tx_no_memory", offsetof(struct netvsc_ethtool_stats, tx_no_memory) },
1328 	{ "tx_no_space",  offsetof(struct netvsc_ethtool_stats, tx_no_space) },
1329 	{ "tx_too_big",	  offsetof(struct netvsc_ethtool_stats, tx_too_big) },
1330 	{ "tx_busy",	  offsetof(struct netvsc_ethtool_stats, tx_busy) },
1331 	{ "tx_send_full", offsetof(struct netvsc_ethtool_stats, tx_send_full) },
1332 	{ "rx_comp_busy", offsetof(struct netvsc_ethtool_stats, rx_comp_busy) },
1333 	{ "rx_no_memory", offsetof(struct netvsc_ethtool_stats, rx_no_memory) },
1334 	{ "stop_queue", offsetof(struct netvsc_ethtool_stats, stop_queue) },
1335 	{ "wake_queue", offsetof(struct netvsc_ethtool_stats, wake_queue) },
1336 }, pcpu_stats[] = {
1337 	{ "cpu%u_rx_packets",
1338 		offsetof(struct netvsc_ethtool_pcpu_stats, rx_packets) },
1339 	{ "cpu%u_rx_bytes",
1340 		offsetof(struct netvsc_ethtool_pcpu_stats, rx_bytes) },
1341 	{ "cpu%u_tx_packets",
1342 		offsetof(struct netvsc_ethtool_pcpu_stats, tx_packets) },
1343 	{ "cpu%u_tx_bytes",
1344 		offsetof(struct netvsc_ethtool_pcpu_stats, tx_bytes) },
1345 	{ "cpu%u_vf_rx_packets",
1346 		offsetof(struct netvsc_ethtool_pcpu_stats, vf_rx_packets) },
1347 	{ "cpu%u_vf_rx_bytes",
1348 		offsetof(struct netvsc_ethtool_pcpu_stats, vf_rx_bytes) },
1349 	{ "cpu%u_vf_tx_packets",
1350 		offsetof(struct netvsc_ethtool_pcpu_stats, vf_tx_packets) },
1351 	{ "cpu%u_vf_tx_bytes",
1352 		offsetof(struct netvsc_ethtool_pcpu_stats, vf_tx_bytes) },
1353 }, vf_stats[] = {
1354 	{ "vf_rx_packets", offsetof(struct netvsc_vf_pcpu_stats, rx_packets) },
1355 	{ "vf_rx_bytes",   offsetof(struct netvsc_vf_pcpu_stats, rx_bytes) },
1356 	{ "vf_tx_packets", offsetof(struct netvsc_vf_pcpu_stats, tx_packets) },
1357 	{ "vf_tx_bytes",   offsetof(struct netvsc_vf_pcpu_stats, tx_bytes) },
1358 	{ "vf_tx_dropped", offsetof(struct netvsc_vf_pcpu_stats, tx_dropped) },
1359 };
1360 
1361 #define NETVSC_GLOBAL_STATS_LEN	ARRAY_SIZE(netvsc_stats)
1362 #define NETVSC_VF_STATS_LEN	ARRAY_SIZE(vf_stats)
1363 
1364 /* statistics per queue (rx/tx packets/bytes) */
1365 #define NETVSC_PCPU_STATS_LEN (num_present_cpus() * ARRAY_SIZE(pcpu_stats))
1366 
1367 /* 4 statistics per queue (rx/tx packets/bytes) */
1368 #define NETVSC_QUEUE_STATS_LEN(dev) ((dev)->num_chn * 4)
1369 
1370 static int netvsc_get_sset_count(struct net_device *dev, int string_set)
1371 {
1372 	struct net_device_context *ndc = netdev_priv(dev);
1373 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1374 
1375 	if (!nvdev)
1376 		return -ENODEV;
1377 
1378 	switch (string_set) {
1379 	case ETH_SS_STATS:
1380 		return NETVSC_GLOBAL_STATS_LEN
1381 			+ NETVSC_VF_STATS_LEN
1382 			+ NETVSC_QUEUE_STATS_LEN(nvdev)
1383 			+ NETVSC_PCPU_STATS_LEN;
1384 	default:
1385 		return -EINVAL;
1386 	}
1387 }
1388 
1389 static void netvsc_get_ethtool_stats(struct net_device *dev,
1390 				     struct ethtool_stats *stats, u64 *data)
1391 {
1392 	struct net_device_context *ndc = netdev_priv(dev);
1393 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1394 	const void *nds = &ndc->eth_stats;
1395 	const struct netvsc_stats *qstats;
1396 	struct netvsc_vf_pcpu_stats sum;
1397 	struct netvsc_ethtool_pcpu_stats *pcpu_sum;
1398 	unsigned int start;
1399 	u64 packets, bytes;
1400 	int i, j, cpu;
1401 
1402 	if (!nvdev)
1403 		return;
1404 
1405 	for (i = 0; i < NETVSC_GLOBAL_STATS_LEN; i++)
1406 		data[i] = *(unsigned long *)(nds + netvsc_stats[i].offset);
1407 
1408 	netvsc_get_vf_stats(dev, &sum);
1409 	for (j = 0; j < NETVSC_VF_STATS_LEN; j++)
1410 		data[i++] = *(u64 *)((void *)&sum + vf_stats[j].offset);
1411 
1412 	for (j = 0; j < nvdev->num_chn; j++) {
1413 		qstats = &nvdev->chan_table[j].tx_stats;
1414 
1415 		do {
1416 			start = u64_stats_fetch_begin_irq(&qstats->syncp);
1417 			packets = qstats->packets;
1418 			bytes = qstats->bytes;
1419 		} while (u64_stats_fetch_retry_irq(&qstats->syncp, start));
1420 		data[i++] = packets;
1421 		data[i++] = bytes;
1422 
1423 		qstats = &nvdev->chan_table[j].rx_stats;
1424 		do {
1425 			start = u64_stats_fetch_begin_irq(&qstats->syncp);
1426 			packets = qstats->packets;
1427 			bytes = qstats->bytes;
1428 		} while (u64_stats_fetch_retry_irq(&qstats->syncp, start));
1429 		data[i++] = packets;
1430 		data[i++] = bytes;
1431 	}
1432 
1433 	pcpu_sum = kvmalloc_array(num_possible_cpus(),
1434 				  sizeof(struct netvsc_ethtool_pcpu_stats),
1435 				  GFP_KERNEL);
1436 	netvsc_get_pcpu_stats(dev, pcpu_sum);
1437 	for_each_present_cpu(cpu) {
1438 		struct netvsc_ethtool_pcpu_stats *this_sum = &pcpu_sum[cpu];
1439 
1440 		for (j = 0; j < ARRAY_SIZE(pcpu_stats); j++)
1441 			data[i++] = *(u64 *)((void *)this_sum
1442 					     + pcpu_stats[j].offset);
1443 	}
1444 	kvfree(pcpu_sum);
1445 }
1446 
1447 static void netvsc_get_strings(struct net_device *dev, u32 stringset, u8 *data)
1448 {
1449 	struct net_device_context *ndc = netdev_priv(dev);
1450 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1451 	u8 *p = data;
1452 	int i, cpu;
1453 
1454 	if (!nvdev)
1455 		return;
1456 
1457 	switch (stringset) {
1458 	case ETH_SS_STATS:
1459 		for (i = 0; i < ARRAY_SIZE(netvsc_stats); i++) {
1460 			memcpy(p, netvsc_stats[i].name, ETH_GSTRING_LEN);
1461 			p += ETH_GSTRING_LEN;
1462 		}
1463 
1464 		for (i = 0; i < ARRAY_SIZE(vf_stats); i++) {
1465 			memcpy(p, vf_stats[i].name, ETH_GSTRING_LEN);
1466 			p += ETH_GSTRING_LEN;
1467 		}
1468 
1469 		for (i = 0; i < nvdev->num_chn; i++) {
1470 			sprintf(p, "tx_queue_%u_packets", i);
1471 			p += ETH_GSTRING_LEN;
1472 			sprintf(p, "tx_queue_%u_bytes", i);
1473 			p += ETH_GSTRING_LEN;
1474 			sprintf(p, "rx_queue_%u_packets", i);
1475 			p += ETH_GSTRING_LEN;
1476 			sprintf(p, "rx_queue_%u_bytes", i);
1477 			p += ETH_GSTRING_LEN;
1478 		}
1479 
1480 		for_each_present_cpu(cpu) {
1481 			for (i = 0; i < ARRAY_SIZE(pcpu_stats); i++) {
1482 				sprintf(p, pcpu_stats[i].name, cpu);
1483 				p += ETH_GSTRING_LEN;
1484 			}
1485 		}
1486 
1487 		break;
1488 	}
1489 }
1490 
1491 static int
1492 netvsc_get_rss_hash_opts(struct net_device_context *ndc,
1493 			 struct ethtool_rxnfc *info)
1494 {
1495 	const u32 l4_flag = RXH_L4_B_0_1 | RXH_L4_B_2_3;
1496 
1497 	info->data = RXH_IP_SRC | RXH_IP_DST;
1498 
1499 	switch (info->flow_type) {
1500 	case TCP_V4_FLOW:
1501 		if (ndc->l4_hash & HV_TCP4_L4HASH)
1502 			info->data |= l4_flag;
1503 
1504 		break;
1505 
1506 	case TCP_V6_FLOW:
1507 		if (ndc->l4_hash & HV_TCP6_L4HASH)
1508 			info->data |= l4_flag;
1509 
1510 		break;
1511 
1512 	case UDP_V4_FLOW:
1513 		if (ndc->l4_hash & HV_UDP4_L4HASH)
1514 			info->data |= l4_flag;
1515 
1516 		break;
1517 
1518 	case UDP_V6_FLOW:
1519 		if (ndc->l4_hash & HV_UDP6_L4HASH)
1520 			info->data |= l4_flag;
1521 
1522 		break;
1523 
1524 	case IPV4_FLOW:
1525 	case IPV6_FLOW:
1526 		break;
1527 	default:
1528 		info->data = 0;
1529 		break;
1530 	}
1531 
1532 	return 0;
1533 }
1534 
1535 static int
1536 netvsc_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info,
1537 		 u32 *rules)
1538 {
1539 	struct net_device_context *ndc = netdev_priv(dev);
1540 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1541 
1542 	if (!nvdev)
1543 		return -ENODEV;
1544 
1545 	switch (info->cmd) {
1546 	case ETHTOOL_GRXRINGS:
1547 		info->data = nvdev->num_chn;
1548 		return 0;
1549 
1550 	case ETHTOOL_GRXFH:
1551 		return netvsc_get_rss_hash_opts(ndc, info);
1552 	}
1553 	return -EOPNOTSUPP;
1554 }
1555 
1556 static int netvsc_set_rss_hash_opts(struct net_device_context *ndc,
1557 				    struct ethtool_rxnfc *info)
1558 {
1559 	if (info->data == (RXH_IP_SRC | RXH_IP_DST |
1560 			   RXH_L4_B_0_1 | RXH_L4_B_2_3)) {
1561 		switch (info->flow_type) {
1562 		case TCP_V4_FLOW:
1563 			ndc->l4_hash |= HV_TCP4_L4HASH;
1564 			break;
1565 
1566 		case TCP_V6_FLOW:
1567 			ndc->l4_hash |= HV_TCP6_L4HASH;
1568 			break;
1569 
1570 		case UDP_V4_FLOW:
1571 			ndc->l4_hash |= HV_UDP4_L4HASH;
1572 			break;
1573 
1574 		case UDP_V6_FLOW:
1575 			ndc->l4_hash |= HV_UDP6_L4HASH;
1576 			break;
1577 
1578 		default:
1579 			return -EOPNOTSUPP;
1580 		}
1581 
1582 		return 0;
1583 	}
1584 
1585 	if (info->data == (RXH_IP_SRC | RXH_IP_DST)) {
1586 		switch (info->flow_type) {
1587 		case TCP_V4_FLOW:
1588 			ndc->l4_hash &= ~HV_TCP4_L4HASH;
1589 			break;
1590 
1591 		case TCP_V6_FLOW:
1592 			ndc->l4_hash &= ~HV_TCP6_L4HASH;
1593 			break;
1594 
1595 		case UDP_V4_FLOW:
1596 			ndc->l4_hash &= ~HV_UDP4_L4HASH;
1597 			break;
1598 
1599 		case UDP_V6_FLOW:
1600 			ndc->l4_hash &= ~HV_UDP6_L4HASH;
1601 			break;
1602 
1603 		default:
1604 			return -EOPNOTSUPP;
1605 		}
1606 
1607 		return 0;
1608 	}
1609 
1610 	return -EOPNOTSUPP;
1611 }
1612 
1613 static int
1614 netvsc_set_rxnfc(struct net_device *ndev, struct ethtool_rxnfc *info)
1615 {
1616 	struct net_device_context *ndc = netdev_priv(ndev);
1617 
1618 	if (info->cmd == ETHTOOL_SRXFH)
1619 		return netvsc_set_rss_hash_opts(ndc, info);
1620 
1621 	return -EOPNOTSUPP;
1622 }
1623 
1624 static u32 netvsc_get_rxfh_key_size(struct net_device *dev)
1625 {
1626 	return NETVSC_HASH_KEYLEN;
1627 }
1628 
1629 static u32 netvsc_rss_indir_size(struct net_device *dev)
1630 {
1631 	return ITAB_NUM;
1632 }
1633 
1634 static int netvsc_get_rxfh(struct net_device *dev, u32 *indir, u8 *key,
1635 			   u8 *hfunc)
1636 {
1637 	struct net_device_context *ndc = netdev_priv(dev);
1638 	struct netvsc_device *ndev = rtnl_dereference(ndc->nvdev);
1639 	struct rndis_device *rndis_dev;
1640 	int i;
1641 
1642 	if (!ndev)
1643 		return -ENODEV;
1644 
1645 	if (hfunc)
1646 		*hfunc = ETH_RSS_HASH_TOP;	/* Toeplitz */
1647 
1648 	rndis_dev = ndev->extension;
1649 	if (indir) {
1650 		for (i = 0; i < ITAB_NUM; i++)
1651 			indir[i] = rndis_dev->rx_table[i];
1652 	}
1653 
1654 	if (key)
1655 		memcpy(key, rndis_dev->rss_key, NETVSC_HASH_KEYLEN);
1656 
1657 	return 0;
1658 }
1659 
1660 static int netvsc_set_rxfh(struct net_device *dev, const u32 *indir,
1661 			   const u8 *key, const u8 hfunc)
1662 {
1663 	struct net_device_context *ndc = netdev_priv(dev);
1664 	struct netvsc_device *ndev = rtnl_dereference(ndc->nvdev);
1665 	struct rndis_device *rndis_dev;
1666 	int i;
1667 
1668 	if (!ndev)
1669 		return -ENODEV;
1670 
1671 	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
1672 		return -EOPNOTSUPP;
1673 
1674 	rndis_dev = ndev->extension;
1675 	if (indir) {
1676 		for (i = 0; i < ITAB_NUM; i++)
1677 			if (indir[i] >= ndev->num_chn)
1678 				return -EINVAL;
1679 
1680 		for (i = 0; i < ITAB_NUM; i++)
1681 			rndis_dev->rx_table[i] = indir[i];
1682 	}
1683 
1684 	if (!key) {
1685 		if (!indir)
1686 			return 0;
1687 
1688 		key = rndis_dev->rss_key;
1689 	}
1690 
1691 	return rndis_filter_set_rss_param(rndis_dev, key);
1692 }
1693 
1694 /* Hyper-V RNDIS protocol does not have ring in the HW sense.
1695  * It does have pre-allocated receive area which is divided into sections.
1696  */
1697 static void __netvsc_get_ringparam(struct netvsc_device *nvdev,
1698 				   struct ethtool_ringparam *ring)
1699 {
1700 	u32 max_buf_size;
1701 
1702 	ring->rx_pending = nvdev->recv_section_cnt;
1703 	ring->tx_pending = nvdev->send_section_cnt;
1704 
1705 	if (nvdev->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
1706 		max_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
1707 	else
1708 		max_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
1709 
1710 	ring->rx_max_pending = max_buf_size / nvdev->recv_section_size;
1711 	ring->tx_max_pending = NETVSC_SEND_BUFFER_SIZE
1712 		/ nvdev->send_section_size;
1713 }
1714 
1715 static void netvsc_get_ringparam(struct net_device *ndev,
1716 				 struct ethtool_ringparam *ring)
1717 {
1718 	struct net_device_context *ndevctx = netdev_priv(ndev);
1719 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1720 
1721 	if (!nvdev)
1722 		return;
1723 
1724 	__netvsc_get_ringparam(nvdev, ring);
1725 }
1726 
1727 static int netvsc_set_ringparam(struct net_device *ndev,
1728 				struct ethtool_ringparam *ring)
1729 {
1730 	struct net_device_context *ndevctx = netdev_priv(ndev);
1731 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1732 	struct netvsc_device_info *device_info;
1733 	struct ethtool_ringparam orig;
1734 	u32 new_tx, new_rx;
1735 	int ret = 0;
1736 
1737 	if (!nvdev || nvdev->destroy)
1738 		return -ENODEV;
1739 
1740 	memset(&orig, 0, sizeof(orig));
1741 	__netvsc_get_ringparam(nvdev, &orig);
1742 
1743 	new_tx = clamp_t(u32, ring->tx_pending,
1744 			 NETVSC_MIN_TX_SECTIONS, orig.tx_max_pending);
1745 	new_rx = clamp_t(u32, ring->rx_pending,
1746 			 NETVSC_MIN_RX_SECTIONS, orig.rx_max_pending);
1747 
1748 	if (new_tx == orig.tx_pending &&
1749 	    new_rx == orig.rx_pending)
1750 		return 0;	 /* no change */
1751 
1752 	device_info = netvsc_devinfo_get(nvdev);
1753 
1754 	if (!device_info)
1755 		return -ENOMEM;
1756 
1757 	device_info->send_sections = new_tx;
1758 	device_info->recv_sections = new_rx;
1759 
1760 	ret = netvsc_detach(ndev, nvdev);
1761 	if (ret)
1762 		goto out;
1763 
1764 	ret = netvsc_attach(ndev, device_info);
1765 	if (ret) {
1766 		device_info->send_sections = orig.tx_pending;
1767 		device_info->recv_sections = orig.rx_pending;
1768 
1769 		if (netvsc_attach(ndev, device_info))
1770 			netdev_err(ndev, "restoring ringparam failed");
1771 	}
1772 
1773 out:
1774 	kfree(device_info);
1775 	return ret;
1776 }
1777 
1778 static int netvsc_set_features(struct net_device *ndev,
1779 			       netdev_features_t features)
1780 {
1781 	netdev_features_t change = features ^ ndev->features;
1782 	struct net_device_context *ndevctx = netdev_priv(ndev);
1783 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1784 	struct ndis_offload_params offloads;
1785 
1786 	if (!nvdev || nvdev->destroy)
1787 		return -ENODEV;
1788 
1789 	if (!(change & NETIF_F_LRO))
1790 		return 0;
1791 
1792 	memset(&offloads, 0, sizeof(struct ndis_offload_params));
1793 
1794 	if (features & NETIF_F_LRO) {
1795 		offloads.rsc_ip_v4 = NDIS_OFFLOAD_PARAMETERS_RSC_ENABLED;
1796 		offloads.rsc_ip_v6 = NDIS_OFFLOAD_PARAMETERS_RSC_ENABLED;
1797 	} else {
1798 		offloads.rsc_ip_v4 = NDIS_OFFLOAD_PARAMETERS_RSC_DISABLED;
1799 		offloads.rsc_ip_v6 = NDIS_OFFLOAD_PARAMETERS_RSC_DISABLED;
1800 	}
1801 
1802 	return rndis_filter_set_offload_params(ndev, nvdev, &offloads);
1803 }
1804 
1805 static u32 netvsc_get_msglevel(struct net_device *ndev)
1806 {
1807 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1808 
1809 	return ndev_ctx->msg_enable;
1810 }
1811 
1812 static void netvsc_set_msglevel(struct net_device *ndev, u32 val)
1813 {
1814 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1815 
1816 	ndev_ctx->msg_enable = val;
1817 }
1818 
1819 static const struct ethtool_ops ethtool_ops = {
1820 	.get_drvinfo	= netvsc_get_drvinfo,
1821 	.get_msglevel	= netvsc_get_msglevel,
1822 	.set_msglevel	= netvsc_set_msglevel,
1823 	.get_link	= ethtool_op_get_link,
1824 	.get_ethtool_stats = netvsc_get_ethtool_stats,
1825 	.get_sset_count = netvsc_get_sset_count,
1826 	.get_strings	= netvsc_get_strings,
1827 	.get_channels   = netvsc_get_channels,
1828 	.set_channels   = netvsc_set_channels,
1829 	.get_ts_info	= ethtool_op_get_ts_info,
1830 	.get_rxnfc	= netvsc_get_rxnfc,
1831 	.set_rxnfc	= netvsc_set_rxnfc,
1832 	.get_rxfh_key_size = netvsc_get_rxfh_key_size,
1833 	.get_rxfh_indir_size = netvsc_rss_indir_size,
1834 	.get_rxfh	= netvsc_get_rxfh,
1835 	.set_rxfh	= netvsc_set_rxfh,
1836 	.get_link_ksettings = netvsc_get_link_ksettings,
1837 	.set_link_ksettings = netvsc_set_link_ksettings,
1838 	.get_ringparam	= netvsc_get_ringparam,
1839 	.set_ringparam	= netvsc_set_ringparam,
1840 };
1841 
1842 static const struct net_device_ops device_ops = {
1843 	.ndo_open =			netvsc_open,
1844 	.ndo_stop =			netvsc_close,
1845 	.ndo_start_xmit =		netvsc_start_xmit,
1846 	.ndo_change_rx_flags =		netvsc_change_rx_flags,
1847 	.ndo_set_rx_mode =		netvsc_set_rx_mode,
1848 	.ndo_set_features =		netvsc_set_features,
1849 	.ndo_change_mtu =		netvsc_change_mtu,
1850 	.ndo_validate_addr =		eth_validate_addr,
1851 	.ndo_set_mac_address =		netvsc_set_mac_addr,
1852 	.ndo_select_queue =		netvsc_select_queue,
1853 	.ndo_get_stats64 =		netvsc_get_stats64,
1854 };
1855 
1856 /*
1857  * Handle link status changes. For RNDIS_STATUS_NETWORK_CHANGE emulate link
1858  * down/up sequence. In case of RNDIS_STATUS_MEDIA_CONNECT when carrier is
1859  * present send GARP packet to network peers with netif_notify_peers().
1860  */
1861 static void netvsc_link_change(struct work_struct *w)
1862 {
1863 	struct net_device_context *ndev_ctx =
1864 		container_of(w, struct net_device_context, dwork.work);
1865 	struct hv_device *device_obj = ndev_ctx->device_ctx;
1866 	struct net_device *net = hv_get_drvdata(device_obj);
1867 	struct netvsc_device *net_device;
1868 	struct rndis_device *rdev;
1869 	struct netvsc_reconfig *event = NULL;
1870 	bool notify = false, reschedule = false;
1871 	unsigned long flags, next_reconfig, delay;
1872 
1873 	/* if changes are happening, comeback later */
1874 	if (!rtnl_trylock()) {
1875 		schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT);
1876 		return;
1877 	}
1878 
1879 	net_device = rtnl_dereference(ndev_ctx->nvdev);
1880 	if (!net_device)
1881 		goto out_unlock;
1882 
1883 	rdev = net_device->extension;
1884 
1885 	next_reconfig = ndev_ctx->last_reconfig + LINKCHANGE_INT;
1886 	if (time_is_after_jiffies(next_reconfig)) {
1887 		/* link_watch only sends one notification with current state
1888 		 * per second, avoid doing reconfig more frequently. Handle
1889 		 * wrap around.
1890 		 */
1891 		delay = next_reconfig - jiffies;
1892 		delay = delay < LINKCHANGE_INT ? delay : LINKCHANGE_INT;
1893 		schedule_delayed_work(&ndev_ctx->dwork, delay);
1894 		goto out_unlock;
1895 	}
1896 	ndev_ctx->last_reconfig = jiffies;
1897 
1898 	spin_lock_irqsave(&ndev_ctx->lock, flags);
1899 	if (!list_empty(&ndev_ctx->reconfig_events)) {
1900 		event = list_first_entry(&ndev_ctx->reconfig_events,
1901 					 struct netvsc_reconfig, list);
1902 		list_del(&event->list);
1903 		reschedule = !list_empty(&ndev_ctx->reconfig_events);
1904 	}
1905 	spin_unlock_irqrestore(&ndev_ctx->lock, flags);
1906 
1907 	if (!event)
1908 		goto out_unlock;
1909 
1910 	switch (event->event) {
1911 		/* Only the following events are possible due to the check in
1912 		 * netvsc_linkstatus_callback()
1913 		 */
1914 	case RNDIS_STATUS_MEDIA_CONNECT:
1915 		if (rdev->link_state) {
1916 			rdev->link_state = false;
1917 			netif_carrier_on(net);
1918 			netvsc_tx_enable(net_device, net);
1919 		} else {
1920 			notify = true;
1921 		}
1922 		kfree(event);
1923 		break;
1924 	case RNDIS_STATUS_MEDIA_DISCONNECT:
1925 		if (!rdev->link_state) {
1926 			rdev->link_state = true;
1927 			netif_carrier_off(net);
1928 			netvsc_tx_disable(net_device, net);
1929 		}
1930 		kfree(event);
1931 		break;
1932 	case RNDIS_STATUS_NETWORK_CHANGE:
1933 		/* Only makes sense if carrier is present */
1934 		if (!rdev->link_state) {
1935 			rdev->link_state = true;
1936 			netif_carrier_off(net);
1937 			netvsc_tx_disable(net_device, net);
1938 			event->event = RNDIS_STATUS_MEDIA_CONNECT;
1939 			spin_lock_irqsave(&ndev_ctx->lock, flags);
1940 			list_add(&event->list, &ndev_ctx->reconfig_events);
1941 			spin_unlock_irqrestore(&ndev_ctx->lock, flags);
1942 			reschedule = true;
1943 		}
1944 		break;
1945 	}
1946 
1947 	rtnl_unlock();
1948 
1949 	if (notify)
1950 		netdev_notify_peers(net);
1951 
1952 	/* link_watch only sends one notification with current state per
1953 	 * second, handle next reconfig event in 2 seconds.
1954 	 */
1955 	if (reschedule)
1956 		schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT);
1957 
1958 	return;
1959 
1960 out_unlock:
1961 	rtnl_unlock();
1962 }
1963 
1964 static struct net_device *get_netvsc_byref(struct net_device *vf_netdev)
1965 {
1966 	struct net_device_context *net_device_ctx;
1967 	struct net_device *dev;
1968 
1969 	dev = netdev_master_upper_dev_get(vf_netdev);
1970 	if (!dev || dev->netdev_ops != &device_ops)
1971 		return NULL;	/* not a netvsc device */
1972 
1973 	net_device_ctx = netdev_priv(dev);
1974 	if (!rtnl_dereference(net_device_ctx->nvdev))
1975 		return NULL;	/* device is removed */
1976 
1977 	return dev;
1978 }
1979 
1980 /* Called when VF is injecting data into network stack.
1981  * Change the associated network device from VF to netvsc.
1982  * note: already called with rcu_read_lock
1983  */
1984 static rx_handler_result_t netvsc_vf_handle_frame(struct sk_buff **pskb)
1985 {
1986 	struct sk_buff *skb = *pskb;
1987 	struct net_device *ndev = rcu_dereference(skb->dev->rx_handler_data);
1988 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1989 	struct netvsc_vf_pcpu_stats *pcpu_stats
1990 		 = this_cpu_ptr(ndev_ctx->vf_stats);
1991 
1992 	skb = skb_share_check(skb, GFP_ATOMIC);
1993 	if (unlikely(!skb))
1994 		return RX_HANDLER_CONSUMED;
1995 
1996 	*pskb = skb;
1997 
1998 	skb->dev = ndev;
1999 
2000 	u64_stats_update_begin(&pcpu_stats->syncp);
2001 	pcpu_stats->rx_packets++;
2002 	pcpu_stats->rx_bytes += skb->len;
2003 	u64_stats_update_end(&pcpu_stats->syncp);
2004 
2005 	return RX_HANDLER_ANOTHER;
2006 }
2007 
2008 static int netvsc_vf_join(struct net_device *vf_netdev,
2009 			  struct net_device *ndev)
2010 {
2011 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
2012 	int ret;
2013 
2014 	ret = netdev_rx_handler_register(vf_netdev,
2015 					 netvsc_vf_handle_frame, ndev);
2016 	if (ret != 0) {
2017 		netdev_err(vf_netdev,
2018 			   "can not register netvsc VF receive handler (err = %d)\n",
2019 			   ret);
2020 		goto rx_handler_failed;
2021 	}
2022 
2023 	ret = netdev_master_upper_dev_link(vf_netdev, ndev,
2024 					   NULL, NULL, NULL);
2025 	if (ret != 0) {
2026 		netdev_err(vf_netdev,
2027 			   "can not set master device %s (err = %d)\n",
2028 			   ndev->name, ret);
2029 		goto upper_link_failed;
2030 	}
2031 
2032 	/* set slave flag before open to prevent IPv6 addrconf */
2033 	vf_netdev->flags |= IFF_SLAVE;
2034 
2035 	schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);
2036 
2037 	call_netdevice_notifiers(NETDEV_JOIN, vf_netdev);
2038 
2039 	netdev_info(vf_netdev, "joined to %s\n", ndev->name);
2040 	return 0;
2041 
2042 upper_link_failed:
2043 	netdev_rx_handler_unregister(vf_netdev);
2044 rx_handler_failed:
2045 	return ret;
2046 }
2047 
2048 static void __netvsc_vf_setup(struct net_device *ndev,
2049 			      struct net_device *vf_netdev)
2050 {
2051 	int ret;
2052 
2053 	/* Align MTU of VF with master */
2054 	ret = dev_set_mtu(vf_netdev, ndev->mtu);
2055 	if (ret)
2056 		netdev_warn(vf_netdev,
2057 			    "unable to change mtu to %u\n", ndev->mtu);
2058 
2059 	/* set multicast etc flags on VF */
2060 	dev_change_flags(vf_netdev, ndev->flags | IFF_SLAVE, NULL);
2061 
2062 	/* sync address list from ndev to VF */
2063 	netif_addr_lock_bh(ndev);
2064 	dev_uc_sync(vf_netdev, ndev);
2065 	dev_mc_sync(vf_netdev, ndev);
2066 	netif_addr_unlock_bh(ndev);
2067 
2068 	if (netif_running(ndev)) {
2069 		ret = dev_open(vf_netdev, NULL);
2070 		if (ret)
2071 			netdev_warn(vf_netdev,
2072 				    "unable to open: %d\n", ret);
2073 	}
2074 }
2075 
2076 /* Setup VF as slave of the synthetic device.
2077  * Runs in workqueue to avoid recursion in netlink callbacks.
2078  */
2079 static void netvsc_vf_setup(struct work_struct *w)
2080 {
2081 	struct net_device_context *ndev_ctx
2082 		= container_of(w, struct net_device_context, vf_takeover.work);
2083 	struct net_device *ndev = hv_get_drvdata(ndev_ctx->device_ctx);
2084 	struct net_device *vf_netdev;
2085 
2086 	if (!rtnl_trylock()) {
2087 		schedule_delayed_work(&ndev_ctx->vf_takeover, 0);
2088 		return;
2089 	}
2090 
2091 	vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
2092 	if (vf_netdev)
2093 		__netvsc_vf_setup(ndev, vf_netdev);
2094 
2095 	rtnl_unlock();
2096 }
2097 
2098 /* Find netvsc by VF serial number.
2099  * The PCI hyperv controller records the serial number as the slot kobj name.
2100  */
2101 static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
2102 {
2103 	struct device *parent = vf_netdev->dev.parent;
2104 	struct net_device_context *ndev_ctx;
2105 	struct pci_dev *pdev;
2106 	u32 serial;
2107 
2108 	if (!parent || !dev_is_pci(parent))
2109 		return NULL; /* not a PCI device */
2110 
2111 	pdev = to_pci_dev(parent);
2112 	if (!pdev->slot) {
2113 		netdev_notice(vf_netdev, "no PCI slot information\n");
2114 		return NULL;
2115 	}
2116 
2117 	if (kstrtou32(pci_slot_name(pdev->slot), 10, &serial)) {
2118 		netdev_notice(vf_netdev, "Invalid vf serial:%s\n",
2119 			      pci_slot_name(pdev->slot));
2120 		return NULL;
2121 	}
2122 
2123 	list_for_each_entry(ndev_ctx, &netvsc_dev_list, list) {
2124 		if (!ndev_ctx->vf_alloc)
2125 			continue;
2126 
2127 		if (ndev_ctx->vf_serial == serial)
2128 			return hv_get_drvdata(ndev_ctx->device_ctx);
2129 	}
2130 
2131 	netdev_notice(vf_netdev,
2132 		      "no netdev found for vf serial:%u\n", serial);
2133 	return NULL;
2134 }
2135 
2136 static int netvsc_register_vf(struct net_device *vf_netdev)
2137 {
2138 	struct net_device_context *net_device_ctx;
2139 	struct netvsc_device *netvsc_dev;
2140 	struct net_device *ndev;
2141 	int ret;
2142 
2143 	if (vf_netdev->addr_len != ETH_ALEN)
2144 		return NOTIFY_DONE;
2145 
2146 	ndev = get_netvsc_byslot(vf_netdev);
2147 	if (!ndev)
2148 		return NOTIFY_DONE;
2149 
2150 	net_device_ctx = netdev_priv(ndev);
2151 	netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
2152 	if (!netvsc_dev || rtnl_dereference(net_device_ctx->vf_netdev))
2153 		return NOTIFY_DONE;
2154 
2155 	/* if synthetic interface is a different namespace,
2156 	 * then move the VF to that namespace; join will be
2157 	 * done again in that context.
2158 	 */
2159 	if (!net_eq(dev_net(ndev), dev_net(vf_netdev))) {
2160 		ret = dev_change_net_namespace(vf_netdev,
2161 					       dev_net(ndev), "eth%d");
2162 		if (ret)
2163 			netdev_err(vf_netdev,
2164 				   "could not move to same namespace as %s: %d\n",
2165 				   ndev->name, ret);
2166 		else
2167 			netdev_info(vf_netdev,
2168 				    "VF moved to namespace with: %s\n",
2169 				    ndev->name);
2170 		return NOTIFY_DONE;
2171 	}
2172 
2173 	netdev_info(ndev, "VF registering: %s\n", vf_netdev->name);
2174 
2175 	if (netvsc_vf_join(vf_netdev, ndev) != 0)
2176 		return NOTIFY_DONE;
2177 
2178 	dev_hold(vf_netdev);
2179 	rcu_assign_pointer(net_device_ctx->vf_netdev, vf_netdev);
2180 	return NOTIFY_OK;
2181 }
2182 
2183 /* VF up/down change detected, schedule to change data path */
2184 static int netvsc_vf_changed(struct net_device *vf_netdev)
2185 {
2186 	struct net_device_context *net_device_ctx;
2187 	struct netvsc_device *netvsc_dev;
2188 	struct net_device *ndev;
2189 	bool vf_is_up = netif_running(vf_netdev);
2190 
2191 	ndev = get_netvsc_byref(vf_netdev);
2192 	if (!ndev)
2193 		return NOTIFY_DONE;
2194 
2195 	net_device_ctx = netdev_priv(ndev);
2196 	netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
2197 	if (!netvsc_dev)
2198 		return NOTIFY_DONE;
2199 
2200 	netvsc_switch_datapath(ndev, vf_is_up);
2201 	netdev_info(ndev, "Data path switched %s VF: %s\n",
2202 		    vf_is_up ? "to" : "from", vf_netdev->name);
2203 
2204 	return NOTIFY_OK;
2205 }
2206 
2207 static int netvsc_unregister_vf(struct net_device *vf_netdev)
2208 {
2209 	struct net_device *ndev;
2210 	struct net_device_context *net_device_ctx;
2211 
2212 	ndev = get_netvsc_byref(vf_netdev);
2213 	if (!ndev)
2214 		return NOTIFY_DONE;
2215 
2216 	net_device_ctx = netdev_priv(ndev);
2217 	cancel_delayed_work_sync(&net_device_ctx->vf_takeover);
2218 
2219 	netdev_info(ndev, "VF unregistering: %s\n", vf_netdev->name);
2220 
2221 	netdev_rx_handler_unregister(vf_netdev);
2222 	netdev_upper_dev_unlink(vf_netdev, ndev);
2223 	RCU_INIT_POINTER(net_device_ctx->vf_netdev, NULL);
2224 	dev_put(vf_netdev);
2225 
2226 	return NOTIFY_OK;
2227 }
2228 
2229 static int netvsc_probe(struct hv_device *dev,
2230 			const struct hv_vmbus_device_id *dev_id)
2231 {
2232 	struct net_device *net = NULL;
2233 	struct net_device_context *net_device_ctx;
2234 	struct netvsc_device_info *device_info = NULL;
2235 	struct netvsc_device *nvdev;
2236 	int ret = -ENOMEM;
2237 
2238 	net = alloc_etherdev_mq(sizeof(struct net_device_context),
2239 				VRSS_CHANNEL_MAX);
2240 	if (!net)
2241 		goto no_net;
2242 
2243 	netif_carrier_off(net);
2244 
2245 	netvsc_init_settings(net);
2246 
2247 	net_device_ctx = netdev_priv(net);
2248 	net_device_ctx->device_ctx = dev;
2249 	net_device_ctx->msg_enable = netif_msg_init(debug, default_msg);
2250 	if (netif_msg_probe(net_device_ctx))
2251 		netdev_dbg(net, "netvsc msg_enable: %d\n",
2252 			   net_device_ctx->msg_enable);
2253 
2254 	hv_set_drvdata(dev, net);
2255 
2256 	INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change);
2257 
2258 	spin_lock_init(&net_device_ctx->lock);
2259 	INIT_LIST_HEAD(&net_device_ctx->reconfig_events);
2260 	INIT_DELAYED_WORK(&net_device_ctx->vf_takeover, netvsc_vf_setup);
2261 
2262 	net_device_ctx->vf_stats
2263 		= netdev_alloc_pcpu_stats(struct netvsc_vf_pcpu_stats);
2264 	if (!net_device_ctx->vf_stats)
2265 		goto no_stats;
2266 
2267 	net->netdev_ops = &device_ops;
2268 	net->ethtool_ops = &ethtool_ops;
2269 	SET_NETDEV_DEV(net, &dev->device);
2270 
2271 	/* We always need headroom for rndis header */
2272 	net->needed_headroom = RNDIS_AND_PPI_SIZE;
2273 
2274 	/* Initialize the number of queues to be 1, we may change it if more
2275 	 * channels are offered later.
2276 	 */
2277 	netif_set_real_num_tx_queues(net, 1);
2278 	netif_set_real_num_rx_queues(net, 1);
2279 
2280 	/* Notify the netvsc driver of the new device */
2281 	device_info = netvsc_devinfo_get(NULL);
2282 
2283 	if (!device_info) {
2284 		ret = -ENOMEM;
2285 		goto devinfo_failed;
2286 	}
2287 
2288 	nvdev = rndis_filter_device_add(dev, device_info);
2289 	if (IS_ERR(nvdev)) {
2290 		ret = PTR_ERR(nvdev);
2291 		netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
2292 		goto rndis_failed;
2293 	}
2294 
2295 	memcpy(net->dev_addr, device_info->mac_adr, ETH_ALEN);
2296 
2297 	/* We must get rtnl lock before scheduling nvdev->subchan_work,
2298 	 * otherwise netvsc_subchan_work() can get rtnl lock first and wait
2299 	 * all subchannels to show up, but that may not happen because
2300 	 * netvsc_probe() can't get rtnl lock and as a result vmbus_onoffer()
2301 	 * -> ... -> device_add() -> ... -> __device_attach() can't get
2302 	 * the device lock, so all the subchannels can't be processed --
2303 	 * finally netvsc_subchan_work() hangs forever.
2304 	 */
2305 	rtnl_lock();
2306 
2307 	if (nvdev->num_chn > 1)
2308 		schedule_work(&nvdev->subchan_work);
2309 
2310 	/* hw_features computed in rndis_netdev_set_hwcaps() */
2311 	net->features = net->hw_features |
2312 		NETIF_F_HIGHDMA | NETIF_F_SG |
2313 		NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX;
2314 	net->vlan_features = net->features;
2315 
2316 	netdev_lockdep_set_classes(net);
2317 
2318 	/* MTU range: 68 - 1500 or 65521 */
2319 	net->min_mtu = NETVSC_MTU_MIN;
2320 	if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
2321 		net->max_mtu = NETVSC_MTU - ETH_HLEN;
2322 	else
2323 		net->max_mtu = ETH_DATA_LEN;
2324 
2325 	ret = register_netdevice(net);
2326 	if (ret != 0) {
2327 		pr_err("Unable to register netdev.\n");
2328 		goto register_failed;
2329 	}
2330 
2331 	list_add(&net_device_ctx->list, &netvsc_dev_list);
2332 	rtnl_unlock();
2333 
2334 	kfree(device_info);
2335 	return 0;
2336 
2337 register_failed:
2338 	rtnl_unlock();
2339 	rndis_filter_device_remove(dev, nvdev);
2340 rndis_failed:
2341 	kfree(device_info);
2342 devinfo_failed:
2343 	free_percpu(net_device_ctx->vf_stats);
2344 no_stats:
2345 	hv_set_drvdata(dev, NULL);
2346 	free_netdev(net);
2347 no_net:
2348 	return ret;
2349 }
2350 
2351 static int netvsc_remove(struct hv_device *dev)
2352 {
2353 	struct net_device_context *ndev_ctx;
2354 	struct net_device *vf_netdev, *net;
2355 	struct netvsc_device *nvdev;
2356 
2357 	net = hv_get_drvdata(dev);
2358 	if (net == NULL) {
2359 		dev_err(&dev->device, "No net device to remove\n");
2360 		return 0;
2361 	}
2362 
2363 	ndev_ctx = netdev_priv(net);
2364 
2365 	cancel_delayed_work_sync(&ndev_ctx->dwork);
2366 
2367 	rtnl_lock();
2368 	nvdev = rtnl_dereference(ndev_ctx->nvdev);
2369 	if (nvdev)
2370 		cancel_work_sync(&nvdev->subchan_work);
2371 
2372 	/*
2373 	 * Call to the vsc driver to let it know that the device is being
2374 	 * removed. Also blocks mtu and channel changes.
2375 	 */
2376 	vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
2377 	if (vf_netdev)
2378 		netvsc_unregister_vf(vf_netdev);
2379 
2380 	if (nvdev)
2381 		rndis_filter_device_remove(dev, nvdev);
2382 
2383 	unregister_netdevice(net);
2384 	list_del(&ndev_ctx->list);
2385 
2386 	rtnl_unlock();
2387 
2388 	hv_set_drvdata(dev, NULL);
2389 
2390 	free_percpu(ndev_ctx->vf_stats);
2391 	free_netdev(net);
2392 	return 0;
2393 }
2394 
2395 static const struct hv_vmbus_device_id id_table[] = {
2396 	/* Network guid */
2397 	{ HV_NIC_GUID, },
2398 	{ },
2399 };
2400 
2401 MODULE_DEVICE_TABLE(vmbus, id_table);
2402 
2403 /* The one and only one */
2404 static struct  hv_driver netvsc_drv = {
2405 	.name = KBUILD_MODNAME,
2406 	.id_table = id_table,
2407 	.probe = netvsc_probe,
2408 	.remove = netvsc_remove,
2409 	.driver = {
2410 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
2411 	},
2412 };
2413 
2414 /*
2415  * On Hyper-V, every VF interface is matched with a corresponding
2416  * synthetic interface. The synthetic interface is presented first
2417  * to the guest. When the corresponding VF instance is registered,
2418  * we will take care of switching the data path.
2419  */
2420 static int netvsc_netdev_event(struct notifier_block *this,
2421 			       unsigned long event, void *ptr)
2422 {
2423 	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2424 
2425 	/* Skip our own events */
2426 	if (event_dev->netdev_ops == &device_ops)
2427 		return NOTIFY_DONE;
2428 
2429 	/* Avoid non-Ethernet type devices */
2430 	if (event_dev->type != ARPHRD_ETHER)
2431 		return NOTIFY_DONE;
2432 
2433 	/* Avoid Vlan dev with same MAC registering as VF */
2434 	if (is_vlan_dev(event_dev))
2435 		return NOTIFY_DONE;
2436 
2437 	/* Avoid Bonding master dev with same MAC registering as VF */
2438 	if ((event_dev->priv_flags & IFF_BONDING) &&
2439 	    (event_dev->flags & IFF_MASTER))
2440 		return NOTIFY_DONE;
2441 
2442 	switch (event) {
2443 	case NETDEV_REGISTER:
2444 		return netvsc_register_vf(event_dev);
2445 	case NETDEV_UNREGISTER:
2446 		return netvsc_unregister_vf(event_dev);
2447 	case NETDEV_UP:
2448 	case NETDEV_DOWN:
2449 		return netvsc_vf_changed(event_dev);
2450 	default:
2451 		return NOTIFY_DONE;
2452 	}
2453 }
2454 
2455 static struct notifier_block netvsc_netdev_notifier = {
2456 	.notifier_call = netvsc_netdev_event,
2457 };
2458 
2459 static void __exit netvsc_drv_exit(void)
2460 {
2461 	unregister_netdevice_notifier(&netvsc_netdev_notifier);
2462 	vmbus_driver_unregister(&netvsc_drv);
2463 }
2464 
2465 static int __init netvsc_drv_init(void)
2466 {
2467 	int ret;
2468 
2469 	if (ring_size < RING_SIZE_MIN) {
2470 		ring_size = RING_SIZE_MIN;
2471 		pr_info("Increased ring_size to %u (min allowed)\n",
2472 			ring_size);
2473 	}
2474 	netvsc_ring_bytes = ring_size * PAGE_SIZE;
2475 
2476 	ret = vmbus_driver_register(&netvsc_drv);
2477 	if (ret)
2478 		return ret;
2479 
2480 	register_netdevice_notifier(&netvsc_netdev_notifier);
2481 	return 0;
2482 }
2483 
2484 MODULE_LICENSE("GPL");
2485 MODULE_DESCRIPTION("Microsoft Hyper-V network driver");
2486 
2487 module_init(netvsc_drv_init);
2488 module_exit(netvsc_drv_exit);
2489