xref: /openbmc/linux/drivers/net/hyperv/netvsc_drv.c (revision a48c7709)
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/skbuff.h>
33 #include <linux/if_vlan.h>
34 #include <linux/in.h>
35 #include <linux/slab.h>
36 #include <linux/rtnetlink.h>
37 #include <linux/netpoll.h>
38 #include <linux/reciprocal_div.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 struct reciprocal_value netvsc_ring_reciprocal __ro_after_init;
62 
63 static const u32 default_msg = NETIF_MSG_DRV | NETIF_MSG_PROBE |
64 				NETIF_MSG_LINK | NETIF_MSG_IFUP |
65 				NETIF_MSG_IFDOWN | NETIF_MSG_RX_ERR |
66 				NETIF_MSG_TX_ERR;
67 
68 static int debug = -1;
69 module_param(debug, int, 0444);
70 MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");
71 
72 static void netvsc_change_rx_flags(struct net_device *net, int change)
73 {
74 	struct net_device_context *ndev_ctx = netdev_priv(net);
75 	struct net_device *vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
76 	int inc;
77 
78 	if (!vf_netdev)
79 		return;
80 
81 	if (change & IFF_PROMISC) {
82 		inc = (net->flags & IFF_PROMISC) ? 1 : -1;
83 		dev_set_promiscuity(vf_netdev, inc);
84 	}
85 
86 	if (change & IFF_ALLMULTI) {
87 		inc = (net->flags & IFF_ALLMULTI) ? 1 : -1;
88 		dev_set_allmulti(vf_netdev, inc);
89 	}
90 }
91 
92 static void netvsc_set_rx_mode(struct net_device *net)
93 {
94 	struct net_device_context *ndev_ctx = netdev_priv(net);
95 	struct net_device *vf_netdev;
96 	struct netvsc_device *nvdev;
97 
98 	rcu_read_lock();
99 	vf_netdev = rcu_dereference(ndev_ctx->vf_netdev);
100 	if (vf_netdev) {
101 		dev_uc_sync(vf_netdev, net);
102 		dev_mc_sync(vf_netdev, net);
103 	}
104 
105 	nvdev = rcu_dereference(ndev_ctx->nvdev);
106 	if (nvdev)
107 		rndis_filter_update(nvdev);
108 	rcu_read_unlock();
109 }
110 
111 static int netvsc_open(struct net_device *net)
112 {
113 	struct net_device_context *ndev_ctx = netdev_priv(net);
114 	struct net_device *vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
115 	struct netvsc_device *nvdev = rtnl_dereference(ndev_ctx->nvdev);
116 	struct rndis_device *rdev;
117 	int ret = 0;
118 
119 	netif_carrier_off(net);
120 
121 	/* Open up the device */
122 	ret = rndis_filter_open(nvdev);
123 	if (ret != 0) {
124 		netdev_err(net, "unable to open device (ret %d).\n", ret);
125 		return ret;
126 	}
127 
128 	rdev = nvdev->extension;
129 	if (!rdev->link_state)
130 		netif_carrier_on(net);
131 
132 	if (vf_netdev) {
133 		/* Setting synthetic device up transparently sets
134 		 * slave as up. If open fails, then slave will be
135 		 * still be offline (and not used).
136 		 */
137 		ret = dev_open(vf_netdev);
138 		if (ret)
139 			netdev_warn(net,
140 				    "unable to open slave: %s: %d\n",
141 				    vf_netdev->name, ret);
142 	}
143 	return 0;
144 }
145 
146 static int netvsc_wait_until_empty(struct netvsc_device *nvdev)
147 {
148 	unsigned int retry = 0;
149 	int i;
150 
151 	/* Ensure pending bytes in ring are read */
152 	for (;;) {
153 		u32 aread = 0;
154 
155 		for (i = 0; i < nvdev->num_chn; i++) {
156 			struct vmbus_channel *chn
157 				= nvdev->chan_table[i].channel;
158 
159 			if (!chn)
160 				continue;
161 
162 			/* make sure receive not running now */
163 			napi_synchronize(&nvdev->chan_table[i].napi);
164 
165 			aread = hv_get_bytes_to_read(&chn->inbound);
166 			if (aread)
167 				break;
168 
169 			aread = hv_get_bytes_to_read(&chn->outbound);
170 			if (aread)
171 				break;
172 		}
173 
174 		if (aread == 0)
175 			return 0;
176 
177 		if (++retry > RETRY_MAX)
178 			return -ETIMEDOUT;
179 
180 		usleep_range(RETRY_US_LO, RETRY_US_HI);
181 	}
182 }
183 
184 static int netvsc_close(struct net_device *net)
185 {
186 	struct net_device_context *net_device_ctx = netdev_priv(net);
187 	struct net_device *vf_netdev
188 		= rtnl_dereference(net_device_ctx->vf_netdev);
189 	struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
190 	int ret;
191 
192 	netif_tx_disable(net);
193 
194 	/* No need to close rndis filter if it is removed already */
195 	if (!nvdev)
196 		return 0;
197 
198 	ret = rndis_filter_close(nvdev);
199 	if (ret != 0) {
200 		netdev_err(net, "unable to close device (ret %d).\n", ret);
201 		return ret;
202 	}
203 
204 	ret = netvsc_wait_until_empty(nvdev);
205 	if (ret)
206 		netdev_err(net, "Ring buffer not empty after closing rndis\n");
207 
208 	if (vf_netdev)
209 		dev_close(vf_netdev);
210 
211 	return ret;
212 }
213 
214 static inline void *init_ppi_data(struct rndis_message *msg,
215 				  u32 ppi_size, u32 pkt_type)
216 {
217 	struct rndis_packet *rndis_pkt = &msg->msg.pkt;
218 	struct rndis_per_packet_info *ppi;
219 
220 	rndis_pkt->data_offset += ppi_size;
221 	ppi = (void *)rndis_pkt + rndis_pkt->per_pkt_info_offset
222 		+ rndis_pkt->per_pkt_info_len;
223 
224 	ppi->size = ppi_size;
225 	ppi->type = pkt_type;
226 	ppi->ppi_offset = sizeof(struct rndis_per_packet_info);
227 
228 	rndis_pkt->per_pkt_info_len += ppi_size;
229 
230 	return ppi + 1;
231 }
232 
233 /* Azure hosts don't support non-TCP port numbers in hashing for fragmented
234  * packets. We can use ethtool to change UDP hash level when necessary.
235  */
236 static inline u32 netvsc_get_hash(
237 	struct sk_buff *skb,
238 	const struct net_device_context *ndc)
239 {
240 	struct flow_keys flow;
241 	u32 hash, pkt_proto = 0;
242 	static u32 hashrnd __read_mostly;
243 
244 	net_get_random_once(&hashrnd, sizeof(hashrnd));
245 
246 	if (!skb_flow_dissect_flow_keys(skb, &flow, 0))
247 		return 0;
248 
249 	switch (flow.basic.ip_proto) {
250 	case IPPROTO_TCP:
251 		if (flow.basic.n_proto == htons(ETH_P_IP))
252 			pkt_proto = HV_TCP4_L4HASH;
253 		else if (flow.basic.n_proto == htons(ETH_P_IPV6))
254 			pkt_proto = HV_TCP6_L4HASH;
255 
256 		break;
257 
258 	case IPPROTO_UDP:
259 		if (flow.basic.n_proto == htons(ETH_P_IP))
260 			pkt_proto = HV_UDP4_L4HASH;
261 		else if (flow.basic.n_proto == htons(ETH_P_IPV6))
262 			pkt_proto = HV_UDP6_L4HASH;
263 
264 		break;
265 	}
266 
267 	if (pkt_proto & ndc->l4_hash) {
268 		return skb_get_hash(skb);
269 	} else {
270 		if (flow.basic.n_proto == htons(ETH_P_IP))
271 			hash = jhash2((u32 *)&flow.addrs.v4addrs, 2, hashrnd);
272 		else if (flow.basic.n_proto == htons(ETH_P_IPV6))
273 			hash = jhash2((u32 *)&flow.addrs.v6addrs, 8, hashrnd);
274 		else
275 			hash = 0;
276 
277 		skb_set_hash(skb, hash, PKT_HASH_TYPE_L3);
278 	}
279 
280 	return hash;
281 }
282 
283 static inline int netvsc_get_tx_queue(struct net_device *ndev,
284 				      struct sk_buff *skb, int old_idx)
285 {
286 	const struct net_device_context *ndc = netdev_priv(ndev);
287 	struct sock *sk = skb->sk;
288 	int q_idx;
289 
290 	q_idx = ndc->tx_table[netvsc_get_hash(skb, ndc) &
291 			      (VRSS_SEND_TAB_SIZE - 1)];
292 
293 	/* If queue index changed record the new value */
294 	if (q_idx != old_idx &&
295 	    sk && sk_fullsock(sk) && rcu_access_pointer(sk->sk_dst_cache))
296 		sk_tx_queue_set(sk, q_idx);
297 
298 	return q_idx;
299 }
300 
301 /*
302  * Select queue for transmit.
303  *
304  * If a valid queue has already been assigned, then use that.
305  * Otherwise compute tx queue based on hash and the send table.
306  *
307  * This is basically similar to default (__netdev_pick_tx) with the added step
308  * of using the host send_table when no other queue has been assigned.
309  *
310  * TODO support XPS - but get_xps_queue not exported
311  */
312 static u16 netvsc_pick_tx(struct net_device *ndev, struct sk_buff *skb)
313 {
314 	int q_idx = sk_tx_queue_get(skb->sk);
315 
316 	if (q_idx < 0 || skb->ooo_okay || q_idx >= ndev->real_num_tx_queues) {
317 		/* If forwarding a packet, we use the recorded queue when
318 		 * available for better cache locality.
319 		 */
320 		if (skb_rx_queue_recorded(skb))
321 			q_idx = skb_get_rx_queue(skb);
322 		else
323 			q_idx = netvsc_get_tx_queue(ndev, skb, q_idx);
324 	}
325 
326 	return q_idx;
327 }
328 
329 static u16 netvsc_select_queue(struct net_device *ndev, struct sk_buff *skb,
330 			       void *accel_priv,
331 			       select_queue_fallback_t fallback)
332 {
333 	struct net_device_context *ndc = netdev_priv(ndev);
334 	struct net_device *vf_netdev;
335 	u16 txq;
336 
337 	rcu_read_lock();
338 	vf_netdev = rcu_dereference(ndc->vf_netdev);
339 	if (vf_netdev) {
340 		const struct net_device_ops *vf_ops = vf_netdev->netdev_ops;
341 
342 		if (vf_ops->ndo_select_queue)
343 			txq = vf_ops->ndo_select_queue(vf_netdev, skb,
344 						       accel_priv, fallback);
345 		else
346 			txq = fallback(vf_netdev, skb);
347 
348 		/* Record the queue selected by VF so that it can be
349 		 * used for common case where VF has more queues than
350 		 * the synthetic device.
351 		 */
352 		qdisc_skb_cb(skb)->slave_dev_queue_mapping = txq;
353 	} else {
354 		txq = netvsc_pick_tx(ndev, skb);
355 	}
356 	rcu_read_unlock();
357 
358 	while (unlikely(txq >= ndev->real_num_tx_queues))
359 		txq -= ndev->real_num_tx_queues;
360 
361 	return txq;
362 }
363 
364 static u32 fill_pg_buf(struct page *page, u32 offset, u32 len,
365 		       struct hv_page_buffer *pb)
366 {
367 	int j = 0;
368 
369 	/* Deal with compund pages by ignoring unused part
370 	 * of the page.
371 	 */
372 	page += (offset >> PAGE_SHIFT);
373 	offset &= ~PAGE_MASK;
374 
375 	while (len > 0) {
376 		unsigned long bytes;
377 
378 		bytes = PAGE_SIZE - offset;
379 		if (bytes > len)
380 			bytes = len;
381 		pb[j].pfn = page_to_pfn(page);
382 		pb[j].offset = offset;
383 		pb[j].len = bytes;
384 
385 		offset += bytes;
386 		len -= bytes;
387 
388 		if (offset == PAGE_SIZE && len) {
389 			page++;
390 			offset = 0;
391 			j++;
392 		}
393 	}
394 
395 	return j + 1;
396 }
397 
398 static u32 init_page_array(void *hdr, u32 len, struct sk_buff *skb,
399 			   struct hv_netvsc_packet *packet,
400 			   struct hv_page_buffer *pb)
401 {
402 	u32 slots_used = 0;
403 	char *data = skb->data;
404 	int frags = skb_shinfo(skb)->nr_frags;
405 	int i;
406 
407 	/* The packet is laid out thus:
408 	 * 1. hdr: RNDIS header and PPI
409 	 * 2. skb linear data
410 	 * 3. skb fragment data
411 	 */
412 	slots_used += fill_pg_buf(virt_to_page(hdr),
413 				  offset_in_page(hdr),
414 				  len, &pb[slots_used]);
415 
416 	packet->rmsg_size = len;
417 	packet->rmsg_pgcnt = slots_used;
418 
419 	slots_used += fill_pg_buf(virt_to_page(data),
420 				offset_in_page(data),
421 				skb_headlen(skb), &pb[slots_used]);
422 
423 	for (i = 0; i < frags; i++) {
424 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
425 
426 		slots_used += fill_pg_buf(skb_frag_page(frag),
427 					frag->page_offset,
428 					skb_frag_size(frag), &pb[slots_used]);
429 	}
430 	return slots_used;
431 }
432 
433 static int count_skb_frag_slots(struct sk_buff *skb)
434 {
435 	int i, frags = skb_shinfo(skb)->nr_frags;
436 	int pages = 0;
437 
438 	for (i = 0; i < frags; i++) {
439 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
440 		unsigned long size = skb_frag_size(frag);
441 		unsigned long offset = frag->page_offset;
442 
443 		/* Skip unused frames from start of page */
444 		offset &= ~PAGE_MASK;
445 		pages += PFN_UP(offset + size);
446 	}
447 	return pages;
448 }
449 
450 static int netvsc_get_slots(struct sk_buff *skb)
451 {
452 	char *data = skb->data;
453 	unsigned int offset = offset_in_page(data);
454 	unsigned int len = skb_headlen(skb);
455 	int slots;
456 	int frag_slots;
457 
458 	slots = DIV_ROUND_UP(offset + len, PAGE_SIZE);
459 	frag_slots = count_skb_frag_slots(skb);
460 	return slots + frag_slots;
461 }
462 
463 static u32 net_checksum_info(struct sk_buff *skb)
464 {
465 	if (skb->protocol == htons(ETH_P_IP)) {
466 		struct iphdr *ip = ip_hdr(skb);
467 
468 		if (ip->protocol == IPPROTO_TCP)
469 			return TRANSPORT_INFO_IPV4_TCP;
470 		else if (ip->protocol == IPPROTO_UDP)
471 			return TRANSPORT_INFO_IPV4_UDP;
472 	} else {
473 		struct ipv6hdr *ip6 = ipv6_hdr(skb);
474 
475 		if (ip6->nexthdr == IPPROTO_TCP)
476 			return TRANSPORT_INFO_IPV6_TCP;
477 		else if (ip6->nexthdr == IPPROTO_UDP)
478 			return TRANSPORT_INFO_IPV6_UDP;
479 	}
480 
481 	return TRANSPORT_INFO_NOT_IP;
482 }
483 
484 /* Send skb on the slave VF device. */
485 static int netvsc_vf_xmit(struct net_device *net, struct net_device *vf_netdev,
486 			  struct sk_buff *skb)
487 {
488 	struct net_device_context *ndev_ctx = netdev_priv(net);
489 	unsigned int len = skb->len;
490 	int rc;
491 
492 	skb->dev = vf_netdev;
493 	skb->queue_mapping = qdisc_skb_cb(skb)->slave_dev_queue_mapping;
494 
495 	rc = dev_queue_xmit(skb);
496 	if (likely(rc == NET_XMIT_SUCCESS || rc == NET_XMIT_CN)) {
497 		struct netvsc_vf_pcpu_stats *pcpu_stats
498 			= this_cpu_ptr(ndev_ctx->vf_stats);
499 
500 		u64_stats_update_begin(&pcpu_stats->syncp);
501 		pcpu_stats->tx_packets++;
502 		pcpu_stats->tx_bytes += len;
503 		u64_stats_update_end(&pcpu_stats->syncp);
504 	} else {
505 		this_cpu_inc(ndev_ctx->vf_stats->tx_dropped);
506 	}
507 
508 	return rc;
509 }
510 
511 static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
512 {
513 	struct net_device_context *net_device_ctx = netdev_priv(net);
514 	struct hv_netvsc_packet *packet = NULL;
515 	int ret;
516 	unsigned int num_data_pgs;
517 	struct rndis_message *rndis_msg;
518 	struct net_device *vf_netdev;
519 	u32 rndis_msg_size;
520 	u32 hash;
521 	struct hv_page_buffer pb[MAX_PAGE_BUFFER_COUNT];
522 
523 	/* if VF is present and up then redirect packets
524 	 * already called with rcu_read_lock_bh
525 	 */
526 	vf_netdev = rcu_dereference_bh(net_device_ctx->vf_netdev);
527 	if (vf_netdev && netif_running(vf_netdev) &&
528 	    !netpoll_tx_running(net))
529 		return netvsc_vf_xmit(net, vf_netdev, skb);
530 
531 	/* We will atmost need two pages to describe the rndis
532 	 * header. We can only transmit MAX_PAGE_BUFFER_COUNT number
533 	 * of pages in a single packet. If skb is scattered around
534 	 * more pages we try linearizing it.
535 	 */
536 
537 	num_data_pgs = netvsc_get_slots(skb) + 2;
538 
539 	if (unlikely(num_data_pgs > MAX_PAGE_BUFFER_COUNT)) {
540 		++net_device_ctx->eth_stats.tx_scattered;
541 
542 		if (skb_linearize(skb))
543 			goto no_memory;
544 
545 		num_data_pgs = netvsc_get_slots(skb) + 2;
546 		if (num_data_pgs > MAX_PAGE_BUFFER_COUNT) {
547 			++net_device_ctx->eth_stats.tx_too_big;
548 			goto drop;
549 		}
550 	}
551 
552 	/*
553 	 * Place the rndis header in the skb head room and
554 	 * the skb->cb will be used for hv_netvsc_packet
555 	 * structure.
556 	 */
557 	ret = skb_cow_head(skb, RNDIS_AND_PPI_SIZE);
558 	if (ret)
559 		goto no_memory;
560 
561 	/* Use the skb control buffer for building up the packet */
562 	BUILD_BUG_ON(sizeof(struct hv_netvsc_packet) >
563 			FIELD_SIZEOF(struct sk_buff, cb));
564 	packet = (struct hv_netvsc_packet *)skb->cb;
565 
566 	packet->q_idx = skb_get_queue_mapping(skb);
567 
568 	packet->total_data_buflen = skb->len;
569 	packet->total_bytes = skb->len;
570 	packet->total_packets = 1;
571 
572 	rndis_msg = (struct rndis_message *)skb->head;
573 
574 	/* Add the rndis header */
575 	rndis_msg->ndis_msg_type = RNDIS_MSG_PACKET;
576 	rndis_msg->msg_len = packet->total_data_buflen;
577 
578 	rndis_msg->msg.pkt = (struct rndis_packet) {
579 		.data_offset = sizeof(struct rndis_packet),
580 		.data_len = packet->total_data_buflen,
581 		.per_pkt_info_offset = sizeof(struct rndis_packet),
582 	};
583 
584 	rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
585 
586 	hash = skb_get_hash_raw(skb);
587 	if (hash != 0 && net->real_num_tx_queues > 1) {
588 		u32 *hash_info;
589 
590 		rndis_msg_size += NDIS_HASH_PPI_SIZE;
591 		hash_info = init_ppi_data(rndis_msg, NDIS_HASH_PPI_SIZE,
592 					  NBL_HASH_VALUE);
593 		*hash_info = hash;
594 	}
595 
596 	if (skb_vlan_tag_present(skb)) {
597 		struct ndis_pkt_8021q_info *vlan;
598 
599 		rndis_msg_size += NDIS_VLAN_PPI_SIZE;
600 		vlan = init_ppi_data(rndis_msg, NDIS_VLAN_PPI_SIZE,
601 				     IEEE_8021Q_INFO);
602 
603 		vlan->value = 0;
604 		vlan->vlanid = skb->vlan_tci & VLAN_VID_MASK;
605 		vlan->pri = (skb->vlan_tci & VLAN_PRIO_MASK) >>
606 				VLAN_PRIO_SHIFT;
607 	}
608 
609 	if (skb_is_gso(skb)) {
610 		struct ndis_tcp_lso_info *lso_info;
611 
612 		rndis_msg_size += NDIS_LSO_PPI_SIZE;
613 		lso_info = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
614 					 TCP_LARGESEND_PKTINFO);
615 
616 		lso_info->value = 0;
617 		lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
618 		if (skb->protocol == htons(ETH_P_IP)) {
619 			lso_info->lso_v2_transmit.ip_version =
620 				NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
621 			ip_hdr(skb)->tot_len = 0;
622 			ip_hdr(skb)->check = 0;
623 			tcp_hdr(skb)->check =
624 				~csum_tcpudp_magic(ip_hdr(skb)->saddr,
625 						   ip_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
626 		} else {
627 			lso_info->lso_v2_transmit.ip_version =
628 				NDIS_TCP_LARGE_SEND_OFFLOAD_IPV6;
629 			ipv6_hdr(skb)->payload_len = 0;
630 			tcp_hdr(skb)->check =
631 				~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
632 						 &ipv6_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
633 		}
634 		lso_info->lso_v2_transmit.tcp_header_offset = skb_transport_offset(skb);
635 		lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
636 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
637 		if (net_checksum_info(skb) & net_device_ctx->tx_checksum_mask) {
638 			struct ndis_tcp_ip_checksum_info *csum_info;
639 
640 			rndis_msg_size += NDIS_CSUM_PPI_SIZE;
641 			csum_info = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
642 						  TCPIP_CHKSUM_PKTINFO);
643 
644 			csum_info->value = 0;
645 			csum_info->transmit.tcp_header_offset = skb_transport_offset(skb);
646 
647 			if (skb->protocol == htons(ETH_P_IP)) {
648 				csum_info->transmit.is_ipv4 = 1;
649 
650 				if (ip_hdr(skb)->protocol == IPPROTO_TCP)
651 					csum_info->transmit.tcp_checksum = 1;
652 				else
653 					csum_info->transmit.udp_checksum = 1;
654 			} else {
655 				csum_info->transmit.is_ipv6 = 1;
656 
657 				if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
658 					csum_info->transmit.tcp_checksum = 1;
659 				else
660 					csum_info->transmit.udp_checksum = 1;
661 			}
662 		} else {
663 			/* Can't do offload of this type of checksum */
664 			if (skb_checksum_help(skb))
665 				goto drop;
666 		}
667 	}
668 
669 	/* Start filling in the page buffers with the rndis hdr */
670 	rndis_msg->msg_len += rndis_msg_size;
671 	packet->total_data_buflen = rndis_msg->msg_len;
672 	packet->page_buf_cnt = init_page_array(rndis_msg, rndis_msg_size,
673 					       skb, packet, pb);
674 
675 	/* timestamp packet in software */
676 	skb_tx_timestamp(skb);
677 
678 	ret = netvsc_send(net, packet, rndis_msg, pb, skb);
679 	if (likely(ret == 0))
680 		return NETDEV_TX_OK;
681 
682 	if (ret == -EAGAIN) {
683 		++net_device_ctx->eth_stats.tx_busy;
684 		return NETDEV_TX_BUSY;
685 	}
686 
687 	if (ret == -ENOSPC)
688 		++net_device_ctx->eth_stats.tx_no_space;
689 
690 drop:
691 	dev_kfree_skb_any(skb);
692 	net->stats.tx_dropped++;
693 
694 	return NETDEV_TX_OK;
695 
696 no_memory:
697 	++net_device_ctx->eth_stats.tx_no_memory;
698 	goto drop;
699 }
700 
701 /*
702  * netvsc_linkstatus_callback - Link up/down notification
703  */
704 void netvsc_linkstatus_callback(struct net_device *net,
705 				struct rndis_message *resp)
706 {
707 	struct rndis_indicate_status *indicate = &resp->msg.indicate_status;
708 	struct net_device_context *ndev_ctx = netdev_priv(net);
709 	struct netvsc_reconfig *event;
710 	unsigned long flags;
711 
712 	/* Update the physical link speed when changing to another vSwitch */
713 	if (indicate->status == RNDIS_STATUS_LINK_SPEED_CHANGE) {
714 		u32 speed;
715 
716 		speed = *(u32 *)((void *)indicate
717 				 + indicate->status_buf_offset) / 10000;
718 		ndev_ctx->speed = speed;
719 		return;
720 	}
721 
722 	/* Handle these link change statuses below */
723 	if (indicate->status != RNDIS_STATUS_NETWORK_CHANGE &&
724 	    indicate->status != RNDIS_STATUS_MEDIA_CONNECT &&
725 	    indicate->status != RNDIS_STATUS_MEDIA_DISCONNECT)
726 		return;
727 
728 	if (net->reg_state != NETREG_REGISTERED)
729 		return;
730 
731 	event = kzalloc(sizeof(*event), GFP_ATOMIC);
732 	if (!event)
733 		return;
734 	event->event = indicate->status;
735 
736 	spin_lock_irqsave(&ndev_ctx->lock, flags);
737 	list_add_tail(&event->list, &ndev_ctx->reconfig_events);
738 	spin_unlock_irqrestore(&ndev_ctx->lock, flags);
739 
740 	schedule_delayed_work(&ndev_ctx->dwork, 0);
741 }
742 
743 static struct sk_buff *netvsc_alloc_recv_skb(struct net_device *net,
744 					     struct napi_struct *napi,
745 					     const struct ndis_tcp_ip_checksum_info *csum_info,
746 					     const struct ndis_pkt_8021q_info *vlan,
747 					     void *data, u32 buflen)
748 {
749 	struct sk_buff *skb;
750 
751 	skb = napi_alloc_skb(napi, buflen);
752 	if (!skb)
753 		return skb;
754 
755 	/*
756 	 * Copy to skb. This copy is needed here since the memory pointed by
757 	 * hv_netvsc_packet cannot be deallocated
758 	 */
759 	skb_put_data(skb, data, buflen);
760 
761 	skb->protocol = eth_type_trans(skb, net);
762 
763 	/* skb is already created with CHECKSUM_NONE */
764 	skb_checksum_none_assert(skb);
765 
766 	/*
767 	 * In Linux, the IP checksum is always checked.
768 	 * Do L4 checksum offload if enabled and present.
769 	 */
770 	if (csum_info && (net->features & NETIF_F_RXCSUM)) {
771 		if (csum_info->receive.tcp_checksum_succeeded ||
772 		    csum_info->receive.udp_checksum_succeeded)
773 			skb->ip_summed = CHECKSUM_UNNECESSARY;
774 	}
775 
776 	if (vlan) {
777 		u16 vlan_tci = vlan->vlanid | (vlan->pri << VLAN_PRIO_SHIFT);
778 
779 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
780 				       vlan_tci);
781 	}
782 
783 	return skb;
784 }
785 
786 /*
787  * netvsc_recv_callback -  Callback when we receive a packet from the
788  * "wire" on the specified device.
789  */
790 int netvsc_recv_callback(struct net_device *net,
791 			 struct netvsc_device *net_device,
792 			 struct vmbus_channel *channel,
793 			 void  *data, u32 len,
794 			 const struct ndis_tcp_ip_checksum_info *csum_info,
795 			 const struct ndis_pkt_8021q_info *vlan)
796 {
797 	struct net_device_context *net_device_ctx = netdev_priv(net);
798 	u16 q_idx = channel->offermsg.offer.sub_channel_index;
799 	struct netvsc_channel *nvchan = &net_device->chan_table[q_idx];
800 	struct sk_buff *skb;
801 	struct netvsc_stats *rx_stats;
802 
803 	if (net->reg_state != NETREG_REGISTERED)
804 		return NVSP_STAT_FAIL;
805 
806 	/* Allocate a skb - TODO direct I/O to pages? */
807 	skb = netvsc_alloc_recv_skb(net, &nvchan->napi,
808 				    csum_info, vlan, data, len);
809 	if (unlikely(!skb)) {
810 		++net_device_ctx->eth_stats.rx_no_memory;
811 		rcu_read_unlock();
812 		return NVSP_STAT_FAIL;
813 	}
814 
815 	skb_record_rx_queue(skb, q_idx);
816 
817 	/*
818 	 * Even if injecting the packet, record the statistics
819 	 * on the synthetic device because modifying the VF device
820 	 * statistics will not work correctly.
821 	 */
822 	rx_stats = &nvchan->rx_stats;
823 	u64_stats_update_begin(&rx_stats->syncp);
824 	rx_stats->packets++;
825 	rx_stats->bytes += len;
826 
827 	if (skb->pkt_type == PACKET_BROADCAST)
828 		++rx_stats->broadcast;
829 	else if (skb->pkt_type == PACKET_MULTICAST)
830 		++rx_stats->multicast;
831 	u64_stats_update_end(&rx_stats->syncp);
832 
833 	napi_gro_receive(&nvchan->napi, skb);
834 	return NVSP_STAT_SUCCESS;
835 }
836 
837 static void netvsc_get_drvinfo(struct net_device *net,
838 			       struct ethtool_drvinfo *info)
839 {
840 	strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
841 	strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
842 }
843 
844 static void netvsc_get_channels(struct net_device *net,
845 				struct ethtool_channels *channel)
846 {
847 	struct net_device_context *net_device_ctx = netdev_priv(net);
848 	struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
849 
850 	if (nvdev) {
851 		channel->max_combined	= nvdev->max_chn;
852 		channel->combined_count = nvdev->num_chn;
853 	}
854 }
855 
856 static int netvsc_detach(struct net_device *ndev,
857 			 struct netvsc_device *nvdev)
858 {
859 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
860 	struct hv_device *hdev = ndev_ctx->device_ctx;
861 	int ret;
862 
863 	/* Don't try continuing to try and setup sub channels */
864 	if (cancel_work_sync(&nvdev->subchan_work))
865 		nvdev->num_chn = 1;
866 
867 	/* If device was up (receiving) then shutdown */
868 	if (netif_running(ndev)) {
869 		netif_tx_disable(ndev);
870 
871 		ret = rndis_filter_close(nvdev);
872 		if (ret) {
873 			netdev_err(ndev,
874 				   "unable to close device (ret %d).\n", ret);
875 			return ret;
876 		}
877 
878 		ret = netvsc_wait_until_empty(nvdev);
879 		if (ret) {
880 			netdev_err(ndev,
881 				   "Ring buffer not empty after closing rndis\n");
882 			return ret;
883 		}
884 	}
885 
886 	netif_device_detach(ndev);
887 
888 	rndis_filter_device_remove(hdev, nvdev);
889 
890 	return 0;
891 }
892 
893 static int netvsc_attach(struct net_device *ndev,
894 			 struct netvsc_device_info *dev_info)
895 {
896 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
897 	struct hv_device *hdev = ndev_ctx->device_ctx;
898 	struct netvsc_device *nvdev;
899 	struct rndis_device *rdev;
900 	int ret;
901 
902 	nvdev = rndis_filter_device_add(hdev, dev_info);
903 	if (IS_ERR(nvdev))
904 		return PTR_ERR(nvdev);
905 
906 	/* Note: enable and attach happen when sub-channels setup */
907 
908 	netif_carrier_off(ndev);
909 
910 	if (netif_running(ndev)) {
911 		ret = rndis_filter_open(nvdev);
912 		if (ret)
913 			return ret;
914 
915 		rdev = nvdev->extension;
916 		if (!rdev->link_state)
917 			netif_carrier_on(ndev);
918 	}
919 
920 	return 0;
921 }
922 
923 static int netvsc_set_channels(struct net_device *net,
924 			       struct ethtool_channels *channels)
925 {
926 	struct net_device_context *net_device_ctx = netdev_priv(net);
927 	struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
928 	unsigned int orig, count = channels->combined_count;
929 	struct netvsc_device_info device_info;
930 	int ret;
931 
932 	/* We do not support separate count for rx, tx, or other */
933 	if (count == 0 ||
934 	    channels->rx_count || channels->tx_count || channels->other_count)
935 		return -EINVAL;
936 
937 	if (!nvdev || nvdev->destroy)
938 		return -ENODEV;
939 
940 	if (nvdev->nvsp_version < NVSP_PROTOCOL_VERSION_5)
941 		return -EINVAL;
942 
943 	if (count > nvdev->max_chn)
944 		return -EINVAL;
945 
946 	orig = nvdev->num_chn;
947 
948 	memset(&device_info, 0, sizeof(device_info));
949 	device_info.num_chn = count;
950 	device_info.send_sections = nvdev->send_section_cnt;
951 	device_info.send_section_size = nvdev->send_section_size;
952 	device_info.recv_sections = nvdev->recv_section_cnt;
953 	device_info.recv_section_size = nvdev->recv_section_size;
954 
955 	ret = netvsc_detach(net, nvdev);
956 	if (ret)
957 		return ret;
958 
959 	ret = netvsc_attach(net, &device_info);
960 	if (ret) {
961 		device_info.num_chn = orig;
962 		if (netvsc_attach(net, &device_info))
963 			netdev_err(net, "restoring channel setting failed\n");
964 	}
965 
966 	return ret;
967 }
968 
969 static bool
970 netvsc_validate_ethtool_ss_cmd(const struct ethtool_link_ksettings *cmd)
971 {
972 	struct ethtool_link_ksettings diff1 = *cmd;
973 	struct ethtool_link_ksettings diff2 = {};
974 
975 	diff1.base.speed = 0;
976 	diff1.base.duplex = 0;
977 	/* advertising and cmd are usually set */
978 	ethtool_link_ksettings_zero_link_mode(&diff1, advertising);
979 	diff1.base.cmd = 0;
980 	/* We set port to PORT_OTHER */
981 	diff2.base.port = PORT_OTHER;
982 
983 	return !memcmp(&diff1, &diff2, sizeof(diff1));
984 }
985 
986 static void netvsc_init_settings(struct net_device *dev)
987 {
988 	struct net_device_context *ndc = netdev_priv(dev);
989 
990 	ndc->l4_hash = HV_DEFAULT_L4HASH;
991 
992 	ndc->speed = SPEED_UNKNOWN;
993 	ndc->duplex = DUPLEX_FULL;
994 }
995 
996 static int netvsc_get_link_ksettings(struct net_device *dev,
997 				     struct ethtool_link_ksettings *cmd)
998 {
999 	struct net_device_context *ndc = netdev_priv(dev);
1000 
1001 	cmd->base.speed = ndc->speed;
1002 	cmd->base.duplex = ndc->duplex;
1003 	cmd->base.port = PORT_OTHER;
1004 
1005 	return 0;
1006 }
1007 
1008 static int netvsc_set_link_ksettings(struct net_device *dev,
1009 				     const struct ethtool_link_ksettings *cmd)
1010 {
1011 	struct net_device_context *ndc = netdev_priv(dev);
1012 	u32 speed;
1013 
1014 	speed = cmd->base.speed;
1015 	if (!ethtool_validate_speed(speed) ||
1016 	    !ethtool_validate_duplex(cmd->base.duplex) ||
1017 	    !netvsc_validate_ethtool_ss_cmd(cmd))
1018 		return -EINVAL;
1019 
1020 	ndc->speed = speed;
1021 	ndc->duplex = cmd->base.duplex;
1022 
1023 	return 0;
1024 }
1025 
1026 static int netvsc_change_mtu(struct net_device *ndev, int mtu)
1027 {
1028 	struct net_device_context *ndevctx = netdev_priv(ndev);
1029 	struct net_device *vf_netdev = rtnl_dereference(ndevctx->vf_netdev);
1030 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1031 	int orig_mtu = ndev->mtu;
1032 	struct netvsc_device_info device_info;
1033 	int ret = 0;
1034 
1035 	if (!nvdev || nvdev->destroy)
1036 		return -ENODEV;
1037 
1038 	/* Change MTU of underlying VF netdev first. */
1039 	if (vf_netdev) {
1040 		ret = dev_set_mtu(vf_netdev, mtu);
1041 		if (ret)
1042 			return ret;
1043 	}
1044 
1045 	memset(&device_info, 0, sizeof(device_info));
1046 	device_info.num_chn = nvdev->num_chn;
1047 	device_info.send_sections = nvdev->send_section_cnt;
1048 	device_info.send_section_size = nvdev->send_section_size;
1049 	device_info.recv_sections = nvdev->recv_section_cnt;
1050 	device_info.recv_section_size = nvdev->recv_section_size;
1051 
1052 	ret = netvsc_detach(ndev, nvdev);
1053 	if (ret)
1054 		goto rollback_vf;
1055 
1056 	ndev->mtu = mtu;
1057 
1058 	ret = netvsc_attach(ndev, &device_info);
1059 	if (ret)
1060 		goto rollback;
1061 
1062 	return 0;
1063 
1064 rollback:
1065 	/* Attempt rollback to original MTU */
1066 	ndev->mtu = orig_mtu;
1067 
1068 	if (netvsc_attach(ndev, &device_info))
1069 		netdev_err(ndev, "restoring mtu failed\n");
1070 rollback_vf:
1071 	if (vf_netdev)
1072 		dev_set_mtu(vf_netdev, orig_mtu);
1073 
1074 	return ret;
1075 }
1076 
1077 static void netvsc_get_vf_stats(struct net_device *net,
1078 				struct netvsc_vf_pcpu_stats *tot)
1079 {
1080 	struct net_device_context *ndev_ctx = netdev_priv(net);
1081 	int i;
1082 
1083 	memset(tot, 0, sizeof(*tot));
1084 
1085 	for_each_possible_cpu(i) {
1086 		const struct netvsc_vf_pcpu_stats *stats
1087 			= per_cpu_ptr(ndev_ctx->vf_stats, i);
1088 		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1089 		unsigned int start;
1090 
1091 		do {
1092 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1093 			rx_packets = stats->rx_packets;
1094 			tx_packets = stats->tx_packets;
1095 			rx_bytes = stats->rx_bytes;
1096 			tx_bytes = stats->tx_bytes;
1097 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1098 
1099 		tot->rx_packets += rx_packets;
1100 		tot->tx_packets += tx_packets;
1101 		tot->rx_bytes   += rx_bytes;
1102 		tot->tx_bytes   += tx_bytes;
1103 		tot->tx_dropped += stats->tx_dropped;
1104 	}
1105 }
1106 
1107 static void netvsc_get_stats64(struct net_device *net,
1108 			       struct rtnl_link_stats64 *t)
1109 {
1110 	struct net_device_context *ndev_ctx = netdev_priv(net);
1111 	struct netvsc_device *nvdev = rcu_dereference_rtnl(ndev_ctx->nvdev);
1112 	struct netvsc_vf_pcpu_stats vf_tot;
1113 	int i;
1114 
1115 	if (!nvdev)
1116 		return;
1117 
1118 	netdev_stats_to_stats64(t, &net->stats);
1119 
1120 	netvsc_get_vf_stats(net, &vf_tot);
1121 	t->rx_packets += vf_tot.rx_packets;
1122 	t->tx_packets += vf_tot.tx_packets;
1123 	t->rx_bytes   += vf_tot.rx_bytes;
1124 	t->tx_bytes   += vf_tot.tx_bytes;
1125 	t->tx_dropped += vf_tot.tx_dropped;
1126 
1127 	for (i = 0; i < nvdev->num_chn; i++) {
1128 		const struct netvsc_channel *nvchan = &nvdev->chan_table[i];
1129 		const struct netvsc_stats *stats;
1130 		u64 packets, bytes, multicast;
1131 		unsigned int start;
1132 
1133 		stats = &nvchan->tx_stats;
1134 		do {
1135 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1136 			packets = stats->packets;
1137 			bytes = stats->bytes;
1138 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1139 
1140 		t->tx_bytes	+= bytes;
1141 		t->tx_packets	+= packets;
1142 
1143 		stats = &nvchan->rx_stats;
1144 		do {
1145 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1146 			packets = stats->packets;
1147 			bytes = stats->bytes;
1148 			multicast = stats->multicast + stats->broadcast;
1149 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1150 
1151 		t->rx_bytes	+= bytes;
1152 		t->rx_packets	+= packets;
1153 		t->multicast	+= multicast;
1154 	}
1155 }
1156 
1157 static int netvsc_set_mac_addr(struct net_device *ndev, void *p)
1158 {
1159 	struct net_device_context *ndc = netdev_priv(ndev);
1160 	struct net_device *vf_netdev = rtnl_dereference(ndc->vf_netdev);
1161 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1162 	struct sockaddr *addr = p;
1163 	int err;
1164 
1165 	err = eth_prepare_mac_addr_change(ndev, p);
1166 	if (err)
1167 		return err;
1168 
1169 	if (!nvdev)
1170 		return -ENODEV;
1171 
1172 	if (vf_netdev) {
1173 		err = dev_set_mac_address(vf_netdev, addr);
1174 		if (err)
1175 			return err;
1176 	}
1177 
1178 	err = rndis_filter_set_device_mac(nvdev, addr->sa_data);
1179 	if (!err) {
1180 		eth_commit_mac_addr_change(ndev, p);
1181 	} else if (vf_netdev) {
1182 		/* rollback change on VF */
1183 		memcpy(addr->sa_data, ndev->dev_addr, ETH_ALEN);
1184 		dev_set_mac_address(vf_netdev, addr);
1185 	}
1186 
1187 	return err;
1188 }
1189 
1190 static const struct {
1191 	char name[ETH_GSTRING_LEN];
1192 	u16 offset;
1193 } netvsc_stats[] = {
1194 	{ "tx_scattered", offsetof(struct netvsc_ethtool_stats, tx_scattered) },
1195 	{ "tx_no_memory", offsetof(struct netvsc_ethtool_stats, tx_no_memory) },
1196 	{ "tx_no_space",  offsetof(struct netvsc_ethtool_stats, tx_no_space) },
1197 	{ "tx_too_big",	  offsetof(struct netvsc_ethtool_stats, tx_too_big) },
1198 	{ "tx_busy",	  offsetof(struct netvsc_ethtool_stats, tx_busy) },
1199 	{ "tx_send_full", offsetof(struct netvsc_ethtool_stats, tx_send_full) },
1200 	{ "rx_comp_busy", offsetof(struct netvsc_ethtool_stats, rx_comp_busy) },
1201 	{ "rx_no_memory", offsetof(struct netvsc_ethtool_stats, rx_no_memory) },
1202 	{ "stop_queue", offsetof(struct netvsc_ethtool_stats, stop_queue) },
1203 	{ "wake_queue", offsetof(struct netvsc_ethtool_stats, wake_queue) },
1204 }, vf_stats[] = {
1205 	{ "vf_rx_packets", offsetof(struct netvsc_vf_pcpu_stats, rx_packets) },
1206 	{ "vf_rx_bytes",   offsetof(struct netvsc_vf_pcpu_stats, rx_bytes) },
1207 	{ "vf_tx_packets", offsetof(struct netvsc_vf_pcpu_stats, tx_packets) },
1208 	{ "vf_tx_bytes",   offsetof(struct netvsc_vf_pcpu_stats, tx_bytes) },
1209 	{ "vf_tx_dropped", offsetof(struct netvsc_vf_pcpu_stats, tx_dropped) },
1210 };
1211 
1212 #define NETVSC_GLOBAL_STATS_LEN	ARRAY_SIZE(netvsc_stats)
1213 #define NETVSC_VF_STATS_LEN	ARRAY_SIZE(vf_stats)
1214 
1215 /* 4 statistics per queue (rx/tx packets/bytes) */
1216 #define NETVSC_QUEUE_STATS_LEN(dev) ((dev)->num_chn * 4)
1217 
1218 static int netvsc_get_sset_count(struct net_device *dev, int string_set)
1219 {
1220 	struct net_device_context *ndc = netdev_priv(dev);
1221 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1222 
1223 	if (!nvdev)
1224 		return -ENODEV;
1225 
1226 	switch (string_set) {
1227 	case ETH_SS_STATS:
1228 		return NETVSC_GLOBAL_STATS_LEN
1229 			+ NETVSC_VF_STATS_LEN
1230 			+ NETVSC_QUEUE_STATS_LEN(nvdev);
1231 	default:
1232 		return -EINVAL;
1233 	}
1234 }
1235 
1236 static void netvsc_get_ethtool_stats(struct net_device *dev,
1237 				     struct ethtool_stats *stats, u64 *data)
1238 {
1239 	struct net_device_context *ndc = netdev_priv(dev);
1240 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1241 	const void *nds = &ndc->eth_stats;
1242 	const struct netvsc_stats *qstats;
1243 	struct netvsc_vf_pcpu_stats sum;
1244 	unsigned int start;
1245 	u64 packets, bytes;
1246 	int i, j;
1247 
1248 	if (!nvdev)
1249 		return;
1250 
1251 	for (i = 0; i < NETVSC_GLOBAL_STATS_LEN; i++)
1252 		data[i] = *(unsigned long *)(nds + netvsc_stats[i].offset);
1253 
1254 	netvsc_get_vf_stats(dev, &sum);
1255 	for (j = 0; j < NETVSC_VF_STATS_LEN; j++)
1256 		data[i++] = *(u64 *)((void *)&sum + vf_stats[j].offset);
1257 
1258 	for (j = 0; j < nvdev->num_chn; j++) {
1259 		qstats = &nvdev->chan_table[j].tx_stats;
1260 
1261 		do {
1262 			start = u64_stats_fetch_begin_irq(&qstats->syncp);
1263 			packets = qstats->packets;
1264 			bytes = qstats->bytes;
1265 		} while (u64_stats_fetch_retry_irq(&qstats->syncp, start));
1266 		data[i++] = packets;
1267 		data[i++] = bytes;
1268 
1269 		qstats = &nvdev->chan_table[j].rx_stats;
1270 		do {
1271 			start = u64_stats_fetch_begin_irq(&qstats->syncp);
1272 			packets = qstats->packets;
1273 			bytes = qstats->bytes;
1274 		} while (u64_stats_fetch_retry_irq(&qstats->syncp, start));
1275 		data[i++] = packets;
1276 		data[i++] = bytes;
1277 	}
1278 }
1279 
1280 static void netvsc_get_strings(struct net_device *dev, u32 stringset, u8 *data)
1281 {
1282 	struct net_device_context *ndc = netdev_priv(dev);
1283 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1284 	u8 *p = data;
1285 	int i;
1286 
1287 	if (!nvdev)
1288 		return;
1289 
1290 	switch (stringset) {
1291 	case ETH_SS_STATS:
1292 		for (i = 0; i < ARRAY_SIZE(netvsc_stats); i++) {
1293 			memcpy(p, netvsc_stats[i].name, ETH_GSTRING_LEN);
1294 			p += ETH_GSTRING_LEN;
1295 		}
1296 
1297 		for (i = 0; i < ARRAY_SIZE(vf_stats); i++) {
1298 			memcpy(p, vf_stats[i].name, ETH_GSTRING_LEN);
1299 			p += ETH_GSTRING_LEN;
1300 		}
1301 
1302 		for (i = 0; i < nvdev->num_chn; i++) {
1303 			sprintf(p, "tx_queue_%u_packets", i);
1304 			p += ETH_GSTRING_LEN;
1305 			sprintf(p, "tx_queue_%u_bytes", i);
1306 			p += ETH_GSTRING_LEN;
1307 			sprintf(p, "rx_queue_%u_packets", i);
1308 			p += ETH_GSTRING_LEN;
1309 			sprintf(p, "rx_queue_%u_bytes", i);
1310 			p += ETH_GSTRING_LEN;
1311 		}
1312 
1313 		break;
1314 	}
1315 }
1316 
1317 static int
1318 netvsc_get_rss_hash_opts(struct net_device_context *ndc,
1319 			 struct ethtool_rxnfc *info)
1320 {
1321 	const u32 l4_flag = RXH_L4_B_0_1 | RXH_L4_B_2_3;
1322 
1323 	info->data = RXH_IP_SRC | RXH_IP_DST;
1324 
1325 	switch (info->flow_type) {
1326 	case TCP_V4_FLOW:
1327 		if (ndc->l4_hash & HV_TCP4_L4HASH)
1328 			info->data |= l4_flag;
1329 
1330 		break;
1331 
1332 	case TCP_V6_FLOW:
1333 		if (ndc->l4_hash & HV_TCP6_L4HASH)
1334 			info->data |= l4_flag;
1335 
1336 		break;
1337 
1338 	case UDP_V4_FLOW:
1339 		if (ndc->l4_hash & HV_UDP4_L4HASH)
1340 			info->data |= l4_flag;
1341 
1342 		break;
1343 
1344 	case UDP_V6_FLOW:
1345 		if (ndc->l4_hash & HV_UDP6_L4HASH)
1346 			info->data |= l4_flag;
1347 
1348 		break;
1349 
1350 	case IPV4_FLOW:
1351 	case IPV6_FLOW:
1352 		break;
1353 	default:
1354 		info->data = 0;
1355 		break;
1356 	}
1357 
1358 	return 0;
1359 }
1360 
1361 static int
1362 netvsc_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info,
1363 		 u32 *rules)
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 (info->cmd) {
1372 	case ETHTOOL_GRXRINGS:
1373 		info->data = nvdev->num_chn;
1374 		return 0;
1375 
1376 	case ETHTOOL_GRXFH:
1377 		return netvsc_get_rss_hash_opts(ndc, info);
1378 	}
1379 	return -EOPNOTSUPP;
1380 }
1381 
1382 static int netvsc_set_rss_hash_opts(struct net_device_context *ndc,
1383 				    struct ethtool_rxnfc *info)
1384 {
1385 	if (info->data == (RXH_IP_SRC | RXH_IP_DST |
1386 			   RXH_L4_B_0_1 | RXH_L4_B_2_3)) {
1387 		switch (info->flow_type) {
1388 		case TCP_V4_FLOW:
1389 			ndc->l4_hash |= HV_TCP4_L4HASH;
1390 			break;
1391 
1392 		case TCP_V6_FLOW:
1393 			ndc->l4_hash |= HV_TCP6_L4HASH;
1394 			break;
1395 
1396 		case UDP_V4_FLOW:
1397 			ndc->l4_hash |= HV_UDP4_L4HASH;
1398 			break;
1399 
1400 		case UDP_V6_FLOW:
1401 			ndc->l4_hash |= HV_UDP6_L4HASH;
1402 			break;
1403 
1404 		default:
1405 			return -EOPNOTSUPP;
1406 		}
1407 
1408 		return 0;
1409 	}
1410 
1411 	if (info->data == (RXH_IP_SRC | RXH_IP_DST)) {
1412 		switch (info->flow_type) {
1413 		case TCP_V4_FLOW:
1414 			ndc->l4_hash &= ~HV_TCP4_L4HASH;
1415 			break;
1416 
1417 		case TCP_V6_FLOW:
1418 			ndc->l4_hash &= ~HV_TCP6_L4HASH;
1419 			break;
1420 
1421 		case UDP_V4_FLOW:
1422 			ndc->l4_hash &= ~HV_UDP4_L4HASH;
1423 			break;
1424 
1425 		case UDP_V6_FLOW:
1426 			ndc->l4_hash &= ~HV_UDP6_L4HASH;
1427 			break;
1428 
1429 		default:
1430 			return -EOPNOTSUPP;
1431 		}
1432 
1433 		return 0;
1434 	}
1435 
1436 	return -EOPNOTSUPP;
1437 }
1438 
1439 static int
1440 netvsc_set_rxnfc(struct net_device *ndev, struct ethtool_rxnfc *info)
1441 {
1442 	struct net_device_context *ndc = netdev_priv(ndev);
1443 
1444 	if (info->cmd == ETHTOOL_SRXFH)
1445 		return netvsc_set_rss_hash_opts(ndc, info);
1446 
1447 	return -EOPNOTSUPP;
1448 }
1449 
1450 #ifdef CONFIG_NET_POLL_CONTROLLER
1451 static void netvsc_poll_controller(struct net_device *dev)
1452 {
1453 	struct net_device_context *ndc = netdev_priv(dev);
1454 	struct netvsc_device *ndev;
1455 	int i;
1456 
1457 	rcu_read_lock();
1458 	ndev = rcu_dereference(ndc->nvdev);
1459 	if (ndev) {
1460 		for (i = 0; i < ndev->num_chn; i++) {
1461 			struct netvsc_channel *nvchan = &ndev->chan_table[i];
1462 
1463 			napi_schedule(&nvchan->napi);
1464 		}
1465 	}
1466 	rcu_read_unlock();
1467 }
1468 #endif
1469 
1470 static u32 netvsc_get_rxfh_key_size(struct net_device *dev)
1471 {
1472 	return NETVSC_HASH_KEYLEN;
1473 }
1474 
1475 static u32 netvsc_rss_indir_size(struct net_device *dev)
1476 {
1477 	return ITAB_NUM;
1478 }
1479 
1480 static int netvsc_get_rxfh(struct net_device *dev, u32 *indir, u8 *key,
1481 			   u8 *hfunc)
1482 {
1483 	struct net_device_context *ndc = netdev_priv(dev);
1484 	struct netvsc_device *ndev = rtnl_dereference(ndc->nvdev);
1485 	struct rndis_device *rndis_dev;
1486 	int i;
1487 
1488 	if (!ndev)
1489 		return -ENODEV;
1490 
1491 	if (hfunc)
1492 		*hfunc = ETH_RSS_HASH_TOP;	/* Toeplitz */
1493 
1494 	rndis_dev = ndev->extension;
1495 	if (indir) {
1496 		for (i = 0; i < ITAB_NUM; i++)
1497 			indir[i] = rndis_dev->rx_table[i];
1498 	}
1499 
1500 	if (key)
1501 		memcpy(key, rndis_dev->rss_key, NETVSC_HASH_KEYLEN);
1502 
1503 	return 0;
1504 }
1505 
1506 static int netvsc_set_rxfh(struct net_device *dev, const u32 *indir,
1507 			   const u8 *key, const u8 hfunc)
1508 {
1509 	struct net_device_context *ndc = netdev_priv(dev);
1510 	struct netvsc_device *ndev = rtnl_dereference(ndc->nvdev);
1511 	struct rndis_device *rndis_dev;
1512 	int i;
1513 
1514 	if (!ndev)
1515 		return -ENODEV;
1516 
1517 	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
1518 		return -EOPNOTSUPP;
1519 
1520 	rndis_dev = ndev->extension;
1521 	if (indir) {
1522 		for (i = 0; i < ITAB_NUM; i++)
1523 			if (indir[i] >= ndev->num_chn)
1524 				return -EINVAL;
1525 
1526 		for (i = 0; i < ITAB_NUM; i++)
1527 			rndis_dev->rx_table[i] = indir[i];
1528 	}
1529 
1530 	if (!key) {
1531 		if (!indir)
1532 			return 0;
1533 
1534 		key = rndis_dev->rss_key;
1535 	}
1536 
1537 	return rndis_filter_set_rss_param(rndis_dev, key);
1538 }
1539 
1540 /* Hyper-V RNDIS protocol does not have ring in the HW sense.
1541  * It does have pre-allocated receive area which is divided into sections.
1542  */
1543 static void __netvsc_get_ringparam(struct netvsc_device *nvdev,
1544 				   struct ethtool_ringparam *ring)
1545 {
1546 	u32 max_buf_size;
1547 
1548 	ring->rx_pending = nvdev->recv_section_cnt;
1549 	ring->tx_pending = nvdev->send_section_cnt;
1550 
1551 	if (nvdev->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
1552 		max_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
1553 	else
1554 		max_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
1555 
1556 	ring->rx_max_pending = max_buf_size / nvdev->recv_section_size;
1557 	ring->tx_max_pending = NETVSC_SEND_BUFFER_SIZE
1558 		/ nvdev->send_section_size;
1559 }
1560 
1561 static void netvsc_get_ringparam(struct net_device *ndev,
1562 				 struct ethtool_ringparam *ring)
1563 {
1564 	struct net_device_context *ndevctx = netdev_priv(ndev);
1565 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1566 
1567 	if (!nvdev)
1568 		return;
1569 
1570 	__netvsc_get_ringparam(nvdev, ring);
1571 }
1572 
1573 static int netvsc_set_ringparam(struct net_device *ndev,
1574 				struct ethtool_ringparam *ring)
1575 {
1576 	struct net_device_context *ndevctx = netdev_priv(ndev);
1577 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1578 	struct netvsc_device_info device_info;
1579 	struct ethtool_ringparam orig;
1580 	u32 new_tx, new_rx;
1581 	int ret = 0;
1582 
1583 	if (!nvdev || nvdev->destroy)
1584 		return -ENODEV;
1585 
1586 	memset(&orig, 0, sizeof(orig));
1587 	__netvsc_get_ringparam(nvdev, &orig);
1588 
1589 	new_tx = clamp_t(u32, ring->tx_pending,
1590 			 NETVSC_MIN_TX_SECTIONS, orig.tx_max_pending);
1591 	new_rx = clamp_t(u32, ring->rx_pending,
1592 			 NETVSC_MIN_RX_SECTIONS, orig.rx_max_pending);
1593 
1594 	if (new_tx == orig.tx_pending &&
1595 	    new_rx == orig.rx_pending)
1596 		return 0;	 /* no change */
1597 
1598 	memset(&device_info, 0, sizeof(device_info));
1599 	device_info.num_chn = nvdev->num_chn;
1600 	device_info.send_sections = new_tx;
1601 	device_info.send_section_size = nvdev->send_section_size;
1602 	device_info.recv_sections = new_rx;
1603 	device_info.recv_section_size = nvdev->recv_section_size;
1604 
1605 	ret = netvsc_detach(ndev, nvdev);
1606 	if (ret)
1607 		return ret;
1608 
1609 	ret = netvsc_attach(ndev, &device_info);
1610 	if (ret) {
1611 		device_info.send_sections = orig.tx_pending;
1612 		device_info.recv_sections = orig.rx_pending;
1613 
1614 		if (netvsc_attach(ndev, &device_info))
1615 			netdev_err(ndev, "restoring ringparam failed");
1616 	}
1617 
1618 	return ret;
1619 }
1620 
1621 static const struct ethtool_ops ethtool_ops = {
1622 	.get_drvinfo	= netvsc_get_drvinfo,
1623 	.get_link	= ethtool_op_get_link,
1624 	.get_ethtool_stats = netvsc_get_ethtool_stats,
1625 	.get_sset_count = netvsc_get_sset_count,
1626 	.get_strings	= netvsc_get_strings,
1627 	.get_channels   = netvsc_get_channels,
1628 	.set_channels   = netvsc_set_channels,
1629 	.get_ts_info	= ethtool_op_get_ts_info,
1630 	.get_rxnfc	= netvsc_get_rxnfc,
1631 	.set_rxnfc	= netvsc_set_rxnfc,
1632 	.get_rxfh_key_size = netvsc_get_rxfh_key_size,
1633 	.get_rxfh_indir_size = netvsc_rss_indir_size,
1634 	.get_rxfh	= netvsc_get_rxfh,
1635 	.set_rxfh	= netvsc_set_rxfh,
1636 	.get_link_ksettings = netvsc_get_link_ksettings,
1637 	.set_link_ksettings = netvsc_set_link_ksettings,
1638 	.get_ringparam	= netvsc_get_ringparam,
1639 	.set_ringparam	= netvsc_set_ringparam,
1640 };
1641 
1642 static const struct net_device_ops device_ops = {
1643 	.ndo_open =			netvsc_open,
1644 	.ndo_stop =			netvsc_close,
1645 	.ndo_start_xmit =		netvsc_start_xmit,
1646 	.ndo_change_rx_flags =		netvsc_change_rx_flags,
1647 	.ndo_set_rx_mode =		netvsc_set_rx_mode,
1648 	.ndo_change_mtu =		netvsc_change_mtu,
1649 	.ndo_validate_addr =		eth_validate_addr,
1650 	.ndo_set_mac_address =		netvsc_set_mac_addr,
1651 	.ndo_select_queue =		netvsc_select_queue,
1652 	.ndo_get_stats64 =		netvsc_get_stats64,
1653 #ifdef CONFIG_NET_POLL_CONTROLLER
1654 	.ndo_poll_controller =		netvsc_poll_controller,
1655 #endif
1656 };
1657 
1658 /*
1659  * Handle link status changes. For RNDIS_STATUS_NETWORK_CHANGE emulate link
1660  * down/up sequence. In case of RNDIS_STATUS_MEDIA_CONNECT when carrier is
1661  * present send GARP packet to network peers with netif_notify_peers().
1662  */
1663 static void netvsc_link_change(struct work_struct *w)
1664 {
1665 	struct net_device_context *ndev_ctx =
1666 		container_of(w, struct net_device_context, dwork.work);
1667 	struct hv_device *device_obj = ndev_ctx->device_ctx;
1668 	struct net_device *net = hv_get_drvdata(device_obj);
1669 	struct netvsc_device *net_device;
1670 	struct rndis_device *rdev;
1671 	struct netvsc_reconfig *event = NULL;
1672 	bool notify = false, reschedule = false;
1673 	unsigned long flags, next_reconfig, delay;
1674 
1675 	/* if changes are happening, comeback later */
1676 	if (!rtnl_trylock()) {
1677 		schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT);
1678 		return;
1679 	}
1680 
1681 	net_device = rtnl_dereference(ndev_ctx->nvdev);
1682 	if (!net_device)
1683 		goto out_unlock;
1684 
1685 	rdev = net_device->extension;
1686 
1687 	next_reconfig = ndev_ctx->last_reconfig + LINKCHANGE_INT;
1688 	if (time_is_after_jiffies(next_reconfig)) {
1689 		/* link_watch only sends one notification with current state
1690 		 * per second, avoid doing reconfig more frequently. Handle
1691 		 * wrap around.
1692 		 */
1693 		delay = next_reconfig - jiffies;
1694 		delay = delay < LINKCHANGE_INT ? delay : LINKCHANGE_INT;
1695 		schedule_delayed_work(&ndev_ctx->dwork, delay);
1696 		goto out_unlock;
1697 	}
1698 	ndev_ctx->last_reconfig = jiffies;
1699 
1700 	spin_lock_irqsave(&ndev_ctx->lock, flags);
1701 	if (!list_empty(&ndev_ctx->reconfig_events)) {
1702 		event = list_first_entry(&ndev_ctx->reconfig_events,
1703 					 struct netvsc_reconfig, list);
1704 		list_del(&event->list);
1705 		reschedule = !list_empty(&ndev_ctx->reconfig_events);
1706 	}
1707 	spin_unlock_irqrestore(&ndev_ctx->lock, flags);
1708 
1709 	if (!event)
1710 		goto out_unlock;
1711 
1712 	switch (event->event) {
1713 		/* Only the following events are possible due to the check in
1714 		 * netvsc_linkstatus_callback()
1715 		 */
1716 	case RNDIS_STATUS_MEDIA_CONNECT:
1717 		if (rdev->link_state) {
1718 			rdev->link_state = false;
1719 			netif_carrier_on(net);
1720 			netif_tx_wake_all_queues(net);
1721 		} else {
1722 			notify = true;
1723 		}
1724 		kfree(event);
1725 		break;
1726 	case RNDIS_STATUS_MEDIA_DISCONNECT:
1727 		if (!rdev->link_state) {
1728 			rdev->link_state = true;
1729 			netif_carrier_off(net);
1730 			netif_tx_stop_all_queues(net);
1731 		}
1732 		kfree(event);
1733 		break;
1734 	case RNDIS_STATUS_NETWORK_CHANGE:
1735 		/* Only makes sense if carrier is present */
1736 		if (!rdev->link_state) {
1737 			rdev->link_state = true;
1738 			netif_carrier_off(net);
1739 			netif_tx_stop_all_queues(net);
1740 			event->event = RNDIS_STATUS_MEDIA_CONNECT;
1741 			spin_lock_irqsave(&ndev_ctx->lock, flags);
1742 			list_add(&event->list, &ndev_ctx->reconfig_events);
1743 			spin_unlock_irqrestore(&ndev_ctx->lock, flags);
1744 			reschedule = true;
1745 		}
1746 		break;
1747 	}
1748 
1749 	rtnl_unlock();
1750 
1751 	if (notify)
1752 		netdev_notify_peers(net);
1753 
1754 	/* link_watch only sends one notification with current state per
1755 	 * second, handle next reconfig event in 2 seconds.
1756 	 */
1757 	if (reschedule)
1758 		schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT);
1759 
1760 	return;
1761 
1762 out_unlock:
1763 	rtnl_unlock();
1764 }
1765 
1766 static struct net_device *get_netvsc_bymac(const u8 *mac)
1767 {
1768 	struct net_device *dev;
1769 
1770 	ASSERT_RTNL();
1771 
1772 	for_each_netdev(&init_net, dev) {
1773 		if (dev->netdev_ops != &device_ops)
1774 			continue;	/* not a netvsc device */
1775 
1776 		if (ether_addr_equal(mac, dev->perm_addr))
1777 			return dev;
1778 	}
1779 
1780 	return NULL;
1781 }
1782 
1783 static struct net_device *get_netvsc_byref(struct net_device *vf_netdev)
1784 {
1785 	struct net_device *dev;
1786 
1787 	ASSERT_RTNL();
1788 
1789 	for_each_netdev(&init_net, dev) {
1790 		struct net_device_context *net_device_ctx;
1791 
1792 		if (dev->netdev_ops != &device_ops)
1793 			continue;	/* not a netvsc device */
1794 
1795 		net_device_ctx = netdev_priv(dev);
1796 		if (!rtnl_dereference(net_device_ctx->nvdev))
1797 			continue;	/* device is removed */
1798 
1799 		if (rtnl_dereference(net_device_ctx->vf_netdev) == vf_netdev)
1800 			return dev;	/* a match */
1801 	}
1802 
1803 	return NULL;
1804 }
1805 
1806 /* Called when VF is injecting data into network stack.
1807  * Change the associated network device from VF to netvsc.
1808  * note: already called with rcu_read_lock
1809  */
1810 static rx_handler_result_t netvsc_vf_handle_frame(struct sk_buff **pskb)
1811 {
1812 	struct sk_buff *skb = *pskb;
1813 	struct net_device *ndev = rcu_dereference(skb->dev->rx_handler_data);
1814 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1815 	struct netvsc_vf_pcpu_stats *pcpu_stats
1816 		 = this_cpu_ptr(ndev_ctx->vf_stats);
1817 
1818 	skb->dev = ndev;
1819 
1820 	u64_stats_update_begin(&pcpu_stats->syncp);
1821 	pcpu_stats->rx_packets++;
1822 	pcpu_stats->rx_bytes += skb->len;
1823 	u64_stats_update_end(&pcpu_stats->syncp);
1824 
1825 	return RX_HANDLER_ANOTHER;
1826 }
1827 
1828 static int netvsc_vf_join(struct net_device *vf_netdev,
1829 			  struct net_device *ndev)
1830 {
1831 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1832 	int ret;
1833 
1834 	ret = netdev_rx_handler_register(vf_netdev,
1835 					 netvsc_vf_handle_frame, ndev);
1836 	if (ret != 0) {
1837 		netdev_err(vf_netdev,
1838 			   "can not register netvsc VF receive handler (err = %d)\n",
1839 			   ret);
1840 		goto rx_handler_failed;
1841 	}
1842 
1843 	ret = netdev_upper_dev_link(vf_netdev, ndev, NULL);
1844 	if (ret != 0) {
1845 		netdev_err(vf_netdev,
1846 			   "can not set master device %s (err = %d)\n",
1847 			   ndev->name, ret);
1848 		goto upper_link_failed;
1849 	}
1850 
1851 	/* set slave flag before open to prevent IPv6 addrconf */
1852 	vf_netdev->flags |= IFF_SLAVE;
1853 
1854 	schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);
1855 
1856 	call_netdevice_notifiers(NETDEV_JOIN, vf_netdev);
1857 
1858 	netdev_info(vf_netdev, "joined to %s\n", ndev->name);
1859 	return 0;
1860 
1861 upper_link_failed:
1862 	netdev_rx_handler_unregister(vf_netdev);
1863 rx_handler_failed:
1864 	return ret;
1865 }
1866 
1867 static void __netvsc_vf_setup(struct net_device *ndev,
1868 			      struct net_device *vf_netdev)
1869 {
1870 	int ret;
1871 
1872 	/* Align MTU of VF with master */
1873 	ret = dev_set_mtu(vf_netdev, ndev->mtu);
1874 	if (ret)
1875 		netdev_warn(vf_netdev,
1876 			    "unable to change mtu to %u\n", ndev->mtu);
1877 
1878 	/* set multicast etc flags on VF */
1879 	dev_change_flags(vf_netdev, ndev->flags | IFF_SLAVE);
1880 
1881 	/* sync address list from ndev to VF */
1882 	netif_addr_lock_bh(ndev);
1883 	dev_uc_sync(vf_netdev, ndev);
1884 	dev_mc_sync(vf_netdev, ndev);
1885 	netif_addr_unlock_bh(ndev);
1886 
1887 	if (netif_running(ndev)) {
1888 		ret = dev_open(vf_netdev);
1889 		if (ret)
1890 			netdev_warn(vf_netdev,
1891 				    "unable to open: %d\n", ret);
1892 	}
1893 }
1894 
1895 /* Setup VF as slave of the synthetic device.
1896  * Runs in workqueue to avoid recursion in netlink callbacks.
1897  */
1898 static void netvsc_vf_setup(struct work_struct *w)
1899 {
1900 	struct net_device_context *ndev_ctx
1901 		= container_of(w, struct net_device_context, vf_takeover.work);
1902 	struct net_device *ndev = hv_get_drvdata(ndev_ctx->device_ctx);
1903 	struct net_device *vf_netdev;
1904 
1905 	if (!rtnl_trylock()) {
1906 		schedule_delayed_work(&ndev_ctx->vf_takeover, 0);
1907 		return;
1908 	}
1909 
1910 	vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
1911 	if (vf_netdev)
1912 		__netvsc_vf_setup(ndev, vf_netdev);
1913 
1914 	rtnl_unlock();
1915 }
1916 
1917 static int netvsc_register_vf(struct net_device *vf_netdev)
1918 {
1919 	struct net_device *ndev;
1920 	struct net_device_context *net_device_ctx;
1921 	struct netvsc_device *netvsc_dev;
1922 
1923 	if (vf_netdev->addr_len != ETH_ALEN)
1924 		return NOTIFY_DONE;
1925 
1926 	/*
1927 	 * We will use the MAC address to locate the synthetic interface to
1928 	 * associate with the VF interface. If we don't find a matching
1929 	 * synthetic interface, move on.
1930 	 */
1931 	ndev = get_netvsc_bymac(vf_netdev->perm_addr);
1932 	if (!ndev)
1933 		return NOTIFY_DONE;
1934 
1935 	net_device_ctx = netdev_priv(ndev);
1936 	netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
1937 	if (!netvsc_dev || rtnl_dereference(net_device_ctx->vf_netdev))
1938 		return NOTIFY_DONE;
1939 
1940 	if (netvsc_vf_join(vf_netdev, ndev) != 0)
1941 		return NOTIFY_DONE;
1942 
1943 	netdev_info(ndev, "VF registering: %s\n", vf_netdev->name);
1944 
1945 	dev_hold(vf_netdev);
1946 	rcu_assign_pointer(net_device_ctx->vf_netdev, vf_netdev);
1947 	return NOTIFY_OK;
1948 }
1949 
1950 /* VF up/down change detected, schedule to change data path */
1951 static int netvsc_vf_changed(struct net_device *vf_netdev)
1952 {
1953 	struct net_device_context *net_device_ctx;
1954 	struct netvsc_device *netvsc_dev;
1955 	struct net_device *ndev;
1956 	bool vf_is_up = netif_running(vf_netdev);
1957 
1958 	ndev = get_netvsc_byref(vf_netdev);
1959 	if (!ndev)
1960 		return NOTIFY_DONE;
1961 
1962 	net_device_ctx = netdev_priv(ndev);
1963 	netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
1964 	if (!netvsc_dev)
1965 		return NOTIFY_DONE;
1966 
1967 	netvsc_switch_datapath(ndev, vf_is_up);
1968 	netdev_info(ndev, "Data path switched %s VF: %s\n",
1969 		    vf_is_up ? "to" : "from", vf_netdev->name);
1970 
1971 	return NOTIFY_OK;
1972 }
1973 
1974 static int netvsc_unregister_vf(struct net_device *vf_netdev)
1975 {
1976 	struct net_device *ndev;
1977 	struct net_device_context *net_device_ctx;
1978 
1979 	ndev = get_netvsc_byref(vf_netdev);
1980 	if (!ndev)
1981 		return NOTIFY_DONE;
1982 
1983 	net_device_ctx = netdev_priv(ndev);
1984 	cancel_delayed_work_sync(&net_device_ctx->vf_takeover);
1985 
1986 	netdev_info(ndev, "VF unregistering: %s\n", vf_netdev->name);
1987 
1988 	netdev_rx_handler_unregister(vf_netdev);
1989 	netdev_upper_dev_unlink(vf_netdev, ndev);
1990 	RCU_INIT_POINTER(net_device_ctx->vf_netdev, NULL);
1991 	dev_put(vf_netdev);
1992 
1993 	return NOTIFY_OK;
1994 }
1995 
1996 static int netvsc_probe(struct hv_device *dev,
1997 			const struct hv_vmbus_device_id *dev_id)
1998 {
1999 	struct net_device *net = NULL;
2000 	struct net_device_context *net_device_ctx;
2001 	struct netvsc_device_info device_info;
2002 	struct netvsc_device *nvdev;
2003 	int ret = -ENOMEM;
2004 
2005 	net = alloc_etherdev_mq(sizeof(struct net_device_context),
2006 				VRSS_CHANNEL_MAX);
2007 	if (!net)
2008 		goto no_net;
2009 
2010 	netif_carrier_off(net);
2011 
2012 	netvsc_init_settings(net);
2013 
2014 	net_device_ctx = netdev_priv(net);
2015 	net_device_ctx->device_ctx = dev;
2016 	net_device_ctx->msg_enable = netif_msg_init(debug, default_msg);
2017 	if (netif_msg_probe(net_device_ctx))
2018 		netdev_dbg(net, "netvsc msg_enable: %d\n",
2019 			   net_device_ctx->msg_enable);
2020 
2021 	hv_set_drvdata(dev, net);
2022 
2023 	INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change);
2024 
2025 	spin_lock_init(&net_device_ctx->lock);
2026 	INIT_LIST_HEAD(&net_device_ctx->reconfig_events);
2027 	INIT_DELAYED_WORK(&net_device_ctx->vf_takeover, netvsc_vf_setup);
2028 
2029 	net_device_ctx->vf_stats
2030 		= netdev_alloc_pcpu_stats(struct netvsc_vf_pcpu_stats);
2031 	if (!net_device_ctx->vf_stats)
2032 		goto no_stats;
2033 
2034 	net->netdev_ops = &device_ops;
2035 	net->ethtool_ops = &ethtool_ops;
2036 	SET_NETDEV_DEV(net, &dev->device);
2037 
2038 	/* We always need headroom for rndis header */
2039 	net->needed_headroom = RNDIS_AND_PPI_SIZE;
2040 
2041 	/* Initialize the number of queues to be 1, we may change it if more
2042 	 * channels are offered later.
2043 	 */
2044 	netif_set_real_num_tx_queues(net, 1);
2045 	netif_set_real_num_rx_queues(net, 1);
2046 
2047 	/* Notify the netvsc driver of the new device */
2048 	memset(&device_info, 0, sizeof(device_info));
2049 	device_info.num_chn = VRSS_CHANNEL_DEFAULT;
2050 	device_info.send_sections = NETVSC_DEFAULT_TX;
2051 	device_info.send_section_size = NETVSC_SEND_SECTION_SIZE;
2052 	device_info.recv_sections = NETVSC_DEFAULT_RX;
2053 	device_info.recv_section_size = NETVSC_RECV_SECTION_SIZE;
2054 
2055 	nvdev = rndis_filter_device_add(dev, &device_info);
2056 	if (IS_ERR(nvdev)) {
2057 		ret = PTR_ERR(nvdev);
2058 		netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
2059 		goto rndis_failed;
2060 	}
2061 
2062 	memcpy(net->dev_addr, device_info.mac_adr, ETH_ALEN);
2063 
2064 	/* hw_features computed in rndis_netdev_set_hwcaps() */
2065 	net->features = net->hw_features |
2066 		NETIF_F_HIGHDMA | NETIF_F_SG |
2067 		NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX;
2068 	net->vlan_features = net->features;
2069 
2070 	netdev_lockdep_set_classes(net);
2071 
2072 	/* MTU range: 68 - 1500 or 65521 */
2073 	net->min_mtu = NETVSC_MTU_MIN;
2074 	if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
2075 		net->max_mtu = NETVSC_MTU - ETH_HLEN;
2076 	else
2077 		net->max_mtu = ETH_DATA_LEN;
2078 
2079 	ret = register_netdev(net);
2080 	if (ret != 0) {
2081 		pr_err("Unable to register netdev.\n");
2082 		goto register_failed;
2083 	}
2084 
2085 	return ret;
2086 
2087 register_failed:
2088 	rndis_filter_device_remove(dev, nvdev);
2089 rndis_failed:
2090 	free_percpu(net_device_ctx->vf_stats);
2091 no_stats:
2092 	hv_set_drvdata(dev, NULL);
2093 	free_netdev(net);
2094 no_net:
2095 	return ret;
2096 }
2097 
2098 static int netvsc_remove(struct hv_device *dev)
2099 {
2100 	struct net_device_context *ndev_ctx;
2101 	struct net_device *vf_netdev, *net;
2102 	struct netvsc_device *nvdev;
2103 
2104 	net = hv_get_drvdata(dev);
2105 	if (net == NULL) {
2106 		dev_err(&dev->device, "No net device to remove\n");
2107 		return 0;
2108 	}
2109 
2110 	ndev_ctx = netdev_priv(net);
2111 
2112 	cancel_delayed_work_sync(&ndev_ctx->dwork);
2113 
2114 	rcu_read_lock();
2115 	nvdev = rcu_dereference(ndev_ctx->nvdev);
2116 
2117 	if  (nvdev)
2118 		cancel_work_sync(&nvdev->subchan_work);
2119 
2120 	/*
2121 	 * Call to the vsc driver to let it know that the device is being
2122 	 * removed. Also blocks mtu and channel changes.
2123 	 */
2124 	rtnl_lock();
2125 	vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
2126 	if (vf_netdev)
2127 		netvsc_unregister_vf(vf_netdev);
2128 
2129 	if (nvdev)
2130 		rndis_filter_device_remove(dev, nvdev);
2131 
2132 	unregister_netdevice(net);
2133 
2134 	rtnl_unlock();
2135 	rcu_read_unlock();
2136 
2137 	hv_set_drvdata(dev, NULL);
2138 
2139 	free_percpu(ndev_ctx->vf_stats);
2140 	free_netdev(net);
2141 	return 0;
2142 }
2143 
2144 static const struct hv_vmbus_device_id id_table[] = {
2145 	/* Network guid */
2146 	{ HV_NIC_GUID, },
2147 	{ },
2148 };
2149 
2150 MODULE_DEVICE_TABLE(vmbus, id_table);
2151 
2152 /* The one and only one */
2153 static struct  hv_driver netvsc_drv = {
2154 	.name = KBUILD_MODNAME,
2155 	.id_table = id_table,
2156 	.probe = netvsc_probe,
2157 	.remove = netvsc_remove,
2158 };
2159 
2160 /*
2161  * On Hyper-V, every VF interface is matched with a corresponding
2162  * synthetic interface. The synthetic interface is presented first
2163  * to the guest. When the corresponding VF instance is registered,
2164  * we will take care of switching the data path.
2165  */
2166 static int netvsc_netdev_event(struct notifier_block *this,
2167 			       unsigned long event, void *ptr)
2168 {
2169 	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2170 
2171 	/* Skip our own events */
2172 	if (event_dev->netdev_ops == &device_ops)
2173 		return NOTIFY_DONE;
2174 
2175 	/* Avoid non-Ethernet type devices */
2176 	if (event_dev->type != ARPHRD_ETHER)
2177 		return NOTIFY_DONE;
2178 
2179 	/* Avoid Vlan dev with same MAC registering as VF */
2180 	if (is_vlan_dev(event_dev))
2181 		return NOTIFY_DONE;
2182 
2183 	/* Avoid Bonding master dev with same MAC registering as VF */
2184 	if ((event_dev->priv_flags & IFF_BONDING) &&
2185 	    (event_dev->flags & IFF_MASTER))
2186 		return NOTIFY_DONE;
2187 
2188 	switch (event) {
2189 	case NETDEV_REGISTER:
2190 		return netvsc_register_vf(event_dev);
2191 	case NETDEV_UNREGISTER:
2192 		return netvsc_unregister_vf(event_dev);
2193 	case NETDEV_UP:
2194 	case NETDEV_DOWN:
2195 		return netvsc_vf_changed(event_dev);
2196 	default:
2197 		return NOTIFY_DONE;
2198 	}
2199 }
2200 
2201 static struct notifier_block netvsc_netdev_notifier = {
2202 	.notifier_call = netvsc_netdev_event,
2203 };
2204 
2205 static void __exit netvsc_drv_exit(void)
2206 {
2207 	unregister_netdevice_notifier(&netvsc_netdev_notifier);
2208 	vmbus_driver_unregister(&netvsc_drv);
2209 }
2210 
2211 static int __init netvsc_drv_init(void)
2212 {
2213 	int ret;
2214 
2215 	if (ring_size < RING_SIZE_MIN) {
2216 		ring_size = RING_SIZE_MIN;
2217 		pr_info("Increased ring_size to %u (min allowed)\n",
2218 			ring_size);
2219 	}
2220 	netvsc_ring_bytes = ring_size * PAGE_SIZE;
2221 	netvsc_ring_reciprocal = reciprocal_value(netvsc_ring_bytes);
2222 
2223 	ret = vmbus_driver_register(&netvsc_drv);
2224 	if (ret)
2225 		return ret;
2226 
2227 	register_netdevice_notifier(&netvsc_netdev_notifier);
2228 	return 0;
2229 }
2230 
2231 MODULE_LICENSE("GPL");
2232 MODULE_DESCRIPTION("Microsoft Hyper-V network driver");
2233 
2234 module_init(netvsc_drv_init);
2235 module_exit(netvsc_drv_exit);
2236