xref: /openbmc/linux/drivers/net/hyperv/netvsc_drv.c (revision e5c86679)
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 <net/arp.h>
37 #include <net/route.h>
38 #include <net/sock.h>
39 #include <net/pkt_sched.h>
40 
41 #include "hyperv_net.h"
42 
43 #define RING_SIZE_MIN 64
44 #define LINKCHANGE_INT (2 * HZ)
45 
46 static int ring_size = 128;
47 module_param(ring_size, int, S_IRUGO);
48 MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
49 
50 static const u32 default_msg = NETIF_MSG_DRV | NETIF_MSG_PROBE |
51 				NETIF_MSG_LINK | NETIF_MSG_IFUP |
52 				NETIF_MSG_IFDOWN | NETIF_MSG_RX_ERR |
53 				NETIF_MSG_TX_ERR;
54 
55 static int debug = -1;
56 module_param(debug, int, S_IRUGO);
57 MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");
58 
59 static void do_set_multicast(struct work_struct *w)
60 {
61 	struct net_device_context *ndevctx =
62 		container_of(w, struct net_device_context, work);
63 	struct hv_device *device_obj = ndevctx->device_ctx;
64 	struct net_device *ndev = hv_get_drvdata(device_obj);
65 	struct netvsc_device *nvdev = ndevctx->nvdev;
66 	struct rndis_device *rdev;
67 
68 	if (!nvdev)
69 		return;
70 
71 	rdev = nvdev->extension;
72 	if (rdev == NULL)
73 		return;
74 
75 	if (ndev->flags & IFF_PROMISC)
76 		rndis_filter_set_packet_filter(rdev,
77 			NDIS_PACKET_TYPE_PROMISCUOUS);
78 	else
79 		rndis_filter_set_packet_filter(rdev,
80 			NDIS_PACKET_TYPE_BROADCAST |
81 			NDIS_PACKET_TYPE_ALL_MULTICAST |
82 			NDIS_PACKET_TYPE_DIRECTED);
83 }
84 
85 static void netvsc_set_multicast_list(struct net_device *net)
86 {
87 	struct net_device_context *net_device_ctx = netdev_priv(net);
88 
89 	schedule_work(&net_device_ctx->work);
90 }
91 
92 static int netvsc_open(struct net_device *net)
93 {
94 	struct netvsc_device *nvdev = net_device_to_netvsc_device(net);
95 	struct rndis_device *rdev;
96 	int ret = 0;
97 
98 	netif_carrier_off(net);
99 
100 	/* Open up the device */
101 	ret = rndis_filter_open(nvdev);
102 	if (ret != 0) {
103 		netdev_err(net, "unable to open device (ret %d).\n", ret);
104 		return ret;
105 	}
106 
107 	netif_tx_wake_all_queues(net);
108 
109 	rdev = nvdev->extension;
110 	if (!rdev->link_state)
111 		netif_carrier_on(net);
112 
113 	return ret;
114 }
115 
116 static int netvsc_close(struct net_device *net)
117 {
118 	struct net_device_context *net_device_ctx = netdev_priv(net);
119 	struct netvsc_device *nvdev = net_device_ctx->nvdev;
120 	int ret;
121 	u32 aread, awrite, i, msec = 10, retry = 0, retry_max = 20;
122 	struct vmbus_channel *chn;
123 
124 	netif_tx_disable(net);
125 
126 	/* Make sure netvsc_set_multicast_list doesn't re-enable filter! */
127 	cancel_work_sync(&net_device_ctx->work);
128 	ret = rndis_filter_close(nvdev);
129 	if (ret != 0) {
130 		netdev_err(net, "unable to close device (ret %d).\n", ret);
131 		return ret;
132 	}
133 
134 	/* Ensure pending bytes in ring are read */
135 	while (true) {
136 		aread = 0;
137 		for (i = 0; i < nvdev->num_chn; i++) {
138 			chn = nvdev->chan_table[i].channel;
139 			if (!chn)
140 				continue;
141 
142 			hv_get_ringbuffer_availbytes(&chn->inbound, &aread,
143 						     &awrite);
144 
145 			if (aread)
146 				break;
147 
148 			hv_get_ringbuffer_availbytes(&chn->outbound, &aread,
149 						     &awrite);
150 
151 			if (aread)
152 				break;
153 		}
154 
155 		retry++;
156 		if (retry > retry_max || aread == 0)
157 			break;
158 
159 		msleep(msec);
160 
161 		if (msec < 1000)
162 			msec *= 2;
163 	}
164 
165 	if (aread) {
166 		netdev_err(net, "Ring buffer not empty after closing rndis\n");
167 		ret = -ETIMEDOUT;
168 	}
169 
170 	return ret;
171 }
172 
173 static void *init_ppi_data(struct rndis_message *msg, u32 ppi_size,
174 				int pkt_type)
175 {
176 	struct rndis_packet *rndis_pkt;
177 	struct rndis_per_packet_info *ppi;
178 
179 	rndis_pkt = &msg->msg.pkt;
180 	rndis_pkt->data_offset += ppi_size;
181 
182 	ppi = (struct rndis_per_packet_info *)((void *)rndis_pkt +
183 		rndis_pkt->per_pkt_info_offset + rndis_pkt->per_pkt_info_len);
184 
185 	ppi->size = ppi_size;
186 	ppi->type = pkt_type;
187 	ppi->ppi_offset = sizeof(struct rndis_per_packet_info);
188 
189 	rndis_pkt->per_pkt_info_len += ppi_size;
190 
191 	return ppi;
192 }
193 
194 /*
195  * Select queue for transmit.
196  *
197  * If a valid queue has already been assigned, then use that.
198  * Otherwise compute tx queue based on hash and the send table.
199  *
200  * This is basically similar to default (__netdev_pick_tx) with the added step
201  * of using the host send_table when no other queue has been assigned.
202  *
203  * TODO support XPS - but get_xps_queue not exported
204  */
205 static u16 netvsc_select_queue(struct net_device *ndev, struct sk_buff *skb,
206 			void *accel_priv, select_queue_fallback_t fallback)
207 {
208 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
209 	unsigned int num_tx_queues = ndev->real_num_tx_queues;
210 	struct sock *sk = skb->sk;
211 	int q_idx = sk_tx_queue_get(sk);
212 
213 	if (q_idx < 0 || skb->ooo_okay || q_idx >= num_tx_queues) {
214 		u16 hash = __skb_tx_hash(ndev, skb, VRSS_SEND_TAB_SIZE);
215 		int new_idx;
216 
217 		new_idx = net_device_ctx->tx_send_table[hash] % num_tx_queues;
218 
219 		if (q_idx != new_idx && sk &&
220 		    sk_fullsock(sk) && rcu_access_pointer(sk->sk_dst_cache))
221 			sk_tx_queue_set(sk, new_idx);
222 
223 		q_idx = new_idx;
224 	}
225 
226 	return q_idx;
227 }
228 
229 static u32 fill_pg_buf(struct page *page, u32 offset, u32 len,
230 			struct hv_page_buffer *pb)
231 {
232 	int j = 0;
233 
234 	/* Deal with compund pages by ignoring unused part
235 	 * of the page.
236 	 */
237 	page += (offset >> PAGE_SHIFT);
238 	offset &= ~PAGE_MASK;
239 
240 	while (len > 0) {
241 		unsigned long bytes;
242 
243 		bytes = PAGE_SIZE - offset;
244 		if (bytes > len)
245 			bytes = len;
246 		pb[j].pfn = page_to_pfn(page);
247 		pb[j].offset = offset;
248 		pb[j].len = bytes;
249 
250 		offset += bytes;
251 		len -= bytes;
252 
253 		if (offset == PAGE_SIZE && len) {
254 			page++;
255 			offset = 0;
256 			j++;
257 		}
258 	}
259 
260 	return j + 1;
261 }
262 
263 static u32 init_page_array(void *hdr, u32 len, struct sk_buff *skb,
264 			   struct hv_netvsc_packet *packet,
265 			   struct hv_page_buffer **page_buf)
266 {
267 	struct hv_page_buffer *pb = *page_buf;
268 	u32 slots_used = 0;
269 	char *data = skb->data;
270 	int frags = skb_shinfo(skb)->nr_frags;
271 	int i;
272 
273 	/* The packet is laid out thus:
274 	 * 1. hdr: RNDIS header and PPI
275 	 * 2. skb linear data
276 	 * 3. skb fragment data
277 	 */
278 	if (hdr != NULL)
279 		slots_used += fill_pg_buf(virt_to_page(hdr),
280 					offset_in_page(hdr),
281 					len, &pb[slots_used]);
282 
283 	packet->rmsg_size = len;
284 	packet->rmsg_pgcnt = slots_used;
285 
286 	slots_used += fill_pg_buf(virt_to_page(data),
287 				offset_in_page(data),
288 				skb_headlen(skb), &pb[slots_used]);
289 
290 	for (i = 0; i < frags; i++) {
291 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
292 
293 		slots_used += fill_pg_buf(skb_frag_page(frag),
294 					frag->page_offset,
295 					skb_frag_size(frag), &pb[slots_used]);
296 	}
297 	return slots_used;
298 }
299 
300 static int count_skb_frag_slots(struct sk_buff *skb)
301 {
302 	int i, frags = skb_shinfo(skb)->nr_frags;
303 	int pages = 0;
304 
305 	for (i = 0; i < frags; i++) {
306 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
307 		unsigned long size = skb_frag_size(frag);
308 		unsigned long offset = frag->page_offset;
309 
310 		/* Skip unused frames from start of page */
311 		offset &= ~PAGE_MASK;
312 		pages += PFN_UP(offset + size);
313 	}
314 	return pages;
315 }
316 
317 static int netvsc_get_slots(struct sk_buff *skb)
318 {
319 	char *data = skb->data;
320 	unsigned int offset = offset_in_page(data);
321 	unsigned int len = skb_headlen(skb);
322 	int slots;
323 	int frag_slots;
324 
325 	slots = DIV_ROUND_UP(offset + len, PAGE_SIZE);
326 	frag_slots = count_skb_frag_slots(skb);
327 	return slots + frag_slots;
328 }
329 
330 static u32 net_checksum_info(struct sk_buff *skb)
331 {
332 	if (skb->protocol == htons(ETH_P_IP)) {
333 		struct iphdr *ip = ip_hdr(skb);
334 
335 		if (ip->protocol == IPPROTO_TCP)
336 			return TRANSPORT_INFO_IPV4_TCP;
337 		else if (ip->protocol == IPPROTO_UDP)
338 			return TRANSPORT_INFO_IPV4_UDP;
339 	} else {
340 		struct ipv6hdr *ip6 = ipv6_hdr(skb);
341 
342 		if (ip6->nexthdr == IPPROTO_TCP)
343 			return TRANSPORT_INFO_IPV6_TCP;
344 		else if (ipv6_hdr(skb)->nexthdr == IPPROTO_UDP)
345 			return TRANSPORT_INFO_IPV6_UDP;
346 	}
347 
348 	return TRANSPORT_INFO_NOT_IP;
349 }
350 
351 static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
352 {
353 	struct net_device_context *net_device_ctx = netdev_priv(net);
354 	struct hv_netvsc_packet *packet = NULL;
355 	int ret;
356 	unsigned int num_data_pgs;
357 	struct rndis_message *rndis_msg;
358 	struct rndis_packet *rndis_pkt;
359 	u32 rndis_msg_size;
360 	struct rndis_per_packet_info *ppi;
361 	u32 hash;
362 	struct hv_page_buffer page_buf[MAX_PAGE_BUFFER_COUNT];
363 	struct hv_page_buffer *pb = page_buf;
364 
365 	/* We will atmost need two pages to describe the rndis
366 	 * header. We can only transmit MAX_PAGE_BUFFER_COUNT number
367 	 * of pages in a single packet. If skb is scattered around
368 	 * more pages we try linearizing it.
369 	 */
370 
371 	num_data_pgs = netvsc_get_slots(skb) + 2;
372 
373 	if (unlikely(num_data_pgs > MAX_PAGE_BUFFER_COUNT)) {
374 		++net_device_ctx->eth_stats.tx_scattered;
375 
376 		if (skb_linearize(skb))
377 			goto no_memory;
378 
379 		num_data_pgs = netvsc_get_slots(skb) + 2;
380 		if (num_data_pgs > MAX_PAGE_BUFFER_COUNT) {
381 			++net_device_ctx->eth_stats.tx_too_big;
382 			goto drop;
383 		}
384 	}
385 
386 	/*
387 	 * Place the rndis header in the skb head room and
388 	 * the skb->cb will be used for hv_netvsc_packet
389 	 * structure.
390 	 */
391 	ret = skb_cow_head(skb, RNDIS_AND_PPI_SIZE);
392 	if (ret)
393 		goto no_memory;
394 
395 	/* Use the skb control buffer for building up the packet */
396 	BUILD_BUG_ON(sizeof(struct hv_netvsc_packet) >
397 			FIELD_SIZEOF(struct sk_buff, cb));
398 	packet = (struct hv_netvsc_packet *)skb->cb;
399 
400 	packet->q_idx = skb_get_queue_mapping(skb);
401 
402 	packet->total_data_buflen = skb->len;
403 	packet->total_bytes = skb->len;
404 	packet->total_packets = 1;
405 
406 	rndis_msg = (struct rndis_message *)skb->head;
407 
408 	memset(rndis_msg, 0, RNDIS_AND_PPI_SIZE);
409 
410 	/* Add the rndis header */
411 	rndis_msg->ndis_msg_type = RNDIS_MSG_PACKET;
412 	rndis_msg->msg_len = packet->total_data_buflen;
413 	rndis_pkt = &rndis_msg->msg.pkt;
414 	rndis_pkt->data_offset = sizeof(struct rndis_packet);
415 	rndis_pkt->data_len = packet->total_data_buflen;
416 	rndis_pkt->per_pkt_info_offset = sizeof(struct rndis_packet);
417 
418 	rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
419 
420 	hash = skb_get_hash_raw(skb);
421 	if (hash != 0 && net->real_num_tx_queues > 1) {
422 		rndis_msg_size += NDIS_HASH_PPI_SIZE;
423 		ppi = init_ppi_data(rndis_msg, NDIS_HASH_PPI_SIZE,
424 				    NBL_HASH_VALUE);
425 		*(u32 *)((void *)ppi + ppi->ppi_offset) = hash;
426 	}
427 
428 	if (skb_vlan_tag_present(skb)) {
429 		struct ndis_pkt_8021q_info *vlan;
430 
431 		rndis_msg_size += NDIS_VLAN_PPI_SIZE;
432 		ppi = init_ppi_data(rndis_msg, NDIS_VLAN_PPI_SIZE,
433 					IEEE_8021Q_INFO);
434 		vlan = (struct ndis_pkt_8021q_info *)((void *)ppi +
435 						ppi->ppi_offset);
436 		vlan->vlanid = skb->vlan_tci & VLAN_VID_MASK;
437 		vlan->pri = (skb->vlan_tci & VLAN_PRIO_MASK) >>
438 				VLAN_PRIO_SHIFT;
439 	}
440 
441 	if (skb_is_gso(skb)) {
442 		struct ndis_tcp_lso_info *lso_info;
443 
444 		rndis_msg_size += NDIS_LSO_PPI_SIZE;
445 		ppi = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
446 				    TCP_LARGESEND_PKTINFO);
447 
448 		lso_info = (struct ndis_tcp_lso_info *)((void *)ppi +
449 							ppi->ppi_offset);
450 
451 		lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
452 		if (skb->protocol == htons(ETH_P_IP)) {
453 			lso_info->lso_v2_transmit.ip_version =
454 				NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
455 			ip_hdr(skb)->tot_len = 0;
456 			ip_hdr(skb)->check = 0;
457 			tcp_hdr(skb)->check =
458 				~csum_tcpudp_magic(ip_hdr(skb)->saddr,
459 						   ip_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
460 		} else {
461 			lso_info->lso_v2_transmit.ip_version =
462 				NDIS_TCP_LARGE_SEND_OFFLOAD_IPV6;
463 			ipv6_hdr(skb)->payload_len = 0;
464 			tcp_hdr(skb)->check =
465 				~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
466 						 &ipv6_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
467 		}
468 		lso_info->lso_v2_transmit.tcp_header_offset = skb_transport_offset(skb);
469 		lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
470 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
471 		if (net_checksum_info(skb) & net_device_ctx->tx_checksum_mask) {
472 			struct ndis_tcp_ip_checksum_info *csum_info;
473 
474 			rndis_msg_size += NDIS_CSUM_PPI_SIZE;
475 			ppi = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
476 					    TCPIP_CHKSUM_PKTINFO);
477 
478 			csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
479 									 ppi->ppi_offset);
480 
481 			csum_info->transmit.tcp_header_offset = skb_transport_offset(skb);
482 
483 			if (skb->protocol == htons(ETH_P_IP)) {
484 				csum_info->transmit.is_ipv4 = 1;
485 
486 				if (ip_hdr(skb)->protocol == IPPROTO_TCP)
487 					csum_info->transmit.tcp_checksum = 1;
488 				else
489 					csum_info->transmit.udp_checksum = 1;
490 			} else {
491 				csum_info->transmit.is_ipv6 = 1;
492 
493 				if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
494 					csum_info->transmit.tcp_checksum = 1;
495 				else
496 					csum_info->transmit.udp_checksum = 1;
497 			}
498 		} else {
499 			/* Can't do offload of this type of checksum */
500 			if (skb_checksum_help(skb))
501 				goto drop;
502 		}
503 	}
504 
505 	/* Start filling in the page buffers with the rndis hdr */
506 	rndis_msg->msg_len += rndis_msg_size;
507 	packet->total_data_buflen = rndis_msg->msg_len;
508 	packet->page_buf_cnt = init_page_array(rndis_msg, rndis_msg_size,
509 					       skb, packet, &pb);
510 
511 	/* timestamp packet in software */
512 	skb_tx_timestamp(skb);
513 	ret = netvsc_send(net_device_ctx->device_ctx, packet,
514 			  rndis_msg, &pb, skb);
515 	if (likely(ret == 0))
516 		return NETDEV_TX_OK;
517 
518 	if (ret == -EAGAIN) {
519 		++net_device_ctx->eth_stats.tx_busy;
520 		return NETDEV_TX_BUSY;
521 	}
522 
523 	if (ret == -ENOSPC)
524 		++net_device_ctx->eth_stats.tx_no_space;
525 
526 drop:
527 	dev_kfree_skb_any(skb);
528 	net->stats.tx_dropped++;
529 
530 	return NETDEV_TX_OK;
531 
532 no_memory:
533 	++net_device_ctx->eth_stats.tx_no_memory;
534 	goto drop;
535 }
536 /*
537  * netvsc_linkstatus_callback - Link up/down notification
538  */
539 void netvsc_linkstatus_callback(struct hv_device *device_obj,
540 				struct rndis_message *resp)
541 {
542 	struct rndis_indicate_status *indicate = &resp->msg.indicate_status;
543 	struct net_device *net;
544 	struct net_device_context *ndev_ctx;
545 	struct netvsc_reconfig *event;
546 	unsigned long flags;
547 
548 	net = hv_get_drvdata(device_obj);
549 
550 	if (!net)
551 		return;
552 
553 	ndev_ctx = netdev_priv(net);
554 
555 	/* Update the physical link speed when changing to another vSwitch */
556 	if (indicate->status == RNDIS_STATUS_LINK_SPEED_CHANGE) {
557 		u32 speed;
558 
559 		speed = *(u32 *)((void *)indicate + indicate->
560 				 status_buf_offset) / 10000;
561 		ndev_ctx->speed = speed;
562 		return;
563 	}
564 
565 	/* Handle these link change statuses below */
566 	if (indicate->status != RNDIS_STATUS_NETWORK_CHANGE &&
567 	    indicate->status != RNDIS_STATUS_MEDIA_CONNECT &&
568 	    indicate->status != RNDIS_STATUS_MEDIA_DISCONNECT)
569 		return;
570 
571 	if (net->reg_state != NETREG_REGISTERED)
572 		return;
573 
574 	event = kzalloc(sizeof(*event), GFP_ATOMIC);
575 	if (!event)
576 		return;
577 	event->event = indicate->status;
578 
579 	spin_lock_irqsave(&ndev_ctx->lock, flags);
580 	list_add_tail(&event->list, &ndev_ctx->reconfig_events);
581 	spin_unlock_irqrestore(&ndev_ctx->lock, flags);
582 
583 	schedule_delayed_work(&ndev_ctx->dwork, 0);
584 }
585 
586 static struct sk_buff *netvsc_alloc_recv_skb(struct net_device *net,
587 					     const struct ndis_tcp_ip_checksum_info *csum_info,
588 					     const struct ndis_pkt_8021q_info *vlan,
589 					     void *data, u32 buflen)
590 {
591 	struct sk_buff *skb;
592 
593 	skb = netdev_alloc_skb_ip_align(net, buflen);
594 	if (!skb)
595 		return skb;
596 
597 	/*
598 	 * Copy to skb. This copy is needed here since the memory pointed by
599 	 * hv_netvsc_packet cannot be deallocated
600 	 */
601 	memcpy(skb_put(skb, buflen), data, buflen);
602 
603 	skb->protocol = eth_type_trans(skb, net);
604 
605 	/* skb is already created with CHECKSUM_NONE */
606 	skb_checksum_none_assert(skb);
607 
608 	/*
609 	 * In Linux, the IP checksum is always checked.
610 	 * Do L4 checksum offload if enabled and present.
611 	 */
612 	if (csum_info && (net->features & NETIF_F_RXCSUM)) {
613 		if (csum_info->receive.tcp_checksum_succeeded ||
614 		    csum_info->receive.udp_checksum_succeeded)
615 			skb->ip_summed = CHECKSUM_UNNECESSARY;
616 	}
617 
618 	if (vlan) {
619 		u16 vlan_tci = vlan->vlanid | (vlan->pri << VLAN_PRIO_SHIFT);
620 
621 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
622 				       vlan_tci);
623 	}
624 
625 	return skb;
626 }
627 
628 /*
629  * netvsc_recv_callback -  Callback when we receive a packet from the
630  * "wire" on the specified device.
631  */
632 int netvsc_recv_callback(struct net_device *net,
633 			 struct vmbus_channel *channel,
634 			 void  *data, u32 len,
635 			 const struct ndis_tcp_ip_checksum_info *csum_info,
636 			 const struct ndis_pkt_8021q_info *vlan)
637 {
638 	struct net_device_context *net_device_ctx = netdev_priv(net);
639 	struct netvsc_device *net_device = net_device_ctx->nvdev;
640 	struct net_device *vf_netdev;
641 	struct sk_buff *skb;
642 	struct netvsc_stats *rx_stats;
643 	u16 q_idx = channel->offermsg.offer.sub_channel_index;
644 
645 
646 	if (net->reg_state != NETREG_REGISTERED)
647 		return NVSP_STAT_FAIL;
648 
649 	/*
650 	 * If necessary, inject this packet into the VF interface.
651 	 * On Hyper-V, multicast and brodcast packets are only delivered
652 	 * to the synthetic interface (after subjecting these to
653 	 * policy filters on the host). Deliver these via the VF
654 	 * interface in the guest.
655 	 */
656 	rcu_read_lock();
657 	vf_netdev = rcu_dereference(net_device_ctx->vf_netdev);
658 	if (vf_netdev && (vf_netdev->flags & IFF_UP))
659 		net = vf_netdev;
660 
661 	/* Allocate a skb - TODO direct I/O to pages? */
662 	skb = netvsc_alloc_recv_skb(net, csum_info, vlan, data, len);
663 	if (unlikely(!skb)) {
664 		++net->stats.rx_dropped;
665 		rcu_read_unlock();
666 		return NVSP_STAT_FAIL;
667 	}
668 
669 	if (net != vf_netdev)
670 		skb_record_rx_queue(skb, q_idx);
671 
672 	/*
673 	 * Even if injecting the packet, record the statistics
674 	 * on the synthetic device because modifying the VF device
675 	 * statistics will not work correctly.
676 	 */
677 	rx_stats = &net_device->chan_table[q_idx].rx_stats;
678 	u64_stats_update_begin(&rx_stats->syncp);
679 	rx_stats->packets++;
680 	rx_stats->bytes += len;
681 
682 	if (skb->pkt_type == PACKET_BROADCAST)
683 		++rx_stats->broadcast;
684 	else if (skb->pkt_type == PACKET_MULTICAST)
685 		++rx_stats->multicast;
686 	u64_stats_update_end(&rx_stats->syncp);
687 
688 	/*
689 	 * Pass the skb back up. Network stack will deallocate the skb when it
690 	 * is done.
691 	 * TODO - use NAPI?
692 	 */
693 	netif_receive_skb(skb);
694 	rcu_read_unlock();
695 
696 	return 0;
697 }
698 
699 static void netvsc_get_drvinfo(struct net_device *net,
700 			       struct ethtool_drvinfo *info)
701 {
702 	strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
703 	strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
704 }
705 
706 static void netvsc_get_channels(struct net_device *net,
707 				struct ethtool_channels *channel)
708 {
709 	struct net_device_context *net_device_ctx = netdev_priv(net);
710 	struct netvsc_device *nvdev = net_device_ctx->nvdev;
711 
712 	if (nvdev) {
713 		channel->max_combined	= nvdev->max_chn;
714 		channel->combined_count = nvdev->num_chn;
715 	}
716 }
717 
718 static int netvsc_set_queues(struct net_device *net, struct hv_device *dev,
719 			     u32 num_chn)
720 {
721 	struct netvsc_device_info device_info;
722 	int ret;
723 
724 	memset(&device_info, 0, sizeof(device_info));
725 	device_info.num_chn = num_chn;
726 	device_info.ring_size = ring_size;
727 	device_info.max_num_vrss_chns = num_chn;
728 
729 	ret = rndis_filter_device_add(dev, &device_info);
730 	if (ret)
731 		return ret;
732 
733 	ret = netif_set_real_num_tx_queues(net, num_chn);
734 	if (ret)
735 		return ret;
736 
737 	ret = netif_set_real_num_rx_queues(net, num_chn);
738 
739 	return ret;
740 }
741 
742 static int netvsc_set_channels(struct net_device *net,
743 			       struct ethtool_channels *channels)
744 {
745 	struct net_device_context *net_device_ctx = netdev_priv(net);
746 	struct hv_device *dev = net_device_ctx->device_ctx;
747 	struct netvsc_device *nvdev = net_device_ctx->nvdev;
748 	unsigned int count = channels->combined_count;
749 	int ret;
750 
751 	/* We do not support separate count for rx, tx, or other */
752 	if (count == 0 ||
753 	    channels->rx_count || channels->tx_count || channels->other_count)
754 		return -EINVAL;
755 
756 	if (count > net->num_tx_queues || count > net->num_rx_queues)
757 		return -EINVAL;
758 
759 	if (net_device_ctx->start_remove || !nvdev || nvdev->destroy)
760 		return -ENODEV;
761 
762 	if (nvdev->nvsp_version < NVSP_PROTOCOL_VERSION_5)
763 		return -EINVAL;
764 
765 	if (count > nvdev->max_chn)
766 		return -EINVAL;
767 
768 	ret = netvsc_close(net);
769 	if (ret)
770 		return ret;
771 
772 	net_device_ctx->start_remove = true;
773 	rndis_filter_device_remove(dev, nvdev);
774 
775 	ret = netvsc_set_queues(net, dev, count);
776 	if (ret == 0)
777 		nvdev->num_chn = count;
778 	else
779 		netvsc_set_queues(net, dev, nvdev->num_chn);
780 
781 	netvsc_open(net);
782 	net_device_ctx->start_remove = false;
783 
784 	/* We may have missed link change notifications */
785 	schedule_delayed_work(&net_device_ctx->dwork, 0);
786 
787 	return ret;
788 }
789 
790 static bool netvsc_validate_ethtool_ss_cmd(const struct ethtool_cmd *cmd)
791 {
792 	struct ethtool_cmd diff1 = *cmd;
793 	struct ethtool_cmd diff2 = {};
794 
795 	ethtool_cmd_speed_set(&diff1, 0);
796 	diff1.duplex = 0;
797 	/* advertising and cmd are usually set */
798 	diff1.advertising = 0;
799 	diff1.cmd = 0;
800 	/* We set port to PORT_OTHER */
801 	diff2.port = PORT_OTHER;
802 
803 	return !memcmp(&diff1, &diff2, sizeof(diff1));
804 }
805 
806 static void netvsc_init_settings(struct net_device *dev)
807 {
808 	struct net_device_context *ndc = netdev_priv(dev);
809 
810 	ndc->speed = SPEED_UNKNOWN;
811 	ndc->duplex = DUPLEX_UNKNOWN;
812 }
813 
814 static int netvsc_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
815 {
816 	struct net_device_context *ndc = netdev_priv(dev);
817 
818 	ethtool_cmd_speed_set(cmd, ndc->speed);
819 	cmd->duplex = ndc->duplex;
820 	cmd->port = PORT_OTHER;
821 
822 	return 0;
823 }
824 
825 static int netvsc_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
826 {
827 	struct net_device_context *ndc = netdev_priv(dev);
828 	u32 speed;
829 
830 	speed = ethtool_cmd_speed(cmd);
831 	if (!ethtool_validate_speed(speed) ||
832 	    !ethtool_validate_duplex(cmd->duplex) ||
833 	    !netvsc_validate_ethtool_ss_cmd(cmd))
834 		return -EINVAL;
835 
836 	ndc->speed = speed;
837 	ndc->duplex = cmd->duplex;
838 
839 	return 0;
840 }
841 
842 static int netvsc_change_mtu(struct net_device *ndev, int mtu)
843 {
844 	struct net_device_context *ndevctx = netdev_priv(ndev);
845 	struct netvsc_device *nvdev = ndevctx->nvdev;
846 	struct hv_device *hdev = ndevctx->device_ctx;
847 	struct netvsc_device_info device_info;
848 	int ret;
849 
850 	if (ndevctx->start_remove || !nvdev || nvdev->destroy)
851 		return -ENODEV;
852 
853 	ret = netvsc_close(ndev);
854 	if (ret)
855 		goto out;
856 
857 	memset(&device_info, 0, sizeof(device_info));
858 	device_info.ring_size = ring_size;
859 	device_info.num_chn = nvdev->num_chn;
860 	device_info.max_num_vrss_chns = nvdev->num_chn;
861 
862 	ndevctx->start_remove = true;
863 	rndis_filter_device_remove(hdev, nvdev);
864 
865 	/* 'nvdev' has been freed in rndis_filter_device_remove() ->
866 	 * netvsc_device_remove () -> free_netvsc_device().
867 	 * We mustn't access it before it's re-created in
868 	 * rndis_filter_device_add() -> netvsc_device_add().
869 	 */
870 
871 	ndev->mtu = mtu;
872 
873 	rndis_filter_device_add(hdev, &device_info);
874 
875 out:
876 	netvsc_open(ndev);
877 	ndevctx->start_remove = false;
878 
879 	/* We may have missed link change notifications */
880 	schedule_delayed_work(&ndevctx->dwork, 0);
881 
882 	return ret;
883 }
884 
885 static void netvsc_get_stats64(struct net_device *net,
886 			       struct rtnl_link_stats64 *t)
887 {
888 	struct net_device_context *ndev_ctx = netdev_priv(net);
889 	struct netvsc_device *nvdev = ndev_ctx->nvdev;
890 	int i;
891 
892 	if (!nvdev)
893 		return;
894 
895 	for (i = 0; i < nvdev->num_chn; i++) {
896 		const struct netvsc_channel *nvchan = &nvdev->chan_table[i];
897 		const struct netvsc_stats *stats;
898 		u64 packets, bytes, multicast;
899 		unsigned int start;
900 
901 		stats = &nvchan->tx_stats;
902 		do {
903 			start = u64_stats_fetch_begin_irq(&stats->syncp);
904 			packets = stats->packets;
905 			bytes = stats->bytes;
906 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
907 
908 		t->tx_bytes	+= bytes;
909 		t->tx_packets	+= packets;
910 
911 		stats = &nvchan->rx_stats;
912 		do {
913 			start = u64_stats_fetch_begin_irq(&stats->syncp);
914 			packets = stats->packets;
915 			bytes = stats->bytes;
916 			multicast = stats->multicast + stats->broadcast;
917 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
918 
919 		t->rx_bytes	+= bytes;
920 		t->rx_packets	+= packets;
921 		t->multicast	+= multicast;
922 	}
923 
924 	t->tx_dropped	= net->stats.tx_dropped;
925 	t->tx_errors	= net->stats.tx_errors;
926 
927 	t->rx_dropped	= net->stats.rx_dropped;
928 	t->rx_errors	= net->stats.rx_errors;
929 }
930 
931 static int netvsc_set_mac_addr(struct net_device *ndev, void *p)
932 {
933 	struct sockaddr *addr = p;
934 	char save_adr[ETH_ALEN];
935 	unsigned char save_aatype;
936 	int err;
937 
938 	memcpy(save_adr, ndev->dev_addr, ETH_ALEN);
939 	save_aatype = ndev->addr_assign_type;
940 
941 	err = eth_mac_addr(ndev, p);
942 	if (err != 0)
943 		return err;
944 
945 	err = rndis_filter_set_device_mac(ndev, addr->sa_data);
946 	if (err != 0) {
947 		/* roll back to saved MAC */
948 		memcpy(ndev->dev_addr, save_adr, ETH_ALEN);
949 		ndev->addr_assign_type = save_aatype;
950 	}
951 
952 	return err;
953 }
954 
955 static const struct {
956 	char name[ETH_GSTRING_LEN];
957 	u16 offset;
958 } netvsc_stats[] = {
959 	{ "tx_scattered", offsetof(struct netvsc_ethtool_stats, tx_scattered) },
960 	{ "tx_no_memory",  offsetof(struct netvsc_ethtool_stats, tx_no_memory) },
961 	{ "tx_no_space",  offsetof(struct netvsc_ethtool_stats, tx_no_space) },
962 	{ "tx_too_big",	  offsetof(struct netvsc_ethtool_stats, tx_too_big) },
963 	{ "tx_busy",	  offsetof(struct netvsc_ethtool_stats, tx_busy) },
964 };
965 
966 #define NETVSC_GLOBAL_STATS_LEN	ARRAY_SIZE(netvsc_stats)
967 
968 /* 4 statistics per queue (rx/tx packets/bytes) */
969 #define NETVSC_QUEUE_STATS_LEN(dev) ((dev)->num_chn * 4)
970 
971 static int netvsc_get_sset_count(struct net_device *dev, int string_set)
972 {
973 	struct net_device_context *ndc = netdev_priv(dev);
974 	struct netvsc_device *nvdev = ndc->nvdev;
975 
976 	switch (string_set) {
977 	case ETH_SS_STATS:
978 		return NETVSC_GLOBAL_STATS_LEN + NETVSC_QUEUE_STATS_LEN(nvdev);
979 	default:
980 		return -EINVAL;
981 	}
982 }
983 
984 static void netvsc_get_ethtool_stats(struct net_device *dev,
985 				     struct ethtool_stats *stats, u64 *data)
986 {
987 	struct net_device_context *ndc = netdev_priv(dev);
988 	struct netvsc_device *nvdev = ndc->nvdev;
989 	const void *nds = &ndc->eth_stats;
990 	const struct netvsc_stats *qstats;
991 	unsigned int start;
992 	u64 packets, bytes;
993 	int i, j;
994 
995 	for (i = 0; i < NETVSC_GLOBAL_STATS_LEN; i++)
996 		data[i] = *(unsigned long *)(nds + netvsc_stats[i].offset);
997 
998 	for (j = 0; j < nvdev->num_chn; j++) {
999 		qstats = &nvdev->chan_table[j].tx_stats;
1000 
1001 		do {
1002 			start = u64_stats_fetch_begin_irq(&qstats->syncp);
1003 			packets = qstats->packets;
1004 			bytes = qstats->bytes;
1005 		} while (u64_stats_fetch_retry_irq(&qstats->syncp, start));
1006 		data[i++] = packets;
1007 		data[i++] = bytes;
1008 
1009 		qstats = &nvdev->chan_table[j].rx_stats;
1010 		do {
1011 			start = u64_stats_fetch_begin_irq(&qstats->syncp);
1012 			packets = qstats->packets;
1013 			bytes = qstats->bytes;
1014 		} while (u64_stats_fetch_retry_irq(&qstats->syncp, start));
1015 		data[i++] = packets;
1016 		data[i++] = bytes;
1017 	}
1018 }
1019 
1020 static void netvsc_get_strings(struct net_device *dev, u32 stringset, u8 *data)
1021 {
1022 	struct net_device_context *ndc = netdev_priv(dev);
1023 	struct netvsc_device *nvdev = ndc->nvdev;
1024 	u8 *p = data;
1025 	int i;
1026 
1027 	switch (stringset) {
1028 	case ETH_SS_STATS:
1029 		for (i = 0; i < ARRAY_SIZE(netvsc_stats); i++)
1030 			memcpy(p + i * ETH_GSTRING_LEN,
1031 			       netvsc_stats[i].name, ETH_GSTRING_LEN);
1032 
1033 		p += i * ETH_GSTRING_LEN;
1034 		for (i = 0; i < nvdev->num_chn; i++) {
1035 			sprintf(p, "tx_queue_%u_packets", i);
1036 			p += ETH_GSTRING_LEN;
1037 			sprintf(p, "tx_queue_%u_bytes", i);
1038 			p += ETH_GSTRING_LEN;
1039 			sprintf(p, "rx_queue_%u_packets", i);
1040 			p += ETH_GSTRING_LEN;
1041 			sprintf(p, "rx_queue_%u_bytes", i);
1042 			p += ETH_GSTRING_LEN;
1043 		}
1044 
1045 		break;
1046 	}
1047 }
1048 
1049 static int
1050 netvsc_get_rss_hash_opts(struct netvsc_device *nvdev,
1051 			 struct ethtool_rxnfc *info)
1052 {
1053 	info->data = RXH_IP_SRC | RXH_IP_DST;
1054 
1055 	switch (info->flow_type) {
1056 	case TCP_V4_FLOW:
1057 	case TCP_V6_FLOW:
1058 		info->data |= RXH_L4_B_0_1 | RXH_L4_B_2_3;
1059 		/* fallthrough */
1060 	case UDP_V4_FLOW:
1061 	case UDP_V6_FLOW:
1062 	case IPV4_FLOW:
1063 	case IPV6_FLOW:
1064 		break;
1065 	default:
1066 		info->data = 0;
1067 		break;
1068 	}
1069 
1070 	return 0;
1071 }
1072 
1073 static int
1074 netvsc_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info,
1075 		 u32 *rules)
1076 {
1077 	struct net_device_context *ndc = netdev_priv(dev);
1078 	struct netvsc_device *nvdev = ndc->nvdev;
1079 
1080 	switch (info->cmd) {
1081 	case ETHTOOL_GRXRINGS:
1082 		info->data = nvdev->num_chn;
1083 		return 0;
1084 
1085 	case ETHTOOL_GRXFH:
1086 		return netvsc_get_rss_hash_opts(nvdev, info);
1087 	}
1088 	return -EOPNOTSUPP;
1089 }
1090 
1091 #ifdef CONFIG_NET_POLL_CONTROLLER
1092 static void netvsc_poll_controller(struct net_device *net)
1093 {
1094 	/* As netvsc_start_xmit() works synchronous we don't have to
1095 	 * trigger anything here.
1096 	 */
1097 }
1098 #endif
1099 
1100 static u32 netvsc_get_rxfh_key_size(struct net_device *dev)
1101 {
1102 	return NETVSC_HASH_KEYLEN;
1103 }
1104 
1105 static u32 netvsc_rss_indir_size(struct net_device *dev)
1106 {
1107 	return ITAB_NUM;
1108 }
1109 
1110 static int netvsc_get_rxfh(struct net_device *dev, u32 *indir, u8 *key,
1111 			   u8 *hfunc)
1112 {
1113 	struct net_device_context *ndc = netdev_priv(dev);
1114 	struct netvsc_device *ndev = ndc->nvdev;
1115 	struct rndis_device *rndis_dev = ndev->extension;
1116 	int i;
1117 
1118 	if (hfunc)
1119 		*hfunc = ETH_RSS_HASH_TOP;	/* Toeplitz */
1120 
1121 	if (indir) {
1122 		for (i = 0; i < ITAB_NUM; i++)
1123 			indir[i] = rndis_dev->ind_table[i];
1124 	}
1125 
1126 	if (key)
1127 		memcpy(key, rndis_dev->rss_key, NETVSC_HASH_KEYLEN);
1128 
1129 	return 0;
1130 }
1131 
1132 static int netvsc_set_rxfh(struct net_device *dev, const u32 *indir,
1133 			   const u8 *key, const u8 hfunc)
1134 {
1135 	struct net_device_context *ndc = netdev_priv(dev);
1136 	struct netvsc_device *ndev = ndc->nvdev;
1137 	struct rndis_device *rndis_dev = ndev->extension;
1138 	int i;
1139 
1140 	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
1141 		return -EOPNOTSUPP;
1142 
1143 	if (indir) {
1144 		for (i = 0; i < ITAB_NUM; i++)
1145 			if (indir[i] >= dev->num_rx_queues)
1146 				return -EINVAL;
1147 
1148 		for (i = 0; i < ITAB_NUM; i++)
1149 			rndis_dev->ind_table[i] = indir[i];
1150 	}
1151 
1152 	if (!key) {
1153 		if (!indir)
1154 			return 0;
1155 
1156 		key = rndis_dev->rss_key;
1157 	}
1158 
1159 	return rndis_filter_set_rss_param(rndis_dev, key, ndev->num_chn);
1160 }
1161 
1162 static const struct ethtool_ops ethtool_ops = {
1163 	.get_drvinfo	= netvsc_get_drvinfo,
1164 	.get_link	= ethtool_op_get_link,
1165 	.get_ethtool_stats = netvsc_get_ethtool_stats,
1166 	.get_sset_count = netvsc_get_sset_count,
1167 	.get_strings	= netvsc_get_strings,
1168 	.get_channels   = netvsc_get_channels,
1169 	.set_channels   = netvsc_set_channels,
1170 	.get_ts_info	= ethtool_op_get_ts_info,
1171 	.get_settings	= netvsc_get_settings,
1172 	.set_settings	= netvsc_set_settings,
1173 	.get_rxnfc	= netvsc_get_rxnfc,
1174 	.get_rxfh_key_size = netvsc_get_rxfh_key_size,
1175 	.get_rxfh_indir_size = netvsc_rss_indir_size,
1176 	.get_rxfh	= netvsc_get_rxfh,
1177 	.set_rxfh	= netvsc_set_rxfh,
1178 };
1179 
1180 static const struct net_device_ops device_ops = {
1181 	.ndo_open =			netvsc_open,
1182 	.ndo_stop =			netvsc_close,
1183 	.ndo_start_xmit =		netvsc_start_xmit,
1184 	.ndo_set_rx_mode =		netvsc_set_multicast_list,
1185 	.ndo_change_mtu =		netvsc_change_mtu,
1186 	.ndo_validate_addr =		eth_validate_addr,
1187 	.ndo_set_mac_address =		netvsc_set_mac_addr,
1188 	.ndo_select_queue =		netvsc_select_queue,
1189 	.ndo_get_stats64 =		netvsc_get_stats64,
1190 #ifdef CONFIG_NET_POLL_CONTROLLER
1191 	.ndo_poll_controller =		netvsc_poll_controller,
1192 #endif
1193 };
1194 
1195 /*
1196  * Handle link status changes. For RNDIS_STATUS_NETWORK_CHANGE emulate link
1197  * down/up sequence. In case of RNDIS_STATUS_MEDIA_CONNECT when carrier is
1198  * present send GARP packet to network peers with netif_notify_peers().
1199  */
1200 static void netvsc_link_change(struct work_struct *w)
1201 {
1202 	struct net_device_context *ndev_ctx =
1203 		container_of(w, struct net_device_context, dwork.work);
1204 	struct hv_device *device_obj = ndev_ctx->device_ctx;
1205 	struct net_device *net = hv_get_drvdata(device_obj);
1206 	struct netvsc_device *net_device;
1207 	struct rndis_device *rdev;
1208 	struct netvsc_reconfig *event = NULL;
1209 	bool notify = false, reschedule = false;
1210 	unsigned long flags, next_reconfig, delay;
1211 
1212 	rtnl_lock();
1213 	if (ndev_ctx->start_remove)
1214 		goto out_unlock;
1215 
1216 	net_device = ndev_ctx->nvdev;
1217 	rdev = net_device->extension;
1218 
1219 	next_reconfig = ndev_ctx->last_reconfig + LINKCHANGE_INT;
1220 	if (time_is_after_jiffies(next_reconfig)) {
1221 		/* link_watch only sends one notification with current state
1222 		 * per second, avoid doing reconfig more frequently. Handle
1223 		 * wrap around.
1224 		 */
1225 		delay = next_reconfig - jiffies;
1226 		delay = delay < LINKCHANGE_INT ? delay : LINKCHANGE_INT;
1227 		schedule_delayed_work(&ndev_ctx->dwork, delay);
1228 		goto out_unlock;
1229 	}
1230 	ndev_ctx->last_reconfig = jiffies;
1231 
1232 	spin_lock_irqsave(&ndev_ctx->lock, flags);
1233 	if (!list_empty(&ndev_ctx->reconfig_events)) {
1234 		event = list_first_entry(&ndev_ctx->reconfig_events,
1235 					 struct netvsc_reconfig, list);
1236 		list_del(&event->list);
1237 		reschedule = !list_empty(&ndev_ctx->reconfig_events);
1238 	}
1239 	spin_unlock_irqrestore(&ndev_ctx->lock, flags);
1240 
1241 	if (!event)
1242 		goto out_unlock;
1243 
1244 	switch (event->event) {
1245 		/* Only the following events are possible due to the check in
1246 		 * netvsc_linkstatus_callback()
1247 		 */
1248 	case RNDIS_STATUS_MEDIA_CONNECT:
1249 		if (rdev->link_state) {
1250 			rdev->link_state = false;
1251 			netif_carrier_on(net);
1252 			netif_tx_wake_all_queues(net);
1253 		} else {
1254 			notify = true;
1255 		}
1256 		kfree(event);
1257 		break;
1258 	case RNDIS_STATUS_MEDIA_DISCONNECT:
1259 		if (!rdev->link_state) {
1260 			rdev->link_state = true;
1261 			netif_carrier_off(net);
1262 			netif_tx_stop_all_queues(net);
1263 		}
1264 		kfree(event);
1265 		break;
1266 	case RNDIS_STATUS_NETWORK_CHANGE:
1267 		/* Only makes sense if carrier is present */
1268 		if (!rdev->link_state) {
1269 			rdev->link_state = true;
1270 			netif_carrier_off(net);
1271 			netif_tx_stop_all_queues(net);
1272 			event->event = RNDIS_STATUS_MEDIA_CONNECT;
1273 			spin_lock_irqsave(&ndev_ctx->lock, flags);
1274 			list_add(&event->list, &ndev_ctx->reconfig_events);
1275 			spin_unlock_irqrestore(&ndev_ctx->lock, flags);
1276 			reschedule = true;
1277 		}
1278 		break;
1279 	}
1280 
1281 	rtnl_unlock();
1282 
1283 	if (notify)
1284 		netdev_notify_peers(net);
1285 
1286 	/* link_watch only sends one notification with current state per
1287 	 * second, handle next reconfig event in 2 seconds.
1288 	 */
1289 	if (reschedule)
1290 		schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT);
1291 
1292 	return;
1293 
1294 out_unlock:
1295 	rtnl_unlock();
1296 }
1297 
1298 static struct net_device *get_netvsc_bymac(const u8 *mac)
1299 {
1300 	struct net_device *dev;
1301 
1302 	ASSERT_RTNL();
1303 
1304 	for_each_netdev(&init_net, dev) {
1305 		if (dev->netdev_ops != &device_ops)
1306 			continue;	/* not a netvsc device */
1307 
1308 		if (ether_addr_equal(mac, dev->perm_addr))
1309 			return dev;
1310 	}
1311 
1312 	return NULL;
1313 }
1314 
1315 static struct net_device *get_netvsc_byref(struct net_device *vf_netdev)
1316 {
1317 	struct net_device *dev;
1318 
1319 	ASSERT_RTNL();
1320 
1321 	for_each_netdev(&init_net, dev) {
1322 		struct net_device_context *net_device_ctx;
1323 
1324 		if (dev->netdev_ops != &device_ops)
1325 			continue;	/* not a netvsc device */
1326 
1327 		net_device_ctx = netdev_priv(dev);
1328 		if (net_device_ctx->nvdev == NULL)
1329 			continue;	/* device is removed */
1330 
1331 		if (rtnl_dereference(net_device_ctx->vf_netdev) == vf_netdev)
1332 			return dev;	/* a match */
1333 	}
1334 
1335 	return NULL;
1336 }
1337 
1338 static int netvsc_register_vf(struct net_device *vf_netdev)
1339 {
1340 	struct net_device *ndev;
1341 	struct net_device_context *net_device_ctx;
1342 	struct netvsc_device *netvsc_dev;
1343 
1344 	if (vf_netdev->addr_len != ETH_ALEN)
1345 		return NOTIFY_DONE;
1346 
1347 	/*
1348 	 * We will use the MAC address to locate the synthetic interface to
1349 	 * associate with the VF interface. If we don't find a matching
1350 	 * synthetic interface, move on.
1351 	 */
1352 	ndev = get_netvsc_bymac(vf_netdev->perm_addr);
1353 	if (!ndev)
1354 		return NOTIFY_DONE;
1355 
1356 	net_device_ctx = netdev_priv(ndev);
1357 	netvsc_dev = net_device_ctx->nvdev;
1358 	if (!netvsc_dev || rtnl_dereference(net_device_ctx->vf_netdev))
1359 		return NOTIFY_DONE;
1360 
1361 	netdev_info(ndev, "VF registering: %s\n", vf_netdev->name);
1362 	/*
1363 	 * Take a reference on the module.
1364 	 */
1365 	try_module_get(THIS_MODULE);
1366 
1367 	dev_hold(vf_netdev);
1368 	rcu_assign_pointer(net_device_ctx->vf_netdev, vf_netdev);
1369 	return NOTIFY_OK;
1370 }
1371 
1372 static int netvsc_vf_up(struct net_device *vf_netdev)
1373 {
1374 	struct net_device *ndev;
1375 	struct netvsc_device *netvsc_dev;
1376 	struct net_device_context *net_device_ctx;
1377 
1378 	ndev = get_netvsc_byref(vf_netdev);
1379 	if (!ndev)
1380 		return NOTIFY_DONE;
1381 
1382 	net_device_ctx = netdev_priv(ndev);
1383 	netvsc_dev = net_device_ctx->nvdev;
1384 
1385 	netdev_info(ndev, "VF up: %s\n", vf_netdev->name);
1386 
1387 	/*
1388 	 * Open the device before switching data path.
1389 	 */
1390 	rndis_filter_open(netvsc_dev);
1391 
1392 	/*
1393 	 * notify the host to switch the data path.
1394 	 */
1395 	netvsc_switch_datapath(ndev, true);
1396 	netdev_info(ndev, "Data path switched to VF: %s\n", vf_netdev->name);
1397 
1398 	netif_carrier_off(ndev);
1399 
1400 	/* Now notify peers through VF device. */
1401 	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, vf_netdev);
1402 
1403 	return NOTIFY_OK;
1404 }
1405 
1406 static int netvsc_vf_down(struct net_device *vf_netdev)
1407 {
1408 	struct net_device *ndev;
1409 	struct netvsc_device *netvsc_dev;
1410 	struct net_device_context *net_device_ctx;
1411 
1412 	ndev = get_netvsc_byref(vf_netdev);
1413 	if (!ndev)
1414 		return NOTIFY_DONE;
1415 
1416 	net_device_ctx = netdev_priv(ndev);
1417 	netvsc_dev = net_device_ctx->nvdev;
1418 
1419 	netdev_info(ndev, "VF down: %s\n", vf_netdev->name);
1420 	netvsc_switch_datapath(ndev, false);
1421 	netdev_info(ndev, "Data path switched from VF: %s\n", vf_netdev->name);
1422 	rndis_filter_close(netvsc_dev);
1423 	netif_carrier_on(ndev);
1424 
1425 	/* Now notify peers through netvsc device. */
1426 	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, ndev);
1427 
1428 	return NOTIFY_OK;
1429 }
1430 
1431 static int netvsc_unregister_vf(struct net_device *vf_netdev)
1432 {
1433 	struct net_device *ndev;
1434 	struct net_device_context *net_device_ctx;
1435 
1436 	ndev = get_netvsc_byref(vf_netdev);
1437 	if (!ndev)
1438 		return NOTIFY_DONE;
1439 
1440 	net_device_ctx = netdev_priv(ndev);
1441 
1442 	netdev_info(ndev, "VF unregistering: %s\n", vf_netdev->name);
1443 
1444 	RCU_INIT_POINTER(net_device_ctx->vf_netdev, NULL);
1445 	dev_put(vf_netdev);
1446 	module_put(THIS_MODULE);
1447 	return NOTIFY_OK;
1448 }
1449 
1450 static int netvsc_probe(struct hv_device *dev,
1451 			const struct hv_vmbus_device_id *dev_id)
1452 {
1453 	struct net_device *net = NULL;
1454 	struct net_device_context *net_device_ctx;
1455 	struct netvsc_device_info device_info;
1456 	struct netvsc_device *nvdev;
1457 	int ret;
1458 
1459 	net = alloc_etherdev_mq(sizeof(struct net_device_context),
1460 				VRSS_CHANNEL_MAX);
1461 	if (!net)
1462 		return -ENOMEM;
1463 
1464 	netif_carrier_off(net);
1465 
1466 	netvsc_init_settings(net);
1467 
1468 	net_device_ctx = netdev_priv(net);
1469 	net_device_ctx->device_ctx = dev;
1470 	net_device_ctx->msg_enable = netif_msg_init(debug, default_msg);
1471 	if (netif_msg_probe(net_device_ctx))
1472 		netdev_dbg(net, "netvsc msg_enable: %d\n",
1473 			   net_device_ctx->msg_enable);
1474 
1475 	hv_set_drvdata(dev, net);
1476 
1477 	net_device_ctx->start_remove = false;
1478 
1479 	INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change);
1480 	INIT_WORK(&net_device_ctx->work, do_set_multicast);
1481 
1482 	spin_lock_init(&net_device_ctx->lock);
1483 	INIT_LIST_HEAD(&net_device_ctx->reconfig_events);
1484 
1485 	net->netdev_ops = &device_ops;
1486 	net->ethtool_ops = &ethtool_ops;
1487 	SET_NETDEV_DEV(net, &dev->device);
1488 
1489 	/* We always need headroom for rndis header */
1490 	net->needed_headroom = RNDIS_AND_PPI_SIZE;
1491 
1492 	/* Notify the netvsc driver of the new device */
1493 	memset(&device_info, 0, sizeof(device_info));
1494 	device_info.ring_size = ring_size;
1495 	device_info.max_num_vrss_chns = min_t(u32, VRSS_CHANNEL_DEFAULT,
1496 					      num_online_cpus());
1497 	ret = rndis_filter_device_add(dev, &device_info);
1498 	if (ret != 0) {
1499 		netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
1500 		free_netdev(net);
1501 		hv_set_drvdata(dev, NULL);
1502 		return ret;
1503 	}
1504 	memcpy(net->dev_addr, device_info.mac_adr, ETH_ALEN);
1505 
1506 	/* hw_features computed in rndis_filter_device_add */
1507 	net->features = net->hw_features |
1508 		NETIF_F_HIGHDMA | NETIF_F_SG |
1509 		NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX;
1510 	net->vlan_features = net->features;
1511 
1512 	nvdev = net_device_ctx->nvdev;
1513 	netif_set_real_num_tx_queues(net, nvdev->num_chn);
1514 	netif_set_real_num_rx_queues(net, nvdev->num_chn);
1515 
1516 	/* MTU range: 68 - 1500 or 65521 */
1517 	net->min_mtu = NETVSC_MTU_MIN;
1518 	if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
1519 		net->max_mtu = NETVSC_MTU - ETH_HLEN;
1520 	else
1521 		net->max_mtu = ETH_DATA_LEN;
1522 
1523 	ret = register_netdev(net);
1524 	if (ret != 0) {
1525 		pr_err("Unable to register netdev.\n");
1526 		rndis_filter_device_remove(dev, nvdev);
1527 		free_netdev(net);
1528 	}
1529 
1530 	return ret;
1531 }
1532 
1533 static int netvsc_remove(struct hv_device *dev)
1534 {
1535 	struct net_device *net;
1536 	struct net_device_context *ndev_ctx;
1537 
1538 	net = hv_get_drvdata(dev);
1539 
1540 	if (net == NULL) {
1541 		dev_err(&dev->device, "No net device to remove\n");
1542 		return 0;
1543 	}
1544 
1545 	ndev_ctx = netdev_priv(net);
1546 
1547 	/* Avoid racing with netvsc_change_mtu()/netvsc_set_channels()
1548 	 * removing the device.
1549 	 */
1550 	rtnl_lock();
1551 	ndev_ctx->start_remove = true;
1552 	rtnl_unlock();
1553 
1554 	cancel_delayed_work_sync(&ndev_ctx->dwork);
1555 	cancel_work_sync(&ndev_ctx->work);
1556 
1557 	/* Stop outbound asap */
1558 	netif_tx_disable(net);
1559 
1560 	unregister_netdev(net);
1561 
1562 	/*
1563 	 * Call to the vsc driver to let it know that the device is being
1564 	 * removed
1565 	 */
1566 	rndis_filter_device_remove(dev, ndev_ctx->nvdev);
1567 
1568 	hv_set_drvdata(dev, NULL);
1569 
1570 	free_netdev(net);
1571 	return 0;
1572 }
1573 
1574 static const struct hv_vmbus_device_id id_table[] = {
1575 	/* Network guid */
1576 	{ HV_NIC_GUID, },
1577 	{ },
1578 };
1579 
1580 MODULE_DEVICE_TABLE(vmbus, id_table);
1581 
1582 /* The one and only one */
1583 static struct  hv_driver netvsc_drv = {
1584 	.name = KBUILD_MODNAME,
1585 	.id_table = id_table,
1586 	.probe = netvsc_probe,
1587 	.remove = netvsc_remove,
1588 };
1589 
1590 /*
1591  * On Hyper-V, every VF interface is matched with a corresponding
1592  * synthetic interface. The synthetic interface is presented first
1593  * to the guest. When the corresponding VF instance is registered,
1594  * we will take care of switching the data path.
1595  */
1596 static int netvsc_netdev_event(struct notifier_block *this,
1597 			       unsigned long event, void *ptr)
1598 {
1599 	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
1600 
1601 	/* Skip our own events */
1602 	if (event_dev->netdev_ops == &device_ops)
1603 		return NOTIFY_DONE;
1604 
1605 	/* Avoid non-Ethernet type devices */
1606 	if (event_dev->type != ARPHRD_ETHER)
1607 		return NOTIFY_DONE;
1608 
1609 	/* Avoid Vlan dev with same MAC registering as VF */
1610 	if (is_vlan_dev(event_dev))
1611 		return NOTIFY_DONE;
1612 
1613 	/* Avoid Bonding master dev with same MAC registering as VF */
1614 	if ((event_dev->priv_flags & IFF_BONDING) &&
1615 	    (event_dev->flags & IFF_MASTER))
1616 		return NOTIFY_DONE;
1617 
1618 	switch (event) {
1619 	case NETDEV_REGISTER:
1620 		return netvsc_register_vf(event_dev);
1621 	case NETDEV_UNREGISTER:
1622 		return netvsc_unregister_vf(event_dev);
1623 	case NETDEV_UP:
1624 		return netvsc_vf_up(event_dev);
1625 	case NETDEV_DOWN:
1626 		return netvsc_vf_down(event_dev);
1627 	default:
1628 		return NOTIFY_DONE;
1629 	}
1630 }
1631 
1632 static struct notifier_block netvsc_netdev_notifier = {
1633 	.notifier_call = netvsc_netdev_event,
1634 };
1635 
1636 static void __exit netvsc_drv_exit(void)
1637 {
1638 	unregister_netdevice_notifier(&netvsc_netdev_notifier);
1639 	vmbus_driver_unregister(&netvsc_drv);
1640 }
1641 
1642 static int __init netvsc_drv_init(void)
1643 {
1644 	int ret;
1645 
1646 	if (ring_size < RING_SIZE_MIN) {
1647 		ring_size = RING_SIZE_MIN;
1648 		pr_info("Increased ring_size to %d (min allowed)\n",
1649 			ring_size);
1650 	}
1651 	ret = vmbus_driver_register(&netvsc_drv);
1652 
1653 	if (ret)
1654 		return ret;
1655 
1656 	register_netdevice_notifier(&netvsc_netdev_notifier);
1657 	return 0;
1658 }
1659 
1660 MODULE_LICENSE("GPL");
1661 MODULE_DESCRIPTION("Microsoft Hyper-V network driver");
1662 
1663 module_init(netvsc_drv_init);
1664 module_exit(netvsc_drv_exit);
1665