xref: /linux/drivers/net/hyperv/netvsc.c (revision 071bf69a0220253a44acb8b2a27f7a262b9a46bf)
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/kernel.h>
23 #include <linux/sched.h>
24 #include <linux/wait.h>
25 #include <linux/mm.h>
26 #include <linux/delay.h>
27 #include <linux/io.h>
28 #include <linux/slab.h>
29 #include <linux/netdevice.h>
30 #include <linux/if_ether.h>
31 #include <linux/vmalloc.h>
32 #include <asm/sync_bitops.h>
33 
34 #include "hyperv_net.h"
35 
36 /*
37  * Switch the data path from the synthetic interface to the VF
38  * interface.
39  */
40 void netvsc_switch_datapath(struct net_device *ndev, bool vf)
41 {
42 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
43 	struct hv_device *dev = net_device_ctx->device_ctx;
44 	struct netvsc_device *nv_dev = net_device_ctx->nvdev;
45 	struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
46 
47 	memset(init_pkt, 0, sizeof(struct nvsp_message));
48 	init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
49 	if (vf)
50 		init_pkt->msg.v4_msg.active_dp.active_datapath =
51 			NVSP_DATAPATH_VF;
52 	else
53 		init_pkt->msg.v4_msg.active_dp.active_datapath =
54 			NVSP_DATAPATH_SYNTHETIC;
55 
56 	vmbus_sendpacket(dev->channel, init_pkt,
57 			       sizeof(struct nvsp_message),
58 			       (unsigned long)init_pkt,
59 			       VM_PKT_DATA_INBAND, 0);
60 }
61 
62 
63 static struct netvsc_device *alloc_net_device(void)
64 {
65 	struct netvsc_device *net_device;
66 
67 	net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
68 	if (!net_device)
69 		return NULL;
70 
71 	net_device->cb_buffer = kzalloc(NETVSC_PACKET_SIZE, GFP_KERNEL);
72 	if (!net_device->cb_buffer) {
73 		kfree(net_device);
74 		return NULL;
75 	}
76 
77 	init_waitqueue_head(&net_device->wait_drain);
78 	net_device->destroy = false;
79 	atomic_set(&net_device->open_cnt, 0);
80 	atomic_set(&net_device->vf_use_cnt, 0);
81 	net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
82 	net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
83 
84 	net_device->vf_netdev = NULL;
85 	net_device->vf_inject = false;
86 
87 	return net_device;
88 }
89 
90 static void free_netvsc_device(struct netvsc_device *nvdev)
91 {
92 	kfree(nvdev->cb_buffer);
93 	kfree(nvdev);
94 }
95 
96 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
97 {
98 	struct netvsc_device *net_device = hv_device_to_netvsc_device(device);
99 
100 	if (net_device && net_device->destroy)
101 		net_device = NULL;
102 
103 	return net_device;
104 }
105 
106 static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
107 {
108 	struct netvsc_device *net_device = hv_device_to_netvsc_device(device);
109 
110 	if (!net_device)
111 		goto get_in_err;
112 
113 	if (net_device->destroy &&
114 		atomic_read(&net_device->num_outstanding_sends) == 0)
115 		net_device = NULL;
116 
117 get_in_err:
118 	return net_device;
119 }
120 
121 
122 static int netvsc_destroy_buf(struct hv_device *device)
123 {
124 	struct nvsp_message *revoke_packet;
125 	int ret = 0;
126 	struct net_device *ndev = hv_get_drvdata(device);
127 	struct netvsc_device *net_device = net_device_to_netvsc_device(ndev);
128 
129 	/*
130 	 * If we got a section count, it means we received a
131 	 * SendReceiveBufferComplete msg (ie sent
132 	 * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
133 	 * to send a revoke msg here
134 	 */
135 	if (net_device->recv_section_cnt) {
136 		/* Send the revoke receive buffer */
137 		revoke_packet = &net_device->revoke_packet;
138 		memset(revoke_packet, 0, sizeof(struct nvsp_message));
139 
140 		revoke_packet->hdr.msg_type =
141 			NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
142 		revoke_packet->msg.v1_msg.
143 		revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
144 
145 		ret = vmbus_sendpacket(device->channel,
146 				       revoke_packet,
147 				       sizeof(struct nvsp_message),
148 				       (unsigned long)revoke_packet,
149 				       VM_PKT_DATA_INBAND, 0);
150 		/*
151 		 * If we failed here, we might as well return and
152 		 * have a leak rather than continue and a bugchk
153 		 */
154 		if (ret != 0) {
155 			netdev_err(ndev, "unable to send "
156 				"revoke receive buffer to netvsp\n");
157 			return ret;
158 		}
159 	}
160 
161 	/* Teardown the gpadl on the vsp end */
162 	if (net_device->recv_buf_gpadl_handle) {
163 		ret = vmbus_teardown_gpadl(device->channel,
164 					   net_device->recv_buf_gpadl_handle);
165 
166 		/* If we failed here, we might as well return and have a leak
167 		 * rather than continue and a bugchk
168 		 */
169 		if (ret != 0) {
170 			netdev_err(ndev,
171 				   "unable to teardown receive buffer's gpadl\n");
172 			return ret;
173 		}
174 		net_device->recv_buf_gpadl_handle = 0;
175 	}
176 
177 	if (net_device->recv_buf) {
178 		/* Free up the receive buffer */
179 		vfree(net_device->recv_buf);
180 		net_device->recv_buf = NULL;
181 	}
182 
183 	if (net_device->recv_section) {
184 		net_device->recv_section_cnt = 0;
185 		kfree(net_device->recv_section);
186 		net_device->recv_section = NULL;
187 	}
188 
189 	/* Deal with the send buffer we may have setup.
190 	 * If we got a  send section size, it means we received a
191 	 * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
192 	 * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
193 	 * to send a revoke msg here
194 	 */
195 	if (net_device->send_section_size) {
196 		/* Send the revoke receive buffer */
197 		revoke_packet = &net_device->revoke_packet;
198 		memset(revoke_packet, 0, sizeof(struct nvsp_message));
199 
200 		revoke_packet->hdr.msg_type =
201 			NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
202 		revoke_packet->msg.v1_msg.revoke_send_buf.id =
203 			NETVSC_SEND_BUFFER_ID;
204 
205 		ret = vmbus_sendpacket(device->channel,
206 				       revoke_packet,
207 				       sizeof(struct nvsp_message),
208 				       (unsigned long)revoke_packet,
209 				       VM_PKT_DATA_INBAND, 0);
210 		/* If we failed here, we might as well return and
211 		 * have a leak rather than continue and a bugchk
212 		 */
213 		if (ret != 0) {
214 			netdev_err(ndev, "unable to send "
215 				   "revoke send buffer to netvsp\n");
216 			return ret;
217 		}
218 	}
219 	/* Teardown the gpadl on the vsp end */
220 	if (net_device->send_buf_gpadl_handle) {
221 		ret = vmbus_teardown_gpadl(device->channel,
222 					   net_device->send_buf_gpadl_handle);
223 
224 		/* If we failed here, we might as well return and have a leak
225 		 * rather than continue and a bugchk
226 		 */
227 		if (ret != 0) {
228 			netdev_err(ndev,
229 				   "unable to teardown send buffer's gpadl\n");
230 			return ret;
231 		}
232 		net_device->send_buf_gpadl_handle = 0;
233 	}
234 	if (net_device->send_buf) {
235 		/* Free up the send buffer */
236 		vfree(net_device->send_buf);
237 		net_device->send_buf = NULL;
238 	}
239 	kfree(net_device->send_section_map);
240 
241 	return ret;
242 }
243 
244 static int netvsc_init_buf(struct hv_device *device)
245 {
246 	int ret = 0;
247 	struct netvsc_device *net_device;
248 	struct nvsp_message *init_packet;
249 	struct net_device *ndev;
250 	int node;
251 
252 	net_device = get_outbound_net_device(device);
253 	if (!net_device)
254 		return -ENODEV;
255 	ndev = hv_get_drvdata(device);
256 
257 	node = cpu_to_node(device->channel->target_cpu);
258 	net_device->recv_buf = vzalloc_node(net_device->recv_buf_size, node);
259 	if (!net_device->recv_buf)
260 		net_device->recv_buf = vzalloc(net_device->recv_buf_size);
261 
262 	if (!net_device->recv_buf) {
263 		netdev_err(ndev, "unable to allocate receive "
264 			"buffer of size %d\n", net_device->recv_buf_size);
265 		ret = -ENOMEM;
266 		goto cleanup;
267 	}
268 
269 	/*
270 	 * Establish the gpadl handle for this buffer on this
271 	 * channel.  Note: This call uses the vmbus connection rather
272 	 * than the channel to establish the gpadl handle.
273 	 */
274 	ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
275 				    net_device->recv_buf_size,
276 				    &net_device->recv_buf_gpadl_handle);
277 	if (ret != 0) {
278 		netdev_err(ndev,
279 			"unable to establish receive buffer's gpadl\n");
280 		goto cleanup;
281 	}
282 
283 
284 	/* Notify the NetVsp of the gpadl handle */
285 	init_packet = &net_device->channel_init_pkt;
286 
287 	memset(init_packet, 0, sizeof(struct nvsp_message));
288 
289 	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
290 	init_packet->msg.v1_msg.send_recv_buf.
291 		gpadl_handle = net_device->recv_buf_gpadl_handle;
292 	init_packet->msg.v1_msg.
293 		send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
294 
295 	/* Send the gpadl notification request */
296 	ret = vmbus_sendpacket(device->channel, init_packet,
297 			       sizeof(struct nvsp_message),
298 			       (unsigned long)init_packet,
299 			       VM_PKT_DATA_INBAND,
300 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
301 	if (ret != 0) {
302 		netdev_err(ndev,
303 			"unable to send receive buffer's gpadl to netvsp\n");
304 		goto cleanup;
305 	}
306 
307 	wait_for_completion(&net_device->channel_init_wait);
308 
309 	/* Check the response */
310 	if (init_packet->msg.v1_msg.
311 	    send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
312 		netdev_err(ndev, "Unable to complete receive buffer "
313 			   "initialization with NetVsp - status %d\n",
314 			   init_packet->msg.v1_msg.
315 			   send_recv_buf_complete.status);
316 		ret = -EINVAL;
317 		goto cleanup;
318 	}
319 
320 	/* Parse the response */
321 
322 	net_device->recv_section_cnt = init_packet->msg.
323 		v1_msg.send_recv_buf_complete.num_sections;
324 
325 	net_device->recv_section = kmemdup(
326 		init_packet->msg.v1_msg.send_recv_buf_complete.sections,
327 		net_device->recv_section_cnt *
328 		sizeof(struct nvsp_1_receive_buffer_section),
329 		GFP_KERNEL);
330 	if (net_device->recv_section == NULL) {
331 		ret = -EINVAL;
332 		goto cleanup;
333 	}
334 
335 	/*
336 	 * For 1st release, there should only be 1 section that represents the
337 	 * entire receive buffer
338 	 */
339 	if (net_device->recv_section_cnt != 1 ||
340 	    net_device->recv_section->offset != 0) {
341 		ret = -EINVAL;
342 		goto cleanup;
343 	}
344 
345 	/* Now setup the send buffer.
346 	 */
347 	net_device->send_buf = vzalloc_node(net_device->send_buf_size, node);
348 	if (!net_device->send_buf)
349 		net_device->send_buf = vzalloc(net_device->send_buf_size);
350 	if (!net_device->send_buf) {
351 		netdev_err(ndev, "unable to allocate send "
352 			   "buffer of size %d\n", net_device->send_buf_size);
353 		ret = -ENOMEM;
354 		goto cleanup;
355 	}
356 
357 	/* Establish the gpadl handle for this buffer on this
358 	 * channel.  Note: This call uses the vmbus connection rather
359 	 * than the channel to establish the gpadl handle.
360 	 */
361 	ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
362 				    net_device->send_buf_size,
363 				    &net_device->send_buf_gpadl_handle);
364 	if (ret != 0) {
365 		netdev_err(ndev,
366 			   "unable to establish send buffer's gpadl\n");
367 		goto cleanup;
368 	}
369 
370 	/* Notify the NetVsp of the gpadl handle */
371 	init_packet = &net_device->channel_init_pkt;
372 	memset(init_packet, 0, sizeof(struct nvsp_message));
373 	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
374 	init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
375 		net_device->send_buf_gpadl_handle;
376 	init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
377 
378 	/* Send the gpadl notification request */
379 	ret = vmbus_sendpacket(device->channel, init_packet,
380 			       sizeof(struct nvsp_message),
381 			       (unsigned long)init_packet,
382 			       VM_PKT_DATA_INBAND,
383 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
384 	if (ret != 0) {
385 		netdev_err(ndev,
386 			   "unable to send send buffer's gpadl to netvsp\n");
387 		goto cleanup;
388 	}
389 
390 	wait_for_completion(&net_device->channel_init_wait);
391 
392 	/* Check the response */
393 	if (init_packet->msg.v1_msg.
394 	    send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
395 		netdev_err(ndev, "Unable to complete send buffer "
396 			   "initialization with NetVsp - status %d\n",
397 			   init_packet->msg.v1_msg.
398 			   send_send_buf_complete.status);
399 		ret = -EINVAL;
400 		goto cleanup;
401 	}
402 
403 	/* Parse the response */
404 	net_device->send_section_size = init_packet->msg.
405 				v1_msg.send_send_buf_complete.section_size;
406 
407 	/* Section count is simply the size divided by the section size.
408 	 */
409 	net_device->send_section_cnt =
410 		net_device->send_buf_size/net_device->send_section_size;
411 
412 	dev_info(&device->device, "Send section size: %d, Section count:%d\n",
413 		 net_device->send_section_size, net_device->send_section_cnt);
414 
415 	/* Setup state for managing the send buffer. */
416 	net_device->map_words = DIV_ROUND_UP(net_device->send_section_cnt,
417 					     BITS_PER_LONG);
418 
419 	net_device->send_section_map =
420 		kzalloc(net_device->map_words * sizeof(ulong), GFP_KERNEL);
421 	if (net_device->send_section_map == NULL) {
422 		ret = -ENOMEM;
423 		goto cleanup;
424 	}
425 
426 	goto exit;
427 
428 cleanup:
429 	netvsc_destroy_buf(device);
430 
431 exit:
432 	return ret;
433 }
434 
435 
436 /* Negotiate NVSP protocol version */
437 static int negotiate_nvsp_ver(struct hv_device *device,
438 			      struct netvsc_device *net_device,
439 			      struct nvsp_message *init_packet,
440 			      u32 nvsp_ver)
441 {
442 	struct net_device *ndev = hv_get_drvdata(device);
443 	int ret;
444 
445 	memset(init_packet, 0, sizeof(struct nvsp_message));
446 	init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
447 	init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
448 	init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
449 
450 	/* Send the init request */
451 	ret = vmbus_sendpacket(device->channel, init_packet,
452 			       sizeof(struct nvsp_message),
453 			       (unsigned long)init_packet,
454 			       VM_PKT_DATA_INBAND,
455 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
456 
457 	if (ret != 0)
458 		return ret;
459 
460 	wait_for_completion(&net_device->channel_init_wait);
461 
462 	if (init_packet->msg.init_msg.init_complete.status !=
463 	    NVSP_STAT_SUCCESS)
464 		return -EINVAL;
465 
466 	if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
467 		return 0;
468 
469 	/* NVSPv2 or later: Send NDIS config */
470 	memset(init_packet, 0, sizeof(struct nvsp_message));
471 	init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
472 	init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;
473 	init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
474 
475 	if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5)
476 		init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
477 
478 	ret = vmbus_sendpacket(device->channel, init_packet,
479 				sizeof(struct nvsp_message),
480 				(unsigned long)init_packet,
481 				VM_PKT_DATA_INBAND, 0);
482 
483 	return ret;
484 }
485 
486 static int netvsc_connect_vsp(struct hv_device *device)
487 {
488 	int ret;
489 	struct netvsc_device *net_device;
490 	struct nvsp_message *init_packet;
491 	int ndis_version;
492 	u32 ver_list[] = { NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
493 		NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5 };
494 	int i, num_ver = 4; /* number of different NVSP versions */
495 
496 	net_device = get_outbound_net_device(device);
497 	if (!net_device)
498 		return -ENODEV;
499 
500 	init_packet = &net_device->channel_init_pkt;
501 
502 	/* Negotiate the latest NVSP protocol supported */
503 	for (i = num_ver - 1; i >= 0; i--)
504 		if (negotiate_nvsp_ver(device, net_device, init_packet,
505 				       ver_list[i])  == 0) {
506 			net_device->nvsp_version = ver_list[i];
507 			break;
508 		}
509 
510 	if (i < 0) {
511 		ret = -EPROTO;
512 		goto cleanup;
513 	}
514 
515 	pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
516 
517 	/* Send the ndis version */
518 	memset(init_packet, 0, sizeof(struct nvsp_message));
519 
520 	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
521 		ndis_version = 0x00060001;
522 	else
523 		ndis_version = 0x0006001e;
524 
525 	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
526 	init_packet->msg.v1_msg.
527 		send_ndis_ver.ndis_major_ver =
528 				(ndis_version & 0xFFFF0000) >> 16;
529 	init_packet->msg.v1_msg.
530 		send_ndis_ver.ndis_minor_ver =
531 				ndis_version & 0xFFFF;
532 
533 	/* Send the init request */
534 	ret = vmbus_sendpacket(device->channel, init_packet,
535 				sizeof(struct nvsp_message),
536 				(unsigned long)init_packet,
537 				VM_PKT_DATA_INBAND, 0);
538 	if (ret != 0)
539 		goto cleanup;
540 
541 	/* Post the big receive buffer to NetVSP */
542 	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
543 		net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
544 	else
545 		net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
546 	net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
547 
548 	ret = netvsc_init_buf(device);
549 
550 cleanup:
551 	return ret;
552 }
553 
554 static void netvsc_disconnect_vsp(struct hv_device *device)
555 {
556 	netvsc_destroy_buf(device);
557 }
558 
559 /*
560  * netvsc_device_remove - Callback when the root bus device is removed
561  */
562 int netvsc_device_remove(struct hv_device *device)
563 {
564 	struct net_device *ndev = hv_get_drvdata(device);
565 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
566 	struct netvsc_device *net_device = net_device_ctx->nvdev;
567 
568 	netvsc_disconnect_vsp(device);
569 
570 	net_device_ctx->nvdev = NULL;
571 
572 	/*
573 	 * At this point, no one should be accessing net_device
574 	 * except in here
575 	 */
576 	dev_notice(&device->device, "net device safe to remove\n");
577 
578 	/* Now, we can close the channel safely */
579 	vmbus_close(device->channel);
580 
581 	/* Release all resources */
582 	vfree(net_device->sub_cb_buf);
583 	free_netvsc_device(net_device);
584 	return 0;
585 }
586 
587 
588 #define RING_AVAIL_PERCENT_HIWATER 20
589 #define RING_AVAIL_PERCENT_LOWATER 10
590 
591 /*
592  * Get the percentage of available bytes to write in the ring.
593  * The return value is in range from 0 to 100.
594  */
595 static inline u32 hv_ringbuf_avail_percent(
596 		struct hv_ring_buffer_info *ring_info)
597 {
598 	u32 avail_read, avail_write;
599 
600 	hv_get_ringbuffer_availbytes(ring_info, &avail_read, &avail_write);
601 
602 	return avail_write * 100 / ring_info->ring_datasize;
603 }
604 
605 static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
606 					 u32 index)
607 {
608 	sync_change_bit(index, net_device->send_section_map);
609 }
610 
611 static void netvsc_send_completion(struct netvsc_device *net_device,
612 				   struct vmbus_channel *incoming_channel,
613 				   struct hv_device *device,
614 				   struct vmpacket_descriptor *packet)
615 {
616 	struct nvsp_message *nvsp_packet;
617 	struct hv_netvsc_packet *nvsc_packet;
618 	struct net_device *ndev = hv_get_drvdata(device);
619 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
620 	u32 send_index;
621 	struct sk_buff *skb;
622 
623 	nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
624 			(packet->offset8 << 3));
625 
626 	if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
627 	    (nvsp_packet->hdr.msg_type ==
628 	     NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
629 	    (nvsp_packet->hdr.msg_type ==
630 	     NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE) ||
631 	    (nvsp_packet->hdr.msg_type ==
632 	     NVSP_MSG5_TYPE_SUBCHANNEL)) {
633 		/* Copy the response back */
634 		memcpy(&net_device->channel_init_pkt, nvsp_packet,
635 		       sizeof(struct nvsp_message));
636 		complete(&net_device->channel_init_wait);
637 	} else if (nvsp_packet->hdr.msg_type ==
638 		   NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
639 		int num_outstanding_sends;
640 		u16 q_idx = 0;
641 		struct vmbus_channel *channel = device->channel;
642 		int queue_sends;
643 
644 		/* Get the send context */
645 		skb = (struct sk_buff *)(unsigned long)packet->trans_id;
646 
647 		/* Notify the layer above us */
648 		if (skb) {
649 			nvsc_packet = (struct hv_netvsc_packet *) skb->cb;
650 			send_index = nvsc_packet->send_buf_index;
651 			if (send_index != NETVSC_INVALID_INDEX)
652 				netvsc_free_send_slot(net_device, send_index);
653 			q_idx = nvsc_packet->q_idx;
654 			channel = incoming_channel;
655 			dev_kfree_skb_any(skb);
656 		}
657 
658 		num_outstanding_sends =
659 			atomic_dec_return(&net_device->num_outstanding_sends);
660 		queue_sends = atomic_dec_return(&net_device->
661 						queue_sends[q_idx]);
662 
663 		if (net_device->destroy && num_outstanding_sends == 0)
664 			wake_up(&net_device->wait_drain);
665 
666 		if (netif_tx_queue_stopped(netdev_get_tx_queue(ndev, q_idx)) &&
667 		    !net_device_ctx->start_remove &&
668 		    (hv_ringbuf_avail_percent(&channel->outbound) >
669 		     RING_AVAIL_PERCENT_HIWATER || queue_sends < 1))
670 				netif_tx_wake_queue(netdev_get_tx_queue(
671 						    ndev, q_idx));
672 	} else {
673 		netdev_err(ndev, "Unknown send completion packet type- "
674 			   "%d received!!\n", nvsp_packet->hdr.msg_type);
675 	}
676 
677 }
678 
679 static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
680 {
681 	unsigned long index;
682 	u32 max_words = net_device->map_words;
683 	unsigned long *map_addr = (unsigned long *)net_device->send_section_map;
684 	u32 section_cnt = net_device->send_section_cnt;
685 	int ret_val = NETVSC_INVALID_INDEX;
686 	int i;
687 	int prev_val;
688 
689 	for (i = 0; i < max_words; i++) {
690 		if (!~(map_addr[i]))
691 			continue;
692 		index = ffz(map_addr[i]);
693 		prev_val = sync_test_and_set_bit(index, &map_addr[i]);
694 		if (prev_val)
695 			continue;
696 		if ((index + (i * BITS_PER_LONG)) >= section_cnt)
697 			break;
698 		ret_val = (index + (i * BITS_PER_LONG));
699 		break;
700 	}
701 	return ret_val;
702 }
703 
704 static u32 netvsc_copy_to_send_buf(struct netvsc_device *net_device,
705 				   unsigned int section_index,
706 				   u32 pend_size,
707 				   struct hv_netvsc_packet *packet,
708 				   struct rndis_message *rndis_msg,
709 				   struct hv_page_buffer **pb,
710 				   struct sk_buff *skb)
711 {
712 	char *start = net_device->send_buf;
713 	char *dest = start + (section_index * net_device->send_section_size)
714 		     + pend_size;
715 	int i;
716 	bool is_data_pkt = (skb != NULL) ? true : false;
717 	bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
718 	u32 msg_size = 0;
719 	u32 padding = 0;
720 	u32 remain = packet->total_data_buflen % net_device->pkt_align;
721 	u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
722 		packet->page_buf_cnt;
723 
724 	/* Add padding */
725 	if (is_data_pkt && xmit_more && remain &&
726 	    !packet->cp_partial) {
727 		padding = net_device->pkt_align - remain;
728 		rndis_msg->msg_len += padding;
729 		packet->total_data_buflen += padding;
730 	}
731 
732 	for (i = 0; i < page_count; i++) {
733 		char *src = phys_to_virt((*pb)[i].pfn << PAGE_SHIFT);
734 		u32 offset = (*pb)[i].offset;
735 		u32 len = (*pb)[i].len;
736 
737 		memcpy(dest, (src + offset), len);
738 		msg_size += len;
739 		dest += len;
740 	}
741 
742 	if (padding) {
743 		memset(dest, 0, padding);
744 		msg_size += padding;
745 	}
746 
747 	return msg_size;
748 }
749 
750 static inline int netvsc_send_pkt(
751 	struct hv_device *device,
752 	struct hv_netvsc_packet *packet,
753 	struct netvsc_device *net_device,
754 	struct hv_page_buffer **pb,
755 	struct sk_buff *skb)
756 {
757 	struct nvsp_message nvmsg;
758 	u16 q_idx = packet->q_idx;
759 	struct vmbus_channel *out_channel = net_device->chn_table[q_idx];
760 	struct net_device *ndev = hv_get_drvdata(device);
761 	u64 req_id;
762 	int ret;
763 	struct hv_page_buffer *pgbuf;
764 	u32 ring_avail = hv_ringbuf_avail_percent(&out_channel->outbound);
765 	bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
766 
767 	nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
768 	if (skb != NULL) {
769 		/* 0 is RMC_DATA; */
770 		nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 0;
771 	} else {
772 		/* 1 is RMC_CONTROL; */
773 		nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 1;
774 	}
775 
776 	nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
777 		packet->send_buf_index;
778 	if (packet->send_buf_index == NETVSC_INVALID_INDEX)
779 		nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
780 	else
781 		nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size =
782 			packet->total_data_buflen;
783 
784 	req_id = (ulong)skb;
785 
786 	if (out_channel->rescind)
787 		return -ENODEV;
788 
789 	/*
790 	 * It is possible that once we successfully place this packet
791 	 * on the ringbuffer, we may stop the queue. In that case, we want
792 	 * to notify the host independent of the xmit_more flag. We don't
793 	 * need to be precise here; in the worst case we may signal the host
794 	 * unnecessarily.
795 	 */
796 	if (ring_avail < (RING_AVAIL_PERCENT_LOWATER + 1))
797 		xmit_more = false;
798 
799 	if (packet->page_buf_cnt) {
800 		pgbuf = packet->cp_partial ? (*pb) +
801 			packet->rmsg_pgcnt : (*pb);
802 		ret = vmbus_sendpacket_pagebuffer_ctl(out_channel,
803 						      pgbuf,
804 						      packet->page_buf_cnt,
805 						      &nvmsg,
806 						      sizeof(struct nvsp_message),
807 						      req_id,
808 						      VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
809 						      !xmit_more);
810 	} else {
811 		ret = vmbus_sendpacket_ctl(out_channel, &nvmsg,
812 					   sizeof(struct nvsp_message),
813 					   req_id,
814 					   VM_PKT_DATA_INBAND,
815 					   VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
816 					   !xmit_more);
817 	}
818 
819 	if (ret == 0) {
820 		atomic_inc(&net_device->num_outstanding_sends);
821 		atomic_inc(&net_device->queue_sends[q_idx]);
822 
823 		if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
824 			netif_tx_stop_queue(netdev_get_tx_queue(ndev, q_idx));
825 
826 			if (atomic_read(&net_device->
827 				queue_sends[q_idx]) < 1)
828 				netif_tx_wake_queue(netdev_get_tx_queue(
829 						    ndev, q_idx));
830 		}
831 	} else if (ret == -EAGAIN) {
832 		netif_tx_stop_queue(netdev_get_tx_queue(
833 				    ndev, q_idx));
834 		if (atomic_read(&net_device->queue_sends[q_idx]) < 1) {
835 			netif_tx_wake_queue(netdev_get_tx_queue(
836 					    ndev, q_idx));
837 			ret = -ENOSPC;
838 		}
839 	} else {
840 		netdev_err(ndev, "Unable to send packet %p ret %d\n",
841 			   packet, ret);
842 	}
843 
844 	return ret;
845 }
846 
847 /* Move packet out of multi send data (msd), and clear msd */
848 static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
849 				struct sk_buff **msd_skb,
850 				struct multi_send_data *msdp)
851 {
852 	*msd_skb = msdp->skb;
853 	*msd_send = msdp->pkt;
854 	msdp->skb = NULL;
855 	msdp->pkt = NULL;
856 	msdp->count = 0;
857 }
858 
859 int netvsc_send(struct hv_device *device,
860 		struct hv_netvsc_packet *packet,
861 		struct rndis_message *rndis_msg,
862 		struct hv_page_buffer **pb,
863 		struct sk_buff *skb)
864 {
865 	struct netvsc_device *net_device;
866 	int ret = 0, m_ret = 0;
867 	struct vmbus_channel *out_channel;
868 	u16 q_idx = packet->q_idx;
869 	u32 pktlen = packet->total_data_buflen, msd_len = 0;
870 	unsigned int section_index = NETVSC_INVALID_INDEX;
871 	struct multi_send_data *msdp;
872 	struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
873 	struct sk_buff *msd_skb = NULL;
874 	bool try_batch;
875 	bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
876 
877 	net_device = get_outbound_net_device(device);
878 	if (!net_device)
879 		return -ENODEV;
880 
881 	out_channel = net_device->chn_table[q_idx];
882 
883 	packet->send_buf_index = NETVSC_INVALID_INDEX;
884 	packet->cp_partial = false;
885 
886 	/* Send control message directly without accessing msd (Multi-Send
887 	 * Data) field which may be changed during data packet processing.
888 	 */
889 	if (!skb) {
890 		cur_send = packet;
891 		goto send_now;
892 	}
893 
894 	msdp = &net_device->msd[q_idx];
895 
896 	/* batch packets in send buffer if possible */
897 	if (msdp->pkt)
898 		msd_len = msdp->pkt->total_data_buflen;
899 
900 	try_batch = (skb != NULL) && msd_len > 0 && msdp->count <
901 		    net_device->max_pkt;
902 
903 	if (try_batch && msd_len + pktlen + net_device->pkt_align <
904 	    net_device->send_section_size) {
905 		section_index = msdp->pkt->send_buf_index;
906 
907 	} else if (try_batch && msd_len + packet->rmsg_size <
908 		   net_device->send_section_size) {
909 		section_index = msdp->pkt->send_buf_index;
910 		packet->cp_partial = true;
911 
912 	} else if ((skb != NULL) && pktlen + net_device->pkt_align <
913 		   net_device->send_section_size) {
914 		section_index = netvsc_get_next_send_section(net_device);
915 		if (section_index != NETVSC_INVALID_INDEX) {
916 			move_pkt_msd(&msd_send, &msd_skb, msdp);
917 			msd_len = 0;
918 		}
919 	}
920 
921 	if (section_index != NETVSC_INVALID_INDEX) {
922 		netvsc_copy_to_send_buf(net_device,
923 					section_index, msd_len,
924 					packet, rndis_msg, pb, skb);
925 
926 		packet->send_buf_index = section_index;
927 
928 		if (packet->cp_partial) {
929 			packet->page_buf_cnt -= packet->rmsg_pgcnt;
930 			packet->total_data_buflen = msd_len + packet->rmsg_size;
931 		} else {
932 			packet->page_buf_cnt = 0;
933 			packet->total_data_buflen += msd_len;
934 		}
935 
936 		if (msdp->skb)
937 			dev_kfree_skb_any(msdp->skb);
938 
939 		if (xmit_more && !packet->cp_partial) {
940 			msdp->skb = skb;
941 			msdp->pkt = packet;
942 			msdp->count++;
943 		} else {
944 			cur_send = packet;
945 			msdp->skb = NULL;
946 			msdp->pkt = NULL;
947 			msdp->count = 0;
948 		}
949 	} else {
950 		move_pkt_msd(&msd_send, &msd_skb, msdp);
951 		cur_send = packet;
952 	}
953 
954 	if (msd_send) {
955 		m_ret = netvsc_send_pkt(device, msd_send, net_device,
956 					NULL, msd_skb);
957 
958 		if (m_ret != 0) {
959 			netvsc_free_send_slot(net_device,
960 					      msd_send->send_buf_index);
961 			dev_kfree_skb_any(msd_skb);
962 		}
963 	}
964 
965 send_now:
966 	if (cur_send)
967 		ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);
968 
969 	if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
970 		netvsc_free_send_slot(net_device, section_index);
971 
972 	return ret;
973 }
974 
975 static void netvsc_send_recv_completion(struct hv_device *device,
976 					struct vmbus_channel *channel,
977 					struct netvsc_device *net_device,
978 					u64 transaction_id, u32 status)
979 {
980 	struct nvsp_message recvcompMessage;
981 	int retries = 0;
982 	int ret;
983 	struct net_device *ndev = hv_get_drvdata(device);
984 
985 	recvcompMessage.hdr.msg_type =
986 				NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
987 
988 	recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status = status;
989 
990 retry_send_cmplt:
991 	/* Send the completion */
992 	ret = vmbus_sendpacket(channel, &recvcompMessage,
993 			       sizeof(struct nvsp_message), transaction_id,
994 			       VM_PKT_COMP, 0);
995 	if (ret == 0) {
996 		/* success */
997 		/* no-op */
998 	} else if (ret == -EAGAIN) {
999 		/* no more room...wait a bit and attempt to retry 3 times */
1000 		retries++;
1001 		netdev_err(ndev, "unable to send receive completion pkt"
1002 			" (tid %llx)...retrying %d\n", transaction_id, retries);
1003 
1004 		if (retries < 4) {
1005 			udelay(100);
1006 			goto retry_send_cmplt;
1007 		} else {
1008 			netdev_err(ndev, "unable to send receive "
1009 				"completion pkt (tid %llx)...give up retrying\n",
1010 				transaction_id);
1011 		}
1012 	} else {
1013 		netdev_err(ndev, "unable to send receive "
1014 			"completion pkt - %llx\n", transaction_id);
1015 	}
1016 }
1017 
1018 static void netvsc_receive(struct netvsc_device *net_device,
1019 			struct vmbus_channel *channel,
1020 			struct hv_device *device,
1021 			struct vmpacket_descriptor *packet)
1022 {
1023 	struct vmtransfer_page_packet_header *vmxferpage_packet;
1024 	struct nvsp_message *nvsp_packet;
1025 	struct hv_netvsc_packet nv_pkt;
1026 	struct hv_netvsc_packet *netvsc_packet = &nv_pkt;
1027 	u32 status = NVSP_STAT_SUCCESS;
1028 	int i;
1029 	int count = 0;
1030 	struct net_device *ndev = hv_get_drvdata(device);
1031 	void *data;
1032 
1033 	/*
1034 	 * All inbound packets other than send completion should be xfer page
1035 	 * packet
1036 	 */
1037 	if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
1038 		netdev_err(ndev, "Unknown packet type received - %d\n",
1039 			   packet->type);
1040 		return;
1041 	}
1042 
1043 	nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
1044 			(packet->offset8 << 3));
1045 
1046 	/* Make sure this is a valid nvsp packet */
1047 	if (nvsp_packet->hdr.msg_type !=
1048 	    NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
1049 		netdev_err(ndev, "Unknown nvsp packet type received-"
1050 			" %d\n", nvsp_packet->hdr.msg_type);
1051 		return;
1052 	}
1053 
1054 	vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
1055 
1056 	if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
1057 		netdev_err(ndev, "Invalid xfer page set id - "
1058 			   "expecting %x got %x\n", NETVSC_RECEIVE_BUFFER_ID,
1059 			   vmxferpage_packet->xfer_pageset_id);
1060 		return;
1061 	}
1062 
1063 	count = vmxferpage_packet->range_cnt;
1064 
1065 	/* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1066 	for (i = 0; i < count; i++) {
1067 		/* Initialize the netvsc packet */
1068 		data = (void *)((unsigned long)net_device->
1069 			recv_buf + vmxferpage_packet->ranges[i].byte_offset);
1070 		netvsc_packet->total_data_buflen =
1071 					vmxferpage_packet->ranges[i].byte_count;
1072 
1073 		/* Pass it to the upper layer */
1074 		status = rndis_filter_receive(device, netvsc_packet, &data,
1075 					      channel);
1076 
1077 	}
1078 
1079 	netvsc_send_recv_completion(device, channel, net_device,
1080 				    vmxferpage_packet->d.trans_id, status);
1081 }
1082 
1083 
1084 static void netvsc_send_table(struct hv_device *hdev,
1085 			      struct nvsp_message *nvmsg)
1086 {
1087 	struct netvsc_device *nvscdev;
1088 	struct net_device *ndev = hv_get_drvdata(hdev);
1089 	int i;
1090 	u32 count, *tab;
1091 
1092 	nvscdev = get_outbound_net_device(hdev);
1093 	if (!nvscdev)
1094 		return;
1095 
1096 	count = nvmsg->msg.v5_msg.send_table.count;
1097 	if (count != VRSS_SEND_TAB_SIZE) {
1098 		netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1099 		return;
1100 	}
1101 
1102 	tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
1103 		      nvmsg->msg.v5_msg.send_table.offset);
1104 
1105 	for (i = 0; i < count; i++)
1106 		nvscdev->send_table[i] = tab[i];
1107 }
1108 
1109 static void netvsc_send_vf(struct netvsc_device *nvdev,
1110 			   struct nvsp_message *nvmsg)
1111 {
1112 	nvdev->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1113 	nvdev->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1114 }
1115 
1116 static inline void netvsc_receive_inband(struct hv_device *hdev,
1117 					 struct netvsc_device *nvdev,
1118 					 struct nvsp_message *nvmsg)
1119 {
1120 	switch (nvmsg->hdr.msg_type) {
1121 	case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1122 		netvsc_send_table(hdev, nvmsg);
1123 		break;
1124 
1125 	case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1126 		netvsc_send_vf(nvdev, nvmsg);
1127 		break;
1128 	}
1129 }
1130 
1131 static void netvsc_process_raw_pkt(struct hv_device *device,
1132 				   struct vmbus_channel *channel,
1133 				   struct netvsc_device *net_device,
1134 				   struct net_device *ndev,
1135 				   u64 request_id,
1136 				   struct vmpacket_descriptor *desc)
1137 {
1138 	struct nvsp_message *nvmsg;
1139 
1140 	nvmsg = (struct nvsp_message *)((unsigned long)
1141 		desc + (desc->offset8 << 3));
1142 
1143 	switch (desc->type) {
1144 	case VM_PKT_COMP:
1145 		netvsc_send_completion(net_device, channel, device, desc);
1146 		break;
1147 
1148 	case VM_PKT_DATA_USING_XFER_PAGES:
1149 		netvsc_receive(net_device, channel, device, desc);
1150 		break;
1151 
1152 	case VM_PKT_DATA_INBAND:
1153 		netvsc_receive_inband(device, net_device, nvmsg);
1154 		break;
1155 
1156 	default:
1157 		netdev_err(ndev, "unhandled packet type %d, tid %llx\n",
1158 			   desc->type, request_id);
1159 		break;
1160 	}
1161 }
1162 
1163 
1164 void netvsc_channel_cb(void *context)
1165 {
1166 	int ret;
1167 	struct vmbus_channel *channel = (struct vmbus_channel *)context;
1168 	struct hv_device *device;
1169 	struct netvsc_device *net_device;
1170 	u32 bytes_recvd;
1171 	u64 request_id;
1172 	struct vmpacket_descriptor *desc;
1173 	unsigned char *buffer;
1174 	int bufferlen = NETVSC_PACKET_SIZE;
1175 	struct net_device *ndev;
1176 	bool need_to_commit = false;
1177 
1178 	if (channel->primary_channel != NULL)
1179 		device = channel->primary_channel->device_obj;
1180 	else
1181 		device = channel->device_obj;
1182 
1183 	net_device = get_inbound_net_device(device);
1184 	if (!net_device)
1185 		return;
1186 	ndev = hv_get_drvdata(device);
1187 	buffer = get_per_channel_state(channel);
1188 
1189 	do {
1190 		desc = get_next_pkt_raw(channel);
1191 		if (desc != NULL) {
1192 			netvsc_process_raw_pkt(device,
1193 					       channel,
1194 					       net_device,
1195 					       ndev,
1196 					       desc->trans_id,
1197 					       desc);
1198 
1199 			put_pkt_raw(channel, desc);
1200 			need_to_commit = true;
1201 			continue;
1202 		}
1203 		if (need_to_commit) {
1204 			need_to_commit = false;
1205 			commit_rd_index(channel);
1206 		}
1207 
1208 		ret = vmbus_recvpacket_raw(channel, buffer, bufferlen,
1209 					   &bytes_recvd, &request_id);
1210 		if (ret == 0) {
1211 			if (bytes_recvd > 0) {
1212 				desc = (struct vmpacket_descriptor *)buffer;
1213 				netvsc_process_raw_pkt(device,
1214 						       channel,
1215 						       net_device,
1216 						       ndev,
1217 						       request_id,
1218 						       desc);
1219 
1220 
1221 			} else {
1222 				/*
1223 				 * We are done for this pass.
1224 				 */
1225 				break;
1226 			}
1227 
1228 		} else if (ret == -ENOBUFS) {
1229 			if (bufferlen > NETVSC_PACKET_SIZE)
1230 				kfree(buffer);
1231 			/* Handle large packet */
1232 			buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
1233 			if (buffer == NULL) {
1234 				/* Try again next time around */
1235 				netdev_err(ndev,
1236 					   "unable to allocate buffer of size "
1237 					   "(%d)!!\n", bytes_recvd);
1238 				break;
1239 			}
1240 
1241 			bufferlen = bytes_recvd;
1242 		}
1243 	} while (1);
1244 
1245 	if (bufferlen > NETVSC_PACKET_SIZE)
1246 		kfree(buffer);
1247 	return;
1248 }
1249 
1250 /*
1251  * netvsc_device_add - Callback when the device belonging to this
1252  * driver is added
1253  */
1254 int netvsc_device_add(struct hv_device *device, void *additional_info)
1255 {
1256 	int i, ret = 0;
1257 	int ring_size =
1258 	((struct netvsc_device_info *)additional_info)->ring_size;
1259 	struct netvsc_device *net_device;
1260 	struct net_device *ndev = hv_get_drvdata(device);
1261 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
1262 
1263 	net_device = alloc_net_device();
1264 	if (!net_device)
1265 		return -ENOMEM;
1266 
1267 	net_device->ring_size = ring_size;
1268 
1269 	/* Initialize the NetVSC channel extension */
1270 	init_completion(&net_device->channel_init_wait);
1271 
1272 	set_per_channel_state(device->channel, net_device->cb_buffer);
1273 
1274 	/* Open the channel */
1275 	ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
1276 			 ring_size * PAGE_SIZE, NULL, 0,
1277 			 netvsc_channel_cb, device->channel);
1278 
1279 	if (ret != 0) {
1280 		netdev_err(ndev, "unable to open channel: %d\n", ret);
1281 		goto cleanup;
1282 	}
1283 
1284 	/* Channel is opened */
1285 	pr_info("hv_netvsc channel opened successfully\n");
1286 
1287 	/* If we're reopening the device we may have multiple queues, fill the
1288 	 * chn_table with the default channel to use it before subchannels are
1289 	 * opened.
1290 	 */
1291 	for (i = 0; i < VRSS_CHANNEL_MAX; i++)
1292 		net_device->chn_table[i] = device->channel;
1293 
1294 	/* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is
1295 	 * populated.
1296 	 */
1297 	wmb();
1298 
1299 	net_device_ctx->nvdev = net_device;
1300 
1301 	/* Connect with the NetVsp */
1302 	ret = netvsc_connect_vsp(device);
1303 	if (ret != 0) {
1304 		netdev_err(ndev,
1305 			"unable to connect to NetVSP - %d\n", ret);
1306 		goto close;
1307 	}
1308 
1309 	return ret;
1310 
1311 close:
1312 	/* Now, we can close the channel safely */
1313 	vmbus_close(device->channel);
1314 
1315 cleanup:
1316 	free_netvsc_device(net_device);
1317 
1318 	return ret;
1319 }
1320