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, write to the Free Software Foundation, Inc., 59 Temple
15  * Place - Suite 330, Boston, MA 02111-1307 USA.
16  *
17  * Authors:
18  *   Haiyang Zhang <haiyangz@microsoft.com>
19  *   Hank Janssen  <hjanssen@microsoft.com>
20  */
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22 
23 #include <linux/kernel.h>
24 #include <linux/sched.h>
25 #include <linux/wait.h>
26 #include <linux/mm.h>
27 #include <linux/delay.h>
28 #include <linux/io.h>
29 #include <linux/slab.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_ether.h>
32 
33 #include "hyperv_net.h"
34 
35 
alloc_net_device(struct hv_device * device)36 static struct netvsc_device *alloc_net_device(struct hv_device *device)
37 {
38 	struct netvsc_device *net_device;
39 	struct net_device *ndev = hv_get_drvdata(device);
40 
41 	net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
42 	if (!net_device)
43 		return NULL;
44 
45 	net_device->start_remove = false;
46 	net_device->destroy = false;
47 	net_device->dev = device;
48 	net_device->ndev = ndev;
49 
50 	hv_set_drvdata(device, net_device);
51 	return net_device;
52 }
53 
get_outbound_net_device(struct hv_device * device)54 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
55 {
56 	struct netvsc_device *net_device;
57 
58 	net_device = hv_get_drvdata(device);
59 	if (net_device && net_device->destroy)
60 		net_device = NULL;
61 
62 	return net_device;
63 }
64 
get_inbound_net_device(struct hv_device * device)65 static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
66 {
67 	struct netvsc_device *net_device;
68 
69 	net_device = hv_get_drvdata(device);
70 
71 	if (!net_device)
72 		goto get_in_err;
73 
74 	if (net_device->destroy &&
75 		atomic_read(&net_device->num_outstanding_sends) == 0)
76 		net_device = NULL;
77 
78 get_in_err:
79 	return net_device;
80 }
81 
82 
netvsc_destroy_recv_buf(struct netvsc_device * net_device)83 static int netvsc_destroy_recv_buf(struct netvsc_device *net_device)
84 {
85 	struct nvsp_message *revoke_packet;
86 	int ret = 0;
87 	struct net_device *ndev = net_device->ndev;
88 
89 	/*
90 	 * If we got a section count, it means we received a
91 	 * SendReceiveBufferComplete msg (ie sent
92 	 * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
93 	 * to send a revoke msg here
94 	 */
95 	if (net_device->recv_section_cnt) {
96 		/* Send the revoke receive buffer */
97 		revoke_packet = &net_device->revoke_packet;
98 		memset(revoke_packet, 0, sizeof(struct nvsp_message));
99 
100 		revoke_packet->hdr.msg_type =
101 			NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
102 		revoke_packet->msg.v1_msg.
103 		revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
104 
105 		ret = vmbus_sendpacket(net_device->dev->channel,
106 				       revoke_packet,
107 				       sizeof(struct nvsp_message),
108 				       (unsigned long)revoke_packet,
109 				       VM_PKT_DATA_INBAND, 0);
110 		/*
111 		 * If we failed here, we might as well return and
112 		 * have a leak rather than continue and a bugchk
113 		 */
114 		if (ret != 0) {
115 			netdev_err(ndev, "unable to send "
116 				"revoke receive buffer to netvsp\n");
117 			return ret;
118 		}
119 	}
120 
121 	/* Teardown the gpadl on the vsp end */
122 	if (net_device->recv_buf_gpadl_handle) {
123 		ret = vmbus_teardown_gpadl(net_device->dev->channel,
124 			   net_device->recv_buf_gpadl_handle);
125 
126 		/* If we failed here, we might as well return and have a leak
127 		 * rather than continue and a bugchk
128 		 */
129 		if (ret != 0) {
130 			netdev_err(ndev,
131 				   "unable to teardown receive buffer's gpadl\n");
132 			return ret;
133 		}
134 		net_device->recv_buf_gpadl_handle = 0;
135 	}
136 
137 	if (net_device->recv_buf) {
138 		/* Free up the receive buffer */
139 		free_pages((unsigned long)net_device->recv_buf,
140 			get_order(net_device->recv_buf_size));
141 		net_device->recv_buf = NULL;
142 	}
143 
144 	if (net_device->recv_section) {
145 		net_device->recv_section_cnt = 0;
146 		kfree(net_device->recv_section);
147 		net_device->recv_section = NULL;
148 	}
149 
150 	return ret;
151 }
152 
netvsc_init_recv_buf(struct hv_device * device)153 static int netvsc_init_recv_buf(struct hv_device *device)
154 {
155 	int ret = 0;
156 	int t;
157 	struct netvsc_device *net_device;
158 	struct nvsp_message *init_packet;
159 	struct net_device *ndev;
160 
161 	net_device = get_outbound_net_device(device);
162 	if (!net_device)
163 		return -ENODEV;
164 	ndev = net_device->ndev;
165 
166 	net_device->recv_buf =
167 		(void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
168 				get_order(net_device->recv_buf_size));
169 	if (!net_device->recv_buf) {
170 		netdev_err(ndev, "unable to allocate receive "
171 			"buffer of size %d\n", net_device->recv_buf_size);
172 		ret = -ENOMEM;
173 		goto cleanup;
174 	}
175 
176 	/*
177 	 * Establish the gpadl handle for this buffer on this
178 	 * channel.  Note: This call uses the vmbus connection rather
179 	 * than the channel to establish the gpadl handle.
180 	 */
181 	ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
182 				    net_device->recv_buf_size,
183 				    &net_device->recv_buf_gpadl_handle);
184 	if (ret != 0) {
185 		netdev_err(ndev,
186 			"unable to establish receive buffer's gpadl\n");
187 		goto cleanup;
188 	}
189 
190 
191 	/* Notify the NetVsp of the gpadl handle */
192 	init_packet = &net_device->channel_init_pkt;
193 
194 	memset(init_packet, 0, sizeof(struct nvsp_message));
195 
196 	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
197 	init_packet->msg.v1_msg.send_recv_buf.
198 		gpadl_handle = net_device->recv_buf_gpadl_handle;
199 	init_packet->msg.v1_msg.
200 		send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
201 
202 	/* Send the gpadl notification request */
203 	ret = vmbus_sendpacket(device->channel, init_packet,
204 			       sizeof(struct nvsp_message),
205 			       (unsigned long)init_packet,
206 			       VM_PKT_DATA_INBAND,
207 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
208 	if (ret != 0) {
209 		netdev_err(ndev,
210 			"unable to send receive buffer's gpadl to netvsp\n");
211 		goto cleanup;
212 	}
213 
214 	t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
215 	BUG_ON(t == 0);
216 
217 
218 	/* Check the response */
219 	if (init_packet->msg.v1_msg.
220 	    send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
221 		netdev_err(ndev, "Unable to complete receive buffer "
222 			   "initialization with NetVsp - status %d\n",
223 			   init_packet->msg.v1_msg.
224 			   send_recv_buf_complete.status);
225 		ret = -EINVAL;
226 		goto cleanup;
227 	}
228 
229 	/* Parse the response */
230 
231 	net_device->recv_section_cnt = init_packet->msg.
232 		v1_msg.send_recv_buf_complete.num_sections;
233 
234 	net_device->recv_section = kmemdup(
235 		init_packet->msg.v1_msg.send_recv_buf_complete.sections,
236 		net_device->recv_section_cnt *
237 		sizeof(struct nvsp_1_receive_buffer_section),
238 		GFP_KERNEL);
239 	if (net_device->recv_section == NULL) {
240 		ret = -EINVAL;
241 		goto cleanup;
242 	}
243 
244 	/*
245 	 * For 1st release, there should only be 1 section that represents the
246 	 * entire receive buffer
247 	 */
248 	if (net_device->recv_section_cnt != 1 ||
249 	    net_device->recv_section->offset != 0) {
250 		ret = -EINVAL;
251 		goto cleanup;
252 	}
253 
254 	goto exit;
255 
256 cleanup:
257 	netvsc_destroy_recv_buf(net_device);
258 
259 exit:
260 	return ret;
261 }
262 
263 
264 /* Negotiate NVSP protocol version */
negotiate_nvsp_ver(struct hv_device * device,struct netvsc_device * net_device,struct nvsp_message * init_packet,u32 nvsp_ver)265 static int negotiate_nvsp_ver(struct hv_device *device,
266 			      struct netvsc_device *net_device,
267 			      struct nvsp_message *init_packet,
268 			      u32 nvsp_ver)
269 {
270 	int ret, t;
271 
272 	memset(init_packet, 0, sizeof(struct nvsp_message));
273 	init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
274 	init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
275 	init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
276 
277 	/* Send the init request */
278 	ret = vmbus_sendpacket(device->channel, init_packet,
279 			       sizeof(struct nvsp_message),
280 			       (unsigned long)init_packet,
281 			       VM_PKT_DATA_INBAND,
282 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
283 
284 	if (ret != 0)
285 		return ret;
286 
287 	t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
288 
289 	if (t == 0)
290 		return -ETIMEDOUT;
291 
292 	if (init_packet->msg.init_msg.init_complete.status !=
293 	    NVSP_STAT_SUCCESS)
294 		return -EINVAL;
295 
296 	if (nvsp_ver != NVSP_PROTOCOL_VERSION_2)
297 		return 0;
298 
299 	/* NVSPv2 only: Send NDIS config */
300 	memset(init_packet, 0, sizeof(struct nvsp_message));
301 	init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
302 	init_packet->msg.v2_msg.send_ndis_config.mtu = net_device->ndev->mtu;
303 	init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
304 
305 	ret = vmbus_sendpacket(device->channel, init_packet,
306 				sizeof(struct nvsp_message),
307 				(unsigned long)init_packet,
308 				VM_PKT_DATA_INBAND, 0);
309 
310 	return ret;
311 }
312 
netvsc_connect_vsp(struct hv_device * device)313 static int netvsc_connect_vsp(struct hv_device *device)
314 {
315 	int ret;
316 	struct netvsc_device *net_device;
317 	struct nvsp_message *init_packet;
318 	int ndis_version;
319 	struct net_device *ndev;
320 
321 	net_device = get_outbound_net_device(device);
322 	if (!net_device)
323 		return -ENODEV;
324 	ndev = net_device->ndev;
325 
326 	init_packet = &net_device->channel_init_pkt;
327 
328 	/* Negotiate the latest NVSP protocol supported */
329 	if (negotiate_nvsp_ver(device, net_device, init_packet,
330 			       NVSP_PROTOCOL_VERSION_2) == 0) {
331 		net_device->nvsp_version = NVSP_PROTOCOL_VERSION_2;
332 	} else if (negotiate_nvsp_ver(device, net_device, init_packet,
333 				    NVSP_PROTOCOL_VERSION_1) == 0) {
334 		net_device->nvsp_version = NVSP_PROTOCOL_VERSION_1;
335 	} else {
336 		ret = -EPROTO;
337 		goto cleanup;
338 	}
339 
340 	pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
341 
342 	/* Send the ndis version */
343 	memset(init_packet, 0, sizeof(struct nvsp_message));
344 
345 	ndis_version = 0x00050001;
346 
347 	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
348 	init_packet->msg.v1_msg.
349 		send_ndis_ver.ndis_major_ver =
350 				(ndis_version & 0xFFFF0000) >> 16;
351 	init_packet->msg.v1_msg.
352 		send_ndis_ver.ndis_minor_ver =
353 				ndis_version & 0xFFFF;
354 
355 	/* Send the init request */
356 	ret = vmbus_sendpacket(device->channel, init_packet,
357 				sizeof(struct nvsp_message),
358 				(unsigned long)init_packet,
359 				VM_PKT_DATA_INBAND, 0);
360 	if (ret != 0)
361 		goto cleanup;
362 
363 	/* Post the big receive buffer to NetVSP */
364 	ret = netvsc_init_recv_buf(device);
365 
366 cleanup:
367 	return ret;
368 }
369 
netvsc_disconnect_vsp(struct netvsc_device * net_device)370 static void netvsc_disconnect_vsp(struct netvsc_device *net_device)
371 {
372 	netvsc_destroy_recv_buf(net_device);
373 }
374 
375 /*
376  * netvsc_device_remove - Callback when the root bus device is removed
377  */
netvsc_device_remove(struct hv_device * device)378 int netvsc_device_remove(struct hv_device *device)
379 {
380 	struct netvsc_device *net_device;
381 	struct hv_netvsc_packet *netvsc_packet, *pos;
382 	unsigned long flags;
383 
384 	net_device = hv_get_drvdata(device);
385 	spin_lock_irqsave(&device->channel->inbound_lock, flags);
386 	net_device->destroy = true;
387 	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
388 
389 	/* Wait for all send completions */
390 	while (atomic_read(&net_device->num_outstanding_sends)) {
391 		dev_info(&device->device,
392 			"waiting for %d requests to complete...\n",
393 			atomic_read(&net_device->num_outstanding_sends));
394 		udelay(100);
395 	}
396 
397 	netvsc_disconnect_vsp(net_device);
398 
399 	/*
400 	 * Since we have already drained, we don't need to busy wait
401 	 * as was done in final_release_stor_device()
402 	 * Note that we cannot set the ext pointer to NULL until
403 	 * we have drained - to drain the outgoing packets, we need to
404 	 * allow incoming packets.
405 	 */
406 
407 	spin_lock_irqsave(&device->channel->inbound_lock, flags);
408 	hv_set_drvdata(device, NULL);
409 	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
410 
411 	/*
412 	 * At this point, no one should be accessing net_device
413 	 * except in here
414 	 */
415 	dev_notice(&device->device, "net device safe to remove\n");
416 
417 	/* Now, we can close the channel safely */
418 	vmbus_close(device->channel);
419 
420 	/* Release all resources */
421 	list_for_each_entry_safe(netvsc_packet, pos,
422 				 &net_device->recv_pkt_list, list_ent) {
423 		list_del(&netvsc_packet->list_ent);
424 		kfree(netvsc_packet);
425 	}
426 
427 	kfree(net_device);
428 	return 0;
429 }
430 
netvsc_send_completion(struct hv_device * device,struct vmpacket_descriptor * packet)431 static void netvsc_send_completion(struct hv_device *device,
432 				   struct vmpacket_descriptor *packet)
433 {
434 	struct netvsc_device *net_device;
435 	struct nvsp_message *nvsp_packet;
436 	struct hv_netvsc_packet *nvsc_packet;
437 	struct net_device *ndev;
438 
439 	net_device = get_inbound_net_device(device);
440 	if (!net_device)
441 		return;
442 	ndev = net_device->ndev;
443 
444 	nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
445 			(packet->offset8 << 3));
446 
447 	if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
448 	    (nvsp_packet->hdr.msg_type ==
449 	     NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
450 	    (nvsp_packet->hdr.msg_type ==
451 	     NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE)) {
452 		/* Copy the response back */
453 		memcpy(&net_device->channel_init_pkt, nvsp_packet,
454 		       sizeof(struct nvsp_message));
455 		complete(&net_device->channel_init_wait);
456 	} else if (nvsp_packet->hdr.msg_type ==
457 		   NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
458 		/* Get the send context */
459 		nvsc_packet = (struct hv_netvsc_packet *)(unsigned long)
460 			packet->trans_id;
461 
462 		/* Notify the layer above us */
463 		nvsc_packet->completion.send.send_completion(
464 			nvsc_packet->completion.send.send_completion_ctx);
465 
466 		atomic_dec(&net_device->num_outstanding_sends);
467 
468 		if (netif_queue_stopped(ndev) && !net_device->start_remove)
469 			netif_wake_queue(ndev);
470 	} else {
471 		netdev_err(ndev, "Unknown send completion packet type- "
472 			   "%d received!!\n", nvsp_packet->hdr.msg_type);
473 	}
474 
475 }
476 
netvsc_send(struct hv_device * device,struct hv_netvsc_packet * packet)477 int netvsc_send(struct hv_device *device,
478 			struct hv_netvsc_packet *packet)
479 {
480 	struct netvsc_device *net_device;
481 	int ret = 0;
482 	struct nvsp_message sendMessage;
483 	struct net_device *ndev;
484 
485 	net_device = get_outbound_net_device(device);
486 	if (!net_device)
487 		return -ENODEV;
488 	ndev = net_device->ndev;
489 
490 	sendMessage.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
491 	if (packet->is_data_pkt) {
492 		/* 0 is RMC_DATA; */
493 		sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 0;
494 	} else {
495 		/* 1 is RMC_CONTROL; */
496 		sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 1;
497 	}
498 
499 	/* Not using send buffer section */
500 	sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
501 		0xFFFFFFFF;
502 	sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
503 
504 	if (packet->page_buf_cnt) {
505 		ret = vmbus_sendpacket_pagebuffer(device->channel,
506 						  packet->page_buf,
507 						  packet->page_buf_cnt,
508 						  &sendMessage,
509 						  sizeof(struct nvsp_message),
510 						  (unsigned long)packet);
511 	} else {
512 		ret = vmbus_sendpacket(device->channel, &sendMessage,
513 				sizeof(struct nvsp_message),
514 				(unsigned long)packet,
515 				VM_PKT_DATA_INBAND,
516 				VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
517 
518 	}
519 
520 	if (ret == 0) {
521 		atomic_inc(&net_device->num_outstanding_sends);
522 	} else if (ret == -EAGAIN) {
523 		netif_stop_queue(ndev);
524 		if (atomic_read(&net_device->num_outstanding_sends) < 1)
525 			netif_wake_queue(ndev);
526 	} else {
527 		netdev_err(ndev, "Unable to send packet %p ret %d\n",
528 			   packet, ret);
529 	}
530 
531 	return ret;
532 }
533 
netvsc_send_recv_completion(struct hv_device * device,u64 transaction_id)534 static void netvsc_send_recv_completion(struct hv_device *device,
535 					u64 transaction_id)
536 {
537 	struct nvsp_message recvcompMessage;
538 	int retries = 0;
539 	int ret;
540 	struct net_device *ndev;
541 	struct netvsc_device *net_device = hv_get_drvdata(device);
542 
543 	ndev = net_device->ndev;
544 
545 	recvcompMessage.hdr.msg_type =
546 				NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
547 
548 	/* FIXME: Pass in the status */
549 	recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status =
550 		NVSP_STAT_SUCCESS;
551 
552 retry_send_cmplt:
553 	/* Send the completion */
554 	ret = vmbus_sendpacket(device->channel, &recvcompMessage,
555 			       sizeof(struct nvsp_message), transaction_id,
556 			       VM_PKT_COMP, 0);
557 	if (ret == 0) {
558 		/* success */
559 		/* no-op */
560 	} else if (ret == -EAGAIN) {
561 		/* no more room...wait a bit and attempt to retry 3 times */
562 		retries++;
563 		netdev_err(ndev, "unable to send receive completion pkt"
564 			" (tid %llx)...retrying %d\n", transaction_id, retries);
565 
566 		if (retries < 4) {
567 			udelay(100);
568 			goto retry_send_cmplt;
569 		} else {
570 			netdev_err(ndev, "unable to send receive "
571 				"completion pkt (tid %llx)...give up retrying\n",
572 				transaction_id);
573 		}
574 	} else {
575 		netdev_err(ndev, "unable to send receive "
576 			"completion pkt - %llx\n", transaction_id);
577 	}
578 }
579 
580 /* Send a receive completion packet to RNDIS device (ie NetVsp) */
netvsc_receive_completion(void * context)581 static void netvsc_receive_completion(void *context)
582 {
583 	struct hv_netvsc_packet *packet = context;
584 	struct hv_device *device = (struct hv_device *)packet->device;
585 	struct netvsc_device *net_device;
586 	u64 transaction_id = 0;
587 	bool fsend_receive_comp = false;
588 	unsigned long flags;
589 	struct net_device *ndev;
590 
591 	/*
592 	 * Even though it seems logical to do a GetOutboundNetDevice() here to
593 	 * send out receive completion, we are using GetInboundNetDevice()
594 	 * since we may have disable outbound traffic already.
595 	 */
596 	net_device = get_inbound_net_device(device);
597 	if (!net_device)
598 		return;
599 	ndev = net_device->ndev;
600 
601 	/* Overloading use of the lock. */
602 	spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
603 
604 	packet->xfer_page_pkt->count--;
605 
606 	/*
607 	 * Last one in the line that represent 1 xfer page packet.
608 	 * Return the xfer page packet itself to the freelist
609 	 */
610 	if (packet->xfer_page_pkt->count == 0) {
611 		fsend_receive_comp = true;
612 		transaction_id = packet->completion.recv.recv_completion_tid;
613 		list_add_tail(&packet->xfer_page_pkt->list_ent,
614 			      &net_device->recv_pkt_list);
615 
616 	}
617 
618 	/* Put the packet back */
619 	list_add_tail(&packet->list_ent, &net_device->recv_pkt_list);
620 	spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
621 
622 	/* Send a receive completion for the xfer page packet */
623 	if (fsend_receive_comp)
624 		netvsc_send_recv_completion(device, transaction_id);
625 
626 }
627 
netvsc_receive(struct hv_device * device,struct vmpacket_descriptor * packet)628 static void netvsc_receive(struct hv_device *device,
629 			    struct vmpacket_descriptor *packet)
630 {
631 	struct netvsc_device *net_device;
632 	struct vmtransfer_page_packet_header *vmxferpage_packet;
633 	struct nvsp_message *nvsp_packet;
634 	struct hv_netvsc_packet *netvsc_packet = NULL;
635 	/* struct netvsc_driver *netvscDriver; */
636 	struct xferpage_packet *xferpage_packet = NULL;
637 	int i;
638 	int count = 0;
639 	unsigned long flags;
640 	struct net_device *ndev;
641 
642 	LIST_HEAD(listHead);
643 
644 	net_device = get_inbound_net_device(device);
645 	if (!net_device)
646 		return;
647 	ndev = net_device->ndev;
648 
649 	/*
650 	 * All inbound packets other than send completion should be xfer page
651 	 * packet
652 	 */
653 	if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
654 		netdev_err(ndev, "Unknown packet type received - %d\n",
655 			   packet->type);
656 		return;
657 	}
658 
659 	nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
660 			(packet->offset8 << 3));
661 
662 	/* Make sure this is a valid nvsp packet */
663 	if (nvsp_packet->hdr.msg_type !=
664 	    NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
665 		netdev_err(ndev, "Unknown nvsp packet type received-"
666 			" %d\n", nvsp_packet->hdr.msg_type);
667 		return;
668 	}
669 
670 	vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
671 
672 	if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
673 		netdev_err(ndev, "Invalid xfer page set id - "
674 			   "expecting %x got %x\n", NETVSC_RECEIVE_BUFFER_ID,
675 			   vmxferpage_packet->xfer_pageset_id);
676 		return;
677 	}
678 
679 	/*
680 	 * Grab free packets (range count + 1) to represent this xfer
681 	 * page packet. +1 to represent the xfer page packet itself.
682 	 * We grab it here so that we know exactly how many we can
683 	 * fulfil
684 	 */
685 	spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
686 	while (!list_empty(&net_device->recv_pkt_list)) {
687 		list_move_tail(net_device->recv_pkt_list.next, &listHead);
688 		if (++count == vmxferpage_packet->range_cnt + 1)
689 			break;
690 	}
691 	spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
692 
693 	/*
694 	 * We need at least 2 netvsc pkts (1 to represent the xfer
695 	 * page and at least 1 for the range) i.e. we can handled
696 	 * some of the xfer page packet ranges...
697 	 */
698 	if (count < 2) {
699 		netdev_err(ndev, "Got only %d netvsc pkt...needed "
700 			"%d pkts. Dropping this xfer page packet completely!\n",
701 			count, vmxferpage_packet->range_cnt + 1);
702 
703 		/* Return it to the freelist */
704 		spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
705 		for (i = count; i != 0; i--) {
706 			list_move_tail(listHead.next,
707 				       &net_device->recv_pkt_list);
708 		}
709 		spin_unlock_irqrestore(&net_device->recv_pkt_list_lock,
710 				       flags);
711 
712 		netvsc_send_recv_completion(device,
713 					    vmxferpage_packet->d.trans_id);
714 
715 		return;
716 	}
717 
718 	/* Remove the 1st packet to represent the xfer page packet itself */
719 	xferpage_packet = (struct xferpage_packet *)listHead.next;
720 	list_del(&xferpage_packet->list_ent);
721 
722 	/* This is how much we can satisfy */
723 	xferpage_packet->count = count - 1;
724 
725 	if (xferpage_packet->count != vmxferpage_packet->range_cnt) {
726 		netdev_err(ndev, "Needed %d netvsc pkts to satisfy "
727 			"this xfer page...got %d\n",
728 			vmxferpage_packet->range_cnt, xferpage_packet->count);
729 	}
730 
731 	/* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
732 	for (i = 0; i < (count - 1); i++) {
733 		netvsc_packet = (struct hv_netvsc_packet *)listHead.next;
734 		list_del(&netvsc_packet->list_ent);
735 
736 		/* Initialize the netvsc packet */
737 		netvsc_packet->xfer_page_pkt = xferpage_packet;
738 		netvsc_packet->completion.recv.recv_completion =
739 					netvsc_receive_completion;
740 		netvsc_packet->completion.recv.recv_completion_ctx =
741 					netvsc_packet;
742 		netvsc_packet->device = device;
743 		/* Save this so that we can send it back */
744 		netvsc_packet->completion.recv.recv_completion_tid =
745 					vmxferpage_packet->d.trans_id;
746 
747 		netvsc_packet->data = (void *)((unsigned long)net_device->
748 			recv_buf + vmxferpage_packet->ranges[i].byte_offset);
749 		netvsc_packet->total_data_buflen =
750 					vmxferpage_packet->ranges[i].byte_count;
751 
752 		/* Pass it to the upper layer */
753 		rndis_filter_receive(device, netvsc_packet);
754 
755 		netvsc_receive_completion(netvsc_packet->
756 				completion.recv.recv_completion_ctx);
757 	}
758 
759 }
760 
netvsc_channel_cb(void * context)761 static void netvsc_channel_cb(void *context)
762 {
763 	int ret;
764 	struct hv_device *device = context;
765 	struct netvsc_device *net_device;
766 	u32 bytes_recvd;
767 	u64 request_id;
768 	unsigned char *packet;
769 	struct vmpacket_descriptor *desc;
770 	unsigned char *buffer;
771 	int bufferlen = NETVSC_PACKET_SIZE;
772 	struct net_device *ndev;
773 
774 	packet = kzalloc(NETVSC_PACKET_SIZE * sizeof(unsigned char),
775 			 GFP_ATOMIC);
776 	if (!packet)
777 		return;
778 	buffer = packet;
779 
780 	net_device = get_inbound_net_device(device);
781 	if (!net_device)
782 		goto out;
783 	ndev = net_device->ndev;
784 
785 	do {
786 		ret = vmbus_recvpacket_raw(device->channel, buffer, bufferlen,
787 					   &bytes_recvd, &request_id);
788 		if (ret == 0) {
789 			if (bytes_recvd > 0) {
790 				desc = (struct vmpacket_descriptor *)buffer;
791 				switch (desc->type) {
792 				case VM_PKT_COMP:
793 					netvsc_send_completion(device, desc);
794 					break;
795 
796 				case VM_PKT_DATA_USING_XFER_PAGES:
797 					netvsc_receive(device, desc);
798 					break;
799 
800 				default:
801 					netdev_err(ndev,
802 						   "unhandled packet type %d, "
803 						   "tid %llx len %d\n",
804 						   desc->type, request_id,
805 						   bytes_recvd);
806 					break;
807 				}
808 
809 				/* reset */
810 				if (bufferlen > NETVSC_PACKET_SIZE) {
811 					kfree(buffer);
812 					buffer = packet;
813 					bufferlen = NETVSC_PACKET_SIZE;
814 				}
815 			} else {
816 				/* reset */
817 				if (bufferlen > NETVSC_PACKET_SIZE) {
818 					kfree(buffer);
819 					buffer = packet;
820 					bufferlen = NETVSC_PACKET_SIZE;
821 				}
822 
823 				break;
824 			}
825 		} else if (ret == -ENOBUFS) {
826 			/* Handle large packet */
827 			buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
828 			if (buffer == NULL) {
829 				/* Try again next time around */
830 				netdev_err(ndev,
831 					   "unable to allocate buffer of size "
832 					   "(%d)!!\n", bytes_recvd);
833 				break;
834 			}
835 
836 			bufferlen = bytes_recvd;
837 		}
838 	} while (1);
839 
840 out:
841 	kfree(buffer);
842 	return;
843 }
844 
845 /*
846  * netvsc_device_add - Callback when the device belonging to this
847  * driver is added
848  */
netvsc_device_add(struct hv_device * device,void * additional_info)849 int netvsc_device_add(struct hv_device *device, void *additional_info)
850 {
851 	int ret = 0;
852 	int i;
853 	int ring_size =
854 	((struct netvsc_device_info *)additional_info)->ring_size;
855 	struct netvsc_device *net_device;
856 	struct hv_netvsc_packet *packet, *pos;
857 	struct net_device *ndev;
858 
859 	net_device = alloc_net_device(device);
860 	if (!net_device) {
861 		ret = -ENOMEM;
862 		goto cleanup;
863 	}
864 
865 	/*
866 	 * Coming into this function, struct net_device * is
867 	 * registered as the driver private data.
868 	 * In alloc_net_device(), we register struct netvsc_device *
869 	 * as the driver private data and stash away struct net_device *
870 	 * in struct netvsc_device *.
871 	 */
872 	ndev = net_device->ndev;
873 
874 	/* Initialize the NetVSC channel extension */
875 	net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
876 	spin_lock_init(&net_device->recv_pkt_list_lock);
877 
878 	INIT_LIST_HEAD(&net_device->recv_pkt_list);
879 
880 	for (i = 0; i < NETVSC_RECEIVE_PACKETLIST_COUNT; i++) {
881 		packet = kzalloc(sizeof(struct hv_netvsc_packet) +
882 				 (NETVSC_RECEIVE_SG_COUNT *
883 				  sizeof(struct hv_page_buffer)), GFP_KERNEL);
884 		if (!packet)
885 			break;
886 
887 		list_add_tail(&packet->list_ent,
888 			      &net_device->recv_pkt_list);
889 	}
890 	init_completion(&net_device->channel_init_wait);
891 
892 	/* Open the channel */
893 	ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
894 			 ring_size * PAGE_SIZE, NULL, 0,
895 			 netvsc_channel_cb, device);
896 
897 	if (ret != 0) {
898 		netdev_err(ndev, "unable to open channel: %d\n", ret);
899 		goto cleanup;
900 	}
901 
902 	/* Channel is opened */
903 	pr_info("hv_netvsc channel opened successfully\n");
904 
905 	/* Connect with the NetVsp */
906 	ret = netvsc_connect_vsp(device);
907 	if (ret != 0) {
908 		netdev_err(ndev,
909 			"unable to connect to NetVSP - %d\n", ret);
910 		goto close;
911 	}
912 
913 	return ret;
914 
915 close:
916 	/* Now, we can close the channel safely */
917 	vmbus_close(device->channel);
918 
919 cleanup:
920 
921 	if (net_device) {
922 		list_for_each_entry_safe(packet, pos,
923 					 &net_device->recv_pkt_list,
924 					 list_ent) {
925 			list_del(&packet->list_ent);
926 			kfree(packet);
927 		}
928 
929 		kfree(net_device);
930 	}
931 
932 	return ret;
933 }
934