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v4.17
 
   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 <linux/rtnetlink.h>
  33#include <linux/prefetch.h>
  34#include <linux/reciprocal_div.h>
  35
  36#include <asm/sync_bitops.h>
 
  37
  38#include "hyperv_net.h"
  39#include "netvsc_trace.h"
  40
  41/*
  42 * Switch the data path from the synthetic interface to the VF
  43 * interface.
  44 */
  45void netvsc_switch_datapath(struct net_device *ndev, bool vf)
  46{
  47	struct net_device_context *net_device_ctx = netdev_priv(ndev);
  48	struct hv_device *dev = net_device_ctx->device_ctx;
  49	struct netvsc_device *nv_dev = rtnl_dereference(net_device_ctx->nvdev);
  50	struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
 
 
 
 
 
  51
  52	memset(init_pkt, 0, sizeof(struct nvsp_message));
  53	init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
  54	if (vf)
  55		init_pkt->msg.v4_msg.active_dp.active_datapath =
  56			NVSP_DATAPATH_VF;
  57	else
  58		init_pkt->msg.v4_msg.active_dp.active_datapath =
  59			NVSP_DATAPATH_SYNTHETIC;
  60
 
  61	trace_nvsp_send(ndev, init_pkt);
  62
  63	vmbus_sendpacket(dev->channel, init_pkt,
  64			       sizeof(struct nvsp_message),
  65			       (unsigned long)init_pkt,
  66			       VM_PKT_DATA_INBAND, 0);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  67}
  68
  69static struct netvsc_device *alloc_net_device(void)
  70{
  71	struct netvsc_device *net_device;
  72
  73	net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
  74	if (!net_device)
  75		return NULL;
  76
  77	init_waitqueue_head(&net_device->wait_drain);
  78	net_device->destroy = false;
 
  79
  80	net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
  81	net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
  82
  83	init_completion(&net_device->channel_init_wait);
  84	init_waitqueue_head(&net_device->subchan_open);
  85	INIT_WORK(&net_device->subchan_work, rndis_set_subchannel);
  86
  87	return net_device;
  88}
  89
  90static void free_netvsc_device(struct rcu_head *head)
  91{
  92	struct netvsc_device *nvdev
  93		= container_of(head, struct netvsc_device, rcu);
  94	int i;
  95
  96	kfree(nvdev->extension);
  97	vfree(nvdev->recv_buf);
  98	vfree(nvdev->send_buf);
  99	kfree(nvdev->send_section_map);
 100
 101	for (i = 0; i < VRSS_CHANNEL_MAX; i++)
 
 
 102		vfree(nvdev->chan_table[i].mrc.slots);
 
 103
 104	kfree(nvdev);
 105}
 106
 107static void free_netvsc_device_rcu(struct netvsc_device *nvdev)
 108{
 109	call_rcu(&nvdev->rcu, free_netvsc_device);
 110}
 111
 112static void netvsc_revoke_recv_buf(struct hv_device *device,
 113				   struct netvsc_device *net_device,
 114				   struct net_device *ndev)
 115{
 116	struct nvsp_message *revoke_packet;
 117	int ret;
 118
 119	/*
 120	 * If we got a section count, it means we received a
 121	 * SendReceiveBufferComplete msg (ie sent
 122	 * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
 123	 * to send a revoke msg here
 124	 */
 125	if (net_device->recv_section_cnt) {
 126		/* Send the revoke receive buffer */
 127		revoke_packet = &net_device->revoke_packet;
 128		memset(revoke_packet, 0, sizeof(struct nvsp_message));
 129
 130		revoke_packet->hdr.msg_type =
 131			NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 132		revoke_packet->msg.v1_msg.
 133		revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 134
 135		trace_nvsp_send(ndev, revoke_packet);
 136
 137		ret = vmbus_sendpacket(device->channel,
 138				       revoke_packet,
 139				       sizeof(struct nvsp_message),
 140				       (unsigned long)revoke_packet,
 141				       VM_PKT_DATA_INBAND, 0);
 142		/* If the failure is because the channel is rescinded;
 143		 * ignore the failure since we cannot send on a rescinded
 144		 * channel. This would allow us to properly cleanup
 145		 * even when the channel is rescinded.
 146		 */
 147		if (device->channel->rescind)
 148			ret = 0;
 149		/*
 150		 * If we failed here, we might as well return and
 151		 * have a leak rather than continue and a bugchk
 152		 */
 153		if (ret != 0) {
 154			netdev_err(ndev, "unable to send "
 155				"revoke receive buffer to netvsp\n");
 156			return;
 157		}
 158		net_device->recv_section_cnt = 0;
 159	}
 160}
 161
 162static void netvsc_revoke_send_buf(struct hv_device *device,
 163				   struct netvsc_device *net_device,
 164				   struct net_device *ndev)
 165{
 166	struct nvsp_message *revoke_packet;
 167	int ret;
 168
 169	/* Deal with the send buffer we may have setup.
 170	 * If we got a  send section size, it means we received a
 171	 * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
 172	 * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
 173	 * to send a revoke msg here
 174	 */
 175	if (net_device->send_section_cnt) {
 176		/* Send the revoke receive buffer */
 177		revoke_packet = &net_device->revoke_packet;
 178		memset(revoke_packet, 0, sizeof(struct nvsp_message));
 179
 180		revoke_packet->hdr.msg_type =
 181			NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
 182		revoke_packet->msg.v1_msg.revoke_send_buf.id =
 183			NETVSC_SEND_BUFFER_ID;
 184
 185		trace_nvsp_send(ndev, revoke_packet);
 186
 187		ret = vmbus_sendpacket(device->channel,
 188				       revoke_packet,
 189				       sizeof(struct nvsp_message),
 190				       (unsigned long)revoke_packet,
 191				       VM_PKT_DATA_INBAND, 0);
 192
 193		/* If the failure is because the channel is rescinded;
 194		 * ignore the failure since we cannot send on a rescinded
 195		 * channel. This would allow us to properly cleanup
 196		 * even when the channel is rescinded.
 197		 */
 198		if (device->channel->rescind)
 199			ret = 0;
 200
 201		/* If we failed here, we might as well return and
 202		 * have a leak rather than continue and a bugchk
 203		 */
 204		if (ret != 0) {
 205			netdev_err(ndev, "unable to send "
 206				   "revoke send buffer to netvsp\n");
 207			return;
 208		}
 209		net_device->send_section_cnt = 0;
 210	}
 211}
 212
 213static void netvsc_teardown_recv_gpadl(struct hv_device *device,
 214				       struct netvsc_device *net_device,
 215				       struct net_device *ndev)
 216{
 217	int ret;
 218
 219	if (net_device->recv_buf_gpadl_handle) {
 220		ret = vmbus_teardown_gpadl(device->channel,
 221					   net_device->recv_buf_gpadl_handle);
 222
 223		/* If we failed here, we might as well return and have a leak
 224		 * rather than continue and a bugchk
 225		 */
 226		if (ret != 0) {
 227			netdev_err(ndev,
 228				   "unable to teardown receive buffer's gpadl\n");
 229			return;
 230		}
 231		net_device->recv_buf_gpadl_handle = 0;
 232	}
 233}
 234
 235static void netvsc_teardown_send_gpadl(struct hv_device *device,
 236				       struct netvsc_device *net_device,
 237				       struct net_device *ndev)
 238{
 239	int ret;
 240
 241	if (net_device->send_buf_gpadl_handle) {
 242		ret = vmbus_teardown_gpadl(device->channel,
 243					   net_device->send_buf_gpadl_handle);
 244
 245		/* If we failed here, we might as well return and have a leak
 246		 * rather than continue and a bugchk
 247		 */
 248		if (ret != 0) {
 249			netdev_err(ndev,
 250				   "unable to teardown send buffer's gpadl\n");
 251			return;
 252		}
 253		net_device->send_buf_gpadl_handle = 0;
 254	}
 255}
 256
 257int netvsc_alloc_recv_comp_ring(struct netvsc_device *net_device, u32 q_idx)
 258{
 259	struct netvsc_channel *nvchan = &net_device->chan_table[q_idx];
 260	int node = cpu_to_node(nvchan->channel->target_cpu);
 261	size_t size;
 262
 263	size = net_device->recv_completion_cnt * sizeof(struct recv_comp_data);
 264	nvchan->mrc.slots = vzalloc_node(size, node);
 265	if (!nvchan->mrc.slots)
 266		nvchan->mrc.slots = vzalloc(size);
 267
 268	return nvchan->mrc.slots ? 0 : -ENOMEM;
 269}
 270
 271static int netvsc_init_buf(struct hv_device *device,
 272			   struct netvsc_device *net_device,
 273			   const struct netvsc_device_info *device_info)
 274{
 275	struct nvsp_1_message_send_receive_buffer_complete *resp;
 276	struct net_device *ndev = hv_get_drvdata(device);
 277	struct nvsp_message *init_packet;
 278	unsigned int buf_size;
 279	size_t map_words;
 280	int ret = 0;
 281
 282	/* Get receive buffer area. */
 283	buf_size = device_info->recv_sections * device_info->recv_section_size;
 284	buf_size = roundup(buf_size, PAGE_SIZE);
 285
 286	/* Legacy hosts only allow smaller receive buffer */
 287	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
 288		buf_size = min_t(unsigned int, buf_size,
 289				 NETVSC_RECEIVE_BUFFER_SIZE_LEGACY);
 290
 291	net_device->recv_buf = vzalloc(buf_size);
 292	if (!net_device->recv_buf) {
 293		netdev_err(ndev,
 294			   "unable to allocate receive buffer of size %u\n",
 295			   buf_size);
 296		ret = -ENOMEM;
 297		goto cleanup;
 298	}
 299
 300	net_device->recv_buf_size = buf_size;
 301
 302	/*
 303	 * Establish the gpadl handle for this buffer on this
 304	 * channel.  Note: This call uses the vmbus connection rather
 305	 * than the channel to establish the gpadl handle.
 306	 */
 307	ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 308				    buf_size,
 309				    &net_device->recv_buf_gpadl_handle);
 310	if (ret != 0) {
 311		netdev_err(ndev,
 312			"unable to establish receive buffer's gpadl\n");
 313		goto cleanup;
 314	}
 315
 316	/* Notify the NetVsp of the gpadl handle */
 317	init_packet = &net_device->channel_init_pkt;
 318	memset(init_packet, 0, sizeof(struct nvsp_message));
 319	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 320	init_packet->msg.v1_msg.send_recv_buf.
 321		gpadl_handle = net_device->recv_buf_gpadl_handle;
 322	init_packet->msg.v1_msg.
 323		send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 324
 325	trace_nvsp_send(ndev, init_packet);
 326
 327	/* Send the gpadl notification request */
 328	ret = vmbus_sendpacket(device->channel, init_packet,
 329			       sizeof(struct nvsp_message),
 330			       (unsigned long)init_packet,
 331			       VM_PKT_DATA_INBAND,
 332			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 333	if (ret != 0) {
 334		netdev_err(ndev,
 335			"unable to send receive buffer's gpadl to netvsp\n");
 336		goto cleanup;
 337	}
 338
 339	wait_for_completion(&net_device->channel_init_wait);
 340
 341	/* Check the response */
 342	resp = &init_packet->msg.v1_msg.send_recv_buf_complete;
 343	if (resp->status != NVSP_STAT_SUCCESS) {
 344		netdev_err(ndev,
 345			   "Unable to complete receive buffer initialization with NetVsp - status %d\n",
 346			   resp->status);
 347		ret = -EINVAL;
 348		goto cleanup;
 349	}
 350
 351	/* Parse the response */
 352	netdev_dbg(ndev, "Receive sections: %u sub_allocs: size %u count: %u\n",
 353		   resp->num_sections, resp->sections[0].sub_alloc_size,
 354		   resp->sections[0].num_sub_allocs);
 355
 356	/* There should only be one section for the entire receive buffer */
 357	if (resp->num_sections != 1 || resp->sections[0].offset != 0) {
 358		ret = -EINVAL;
 359		goto cleanup;
 360	}
 361
 362	net_device->recv_section_size = resp->sections[0].sub_alloc_size;
 363	net_device->recv_section_cnt = resp->sections[0].num_sub_allocs;
 364
 365	/* Setup receive completion ring */
 366	net_device->recv_completion_cnt
 367		= round_up(net_device->recv_section_cnt + 1,
 368			   PAGE_SIZE / sizeof(u64));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 369	ret = netvsc_alloc_recv_comp_ring(net_device, 0);
 370	if (ret)
 371		goto cleanup;
 372
 373	/* Now setup the send buffer. */
 374	buf_size = device_info->send_sections * device_info->send_section_size;
 375	buf_size = round_up(buf_size, PAGE_SIZE);
 376
 377	net_device->send_buf = vzalloc(buf_size);
 378	if (!net_device->send_buf) {
 379		netdev_err(ndev, "unable to allocate send buffer of size %u\n",
 380			   buf_size);
 381		ret = -ENOMEM;
 382		goto cleanup;
 383	}
 384
 385	/* Establish the gpadl handle for this buffer on this
 386	 * channel.  Note: This call uses the vmbus connection rather
 387	 * than the channel to establish the gpadl handle.
 388	 */
 389	ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
 390				    buf_size,
 391				    &net_device->send_buf_gpadl_handle);
 392	if (ret != 0) {
 393		netdev_err(ndev,
 394			   "unable to establish send buffer's gpadl\n");
 395		goto cleanup;
 396	}
 397
 398	/* Notify the NetVsp of the gpadl handle */
 399	init_packet = &net_device->channel_init_pkt;
 400	memset(init_packet, 0, sizeof(struct nvsp_message));
 401	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
 402	init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
 403		net_device->send_buf_gpadl_handle;
 404	init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
 405
 406	trace_nvsp_send(ndev, init_packet);
 407
 408	/* Send the gpadl notification request */
 409	ret = vmbus_sendpacket(device->channel, init_packet,
 410			       sizeof(struct nvsp_message),
 411			       (unsigned long)init_packet,
 412			       VM_PKT_DATA_INBAND,
 413			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 414	if (ret != 0) {
 415		netdev_err(ndev,
 416			   "unable to send send buffer's gpadl to netvsp\n");
 417		goto cleanup;
 418	}
 419
 420	wait_for_completion(&net_device->channel_init_wait);
 421
 422	/* Check the response */
 423	if (init_packet->msg.v1_msg.
 424	    send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
 425		netdev_err(ndev, "Unable to complete send buffer "
 426			   "initialization with NetVsp - status %d\n",
 427			   init_packet->msg.v1_msg.
 428			   send_send_buf_complete.status);
 429		ret = -EINVAL;
 430		goto cleanup;
 431	}
 432
 433	/* Parse the response */
 434	net_device->send_section_size = init_packet->msg.
 435				v1_msg.send_send_buf_complete.section_size;
 
 
 
 
 
 
 436
 437	/* Section count is simply the size divided by the section size. */
 438	net_device->send_section_cnt = buf_size / net_device->send_section_size;
 439
 440	netdev_dbg(ndev, "Send section size: %d, Section count:%d\n",
 441		   net_device->send_section_size, net_device->send_section_cnt);
 442
 443	/* Setup state for managing the send buffer. */
 444	map_words = DIV_ROUND_UP(net_device->send_section_cnt, BITS_PER_LONG);
 445
 446	net_device->send_section_map = kcalloc(map_words, sizeof(ulong), GFP_KERNEL);
 447	if (net_device->send_section_map == NULL) {
 448		ret = -ENOMEM;
 449		goto cleanup;
 450	}
 451
 452	goto exit;
 453
 454cleanup:
 455	netvsc_revoke_recv_buf(device, net_device, ndev);
 456	netvsc_revoke_send_buf(device, net_device, ndev);
 457	netvsc_teardown_recv_gpadl(device, net_device, ndev);
 458	netvsc_teardown_send_gpadl(device, net_device, ndev);
 459
 460exit:
 461	return ret;
 462}
 463
 464/* Negotiate NVSP protocol version */
 465static int negotiate_nvsp_ver(struct hv_device *device,
 466			      struct netvsc_device *net_device,
 467			      struct nvsp_message *init_packet,
 468			      u32 nvsp_ver)
 469{
 470	struct net_device *ndev = hv_get_drvdata(device);
 471	int ret;
 472
 473	memset(init_packet, 0, sizeof(struct nvsp_message));
 474	init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 475	init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
 476	init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
 477	trace_nvsp_send(ndev, init_packet);
 478
 479	/* Send the init request */
 480	ret = vmbus_sendpacket(device->channel, init_packet,
 481			       sizeof(struct nvsp_message),
 482			       (unsigned long)init_packet,
 483			       VM_PKT_DATA_INBAND,
 484			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 485
 486	if (ret != 0)
 487		return ret;
 488
 489	wait_for_completion(&net_device->channel_init_wait);
 490
 491	if (init_packet->msg.init_msg.init_complete.status !=
 492	    NVSP_STAT_SUCCESS)
 493		return -EINVAL;
 494
 495	if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
 496		return 0;
 497
 498	/* NVSPv2 or later: Send NDIS config */
 499	memset(init_packet, 0, sizeof(struct nvsp_message));
 500	init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
 501	init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;
 502	init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
 503
 504	if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5) {
 505		init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
 
 
 
 506
 507		/* Teaming bit is needed to receive link speed updates */
 508		init_packet->msg.v2_msg.send_ndis_config.capability.teaming = 1;
 509	}
 510
 
 
 
 511	trace_nvsp_send(ndev, init_packet);
 512
 513	ret = vmbus_sendpacket(device->channel, init_packet,
 514				sizeof(struct nvsp_message),
 515				(unsigned long)init_packet,
 516				VM_PKT_DATA_INBAND, 0);
 517
 518	return ret;
 519}
 520
 521static int netvsc_connect_vsp(struct hv_device *device,
 522			      struct netvsc_device *net_device,
 523			      const struct netvsc_device_info *device_info)
 524{
 525	struct net_device *ndev = hv_get_drvdata(device);
 526	static const u32 ver_list[] = {
 527		NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
 528		NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5
 
 529	};
 530	struct nvsp_message *init_packet;
 531	int ndis_version, i, ret;
 532
 533	init_packet = &net_device->channel_init_pkt;
 534
 535	/* Negotiate the latest NVSP protocol supported */
 536	for (i = ARRAY_SIZE(ver_list) - 1; i >= 0; i--)
 537		if (negotiate_nvsp_ver(device, net_device, init_packet,
 538				       ver_list[i])  == 0) {
 539			net_device->nvsp_version = ver_list[i];
 540			break;
 541		}
 542
 543	if (i < 0) {
 544		ret = -EPROTO;
 545		goto cleanup;
 546	}
 547
 
 
 
 
 
 
 
 548	pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
 549
 550	/* Send the ndis version */
 551	memset(init_packet, 0, sizeof(struct nvsp_message));
 552
 553	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
 554		ndis_version = 0x00060001;
 555	else
 556		ndis_version = 0x0006001e;
 557
 558	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 559	init_packet->msg.v1_msg.
 560		send_ndis_ver.ndis_major_ver =
 561				(ndis_version & 0xFFFF0000) >> 16;
 562	init_packet->msg.v1_msg.
 563		send_ndis_ver.ndis_minor_ver =
 564				ndis_version & 0xFFFF;
 565
 566	trace_nvsp_send(ndev, init_packet);
 567
 568	/* Send the init request */
 569	ret = vmbus_sendpacket(device->channel, init_packet,
 570				sizeof(struct nvsp_message),
 571				(unsigned long)init_packet,
 572				VM_PKT_DATA_INBAND, 0);
 573	if (ret != 0)
 574		goto cleanup;
 575
 576
 577	ret = netvsc_init_buf(device, net_device, device_info);
 578
 579cleanup:
 580	return ret;
 581}
 582
 583/*
 584 * netvsc_device_remove - Callback when the root bus device is removed
 585 */
 586void netvsc_device_remove(struct hv_device *device)
 587{
 588	struct net_device *ndev = hv_get_drvdata(device);
 589	struct net_device_context *net_device_ctx = netdev_priv(ndev);
 590	struct netvsc_device *net_device
 591		= rtnl_dereference(net_device_ctx->nvdev);
 592	int i;
 593
 594	/*
 595	 * Revoke receive buffer. If host is pre-Win2016 then tear down
 596	 * receive buffer GPADL. Do the same for send buffer.
 597	 */
 598	netvsc_revoke_recv_buf(device, net_device, ndev);
 599	if (vmbus_proto_version < VERSION_WIN10)
 600		netvsc_teardown_recv_gpadl(device, net_device, ndev);
 601
 602	netvsc_revoke_send_buf(device, net_device, ndev);
 603	if (vmbus_proto_version < VERSION_WIN10)
 604		netvsc_teardown_send_gpadl(device, net_device, ndev);
 605
 606	RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
 607
 608	/* And disassociate NAPI context from device */
 609	for (i = 0; i < net_device->num_chn; i++)
 
 
 610		netif_napi_del(&net_device->chan_table[i].napi);
 
 611
 612	/*
 613	 * At this point, no one should be accessing net_device
 614	 * except in here
 615	 */
 616	netdev_dbg(ndev, "net device safe to remove\n");
 617
 618	/* Now, we can close the channel safely */
 619	vmbus_close(device->channel);
 620
 621	/*
 622	 * If host is Win2016 or higher then we do the GPADL tear down
 623	 * here after VMBus is closed.
 624	*/
 625	if (vmbus_proto_version >= VERSION_WIN10) {
 626		netvsc_teardown_recv_gpadl(device, net_device, ndev);
 627		netvsc_teardown_send_gpadl(device, net_device, ndev);
 628	}
 629
 630	/* Release all resources */
 631	free_netvsc_device_rcu(net_device);
 632}
 633
 634#define RING_AVAIL_PERCENT_HIWATER 20
 635#define RING_AVAIL_PERCENT_LOWATER 10
 636
 637/*
 638 * Get the percentage of available bytes to write in the ring.
 639 * The return value is in range from 0 to 100.
 640 */
 641static u32 hv_ringbuf_avail_percent(const struct hv_ring_buffer_info *ring_info)
 642{
 643	u32 avail_write = hv_get_bytes_to_write(ring_info);
 644
 645	return reciprocal_divide(avail_write  * 100, netvsc_ring_reciprocal);
 646}
 647
 648static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
 649					 u32 index)
 650{
 651	sync_change_bit(index, net_device->send_section_map);
 652}
 653
 654static void netvsc_send_tx_complete(struct netvsc_device *net_device,
 655				    struct vmbus_channel *incoming_channel,
 656				    struct hv_device *device,
 657				    const struct vmpacket_descriptor *desc,
 658				    int budget)
 659{
 660	struct sk_buff *skb = (struct sk_buff *)(unsigned long)desc->trans_id;
 661	struct net_device *ndev = hv_get_drvdata(device);
 662	struct net_device_context *ndev_ctx = netdev_priv(ndev);
 663	struct vmbus_channel *channel = device->channel;
 664	u16 q_idx = 0;
 665	int queue_sends;
 
 
 
 
 
 
 
 
 
 666
 667	/* Notify the layer above us */
 668	if (likely(skb)) {
 669		const struct hv_netvsc_packet *packet
 670			= (struct hv_netvsc_packet *)skb->cb;
 671		u32 send_index = packet->send_buf_index;
 672		struct netvsc_stats *tx_stats;
 673
 674		if (send_index != NETVSC_INVALID_INDEX)
 675			netvsc_free_send_slot(net_device, send_index);
 676		q_idx = packet->q_idx;
 677		channel = incoming_channel;
 678
 679		tx_stats = &net_device->chan_table[q_idx].tx_stats;
 680
 681		u64_stats_update_begin(&tx_stats->syncp);
 682		tx_stats->packets += packet->total_packets;
 683		tx_stats->bytes += packet->total_bytes;
 684		u64_stats_update_end(&tx_stats->syncp);
 685
 686		napi_consume_skb(skb, budget);
 687	}
 688
 689	queue_sends =
 690		atomic_dec_return(&net_device->chan_table[q_idx].queue_sends);
 691
 692	if (unlikely(net_device->destroy)) {
 693		if (queue_sends == 0)
 694			wake_up(&net_device->wait_drain);
 695	} else {
 696		struct netdev_queue *txq = netdev_get_tx_queue(ndev, q_idx);
 697
 698		if (netif_tx_queue_stopped(txq) &&
 699		    (hv_ringbuf_avail_percent(&channel->outbound) > RING_AVAIL_PERCENT_HIWATER ||
 700		     queue_sends < 1)) {
 701			netif_tx_wake_queue(txq);
 702			ndev_ctx->eth_stats.wake_queue++;
 703		}
 704	}
 705}
 706
 707static void netvsc_send_completion(struct netvsc_device *net_device,
 
 708				   struct vmbus_channel *incoming_channel,
 709				   struct hv_device *device,
 710				   const struct vmpacket_descriptor *desc,
 711				   int budget)
 712{
 713	struct nvsp_message *nvsp_packet = hv_pkt_data(desc);
 714	struct net_device *ndev = hv_get_drvdata(device);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 715
 
 716	switch (nvsp_packet->hdr.msg_type) {
 717	case NVSP_MSG_TYPE_INIT_COMPLETE:
 
 
 
 
 
 
 
 
 718	case NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE:
 
 
 
 
 
 
 
 
 719	case NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE:
 
 
 
 
 
 
 
 
 720	case NVSP_MSG5_TYPE_SUBCHANNEL:
 
 
 
 
 
 
 721		/* Copy the response back */
 722		memcpy(&net_device->channel_init_pkt, nvsp_packet,
 723		       sizeof(struct nvsp_message));
 724		complete(&net_device->channel_init_wait);
 725		break;
 726
 727	case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
 728		netvsc_send_tx_complete(net_device, incoming_channel,
 729					device, desc, budget);
 730		break;
 731
 732	default:
 733		netdev_err(ndev,
 734			   "Unknown send completion type %d received!!\n",
 735			   nvsp_packet->hdr.msg_type);
 736	}
 737}
 738
 739static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
 740{
 741	unsigned long *map_addr = net_device->send_section_map;
 742	unsigned int i;
 743
 744	for_each_clear_bit(i, map_addr, net_device->send_section_cnt) {
 745		if (sync_test_and_set_bit(i, map_addr) == 0)
 746			return i;
 747	}
 748
 749	return NETVSC_INVALID_INDEX;
 750}
 751
 752static void netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 753				    unsigned int section_index,
 754				    u32 pend_size,
 755				    struct hv_netvsc_packet *packet,
 756				    struct rndis_message *rndis_msg,
 757				    struct hv_page_buffer *pb,
 758				    bool xmit_more)
 759{
 760	char *start = net_device->send_buf;
 761	char *dest = start + (section_index * net_device->send_section_size)
 762		     + pend_size;
 763	int i;
 764	u32 padding = 0;
 765	u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
 766		packet->page_buf_cnt;
 767	u32 remain;
 768
 769	/* Add padding */
 770	remain = packet->total_data_buflen & (net_device->pkt_align - 1);
 771	if (xmit_more && remain) {
 772		padding = net_device->pkt_align - remain;
 773		rndis_msg->msg_len += padding;
 774		packet->total_data_buflen += padding;
 775	}
 776
 777	for (i = 0; i < page_count; i++) {
 778		char *src = phys_to_virt(pb[i].pfn << PAGE_SHIFT);
 779		u32 offset = pb[i].offset;
 780		u32 len = pb[i].len;
 781
 782		memcpy(dest, (src + offset), len);
 783		dest += len;
 784	}
 785
 786	if (padding)
 787		memset(dest, 0, padding);
 788}
 789
 790static inline int netvsc_send_pkt(
 791	struct hv_device *device,
 792	struct hv_netvsc_packet *packet,
 793	struct netvsc_device *net_device,
 794	struct hv_page_buffer *pb,
 795	struct sk_buff *skb)
 796{
 797	struct nvsp_message nvmsg;
 798	struct nvsp_1_message_send_rndis_packet *rpkt =
 799		&nvmsg.msg.v1_msg.send_rndis_pkt;
 800	struct netvsc_channel * const nvchan =
 801		&net_device->chan_table[packet->q_idx];
 802	struct vmbus_channel *out_channel = nvchan->channel;
 803	struct net_device *ndev = hv_get_drvdata(device);
 804	struct net_device_context *ndev_ctx = netdev_priv(ndev);
 805	struct netdev_queue *txq = netdev_get_tx_queue(ndev, packet->q_idx);
 806	u64 req_id;
 807	int ret;
 808	u32 ring_avail = hv_ringbuf_avail_percent(&out_channel->outbound);
 809
 
 810	nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 811	if (skb)
 812		rpkt->channel_type = 0;		/* 0 is RMC_DATA */
 813	else
 814		rpkt->channel_type = 1;		/* 1 is RMC_CONTROL */
 815
 816	rpkt->send_buf_section_index = packet->send_buf_index;
 817	if (packet->send_buf_index == NETVSC_INVALID_INDEX)
 818		rpkt->send_buf_section_size = 0;
 819	else
 820		rpkt->send_buf_section_size = packet->total_data_buflen;
 821
 822	req_id = (ulong)skb;
 823
 824	if (out_channel->rescind)
 825		return -ENODEV;
 826
 827	trace_nvsp_send_pkt(ndev, out_channel, rpkt);
 828
 829	if (packet->page_buf_cnt) {
 830		if (packet->cp_partial)
 831			pb += packet->rmsg_pgcnt;
 832
 833		ret = vmbus_sendpacket_pagebuffer(out_channel,
 834						  pb, packet->page_buf_cnt,
 835						  &nvmsg, sizeof(nvmsg),
 836						  req_id);
 837	} else {
 838		ret = vmbus_sendpacket(out_channel,
 839				       &nvmsg, sizeof(nvmsg),
 840				       req_id, VM_PKT_DATA_INBAND,
 841				       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 842	}
 843
 844	if (ret == 0) {
 845		atomic_inc_return(&nvchan->queue_sends);
 846
 847		if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
 848			netif_tx_stop_queue(txq);
 849			ndev_ctx->eth_stats.stop_queue++;
 850		}
 851	} else if (ret == -EAGAIN) {
 852		netif_tx_stop_queue(txq);
 853		ndev_ctx->eth_stats.stop_queue++;
 854		if (atomic_read(&nvchan->queue_sends) < 1) {
 855			netif_tx_wake_queue(txq);
 856			ndev_ctx->eth_stats.wake_queue++;
 857			ret = -ENOSPC;
 858		}
 859	} else {
 860		netdev_err(ndev,
 861			   "Unable to send packet pages %u len %u, ret %d\n",
 862			   packet->page_buf_cnt, packet->total_data_buflen,
 863			   ret);
 864	}
 865
 
 
 
 
 
 
 
 
 
 866	return ret;
 867}
 868
 869/* Move packet out of multi send data (msd), and clear msd */
 870static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
 871				struct sk_buff **msd_skb,
 872				struct multi_send_data *msdp)
 873{
 874	*msd_skb = msdp->skb;
 875	*msd_send = msdp->pkt;
 876	msdp->skb = NULL;
 877	msdp->pkt = NULL;
 878	msdp->count = 0;
 879}
 880
 881/* RCU already held by caller */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 882int netvsc_send(struct net_device *ndev,
 883		struct hv_netvsc_packet *packet,
 884		struct rndis_message *rndis_msg,
 885		struct hv_page_buffer *pb,
 886		struct sk_buff *skb)
 
 887{
 888	struct net_device_context *ndev_ctx = netdev_priv(ndev);
 889	struct netvsc_device *net_device
 890		= rcu_dereference_bh(ndev_ctx->nvdev);
 891	struct hv_device *device = ndev_ctx->device_ctx;
 892	int ret = 0;
 893	struct netvsc_channel *nvchan;
 894	u32 pktlen = packet->total_data_buflen, msd_len = 0;
 895	unsigned int section_index = NETVSC_INVALID_INDEX;
 896	struct multi_send_data *msdp;
 897	struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
 898	struct sk_buff *msd_skb = NULL;
 899	bool try_batch, xmit_more;
 900
 901	/* If device is rescinded, return error and packet will get dropped. */
 902	if (unlikely(!net_device || net_device->destroy))
 903		return -ENODEV;
 904
 905	nvchan = &net_device->chan_table[packet->q_idx];
 906	packet->send_buf_index = NETVSC_INVALID_INDEX;
 907	packet->cp_partial = false;
 908
 909	/* Send control message directly without accessing msd (Multi-Send
 910	 * Data) field which may be changed during data packet processing.
 
 911	 */
 912	if (!skb)
 913		return netvsc_send_pkt(device, packet, net_device, pb, skb);
 914
 915	/* batch packets in send buffer if possible */
 916	msdp = &nvchan->msd;
 917	if (msdp->pkt)
 918		msd_len = msdp->pkt->total_data_buflen;
 919
 920	try_batch =  msd_len > 0 && msdp->count < net_device->max_pkt;
 921	if (try_batch && msd_len + pktlen + net_device->pkt_align <
 922	    net_device->send_section_size) {
 923		section_index = msdp->pkt->send_buf_index;
 924
 925	} else if (try_batch && msd_len + packet->rmsg_size <
 926		   net_device->send_section_size) {
 927		section_index = msdp->pkt->send_buf_index;
 928		packet->cp_partial = true;
 929
 930	} else if (pktlen + net_device->pkt_align <
 931		   net_device->send_section_size) {
 932		section_index = netvsc_get_next_send_section(net_device);
 933		if (unlikely(section_index == NETVSC_INVALID_INDEX)) {
 934			++ndev_ctx->eth_stats.tx_send_full;
 935		} else {
 936			move_pkt_msd(&msd_send, &msd_skb, msdp);
 937			msd_len = 0;
 938		}
 939	}
 940
 941	/* Keep aggregating only if stack says more data is coming
 942	 * and not doing mixed modes send and not flow blocked
 943	 */
 944	xmit_more = skb->xmit_more &&
 945		!packet->cp_partial &&
 946		!netif_xmit_stopped(netdev_get_tx_queue(ndev, packet->q_idx));
 947
 948	if (section_index != NETVSC_INVALID_INDEX) {
 949		netvsc_copy_to_send_buf(net_device,
 950					section_index, msd_len,
 951					packet, rndis_msg, pb, xmit_more);
 952
 953		packet->send_buf_index = section_index;
 954
 955		if (packet->cp_partial) {
 956			packet->page_buf_cnt -= packet->rmsg_pgcnt;
 957			packet->total_data_buflen = msd_len + packet->rmsg_size;
 958		} else {
 959			packet->page_buf_cnt = 0;
 960			packet->total_data_buflen += msd_len;
 961		}
 962
 963		if (msdp->pkt) {
 964			packet->total_packets += msdp->pkt->total_packets;
 965			packet->total_bytes += msdp->pkt->total_bytes;
 966		}
 967
 968		if (msdp->skb)
 969			dev_consume_skb_any(msdp->skb);
 970
 971		if (xmit_more) {
 972			msdp->skb = skb;
 973			msdp->pkt = packet;
 974			msdp->count++;
 975		} else {
 976			cur_send = packet;
 977			msdp->skb = NULL;
 978			msdp->pkt = NULL;
 979			msdp->count = 0;
 980		}
 981	} else {
 982		move_pkt_msd(&msd_send, &msd_skb, msdp);
 983		cur_send = packet;
 984	}
 985
 986	if (msd_send) {
 987		int m_ret = netvsc_send_pkt(device, msd_send, net_device,
 988					    NULL, msd_skb);
 989
 990		if (m_ret != 0) {
 991			netvsc_free_send_slot(net_device,
 992					      msd_send->send_buf_index);
 993			dev_kfree_skb_any(msd_skb);
 994		}
 995	}
 996
 997	if (cur_send)
 998		ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);
 999
1000	if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
1001		netvsc_free_send_slot(net_device, section_index);
1002
1003	return ret;
1004}
1005
1006/* Send pending recv completions */
1007static int send_recv_completions(struct net_device *ndev,
1008				 struct netvsc_device *nvdev,
1009				 struct netvsc_channel *nvchan)
1010{
1011	struct multi_recv_comp *mrc = &nvchan->mrc;
1012	struct recv_comp_msg {
1013		struct nvsp_message_header hdr;
1014		u32 status;
1015	}  __packed;
1016	struct recv_comp_msg msg = {
1017		.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE,
1018	};
1019	int ret;
1020
1021	while (mrc->first != mrc->next) {
1022		const struct recv_comp_data *rcd
1023			= mrc->slots + mrc->first;
1024
1025		msg.status = rcd->status;
1026		ret = vmbus_sendpacket(nvchan->channel, &msg, sizeof(msg),
1027				       rcd->tid, VM_PKT_COMP, 0);
1028		if (unlikely(ret)) {
1029			struct net_device_context *ndev_ctx = netdev_priv(ndev);
1030
1031			++ndev_ctx->eth_stats.rx_comp_busy;
1032			return ret;
1033		}
1034
1035		if (++mrc->first == nvdev->recv_completion_cnt)
1036			mrc->first = 0;
1037	}
1038
1039	/* receive completion ring has been emptied */
1040	if (unlikely(nvdev->destroy))
1041		wake_up(&nvdev->wait_drain);
1042
1043	return 0;
1044}
1045
1046/* Count how many receive completions are outstanding */
1047static void recv_comp_slot_avail(const struct netvsc_device *nvdev,
1048				 const struct multi_recv_comp *mrc,
1049				 u32 *filled, u32 *avail)
1050{
1051	u32 count = nvdev->recv_completion_cnt;
1052
1053	if (mrc->next >= mrc->first)
1054		*filled = mrc->next - mrc->first;
1055	else
1056		*filled = (count - mrc->first) + mrc->next;
1057
1058	*avail = count - *filled - 1;
1059}
1060
1061/* Add receive complete to ring to send to host. */
1062static void enq_receive_complete(struct net_device *ndev,
1063				 struct netvsc_device *nvdev, u16 q_idx,
1064				 u64 tid, u32 status)
1065{
1066	struct netvsc_channel *nvchan = &nvdev->chan_table[q_idx];
1067	struct multi_recv_comp *mrc = &nvchan->mrc;
1068	struct recv_comp_data *rcd;
1069	u32 filled, avail;
1070
1071	recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1072
1073	if (unlikely(filled > NAPI_POLL_WEIGHT)) {
1074		send_recv_completions(ndev, nvdev, nvchan);
1075		recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1076	}
1077
1078	if (unlikely(!avail)) {
1079		netdev_err(ndev, "Recv_comp full buf q:%hd, tid:%llx\n",
1080			   q_idx, tid);
1081		return;
1082	}
1083
1084	rcd = mrc->slots + mrc->next;
1085	rcd->tid = tid;
1086	rcd->status = status;
1087
1088	if (++mrc->next == nvdev->recv_completion_cnt)
1089		mrc->next = 0;
1090}
1091
1092static int netvsc_receive(struct net_device *ndev,
1093			  struct netvsc_device *net_device,
1094			  struct net_device_context *net_device_ctx,
1095			  struct hv_device *device,
1096			  struct vmbus_channel *channel,
1097			  const struct vmpacket_descriptor *desc,
1098			  struct nvsp_message *nvsp)
1099{
 
 
1100	const struct vmtransfer_page_packet_header *vmxferpage_packet
1101		= container_of(desc, const struct vmtransfer_page_packet_header, d);
 
 
1102	u16 q_idx = channel->offermsg.offer.sub_channel_index;
1103	char *recv_buf = net_device->recv_buf;
1104	u32 status = NVSP_STAT_SUCCESS;
1105	int i;
1106	int count = 0;
1107
 
 
 
 
 
 
 
 
1108	/* Make sure this is a valid nvsp packet */
1109	if (unlikely(nvsp->hdr.msg_type != NVSP_MSG1_TYPE_SEND_RNDIS_PKT)) {
1110		netif_err(net_device_ctx, rx_err, ndev,
1111			  "Unknown nvsp packet type received %u\n",
1112			  nvsp->hdr.msg_type);
1113		return 0;
1114	}
1115
 
 
 
 
 
 
 
 
1116	if (unlikely(vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID)) {
1117		netif_err(net_device_ctx, rx_err, ndev,
1118			  "Invalid xfer page set id - expecting %x got %x\n",
1119			  NETVSC_RECEIVE_BUFFER_ID,
1120			  vmxferpage_packet->xfer_pageset_id);
1121		return 0;
1122	}
1123
1124	count = vmxferpage_packet->range_cnt;
1125
 
 
 
 
 
 
 
 
1126	/* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1127	for (i = 0; i < count; i++) {
1128		u32 offset = vmxferpage_packet->ranges[i].byte_offset;
1129		u32 buflen = vmxferpage_packet->ranges[i].byte_count;
1130		void *data;
1131		int ret;
1132
1133		if (unlikely(offset + buflen > net_device->recv_buf_size)) {
 
 
1134			status = NVSP_STAT_FAIL;
1135			netif_err(net_device_ctx, rx_err, ndev,
1136				  "Packet offset:%u + len:%u too big\n",
1137				  offset, buflen);
1138
1139			continue;
1140		}
1141
 
 
 
 
 
 
 
 
 
 
 
 
 
1142		data = recv_buf + offset;
1143
 
 
1144		trace_rndis_recv(ndev, q_idx, data);
1145
1146		/* Pass it to the upper layer */
1147		ret = rndis_filter_receive(ndev, net_device,
1148					   channel, data, buflen);
1149
1150		if (unlikely(ret != NVSP_STAT_SUCCESS))
 
 
1151			status = NVSP_STAT_FAIL;
 
1152	}
1153
1154	enq_receive_complete(ndev, net_device, q_idx,
1155			     vmxferpage_packet->d.trans_id, status);
1156
1157	return count;
1158}
1159
1160static void netvsc_send_table(struct hv_device *hdev,
1161			      struct nvsp_message *nvmsg)
 
 
1162{
1163	struct net_device *ndev = hv_get_drvdata(hdev);
1164	struct net_device_context *net_device_ctx = netdev_priv(ndev);
 
1165	int i;
1166	u32 count, *tab;
 
 
 
 
 
 
1167
1168	count = nvmsg->msg.v5_msg.send_table.count;
 
 
1169	if (count != VRSS_SEND_TAB_SIZE) {
1170		netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1171		return;
1172	}
1173
1174	tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
1175		      nvmsg->msg.v5_msg.send_table.offset);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1176
1177	for (i = 0; i < count; i++)
1178		net_device_ctx->tx_table[i] = tab[i];
1179}
1180
1181static void netvsc_send_vf(struct net_device_context *net_device_ctx,
1182			   struct nvsp_message *nvmsg)
 
1183{
 
 
 
 
 
 
 
 
 
1184	net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1185	net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
 
 
 
1186}
1187
1188static inline void netvsc_receive_inband(struct hv_device *hdev,
1189				 struct net_device_context *net_device_ctx,
1190				 struct nvsp_message *nvmsg)
1191{
 
 
 
 
 
 
 
 
 
1192	switch (nvmsg->hdr.msg_type) {
1193	case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1194		netvsc_send_table(hdev, nvmsg);
1195		break;
1196
1197	case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1198		netvsc_send_vf(net_device_ctx, nvmsg);
 
 
 
1199		break;
1200	}
1201}
1202
1203static int netvsc_process_raw_pkt(struct hv_device *device,
1204				  struct vmbus_channel *channel,
1205				  struct netvsc_device *net_device,
1206				  struct net_device *ndev,
1207				  const struct vmpacket_descriptor *desc,
1208				  int budget)
1209{
1210	struct net_device_context *net_device_ctx = netdev_priv(ndev);
1211	struct nvsp_message *nvmsg = hv_pkt_data(desc);
1212
1213	trace_nvsp_recv(ndev, channel, nvmsg);
1214
1215	switch (desc->type) {
1216	case VM_PKT_COMP:
1217		netvsc_send_completion(net_device, channel, device,
1218				       desc, budget);
1219		break;
1220
1221	case VM_PKT_DATA_USING_XFER_PAGES:
1222		return netvsc_receive(ndev, net_device, net_device_ctx,
1223				      device, channel, desc, nvmsg);
1224		break;
1225
1226	case VM_PKT_DATA_INBAND:
1227		netvsc_receive_inband(device, net_device_ctx, nvmsg);
1228		break;
1229
1230	default:
1231		netdev_err(ndev, "unhandled packet type %d, tid %llx\n",
1232			   desc->type, desc->trans_id);
1233		break;
1234	}
1235
1236	return 0;
1237}
1238
1239static struct hv_device *netvsc_channel_to_device(struct vmbus_channel *channel)
1240{
1241	struct vmbus_channel *primary = channel->primary_channel;
1242
1243	return primary ? primary->device_obj : channel->device_obj;
1244}
1245
1246/* Network processing softirq
1247 * Process data in incoming ring buffer from host
1248 * Stops when ring is empty or budget is met or exceeded.
1249 */
1250int netvsc_poll(struct napi_struct *napi, int budget)
1251{
1252	struct netvsc_channel *nvchan
1253		= container_of(napi, struct netvsc_channel, napi);
1254	struct netvsc_device *net_device = nvchan->net_device;
1255	struct vmbus_channel *channel = nvchan->channel;
1256	struct hv_device *device = netvsc_channel_to_device(channel);
1257	struct net_device *ndev = hv_get_drvdata(device);
1258	int work_done = 0;
 
1259
1260	/* If starting a new interval */
1261	if (!nvchan->desc)
1262		nvchan->desc = hv_pkt_iter_first(channel);
1263
1264	while (nvchan->desc && work_done < budget) {
1265		work_done += netvsc_process_raw_pkt(device, channel, net_device,
1266						    ndev, nvchan->desc, budget);
1267		nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc);
1268	}
1269
1270	/* If send of pending receive completions suceeded
1271	 *   and did not exhaust NAPI budget this time
1272	 *   and not doing busy poll
 
 
1273	 * then re-enable host interrupts
1274	 *     and reschedule if ring is not empty.
 
1275	 */
1276	if (send_recv_completions(ndev, net_device, nvchan) == 0 &&
1277	    work_done < budget &&
1278	    napi_complete_done(napi, work_done) &&
1279	    hv_end_read(&channel->inbound) &&
1280	    napi_schedule_prep(napi)) {
1281		hv_begin_read(&channel->inbound);
1282		__napi_schedule(napi);
1283	}
1284
1285	/* Driver may overshoot since multiple packets per descriptor */
1286	return min(work_done, budget);
1287}
1288
1289/* Call back when data is available in host ring buffer.
1290 * Processing is deferred until network softirq (NAPI)
1291 */
1292void netvsc_channel_cb(void *context)
1293{
1294	struct netvsc_channel *nvchan = context;
1295	struct vmbus_channel *channel = nvchan->channel;
1296	struct hv_ring_buffer_info *rbi = &channel->inbound;
1297
1298	/* preload first vmpacket descriptor */
1299	prefetch(hv_get_ring_buffer(rbi) + rbi->priv_read_index);
1300
1301	if (napi_schedule_prep(&nvchan->napi)) {
1302		/* disable interupts from host */
1303		hv_begin_read(rbi);
1304
1305		__napi_schedule_irqoff(&nvchan->napi);
1306	}
1307}
1308
1309/*
1310 * netvsc_device_add - Callback when the device belonging to this
1311 * driver is added
1312 */
1313struct netvsc_device *netvsc_device_add(struct hv_device *device,
1314				const struct netvsc_device_info *device_info)
1315{
1316	int i, ret = 0;
1317	struct netvsc_device *net_device;
1318	struct net_device *ndev = hv_get_drvdata(device);
1319	struct net_device_context *net_device_ctx = netdev_priv(ndev);
1320
1321	net_device = alloc_net_device();
1322	if (!net_device)
1323		return ERR_PTR(-ENOMEM);
1324
1325	for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)
1326		net_device_ctx->tx_table[i] = 0;
1327
1328	/* Because the device uses NAPI, all the interrupt batching and
1329	 * control is done via Net softirq, not the channel handling
1330	 */
1331	set_channel_read_mode(device->channel, HV_CALL_ISR);
1332
1333	/* If we're reopening the device we may have multiple queues, fill the
1334	 * chn_table with the default channel to use it before subchannels are
1335	 * opened.
1336	 * Initialize the channel state before we open;
1337	 * we can be interrupted as soon as we open the channel.
1338	 */
1339
1340	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
1341		struct netvsc_channel *nvchan = &net_device->chan_table[i];
1342
1343		nvchan->channel = device->channel;
1344		nvchan->net_device = net_device;
1345		u64_stats_init(&nvchan->tx_stats.syncp);
1346		u64_stats_init(&nvchan->rx_stats.syncp);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1347	}
1348
1349	/* Enable NAPI handler before init callbacks */
1350	netif_napi_add(ndev, &net_device->chan_table[0].napi,
1351		       netvsc_poll, NAPI_POLL_WEIGHT);
1352
1353	/* Open the channel */
 
 
 
 
 
1354	ret = vmbus_open(device->channel, netvsc_ring_bytes,
1355			 netvsc_ring_bytes,  NULL, 0,
1356			 netvsc_channel_cb, net_device->chan_table);
1357
1358	if (ret != 0) {
1359		netdev_err(ndev, "unable to open channel: %d\n", ret);
1360		goto cleanup;
1361	}
1362
1363	/* Channel is opened */
1364	netdev_dbg(ndev, "hv_netvsc channel opened successfully\n");
1365
1366	napi_enable(&net_device->chan_table[0].napi);
1367
1368	/* Connect with the NetVsp */
1369	ret = netvsc_connect_vsp(device, net_device, device_info);
1370	if (ret != 0) {
1371		netdev_err(ndev,
1372			"unable to connect to NetVSP - %d\n", ret);
1373		goto close;
1374	}
1375
1376	/* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is
1377	 * populated.
1378	 */
1379	rcu_assign_pointer(net_device_ctx->nvdev, net_device);
1380
1381	return net_device;
1382
1383close:
1384	RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
1385	napi_disable(&net_device->chan_table[0].napi);
1386
1387	/* Now, we can close the channel safely */
1388	vmbus_close(device->channel);
1389
1390cleanup:
1391	netif_napi_del(&net_device->chan_table[0].napi);
 
 
1392	free_netvsc_device(&net_device->rcu);
1393
1394	return ERR_PTR(ret);
1395}
v5.14.15
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (c) 2009, Microsoft Corporation.
   4 *
 
 
 
 
 
 
 
 
 
 
 
 
   5 * Authors:
   6 *   Haiyang Zhang <haiyangz@microsoft.com>
   7 *   Hank Janssen  <hjanssen@microsoft.com>
   8 */
   9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11#include <linux/kernel.h>
  12#include <linux/sched.h>
  13#include <linux/wait.h>
  14#include <linux/mm.h>
  15#include <linux/delay.h>
  16#include <linux/io.h>
  17#include <linux/slab.h>
  18#include <linux/netdevice.h>
  19#include <linux/if_ether.h>
  20#include <linux/vmalloc.h>
  21#include <linux/rtnetlink.h>
  22#include <linux/prefetch.h>
 
  23
  24#include <asm/sync_bitops.h>
  25#include <asm/mshyperv.h>
  26
  27#include "hyperv_net.h"
  28#include "netvsc_trace.h"
  29
  30/*
  31 * Switch the data path from the synthetic interface to the VF
  32 * interface.
  33 */
  34int netvsc_switch_datapath(struct net_device *ndev, bool vf)
  35{
  36	struct net_device_context *net_device_ctx = netdev_priv(ndev);
  37	struct hv_device *dev = net_device_ctx->device_ctx;
  38	struct netvsc_device *nv_dev = rtnl_dereference(net_device_ctx->nvdev);
  39	struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
  40	int ret, retry = 0;
  41
  42	/* Block sending traffic to VF if it's about to be gone */
  43	if (!vf)
  44		net_device_ctx->data_path_is_vf = vf;
  45
  46	memset(init_pkt, 0, sizeof(struct nvsp_message));
  47	init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
  48	if (vf)
  49		init_pkt->msg.v4_msg.active_dp.active_datapath =
  50			NVSP_DATAPATH_VF;
  51	else
  52		init_pkt->msg.v4_msg.active_dp.active_datapath =
  53			NVSP_DATAPATH_SYNTHETIC;
  54
  55again:
  56	trace_nvsp_send(ndev, init_pkt);
  57
  58	ret = vmbus_sendpacket(dev->channel, init_pkt,
  59			       sizeof(struct nvsp_message),
  60			       (unsigned long)init_pkt, VM_PKT_DATA_INBAND,
  61			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
  62
  63	/* If failed to switch to/from VF, let data_path_is_vf stay false,
  64	 * so we use synthetic path to send data.
  65	 */
  66	if (ret) {
  67		if (ret != -EAGAIN) {
  68			netdev_err(ndev,
  69				   "Unable to send sw datapath msg, err: %d\n",
  70				   ret);
  71			return ret;
  72		}
  73
  74		if (retry++ < RETRY_MAX) {
  75			usleep_range(RETRY_US_LO, RETRY_US_HI);
  76			goto again;
  77		} else {
  78			netdev_err(
  79				ndev,
  80				"Retry failed to send sw datapath msg, err: %d\n",
  81				ret);
  82			return ret;
  83		}
  84	}
  85
  86	wait_for_completion(&nv_dev->channel_init_wait);
  87	net_device_ctx->data_path_is_vf = vf;
  88
  89	return 0;
  90}
  91
  92/* Worker to setup sub channels on initial setup
  93 * Initial hotplug event occurs in softirq context
  94 * and can't wait for channels.
  95 */
  96static void netvsc_subchan_work(struct work_struct *w)
  97{
  98	struct netvsc_device *nvdev =
  99		container_of(w, struct netvsc_device, subchan_work);
 100	struct rndis_device *rdev;
 101	int i, ret;
 102
 103	/* Avoid deadlock with device removal already under RTNL */
 104	if (!rtnl_trylock()) {
 105		schedule_work(w);
 106		return;
 107	}
 108
 109	rdev = nvdev->extension;
 110	if (rdev) {
 111		ret = rndis_set_subchannel(rdev->ndev, nvdev, NULL);
 112		if (ret == 0) {
 113			netif_device_attach(rdev->ndev);
 114		} else {
 115			/* fallback to only primary channel */
 116			for (i = 1; i < nvdev->num_chn; i++)
 117				netif_napi_del(&nvdev->chan_table[i].napi);
 118
 119			nvdev->max_chn = 1;
 120			nvdev->num_chn = 1;
 121		}
 122	}
 123
 124	rtnl_unlock();
 125}
 126
 127static struct netvsc_device *alloc_net_device(void)
 128{
 129	struct netvsc_device *net_device;
 130
 131	net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
 132	if (!net_device)
 133		return NULL;
 134
 135	init_waitqueue_head(&net_device->wait_drain);
 136	net_device->destroy = false;
 137	net_device->tx_disable = true;
 138
 139	net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
 140	net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
 141
 142	init_completion(&net_device->channel_init_wait);
 143	init_waitqueue_head(&net_device->subchan_open);
 144	INIT_WORK(&net_device->subchan_work, netvsc_subchan_work);
 145
 146	return net_device;
 147}
 148
 149static void free_netvsc_device(struct rcu_head *head)
 150{
 151	struct netvsc_device *nvdev
 152		= container_of(head, struct netvsc_device, rcu);
 153	int i;
 154
 155	kfree(nvdev->extension);
 156	vfree(nvdev->recv_buf);
 157	vfree(nvdev->send_buf);
 158	kfree(nvdev->send_section_map);
 159
 160	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
 161		xdp_rxq_info_unreg(&nvdev->chan_table[i].xdp_rxq);
 162		kfree(nvdev->chan_table[i].recv_buf);
 163		vfree(nvdev->chan_table[i].mrc.slots);
 164	}
 165
 166	kfree(nvdev);
 167}
 168
 169static void free_netvsc_device_rcu(struct netvsc_device *nvdev)
 170{
 171	call_rcu(&nvdev->rcu, free_netvsc_device);
 172}
 173
 174static void netvsc_revoke_recv_buf(struct hv_device *device,
 175				   struct netvsc_device *net_device,
 176				   struct net_device *ndev)
 177{
 178	struct nvsp_message *revoke_packet;
 179	int ret;
 180
 181	/*
 182	 * If we got a section count, it means we received a
 183	 * SendReceiveBufferComplete msg (ie sent
 184	 * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
 185	 * to send a revoke msg here
 186	 */
 187	if (net_device->recv_section_cnt) {
 188		/* Send the revoke receive buffer */
 189		revoke_packet = &net_device->revoke_packet;
 190		memset(revoke_packet, 0, sizeof(struct nvsp_message));
 191
 192		revoke_packet->hdr.msg_type =
 193			NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 194		revoke_packet->msg.v1_msg.
 195		revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 196
 197		trace_nvsp_send(ndev, revoke_packet);
 198
 199		ret = vmbus_sendpacket(device->channel,
 200				       revoke_packet,
 201				       sizeof(struct nvsp_message),
 202				       VMBUS_RQST_ID_NO_RESPONSE,
 203				       VM_PKT_DATA_INBAND, 0);
 204		/* If the failure is because the channel is rescinded;
 205		 * ignore the failure since we cannot send on a rescinded
 206		 * channel. This would allow us to properly cleanup
 207		 * even when the channel is rescinded.
 208		 */
 209		if (device->channel->rescind)
 210			ret = 0;
 211		/*
 212		 * If we failed here, we might as well return and
 213		 * have a leak rather than continue and a bugchk
 214		 */
 215		if (ret != 0) {
 216			netdev_err(ndev, "unable to send "
 217				"revoke receive buffer to netvsp\n");
 218			return;
 219		}
 220		net_device->recv_section_cnt = 0;
 221	}
 222}
 223
 224static void netvsc_revoke_send_buf(struct hv_device *device,
 225				   struct netvsc_device *net_device,
 226				   struct net_device *ndev)
 227{
 228	struct nvsp_message *revoke_packet;
 229	int ret;
 230
 231	/* Deal with the send buffer we may have setup.
 232	 * If we got a  send section size, it means we received a
 233	 * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
 234	 * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
 235	 * to send a revoke msg here
 236	 */
 237	if (net_device->send_section_cnt) {
 238		/* Send the revoke receive buffer */
 239		revoke_packet = &net_device->revoke_packet;
 240		memset(revoke_packet, 0, sizeof(struct nvsp_message));
 241
 242		revoke_packet->hdr.msg_type =
 243			NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
 244		revoke_packet->msg.v1_msg.revoke_send_buf.id =
 245			NETVSC_SEND_BUFFER_ID;
 246
 247		trace_nvsp_send(ndev, revoke_packet);
 248
 249		ret = vmbus_sendpacket(device->channel,
 250				       revoke_packet,
 251				       sizeof(struct nvsp_message),
 252				       VMBUS_RQST_ID_NO_RESPONSE,
 253				       VM_PKT_DATA_INBAND, 0);
 254
 255		/* If the failure is because the channel is rescinded;
 256		 * ignore the failure since we cannot send on a rescinded
 257		 * channel. This would allow us to properly cleanup
 258		 * even when the channel is rescinded.
 259		 */
 260		if (device->channel->rescind)
 261			ret = 0;
 262
 263		/* If we failed here, we might as well return and
 264		 * have a leak rather than continue and a bugchk
 265		 */
 266		if (ret != 0) {
 267			netdev_err(ndev, "unable to send "
 268				   "revoke send buffer to netvsp\n");
 269			return;
 270		}
 271		net_device->send_section_cnt = 0;
 272	}
 273}
 274
 275static void netvsc_teardown_recv_gpadl(struct hv_device *device,
 276				       struct netvsc_device *net_device,
 277				       struct net_device *ndev)
 278{
 279	int ret;
 280
 281	if (net_device->recv_buf_gpadl_handle) {
 282		ret = vmbus_teardown_gpadl(device->channel,
 283					   net_device->recv_buf_gpadl_handle);
 284
 285		/* If we failed here, we might as well return and have a leak
 286		 * rather than continue and a bugchk
 287		 */
 288		if (ret != 0) {
 289			netdev_err(ndev,
 290				   "unable to teardown receive buffer's gpadl\n");
 291			return;
 292		}
 293		net_device->recv_buf_gpadl_handle = 0;
 294	}
 295}
 296
 297static void netvsc_teardown_send_gpadl(struct hv_device *device,
 298				       struct netvsc_device *net_device,
 299				       struct net_device *ndev)
 300{
 301	int ret;
 302
 303	if (net_device->send_buf_gpadl_handle) {
 304		ret = vmbus_teardown_gpadl(device->channel,
 305					   net_device->send_buf_gpadl_handle);
 306
 307		/* If we failed here, we might as well return and have a leak
 308		 * rather than continue and a bugchk
 309		 */
 310		if (ret != 0) {
 311			netdev_err(ndev,
 312				   "unable to teardown send buffer's gpadl\n");
 313			return;
 314		}
 315		net_device->send_buf_gpadl_handle = 0;
 316	}
 317}
 318
 319int netvsc_alloc_recv_comp_ring(struct netvsc_device *net_device, u32 q_idx)
 320{
 321	struct netvsc_channel *nvchan = &net_device->chan_table[q_idx];
 322	int node = cpu_to_node(nvchan->channel->target_cpu);
 323	size_t size;
 324
 325	size = net_device->recv_completion_cnt * sizeof(struct recv_comp_data);
 326	nvchan->mrc.slots = vzalloc_node(size, node);
 327	if (!nvchan->mrc.slots)
 328		nvchan->mrc.slots = vzalloc(size);
 329
 330	return nvchan->mrc.slots ? 0 : -ENOMEM;
 331}
 332
 333static int netvsc_init_buf(struct hv_device *device,
 334			   struct netvsc_device *net_device,
 335			   const struct netvsc_device_info *device_info)
 336{
 337	struct nvsp_1_message_send_receive_buffer_complete *resp;
 338	struct net_device *ndev = hv_get_drvdata(device);
 339	struct nvsp_message *init_packet;
 340	unsigned int buf_size;
 341	size_t map_words;
 342	int i, ret = 0;
 343
 344	/* Get receive buffer area. */
 345	buf_size = device_info->recv_sections * device_info->recv_section_size;
 346	buf_size = roundup(buf_size, PAGE_SIZE);
 347
 348	/* Legacy hosts only allow smaller receive buffer */
 349	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
 350		buf_size = min_t(unsigned int, buf_size,
 351				 NETVSC_RECEIVE_BUFFER_SIZE_LEGACY);
 352
 353	net_device->recv_buf = vzalloc(buf_size);
 354	if (!net_device->recv_buf) {
 355		netdev_err(ndev,
 356			   "unable to allocate receive buffer of size %u\n",
 357			   buf_size);
 358		ret = -ENOMEM;
 359		goto cleanup;
 360	}
 361
 362	net_device->recv_buf_size = buf_size;
 363
 364	/*
 365	 * Establish the gpadl handle for this buffer on this
 366	 * channel.  Note: This call uses the vmbus connection rather
 367	 * than the channel to establish the gpadl handle.
 368	 */
 369	ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 370				    buf_size,
 371				    &net_device->recv_buf_gpadl_handle);
 372	if (ret != 0) {
 373		netdev_err(ndev,
 374			"unable to establish receive buffer's gpadl\n");
 375		goto cleanup;
 376	}
 377
 378	/* Notify the NetVsp of the gpadl handle */
 379	init_packet = &net_device->channel_init_pkt;
 380	memset(init_packet, 0, sizeof(struct nvsp_message));
 381	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 382	init_packet->msg.v1_msg.send_recv_buf.
 383		gpadl_handle = net_device->recv_buf_gpadl_handle;
 384	init_packet->msg.v1_msg.
 385		send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 386
 387	trace_nvsp_send(ndev, init_packet);
 388
 389	/* Send the gpadl notification request */
 390	ret = vmbus_sendpacket(device->channel, init_packet,
 391			       sizeof(struct nvsp_message),
 392			       (unsigned long)init_packet,
 393			       VM_PKT_DATA_INBAND,
 394			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 395	if (ret != 0) {
 396		netdev_err(ndev,
 397			"unable to send receive buffer's gpadl to netvsp\n");
 398		goto cleanup;
 399	}
 400
 401	wait_for_completion(&net_device->channel_init_wait);
 402
 403	/* Check the response */
 404	resp = &init_packet->msg.v1_msg.send_recv_buf_complete;
 405	if (resp->status != NVSP_STAT_SUCCESS) {
 406		netdev_err(ndev,
 407			   "Unable to complete receive buffer initialization with NetVsp - status %d\n",
 408			   resp->status);
 409		ret = -EINVAL;
 410		goto cleanup;
 411	}
 412
 413	/* Parse the response */
 414	netdev_dbg(ndev, "Receive sections: %u sub_allocs: size %u count: %u\n",
 415		   resp->num_sections, resp->sections[0].sub_alloc_size,
 416		   resp->sections[0].num_sub_allocs);
 417
 418	/* There should only be one section for the entire receive buffer */
 419	if (resp->num_sections != 1 || resp->sections[0].offset != 0) {
 420		ret = -EINVAL;
 421		goto cleanup;
 422	}
 423
 424	net_device->recv_section_size = resp->sections[0].sub_alloc_size;
 425	net_device->recv_section_cnt = resp->sections[0].num_sub_allocs;
 426
 427	/* Ensure buffer will not overflow */
 428	if (net_device->recv_section_size < NETVSC_MTU_MIN || (u64)net_device->recv_section_size *
 429	    (u64)net_device->recv_section_cnt > (u64)buf_size) {
 430		netdev_err(ndev, "invalid recv_section_size %u\n",
 431			   net_device->recv_section_size);
 432		ret = -EINVAL;
 433		goto cleanup;
 434	}
 435
 436	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
 437		struct netvsc_channel *nvchan = &net_device->chan_table[i];
 438
 439		nvchan->recv_buf = kzalloc(net_device->recv_section_size, GFP_KERNEL);
 440		if (nvchan->recv_buf == NULL) {
 441			ret = -ENOMEM;
 442			goto cleanup;
 443		}
 444	}
 445
 446	/* Setup receive completion ring.
 447	 * Add 1 to the recv_section_cnt because at least one entry in a
 448	 * ring buffer has to be empty.
 449	 */
 450	net_device->recv_completion_cnt = net_device->recv_section_cnt + 1;
 451	ret = netvsc_alloc_recv_comp_ring(net_device, 0);
 452	if (ret)
 453		goto cleanup;
 454
 455	/* Now setup the send buffer. */
 456	buf_size = device_info->send_sections * device_info->send_section_size;
 457	buf_size = round_up(buf_size, PAGE_SIZE);
 458
 459	net_device->send_buf = vzalloc(buf_size);
 460	if (!net_device->send_buf) {
 461		netdev_err(ndev, "unable to allocate send buffer of size %u\n",
 462			   buf_size);
 463		ret = -ENOMEM;
 464		goto cleanup;
 465	}
 466
 467	/* Establish the gpadl handle for this buffer on this
 468	 * channel.  Note: This call uses the vmbus connection rather
 469	 * than the channel to establish the gpadl handle.
 470	 */
 471	ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
 472				    buf_size,
 473				    &net_device->send_buf_gpadl_handle);
 474	if (ret != 0) {
 475		netdev_err(ndev,
 476			   "unable to establish send buffer's gpadl\n");
 477		goto cleanup;
 478	}
 479
 480	/* Notify the NetVsp of the gpadl handle */
 481	init_packet = &net_device->channel_init_pkt;
 482	memset(init_packet, 0, sizeof(struct nvsp_message));
 483	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
 484	init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
 485		net_device->send_buf_gpadl_handle;
 486	init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
 487
 488	trace_nvsp_send(ndev, init_packet);
 489
 490	/* Send the gpadl notification request */
 491	ret = vmbus_sendpacket(device->channel, init_packet,
 492			       sizeof(struct nvsp_message),
 493			       (unsigned long)init_packet,
 494			       VM_PKT_DATA_INBAND,
 495			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 496	if (ret != 0) {
 497		netdev_err(ndev,
 498			   "unable to send send buffer's gpadl to netvsp\n");
 499		goto cleanup;
 500	}
 501
 502	wait_for_completion(&net_device->channel_init_wait);
 503
 504	/* Check the response */
 505	if (init_packet->msg.v1_msg.
 506	    send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
 507		netdev_err(ndev, "Unable to complete send buffer "
 508			   "initialization with NetVsp - status %d\n",
 509			   init_packet->msg.v1_msg.
 510			   send_send_buf_complete.status);
 511		ret = -EINVAL;
 512		goto cleanup;
 513	}
 514
 515	/* Parse the response */
 516	net_device->send_section_size = init_packet->msg.
 517				v1_msg.send_send_buf_complete.section_size;
 518	if (net_device->send_section_size < NETVSC_MTU_MIN) {
 519		netdev_err(ndev, "invalid send_section_size %u\n",
 520			   net_device->send_section_size);
 521		ret = -EINVAL;
 522		goto cleanup;
 523	}
 524
 525	/* Section count is simply the size divided by the section size. */
 526	net_device->send_section_cnt = buf_size / net_device->send_section_size;
 527
 528	netdev_dbg(ndev, "Send section size: %d, Section count:%d\n",
 529		   net_device->send_section_size, net_device->send_section_cnt);
 530
 531	/* Setup state for managing the send buffer. */
 532	map_words = DIV_ROUND_UP(net_device->send_section_cnt, BITS_PER_LONG);
 533
 534	net_device->send_section_map = kcalloc(map_words, sizeof(ulong), GFP_KERNEL);
 535	if (net_device->send_section_map == NULL) {
 536		ret = -ENOMEM;
 537		goto cleanup;
 538	}
 539
 540	goto exit;
 541
 542cleanup:
 543	netvsc_revoke_recv_buf(device, net_device, ndev);
 544	netvsc_revoke_send_buf(device, net_device, ndev);
 545	netvsc_teardown_recv_gpadl(device, net_device, ndev);
 546	netvsc_teardown_send_gpadl(device, net_device, ndev);
 547
 548exit:
 549	return ret;
 550}
 551
 552/* Negotiate NVSP protocol version */
 553static int negotiate_nvsp_ver(struct hv_device *device,
 554			      struct netvsc_device *net_device,
 555			      struct nvsp_message *init_packet,
 556			      u32 nvsp_ver)
 557{
 558	struct net_device *ndev = hv_get_drvdata(device);
 559	int ret;
 560
 561	memset(init_packet, 0, sizeof(struct nvsp_message));
 562	init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 563	init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
 564	init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
 565	trace_nvsp_send(ndev, init_packet);
 566
 567	/* Send the init request */
 568	ret = vmbus_sendpacket(device->channel, init_packet,
 569			       sizeof(struct nvsp_message),
 570			       (unsigned long)init_packet,
 571			       VM_PKT_DATA_INBAND,
 572			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 573
 574	if (ret != 0)
 575		return ret;
 576
 577	wait_for_completion(&net_device->channel_init_wait);
 578
 579	if (init_packet->msg.init_msg.init_complete.status !=
 580	    NVSP_STAT_SUCCESS)
 581		return -EINVAL;
 582
 583	if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
 584		return 0;
 585
 586	/* NVSPv2 or later: Send NDIS config */
 587	memset(init_packet, 0, sizeof(struct nvsp_message));
 588	init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
 589	init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;
 590	init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
 591
 592	if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5) {
 593		if (hv_is_isolation_supported())
 594			netdev_info(ndev, "SR-IOV not advertised by guests on the host supporting isolation\n");
 595		else
 596			init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
 597
 598		/* Teaming bit is needed to receive link speed updates */
 599		init_packet->msg.v2_msg.send_ndis_config.capability.teaming = 1;
 600	}
 601
 602	if (nvsp_ver >= NVSP_PROTOCOL_VERSION_61)
 603		init_packet->msg.v2_msg.send_ndis_config.capability.rsc = 1;
 604
 605	trace_nvsp_send(ndev, init_packet);
 606
 607	ret = vmbus_sendpacket(device->channel, init_packet,
 608				sizeof(struct nvsp_message),
 609				VMBUS_RQST_ID_NO_RESPONSE,
 610				VM_PKT_DATA_INBAND, 0);
 611
 612	return ret;
 613}
 614
 615static int netvsc_connect_vsp(struct hv_device *device,
 616			      struct netvsc_device *net_device,
 617			      const struct netvsc_device_info *device_info)
 618{
 619	struct net_device *ndev = hv_get_drvdata(device);
 620	static const u32 ver_list[] = {
 621		NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
 622		NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5,
 623		NVSP_PROTOCOL_VERSION_6, NVSP_PROTOCOL_VERSION_61
 624	};
 625	struct nvsp_message *init_packet;
 626	int ndis_version, i, ret;
 627
 628	init_packet = &net_device->channel_init_pkt;
 629
 630	/* Negotiate the latest NVSP protocol supported */
 631	for (i = ARRAY_SIZE(ver_list) - 1; i >= 0; i--)
 632		if (negotiate_nvsp_ver(device, net_device, init_packet,
 633				       ver_list[i])  == 0) {
 634			net_device->nvsp_version = ver_list[i];
 635			break;
 636		}
 637
 638	if (i < 0) {
 639		ret = -EPROTO;
 640		goto cleanup;
 641	}
 642
 643	if (hv_is_isolation_supported() && net_device->nvsp_version < NVSP_PROTOCOL_VERSION_61) {
 644		netdev_err(ndev, "Invalid NVSP version 0x%x (expected >= 0x%x) from the host supporting isolation\n",
 645			   net_device->nvsp_version, NVSP_PROTOCOL_VERSION_61);
 646		ret = -EPROTO;
 647		goto cleanup;
 648	}
 649
 650	pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
 651
 652	/* Send the ndis version */
 653	memset(init_packet, 0, sizeof(struct nvsp_message));
 654
 655	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
 656		ndis_version = 0x00060001;
 657	else
 658		ndis_version = 0x0006001e;
 659
 660	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 661	init_packet->msg.v1_msg.
 662		send_ndis_ver.ndis_major_ver =
 663				(ndis_version & 0xFFFF0000) >> 16;
 664	init_packet->msg.v1_msg.
 665		send_ndis_ver.ndis_minor_ver =
 666				ndis_version & 0xFFFF;
 667
 668	trace_nvsp_send(ndev, init_packet);
 669
 670	/* Send the init request */
 671	ret = vmbus_sendpacket(device->channel, init_packet,
 672				sizeof(struct nvsp_message),
 673				VMBUS_RQST_ID_NO_RESPONSE,
 674				VM_PKT_DATA_INBAND, 0);
 675	if (ret != 0)
 676		goto cleanup;
 677
 678
 679	ret = netvsc_init_buf(device, net_device, device_info);
 680
 681cleanup:
 682	return ret;
 683}
 684
 685/*
 686 * netvsc_device_remove - Callback when the root bus device is removed
 687 */
 688void netvsc_device_remove(struct hv_device *device)
 689{
 690	struct net_device *ndev = hv_get_drvdata(device);
 691	struct net_device_context *net_device_ctx = netdev_priv(ndev);
 692	struct netvsc_device *net_device
 693		= rtnl_dereference(net_device_ctx->nvdev);
 694	int i;
 695
 696	/*
 697	 * Revoke receive buffer. If host is pre-Win2016 then tear down
 698	 * receive buffer GPADL. Do the same for send buffer.
 699	 */
 700	netvsc_revoke_recv_buf(device, net_device, ndev);
 701	if (vmbus_proto_version < VERSION_WIN10)
 702		netvsc_teardown_recv_gpadl(device, net_device, ndev);
 703
 704	netvsc_revoke_send_buf(device, net_device, ndev);
 705	if (vmbus_proto_version < VERSION_WIN10)
 706		netvsc_teardown_send_gpadl(device, net_device, ndev);
 707
 708	RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
 709
 710	/* Disable NAPI and disassociate its context from the device. */
 711	for (i = 0; i < net_device->num_chn; i++) {
 712		/* See also vmbus_reset_channel_cb(). */
 713		napi_disable(&net_device->chan_table[i].napi);
 714		netif_napi_del(&net_device->chan_table[i].napi);
 715	}
 716
 717	/*
 718	 * At this point, no one should be accessing net_device
 719	 * except in here
 720	 */
 721	netdev_dbg(ndev, "net device safe to remove\n");
 722
 723	/* Now, we can close the channel safely */
 724	vmbus_close(device->channel);
 725
 726	/*
 727	 * If host is Win2016 or higher then we do the GPADL tear down
 728	 * here after VMBus is closed.
 729	*/
 730	if (vmbus_proto_version >= VERSION_WIN10) {
 731		netvsc_teardown_recv_gpadl(device, net_device, ndev);
 732		netvsc_teardown_send_gpadl(device, net_device, ndev);
 733	}
 734
 735	/* Release all resources */
 736	free_netvsc_device_rcu(net_device);
 737}
 738
 739#define RING_AVAIL_PERCENT_HIWATER 20
 740#define RING_AVAIL_PERCENT_LOWATER 10
 741
 
 
 
 
 
 
 
 
 
 
 
 742static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
 743					 u32 index)
 744{
 745	sync_change_bit(index, net_device->send_section_map);
 746}
 747
 748static void netvsc_send_tx_complete(struct net_device *ndev,
 749				    struct netvsc_device *net_device,
 750				    struct vmbus_channel *channel,
 751				    const struct vmpacket_descriptor *desc,
 752				    int budget)
 753{
 
 
 754	struct net_device_context *ndev_ctx = netdev_priv(ndev);
 755	struct sk_buff *skb;
 756	u16 q_idx = 0;
 757	int queue_sends;
 758	u64 cmd_rqst;
 759
 760	cmd_rqst = channel->request_addr_callback(channel, (u64)desc->trans_id);
 761	if (cmd_rqst == VMBUS_RQST_ERROR) {
 762		netdev_err(ndev, "Incorrect transaction id\n");
 763		return;
 764	}
 765
 766	skb = (struct sk_buff *)(unsigned long)cmd_rqst;
 767
 768	/* Notify the layer above us */
 769	if (likely(skb)) {
 770		const struct hv_netvsc_packet *packet
 771			= (struct hv_netvsc_packet *)skb->cb;
 772		u32 send_index = packet->send_buf_index;
 773		struct netvsc_stats *tx_stats;
 774
 775		if (send_index != NETVSC_INVALID_INDEX)
 776			netvsc_free_send_slot(net_device, send_index);
 777		q_idx = packet->q_idx;
 
 778
 779		tx_stats = &net_device->chan_table[q_idx].tx_stats;
 780
 781		u64_stats_update_begin(&tx_stats->syncp);
 782		tx_stats->packets += packet->total_packets;
 783		tx_stats->bytes += packet->total_bytes;
 784		u64_stats_update_end(&tx_stats->syncp);
 785
 786		napi_consume_skb(skb, budget);
 787	}
 788
 789	queue_sends =
 790		atomic_dec_return(&net_device->chan_table[q_idx].queue_sends);
 791
 792	if (unlikely(net_device->destroy)) {
 793		if (queue_sends == 0)
 794			wake_up(&net_device->wait_drain);
 795	} else {
 796		struct netdev_queue *txq = netdev_get_tx_queue(ndev, q_idx);
 797
 798		if (netif_tx_queue_stopped(txq) && !net_device->tx_disable &&
 799		    (hv_get_avail_to_write_percent(&channel->outbound) >
 800		     RING_AVAIL_PERCENT_HIWATER || queue_sends < 1)) {
 801			netif_tx_wake_queue(txq);
 802			ndev_ctx->eth_stats.wake_queue++;
 803		}
 804	}
 805}
 806
 807static void netvsc_send_completion(struct net_device *ndev,
 808				   struct netvsc_device *net_device,
 809				   struct vmbus_channel *incoming_channel,
 
 810				   const struct vmpacket_descriptor *desc,
 811				   int budget)
 812{
 813	const struct nvsp_message *nvsp_packet;
 814	u32 msglen = hv_pkt_datalen(desc);
 815	struct nvsp_message *pkt_rqst;
 816	u64 cmd_rqst;
 817
 818	/* First check if this is a VMBUS completion without data payload */
 819	if (!msglen) {
 820		cmd_rqst = incoming_channel->request_addr_callback(incoming_channel,
 821								   (u64)desc->trans_id);
 822		if (cmd_rqst == VMBUS_RQST_ERROR) {
 823			netdev_err(ndev, "Invalid transaction id\n");
 824			return;
 825		}
 826
 827		pkt_rqst = (struct nvsp_message *)(uintptr_t)cmd_rqst;
 828		switch (pkt_rqst->hdr.msg_type) {
 829		case NVSP_MSG4_TYPE_SWITCH_DATA_PATH:
 830			complete(&net_device->channel_init_wait);
 831			break;
 832
 833		default:
 834			netdev_err(ndev, "Unexpected VMBUS completion!!\n");
 835		}
 836		return;
 837	}
 838
 839	/* Ensure packet is big enough to read header fields */
 840	if (msglen < sizeof(struct nvsp_message_header)) {
 841		netdev_err(ndev, "nvsp_message length too small: %u\n", msglen);
 842		return;
 843	}
 844
 845	nvsp_packet = hv_pkt_data(desc);
 846	switch (nvsp_packet->hdr.msg_type) {
 847	case NVSP_MSG_TYPE_INIT_COMPLETE:
 848		if (msglen < sizeof(struct nvsp_message_header) +
 849				sizeof(struct nvsp_message_init_complete)) {
 850			netdev_err(ndev, "nvsp_msg length too small: %u\n",
 851				   msglen);
 852			return;
 853		}
 854		fallthrough;
 855
 856	case NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE:
 857		if (msglen < sizeof(struct nvsp_message_header) +
 858				sizeof(struct nvsp_1_message_send_receive_buffer_complete)) {
 859			netdev_err(ndev, "nvsp_msg1 length too small: %u\n",
 860				   msglen);
 861			return;
 862		}
 863		fallthrough;
 864
 865	case NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE:
 866		if (msglen < sizeof(struct nvsp_message_header) +
 867				sizeof(struct nvsp_1_message_send_send_buffer_complete)) {
 868			netdev_err(ndev, "nvsp_msg1 length too small: %u\n",
 869				   msglen);
 870			return;
 871		}
 872		fallthrough;
 873
 874	case NVSP_MSG5_TYPE_SUBCHANNEL:
 875		if (msglen < sizeof(struct nvsp_message_header) +
 876				sizeof(struct nvsp_5_subchannel_complete)) {
 877			netdev_err(ndev, "nvsp_msg5 length too small: %u\n",
 878				   msglen);
 879			return;
 880		}
 881		/* Copy the response back */
 882		memcpy(&net_device->channel_init_pkt, nvsp_packet,
 883		       sizeof(struct nvsp_message));
 884		complete(&net_device->channel_init_wait);
 885		break;
 886
 887	case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
 888		netvsc_send_tx_complete(ndev, net_device, incoming_channel,
 889					desc, budget);
 890		break;
 891
 892	default:
 893		netdev_err(ndev,
 894			   "Unknown send completion type %d received!!\n",
 895			   nvsp_packet->hdr.msg_type);
 896	}
 897}
 898
 899static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
 900{
 901	unsigned long *map_addr = net_device->send_section_map;
 902	unsigned int i;
 903
 904	for_each_clear_bit(i, map_addr, net_device->send_section_cnt) {
 905		if (sync_test_and_set_bit(i, map_addr) == 0)
 906			return i;
 907	}
 908
 909	return NETVSC_INVALID_INDEX;
 910}
 911
 912static void netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 913				    unsigned int section_index,
 914				    u32 pend_size,
 915				    struct hv_netvsc_packet *packet,
 916				    struct rndis_message *rndis_msg,
 917				    struct hv_page_buffer *pb,
 918				    bool xmit_more)
 919{
 920	char *start = net_device->send_buf;
 921	char *dest = start + (section_index * net_device->send_section_size)
 922		     + pend_size;
 923	int i;
 924	u32 padding = 0;
 925	u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
 926		packet->page_buf_cnt;
 927	u32 remain;
 928
 929	/* Add padding */
 930	remain = packet->total_data_buflen & (net_device->pkt_align - 1);
 931	if (xmit_more && remain) {
 932		padding = net_device->pkt_align - remain;
 933		rndis_msg->msg_len += padding;
 934		packet->total_data_buflen += padding;
 935	}
 936
 937	for (i = 0; i < page_count; i++) {
 938		char *src = phys_to_virt(pb[i].pfn << HV_HYP_PAGE_SHIFT);
 939		u32 offset = pb[i].offset;
 940		u32 len = pb[i].len;
 941
 942		memcpy(dest, (src + offset), len);
 943		dest += len;
 944	}
 945
 946	if (padding)
 947		memset(dest, 0, padding);
 948}
 949
 950static inline int netvsc_send_pkt(
 951	struct hv_device *device,
 952	struct hv_netvsc_packet *packet,
 953	struct netvsc_device *net_device,
 954	struct hv_page_buffer *pb,
 955	struct sk_buff *skb)
 956{
 957	struct nvsp_message nvmsg;
 958	struct nvsp_1_message_send_rndis_packet *rpkt =
 959		&nvmsg.msg.v1_msg.send_rndis_pkt;
 960	struct netvsc_channel * const nvchan =
 961		&net_device->chan_table[packet->q_idx];
 962	struct vmbus_channel *out_channel = nvchan->channel;
 963	struct net_device *ndev = hv_get_drvdata(device);
 964	struct net_device_context *ndev_ctx = netdev_priv(ndev);
 965	struct netdev_queue *txq = netdev_get_tx_queue(ndev, packet->q_idx);
 966	u64 req_id;
 967	int ret;
 968	u32 ring_avail = hv_get_avail_to_write_percent(&out_channel->outbound);
 969
 970	memset(&nvmsg, 0, sizeof(struct nvsp_message));
 971	nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 972	if (skb)
 973		rpkt->channel_type = 0;		/* 0 is RMC_DATA */
 974	else
 975		rpkt->channel_type = 1;		/* 1 is RMC_CONTROL */
 976
 977	rpkt->send_buf_section_index = packet->send_buf_index;
 978	if (packet->send_buf_index == NETVSC_INVALID_INDEX)
 979		rpkt->send_buf_section_size = 0;
 980	else
 981		rpkt->send_buf_section_size = packet->total_data_buflen;
 982
 983	req_id = (ulong)skb;
 984
 985	if (out_channel->rescind)
 986		return -ENODEV;
 987
 988	trace_nvsp_send_pkt(ndev, out_channel, rpkt);
 989
 990	if (packet->page_buf_cnt) {
 991		if (packet->cp_partial)
 992			pb += packet->rmsg_pgcnt;
 993
 994		ret = vmbus_sendpacket_pagebuffer(out_channel,
 995						  pb, packet->page_buf_cnt,
 996						  &nvmsg, sizeof(nvmsg),
 997						  req_id);
 998	} else {
 999		ret = vmbus_sendpacket(out_channel,
1000				       &nvmsg, sizeof(nvmsg),
1001				       req_id, VM_PKT_DATA_INBAND,
1002				       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1003	}
1004
1005	if (ret == 0) {
1006		atomic_inc_return(&nvchan->queue_sends);
1007
1008		if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
1009			netif_tx_stop_queue(txq);
1010			ndev_ctx->eth_stats.stop_queue++;
1011		}
1012	} else if (ret == -EAGAIN) {
1013		netif_tx_stop_queue(txq);
1014		ndev_ctx->eth_stats.stop_queue++;
 
 
 
 
 
1015	} else {
1016		netdev_err(ndev,
1017			   "Unable to send packet pages %u len %u, ret %d\n",
1018			   packet->page_buf_cnt, packet->total_data_buflen,
1019			   ret);
1020	}
1021
1022	if (netif_tx_queue_stopped(txq) &&
1023	    atomic_read(&nvchan->queue_sends) < 1 &&
1024	    !net_device->tx_disable) {
1025		netif_tx_wake_queue(txq);
1026		ndev_ctx->eth_stats.wake_queue++;
1027		if (ret == -EAGAIN)
1028			ret = -ENOSPC;
1029	}
1030
1031	return ret;
1032}
1033
1034/* Move packet out of multi send data (msd), and clear msd */
1035static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
1036				struct sk_buff **msd_skb,
1037				struct multi_send_data *msdp)
1038{
1039	*msd_skb = msdp->skb;
1040	*msd_send = msdp->pkt;
1041	msdp->skb = NULL;
1042	msdp->pkt = NULL;
1043	msdp->count = 0;
1044}
1045
1046/* RCU already held by caller */
1047/* Batching/bouncing logic is designed to attempt to optimize
1048 * performance.
1049 *
1050 * For small, non-LSO packets we copy the packet to a send buffer
1051 * which is pre-registered with the Hyper-V side. This enables the
1052 * hypervisor to avoid remapping the aperture to access the packet
1053 * descriptor and data.
1054 *
1055 * If we already started using a buffer and the netdev is transmitting
1056 * a burst of packets, keep on copying into the buffer until it is
1057 * full or we are done collecting a burst. If there is an existing
1058 * buffer with space for the RNDIS descriptor but not the packet, copy
1059 * the RNDIS descriptor to the buffer, keeping the packet in place.
1060 *
1061 * If we do batching and send more than one packet using a single
1062 * NetVSC message, free the SKBs of the packets copied, except for the
1063 * last packet. This is done to streamline the handling of the case
1064 * where the last packet only had the RNDIS descriptor copied to the
1065 * send buffer, with the data pointers included in the NetVSC message.
1066 */
1067int netvsc_send(struct net_device *ndev,
1068		struct hv_netvsc_packet *packet,
1069		struct rndis_message *rndis_msg,
1070		struct hv_page_buffer *pb,
1071		struct sk_buff *skb,
1072		bool xdp_tx)
1073{
1074	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1075	struct netvsc_device *net_device
1076		= rcu_dereference_bh(ndev_ctx->nvdev);
1077	struct hv_device *device = ndev_ctx->device_ctx;
1078	int ret = 0;
1079	struct netvsc_channel *nvchan;
1080	u32 pktlen = packet->total_data_buflen, msd_len = 0;
1081	unsigned int section_index = NETVSC_INVALID_INDEX;
1082	struct multi_send_data *msdp;
1083	struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
1084	struct sk_buff *msd_skb = NULL;
1085	bool try_batch, xmit_more;
1086
1087	/* If device is rescinded, return error and packet will get dropped. */
1088	if (unlikely(!net_device || net_device->destroy))
1089		return -ENODEV;
1090
1091	nvchan = &net_device->chan_table[packet->q_idx];
1092	packet->send_buf_index = NETVSC_INVALID_INDEX;
1093	packet->cp_partial = false;
1094
1095	/* Send a control message or XDP packet directly without accessing
1096	 * msd (Multi-Send Data) field which may be changed during data packet
1097	 * processing.
1098	 */
1099	if (!skb || xdp_tx)
1100		return netvsc_send_pkt(device, packet, net_device, pb, skb);
1101
1102	/* batch packets in send buffer if possible */
1103	msdp = &nvchan->msd;
1104	if (msdp->pkt)
1105		msd_len = msdp->pkt->total_data_buflen;
1106
1107	try_batch =  msd_len > 0 && msdp->count < net_device->max_pkt;
1108	if (try_batch && msd_len + pktlen + net_device->pkt_align <
1109	    net_device->send_section_size) {
1110		section_index = msdp->pkt->send_buf_index;
1111
1112	} else if (try_batch && msd_len + packet->rmsg_size <
1113		   net_device->send_section_size) {
1114		section_index = msdp->pkt->send_buf_index;
1115		packet->cp_partial = true;
1116
1117	} else if (pktlen + net_device->pkt_align <
1118		   net_device->send_section_size) {
1119		section_index = netvsc_get_next_send_section(net_device);
1120		if (unlikely(section_index == NETVSC_INVALID_INDEX)) {
1121			++ndev_ctx->eth_stats.tx_send_full;
1122		} else {
1123			move_pkt_msd(&msd_send, &msd_skb, msdp);
1124			msd_len = 0;
1125		}
1126	}
1127
1128	/* Keep aggregating only if stack says more data is coming
1129	 * and not doing mixed modes send and not flow blocked
1130	 */
1131	xmit_more = netdev_xmit_more() &&
1132		!packet->cp_partial &&
1133		!netif_xmit_stopped(netdev_get_tx_queue(ndev, packet->q_idx));
1134
1135	if (section_index != NETVSC_INVALID_INDEX) {
1136		netvsc_copy_to_send_buf(net_device,
1137					section_index, msd_len,
1138					packet, rndis_msg, pb, xmit_more);
1139
1140		packet->send_buf_index = section_index;
1141
1142		if (packet->cp_partial) {
1143			packet->page_buf_cnt -= packet->rmsg_pgcnt;
1144			packet->total_data_buflen = msd_len + packet->rmsg_size;
1145		} else {
1146			packet->page_buf_cnt = 0;
1147			packet->total_data_buflen += msd_len;
1148		}
1149
1150		if (msdp->pkt) {
1151			packet->total_packets += msdp->pkt->total_packets;
1152			packet->total_bytes += msdp->pkt->total_bytes;
1153		}
1154
1155		if (msdp->skb)
1156			dev_consume_skb_any(msdp->skb);
1157
1158		if (xmit_more) {
1159			msdp->skb = skb;
1160			msdp->pkt = packet;
1161			msdp->count++;
1162		} else {
1163			cur_send = packet;
1164			msdp->skb = NULL;
1165			msdp->pkt = NULL;
1166			msdp->count = 0;
1167		}
1168	} else {
1169		move_pkt_msd(&msd_send, &msd_skb, msdp);
1170		cur_send = packet;
1171	}
1172
1173	if (msd_send) {
1174		int m_ret = netvsc_send_pkt(device, msd_send, net_device,
1175					    NULL, msd_skb);
1176
1177		if (m_ret != 0) {
1178			netvsc_free_send_slot(net_device,
1179					      msd_send->send_buf_index);
1180			dev_kfree_skb_any(msd_skb);
1181		}
1182	}
1183
1184	if (cur_send)
1185		ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);
1186
1187	if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
1188		netvsc_free_send_slot(net_device, section_index);
1189
1190	return ret;
1191}
1192
1193/* Send pending recv completions */
1194static int send_recv_completions(struct net_device *ndev,
1195				 struct netvsc_device *nvdev,
1196				 struct netvsc_channel *nvchan)
1197{
1198	struct multi_recv_comp *mrc = &nvchan->mrc;
1199	struct recv_comp_msg {
1200		struct nvsp_message_header hdr;
1201		u32 status;
1202	}  __packed;
1203	struct recv_comp_msg msg = {
1204		.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE,
1205	};
1206	int ret;
1207
1208	while (mrc->first != mrc->next) {
1209		const struct recv_comp_data *rcd
1210			= mrc->slots + mrc->first;
1211
1212		msg.status = rcd->status;
1213		ret = vmbus_sendpacket(nvchan->channel, &msg, sizeof(msg),
1214				       rcd->tid, VM_PKT_COMP, 0);
1215		if (unlikely(ret)) {
1216			struct net_device_context *ndev_ctx = netdev_priv(ndev);
1217
1218			++ndev_ctx->eth_stats.rx_comp_busy;
1219			return ret;
1220		}
1221
1222		if (++mrc->first == nvdev->recv_completion_cnt)
1223			mrc->first = 0;
1224	}
1225
1226	/* receive completion ring has been emptied */
1227	if (unlikely(nvdev->destroy))
1228		wake_up(&nvdev->wait_drain);
1229
1230	return 0;
1231}
1232
1233/* Count how many receive completions are outstanding */
1234static void recv_comp_slot_avail(const struct netvsc_device *nvdev,
1235				 const struct multi_recv_comp *mrc,
1236				 u32 *filled, u32 *avail)
1237{
1238	u32 count = nvdev->recv_completion_cnt;
1239
1240	if (mrc->next >= mrc->first)
1241		*filled = mrc->next - mrc->first;
1242	else
1243		*filled = (count - mrc->first) + mrc->next;
1244
1245	*avail = count - *filled - 1;
1246}
1247
1248/* Add receive complete to ring to send to host. */
1249static void enq_receive_complete(struct net_device *ndev,
1250				 struct netvsc_device *nvdev, u16 q_idx,
1251				 u64 tid, u32 status)
1252{
1253	struct netvsc_channel *nvchan = &nvdev->chan_table[q_idx];
1254	struct multi_recv_comp *mrc = &nvchan->mrc;
1255	struct recv_comp_data *rcd;
1256	u32 filled, avail;
1257
1258	recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1259
1260	if (unlikely(filled > NAPI_POLL_WEIGHT)) {
1261		send_recv_completions(ndev, nvdev, nvchan);
1262		recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1263	}
1264
1265	if (unlikely(!avail)) {
1266		netdev_err(ndev, "Recv_comp full buf q:%hd, tid:%llx\n",
1267			   q_idx, tid);
1268		return;
1269	}
1270
1271	rcd = mrc->slots + mrc->next;
1272	rcd->tid = tid;
1273	rcd->status = status;
1274
1275	if (++mrc->next == nvdev->recv_completion_cnt)
1276		mrc->next = 0;
1277}
1278
1279static int netvsc_receive(struct net_device *ndev,
1280			  struct netvsc_device *net_device,
1281			  struct netvsc_channel *nvchan,
1282			  const struct vmpacket_descriptor *desc)
 
 
 
1283{
1284	struct net_device_context *net_device_ctx = netdev_priv(ndev);
1285	struct vmbus_channel *channel = nvchan->channel;
1286	const struct vmtransfer_page_packet_header *vmxferpage_packet
1287		= container_of(desc, const struct vmtransfer_page_packet_header, d);
1288	const struct nvsp_message *nvsp = hv_pkt_data(desc);
1289	u32 msglen = hv_pkt_datalen(desc);
1290	u16 q_idx = channel->offermsg.offer.sub_channel_index;
1291	char *recv_buf = net_device->recv_buf;
1292	u32 status = NVSP_STAT_SUCCESS;
1293	int i;
1294	int count = 0;
1295
1296	/* Ensure packet is big enough to read header fields */
1297	if (msglen < sizeof(struct nvsp_message_header)) {
1298		netif_err(net_device_ctx, rx_err, ndev,
1299			  "invalid nvsp header, length too small: %u\n",
1300			  msglen);
1301		return 0;
1302	}
1303
1304	/* Make sure this is a valid nvsp packet */
1305	if (unlikely(nvsp->hdr.msg_type != NVSP_MSG1_TYPE_SEND_RNDIS_PKT)) {
1306		netif_err(net_device_ctx, rx_err, ndev,
1307			  "Unknown nvsp packet type received %u\n",
1308			  nvsp->hdr.msg_type);
1309		return 0;
1310	}
1311
1312	/* Validate xfer page pkt header */
1313	if ((desc->offset8 << 3) < sizeof(struct vmtransfer_page_packet_header)) {
1314		netif_err(net_device_ctx, rx_err, ndev,
1315			  "Invalid xfer page pkt, offset too small: %u\n",
1316			  desc->offset8 << 3);
1317		return 0;
1318	}
1319
1320	if (unlikely(vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID)) {
1321		netif_err(net_device_ctx, rx_err, ndev,
1322			  "Invalid xfer page set id - expecting %x got %x\n",
1323			  NETVSC_RECEIVE_BUFFER_ID,
1324			  vmxferpage_packet->xfer_pageset_id);
1325		return 0;
1326	}
1327
1328	count = vmxferpage_packet->range_cnt;
1329
1330	/* Check count for a valid value */
1331	if (NETVSC_XFER_HEADER_SIZE(count) > desc->offset8 << 3) {
1332		netif_err(net_device_ctx, rx_err, ndev,
1333			  "Range count is not valid: %d\n",
1334			  count);
1335		return 0;
1336	}
1337
1338	/* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1339	for (i = 0; i < count; i++) {
1340		u32 offset = vmxferpage_packet->ranges[i].byte_offset;
1341		u32 buflen = vmxferpage_packet->ranges[i].byte_count;
1342		void *data;
1343		int ret;
1344
1345		if (unlikely(offset > net_device->recv_buf_size ||
1346			     buflen > net_device->recv_buf_size - offset)) {
1347			nvchan->rsc.cnt = 0;
1348			status = NVSP_STAT_FAIL;
1349			netif_err(net_device_ctx, rx_err, ndev,
1350				  "Packet offset:%u + len:%u too big\n",
1351				  offset, buflen);
1352
1353			continue;
1354		}
1355
1356		/* We're going to copy (sections of) the packet into nvchan->recv_buf;
1357		 * make sure that nvchan->recv_buf is large enough to hold the packet.
1358		 */
1359		if (unlikely(buflen > net_device->recv_section_size)) {
1360			nvchan->rsc.cnt = 0;
1361			status = NVSP_STAT_FAIL;
1362			netif_err(net_device_ctx, rx_err, ndev,
1363				  "Packet too big: buflen=%u recv_section_size=%u\n",
1364				  buflen, net_device->recv_section_size);
1365
1366			continue;
1367		}
1368
1369		data = recv_buf + offset;
1370
1371		nvchan->rsc.is_last = (i == count - 1);
1372
1373		trace_rndis_recv(ndev, q_idx, data);
1374
1375		/* Pass it to the upper layer */
1376		ret = rndis_filter_receive(ndev, net_device,
1377					   nvchan, data, buflen);
1378
1379		if (unlikely(ret != NVSP_STAT_SUCCESS)) {
1380			/* Drop incomplete packet */
1381			nvchan->rsc.cnt = 0;
1382			status = NVSP_STAT_FAIL;
1383		}
1384	}
1385
1386	enq_receive_complete(ndev, net_device, q_idx,
1387			     vmxferpage_packet->d.trans_id, status);
1388
1389	return count;
1390}
1391
1392static void netvsc_send_table(struct net_device *ndev,
1393			      struct netvsc_device *nvscdev,
1394			      const struct nvsp_message *nvmsg,
1395			      u32 msglen)
1396{
 
1397	struct net_device_context *net_device_ctx = netdev_priv(ndev);
1398	u32 count, offset, *tab;
1399	int i;
1400
1401	/* Ensure packet is big enough to read send_table fields */
1402	if (msglen < sizeof(struct nvsp_message_header) +
1403		     sizeof(struct nvsp_5_send_indirect_table)) {
1404		netdev_err(ndev, "nvsp_v5_msg length too small: %u\n", msglen);
1405		return;
1406	}
1407
1408	count = nvmsg->msg.v5_msg.send_table.count;
1409	offset = nvmsg->msg.v5_msg.send_table.offset;
1410
1411	if (count != VRSS_SEND_TAB_SIZE) {
1412		netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1413		return;
1414	}
1415
1416	/* If negotiated version <= NVSP_PROTOCOL_VERSION_6, the offset may be
1417	 * wrong due to a host bug. So fix the offset here.
1418	 */
1419	if (nvscdev->nvsp_version <= NVSP_PROTOCOL_VERSION_6 &&
1420	    msglen >= sizeof(struct nvsp_message_header) +
1421	    sizeof(union nvsp_6_message_uber) + count * sizeof(u32))
1422		offset = sizeof(struct nvsp_message_header) +
1423			 sizeof(union nvsp_6_message_uber);
1424
1425	/* Boundary check for all versions */
1426	if (msglen < count * sizeof(u32) || offset > msglen - count * sizeof(u32)) {
1427		netdev_err(ndev, "Received send-table offset too big:%u\n",
1428			   offset);
1429		return;
1430	}
1431
1432	tab = (void *)nvmsg + offset;
1433
1434	for (i = 0; i < count; i++)
1435		net_device_ctx->tx_table[i] = tab[i];
1436}
1437
1438static void netvsc_send_vf(struct net_device *ndev,
1439			   const struct nvsp_message *nvmsg,
1440			   u32 msglen)
1441{
1442	struct net_device_context *net_device_ctx = netdev_priv(ndev);
1443
1444	/* Ensure packet is big enough to read its fields */
1445	if (msglen < sizeof(struct nvsp_message_header) +
1446		     sizeof(struct nvsp_4_send_vf_association)) {
1447		netdev_err(ndev, "nvsp_v4_msg length too small: %u\n", msglen);
1448		return;
1449	}
1450
1451	net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1452	net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1453	netdev_info(ndev, "VF slot %u %s\n",
1454		    net_device_ctx->vf_serial,
1455		    net_device_ctx->vf_alloc ? "added" : "removed");
1456}
1457
1458static void netvsc_receive_inband(struct net_device *ndev,
1459				  struct netvsc_device *nvscdev,
1460				  const struct vmpacket_descriptor *desc)
1461{
1462	const struct nvsp_message *nvmsg = hv_pkt_data(desc);
1463	u32 msglen = hv_pkt_datalen(desc);
1464
1465	/* Ensure packet is big enough to read header fields */
1466	if (msglen < sizeof(struct nvsp_message_header)) {
1467		netdev_err(ndev, "inband nvsp_message length too small: %u\n", msglen);
1468		return;
1469	}
1470
1471	switch (nvmsg->hdr.msg_type) {
1472	case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1473		netvsc_send_table(ndev, nvscdev, nvmsg, msglen);
1474		break;
1475
1476	case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1477		if (hv_is_isolation_supported())
1478			netdev_err(ndev, "Ignore VF_ASSOCIATION msg from the host supporting isolation\n");
1479		else
1480			netvsc_send_vf(ndev, nvmsg, msglen);
1481		break;
1482	}
1483}
1484
1485static int netvsc_process_raw_pkt(struct hv_device *device,
1486				  struct netvsc_channel *nvchan,
1487				  struct netvsc_device *net_device,
1488				  struct net_device *ndev,
1489				  const struct vmpacket_descriptor *desc,
1490				  int budget)
1491{
1492	struct vmbus_channel *channel = nvchan->channel;
1493	const struct nvsp_message *nvmsg = hv_pkt_data(desc);
1494
1495	trace_nvsp_recv(ndev, channel, nvmsg);
1496
1497	switch (desc->type) {
1498	case VM_PKT_COMP:
1499		netvsc_send_completion(ndev, net_device, channel, desc, budget);
 
1500		break;
1501
1502	case VM_PKT_DATA_USING_XFER_PAGES:
1503		return netvsc_receive(ndev, net_device, nvchan, desc);
 
1504		break;
1505
1506	case VM_PKT_DATA_INBAND:
1507		netvsc_receive_inband(ndev, net_device, desc);
1508		break;
1509
1510	default:
1511		netdev_err(ndev, "unhandled packet type %d, tid %llx\n",
1512			   desc->type, desc->trans_id);
1513		break;
1514	}
1515
1516	return 0;
1517}
1518
1519static struct hv_device *netvsc_channel_to_device(struct vmbus_channel *channel)
1520{
1521	struct vmbus_channel *primary = channel->primary_channel;
1522
1523	return primary ? primary->device_obj : channel->device_obj;
1524}
1525
1526/* Network processing softirq
1527 * Process data in incoming ring buffer from host
1528 * Stops when ring is empty or budget is met or exceeded.
1529 */
1530int netvsc_poll(struct napi_struct *napi, int budget)
1531{
1532	struct netvsc_channel *nvchan
1533		= container_of(napi, struct netvsc_channel, napi);
1534	struct netvsc_device *net_device = nvchan->net_device;
1535	struct vmbus_channel *channel = nvchan->channel;
1536	struct hv_device *device = netvsc_channel_to_device(channel);
1537	struct net_device *ndev = hv_get_drvdata(device);
1538	int work_done = 0;
1539	int ret;
1540
1541	/* If starting a new interval */
1542	if (!nvchan->desc)
1543		nvchan->desc = hv_pkt_iter_first(channel);
1544
1545	while (nvchan->desc && work_done < budget) {
1546		work_done += netvsc_process_raw_pkt(device, nvchan, net_device,
1547						    ndev, nvchan->desc, budget);
1548		nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc);
1549	}
1550
1551	/* Send any pending receive completions */
1552	ret = send_recv_completions(ndev, net_device, nvchan);
1553
1554	/* If it did not exhaust NAPI budget this time
1555	 *  and not doing busy poll
1556	 * then re-enable host interrupts
1557	 *  and reschedule if ring is not empty
1558	 *   or sending receive completion failed.
1559	 */
1560	if (work_done < budget &&
 
1561	    napi_complete_done(napi, work_done) &&
1562	    (ret || hv_end_read(&channel->inbound)) &&
1563	    napi_schedule_prep(napi)) {
1564		hv_begin_read(&channel->inbound);
1565		__napi_schedule(napi);
1566	}
1567
1568	/* Driver may overshoot since multiple packets per descriptor */
1569	return min(work_done, budget);
1570}
1571
1572/* Call back when data is available in host ring buffer.
1573 * Processing is deferred until network softirq (NAPI)
1574 */
1575void netvsc_channel_cb(void *context)
1576{
1577	struct netvsc_channel *nvchan = context;
1578	struct vmbus_channel *channel = nvchan->channel;
1579	struct hv_ring_buffer_info *rbi = &channel->inbound;
1580
1581	/* preload first vmpacket descriptor */
1582	prefetch(hv_get_ring_buffer(rbi) + rbi->priv_read_index);
1583
1584	if (napi_schedule_prep(&nvchan->napi)) {
1585		/* disable interrupts from host */
1586		hv_begin_read(rbi);
1587
1588		__napi_schedule_irqoff(&nvchan->napi);
1589	}
1590}
1591
1592/*
1593 * netvsc_device_add - Callback when the device belonging to this
1594 * driver is added
1595 */
1596struct netvsc_device *netvsc_device_add(struct hv_device *device,
1597				const struct netvsc_device_info *device_info)
1598{
1599	int i, ret = 0;
1600	struct netvsc_device *net_device;
1601	struct net_device *ndev = hv_get_drvdata(device);
1602	struct net_device_context *net_device_ctx = netdev_priv(ndev);
1603
1604	net_device = alloc_net_device();
1605	if (!net_device)
1606		return ERR_PTR(-ENOMEM);
1607
1608	for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)
1609		net_device_ctx->tx_table[i] = 0;
1610
1611	/* Because the device uses NAPI, all the interrupt batching and
1612	 * control is done via Net softirq, not the channel handling
1613	 */
1614	set_channel_read_mode(device->channel, HV_CALL_ISR);
1615
1616	/* If we're reopening the device we may have multiple queues, fill the
1617	 * chn_table with the default channel to use it before subchannels are
1618	 * opened.
1619	 * Initialize the channel state before we open;
1620	 * we can be interrupted as soon as we open the channel.
1621	 */
1622
1623	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
1624		struct netvsc_channel *nvchan = &net_device->chan_table[i];
1625
1626		nvchan->channel = device->channel;
1627		nvchan->net_device = net_device;
1628		u64_stats_init(&nvchan->tx_stats.syncp);
1629		u64_stats_init(&nvchan->rx_stats.syncp);
1630
1631		ret = xdp_rxq_info_reg(&nvchan->xdp_rxq, ndev, i, 0);
1632
1633		if (ret) {
1634			netdev_err(ndev, "xdp_rxq_info_reg fail: %d\n", ret);
1635			goto cleanup2;
1636		}
1637
1638		ret = xdp_rxq_info_reg_mem_model(&nvchan->xdp_rxq,
1639						 MEM_TYPE_PAGE_SHARED, NULL);
1640
1641		if (ret) {
1642			netdev_err(ndev, "xdp reg_mem_model fail: %d\n", ret);
1643			goto cleanup2;
1644		}
1645	}
1646
1647	/* Enable NAPI handler before init callbacks */
1648	netif_napi_add(ndev, &net_device->chan_table[0].napi,
1649		       netvsc_poll, NAPI_POLL_WEIGHT);
1650
1651	/* Open the channel */
1652	device->channel->next_request_id_callback = vmbus_next_request_id;
1653	device->channel->request_addr_callback = vmbus_request_addr;
1654	device->channel->rqstor_size = netvsc_rqstor_size(netvsc_ring_bytes);
1655	device->channel->max_pkt_size = NETVSC_MAX_PKT_SIZE;
1656
1657	ret = vmbus_open(device->channel, netvsc_ring_bytes,
1658			 netvsc_ring_bytes,  NULL, 0,
1659			 netvsc_channel_cb, net_device->chan_table);
1660
1661	if (ret != 0) {
1662		netdev_err(ndev, "unable to open channel: %d\n", ret);
1663		goto cleanup;
1664	}
1665
1666	/* Channel is opened */
1667	netdev_dbg(ndev, "hv_netvsc channel opened successfully\n");
1668
1669	napi_enable(&net_device->chan_table[0].napi);
1670
1671	/* Connect with the NetVsp */
1672	ret = netvsc_connect_vsp(device, net_device, device_info);
1673	if (ret != 0) {
1674		netdev_err(ndev,
1675			"unable to connect to NetVSP - %d\n", ret);
1676		goto close;
1677	}
1678
1679	/* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is
1680	 * populated.
1681	 */
1682	rcu_assign_pointer(net_device_ctx->nvdev, net_device);
1683
1684	return net_device;
1685
1686close:
1687	RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
1688	napi_disable(&net_device->chan_table[0].napi);
1689
1690	/* Now, we can close the channel safely */
1691	vmbus_close(device->channel);
1692
1693cleanup:
1694	netif_napi_del(&net_device->chan_table[0].napi);
1695
1696cleanup2:
1697	free_netvsc_device(&net_device->rcu);
1698
1699	return ERR_PTR(ret);
1700}