drivers/staging/hv/netvsc.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  */
  21 #include <linux/kernel.h>
  22 #include <linux/mm.h>
  23 #include <linux/delay.h>
  24 #include <linux/io.h>
  25 #include <linux/slab.h>
  26 #include "osd.h"
  27 #include "logging.h"
  28 #include "netvsc.h"
  29 #include "rndis_filter.h"
  30 #include "channel.h"
  31
  32
  33 /* Globals */
  34 static const char *driver_name = "netvsc";
  35
  36 /* {F8615163-DF3E-46c5-913F-F2D2F965ED0E} */
  37 static const struct hv_guid netvsc_device_type = {
  38         .data = {
  39                 0x63, 0x51, 0x61, 0xF8, 0x3E, 0xDF, 0xc5, 0x46,
  40                 0x91, 0x3F, 0xF2, 0xD2, 0xF9, 0x65, 0xED, 0x0E
  41         }
  42 };
  43
  44 static int netvsc_device_add(struct hv_device *device, void *additional_info);
  45
  46 static int netvsc_device_remove(struct hv_device *device);
  47
  48 static void netvsc_cleanup(struct hv_driver *driver);
  49
  50 static void netvsc_channel_cb(void *context);
  51
  52 static int netvsc_init_send_buf(struct hv_device *device);
  53
  54 static int netvsc_init_recv_buf(struct hv_device *device);
  55
  56 static int netvsc_destroy_send_buf(struct netvsc_device *net_device);
  57
  58 static int netvsc_destroy_recv_buf(struct netvsc_device *net_device);
  59
  60 static int netvsc_connect_vsp(struct hv_device *device);
  61
  62 static void netvsc_send_completion(struct hv_device *device,
  63                                    struct vmpacket_descriptor *packet);
  64
  65 static int netvsc_send(struct hv_device *device,
  66                         struct hv_netvsc_packet *packet);
  67
  68 static void netvsc_receive(struct hv_device *device,
  69                             struct vmpacket_descriptor *packet);
  70
  71 static void netvsc_receive_completion(void *context);
  72
  73 static void netvsc_send_recv_completion(struct hv_device *device,
  74                                         u64 transaction_id);
  75
  76
  77 static struct netvsc_device *alloc_net_device(struct hv_device *device)
  78 {
  79         struct netvsc_device *net_device;
  80
  81         net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
  82         if (!net_device)
  83                 return NULL;
  84
  85         /* Set to 2 to allow both inbound and outbound traffic */
  86         atomic_cmpxchg(&net_device->refcnt, 0, 2);
  87
  88         net_device->dev = device;
  89         device->Extension = net_device;
  90
  91         return net_device;
  92 }
  93
  94 static void free_net_device(struct netvsc_device *device)
  95 {
  96         WARN_ON(atomic_read(&device->refcnt) == 0);
  97         device->dev->Extension = NULL;
  98         kfree(device);
  99 }
 100
 101
 102 /* Get the net device object iff exists and its refcount > 1 */
 103 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
 104 {
 105         struct netvsc_device *net_device;
 106
 107         net_device = device->Extension;
 108         if (net_device && atomic_read(&net_device->refcnt) > 1)
 109                 atomic_inc(&net_device->refcnt);
 110         else
 111                 net_device = NULL;
 112
 113         return net_device;
 114 }
 115
 116 /* Get the net device object iff exists and its refcount > 0 */
 117 static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
 118 {
 119         struct netvsc_device *net_device;
 120
 121         net_device = device->Extension;
 122         if (net_device && atomic_read(&net_device->refcnt))
 123                 atomic_inc(&net_device->refcnt);
 124         else
 125                 net_device = NULL;
 126
 127         return net_device;
 128 }
 129
 130 static void put_net_device(struct hv_device *device)
 131 {
 132         struct netvsc_device *net_device;
 133
 134         net_device = device->Extension;
 135         /* ASSERT(netDevice); */
 136
 137         atomic_dec(&net_device->refcnt);
 138 }
 139
 140 static struct netvsc_device *release_outbound_net_device(
 141                 struct hv_device *device)
 142 {
 143         struct netvsc_device *net_device;
 144
 145         net_device = device->Extension;
 146         if (net_device == NULL)
 147                 return NULL;
 148
 149         /* Busy wait until the ref drop to 2, then set it to 1 */
 150         while (atomic_cmpxchg(&net_device->refcnt, 2, 1) != 2)
 151                 udelay(100);
 152
 153         return net_device;
 154 }
 155
 156 static struct netvsc_device *release_inbound_net_device(
 157                 struct hv_device *device)
 158 {
 159         struct netvsc_device *net_device;
 160
 161         net_device = device->Extension;
 162         if (net_device == NULL)
 163                 return NULL;
 164
 165         /* Busy wait until the ref drop to 1, then set it to 0 */
 166         while (atomic_cmpxchg(&net_device->refcnt, 1, 0) != 1)
 167                 udelay(100);
 168
 169         device->Extension = NULL;
 170         return net_device;
 171 }
 172
 173 /*
 174  * netvsc_initialize - Main entry point
 175  */
 176 int netvsc_initialize(struct hv_driver *drv)
 177 {
 178         struct netvsc_driver *driver = (struct netvsc_driver *)drv;
 179
 180         DPRINT_DBG(NETVSC, "sizeof(struct hv_netvsc_packet)=%zd, "
 181                    "sizeof(struct nvsp_message)=%zd, "
 182                    "sizeof(struct vmtransfer_page_packet_header)=%zd",
 183                    sizeof(struct hv_netvsc_packet),
 184                    sizeof(struct nvsp_message),
 185                    sizeof(struct vmtransfer_page_packet_header));
 186
 187         /* Make sure we are at least 2 pages since 1 page is used for control */
 188         /* ASSERT(driver->RingBufferSize >= (PAGE_SIZE << 1)); */
 189
 190         drv->name = driver_name;
 191         memcpy(&drv->deviceType, &netvsc_device_type, sizeof(struct hv_guid));
 192
 193         /* Make sure it is set by the caller */
 194         /* FIXME: These probably should still be tested in some way */
 195         /* ASSERT(driver->OnReceiveCallback); */
 196         /* ASSERT(driver->OnLinkStatusChanged); */
 197
 198         /* Setup the dispatch table */
 199         driver->base.OnDeviceAdd        = netvsc_device_add;
 200         driver->base.OnDeviceRemove     = netvsc_device_remove;
 201         driver->base.OnCleanup          = netvsc_cleanup;
 202
 203         driver->send                    = netvsc_send;
 204
 205         rndis_filter_init(driver);
 206         return 0;
 207 }
 208
 209 static int netvsc_init_recv_buf(struct hv_device *device)
 210 {
 211         int ret = 0;
 212         struct netvsc_device *net_device;
 213         struct nvsp_message *init_packet;
 214
 215         net_device = get_outbound_net_device(device);
 216         if (!net_device) {
 217                 DPRINT_ERR(NETVSC, "unable to get net device..."
 218                            "device being destroyed?");
 219                 return -1;
 220         }
 221         /* ASSERT(netDevice->ReceiveBufferSize > 0); */
 222         /* page-size grandularity */
 223         /* ASSERT((netDevice->ReceiveBufferSize & (PAGE_SIZE - 1)) == 0); */
 224
 225         net_device->recv_buf =
 226                 osd_page_alloc(net_device->recv_buf_size >> PAGE_SHIFT);
 227         if (!net_device->recv_buf) {
 228                 DPRINT_ERR(NETVSC,
 229                            "unable to allocate receive buffer of size %d",
 230                            net_device->recv_buf_size);
 231                 ret = -1;
 232                 goto Cleanup;
 233         }
 234         /* page-aligned buffer */
 235         /* ASSERT(((unsigned long)netDevice->ReceiveBuffer & (PAGE_SIZE - 1)) == */
 236         /*      0); */
 237
 238         DPRINT_INFO(NETVSC, "Establishing receive buffer's GPADL...");
 239
 240         /*
 241          * Establish the gpadl handle for this buffer on this
 242          * channel.  Note: This call uses the vmbus connection rather
 243          * than the channel to establish the gpadl handle.
 244          */
 245         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 246                                     net_device->recv_buf_size,
 247                                     &net_device->recv_buf_gpadl_handle);
 248         if (ret != 0) {
 249                 DPRINT_ERR(NETVSC,
 250                            "unable to establish receive buffer's gpadl");
 251                 goto Cleanup;
 252         }
 253
 254         /* osd_waitevent_wait(ext->ChannelInitEvent); */
 255
 256         /* Notify the NetVsp of the gpadl handle */
 257         DPRINT_INFO(NETVSC, "Sending NvspMessage1TypeSendReceiveBuffer...");
 258
 259         init_packet = &net_device->channel_init_pkt;
 260
 261         memset(init_packet, 0, sizeof(struct nvsp_message));
 262
 263         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 264         init_packet->msg.v1_msg.send_recv_buf.
 265                 gpadl_handle = net_device->recv_buf_gpadl_handle;
 266         init_packet->msg.v1_msg.
 267                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 268
 269         /* Send the gpadl notification request */
 270         ret = vmbus_sendpacket(device->channel, init_packet,
 271                                sizeof(struct nvsp_message),
 272                                (unsigned long)init_packet,
 273                                VmbusPacketTypeDataInBand,
 274                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 275         if (ret != 0) {
 276                 DPRINT_ERR(NETVSC,
 277                            "unable to send receive buffer's gpadl to netvsp");
 278                 goto Cleanup;
 279         }
 280
 281         osd_waitevent_wait(net_device->channel_init_event);
 282
 283         /* Check the response */
 284         if (init_packet->msg.v1_msg.
 285             send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
 286                 DPRINT_ERR(NETVSC, "Unable to complete receive buffer "
 287                            "initialzation with NetVsp - status %d",
 288                            init_packet->msg.v1_msg.
 289                            send_recv_buf_complete.status);
 290                 ret = -1;
 291                 goto Cleanup;
 292         }
 293
 294         /* Parse the response */
 295         /* ASSERT(netDevice->ReceiveSectionCount == 0); */
 296         /* ASSERT(netDevice->ReceiveSections == NULL); */
 297
 298         net_device->recv_section_cnt = init_packet->msg.
 299                 v1_msg.send_recv_buf_complete.num_sections;
 300
 301         net_device->recv_section = kmalloc(net_device->recv_section_cnt
 302                 * sizeof(struct nvsp_1_receive_buffer_section), GFP_KERNEL);
 303         if (net_device->recv_section == NULL) {
 304                 ret = -1;
 305                 goto Cleanup;
 306         }
 307
 308         memcpy(net_device->recv_section,
 309                 init_packet->msg.v1_msg.
 310                send_recv_buf_complete.sections,
 311                 net_device->recv_section_cnt *
 312                sizeof(struct nvsp_1_receive_buffer_section));
 313
 314         DPRINT_INFO(NETVSC, "Receive sections info (count %d, offset %d, "
 315                     "endoffset %d, suballoc size %d, num suballocs %d)",
 316                     net_device->recv_section_cnt,
 317                     net_device->recv_section[0].offset,
 318                     net_device->recv_section[0].end_offset,
 319                     net_device->recv_section[0].sub_alloc_size,
 320                     net_device->recv_section[0].num_sub_allocs);
 321
 322         /*
 323          * For 1st release, there should only be 1 section that represents the
 324          * entire receive buffer
 325          */
 326         if (net_device->recv_section_cnt != 1 ||
 327             net_device->recv_section->offset != 0) {
 328                 ret = -1;
 329                 goto Cleanup;
 330         }
 331
 332         goto Exit;
 333
 334 Cleanup:
 335         netvsc_destroy_recv_buf(net_device);
 336
 337 Exit:
 338         put_net_device(device);
 339         return ret;
 340 }
 341
 342 static int netvsc_init_send_buf(struct hv_device *device)
 343 {
 344         int ret = 0;
 345         struct netvsc_device *net_device;
 346         struct nvsp_message *init_packet;
 347
 348         net_device = get_outbound_net_device(device);
 349         if (!net_device) {
 350                 DPRINT_ERR(NETVSC, "unable to get net device..."
 351                            "device being destroyed?");
 352                 return -1;
 353         }
 354         if (net_device->send_buf_size <= 0) {
 355                 ret = -EINVAL;
 356                 goto Cleanup;
 357         }
 358
 359         /* page-size grandularity */
 360         /* ASSERT((netDevice->SendBufferSize & (PAGE_SIZE - 1)) == 0); */
 361
 362         net_device->send_buf =
 363                 osd_page_alloc(net_device->send_buf_size >> PAGE_SHIFT);
 364         if (!net_device->send_buf) {
 365                 DPRINT_ERR(NETVSC, "unable to allocate send buffer of size %d",
 366                            net_device->send_buf_size);
 367                 ret = -1;
 368                 goto Cleanup;
 369         }
 370         /* page-aligned buffer */
 371         /* ASSERT(((unsigned long)netDevice->SendBuffer & (PAGE_SIZE - 1)) == 0); */
 372
 373         DPRINT_INFO(NETVSC, "Establishing send buffer's GPADL...");
 374
 375         /*
 376          * Establish the gpadl handle for this buffer on this
 377          * channel.  Note: This call uses the vmbus connection rather
 378          * than the channel to establish the gpadl handle.
 379          */
 380         ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
 381                                     net_device->send_buf_size,
 382                                     &net_device->send_buf_gpadl_handle);
 383         if (ret != 0) {
 384                 DPRINT_ERR(NETVSC, "unable to establish send buffer's gpadl");
 385                 goto Cleanup;
 386         }
 387
 388         /* osd_waitevent_wait(ext->ChannelInitEvent); */
 389
 390         /* Notify the NetVsp of the gpadl handle */
 391         DPRINT_INFO(NETVSC, "Sending NvspMessage1TypeSendSendBuffer...");
 392
 393         init_packet = &net_device->channel_init_pkt;
 394
 395         memset(init_packet, 0, sizeof(struct nvsp_message));
 396
 397         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
 398         init_packet->msg.v1_msg.send_recv_buf.
 399                 gpadl_handle = net_device->send_buf_gpadl_handle;
 400         init_packet->msg.v1_msg.send_recv_buf.id =
 401                 NETVSC_SEND_BUFFER_ID;
 402
 403         /* Send the gpadl notification request */
 404         ret = vmbus_sendpacket(device->channel, init_packet,
 405                                sizeof(struct nvsp_message),
 406                                (unsigned long)init_packet,
 407                                VmbusPacketTypeDataInBand,
 408                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 409         if (ret != 0) {
 410                 DPRINT_ERR(NETVSC,
 411                            "unable to send receive buffer's gpadl to netvsp");
 412                 goto Cleanup;
 413         }
 414
 415         osd_waitevent_wait(net_device->channel_init_event);
 416
 417         /* Check the response */
 418         if (init_packet->msg.v1_msg.
 419             send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
 420                 DPRINT_ERR(NETVSC, "Unable to complete send buffer "
 421                            "initialzation with NetVsp - status %d",
 422                            init_packet->msg.v1_msg.
 423                            send_send_buf_complete.status);
 424                 ret = -1;
 425                 goto Cleanup;
 426         }
 427
 428         net_device->send_section_size = init_packet->
 429         msg.v1_msg.send_send_buf_complete.section_size;
 430
 431         goto Exit;
 432
 433 Cleanup:
 434         netvsc_destroy_send_buf(net_device);
 435
 436 Exit:
 437         put_net_device(device);
 438         return ret;
 439 }
 440
 441 static int netvsc_destroy_recv_buf(struct netvsc_device *net_device)
 442 {
 443         struct nvsp_message *revoke_packet;
 444         int ret = 0;
 445
 446         /*
 447          * If we got a section count, it means we received a
 448          * SendReceiveBufferComplete msg (ie sent
 449          * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
 450          * to send a revoke msg here
 451          */
 452         if (net_device->recv_section_cnt) {
 453                 DPRINT_INFO(NETVSC,
 454                             "Sending NvspMessage1TypeRevokeReceiveBuffer...");
 455
 456                 /* Send the revoke receive buffer */
 457                 revoke_packet = &net_device->revoke_packet;
 458                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 459
 460                 revoke_packet->hdr.msg_type =
 461                         NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 462                 revoke_packet->msg.v1_msg.
 463                 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 464
 465                 ret = vmbus_sendpacket(net_device->dev->channel,
 466                                        revoke_packet,
 467                                        sizeof(struct nvsp_message),
 468                                        (unsigned long)revoke_packet,
 469                                        VmbusPacketTypeDataInBand, 0);
 470                 /*
 471                  * If we failed here, we might as well return and
 472                  * have a leak rather than continue and a bugchk
 473                  */
 474                 if (ret != 0) {
 475                         DPRINT_ERR(NETVSC, "unable to send revoke receive "
 476                                    "buffer to netvsp");
 477                         return -1;
 478                 }
 479         }
 480
 481         /* Teardown the gpadl on the vsp end */
 482         if (net_device->recv_buf_gpadl_handle) {
 483                 DPRINT_INFO(NETVSC, "Tearing down receive buffer's GPADL...");
 484
 485                 ret = vmbus_teardown_gpadl(net_device->dev->channel,
 486                            net_device->recv_buf_gpadl_handle);
 487
 488                 /* If we failed here, we might as well return and have a leak rather than continue and a bugchk */
 489                 if (ret != 0) {
 490                         DPRINT_ERR(NETVSC,
 491                                    "unable to teardown receive buffer's gpadl");
 492                         return -1;
 493                 }
 494                 net_device->recv_buf_gpadl_handle = 0;
 495         }
 496
 497         if (net_device->recv_buf) {
 498                 DPRINT_INFO(NETVSC, "Freeing up receive buffer...");
 499
 500                 /* Free up the receive buffer */
 501                 osd_page_free(net_device->recv_buf,
 502                              net_device->recv_buf_size >> PAGE_SHIFT);
 503                 net_device->recv_buf = NULL;
 504         }
 505
 506         if (net_device->recv_section) {
 507                 net_device->recv_section_cnt = 0;
 508                 kfree(net_device->recv_section);
 509                 net_device->recv_section = NULL;
 510         }
 511
 512         return ret;
 513 }
 514
 515 static int netvsc_destroy_send_buf(struct netvsc_device *net_device)
 516 {
 517         struct nvsp_message *revoke_packet;
 518         int ret = 0;
 519
 520         /*
 521          * If we got a section count, it means we received a
 522          *  SendReceiveBufferComplete msg (ie sent
 523          *  NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
 524          *  to send a revoke msg here
 525          */
 526         if (net_device->send_section_size) {
 527                 DPRINT_INFO(NETVSC,
 528                             "Sending NvspMessage1TypeRevokeSendBuffer...");
 529
 530                 /* Send the revoke send buffer */
 531                 revoke_packet = &net_device->revoke_packet;
 532                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 533
 534                 revoke_packet->hdr.msg_type =
 535                         NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
 536                 revoke_packet->msg.v1_msg.
 537                         revoke_send_buf.id = NETVSC_SEND_BUFFER_ID;
 538
 539                 ret = vmbus_sendpacket(net_device->dev->channel,
 540                                        revoke_packet,
 541                                        sizeof(struct nvsp_message),
 542                                        (unsigned long)revoke_packet,
 543                                        VmbusPacketTypeDataInBand, 0);
 544                 /*
 545                  * If we failed here, we might as well return and have a leak
 546                  * rather than continue and a bugchk
 547                  */
 548                 if (ret != 0) {
 549                         DPRINT_ERR(NETVSC, "unable to send revoke send buffer "
 550                                    "to netvsp");
 551                         return -1;
 552                 }
 553         }
 554
 555         /* Teardown the gpadl on the vsp end */
 556         if (net_device->send_buf_gpadl_handle) {
 557                 DPRINT_INFO(NETVSC, "Tearing down send buffer's GPADL...");
 558                 ret = vmbus_teardown_gpadl(net_device->dev->channel,
 559                                            net_device->send_buf_gpadl_handle);
 560
 561                 /*
 562                  * If we failed here, we might as well return and have a leak
 563                  * rather than continue and a bugchk
 564                  */
 565                 if (ret != 0) {
 566                         DPRINT_ERR(NETVSC, "unable to teardown send buffer's "
 567                                    "gpadl");
 568                         return -1;
 569                 }
 570                 net_device->send_buf_gpadl_handle = 0;
 571         }
 572
 573         if (net_device->send_buf) {
 574                 DPRINT_INFO(NETVSC, "Freeing up send buffer...");
 575
 576                 /* Free up the receive buffer */
 577                 osd_page_free(net_device->send_buf,
 578                              net_device->send_buf_size >> PAGE_SHIFT);
 579                 net_device->send_buf = NULL;
 580         }
 581
 582         return ret;
 583 }
 584
 585
 586 static int netvsc_connect_vsp(struct hv_device *device)
 587 {
 588         int ret;
 589         struct netvsc_device *net_device;
 590         struct nvsp_message *init_packet;
 591         int ndis_version;
 592
 593         net_device = get_outbound_net_device(device);
 594         if (!net_device) {
 595                 DPRINT_ERR(NETVSC, "unable to get net device..."
 596                            "device being destroyed?");
 597                 return -1;
 598         }
 599
 600         init_packet = &net_device->channel_init_pkt;
 601
 602         memset(init_packet, 0, sizeof(struct nvsp_message));
 603         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 604         init_packet->msg.init_msg.init.min_protocol_ver =
 605                 NVSP_MIN_PROTOCOL_VERSION;
 606         init_packet->msg.init_msg.init.max_protocol_ver =
 607                 NVSP_MAX_PROTOCOL_VERSION;
 608
 609         DPRINT_INFO(NETVSC, "Sending NvspMessageTypeInit...");
 610
 611         /* Send the init request */
 612         ret = vmbus_sendpacket(device->channel, init_packet,
 613                                sizeof(struct nvsp_message),
 614                                (unsigned long)init_packet,
 615                                VmbusPacketTypeDataInBand,
 616                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 617
 618         if (ret != 0) {
 619                 DPRINT_ERR(NETVSC, "unable to send NvspMessageTypeInit");
 620                 goto Cleanup;
 621         }
 622
 623         osd_waitevent_wait(net_device->channel_init_event);
 624
 625         /* Now, check the response */
 626         /* ASSERT(initPacket->Messages.InitMessages.InitComplete.MaximumMdlChainLength <= MAX_MULTIPAGE_BUFFER_COUNT); */
 627         DPRINT_INFO(NETVSC, "NvspMessageTypeInit status(%d) max mdl chain (%d)",
 628                 init_packet->msg.init_msg.init_complete.status,
 629                 init_packet->msg.init_msg.
 630                     init_complete.max_mdl_chain_len);
 631
 632         if (init_packet->msg.init_msg.init_complete.status !=
 633             NVSP_STAT_SUCCESS) {
 634                 DPRINT_ERR(NETVSC,
 635                         "unable to initialize with netvsp (status 0x%x)",
 636                         init_packet->msg.init_msg.init_complete.status);
 637                 ret = -1;
 638                 goto Cleanup;
 639         }
 640
 641         if (init_packet->msg.init_msg.init_complete.
 642             negotiated_protocol_ver != NVSP_PROTOCOL_VERSION_1) {
 643                 DPRINT_ERR(NETVSC, "unable to initialize with netvsp "
 644                            "(version expected 1 got %d)",
 645                            init_packet->msg.init_msg.
 646                            init_complete.negotiated_protocol_ver);
 647                 ret = -1;
 648                 goto Cleanup;
 649         }
 650         DPRINT_INFO(NETVSC, "Sending NvspMessage1TypeSendNdisVersion...");
 651
 652         /* Send the ndis version */
 653         memset(init_packet, 0, sizeof(struct nvsp_message));
 654
 655         ndis_version = 0x00050000;
 656
 657         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 658         init_packet->msg.v1_msg.
 659                 send_ndis_ver.ndis_major_ver =
 660                                 (ndis_version & 0xFFFF0000) >> 16;
 661         init_packet->msg.v1_msg.
 662                 send_ndis_ver.ndis_minor_ver =
 663                                 ndis_version & 0xFFFF;
 664
 665         /* Send the init request */
 666         ret = vmbus_sendpacket(device->channel, init_packet,
 667                                sizeof(struct nvsp_message),
 668                                (unsigned long)init_packet,
 669                                VmbusPacketTypeDataInBand, 0);
 670         if (ret != 0) {
 671                 DPRINT_ERR(NETVSC,
 672                            "unable to send NvspMessage1TypeSendNdisVersion");
 673                 ret = -1;
 674                 goto Cleanup;
 675         }
 676         /*
 677          * BUGBUG - We have to wait for the above msg since the
 678          * netvsp uses KMCL which acknowledges packet (completion
 679          * packet) since our Vmbus always set the
 680          * VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED flag
 681          */
 682          /* osd_waitevent_wait(NetVscChannel->ChannelInitEvent); */
 683
 684         /* Post the big receive buffer to NetVSP */
 685         ret = netvsc_init_recv_buf(device);
 686         if (ret == 0)
 687                 ret = netvsc_init_send_buf(device);
 688
 689 Cleanup:
 690         put_net_device(device);
 691         return ret;
 692 }
 693
 694 static void NetVscDisconnectFromVsp(struct netvsc_device *net_device)
 695 {
 696         netvsc_destroy_recv_buf(net_device);
 697         netvsc_destroy_send_buf(net_device);
 698 }
 699
 700 /*
 701  * netvsc_device_add - Callback when the device belonging to this
 702  * driver is added
 703  */
 704 static int netvsc_device_add(struct hv_device *device, void *additional_info)
 705 {
 706         int ret = 0;
 707         int i;
 708         struct netvsc_device *net_device;
 709         struct hv_netvsc_packet *packet, *pos;
 710         struct netvsc_driver *net_driver =
 711                                 (struct netvsc_driver *)device->Driver;
 712
 713         net_device = alloc_net_device(device);
 714         if (!net_device) {
 715                 ret = -1;
 716                 goto Cleanup;
 717         }
 718
 719         DPRINT_DBG(NETVSC, "netvsc channel object allocated - %p", net_device);
 720
 721         /* Initialize the NetVSC channel extension */
 722         net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 723         spin_lock_init(&net_device->recv_pkt_list_lock);
 724
 725         net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
 726
 727         INIT_LIST_HEAD(&net_device->recv_pkt_list);
 728
 729         for (i = 0; i < NETVSC_RECEIVE_PACKETLIST_COUNT; i++) {
 730                 packet = kzalloc(sizeof(struct hv_netvsc_packet) +
 731                                  (NETVSC_RECEIVE_SG_COUNT *
 732                                   sizeof(struct hv_page_buffer)), GFP_KERNEL);
 733                 if (!packet) {
 734                         DPRINT_DBG(NETVSC, "unable to allocate netvsc pkts "
 735                                    "for receive pool (wanted %d got %d)",
 736                                    NETVSC_RECEIVE_PACKETLIST_COUNT, i);
 737                         break;
 738                 }
 739                 list_add_tail(&packet->list_ent,
 740                               &net_device->recv_pkt_list);
 741         }
 742         net_device->channel_init_event = osd_waitevent_create();
 743         if (!net_device->channel_init_event) {
 744                 ret = -ENOMEM;
 745                 goto Cleanup;
 746         }
 747
 748         /* Open the channel */
 749         ret = vmbus_open(device->channel, net_driver->ring_buf_size,
 750                          net_driver->ring_buf_size, NULL, 0,
 751                          netvsc_channel_cb, device);
 752
 753         if (ret != 0) {
 754                 DPRINT_ERR(NETVSC, "unable to open channel: %d", ret);
 755                 ret = -1;
 756                 goto Cleanup;
 757         }
 758
 759         /* Channel is opened */
 760         DPRINT_INFO(NETVSC, "*** NetVSC channel opened successfully! ***");
 761
 762         /* Connect with the NetVsp */
 763         ret = netvsc_connect_vsp(device);
 764         if (ret != 0) {
 765                 DPRINT_ERR(NETVSC, "unable to connect to NetVSP - %d", ret);
 766                 ret = -1;
 767                 goto close;
 768         }
 769
 770         DPRINT_INFO(NETVSC, "*** NetVSC channel handshake result - %d ***",
 771                     ret);
 772
 773         return ret;
 774
 775 close:
 776         /* Now, we can close the channel safely */
 777         vmbus_close(device->channel);
 778
 779 Cleanup:
 780
 781         if (net_device) {
 782                 kfree(net_device->channel_init_event);
 783
 784                 list_for_each_entry_safe(packet, pos,
 785                                          &net_device->recv_pkt_list,
 786                                          list_ent) {
 787                         list_del(&packet->list_ent);
 788                         kfree(packet);
 789                 }
 790
 791                 release_outbound_net_device(device);
 792                 release_inbound_net_device(device);
 793
 794                 free_net_device(net_device);
 795         }
 796
 797         return ret;
 798 }
 799
 800 /*
 801  * netvsc_device_remove - Callback when the root bus device is removed
 802  */
 803 static int netvsc_device_remove(struct hv_device *device)
 804 {
 805         struct netvsc_device *net_device;
 806         struct hv_netvsc_packet *netvsc_packet, *pos;
 807
 808         DPRINT_INFO(NETVSC, "Disabling outbound traffic on net device (%p)...",
 809                     device->Extension);
 810
 811         /* Stop outbound traffic ie sends and receives completions */
 812         net_device = release_outbound_net_device(device);
 813         if (!net_device) {
 814                 DPRINT_ERR(NETVSC, "No net device present!!");
 815                 return -1;
 816         }
 817
 818         /* Wait for all send completions */
 819         while (atomic_read(&net_device->num_outstanding_sends)) {
 820                 DPRINT_INFO(NETVSC, "waiting for %d requests to complete...",
 821                             atomic_read(&net_device->num_outstanding_sends));
 822                 udelay(100);
 823         }
 824
 825         DPRINT_INFO(NETVSC, "Disconnecting from netvsp...");
 826
 827         NetVscDisconnectFromVsp(net_device);
 828
 829         DPRINT_INFO(NETVSC, "Disabling inbound traffic on net device (%p)...",
 830                     device->Extension);
 831
 832         /* Stop inbound traffic ie receives and sends completions */
 833         net_device = release_inbound_net_device(device);
 834
 835         /* At this point, no one should be accessing netDevice except in here */
 836         DPRINT_INFO(NETVSC, "net device (%p) safe to remove", net_device);
 837
 838         /* Now, we can close the channel safely */
 839         vmbus_close(device->channel);
 840
 841         /* Release all resources */
 842         list_for_each_entry_safe(netvsc_packet, pos,
 843                                  &net_device->recv_pkt_list, list_ent) {
 844                 list_del(&netvsc_packet->list_ent);
 845                 kfree(netvsc_packet);
 846         }
 847
 848         kfree(net_device->channel_init_event);
 849         free_net_device(net_device);
 850         return 0;
 851 }
 852
 853 /*
 854  * netvsc_cleanup - Perform any cleanup when the driver is removed
 855  */
 856 static void netvsc_cleanup(struct hv_driver *drv)
 857 {
 858 }
 859
 860 static void netvsc_send_completion(struct hv_device *device,
 861                                    struct vmpacket_descriptor *packet)
 862 {
 863         struct netvsc_device *net_device;
 864         struct nvsp_message *nvsp_packet;
 865         struct hv_netvsc_packet *nvsc_packet;
 866
 867         net_device = get_inbound_net_device(device);
 868         if (!net_device) {
 869                 DPRINT_ERR(NETVSC, "unable to get net device..."
 870                            "device being destroyed?");
 871                 return;
 872         }
 873
 874         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 875                         (packet->DataOffset8 << 3));
 876
 877         DPRINT_DBG(NETVSC, "send completion packet - type %d",
 878                    nvsp_packet->hdr.msg_type);
 879
 880         if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
 881             (nvsp_packet->hdr.msg_type ==
 882              NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
 883             (nvsp_packet->hdr.msg_type ==
 884              NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE)) {
 885                 /* Copy the response back */
 886                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 887                        sizeof(struct nvsp_message));
 888                 osd_waitevent_set(net_device->channel_init_event);
 889         } else if (nvsp_packet->hdr.msg_type ==
 890                    NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
 891                 /* Get the send context */
 892                 nvsc_packet = (struct hv_netvsc_packet *)(unsigned long)
 893                         packet->TransactionId;
 894                 /* ASSERT(nvscPacket); */
 895
 896                 /* Notify the layer above us */
 897                 nvsc_packet->completion.send.send_completion(
 898                         nvsc_packet->completion.send.send_completion_ctx);
 899
 900                 atomic_dec(&net_device->num_outstanding_sends);
 901         } else {
 902                 DPRINT_ERR(NETVSC, "Unknown send completion packet type - "
 903                            "%d received!!", nvsp_packet->hdr.msg_type);
 904         }
 905
 906         put_net_device(device);
 907 }
 908
 909 static int netvsc_send(struct hv_device *device,
 910                         struct hv_netvsc_packet *packet)
 911 {
 912         struct netvsc_device *net_device;
 913         int ret = 0;
 914
 915         struct nvsp_message sendMessage;
 916
 917         net_device = get_outbound_net_device(device);
 918         if (!net_device) {
 919                 DPRINT_ERR(NETVSC, "net device (%p) shutting down..."
 920                            "ignoring outbound packets", net_device);
 921                 return -2;
 922         }
 923
 924         sendMessage.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 925         if (packet->is_data_pkt) {
 926                 /* 0 is RMC_DATA; */
 927                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 0;
 928         } else {
 929                 /* 1 is RMC_CONTROL; */
 930                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 1;
 931         }
 932
 933         /* Not using send buffer section */
 934         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
 935                 0xFFFFFFFF;
 936         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
 937
 938         if (packet->page_buf_cnt) {
 939                 ret = vmbus_sendpacket_pagebuffer(device->channel,
 940                                                   packet->page_buf,
 941                                                   packet->page_buf_cnt,
 942                                                   &sendMessage,
 943                                                   sizeof(struct nvsp_message),
 944                                                   (unsigned long)packet);
 945         } else {
 946                 ret = vmbus_sendpacket(device->channel, &sendMessage,
 947                                        sizeof(struct nvsp_message),
 948                                        (unsigned long)packet,
 949                                        VmbusPacketTypeDataInBand,
 950                                        VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 951
 952         }
 953
 954         if (ret != 0)
 955                 DPRINT_ERR(NETVSC, "Unable to send packet %p ret %d",
 956                            packet, ret);
 957
 958         atomic_inc(&net_device->num_outstanding_sends);
 959         put_net_device(device);
 960         return ret;
 961 }
 962
 963 static void netvsc_receive(struct hv_device *device,
 964                             struct vmpacket_descriptor *packet)
 965 {
 966         struct netvsc_device *net_device;
 967         struct vmtransfer_page_packet_header *vmxferpage_packet;
 968         struct nvsp_message *nvsp_packet;
 969         struct hv_netvsc_packet *netvsc_packet = NULL;
 970         unsigned long start;
 971         unsigned long end, end_virtual;
 972         /* struct netvsc_driver *netvscDriver; */
 973         struct xferpage_packet *xferpage_packet = NULL;
 974         int i, j;
 975         int count = 0, bytes_remain = 0;
 976         unsigned long flags;
 977         LIST_HEAD(listHead);
 978
 979         net_device = get_inbound_net_device(device);
 980         if (!net_device) {
 981                 DPRINT_ERR(NETVSC, "unable to get net device..."
 982                            "device being destroyed?");
 983                 return;
 984         }
 985
 986         /*
 987          * All inbound packets other than send completion should be xfer page
 988          * packet
 989          */
 990         if (packet->Type != VmbusPacketTypeDataUsingTransferPages) {
 991                 DPRINT_ERR(NETVSC, "Unknown packet type received - %d",
 992                            packet->Type);
 993                 put_net_device(device);
 994                 return;
 995         }
 996
 997         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 998                         (packet->DataOffset8 << 3));
 999
1000         /* Make sure this is a valid nvsp packet */
1001         if (nvsp_packet->hdr.msg_type !=
1002             NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
1003                 DPRINT_ERR(NETVSC, "Unknown nvsp packet type received - %d",
1004                            nvsp_packet->hdr.msg_type);
1005                 put_net_device(device);
1006                 return;
1007         }
1008
1009         DPRINT_DBG(NETVSC, "NVSP packet received - type %d",
1010                    nvsp_packet->hdr.msg_type);
1011
1012         vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
1013
1014         if (vmxferpage_packet->TransferPageSetId != NETVSC_RECEIVE_BUFFER_ID) {
1015                 DPRINT_ERR(NETVSC, "Invalid xfer page set id - "
1016                            "expecting %x got %x", NETVSC_RECEIVE_BUFFER_ID,
1017                            vmxferpage_packet->TransferPageSetId);
1018                 put_net_device(device);
1019                 return;
1020         }
1021
1022         DPRINT_DBG(NETVSC, "xfer page - range count %d",
1023                    vmxferpage_packet->RangeCount);
1024
1025         /*
1026          * Grab free packets (range count + 1) to represent this xfer
1027          * page packet. +1 to represent the xfer page packet itself.
1028          * We grab it here so that we know exactly how many we can
1029          * fulfil
1030          */
1031         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
1032         while (!list_empty(&net_device->recv_pkt_list)) {
1033                 list_move_tail(net_device->recv_pkt_list.next, &listHead);
1034                 if (++count == vmxferpage_packet->RangeCount + 1)
1035                         break;
1036         }
1037         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
1038
1039         /*
1040          * We need at least 2 netvsc pkts (1 to represent the xfer
1041          * page and at least 1 for the range) i.e. we can handled
1042          * some of the xfer page packet ranges...
1043          */
1044         if (count < 2) {
1045                 DPRINT_ERR(NETVSC, "Got only %d netvsc pkt...needed %d pkts. "
1046                            "Dropping this xfer page packet completely!",
1047                            count, vmxferpage_packet->RangeCount + 1);
1048
1049                 /* Return it to the freelist */
1050                 spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
1051                 for (i = count; i != 0; i--) {
1052                         list_move_tail(listHead.next,
1053                                        &net_device->recv_pkt_list);
1054                 }
1055                 spin_unlock_irqrestore(&net_device->recv_pkt_list_lock,
1056                                        flags);
1057
1058                 netvsc_send_recv_completion(device,
1059                                             vmxferpage_packet->d.TransactionId);
1060
1061                 put_net_device(device);
1062                 return;
1063         }
1064
1065         /* Remove the 1st packet to represent the xfer page packet itself */
1066         xferpage_packet = (struct xferpage_packet *)listHead.next;
1067         list_del(&xferpage_packet->list_ent);
1068
1069         /* This is how much we can satisfy */
1070         xferpage_packet->count = count - 1;
1071         /* ASSERT(xferpagePacket->Count > 0 && xferpagePacket->Count <= */
1072         /*      vmxferpagePacket->RangeCount); */
1073
1074         if (xferpage_packet->count != vmxferpage_packet->RangeCount) {
1075                 DPRINT_INFO(NETVSC, "Needed %d netvsc pkts to satisy this xfer "
1076                             "page...got %d", vmxferpage_packet->RangeCount,
1077                             xferpage_packet->count);
1078         }
1079
1080         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1081         for (i = 0; i < (count - 1); i++) {
1082                 netvsc_packet = (struct hv_netvsc_packet *)listHead.next;
1083                 list_del(&netvsc_packet->list_ent);
1084
1085                 /* Initialize the netvsc packet */
1086                 netvsc_packet->xfer_page_pkt = xferpage_packet;
1087                 netvsc_packet->completion.recv.recv_completion =
1088                                         netvsc_receive_completion;
1089                 netvsc_packet->completion.recv.recv_completion_ctx =
1090                                         netvsc_packet;
1091                 netvsc_packet->device = device;
1092                 /* Save this so that we can send it back */
1093                 netvsc_packet->completion.recv.recv_completion_tid =
1094                                         vmxferpage_packet->d.TransactionId;
1095
1096                 netvsc_packet->total_data_buflen =
1097                                         vmxferpage_packet->Ranges[i].ByteCount;
1098                 netvsc_packet->page_buf_cnt = 1;
1099
1100                 /* ASSERT(vmxferpagePacket->Ranges[i].ByteOffset + */
1101                 /*      vmxferpagePacket->Ranges[i].ByteCount < */
1102                 /*      netDevice->ReceiveBufferSize); */
1103
1104                 netvsc_packet->page_buf[0].Length =
1105                                         vmxferpage_packet->Ranges[i].ByteCount;
1106
1107                 start = virt_to_phys((void *)((unsigned long)net_device->
1108                 recv_buf + vmxferpage_packet->Ranges[i].ByteOffset));
1109
1110                 netvsc_packet->page_buf[0].Pfn = start >> PAGE_SHIFT;
1111                 end_virtual = (unsigned long)net_device->recv_buf
1112                     + vmxferpage_packet->Ranges[i].ByteOffset
1113                     + vmxferpage_packet->Ranges[i].ByteCount - 1;
1114                 end = virt_to_phys((void *)end_virtual);
1115
1116                 /* Calculate the page relative offset */
1117                 netvsc_packet->page_buf[0].Offset =
1118                         vmxferpage_packet->Ranges[i].ByteOffset &
1119                         (PAGE_SIZE - 1);
1120                 if ((end >> PAGE_SHIFT) != (start >> PAGE_SHIFT)) {
1121                         /* Handle frame across multiple pages: */
1122                         netvsc_packet->page_buf[0].Length =
1123                                 (netvsc_packet->page_buf[0].Pfn <<
1124                                  PAGE_SHIFT)
1125                                 + PAGE_SIZE - start;
1126                         bytes_remain = netvsc_packet->total_data_buflen -
1127                                         netvsc_packet->page_buf[0].Length;
1128                         for (j = 1; j < NETVSC_PACKET_MAXPAGE; j++) {
1129                                 netvsc_packet->page_buf[j].Offset = 0;
1130                                 if (bytes_remain <= PAGE_SIZE) {
1131                                         netvsc_packet->page_buf[j].Length =
1132                                                 bytes_remain;
1133                                         bytes_remain = 0;
1134                                 } else {
1135                                         netvsc_packet->page_buf[j].Length =
1136                                                 PAGE_SIZE;
1137                                         bytes_remain -= PAGE_SIZE;
1138                                 }
1139                                 netvsc_packet->page_buf[j].Pfn =
1140                                     virt_to_phys((void *)(end_virtual -
1141                                                 bytes_remain)) >> PAGE_SHIFT;
1142                                 netvsc_packet->page_buf_cnt++;
1143                                 if (bytes_remain == 0)
1144                                         break;
1145                         }
1146                         /* ASSERT(bytesRemain == 0); */
1147                 }
1148                 DPRINT_DBG(NETVSC, "[%d] - (abs offset %u len %u) => "
1149                            "(pfn %llx, offset %u, len %u)", i,
1150                            vmxferpage_packet->Ranges[i].ByteOffset,
1151                            vmxferpage_packet->Ranges[i].ByteCount,
1152                            netvsc_packet->page_buf[0].Pfn,
1153                            netvsc_packet->page_buf[0].Offset,
1154                            netvsc_packet->page_buf[0].Length);
1155
1156                 /* Pass it to the upper layer */
1157                 ((struct netvsc_driver *)device->Driver)->
1158                         recv_cb(device, netvsc_packet);
1159
1160                 netvsc_receive_completion(netvsc_packet->
1161                                 completion.recv.recv_completion_ctx);
1162         }
1163
1164         /* ASSERT(list_empty(&listHead)); */
1165
1166         put_net_device(device);
1167 }
1168
1169 static void netvsc_send_recv_completion(struct hv_device *device,
1170                                         u64 transaction_id)
1171 {
1172         struct nvsp_message recvcompMessage;
1173         int retries = 0;
1174         int ret;
1175
1176         DPRINT_DBG(NETVSC, "Sending receive completion pkt - %llx",
1177                    transaction_id);
1178
1179         recvcompMessage.hdr.msg_type =
1180                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
1181
1182         /* FIXME: Pass in the status */
1183         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status =
1184                 NVSP_STAT_SUCCESS;
1185
1186 retry_send_cmplt:
1187         /* Send the completion */
1188         ret = vmbus_sendpacket(device->channel, &recvcompMessage,
1189                                sizeof(struct nvsp_message), transaction_id,
1190                                VmbusPacketTypeCompletion, 0);
1191         if (ret == 0) {
1192                 /* success */
1193                 /* no-op */
1194         } else if (ret == -1) {
1195                 /* no more room...wait a bit and attempt to retry 3 times */
1196                 retries++;
1197                 DPRINT_ERR(NETVSC, "unable to send receive completion pkt "
1198                            "(tid %llx)...retrying %d", transaction_id, retries);
1199
1200                 if (retries < 4) {
1201                         udelay(100);
1202                         goto retry_send_cmplt;
1203                 } else {
1204                         DPRINT_ERR(NETVSC, "unable to send receive completion "
1205                                   "pkt (tid %llx)...give up retrying",
1206                                   transaction_id);
1207                 }
1208         } else {
1209                 DPRINT_ERR(NETVSC, "unable to send receive completion pkt - "
1210                            "%llx", transaction_id);
1211         }
1212 }
1213
1214 /* Send a receive completion packet to RNDIS device (ie NetVsp) */
1215 static void netvsc_receive_completion(void *context)
1216 {
1217         struct hv_netvsc_packet *packet = context;
1218         struct hv_device *device = (struct hv_device *)packet->device;
1219         struct netvsc_device *net_device;
1220         u64 transaction_id = 0;
1221         bool fsend_receive_comp = false;
1222         unsigned long flags;
1223
1224         /* ASSERT(packet->XferPagePacket); */
1225
1226         /*
1227          * Even though it seems logical to do a GetOutboundNetDevice() here to
1228          * send out receive completion, we are using GetInboundNetDevice()
1229          * since we may have disable outbound traffic already.
1230          */
1231         net_device = get_inbound_net_device(device);
1232         if (!net_device) {
1233                 DPRINT_ERR(NETVSC, "unable to get net device..."
1234                            "device being destroyed?");
1235                 return;
1236         }
1237
1238         /* Overloading use of the lock. */
1239         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
1240
1241         /* ASSERT(packet->XferPagePacket->Count > 0); */
1242         packet->xfer_page_pkt->count--;
1243
1244         /*
1245          * Last one in the line that represent 1 xfer page packet.
1246          * Return the xfer page packet itself to the freelist
1247          */
1248         if (packet->xfer_page_pkt->count == 0) {
1249                 fsend_receive_comp = true;
1250                 transaction_id = packet->completion.recv.recv_completion_tid;
1251                 list_add_tail(&packet->xfer_page_pkt->list_ent,
1252                               &net_device->recv_pkt_list);
1253
1254         }
1255
1256         /* Put the packet back */
1257         list_add_tail(&packet->list_ent, &net_device->recv_pkt_list);
1258         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
1259
1260         /* Send a receive completion for the xfer page packet */
1261         if (fsend_receive_comp)
1262                 netvsc_send_recv_completion(device, transaction_id);
1263
1264         put_net_device(device);
1265 }
1266
1267 static void netvsc_channel_cb(void *context)
1268 {
1269         int ret;
1270         struct hv_device *device = context;
1271         struct netvsc_device *net_device;
1272         u32 bytes_recvd;
1273         u64 request_id;
1274         unsigned char *packet;
1275         struct vmpacket_descriptor *desc;
1276         unsigned char *buffer;
1277         int bufferlen = NETVSC_PACKET_SIZE;
1278
1279         /* ASSERT(device); */
1280
1281         packet = kzalloc(NETVSC_PACKET_SIZE * sizeof(unsigned char),
1282                          GFP_KERNEL);
1283         if (!packet)
1284                 return;
1285         buffer = packet;
1286
1287         net_device = get_inbound_net_device(device);
1288         if (!net_device) {
1289                 DPRINT_ERR(NETVSC, "net device (%p) shutting down..."
1290                            "ignoring inbound packets", net_device);
1291                 goto out;
1292         }
1293
1294         do {
1295                 ret = vmbus_recvpacket_raw(device->channel, buffer, bufferlen,
1296                                            &bytes_recvd, &request_id);
1297                 if (ret == 0) {
1298                         if (bytes_recvd > 0) {
1299                                 DPRINT_DBG(NETVSC, "receive %d bytes, tid %llx",
1300                                            bytes_recvd, request_id);
1301
1302                                 desc = (struct vmpacket_descriptor *)buffer;
1303                                 switch (desc->Type) {
1304                                 case VmbusPacketTypeCompletion:
1305                                         netvsc_send_completion(device, desc);
1306                                         break;
1307
1308                                 case VmbusPacketTypeDataUsingTransferPages:
1309                                         netvsc_receive(device, desc);
1310                                         break;
1311
1312                                 default:
1313                                         DPRINT_ERR(NETVSC,
1314                                                    "unhandled packet type %d, "
1315                                                    "tid %llx len %d\n",
1316                                                    desc->Type, request_id,
1317                                                    bytes_recvd);
1318                                         break;
1319                                 }
1320
1321                                 /* reset */
1322                                 if (bufferlen > NETVSC_PACKET_SIZE) {
1323                                         kfree(buffer);
1324                                         buffer = packet;
1325                                         bufferlen = NETVSC_PACKET_SIZE;
1326                                 }
1327                         } else {
1328                                 /* reset */
1329                                 if (bufferlen > NETVSC_PACKET_SIZE) {
1330                                         kfree(buffer);
1331                                         buffer = packet;
1332                                         bufferlen = NETVSC_PACKET_SIZE;
1333                                 }
1334
1335                                 break;
1336                         }
1337                 } else if (ret == -2) {
1338                         /* Handle large packet */
1339                         buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
1340                         if (buffer == NULL) {
1341                                 /* Try again next time around */
1342                                 DPRINT_ERR(NETVSC,
1343                                            "unable to allocate buffer of size "
1344                                            "(%d)!!", bytes_recvd);
1345                                 break;
1346                         }
1347
1348                         bufferlen = bytes_recvd;
1349                 }
1350         } while (1);
1351
1352         put_net_device(device);
1353 out:
1354         kfree(buffer);
1355         return;
1356 }