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/sched.h>
  23 #include <linux/wait.h>
  24 #include <linux/mm.h>
  25 #include <linux/delay.h>
  26 #include <linux/io.h>
  27 #include <linux/slab.h>
  28 #include "hv_api.h"
  29 #include "logging.h"
  30 #include "netvsc.h"
  31 #include "rndis_filter.h"
  32 #include "channel.h"
  33
  34
  35 /* Globals */
  36 static const char *driver_name = "netvsc";
  37
  38 /* {F8615163-DF3E-46c5-913F-F2D2F965ED0E} */
  39 static const struct hv_guid netvsc_device_type = {
  40         .data = {
  41                 0x63, 0x51, 0x61, 0xF8, 0x3E, 0xDF, 0xc5, 0x46,
  42                 0x91, 0x3F, 0xF2, 0xD2, 0xF9, 0x65, 0xED, 0x0E
  43         }
  44 };
  45
  46 static int netvsc_device_add(struct hv_device *device, void *additional_info);
  47
  48 static int netvsc_device_remove(struct hv_device *device);
  49
  50 static void netvsc_cleanup(struct hv_driver *driver);
  51
  52 static void netvsc_channel_cb(void *context);
  53
  54 static int netvsc_init_send_buf(struct hv_device *device);
  55
  56 static int netvsc_init_recv_buf(struct hv_device *device);
  57
  58 static int netvsc_destroy_send_buf(struct netvsc_device *net_device);
  59
  60 static int netvsc_destroy_recv_buf(struct netvsc_device *net_device);
  61
  62 static int netvsc_connect_vsp(struct hv_device *device);
  63
  64 static void netvsc_send_completion(struct hv_device *device,
  65                                    struct vmpacket_descriptor *packet);
  66
  67 static int netvsc_send(struct hv_device *device,
  68                         struct hv_netvsc_packet *packet);
  69
  70 static void netvsc_receive(struct hv_device *device,
  71                             struct vmpacket_descriptor *packet);
  72
  73 static void netvsc_receive_completion(void *context);
  74
  75 static void netvsc_send_recv_completion(struct hv_device *device,
  76                                         u64 transaction_id);
  77
  78
  79 static struct netvsc_device *alloc_net_device(struct hv_device *device)
  80 {
  81         struct netvsc_device *net_device;
  82
  83         net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
  84         if (!net_device)
  85                 return NULL;
  86
  87         /* Set to 2 to allow both inbound and outbound traffic */
  88         atomic_cmpxchg(&net_device->refcnt, 0, 2);
  89
  90         net_device->dev = device;
  91         device->ext = net_device;
  92
  93         return net_device;
  94 }
  95
  96 static void free_net_device(struct netvsc_device *device)
  97 {
  98         WARN_ON(atomic_read(&device->refcnt) == 0);
  99         device->dev->ext = NULL;
 100         kfree(device);
 101 }
 102
 103
 104 /* Get the net device object iff exists and its refcount > 1 */
 105 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
 106 {
 107         struct netvsc_device *net_device;
 108
 109         net_device = device->ext;
 110         if (net_device && atomic_read(&net_device->refcnt) > 1)
 111                 atomic_inc(&net_device->refcnt);
 112         else
 113                 net_device = NULL;
 114
 115         return net_device;
 116 }
 117
 118 /* Get the net device object iff exists and its refcount > 0 */
 119 static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
 120 {
 121         struct netvsc_device *net_device;
 122
 123         net_device = device->ext;
 124         if (net_device && atomic_read(&net_device->refcnt))
 125                 atomic_inc(&net_device->refcnt);
 126         else
 127                 net_device = NULL;
 128
 129         return net_device;
 130 }
 131
 132 static void put_net_device(struct hv_device *device)
 133 {
 134         struct netvsc_device *net_device;
 135
 136         net_device = device->ext;
 137         /* ASSERT(netDevice); */
 138
 139         atomic_dec(&net_device->refcnt);
 140 }
 141
 142 static struct netvsc_device *release_outbound_net_device(
 143                 struct hv_device *device)
 144 {
 145         struct netvsc_device *net_device;
 146
 147         net_device = device->ext;
 148         if (net_device == NULL)
 149                 return NULL;
 150
 151         /* Busy wait until the ref drop to 2, then set it to 1 */
 152         while (atomic_cmpxchg(&net_device->refcnt, 2, 1) != 2)
 153                 udelay(100);
 154
 155         return net_device;
 156 }
 157
 158 static struct netvsc_device *release_inbound_net_device(
 159                 struct hv_device *device)
 160 {
 161         struct netvsc_device *net_device;
 162
 163         net_device = device->ext;
 164         if (net_device == NULL)
 165                 return NULL;
 166
 167         /* Busy wait until the ref drop to 1, then set it to 0 */
 168         while (atomic_cmpxchg(&net_device->refcnt, 1, 0) != 1)
 169                 udelay(100);
 170
 171         device->ext = NULL;
 172         return net_device;
 173 }
 174
 175 /*
 176  * netvsc_initialize - Main entry point
 177  */
 178 int netvsc_initialize(struct hv_driver *drv)
 179 {
 180         struct netvsc_driver *driver = (struct netvsc_driver *)drv;
 181
 182         DPRINT_DBG(NETVSC, "sizeof(struct hv_netvsc_packet)=%zd, "
 183                    "sizeof(struct nvsp_message)=%zd, "
 184                    "sizeof(struct vmtransfer_page_packet_header)=%zd",
 185                    sizeof(struct hv_netvsc_packet),
 186                    sizeof(struct nvsp_message),
 187                    sizeof(struct vmtransfer_page_packet_header));
 188
 189         /* Make sure we are at least 2 pages since 1 page is used for control */
 190         /* ASSERT(driver->RingBufferSize >= (PAGE_SIZE << 1)); */
 191
 192         drv->name = driver_name;
 193         memcpy(&drv->dev_type, &netvsc_device_type, sizeof(struct hv_guid));
 194
 195         /* Make sure it is set by the caller */
 196         /* FIXME: These probably should still be tested in some way */
 197         /* ASSERT(driver->OnReceiveCallback); */
 198         /* ASSERT(driver->OnLinkStatusChanged); */
 199
 200         /* Setup the dispatch table */
 201         driver->base.dev_add    = netvsc_device_add;
 202         driver->base.dev_rm     = netvsc_device_remove;
 203         driver->base.cleanup            = netvsc_cleanup;
 204
 205         driver->send                    = netvsc_send;
 206
 207         rndis_filter_init(driver);
 208         return 0;
 209 }
 210
 211 static int netvsc_init_recv_buf(struct hv_device *device)
 212 {
 213         int ret = 0;
 214         struct netvsc_device *net_device;
 215         struct nvsp_message *init_packet;
 216
 217         net_device = get_outbound_net_device(device);
 218         if (!net_device) {
 219                 DPRINT_ERR(NETVSC, "unable to get net device..."
 220                            "device being destroyed?");
 221                 return -1;
 222         }
 223         /* ASSERT(netDevice->ReceiveBufferSize > 0); */
 224         /* page-size grandularity */
 225         /* ASSERT((netDevice->ReceiveBufferSize & (PAGE_SIZE - 1)) == 0); */
 226
 227         net_device->recv_buf =
 228                 (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
 229                                 get_order(net_device->recv_buf_size));
 230         if (!net_device->recv_buf) {
 231                 DPRINT_ERR(NETVSC,
 232                            "unable to allocate receive buffer of size %d",
 233                            net_device->recv_buf_size);
 234                 ret = -1;
 235                 goto cleanup;
 236         }
 237         /* page-aligned buffer */
 238         /* ASSERT(((unsigned long)netDevice->ReceiveBuffer & (PAGE_SIZE - 1)) == */
 239         /*      0); */
 240
 241         DPRINT_INFO(NETVSC, "Establishing receive buffer's GPADL...");
 242
 243         /*
 244          * Establish the gpadl handle for this buffer on this
 245          * channel.  Note: This call uses the vmbus connection rather
 246          * than the channel to establish the gpadl handle.
 247          */
 248         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 249                                     net_device->recv_buf_size,
 250                                     &net_device->recv_buf_gpadl_handle);
 251         if (ret != 0) {
 252                 DPRINT_ERR(NETVSC,
 253                            "unable to establish receive buffer's gpadl");
 254                 goto cleanup;
 255         }
 256
 257
 258         /* Notify the NetVsp of the gpadl handle */
 259         DPRINT_INFO(NETVSC, "Sending NvspMessage1TypeSendReceiveBuffer...");
 260
 261         init_packet = &net_device->channel_init_pkt;
 262
 263         memset(init_packet, 0, sizeof(struct nvsp_message));
 264
 265         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 266         init_packet->msg.v1_msg.send_recv_buf.
 267                 gpadl_handle = net_device->recv_buf_gpadl_handle;
 268         init_packet->msg.v1_msg.
 269                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 270
 271         /* Send the gpadl notification request */
 272         net_device->wait_condition = 0;
 273         ret = vmbus_sendpacket(device->channel, init_packet,
 274                                sizeof(struct nvsp_message),
 275                                (unsigned long)init_packet,
 276                                VM_PKT_DATA_INBAND,
 277                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 278         if (ret != 0) {
 279                 DPRINT_ERR(NETVSC,
 280                            "unable to send receive buffer's gpadl to netvsp");
 281                 goto cleanup;
 282         }
 283
 284         wait_event_timeout(net_device->channel_init_wait,
 285                         net_device->wait_condition,
 286                         msecs_to_jiffies(1000));
 287         BUG_ON(net_device->wait_condition == 0);
 288
 289
 290         /* Check the response */
 291         if (init_packet->msg.v1_msg.
 292             send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
 293                 DPRINT_ERR(NETVSC, "Unable to complete receive buffer "
 294                            "initialzation with NetVsp - status %d",
 295                            init_packet->msg.v1_msg.
 296                            send_recv_buf_complete.status);
 297                 ret = -1;
 298                 goto cleanup;
 299         }
 300
 301         /* Parse the response */
 302         /* ASSERT(netDevice->ReceiveSectionCount == 0); */
 303         /* ASSERT(netDevice->ReceiveSections == NULL); */
 304
 305         net_device->recv_section_cnt = init_packet->msg.
 306                 v1_msg.send_recv_buf_complete.num_sections;
 307
 308         net_device->recv_section = kmalloc(net_device->recv_section_cnt
 309                 * sizeof(struct nvsp_1_receive_buffer_section), GFP_KERNEL);
 310         if (net_device->recv_section == NULL) {
 311                 ret = -1;
 312                 goto cleanup;
 313         }
 314
 315         memcpy(net_device->recv_section,
 316                 init_packet->msg.v1_msg.
 317                send_recv_buf_complete.sections,
 318                 net_device->recv_section_cnt *
 319                sizeof(struct nvsp_1_receive_buffer_section));
 320
 321         DPRINT_INFO(NETVSC, "Receive sections info (count %d, offset %d, "
 322                     "endoffset %d, suballoc size %d, num suballocs %d)",
 323                     net_device->recv_section_cnt,
 324                     net_device->recv_section[0].offset,
 325                     net_device->recv_section[0].end_offset,
 326                     net_device->recv_section[0].sub_alloc_size,
 327                     net_device->recv_section[0].num_sub_allocs);
 328
 329         /*
 330          * For 1st release, there should only be 1 section that represents the
 331          * entire receive buffer
 332          */
 333         if (net_device->recv_section_cnt != 1 ||
 334             net_device->recv_section->offset != 0) {
 335                 ret = -1;
 336                 goto cleanup;
 337         }
 338
 339         goto exit;
 340
 341 cleanup:
 342         netvsc_destroy_recv_buf(net_device);
 343
 344 exit:
 345         put_net_device(device);
 346         return ret;
 347 }
 348
 349 static int netvsc_init_send_buf(struct hv_device *device)
 350 {
 351         int ret = 0;
 352         struct netvsc_device *net_device;
 353         struct nvsp_message *init_packet;
 354
 355         net_device = get_outbound_net_device(device);
 356         if (!net_device) {
 357                 DPRINT_ERR(NETVSC, "unable to get net device..."
 358                            "device being destroyed?");
 359                 return -1;
 360         }
 361         if (net_device->send_buf_size <= 0) {
 362                 ret = -EINVAL;
 363                 goto cleanup;
 364         }
 365
 366         /* page-size grandularity */
 367         /* ASSERT((netDevice->SendBufferSize & (PAGE_SIZE - 1)) == 0); */
 368
 369         net_device->send_buf =
 370                 (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
 371                                 get_order(net_device->send_buf_size));
 372         if (!net_device->send_buf) {
 373                 DPRINT_ERR(NETVSC, "unable to allocate send buffer of size %d",
 374                            net_device->send_buf_size);
 375                 ret = -1;
 376                 goto cleanup;
 377         }
 378         /* page-aligned buffer */
 379         /* ASSERT(((unsigned long)netDevice->SendBuffer & (PAGE_SIZE - 1)) == 0); */
 380
 381         DPRINT_INFO(NETVSC, "Establishing send buffer's GPADL...");
 382
 383         /*
 384          * Establish the gpadl handle for this buffer on this
 385          * channel.  Note: This call uses the vmbus connection rather
 386          * than the channel to establish the gpadl handle.
 387          */
 388         ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
 389                                     net_device->send_buf_size,
 390                                     &net_device->send_buf_gpadl_handle);
 391         if (ret != 0) {
 392                 DPRINT_ERR(NETVSC, "unable to establish send buffer's gpadl");
 393                 goto cleanup;
 394         }
 395
 396         /* Notify the NetVsp of the gpadl handle */
 397         DPRINT_INFO(NETVSC, "Sending NvspMessage1TypeSendSendBuffer...");
 398
 399         init_packet = &net_device->channel_init_pkt;
 400
 401         memset(init_packet, 0, sizeof(struct nvsp_message));
 402
 403         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
 404         init_packet->msg.v1_msg.send_recv_buf.
 405                 gpadl_handle = net_device->send_buf_gpadl_handle;
 406         init_packet->msg.v1_msg.send_recv_buf.id =
 407                 NETVSC_SEND_BUFFER_ID;
 408
 409         /* Send the gpadl notification request */
 410         net_device->wait_condition = 0;
 411         ret = vmbus_sendpacket(device->channel, init_packet,
 412                                sizeof(struct nvsp_message),
 413                                (unsigned long)init_packet,
 414                                VM_PKT_DATA_INBAND,
 415                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 416         if (ret != 0) {
 417                 DPRINT_ERR(NETVSC,
 418                            "unable to send receive buffer's gpadl to netvsp");
 419                 goto cleanup;
 420         }
 421
 422         wait_event_timeout(net_device->channel_init_wait,
 423                         net_device->wait_condition,
 424                         msecs_to_jiffies(1000));
 425         BUG_ON(net_device->wait_condition == 0);
 426
 427         /* Check the response */
 428         if (init_packet->msg.v1_msg.
 429             send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
 430                 DPRINT_ERR(NETVSC, "Unable to complete send buffer "
 431                            "initialzation with NetVsp - status %d",
 432                            init_packet->msg.v1_msg.
 433                            send_send_buf_complete.status);
 434                 ret = -1;
 435                 goto cleanup;
 436         }
 437
 438         net_device->send_section_size = init_packet->
 439         msg.v1_msg.send_send_buf_complete.section_size;
 440
 441         goto exit;
 442
 443 cleanup:
 444         netvsc_destroy_send_buf(net_device);
 445
 446 exit:
 447         put_net_device(device);
 448         return ret;
 449 }
 450
 451 static int netvsc_destroy_recv_buf(struct netvsc_device *net_device)
 452 {
 453         struct nvsp_message *revoke_packet;
 454         int ret = 0;
 455
 456         /*
 457          * If we got a section count, it means we received a
 458          * SendReceiveBufferComplete msg (ie sent
 459          * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
 460          * to send a revoke msg here
 461          */
 462         if (net_device->recv_section_cnt) {
 463                 DPRINT_INFO(NETVSC,
 464                             "Sending NvspMessage1TypeRevokeReceiveBuffer...");
 465
 466                 /* Send the revoke receive buffer */
 467                 revoke_packet = &net_device->revoke_packet;
 468                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 469
 470                 revoke_packet->hdr.msg_type =
 471                         NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 472                 revoke_packet->msg.v1_msg.
 473                 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 474
 475                 ret = vmbus_sendpacket(net_device->dev->channel,
 476                                        revoke_packet,
 477                                        sizeof(struct nvsp_message),
 478                                        (unsigned long)revoke_packet,
 479                                        VM_PKT_DATA_INBAND, 0);
 480                 /*
 481                  * If we failed here, we might as well return and
 482                  * have a leak rather than continue and a bugchk
 483                  */
 484                 if (ret != 0) {
 485                         DPRINT_ERR(NETVSC, "unable to send revoke receive "
 486                                    "buffer to netvsp");
 487                         return -1;
 488                 }
 489         }
 490
 491         /* Teardown the gpadl on the vsp end */
 492         if (net_device->recv_buf_gpadl_handle) {
 493                 DPRINT_INFO(NETVSC, "Tearing down receive buffer's GPADL...");
 494
 495                 ret = vmbus_teardown_gpadl(net_device->dev->channel,
 496                            net_device->recv_buf_gpadl_handle);
 497
 498                 /* If we failed here, we might as well return and have a leak rather than continue and a bugchk */
 499                 if (ret != 0) {
 500                         DPRINT_ERR(NETVSC,
 501                                    "unable to teardown receive buffer's gpadl");
 502                         return -1;
 503                 }
 504                 net_device->recv_buf_gpadl_handle = 0;
 505         }
 506
 507         if (net_device->recv_buf) {
 508                 DPRINT_INFO(NETVSC, "Freeing up receive buffer...");
 509
 510                 /* Free up the receive buffer */
 511                 free_pages((unsigned long)net_device->recv_buf,
 512                         get_order(net_device->recv_buf_size));
 513                 net_device->recv_buf = NULL;
 514         }
 515
 516         if (net_device->recv_section) {
 517                 net_device->recv_section_cnt = 0;
 518                 kfree(net_device->recv_section);
 519                 net_device->recv_section = NULL;
 520         }
 521
 522         return ret;
 523 }
 524
 525 static int netvsc_destroy_send_buf(struct netvsc_device *net_device)
 526 {
 527         struct nvsp_message *revoke_packet;
 528         int ret = 0;
 529
 530         /*
 531          * If we got a section count, it means we received a
 532          *  SendReceiveBufferComplete msg (ie sent
 533          *  NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
 534          *  to send a revoke msg here
 535          */
 536         if (net_device->send_section_size) {
 537                 DPRINT_INFO(NETVSC,
 538                             "Sending NvspMessage1TypeRevokeSendBuffer...");
 539
 540                 /* Send the revoke send buffer */
 541                 revoke_packet = &net_device->revoke_packet;
 542                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 543
 544                 revoke_packet->hdr.msg_type =
 545                         NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
 546                 revoke_packet->msg.v1_msg.
 547                         revoke_send_buf.id = NETVSC_SEND_BUFFER_ID;
 548
 549                 ret = vmbus_sendpacket(net_device->dev->channel,
 550                                        revoke_packet,
 551                                        sizeof(struct nvsp_message),
 552                                        (unsigned long)revoke_packet,
 553                                        VM_PKT_DATA_INBAND, 0);
 554                 /*
 555                  * If we failed here, we might as well return and have a leak
 556                  * rather than continue and a bugchk
 557                  */
 558                 if (ret != 0) {
 559                         DPRINT_ERR(NETVSC, "unable to send revoke send buffer "
 560                                    "to netvsp");
 561                         return -1;
 562                 }
 563         }
 564
 565         /* Teardown the gpadl on the vsp end */
 566         if (net_device->send_buf_gpadl_handle) {
 567                 DPRINT_INFO(NETVSC, "Tearing down send buffer's GPADL...");
 568                 ret = vmbus_teardown_gpadl(net_device->dev->channel,
 569                                            net_device->send_buf_gpadl_handle);
 570
 571                 /*
 572                  * If we failed here, we might as well return and have a leak
 573                  * rather than continue and a bugchk
 574                  */
 575                 if (ret != 0) {
 576                         DPRINT_ERR(NETVSC, "unable to teardown send buffer's "
 577                                    "gpadl");
 578                         return -1;
 579                 }
 580                 net_device->send_buf_gpadl_handle = 0;
 581         }
 582
 583         if (net_device->send_buf) {
 584                 DPRINT_INFO(NETVSC, "Freeing up send buffer...");
 585
 586                 /* Free up the receive buffer */
 587                 free_pages((unsigned long)net_device->send_buf,
 588                                 get_order(net_device->send_buf_size));
 589                 net_device->send_buf = NULL;
 590         }
 591
 592         return ret;
 593 }
 594
 595
 596 static int netvsc_connect_vsp(struct hv_device *device)
 597 {
 598         int ret;
 599         struct netvsc_device *net_device;
 600         struct nvsp_message *init_packet;
 601         int ndis_version;
 602
 603         net_device = get_outbound_net_device(device);
 604         if (!net_device) {
 605                 DPRINT_ERR(NETVSC, "unable to get net device..."
 606                            "device being destroyed?");
 607                 return -1;
 608         }
 609
 610         init_packet = &net_device->channel_init_pkt;
 611
 612         memset(init_packet, 0, sizeof(struct nvsp_message));
 613         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 614         init_packet->msg.init_msg.init.min_protocol_ver =
 615                 NVSP_MIN_PROTOCOL_VERSION;
 616         init_packet->msg.init_msg.init.max_protocol_ver =
 617                 NVSP_MAX_PROTOCOL_VERSION;
 618
 619         DPRINT_INFO(NETVSC, "Sending NvspMessageTypeInit...");
 620
 621         /* Send the init request */
 622         net_device->wait_condition = 0;
 623         ret = vmbus_sendpacket(device->channel, init_packet,
 624                                sizeof(struct nvsp_message),
 625                                (unsigned long)init_packet,
 626                                VM_PKT_DATA_INBAND,
 627                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 628
 629         if (ret != 0) {
 630                 DPRINT_ERR(NETVSC, "unable to send NvspMessageTypeInit");
 631                 goto cleanup;
 632         }
 633
 634         wait_event_timeout(net_device->channel_init_wait,
 635                         net_device->wait_condition,
 636                         msecs_to_jiffies(1000));
 637         if (net_device->wait_condition == 0) {
 638                 ret = -ETIMEDOUT;
 639                 goto cleanup;
 640         }
 641
 642         /* Now, check the response */
 643         /* ASSERT(initPacket->Messages.InitMessages.InitComplete.MaximumMdlChainLength <= MAX_MULTIPAGE_BUFFER_COUNT); */
 644         DPRINT_INFO(NETVSC, "NvspMessageTypeInit status(%d) max mdl chain (%d)",
 645                 init_packet->msg.init_msg.init_complete.status,
 646                 init_packet->msg.init_msg.
 647                     init_complete.max_mdl_chain_len);
 648
 649         if (init_packet->msg.init_msg.init_complete.status !=
 650             NVSP_STAT_SUCCESS) {
 651                 DPRINT_ERR(NETVSC,
 652                         "unable to initialize with netvsp (status 0x%x)",
 653                         init_packet->msg.init_msg.init_complete.status);
 654                 ret = -1;
 655                 goto cleanup;
 656         }
 657
 658         if (init_packet->msg.init_msg.init_complete.
 659             negotiated_protocol_ver != NVSP_PROTOCOL_VERSION_1) {
 660                 DPRINT_ERR(NETVSC, "unable to initialize with netvsp "
 661                            "(version expected 1 got %d)",
 662                            init_packet->msg.init_msg.
 663                            init_complete.negotiated_protocol_ver);
 664                 ret = -1;
 665                 goto cleanup;
 666         }
 667         DPRINT_INFO(NETVSC, "Sending NvspMessage1TypeSendNdisVersion...");
 668
 669         /* Send the ndis version */
 670         memset(init_packet, 0, sizeof(struct nvsp_message));
 671
 672         ndis_version = 0x00050000;
 673
 674         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 675         init_packet->msg.v1_msg.
 676                 send_ndis_ver.ndis_major_ver =
 677                                 (ndis_version & 0xFFFF0000) >> 16;
 678         init_packet->msg.v1_msg.
 679                 send_ndis_ver.ndis_minor_ver =
 680                                 ndis_version & 0xFFFF;
 681
 682         /* Send the init request */
 683         ret = vmbus_sendpacket(device->channel, init_packet,
 684                                 sizeof(struct nvsp_message),
 685                                 (unsigned long)init_packet,
 686                                 VM_PKT_DATA_INBAND, 0);
 687         if (ret != 0) {
 688                 DPRINT_ERR(NETVSC,
 689                            "unable to send NvspMessage1TypeSendNdisVersion");
 690                 ret = -1;
 691                 goto cleanup;
 692         }
 693
 694         /* Post the big receive buffer to NetVSP */
 695         ret = netvsc_init_recv_buf(device);
 696         if (ret == 0)
 697                 ret = netvsc_init_send_buf(device);
 698
 699 cleanup:
 700         put_net_device(device);
 701         return ret;
 702 }
 703
 704 static void NetVscDisconnectFromVsp(struct netvsc_device *net_device)
 705 {
 706         netvsc_destroy_recv_buf(net_device);
 707         netvsc_destroy_send_buf(net_device);
 708 }
 709
 710 /*
 711  * netvsc_device_add - Callback when the device belonging to this
 712  * driver is added
 713  */
 714 static int netvsc_device_add(struct hv_device *device, void *additional_info)
 715 {
 716         int ret = 0;
 717         int i;
 718         struct netvsc_device *net_device;
 719         struct hv_netvsc_packet *packet, *pos;
 720         struct netvsc_driver *net_driver =
 721                                 (struct netvsc_driver *)device->drv;
 722
 723         net_device = alloc_net_device(device);
 724         if (!net_device) {
 725                 ret = -1;
 726                 goto cleanup;
 727         }
 728
 729         DPRINT_DBG(NETVSC, "netvsc channel object allocated - %p", net_device);
 730
 731         /* Initialize the NetVSC channel extension */
 732         net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 733         spin_lock_init(&net_device->recv_pkt_list_lock);
 734
 735         net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
 736
 737         INIT_LIST_HEAD(&net_device->recv_pkt_list);
 738
 739         for (i = 0; i < NETVSC_RECEIVE_PACKETLIST_COUNT; i++) {
 740                 packet = kzalloc(sizeof(struct hv_netvsc_packet) +
 741                                  (NETVSC_RECEIVE_SG_COUNT *
 742                                   sizeof(struct hv_page_buffer)), GFP_KERNEL);
 743                 if (!packet) {
 744                         DPRINT_DBG(NETVSC, "unable to allocate netvsc pkts "
 745                                    "for receive pool (wanted %d got %d)",
 746                                    NETVSC_RECEIVE_PACKETLIST_COUNT, i);
 747                         break;
 748                 }
 749                 list_add_tail(&packet->list_ent,
 750                               &net_device->recv_pkt_list);
 751         }
 752         init_waitqueue_head(&net_device->channel_init_wait);
 753
 754         /* Open the channel */
 755         ret = vmbus_open(device->channel, net_driver->ring_buf_size,
 756                          net_driver->ring_buf_size, NULL, 0,
 757                          netvsc_channel_cb, device);
 758
 759         if (ret != 0) {
 760                 DPRINT_ERR(NETVSC, "unable to open channel: %d", ret);
 761                 ret = -1;
 762                 goto cleanup;
 763         }
 764
 765         /* Channel is opened */
 766         DPRINT_INFO(NETVSC, "*** NetVSC channel opened successfully! ***");
 767
 768         /* Connect with the NetVsp */
 769         ret = netvsc_connect_vsp(device);
 770         if (ret != 0) {
 771                 DPRINT_ERR(NETVSC, "unable to connect to NetVSP - %d", ret);
 772                 ret = -1;
 773                 goto close;
 774         }
 775
 776         DPRINT_INFO(NETVSC, "*** NetVSC channel handshake result - %d ***",
 777                     ret);
 778
 779         return ret;
 780
 781 close:
 782         /* Now, we can close the channel safely */
 783         vmbus_close(device->channel);
 784
 785 cleanup:
 786
 787         if (net_device) {
 788                 list_for_each_entry_safe(packet, pos,
 789                                          &net_device->recv_pkt_list,
 790                                          list_ent) {
 791                         list_del(&packet->list_ent);
 792                         kfree(packet);
 793                 }
 794
 795                 release_outbound_net_device(device);
 796                 release_inbound_net_device(device);
 797
 798                 free_net_device(net_device);
 799         }
 800
 801         return ret;
 802 }
 803
 804 /*
 805  * netvsc_device_remove - Callback when the root bus device is removed
 806  */
 807 static int netvsc_device_remove(struct hv_device *device)
 808 {
 809         struct netvsc_device *net_device;
 810         struct hv_netvsc_packet *netvsc_packet, *pos;
 811
 812         DPRINT_INFO(NETVSC, "Disabling outbound traffic on net device (%p)...",
 813                     device->ext);
 814
 815         /* Stop outbound traffic ie sends and receives completions */
 816         net_device = release_outbound_net_device(device);
 817         if (!net_device) {
 818                 DPRINT_ERR(NETVSC, "No net device present!!");
 819                 return -1;
 820         }
 821
 822         /* Wait for all send completions */
 823         while (atomic_read(&net_device->num_outstanding_sends)) {
 824                 DPRINT_INFO(NETVSC, "waiting for %d requests to complete...",
 825                             atomic_read(&net_device->num_outstanding_sends));
 826                 udelay(100);
 827         }
 828
 829         DPRINT_INFO(NETVSC, "Disconnecting from netvsp...");
 830
 831         NetVscDisconnectFromVsp(net_device);
 832
 833         DPRINT_INFO(NETVSC, "Disabling inbound traffic on net device (%p)...",
 834                     device->ext);
 835
 836         /* Stop inbound traffic ie receives and sends completions */
 837         net_device = release_inbound_net_device(device);
 838
 839         /* At this point, no one should be accessing netDevice except in here */
 840         DPRINT_INFO(NETVSC, "net device (%p) safe to remove", net_device);
 841
 842         /* Now, we can close the channel safely */
 843         vmbus_close(device->channel);
 844
 845         /* Release all resources */
 846         list_for_each_entry_safe(netvsc_packet, pos,
 847                                  &net_device->recv_pkt_list, list_ent) {
 848                 list_del(&netvsc_packet->list_ent);
 849                 kfree(netvsc_packet);
 850         }
 851
 852         free_net_device(net_device);
 853         return 0;
 854 }
 855
 856 /*
 857  * netvsc_cleanup - Perform any cleanup when the driver is removed
 858  */
 859 static void netvsc_cleanup(struct hv_driver *drv)
 860 {
 861 }
 862
 863 static void netvsc_send_completion(struct hv_device *device,
 864                                    struct vmpacket_descriptor *packet)
 865 {
 866         struct netvsc_device *net_device;
 867         struct nvsp_message *nvsp_packet;
 868         struct hv_netvsc_packet *nvsc_packet;
 869
 870         net_device = get_inbound_net_device(device);
 871         if (!net_device) {
 872                 DPRINT_ERR(NETVSC, "unable to get net device..."
 873                            "device being destroyed?");
 874                 return;
 875         }
 876
 877         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 878                         (packet->offset8 << 3));
 879
 880         DPRINT_DBG(NETVSC, "send completion packet - type %d",
 881                    nvsp_packet->hdr.msg_type);
 882
 883         if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
 884             (nvsp_packet->hdr.msg_type ==
 885              NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
 886             (nvsp_packet->hdr.msg_type ==
 887              NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE)) {
 888                 /* Copy the response back */
 889                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 890                        sizeof(struct nvsp_message));
 891                 net_device->wait_condition = 1;
 892                 wake_up(&net_device->channel_init_wait);
 893         } else if (nvsp_packet->hdr.msg_type ==
 894                    NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
 895                 /* Get the send context */
 896                 nvsc_packet = (struct hv_netvsc_packet *)(unsigned long)
 897                         packet->trans_id;
 898                 /* ASSERT(nvscPacket); */
 899
 900                 /* Notify the layer above us */
 901                 nvsc_packet->completion.send.send_completion(
 902                         nvsc_packet->completion.send.send_completion_ctx);
 903
 904                 atomic_dec(&net_device->num_outstanding_sends);
 905         } else {
 906                 DPRINT_ERR(NETVSC, "Unknown send completion packet type - "
 907                            "%d received!!", nvsp_packet->hdr.msg_type);
 908         }
 909
 910         put_net_device(device);
 911 }
 912
 913 static int netvsc_send(struct hv_device *device,
 914                         struct hv_netvsc_packet *packet)
 915 {
 916         struct netvsc_device *net_device;
 917         int ret = 0;
 918
 919         struct nvsp_message sendMessage;
 920
 921         net_device = get_outbound_net_device(device);
 922         if (!net_device) {
 923                 DPRINT_ERR(NETVSC, "net device (%p) shutting down..."
 924                            "ignoring outbound packets", net_device);
 925                 return -2;
 926         }
 927
 928         sendMessage.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 929         if (packet->is_data_pkt) {
 930                 /* 0 is RMC_DATA; */
 931                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 0;
 932         } else {
 933                 /* 1 is RMC_CONTROL; */
 934                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 1;
 935         }
 936
 937         /* Not using send buffer section */
 938         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
 939                 0xFFFFFFFF;
 940         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
 941
 942         if (packet->page_buf_cnt) {
 943                 ret = vmbus_sendpacket_pagebuffer(device->channel,
 944                                                   packet->page_buf,
 945                                                   packet->page_buf_cnt,
 946                                                   &sendMessage,
 947                                                   sizeof(struct nvsp_message),
 948                                                   (unsigned long)packet);
 949         } else {
 950                 ret = vmbus_sendpacket(device->channel, &sendMessage,
 951                                        sizeof(struct nvsp_message),
 952                                        (unsigned long)packet,
 953                                        VM_PKT_DATA_INBAND,
 954                                        VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 955
 956         }
 957
 958         if (ret != 0)
 959                 DPRINT_ERR(NETVSC, "Unable to send packet %p ret %d",
 960                            packet, ret);
 961
 962         atomic_inc(&net_device->num_outstanding_sends);
 963         put_net_device(device);
 964         return ret;
 965 }
 966
 967 static void netvsc_receive(struct hv_device *device,
 968                             struct vmpacket_descriptor *packet)
 969 {
 970         struct netvsc_device *net_device;
 971         struct vmtransfer_page_packet_header *vmxferpage_packet;
 972         struct nvsp_message *nvsp_packet;
 973         struct hv_netvsc_packet *netvsc_packet = NULL;
 974         unsigned long start;
 975         unsigned long end, end_virtual;
 976         /* struct netvsc_driver *netvscDriver; */
 977         struct xferpage_packet *xferpage_packet = NULL;
 978         int i, j;
 979         int count = 0, bytes_remain = 0;
 980         unsigned long flags;
 981         LIST_HEAD(listHead);
 982
 983         net_device = get_inbound_net_device(device);
 984         if (!net_device) {
 985                 DPRINT_ERR(NETVSC, "unable to get net device..."
 986                            "device being destroyed?");
 987                 return;
 988         }
 989
 990         /*
 991          * All inbound packets other than send completion should be xfer page
 992          * packet
 993          */
 994         if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
 995                 DPRINT_ERR(NETVSC, "Unknown packet type received - %d",
 996                            packet->type);
 997                 put_net_device(device);
 998                 return;
 999         }
1000
1001         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
1002                         (packet->offset8 << 3));
1003
1004         /* Make sure this is a valid nvsp packet */
1005         if (nvsp_packet->hdr.msg_type !=
1006             NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
1007                 DPRINT_ERR(NETVSC, "Unknown nvsp packet type received - %d",
1008                            nvsp_packet->hdr.msg_type);
1009                 put_net_device(device);
1010                 return;
1011         }
1012
1013         DPRINT_DBG(NETVSC, "NVSP packet received - type %d",
1014                    nvsp_packet->hdr.msg_type);
1015
1016         vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
1017
1018         if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
1019                 DPRINT_ERR(NETVSC, "Invalid xfer page set id - "
1020                            "expecting %x got %x", NETVSC_RECEIVE_BUFFER_ID,
1021                            vmxferpage_packet->xfer_pageset_id);
1022                 put_net_device(device);
1023                 return;
1024         }
1025
1026         DPRINT_DBG(NETVSC, "xfer page - range count %d",
1027                    vmxferpage_packet->range_cnt);
1028
1029         /*
1030          * Grab free packets (range count + 1) to represent this xfer
1031          * page packet. +1 to represent the xfer page packet itself.
1032          * We grab it here so that we know exactly how many we can
1033          * fulfil
1034          */
1035         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
1036         while (!list_empty(&net_device->recv_pkt_list)) {
1037                 list_move_tail(net_device->recv_pkt_list.next, &listHead);
1038                 if (++count == vmxferpage_packet->range_cnt + 1)
1039                         break;
1040         }
1041         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
1042
1043         /*
1044          * We need at least 2 netvsc pkts (1 to represent the xfer
1045          * page and at least 1 for the range) i.e. we can handled
1046          * some of the xfer page packet ranges...
1047          */
1048         if (count < 2) {
1049                 DPRINT_ERR(NETVSC, "Got only %d netvsc pkt...needed %d pkts. "
1050                            "Dropping this xfer page packet completely!",
1051                            count, vmxferpage_packet->range_cnt + 1);
1052
1053                 /* Return it to the freelist */
1054                 spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
1055                 for (i = count; i != 0; i--) {
1056                         list_move_tail(listHead.next,
1057                                        &net_device->recv_pkt_list);
1058                 }
1059                 spin_unlock_irqrestore(&net_device->recv_pkt_list_lock,
1060                                        flags);
1061
1062                 netvsc_send_recv_completion(device,
1063                                             vmxferpage_packet->d.trans_id);
1064
1065                 put_net_device(device);
1066                 return;
1067         }
1068
1069         /* Remove the 1st packet to represent the xfer page packet itself */
1070         xferpage_packet = (struct xferpage_packet *)listHead.next;
1071         list_del(&xferpage_packet->list_ent);
1072
1073         /* This is how much we can satisfy */
1074         xferpage_packet->count = count - 1;
1075         /* ASSERT(xferpagePacket->Count > 0 && xferpagePacket->Count <= */
1076         /*      vmxferpagePacket->RangeCount); */
1077
1078         if (xferpage_packet->count != vmxferpage_packet->range_cnt) {
1079                 DPRINT_INFO(NETVSC, "Needed %d netvsc pkts to satisy this xfer "
1080                             "page...got %d", vmxferpage_packet->range_cnt,
1081                             xferpage_packet->count);
1082         }
1083
1084         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1085         for (i = 0; i < (count - 1); i++) {
1086                 netvsc_packet = (struct hv_netvsc_packet *)listHead.next;
1087                 list_del(&netvsc_packet->list_ent);
1088
1089                 /* Initialize the netvsc packet */
1090                 netvsc_packet->xfer_page_pkt = xferpage_packet;
1091                 netvsc_packet->completion.recv.recv_completion =
1092                                         netvsc_receive_completion;
1093                 netvsc_packet->completion.recv.recv_completion_ctx =
1094                                         netvsc_packet;
1095                 netvsc_packet->device = device;
1096                 /* Save this so that we can send it back */
1097                 netvsc_packet->completion.recv.recv_completion_tid =
1098                                         vmxferpage_packet->d.trans_id;
1099
1100                 netvsc_packet->total_data_buflen =
1101                                         vmxferpage_packet->ranges[i].byte_count;
1102                 netvsc_packet->page_buf_cnt = 1;
1103
1104                 /* ASSERT(vmxferpagePacket->Ranges[i].ByteOffset + */
1105                 /*      vmxferpagePacket->Ranges[i].ByteCount < */
1106                 /*      netDevice->ReceiveBufferSize); */
1107
1108                 netvsc_packet->page_buf[0].len =
1109                                         vmxferpage_packet->ranges[i].byte_count;
1110
1111                 start = virt_to_phys((void *)((unsigned long)net_device->
1112                 recv_buf + vmxferpage_packet->ranges[i].byte_offset));
1113
1114                 netvsc_packet->page_buf[0].pfn = start >> PAGE_SHIFT;
1115                 end_virtual = (unsigned long)net_device->recv_buf
1116                     + vmxferpage_packet->ranges[i].byte_offset
1117                     + vmxferpage_packet->ranges[i].byte_count - 1;
1118                 end = virt_to_phys((void *)end_virtual);
1119
1120                 /* Calculate the page relative offset */
1121                 netvsc_packet->page_buf[0].offset =
1122                         vmxferpage_packet->ranges[i].byte_offset &
1123                         (PAGE_SIZE - 1);
1124                 if ((end >> PAGE_SHIFT) != (start >> PAGE_SHIFT)) {
1125                         /* Handle frame across multiple pages: */
1126                         netvsc_packet->page_buf[0].len =
1127                                 (netvsc_packet->page_buf[0].pfn <<
1128                                  PAGE_SHIFT)
1129                                 + PAGE_SIZE - start;
1130                         bytes_remain = netvsc_packet->total_data_buflen -
1131                                         netvsc_packet->page_buf[0].len;
1132                         for (j = 1; j < NETVSC_PACKET_MAXPAGE; j++) {
1133                                 netvsc_packet->page_buf[j].offset = 0;
1134                                 if (bytes_remain <= PAGE_SIZE) {
1135                                         netvsc_packet->page_buf[j].len =
1136                                                 bytes_remain;
1137                                         bytes_remain = 0;
1138                                 } else {
1139                                         netvsc_packet->page_buf[j].len =
1140                                                 PAGE_SIZE;
1141                                         bytes_remain -= PAGE_SIZE;
1142                                 }
1143                                 netvsc_packet->page_buf[j].pfn =
1144                                     virt_to_phys((void *)(end_virtual -
1145                                                 bytes_remain)) >> PAGE_SHIFT;
1146                                 netvsc_packet->page_buf_cnt++;
1147                                 if (bytes_remain == 0)
1148                                         break;
1149                         }
1150                         /* ASSERT(bytesRemain == 0); */
1151                 }
1152                 DPRINT_DBG(NETVSC, "[%d] - (abs offset %u len %u) => "
1153                            "(pfn %llx, offset %u, len %u)", i,
1154                            vmxferpage_packet->ranges[i].byte_offset,
1155                            vmxferpage_packet->ranges[i].byte_count,
1156                            netvsc_packet->page_buf[0].pfn,
1157                            netvsc_packet->page_buf[0].offset,
1158                            netvsc_packet->page_buf[0].len);
1159
1160                 /* Pass it to the upper layer */
1161                 ((struct netvsc_driver *)device->drv)->
1162                         recv_cb(device, netvsc_packet);
1163
1164                 netvsc_receive_completion(netvsc_packet->
1165                                 completion.recv.recv_completion_ctx);
1166         }
1167
1168         /* ASSERT(list_empty(&listHead)); */
1169
1170         put_net_device(device);
1171 }
1172
1173 static void netvsc_send_recv_completion(struct hv_device *device,
1174                                         u64 transaction_id)
1175 {
1176         struct nvsp_message recvcompMessage;
1177         int retries = 0;
1178         int ret;
1179
1180         DPRINT_DBG(NETVSC, "Sending receive completion pkt - %llx",
1181                    transaction_id);
1182
1183         recvcompMessage.hdr.msg_type =
1184                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
1185
1186         /* FIXME: Pass in the status */
1187         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status =
1188                 NVSP_STAT_SUCCESS;
1189
1190 retry_send_cmplt:
1191         /* Send the completion */
1192         ret = vmbus_sendpacket(device->channel, &recvcompMessage,
1193                                sizeof(struct nvsp_message), transaction_id,
1194                                VM_PKT_COMP, 0);
1195         if (ret == 0) {
1196                 /* success */
1197                 /* no-op */
1198         } else if (ret == -1) {
1199                 /* no more room...wait a bit and attempt to retry 3 times */
1200                 retries++;
1201                 DPRINT_ERR(NETVSC, "unable to send receive completion pkt "
1202                            "(tid %llx)...retrying %d", transaction_id, retries);
1203
1204                 if (retries < 4) {
1205                         udelay(100);
1206                         goto retry_send_cmplt;
1207                 } else {
1208                         DPRINT_ERR(NETVSC, "unable to send receive completion "
1209                                   "pkt (tid %llx)...give up retrying",
1210                                   transaction_id);
1211                 }
1212         } else {
1213                 DPRINT_ERR(NETVSC, "unable to send receive completion pkt - "
1214                            "%llx", transaction_id);
1215         }
1216 }
1217
1218 /* Send a receive completion packet to RNDIS device (ie NetVsp) */
1219 static void netvsc_receive_completion(void *context)
1220 {
1221         struct hv_netvsc_packet *packet = context;
1222         struct hv_device *device = (struct hv_device *)packet->device;
1223         struct netvsc_device *net_device;
1224         u64 transaction_id = 0;
1225         bool fsend_receive_comp = false;
1226         unsigned long flags;
1227
1228         /* ASSERT(packet->XferPagePacket); */
1229
1230         /*
1231          * Even though it seems logical to do a GetOutboundNetDevice() here to
1232          * send out receive completion, we are using GetInboundNetDevice()
1233          * since we may have disable outbound traffic already.
1234          */
1235         net_device = get_inbound_net_device(device);
1236         if (!net_device) {
1237                 DPRINT_ERR(NETVSC, "unable to get net device..."
1238                            "device being destroyed?");
1239                 return;
1240         }
1241
1242         /* Overloading use of the lock. */
1243         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
1244
1245         /* ASSERT(packet->XferPagePacket->Count > 0); */
1246         packet->xfer_page_pkt->count--;
1247
1248         /*
1249          * Last one in the line that represent 1 xfer page packet.
1250          * Return the xfer page packet itself to the freelist
1251          */
1252         if (packet->xfer_page_pkt->count == 0) {
1253                 fsend_receive_comp = true;
1254                 transaction_id = packet->completion.recv.recv_completion_tid;
1255                 list_add_tail(&packet->xfer_page_pkt->list_ent,
1256                               &net_device->recv_pkt_list);
1257
1258         }
1259
1260         /* Put the packet back */
1261         list_add_tail(&packet->list_ent, &net_device->recv_pkt_list);
1262         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
1263
1264         /* Send a receive completion for the xfer page packet */
1265         if (fsend_receive_comp)
1266                 netvsc_send_recv_completion(device, transaction_id);
1267
1268         put_net_device(device);
1269 }
1270
1271 static void netvsc_channel_cb(void *context)
1272 {
1273         int ret;
1274         struct hv_device *device = context;
1275         struct netvsc_device *net_device;
1276         u32 bytes_recvd;
1277         u64 request_id;
1278         unsigned char *packet;
1279         struct vmpacket_descriptor *desc;
1280         unsigned char *buffer;
1281         int bufferlen = NETVSC_PACKET_SIZE;
1282
1283         /* ASSERT(device); */
1284
1285         packet = kzalloc(NETVSC_PACKET_SIZE * sizeof(unsigned char),
1286                          GFP_ATOMIC);
1287         if (!packet)
1288                 return;
1289         buffer = packet;
1290
1291         net_device = get_inbound_net_device(device);
1292         if (!net_device) {
1293                 DPRINT_ERR(NETVSC, "net device (%p) shutting down..."
1294                            "ignoring inbound packets", net_device);
1295                 goto out;
1296         }
1297
1298         do {
1299                 ret = vmbus_recvpacket_raw(device->channel, buffer, bufferlen,
1300                                            &bytes_recvd, &request_id);
1301                 if (ret == 0) {
1302                         if (bytes_recvd > 0) {
1303                                 DPRINT_DBG(NETVSC, "receive %d bytes, tid %llx",
1304                                            bytes_recvd, request_id);
1305
1306                                 desc = (struct vmpacket_descriptor *)buffer;
1307                                 switch (desc->type) {
1308                                 case VM_PKT_COMP:
1309                                         netvsc_send_completion(device, desc);
1310                                         break;
1311
1312                                 case VM_PKT_DATA_USING_XFER_PAGES:
1313                                         netvsc_receive(device, desc);
1314                                         break;
1315
1316                                 default:
1317                                         DPRINT_ERR(NETVSC,
1318                                                    "unhandled packet type %d, "
1319                                                    "tid %llx len %d\n",
1320                                                    desc->type, request_id,
1321                                                    bytes_recvd);
1322                                         break;
1323                                 }
1324
1325                                 /* reset */
1326                                 if (bufferlen > NETVSC_PACKET_SIZE) {
1327                                         kfree(buffer);
1328                                         buffer = packet;
1329                                         bufferlen = NETVSC_PACKET_SIZE;
1330                                 }
1331                         } else {
1332                                 /* reset */
1333                                 if (bufferlen > NETVSC_PACKET_SIZE) {
1334                                         kfree(buffer);
1335                                         buffer = packet;
1336                                         bufferlen = NETVSC_PACKET_SIZE;
1337                                 }
1338
1339                                 break;
1340                         }
1341                 } else if (ret == -2) {
1342                         /* Handle large packet */
1343                         buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
1344                         if (buffer == NULL) {
1345                                 /* Try again next time around */
1346                                 DPRINT_ERR(NETVSC,
1347                                            "unable to allocate buffer of size "
1348                                            "(%d)!!", bytes_recvd);
1349                                 break;
1350                         }
1351
1352                         bufferlen = bytes_recvd;
1353                 }
1354         } while (1);
1355
1356         put_net_device(device);
1357 out:
1358         kfree(buffer);
1359         return;
1360 }