drivers/net/hyperv/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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  22
  23 #include <linux/kernel.h>
  24 #include <linux/sched.h>
  25 #include <linux/wait.h>
  26 #include <linux/mm.h>
  27 #include <linux/delay.h>
  28 #include <linux/io.h>
  29 #include <linux/slab.h>
  30 #include <linux/netdevice.h>
  31 #include <linux/if_ether.h>
  32
  33 #include "hyperv_net.h"
  34
  35
  36 static struct netvsc_device *alloc_net_device(struct hv_device *device)
  37 {
  38         struct netvsc_device *net_device;
  39         struct net_device *ndev = hv_get_drvdata(device);
  40
  41         net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
  42         if (!net_device)
  43                 return NULL;
  44
  45         net_device->start_remove = false;
  46         net_device->destroy = false;
  47         net_device->dev = device;
  48         net_device->ndev = ndev;
  49
  50         hv_set_drvdata(device, net_device);
  51         return net_device;
  52 }
  53
  54 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
  55 {
  56         struct netvsc_device *net_device;
  57
  58         net_device = hv_get_drvdata(device);
  59         if (net_device && net_device->destroy)
  60                 net_device = NULL;
  61
  62         return net_device;
  63 }
  64
  65 static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
  66 {
  67         struct netvsc_device *net_device;
  68
  69         net_device = hv_get_drvdata(device);
  70
  71         if (!net_device)
  72                 goto get_in_err;
  73
  74         if (net_device->destroy &&
  75                 atomic_read(&net_device->num_outstanding_sends) == 0)
  76                 net_device = NULL;
  77
  78 get_in_err:
  79         return net_device;
  80 }
  81
  82
  83 static int netvsc_destroy_recv_buf(struct netvsc_device *net_device)
  84 {
  85         struct nvsp_message *revoke_packet;
  86         int ret = 0;
  87         struct net_device *ndev = net_device->ndev;
  88
  89         /*
  90          * If we got a section count, it means we received a
  91          * SendReceiveBufferComplete msg (ie sent
  92          * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
  93          * to send a revoke msg here
  94          */
  95         if (net_device->recv_section_cnt) {
  96                 /* Send the revoke receive buffer */
  97                 revoke_packet = &net_device->revoke_packet;
  98                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
  99
 100                 revoke_packet->hdr.msg_type =
 101                         NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 102                 revoke_packet->msg.v1_msg.
 103                 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 104
 105                 ret = vmbus_sendpacket(net_device->dev->channel,
 106                                        revoke_packet,
 107                                        sizeof(struct nvsp_message),
 108                                        (unsigned long)revoke_packet,
 109                                        VM_PKT_DATA_INBAND, 0);
 110                 /*
 111                  * If we failed here, we might as well return and
 112                  * have a leak rather than continue and a bugchk
 113                  */
 114                 if (ret != 0) {
 115                         netdev_err(ndev, "unable to send "
 116                                 "revoke receive buffer to netvsp\n");
 117                         return ret;
 118                 }
 119         }
 120
 121         /* Teardown the gpadl on the vsp end */
 122         if (net_device->recv_buf_gpadl_handle) {
 123                 ret = vmbus_teardown_gpadl(net_device->dev->channel,
 124                            net_device->recv_buf_gpadl_handle);
 125
 126                 /* If we failed here, we might as well return and have a leak
 127                  * rather than continue and a bugchk
 128                  */
 129                 if (ret != 0) {
 130                         netdev_err(ndev,
 131                                    "unable to teardown receive buffer's gpadl\n");
 132                         return ret;
 133                 }
 134                 net_device->recv_buf_gpadl_handle = 0;
 135         }
 136
 137         if (net_device->recv_buf) {
 138                 /* Free up the receive buffer */
 139                 free_pages((unsigned long)net_device->recv_buf,
 140                         get_order(net_device->recv_buf_size));
 141                 net_device->recv_buf = NULL;
 142         }
 143
 144         if (net_device->recv_section) {
 145                 net_device->recv_section_cnt = 0;
 146                 kfree(net_device->recv_section);
 147                 net_device->recv_section = NULL;
 148         }
 149
 150         return ret;
 151 }
 152
 153 static int netvsc_init_recv_buf(struct hv_device *device)
 154 {
 155         int ret = 0;
 156         int t;
 157         struct netvsc_device *net_device;
 158         struct nvsp_message *init_packet;
 159         struct net_device *ndev;
 160
 161         net_device = get_outbound_net_device(device);
 162         if (!net_device)
 163                 return -ENODEV;
 164         ndev = net_device->ndev;
 165
 166         net_device->recv_buf =
 167                 (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
 168                                 get_order(net_device->recv_buf_size));
 169         if (!net_device->recv_buf) {
 170                 netdev_err(ndev, "unable to allocate receive "
 171                         "buffer of size %d\n", net_device->recv_buf_size);
 172                 ret = -ENOMEM;
 173                 goto cleanup;
 174         }
 175
 176         /*
 177          * Establish the gpadl handle for this buffer on this
 178          * channel.  Note: This call uses the vmbus connection rather
 179          * than the channel to establish the gpadl handle.
 180          */
 181         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 182                                     net_device->recv_buf_size,
 183                                     &net_device->recv_buf_gpadl_handle);
 184         if (ret != 0) {
 185                 netdev_err(ndev,
 186                         "unable to establish receive buffer's gpadl\n");
 187                 goto cleanup;
 188         }
 189
 190
 191         /* Notify the NetVsp of the gpadl handle */
 192         init_packet = &net_device->channel_init_pkt;
 193
 194         memset(init_packet, 0, sizeof(struct nvsp_message));
 195
 196         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 197         init_packet->msg.v1_msg.send_recv_buf.
 198                 gpadl_handle = net_device->recv_buf_gpadl_handle;
 199         init_packet->msg.v1_msg.
 200                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 201
 202         /* Send the gpadl notification request */
 203         ret = vmbus_sendpacket(device->channel, init_packet,
 204                                sizeof(struct nvsp_message),
 205                                (unsigned long)init_packet,
 206                                VM_PKT_DATA_INBAND,
 207                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 208         if (ret != 0) {
 209                 netdev_err(ndev,
 210                         "unable to send receive buffer's gpadl to netvsp\n");
 211                 goto cleanup;
 212         }
 213
 214         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 215         BUG_ON(t == 0);
 216
 217
 218         /* Check the response */
 219         if (init_packet->msg.v1_msg.
 220             send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
 221                 netdev_err(ndev, "Unable to complete receive buffer "
 222                            "initialization with NetVsp - status %d\n",
 223                            init_packet->msg.v1_msg.
 224                            send_recv_buf_complete.status);
 225                 ret = -EINVAL;
 226                 goto cleanup;
 227         }
 228
 229         /* Parse the response */
 230
 231         net_device->recv_section_cnt = init_packet->msg.
 232                 v1_msg.send_recv_buf_complete.num_sections;
 233
 234         net_device->recv_section = kmemdup(
 235                 init_packet->msg.v1_msg.send_recv_buf_complete.sections,
 236                 net_device->recv_section_cnt *
 237                 sizeof(struct nvsp_1_receive_buffer_section),
 238                 GFP_KERNEL);
 239         if (net_device->recv_section == NULL) {
 240                 ret = -EINVAL;
 241                 goto cleanup;
 242         }
 243
 244         /*
 245          * For 1st release, there should only be 1 section that represents the
 246          * entire receive buffer
 247          */
 248         if (net_device->recv_section_cnt != 1 ||
 249             net_device->recv_section->offset != 0) {
 250                 ret = -EINVAL;
 251                 goto cleanup;
 252         }
 253
 254         goto exit;
 255
 256 cleanup:
 257         netvsc_destroy_recv_buf(net_device);
 258
 259 exit:
 260         return ret;
 261 }
 262
 263
 264 /* Negotiate NVSP protocol version */
 265 static int negotiate_nvsp_ver(struct hv_device *device,
 266                               struct netvsc_device *net_device,
 267                               struct nvsp_message *init_packet,
 268                               u32 nvsp_ver)
 269 {
 270         int ret, t;
 271
 272         memset(init_packet, 0, sizeof(struct nvsp_message));
 273         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 274         init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
 275         init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
 276
 277         /* Send the init request */
 278         ret = vmbus_sendpacket(device->channel, init_packet,
 279                                sizeof(struct nvsp_message),
 280                                (unsigned long)init_packet,
 281                                VM_PKT_DATA_INBAND,
 282                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 283
 284         if (ret != 0)
 285                 return ret;
 286
 287         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 288
 289         if (t == 0)
 290                 return -ETIMEDOUT;
 291
 292         if (init_packet->msg.init_msg.init_complete.status !=
 293             NVSP_STAT_SUCCESS)
 294                 return -EINVAL;
 295
 296         if (nvsp_ver != NVSP_PROTOCOL_VERSION_2)
 297                 return 0;
 298
 299         /* NVSPv2 only: Send NDIS config */
 300         memset(init_packet, 0, sizeof(struct nvsp_message));
 301         init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
 302         init_packet->msg.v2_msg.send_ndis_config.mtu = net_device->ndev->mtu;
 303
 304         ret = vmbus_sendpacket(device->channel, init_packet,
 305                                 sizeof(struct nvsp_message),
 306                                 (unsigned long)init_packet,
 307                                 VM_PKT_DATA_INBAND, 0);
 308
 309         return ret;
 310 }
 311
 312 static int netvsc_connect_vsp(struct hv_device *device)
 313 {
 314         int ret;
 315         struct netvsc_device *net_device;
 316         struct nvsp_message *init_packet;
 317         int ndis_version;
 318         struct net_device *ndev;
 319
 320         net_device = get_outbound_net_device(device);
 321         if (!net_device)
 322                 return -ENODEV;
 323         ndev = net_device->ndev;
 324
 325         init_packet = &net_device->channel_init_pkt;
 326
 327         /* Negotiate the latest NVSP protocol supported */
 328         if (negotiate_nvsp_ver(device, net_device, init_packet,
 329                                NVSP_PROTOCOL_VERSION_2) == 0) {
 330                 net_device->nvsp_version = NVSP_PROTOCOL_VERSION_2;
 331         } else if (negotiate_nvsp_ver(device, net_device, init_packet,
 332                                     NVSP_PROTOCOL_VERSION_1) == 0) {
 333                 net_device->nvsp_version = NVSP_PROTOCOL_VERSION_1;
 334         } else {
 335                 ret = -EPROTO;
 336                 goto cleanup;
 337         }
 338
 339         pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
 340
 341         /* Send the ndis version */
 342         memset(init_packet, 0, sizeof(struct nvsp_message));
 343
 344         ndis_version = 0x00050000;
 345
 346         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 347         init_packet->msg.v1_msg.
 348                 send_ndis_ver.ndis_major_ver =
 349                                 (ndis_version & 0xFFFF0000) >> 16;
 350         init_packet->msg.v1_msg.
 351                 send_ndis_ver.ndis_minor_ver =
 352                                 ndis_version & 0xFFFF;
 353
 354         /* Send the init request */
 355         ret = vmbus_sendpacket(device->channel, init_packet,
 356                                 sizeof(struct nvsp_message),
 357                                 (unsigned long)init_packet,
 358                                 VM_PKT_DATA_INBAND, 0);
 359         if (ret != 0)
 360                 goto cleanup;
 361
 362         /* Post the big receive buffer to NetVSP */
 363         ret = netvsc_init_recv_buf(device);
 364
 365 cleanup:
 366         return ret;
 367 }
 368
 369 static void netvsc_disconnect_vsp(struct netvsc_device *net_device)
 370 {
 371         netvsc_destroy_recv_buf(net_device);
 372 }
 373
 374 /*
 375  * netvsc_device_remove - Callback when the root bus device is removed
 376  */
 377 int netvsc_device_remove(struct hv_device *device)
 378 {
 379         struct netvsc_device *net_device;
 380         struct hv_netvsc_packet *netvsc_packet, *pos;
 381         unsigned long flags;
 382
 383         net_device = hv_get_drvdata(device);
 384         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 385         net_device->destroy = true;
 386         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 387
 388         /* Wait for all send completions */
 389         while (atomic_read(&net_device->num_outstanding_sends)) {
 390                 dev_info(&device->device,
 391                         "waiting for %d requests to complete...\n",
 392                         atomic_read(&net_device->num_outstanding_sends));
 393                 udelay(100);
 394         }
 395
 396         netvsc_disconnect_vsp(net_device);
 397
 398         /*
 399          * Since we have already drained, we don't need to busy wait
 400          * as was done in final_release_stor_device()
 401          * Note that we cannot set the ext pointer to NULL until
 402          * we have drained - to drain the outgoing packets, we need to
 403          * allow incoming packets.
 404          */
 405
 406         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 407         hv_set_drvdata(device, NULL);
 408         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 409
 410         /*
 411          * At this point, no one should be accessing net_device
 412          * except in here
 413          */
 414         dev_notice(&device->device, "net device safe to remove\n");
 415
 416         /* Now, we can close the channel safely */
 417         vmbus_close(device->channel);
 418
 419         /* Release all resources */
 420         list_for_each_entry_safe(netvsc_packet, pos,
 421                                  &net_device->recv_pkt_list, list_ent) {
 422                 list_del(&netvsc_packet->list_ent);
 423                 kfree(netvsc_packet);
 424         }
 425
 426         kfree(net_device);
 427         return 0;
 428 }
 429
 430 static void netvsc_send_completion(struct hv_device *device,
 431                                    struct vmpacket_descriptor *packet)
 432 {
 433         struct netvsc_device *net_device;
 434         struct nvsp_message *nvsp_packet;
 435         struct hv_netvsc_packet *nvsc_packet;
 436         struct net_device *ndev;
 437
 438         net_device = get_inbound_net_device(device);
 439         if (!net_device)
 440                 return;
 441         ndev = net_device->ndev;
 442
 443         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 444                         (packet->offset8 << 3));
 445
 446         if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
 447             (nvsp_packet->hdr.msg_type ==
 448              NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
 449             (nvsp_packet->hdr.msg_type ==
 450              NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE)) {
 451                 /* Copy the response back */
 452                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 453                        sizeof(struct nvsp_message));
 454                 complete(&net_device->channel_init_wait);
 455         } else if (nvsp_packet->hdr.msg_type ==
 456                    NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
 457                 /* Get the send context */
 458                 nvsc_packet = (struct hv_netvsc_packet *)(unsigned long)
 459                         packet->trans_id;
 460
 461                 /* Notify the layer above us */
 462                 nvsc_packet->completion.send.send_completion(
 463                         nvsc_packet->completion.send.send_completion_ctx);
 464
 465                 atomic_dec(&net_device->num_outstanding_sends);
 466
 467                 if (netif_queue_stopped(ndev) && !net_device->start_remove)
 468                         netif_wake_queue(ndev);
 469         } else {
 470                 netdev_err(ndev, "Unknown send completion packet type- "
 471                            "%d received!!\n", nvsp_packet->hdr.msg_type);
 472         }
 473
 474 }
 475
 476 int netvsc_send(struct hv_device *device,
 477                         struct hv_netvsc_packet *packet)
 478 {
 479         struct netvsc_device *net_device;
 480         int ret = 0;
 481         struct nvsp_message sendMessage;
 482         struct net_device *ndev;
 483
 484         net_device = get_outbound_net_device(device);
 485         if (!net_device)
 486                 return -ENODEV;
 487         ndev = net_device->ndev;
 488
 489         sendMessage.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 490         if (packet->is_data_pkt) {
 491                 /* 0 is RMC_DATA; */
 492                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 0;
 493         } else {
 494                 /* 1 is RMC_CONTROL; */
 495                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 1;
 496         }
 497
 498         /* Not using send buffer section */
 499         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
 500                 0xFFFFFFFF;
 501         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
 502
 503         if (packet->page_buf_cnt) {
 504                 ret = vmbus_sendpacket_pagebuffer(device->channel,
 505                                                   packet->page_buf,
 506                                                   packet->page_buf_cnt,
 507                                                   &sendMessage,
 508                                                   sizeof(struct nvsp_message),
 509                                                   (unsigned long)packet);
 510         } else {
 511                 ret = vmbus_sendpacket(device->channel, &sendMessage,
 512                                 sizeof(struct nvsp_message),
 513                                 (unsigned long)packet,
 514                                 VM_PKT_DATA_INBAND,
 515                                 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 516
 517         }
 518
 519         if (ret == 0) {
 520                 atomic_inc(&net_device->num_outstanding_sends);
 521         } else if (ret == -EAGAIN) {
 522                 netif_stop_queue(ndev);
 523                 if (atomic_read(&net_device->num_outstanding_sends) < 1)
 524                         netif_wake_queue(ndev);
 525         } else {
 526                 netdev_err(ndev, "Unable to send packet %p ret %d\n",
 527                            packet, ret);
 528         }
 529
 530         return ret;
 531 }
 532
 533 static void netvsc_send_recv_completion(struct hv_device *device,
 534                                         u64 transaction_id)
 535 {
 536         struct nvsp_message recvcompMessage;
 537         int retries = 0;
 538         int ret;
 539         struct net_device *ndev;
 540         struct netvsc_device *net_device = hv_get_drvdata(device);
 541
 542         ndev = net_device->ndev;
 543
 544         recvcompMessage.hdr.msg_type =
 545                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
 546
 547         /* FIXME: Pass in the status */
 548         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status =
 549                 NVSP_STAT_SUCCESS;
 550
 551 retry_send_cmplt:
 552         /* Send the completion */
 553         ret = vmbus_sendpacket(device->channel, &recvcompMessage,
 554                                sizeof(struct nvsp_message), transaction_id,
 555                                VM_PKT_COMP, 0);
 556         if (ret == 0) {
 557                 /* success */
 558                 /* no-op */
 559         } else if (ret == -EAGAIN) {
 560                 /* no more room...wait a bit and attempt to retry 3 times */
 561                 retries++;
 562                 netdev_err(ndev, "unable to send receive completion pkt"
 563                         " (tid %llx)...retrying %d\n", transaction_id, retries);
 564
 565                 if (retries < 4) {
 566                         udelay(100);
 567                         goto retry_send_cmplt;
 568                 } else {
 569                         netdev_err(ndev, "unable to send receive "
 570                                 "completion pkt (tid %llx)...give up retrying\n",
 571                                 transaction_id);
 572                 }
 573         } else {
 574                 netdev_err(ndev, "unable to send receive "
 575                         "completion pkt - %llx\n", transaction_id);
 576         }
 577 }
 578
 579 /* Send a receive completion packet to RNDIS device (ie NetVsp) */
 580 static void netvsc_receive_completion(void *context)
 581 {
 582         struct hv_netvsc_packet *packet = context;
 583         struct hv_device *device = (struct hv_device *)packet->device;
 584         struct netvsc_device *net_device;
 585         u64 transaction_id = 0;
 586         bool fsend_receive_comp = false;
 587         unsigned long flags;
 588         struct net_device *ndev;
 589
 590         /*
 591          * Even though it seems logical to do a GetOutboundNetDevice() here to
 592          * send out receive completion, we are using GetInboundNetDevice()
 593          * since we may have disable outbound traffic already.
 594          */
 595         net_device = get_inbound_net_device(device);
 596         if (!net_device)
 597                 return;
 598         ndev = net_device->ndev;
 599
 600         /* Overloading use of the lock. */
 601         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 602
 603         packet->xfer_page_pkt->count--;
 604
 605         /*
 606          * Last one in the line that represent 1 xfer page packet.
 607          * Return the xfer page packet itself to the freelist
 608          */
 609         if (packet->xfer_page_pkt->count == 0) {
 610                 fsend_receive_comp = true;
 611                 transaction_id = packet->completion.recv.recv_completion_tid;
 612                 list_add_tail(&packet->xfer_page_pkt->list_ent,
 613                               &net_device->recv_pkt_list);
 614
 615         }
 616
 617         /* Put the packet back */
 618         list_add_tail(&packet->list_ent, &net_device->recv_pkt_list);
 619         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
 620
 621         /* Send a receive completion for the xfer page packet */
 622         if (fsend_receive_comp)
 623                 netvsc_send_recv_completion(device, transaction_id);
 624
 625 }
 626
 627 static void netvsc_receive(struct hv_device *device,
 628                             struct vmpacket_descriptor *packet)
 629 {
 630         struct netvsc_device *net_device;
 631         struct vmtransfer_page_packet_header *vmxferpage_packet;
 632         struct nvsp_message *nvsp_packet;
 633         struct hv_netvsc_packet *netvsc_packet = NULL;
 634         /* struct netvsc_driver *netvscDriver; */
 635         struct xferpage_packet *xferpage_packet = NULL;
 636         int i;
 637         int count = 0;
 638         unsigned long flags;
 639         struct net_device *ndev;
 640
 641         LIST_HEAD(listHead);
 642
 643         net_device = get_inbound_net_device(device);
 644         if (!net_device)
 645                 return;
 646         ndev = net_device->ndev;
 647
 648         /*
 649          * All inbound packets other than send completion should be xfer page
 650          * packet
 651          */
 652         if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
 653                 netdev_err(ndev, "Unknown packet type received - %d\n",
 654                            packet->type);
 655                 return;
 656         }
 657
 658         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 659                         (packet->offset8 << 3));
 660
 661         /* Make sure this is a valid nvsp packet */
 662         if (nvsp_packet->hdr.msg_type !=
 663             NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
 664                 netdev_err(ndev, "Unknown nvsp packet type received-"
 665                         " %d\n", nvsp_packet->hdr.msg_type);
 666                 return;
 667         }
 668
 669         vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
 670
 671         if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
 672                 netdev_err(ndev, "Invalid xfer page set id - "
 673                            "expecting %x got %x\n", NETVSC_RECEIVE_BUFFER_ID,
 674                            vmxferpage_packet->xfer_pageset_id);
 675                 return;
 676         }
 677
 678         /*
 679          * Grab free packets (range count + 1) to represent this xfer
 680          * page packet. +1 to represent the xfer page packet itself.
 681          * We grab it here so that we know exactly how many we can
 682          * fulfil
 683          */
 684         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 685         while (!list_empty(&net_device->recv_pkt_list)) {
 686                 list_move_tail(net_device->recv_pkt_list.next, &listHead);
 687                 if (++count == vmxferpage_packet->range_cnt + 1)
 688                         break;
 689         }
 690         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
 691
 692         /*
 693          * We need at least 2 netvsc pkts (1 to represent the xfer
 694          * page and at least 1 for the range) i.e. we can handled
 695          * some of the xfer page packet ranges...
 696          */
 697         if (count < 2) {
 698                 netdev_err(ndev, "Got only %d netvsc pkt...needed "
 699                         "%d pkts. Dropping this xfer page packet completely!\n",
 700                         count, vmxferpage_packet->range_cnt + 1);
 701
 702                 /* Return it to the freelist */
 703                 spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 704                 for (i = count; i != 0; i--) {
 705                         list_move_tail(listHead.next,
 706                                        &net_device->recv_pkt_list);
 707                 }
 708                 spin_unlock_irqrestore(&net_device->recv_pkt_list_lock,
 709                                        flags);
 710
 711                 netvsc_send_recv_completion(device,
 712                                             vmxferpage_packet->d.trans_id);
 713
 714                 return;
 715         }
 716
 717         /* Remove the 1st packet to represent the xfer page packet itself */
 718         xferpage_packet = (struct xferpage_packet *)listHead.next;
 719         list_del(&xferpage_packet->list_ent);
 720
 721         /* This is how much we can satisfy */
 722         xferpage_packet->count = count - 1;
 723
 724         if (xferpage_packet->count != vmxferpage_packet->range_cnt) {
 725                 netdev_err(ndev, "Needed %d netvsc pkts to satisfy "
 726                         "this xfer page...got %d\n",
 727                         vmxferpage_packet->range_cnt, xferpage_packet->count);
 728         }
 729
 730         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
 731         for (i = 0; i < (count - 1); i++) {
 732                 netvsc_packet = (struct hv_netvsc_packet *)listHead.next;
 733                 list_del(&netvsc_packet->list_ent);
 734
 735                 /* Initialize the netvsc packet */
 736                 netvsc_packet->xfer_page_pkt = xferpage_packet;
 737                 netvsc_packet->completion.recv.recv_completion =
 738                                         netvsc_receive_completion;
 739                 netvsc_packet->completion.recv.recv_completion_ctx =
 740                                         netvsc_packet;
 741                 netvsc_packet->device = device;
 742                 /* Save this so that we can send it back */
 743                 netvsc_packet->completion.recv.recv_completion_tid =
 744                                         vmxferpage_packet->d.trans_id;
 745
 746                 netvsc_packet->data = (void *)((unsigned long)net_device->
 747                         recv_buf + vmxferpage_packet->ranges[i].byte_offset);
 748                 netvsc_packet->total_data_buflen =
 749                                         vmxferpage_packet->ranges[i].byte_count;
 750
 751                 /* Pass it to the upper layer */
 752                 rndis_filter_receive(device, netvsc_packet);
 753
 754                 netvsc_receive_completion(netvsc_packet->
 755                                 completion.recv.recv_completion_ctx);
 756         }
 757
 758 }
 759
 760 static void netvsc_channel_cb(void *context)
 761 {
 762         int ret;
 763         struct hv_device *device = context;
 764         struct netvsc_device *net_device;
 765         u32 bytes_recvd;
 766         u64 request_id;
 767         unsigned char *packet;
 768         struct vmpacket_descriptor *desc;
 769         unsigned char *buffer;
 770         int bufferlen = NETVSC_PACKET_SIZE;
 771         struct net_device *ndev;
 772
 773         packet = kzalloc(NETVSC_PACKET_SIZE * sizeof(unsigned char),
 774                          GFP_ATOMIC);
 775         if (!packet)
 776                 return;
 777         buffer = packet;
 778
 779         net_device = get_inbound_net_device(device);
 780         if (!net_device)
 781                 goto out;
 782         ndev = net_device->ndev;
 783
 784         do {
 785                 ret = vmbus_recvpacket_raw(device->channel, buffer, bufferlen,
 786                                            &bytes_recvd, &request_id);
 787                 if (ret == 0) {
 788                         if (bytes_recvd > 0) {
 789                                 desc = (struct vmpacket_descriptor *)buffer;
 790                                 switch (desc->type) {
 791                                 case VM_PKT_COMP:
 792                                         netvsc_send_completion(device, desc);
 793                                         break;
 794
 795                                 case VM_PKT_DATA_USING_XFER_PAGES:
 796                                         netvsc_receive(device, desc);
 797                                         break;
 798
 799                                 default:
 800                                         netdev_err(ndev,
 801                                                    "unhandled packet type %d, "
 802                                                    "tid %llx len %d\n",
 803                                                    desc->type, request_id,
 804                                                    bytes_recvd);
 805                                         break;
 806                                 }
 807
 808                                 /* reset */
 809                                 if (bufferlen > NETVSC_PACKET_SIZE) {
 810                                         kfree(buffer);
 811                                         buffer = packet;
 812                                         bufferlen = NETVSC_PACKET_SIZE;
 813                                 }
 814                         } else {
 815                                 /* reset */
 816                                 if (bufferlen > NETVSC_PACKET_SIZE) {
 817                                         kfree(buffer);
 818                                         buffer = packet;
 819                                         bufferlen = NETVSC_PACKET_SIZE;
 820                                 }
 821
 822                                 break;
 823                         }
 824                 } else if (ret == -ENOBUFS) {
 825                         /* Handle large packet */
 826                         buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
 827                         if (buffer == NULL) {
 828                                 /* Try again next time around */
 829                                 netdev_err(ndev,
 830                                            "unable to allocate buffer of size "
 831                                            "(%d)!!\n", bytes_recvd);
 832                                 break;
 833                         }
 834
 835                         bufferlen = bytes_recvd;
 836                 }
 837         } while (1);
 838
 839 out:
 840         kfree(buffer);
 841         return;
 842 }
 843
 844 /*
 845  * netvsc_device_add - Callback when the device belonging to this
 846  * driver is added
 847  */
 848 int netvsc_device_add(struct hv_device *device, void *additional_info)
 849 {
 850         int ret = 0;
 851         int i;
 852         int ring_size =
 853         ((struct netvsc_device_info *)additional_info)->ring_size;
 854         struct netvsc_device *net_device;
 855         struct hv_netvsc_packet *packet, *pos;
 856         struct net_device *ndev;
 857
 858         net_device = alloc_net_device(device);
 859         if (!net_device) {
 860                 ret = -ENOMEM;
 861                 goto cleanup;
 862         }
 863
 864         /*
 865          * Coming into this function, struct net_device * is
 866          * registered as the driver private data.
 867          * In alloc_net_device(), we register struct netvsc_device *
 868          * as the driver private data and stash away struct net_device *
 869          * in struct netvsc_device *.
 870          */
 871         ndev = net_device->ndev;
 872
 873         /* Initialize the NetVSC channel extension */
 874         net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 875         spin_lock_init(&net_device->recv_pkt_list_lock);
 876
 877         INIT_LIST_HEAD(&net_device->recv_pkt_list);
 878
 879         for (i = 0; i < NETVSC_RECEIVE_PACKETLIST_COUNT; i++) {
 880                 packet = kzalloc(sizeof(struct hv_netvsc_packet) +
 881                                  (NETVSC_RECEIVE_SG_COUNT *
 882                                   sizeof(struct hv_page_buffer)), GFP_KERNEL);
 883                 if (!packet)
 884                         break;
 885
 886                 list_add_tail(&packet->list_ent,
 887                               &net_device->recv_pkt_list);
 888         }
 889         init_completion(&net_device->channel_init_wait);
 890
 891         /* Open the channel */
 892         ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
 893                          ring_size * PAGE_SIZE, NULL, 0,
 894                          netvsc_channel_cb, device);
 895
 896         if (ret != 0) {
 897                 netdev_err(ndev, "unable to open channel: %d\n", ret);
 898                 goto cleanup;
 899         }
 900
 901         /* Channel is opened */
 902         pr_info("hv_netvsc channel opened successfully\n");
 903
 904         /* Connect with the NetVsp */
 905         ret = netvsc_connect_vsp(device);
 906         if (ret != 0) {
 907                 netdev_err(ndev,
 908                         "unable to connect to NetVSP - %d\n", ret);
 909                 goto close;
 910         }
 911
 912         return ret;
 913
 914 close:
 915         /* Now, we can close the channel safely */
 916         vmbus_close(device->channel);
 917
 918 cleanup:
 919
 920         if (net_device) {
 921                 list_for_each_entry_safe(packet, pos,
 922                                          &net_device->recv_pkt_list,
 923                                          list_ent) {
 924                         list_del(&packet->list_ent);
 925                         kfree(packet);
 926                 }
 927
 928                 kfree(net_device);
 929         }
 930
 931         return ret;
 932 }