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, see <http://www.gnu.org/licenses/>.
  15  *
  16  * Authors:
  17  *   Haiyang Zhang <haiyangz@microsoft.com>
  18  *   Hank Janssen  <hjanssen@microsoft.com>
  19  */
  20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22 #include <linux/kernel.h>
  23 #include <linux/sched.h>
  24 #include <linux/wait.h>
  25 #include <linux/mm.h>
  26 #include <linux/delay.h>
  27 #include <linux/io.h>
  28 #include <linux/slab.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/if_ether.h>
  31 #include <linux/vmalloc.h>
  32 #include <asm/sync_bitops.h>
  33
  34 #include "hyperv_net.h"
  35
  36 /*
  37  * Switch the data path from the synthetic interface to the VF
  38  * interface.
  39  */
  40 void netvsc_switch_datapath(struct net_device *ndev, bool vf)
  41 {
  42         struct net_device_context *net_device_ctx = netdev_priv(ndev);
  43         struct hv_device *dev = net_device_ctx->device_ctx;
  44         struct netvsc_device *nv_dev = net_device_ctx->nvdev;
  45         struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
  46
  47         memset(init_pkt, 0, sizeof(struct nvsp_message));
  48         init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
  49         if (vf)
  50                 init_pkt->msg.v4_msg.active_dp.active_datapath =
  51                         NVSP_DATAPATH_VF;
  52         else
  53                 init_pkt->msg.v4_msg.active_dp.active_datapath =
  54                         NVSP_DATAPATH_SYNTHETIC;
  55
  56         vmbus_sendpacket(dev->channel, init_pkt,
  57                                sizeof(struct nvsp_message),
  58                                (unsigned long)init_pkt,
  59                                VM_PKT_DATA_INBAND, 0);
  60 }
  61
  62
  63 static struct netvsc_device *alloc_net_device(void)
  64 {
  65         struct netvsc_device *net_device;
  66
  67         net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
  68         if (!net_device)
  69                 return NULL;
  70
  71         net_device->cb_buffer = kzalloc(NETVSC_PACKET_SIZE, GFP_KERNEL);
  72         if (!net_device->cb_buffer) {
  73                 kfree(net_device);
  74                 return NULL;
  75         }
  76
  77         init_waitqueue_head(&net_device->wait_drain);
  78         net_device->destroy = false;
  79         atomic_set(&net_device->open_cnt, 0);
  80         atomic_set(&net_device->vf_use_cnt, 0);
  81         net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
  82         net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
  83
  84         net_device->vf_netdev = NULL;
  85         net_device->vf_inject = false;
  86
  87         return net_device;
  88 }
  89
  90 static void free_netvsc_device(struct netvsc_device *nvdev)
  91 {
  92         kfree(nvdev->cb_buffer);
  93         kfree(nvdev);
  94 }
  95
  96 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
  97 {
  98         struct netvsc_device *net_device = hv_device_to_netvsc_device(device);
  99
 100         if (net_device && net_device->destroy)
 101                 net_device = NULL;
 102
 103         return net_device;
 104 }
 105
 106 static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
 107 {
 108         struct netvsc_device *net_device = hv_device_to_netvsc_device(device);
 109
 110         if (!net_device)
 111                 goto get_in_err;
 112
 113         if (net_device->destroy &&
 114                 atomic_read(&net_device->num_outstanding_sends) == 0)
 115                 net_device = NULL;
 116
 117 get_in_err:
 118         return net_device;
 119 }
 120
 121
 122 static int netvsc_destroy_buf(struct hv_device *device)
 123 {
 124         struct nvsp_message *revoke_packet;
 125         int ret = 0;
 126         struct net_device *ndev = hv_get_drvdata(device);
 127         struct netvsc_device *net_device = net_device_to_netvsc_device(ndev);
 128
 129         /*
 130          * If we got a section count, it means we received a
 131          * SendReceiveBufferComplete msg (ie sent
 132          * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
 133          * to send a revoke msg here
 134          */
 135         if (net_device->recv_section_cnt) {
 136                 /* Send the revoke receive buffer */
 137                 revoke_packet = &net_device->revoke_packet;
 138                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 139
 140                 revoke_packet->hdr.msg_type =
 141                         NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 142                 revoke_packet->msg.v1_msg.
 143                 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 144
 145                 ret = vmbus_sendpacket(device->channel,
 146                                        revoke_packet,
 147                                        sizeof(struct nvsp_message),
 148                                        (unsigned long)revoke_packet,
 149                                        VM_PKT_DATA_INBAND, 0);
 150                 /*
 151                  * If we failed here, we might as well return and
 152                  * have a leak rather than continue and a bugchk
 153                  */
 154                 if (ret != 0) {
 155                         netdev_err(ndev, "unable to send "
 156                                 "revoke receive buffer to netvsp\n");
 157                         return ret;
 158                 }
 159         }
 160
 161         /* Teardown the gpadl on the vsp end */
 162         if (net_device->recv_buf_gpadl_handle) {
 163                 ret = vmbus_teardown_gpadl(device->channel,
 164                                            net_device->recv_buf_gpadl_handle);
 165
 166                 /* If we failed here, we might as well return and have a leak
 167                  * rather than continue and a bugchk
 168                  */
 169                 if (ret != 0) {
 170                         netdev_err(ndev,
 171                                    "unable to teardown receive buffer's gpadl\n");
 172                         return ret;
 173                 }
 174                 net_device->recv_buf_gpadl_handle = 0;
 175         }
 176
 177         if (net_device->recv_buf) {
 178                 /* Free up the receive buffer */
 179                 vfree(net_device->recv_buf);
 180                 net_device->recv_buf = NULL;
 181         }
 182
 183         if (net_device->recv_section) {
 184                 net_device->recv_section_cnt = 0;
 185                 kfree(net_device->recv_section);
 186                 net_device->recv_section = NULL;
 187         }
 188
 189         /* Deal with the send buffer we may have setup.
 190          * If we got a  send section size, it means we received a
 191          * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
 192          * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
 193          * to send a revoke msg here
 194          */
 195         if (net_device->send_section_size) {
 196                 /* Send the revoke receive buffer */
 197                 revoke_packet = &net_device->revoke_packet;
 198                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 199
 200                 revoke_packet->hdr.msg_type =
 201                         NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
 202                 revoke_packet->msg.v1_msg.revoke_send_buf.id =
 203                         NETVSC_SEND_BUFFER_ID;
 204
 205                 ret = vmbus_sendpacket(device->channel,
 206                                        revoke_packet,
 207                                        sizeof(struct nvsp_message),
 208                                        (unsigned long)revoke_packet,
 209                                        VM_PKT_DATA_INBAND, 0);
 210                 /* If we failed here, we might as well return and
 211                  * have a leak rather than continue and a bugchk
 212                  */
 213                 if (ret != 0) {
 214                         netdev_err(ndev, "unable to send "
 215                                    "revoke send buffer to netvsp\n");
 216                         return ret;
 217                 }
 218         }
 219         /* Teardown the gpadl on the vsp end */
 220         if (net_device->send_buf_gpadl_handle) {
 221                 ret = vmbus_teardown_gpadl(device->channel,
 222                                            net_device->send_buf_gpadl_handle);
 223
 224                 /* If we failed here, we might as well return and have a leak
 225                  * rather than continue and a bugchk
 226                  */
 227                 if (ret != 0) {
 228                         netdev_err(ndev,
 229                                    "unable to teardown send buffer's gpadl\n");
 230                         return ret;
 231                 }
 232                 net_device->send_buf_gpadl_handle = 0;
 233         }
 234         if (net_device->send_buf) {
 235                 /* Free up the send buffer */
 236                 vfree(net_device->send_buf);
 237                 net_device->send_buf = NULL;
 238         }
 239         kfree(net_device->send_section_map);
 240
 241         return ret;
 242 }
 243
 244 static int netvsc_init_buf(struct hv_device *device)
 245 {
 246         int ret = 0;
 247         unsigned long t;
 248         struct netvsc_device *net_device;
 249         struct nvsp_message *init_packet;
 250         struct net_device *ndev;
 251         int node;
 252
 253         net_device = get_outbound_net_device(device);
 254         if (!net_device)
 255                 return -ENODEV;
 256         ndev = hv_get_drvdata(device);
 257
 258         node = cpu_to_node(device->channel->target_cpu);
 259         net_device->recv_buf = vzalloc_node(net_device->recv_buf_size, node);
 260         if (!net_device->recv_buf)
 261                 net_device->recv_buf = vzalloc(net_device->recv_buf_size);
 262
 263         if (!net_device->recv_buf) {
 264                 netdev_err(ndev, "unable to allocate receive "
 265                         "buffer of size %d\n", net_device->recv_buf_size);
 266                 ret = -ENOMEM;
 267                 goto cleanup;
 268         }
 269
 270         /*
 271          * Establish the gpadl handle for this buffer on this
 272          * channel.  Note: This call uses the vmbus connection rather
 273          * than the channel to establish the gpadl handle.
 274          */
 275         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 276                                     net_device->recv_buf_size,
 277                                     &net_device->recv_buf_gpadl_handle);
 278         if (ret != 0) {
 279                 netdev_err(ndev,
 280                         "unable to establish receive buffer's gpadl\n");
 281                 goto cleanup;
 282         }
 283
 284
 285         /* Notify the NetVsp of the gpadl handle */
 286         init_packet = &net_device->channel_init_pkt;
 287
 288         memset(init_packet, 0, sizeof(struct nvsp_message));
 289
 290         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 291         init_packet->msg.v1_msg.send_recv_buf.
 292                 gpadl_handle = net_device->recv_buf_gpadl_handle;
 293         init_packet->msg.v1_msg.
 294                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 295
 296         /* Send the gpadl notification request */
 297         ret = vmbus_sendpacket(device->channel, init_packet,
 298                                sizeof(struct nvsp_message),
 299                                (unsigned long)init_packet,
 300                                VM_PKT_DATA_INBAND,
 301                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 302         if (ret != 0) {
 303                 netdev_err(ndev,
 304                         "unable to send receive buffer's gpadl to netvsp\n");
 305                 goto cleanup;
 306         }
 307
 308         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 309         BUG_ON(t == 0);
 310
 311
 312         /* Check the response */
 313         if (init_packet->msg.v1_msg.
 314             send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
 315                 netdev_err(ndev, "Unable to complete receive buffer "
 316                            "initialization with NetVsp - status %d\n",
 317                            init_packet->msg.v1_msg.
 318                            send_recv_buf_complete.status);
 319                 ret = -EINVAL;
 320                 goto cleanup;
 321         }
 322
 323         /* Parse the response */
 324
 325         net_device->recv_section_cnt = init_packet->msg.
 326                 v1_msg.send_recv_buf_complete.num_sections;
 327
 328         net_device->recv_section = kmemdup(
 329                 init_packet->msg.v1_msg.send_recv_buf_complete.sections,
 330                 net_device->recv_section_cnt *
 331                 sizeof(struct nvsp_1_receive_buffer_section),
 332                 GFP_KERNEL);
 333         if (net_device->recv_section == NULL) {
 334                 ret = -EINVAL;
 335                 goto cleanup;
 336         }
 337
 338         /*
 339          * For 1st release, there should only be 1 section that represents the
 340          * entire receive buffer
 341          */
 342         if (net_device->recv_section_cnt != 1 ||
 343             net_device->recv_section->offset != 0) {
 344                 ret = -EINVAL;
 345                 goto cleanup;
 346         }
 347
 348         /* Now setup the send buffer.
 349          */
 350         net_device->send_buf = vzalloc_node(net_device->send_buf_size, node);
 351         if (!net_device->send_buf)
 352                 net_device->send_buf = vzalloc(net_device->send_buf_size);
 353         if (!net_device->send_buf) {
 354                 netdev_err(ndev, "unable to allocate send "
 355                            "buffer of size %d\n", net_device->send_buf_size);
 356                 ret = -ENOMEM;
 357                 goto cleanup;
 358         }
 359
 360         /* Establish the gpadl handle for this buffer on this
 361          * channel.  Note: This call uses the vmbus connection rather
 362          * than the channel to establish the gpadl handle.
 363          */
 364         ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
 365                                     net_device->send_buf_size,
 366                                     &net_device->send_buf_gpadl_handle);
 367         if (ret != 0) {
 368                 netdev_err(ndev,
 369                            "unable to establish send buffer's gpadl\n");
 370                 goto cleanup;
 371         }
 372
 373         /* Notify the NetVsp of the gpadl handle */
 374         init_packet = &net_device->channel_init_pkt;
 375         memset(init_packet, 0, sizeof(struct nvsp_message));
 376         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
 377         init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
 378                 net_device->send_buf_gpadl_handle;
 379         init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
 380
 381         /* Send the gpadl notification request */
 382         ret = vmbus_sendpacket(device->channel, init_packet,
 383                                sizeof(struct nvsp_message),
 384                                (unsigned long)init_packet,
 385                                VM_PKT_DATA_INBAND,
 386                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 387         if (ret != 0) {
 388                 netdev_err(ndev,
 389                            "unable to send send buffer's gpadl to netvsp\n");
 390                 goto cleanup;
 391         }
 392
 393         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 394         BUG_ON(t == 0);
 395
 396         /* Check the response */
 397         if (init_packet->msg.v1_msg.
 398             send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
 399                 netdev_err(ndev, "Unable to complete send buffer "
 400                            "initialization with NetVsp - status %d\n",
 401                            init_packet->msg.v1_msg.
 402                            send_send_buf_complete.status);
 403                 ret = -EINVAL;
 404                 goto cleanup;
 405         }
 406
 407         /* Parse the response */
 408         net_device->send_section_size = init_packet->msg.
 409                                 v1_msg.send_send_buf_complete.section_size;
 410
 411         /* Section count is simply the size divided by the section size.
 412          */
 413         net_device->send_section_cnt =
 414                 net_device->send_buf_size/net_device->send_section_size;
 415
 416         dev_info(&device->device, "Send section size: %d, Section count:%d\n",
 417                  net_device->send_section_size, net_device->send_section_cnt);
 418
 419         /* Setup state for managing the send buffer. */
 420         net_device->map_words = DIV_ROUND_UP(net_device->send_section_cnt,
 421                                              BITS_PER_LONG);
 422
 423         net_device->send_section_map =
 424                 kzalloc(net_device->map_words * sizeof(ulong), GFP_KERNEL);
 425         if (net_device->send_section_map == NULL) {
 426                 ret = -ENOMEM;
 427                 goto cleanup;
 428         }
 429
 430         goto exit;
 431
 432 cleanup:
 433         netvsc_destroy_buf(device);
 434
 435 exit:
 436         return ret;
 437 }
 438
 439
 440 /* Negotiate NVSP protocol version */
 441 static int negotiate_nvsp_ver(struct hv_device *device,
 442                               struct netvsc_device *net_device,
 443                               struct nvsp_message *init_packet,
 444                               u32 nvsp_ver)
 445 {
 446         struct net_device *ndev = hv_get_drvdata(device);
 447         int ret;
 448         unsigned long t;
 449
 450         memset(init_packet, 0, sizeof(struct nvsp_message));
 451         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 452         init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
 453         init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
 454
 455         /* Send the init request */
 456         ret = vmbus_sendpacket(device->channel, init_packet,
 457                                sizeof(struct nvsp_message),
 458                                (unsigned long)init_packet,
 459                                VM_PKT_DATA_INBAND,
 460                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 461
 462         if (ret != 0)
 463                 return ret;
 464
 465         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 466
 467         if (t == 0)
 468                 return -ETIMEDOUT;
 469
 470         if (init_packet->msg.init_msg.init_complete.status !=
 471             NVSP_STAT_SUCCESS)
 472                 return -EINVAL;
 473
 474         if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
 475                 return 0;
 476
 477         /* NVSPv2 or later: Send NDIS config */
 478         memset(init_packet, 0, sizeof(struct nvsp_message));
 479         init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
 480         init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;
 481         init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
 482
 483         if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5)
 484                 init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
 485
 486         ret = vmbus_sendpacket(device->channel, init_packet,
 487                                 sizeof(struct nvsp_message),
 488                                 (unsigned long)init_packet,
 489                                 VM_PKT_DATA_INBAND, 0);
 490
 491         return ret;
 492 }
 493
 494 static int netvsc_connect_vsp(struct hv_device *device)
 495 {
 496         int ret;
 497         struct netvsc_device *net_device;
 498         struct nvsp_message *init_packet;
 499         int ndis_version;
 500         u32 ver_list[] = { NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
 501                 NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5 };
 502         int i, num_ver = 4; /* number of different NVSP versions */
 503
 504         net_device = get_outbound_net_device(device);
 505         if (!net_device)
 506                 return -ENODEV;
 507
 508         init_packet = &net_device->channel_init_pkt;
 509
 510         /* Negotiate the latest NVSP protocol supported */
 511         for (i = num_ver - 1; i >= 0; i--)
 512                 if (negotiate_nvsp_ver(device, net_device, init_packet,
 513                                        ver_list[i])  == 0) {
 514                         net_device->nvsp_version = ver_list[i];
 515                         break;
 516                 }
 517
 518         if (i < 0) {
 519                 ret = -EPROTO;
 520                 goto cleanup;
 521         }
 522
 523         pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
 524
 525         /* Send the ndis version */
 526         memset(init_packet, 0, sizeof(struct nvsp_message));
 527
 528         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
 529                 ndis_version = 0x00060001;
 530         else
 531                 ndis_version = 0x0006001e;
 532
 533         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 534         init_packet->msg.v1_msg.
 535                 send_ndis_ver.ndis_major_ver =
 536                                 (ndis_version & 0xFFFF0000) >> 16;
 537         init_packet->msg.v1_msg.
 538                 send_ndis_ver.ndis_minor_ver =
 539                                 ndis_version & 0xFFFF;
 540
 541         /* Send the init request */
 542         ret = vmbus_sendpacket(device->channel, init_packet,
 543                                 sizeof(struct nvsp_message),
 544                                 (unsigned long)init_packet,
 545                                 VM_PKT_DATA_INBAND, 0);
 546         if (ret != 0)
 547                 goto cleanup;
 548
 549         /* Post the big receive buffer to NetVSP */
 550         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
 551                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
 552         else
 553                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 554         net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
 555
 556         ret = netvsc_init_buf(device);
 557
 558 cleanup:
 559         return ret;
 560 }
 561
 562 static void netvsc_disconnect_vsp(struct hv_device *device)
 563 {
 564         netvsc_destroy_buf(device);
 565 }
 566
 567 /*
 568  * netvsc_device_remove - Callback when the root bus device is removed
 569  */
 570 int netvsc_device_remove(struct hv_device *device)
 571 {
 572         struct net_device *ndev = hv_get_drvdata(device);
 573         struct net_device_context *net_device_ctx = netdev_priv(ndev);
 574         struct netvsc_device *net_device = net_device_ctx->nvdev;
 575
 576         netvsc_disconnect_vsp(device);
 577
 578         net_device_ctx->nvdev = NULL;
 579
 580         /*
 581          * At this point, no one should be accessing net_device
 582          * except in here
 583          */
 584         dev_notice(&device->device, "net device safe to remove\n");
 585
 586         /* Now, we can close the channel safely */
 587         vmbus_close(device->channel);
 588
 589         /* Release all resources */
 590         vfree(net_device->sub_cb_buf);
 591         free_netvsc_device(net_device);
 592         return 0;
 593 }
 594
 595
 596 #define RING_AVAIL_PERCENT_HIWATER 20
 597 #define RING_AVAIL_PERCENT_LOWATER 10
 598
 599 /*
 600  * Get the percentage of available bytes to write in the ring.
 601  * The return value is in range from 0 to 100.
 602  */
 603 static inline u32 hv_ringbuf_avail_percent(
 604                 struct hv_ring_buffer_info *ring_info)
 605 {
 606         u32 avail_read, avail_write;
 607
 608         hv_get_ringbuffer_availbytes(ring_info, &avail_read, &avail_write);
 609
 610         return avail_write * 100 / ring_info->ring_datasize;
 611 }
 612
 613 static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
 614                                          u32 index)
 615 {
 616         sync_change_bit(index, net_device->send_section_map);
 617 }
 618
 619 static void netvsc_send_completion(struct netvsc_device *net_device,
 620                                    struct vmbus_channel *incoming_channel,
 621                                    struct hv_device *device,
 622                                    struct vmpacket_descriptor *packet)
 623 {
 624         struct nvsp_message *nvsp_packet;
 625         struct hv_netvsc_packet *nvsc_packet;
 626         struct net_device *ndev = hv_get_drvdata(device);
 627         struct net_device_context *net_device_ctx = netdev_priv(ndev);
 628         u32 send_index;
 629         struct sk_buff *skb;
 630
 631         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 632                         (packet->offset8 << 3));
 633
 634         if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
 635             (nvsp_packet->hdr.msg_type ==
 636              NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
 637             (nvsp_packet->hdr.msg_type ==
 638              NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE) ||
 639             (nvsp_packet->hdr.msg_type ==
 640              NVSP_MSG5_TYPE_SUBCHANNEL)) {
 641                 /* Copy the response back */
 642                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 643                        sizeof(struct nvsp_message));
 644                 complete(&net_device->channel_init_wait);
 645         } else if (nvsp_packet->hdr.msg_type ==
 646                    NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
 647                 int num_outstanding_sends;
 648                 u16 q_idx = 0;
 649                 struct vmbus_channel *channel = device->channel;
 650                 int queue_sends;
 651
 652                 /* Get the send context */
 653                 skb = (struct sk_buff *)(unsigned long)packet->trans_id;
 654
 655                 /* Notify the layer above us */
 656                 if (skb) {
 657                         nvsc_packet = (struct hv_netvsc_packet *) skb->cb;
 658                         send_index = nvsc_packet->send_buf_index;
 659                         if (send_index != NETVSC_INVALID_INDEX)
 660                                 netvsc_free_send_slot(net_device, send_index);
 661                         q_idx = nvsc_packet->q_idx;
 662                         channel = incoming_channel;
 663                         dev_kfree_skb_any(skb);
 664                 }
 665
 666                 num_outstanding_sends =
 667                         atomic_dec_return(&net_device->num_outstanding_sends);
 668                 queue_sends = atomic_dec_return(&net_device->
 669                                                 queue_sends[q_idx]);
 670
 671                 if (net_device->destroy && num_outstanding_sends == 0)
 672                         wake_up(&net_device->wait_drain);
 673
 674                 if (netif_tx_queue_stopped(netdev_get_tx_queue(ndev, q_idx)) &&
 675                     !net_device_ctx->start_remove &&
 676                     (hv_ringbuf_avail_percent(&channel->outbound) >
 677                      RING_AVAIL_PERCENT_HIWATER || queue_sends < 1))
 678                                 netif_tx_wake_queue(netdev_get_tx_queue(
 679                                                     ndev, q_idx));
 680         } else {
 681                 netdev_err(ndev, "Unknown send completion packet type- "
 682                            "%d received!!\n", nvsp_packet->hdr.msg_type);
 683         }
 684
 685 }
 686
 687 static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
 688 {
 689         unsigned long index;
 690         u32 max_words = net_device->map_words;
 691         unsigned long *map_addr = (unsigned long *)net_device->send_section_map;
 692         u32 section_cnt = net_device->send_section_cnt;
 693         int ret_val = NETVSC_INVALID_INDEX;
 694         int i;
 695         int prev_val;
 696
 697         for (i = 0; i < max_words; i++) {
 698                 if (!~(map_addr[i]))
 699                         continue;
 700                 index = ffz(map_addr[i]);
 701                 prev_val = sync_test_and_set_bit(index, &map_addr[i]);
 702                 if (prev_val)
 703                         continue;
 704                 if ((index + (i * BITS_PER_LONG)) >= section_cnt)
 705                         break;
 706                 ret_val = (index + (i * BITS_PER_LONG));
 707                 break;
 708         }
 709         return ret_val;
 710 }
 711
 712 static u32 netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 713                                    unsigned int section_index,
 714                                    u32 pend_size,
 715                                    struct hv_netvsc_packet *packet,
 716                                    struct rndis_message *rndis_msg,
 717                                    struct hv_page_buffer **pb,
 718                                    struct sk_buff *skb)
 719 {
 720         char *start = net_device->send_buf;
 721         char *dest = start + (section_index * net_device->send_section_size)
 722                      + pend_size;
 723         int i;
 724         bool is_data_pkt = (skb != NULL) ? true : false;
 725         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 726         u32 msg_size = 0;
 727         u32 padding = 0;
 728         u32 remain = packet->total_data_buflen % net_device->pkt_align;
 729         u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
 730                 packet->page_buf_cnt;
 731
 732         /* Add padding */
 733         if (is_data_pkt && xmit_more && remain &&
 734             !packet->cp_partial) {
 735                 padding = net_device->pkt_align - remain;
 736                 rndis_msg->msg_len += padding;
 737                 packet->total_data_buflen += padding;
 738         }
 739
 740         for (i = 0; i < page_count; i++) {
 741                 char *src = phys_to_virt((*pb)[i].pfn << PAGE_SHIFT);
 742                 u32 offset = (*pb)[i].offset;
 743                 u32 len = (*pb)[i].len;
 744
 745                 memcpy(dest, (src + offset), len);
 746                 msg_size += len;
 747                 dest += len;
 748         }
 749
 750         if (padding) {
 751                 memset(dest, 0, padding);
 752                 msg_size += padding;
 753         }
 754
 755         return msg_size;
 756 }
 757
 758 static inline int netvsc_send_pkt(
 759         struct hv_device *device,
 760         struct hv_netvsc_packet *packet,
 761         struct netvsc_device *net_device,
 762         struct hv_page_buffer **pb,
 763         struct sk_buff *skb)
 764 {
 765         struct nvsp_message nvmsg;
 766         u16 q_idx = packet->q_idx;
 767         struct vmbus_channel *out_channel = net_device->chn_table[q_idx];
 768         struct net_device *ndev = hv_get_drvdata(device);
 769         u64 req_id;
 770         int ret;
 771         struct hv_page_buffer *pgbuf;
 772         u32 ring_avail = hv_ringbuf_avail_percent(&out_channel->outbound);
 773         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 774
 775         nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 776         if (skb != NULL) {
 777                 /* 0 is RMC_DATA; */
 778                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 0;
 779         } else {
 780                 /* 1 is RMC_CONTROL; */
 781                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 1;
 782         }
 783
 784         nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
 785                 packet->send_buf_index;
 786         if (packet->send_buf_index == NETVSC_INVALID_INDEX)
 787                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
 788         else
 789                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size =
 790                         packet->total_data_buflen;
 791
 792         req_id = (ulong)skb;
 793
 794         if (out_channel->rescind)
 795                 return -ENODEV;
 796
 797         /*
 798          * It is possible that once we successfully place this packet
 799          * on the ringbuffer, we may stop the queue. In that case, we want
 800          * to notify the host independent of the xmit_more flag. We don't
 801          * need to be precise here; in the worst case we may signal the host
 802          * unnecessarily.
 803          */
 804         if (ring_avail < (RING_AVAIL_PERCENT_LOWATER + 1))
 805                 xmit_more = false;
 806
 807         if (packet->page_buf_cnt) {
 808                 pgbuf = packet->cp_partial ? (*pb) +
 809                         packet->rmsg_pgcnt : (*pb);
 810                 ret = vmbus_sendpacket_pagebuffer_ctl(out_channel,
 811                                                       pgbuf,
 812                                                       packet->page_buf_cnt,
 813                                                       &nvmsg,
 814                                                       sizeof(struct nvsp_message),
 815                                                       req_id,
 816                                                       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
 817                                                       !xmit_more);
 818         } else {
 819                 ret = vmbus_sendpacket_ctl(out_channel, &nvmsg,
 820                                            sizeof(struct nvsp_message),
 821                                            req_id,
 822                                            VM_PKT_DATA_INBAND,
 823                                            VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
 824                                            !xmit_more);
 825         }
 826
 827         if (ret == 0) {
 828                 atomic_inc(&net_device->num_outstanding_sends);
 829                 atomic_inc(&net_device->queue_sends[q_idx]);
 830
 831                 if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
 832                         netif_tx_stop_queue(netdev_get_tx_queue(ndev, q_idx));
 833
 834                         if (atomic_read(&net_device->
 835                                 queue_sends[q_idx]) < 1)
 836                                 netif_tx_wake_queue(netdev_get_tx_queue(
 837                                                     ndev, q_idx));
 838                 }
 839         } else if (ret == -EAGAIN) {
 840                 netif_tx_stop_queue(netdev_get_tx_queue(
 841                                     ndev, q_idx));
 842                 if (atomic_read(&net_device->queue_sends[q_idx]) < 1) {
 843                         netif_tx_wake_queue(netdev_get_tx_queue(
 844                                             ndev, q_idx));
 845                         ret = -ENOSPC;
 846                 }
 847         } else {
 848                 netdev_err(ndev, "Unable to send packet %p ret %d\n",
 849                            packet, ret);
 850         }
 851
 852         return ret;
 853 }
 854
 855 /* Move packet out of multi send data (msd), and clear msd */
 856 static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
 857                                 struct sk_buff **msd_skb,
 858                                 struct multi_send_data *msdp)
 859 {
 860         *msd_skb = msdp->skb;
 861         *msd_send = msdp->pkt;
 862         msdp->skb = NULL;
 863         msdp->pkt = NULL;
 864         msdp->count = 0;
 865 }
 866
 867 int netvsc_send(struct hv_device *device,
 868                 struct hv_netvsc_packet *packet,
 869                 struct rndis_message *rndis_msg,
 870                 struct hv_page_buffer **pb,
 871                 struct sk_buff *skb)
 872 {
 873         struct netvsc_device *net_device;
 874         int ret = 0, m_ret = 0;
 875         struct vmbus_channel *out_channel;
 876         u16 q_idx = packet->q_idx;
 877         u32 pktlen = packet->total_data_buflen, msd_len = 0;
 878         unsigned int section_index = NETVSC_INVALID_INDEX;
 879         struct multi_send_data *msdp;
 880         struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
 881         struct sk_buff *msd_skb = NULL;
 882         bool try_batch;
 883         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 884
 885         net_device = get_outbound_net_device(device);
 886         if (!net_device)
 887                 return -ENODEV;
 888
 889         out_channel = net_device->chn_table[q_idx];
 890
 891         packet->send_buf_index = NETVSC_INVALID_INDEX;
 892         packet->cp_partial = false;
 893
 894         /* Send control message directly without accessing msd (Multi-Send
 895          * Data) field which may be changed during data packet processing.
 896          */
 897         if (!skb) {
 898                 cur_send = packet;
 899                 goto send_now;
 900         }
 901
 902         msdp = &net_device->msd[q_idx];
 903
 904         /* batch packets in send buffer if possible */
 905         if (msdp->pkt)
 906                 msd_len = msdp->pkt->total_data_buflen;
 907
 908         try_batch = (skb != NULL) && msd_len > 0 && msdp->count <
 909                     net_device->max_pkt;
 910
 911         if (try_batch && msd_len + pktlen + net_device->pkt_align <
 912             net_device->send_section_size) {
 913                 section_index = msdp->pkt->send_buf_index;
 914
 915         } else if (try_batch && msd_len + packet->rmsg_size <
 916                    net_device->send_section_size) {
 917                 section_index = msdp->pkt->send_buf_index;
 918                 packet->cp_partial = true;
 919
 920         } else if ((skb != NULL) && pktlen + net_device->pkt_align <
 921                    net_device->send_section_size) {
 922                 section_index = netvsc_get_next_send_section(net_device);
 923                 if (section_index != NETVSC_INVALID_INDEX) {
 924                         move_pkt_msd(&msd_send, &msd_skb, msdp);
 925                         msd_len = 0;
 926                 }
 927         }
 928
 929         if (section_index != NETVSC_INVALID_INDEX) {
 930                 netvsc_copy_to_send_buf(net_device,
 931                                         section_index, msd_len,
 932                                         packet, rndis_msg, pb, skb);
 933
 934                 packet->send_buf_index = section_index;
 935
 936                 if (packet->cp_partial) {
 937                         packet->page_buf_cnt -= packet->rmsg_pgcnt;
 938                         packet->total_data_buflen = msd_len + packet->rmsg_size;
 939                 } else {
 940                         packet->page_buf_cnt = 0;
 941                         packet->total_data_buflen += msd_len;
 942                 }
 943
 944                 if (msdp->skb)
 945                         dev_kfree_skb_any(msdp->skb);
 946
 947                 if (xmit_more && !packet->cp_partial) {
 948                         msdp->skb = skb;
 949                         msdp->pkt = packet;
 950                         msdp->count++;
 951                 } else {
 952                         cur_send = packet;
 953                         msdp->skb = NULL;
 954                         msdp->pkt = NULL;
 955                         msdp->count = 0;
 956                 }
 957         } else {
 958                 move_pkt_msd(&msd_send, &msd_skb, msdp);
 959                 cur_send = packet;
 960         }
 961
 962         if (msd_send) {
 963                 m_ret = netvsc_send_pkt(device, msd_send, net_device,
 964                                         NULL, msd_skb);
 965
 966                 if (m_ret != 0) {
 967                         netvsc_free_send_slot(net_device,
 968                                               msd_send->send_buf_index);
 969                         dev_kfree_skb_any(msd_skb);
 970                 }
 971         }
 972
 973 send_now:
 974         if (cur_send)
 975                 ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);
 976
 977         if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
 978                 netvsc_free_send_slot(net_device, section_index);
 979
 980         return ret;
 981 }
 982
 983 static void netvsc_send_recv_completion(struct hv_device *device,
 984                                         struct vmbus_channel *channel,
 985                                         struct netvsc_device *net_device,
 986                                         u64 transaction_id, u32 status)
 987 {
 988         struct nvsp_message recvcompMessage;
 989         int retries = 0;
 990         int ret;
 991         struct net_device *ndev = hv_get_drvdata(device);
 992
 993         recvcompMessage.hdr.msg_type =
 994                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
 995
 996         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status = status;
 997
 998 retry_send_cmplt:
 999         /* Send the completion */
1000         ret = vmbus_sendpacket(channel, &recvcompMessage,
1001                                sizeof(struct nvsp_message), transaction_id,
1002                                VM_PKT_COMP, 0);
1003         if (ret == 0) {
1004                 /* success */
1005                 /* no-op */
1006         } else if (ret == -EAGAIN) {
1007                 /* no more room...wait a bit and attempt to retry 3 times */
1008                 retries++;
1009                 netdev_err(ndev, "unable to send receive completion pkt"
1010                         " (tid %llx)...retrying %d\n", transaction_id, retries);
1011
1012                 if (retries < 4) {
1013                         udelay(100);
1014                         goto retry_send_cmplt;
1015                 } else {
1016                         netdev_err(ndev, "unable to send receive "
1017                                 "completion pkt (tid %llx)...give up retrying\n",
1018                                 transaction_id);
1019                 }
1020         } else {
1021                 netdev_err(ndev, "unable to send receive "
1022                         "completion pkt - %llx\n", transaction_id);
1023         }
1024 }
1025
1026 static void netvsc_receive(struct netvsc_device *net_device,
1027                         struct vmbus_channel *channel,
1028                         struct hv_device *device,
1029                         struct vmpacket_descriptor *packet)
1030 {
1031         struct vmtransfer_page_packet_header *vmxferpage_packet;
1032         struct nvsp_message *nvsp_packet;
1033         struct hv_netvsc_packet nv_pkt;
1034         struct hv_netvsc_packet *netvsc_packet = &nv_pkt;
1035         u32 status = NVSP_STAT_SUCCESS;
1036         int i;
1037         int count = 0;
1038         struct net_device *ndev = hv_get_drvdata(device);
1039         void *data;
1040
1041         /*
1042          * All inbound packets other than send completion should be xfer page
1043          * packet
1044          */
1045         if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
1046                 netdev_err(ndev, "Unknown packet type received - %d\n",
1047                            packet->type);
1048                 return;
1049         }
1050
1051         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
1052                         (packet->offset8 << 3));
1053
1054         /* Make sure this is a valid nvsp packet */
1055         if (nvsp_packet->hdr.msg_type !=
1056             NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
1057                 netdev_err(ndev, "Unknown nvsp packet type received-"
1058                         " %d\n", nvsp_packet->hdr.msg_type);
1059                 return;
1060         }
1061
1062         vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
1063
1064         if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
1065                 netdev_err(ndev, "Invalid xfer page set id - "
1066                            "expecting %x got %x\n", NETVSC_RECEIVE_BUFFER_ID,
1067                            vmxferpage_packet->xfer_pageset_id);
1068                 return;
1069         }
1070
1071         count = vmxferpage_packet->range_cnt;
1072
1073         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1074         for (i = 0; i < count; i++) {
1075                 /* Initialize the netvsc packet */
1076                 data = (void *)((unsigned long)net_device->
1077                         recv_buf + vmxferpage_packet->ranges[i].byte_offset);
1078                 netvsc_packet->total_data_buflen =
1079                                         vmxferpage_packet->ranges[i].byte_count;
1080
1081                 /* Pass it to the upper layer */
1082                 status = rndis_filter_receive(device, netvsc_packet, &data,
1083                                               channel);
1084
1085         }
1086
1087         netvsc_send_recv_completion(device, channel, net_device,
1088                                     vmxferpage_packet->d.trans_id, status);
1089 }
1090
1091
1092 static void netvsc_send_table(struct hv_device *hdev,
1093                               struct nvsp_message *nvmsg)
1094 {
1095         struct netvsc_device *nvscdev;
1096         struct net_device *ndev = hv_get_drvdata(hdev);
1097         int i;
1098         u32 count, *tab;
1099
1100         nvscdev = get_outbound_net_device(hdev);
1101         if (!nvscdev)
1102                 return;
1103
1104         count = nvmsg->msg.v5_msg.send_table.count;
1105         if (count != VRSS_SEND_TAB_SIZE) {
1106                 netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1107                 return;
1108         }
1109
1110         tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
1111                       nvmsg->msg.v5_msg.send_table.offset);
1112
1113         for (i = 0; i < count; i++)
1114                 nvscdev->send_table[i] = tab[i];
1115 }
1116
1117 static void netvsc_send_vf(struct netvsc_device *nvdev,
1118                            struct nvsp_message *nvmsg)
1119 {
1120         nvdev->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1121         nvdev->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1122 }
1123
1124 static inline void netvsc_receive_inband(struct hv_device *hdev,
1125                                          struct netvsc_device *nvdev,
1126                                          struct nvsp_message *nvmsg)
1127 {
1128         switch (nvmsg->hdr.msg_type) {
1129         case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1130                 netvsc_send_table(hdev, nvmsg);
1131                 break;
1132
1133         case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1134                 netvsc_send_vf(nvdev, nvmsg);
1135                 break;
1136         }
1137 }
1138
1139 void netvsc_channel_cb(void *context)
1140 {
1141         int ret;
1142         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1143         struct hv_device *device;
1144         struct netvsc_device *net_device;
1145         u32 bytes_recvd;
1146         u64 request_id;
1147         struct vmpacket_descriptor *desc;
1148         unsigned char *buffer;
1149         int bufferlen = NETVSC_PACKET_SIZE;
1150         struct net_device *ndev;
1151         struct nvsp_message *nvmsg;
1152
1153         if (channel->primary_channel != NULL)
1154                 device = channel->primary_channel->device_obj;
1155         else
1156                 device = channel->device_obj;
1157
1158         net_device = get_inbound_net_device(device);
1159         if (!net_device)
1160                 return;
1161         ndev = hv_get_drvdata(device);
1162         buffer = get_per_channel_state(channel);
1163
1164         do {
1165                 ret = vmbus_recvpacket_raw(channel, buffer, bufferlen,
1166                                            &bytes_recvd, &request_id);
1167                 if (ret == 0) {
1168                         if (bytes_recvd > 0) {
1169                                 desc = (struct vmpacket_descriptor *)buffer;
1170                                 nvmsg = (struct nvsp_message *)((unsigned long)
1171                                          desc + (desc->offset8 << 3));
1172                                 switch (desc->type) {
1173                                 case VM_PKT_COMP:
1174                                         netvsc_send_completion(net_device,
1175                                                                 channel,
1176                                                                 device, desc);
1177                                         break;
1178
1179                                 case VM_PKT_DATA_USING_XFER_PAGES:
1180                                         netvsc_receive(net_device, channel,
1181                                                        device, desc);
1182                                         break;
1183
1184                                 case VM_PKT_DATA_INBAND:
1185                                         netvsc_receive_inband(device,
1186                                                               net_device,
1187                                                               nvmsg);
1188                                         break;
1189
1190                                 default:
1191                                         netdev_err(ndev,
1192                                                    "unhandled packet type %d, "
1193                                                    "tid %llx len %d\n",
1194                                                    desc->type, request_id,
1195                                                    bytes_recvd);
1196                                         break;
1197                                 }
1198
1199                         } else {
1200                                 /*
1201                                  * We are done for this pass.
1202                                  */
1203                                 break;
1204                         }
1205
1206                 } else if (ret == -ENOBUFS) {
1207                         if (bufferlen > NETVSC_PACKET_SIZE)
1208                                 kfree(buffer);
1209                         /* Handle large packet */
1210                         buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
1211                         if (buffer == NULL) {
1212                                 /* Try again next time around */
1213                                 netdev_err(ndev,
1214                                            "unable to allocate buffer of size "
1215                                            "(%d)!!\n", bytes_recvd);
1216                                 break;
1217                         }
1218
1219                         bufferlen = bytes_recvd;
1220                 }
1221         } while (1);
1222
1223         if (bufferlen > NETVSC_PACKET_SIZE)
1224                 kfree(buffer);
1225         return;
1226 }
1227
1228 /*
1229  * netvsc_device_add - Callback when the device belonging to this
1230  * driver is added
1231  */
1232 int netvsc_device_add(struct hv_device *device, void *additional_info)
1233 {
1234         int i, ret = 0;
1235         int ring_size =
1236         ((struct netvsc_device_info *)additional_info)->ring_size;
1237         struct netvsc_device *net_device;
1238         struct net_device *ndev = hv_get_drvdata(device);
1239         struct net_device_context *net_device_ctx = netdev_priv(ndev);
1240
1241         net_device = alloc_net_device();
1242         if (!net_device)
1243                 return -ENOMEM;
1244
1245         net_device->ring_size = ring_size;
1246
1247         /* Initialize the NetVSC channel extension */
1248         init_completion(&net_device->channel_init_wait);
1249
1250         set_per_channel_state(device->channel, net_device->cb_buffer);
1251
1252         /* Open the channel */
1253         ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
1254                          ring_size * PAGE_SIZE, NULL, 0,
1255                          netvsc_channel_cb, device->channel);
1256
1257         if (ret != 0) {
1258                 netdev_err(ndev, "unable to open channel: %d\n", ret);
1259                 goto cleanup;
1260         }
1261
1262         /* Channel is opened */
1263         pr_info("hv_netvsc channel opened successfully\n");
1264
1265         /* If we're reopening the device we may have multiple queues, fill the
1266          * chn_table with the default channel to use it before subchannels are
1267          * opened.
1268          */
1269         for (i = 0; i < VRSS_CHANNEL_MAX; i++)
1270                 net_device->chn_table[i] = device->channel;
1271
1272         /* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is
1273          * populated.
1274          */
1275         wmb();
1276
1277         net_device_ctx->nvdev = net_device;
1278
1279         /* Connect with the NetVsp */
1280         ret = netvsc_connect_vsp(device);
1281         if (ret != 0) {
1282                 netdev_err(ndev,
1283                         "unable to connect to NetVSP - %d\n", ret);
1284                 goto close;
1285         }
1286
1287         return ret;
1288
1289 close:
1290         /* Now, we can close the channel safely */
1291         vmbus_close(device->channel);
1292
1293 cleanup:
1294         free_netvsc_device(net_device);
1295
1296         return ret;
1297 }