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 netvsc_device *nv_dev, bool vf)
  41 {
  42         struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
  43         struct hv_device *dev = nv_dev->dev;
  44
  45         memset(init_pkt, 0, sizeof(struct nvsp_message));
  46         init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
  47         if (vf)
  48                 init_pkt->msg.v4_msg.active_dp.active_datapath =
  49                         NVSP_DATAPATH_VF;
  50         else
  51                 init_pkt->msg.v4_msg.active_dp.active_datapath =
  52                         NVSP_DATAPATH_SYNTHETIC;
  53
  54         vmbus_sendpacket(dev->channel, init_pkt,
  55                                sizeof(struct nvsp_message),
  56                                (unsigned long)init_pkt,
  57                                VM_PKT_DATA_INBAND, 0);
  58 }
  59
  60
  61 static struct netvsc_device *alloc_net_device(struct hv_device *device)
  62 {
  63         struct netvsc_device *net_device;
  64         struct net_device *ndev = hv_get_drvdata(device);
  65
  66         net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
  67         if (!net_device)
  68                 return NULL;
  69
  70         net_device->cb_buffer = kzalloc(NETVSC_PACKET_SIZE, GFP_KERNEL);
  71         if (!net_device->cb_buffer) {
  72                 kfree(net_device);
  73                 return NULL;
  74         }
  75
  76         init_waitqueue_head(&net_device->wait_drain);
  77         net_device->destroy = false;
  78         atomic_set(&net_device->open_cnt, 0);
  79         atomic_set(&net_device->vf_use_cnt, 0);
  80         net_device->dev = device;
  81         net_device->ndev = ndev;
  82         net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
  83         net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
  84
  85         net_device->vf_netdev = NULL;
  86         net_device->vf_inject = false;
  87
  88         hv_set_drvdata(device, net_device);
  89         return net_device;
  90 }
  91
  92 static void free_netvsc_device(struct netvsc_device *nvdev)
  93 {
  94         kfree(nvdev->cb_buffer);
  95         kfree(nvdev);
  96 }
  97
  98 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
  99 {
 100         struct netvsc_device *net_device;
 101
 102         net_device = hv_get_drvdata(device);
 103         if (net_device && net_device->destroy)
 104                 net_device = NULL;
 105
 106         return net_device;
 107 }
 108
 109 static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
 110 {
 111         struct netvsc_device *net_device;
 112
 113         net_device = hv_get_drvdata(device);
 114
 115         if (!net_device)
 116                 goto get_in_err;
 117
 118         if (net_device->destroy &&
 119                 atomic_read(&net_device->num_outstanding_sends) == 0)
 120                 net_device = NULL;
 121
 122 get_in_err:
 123         return net_device;
 124 }
 125
 126
 127 static int netvsc_destroy_buf(struct netvsc_device *net_device)
 128 {
 129         struct nvsp_message *revoke_packet;
 130         int ret = 0;
 131         struct net_device *ndev = net_device->ndev;
 132
 133         /*
 134          * If we got a section count, it means we received a
 135          * SendReceiveBufferComplete msg (ie sent
 136          * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
 137          * to send a revoke msg here
 138          */
 139         if (net_device->recv_section_cnt) {
 140                 /* Send the revoke receive buffer */
 141                 revoke_packet = &net_device->revoke_packet;
 142                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 143
 144                 revoke_packet->hdr.msg_type =
 145                         NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 146                 revoke_packet->msg.v1_msg.
 147                 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 148
 149                 ret = vmbus_sendpacket(net_device->dev->channel,
 150                                        revoke_packet,
 151                                        sizeof(struct nvsp_message),
 152                                        (unsigned long)revoke_packet,
 153                                        VM_PKT_DATA_INBAND, 0);
 154                 /*
 155                  * If we failed here, we might as well return and
 156                  * have a leak rather than continue and a bugchk
 157                  */
 158                 if (ret != 0) {
 159                         netdev_err(ndev, "unable to send "
 160                                 "revoke receive buffer to netvsp\n");
 161                         return ret;
 162                 }
 163         }
 164
 165         /* Teardown the gpadl on the vsp end */
 166         if (net_device->recv_buf_gpadl_handle) {
 167                 ret = vmbus_teardown_gpadl(net_device->dev->channel,
 168                            net_device->recv_buf_gpadl_handle);
 169
 170                 /* If we failed here, we might as well return and have a leak
 171                  * rather than continue and a bugchk
 172                  */
 173                 if (ret != 0) {
 174                         netdev_err(ndev,
 175                                    "unable to teardown receive buffer's gpadl\n");
 176                         return ret;
 177                 }
 178                 net_device->recv_buf_gpadl_handle = 0;
 179         }
 180
 181         if (net_device->recv_buf) {
 182                 /* Free up the receive buffer */
 183                 vfree(net_device->recv_buf);
 184                 net_device->recv_buf = NULL;
 185         }
 186
 187         if (net_device->recv_section) {
 188                 net_device->recv_section_cnt = 0;
 189                 kfree(net_device->recv_section);
 190                 net_device->recv_section = NULL;
 191         }
 192
 193         /* Deal with the send buffer we may have setup.
 194          * If we got a  send section size, it means we received a
 195          * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
 196          * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
 197          * to send a revoke msg here
 198          */
 199         if (net_device->send_section_size) {
 200                 /* Send the revoke receive buffer */
 201                 revoke_packet = &net_device->revoke_packet;
 202                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 203
 204                 revoke_packet->hdr.msg_type =
 205                         NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
 206                 revoke_packet->msg.v1_msg.revoke_send_buf.id =
 207                         NETVSC_SEND_BUFFER_ID;
 208
 209                 ret = vmbus_sendpacket(net_device->dev->channel,
 210                                        revoke_packet,
 211                                        sizeof(struct nvsp_message),
 212                                        (unsigned long)revoke_packet,
 213                                        VM_PKT_DATA_INBAND, 0);
 214                 /* If we failed here, we might as well return and
 215                  * have a leak rather than continue and a bugchk
 216                  */
 217                 if (ret != 0) {
 218                         netdev_err(ndev, "unable to send "
 219                                    "revoke send buffer to netvsp\n");
 220                         return ret;
 221                 }
 222         }
 223         /* Teardown the gpadl on the vsp end */
 224         if (net_device->send_buf_gpadl_handle) {
 225                 ret = vmbus_teardown_gpadl(net_device->dev->channel,
 226                                            net_device->send_buf_gpadl_handle);
 227
 228                 /* If we failed here, we might as well return and have a leak
 229                  * rather than continue and a bugchk
 230                  */
 231                 if (ret != 0) {
 232                         netdev_err(ndev,
 233                                    "unable to teardown send buffer's gpadl\n");
 234                         return ret;
 235                 }
 236                 net_device->send_buf_gpadl_handle = 0;
 237         }
 238         if (net_device->send_buf) {
 239                 /* Free up the send buffer */
 240                 vfree(net_device->send_buf);
 241                 net_device->send_buf = NULL;
 242         }
 243         kfree(net_device->send_section_map);
 244
 245         return ret;
 246 }
 247
 248 static int netvsc_init_buf(struct hv_device *device)
 249 {
 250         int ret = 0;
 251         unsigned long t;
 252         struct netvsc_device *net_device;
 253         struct nvsp_message *init_packet;
 254         struct net_device *ndev;
 255         int node;
 256
 257         net_device = get_outbound_net_device(device);
 258         if (!net_device)
 259                 return -ENODEV;
 260         ndev = net_device->ndev;
 261
 262         node = cpu_to_node(device->channel->target_cpu);
 263         net_device->recv_buf = vzalloc_node(net_device->recv_buf_size, node);
 264         if (!net_device->recv_buf)
 265                 net_device->recv_buf = vzalloc(net_device->recv_buf_size);
 266
 267         if (!net_device->recv_buf) {
 268                 netdev_err(ndev, "unable to allocate receive "
 269                         "buffer of size %d\n", net_device->recv_buf_size);
 270                 ret = -ENOMEM;
 271                 goto cleanup;
 272         }
 273
 274         /*
 275          * Establish the gpadl handle for this buffer on this
 276          * channel.  Note: This call uses the vmbus connection rather
 277          * than the channel to establish the gpadl handle.
 278          */
 279         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 280                                     net_device->recv_buf_size,
 281                                     &net_device->recv_buf_gpadl_handle);
 282         if (ret != 0) {
 283                 netdev_err(ndev,
 284                         "unable to establish receive buffer's gpadl\n");
 285                 goto cleanup;
 286         }
 287
 288
 289         /* Notify the NetVsp of the gpadl handle */
 290         init_packet = &net_device->channel_init_pkt;
 291
 292         memset(init_packet, 0, sizeof(struct nvsp_message));
 293
 294         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 295         init_packet->msg.v1_msg.send_recv_buf.
 296                 gpadl_handle = net_device->recv_buf_gpadl_handle;
 297         init_packet->msg.v1_msg.
 298                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 299
 300         /* Send the gpadl notification request */
 301         ret = vmbus_sendpacket(device->channel, init_packet,
 302                                sizeof(struct nvsp_message),
 303                                (unsigned long)init_packet,
 304                                VM_PKT_DATA_INBAND,
 305                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 306         if (ret != 0) {
 307                 netdev_err(ndev,
 308                         "unable to send receive buffer's gpadl to netvsp\n");
 309                 goto cleanup;
 310         }
 311
 312         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 313         BUG_ON(t == 0);
 314
 315
 316         /* Check the response */
 317         if (init_packet->msg.v1_msg.
 318             send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
 319                 netdev_err(ndev, "Unable to complete receive buffer "
 320                            "initialization with NetVsp - status %d\n",
 321                            init_packet->msg.v1_msg.
 322                            send_recv_buf_complete.status);
 323                 ret = -EINVAL;
 324                 goto cleanup;
 325         }
 326
 327         /* Parse the response */
 328
 329         net_device->recv_section_cnt = init_packet->msg.
 330                 v1_msg.send_recv_buf_complete.num_sections;
 331
 332         net_device->recv_section = kmemdup(
 333                 init_packet->msg.v1_msg.send_recv_buf_complete.sections,
 334                 net_device->recv_section_cnt *
 335                 sizeof(struct nvsp_1_receive_buffer_section),
 336                 GFP_KERNEL);
 337         if (net_device->recv_section == NULL) {
 338                 ret = -EINVAL;
 339                 goto cleanup;
 340         }
 341
 342         /*
 343          * For 1st release, there should only be 1 section that represents the
 344          * entire receive buffer
 345          */
 346         if (net_device->recv_section_cnt != 1 ||
 347             net_device->recv_section->offset != 0) {
 348                 ret = -EINVAL;
 349                 goto cleanup;
 350         }
 351
 352         /* Now setup the send buffer.
 353          */
 354         net_device->send_buf = vzalloc_node(net_device->send_buf_size, node);
 355         if (!net_device->send_buf)
 356                 net_device->send_buf = vzalloc(net_device->send_buf_size);
 357         if (!net_device->send_buf) {
 358                 netdev_err(ndev, "unable to allocate send "
 359                            "buffer of size %d\n", net_device->send_buf_size);
 360                 ret = -ENOMEM;
 361                 goto cleanup;
 362         }
 363
 364         /* Establish the gpadl handle for this buffer on this
 365          * channel.  Note: This call uses the vmbus connection rather
 366          * than the channel to establish the gpadl handle.
 367          */
 368         ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
 369                                     net_device->send_buf_size,
 370                                     &net_device->send_buf_gpadl_handle);
 371         if (ret != 0) {
 372                 netdev_err(ndev,
 373                            "unable to establish send buffer's gpadl\n");
 374                 goto cleanup;
 375         }
 376
 377         /* Notify the NetVsp of the gpadl handle */
 378         init_packet = &net_device->channel_init_pkt;
 379         memset(init_packet, 0, sizeof(struct nvsp_message));
 380         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
 381         init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
 382                 net_device->send_buf_gpadl_handle;
 383         init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
 384
 385         /* Send the gpadl notification request */
 386         ret = vmbus_sendpacket(device->channel, init_packet,
 387                                sizeof(struct nvsp_message),
 388                                (unsigned long)init_packet,
 389                                VM_PKT_DATA_INBAND,
 390                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 391         if (ret != 0) {
 392                 netdev_err(ndev,
 393                            "unable to send send buffer's gpadl to netvsp\n");
 394                 goto cleanup;
 395         }
 396
 397         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 398         BUG_ON(t == 0);
 399
 400         /* Check the response */
 401         if (init_packet->msg.v1_msg.
 402             send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
 403                 netdev_err(ndev, "Unable to complete send buffer "
 404                            "initialization with NetVsp - status %d\n",
 405                            init_packet->msg.v1_msg.
 406                            send_send_buf_complete.status);
 407                 ret = -EINVAL;
 408                 goto cleanup;
 409         }
 410
 411         /* Parse the response */
 412         net_device->send_section_size = init_packet->msg.
 413                                 v1_msg.send_send_buf_complete.section_size;
 414
 415         /* Section count is simply the size divided by the section size.
 416          */
 417         net_device->send_section_cnt =
 418                 net_device->send_buf_size/net_device->send_section_size;
 419
 420         dev_info(&device->device, "Send section size: %d, Section count:%d\n",
 421                  net_device->send_section_size, net_device->send_section_cnt);
 422
 423         /* Setup state for managing the send buffer. */
 424         net_device->map_words = DIV_ROUND_UP(net_device->send_section_cnt,
 425                                              BITS_PER_LONG);
 426
 427         net_device->send_section_map =
 428                 kzalloc(net_device->map_words * sizeof(ulong), GFP_KERNEL);
 429         if (net_device->send_section_map == NULL) {
 430                 ret = -ENOMEM;
 431                 goto cleanup;
 432         }
 433
 434         goto exit;
 435
 436 cleanup:
 437         netvsc_destroy_buf(net_device);
 438
 439 exit:
 440         return ret;
 441 }
 442
 443
 444 /* Negotiate NVSP protocol version */
 445 static int negotiate_nvsp_ver(struct hv_device *device,
 446                               struct netvsc_device *net_device,
 447                               struct nvsp_message *init_packet,
 448                               u32 nvsp_ver)
 449 {
 450         int ret;
 451         unsigned long t;
 452
 453         memset(init_packet, 0, sizeof(struct nvsp_message));
 454         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 455         init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
 456         init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
 457
 458         /* Send the init request */
 459         ret = vmbus_sendpacket(device->channel, init_packet,
 460                                sizeof(struct nvsp_message),
 461                                (unsigned long)init_packet,
 462                                VM_PKT_DATA_INBAND,
 463                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 464
 465         if (ret != 0)
 466                 return ret;
 467
 468         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 469
 470         if (t == 0)
 471                 return -ETIMEDOUT;
 472
 473         if (init_packet->msg.init_msg.init_complete.status !=
 474             NVSP_STAT_SUCCESS)
 475                 return -EINVAL;
 476
 477         if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
 478                 return 0;
 479
 480         /* NVSPv2 or later: Send NDIS config */
 481         memset(init_packet, 0, sizeof(struct nvsp_message));
 482         init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
 483         init_packet->msg.v2_msg.send_ndis_config.mtu = net_device->ndev->mtu +
 484                                                        ETH_HLEN;
 485         init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
 486
 487         if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5)
 488                 init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
 489
 490         ret = vmbus_sendpacket(device->channel, init_packet,
 491                                 sizeof(struct nvsp_message),
 492                                 (unsigned long)init_packet,
 493                                 VM_PKT_DATA_INBAND, 0);
 494
 495         return ret;
 496 }
 497
 498 static int netvsc_connect_vsp(struct hv_device *device)
 499 {
 500         int ret;
 501         struct netvsc_device *net_device;
 502         struct nvsp_message *init_packet;
 503         int ndis_version;
 504         struct net_device *ndev;
 505         u32 ver_list[] = { NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
 506                 NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5 };
 507         int i, num_ver = 4; /* number of different NVSP versions */
 508
 509         net_device = get_outbound_net_device(device);
 510         if (!net_device)
 511                 return -ENODEV;
 512         ndev = net_device->ndev;
 513
 514         init_packet = &net_device->channel_init_pkt;
 515
 516         /* Negotiate the latest NVSP protocol supported */
 517         for (i = num_ver - 1; i >= 0; i--)
 518                 if (negotiate_nvsp_ver(device, net_device, init_packet,
 519                                        ver_list[i])  == 0) {
 520                         net_device->nvsp_version = ver_list[i];
 521                         break;
 522                 }
 523
 524         if (i < 0) {
 525                 ret = -EPROTO;
 526                 goto cleanup;
 527         }
 528
 529         pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
 530
 531         /* Send the ndis version */
 532         memset(init_packet, 0, sizeof(struct nvsp_message));
 533
 534         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
 535                 ndis_version = 0x00060001;
 536         else
 537                 ndis_version = 0x0006001e;
 538
 539         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 540         init_packet->msg.v1_msg.
 541                 send_ndis_ver.ndis_major_ver =
 542                                 (ndis_version & 0xFFFF0000) >> 16;
 543         init_packet->msg.v1_msg.
 544                 send_ndis_ver.ndis_minor_ver =
 545                                 ndis_version & 0xFFFF;
 546
 547         /* Send the init request */
 548         ret = vmbus_sendpacket(device->channel, init_packet,
 549                                 sizeof(struct nvsp_message),
 550                                 (unsigned long)init_packet,
 551                                 VM_PKT_DATA_INBAND, 0);
 552         if (ret != 0)
 553                 goto cleanup;
 554
 555         /* Post the big receive buffer to NetVSP */
 556         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
 557                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
 558         else
 559                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 560         net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
 561
 562         ret = netvsc_init_buf(device);
 563
 564 cleanup:
 565         return ret;
 566 }
 567
 568 static void netvsc_disconnect_vsp(struct netvsc_device *net_device)
 569 {
 570         netvsc_destroy_buf(net_device);
 571 }
 572
 573 /*
 574  * netvsc_device_remove - Callback when the root bus device is removed
 575  */
 576 int netvsc_device_remove(struct hv_device *device)
 577 {
 578         struct netvsc_device *net_device;
 579         unsigned long flags;
 580
 581         net_device = hv_get_drvdata(device);
 582
 583         netvsc_disconnect_vsp(net_device);
 584
 585         /*
 586          * Since we have already drained, we don't need to busy wait
 587          * as was done in final_release_stor_device()
 588          * Note that we cannot set the ext pointer to NULL until
 589          * we have drained - to drain the outgoing packets, we need to
 590          * allow incoming packets.
 591          */
 592
 593         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 594         hv_set_drvdata(device, NULL);
 595         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 596
 597         /*
 598          * At this point, no one should be accessing net_device
 599          * except in here
 600          */
 601         dev_notice(&device->device, "net device safe to remove\n");
 602
 603         /* Now, we can close the channel safely */
 604         vmbus_close(device->channel);
 605
 606         /* Release all resources */
 607         vfree(net_device->sub_cb_buf);
 608         free_netvsc_device(net_device);
 609         return 0;
 610 }
 611
 612
 613 #define RING_AVAIL_PERCENT_HIWATER 20
 614 #define RING_AVAIL_PERCENT_LOWATER 10
 615
 616 /*
 617  * Get the percentage of available bytes to write in the ring.
 618  * The return value is in range from 0 to 100.
 619  */
 620 static inline u32 hv_ringbuf_avail_percent(
 621                 struct hv_ring_buffer_info *ring_info)
 622 {
 623         u32 avail_read, avail_write;
 624
 625         hv_get_ringbuffer_availbytes(ring_info, &avail_read, &avail_write);
 626
 627         return avail_write * 100 / ring_info->ring_datasize;
 628 }
 629
 630 static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
 631                                          u32 index)
 632 {
 633         sync_change_bit(index, net_device->send_section_map);
 634 }
 635
 636 static void netvsc_send_completion(struct netvsc_device *net_device,
 637                                    struct vmbus_channel *incoming_channel,
 638                                    struct hv_device *device,
 639                                    struct vmpacket_descriptor *packet)
 640 {
 641         struct nvsp_message *nvsp_packet;
 642         struct hv_netvsc_packet *nvsc_packet;
 643         struct net_device *ndev;
 644         u32 send_index;
 645         struct sk_buff *skb;
 646
 647         ndev = net_device->ndev;
 648
 649         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 650                         (packet->offset8 << 3));
 651
 652         if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
 653             (nvsp_packet->hdr.msg_type ==
 654              NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
 655             (nvsp_packet->hdr.msg_type ==
 656              NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE) ||
 657             (nvsp_packet->hdr.msg_type ==
 658              NVSP_MSG5_TYPE_SUBCHANNEL)) {
 659                 /* Copy the response back */
 660                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 661                        sizeof(struct nvsp_message));
 662                 complete(&net_device->channel_init_wait);
 663         } else if (nvsp_packet->hdr.msg_type ==
 664                    NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
 665                 int num_outstanding_sends;
 666                 u16 q_idx = 0;
 667                 struct vmbus_channel *channel = device->channel;
 668                 int queue_sends;
 669
 670                 /* Get the send context */
 671                 skb = (struct sk_buff *)(unsigned long)packet->trans_id;
 672
 673                 /* Notify the layer above us */
 674                 if (skb) {
 675                         nvsc_packet = (struct hv_netvsc_packet *) skb->cb;
 676                         send_index = nvsc_packet->send_buf_index;
 677                         if (send_index != NETVSC_INVALID_INDEX)
 678                                 netvsc_free_send_slot(net_device, send_index);
 679                         q_idx = nvsc_packet->q_idx;
 680                         channel = incoming_channel;
 681                         dev_kfree_skb_any(skb);
 682                 }
 683
 684                 num_outstanding_sends =
 685                         atomic_dec_return(&net_device->num_outstanding_sends);
 686                 queue_sends = atomic_dec_return(&net_device->
 687                                                 queue_sends[q_idx]);
 688
 689                 if (net_device->destroy && num_outstanding_sends == 0)
 690                         wake_up(&net_device->wait_drain);
 691
 692                 if (netif_tx_queue_stopped(netdev_get_tx_queue(ndev, q_idx)) &&
 693                     !net_device->nd_ctx->start_remove &&
 694                     (hv_ringbuf_avail_percent(&channel->outbound) >
 695                      RING_AVAIL_PERCENT_HIWATER || queue_sends < 1))
 696                                 netif_tx_wake_queue(netdev_get_tx_queue(
 697                                                     ndev, q_idx));
 698         } else {
 699                 netdev_err(ndev, "Unknown send completion packet type- "
 700                            "%d received!!\n", nvsp_packet->hdr.msg_type);
 701         }
 702
 703 }
 704
 705 static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
 706 {
 707         unsigned long index;
 708         u32 max_words = net_device->map_words;
 709         unsigned long *map_addr = (unsigned long *)net_device->send_section_map;
 710         u32 section_cnt = net_device->send_section_cnt;
 711         int ret_val = NETVSC_INVALID_INDEX;
 712         int i;
 713         int prev_val;
 714
 715         for (i = 0; i < max_words; i++) {
 716                 if (!~(map_addr[i]))
 717                         continue;
 718                 index = ffz(map_addr[i]);
 719                 prev_val = sync_test_and_set_bit(index, &map_addr[i]);
 720                 if (prev_val)
 721                         continue;
 722                 if ((index + (i * BITS_PER_LONG)) >= section_cnt)
 723                         break;
 724                 ret_val = (index + (i * BITS_PER_LONG));
 725                 break;
 726         }
 727         return ret_val;
 728 }
 729
 730 static u32 netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 731                                    unsigned int section_index,
 732                                    u32 pend_size,
 733                                    struct hv_netvsc_packet *packet,
 734                                    struct rndis_message *rndis_msg,
 735                                    struct hv_page_buffer **pb,
 736                                    struct sk_buff *skb)
 737 {
 738         char *start = net_device->send_buf;
 739         char *dest = start + (section_index * net_device->send_section_size)
 740                      + pend_size;
 741         int i;
 742         bool is_data_pkt = (skb != NULL) ? true : false;
 743         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 744         u32 msg_size = 0;
 745         u32 padding = 0;
 746         u32 remain = packet->total_data_buflen % net_device->pkt_align;
 747         u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
 748                 packet->page_buf_cnt;
 749
 750         /* Add padding */
 751         if (is_data_pkt && xmit_more && remain &&
 752             !packet->cp_partial) {
 753                 padding = net_device->pkt_align - remain;
 754                 rndis_msg->msg_len += padding;
 755                 packet->total_data_buflen += padding;
 756         }
 757
 758         for (i = 0; i < page_count; i++) {
 759                 char *src = phys_to_virt((*pb)[i].pfn << PAGE_SHIFT);
 760                 u32 offset = (*pb)[i].offset;
 761                 u32 len = (*pb)[i].len;
 762
 763                 memcpy(dest, (src + offset), len);
 764                 msg_size += len;
 765                 dest += len;
 766         }
 767
 768         if (padding) {
 769                 memset(dest, 0, padding);
 770                 msg_size += padding;
 771         }
 772
 773         return msg_size;
 774 }
 775
 776 static inline int netvsc_send_pkt(
 777         struct hv_netvsc_packet *packet,
 778         struct netvsc_device *net_device,
 779         struct hv_page_buffer **pb,
 780         struct sk_buff *skb)
 781 {
 782         struct nvsp_message nvmsg;
 783         u16 q_idx = packet->q_idx;
 784         struct vmbus_channel *out_channel = net_device->chn_table[q_idx];
 785         struct net_device *ndev = net_device->ndev;
 786         u64 req_id;
 787         int ret;
 788         struct hv_page_buffer *pgbuf;
 789         u32 ring_avail = hv_ringbuf_avail_percent(&out_channel->outbound);
 790         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 791
 792         nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 793         if (skb != NULL) {
 794                 /* 0 is RMC_DATA; */
 795                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 0;
 796         } else {
 797                 /* 1 is RMC_CONTROL; */
 798                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 1;
 799         }
 800
 801         nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
 802                 packet->send_buf_index;
 803         if (packet->send_buf_index == NETVSC_INVALID_INDEX)
 804                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
 805         else
 806                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size =
 807                         packet->total_data_buflen;
 808
 809         req_id = (ulong)skb;
 810
 811         if (out_channel->rescind)
 812                 return -ENODEV;
 813
 814         /*
 815          * It is possible that once we successfully place this packet
 816          * on the ringbuffer, we may stop the queue. In that case, we want
 817          * to notify the host independent of the xmit_more flag. We don't
 818          * need to be precise here; in the worst case we may signal the host
 819          * unnecessarily.
 820          */
 821         if (ring_avail < (RING_AVAIL_PERCENT_LOWATER + 1))
 822                 xmit_more = false;
 823
 824         if (packet->page_buf_cnt) {
 825                 pgbuf = packet->cp_partial ? (*pb) +
 826                         packet->rmsg_pgcnt : (*pb);
 827                 ret = vmbus_sendpacket_pagebuffer_ctl(out_channel,
 828                                                       pgbuf,
 829                                                       packet->page_buf_cnt,
 830                                                       &nvmsg,
 831                                                       sizeof(struct nvsp_message),
 832                                                       req_id,
 833                                                       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
 834                                                       !xmit_more);
 835         } else {
 836                 ret = vmbus_sendpacket_ctl(out_channel, &nvmsg,
 837                                            sizeof(struct nvsp_message),
 838                                            req_id,
 839                                            VM_PKT_DATA_INBAND,
 840                                            VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
 841                                            !xmit_more);
 842         }
 843
 844         if (ret == 0) {
 845                 atomic_inc(&net_device->num_outstanding_sends);
 846                 atomic_inc(&net_device->queue_sends[q_idx]);
 847
 848                 if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
 849                         netif_tx_stop_queue(netdev_get_tx_queue(ndev, q_idx));
 850
 851                         if (atomic_read(&net_device->
 852                                 queue_sends[q_idx]) < 1)
 853                                 netif_tx_wake_queue(netdev_get_tx_queue(
 854                                                     ndev, q_idx));
 855                 }
 856         } else if (ret == -EAGAIN) {
 857                 netif_tx_stop_queue(netdev_get_tx_queue(
 858                                     ndev, q_idx));
 859                 if (atomic_read(&net_device->queue_sends[q_idx]) < 1) {
 860                         netif_tx_wake_queue(netdev_get_tx_queue(
 861                                             ndev, q_idx));
 862                         ret = -ENOSPC;
 863                 }
 864         } else {
 865                 netdev_err(ndev, "Unable to send packet %p ret %d\n",
 866                            packet, ret);
 867         }
 868
 869         return ret;
 870 }
 871
 872 /* Move packet out of multi send data (msd), and clear msd */
 873 static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
 874                                 struct sk_buff **msd_skb,
 875                                 struct multi_send_data *msdp)
 876 {
 877         *msd_skb = msdp->skb;
 878         *msd_send = msdp->pkt;
 879         msdp->skb = NULL;
 880         msdp->pkt = NULL;
 881         msdp->count = 0;
 882 }
 883
 884 int netvsc_send(struct hv_device *device,
 885                 struct hv_netvsc_packet *packet,
 886                 struct rndis_message *rndis_msg,
 887                 struct hv_page_buffer **pb,
 888                 struct sk_buff *skb)
 889 {
 890         struct netvsc_device *net_device;
 891         int ret = 0, m_ret = 0;
 892         struct vmbus_channel *out_channel;
 893         u16 q_idx = packet->q_idx;
 894         u32 pktlen = packet->total_data_buflen, msd_len = 0;
 895         unsigned int section_index = NETVSC_INVALID_INDEX;
 896         struct multi_send_data *msdp;
 897         struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
 898         struct sk_buff *msd_skb = NULL;
 899         bool try_batch;
 900         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 901
 902         net_device = get_outbound_net_device(device);
 903         if (!net_device)
 904                 return -ENODEV;
 905
 906         out_channel = net_device->chn_table[q_idx];
 907
 908         packet->send_buf_index = NETVSC_INVALID_INDEX;
 909         packet->cp_partial = false;
 910
 911         /* Send control message directly without accessing msd (Multi-Send
 912          * Data) field which may be changed during data packet processing.
 913          */
 914         if (!skb) {
 915                 cur_send = packet;
 916                 goto send_now;
 917         }
 918
 919         msdp = &net_device->msd[q_idx];
 920
 921         /* batch packets in send buffer if possible */
 922         if (msdp->pkt)
 923                 msd_len = msdp->pkt->total_data_buflen;
 924
 925         try_batch = (skb != NULL) && msd_len > 0 && msdp->count <
 926                     net_device->max_pkt;
 927
 928         if (try_batch && msd_len + pktlen + net_device->pkt_align <
 929             net_device->send_section_size) {
 930                 section_index = msdp->pkt->send_buf_index;
 931
 932         } else if (try_batch && msd_len + packet->rmsg_size <
 933                    net_device->send_section_size) {
 934                 section_index = msdp->pkt->send_buf_index;
 935                 packet->cp_partial = true;
 936
 937         } else if ((skb != NULL) && pktlen + net_device->pkt_align <
 938                    net_device->send_section_size) {
 939                 section_index = netvsc_get_next_send_section(net_device);
 940                 if (section_index != NETVSC_INVALID_INDEX) {
 941                         move_pkt_msd(&msd_send, &msd_skb, msdp);
 942                         msd_len = 0;
 943                 }
 944         }
 945
 946         if (section_index != NETVSC_INVALID_INDEX) {
 947                 netvsc_copy_to_send_buf(net_device,
 948                                         section_index, msd_len,
 949                                         packet, rndis_msg, pb, skb);
 950
 951                 packet->send_buf_index = section_index;
 952
 953                 if (packet->cp_partial) {
 954                         packet->page_buf_cnt -= packet->rmsg_pgcnt;
 955                         packet->total_data_buflen = msd_len + packet->rmsg_size;
 956                 } else {
 957                         packet->page_buf_cnt = 0;
 958                         packet->total_data_buflen += msd_len;
 959                 }
 960
 961                 if (msdp->skb)
 962                         dev_kfree_skb_any(msdp->skb);
 963
 964                 if (xmit_more && !packet->cp_partial) {
 965                         msdp->skb = skb;
 966                         msdp->pkt = packet;
 967                         msdp->count++;
 968                 } else {
 969                         cur_send = packet;
 970                         msdp->skb = NULL;
 971                         msdp->pkt = NULL;
 972                         msdp->count = 0;
 973                 }
 974         } else {
 975                 move_pkt_msd(&msd_send, &msd_skb, msdp);
 976                 cur_send = packet;
 977         }
 978
 979         if (msd_send) {
 980                 m_ret = netvsc_send_pkt(msd_send, net_device, NULL, msd_skb);
 981
 982                 if (m_ret != 0) {
 983                         netvsc_free_send_slot(net_device,
 984                                               msd_send->send_buf_index);
 985                         dev_kfree_skb_any(msd_skb);
 986                 }
 987         }
 988
 989 send_now:
 990         if (cur_send)
 991                 ret = netvsc_send_pkt(cur_send, net_device, pb, skb);
 992
 993         if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
 994                 netvsc_free_send_slot(net_device, section_index);
 995
 996         return ret;
 997 }
 998
 999 static void netvsc_send_recv_completion(struct hv_device *device,
1000                                         struct vmbus_channel *channel,
1001                                         struct netvsc_device *net_device,
1002                                         u64 transaction_id, u32 status)
1003 {
1004         struct nvsp_message recvcompMessage;
1005         int retries = 0;
1006         int ret;
1007         struct net_device *ndev;
1008
1009         ndev = net_device->ndev;
1010
1011         recvcompMessage.hdr.msg_type =
1012                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
1013
1014         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status = status;
1015
1016 retry_send_cmplt:
1017         /* Send the completion */
1018         ret = vmbus_sendpacket(channel, &recvcompMessage,
1019                                sizeof(struct nvsp_message), transaction_id,
1020                                VM_PKT_COMP, 0);
1021         if (ret == 0) {
1022                 /* success */
1023                 /* no-op */
1024         } else if (ret == -EAGAIN) {
1025                 /* no more room...wait a bit and attempt to retry 3 times */
1026                 retries++;
1027                 netdev_err(ndev, "unable to send receive completion pkt"
1028                         " (tid %llx)...retrying %d\n", transaction_id, retries);
1029
1030                 if (retries < 4) {
1031                         udelay(100);
1032                         goto retry_send_cmplt;
1033                 } else {
1034                         netdev_err(ndev, "unable to send receive "
1035                                 "completion pkt (tid %llx)...give up retrying\n",
1036                                 transaction_id);
1037                 }
1038         } else {
1039                 netdev_err(ndev, "unable to send receive "
1040                         "completion pkt - %llx\n", transaction_id);
1041         }
1042 }
1043
1044 static void netvsc_receive(struct netvsc_device *net_device,
1045                         struct vmbus_channel *channel,
1046                         struct hv_device *device,
1047                         struct vmpacket_descriptor *packet)
1048 {
1049         struct vmtransfer_page_packet_header *vmxferpage_packet;
1050         struct nvsp_message *nvsp_packet;
1051         struct hv_netvsc_packet nv_pkt;
1052         struct hv_netvsc_packet *netvsc_packet = &nv_pkt;
1053         u32 status = NVSP_STAT_SUCCESS;
1054         int i;
1055         int count = 0;
1056         struct net_device *ndev;
1057         void *data;
1058
1059         ndev = net_device->ndev;
1060
1061         /*
1062          * All inbound packets other than send completion should be xfer page
1063          * packet
1064          */
1065         if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
1066                 netdev_err(ndev, "Unknown packet type received - %d\n",
1067                            packet->type);
1068                 return;
1069         }
1070
1071         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
1072                         (packet->offset8 << 3));
1073
1074         /* Make sure this is a valid nvsp packet */
1075         if (nvsp_packet->hdr.msg_type !=
1076             NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
1077                 netdev_err(ndev, "Unknown nvsp packet type received-"
1078                         " %d\n", nvsp_packet->hdr.msg_type);
1079                 return;
1080         }
1081
1082         vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
1083
1084         if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
1085                 netdev_err(ndev, "Invalid xfer page set id - "
1086                            "expecting %x got %x\n", NETVSC_RECEIVE_BUFFER_ID,
1087                            vmxferpage_packet->xfer_pageset_id);
1088                 return;
1089         }
1090
1091         count = vmxferpage_packet->range_cnt;
1092
1093         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1094         for (i = 0; i < count; i++) {
1095                 /* Initialize the netvsc packet */
1096                 data = (void *)((unsigned long)net_device->
1097                         recv_buf + vmxferpage_packet->ranges[i].byte_offset);
1098                 netvsc_packet->total_data_buflen =
1099                                         vmxferpage_packet->ranges[i].byte_count;
1100
1101                 /* Pass it to the upper layer */
1102                 status = rndis_filter_receive(device, netvsc_packet, &data,
1103                                               channel);
1104
1105         }
1106
1107         netvsc_send_recv_completion(device, channel, net_device,
1108                                     vmxferpage_packet->d.trans_id, status);
1109 }
1110
1111
1112 static void netvsc_send_table(struct hv_device *hdev,
1113                               struct nvsp_message *nvmsg)
1114 {
1115         struct netvsc_device *nvscdev;
1116         struct net_device *ndev;
1117         int i;
1118         u32 count, *tab;
1119
1120         nvscdev = get_outbound_net_device(hdev);
1121         if (!nvscdev)
1122                 return;
1123         ndev = nvscdev->ndev;
1124
1125         count = nvmsg->msg.v5_msg.send_table.count;
1126         if (count != VRSS_SEND_TAB_SIZE) {
1127                 netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1128                 return;
1129         }
1130
1131         tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
1132                       nvmsg->msg.v5_msg.send_table.offset);
1133
1134         for (i = 0; i < count; i++)
1135                 nvscdev->send_table[i] = tab[i];
1136 }
1137
1138 static void netvsc_send_vf(struct netvsc_device *nvdev,
1139                            struct nvsp_message *nvmsg)
1140 {
1141         nvdev->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1142         nvdev->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1143 }
1144
1145 static inline void netvsc_receive_inband(struct hv_device *hdev,
1146                                          struct netvsc_device *nvdev,
1147                                          struct nvsp_message *nvmsg)
1148 {
1149         switch (nvmsg->hdr.msg_type) {
1150         case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1151                 netvsc_send_table(hdev, nvmsg);
1152                 break;
1153
1154         case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1155                 netvsc_send_vf(nvdev, nvmsg);
1156                 break;
1157         }
1158 }
1159
1160 void netvsc_channel_cb(void *context)
1161 {
1162         int ret;
1163         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1164         struct hv_device *device;
1165         struct netvsc_device *net_device;
1166         u32 bytes_recvd;
1167         u64 request_id;
1168         struct vmpacket_descriptor *desc;
1169         unsigned char *buffer;
1170         int bufferlen = NETVSC_PACKET_SIZE;
1171         struct net_device *ndev;
1172         struct nvsp_message *nvmsg;
1173
1174         if (channel->primary_channel != NULL)
1175                 device = channel->primary_channel->device_obj;
1176         else
1177                 device = channel->device_obj;
1178
1179         net_device = get_inbound_net_device(device);
1180         if (!net_device)
1181                 return;
1182         ndev = net_device->ndev;
1183         buffer = get_per_channel_state(channel);
1184
1185         do {
1186                 ret = vmbus_recvpacket_raw(channel, buffer, bufferlen,
1187                                            &bytes_recvd, &request_id);
1188                 if (ret == 0) {
1189                         if (bytes_recvd > 0) {
1190                                 desc = (struct vmpacket_descriptor *)buffer;
1191                                 nvmsg = (struct nvsp_message *)((unsigned long)
1192                                          desc + (desc->offset8 << 3));
1193                                 switch (desc->type) {
1194                                 case VM_PKT_COMP:
1195                                         netvsc_send_completion(net_device,
1196                                                                 channel,
1197                                                                 device, desc);
1198                                         break;
1199
1200                                 case VM_PKT_DATA_USING_XFER_PAGES:
1201                                         netvsc_receive(net_device, channel,
1202                                                        device, desc);
1203                                         break;
1204
1205                                 case VM_PKT_DATA_INBAND:
1206                                         netvsc_receive_inband(device,
1207                                                               net_device,
1208                                                               nvmsg);
1209                                         break;
1210
1211                                 default:
1212                                         netdev_err(ndev,
1213                                                    "unhandled packet type %d, "
1214                                                    "tid %llx len %d\n",
1215                                                    desc->type, request_id,
1216                                                    bytes_recvd);
1217                                         break;
1218                                 }
1219
1220                         } else {
1221                                 /*
1222                                  * We are done for this pass.
1223                                  */
1224                                 break;
1225                         }
1226
1227                 } else if (ret == -ENOBUFS) {
1228                         if (bufferlen > NETVSC_PACKET_SIZE)
1229                                 kfree(buffer);
1230                         /* Handle large packet */
1231                         buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
1232                         if (buffer == NULL) {
1233                                 /* Try again next time around */
1234                                 netdev_err(ndev,
1235                                            "unable to allocate buffer of size "
1236                                            "(%d)!!\n", bytes_recvd);
1237                                 break;
1238                         }
1239
1240                         bufferlen = bytes_recvd;
1241                 }
1242         } while (1);
1243
1244         if (bufferlen > NETVSC_PACKET_SIZE)
1245                 kfree(buffer);
1246         return;
1247 }
1248
1249 /*
1250  * netvsc_device_add - Callback when the device belonging to this
1251  * driver is added
1252  */
1253 int netvsc_device_add(struct hv_device *device, void *additional_info)
1254 {
1255         int ret = 0;
1256         int ring_size =
1257         ((struct netvsc_device_info *)additional_info)->ring_size;
1258         struct netvsc_device *net_device;
1259         struct net_device *ndev;
1260
1261         net_device = alloc_net_device(device);
1262         if (!net_device)
1263                 return -ENOMEM;
1264
1265         net_device->ring_size = ring_size;
1266
1267         /*
1268          * Coming into this function, struct net_device * is
1269          * registered as the driver private data.
1270          * In alloc_net_device(), we register struct netvsc_device *
1271          * as the driver private data and stash away struct net_device *
1272          * in struct netvsc_device *.
1273          */
1274         ndev = net_device->ndev;
1275
1276         /* Add netvsc_device context to netvsc_device */
1277         net_device->nd_ctx = netdev_priv(ndev);
1278
1279         /* Initialize the NetVSC channel extension */
1280         init_completion(&net_device->channel_init_wait);
1281
1282         set_per_channel_state(device->channel, net_device->cb_buffer);
1283
1284         /* Open the channel */
1285         ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
1286                          ring_size * PAGE_SIZE, NULL, 0,
1287                          netvsc_channel_cb, device->channel);
1288
1289         if (ret != 0) {
1290                 netdev_err(ndev, "unable to open channel: %d\n", ret);
1291                 goto cleanup;
1292         }
1293
1294         /* Channel is opened */
1295         pr_info("hv_netvsc channel opened successfully\n");
1296
1297         net_device->chn_table[0] = device->channel;
1298
1299         /* Connect with the NetVsp */
1300         ret = netvsc_connect_vsp(device);
1301         if (ret != 0) {
1302                 netdev_err(ndev,
1303                         "unable to connect to NetVSP - %d\n", ret);
1304                 goto close;
1305         }
1306
1307         return ret;
1308
1309 close:
1310         /* Now, we can close the channel safely */
1311         vmbus_close(device->channel);
1312
1313 cleanup:
1314         free_netvsc_device(net_device);
1315
1316         return ret;
1317 }