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