drivers/net/hyperv/netvsc.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, see <http://www.gnu.org/licenses/>.
  15  *
  16  * Authors:
  17  *   Haiyang Zhang <haiyangz@microsoft.com>
  18  *   Hank Janssen  <hjanssen@microsoft.com>
  19  */
  20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22 #include <linux/kernel.h>
  23 #include <linux/sched.h>
  24 #include <linux/wait.h>
  25 #include <linux/mm.h>
  26 #include <linux/delay.h>
  27 #include <linux/io.h>
  28 #include <linux/slab.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/if_ether.h>
  31 #include <linux/vmalloc.h>
  32 #include <asm/sync_bitops.h>
  33
  34 #include "hyperv_net.h"
  35
  36 /*
  37  * Switch the data path from the synthetic interface to the VF
  38  * interface.
  39  */
  40 void netvsc_switch_datapath(struct net_device *ndev, bool vf)
  41 {
  42         struct net_device_context *net_device_ctx = netdev_priv(ndev);
  43         struct hv_device *dev = net_device_ctx->device_ctx;
  44         struct netvsc_device *nv_dev = net_device_ctx->nvdev;
  45         struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
  46
  47         memset(init_pkt, 0, sizeof(struct nvsp_message));
  48         init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
  49         if (vf)
  50                 init_pkt->msg.v4_msg.active_dp.active_datapath =
  51                         NVSP_DATAPATH_VF;
  52         else
  53                 init_pkt->msg.v4_msg.active_dp.active_datapath =
  54                         NVSP_DATAPATH_SYNTHETIC;
  55
  56         vmbus_sendpacket(dev->channel, init_pkt,
  57                                sizeof(struct nvsp_message),
  58                                (unsigned long)init_pkt,
  59                                VM_PKT_DATA_INBAND, 0);
  60 }
  61
  62
  63 static struct netvsc_device *alloc_net_device(void)
  64 {
  65         struct netvsc_device *net_device;
  66
  67         net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
  68         if (!net_device)
  69                 return NULL;
  70
  71         net_device->cb_buffer = kzalloc(NETVSC_PACKET_SIZE, GFP_KERNEL);
  72         if (!net_device->cb_buffer) {
  73                 kfree(net_device);
  74                 return NULL;
  75         }
  76
  77         init_waitqueue_head(&net_device->wait_drain);
  78         net_device->destroy = false;
  79         atomic_set(&net_device->open_cnt, 0);
  80         net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
  81         net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
  82
  83         return net_device;
  84 }
  85
  86 static void free_netvsc_device(struct netvsc_device *nvdev)
  87 {
  88         kfree(nvdev->cb_buffer);
  89         kfree(nvdev);
  90 }
  91
  92 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
  93 {
  94         struct netvsc_device *net_device = hv_device_to_netvsc_device(device);
  95
  96         if (net_device && net_device->destroy)
  97                 net_device = NULL;
  98
  99         return net_device;
 100 }
 101
 102 static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
 103 {
 104         struct netvsc_device *net_device = hv_device_to_netvsc_device(device);
 105
 106         if (!net_device)
 107                 goto get_in_err;
 108
 109         if (net_device->destroy &&
 110                 atomic_read(&net_device->num_outstanding_sends) == 0)
 111                 net_device = NULL;
 112
 113 get_in_err:
 114         return net_device;
 115 }
 116
 117
 118 static int netvsc_destroy_buf(struct hv_device *device)
 119 {
 120         struct nvsp_message *revoke_packet;
 121         int ret = 0;
 122         struct net_device *ndev = hv_get_drvdata(device);
 123         struct netvsc_device *net_device = net_device_to_netvsc_device(ndev);
 124
 125         /*
 126          * If we got a section count, it means we received a
 127          * SendReceiveBufferComplete msg (ie sent
 128          * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
 129          * to send a revoke msg here
 130          */
 131         if (net_device->recv_section_cnt) {
 132                 /* Send the revoke receive buffer */
 133                 revoke_packet = &net_device->revoke_packet;
 134                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 135
 136                 revoke_packet->hdr.msg_type =
 137                         NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 138                 revoke_packet->msg.v1_msg.
 139                 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 140
 141                 ret = vmbus_sendpacket(device->channel,
 142                                        revoke_packet,
 143                                        sizeof(struct nvsp_message),
 144                                        (unsigned long)revoke_packet,
 145                                        VM_PKT_DATA_INBAND, 0);
 146                 /*
 147                  * If we failed here, we might as well return and
 148                  * have a leak rather than continue and a bugchk
 149                  */
 150                 if (ret != 0) {
 151                         netdev_err(ndev, "unable to send "
 152                                 "revoke receive buffer to netvsp\n");
 153                         return ret;
 154                 }
 155         }
 156
 157         /* Teardown the gpadl on the vsp end */
 158         if (net_device->recv_buf_gpadl_handle) {
 159                 ret = vmbus_teardown_gpadl(device->channel,
 160                                            net_device->recv_buf_gpadl_handle);
 161
 162                 /* If we failed here, we might as well return and have a leak
 163                  * rather than continue and a bugchk
 164                  */
 165                 if (ret != 0) {
 166                         netdev_err(ndev,
 167                                    "unable to teardown receive buffer's gpadl\n");
 168                         return ret;
 169                 }
 170                 net_device->recv_buf_gpadl_handle = 0;
 171         }
 172
 173         if (net_device->recv_buf) {
 174                 /* Free up the receive buffer */
 175                 vfree(net_device->recv_buf);
 176                 net_device->recv_buf = NULL;
 177         }
 178
 179         if (net_device->recv_section) {
 180                 net_device->recv_section_cnt = 0;
 181                 kfree(net_device->recv_section);
 182                 net_device->recv_section = NULL;
 183         }
 184
 185         /* Deal with the send buffer we may have setup.
 186          * If we got a  send section size, it means we received a
 187          * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
 188          * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
 189          * to send a revoke msg here
 190          */
 191         if (net_device->send_section_size) {
 192                 /* Send the revoke receive buffer */
 193                 revoke_packet = &net_device->revoke_packet;
 194                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 195
 196                 revoke_packet->hdr.msg_type =
 197                         NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
 198                 revoke_packet->msg.v1_msg.revoke_send_buf.id =
 199                         NETVSC_SEND_BUFFER_ID;
 200
 201                 ret = vmbus_sendpacket(device->channel,
 202                                        revoke_packet,
 203                                        sizeof(struct nvsp_message),
 204                                        (unsigned long)revoke_packet,
 205                                        VM_PKT_DATA_INBAND, 0);
 206                 /* If we failed here, we might as well return and
 207                  * have a leak rather than continue and a bugchk
 208                  */
 209                 if (ret != 0) {
 210                         netdev_err(ndev, "unable to send "
 211                                    "revoke send buffer to netvsp\n");
 212                         return ret;
 213                 }
 214         }
 215         /* Teardown the gpadl on the vsp end */
 216         if (net_device->send_buf_gpadl_handle) {
 217                 ret = vmbus_teardown_gpadl(device->channel,
 218                                            net_device->send_buf_gpadl_handle);
 219
 220                 /* If we failed here, we might as well return and have a leak
 221                  * rather than continue and a bugchk
 222                  */
 223                 if (ret != 0) {
 224                         netdev_err(ndev,
 225                                    "unable to teardown send buffer's gpadl\n");
 226                         return ret;
 227                 }
 228                 net_device->send_buf_gpadl_handle = 0;
 229         }
 230         if (net_device->send_buf) {
 231                 /* Free up the send buffer */
 232                 vfree(net_device->send_buf);
 233                 net_device->send_buf = NULL;
 234         }
 235         kfree(net_device->send_section_map);
 236
 237         return ret;
 238 }
 239
 240 static int netvsc_init_buf(struct hv_device *device)
 241 {
 242         int ret = 0;
 243         struct netvsc_device *net_device;
 244         struct nvsp_message *init_packet;
 245         struct net_device *ndev;
 246         int node;
 247
 248         net_device = get_outbound_net_device(device);
 249         if (!net_device)
 250                 return -ENODEV;
 251         ndev = hv_get_drvdata(device);
 252
 253         node = cpu_to_node(device->channel->target_cpu);
 254         net_device->recv_buf = vzalloc_node(net_device->recv_buf_size, node);
 255         if (!net_device->recv_buf)
 256                 net_device->recv_buf = vzalloc(net_device->recv_buf_size);
 257
 258         if (!net_device->recv_buf) {
 259                 netdev_err(ndev, "unable to allocate receive "
 260                         "buffer of size %d\n", net_device->recv_buf_size);
 261                 ret = -ENOMEM;
 262                 goto cleanup;
 263         }
 264
 265         /*
 266          * Establish the gpadl handle for this buffer on this
 267          * channel.  Note: This call uses the vmbus connection rather
 268          * than the channel to establish the gpadl handle.
 269          */
 270         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 271                                     net_device->recv_buf_size,
 272                                     &net_device->recv_buf_gpadl_handle);
 273         if (ret != 0) {
 274                 netdev_err(ndev,
 275                         "unable to establish receive buffer's gpadl\n");
 276                 goto cleanup;
 277         }
 278
 279
 280         /* Notify the NetVsp of the gpadl handle */
 281         init_packet = &net_device->channel_init_pkt;
 282
 283         memset(init_packet, 0, sizeof(struct nvsp_message));
 284
 285         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 286         init_packet->msg.v1_msg.send_recv_buf.
 287                 gpadl_handle = net_device->recv_buf_gpadl_handle;
 288         init_packet->msg.v1_msg.
 289                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 290
 291         /* Send the gpadl notification request */
 292         ret = vmbus_sendpacket(device->channel, init_packet,
 293                                sizeof(struct nvsp_message),
 294                                (unsigned long)init_packet,
 295                                VM_PKT_DATA_INBAND,
 296                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 297         if (ret != 0) {
 298                 netdev_err(ndev,
 299                         "unable to send receive buffer's gpadl to netvsp\n");
 300                 goto cleanup;
 301         }
 302
 303         wait_for_completion(&net_device->channel_init_wait);
 304
 305         /* Check the response */
 306         if (init_packet->msg.v1_msg.
 307             send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
 308                 netdev_err(ndev, "Unable to complete receive buffer "
 309                            "initialization with NetVsp - status %d\n",
 310                            init_packet->msg.v1_msg.
 311                            send_recv_buf_complete.status);
 312                 ret = -EINVAL;
 313                 goto cleanup;
 314         }
 315
 316         /* Parse the response */
 317
 318         net_device->recv_section_cnt = init_packet->msg.
 319                 v1_msg.send_recv_buf_complete.num_sections;
 320
 321         net_device->recv_section = kmemdup(
 322                 init_packet->msg.v1_msg.send_recv_buf_complete.sections,
 323                 net_device->recv_section_cnt *
 324                 sizeof(struct nvsp_1_receive_buffer_section),
 325                 GFP_KERNEL);
 326         if (net_device->recv_section == NULL) {
 327                 ret = -EINVAL;
 328                 goto cleanup;
 329         }
 330
 331         /*
 332          * For 1st release, there should only be 1 section that represents the
 333          * entire receive buffer
 334          */
 335         if (net_device->recv_section_cnt != 1 ||
 336             net_device->recv_section->offset != 0) {
 337                 ret = -EINVAL;
 338                 goto cleanup;
 339         }
 340
 341         /* Now setup the send buffer.
 342          */
 343         net_device->send_buf = vzalloc_node(net_device->send_buf_size, node);
 344         if (!net_device->send_buf)
 345                 net_device->send_buf = vzalloc(net_device->send_buf_size);
 346         if (!net_device->send_buf) {
 347                 netdev_err(ndev, "unable to allocate send "
 348                            "buffer of size %d\n", net_device->send_buf_size);
 349                 ret = -ENOMEM;
 350                 goto cleanup;
 351         }
 352
 353         /* Establish the gpadl handle for this buffer on this
 354          * channel.  Note: This call uses the vmbus connection rather
 355          * than the channel to establish the gpadl handle.
 356          */
 357         ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
 358                                     net_device->send_buf_size,
 359                                     &net_device->send_buf_gpadl_handle);
 360         if (ret != 0) {
 361                 netdev_err(ndev,
 362                            "unable to establish send buffer's gpadl\n");
 363                 goto cleanup;
 364         }
 365
 366         /* Notify the NetVsp of the gpadl handle */
 367         init_packet = &net_device->channel_init_pkt;
 368         memset(init_packet, 0, sizeof(struct nvsp_message));
 369         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
 370         init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
 371                 net_device->send_buf_gpadl_handle;
 372         init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
 373
 374         /* Send the gpadl notification request */
 375         ret = vmbus_sendpacket(device->channel, init_packet,
 376                                sizeof(struct nvsp_message),
 377                                (unsigned long)init_packet,
 378                                VM_PKT_DATA_INBAND,
 379                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 380         if (ret != 0) {
 381                 netdev_err(ndev,
 382                            "unable to send send buffer's gpadl to netvsp\n");
 383                 goto cleanup;
 384         }
 385
 386         wait_for_completion(&net_device->channel_init_wait);
 387
 388         /* Check the response */
 389         if (init_packet->msg.v1_msg.
 390             send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
 391                 netdev_err(ndev, "Unable to complete send buffer "
 392                            "initialization with NetVsp - status %d\n",
 393                            init_packet->msg.v1_msg.
 394                            send_send_buf_complete.status);
 395                 ret = -EINVAL;
 396                 goto cleanup;
 397         }
 398
 399         /* Parse the response */
 400         net_device->send_section_size = init_packet->msg.
 401                                 v1_msg.send_send_buf_complete.section_size;
 402
 403         /* Section count is simply the size divided by the section size.
 404          */
 405         net_device->send_section_cnt =
 406                 net_device->send_buf_size/net_device->send_section_size;
 407
 408         dev_info(&device->device, "Send section size: %d, Section count:%d\n",
 409                  net_device->send_section_size, net_device->send_section_cnt);
 410
 411         /* Setup state for managing the send buffer. */
 412         net_device->map_words = DIV_ROUND_UP(net_device->send_section_cnt,
 413                                              BITS_PER_LONG);
 414
 415         net_device->send_section_map =
 416                 kzalloc(net_device->map_words * sizeof(ulong), GFP_KERNEL);
 417         if (net_device->send_section_map == NULL) {
 418                 ret = -ENOMEM;
 419                 goto cleanup;
 420         }
 421
 422         goto exit;
 423
 424 cleanup:
 425         netvsc_destroy_buf(device);
 426
 427 exit:
 428         return ret;
 429 }
 430
 431
 432 /* Negotiate NVSP protocol version */
 433 static int negotiate_nvsp_ver(struct hv_device *device,
 434                               struct netvsc_device *net_device,
 435                               struct nvsp_message *init_packet,
 436                               u32 nvsp_ver)
 437 {
 438         struct net_device *ndev = hv_get_drvdata(device);
 439         int ret;
 440
 441         memset(init_packet, 0, sizeof(struct nvsp_message));
 442         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 443         init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
 444         init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
 445
 446         /* Send the init request */
 447         ret = vmbus_sendpacket(device->channel, init_packet,
 448                                sizeof(struct nvsp_message),
 449                                (unsigned long)init_packet,
 450                                VM_PKT_DATA_INBAND,
 451                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 452
 453         if (ret != 0)
 454                 return ret;
 455
 456         wait_for_completion(&net_device->channel_init_wait);
 457
 458         if (init_packet->msg.init_msg.init_complete.status !=
 459             NVSP_STAT_SUCCESS)
 460                 return -EINVAL;
 461
 462         if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
 463                 return 0;
 464
 465         /* NVSPv2 or later: Send NDIS config */
 466         memset(init_packet, 0, sizeof(struct nvsp_message));
 467         init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
 468         init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;
 469         init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
 470
 471         if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5)
 472                 init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
 473
 474         ret = vmbus_sendpacket(device->channel, init_packet,
 475                                 sizeof(struct nvsp_message),
 476                                 (unsigned long)init_packet,
 477                                 VM_PKT_DATA_INBAND, 0);
 478
 479         return ret;
 480 }
 481
 482 static int netvsc_connect_vsp(struct hv_device *device)
 483 {
 484         int ret;
 485         struct netvsc_device *net_device;
 486         struct nvsp_message *init_packet;
 487         int ndis_version;
 488         u32 ver_list[] = { NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
 489                 NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5 };
 490         int i, num_ver = 4; /* number of different NVSP versions */
 491
 492         net_device = get_outbound_net_device(device);
 493         if (!net_device)
 494                 return -ENODEV;
 495
 496         init_packet = &net_device->channel_init_pkt;
 497
 498         /* Negotiate the latest NVSP protocol supported */
 499         for (i = num_ver - 1; i >= 0; i--)
 500                 if (negotiate_nvsp_ver(device, net_device, init_packet,
 501                                        ver_list[i])  == 0) {
 502                         net_device->nvsp_version = ver_list[i];
 503                         break;
 504                 }
 505
 506         if (i < 0) {
 507                 ret = -EPROTO;
 508                 goto cleanup;
 509         }
 510
 511         pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
 512
 513         /* Send the ndis version */
 514         memset(init_packet, 0, sizeof(struct nvsp_message));
 515
 516         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
 517                 ndis_version = 0x00060001;
 518         else
 519                 ndis_version = 0x0006001e;
 520
 521         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 522         init_packet->msg.v1_msg.
 523                 send_ndis_ver.ndis_major_ver =
 524                                 (ndis_version & 0xFFFF0000) >> 16;
 525         init_packet->msg.v1_msg.
 526                 send_ndis_ver.ndis_minor_ver =
 527                                 ndis_version & 0xFFFF;
 528
 529         /* Send the init request */
 530         ret = vmbus_sendpacket(device->channel, init_packet,
 531                                 sizeof(struct nvsp_message),
 532                                 (unsigned long)init_packet,
 533                                 VM_PKT_DATA_INBAND, 0);
 534         if (ret != 0)
 535                 goto cleanup;
 536
 537         /* Post the big receive buffer to NetVSP */
 538         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
 539                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
 540         else
 541                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 542         net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
 543
 544         ret = netvsc_init_buf(device);
 545
 546 cleanup:
 547         return ret;
 548 }
 549
 550 static void netvsc_disconnect_vsp(struct hv_device *device)
 551 {
 552         netvsc_destroy_buf(device);
 553 }
 554
 555 /*
 556  * netvsc_device_remove - Callback when the root bus device is removed
 557  */
 558 int netvsc_device_remove(struct hv_device *device)
 559 {
 560         struct net_device *ndev = hv_get_drvdata(device);
 561         struct net_device_context *net_device_ctx = netdev_priv(ndev);
 562         struct netvsc_device *net_device = net_device_ctx->nvdev;
 563
 564         netvsc_disconnect_vsp(device);
 565
 566         net_device_ctx->nvdev = NULL;
 567
 568         /*
 569          * At this point, no one should be accessing net_device
 570          * except in here
 571          */
 572         dev_notice(&device->device, "net device safe to remove\n");
 573
 574         /* Now, we can close the channel safely */
 575         vmbus_close(device->channel);
 576
 577         /* Release all resources */
 578         vfree(net_device->sub_cb_buf);
 579         free_netvsc_device(net_device);
 580         return 0;
 581 }
 582
 583
 584 #define RING_AVAIL_PERCENT_HIWATER 20
 585 #define RING_AVAIL_PERCENT_LOWATER 10
 586
 587 /*
 588  * Get the percentage of available bytes to write in the ring.
 589  * The return value is in range from 0 to 100.
 590  */
 591 static inline u32 hv_ringbuf_avail_percent(
 592                 struct hv_ring_buffer_info *ring_info)
 593 {
 594         u32 avail_read, avail_write;
 595
 596         hv_get_ringbuffer_availbytes(ring_info, &avail_read, &avail_write);
 597
 598         return avail_write * 100 / ring_info->ring_datasize;
 599 }
 600
 601 static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
 602                                          u32 index)
 603 {
 604         sync_change_bit(index, net_device->send_section_map);
 605 }
 606
 607 static void netvsc_send_completion(struct netvsc_device *net_device,
 608                                    struct vmbus_channel *incoming_channel,
 609                                    struct hv_device *device,
 610                                    struct vmpacket_descriptor *packet)
 611 {
 612         struct nvsp_message *nvsp_packet;
 613         struct hv_netvsc_packet *nvsc_packet;
 614         struct net_device *ndev = hv_get_drvdata(device);
 615         struct net_device_context *net_device_ctx = netdev_priv(ndev);
 616         u32 send_index;
 617         struct sk_buff *skb;
 618
 619         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 620                         (packet->offset8 << 3));
 621
 622         if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
 623             (nvsp_packet->hdr.msg_type ==
 624              NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
 625             (nvsp_packet->hdr.msg_type ==
 626              NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE) ||
 627             (nvsp_packet->hdr.msg_type ==
 628              NVSP_MSG5_TYPE_SUBCHANNEL)) {
 629                 /* Copy the response back */
 630                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 631                        sizeof(struct nvsp_message));
 632                 complete(&net_device->channel_init_wait);
 633         } else if (nvsp_packet->hdr.msg_type ==
 634                    NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
 635                 int num_outstanding_sends;
 636                 u16 q_idx = 0;
 637                 struct vmbus_channel *channel = device->channel;
 638                 int queue_sends;
 639
 640                 /* Get the send context */
 641                 skb = (struct sk_buff *)(unsigned long)packet->trans_id;
 642
 643                 /* Notify the layer above us */
 644                 if (skb) {
 645                         nvsc_packet = (struct hv_netvsc_packet *) skb->cb;
 646                         send_index = nvsc_packet->send_buf_index;
 647                         if (send_index != NETVSC_INVALID_INDEX)
 648                                 netvsc_free_send_slot(net_device, send_index);
 649                         q_idx = nvsc_packet->q_idx;
 650                         channel = incoming_channel;
 651                         dev_kfree_skb_any(skb);
 652                 }
 653
 654                 num_outstanding_sends =
 655                         atomic_dec_return(&net_device->num_outstanding_sends);
 656                 queue_sends = atomic_dec_return(&net_device->
 657                                                 queue_sends[q_idx]);
 658
 659                 if (net_device->destroy && num_outstanding_sends == 0)
 660                         wake_up(&net_device->wait_drain);
 661
 662                 if (netif_tx_queue_stopped(netdev_get_tx_queue(ndev, q_idx)) &&
 663                     !net_device_ctx->start_remove &&
 664                     (hv_ringbuf_avail_percent(&channel->outbound) >
 665                      RING_AVAIL_PERCENT_HIWATER || queue_sends < 1))
 666                                 netif_tx_wake_queue(netdev_get_tx_queue(
 667                                                     ndev, q_idx));
 668         } else {
 669                 netdev_err(ndev, "Unknown send completion packet type- "
 670                            "%d received!!\n", nvsp_packet->hdr.msg_type);
 671         }
 672
 673 }
 674
 675 static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
 676 {
 677         unsigned long index;
 678         u32 max_words = net_device->map_words;
 679         unsigned long *map_addr = (unsigned long *)net_device->send_section_map;
 680         u32 section_cnt = net_device->send_section_cnt;
 681         int ret_val = NETVSC_INVALID_INDEX;
 682         int i;
 683         int prev_val;
 684
 685         for (i = 0; i < max_words; i++) {
 686                 if (!~(map_addr[i]))
 687                         continue;
 688                 index = ffz(map_addr[i]);
 689                 prev_val = sync_test_and_set_bit(index, &map_addr[i]);
 690                 if (prev_val)
 691                         continue;
 692                 if ((index + (i * BITS_PER_LONG)) >= section_cnt)
 693                         break;
 694                 ret_val = (index + (i * BITS_PER_LONG));
 695                 break;
 696         }
 697         return ret_val;
 698 }
 699
 700 static u32 netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 701                                    unsigned int section_index,
 702                                    u32 pend_size,
 703                                    struct hv_netvsc_packet *packet,
 704                                    struct rndis_message *rndis_msg,
 705                                    struct hv_page_buffer **pb,
 706                                    struct sk_buff *skb)
 707 {
 708         char *start = net_device->send_buf;
 709         char *dest = start + (section_index * net_device->send_section_size)
 710                      + pend_size;
 711         int i;
 712         bool is_data_pkt = (skb != NULL) ? true : false;
 713         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 714         u32 msg_size = 0;
 715         u32 padding = 0;
 716         u32 remain = packet->total_data_buflen % net_device->pkt_align;
 717         u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
 718                 packet->page_buf_cnt;
 719
 720         /* Add padding */
 721         if (is_data_pkt && xmit_more && remain &&
 722             !packet->cp_partial) {
 723                 padding = net_device->pkt_align - remain;
 724                 rndis_msg->msg_len += padding;
 725                 packet->total_data_buflen += padding;
 726         }
 727
 728         for (i = 0; i < page_count; i++) {
 729                 char *src = phys_to_virt((*pb)[i].pfn << PAGE_SHIFT);
 730                 u32 offset = (*pb)[i].offset;
 731                 u32 len = (*pb)[i].len;
 732
 733                 memcpy(dest, (src + offset), len);
 734                 msg_size += len;
 735                 dest += len;
 736         }
 737
 738         if (padding) {
 739                 memset(dest, 0, padding);
 740                 msg_size += padding;
 741         }
 742
 743         return msg_size;
 744 }
 745
 746 static inline int netvsc_send_pkt(
 747         struct hv_device *device,
 748         struct hv_netvsc_packet *packet,
 749         struct netvsc_device *net_device,
 750         struct hv_page_buffer **pb,
 751         struct sk_buff *skb)
 752 {
 753         struct nvsp_message nvmsg;
 754         u16 q_idx = packet->q_idx;
 755         struct vmbus_channel *out_channel = net_device->chn_table[q_idx];
 756         struct net_device *ndev = hv_get_drvdata(device);
 757         u64 req_id;
 758         int ret;
 759         struct hv_page_buffer *pgbuf;
 760         u32 ring_avail = hv_ringbuf_avail_percent(&out_channel->outbound);
 761         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 762
 763         nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 764         if (skb != NULL) {
 765                 /* 0 is RMC_DATA; */
 766                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 0;
 767         } else {
 768                 /* 1 is RMC_CONTROL; */
 769                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 1;
 770         }
 771
 772         nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
 773                 packet->send_buf_index;
 774         if (packet->send_buf_index == NETVSC_INVALID_INDEX)
 775                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
 776         else
 777                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size =
 778                         packet->total_data_buflen;
 779
 780         req_id = (ulong)skb;
 781
 782         if (out_channel->rescind)
 783                 return -ENODEV;
 784
 785         /*
 786          * It is possible that once we successfully place this packet
 787          * on the ringbuffer, we may stop the queue. In that case, we want
 788          * to notify the host independent of the xmit_more flag. We don't
 789          * need to be precise here; in the worst case we may signal the host
 790          * unnecessarily.
 791          */
 792         if (ring_avail < (RING_AVAIL_PERCENT_LOWATER + 1))
 793                 xmit_more = false;
 794
 795         if (packet->page_buf_cnt) {
 796                 pgbuf = packet->cp_partial ? (*pb) +
 797                         packet->rmsg_pgcnt : (*pb);
 798                 ret = vmbus_sendpacket_pagebuffer_ctl(out_channel,
 799                                                       pgbuf,
 800                                                       packet->page_buf_cnt,
 801                                                       &nvmsg,
 802                                                       sizeof(struct nvsp_message),
 803                                                       req_id,
 804                                                       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
 805                                                       !xmit_more);
 806         } else {
 807                 ret = vmbus_sendpacket_ctl(out_channel, &nvmsg,
 808                                            sizeof(struct nvsp_message),
 809                                            req_id,
 810                                            VM_PKT_DATA_INBAND,
 811                                            VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
 812                                            !xmit_more);
 813         }
 814
 815         if (ret == 0) {
 816                 atomic_inc(&net_device->num_outstanding_sends);
 817                 atomic_inc(&net_device->queue_sends[q_idx]);
 818
 819                 if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
 820                         netif_tx_stop_queue(netdev_get_tx_queue(ndev, q_idx));
 821
 822                         if (atomic_read(&net_device->
 823                                 queue_sends[q_idx]) < 1)
 824                                 netif_tx_wake_queue(netdev_get_tx_queue(
 825                                                     ndev, q_idx));
 826                 }
 827         } else if (ret == -EAGAIN) {
 828                 netif_tx_stop_queue(netdev_get_tx_queue(
 829                                     ndev, q_idx));
 830                 if (atomic_read(&net_device->queue_sends[q_idx]) < 1) {
 831                         netif_tx_wake_queue(netdev_get_tx_queue(
 832                                             ndev, q_idx));
 833                         ret = -ENOSPC;
 834                 }
 835         } else {
 836                 netdev_err(ndev, "Unable to send packet %p ret %d\n",
 837                            packet, ret);
 838         }
 839
 840         return ret;
 841 }
 842
 843 /* Move packet out of multi send data (msd), and clear msd */
 844 static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
 845                                 struct sk_buff **msd_skb,
 846                                 struct multi_send_data *msdp)
 847 {
 848         *msd_skb = msdp->skb;
 849         *msd_send = msdp->pkt;
 850         msdp->skb = NULL;
 851         msdp->pkt = NULL;
 852         msdp->count = 0;
 853 }
 854
 855 int netvsc_send(struct hv_device *device,
 856                 struct hv_netvsc_packet *packet,
 857                 struct rndis_message *rndis_msg,
 858                 struct hv_page_buffer **pb,
 859                 struct sk_buff *skb)
 860 {
 861         struct netvsc_device *net_device;
 862         int ret = 0, m_ret = 0;
 863         struct vmbus_channel *out_channel;
 864         u16 q_idx = packet->q_idx;
 865         u32 pktlen = packet->total_data_buflen, msd_len = 0;
 866         unsigned int section_index = NETVSC_INVALID_INDEX;
 867         struct multi_send_data *msdp;
 868         struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
 869         struct sk_buff *msd_skb = NULL;
 870         bool try_batch;
 871         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 872
 873         net_device = get_outbound_net_device(device);
 874         if (!net_device)
 875                 return -ENODEV;
 876
 877         out_channel = net_device->chn_table[q_idx];
 878
 879         packet->send_buf_index = NETVSC_INVALID_INDEX;
 880         packet->cp_partial = false;
 881
 882         /* Send control message directly without accessing msd (Multi-Send
 883          * Data) field which may be changed during data packet processing.
 884          */
 885         if (!skb) {
 886                 cur_send = packet;
 887                 goto send_now;
 888         }
 889
 890         msdp = &net_device->msd[q_idx];
 891
 892         /* batch packets in send buffer if possible */
 893         if (msdp->pkt)
 894                 msd_len = msdp->pkt->total_data_buflen;
 895
 896         try_batch = (skb != NULL) && msd_len > 0 && msdp->count <
 897                     net_device->max_pkt;
 898
 899         if (try_batch && msd_len + pktlen + net_device->pkt_align <
 900             net_device->send_section_size) {
 901                 section_index = msdp->pkt->send_buf_index;
 902
 903         } else if (try_batch && msd_len + packet->rmsg_size <
 904                    net_device->send_section_size) {
 905                 section_index = msdp->pkt->send_buf_index;
 906                 packet->cp_partial = true;
 907
 908         } else if ((skb != NULL) && pktlen + net_device->pkt_align <
 909                    net_device->send_section_size) {
 910                 section_index = netvsc_get_next_send_section(net_device);
 911                 if (section_index != NETVSC_INVALID_INDEX) {
 912                         move_pkt_msd(&msd_send, &msd_skb, msdp);
 913                         msd_len = 0;
 914                 }
 915         }
 916
 917         if (section_index != NETVSC_INVALID_INDEX) {
 918                 netvsc_copy_to_send_buf(net_device,
 919                                         section_index, msd_len,
 920                                         packet, rndis_msg, pb, skb);
 921
 922                 packet->send_buf_index = section_index;
 923
 924                 if (packet->cp_partial) {
 925                         packet->page_buf_cnt -= packet->rmsg_pgcnt;
 926                         packet->total_data_buflen = msd_len + packet->rmsg_size;
 927                 } else {
 928                         packet->page_buf_cnt = 0;
 929                         packet->total_data_buflen += msd_len;
 930                 }
 931
 932                 if (msdp->skb)
 933                         dev_kfree_skb_any(msdp->skb);
 934
 935                 if (xmit_more && !packet->cp_partial) {
 936                         msdp->skb = skb;
 937                         msdp->pkt = packet;
 938                         msdp->count++;
 939                 } else {
 940                         cur_send = packet;
 941                         msdp->skb = NULL;
 942                         msdp->pkt = NULL;
 943                         msdp->count = 0;
 944                 }
 945         } else {
 946                 move_pkt_msd(&msd_send, &msd_skb, msdp);
 947                 cur_send = packet;
 948         }
 949
 950         if (msd_send) {
 951                 m_ret = netvsc_send_pkt(device, msd_send, net_device,
 952                                         NULL, msd_skb);
 953
 954                 if (m_ret != 0) {
 955                         netvsc_free_send_slot(net_device,
 956                                               msd_send->send_buf_index);
 957                         dev_kfree_skb_any(msd_skb);
 958                 }
 959         }
 960
 961 send_now:
 962         if (cur_send)
 963                 ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);
 964
 965         if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
 966                 netvsc_free_send_slot(net_device, section_index);
 967
 968         return ret;
 969 }
 970
 971 static void netvsc_send_recv_completion(struct hv_device *device,
 972                                         struct vmbus_channel *channel,
 973                                         struct netvsc_device *net_device,
 974                                         u64 transaction_id, u32 status)
 975 {
 976         struct nvsp_message recvcompMessage;
 977         int retries = 0;
 978         int ret;
 979         struct net_device *ndev = hv_get_drvdata(device);
 980
 981         recvcompMessage.hdr.msg_type =
 982                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
 983
 984         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status = status;
 985
 986 retry_send_cmplt:
 987         /* Send the completion */
 988         ret = vmbus_sendpacket(channel, &recvcompMessage,
 989                                sizeof(struct nvsp_message), transaction_id,
 990                                VM_PKT_COMP, 0);
 991         if (ret == 0) {
 992                 /* success */
 993                 /* no-op */
 994         } else if (ret == -EAGAIN) {
 995                 /* no more room...wait a bit and attempt to retry 3 times */
 996                 retries++;
 997                 netdev_err(ndev, "unable to send receive completion pkt"
 998                         " (tid %llx)...retrying %d\n", transaction_id, retries);
 999
1000                 if (retries < 4) {
1001                         udelay(100);
1002                         goto retry_send_cmplt;
1003                 } else {
1004                         netdev_err(ndev, "unable to send receive "
1005                                 "completion pkt (tid %llx)...give up retrying\n",
1006                                 transaction_id);
1007                 }
1008         } else {
1009                 netdev_err(ndev, "unable to send receive "
1010                         "completion pkt - %llx\n", transaction_id);
1011         }
1012 }
1013
1014 static void netvsc_receive(struct netvsc_device *net_device,
1015                         struct vmbus_channel *channel,
1016                         struct hv_device *device,
1017                         struct vmpacket_descriptor *packet)
1018 {
1019         struct vmtransfer_page_packet_header *vmxferpage_packet;
1020         struct nvsp_message *nvsp_packet;
1021         struct hv_netvsc_packet nv_pkt;
1022         struct hv_netvsc_packet *netvsc_packet = &nv_pkt;
1023         u32 status = NVSP_STAT_SUCCESS;
1024         int i;
1025         int count = 0;
1026         struct net_device *ndev = hv_get_drvdata(device);
1027         void *data;
1028
1029         /*
1030          * All inbound packets other than send completion should be xfer page
1031          * packet
1032          */
1033         if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
1034                 netdev_err(ndev, "Unknown packet type received - %d\n",
1035                            packet->type);
1036                 return;
1037         }
1038
1039         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
1040                         (packet->offset8 << 3));
1041
1042         /* Make sure this is a valid nvsp packet */
1043         if (nvsp_packet->hdr.msg_type !=
1044             NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
1045                 netdev_err(ndev, "Unknown nvsp packet type received-"
1046                         " %d\n", nvsp_packet->hdr.msg_type);
1047                 return;
1048         }
1049
1050         vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
1051
1052         if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
1053                 netdev_err(ndev, "Invalid xfer page set id - "
1054                            "expecting %x got %x\n", NETVSC_RECEIVE_BUFFER_ID,
1055                            vmxferpage_packet->xfer_pageset_id);
1056                 return;
1057         }
1058
1059         count = vmxferpage_packet->range_cnt;
1060
1061         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1062         for (i = 0; i < count; i++) {
1063                 /* Initialize the netvsc packet */
1064                 data = (void *)((unsigned long)net_device->
1065                         recv_buf + vmxferpage_packet->ranges[i].byte_offset);
1066                 netvsc_packet->total_data_buflen =
1067                                         vmxferpage_packet->ranges[i].byte_count;
1068
1069                 /* Pass it to the upper layer */
1070                 status = rndis_filter_receive(device, netvsc_packet, &data,
1071                                               channel);
1072
1073         }
1074
1075         netvsc_send_recv_completion(device, channel, net_device,
1076                                     vmxferpage_packet->d.trans_id, status);
1077 }
1078
1079
1080 static void netvsc_send_table(struct hv_device *hdev,
1081                               struct nvsp_message *nvmsg)
1082 {
1083         struct netvsc_device *nvscdev;
1084         struct net_device *ndev = hv_get_drvdata(hdev);
1085         int i;
1086         u32 count, *tab;
1087
1088         nvscdev = get_outbound_net_device(hdev);
1089         if (!nvscdev)
1090                 return;
1091
1092         count = nvmsg->msg.v5_msg.send_table.count;
1093         if (count != VRSS_SEND_TAB_SIZE) {
1094                 netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1095                 return;
1096         }
1097
1098         tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
1099                       nvmsg->msg.v5_msg.send_table.offset);
1100
1101         for (i = 0; i < count; i++)
1102                 nvscdev->send_table[i] = tab[i];
1103 }
1104
1105 static void netvsc_send_vf(struct net_device_context *net_device_ctx,
1106                            struct nvsp_message *nvmsg)
1107 {
1108         net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1109         net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1110 }
1111
1112 static inline void netvsc_receive_inband(struct hv_device *hdev,
1113                                  struct net_device_context *net_device_ctx,
1114                                  struct nvsp_message *nvmsg)
1115 {
1116         switch (nvmsg->hdr.msg_type) {
1117         case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1118                 netvsc_send_table(hdev, nvmsg);
1119                 break;
1120
1121         case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1122                 netvsc_send_vf(net_device_ctx, nvmsg);
1123                 break;
1124         }
1125 }
1126
1127 static void netvsc_process_raw_pkt(struct hv_device *device,
1128                                    struct vmbus_channel *channel,
1129                                    struct netvsc_device *net_device,
1130                                    struct net_device *ndev,
1131                                    u64 request_id,
1132                                    struct vmpacket_descriptor *desc)
1133 {
1134         struct nvsp_message *nvmsg;
1135         struct net_device_context *net_device_ctx = netdev_priv(ndev);
1136
1137         nvmsg = (struct nvsp_message *)((unsigned long)
1138                 desc + (desc->offset8 << 3));
1139
1140         switch (desc->type) {
1141         case VM_PKT_COMP:
1142                 netvsc_send_completion(net_device, channel, device, desc);
1143                 break;
1144
1145         case VM_PKT_DATA_USING_XFER_PAGES:
1146                 netvsc_receive(net_device, channel, device, desc);
1147                 break;
1148
1149         case VM_PKT_DATA_INBAND:
1150                 netvsc_receive_inband(device, net_device_ctx, nvmsg);
1151                 break;
1152
1153         default:
1154                 netdev_err(ndev, "unhandled packet type %d, tid %llx\n",
1155                            desc->type, request_id);
1156                 break;
1157         }
1158 }
1159
1160
1161 void netvsc_channel_cb(void *context)
1162 {
1163         int ret;
1164         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1165         struct hv_device *device;
1166         struct netvsc_device *net_device;
1167         u32 bytes_recvd;
1168         u64 request_id;
1169         struct vmpacket_descriptor *desc;
1170         unsigned char *buffer;
1171         int bufferlen = NETVSC_PACKET_SIZE;
1172         struct net_device *ndev;
1173         bool need_to_commit = false;
1174
1175         if (channel->primary_channel != NULL)
1176                 device = channel->primary_channel->device_obj;
1177         else
1178                 device = channel->device_obj;
1179
1180         net_device = get_inbound_net_device(device);
1181         if (!net_device)
1182                 return;
1183         ndev = hv_get_drvdata(device);
1184         buffer = get_per_channel_state(channel);
1185
1186         do {
1187                 desc = get_next_pkt_raw(channel);
1188                 if (desc != NULL) {
1189                         netvsc_process_raw_pkt(device,
1190                                                channel,
1191                                                net_device,
1192                                                ndev,
1193                                                desc->trans_id,
1194                                                desc);
1195
1196                         put_pkt_raw(channel, desc);
1197                         need_to_commit = true;
1198                         continue;
1199                 }
1200                 if (need_to_commit) {
1201                         need_to_commit = false;
1202                         commit_rd_index(channel);
1203                 }
1204
1205                 ret = vmbus_recvpacket_raw(channel, buffer, bufferlen,
1206                                            &bytes_recvd, &request_id);
1207                 if (ret == 0) {
1208                         if (bytes_recvd > 0) {
1209                                 desc = (struct vmpacket_descriptor *)buffer;
1210                                 netvsc_process_raw_pkt(device,
1211                                                        channel,
1212                                                        net_device,
1213                                                        ndev,
1214                                                        request_id,
1215                                                        desc);
1216
1217
1218                         } else {
1219                                 /*
1220                                  * We are done for this pass.
1221                                  */
1222                                 break;
1223                         }
1224
1225                 } else if (ret == -ENOBUFS) {
1226                         if (bufferlen > NETVSC_PACKET_SIZE)
1227                                 kfree(buffer);
1228                         /* Handle large packet */
1229                         buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
1230                         if (buffer == NULL) {
1231                                 /* Try again next time around */
1232                                 netdev_err(ndev,
1233                                            "unable to allocate buffer of size "
1234                                            "(%d)!!\n", bytes_recvd);
1235                                 break;
1236                         }
1237
1238                         bufferlen = bytes_recvd;
1239                 }
1240         } while (1);
1241
1242         if (bufferlen > NETVSC_PACKET_SIZE)
1243                 kfree(buffer);
1244         return;
1245 }
1246
1247 /*
1248  * netvsc_device_add - Callback when the device belonging to this
1249  * driver is added
1250  */
1251 int netvsc_device_add(struct hv_device *device, void *additional_info)
1252 {
1253         int i, ret = 0;
1254         int ring_size =
1255         ((struct netvsc_device_info *)additional_info)->ring_size;
1256         struct netvsc_device *net_device;
1257         struct net_device *ndev = hv_get_drvdata(device);
1258         struct net_device_context *net_device_ctx = netdev_priv(ndev);
1259
1260         net_device = alloc_net_device();
1261         if (!net_device)
1262                 return -ENOMEM;
1263
1264         net_device->ring_size = ring_size;
1265
1266         /* Initialize the NetVSC channel extension */
1267         init_completion(&net_device->channel_init_wait);
1268
1269         set_per_channel_state(device->channel, net_device->cb_buffer);
1270
1271         /* Open the channel */
1272         ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
1273                          ring_size * PAGE_SIZE, NULL, 0,
1274                          netvsc_channel_cb, device->channel);
1275
1276         if (ret != 0) {
1277                 netdev_err(ndev, "unable to open channel: %d\n", ret);
1278                 goto cleanup;
1279         }
1280
1281         /* Channel is opened */
1282         pr_info("hv_netvsc channel opened successfully\n");
1283
1284         /* If we're reopening the device we may have multiple queues, fill the
1285          * chn_table with the default channel to use it before subchannels are
1286          * opened.
1287          */
1288         for (i = 0; i < VRSS_CHANNEL_MAX; i++)
1289                 net_device->chn_table[i] = device->channel;
1290
1291         /* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is
1292          * populated.
1293          */
1294         wmb();
1295
1296         net_device_ctx->nvdev = net_device;
1297
1298         /* Connect with the NetVsp */
1299         ret = netvsc_connect_vsp(device);
1300         if (ret != 0) {
1301                 netdev_err(ndev,
1302                         "unable to connect to NetVSP - %d\n", ret);
1303                 goto close;
1304         }
1305
1306         return ret;
1307
1308 close:
1309         /* Now, we can close the channel safely */
1310         vmbus_close(device->channel);
1311
1312 cleanup:
1313         free_netvsc_device(net_device);
1314
1315         return ret;
1316 }