drivers/net/hyperv/netvsc.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, see <http://www.gnu.org/licenses/>.
  15  *
  16  * Authors:
  17  *   Haiyang Zhang <haiyangz@microsoft.com>
  18  *   Hank Janssen  <hjanssen@microsoft.com>
  19  */
  20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22 #include <linux/kernel.h>
  23 #include <linux/sched.h>
  24 #include <linux/wait.h>
  25 #include <linux/mm.h>
  26 #include <linux/delay.h>
  27 #include <linux/io.h>
  28 #include <linux/slab.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/if_ether.h>
  31 #include <linux/vmalloc.h>
  32 #include <asm/sync_bitops.h>
  33
  34 #include "hyperv_net.h"
  35
  36 /*
  37  * Switch the data path from the synthetic interface to the VF
  38  * interface.
  39  */
  40 void netvsc_switch_datapath(struct net_device *ndev, bool vf)
  41 {
  42         struct net_device_context *net_device_ctx = netdev_priv(ndev);
  43         struct hv_device *dev = net_device_ctx->device_ctx;
  44         struct netvsc_device *nv_dev = net_device_ctx->nvdev;
  45         struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
  46
  47         memset(init_pkt, 0, sizeof(struct nvsp_message));
  48         init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
  49         if (vf)
  50                 init_pkt->msg.v4_msg.active_dp.active_datapath =
  51                         NVSP_DATAPATH_VF;
  52         else
  53                 init_pkt->msg.v4_msg.active_dp.active_datapath =
  54                         NVSP_DATAPATH_SYNTHETIC;
  55
  56         vmbus_sendpacket(dev->channel, init_pkt,
  57                                sizeof(struct nvsp_message),
  58                                (unsigned long)init_pkt,
  59                                VM_PKT_DATA_INBAND, 0);
  60 }
  61
  62
  63 static struct netvsc_device *alloc_net_device(void)
  64 {
  65         struct netvsc_device *net_device;
  66
  67         net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
  68         if (!net_device)
  69                 return NULL;
  70
  71         net_device->cb_buffer = kzalloc(NETVSC_PACKET_SIZE, GFP_KERNEL);
  72         if (!net_device->cb_buffer) {
  73                 kfree(net_device);
  74                 return NULL;
  75         }
  76
  77         init_waitqueue_head(&net_device->wait_drain);
  78         net_device->destroy = false;
  79         atomic_set(&net_device->open_cnt, 0);
  80         atomic_set(&net_device->vf_use_cnt, 0);
  81         net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
  82         net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
  83
  84         net_device->vf_netdev = NULL;
  85         net_device->vf_inject = false;
  86
  87         return net_device;
  88 }
  89
  90 static void free_netvsc_device(struct netvsc_device *nvdev)
  91 {
  92         kfree(nvdev->cb_buffer);
  93         kfree(nvdev);
  94 }
  95
  96 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
  97 {
  98         struct netvsc_device *net_device = hv_device_to_netvsc_device(device);
  99
 100         if (net_device && net_device->destroy)
 101                 net_device = NULL;
 102
 103         return net_device;
 104 }
 105
 106 static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
 107 {
 108         struct netvsc_device *net_device = hv_device_to_netvsc_device(device);
 109
 110         if (!net_device)
 111                 goto get_in_err;
 112
 113         if (net_device->destroy &&
 114                 atomic_read(&net_device->num_outstanding_sends) == 0)
 115                 net_device = NULL;
 116
 117 get_in_err:
 118         return net_device;
 119 }
 120
 121
 122 static int netvsc_destroy_buf(struct hv_device *device)
 123 {
 124         struct nvsp_message *revoke_packet;
 125         int ret = 0;
 126         struct net_device *ndev = hv_get_drvdata(device);
 127         struct netvsc_device *net_device = net_device_to_netvsc_device(ndev);
 128
 129         /*
 130          * If we got a section count, it means we received a
 131          * SendReceiveBufferComplete msg (ie sent
 132          * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
 133          * to send a revoke msg here
 134          */
 135         if (net_device->recv_section_cnt) {
 136                 /* Send the revoke receive buffer */
 137                 revoke_packet = &net_device->revoke_packet;
 138                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 139
 140                 revoke_packet->hdr.msg_type =
 141                         NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 142                 revoke_packet->msg.v1_msg.
 143                 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 144
 145                 ret = vmbus_sendpacket(device->channel,
 146                                        revoke_packet,
 147                                        sizeof(struct nvsp_message),
 148                                        (unsigned long)revoke_packet,
 149                                        VM_PKT_DATA_INBAND, 0);
 150                 /*
 151                  * If we failed here, we might as well return and
 152                  * have a leak rather than continue and a bugchk
 153                  */
 154                 if (ret != 0) {
 155                         netdev_err(ndev, "unable to send "
 156                                 "revoke receive buffer to netvsp\n");
 157                         return ret;
 158                 }
 159         }
 160
 161         /* Teardown the gpadl on the vsp end */
 162         if (net_device->recv_buf_gpadl_handle) {
 163                 ret = vmbus_teardown_gpadl(device->channel,
 164                                            net_device->recv_buf_gpadl_handle);
 165
 166                 /* If we failed here, we might as well return and have a leak
 167                  * rather than continue and a bugchk
 168                  */
 169                 if (ret != 0) {
 170                         netdev_err(ndev,
 171                                    "unable to teardown receive buffer's gpadl\n");
 172                         return ret;
 173                 }
 174                 net_device->recv_buf_gpadl_handle = 0;
 175         }
 176
 177         if (net_device->recv_buf) {
 178                 /* Free up the receive buffer */
 179                 vfree(net_device->recv_buf);
 180                 net_device->recv_buf = NULL;
 181         }
 182
 183         if (net_device->recv_section) {
 184                 net_device->recv_section_cnt = 0;
 185                 kfree(net_device->recv_section);
 186                 net_device->recv_section = NULL;
 187         }
 188
 189         /* Deal with the send buffer we may have setup.
 190          * If we got a  send section size, it means we received a
 191          * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
 192          * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
 193          * to send a revoke msg here
 194          */
 195         if (net_device->send_section_size) {
 196                 /* Send the revoke receive buffer */
 197                 revoke_packet = &net_device->revoke_packet;
 198                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 199
 200                 revoke_packet->hdr.msg_type =
 201                         NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
 202                 revoke_packet->msg.v1_msg.revoke_send_buf.id =
 203                         NETVSC_SEND_BUFFER_ID;
 204
 205                 ret = vmbus_sendpacket(device->channel,
 206                                        revoke_packet,
 207                                        sizeof(struct nvsp_message),
 208                                        (unsigned long)revoke_packet,
 209                                        VM_PKT_DATA_INBAND, 0);
 210                 /* If we failed here, we might as well return and
 211                  * have a leak rather than continue and a bugchk
 212                  */
 213                 if (ret != 0) {
 214                         netdev_err(ndev, "unable to send "
 215                                    "revoke send buffer to netvsp\n");
 216                         return ret;
 217                 }
 218         }
 219         /* Teardown the gpadl on the vsp end */
 220         if (net_device->send_buf_gpadl_handle) {
 221                 ret = vmbus_teardown_gpadl(device->channel,
 222                                            net_device->send_buf_gpadl_handle);
 223
 224                 /* If we failed here, we might as well return and have a leak
 225                  * rather than continue and a bugchk
 226                  */
 227                 if (ret != 0) {
 228                         netdev_err(ndev,
 229                                    "unable to teardown send buffer's gpadl\n");
 230                         return ret;
 231                 }
 232                 net_device->send_buf_gpadl_handle = 0;
 233         }
 234         if (net_device->send_buf) {
 235                 /* Free up the send buffer */
 236                 vfree(net_device->send_buf);
 237                 net_device->send_buf = NULL;
 238         }
 239         kfree(net_device->send_section_map);
 240
 241         return ret;
 242 }
 243
 244 static int netvsc_init_buf(struct hv_device *device)
 245 {
 246         int ret = 0;
 247         struct netvsc_device *net_device;
 248         struct nvsp_message *init_packet;
 249         struct net_device *ndev;
 250         int node;
 251
 252         net_device = get_outbound_net_device(device);
 253         if (!net_device)
 254                 return -ENODEV;
 255         ndev = hv_get_drvdata(device);
 256
 257         node = cpu_to_node(device->channel->target_cpu);
 258         net_device->recv_buf = vzalloc_node(net_device->recv_buf_size, node);
 259         if (!net_device->recv_buf)
 260                 net_device->recv_buf = vzalloc(net_device->recv_buf_size);
 261
 262         if (!net_device->recv_buf) {
 263                 netdev_err(ndev, "unable to allocate receive "
 264                         "buffer of size %d\n", net_device->recv_buf_size);
 265                 ret = -ENOMEM;
 266                 goto cleanup;
 267         }
 268
 269         /*
 270          * Establish the gpadl handle for this buffer on this
 271          * channel.  Note: This call uses the vmbus connection rather
 272          * than the channel to establish the gpadl handle.
 273          */
 274         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 275                                     net_device->recv_buf_size,
 276                                     &net_device->recv_buf_gpadl_handle);
 277         if (ret != 0) {
 278                 netdev_err(ndev,
 279                         "unable to establish receive buffer's gpadl\n");
 280                 goto cleanup;
 281         }
 282
 283
 284         /* Notify the NetVsp of the gpadl handle */
 285         init_packet = &net_device->channel_init_pkt;
 286
 287         memset(init_packet, 0, sizeof(struct nvsp_message));
 288
 289         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 290         init_packet->msg.v1_msg.send_recv_buf.
 291                 gpadl_handle = net_device->recv_buf_gpadl_handle;
 292         init_packet->msg.v1_msg.
 293                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 294
 295         /* Send the gpadl notification request */
 296         ret = vmbus_sendpacket(device->channel, init_packet,
 297                                sizeof(struct nvsp_message),
 298                                (unsigned long)init_packet,
 299                                VM_PKT_DATA_INBAND,
 300                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 301         if (ret != 0) {
 302                 netdev_err(ndev,
 303                         "unable to send receive buffer's gpadl to netvsp\n");
 304                 goto cleanup;
 305         }
 306
 307         wait_for_completion(&net_device->channel_init_wait);
 308
 309         /* Check the response */
 310         if (init_packet->msg.v1_msg.
 311             send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
 312                 netdev_err(ndev, "Unable to complete receive buffer "
 313                            "initialization with NetVsp - status %d\n",
 314                            init_packet->msg.v1_msg.
 315                            send_recv_buf_complete.status);
 316                 ret = -EINVAL;
 317                 goto cleanup;
 318         }
 319
 320         /* Parse the response */
 321
 322         net_device->recv_section_cnt = init_packet->msg.
 323                 v1_msg.send_recv_buf_complete.num_sections;
 324
 325         net_device->recv_section = kmemdup(
 326                 init_packet->msg.v1_msg.send_recv_buf_complete.sections,
 327                 net_device->recv_section_cnt *
 328                 sizeof(struct nvsp_1_receive_buffer_section),
 329                 GFP_KERNEL);
 330         if (net_device->recv_section == NULL) {
 331                 ret = -EINVAL;
 332                 goto cleanup;
 333         }
 334
 335         /*
 336          * For 1st release, there should only be 1 section that represents the
 337          * entire receive buffer
 338          */
 339         if (net_device->recv_section_cnt != 1 ||
 340             net_device->recv_section->offset != 0) {
 341                 ret = -EINVAL;
 342                 goto cleanup;
 343         }
 344
 345         /* Now setup the send buffer.
 346          */
 347         net_device->send_buf = vzalloc_node(net_device->send_buf_size, node);
 348         if (!net_device->send_buf)
 349                 net_device->send_buf = vzalloc(net_device->send_buf_size);
 350         if (!net_device->send_buf) {
 351                 netdev_err(ndev, "unable to allocate send "
 352                            "buffer of size %d\n", net_device->send_buf_size);
 353                 ret = -ENOMEM;
 354                 goto cleanup;
 355         }
 356
 357         /* Establish the gpadl handle for this buffer on this
 358          * channel.  Note: This call uses the vmbus connection rather
 359          * than the channel to establish the gpadl handle.
 360          */
 361         ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
 362                                     net_device->send_buf_size,
 363                                     &net_device->send_buf_gpadl_handle);
 364         if (ret != 0) {
 365                 netdev_err(ndev,
 366                            "unable to establish send buffer's gpadl\n");
 367                 goto cleanup;
 368         }
 369
 370         /* Notify the NetVsp of the gpadl handle */
 371         init_packet = &net_device->channel_init_pkt;
 372         memset(init_packet, 0, sizeof(struct nvsp_message));
 373         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
 374         init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
 375                 net_device->send_buf_gpadl_handle;
 376         init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
 377
 378         /* Send the gpadl notification request */
 379         ret = vmbus_sendpacket(device->channel, init_packet,
 380                                sizeof(struct nvsp_message),
 381                                (unsigned long)init_packet,
 382                                VM_PKT_DATA_INBAND,
 383                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 384         if (ret != 0) {
 385                 netdev_err(ndev,
 386                            "unable to send send buffer's gpadl to netvsp\n");
 387                 goto cleanup;
 388         }
 389
 390         wait_for_completion(&net_device->channel_init_wait);
 391
 392         /* Check the response */
 393         if (init_packet->msg.v1_msg.
 394             send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
 395                 netdev_err(ndev, "Unable to complete send buffer "
 396                            "initialization with NetVsp - status %d\n",
 397                            init_packet->msg.v1_msg.
 398                            send_send_buf_complete.status);
 399                 ret = -EINVAL;
 400                 goto cleanup;
 401         }
 402
 403         /* Parse the response */
 404         net_device->send_section_size = init_packet->msg.
 405                                 v1_msg.send_send_buf_complete.section_size;
 406
 407         /* Section count is simply the size divided by the section size.
 408          */
 409         net_device->send_section_cnt =
 410                 net_device->send_buf_size/net_device->send_section_size;
 411
 412         dev_info(&device->device, "Send section size: %d, Section count:%d\n",
 413                  net_device->send_section_size, net_device->send_section_cnt);
 414
 415         /* Setup state for managing the send buffer. */
 416         net_device->map_words = DIV_ROUND_UP(net_device->send_section_cnt,
 417                                              BITS_PER_LONG);
 418
 419         net_device->send_section_map =
 420                 kzalloc(net_device->map_words * sizeof(ulong), GFP_KERNEL);
 421         if (net_device->send_section_map == NULL) {
 422                 ret = -ENOMEM;
 423                 goto cleanup;
 424         }
 425
 426         goto exit;
 427
 428 cleanup:
 429         netvsc_destroy_buf(device);
 430
 431 exit:
 432         return ret;
 433 }
 434
 435
 436 /* Negotiate NVSP protocol version */
 437 static int negotiate_nvsp_ver(struct hv_device *device,
 438                               struct netvsc_device *net_device,
 439                               struct nvsp_message *init_packet,
 440                               u32 nvsp_ver)
 441 {
 442         struct net_device *ndev = hv_get_drvdata(device);
 443         int ret;
 444
 445         memset(init_packet, 0, sizeof(struct nvsp_message));
 446         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 447         init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
 448         init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
 449
 450         /* Send the init request */
 451         ret = vmbus_sendpacket(device->channel, init_packet,
 452                                sizeof(struct nvsp_message),
 453                                (unsigned long)init_packet,
 454                                VM_PKT_DATA_INBAND,
 455                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 456
 457         if (ret != 0)
 458                 return ret;
 459
 460         wait_for_completion(&net_device->channel_init_wait);
 461
 462         if (init_packet->msg.init_msg.init_complete.status !=
 463             NVSP_STAT_SUCCESS)
 464                 return -EINVAL;
 465
 466         if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
 467                 return 0;
 468
 469         /* NVSPv2 or later: Send NDIS config */
 470         memset(init_packet, 0, sizeof(struct nvsp_message));
 471         init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
 472         init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;
 473         init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
 474
 475         if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5)
 476                 init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
 477
 478         ret = vmbus_sendpacket(device->channel, init_packet,
 479                                 sizeof(struct nvsp_message),
 480                                 (unsigned long)init_packet,
 481                                 VM_PKT_DATA_INBAND, 0);
 482
 483         return ret;
 484 }
 485
 486 static int netvsc_connect_vsp(struct hv_device *device)
 487 {
 488         int ret;
 489         struct netvsc_device *net_device;
 490         struct nvsp_message *init_packet;
 491         int ndis_version;
 492         u32 ver_list[] = { NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
 493                 NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5 };
 494         int i, num_ver = 4; /* number of different NVSP versions */
 495
 496         net_device = get_outbound_net_device(device);
 497         if (!net_device)
 498                 return -ENODEV;
 499
 500         init_packet = &net_device->channel_init_pkt;
 501
 502         /* Negotiate the latest NVSP protocol supported */
 503         for (i = num_ver - 1; i >= 0; i--)
 504                 if (negotiate_nvsp_ver(device, net_device, init_packet,
 505                                        ver_list[i])  == 0) {
 506                         net_device->nvsp_version = ver_list[i];
 507                         break;
 508                 }
 509
 510         if (i < 0) {
 511                 ret = -EPROTO;
 512                 goto cleanup;
 513         }
 514
 515         pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
 516
 517         /* Send the ndis version */
 518         memset(init_packet, 0, sizeof(struct nvsp_message));
 519
 520         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
 521                 ndis_version = 0x00060001;
 522         else
 523                 ndis_version = 0x0006001e;
 524
 525         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 526         init_packet->msg.v1_msg.
 527                 send_ndis_ver.ndis_major_ver =
 528                                 (ndis_version & 0xFFFF0000) >> 16;
 529         init_packet->msg.v1_msg.
 530                 send_ndis_ver.ndis_minor_ver =
 531                                 ndis_version & 0xFFFF;
 532
 533         /* Send the init request */
 534         ret = vmbus_sendpacket(device->channel, init_packet,
 535                                 sizeof(struct nvsp_message),
 536                                 (unsigned long)init_packet,
 537                                 VM_PKT_DATA_INBAND, 0);
 538         if (ret != 0)
 539                 goto cleanup;
 540
 541         /* Post the big receive buffer to NetVSP */
 542         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
 543                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
 544         else
 545                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 546         net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
 547
 548         ret = netvsc_init_buf(device);
 549
 550 cleanup:
 551         return ret;
 552 }
 553
 554 static void netvsc_disconnect_vsp(struct hv_device *device)
 555 {
 556         netvsc_destroy_buf(device);
 557 }
 558
 559 /*
 560  * netvsc_device_remove - Callback when the root bus device is removed
 561  */
 562 int netvsc_device_remove(struct hv_device *device)
 563 {
 564         struct net_device *ndev = hv_get_drvdata(device);
 565         struct net_device_context *net_device_ctx = netdev_priv(ndev);
 566         struct netvsc_device *net_device = net_device_ctx->nvdev;
 567
 568         netvsc_disconnect_vsp(device);
 569
 570         net_device_ctx->nvdev = NULL;
 571
 572         /*
 573          * At this point, no one should be accessing net_device
 574          * except in here
 575          */
 576         dev_notice(&device->device, "net device safe to remove\n");
 577
 578         /* Now, we can close the channel safely */
 579         vmbus_close(device->channel);
 580
 581         /* Release all resources */
 582         vfree(net_device->sub_cb_buf);
 583         free_netvsc_device(net_device);
 584         return 0;
 585 }
 586
 587
 588 #define RING_AVAIL_PERCENT_HIWATER 20
 589 #define RING_AVAIL_PERCENT_LOWATER 10
 590
 591 /*
 592  * Get the percentage of available bytes to write in the ring.
 593  * The return value is in range from 0 to 100.
 594  */
 595 static inline u32 hv_ringbuf_avail_percent(
 596                 struct hv_ring_buffer_info *ring_info)
 597 {
 598         u32 avail_read, avail_write;
 599
 600         hv_get_ringbuffer_availbytes(ring_info, &avail_read, &avail_write);
 601
 602         return avail_write * 100 / ring_info->ring_datasize;
 603 }
 604
 605 static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
 606                                          u32 index)
 607 {
 608         sync_change_bit(index, net_device->send_section_map);
 609 }
 610
 611 static void netvsc_send_completion(struct netvsc_device *net_device,
 612                                    struct vmbus_channel *incoming_channel,
 613                                    struct hv_device *device,
 614                                    struct vmpacket_descriptor *packet)
 615 {
 616         struct nvsp_message *nvsp_packet;
 617         struct hv_netvsc_packet *nvsc_packet;
 618         struct net_device *ndev = hv_get_drvdata(device);
 619         struct net_device_context *net_device_ctx = netdev_priv(ndev);
 620         u32 send_index;
 621         struct sk_buff *skb;
 622
 623         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 624                         (packet->offset8 << 3));
 625
 626         if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
 627             (nvsp_packet->hdr.msg_type ==
 628              NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
 629             (nvsp_packet->hdr.msg_type ==
 630              NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE) ||
 631             (nvsp_packet->hdr.msg_type ==
 632              NVSP_MSG5_TYPE_SUBCHANNEL)) {
 633                 /* Copy the response back */
 634                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 635                        sizeof(struct nvsp_message));
 636                 complete(&net_device->channel_init_wait);
 637         } else if (nvsp_packet->hdr.msg_type ==
 638                    NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
 639                 int num_outstanding_sends;
 640                 u16 q_idx = 0;
 641                 struct vmbus_channel *channel = device->channel;
 642                 int queue_sends;
 643
 644                 /* Get the send context */
 645                 skb = (struct sk_buff *)(unsigned long)packet->trans_id;
 646
 647                 /* Notify the layer above us */
 648                 if (skb) {
 649                         nvsc_packet = (struct hv_netvsc_packet *) skb->cb;
 650                         send_index = nvsc_packet->send_buf_index;
 651                         if (send_index != NETVSC_INVALID_INDEX)
 652                                 netvsc_free_send_slot(net_device, send_index);
 653                         q_idx = nvsc_packet->q_idx;
 654                         channel = incoming_channel;
 655                         dev_kfree_skb_any(skb);
 656                 }
 657
 658                 num_outstanding_sends =
 659                         atomic_dec_return(&net_device->num_outstanding_sends);
 660                 queue_sends = atomic_dec_return(&net_device->
 661                                                 queue_sends[q_idx]);
 662
 663                 if (net_device->destroy && num_outstanding_sends == 0)
 664                         wake_up(&net_device->wait_drain);
 665
 666                 if (netif_tx_queue_stopped(netdev_get_tx_queue(ndev, q_idx)) &&
 667                     !net_device_ctx->start_remove &&
 668                     (hv_ringbuf_avail_percent(&channel->outbound) >
 669                      RING_AVAIL_PERCENT_HIWATER || queue_sends < 1))
 670                                 netif_tx_wake_queue(netdev_get_tx_queue(
 671                                                     ndev, q_idx));
 672         } else {
 673                 netdev_err(ndev, "Unknown send completion packet type- "
 674                            "%d received!!\n", nvsp_packet->hdr.msg_type);
 675         }
 676
 677 }
 678
 679 static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
 680 {
 681         unsigned long index;
 682         u32 max_words = net_device->map_words;
 683         unsigned long *map_addr = (unsigned long *)net_device->send_section_map;
 684         u32 section_cnt = net_device->send_section_cnt;
 685         int ret_val = NETVSC_INVALID_INDEX;
 686         int i;
 687         int prev_val;
 688
 689         for (i = 0; i < max_words; i++) {
 690                 if (!~(map_addr[i]))
 691                         continue;
 692                 index = ffz(map_addr[i]);
 693                 prev_val = sync_test_and_set_bit(index, &map_addr[i]);
 694                 if (prev_val)
 695                         continue;
 696                 if ((index + (i * BITS_PER_LONG)) >= section_cnt)
 697                         break;
 698                 ret_val = (index + (i * BITS_PER_LONG));
 699                 break;
 700         }
 701         return ret_val;
 702 }
 703
 704 static u32 netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 705                                    unsigned int section_index,
 706                                    u32 pend_size,
 707                                    struct hv_netvsc_packet *packet,
 708                                    struct rndis_message *rndis_msg,
 709                                    struct hv_page_buffer **pb,
 710                                    struct sk_buff *skb)
 711 {
 712         char *start = net_device->send_buf;
 713         char *dest = start + (section_index * net_device->send_section_size)
 714                      + pend_size;
 715         int i;
 716         bool is_data_pkt = (skb != NULL) ? true : false;
 717         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 718         u32 msg_size = 0;
 719         u32 padding = 0;
 720         u32 remain = packet->total_data_buflen % net_device->pkt_align;
 721         u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
 722                 packet->page_buf_cnt;
 723
 724         /* Add padding */
 725         if (is_data_pkt && xmit_more && remain &&
 726             !packet->cp_partial) {
 727                 padding = net_device->pkt_align - remain;
 728                 rndis_msg->msg_len += padding;
 729                 packet->total_data_buflen += padding;
 730         }
 731
 732         for (i = 0; i < page_count; i++) {
 733                 char *src = phys_to_virt((*pb)[i].pfn << PAGE_SHIFT);
 734                 u32 offset = (*pb)[i].offset;
 735                 u32 len = (*pb)[i].len;
 736
 737                 memcpy(dest, (src + offset), len);
 738                 msg_size += len;
 739                 dest += len;
 740         }
 741
 742         if (padding) {
 743                 memset(dest, 0, padding);
 744                 msg_size += padding;
 745         }
 746
 747         return msg_size;
 748 }
 749
 750 static inline int netvsc_send_pkt(
 751         struct hv_device *device,
 752         struct hv_netvsc_packet *packet,
 753         struct netvsc_device *net_device,
 754         struct hv_page_buffer **pb,
 755         struct sk_buff *skb)
 756 {
 757         struct nvsp_message nvmsg;
 758         u16 q_idx = packet->q_idx;
 759         struct vmbus_channel *out_channel = net_device->chn_table[q_idx];
 760         struct net_device *ndev = hv_get_drvdata(device);
 761         u64 req_id;
 762         int ret;
 763         struct hv_page_buffer *pgbuf;
 764         u32 ring_avail = hv_ringbuf_avail_percent(&out_channel->outbound);
 765         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 766
 767         nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 768         if (skb != NULL) {
 769                 /* 0 is RMC_DATA; */
 770                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 0;
 771         } else {
 772                 /* 1 is RMC_CONTROL; */
 773                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 1;
 774         }
 775
 776         nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
 777                 packet->send_buf_index;
 778         if (packet->send_buf_index == NETVSC_INVALID_INDEX)
 779                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
 780         else
 781                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size =
 782                         packet->total_data_buflen;
 783
 784         req_id = (ulong)skb;
 785
 786         if (out_channel->rescind)
 787                 return -ENODEV;
 788
 789         /*
 790          * It is possible that once we successfully place this packet
 791          * on the ringbuffer, we may stop the queue. In that case, we want
 792          * to notify the host independent of the xmit_more flag. We don't
 793          * need to be precise here; in the worst case we may signal the host
 794          * unnecessarily.
 795          */
 796         if (ring_avail < (RING_AVAIL_PERCENT_LOWATER + 1))
 797                 xmit_more = false;
 798
 799         if (packet->page_buf_cnt) {
 800                 pgbuf = packet->cp_partial ? (*pb) +
 801                         packet->rmsg_pgcnt : (*pb);
 802                 ret = vmbus_sendpacket_pagebuffer_ctl(out_channel,
 803                                                       pgbuf,
 804                                                       packet->page_buf_cnt,
 805                                                       &nvmsg,
 806                                                       sizeof(struct nvsp_message),
 807                                                       req_id,
 808                                                       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
 809                                                       !xmit_more);
 810         } else {
 811                 ret = vmbus_sendpacket_ctl(out_channel, &nvmsg,
 812                                            sizeof(struct nvsp_message),
 813                                            req_id,
 814                                            VM_PKT_DATA_INBAND,
 815                                            VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
 816                                            !xmit_more);
 817         }
 818
 819         if (ret == 0) {
 820                 atomic_inc(&net_device->num_outstanding_sends);
 821                 atomic_inc(&net_device->queue_sends[q_idx]);
 822
 823                 if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
 824                         netif_tx_stop_queue(netdev_get_tx_queue(ndev, q_idx));
 825
 826                         if (atomic_read(&net_device->
 827                                 queue_sends[q_idx]) < 1)
 828                                 netif_tx_wake_queue(netdev_get_tx_queue(
 829                                                     ndev, q_idx));
 830                 }
 831         } else if (ret == -EAGAIN) {
 832                 netif_tx_stop_queue(netdev_get_tx_queue(
 833                                     ndev, q_idx));
 834                 if (atomic_read(&net_device->queue_sends[q_idx]) < 1) {
 835                         netif_tx_wake_queue(netdev_get_tx_queue(
 836                                             ndev, q_idx));
 837                         ret = -ENOSPC;
 838                 }
 839         } else {
 840                 netdev_err(ndev, "Unable to send packet %p ret %d\n",
 841                            packet, ret);
 842         }
 843
 844         return ret;
 845 }
 846
 847 /* Move packet out of multi send data (msd), and clear msd */
 848 static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
 849                                 struct sk_buff **msd_skb,
 850                                 struct multi_send_data *msdp)
 851 {
 852         *msd_skb = msdp->skb;
 853         *msd_send = msdp->pkt;
 854         msdp->skb = NULL;
 855         msdp->pkt = NULL;
 856         msdp->count = 0;
 857 }
 858
 859 int netvsc_send(struct hv_device *device,
 860                 struct hv_netvsc_packet *packet,
 861                 struct rndis_message *rndis_msg,
 862                 struct hv_page_buffer **pb,
 863                 struct sk_buff *skb)
 864 {
 865         struct netvsc_device *net_device;
 866         int ret = 0, m_ret = 0;
 867         struct vmbus_channel *out_channel;
 868         u16 q_idx = packet->q_idx;
 869         u32 pktlen = packet->total_data_buflen, msd_len = 0;
 870         unsigned int section_index = NETVSC_INVALID_INDEX;
 871         struct multi_send_data *msdp;
 872         struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
 873         struct sk_buff *msd_skb = NULL;
 874         bool try_batch;
 875         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 876
 877         net_device = get_outbound_net_device(device);
 878         if (!net_device)
 879                 return -ENODEV;
 880
 881         out_channel = net_device->chn_table[q_idx];
 882
 883         packet->send_buf_index = NETVSC_INVALID_INDEX;
 884         packet->cp_partial = false;
 885
 886         /* Send control message directly without accessing msd (Multi-Send
 887          * Data) field which may be changed during data packet processing.
 888          */
 889         if (!skb) {
 890                 cur_send = packet;
 891                 goto send_now;
 892         }
 893
 894         msdp = &net_device->msd[q_idx];
 895
 896         /* batch packets in send buffer if possible */
 897         if (msdp->pkt)
 898                 msd_len = msdp->pkt->total_data_buflen;
 899
 900         try_batch = (skb != NULL) && msd_len > 0 && msdp->count <
 901                     net_device->max_pkt;
 902
 903         if (try_batch && msd_len + pktlen + net_device->pkt_align <
 904             net_device->send_section_size) {
 905                 section_index = msdp->pkt->send_buf_index;
 906
 907         } else if (try_batch && msd_len + packet->rmsg_size <
 908                    net_device->send_section_size) {
 909                 section_index = msdp->pkt->send_buf_index;
 910                 packet->cp_partial = true;
 911
 912         } else if ((skb != NULL) && pktlen + net_device->pkt_align <
 913                    net_device->send_section_size) {
 914                 section_index = netvsc_get_next_send_section(net_device);
 915                 if (section_index != NETVSC_INVALID_INDEX) {
 916                         move_pkt_msd(&msd_send, &msd_skb, msdp);
 917                         msd_len = 0;
 918                 }
 919         }
 920
 921         if (section_index != NETVSC_INVALID_INDEX) {
 922                 netvsc_copy_to_send_buf(net_device,
 923                                         section_index, msd_len,
 924                                         packet, rndis_msg, pb, skb);
 925
 926                 packet->send_buf_index = section_index;
 927
 928                 if (packet->cp_partial) {
 929                         packet->page_buf_cnt -= packet->rmsg_pgcnt;
 930                         packet->total_data_buflen = msd_len + packet->rmsg_size;
 931                 } else {
 932                         packet->page_buf_cnt = 0;
 933                         packet->total_data_buflen += msd_len;
 934                 }
 935
 936                 if (msdp->skb)
 937                         dev_kfree_skb_any(msdp->skb);
 938
 939                 if (xmit_more && !packet->cp_partial) {
 940                         msdp->skb = skb;
 941                         msdp->pkt = packet;
 942                         msdp->count++;
 943                 } else {
 944                         cur_send = packet;
 945                         msdp->skb = NULL;
 946                         msdp->pkt = NULL;
 947                         msdp->count = 0;
 948                 }
 949         } else {
 950                 move_pkt_msd(&msd_send, &msd_skb, msdp);
 951                 cur_send = packet;
 952         }
 953
 954         if (msd_send) {
 955                 m_ret = netvsc_send_pkt(device, msd_send, net_device,
 956                                         NULL, msd_skb);
 957
 958                 if (m_ret != 0) {
 959                         netvsc_free_send_slot(net_device,
 960                                               msd_send->send_buf_index);
 961                         dev_kfree_skb_any(msd_skb);
 962                 }
 963         }
 964
 965 send_now:
 966         if (cur_send)
 967                 ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);
 968
 969         if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
 970                 netvsc_free_send_slot(net_device, section_index);
 971
 972         return ret;
 973 }
 974
 975 static void netvsc_send_recv_completion(struct hv_device *device,
 976                                         struct vmbus_channel *channel,
 977                                         struct netvsc_device *net_device,
 978                                         u64 transaction_id, u32 status)
 979 {
 980         struct nvsp_message recvcompMessage;
 981         int retries = 0;
 982         int ret;
 983         struct net_device *ndev = hv_get_drvdata(device);
 984
 985         recvcompMessage.hdr.msg_type =
 986                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
 987
 988         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status = status;
 989
 990 retry_send_cmplt:
 991         /* Send the completion */
 992         ret = vmbus_sendpacket(channel, &recvcompMessage,
 993                                sizeof(struct nvsp_message), transaction_id,
 994                                VM_PKT_COMP, 0);
 995         if (ret == 0) {
 996                 /* success */
 997                 /* no-op */
 998         } else if (ret == -EAGAIN) {
 999                 /* no more room...wait a bit and attempt to retry 3 times */
1000                 retries++;
1001                 netdev_err(ndev, "unable to send receive completion pkt"
1002                         " (tid %llx)...retrying %d\n", transaction_id, retries);
1003
1004                 if (retries < 4) {
1005                         udelay(100);
1006                         goto retry_send_cmplt;
1007                 } else {
1008                         netdev_err(ndev, "unable to send receive "
1009                                 "completion pkt (tid %llx)...give up retrying\n",
1010                                 transaction_id);
1011                 }
1012         } else {
1013                 netdev_err(ndev, "unable to send receive "
1014                         "completion pkt - %llx\n", transaction_id);
1015         }
1016 }
1017
1018 static void netvsc_receive(struct netvsc_device *net_device,
1019                         struct vmbus_channel *channel,
1020                         struct hv_device *device,
1021                         struct vmpacket_descriptor *packet)
1022 {
1023         struct vmtransfer_page_packet_header *vmxferpage_packet;
1024         struct nvsp_message *nvsp_packet;
1025         struct hv_netvsc_packet nv_pkt;
1026         struct hv_netvsc_packet *netvsc_packet = &nv_pkt;
1027         u32 status = NVSP_STAT_SUCCESS;
1028         int i;
1029         int count = 0;
1030         struct net_device *ndev = hv_get_drvdata(device);
1031         void *data;
1032
1033         /*
1034          * All inbound packets other than send completion should be xfer page
1035          * packet
1036          */
1037         if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
1038                 netdev_err(ndev, "Unknown packet type received - %d\n",
1039                            packet->type);
1040                 return;
1041         }
1042
1043         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
1044                         (packet->offset8 << 3));
1045
1046         /* Make sure this is a valid nvsp packet */
1047         if (nvsp_packet->hdr.msg_type !=
1048             NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
1049                 netdev_err(ndev, "Unknown nvsp packet type received-"
1050                         " %d\n", nvsp_packet->hdr.msg_type);
1051                 return;
1052         }
1053
1054         vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
1055
1056         if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
1057                 netdev_err(ndev, "Invalid xfer page set id - "
1058                            "expecting %x got %x\n", NETVSC_RECEIVE_BUFFER_ID,
1059                            vmxferpage_packet->xfer_pageset_id);
1060                 return;
1061         }
1062
1063         count = vmxferpage_packet->range_cnt;
1064
1065         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1066         for (i = 0; i < count; i++) {
1067                 /* Initialize the netvsc packet */
1068                 data = (void *)((unsigned long)net_device->
1069                         recv_buf + vmxferpage_packet->ranges[i].byte_offset);
1070                 netvsc_packet->total_data_buflen =
1071                                         vmxferpage_packet->ranges[i].byte_count;
1072
1073                 /* Pass it to the upper layer */
1074                 status = rndis_filter_receive(device, netvsc_packet, &data,
1075                                               channel);
1076
1077         }
1078
1079         netvsc_send_recv_completion(device, channel, net_device,
1080                                     vmxferpage_packet->d.trans_id, status);
1081 }
1082
1083
1084 static void netvsc_send_table(struct hv_device *hdev,
1085                               struct nvsp_message *nvmsg)
1086 {
1087         struct netvsc_device *nvscdev;
1088         struct net_device *ndev = hv_get_drvdata(hdev);
1089         int i;
1090         u32 count, *tab;
1091
1092         nvscdev = get_outbound_net_device(hdev);
1093         if (!nvscdev)
1094                 return;
1095
1096         count = nvmsg->msg.v5_msg.send_table.count;
1097         if (count != VRSS_SEND_TAB_SIZE) {
1098                 netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1099                 return;
1100         }
1101
1102         tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
1103                       nvmsg->msg.v5_msg.send_table.offset);
1104
1105         for (i = 0; i < count; i++)
1106                 nvscdev->send_table[i] = tab[i];
1107 }
1108
1109 static void netvsc_send_vf(struct netvsc_device *nvdev,
1110                            struct nvsp_message *nvmsg)
1111 {
1112         nvdev->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1113         nvdev->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1114 }
1115
1116 static inline void netvsc_receive_inband(struct hv_device *hdev,
1117                                          struct netvsc_device *nvdev,
1118                                          struct nvsp_message *nvmsg)
1119 {
1120         switch (nvmsg->hdr.msg_type) {
1121         case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1122                 netvsc_send_table(hdev, nvmsg);
1123                 break;
1124
1125         case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1126                 netvsc_send_vf(nvdev, nvmsg);
1127                 break;
1128         }
1129 }
1130
1131 static void netvsc_process_raw_pkt(struct hv_device *device,
1132                                    struct vmbus_channel *channel,
1133                                    struct netvsc_device *net_device,
1134                                    struct net_device *ndev,
1135                                    u64 request_id,
1136                                    struct vmpacket_descriptor *desc)
1137 {
1138         struct nvsp_message *nvmsg;
1139
1140         nvmsg = (struct nvsp_message *)((unsigned long)
1141                 desc + (desc->offset8 << 3));
1142
1143         switch (desc->type) {
1144         case VM_PKT_COMP:
1145                 netvsc_send_completion(net_device, channel, device, desc);
1146                 break;
1147
1148         case VM_PKT_DATA_USING_XFER_PAGES:
1149                 netvsc_receive(net_device, channel, device, desc);
1150                 break;
1151
1152         case VM_PKT_DATA_INBAND:
1153                 netvsc_receive_inband(device, net_device, nvmsg);
1154                 break;
1155
1156         default:
1157                 netdev_err(ndev, "unhandled packet type %d, tid %llx\n",
1158                            desc->type, request_id);
1159                 break;
1160         }
1161 }
1162
1163
1164 void netvsc_channel_cb(void *context)
1165 {
1166         int ret;
1167         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1168         struct hv_device *device;
1169         struct netvsc_device *net_device;
1170         u32 bytes_recvd;
1171         u64 request_id;
1172         struct vmpacket_descriptor *desc;
1173         unsigned char *buffer;
1174         int bufferlen = NETVSC_PACKET_SIZE;
1175         struct net_device *ndev;
1176         bool need_to_commit = false;
1177
1178         if (channel->primary_channel != NULL)
1179                 device = channel->primary_channel->device_obj;
1180         else
1181                 device = channel->device_obj;
1182
1183         net_device = get_inbound_net_device(device);
1184         if (!net_device)
1185                 return;
1186         ndev = hv_get_drvdata(device);
1187         buffer = get_per_channel_state(channel);
1188
1189         do {
1190                 desc = get_next_pkt_raw(channel);
1191                 if (desc != NULL) {
1192                         netvsc_process_raw_pkt(device,
1193                                                channel,
1194                                                net_device,
1195                                                ndev,
1196                                                desc->trans_id,
1197                                                desc);
1198
1199                         put_pkt_raw(channel, desc);
1200                         need_to_commit = true;
1201                         continue;
1202                 }
1203                 if (need_to_commit) {
1204                         need_to_commit = false;
1205                         commit_rd_index(channel);
1206                 }
1207
1208                 ret = vmbus_recvpacket_raw(channel, buffer, bufferlen,
1209                                            &bytes_recvd, &request_id);
1210                 if (ret == 0) {
1211                         if (bytes_recvd > 0) {
1212                                 desc = (struct vmpacket_descriptor *)buffer;
1213                                 netvsc_process_raw_pkt(device,
1214                                                        channel,
1215                                                        net_device,
1216                                                        ndev,
1217                                                        request_id,
1218                                                        desc);
1219
1220
1221                         } else {
1222                                 /*
1223                                  * We are done for this pass.
1224                                  */
1225                                 break;
1226                         }
1227
1228                 } else if (ret == -ENOBUFS) {
1229                         if (bufferlen > NETVSC_PACKET_SIZE)
1230                                 kfree(buffer);
1231                         /* Handle large packet */
1232                         buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
1233                         if (buffer == NULL) {
1234                                 /* Try again next time around */
1235                                 netdev_err(ndev,
1236                                            "unable to allocate buffer of size "
1237                                            "(%d)!!\n", bytes_recvd);
1238                                 break;
1239                         }
1240
1241                         bufferlen = bytes_recvd;
1242                 }
1243         } while (1);
1244
1245         if (bufferlen > NETVSC_PACKET_SIZE)
1246                 kfree(buffer);
1247         return;
1248 }
1249
1250 /*
1251  * netvsc_device_add - Callback when the device belonging to this
1252  * driver is added
1253  */
1254 int netvsc_device_add(struct hv_device *device, void *additional_info)
1255 {
1256         int i, ret = 0;
1257         int ring_size =
1258         ((struct netvsc_device_info *)additional_info)->ring_size;
1259         struct netvsc_device *net_device;
1260         struct net_device *ndev = hv_get_drvdata(device);
1261         struct net_device_context *net_device_ctx = netdev_priv(ndev);
1262
1263         net_device = alloc_net_device();
1264         if (!net_device)
1265                 return -ENOMEM;
1266
1267         net_device->ring_size = ring_size;
1268
1269         /* Initialize the NetVSC channel extension */
1270         init_completion(&net_device->channel_init_wait);
1271
1272         set_per_channel_state(device->channel, net_device->cb_buffer);
1273
1274         /* Open the channel */
1275         ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
1276                          ring_size * PAGE_SIZE, NULL, 0,
1277                          netvsc_channel_cb, device->channel);
1278
1279         if (ret != 0) {
1280                 netdev_err(ndev, "unable to open channel: %d\n", ret);
1281                 goto cleanup;
1282         }
1283
1284         /* Channel is opened */
1285         pr_info("hv_netvsc channel opened successfully\n");
1286
1287         /* If we're reopening the device we may have multiple queues, fill the
1288          * chn_table with the default channel to use it before subchannels are
1289          * opened.
1290          */
1291         for (i = 0; i < VRSS_CHANNEL_MAX; i++)
1292                 net_device->chn_table[i] = device->channel;
1293
1294         /* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is
1295          * populated.
1296          */
1297         wmb();
1298
1299         net_device_ctx->nvdev = net_device;
1300
1301         /* Connect with the NetVsp */
1302         ret = netvsc_connect_vsp(device);
1303         if (ret != 0) {
1304                 netdev_err(ndev,
1305                         "unable to connect to NetVSP - %d\n", ret);
1306                 goto close;
1307         }
1308
1309         return ret;
1310
1311 close:
1312         /* Now, we can close the channel safely */
1313         vmbus_close(device->channel);
1314
1315 cleanup:
1316         free_netvsc_device(net_device);
1317
1318         return ret;
1319 }