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