Pileus Git - ~andy/linux/blob - 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
  32 #include "hyperv_net.h"
  33
  34
  35 static struct netvsc_device *alloc_net_device(struct hv_device *device)
  36 {
  37         struct netvsc_device *net_device;
  38         struct net_device *ndev = hv_get_drvdata(device);
  39
  40         net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
  41         if (!net_device)
  42                 return NULL;
  43
  44         init_waitqueue_head(&net_device->wait_drain);
  45         net_device->start_remove = false;
  46         net_device->destroy = false;
  47         net_device->dev = device;
  48         net_device->ndev = ndev;
  49
  50         hv_set_drvdata(device, net_device);
  51         return net_device;
  52 }
  53
  54 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
  55 {
  56         struct netvsc_device *net_device;
  57
  58         net_device = hv_get_drvdata(device);
  59         if (net_device && net_device->destroy)
  60                 net_device = NULL;
  61
  62         return net_device;
  63 }
  64
  65 static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
  66 {
  67         struct netvsc_device *net_device;
  68
  69         net_device = hv_get_drvdata(device);
  70
  71         if (!net_device)
  72                 goto get_in_err;
  73
  74         if (net_device->destroy &&
  75                 atomic_read(&net_device->num_outstanding_sends) == 0)
  76                 net_device = NULL;
  77
  78 get_in_err:
  79         return net_device;
  80 }
  81
  82
  83 static int netvsc_destroy_recv_buf(struct netvsc_device *net_device)
  84 {
  85         struct nvsp_message *revoke_packet;
  86         int ret = 0;
  87         struct net_device *ndev = net_device->ndev;
  88
  89         /*
  90          * If we got a section count, it means we received a
  91          * SendReceiveBufferComplete msg (ie sent
  92          * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
  93          * to send a revoke msg here
  94          */
  95         if (net_device->recv_section_cnt) {
  96                 /* Send the revoke receive buffer */
  97                 revoke_packet = &net_device->revoke_packet;
  98                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
  99
 100                 revoke_packet->hdr.msg_type =
 101                         NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 102                 revoke_packet->msg.v1_msg.
 103                 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 104
 105                 ret = vmbus_sendpacket(net_device->dev->channel,
 106                                        revoke_packet,
 107                                        sizeof(struct nvsp_message),
 108                                        (unsigned long)revoke_packet,
 109                                        VM_PKT_DATA_INBAND, 0);
 110                 /*
 111                  * If we failed here, we might as well return and
 112                  * have a leak rather than continue and a bugchk
 113                  */
 114                 if (ret != 0) {
 115                         netdev_err(ndev, "unable to send "
 116                                 "revoke receive buffer to netvsp\n");
 117                         return ret;
 118                 }
 119         }
 120
 121         /* Teardown the gpadl on the vsp end */
 122         if (net_device->recv_buf_gpadl_handle) {
 123                 ret = vmbus_teardown_gpadl(net_device->dev->channel,
 124                            net_device->recv_buf_gpadl_handle);
 125
 126                 /* If we failed here, we might as well return and have a leak
 127                  * rather than continue and a bugchk
 128                  */
 129                 if (ret != 0) {
 130                         netdev_err(ndev,
 131                                    "unable to teardown receive buffer's gpadl\n");
 132                         return ret;
 133                 }
 134                 net_device->recv_buf_gpadl_handle = 0;
 135         }
 136
 137         if (net_device->recv_buf) {
 138                 /* Free up the receive buffer */
 139                 vfree(net_device->recv_buf);
 140                 net_device->recv_buf = NULL;
 141         }
 142
 143         if (net_device->recv_section) {
 144                 net_device->recv_section_cnt = 0;
 145                 kfree(net_device->recv_section);
 146                 net_device->recv_section = NULL;
 147         }
 148
 149         return ret;
 150 }
 151
 152 static int netvsc_init_recv_buf(struct hv_device *device)
 153 {
 154         int ret = 0;
 155         int t;
 156         struct netvsc_device *net_device;
 157         struct nvsp_message *init_packet;
 158         struct net_device *ndev;
 159
 160         net_device = get_outbound_net_device(device);
 161         if (!net_device)
 162                 return -ENODEV;
 163         ndev = net_device->ndev;
 164
 165         net_device->recv_buf = vzalloc(net_device->recv_buf_size);
 166         if (!net_device->recv_buf) {
 167                 netdev_err(ndev, "unable to allocate receive "
 168                         "buffer of size %d\n", net_device->recv_buf_size);
 169                 ret = -ENOMEM;
 170                 goto cleanup;
 171         }
 172
 173         /*
 174          * Establish the gpadl handle for this buffer on this
 175          * channel.  Note: This call uses the vmbus connection rather
 176          * than the channel to establish the gpadl handle.
 177          */
 178         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 179                                     net_device->recv_buf_size,
 180                                     &net_device->recv_buf_gpadl_handle);
 181         if (ret != 0) {
 182                 netdev_err(ndev,
 183                         "unable to establish receive buffer's gpadl\n");
 184                 goto cleanup;
 185         }
 186
 187
 188         /* Notify the NetVsp of the gpadl handle */
 189         init_packet = &net_device->channel_init_pkt;
 190
 191         memset(init_packet, 0, sizeof(struct nvsp_message));
 192
 193         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 194         init_packet->msg.v1_msg.send_recv_buf.
 195                 gpadl_handle = net_device->recv_buf_gpadl_handle;
 196         init_packet->msg.v1_msg.
 197                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 198
 199         /* Send the gpadl notification request */
 200         ret = vmbus_sendpacket(device->channel, init_packet,
 201                                sizeof(struct nvsp_message),
 202                                (unsigned long)init_packet,
 203                                VM_PKT_DATA_INBAND,
 204                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 205         if (ret != 0) {
 206                 netdev_err(ndev,
 207                         "unable to send receive buffer's gpadl to netvsp\n");
 208                 goto cleanup;
 209         }
 210
 211         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 212         BUG_ON(t == 0);
 213
 214
 215         /* Check the response */
 216         if (init_packet->msg.v1_msg.
 217             send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
 218                 netdev_err(ndev, "Unable to complete receive buffer "
 219                            "initialization with NetVsp - status %d\n",
 220                            init_packet->msg.v1_msg.
 221                            send_recv_buf_complete.status);
 222                 ret = -EINVAL;
 223                 goto cleanup;
 224         }
 225
 226         /* Parse the response */
 227
 228         net_device->recv_section_cnt = init_packet->msg.
 229                 v1_msg.send_recv_buf_complete.num_sections;
 230
 231         net_device->recv_section = kmemdup(
 232                 init_packet->msg.v1_msg.send_recv_buf_complete.sections,
 233                 net_device->recv_section_cnt *
 234                 sizeof(struct nvsp_1_receive_buffer_section),
 235                 GFP_KERNEL);
 236         if (net_device->recv_section == NULL) {
 237                 ret = -EINVAL;
 238                 goto cleanup;
 239         }
 240
 241         /*
 242          * For 1st release, there should only be 1 section that represents the
 243          * entire receive buffer
 244          */
 245         if (net_device->recv_section_cnt != 1 ||
 246             net_device->recv_section->offset != 0) {
 247                 ret = -EINVAL;
 248                 goto cleanup;
 249         }
 250
 251         goto exit;
 252
 253 cleanup:
 254         netvsc_destroy_recv_buf(net_device);
 255
 256 exit:
 257         return ret;
 258 }
 259
 260
 261 /* Negotiate NVSP protocol version */
 262 static int negotiate_nvsp_ver(struct hv_device *device,
 263                               struct netvsc_device *net_device,
 264                               struct nvsp_message *init_packet,
 265                               u32 nvsp_ver)
 266 {
 267         int ret, t;
 268
 269         memset(init_packet, 0, sizeof(struct nvsp_message));
 270         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 271         init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
 272         init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
 273
 274         /* Send the init request */
 275         ret = vmbus_sendpacket(device->channel, init_packet,
 276                                sizeof(struct nvsp_message),
 277                                (unsigned long)init_packet,
 278                                VM_PKT_DATA_INBAND,
 279                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 280
 281         if (ret != 0)
 282                 return ret;
 283
 284         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 285
 286         if (t == 0)
 287                 return -ETIMEDOUT;
 288
 289         if (init_packet->msg.init_msg.init_complete.status !=
 290             NVSP_STAT_SUCCESS)
 291                 return -EINVAL;
 292
 293         if (nvsp_ver != NVSP_PROTOCOL_VERSION_2)
 294                 return 0;
 295
 296         /* NVSPv2 only: Send NDIS config */
 297         memset(init_packet, 0, sizeof(struct nvsp_message));
 298         init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
 299         init_packet->msg.v2_msg.send_ndis_config.mtu = net_device->ndev->mtu;
 300         init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
 301
 302         ret = vmbus_sendpacket(device->channel, init_packet,
 303                                 sizeof(struct nvsp_message),
 304                                 (unsigned long)init_packet,
 305                                 VM_PKT_DATA_INBAND, 0);
 306
 307         return ret;
 308 }
 309
 310 static int netvsc_connect_vsp(struct hv_device *device)
 311 {
 312         int ret;
 313         struct netvsc_device *net_device;
 314         struct nvsp_message *init_packet;
 315         int ndis_version;
 316         struct net_device *ndev;
 317
 318         net_device = get_outbound_net_device(device);
 319         if (!net_device)
 320                 return -ENODEV;
 321         ndev = net_device->ndev;
 322
 323         init_packet = &net_device->channel_init_pkt;
 324
 325         /* Negotiate the latest NVSP protocol supported */
 326         if (negotiate_nvsp_ver(device, net_device, init_packet,
 327                                NVSP_PROTOCOL_VERSION_2) == 0) {
 328                 net_device->nvsp_version = NVSP_PROTOCOL_VERSION_2;
 329         } else if (negotiate_nvsp_ver(device, net_device, init_packet,
 330                                     NVSP_PROTOCOL_VERSION_1) == 0) {
 331                 net_device->nvsp_version = NVSP_PROTOCOL_VERSION_1;
 332         } else {
 333                 ret = -EPROTO;
 334                 goto cleanup;
 335         }
 336
 337         pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
 338
 339         /* Send the ndis version */
 340         memset(init_packet, 0, sizeof(struct nvsp_message));
 341
 342         ndis_version = 0x00050001;
 343
 344         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 345         init_packet->msg.v1_msg.
 346                 send_ndis_ver.ndis_major_ver =
 347                                 (ndis_version & 0xFFFF0000) >> 16;
 348         init_packet->msg.v1_msg.
 349                 send_ndis_ver.ndis_minor_ver =
 350                                 ndis_version & 0xFFFF;
 351
 352         /* Send the init request */
 353         ret = vmbus_sendpacket(device->channel, init_packet,
 354                                 sizeof(struct nvsp_message),
 355                                 (unsigned long)init_packet,
 356                                 VM_PKT_DATA_INBAND, 0);
 357         if (ret != 0)
 358                 goto cleanup;
 359
 360         /* Post the big receive buffer to NetVSP */
 361         ret = netvsc_init_recv_buf(device);
 362
 363 cleanup:
 364         return ret;
 365 }
 366
 367 static void netvsc_disconnect_vsp(struct netvsc_device *net_device)
 368 {
 369         netvsc_destroy_recv_buf(net_device);
 370 }
 371
 372 /*
 373  * netvsc_device_remove - Callback when the root bus device is removed
 374  */
 375 int netvsc_device_remove(struct hv_device *device)
 376 {
 377         struct netvsc_device *net_device;
 378         struct hv_netvsc_packet *netvsc_packet, *pos;
 379         unsigned long flags;
 380
 381         net_device = hv_get_drvdata(device);
 382
 383         netvsc_disconnect_vsp(net_device);
 384
 385         /*
 386          * Since we have already drained, we don't need to busy wait
 387          * as was done in final_release_stor_device()
 388          * Note that we cannot set the ext pointer to NULL until
 389          * we have drained - to drain the outgoing packets, we need to
 390          * allow incoming packets.
 391          */
 392
 393         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 394         hv_set_drvdata(device, NULL);
 395         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 396
 397         /*
 398          * At this point, no one should be accessing net_device
 399          * except in here
 400          */
 401         dev_notice(&device->device, "net device safe to remove\n");
 402
 403         /* Now, we can close the channel safely */
 404         vmbus_close(device->channel);
 405
 406         /* Release all resources */
 407         list_for_each_entry_safe(netvsc_packet, pos,
 408                                  &net_device->recv_pkt_list, list_ent) {
 409                 list_del(&netvsc_packet->list_ent);
 410                 kfree(netvsc_packet);
 411         }
 412
 413         kfree(net_device);
 414         return 0;
 415 }
 416
 417
 418 #define RING_AVAIL_PERCENT_HIWATER 20
 419 #define RING_AVAIL_PERCENT_LOWATER 10
 420
 421 /*
 422  * Get the percentage of available bytes to write in the ring.
 423  * The return value is in range from 0 to 100.
 424  */
 425 static inline u32 hv_ringbuf_avail_percent(
 426                 struct hv_ring_buffer_info *ring_info)
 427 {
 428         u32 avail_read, avail_write;
 429
 430         hv_get_ringbuffer_availbytes(ring_info, &avail_read, &avail_write);
 431
 432         return avail_write * 100 / ring_info->ring_datasize;
 433 }
 434
 435 static void netvsc_send_completion(struct hv_device *device,
 436                                    struct vmpacket_descriptor *packet)
 437 {
 438         struct netvsc_device *net_device;
 439         struct nvsp_message *nvsp_packet;
 440         struct hv_netvsc_packet *nvsc_packet;
 441         struct net_device *ndev;
 442
 443         net_device = get_inbound_net_device(device);
 444         if (!net_device)
 445                 return;
 446         ndev = net_device->ndev;
 447
 448         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 449                         (packet->offset8 << 3));
 450
 451         if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
 452             (nvsp_packet->hdr.msg_type ==
 453              NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
 454             (nvsp_packet->hdr.msg_type ==
 455              NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE)) {
 456                 /* Copy the response back */
 457                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 458                        sizeof(struct nvsp_message));
 459                 complete(&net_device->channel_init_wait);
 460         } else if (nvsp_packet->hdr.msg_type ==
 461                    NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
 462                 int num_outstanding_sends;
 463
 464                 /* Get the send context */
 465                 nvsc_packet = (struct hv_netvsc_packet *)(unsigned long)
 466                         packet->trans_id;
 467
 468                 /* Notify the layer above us */
 469                 if (nvsc_packet)
 470                         nvsc_packet->completion.send.send_completion(
 471                                 nvsc_packet->completion.send.
 472                                 send_completion_ctx);
 473
 474                 num_outstanding_sends =
 475                         atomic_dec_return(&net_device->num_outstanding_sends);
 476
 477                 if (net_device->destroy && num_outstanding_sends == 0)
 478                         wake_up(&net_device->wait_drain);
 479
 480                 if (netif_queue_stopped(ndev) && !net_device->start_remove &&
 481                         (hv_ringbuf_avail_percent(&device->channel->outbound)
 482                         > RING_AVAIL_PERCENT_HIWATER ||
 483                         num_outstanding_sends < 1))
 484                                 netif_wake_queue(ndev);
 485         } else {
 486                 netdev_err(ndev, "Unknown send completion packet type- "
 487                            "%d received!!\n", nvsp_packet->hdr.msg_type);
 488         }
 489
 490 }
 491
 492 int netvsc_send(struct hv_device *device,
 493                         struct hv_netvsc_packet *packet)
 494 {
 495         struct netvsc_device *net_device;
 496         int ret = 0;
 497         struct nvsp_message sendMessage;
 498         struct net_device *ndev;
 499         u64 req_id;
 500
 501         net_device = get_outbound_net_device(device);
 502         if (!net_device)
 503                 return -ENODEV;
 504         ndev = net_device->ndev;
 505
 506         sendMessage.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 507         if (packet->is_data_pkt) {
 508                 /* 0 is RMC_DATA; */
 509                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 0;
 510         } else {
 511                 /* 1 is RMC_CONTROL; */
 512                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 1;
 513         }
 514
 515         /* Not using send buffer section */
 516         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
 517                 0xFFFFFFFF;
 518         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
 519
 520         if (packet->completion.send.send_completion)
 521                 req_id = (ulong)packet;
 522         else
 523                 req_id = 0;
 524
 525         if (packet->page_buf_cnt) {
 526                 ret = vmbus_sendpacket_pagebuffer(device->channel,
 527                                                   packet->page_buf,
 528                                                   packet->page_buf_cnt,
 529                                                   &sendMessage,
 530                                                   sizeof(struct nvsp_message),
 531                                                   req_id);
 532         } else {
 533                 ret = vmbus_sendpacket(device->channel, &sendMessage,
 534                                 sizeof(struct nvsp_message),
 535                                 req_id,
 536                                 VM_PKT_DATA_INBAND,
 537                                 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 538         }
 539
 540         if (ret == 0) {
 541                 atomic_inc(&net_device->num_outstanding_sends);
 542                 if (hv_ringbuf_avail_percent(&device->channel->outbound) <
 543                         RING_AVAIL_PERCENT_LOWATER) {
 544                         netif_stop_queue(ndev);
 545                         if (atomic_read(&net_device->
 546                                 num_outstanding_sends) < 1)
 547                                 netif_wake_queue(ndev);
 548                 }
 549         } else if (ret == -EAGAIN) {
 550                 netif_stop_queue(ndev);
 551                 if (atomic_read(&net_device->num_outstanding_sends) < 1) {
 552                         netif_wake_queue(ndev);
 553                         ret = -ENOSPC;
 554                 }
 555         } else {
 556                 netdev_err(ndev, "Unable to send packet %p ret %d\n",
 557                            packet, ret);
 558         }
 559
 560         return ret;
 561 }
 562
 563 static void netvsc_send_recv_completion(struct hv_device *device,
 564                                         u64 transaction_id, u32 status)
 565 {
 566         struct nvsp_message recvcompMessage;
 567         int retries = 0;
 568         int ret;
 569         struct net_device *ndev;
 570         struct netvsc_device *net_device = hv_get_drvdata(device);
 571
 572         ndev = net_device->ndev;
 573
 574         recvcompMessage.hdr.msg_type =
 575                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
 576
 577         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status = status;
 578
 579 retry_send_cmplt:
 580         /* Send the completion */
 581         ret = vmbus_sendpacket(device->channel, &recvcompMessage,
 582                                sizeof(struct nvsp_message), transaction_id,
 583                                VM_PKT_COMP, 0);
 584         if (ret == 0) {
 585                 /* success */
 586                 /* no-op */
 587         } else if (ret == -EAGAIN) {
 588                 /* no more room...wait a bit and attempt to retry 3 times */
 589                 retries++;
 590                 netdev_err(ndev, "unable to send receive completion pkt"
 591                         " (tid %llx)...retrying %d\n", transaction_id, retries);
 592
 593                 if (retries < 4) {
 594                         udelay(100);
 595                         goto retry_send_cmplt;
 596                 } else {
 597                         netdev_err(ndev, "unable to send receive "
 598                                 "completion pkt (tid %llx)...give up retrying\n",
 599                                 transaction_id);
 600                 }
 601         } else {
 602                 netdev_err(ndev, "unable to send receive "
 603                         "completion pkt - %llx\n", transaction_id);
 604         }
 605 }
 606
 607 /* Send a receive completion packet to RNDIS device (ie NetVsp) */
 608 static void netvsc_receive_completion(void *context)
 609 {
 610         struct hv_netvsc_packet *packet = context;
 611         struct hv_device *device = packet->device;
 612         struct netvsc_device *net_device;
 613         u64 transaction_id = 0;
 614         bool fsend_receive_comp = false;
 615         unsigned long flags;
 616         struct net_device *ndev;
 617         u32 status = NVSP_STAT_NONE;
 618
 619         /*
 620          * Even though it seems logical to do a GetOutboundNetDevice() here to
 621          * send out receive completion, we are using GetInboundNetDevice()
 622          * since we may have disable outbound traffic already.
 623          */
 624         net_device = get_inbound_net_device(device);
 625         if (!net_device)
 626                 return;
 627         ndev = net_device->ndev;
 628
 629         /* Overloading use of the lock. */
 630         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 631
 632         if (packet->status != NVSP_STAT_SUCCESS)
 633                 packet->xfer_page_pkt->status = NVSP_STAT_FAIL;
 634
 635         packet->xfer_page_pkt->count--;
 636
 637         /*
 638          * Last one in the line that represent 1 xfer page packet.
 639          * Return the xfer page packet itself to the freelist
 640          */
 641         if (packet->xfer_page_pkt->count == 0) {
 642                 fsend_receive_comp = true;
 643                 transaction_id = packet->completion.recv.recv_completion_tid;
 644                 status = packet->xfer_page_pkt->status;
 645                 list_add_tail(&packet->xfer_page_pkt->list_ent,
 646                               &net_device->recv_pkt_list);
 647
 648         }
 649
 650         /* Put the packet back */
 651         list_add_tail(&packet->list_ent, &net_device->recv_pkt_list);
 652         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
 653
 654         /* Send a receive completion for the xfer page packet */
 655         if (fsend_receive_comp)
 656                 netvsc_send_recv_completion(device, transaction_id, status);
 657
 658 }
 659
 660 static void netvsc_receive(struct hv_device *device,
 661                             struct vmpacket_descriptor *packet)
 662 {
 663         struct netvsc_device *net_device;
 664         struct vmtransfer_page_packet_header *vmxferpage_packet;
 665         struct nvsp_message *nvsp_packet;
 666         struct hv_netvsc_packet *netvsc_packet = NULL;
 667         /* struct netvsc_driver *netvscDriver; */
 668         struct xferpage_packet *xferpage_packet = NULL;
 669         int i;
 670         int count = 0;
 671         unsigned long flags;
 672         struct net_device *ndev;
 673
 674         LIST_HEAD(listHead);
 675
 676         net_device = get_inbound_net_device(device);
 677         if (!net_device)
 678                 return;
 679         ndev = net_device->ndev;
 680
 681         /*
 682          * All inbound packets other than send completion should be xfer page
 683          * packet
 684          */
 685         if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
 686                 netdev_err(ndev, "Unknown packet type received - %d\n",
 687                            packet->type);
 688                 return;
 689         }
 690
 691         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 692                         (packet->offset8 << 3));
 693
 694         /* Make sure this is a valid nvsp packet */
 695         if (nvsp_packet->hdr.msg_type !=
 696             NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
 697                 netdev_err(ndev, "Unknown nvsp packet type received-"
 698                         " %d\n", nvsp_packet->hdr.msg_type);
 699                 return;
 700         }
 701
 702         vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
 703
 704         if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
 705                 netdev_err(ndev, "Invalid xfer page set id - "
 706                            "expecting %x got %x\n", NETVSC_RECEIVE_BUFFER_ID,
 707                            vmxferpage_packet->xfer_pageset_id);
 708                 return;
 709         }
 710
 711         /*
 712          * Grab free packets (range count + 1) to represent this xfer
 713          * page packet. +1 to represent the xfer page packet itself.
 714          * We grab it here so that we know exactly how many we can
 715          * fulfil
 716          */
 717         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 718         while (!list_empty(&net_device->recv_pkt_list)) {
 719                 list_move_tail(net_device->recv_pkt_list.next, &listHead);
 720                 if (++count == vmxferpage_packet->range_cnt + 1)
 721                         break;
 722         }
 723         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
 724
 725         /*
 726          * We need at least 2 netvsc pkts (1 to represent the xfer
 727          * page and at least 1 for the range) i.e. we can handled
 728          * some of the xfer page packet ranges...
 729          */
 730         if (count < 2) {
 731                 netdev_err(ndev, "Got only %d netvsc pkt...needed "
 732                         "%d pkts. Dropping this xfer page packet completely!\n",
 733                         count, vmxferpage_packet->range_cnt + 1);
 734
 735                 /* Return it to the freelist */
 736                 spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 737                 for (i = count; i != 0; i--) {
 738                         list_move_tail(listHead.next,
 739                                        &net_device->recv_pkt_list);
 740                 }
 741                 spin_unlock_irqrestore(&net_device->recv_pkt_list_lock,
 742                                        flags);
 743
 744                 netvsc_send_recv_completion(device,
 745                                             vmxferpage_packet->d.trans_id,
 746                                             NVSP_STAT_FAIL);
 747
 748                 return;
 749         }
 750
 751         /* Remove the 1st packet to represent the xfer page packet itself */
 752         xferpage_packet = (struct xferpage_packet *)listHead.next;
 753         list_del(&xferpage_packet->list_ent);
 754         xferpage_packet->status = NVSP_STAT_SUCCESS;
 755
 756         /* This is how much we can satisfy */
 757         xferpage_packet->count = count - 1;
 758
 759         if (xferpage_packet->count != vmxferpage_packet->range_cnt) {
 760                 netdev_err(ndev, "Needed %d netvsc pkts to satisfy "
 761                         "this xfer page...got %d\n",
 762                         vmxferpage_packet->range_cnt, xferpage_packet->count);
 763         }
 764
 765         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
 766         for (i = 0; i < (count - 1); i++) {
 767                 netvsc_packet = (struct hv_netvsc_packet *)listHead.next;
 768                 list_del(&netvsc_packet->list_ent);
 769
 770                 /* Initialize the netvsc packet */
 771                 netvsc_packet->status = NVSP_STAT_SUCCESS;
 772                 netvsc_packet->xfer_page_pkt = xferpage_packet;
 773                 netvsc_packet->completion.recv.recv_completion =
 774                                         netvsc_receive_completion;
 775                 netvsc_packet->completion.recv.recv_completion_ctx =
 776                                         netvsc_packet;
 777                 netvsc_packet->device = device;
 778                 /* Save this so that we can send it back */
 779                 netvsc_packet->completion.recv.recv_completion_tid =
 780                                         vmxferpage_packet->d.trans_id;
 781
 782                 netvsc_packet->data = (void *)((unsigned long)net_device->
 783                         recv_buf + vmxferpage_packet->ranges[i].byte_offset);
 784                 netvsc_packet->total_data_buflen =
 785                                         vmxferpage_packet->ranges[i].byte_count;
 786
 787                 /* Pass it to the upper layer */
 788                 rndis_filter_receive(device, netvsc_packet);
 789
 790                 netvsc_receive_completion(netvsc_packet->
 791                                 completion.recv.recv_completion_ctx);
 792         }
 793
 794 }
 795
 796 static void netvsc_channel_cb(void *context)
 797 {
 798         int ret;
 799         struct hv_device *device = context;
 800         struct netvsc_device *net_device;
 801         u32 bytes_recvd;
 802         u64 request_id;
 803         unsigned char *packet;
 804         struct vmpacket_descriptor *desc;
 805         unsigned char *buffer;
 806         int bufferlen = NETVSC_PACKET_SIZE;
 807         struct net_device *ndev;
 808
 809         packet = kzalloc(NETVSC_PACKET_SIZE * sizeof(unsigned char),
 810                          GFP_ATOMIC);
 811         if (!packet)
 812                 return;
 813         buffer = packet;
 814
 815         net_device = get_inbound_net_device(device);
 816         if (!net_device)
 817                 goto out;
 818         ndev = net_device->ndev;
 819
 820         do {
 821                 ret = vmbus_recvpacket_raw(device->channel, buffer, bufferlen,
 822                                            &bytes_recvd, &request_id);
 823                 if (ret == 0) {
 824                         if (bytes_recvd > 0) {
 825                                 desc = (struct vmpacket_descriptor *)buffer;
 826                                 switch (desc->type) {
 827                                 case VM_PKT_COMP:
 828                                         netvsc_send_completion(device, desc);
 829                                         break;
 830
 831                                 case VM_PKT_DATA_USING_XFER_PAGES:
 832                                         netvsc_receive(device, desc);
 833                                         break;
 834
 835                                 default:
 836                                         netdev_err(ndev,
 837                                                    "unhandled packet type %d, "
 838                                                    "tid %llx len %d\n",
 839                                                    desc->type, request_id,
 840                                                    bytes_recvd);
 841                                         break;
 842                                 }
 843
 844                                 /* reset */
 845                                 if (bufferlen > NETVSC_PACKET_SIZE) {
 846                                         kfree(buffer);
 847                                         buffer = packet;
 848                                         bufferlen = NETVSC_PACKET_SIZE;
 849                                 }
 850                         } else {
 851                                 /* reset */
 852                                 if (bufferlen > NETVSC_PACKET_SIZE) {
 853                                         kfree(buffer);
 854                                         buffer = packet;
 855                                         bufferlen = NETVSC_PACKET_SIZE;
 856                                 }
 857
 858                                 break;
 859                         }
 860                 } else if (ret == -ENOBUFS) {
 861                         /* Handle large packet */
 862                         buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
 863                         if (buffer == NULL) {
 864                                 /* Try again next time around */
 865                                 netdev_err(ndev,
 866                                            "unable to allocate buffer of size "
 867                                            "(%d)!!\n", bytes_recvd);
 868                                 break;
 869                         }
 870
 871                         bufferlen = bytes_recvd;
 872                 }
 873         } while (1);
 874
 875 out:
 876         kfree(buffer);
 877         return;
 878 }
 879
 880 /*
 881  * netvsc_device_add - Callback when the device belonging to this
 882  * driver is added
 883  */
 884 int netvsc_device_add(struct hv_device *device, void *additional_info)
 885 {
 886         int ret = 0;
 887         int i;
 888         int ring_size =
 889         ((struct netvsc_device_info *)additional_info)->ring_size;
 890         struct netvsc_device *net_device;
 891         struct hv_netvsc_packet *packet, *pos;
 892         struct net_device *ndev;
 893
 894         net_device = alloc_net_device(device);
 895         if (!net_device) {
 896                 ret = -ENOMEM;
 897                 goto cleanup;
 898         }
 899
 900         /*
 901          * Coming into this function, struct net_device * is
 902          * registered as the driver private data.
 903          * In alloc_net_device(), we register struct netvsc_device *
 904          * as the driver private data and stash away struct net_device *
 905          * in struct netvsc_device *.
 906          */
 907         ndev = net_device->ndev;
 908
 909         /* Initialize the NetVSC channel extension */
 910         net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 911         spin_lock_init(&net_device->recv_pkt_list_lock);
 912
 913         INIT_LIST_HEAD(&net_device->recv_pkt_list);
 914
 915         for (i = 0; i < NETVSC_RECEIVE_PACKETLIST_COUNT; i++) {
 916                 packet = kzalloc(sizeof(struct hv_netvsc_packet), GFP_KERNEL);
 917                 if (!packet)
 918                         break;
 919
 920                 list_add_tail(&packet->list_ent,
 921                               &net_device->recv_pkt_list);
 922         }
 923         init_completion(&net_device->channel_init_wait);
 924
 925         /* Open the channel */
 926         ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
 927                          ring_size * PAGE_SIZE, NULL, 0,
 928                          netvsc_channel_cb, device);
 929
 930         if (ret != 0) {
 931                 netdev_err(ndev, "unable to open channel: %d\n", ret);
 932                 goto cleanup;
 933         }
 934
 935         /* Channel is opened */
 936         pr_info("hv_netvsc channel opened successfully\n");
 937
 938         /* Connect with the NetVsp */
 939         ret = netvsc_connect_vsp(device);
 940         if (ret != 0) {
 941                 netdev_err(ndev,
 942                         "unable to connect to NetVSP - %d\n", ret);
 943                 goto close;
 944         }
 945
 946         return ret;
 947
 948 close:
 949         /* Now, we can close the channel safely */
 950         vmbus_close(device->channel);
 951
 952 cleanup:
 953
 954         if (net_device) {
 955                 list_for_each_entry_safe(packet, pos,
 956                                          &net_device->recv_pkt_list,
 957                                          list_ent) {
 958                         list_del(&packet->list_ent);
 959                         kfree(packet);
 960                 }
 961
 962                 kfree(net_device);
 963         }
 964
 965         return ret;
 966 }