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                 free_pages((unsigned long)net_device->recv_buf,
 140                         get_order(net_device->recv_buf_size));
 141                 net_device->recv_buf = NULL;
 142         }
 143
 144         if (net_device->recv_section) {
 145                 net_device->recv_section_cnt = 0;
 146                 kfree(net_device->recv_section);
 147                 net_device->recv_section = NULL;
 148         }
 149
 150         return ret;
 151 }
 152
 153 static int netvsc_init_recv_buf(struct hv_device *device)
 154 {
 155         int ret = 0;
 156         int t;
 157         struct netvsc_device *net_device;
 158         struct nvsp_message *init_packet;
 159         struct net_device *ndev;
 160
 161         net_device = get_outbound_net_device(device);
 162         if (!net_device)
 163                 return -ENODEV;
 164         ndev = net_device->ndev;
 165
 166         net_device->recv_buf =
 167                 (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
 168                                 get_order(net_device->recv_buf_size));
 169         if (!net_device->recv_buf) {
 170                 netdev_err(ndev, "unable to allocate receive "
 171                         "buffer of size %d\n", net_device->recv_buf_size);
 172                 ret = -ENOMEM;
 173                 goto cleanup;
 174         }
 175
 176         /*
 177          * Establish the gpadl handle for this buffer on this
 178          * channel.  Note: This call uses the vmbus connection rather
 179          * than the channel to establish the gpadl handle.
 180          */
 181         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 182                                     net_device->recv_buf_size,
 183                                     &net_device->recv_buf_gpadl_handle);
 184         if (ret != 0) {
 185                 netdev_err(ndev,
 186                         "unable to establish receive buffer's gpadl\n");
 187                 goto cleanup;
 188         }
 189
 190
 191         /* Notify the NetVsp of the gpadl handle */
 192         init_packet = &net_device->channel_init_pkt;
 193
 194         memset(init_packet, 0, sizeof(struct nvsp_message));
 195
 196         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 197         init_packet->msg.v1_msg.send_recv_buf.
 198                 gpadl_handle = net_device->recv_buf_gpadl_handle;
 199         init_packet->msg.v1_msg.
 200                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 201
 202         /* Send the gpadl notification request */
 203         ret = vmbus_sendpacket(device->channel, init_packet,
 204                                sizeof(struct nvsp_message),
 205                                (unsigned long)init_packet,
 206                                VM_PKT_DATA_INBAND,
 207                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 208         if (ret != 0) {
 209                 netdev_err(ndev,
 210                         "unable to send receive buffer's gpadl to netvsp\n");
 211                 goto cleanup;
 212         }
 213
 214         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 215         BUG_ON(t == 0);
 216
 217
 218         /* Check the response */
 219         if (init_packet->msg.v1_msg.
 220             send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
 221                 netdev_err(ndev, "Unable to complete receive buffer "
 222                            "initialization with NetVsp - status %d\n",
 223                            init_packet->msg.v1_msg.
 224                            send_recv_buf_complete.status);
 225                 ret = -EINVAL;
 226                 goto cleanup;
 227         }
 228
 229         /* Parse the response */
 230
 231         net_device->recv_section_cnt = init_packet->msg.
 232                 v1_msg.send_recv_buf_complete.num_sections;
 233
 234         net_device->recv_section = kmemdup(
 235                 init_packet->msg.v1_msg.send_recv_buf_complete.sections,
 236                 net_device->recv_section_cnt *
 237                 sizeof(struct nvsp_1_receive_buffer_section),
 238                 GFP_KERNEL);
 239         if (net_device->recv_section == NULL) {
 240                 ret = -EINVAL;
 241                 goto cleanup;
 242         }
 243
 244         /*
 245          * For 1st release, there should only be 1 section that represents the
 246          * entire receive buffer
 247          */
 248         if (net_device->recv_section_cnt != 1 ||
 249             net_device->recv_section->offset != 0) {
 250                 ret = -EINVAL;
 251                 goto cleanup;
 252         }
 253
 254         goto exit;
 255
 256 cleanup:
 257         netvsc_destroy_recv_buf(net_device);
 258
 259 exit:
 260         return ret;
 261 }
 262
 263
 264 /* Negotiate NVSP protocol version */
 265 static int negotiate_nvsp_ver(struct hv_device *device,
 266                               struct netvsc_device *net_device,
 267                               struct nvsp_message *init_packet,
 268                               u32 nvsp_ver)
 269 {
 270         int ret, t;
 271
 272         memset(init_packet, 0, sizeof(struct nvsp_message));
 273         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 274         init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
 275         init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
 276
 277         /* Send the init request */
 278         ret = vmbus_sendpacket(device->channel, init_packet,
 279                                sizeof(struct nvsp_message),
 280                                (unsigned long)init_packet,
 281                                VM_PKT_DATA_INBAND,
 282                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 283
 284         if (ret != 0)
 285                 return ret;
 286
 287         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 288
 289         if (t == 0)
 290                 return -ETIMEDOUT;
 291
 292         if (init_packet->msg.init_msg.init_complete.status !=
 293             NVSP_STAT_SUCCESS)
 294                 return -EINVAL;
 295
 296         if (nvsp_ver != NVSP_PROTOCOL_VERSION_2)
 297                 return 0;
 298
 299         /* NVSPv2 only: Send NDIS config */
 300         memset(init_packet, 0, sizeof(struct nvsp_message));
 301         init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
 302         init_packet->msg.v2_msg.send_ndis_config.mtu = net_device->ndev->mtu;
 303         init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
 304
 305         ret = vmbus_sendpacket(device->channel, init_packet,
 306                                 sizeof(struct nvsp_message),
 307                                 (unsigned long)init_packet,
 308                                 VM_PKT_DATA_INBAND, 0);
 309
 310         return ret;
 311 }
 312
 313 static int netvsc_connect_vsp(struct hv_device *device)
 314 {
 315         int ret;
 316         struct netvsc_device *net_device;
 317         struct nvsp_message *init_packet;
 318         int ndis_version;
 319         struct net_device *ndev;
 320
 321         net_device = get_outbound_net_device(device);
 322         if (!net_device)
 323                 return -ENODEV;
 324         ndev = net_device->ndev;
 325
 326         init_packet = &net_device->channel_init_pkt;
 327
 328         /* Negotiate the latest NVSP protocol supported */
 329         if (negotiate_nvsp_ver(device, net_device, init_packet,
 330                                NVSP_PROTOCOL_VERSION_2) == 0) {
 331                 net_device->nvsp_version = NVSP_PROTOCOL_VERSION_2;
 332         } else if (negotiate_nvsp_ver(device, net_device, init_packet,
 333                                     NVSP_PROTOCOL_VERSION_1) == 0) {
 334                 net_device->nvsp_version = NVSP_PROTOCOL_VERSION_1;
 335         } else {
 336                 ret = -EPROTO;
 337                 goto cleanup;
 338         }
 339
 340         pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
 341
 342         /* Send the ndis version */
 343         memset(init_packet, 0, sizeof(struct nvsp_message));
 344
 345         ndis_version = 0x00050001;
 346
 347         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 348         init_packet->msg.v1_msg.
 349                 send_ndis_ver.ndis_major_ver =
 350                                 (ndis_version & 0xFFFF0000) >> 16;
 351         init_packet->msg.v1_msg.
 352                 send_ndis_ver.ndis_minor_ver =
 353                                 ndis_version & 0xFFFF;
 354
 355         /* Send the init request */
 356         ret = vmbus_sendpacket(device->channel, init_packet,
 357                                 sizeof(struct nvsp_message),
 358                                 (unsigned long)init_packet,
 359                                 VM_PKT_DATA_INBAND, 0);
 360         if (ret != 0)
 361                 goto cleanup;
 362
 363         /* Post the big receive buffer to NetVSP */
 364         ret = netvsc_init_recv_buf(device);
 365
 366 cleanup:
 367         return ret;
 368 }
 369
 370 static void netvsc_disconnect_vsp(struct netvsc_device *net_device)
 371 {
 372         netvsc_destroy_recv_buf(net_device);
 373 }
 374
 375 /*
 376  * netvsc_device_remove - Callback when the root bus device is removed
 377  */
 378 int netvsc_device_remove(struct hv_device *device)
 379 {
 380         struct netvsc_device *net_device;
 381         struct hv_netvsc_packet *netvsc_packet, *pos;
 382         unsigned long flags;
 383
 384         net_device = hv_get_drvdata(device);
 385
 386         netvsc_disconnect_vsp(net_device);
 387
 388         /*
 389          * Since we have already drained, we don't need to busy wait
 390          * as was done in final_release_stor_device()
 391          * Note that we cannot set the ext pointer to NULL until
 392          * we have drained - to drain the outgoing packets, we need to
 393          * allow incoming packets.
 394          */
 395
 396         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 397         hv_set_drvdata(device, NULL);
 398         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 399
 400         /*
 401          * At this point, no one should be accessing net_device
 402          * except in here
 403          */
 404         dev_notice(&device->device, "net device safe to remove\n");
 405
 406         /* Now, we can close the channel safely */
 407         vmbus_close(device->channel);
 408
 409         /* Release all resources */
 410         list_for_each_entry_safe(netvsc_packet, pos,
 411                                  &net_device->recv_pkt_list, list_ent) {
 412                 list_del(&netvsc_packet->list_ent);
 413                 kfree(netvsc_packet);
 414         }
 415
 416         kfree(net_device);
 417         return 0;
 418 }
 419
 420
 421 #define RING_AVAIL_PERCENT_HIWATER 20
 422 #define RING_AVAIL_PERCENT_LOWATER 10
 423
 424 /*
 425  * Get the percentage of available bytes to write in the ring.
 426  * The return value is in range from 0 to 100.
 427  */
 428 static inline u32 hv_ringbuf_avail_percent(
 429                 struct hv_ring_buffer_info *ring_info)
 430 {
 431         u32 avail_read, avail_write;
 432
 433         hv_get_ringbuffer_availbytes(ring_info, &avail_read, &avail_write);
 434
 435         return avail_write * 100 / ring_info->ring_datasize;
 436 }
 437
 438 static void netvsc_send_completion(struct hv_device *device,
 439                                    struct vmpacket_descriptor *packet)
 440 {
 441         struct netvsc_device *net_device;
 442         struct nvsp_message *nvsp_packet;
 443         struct hv_netvsc_packet *nvsc_packet;
 444         struct net_device *ndev;
 445
 446         net_device = get_inbound_net_device(device);
 447         if (!net_device)
 448                 return;
 449         ndev = net_device->ndev;
 450
 451         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 452                         (packet->offset8 << 3));
 453
 454         if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
 455             (nvsp_packet->hdr.msg_type ==
 456              NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
 457             (nvsp_packet->hdr.msg_type ==
 458              NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE)) {
 459                 /* Copy the response back */
 460                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 461                        sizeof(struct nvsp_message));
 462                 complete(&net_device->channel_init_wait);
 463         } else if (nvsp_packet->hdr.msg_type ==
 464                    NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
 465                 int num_outstanding_sends;
 466
 467                 /* Get the send context */
 468                 nvsc_packet = (struct hv_netvsc_packet *)(unsigned long)
 469                         packet->trans_id;
 470
 471                 /* Notify the layer above us */
 472                 if (nvsc_packet)
 473                         nvsc_packet->completion.send.send_completion(
 474                                 nvsc_packet->completion.send.
 475                                 send_completion_ctx);
 476
 477                 num_outstanding_sends =
 478                         atomic_dec_return(&net_device->num_outstanding_sends);
 479
 480                 if (net_device->destroy && num_outstanding_sends == 0)
 481                         wake_up(&net_device->wait_drain);
 482
 483                 if (netif_queue_stopped(ndev) && !net_device->start_remove &&
 484                         (hv_ringbuf_avail_percent(&device->channel->outbound)
 485                         > RING_AVAIL_PERCENT_HIWATER ||
 486                         num_outstanding_sends < 1))
 487                                 netif_wake_queue(ndev);
 488         } else {
 489                 netdev_err(ndev, "Unknown send completion packet type- "
 490                            "%d received!!\n", nvsp_packet->hdr.msg_type);
 491         }
 492
 493 }
 494
 495 int netvsc_send(struct hv_device *device,
 496                         struct hv_netvsc_packet *packet)
 497 {
 498         struct netvsc_device *net_device;
 499         int ret = 0;
 500         struct nvsp_message sendMessage;
 501         struct net_device *ndev;
 502         u64 req_id;
 503
 504         net_device = get_outbound_net_device(device);
 505         if (!net_device)
 506                 return -ENODEV;
 507         ndev = net_device->ndev;
 508
 509         sendMessage.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 510         if (packet->is_data_pkt) {
 511                 /* 0 is RMC_DATA; */
 512                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 0;
 513         } else {
 514                 /* 1 is RMC_CONTROL; */
 515                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 1;
 516         }
 517
 518         /* Not using send buffer section */
 519         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
 520                 0xFFFFFFFF;
 521         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
 522
 523         if (packet->completion.send.send_completion)
 524                 req_id = (ulong)packet;
 525         else
 526                 req_id = 0;
 527
 528         if (packet->page_buf_cnt) {
 529                 ret = vmbus_sendpacket_pagebuffer(device->channel,
 530                                                   packet->page_buf,
 531                                                   packet->page_buf_cnt,
 532                                                   &sendMessage,
 533                                                   sizeof(struct nvsp_message),
 534                                                   req_id);
 535         } else {
 536                 ret = vmbus_sendpacket(device->channel, &sendMessage,
 537                                 sizeof(struct nvsp_message),
 538                                 req_id,
 539                                 VM_PKT_DATA_INBAND,
 540                                 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 541         }
 542
 543         if (ret == 0) {
 544                 atomic_inc(&net_device->num_outstanding_sends);
 545                 if (hv_ringbuf_avail_percent(&device->channel->outbound) <
 546                         RING_AVAIL_PERCENT_LOWATER) {
 547                         netif_stop_queue(ndev);
 548                         if (atomic_read(&net_device->
 549                                 num_outstanding_sends) < 1)
 550                                 netif_wake_queue(ndev);
 551                 }
 552         } else if (ret == -EAGAIN) {
 553                 netif_stop_queue(ndev);
 554                 if (atomic_read(&net_device->num_outstanding_sends) < 1) {
 555                         netif_wake_queue(ndev);
 556                         ret = -ENOSPC;
 557                 }
 558         } else {
 559                 netdev_err(ndev, "Unable to send packet %p ret %d\n",
 560                            packet, ret);
 561         }
 562
 563         return ret;
 564 }
 565
 566 static void netvsc_send_recv_completion(struct hv_device *device,
 567                                         u64 transaction_id, u32 status)
 568 {
 569         struct nvsp_message recvcompMessage;
 570         int retries = 0;
 571         int ret;
 572         struct net_device *ndev;
 573         struct netvsc_device *net_device = hv_get_drvdata(device);
 574
 575         ndev = net_device->ndev;
 576
 577         recvcompMessage.hdr.msg_type =
 578                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
 579
 580         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status = status;
 581
 582 retry_send_cmplt:
 583         /* Send the completion */
 584         ret = vmbus_sendpacket(device->channel, &recvcompMessage,
 585                                sizeof(struct nvsp_message), transaction_id,
 586                                VM_PKT_COMP, 0);
 587         if (ret == 0) {
 588                 /* success */
 589                 /* no-op */
 590         } else if (ret == -EAGAIN) {
 591                 /* no more room...wait a bit and attempt to retry 3 times */
 592                 retries++;
 593                 netdev_err(ndev, "unable to send receive completion pkt"
 594                         " (tid %llx)...retrying %d\n", transaction_id, retries);
 595
 596                 if (retries < 4) {
 597                         udelay(100);
 598                         goto retry_send_cmplt;
 599                 } else {
 600                         netdev_err(ndev, "unable to send receive "
 601                                 "completion pkt (tid %llx)...give up retrying\n",
 602                                 transaction_id);
 603                 }
 604         } else {
 605                 netdev_err(ndev, "unable to send receive "
 606                         "completion pkt - %llx\n", transaction_id);
 607         }
 608 }
 609
 610 /* Send a receive completion packet to RNDIS device (ie NetVsp) */
 611 static void netvsc_receive_completion(void *context)
 612 {
 613         struct hv_netvsc_packet *packet = context;
 614         struct hv_device *device = packet->device;
 615         struct netvsc_device *net_device;
 616         u64 transaction_id = 0;
 617         bool fsend_receive_comp = false;
 618         unsigned long flags;
 619         struct net_device *ndev;
 620         u32 status = NVSP_STAT_NONE;
 621
 622         /*
 623          * Even though it seems logical to do a GetOutboundNetDevice() here to
 624          * send out receive completion, we are using GetInboundNetDevice()
 625          * since we may have disable outbound traffic already.
 626          */
 627         net_device = get_inbound_net_device(device);
 628         if (!net_device)
 629                 return;
 630         ndev = net_device->ndev;
 631
 632         /* Overloading use of the lock. */
 633         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 634
 635         if (packet->status != NVSP_STAT_SUCCESS)
 636                 packet->xfer_page_pkt->status = NVSP_STAT_FAIL;
 637
 638         packet->xfer_page_pkt->count--;
 639
 640         /*
 641          * Last one in the line that represent 1 xfer page packet.
 642          * Return the xfer page packet itself to the freelist
 643          */
 644         if (packet->xfer_page_pkt->count == 0) {
 645                 fsend_receive_comp = true;
 646                 transaction_id = packet->completion.recv.recv_completion_tid;
 647                 status = packet->xfer_page_pkt->status;
 648                 list_add_tail(&packet->xfer_page_pkt->list_ent,
 649                               &net_device->recv_pkt_list);
 650
 651         }
 652
 653         /* Put the packet back */
 654         list_add_tail(&packet->list_ent, &net_device->recv_pkt_list);
 655         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
 656
 657         /* Send a receive completion for the xfer page packet */
 658         if (fsend_receive_comp)
 659                 netvsc_send_recv_completion(device, transaction_id, status);
 660
 661 }
 662
 663 static void netvsc_receive(struct hv_device *device,
 664                             struct vmpacket_descriptor *packet)
 665 {
 666         struct netvsc_device *net_device;
 667         struct vmtransfer_page_packet_header *vmxferpage_packet;
 668         struct nvsp_message *nvsp_packet;
 669         struct hv_netvsc_packet *netvsc_packet = NULL;
 670         /* struct netvsc_driver *netvscDriver; */
 671         struct xferpage_packet *xferpage_packet = NULL;
 672         int i;
 673         int count = 0;
 674         unsigned long flags;
 675         struct net_device *ndev;
 676
 677         LIST_HEAD(listHead);
 678
 679         net_device = get_inbound_net_device(device);
 680         if (!net_device)
 681                 return;
 682         ndev = net_device->ndev;
 683
 684         /*
 685          * All inbound packets other than send completion should be xfer page
 686          * packet
 687          */
 688         if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
 689                 netdev_err(ndev, "Unknown packet type received - %d\n",
 690                            packet->type);
 691                 return;
 692         }
 693
 694         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 695                         (packet->offset8 << 3));
 696
 697         /* Make sure this is a valid nvsp packet */
 698         if (nvsp_packet->hdr.msg_type !=
 699             NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
 700                 netdev_err(ndev, "Unknown nvsp packet type received-"
 701                         " %d\n", nvsp_packet->hdr.msg_type);
 702                 return;
 703         }
 704
 705         vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
 706
 707         if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
 708                 netdev_err(ndev, "Invalid xfer page set id - "
 709                            "expecting %x got %x\n", NETVSC_RECEIVE_BUFFER_ID,
 710                            vmxferpage_packet->xfer_pageset_id);
 711                 return;
 712         }
 713
 714         /*
 715          * Grab free packets (range count + 1) to represent this xfer
 716          * page packet. +1 to represent the xfer page packet itself.
 717          * We grab it here so that we know exactly how many we can
 718          * fulfil
 719          */
 720         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 721         while (!list_empty(&net_device->recv_pkt_list)) {
 722                 list_move_tail(net_device->recv_pkt_list.next, &listHead);
 723                 if (++count == vmxferpage_packet->range_cnt + 1)
 724                         break;
 725         }
 726         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
 727
 728         /*
 729          * We need at least 2 netvsc pkts (1 to represent the xfer
 730          * page and at least 1 for the range) i.e. we can handled
 731          * some of the xfer page packet ranges...
 732          */
 733         if (count < 2) {
 734                 netdev_err(ndev, "Got only %d netvsc pkt...needed "
 735                         "%d pkts. Dropping this xfer page packet completely!\n",
 736                         count, vmxferpage_packet->range_cnt + 1);
 737
 738                 /* Return it to the freelist */
 739                 spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 740                 for (i = count; i != 0; i--) {
 741                         list_move_tail(listHead.next,
 742                                        &net_device->recv_pkt_list);
 743                 }
 744                 spin_unlock_irqrestore(&net_device->recv_pkt_list_lock,
 745                                        flags);
 746
 747                 netvsc_send_recv_completion(device,
 748                                             vmxferpage_packet->d.trans_id,
 749                                             NVSP_STAT_FAIL);
 750
 751                 return;
 752         }
 753
 754         /* Remove the 1st packet to represent the xfer page packet itself */
 755         xferpage_packet = (struct xferpage_packet *)listHead.next;
 756         list_del(&xferpage_packet->list_ent);
 757         xferpage_packet->status = NVSP_STAT_SUCCESS;
 758
 759         /* This is how much we can satisfy */
 760         xferpage_packet->count = count - 1;
 761
 762         if (xferpage_packet->count != vmxferpage_packet->range_cnt) {
 763                 netdev_err(ndev, "Needed %d netvsc pkts to satisfy "
 764                         "this xfer page...got %d\n",
 765                         vmxferpage_packet->range_cnt, xferpage_packet->count);
 766         }
 767
 768         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
 769         for (i = 0; i < (count - 1); i++) {
 770                 netvsc_packet = (struct hv_netvsc_packet *)listHead.next;
 771                 list_del(&netvsc_packet->list_ent);
 772
 773                 /* Initialize the netvsc packet */
 774                 netvsc_packet->status = NVSP_STAT_SUCCESS;
 775                 netvsc_packet->xfer_page_pkt = xferpage_packet;
 776                 netvsc_packet->completion.recv.recv_completion =
 777                                         netvsc_receive_completion;
 778                 netvsc_packet->completion.recv.recv_completion_ctx =
 779                                         netvsc_packet;
 780                 netvsc_packet->device = device;
 781                 /* Save this so that we can send it back */
 782                 netvsc_packet->completion.recv.recv_completion_tid =
 783                                         vmxferpage_packet->d.trans_id;
 784
 785                 netvsc_packet->data = (void *)((unsigned long)net_device->
 786                         recv_buf + vmxferpage_packet->ranges[i].byte_offset);
 787                 netvsc_packet->total_data_buflen =
 788                                         vmxferpage_packet->ranges[i].byte_count;
 789
 790                 /* Pass it to the upper layer */
 791                 rndis_filter_receive(device, netvsc_packet);
 792
 793                 netvsc_receive_completion(netvsc_packet->
 794                                 completion.recv.recv_completion_ctx);
 795         }
 796
 797 }
 798
 799 static void netvsc_channel_cb(void *context)
 800 {
 801         int ret;
 802         struct hv_device *device = context;
 803         struct netvsc_device *net_device;
 804         u32 bytes_recvd;
 805         u64 request_id;
 806         unsigned char *packet;
 807         struct vmpacket_descriptor *desc;
 808         unsigned char *buffer;
 809         int bufferlen = NETVSC_PACKET_SIZE;
 810         struct net_device *ndev;
 811
 812         packet = kzalloc(NETVSC_PACKET_SIZE * sizeof(unsigned char),
 813                          GFP_ATOMIC);
 814         if (!packet)
 815                 return;
 816         buffer = packet;
 817
 818         net_device = get_inbound_net_device(device);
 819         if (!net_device)
 820                 goto out;
 821         ndev = net_device->ndev;
 822
 823         do {
 824                 ret = vmbus_recvpacket_raw(device->channel, buffer, bufferlen,
 825                                            &bytes_recvd, &request_id);
 826                 if (ret == 0) {
 827                         if (bytes_recvd > 0) {
 828                                 desc = (struct vmpacket_descriptor *)buffer;
 829                                 switch (desc->type) {
 830                                 case VM_PKT_COMP:
 831                                         netvsc_send_completion(device, desc);
 832                                         break;
 833
 834                                 case VM_PKT_DATA_USING_XFER_PAGES:
 835                                         netvsc_receive(device, desc);
 836                                         break;
 837
 838                                 default:
 839                                         netdev_err(ndev,
 840                                                    "unhandled packet type %d, "
 841                                                    "tid %llx len %d\n",
 842                                                    desc->type, request_id,
 843                                                    bytes_recvd);
 844                                         break;
 845                                 }
 846
 847                                 /* reset */
 848                                 if (bufferlen > NETVSC_PACKET_SIZE) {
 849                                         kfree(buffer);
 850                                         buffer = packet;
 851                                         bufferlen = NETVSC_PACKET_SIZE;
 852                                 }
 853                         } else {
 854                                 /* reset */
 855                                 if (bufferlen > NETVSC_PACKET_SIZE) {
 856                                         kfree(buffer);
 857                                         buffer = packet;
 858                                         bufferlen = NETVSC_PACKET_SIZE;
 859                                 }
 860
 861                                 break;
 862                         }
 863                 } else if (ret == -ENOBUFS) {
 864                         /* Handle large packet */
 865                         buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
 866                         if (buffer == NULL) {
 867                                 /* Try again next time around */
 868                                 netdev_err(ndev,
 869                                            "unable to allocate buffer of size "
 870                                            "(%d)!!\n", bytes_recvd);
 871                                 break;
 872                         }
 873
 874                         bufferlen = bytes_recvd;
 875                 }
 876         } while (1);
 877
 878 out:
 879         kfree(buffer);
 880         return;
 881 }
 882
 883 /*
 884  * netvsc_device_add - Callback when the device belonging to this
 885  * driver is added
 886  */
 887 int netvsc_device_add(struct hv_device *device, void *additional_info)
 888 {
 889         int ret = 0;
 890         int i;
 891         int ring_size =
 892         ((struct netvsc_device_info *)additional_info)->ring_size;
 893         struct netvsc_device *net_device;
 894         struct hv_netvsc_packet *packet, *pos;
 895         struct net_device *ndev;
 896
 897         net_device = alloc_net_device(device);
 898         if (!net_device) {
 899                 ret = -ENOMEM;
 900                 goto cleanup;
 901         }
 902
 903         /*
 904          * Coming into this function, struct net_device * is
 905          * registered as the driver private data.
 906          * In alloc_net_device(), we register struct netvsc_device *
 907          * as the driver private data and stash away struct net_device *
 908          * in struct netvsc_device *.
 909          */
 910         ndev = net_device->ndev;
 911
 912         /* Initialize the NetVSC channel extension */
 913         net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 914         spin_lock_init(&net_device->recv_pkt_list_lock);
 915
 916         INIT_LIST_HEAD(&net_device->recv_pkt_list);
 917
 918         for (i = 0; i < NETVSC_RECEIVE_PACKETLIST_COUNT; i++) {
 919                 packet = kzalloc(sizeof(struct hv_netvsc_packet), GFP_KERNEL);
 920                 if (!packet)
 921                         break;
 922
 923                 list_add_tail(&packet->list_ent,
 924                               &net_device->recv_pkt_list);
 925         }
 926         init_completion(&net_device->channel_init_wait);
 927
 928         /* Open the channel */
 929         ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
 930                          ring_size * PAGE_SIZE, NULL, 0,
 931                          netvsc_channel_cb, device);
 932
 933         if (ret != 0) {
 934                 netdev_err(ndev, "unable to open channel: %d\n", ret);
 935                 goto cleanup;
 936         }
 937
 938         /* Channel is opened */
 939         pr_info("hv_netvsc channel opened successfully\n");
 940
 941         /* Connect with the NetVsp */
 942         ret = netvsc_connect_vsp(device);
 943         if (ret != 0) {
 944                 netdev_err(ndev,
 945                         "unable to connect to NetVSP - %d\n", ret);
 946                 goto close;
 947         }
 948
 949         return ret;
 950
 951 close:
 952         /* Now, we can close the channel safely */
 953         vmbus_close(device->channel);
 954
 955 cleanup:
 956
 957         if (net_device) {
 958                 list_for_each_entry_safe(packet, pos,
 959                                          &net_device->recv_pkt_list,
 960                                          list_ent) {
 961                         list_del(&packet->list_ent);
 962                         kfree(packet);
 963                 }
 964
 965                 kfree(net_device);
 966         }
 967
 968         return ret;
 969 }