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_1)
 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         u32 ver_list[] = { NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
 318                 NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5 };
 319         int i, num_ver = 4; /* number of different NVSP versions */
 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         for (i = num_ver - 1; i >= 0; i--)
 330                 if (negotiate_nvsp_ver(device, net_device, init_packet,
 331                                        ver_list[i])  == 0) {
 332                         net_device->nvsp_version = ver_list[i];
 333                         break;
 334                 }
 335
 336         if (i < 0) {
 337                 ret = -EPROTO;
 338                 goto cleanup;
 339         }
 340
 341         pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
 342
 343         /* Send the ndis version */
 344         memset(init_packet, 0, sizeof(struct nvsp_message));
 345
 346         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
 347                 ndis_version = 0x00060001;
 348         else
 349                 ndis_version = 0x0006001e;
 350
 351         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 352         init_packet->msg.v1_msg.
 353                 send_ndis_ver.ndis_major_ver =
 354                                 (ndis_version & 0xFFFF0000) >> 16;
 355         init_packet->msg.v1_msg.
 356                 send_ndis_ver.ndis_minor_ver =
 357                                 ndis_version & 0xFFFF;
 358
 359         /* Send the init request */
 360         ret = vmbus_sendpacket(device->channel, init_packet,
 361                                 sizeof(struct nvsp_message),
 362                                 (unsigned long)init_packet,
 363                                 VM_PKT_DATA_INBAND, 0);
 364         if (ret != 0)
 365                 goto cleanup;
 366
 367         /* Post the big receive buffer to NetVSP */
 368         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
 369                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
 370         else
 371                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 372
 373         ret = netvsc_init_recv_buf(device);
 374
 375 cleanup:
 376         return ret;
 377 }
 378
 379 static void netvsc_disconnect_vsp(struct netvsc_device *net_device)
 380 {
 381         netvsc_destroy_recv_buf(net_device);
 382 }
 383
 384 /*
 385  * netvsc_device_remove - Callback when the root bus device is removed
 386  */
 387 int netvsc_device_remove(struct hv_device *device)
 388 {
 389         struct netvsc_device *net_device;
 390         struct hv_netvsc_packet *netvsc_packet, *pos;
 391         unsigned long flags;
 392
 393         net_device = hv_get_drvdata(device);
 394
 395         netvsc_disconnect_vsp(net_device);
 396
 397         /*
 398          * Since we have already drained, we don't need to busy wait
 399          * as was done in final_release_stor_device()
 400          * Note that we cannot set the ext pointer to NULL until
 401          * we have drained - to drain the outgoing packets, we need to
 402          * allow incoming packets.
 403          */
 404
 405         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 406         hv_set_drvdata(device, NULL);
 407         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 408
 409         /*
 410          * At this point, no one should be accessing net_device
 411          * except in here
 412          */
 413         dev_notice(&device->device, "net device safe to remove\n");
 414
 415         /* Now, we can close the channel safely */
 416         vmbus_close(device->channel);
 417
 418         /* Release all resources */
 419         list_for_each_entry_safe(netvsc_packet, pos,
 420                                  &net_device->recv_pkt_list, list_ent) {
 421                 list_del(&netvsc_packet->list_ent);
 422                 kfree(netvsc_packet);
 423         }
 424
 425         kfree(net_device);
 426         return 0;
 427 }
 428
 429
 430 #define RING_AVAIL_PERCENT_HIWATER 20
 431 #define RING_AVAIL_PERCENT_LOWATER 10
 432
 433 /*
 434  * Get the percentage of available bytes to write in the ring.
 435  * The return value is in range from 0 to 100.
 436  */
 437 static inline u32 hv_ringbuf_avail_percent(
 438                 struct hv_ring_buffer_info *ring_info)
 439 {
 440         u32 avail_read, avail_write;
 441
 442         hv_get_ringbuffer_availbytes(ring_info, &avail_read, &avail_write);
 443
 444         return avail_write * 100 / ring_info->ring_datasize;
 445 }
 446
 447 static void netvsc_send_completion(struct netvsc_device *net_device,
 448                                    struct hv_device *device,
 449                                    struct vmpacket_descriptor *packet)
 450 {
 451         struct nvsp_message *nvsp_packet;
 452         struct hv_netvsc_packet *nvsc_packet;
 453         struct net_device *ndev;
 454
 455         ndev = net_device->ndev;
 456
 457         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 458                         (packet->offset8 << 3));
 459
 460         if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
 461             (nvsp_packet->hdr.msg_type ==
 462              NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
 463             (nvsp_packet->hdr.msg_type ==
 464              NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE)) {
 465                 /* Copy the response back */
 466                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 467                        sizeof(struct nvsp_message));
 468                 complete(&net_device->channel_init_wait);
 469         } else if (nvsp_packet->hdr.msg_type ==
 470                    NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
 471                 int num_outstanding_sends;
 472
 473                 /* Get the send context */
 474                 nvsc_packet = (struct hv_netvsc_packet *)(unsigned long)
 475                         packet->trans_id;
 476
 477                 /* Notify the layer above us */
 478                 if (nvsc_packet)
 479                         nvsc_packet->completion.send.send_completion(
 480                                 nvsc_packet->completion.send.
 481                                 send_completion_ctx);
 482
 483                 num_outstanding_sends =
 484                         atomic_dec_return(&net_device->num_outstanding_sends);
 485
 486                 if (net_device->destroy && num_outstanding_sends == 0)
 487                         wake_up(&net_device->wait_drain);
 488
 489                 if (netif_queue_stopped(ndev) && !net_device->start_remove &&
 490                         (hv_ringbuf_avail_percent(&device->channel->outbound)
 491                         > RING_AVAIL_PERCENT_HIWATER ||
 492                         num_outstanding_sends < 1))
 493                                 netif_wake_queue(ndev);
 494         } else {
 495                 netdev_err(ndev, "Unknown send completion packet type- "
 496                            "%d received!!\n", nvsp_packet->hdr.msg_type);
 497         }
 498
 499 }
 500
 501 int netvsc_send(struct hv_device *device,
 502                         struct hv_netvsc_packet *packet)
 503 {
 504         struct netvsc_device *net_device;
 505         int ret = 0;
 506         struct nvsp_message sendMessage;
 507         struct net_device *ndev;
 508         u64 req_id;
 509
 510         net_device = get_outbound_net_device(device);
 511         if (!net_device)
 512                 return -ENODEV;
 513         ndev = net_device->ndev;
 514
 515         sendMessage.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 516         if (packet->is_data_pkt) {
 517                 /* 0 is RMC_DATA; */
 518                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 0;
 519         } else {
 520                 /* 1 is RMC_CONTROL; */
 521                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 1;
 522         }
 523
 524         /* Not using send buffer section */
 525         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
 526                 0xFFFFFFFF;
 527         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
 528
 529         if (packet->completion.send.send_completion)
 530                 req_id = (ulong)packet;
 531         else
 532                 req_id = 0;
 533
 534         if (packet->page_buf_cnt) {
 535                 ret = vmbus_sendpacket_pagebuffer(device->channel,
 536                                                   packet->page_buf,
 537                                                   packet->page_buf_cnt,
 538                                                   &sendMessage,
 539                                                   sizeof(struct nvsp_message),
 540                                                   req_id);
 541         } else {
 542                 ret = vmbus_sendpacket(device->channel, &sendMessage,
 543                                 sizeof(struct nvsp_message),
 544                                 req_id,
 545                                 VM_PKT_DATA_INBAND,
 546                                 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 547         }
 548
 549         if (ret == 0) {
 550                 atomic_inc(&net_device->num_outstanding_sends);
 551                 if (hv_ringbuf_avail_percent(&device->channel->outbound) <
 552                         RING_AVAIL_PERCENT_LOWATER) {
 553                         netif_stop_queue(ndev);
 554                         if (atomic_read(&net_device->
 555                                 num_outstanding_sends) < 1)
 556                                 netif_wake_queue(ndev);
 557                 }
 558         } else if (ret == -EAGAIN) {
 559                 netif_stop_queue(ndev);
 560                 if (atomic_read(&net_device->num_outstanding_sends) < 1) {
 561                         netif_wake_queue(ndev);
 562                         ret = -ENOSPC;
 563                 }
 564         } else {
 565                 netdev_err(ndev, "Unable to send packet %p ret %d\n",
 566                            packet, ret);
 567         }
 568
 569         return ret;
 570 }
 571
 572 static void netvsc_send_recv_completion(struct hv_device *device,
 573                                         struct netvsc_device *net_device,
 574                                         u64 transaction_id, u32 status)
 575 {
 576         struct nvsp_message recvcompMessage;
 577         int retries = 0;
 578         int ret;
 579         struct net_device *ndev;
 580
 581         ndev = net_device->ndev;
 582
 583         recvcompMessage.hdr.msg_type =
 584                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
 585
 586         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status = status;
 587
 588 retry_send_cmplt:
 589         /* Send the completion */
 590         ret = vmbus_sendpacket(device->channel, &recvcompMessage,
 591                                sizeof(struct nvsp_message), transaction_id,
 592                                VM_PKT_COMP, 0);
 593         if (ret == 0) {
 594                 /* success */
 595                 /* no-op */
 596         } else if (ret == -EAGAIN) {
 597                 /* no more room...wait a bit and attempt to retry 3 times */
 598                 retries++;
 599                 netdev_err(ndev, "unable to send receive completion pkt"
 600                         " (tid %llx)...retrying %d\n", transaction_id, retries);
 601
 602                 if (retries < 4) {
 603                         udelay(100);
 604                         goto retry_send_cmplt;
 605                 } else {
 606                         netdev_err(ndev, "unable to send receive "
 607                                 "completion pkt (tid %llx)...give up retrying\n",
 608                                 transaction_id);
 609                 }
 610         } else {
 611                 netdev_err(ndev, "unable to send receive "
 612                         "completion pkt - %llx\n", transaction_id);
 613         }
 614 }
 615
 616 /* Send a receive completion packet to RNDIS device (ie NetVsp) */
 617 static void netvsc_receive_completion(void *context)
 618 {
 619         struct hv_netvsc_packet *packet = context;
 620         struct hv_device *device = packet->device;
 621         struct netvsc_device *net_device;
 622         u64 transaction_id = 0;
 623         bool fsend_receive_comp = false;
 624         unsigned long flags;
 625         struct net_device *ndev;
 626         u32 status = NVSP_STAT_NONE;
 627
 628         /*
 629          * Even though it seems logical to do a GetOutboundNetDevice() here to
 630          * send out receive completion, we are using GetInboundNetDevice()
 631          * since we may have disable outbound traffic already.
 632          */
 633         net_device = get_inbound_net_device(device);
 634         if (!net_device)
 635                 return;
 636         ndev = net_device->ndev;
 637
 638         /* Overloading use of the lock. */
 639         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 640
 641         if (packet->status != NVSP_STAT_SUCCESS)
 642                 packet->xfer_page_pkt->status = NVSP_STAT_FAIL;
 643
 644         packet->xfer_page_pkt->count--;
 645
 646         /*
 647          * Last one in the line that represent 1 xfer page packet.
 648          * Return the xfer page packet itself to the freelist
 649          */
 650         if (packet->xfer_page_pkt->count == 0) {
 651                 fsend_receive_comp = true;
 652                 transaction_id = packet->completion.recv.recv_completion_tid;
 653                 status = packet->xfer_page_pkt->status;
 654                 list_add_tail(&packet->xfer_page_pkt->list_ent,
 655                               &net_device->recv_pkt_list);
 656
 657         }
 658
 659         /* Put the packet back */
 660         list_add_tail(&packet->list_ent, &net_device->recv_pkt_list);
 661         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
 662
 663         /* Send a receive completion for the xfer page packet */
 664         if (fsend_receive_comp)
 665                 netvsc_send_recv_completion(device, net_device, transaction_id,
 666                                         status);
 667
 668 }
 669
 670 static void netvsc_receive(struct netvsc_device *net_device,
 671                         struct hv_device *device,
 672                         struct vmpacket_descriptor *packet)
 673 {
 674         struct vmtransfer_page_packet_header *vmxferpage_packet;
 675         struct nvsp_message *nvsp_packet;
 676         struct hv_netvsc_packet *netvsc_packet = NULL;
 677         /* struct netvsc_driver *netvscDriver; */
 678         struct xferpage_packet *xferpage_packet = NULL;
 679         int i;
 680         int count = 0;
 681         unsigned long flags;
 682         struct net_device *ndev;
 683
 684         LIST_HEAD(listHead);
 685
 686         ndev = net_device->ndev;
 687
 688         /*
 689          * All inbound packets other than send completion should be xfer page
 690          * packet
 691          */
 692         if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
 693                 netdev_err(ndev, "Unknown packet type received - %d\n",
 694                            packet->type);
 695                 return;
 696         }
 697
 698         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 699                         (packet->offset8 << 3));
 700
 701         /* Make sure this is a valid nvsp packet */
 702         if (nvsp_packet->hdr.msg_type !=
 703             NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
 704                 netdev_err(ndev, "Unknown nvsp packet type received-"
 705                         " %d\n", nvsp_packet->hdr.msg_type);
 706                 return;
 707         }
 708
 709         vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
 710
 711         if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
 712                 netdev_err(ndev, "Invalid xfer page set id - "
 713                            "expecting %x got %x\n", NETVSC_RECEIVE_BUFFER_ID,
 714                            vmxferpage_packet->xfer_pageset_id);
 715                 return;
 716         }
 717
 718         /*
 719          * Grab free packets (range count + 1) to represent this xfer
 720          * page packet. +1 to represent the xfer page packet itself.
 721          * We grab it here so that we know exactly how many we can
 722          * fulfil
 723          */
 724         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 725         while (!list_empty(&net_device->recv_pkt_list)) {
 726                 list_move_tail(net_device->recv_pkt_list.next, &listHead);
 727                 if (++count == vmxferpage_packet->range_cnt + 1)
 728                         break;
 729         }
 730         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
 731
 732         /*
 733          * We need at least 2 netvsc pkts (1 to represent the xfer
 734          * page and at least 1 for the range) i.e. we can handled
 735          * some of the xfer page packet ranges...
 736          */
 737         if (count < 2) {
 738                 netdev_err(ndev, "Got only %d netvsc pkt...needed "
 739                         "%d pkts. Dropping this xfer page packet completely!\n",
 740                         count, vmxferpage_packet->range_cnt + 1);
 741
 742                 /* Return it to the freelist */
 743                 spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 744                 for (i = count; i != 0; i--) {
 745                         list_move_tail(listHead.next,
 746                                        &net_device->recv_pkt_list);
 747                 }
 748                 spin_unlock_irqrestore(&net_device->recv_pkt_list_lock,
 749                                        flags);
 750
 751                 netvsc_send_recv_completion(device, net_device,
 752                                             vmxferpage_packet->d.trans_id,
 753                                             NVSP_STAT_FAIL);
 754
 755                 return;
 756         }
 757
 758         /* Remove the 1st packet to represent the xfer page packet itself */
 759         xferpage_packet = (struct xferpage_packet *)listHead.next;
 760         list_del(&xferpage_packet->list_ent);
 761         xferpage_packet->status = NVSP_STAT_SUCCESS;
 762
 763         /* This is how much we can satisfy */
 764         xferpage_packet->count = count - 1;
 765
 766         if (xferpage_packet->count != vmxferpage_packet->range_cnt) {
 767                 netdev_err(ndev, "Needed %d netvsc pkts to satisfy "
 768                         "this xfer page...got %d\n",
 769                         vmxferpage_packet->range_cnt, xferpage_packet->count);
 770         }
 771
 772         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
 773         for (i = 0; i < (count - 1); i++) {
 774                 netvsc_packet = (struct hv_netvsc_packet *)listHead.next;
 775                 list_del(&netvsc_packet->list_ent);
 776
 777                 /* Initialize the netvsc packet */
 778                 netvsc_packet->status = NVSP_STAT_SUCCESS;
 779                 netvsc_packet->xfer_page_pkt = xferpage_packet;
 780                 netvsc_packet->completion.recv.recv_completion =
 781                                         netvsc_receive_completion;
 782                 netvsc_packet->completion.recv.recv_completion_ctx =
 783                                         netvsc_packet;
 784                 netvsc_packet->device = device;
 785                 /* Save this so that we can send it back */
 786                 netvsc_packet->completion.recv.recv_completion_tid =
 787                                         vmxferpage_packet->d.trans_id;
 788
 789                 netvsc_packet->data = (void *)((unsigned long)net_device->
 790                         recv_buf + vmxferpage_packet->ranges[i].byte_offset);
 791                 netvsc_packet->total_data_buflen =
 792                                         vmxferpage_packet->ranges[i].byte_count;
 793
 794                 /* Pass it to the upper layer */
 795                 rndis_filter_receive(device, netvsc_packet);
 796
 797                 netvsc_receive_completion(netvsc_packet->
 798                                 completion.recv.recv_completion_ctx);
 799         }
 800
 801 }
 802
 803 static void netvsc_channel_cb(void *context)
 804 {
 805         int ret;
 806         struct hv_device *device = context;
 807         struct netvsc_device *net_device;
 808         u32 bytes_recvd;
 809         u64 request_id;
 810         struct vmpacket_descriptor *desc;
 811         unsigned char *buffer;
 812         int bufferlen = NETVSC_PACKET_SIZE;
 813         struct net_device *ndev;
 814
 815         net_device = get_inbound_net_device(device);
 816         if (!net_device)
 817                 return;
 818         ndev = net_device->ndev;
 819         buffer = net_device->cb_buffer;
 820
 821         do {
 822                 ret = vmbus_recvpacket_raw(device->channel, buffer, bufferlen,
 823                                            &bytes_recvd, &request_id);
 824                 if (ret == 0) {
 825                         if (bytes_recvd > 0) {
 826                                 desc = (struct vmpacket_descriptor *)buffer;
 827                                 switch (desc->type) {
 828                                 case VM_PKT_COMP:
 829                                         netvsc_send_completion(net_device,
 830                                                                 device, desc);
 831                                         break;
 832
 833                                 case VM_PKT_DATA_USING_XFER_PAGES:
 834                                         netvsc_receive(net_device,
 835                                                         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                         } else {
 848                                 /*
 849                                  * We are done for this pass.
 850                                  */
 851                                 break;
 852                         }
 853
 854                 } else if (ret == -ENOBUFS) {
 855                         if (bufferlen > NETVSC_PACKET_SIZE)
 856                                 kfree(buffer);
 857                         /* Handle large packet */
 858                         buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
 859                         if (buffer == NULL) {
 860                                 /* Try again next time around */
 861                                 netdev_err(ndev,
 862                                            "unable to allocate buffer of size "
 863                                            "(%d)!!\n", bytes_recvd);
 864                                 break;
 865                         }
 866
 867                         bufferlen = bytes_recvd;
 868                 }
 869         } while (1);
 870
 871         if (bufferlen > NETVSC_PACKET_SIZE)
 872                 kfree(buffer);
 873         return;
 874 }
 875
 876 /*
 877  * netvsc_device_add - Callback when the device belonging to this
 878  * driver is added
 879  */
 880 int netvsc_device_add(struct hv_device *device, void *additional_info)
 881 {
 882         int ret = 0;
 883         int i;
 884         int ring_size =
 885         ((struct netvsc_device_info *)additional_info)->ring_size;
 886         struct netvsc_device *net_device;
 887         struct hv_netvsc_packet *packet, *pos;
 888         struct net_device *ndev;
 889
 890         net_device = alloc_net_device(device);
 891         if (!net_device) {
 892                 ret = -ENOMEM;
 893                 goto cleanup;
 894         }
 895
 896         /*
 897          * Coming into this function, struct net_device * is
 898          * registered as the driver private data.
 899          * In alloc_net_device(), we register struct netvsc_device *
 900          * as the driver private data and stash away struct net_device *
 901          * in struct netvsc_device *.
 902          */
 903         ndev = net_device->ndev;
 904
 905         /* Initialize the NetVSC channel extension */
 906         spin_lock_init(&net_device->recv_pkt_list_lock);
 907
 908         INIT_LIST_HEAD(&net_device->recv_pkt_list);
 909
 910         for (i = 0; i < NETVSC_RECEIVE_PACKETLIST_COUNT; i++) {
 911                 packet = kzalloc(sizeof(struct hv_netvsc_packet), GFP_KERNEL);
 912                 if (!packet)
 913                         break;
 914
 915                 list_add_tail(&packet->list_ent,
 916                               &net_device->recv_pkt_list);
 917         }
 918         init_completion(&net_device->channel_init_wait);
 919
 920         /* Open the channel */
 921         ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
 922                          ring_size * PAGE_SIZE, NULL, 0,
 923                          netvsc_channel_cb, device);
 924
 925         if (ret != 0) {
 926                 netdev_err(ndev, "unable to open channel: %d\n", ret);
 927                 goto cleanup;
 928         }
 929
 930         /* Channel is opened */
 931         pr_info("hv_netvsc channel opened successfully\n");
 932
 933         /* Connect with the NetVsp */
 934         ret = netvsc_connect_vsp(device);
 935         if (ret != 0) {
 936                 netdev_err(ndev,
 937                         "unable to connect to NetVSP - %d\n", ret);
 938                 goto close;
 939         }
 940
 941         return ret;
 942
 943 close:
 944         /* Now, we can close the channel safely */
 945         vmbus_close(device->channel);
 946
 947 cleanup:
 948
 949         if (net_device) {
 950                 list_for_each_entry_safe(packet, pos,
 951                                          &net_device->recv_pkt_list,
 952                                          list_ent) {
 953                         list_del(&packet->list_ent);
 954                         kfree(packet);
 955                 }
 956
 957                 kfree(net_device);
 958         }
 959
 960         return ret;
 961 }