drivers/staging/hv/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, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  */
  21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  22
  23 #include <linux/kernel.h>
  24 #include <linux/sched.h>
  25 #include <linux/wait.h>
  26 #include <linux/mm.h>
  27 #include <linux/delay.h>
  28 #include <linux/io.h>
  29 #include <linux/slab.h>
  30 #include <linux/netdevice.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
  45         net_device->destroy = false;
  46         net_device->dev = device;
  47         net_device->ndev = ndev;
  48
  49         hv_set_drvdata(device, net_device);
  50         return net_device;
  51 }
  52
  53 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
  54 {
  55         struct netvsc_device *net_device;
  56
  57         net_device = hv_get_drvdata(device);
  58         if (net_device && net_device->destroy)
  59                 net_device = NULL;
  60
  61         return net_device;
  62 }
  63
  64 static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
  65 {
  66         struct netvsc_device *net_device;
  67
  68         net_device = hv_get_drvdata(device);
  69
  70         if (!net_device)
  71                 goto get_in_err;
  72
  73         if (net_device->destroy &&
  74                 atomic_read(&net_device->num_outstanding_sends) == 0)
  75                 net_device = NULL;
  76
  77 get_in_err:
  78         return net_device;
  79 }
  80
  81
  82 static int netvsc_destroy_recv_buf(struct netvsc_device *net_device)
  83 {
  84         struct nvsp_message *revoke_packet;
  85         int ret = 0;
  86         struct net_device *ndev = net_device->ndev;
  87
  88         /*
  89          * If we got a section count, it means we received a
  90          * SendReceiveBufferComplete msg (ie sent
  91          * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
  92          * to send a revoke msg here
  93          */
  94         if (net_device->recv_section_cnt) {
  95                 /* Send the revoke receive buffer */
  96                 revoke_packet = &net_device->revoke_packet;
  97                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
  98
  99                 revoke_packet->hdr.msg_type =
 100                         NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 101                 revoke_packet->msg.v1_msg.
 102                 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 103
 104                 ret = vmbus_sendpacket(net_device->dev->channel,
 105                                        revoke_packet,
 106                                        sizeof(struct nvsp_message),
 107                                        (unsigned long)revoke_packet,
 108                                        VM_PKT_DATA_INBAND, 0);
 109                 /*
 110                  * If we failed here, we might as well return and
 111                  * have a leak rather than continue and a bugchk
 112                  */
 113                 if (ret != 0) {
 114                         netdev_err(ndev, "unable to send "
 115                                 "revoke receive buffer to netvsp\n");
 116                         return ret;
 117                 }
 118         }
 119
 120         /* Teardown the gpadl on the vsp end */
 121         if (net_device->recv_buf_gpadl_handle) {
 122                 ret = vmbus_teardown_gpadl(net_device->dev->channel,
 123                            net_device->recv_buf_gpadl_handle);
 124
 125                 /* If we failed here, we might as well return and have a leak
 126                  * rather than continue and a bugchk
 127                  */
 128                 if (ret != 0) {
 129                         netdev_err(ndev,
 130                                    "unable to teardown receive buffer's gpadl\n");
 131                         return ret;
 132                 }
 133                 net_device->recv_buf_gpadl_handle = 0;
 134         }
 135
 136         if (net_device->recv_buf) {
 137                 /* Free up the receive buffer */
 138                 free_pages((unsigned long)net_device->recv_buf,
 139                         get_order(net_device->recv_buf_size));
 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 =
 166                 (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
 167                                 get_order(net_device->recv_buf_size));
 168         if (!net_device->recv_buf) {
 169                 netdev_err(ndev, "unable to allocate receive "
 170                         "buffer of size %d\n", net_device->recv_buf_size);
 171                 ret = -ENOMEM;
 172                 goto cleanup;
 173         }
 174
 175         /*
 176          * Establish the gpadl handle for this buffer on this
 177          * channel.  Note: This call uses the vmbus connection rather
 178          * than the channel to establish the gpadl handle.
 179          */
 180         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 181                                     net_device->recv_buf_size,
 182                                     &net_device->recv_buf_gpadl_handle);
 183         if (ret != 0) {
 184                 netdev_err(ndev,
 185                         "unable to establish receive buffer's gpadl\n");
 186                 goto cleanup;
 187         }
 188
 189
 190         /* Notify the NetVsp of the gpadl handle */
 191         init_packet = &net_device->channel_init_pkt;
 192
 193         memset(init_packet, 0, sizeof(struct nvsp_message));
 194
 195         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 196         init_packet->msg.v1_msg.send_recv_buf.
 197                 gpadl_handle = net_device->recv_buf_gpadl_handle;
 198         init_packet->msg.v1_msg.
 199                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 200
 201         /* Send the gpadl notification request */
 202         ret = vmbus_sendpacket(device->channel, init_packet,
 203                                sizeof(struct nvsp_message),
 204                                (unsigned long)init_packet,
 205                                VM_PKT_DATA_INBAND,
 206                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 207         if (ret != 0) {
 208                 netdev_err(ndev,
 209                         "unable to send receive buffer's gpadl to netvsp\n");
 210                 goto cleanup;
 211         }
 212
 213         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 214         BUG_ON(t == 0);
 215
 216
 217         /* Check the response */
 218         if (init_packet->msg.v1_msg.
 219             send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
 220                 netdev_err(ndev, "Unable to complete receive buffer "
 221                            "initialization with NetVsp - status %d\n",
 222                            init_packet->msg.v1_msg.
 223                            send_recv_buf_complete.status);
 224                 ret = -EINVAL;
 225                 goto cleanup;
 226         }
 227
 228         /* Parse the response */
 229
 230         net_device->recv_section_cnt = init_packet->msg.
 231                 v1_msg.send_recv_buf_complete.num_sections;
 232
 233         net_device->recv_section = kmalloc(net_device->recv_section_cnt
 234                 * sizeof(struct nvsp_1_receive_buffer_section), GFP_KERNEL);
 235         if (net_device->recv_section == NULL) {
 236                 ret = -EINVAL;
 237                 goto cleanup;
 238         }
 239
 240         memcpy(net_device->recv_section,
 241                 init_packet->msg.v1_msg.
 242                send_recv_buf_complete.sections,
 243                 net_device->recv_section_cnt *
 244                sizeof(struct nvsp_1_receive_buffer_section));
 245
 246         /*
 247          * For 1st release, there should only be 1 section that represents the
 248          * entire receive buffer
 249          */
 250         if (net_device->recv_section_cnt != 1 ||
 251             net_device->recv_section->offset != 0) {
 252                 ret = -EINVAL;
 253                 goto cleanup;
 254         }
 255
 256         goto exit;
 257
 258 cleanup:
 259         netvsc_destroy_recv_buf(net_device);
 260
 261 exit:
 262         return ret;
 263 }
 264
 265
 266 static int netvsc_connect_vsp(struct hv_device *device)
 267 {
 268         int ret, t;
 269         struct netvsc_device *net_device;
 270         struct nvsp_message *init_packet;
 271         int ndis_version;
 272         struct net_device *ndev;
 273
 274         net_device = get_outbound_net_device(device);
 275         if (!net_device)
 276                 return -ENODEV;
 277         ndev = net_device->ndev;
 278
 279         init_packet = &net_device->channel_init_pkt;
 280
 281         memset(init_packet, 0, sizeof(struct nvsp_message));
 282         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 283         init_packet->msg.init_msg.init.min_protocol_ver =
 284                 NVSP_MIN_PROTOCOL_VERSION;
 285         init_packet->msg.init_msg.init.max_protocol_ver =
 286                 NVSP_MAX_PROTOCOL_VERSION;
 287
 288         /* Send the init request */
 289         ret = vmbus_sendpacket(device->channel, init_packet,
 290                                sizeof(struct nvsp_message),
 291                                (unsigned long)init_packet,
 292                                VM_PKT_DATA_INBAND,
 293                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 294
 295         if (ret != 0)
 296                 goto cleanup;
 297
 298         t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
 299
 300         if (t == 0) {
 301                 ret = -ETIMEDOUT;
 302                 goto cleanup;
 303         }
 304
 305         if (init_packet->msg.init_msg.init_complete.status !=
 306             NVSP_STAT_SUCCESS) {
 307                 ret = -EINVAL;
 308                 goto cleanup;
 309         }
 310
 311         if (init_packet->msg.init_msg.init_complete.
 312             negotiated_protocol_ver != NVSP_PROTOCOL_VERSION_1) {
 313                 ret = -EPROTO;
 314                 goto cleanup;
 315         }
 316         /* Send the ndis version */
 317         memset(init_packet, 0, sizeof(struct nvsp_message));
 318
 319         ndis_version = 0x00050000;
 320
 321         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 322         init_packet->msg.v1_msg.
 323                 send_ndis_ver.ndis_major_ver =
 324                                 (ndis_version & 0xFFFF0000) >> 16;
 325         init_packet->msg.v1_msg.
 326                 send_ndis_ver.ndis_minor_ver =
 327                                 ndis_version & 0xFFFF;
 328
 329         /* Send the init request */
 330         ret = vmbus_sendpacket(device->channel, init_packet,
 331                                 sizeof(struct nvsp_message),
 332                                 (unsigned long)init_packet,
 333                                 VM_PKT_DATA_INBAND, 0);
 334         if (ret != 0)
 335                 goto cleanup;
 336
 337         /* Post the big receive buffer to NetVSP */
 338         ret = netvsc_init_recv_buf(device);
 339
 340 cleanup:
 341         return ret;
 342 }
 343
 344 static void netvsc_disconnect_vsp(struct netvsc_device *net_device)
 345 {
 346         netvsc_destroy_recv_buf(net_device);
 347 }
 348
 349 /*
 350  * netvsc_device_remove - Callback when the root bus device is removed
 351  */
 352 int netvsc_device_remove(struct hv_device *device)
 353 {
 354         struct netvsc_device *net_device;
 355         struct hv_netvsc_packet *netvsc_packet, *pos;
 356         unsigned long flags;
 357
 358         net_device = hv_get_drvdata(device);
 359         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 360         net_device->destroy = true;
 361         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 362
 363         /* Wait for all send completions */
 364         while (atomic_read(&net_device->num_outstanding_sends)) {
 365                 dev_info(&device->device,
 366                         "waiting for %d requests to complete...\n",
 367                         atomic_read(&net_device->num_outstanding_sends));
 368                 udelay(100);
 369         }
 370
 371         netvsc_disconnect_vsp(net_device);
 372
 373         /*
 374          * Since we have already drained, we don't need to busy wait
 375          * as was done in final_release_stor_device()
 376          * Note that we cannot set the ext pointer to NULL until
 377          * we have drained - to drain the outgoing packets, we need to
 378          * allow incoming packets.
 379          */
 380
 381         spin_lock_irqsave(&device->channel->inbound_lock, flags);
 382         hv_set_drvdata(device, NULL);
 383         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 384
 385         /*
 386          * At this point, no one should be accessing net_device
 387          * except in here
 388          */
 389         dev_notice(&device->device, "net device safe to remove\n");
 390
 391         /* Now, we can close the channel safely */
 392         vmbus_close(device->channel);
 393
 394         /* Release all resources */
 395         list_for_each_entry_safe(netvsc_packet, pos,
 396                                  &net_device->recv_pkt_list, list_ent) {
 397                 list_del(&netvsc_packet->list_ent);
 398                 kfree(netvsc_packet);
 399         }
 400
 401         kfree(net_device);
 402         return 0;
 403 }
 404
 405 static void netvsc_send_completion(struct hv_device *device,
 406                                    struct vmpacket_descriptor *packet)
 407 {
 408         struct netvsc_device *net_device;
 409         struct nvsp_message *nvsp_packet;
 410         struct hv_netvsc_packet *nvsc_packet;
 411         struct net_device *ndev;
 412
 413         net_device = get_inbound_net_device(device);
 414         if (!net_device)
 415                 return;
 416         ndev = net_device->ndev;
 417
 418         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 419                         (packet->offset8 << 3));
 420
 421         if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
 422             (nvsp_packet->hdr.msg_type ==
 423              NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
 424             (nvsp_packet->hdr.msg_type ==
 425              NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE)) {
 426                 /* Copy the response back */
 427                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 428                        sizeof(struct nvsp_message));
 429                 complete(&net_device->channel_init_wait);
 430         } else if (nvsp_packet->hdr.msg_type ==
 431                    NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
 432                 /* Get the send context */
 433                 nvsc_packet = (struct hv_netvsc_packet *)(unsigned long)
 434                         packet->trans_id;
 435
 436                 /* Notify the layer above us */
 437                 nvsc_packet->completion.send.send_completion(
 438                         nvsc_packet->completion.send.send_completion_ctx);
 439
 440                 atomic_dec(&net_device->num_outstanding_sends);
 441         } else {
 442                 netdev_err(ndev, "Unknown send completion packet type- "
 443                            "%d received!!\n", nvsp_packet->hdr.msg_type);
 444         }
 445
 446 }
 447
 448 int netvsc_send(struct hv_device *device,
 449                         struct hv_netvsc_packet *packet)
 450 {
 451         struct netvsc_device *net_device;
 452         int ret = 0;
 453         struct nvsp_message sendMessage;
 454         struct net_device *ndev;
 455
 456         net_device = get_outbound_net_device(device);
 457         if (!net_device)
 458                 return -ENODEV;
 459         ndev = net_device->ndev;
 460
 461         sendMessage.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 462         if (packet->is_data_pkt) {
 463                 /* 0 is RMC_DATA; */
 464                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 0;
 465         } else {
 466                 /* 1 is RMC_CONTROL; */
 467                 sendMessage.msg.v1_msg.send_rndis_pkt.channel_type = 1;
 468         }
 469
 470         /* Not using send buffer section */
 471         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
 472                 0xFFFFFFFF;
 473         sendMessage.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
 474
 475         if (packet->page_buf_cnt) {
 476                 ret = vmbus_sendpacket_pagebuffer(device->channel,
 477                                                   packet->page_buf,
 478                                                   packet->page_buf_cnt,
 479                                                   &sendMessage,
 480                                                   sizeof(struct nvsp_message),
 481                                                   (unsigned long)packet);
 482         } else {
 483                 ret = vmbus_sendpacket(device->channel, &sendMessage,
 484                                 sizeof(struct nvsp_message),
 485                                 (unsigned long)packet,
 486                                 VM_PKT_DATA_INBAND,
 487                                 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 488
 489         }
 490
 491         if (ret != 0)
 492                 netdev_err(ndev, "Unable to send packet %p ret %d\n",
 493                            packet, ret);
 494         else
 495                 atomic_inc(&net_device->num_outstanding_sends);
 496
 497         return ret;
 498 }
 499
 500 static void netvsc_send_recv_completion(struct hv_device *device,
 501                                         u64 transaction_id)
 502 {
 503         struct nvsp_message recvcompMessage;
 504         int retries = 0;
 505         int ret;
 506         struct net_device *ndev;
 507         struct netvsc_device *net_device = hv_get_drvdata(device);
 508
 509         ndev = net_device->ndev;
 510
 511         recvcompMessage.hdr.msg_type =
 512                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
 513
 514         /* FIXME: Pass in the status */
 515         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status =
 516                 NVSP_STAT_SUCCESS;
 517
 518 retry_send_cmplt:
 519         /* Send the completion */
 520         ret = vmbus_sendpacket(device->channel, &recvcompMessage,
 521                                sizeof(struct nvsp_message), transaction_id,
 522                                VM_PKT_COMP, 0);
 523         if (ret == 0) {
 524                 /* success */
 525                 /* no-op */
 526         } else if (ret == -EAGAIN) {
 527                 /* no more room...wait a bit and attempt to retry 3 times */
 528                 retries++;
 529                 netdev_err(ndev, "unable to send receive completion pkt"
 530                         " (tid %llx)...retrying %d\n", transaction_id, retries);
 531
 532                 if (retries < 4) {
 533                         udelay(100);
 534                         goto retry_send_cmplt;
 535                 } else {
 536                         netdev_err(ndev, "unable to send receive "
 537                                 "completion pkt (tid %llx)...give up retrying\n",
 538                                 transaction_id);
 539                 }
 540         } else {
 541                 netdev_err(ndev, "unable to send receive "
 542                         "completion pkt - %llx\n", transaction_id);
 543         }
 544 }
 545
 546 /* Send a receive completion packet to RNDIS device (ie NetVsp) */
 547 static void netvsc_receive_completion(void *context)
 548 {
 549         struct hv_netvsc_packet *packet = context;
 550         struct hv_device *device = (struct hv_device *)packet->device;
 551         struct netvsc_device *net_device;
 552         u64 transaction_id = 0;
 553         bool fsend_receive_comp = false;
 554         unsigned long flags;
 555         struct net_device *ndev;
 556
 557         /*
 558          * Even though it seems logical to do a GetOutboundNetDevice() here to
 559          * send out receive completion, we are using GetInboundNetDevice()
 560          * since we may have disable outbound traffic already.
 561          */
 562         net_device = get_inbound_net_device(device);
 563         if (!net_device)
 564                 return;
 565         ndev = net_device->ndev;
 566
 567         /* Overloading use of the lock. */
 568         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 569
 570         packet->xfer_page_pkt->count--;
 571
 572         /*
 573          * Last one in the line that represent 1 xfer page packet.
 574          * Return the xfer page packet itself to the freelist
 575          */
 576         if (packet->xfer_page_pkt->count == 0) {
 577                 fsend_receive_comp = true;
 578                 transaction_id = packet->completion.recv.recv_completion_tid;
 579                 list_add_tail(&packet->xfer_page_pkt->list_ent,
 580                               &net_device->recv_pkt_list);
 581
 582         }
 583
 584         /* Put the packet back */
 585         list_add_tail(&packet->list_ent, &net_device->recv_pkt_list);
 586         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
 587
 588         /* Send a receive completion for the xfer page packet */
 589         if (fsend_receive_comp)
 590                 netvsc_send_recv_completion(device, transaction_id);
 591
 592 }
 593
 594 static void netvsc_receive(struct hv_device *device,
 595                             struct vmpacket_descriptor *packet)
 596 {
 597         struct netvsc_device *net_device;
 598         struct vmtransfer_page_packet_header *vmxferpage_packet;
 599         struct nvsp_message *nvsp_packet;
 600         struct hv_netvsc_packet *netvsc_packet = NULL;
 601         unsigned long start;
 602         unsigned long end, end_virtual;
 603         /* struct netvsc_driver *netvscDriver; */
 604         struct xferpage_packet *xferpage_packet = NULL;
 605         int i, j;
 606         int count = 0, bytes_remain = 0;
 607         unsigned long flags;
 608         struct net_device *ndev;
 609
 610         LIST_HEAD(listHead);
 611
 612         net_device = get_inbound_net_device(device);
 613         if (!net_device)
 614                 return;
 615         ndev = net_device->ndev;
 616
 617         /*
 618          * All inbound packets other than send completion should be xfer page
 619          * packet
 620          */
 621         if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
 622                 netdev_err(ndev, "Unknown packet type received - %d\n",
 623                            packet->type);
 624                 return;
 625         }
 626
 627         nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
 628                         (packet->offset8 << 3));
 629
 630         /* Make sure this is a valid nvsp packet */
 631         if (nvsp_packet->hdr.msg_type !=
 632             NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
 633                 netdev_err(ndev, "Unknown nvsp packet type received-"
 634                         " %d\n", nvsp_packet->hdr.msg_type);
 635                 return;
 636         }
 637
 638         vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
 639
 640         if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
 641                 netdev_err(ndev, "Invalid xfer page set id - "
 642                            "expecting %x got %x\n", NETVSC_RECEIVE_BUFFER_ID,
 643                            vmxferpage_packet->xfer_pageset_id);
 644                 return;
 645         }
 646
 647         /*
 648          * Grab free packets (range count + 1) to represent this xfer
 649          * page packet. +1 to represent the xfer page packet itself.
 650          * We grab it here so that we know exactly how many we can
 651          * fulfil
 652          */
 653         spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 654         while (!list_empty(&net_device->recv_pkt_list)) {
 655                 list_move_tail(net_device->recv_pkt_list.next, &listHead);
 656                 if (++count == vmxferpage_packet->range_cnt + 1)
 657                         break;
 658         }
 659         spin_unlock_irqrestore(&net_device->recv_pkt_list_lock, flags);
 660
 661         /*
 662          * We need at least 2 netvsc pkts (1 to represent the xfer
 663          * page and at least 1 for the range) i.e. we can handled
 664          * some of the xfer page packet ranges...
 665          */
 666         if (count < 2) {
 667                 netdev_err(ndev, "Got only %d netvsc pkt...needed "
 668                         "%d pkts. Dropping this xfer page packet completely!\n",
 669                         count, vmxferpage_packet->range_cnt + 1);
 670
 671                 /* Return it to the freelist */
 672                 spin_lock_irqsave(&net_device->recv_pkt_list_lock, flags);
 673                 for (i = count; i != 0; i--) {
 674                         list_move_tail(listHead.next,
 675                                        &net_device->recv_pkt_list);
 676                 }
 677                 spin_unlock_irqrestore(&net_device->recv_pkt_list_lock,
 678                                        flags);
 679
 680                 netvsc_send_recv_completion(device,
 681                                             vmxferpage_packet->d.trans_id);
 682
 683                 return;
 684         }
 685
 686         /* Remove the 1st packet to represent the xfer page packet itself */
 687         xferpage_packet = (struct xferpage_packet *)listHead.next;
 688         list_del(&xferpage_packet->list_ent);
 689
 690         /* This is how much we can satisfy */
 691         xferpage_packet->count = count - 1;
 692
 693         if (xferpage_packet->count != vmxferpage_packet->range_cnt) {
 694                 netdev_err(ndev, "Needed %d netvsc pkts to satisfy "
 695                         "this xfer page...got %d\n",
 696                         vmxferpage_packet->range_cnt, xferpage_packet->count);
 697         }
 698
 699         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
 700         for (i = 0; i < (count - 1); i++) {
 701                 netvsc_packet = (struct hv_netvsc_packet *)listHead.next;
 702                 list_del(&netvsc_packet->list_ent);
 703
 704                 /* Initialize the netvsc packet */
 705                 netvsc_packet->xfer_page_pkt = xferpage_packet;
 706                 netvsc_packet->completion.recv.recv_completion =
 707                                         netvsc_receive_completion;
 708                 netvsc_packet->completion.recv.recv_completion_ctx =
 709                                         netvsc_packet;
 710                 netvsc_packet->device = device;
 711                 /* Save this so that we can send it back */
 712                 netvsc_packet->completion.recv.recv_completion_tid =
 713                                         vmxferpage_packet->d.trans_id;
 714
 715                 netvsc_packet->total_data_buflen =
 716                                         vmxferpage_packet->ranges[i].byte_count;
 717                 netvsc_packet->page_buf_cnt = 1;
 718
 719                 netvsc_packet->page_buf[0].len =
 720                                         vmxferpage_packet->ranges[i].byte_count;
 721
 722                 start = virt_to_phys((void *)((unsigned long)net_device->
 723                 recv_buf + vmxferpage_packet->ranges[i].byte_offset));
 724
 725                 netvsc_packet->page_buf[0].pfn = start >> PAGE_SHIFT;
 726                 end_virtual = (unsigned long)net_device->recv_buf
 727                     + vmxferpage_packet->ranges[i].byte_offset
 728                     + vmxferpage_packet->ranges[i].byte_count - 1;
 729                 end = virt_to_phys((void *)end_virtual);
 730
 731                 /* Calculate the page relative offset */
 732                 netvsc_packet->page_buf[0].offset =
 733                         vmxferpage_packet->ranges[i].byte_offset &
 734                         (PAGE_SIZE - 1);
 735                 if ((end >> PAGE_SHIFT) != (start >> PAGE_SHIFT)) {
 736                         /* Handle frame across multiple pages: */
 737                         netvsc_packet->page_buf[0].len =
 738                                 (netvsc_packet->page_buf[0].pfn <<
 739                                  PAGE_SHIFT)
 740                                 + PAGE_SIZE - start;
 741                         bytes_remain = netvsc_packet->total_data_buflen -
 742                                         netvsc_packet->page_buf[0].len;
 743                         for (j = 1; j < NETVSC_PACKET_MAXPAGE; j++) {
 744                                 netvsc_packet->page_buf[j].offset = 0;
 745                                 if (bytes_remain <= PAGE_SIZE) {
 746                                         netvsc_packet->page_buf[j].len =
 747                                                 bytes_remain;
 748                                         bytes_remain = 0;
 749                                 } else {
 750                                         netvsc_packet->page_buf[j].len =
 751                                                 PAGE_SIZE;
 752                                         bytes_remain -= PAGE_SIZE;
 753                                 }
 754                                 netvsc_packet->page_buf[j].pfn =
 755                                     virt_to_phys((void *)(end_virtual -
 756                                                 bytes_remain)) >> PAGE_SHIFT;
 757                                 netvsc_packet->page_buf_cnt++;
 758                                 if (bytes_remain == 0)
 759                                         break;
 760                         }
 761                 }
 762
 763                 /* Pass it to the upper layer */
 764                 rndis_filter_receive(device, netvsc_packet);
 765
 766                 netvsc_receive_completion(netvsc_packet->
 767                                 completion.recv.recv_completion_ctx);
 768         }
 769
 770 }
 771
 772 static void netvsc_channel_cb(void *context)
 773 {
 774         int ret;
 775         struct hv_device *device = context;
 776         struct netvsc_device *net_device;
 777         u32 bytes_recvd;
 778         u64 request_id;
 779         unsigned char *packet;
 780         struct vmpacket_descriptor *desc;
 781         unsigned char *buffer;
 782         int bufferlen = NETVSC_PACKET_SIZE;
 783         struct net_device *ndev;
 784
 785         packet = kzalloc(NETVSC_PACKET_SIZE * sizeof(unsigned char),
 786                          GFP_ATOMIC);
 787         if (!packet)
 788                 return;
 789         buffer = packet;
 790
 791         net_device = get_inbound_net_device(device);
 792         if (!net_device)
 793                 goto out;
 794         ndev = net_device->ndev;
 795
 796         do {
 797                 ret = vmbus_recvpacket_raw(device->channel, buffer, bufferlen,
 798                                            &bytes_recvd, &request_id);
 799                 if (ret == 0) {
 800                         if (bytes_recvd > 0) {
 801                                 desc = (struct vmpacket_descriptor *)buffer;
 802                                 switch (desc->type) {
 803                                 case VM_PKT_COMP:
 804                                         netvsc_send_completion(device, desc);
 805                                         break;
 806
 807                                 case VM_PKT_DATA_USING_XFER_PAGES:
 808                                         netvsc_receive(device, desc);
 809                                         break;
 810
 811                                 default:
 812                                         netdev_err(ndev,
 813                                                    "unhandled packet type %d, "
 814                                                    "tid %llx len %d\n",
 815                                                    desc->type, request_id,
 816                                                    bytes_recvd);
 817                                         break;
 818                                 }
 819
 820                                 /* reset */
 821                                 if (bufferlen > NETVSC_PACKET_SIZE) {
 822                                         kfree(buffer);
 823                                         buffer = packet;
 824                                         bufferlen = NETVSC_PACKET_SIZE;
 825                                 }
 826                         } else {
 827                                 /* reset */
 828                                 if (bufferlen > NETVSC_PACKET_SIZE) {
 829                                         kfree(buffer);
 830                                         buffer = packet;
 831                                         bufferlen = NETVSC_PACKET_SIZE;
 832                                 }
 833
 834                                 break;
 835                         }
 836                 } else if (ret == -ENOBUFS) {
 837                         /* Handle large packet */
 838                         buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
 839                         if (buffer == NULL) {
 840                                 /* Try again next time around */
 841                                 netdev_err(ndev,
 842                                            "unable to allocate buffer of size "
 843                                            "(%d)!!\n", bytes_recvd);
 844                                 break;
 845                         }
 846
 847                         bufferlen = bytes_recvd;
 848                 }
 849         } while (1);
 850
 851 out:
 852         kfree(buffer);
 853         return;
 854 }
 855
 856 /*
 857  * netvsc_device_add - Callback when the device belonging to this
 858  * driver is added
 859  */
 860 int netvsc_device_add(struct hv_device *device, void *additional_info)
 861 {
 862         int ret = 0;
 863         int i;
 864         int ring_size =
 865         ((struct netvsc_device_info *)additional_info)->ring_size;
 866         struct netvsc_device *net_device;
 867         struct hv_netvsc_packet *packet, *pos;
 868         struct net_device *ndev;
 869
 870         net_device = alloc_net_device(device);
 871         if (!net_device) {
 872                 ret = -ENOMEM;
 873                 goto cleanup;
 874         }
 875
 876         /*
 877          * Coming into this function, struct net_device * is
 878          * registered as the driver private data.
 879          * In alloc_net_device(), we register struct netvsc_device *
 880          * as the driver private data and stash away struct net_device *
 881          * in struct netvsc_device *.
 882          */
 883         ndev = net_device->ndev;
 884
 885         /* Initialize the NetVSC channel extension */
 886         net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 887         spin_lock_init(&net_device->recv_pkt_list_lock);
 888
 889         INIT_LIST_HEAD(&net_device->recv_pkt_list);
 890
 891         for (i = 0; i < NETVSC_RECEIVE_PACKETLIST_COUNT; i++) {
 892                 packet = kzalloc(sizeof(struct hv_netvsc_packet) +
 893                                  (NETVSC_RECEIVE_SG_COUNT *
 894                                   sizeof(struct hv_page_buffer)), GFP_KERNEL);
 895                 if (!packet)
 896                         break;
 897
 898                 list_add_tail(&packet->list_ent,
 899                               &net_device->recv_pkt_list);
 900         }
 901         init_completion(&net_device->channel_init_wait);
 902
 903         /* Open the channel */
 904         ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
 905                          ring_size * PAGE_SIZE, NULL, 0,
 906                          netvsc_channel_cb, device);
 907
 908         if (ret != 0) {
 909                 netdev_err(ndev, "unable to open channel: %d\n", ret);
 910                 goto cleanup;
 911         }
 912
 913         /* Channel is opened */
 914         pr_info("hv_netvsc channel opened successfully\n");
 915
 916         /* Connect with the NetVsp */
 917         ret = netvsc_connect_vsp(device);
 918         if (ret != 0) {
 919                 netdev_err(ndev,
 920                         "unable to connect to NetVSP - %d\n", ret);
 921                 goto close;
 922         }
 923
 924         return ret;
 925
 926 close:
 927         /* Now, we can close the channel safely */
 928         vmbus_close(device->channel);
 929
 930 cleanup:
 931
 932         if (net_device) {
 933                 list_for_each_entry_safe(packet, pos,
 934                                          &net_device->recv_pkt_list,
 935                                          list_ent) {
 936                         list_del(&packet->list_ent);
 937                         kfree(packet);
 938                 }
 939
 940                 kfree(net_device);
 941         }
 942
 943         return ret;
 944 }