Pileus Git - ~andy/linux/blob - drivers/hv/channel_mgmt.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/slab.h>
  28 #include <linux/list.h>
  29 #include <linux/module.h>
  30 #include <linux/completion.h>
  31 #include <linux/hyperv.h>
  32
  33 #include "hyperv_vmbus.h"
  34
  35 struct vmbus_channel_message_table_entry {
  36         enum vmbus_channel_message_type message_type;
  37         void (*message_handler)(struct vmbus_channel_message_header *msg);
  38 };
  39
  40
  41 /**
  42  * vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message
  43  * @icmsghdrp: Pointer to msg header structure
  44  * @icmsg_negotiate: Pointer to negotiate message structure
  45  * @buf: Raw buffer channel data
  46  *
  47  * @icmsghdrp is of type &struct icmsg_hdr.
  48  * @negop is of type &struct icmsg_negotiate.
  49  * Set up and fill in default negotiate response message.
  50  *
  51  * The fw_version specifies the  framework version that
  52  * we can support and srv_version specifies the service
  53  * version we can support.
  54  *
  55  * Mainly used by Hyper-V drivers.
  56  */
  57 bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
  58                                 struct icmsg_negotiate *negop, u8 *buf,
  59                                 int fw_version, int srv_version)
  60 {
  61         int icframe_major, icframe_minor;
  62         int icmsg_major, icmsg_minor;
  63         int fw_major, fw_minor;
  64         int srv_major, srv_minor;
  65         int i;
  66         bool found_match = false;
  67
  68         icmsghdrp->icmsgsize = 0x10;
  69         fw_major = (fw_version >> 16);
  70         fw_minor = (fw_version & 0xFFFF);
  71
  72         srv_major = (srv_version >> 16);
  73         srv_minor = (srv_version & 0xFFFF);
  74
  75         negop = (struct icmsg_negotiate *)&buf[
  76                 sizeof(struct vmbuspipe_hdr) +
  77                 sizeof(struct icmsg_hdr)];
  78
  79         icframe_major = negop->icframe_vercnt;
  80         icframe_minor = 0;
  81
  82         icmsg_major = negop->icmsg_vercnt;
  83         icmsg_minor = 0;
  84
  85         /*
  86          * Select the framework version number we will
  87          * support.
  88          */
  89
  90         for (i = 0; i < negop->icframe_vercnt; i++) {
  91                 if ((negop->icversion_data[i].major == fw_major) &&
  92                    (negop->icversion_data[i].minor == fw_minor)) {
  93                         icframe_major = negop->icversion_data[i].major;
  94                         icframe_minor = negop->icversion_data[i].minor;
  95                         found_match = true;
  96                 }
  97         }
  98
  99         if (!found_match)
 100                 goto fw_error;
 101
 102         found_match = false;
 103
 104         for (i = negop->icframe_vercnt;
 105                  (i < negop->icframe_vercnt + negop->icmsg_vercnt); i++) {
 106                 if ((negop->icversion_data[i].major == srv_major) &&
 107                    (negop->icversion_data[i].minor == srv_minor)) {
 108                         icmsg_major = negop->icversion_data[i].major;
 109                         icmsg_minor = negop->icversion_data[i].minor;
 110                         found_match = true;
 111                 }
 112         }
 113
 114         /*
 115          * Respond with the framework and service
 116          * version numbers we can support.
 117          */
 118
 119 fw_error:
 120         if (!found_match) {
 121                 negop->icframe_vercnt = 0;
 122                 negop->icmsg_vercnt = 0;
 123         } else {
 124                 negop->icframe_vercnt = 1;
 125                 negop->icmsg_vercnt = 1;
 126         }
 127
 128         negop->icversion_data[0].major = icframe_major;
 129         negop->icversion_data[0].minor = icframe_minor;
 130         negop->icversion_data[1].major = icmsg_major;
 131         negop->icversion_data[1].minor = icmsg_minor;
 132         return found_match;
 133 }
 134
 135 EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp);
 136
 137 /*
 138  * alloc_channel - Allocate and initialize a vmbus channel object
 139  */
 140 static struct vmbus_channel *alloc_channel(void)
 141 {
 142         struct vmbus_channel *channel;
 143
 144         channel = kzalloc(sizeof(*channel), GFP_ATOMIC);
 145         if (!channel)
 146                 return NULL;
 147
 148         spin_lock_init(&channel->inbound_lock);
 149         spin_lock_init(&channel->sc_lock);
 150
 151         INIT_LIST_HEAD(&channel->sc_list);
 152
 153         channel->controlwq = create_workqueue("hv_vmbus_ctl");
 154         if (!channel->controlwq) {
 155                 kfree(channel);
 156                 return NULL;
 157         }
 158
 159         return channel;
 160 }
 161
 162 /*
 163  * release_hannel - Release the vmbus channel object itself
 164  */
 165 static void release_channel(struct work_struct *work)
 166 {
 167         struct vmbus_channel *channel = container_of(work,
 168                                                      struct vmbus_channel,
 169                                                      work);
 170
 171         destroy_workqueue(channel->controlwq);
 172
 173         kfree(channel);
 174 }
 175
 176 /*
 177  * free_channel - Release the resources used by the vmbus channel object
 178  */
 179 static void free_channel(struct vmbus_channel *channel)
 180 {
 181
 182         /*
 183          * We have to release the channel's workqueue/thread in the vmbus's
 184          * workqueue/thread context
 185          * ie we can't destroy ourselves.
 186          */
 187         INIT_WORK(&channel->work, release_channel);
 188         queue_work(vmbus_connection.work_queue, &channel->work);
 189 }
 190
 191
 192
 193 /*
 194  * vmbus_process_rescind_offer -
 195  * Rescind the offer by initiating a device removal
 196  */
 197 static void vmbus_process_rescind_offer(struct work_struct *work)
 198 {
 199         struct vmbus_channel *channel = container_of(work,
 200                                                      struct vmbus_channel,
 201                                                      work);
 202         unsigned long flags;
 203         struct vmbus_channel *primary_channel;
 204         struct vmbus_channel_relid_released msg;
 205
 206         if (channel->device_obj)
 207                 vmbus_device_unregister(channel->device_obj);
 208         memset(&msg, 0, sizeof(struct vmbus_channel_relid_released));
 209         msg.child_relid = channel->offermsg.child_relid;
 210         msg.header.msgtype = CHANNELMSG_RELID_RELEASED;
 211         vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released));
 212
 213         if (channel->primary_channel == NULL) {
 214                 spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
 215                 list_del(&channel->listentry);
 216                 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
 217         } else {
 218                 primary_channel = channel->primary_channel;
 219                 spin_lock_irqsave(&primary_channel->sc_lock, flags);
 220                 list_del(&channel->sc_list);
 221                 spin_unlock_irqrestore(&primary_channel->sc_lock, flags);
 222         }
 223         free_channel(channel);
 224 }
 225
 226 void vmbus_free_channels(void)
 227 {
 228         struct vmbus_channel *channel;
 229
 230         list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
 231                 vmbus_device_unregister(channel->device_obj);
 232                 kfree(channel->device_obj);
 233                 free_channel(channel);
 234         }
 235 }
 236
 237 /*
 238  * vmbus_process_offer - Process the offer by creating a channel/device
 239  * associated with this offer
 240  */
 241 static void vmbus_process_offer(struct work_struct *work)
 242 {
 243         struct vmbus_channel *newchannel = container_of(work,
 244                                                         struct vmbus_channel,
 245                                                         work);
 246         struct vmbus_channel *channel;
 247         bool fnew = true;
 248         int ret;
 249         unsigned long flags;
 250
 251         /* The next possible work is rescind handling */
 252         INIT_WORK(&newchannel->work, vmbus_process_rescind_offer);
 253
 254         /* Make sure this is a new offer */
 255         spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
 256
 257         list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
 258                 if (!uuid_le_cmp(channel->offermsg.offer.if_type,
 259                         newchannel->offermsg.offer.if_type) &&
 260                         !uuid_le_cmp(channel->offermsg.offer.if_instance,
 261                                 newchannel->offermsg.offer.if_instance)) {
 262                         fnew = false;
 263                         break;
 264                 }
 265         }
 266
 267         if (fnew)
 268                 list_add_tail(&newchannel->listentry,
 269                               &vmbus_connection.chn_list);
 270
 271         spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
 272
 273         if (!fnew) {
 274                 /*
 275                  * Check to see if this is a sub-channel.
 276                  */
 277                 if (newchannel->offermsg.offer.sub_channel_index != 0) {
 278                         /*
 279                          * Process the sub-channel.
 280                          */
 281                         newchannel->primary_channel = channel;
 282                         spin_lock_irqsave(&channel->sc_lock, flags);
 283                         list_add_tail(&newchannel->sc_list, &channel->sc_list);
 284                         spin_unlock_irqrestore(&channel->sc_lock, flags);
 285                         newchannel->state = CHANNEL_OPEN_STATE;
 286                         if (channel->sc_creation_callback != NULL)
 287                                 channel->sc_creation_callback(newchannel);
 288
 289                         return;
 290                 }
 291
 292                 free_channel(newchannel);
 293                 return;
 294         }
 295
 296         /*
 297          * This state is used to indicate a successful open
 298          * so that when we do close the channel normally, we
 299          * can cleanup properly
 300          */
 301         newchannel->state = CHANNEL_OPEN_STATE;
 302
 303         /*
 304          * Start the process of binding this offer to the driver
 305          * We need to set the DeviceObject field before calling
 306          * vmbus_child_dev_add()
 307          */
 308         newchannel->device_obj = vmbus_device_create(
 309                 &newchannel->offermsg.offer.if_type,
 310                 &newchannel->offermsg.offer.if_instance,
 311                 newchannel);
 312
 313         /*
 314          * Add the new device to the bus. This will kick off device-driver
 315          * binding which eventually invokes the device driver's AddDevice()
 316          * method.
 317          */
 318         ret = vmbus_device_register(newchannel->device_obj);
 319         if (ret != 0) {
 320                 pr_err("unable to add child device object (relid %d)\n",
 321                            newchannel->offermsg.child_relid);
 322
 323                 spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
 324                 list_del(&newchannel->listentry);
 325                 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
 326                 kfree(newchannel->device_obj);
 327
 328                 free_channel(newchannel);
 329         }
 330 }
 331
 332 enum {
 333         IDE = 0,
 334         SCSI,
 335         NIC,
 336         MAX_PERF_CHN,
 337 };
 338
 339 /*
 340  * This is an array of device_ids (device types) that are performance critical.
 341  * We attempt to distribute the interrupt load for these devices across
 342  * all available CPUs.
 343  */
 344 static const struct hv_vmbus_device_id hp_devs[] = {
 345         /* IDE */
 346         { HV_IDE_GUID, },
 347         /* Storage - SCSI */
 348         { HV_SCSI_GUID, },
 349         /* Network */
 350         { HV_NIC_GUID, },
 351 };
 352
 353
 354 /*
 355  * We use this state to statically distribute the channel interrupt load.
 356  */
 357 static u32  next_vp;
 358
 359 /*
 360  * Starting with Win8, we can statically distribute the incoming
 361  * channel interrupt load by binding a channel to VCPU. We
 362  * implement here a simple round robin scheme for distributing
 363  * the interrupt load.
 364  * We will bind channels that are not performance critical to cpu 0 and
 365  * performance critical channels (IDE, SCSI and Network) will be uniformly
 366  * distributed across all available CPUs.
 367  */
 368 static u32 get_vp_index(uuid_le *type_guid)
 369 {
 370         u32 cur_cpu;
 371         int i;
 372         bool perf_chn = false;
 373         u32 max_cpus = num_online_cpus();
 374
 375         for (i = IDE; i < MAX_PERF_CHN; i++) {
 376                 if (!memcmp(type_guid->b, hp_devs[i].guid,
 377                                  sizeof(uuid_le))) {
 378                         perf_chn = true;
 379                         break;
 380                 }
 381         }
 382         if ((vmbus_proto_version == VERSION_WS2008) ||
 383             (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) {
 384                 /*
 385                  * Prior to win8, all channel interrupts are
 386                  * delivered on cpu 0.
 387                  * Also if the channel is not a performance critical
 388                  * channel, bind it to cpu 0.
 389                  */
 390                 return 0;
 391         }
 392         cur_cpu = (++next_vp % max_cpus);
 393         return hv_context.vp_index[cur_cpu];
 394 }
 395
 396 /*
 397  * vmbus_onoffer - Handler for channel offers from vmbus in parent partition.
 398  *
 399  */
 400 static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
 401 {
 402         struct vmbus_channel_offer_channel *offer;
 403         struct vmbus_channel *newchannel;
 404
 405         offer = (struct vmbus_channel_offer_channel *)hdr;
 406
 407         /* Allocate the channel object and save this offer. */
 408         newchannel = alloc_channel();
 409         if (!newchannel) {
 410                 pr_err("Unable to allocate channel object\n");
 411                 return;
 412         }
 413
 414         /*
 415          * By default we setup state to enable batched
 416          * reading. A specific service can choose to
 417          * disable this prior to opening the channel.
 418          */
 419         newchannel->batched_reading = true;
 420
 421         /*
 422          * Setup state for signalling the host.
 423          */
 424         newchannel->sig_event = (struct hv_input_signal_event *)
 425                                 (ALIGN((unsigned long)
 426                                 &newchannel->sig_buf,
 427                                 HV_HYPERCALL_PARAM_ALIGN));
 428
 429         newchannel->sig_event->connectionid.asu32 = 0;
 430         newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID;
 431         newchannel->sig_event->flag_number = 0;
 432         newchannel->sig_event->rsvdz = 0;
 433
 434         if (vmbus_proto_version != VERSION_WS2008) {
 435                 newchannel->is_dedicated_interrupt =
 436                                 (offer->is_dedicated_interrupt != 0);
 437                 newchannel->sig_event->connectionid.u.id =
 438                                 offer->connection_id;
 439         }
 440
 441         newchannel->target_vp = get_vp_index(&offer->offer.if_type);
 442
 443         memcpy(&newchannel->offermsg, offer,
 444                sizeof(struct vmbus_channel_offer_channel));
 445         newchannel->monitor_grp = (u8)offer->monitorid / 32;
 446         newchannel->monitor_bit = (u8)offer->monitorid % 32;
 447
 448         INIT_WORK(&newchannel->work, vmbus_process_offer);
 449         queue_work(newchannel->controlwq, &newchannel->work);
 450 }
 451
 452 /*
 453  * vmbus_onoffer_rescind - Rescind offer handler.
 454  *
 455  * We queue a work item to process this offer synchronously
 456  */
 457 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
 458 {
 459         struct vmbus_channel_rescind_offer *rescind;
 460         struct vmbus_channel *channel;
 461
 462         rescind = (struct vmbus_channel_rescind_offer *)hdr;
 463         channel = relid2channel(rescind->child_relid);
 464
 465         if (channel == NULL)
 466                 /* Just return here, no channel found */
 467                 return;
 468
 469         /* work is initialized for vmbus_process_rescind_offer() from
 470          * vmbus_process_offer() where the channel got created */
 471         queue_work(channel->controlwq, &channel->work);
 472 }
 473
 474 /*
 475  * vmbus_onoffers_delivered -
 476  * This is invoked when all offers have been delivered.
 477  *
 478  * Nothing to do here.
 479  */
 480 static void vmbus_onoffers_delivered(
 481                         struct vmbus_channel_message_header *hdr)
 482 {
 483 }
 484
 485 /*
 486  * vmbus_onopen_result - Open result handler.
 487  *
 488  * This is invoked when we received a response to our channel open request.
 489  * Find the matching request, copy the response and signal the requesting
 490  * thread.
 491  */
 492 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr)
 493 {
 494         struct vmbus_channel_open_result *result;
 495         struct vmbus_channel_msginfo *msginfo;
 496         struct vmbus_channel_message_header *requestheader;
 497         struct vmbus_channel_open_channel *openmsg;
 498         unsigned long flags;
 499
 500         result = (struct vmbus_channel_open_result *)hdr;
 501
 502         /*
 503          * Find the open msg, copy the result and signal/unblock the wait event
 504          */
 505         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 506
 507         list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
 508                                 msglistentry) {
 509                 requestheader =
 510                         (struct vmbus_channel_message_header *)msginfo->msg;
 511
 512                 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) {
 513                         openmsg =
 514                         (struct vmbus_channel_open_channel *)msginfo->msg;
 515                         if (openmsg->child_relid == result->child_relid &&
 516                             openmsg->openid == result->openid) {
 517                                 memcpy(&msginfo->response.open_result,
 518                                        result,
 519                                        sizeof(
 520                                         struct vmbus_channel_open_result));
 521                                 complete(&msginfo->waitevent);
 522                                 break;
 523                         }
 524                 }
 525         }
 526         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 527 }
 528
 529 /*
 530  * vmbus_ongpadl_created - GPADL created handler.
 531  *
 532  * This is invoked when we received a response to our gpadl create request.
 533  * Find the matching request, copy the response and signal the requesting
 534  * thread.
 535  */
 536 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr)
 537 {
 538         struct vmbus_channel_gpadl_created *gpadlcreated;
 539         struct vmbus_channel_msginfo *msginfo;
 540         struct vmbus_channel_message_header *requestheader;
 541         struct vmbus_channel_gpadl_header *gpadlheader;
 542         unsigned long flags;
 543
 544         gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr;
 545
 546         /*
 547          * Find the establish msg, copy the result and signal/unblock the wait
 548          * event
 549          */
 550         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 551
 552         list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
 553                                 msglistentry) {
 554                 requestheader =
 555                         (struct vmbus_channel_message_header *)msginfo->msg;
 556
 557                 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) {
 558                         gpadlheader =
 559                         (struct vmbus_channel_gpadl_header *)requestheader;
 560
 561                         if ((gpadlcreated->child_relid ==
 562                              gpadlheader->child_relid) &&
 563                             (gpadlcreated->gpadl == gpadlheader->gpadl)) {
 564                                 memcpy(&msginfo->response.gpadl_created,
 565                                        gpadlcreated,
 566                                        sizeof(
 567                                         struct vmbus_channel_gpadl_created));
 568                                 complete(&msginfo->waitevent);
 569                                 break;
 570                         }
 571                 }
 572         }
 573         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 574 }
 575
 576 /*
 577  * vmbus_ongpadl_torndown - GPADL torndown handler.
 578  *
 579  * This is invoked when we received a response to our gpadl teardown request.
 580  * Find the matching request, copy the response and signal the requesting
 581  * thread.
 582  */
 583 static void vmbus_ongpadl_torndown(
 584                         struct vmbus_channel_message_header *hdr)
 585 {
 586         struct vmbus_channel_gpadl_torndown *gpadl_torndown;
 587         struct vmbus_channel_msginfo *msginfo;
 588         struct vmbus_channel_message_header *requestheader;
 589         struct vmbus_channel_gpadl_teardown *gpadl_teardown;
 590         unsigned long flags;
 591
 592         gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr;
 593
 594         /*
 595          * Find the open msg, copy the result and signal/unblock the wait event
 596          */
 597         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 598
 599         list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
 600                                 msglistentry) {
 601                 requestheader =
 602                         (struct vmbus_channel_message_header *)msginfo->msg;
 603
 604                 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) {
 605                         gpadl_teardown =
 606                         (struct vmbus_channel_gpadl_teardown *)requestheader;
 607
 608                         if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) {
 609                                 memcpy(&msginfo->response.gpadl_torndown,
 610                                        gpadl_torndown,
 611                                        sizeof(
 612                                         struct vmbus_channel_gpadl_torndown));
 613                                 complete(&msginfo->waitevent);
 614                                 break;
 615                         }
 616                 }
 617         }
 618         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 619 }
 620
 621 /*
 622  * vmbus_onversion_response - Version response handler
 623  *
 624  * This is invoked when we received a response to our initiate contact request.
 625  * Find the matching request, copy the response and signal the requesting
 626  * thread.
 627  */
 628 static void vmbus_onversion_response(
 629                 struct vmbus_channel_message_header *hdr)
 630 {
 631         struct vmbus_channel_msginfo *msginfo;
 632         struct vmbus_channel_message_header *requestheader;
 633         struct vmbus_channel_version_response *version_response;
 634         unsigned long flags;
 635
 636         version_response = (struct vmbus_channel_version_response *)hdr;
 637         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 638
 639         list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
 640                                 msglistentry) {
 641                 requestheader =
 642                         (struct vmbus_channel_message_header *)msginfo->msg;
 643
 644                 if (requestheader->msgtype ==
 645                     CHANNELMSG_INITIATE_CONTACT) {
 646                         memcpy(&msginfo->response.version_response,
 647                               version_response,
 648                               sizeof(struct vmbus_channel_version_response));
 649                         complete(&msginfo->waitevent);
 650                 }
 651         }
 652         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 653 }
 654
 655 /* Channel message dispatch table */
 656 static struct vmbus_channel_message_table_entry
 657         channel_message_table[CHANNELMSG_COUNT] = {
 658         {CHANNELMSG_INVALID,                    NULL},
 659         {CHANNELMSG_OFFERCHANNEL,               vmbus_onoffer},
 660         {CHANNELMSG_RESCIND_CHANNELOFFER,       vmbus_onoffer_rescind},
 661         {CHANNELMSG_REQUESTOFFERS,              NULL},
 662         {CHANNELMSG_ALLOFFERS_DELIVERED,        vmbus_onoffers_delivered},
 663         {CHANNELMSG_OPENCHANNEL,                NULL},
 664         {CHANNELMSG_OPENCHANNEL_RESULT, vmbus_onopen_result},
 665         {CHANNELMSG_CLOSECHANNEL,               NULL},
 666         {CHANNELMSG_GPADL_HEADER,               NULL},
 667         {CHANNELMSG_GPADL_BODY,         NULL},
 668         {CHANNELMSG_GPADL_CREATED,              vmbus_ongpadl_created},
 669         {CHANNELMSG_GPADL_TEARDOWN,             NULL},
 670         {CHANNELMSG_GPADL_TORNDOWN,             vmbus_ongpadl_torndown},
 671         {CHANNELMSG_RELID_RELEASED,             NULL},
 672         {CHANNELMSG_INITIATE_CONTACT,           NULL},
 673         {CHANNELMSG_VERSION_RESPONSE,           vmbus_onversion_response},
 674         {CHANNELMSG_UNLOAD,                     NULL},
 675 };
 676
 677 /*
 678  * vmbus_onmessage - Handler for channel protocol messages.
 679  *
 680  * This is invoked in the vmbus worker thread context.
 681  */
 682 void vmbus_onmessage(void *context)
 683 {
 684         struct hv_message *msg = context;
 685         struct vmbus_channel_message_header *hdr;
 686         int size;
 687
 688         hdr = (struct vmbus_channel_message_header *)msg->u.payload;
 689         size = msg->header.payload_size;
 690
 691         if (hdr->msgtype >= CHANNELMSG_COUNT) {
 692                 pr_err("Received invalid channel message type %d size %d\n",
 693                            hdr->msgtype, size);
 694                 print_hex_dump_bytes("", DUMP_PREFIX_NONE,
 695                                      (unsigned char *)msg->u.payload, size);
 696                 return;
 697         }
 698
 699         if (channel_message_table[hdr->msgtype].message_handler)
 700                 channel_message_table[hdr->msgtype].message_handler(hdr);
 701         else
 702                 pr_err("Unhandled channel message type %d\n", hdr->msgtype);
 703 }
 704
 705 /*
 706  * vmbus_request_offers - Send a request to get all our pending offers.
 707  */
 708 int vmbus_request_offers(void)
 709 {
 710         struct vmbus_channel_message_header *msg;
 711         struct vmbus_channel_msginfo *msginfo;
 712         int ret, t;
 713
 714         msginfo = kmalloc(sizeof(*msginfo) +
 715                           sizeof(struct vmbus_channel_message_header),
 716                           GFP_KERNEL);
 717         if (!msginfo)
 718                 return -ENOMEM;
 719
 720         init_completion(&msginfo->waitevent);
 721
 722         msg = (struct vmbus_channel_message_header *)msginfo->msg;
 723
 724         msg->msgtype = CHANNELMSG_REQUESTOFFERS;
 725
 726
 727         ret = vmbus_post_msg(msg,
 728                                sizeof(struct vmbus_channel_message_header));
 729         if (ret != 0) {
 730                 pr_err("Unable to request offers - %d\n", ret);
 731
 732                 goto cleanup;
 733         }
 734
 735         t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
 736         if (t == 0) {
 737                 ret = -ETIMEDOUT;
 738                 goto cleanup;
 739         }
 740
 741
 742
 743 cleanup:
 744         kfree(msginfo);
 745
 746         return ret;
 747 }
 748
 749 /*
 750  * Retrieve the (sub) channel on which to send an outgoing request.
 751  * When a primary channel has multiple sub-channels, we choose a
 752  * channel whose VCPU binding is closest to the VCPU on which
 753  * this call is being made.
 754  */
 755 struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary)
 756 {
 757         struct list_head *cur, *tmp;
 758         int cur_cpu = hv_context.vp_index[smp_processor_id()];
 759         struct vmbus_channel *cur_channel;
 760         struct vmbus_channel *outgoing_channel = primary;
 761         int cpu_distance, new_cpu_distance;
 762
 763         if (list_empty(&primary->sc_list))
 764                 return outgoing_channel;
 765
 766         list_for_each_safe(cur, tmp, &primary->sc_list) {
 767                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 768                 if (cur_channel->state != CHANNEL_OPENED_STATE)
 769                         continue;
 770
 771                 if (cur_channel->target_vp == cur_cpu)
 772                         return cur_channel;
 773
 774                 cpu_distance = ((outgoing_channel->target_vp > cur_cpu) ?
 775                                 (outgoing_channel->target_vp - cur_cpu) :
 776                                 (cur_cpu - outgoing_channel->target_vp));
 777
 778                 new_cpu_distance = ((cur_channel->target_vp > cur_cpu) ?
 779                                 (cur_channel->target_vp - cur_cpu) :
 780                                 (cur_cpu - cur_channel->target_vp));
 781
 782                 if (cpu_distance < new_cpu_distance)
 783                         continue;
 784
 785                 outgoing_channel = cur_channel;
 786         }
 787
 788         return outgoing_channel;
 789 }
 790 EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel);
 791
 792 static void invoke_sc_cb(struct vmbus_channel *primary_channel)
 793 {
 794         struct list_head *cur, *tmp;
 795         struct vmbus_channel *cur_channel;
 796
 797         if (primary_channel->sc_creation_callback == NULL)
 798                 return;
 799
 800         list_for_each_safe(cur, tmp, &primary_channel->sc_list) {
 801                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 802
 803                 primary_channel->sc_creation_callback(cur_channel);
 804         }
 805 }
 806
 807 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel,
 808                                 void (*sc_cr_cb)(struct vmbus_channel *new_sc))
 809 {
 810         primary_channel->sc_creation_callback = sc_cr_cb;
 811 }
 812 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback);
 813
 814 bool vmbus_are_subchannels_present(struct vmbus_channel *primary)
 815 {
 816         bool ret;
 817
 818         ret = !list_empty(&primary->sc_list);
 819
 820         if (ret) {
 821                 /*
 822                  * Invoke the callback on sub-channel creation.
 823                  * This will present a uniform interface to the
 824                  * clients.
 825                  */
 826                 invoke_sc_cb(primary);
 827         }
 828
 829         return ret;
 830 }
 831 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present);