drivers/staging/hv/channel.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 #include <linux/kernel.h>
  22 #include <linux/mm.h>
  23 #include <linux/slab.h>
  24 #include <linux/module.h>
  25 #include "osd.h"
  26 #include "logging.h"
  27 #include "vmbus_private.h"
  28
  29 /* Internal routines */
  30 static int VmbusChannelCreateGpadlHeader(
  31         void *Kbuffer,  /* must be phys and virt contiguous */
  32         u32 Size,       /* page-size multiple */
  33         struct vmbus_channel_msginfo **msgInfo,
  34         u32 *MessageCount);
  35 static void DumpVmbusChannel(struct vmbus_channel *channel);
  36 static void VmbusChannelSetEvent(struct vmbus_channel *channel);
  37
  38
  39 #if 0
  40 static void DumpMonitorPage(struct hv_monitor_page *MonitorPage)
  41 {
  42         int i = 0;
  43         int j = 0;
  44
  45         DPRINT_DBG(VMBUS, "monitorPage - %p, trigger state - %d",
  46                    MonitorPage, MonitorPage->TriggerState);
  47
  48         for (i = 0; i < 4; i++)
  49                 DPRINT_DBG(VMBUS, "trigger group (%d) - %llx", i,
  50                            MonitorPage->TriggerGroup[i].AsUINT64);
  51
  52         for (i = 0; i < 4; i++) {
  53                 for (j = 0; j < 32; j++) {
  54                         DPRINT_DBG(VMBUS, "latency (%d)(%d) - %llx", i, j,
  55                                    MonitorPage->Latency[i][j]);
  56                 }
  57         }
  58         for (i = 0; i < 4; i++) {
  59                 for (j = 0; j < 32; j++) {
  60                         DPRINT_DBG(VMBUS, "param-conn id (%d)(%d) - %d", i, j,
  61                                MonitorPage->Parameter[i][j].ConnectionId.Asu32);
  62                         DPRINT_DBG(VMBUS, "param-flag (%d)(%d) - %d", i, j,
  63                                 MonitorPage->Parameter[i][j].FlagNumber);
  64                 }
  65         }
  66 }
  67 #endif
  68
  69 /*
  70  * VmbusChannelSetEvent - Trigger an event notification on the specified
  71  * channel.
  72  */
  73 static void VmbusChannelSetEvent(struct vmbus_channel *Channel)
  74 {
  75         struct hv_monitor_page *monitorPage;
  76
  77         DPRINT_ENTER(VMBUS);
  78
  79         if (Channel->OfferMsg.MonitorAllocated) {
  80                 /* Each u32 represents 32 channels */
  81                 set_bit(Channel->OfferMsg.ChildRelId & 31,
  82                         (unsigned long *) gVmbusConnection.SendInterruptPage +
  83                         (Channel->OfferMsg.ChildRelId >> 5));
  84
  85                 monitorPage = gVmbusConnection.MonitorPages;
  86                 monitorPage++; /* Get the child to parent monitor page */
  87
  88                 set_bit(Channel->MonitorBit,
  89                         (unsigned long *)&monitorPage->TriggerGroup
  90                                         [Channel->MonitorGroup].Pending);
  91
  92         } else {
  93                 VmbusSetEvent(Channel->OfferMsg.ChildRelId);
  94         }
  95
  96         DPRINT_EXIT(VMBUS);
  97 }
  98
  99 #if 0
 100 static void VmbusChannelClearEvent(struct vmbus_channel *channel)
 101 {
 102         struct hv_monitor_page *monitorPage;
 103
 104         DPRINT_ENTER(VMBUS);
 105
 106         if (Channel->OfferMsg.MonitorAllocated) {
 107                 /* Each u32 represents 32 channels */
 108                 clear_bit(Channel->OfferMsg.ChildRelId & 31,
 109                           (unsigned long *)gVmbusConnection.SendInterruptPage +
 110                           (Channel->OfferMsg.ChildRelId >> 5));
 111
 112                 monitorPage =
 113                         (struct hv_monitor_page *)gVmbusConnection.MonitorPages;
 114                 monitorPage++; /* Get the child to parent monitor page */
 115
 116                 clear_bit(Channel->MonitorBit,
 117                           (unsigned long *)&monitorPage->TriggerGroup
 118                                         [Channel->MonitorGroup].Pending);
 119         }
 120
 121         DPRINT_EXIT(VMBUS);
 122 }
 123
 124 #endif
 125 /*
 126  * VmbusChannelGetDebugInfo -Retrieve various channel debug info
 127  */
 128 void VmbusChannelGetDebugInfo(struct vmbus_channel *Channel,
 129                               struct vmbus_channel_debug_info *DebugInfo)
 130 {
 131         struct hv_monitor_page *monitorPage;
 132         u8 monitorGroup = (u8)Channel->OfferMsg.MonitorId / 32;
 133         u8 monitorOffset = (u8)Channel->OfferMsg.MonitorId % 32;
 134         /* u32 monitorBit       = 1 << monitorOffset; */
 135
 136         DebugInfo->RelId = Channel->OfferMsg.ChildRelId;
 137         DebugInfo->State = Channel->State;
 138         memcpy(&DebugInfo->InterfaceType,
 139                &Channel->OfferMsg.Offer.InterfaceType, sizeof(struct hv_guid));
 140         memcpy(&DebugInfo->InterfaceInstance,
 141                &Channel->OfferMsg.Offer.InterfaceInstance,
 142                sizeof(struct hv_guid));
 143
 144         monitorPage = (struct hv_monitor_page *)gVmbusConnection.MonitorPages;
 145
 146         DebugInfo->MonitorId = Channel->OfferMsg.MonitorId;
 147
 148         DebugInfo->ServerMonitorPending =
 149                         monitorPage->TriggerGroup[monitorGroup].Pending;
 150         DebugInfo->ServerMonitorLatency =
 151                         monitorPage->Latency[monitorGroup][monitorOffset];
 152         DebugInfo->ServerMonitorConnectionId =
 153                         monitorPage->Parameter[monitorGroup]
 154                                               [monitorOffset].ConnectionId.u.Id;
 155
 156         monitorPage++;
 157
 158         DebugInfo->ClientMonitorPending =
 159                         monitorPage->TriggerGroup[monitorGroup].Pending;
 160         DebugInfo->ClientMonitorLatency =
 161                         monitorPage->Latency[monitorGroup][monitorOffset];
 162         DebugInfo->ClientMonitorConnectionId =
 163                         monitorPage->Parameter[monitorGroup]
 164                                               [monitorOffset].ConnectionId.u.Id;
 165
 166         RingBufferGetDebugInfo(&Channel->Inbound, &DebugInfo->Inbound);
 167         RingBufferGetDebugInfo(&Channel->Outbound, &DebugInfo->Outbound);
 168 }
 169
 170 /*
 171  * VmbusChannelOpen - Open the specified channel.
 172  */
 173 int VmbusChannelOpen(struct vmbus_channel *NewChannel, u32 SendRingBufferSize,
 174                      u32 RecvRingBufferSize, void *UserData, u32 UserDataLen,
 175                      void (*OnChannelCallback)(void *context), void *Context)
 176 {
 177         struct vmbus_channel_open_channel *openMsg;
 178         struct vmbus_channel_msginfo *openInfo = NULL;
 179         void *in, *out;
 180         unsigned long flags;
 181         int ret, err = 0;
 182
 183         DPRINT_ENTER(VMBUS);
 184
 185         /* Aligned to page size */
 186         /* ASSERT(!(SendRingBufferSize & (PAGE_SIZE - 1))); */
 187         /* ASSERT(!(RecvRingBufferSize & (PAGE_SIZE - 1))); */
 188
 189         NewChannel->OnChannelCallback = OnChannelCallback;
 190         NewChannel->ChannelCallbackContext = Context;
 191
 192         /* Allocate the ring buffer */
 193         out = osd_PageAlloc((SendRingBufferSize + RecvRingBufferSize)
 194                              >> PAGE_SHIFT);
 195         if (!out)
 196                 return -ENOMEM;
 197
 198         /* ASSERT(((unsigned long)out & (PAGE_SIZE-1)) == 0); */
 199
 200         in = (void *)((unsigned long)out + SendRingBufferSize);
 201
 202         NewChannel->RingBufferPages = out;
 203         NewChannel->RingBufferPageCount = (SendRingBufferSize +
 204                                            RecvRingBufferSize) >> PAGE_SHIFT;
 205
 206         ret = RingBufferInit(&NewChannel->Outbound, out, SendRingBufferSize);
 207         if (ret != 0) {
 208                 err = ret;
 209                 goto errorout;
 210         }
 211
 212         ret = RingBufferInit(&NewChannel->Inbound, in, RecvRingBufferSize);
 213         if (ret != 0) {
 214                 err = ret;
 215                 goto errorout;
 216         }
 217
 218
 219         /* Establish the gpadl for the ring buffer */
 220         DPRINT_DBG(VMBUS, "Establishing ring buffer's gpadl for channel %p...",
 221                    NewChannel);
 222
 223         NewChannel->RingBufferGpadlHandle = 0;
 224
 225         ret = VmbusChannelEstablishGpadl(NewChannel,
 226                                          NewChannel->Outbound.RingBuffer,
 227                                          SendRingBufferSize +
 228                                          RecvRingBufferSize,
 229                                          &NewChannel->RingBufferGpadlHandle);
 230
 231         if (ret != 0) {
 232                 err = ret;
 233                 goto errorout;
 234         }
 235
 236         DPRINT_DBG(VMBUS, "channel %p <relid %d gpadl 0x%x send ring %p "
 237                    "size %d recv ring %p size %d, downstreamoffset %d>",
 238                    NewChannel, NewChannel->OfferMsg.ChildRelId,
 239                    NewChannel->RingBufferGpadlHandle,
 240                    NewChannel->Outbound.RingBuffer,
 241                    NewChannel->Outbound.RingSize,
 242                    NewChannel->Inbound.RingBuffer,
 243                    NewChannel->Inbound.RingSize,
 244                    SendRingBufferSize);
 245
 246         /* Create and init the channel open message */
 247         openInfo = kmalloc(sizeof(*openInfo) +
 248                            sizeof(struct vmbus_channel_open_channel),
 249                            GFP_KERNEL);
 250         if (!openInfo) {
 251                 err = -ENOMEM;
 252                 goto errorout;
 253         }
 254
 255         openInfo->WaitEvent = osd_WaitEventCreate();
 256         if (!openInfo->WaitEvent) {
 257                 err = -ENOMEM;
 258                 goto errorout;
 259         }
 260
 261         openMsg = (struct vmbus_channel_open_channel *)openInfo->Msg;
 262         openMsg->Header.MessageType = ChannelMessageOpenChannel;
 263         openMsg->OpenId = NewChannel->OfferMsg.ChildRelId; /* FIXME */
 264         openMsg->ChildRelId = NewChannel->OfferMsg.ChildRelId;
 265         openMsg->RingBufferGpadlHandle = NewChannel->RingBufferGpadlHandle;
 266         openMsg->DownstreamRingBufferPageOffset = SendRingBufferSize >>
 267                                                   PAGE_SHIFT;
 268         openMsg->ServerContextAreaGpadlHandle = 0; /* TODO */
 269
 270         if (UserDataLen > MAX_USER_DEFINED_BYTES) {
 271                 err = -EINVAL;
 272                 goto errorout;
 273         }
 274
 275         if (UserDataLen)
 276                 memcpy(openMsg->UserData, UserData, UserDataLen);
 277
 278         spin_lock_irqsave(&gVmbusConnection.channelmsg_lock, flags);
 279         list_add_tail(&openInfo->MsgListEntry,
 280                       &gVmbusConnection.ChannelMsgList);
 281         spin_unlock_irqrestore(&gVmbusConnection.channelmsg_lock, flags);
 282
 283         DPRINT_DBG(VMBUS, "Sending channel open msg...");
 284
 285         ret = VmbusPostMessage(openMsg,
 286                                sizeof(struct vmbus_channel_open_channel));
 287         if (ret != 0) {
 288                 DPRINT_ERR(VMBUS, "unable to open channel - %d", ret);
 289                 goto Cleanup;
 290         }
 291
 292         /* FIXME: Need to time-out here */
 293         osd_WaitEventWait(openInfo->WaitEvent);
 294
 295         if (openInfo->Response.OpenResult.Status == 0)
 296                 DPRINT_INFO(VMBUS, "channel <%p> open success!!", NewChannel);
 297         else
 298                 DPRINT_INFO(VMBUS, "channel <%p> open failed - %d!!",
 299                             NewChannel, openInfo->Response.OpenResult.Status);
 300
 301 Cleanup:
 302         spin_lock_irqsave(&gVmbusConnection.channelmsg_lock, flags);
 303         list_del(&openInfo->MsgListEntry);
 304         spin_unlock_irqrestore(&gVmbusConnection.channelmsg_lock, flags);
 305
 306         kfree(openInfo->WaitEvent);
 307         kfree(openInfo);
 308
 309         DPRINT_EXIT(VMBUS);
 310
 311         return 0;
 312
 313 errorout:
 314         RingBufferCleanup(&NewChannel->Outbound);
 315         RingBufferCleanup(&NewChannel->Inbound);
 316         osd_PageFree(out, (SendRingBufferSize + RecvRingBufferSize)
 317                      >> PAGE_SHIFT);
 318         kfree(openInfo);
 319         return err;
 320 }
 321
 322 /*
 323  * DumpGpadlBody - Dump the gpadl body message to the console for
 324  * debugging purposes.
 325  */
 326 static void DumpGpadlBody(struct vmbus_channel_gpadl_body *Gpadl, u32 Len)
 327 {
 328         int i;
 329         int pfnCount;
 330
 331         pfnCount = (Len - sizeof(struct vmbus_channel_gpadl_body)) /
 332                    sizeof(u64);
 333         DPRINT_DBG(VMBUS, "gpadl body - len %d pfn count %d", Len, pfnCount);
 334
 335         for (i = 0; i < pfnCount; i++)
 336                 DPRINT_DBG(VMBUS, "gpadl body  - %d) pfn %llu",
 337                            i, Gpadl->Pfn[i]);
 338 }
 339
 340 /*
 341  * DumpGpadlHeader - Dump the gpadl header message to the console for
 342  * debugging purposes.
 343  */
 344 static void DumpGpadlHeader(struct vmbus_channel_gpadl_header *Gpadl)
 345 {
 346         int i, j;
 347         int pageCount;
 348
 349         DPRINT_DBG(VMBUS,
 350                    "gpadl header - relid %d, range count %d, range buflen %d",
 351                    Gpadl->ChildRelId, Gpadl->RangeCount, Gpadl->RangeBufLen);
 352         for (i = 0; i < Gpadl->RangeCount; i++) {
 353                 pageCount = Gpadl->Range[i].ByteCount >> PAGE_SHIFT;
 354                 pageCount = (pageCount > 26) ? 26 : pageCount;
 355
 356                 DPRINT_DBG(VMBUS, "gpadl range %d - len %d offset %d "
 357                            "page count %d", i, Gpadl->Range[i].ByteCount,
 358                            Gpadl->Range[i].ByteOffset, pageCount);
 359
 360                 for (j = 0; j < pageCount; j++)
 361                         DPRINT_DBG(VMBUS, "%d) pfn %llu", j,
 362                                    Gpadl->Range[i].PfnArray[j]);
 363         }
 364 }
 365
 366 /*
 367  * VmbusChannelCreateGpadlHeader - Creates a gpadl for the specified buffer
 368  */
 369 static int VmbusChannelCreateGpadlHeader(void *Kbuffer, u32 Size,
 370                                          struct vmbus_channel_msginfo **MsgInfo,
 371                                          u32 *MessageCount)
 372 {
 373         int i;
 374         int pageCount;
 375         unsigned long long pfn;
 376         struct vmbus_channel_gpadl_header *gpaHeader;
 377         struct vmbus_channel_gpadl_body *gpadlBody;
 378         struct vmbus_channel_msginfo *msgHeader;
 379         struct vmbus_channel_msginfo *msgBody = NULL;
 380         u32 msgSize;
 381
 382         int pfnSum, pfnCount, pfnLeft, pfnCurr, pfnSize;
 383
 384         /* ASSERT((kbuffer & (PAGE_SIZE-1)) == 0); */
 385         /* ASSERT((Size & (PAGE_SIZE-1)) == 0); */
 386
 387         pageCount = Size >> PAGE_SHIFT;
 388         pfn = virt_to_phys(Kbuffer) >> PAGE_SHIFT;
 389
 390         /* do we need a gpadl body msg */
 391         pfnSize = MAX_SIZE_CHANNEL_MESSAGE -
 392                   sizeof(struct vmbus_channel_gpadl_header) -
 393                   sizeof(struct gpa_range);
 394         pfnCount = pfnSize / sizeof(u64);
 395
 396         if (pageCount > pfnCount) {
 397                 /* we need a gpadl body */
 398                 /* fill in the header */
 399                 msgSize = sizeof(struct vmbus_channel_msginfo) +
 400                           sizeof(struct vmbus_channel_gpadl_header) +
 401                           sizeof(struct gpa_range) + pfnCount * sizeof(u64);
 402                 msgHeader =  kzalloc(msgSize, GFP_KERNEL);
 403                 if (!msgHeader)
 404                         goto nomem;
 405
 406                 INIT_LIST_HEAD(&msgHeader->SubMsgList);
 407                 msgHeader->MessageSize = msgSize;
 408
 409                 gpaHeader = (struct vmbus_channel_gpadl_header *)msgHeader->Msg;
 410                 gpaHeader->RangeCount = 1;
 411                 gpaHeader->RangeBufLen = sizeof(struct gpa_range) +
 412                                          pageCount * sizeof(u64);
 413                 gpaHeader->Range[0].ByteOffset = 0;
 414                 gpaHeader->Range[0].ByteCount = Size;
 415                 for (i = 0; i < pfnCount; i++)
 416                         gpaHeader->Range[0].PfnArray[i] = pfn+i;
 417                 *MsgInfo = msgHeader;
 418                 *MessageCount = 1;
 419
 420                 pfnSum = pfnCount;
 421                 pfnLeft = pageCount - pfnCount;
 422
 423                 /* how many pfns can we fit */
 424                 pfnSize = MAX_SIZE_CHANNEL_MESSAGE -
 425                           sizeof(struct vmbus_channel_gpadl_body);
 426                 pfnCount = pfnSize / sizeof(u64);
 427
 428                 /* fill in the body */
 429                 while (pfnLeft) {
 430                         if (pfnLeft > pfnCount)
 431                                 pfnCurr = pfnCount;
 432                         else
 433                                 pfnCurr = pfnLeft;
 434
 435                         msgSize = sizeof(struct vmbus_channel_msginfo) +
 436                                   sizeof(struct vmbus_channel_gpadl_body) +
 437                                   pfnCurr * sizeof(u64);
 438                         msgBody = kzalloc(msgSize, GFP_KERNEL);
 439                         /* FIXME: we probably need to more if this fails */
 440                         if (!msgBody)
 441                                 goto nomem;
 442                         msgBody->MessageSize = msgSize;
 443                         (*MessageCount)++;
 444                         gpadlBody =
 445                                 (struct vmbus_channel_gpadl_body *)msgBody->Msg;
 446
 447                         /*
 448                          * FIXME:
 449                          * Gpadl is u32 and we are using a pointer which could
 450                          * be 64-bit
 451                          */
 452                         /* gpadlBody->Gpadl = kbuffer; */
 453                         for (i = 0; i < pfnCurr; i++)
 454                                 gpadlBody->Pfn[i] = pfn + pfnSum + i;
 455
 456                         /* add to msg header */
 457                         list_add_tail(&msgBody->MsgListEntry,
 458                                       &msgHeader->SubMsgList);
 459                         pfnSum += pfnCurr;
 460                         pfnLeft -= pfnCurr;
 461                 }
 462         } else {
 463                 /* everything fits in a header */
 464                 msgSize = sizeof(struct vmbus_channel_msginfo) +
 465                           sizeof(struct vmbus_channel_gpadl_header) +
 466                           sizeof(struct gpa_range) + pageCount * sizeof(u64);
 467                 msgHeader = kzalloc(msgSize, GFP_KERNEL);
 468                 msgHeader->MessageSize = msgSize;
 469
 470                 gpaHeader = (struct vmbus_channel_gpadl_header *)msgHeader->Msg;
 471                 gpaHeader->RangeCount = 1;
 472                 gpaHeader->RangeBufLen = sizeof(struct gpa_range) +
 473                                          pageCount * sizeof(u64);
 474                 gpaHeader->Range[0].ByteOffset = 0;
 475                 gpaHeader->Range[0].ByteCount = Size;
 476                 for (i = 0; i < pageCount; i++)
 477                         gpaHeader->Range[0].PfnArray[i] = pfn+i;
 478
 479                 *MsgInfo = msgHeader;
 480                 *MessageCount = 1;
 481         }
 482
 483         return 0;
 484 nomem:
 485         kfree(msgHeader);
 486         kfree(msgBody);
 487         return -ENOMEM;
 488 }
 489
 490 /*
 491  * VmbusChannelEstablishGpadl - Estabish a GPADL for the specified buffer
 492  *
 493  * @Channel: a channel
 494  * @Kbuffer: from kmalloc
 495  * @Size: page-size multiple
 496  * @GpadlHandle: some funky thing
 497  */
 498 int VmbusChannelEstablishGpadl(struct vmbus_channel *Channel, void *Kbuffer,
 499                                u32 Size, u32 *GpadlHandle)
 500 {
 501         struct vmbus_channel_gpadl_header *gpadlMsg;
 502         struct vmbus_channel_gpadl_body *gpadlBody;
 503         /* struct vmbus_channel_gpadl_created *gpadlCreated; */
 504         struct vmbus_channel_msginfo *msgInfo = NULL;
 505         struct vmbus_channel_msginfo *subMsgInfo;
 506         u32 msgCount;
 507         struct list_head *curr;
 508         u32 nextGpadlHandle;
 509         unsigned long flags;
 510         int ret = 0;
 511
 512         DPRINT_ENTER(VMBUS);
 513
 514         nextGpadlHandle = atomic_read(&gVmbusConnection.NextGpadlHandle);
 515         atomic_inc(&gVmbusConnection.NextGpadlHandle);
 516
 517         ret = VmbusChannelCreateGpadlHeader(Kbuffer, Size, &msgInfo, &msgCount);
 518         if (ret)
 519                 return ret;
 520
 521         msgInfo->WaitEvent = osd_WaitEventCreate();
 522         if (!msgInfo->WaitEvent) {
 523                 ret = -ENOMEM;
 524                 goto Cleanup;
 525         }
 526
 527         gpadlMsg = (struct vmbus_channel_gpadl_header *)msgInfo->Msg;
 528         gpadlMsg->Header.MessageType = ChannelMessageGpadlHeader;
 529         gpadlMsg->ChildRelId = Channel->OfferMsg.ChildRelId;
 530         gpadlMsg->Gpadl = nextGpadlHandle;
 531
 532         DumpGpadlHeader(gpadlMsg);
 533
 534         spin_lock_irqsave(&gVmbusConnection.channelmsg_lock, flags);
 535         list_add_tail(&msgInfo->MsgListEntry,
 536                       &gVmbusConnection.ChannelMsgList);
 537
 538         spin_unlock_irqrestore(&gVmbusConnection.channelmsg_lock, flags);
 539         DPRINT_DBG(VMBUS, "buffer %p, size %d msg cnt %d",
 540                    Kbuffer, Size, msgCount);
 541
 542         DPRINT_DBG(VMBUS, "Sending GPADL Header - len %zd",
 543                    msgInfo->MessageSize - sizeof(*msgInfo));
 544
 545         ret = VmbusPostMessage(gpadlMsg, msgInfo->MessageSize -
 546                                sizeof(*msgInfo));
 547         if (ret != 0) {
 548                 DPRINT_ERR(VMBUS, "Unable to open channel - %d", ret);
 549                 goto Cleanup;
 550         }
 551
 552         if (msgCount > 1) {
 553                 list_for_each(curr, &msgInfo->SubMsgList) {
 554
 555                         /* FIXME: should this use list_entry() instead ? */
 556                         subMsgInfo = (struct vmbus_channel_msginfo *)curr;
 557                         gpadlBody =
 558                              (struct vmbus_channel_gpadl_body *)subMsgInfo->Msg;
 559
 560                         gpadlBody->Header.MessageType = ChannelMessageGpadlBody;
 561                         gpadlBody->Gpadl = nextGpadlHandle;
 562
 563                         DPRINT_DBG(VMBUS, "Sending GPADL Body - len %zd",
 564                                    subMsgInfo->MessageSize -
 565                                    sizeof(*subMsgInfo));
 566
 567                         DumpGpadlBody(gpadlBody, subMsgInfo->MessageSize -
 568                                       sizeof(*subMsgInfo));
 569                         ret = VmbusPostMessage(gpadlBody,
 570                                                subMsgInfo->MessageSize -
 571                                                sizeof(*subMsgInfo));
 572                         if (ret != 0)
 573                                 goto Cleanup;
 574
 575                 }
 576         }
 577         osd_WaitEventWait(msgInfo->WaitEvent);
 578
 579         /* At this point, we received the gpadl created msg */
 580         DPRINT_DBG(VMBUS, "Received GPADL created "
 581                    "(relid %d, status %d handle %x)",
 582                    Channel->OfferMsg.ChildRelId,
 583                    msgInfo->Response.GpadlCreated.CreationStatus,
 584                    gpadlMsg->Gpadl);
 585
 586         *GpadlHandle = gpadlMsg->Gpadl;
 587
 588 Cleanup:
 589         spin_lock_irqsave(&gVmbusConnection.channelmsg_lock, flags);
 590         list_del(&msgInfo->MsgListEntry);
 591         spin_unlock_irqrestore(&gVmbusConnection.channelmsg_lock, flags);
 592
 593         kfree(msgInfo->WaitEvent);
 594         kfree(msgInfo);
 595
 596         DPRINT_EXIT(VMBUS);
 597
 598         return ret;
 599 }
 600
 601 /*
 602  * VmbusChannelTeardownGpadl -Teardown the specified GPADL handle
 603  */
 604 int VmbusChannelTeardownGpadl(struct vmbus_channel *Channel, u32 GpadlHandle)
 605 {
 606         struct vmbus_channel_gpadl_teardown *msg;
 607         struct vmbus_channel_msginfo *info;
 608         unsigned long flags;
 609         int ret;
 610
 611         DPRINT_ENTER(VMBUS);
 612
 613         /* ASSERT(GpadlHandle != 0); */
 614
 615         info = kmalloc(sizeof(*info) +
 616                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 617         if (!info)
 618                 return -ENOMEM;
 619
 620         info->WaitEvent = osd_WaitEventCreate();
 621         if (!info->WaitEvent) {
 622                 kfree(info);
 623                 return -ENOMEM;
 624         }
 625
 626         msg = (struct vmbus_channel_gpadl_teardown *)info->Msg;
 627
 628         msg->Header.MessageType = ChannelMessageGpadlTeardown;
 629         msg->ChildRelId = Channel->OfferMsg.ChildRelId;
 630         msg->Gpadl = GpadlHandle;
 631
 632         spin_lock_irqsave(&gVmbusConnection.channelmsg_lock, flags);
 633         list_add_tail(&info->MsgListEntry,
 634                       &gVmbusConnection.ChannelMsgList);
 635         spin_unlock_irqrestore(&gVmbusConnection.channelmsg_lock, flags);
 636
 637         ret = VmbusPostMessage(msg,
 638                                sizeof(struct vmbus_channel_gpadl_teardown));
 639         if (ret != 0) {
 640                 /* TODO: */
 641                 /* something... */
 642         }
 643
 644         osd_WaitEventWait(info->WaitEvent);
 645
 646         /* Received a torndown response */
 647         spin_lock_irqsave(&gVmbusConnection.channelmsg_lock, flags);
 648         list_del(&info->MsgListEntry);
 649         spin_unlock_irqrestore(&gVmbusConnection.channelmsg_lock, flags);
 650
 651         kfree(info->WaitEvent);
 652         kfree(info);
 653
 654         DPRINT_EXIT(VMBUS);
 655
 656         return ret;
 657 }
 658
 659 /*
 660  * VmbusChannelClose - Close the specified channel
 661  */
 662 void VmbusChannelClose(struct vmbus_channel *Channel)
 663 {
 664         struct vmbus_channel_close_channel *msg;
 665         struct vmbus_channel_msginfo *info;
 666         unsigned long flags;
 667         int ret;
 668
 669         DPRINT_ENTER(VMBUS);
 670
 671         /* Stop callback and cancel the timer asap */
 672         Channel->OnChannelCallback = NULL;
 673         del_timer_sync(&Channel->poll_timer);
 674
 675         /* Send a closing message */
 676         info = kmalloc(sizeof(*info) +
 677                        sizeof(struct vmbus_channel_close_channel), GFP_KERNEL);
 678         /* FIXME: can't do anything other than return here because the
 679          *        function is void */
 680         if (!info)
 681                 return;
 682
 683         /* info->waitEvent = osd_WaitEventCreate(); */
 684
 685         msg = (struct vmbus_channel_close_channel *)info->Msg;
 686         msg->Header.MessageType = ChannelMessageCloseChannel;
 687         msg->ChildRelId = Channel->OfferMsg.ChildRelId;
 688
 689         ret = VmbusPostMessage(msg, sizeof(struct vmbus_channel_close_channel));
 690         if (ret != 0) {
 691                 /* TODO: */
 692                 /* something... */
 693         }
 694
 695         /* Tear down the gpadl for the channel's ring buffer */
 696         if (Channel->RingBufferGpadlHandle)
 697                 VmbusChannelTeardownGpadl(Channel,
 698                                           Channel->RingBufferGpadlHandle);
 699
 700         /* TODO: Send a msg to release the childRelId */
 701
 702         /* Cleanup the ring buffers for this channel */
 703         RingBufferCleanup(&Channel->Outbound);
 704         RingBufferCleanup(&Channel->Inbound);
 705
 706         osd_PageFree(Channel->RingBufferPages, Channel->RingBufferPageCount);
 707
 708         kfree(info);
 709
 710         /*
 711          * If we are closing the channel during an error path in
 712          * opening the channel, don't free the channel since the
 713          * caller will free the channel
 714          */
 715
 716         if (Channel->State == CHANNEL_OPEN_STATE) {
 717                 spin_lock_irqsave(&gVmbusConnection.channel_lock, flags);
 718                 list_del(&Channel->ListEntry);
 719                 spin_unlock_irqrestore(&gVmbusConnection.channel_lock, flags);
 720
 721                 FreeVmbusChannel(Channel);
 722         }
 723
 724         DPRINT_EXIT(VMBUS);
 725 }
 726
 727 /**
 728  * VmbusChannelSendPacket() - Send the specified buffer on the given channel
 729  * @Channel: Pointer to vmbus_channel structure.
 730  * @Buffer: Pointer to the buffer you want to receive the data into.
 731  * @BufferLen: Maximum size of what the the buffer will hold
 732  * @RequestId: Identifier of the request
 733  * @vmbus_packet_type: Type of packet that is being send e.g. negotiate, time
 734  * packet etc.
 735  *
 736  * Sends data in @Buffer directly to hyper-v via the vmbus
 737  * This will send the data unparsed to hyper-v.
 738  *
 739  * Mainly used by Hyper-V drivers.
 740  */
 741 int VmbusChannelSendPacket(struct vmbus_channel *Channel, const void *Buffer,
 742                            u32 BufferLen, u64 RequestId,
 743                            enum vmbus_packet_type Type, u32 Flags)
 744 {
 745         struct vmpacket_descriptor desc;
 746         u32 packetLen = sizeof(struct vmpacket_descriptor) + BufferLen;
 747         u32 packetLenAligned = ALIGN_UP(packetLen, sizeof(u64));
 748         struct scatterlist bufferList[3];
 749         u64 alignedData = 0;
 750         int ret;
 751
 752         DPRINT_ENTER(VMBUS);
 753         DPRINT_DBG(VMBUS, "channel %p buffer %p len %d",
 754                    Channel, Buffer, BufferLen);
 755
 756         DumpVmbusChannel(Channel);
 757
 758         /* ASSERT((packetLenAligned - packetLen) < sizeof(u64)); */
 759
 760         /* Setup the descriptor */
 761         desc.Type = Type; /* VmbusPacketTypeDataInBand; */
 762         desc.Flags = Flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 763         /* in 8-bytes granularity */
 764         desc.DataOffset8 = sizeof(struct vmpacket_descriptor) >> 3;
 765         desc.Length8 = (u16)(packetLenAligned >> 3);
 766         desc.TransactionId = RequestId;
 767
 768         sg_init_table(bufferList, 3);
 769         sg_set_buf(&bufferList[0], &desc, sizeof(struct vmpacket_descriptor));
 770         sg_set_buf(&bufferList[1], Buffer, BufferLen);
 771         sg_set_buf(&bufferList[2], &alignedData, packetLenAligned - packetLen);
 772
 773         ret = RingBufferWrite(&Channel->Outbound, bufferList, 3);
 774
 775         /* TODO: We should determine if this is optional */
 776         if (ret == 0 && !GetRingBufferInterruptMask(&Channel->Outbound))
 777                 VmbusChannelSetEvent(Channel);
 778
 779         DPRINT_EXIT(VMBUS);
 780
 781         return ret;
 782 }
 783 EXPORT_SYMBOL(VmbusChannelSendPacket);
 784
 785 /*
 786  * VmbusChannelSendPacketPageBuffer - Send a range of single-page buffer
 787  * packets using a GPADL Direct packet type.
 788  */
 789 int VmbusChannelSendPacketPageBuffer(struct vmbus_channel *Channel,
 790                                      struct hv_page_buffer PageBuffers[],
 791                                      u32 PageCount, void *Buffer, u32 BufferLen,
 792                                      u64 RequestId)
 793 {
 794         int ret;
 795         int i;
 796         struct VMBUS_CHANNEL_PACKET_PAGE_BUFFER desc;
 797         u32 descSize;
 798         u32 packetLen;
 799         u32 packetLenAligned;
 800         struct scatterlist bufferList[3];
 801         u64 alignedData = 0;
 802
 803         DPRINT_ENTER(VMBUS);
 804
 805         if (PageCount > MAX_PAGE_BUFFER_COUNT)
 806                 return -EINVAL;
 807
 808         DumpVmbusChannel(Channel);
 809
 810         /*
 811          * Adjust the size down since VMBUS_CHANNEL_PACKET_PAGE_BUFFER is the
 812          * largest size we support
 813          */
 814         descSize = sizeof(struct VMBUS_CHANNEL_PACKET_PAGE_BUFFER) -
 815                           ((MAX_PAGE_BUFFER_COUNT - PageCount) *
 816                           sizeof(struct hv_page_buffer));
 817         packetLen = descSize + BufferLen;
 818         packetLenAligned = ALIGN_UP(packetLen, sizeof(u64));
 819
 820         /* ASSERT((packetLenAligned - packetLen) < sizeof(u64)); */
 821
 822         /* Setup the descriptor */
 823         desc.Type = VmbusPacketTypeDataUsingGpaDirect;
 824         desc.Flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 825         desc.DataOffset8 = descSize >> 3; /* in 8-bytes grandularity */
 826         desc.Length8 = (u16)(packetLenAligned >> 3);
 827         desc.TransactionId = RequestId;
 828         desc.RangeCount = PageCount;
 829
 830         for (i = 0; i < PageCount; i++) {
 831                 desc.Range[i].Length = PageBuffers[i].Length;
 832                 desc.Range[i].Offset = PageBuffers[i].Offset;
 833                 desc.Range[i].Pfn        = PageBuffers[i].Pfn;
 834         }
 835
 836         sg_init_table(bufferList, 3);
 837         sg_set_buf(&bufferList[0], &desc, descSize);
 838         sg_set_buf(&bufferList[1], Buffer, BufferLen);
 839         sg_set_buf(&bufferList[2], &alignedData, packetLenAligned - packetLen);
 840
 841         ret = RingBufferWrite(&Channel->Outbound, bufferList, 3);
 842
 843         /* TODO: We should determine if this is optional */
 844         if (ret == 0 && !GetRingBufferInterruptMask(&Channel->Outbound))
 845                 VmbusChannelSetEvent(Channel);
 846
 847         DPRINT_EXIT(VMBUS);
 848
 849         return ret;
 850 }
 851
 852 /*
 853  * VmbusChannelSendPacketMultiPageBuffer - Send a multi-page buffer packet
 854  * using a GPADL Direct packet type.
 855  */
 856 int VmbusChannelSendPacketMultiPageBuffer(struct vmbus_channel *Channel,
 857                                 struct hv_multipage_buffer *MultiPageBuffer,
 858                                 void *Buffer, u32 BufferLen, u64 RequestId)
 859 {
 860         int ret;
 861         struct VMBUS_CHANNEL_PACKET_MULITPAGE_BUFFER desc;
 862         u32 descSize;
 863         u32 packetLen;
 864         u32 packetLenAligned;
 865         struct scatterlist bufferList[3];
 866         u64 alignedData = 0;
 867         u32 PfnCount = NUM_PAGES_SPANNED(MultiPageBuffer->Offset,
 868                                          MultiPageBuffer->Length);
 869
 870         DPRINT_ENTER(VMBUS);
 871
 872         DumpVmbusChannel(Channel);
 873
 874         DPRINT_DBG(VMBUS, "data buffer - offset %u len %u pfn count %u",
 875                    MultiPageBuffer->Offset, MultiPageBuffer->Length, PfnCount);
 876
 877         if ((PfnCount < 0) || (PfnCount > MAX_MULTIPAGE_BUFFER_COUNT))
 878                 return -EINVAL;
 879
 880         /*
 881          * Adjust the size down since VMBUS_CHANNEL_PACKET_MULITPAGE_BUFFER is
 882          * the largest size we support
 883          */
 884         descSize = sizeof(struct VMBUS_CHANNEL_PACKET_MULITPAGE_BUFFER) -
 885                           ((MAX_MULTIPAGE_BUFFER_COUNT - PfnCount) *
 886                           sizeof(u64));
 887         packetLen = descSize + BufferLen;
 888         packetLenAligned = ALIGN_UP(packetLen, sizeof(u64));
 889
 890         /* ASSERT((packetLenAligned - packetLen) < sizeof(u64)); */
 891
 892         /* Setup the descriptor */
 893         desc.Type = VmbusPacketTypeDataUsingGpaDirect;
 894         desc.Flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 895         desc.DataOffset8 = descSize >> 3; /* in 8-bytes grandularity */
 896         desc.Length8 = (u16)(packetLenAligned >> 3);
 897         desc.TransactionId = RequestId;
 898         desc.RangeCount = 1;
 899
 900         desc.Range.Length = MultiPageBuffer->Length;
 901         desc.Range.Offset = MultiPageBuffer->Offset;
 902
 903         memcpy(desc.Range.PfnArray, MultiPageBuffer->PfnArray,
 904                PfnCount * sizeof(u64));
 905
 906         sg_init_table(bufferList, 3);
 907         sg_set_buf(&bufferList[0], &desc, descSize);
 908         sg_set_buf(&bufferList[1], Buffer, BufferLen);
 909         sg_set_buf(&bufferList[2], &alignedData, packetLenAligned - packetLen);
 910
 911         ret = RingBufferWrite(&Channel->Outbound, bufferList, 3);
 912
 913         /* TODO: We should determine if this is optional */
 914         if (ret == 0 && !GetRingBufferInterruptMask(&Channel->Outbound))
 915                 VmbusChannelSetEvent(Channel);
 916
 917         DPRINT_EXIT(VMBUS);
 918
 919         return ret;
 920 }
 921
 922
 923 /**
 924  * VmbusChannelRecvPacket() - Retrieve the user packet on the specified channel
 925  * @Channel: Pointer to vmbus_channel structure.
 926  * @Buffer: Pointer to the buffer you want to receive the data into.
 927  * @BufferLen: Maximum size of what the the buffer will hold
 928  * @BufferActualLen: The actual size of the data after it was received
 929  * @RequestId: Identifier of the request
 930  *
 931  * Receives directly from the hyper-v vmbus and puts the data it received
 932  * into Buffer. This will receive the data unparsed from hyper-v.
 933  *
 934  * Mainly used by Hyper-V drivers.
 935  */
 936 int VmbusChannelRecvPacket(struct vmbus_channel *Channel, void *Buffer,
 937                            u32 BufferLen, u32 *BufferActualLen, u64 *RequestId)
 938 {
 939         struct vmpacket_descriptor desc;
 940         u32 packetLen;
 941         u32 userLen;
 942         int ret;
 943         unsigned long flags;
 944
 945         DPRINT_ENTER(VMBUS);
 946
 947         *BufferActualLen = 0;
 948         *RequestId = 0;
 949
 950         spin_lock_irqsave(&Channel->inbound_lock, flags);
 951
 952         ret = RingBufferPeek(&Channel->Inbound, &desc,
 953                              sizeof(struct vmpacket_descriptor));
 954         if (ret != 0) {
 955                 spin_unlock_irqrestore(&Channel->inbound_lock, flags);
 956
 957                 /* DPRINT_DBG(VMBUS, "nothing to read!!"); */
 958                 DPRINT_EXIT(VMBUS);
 959                 return 0;
 960         }
 961
 962         /* VmbusChannelClearEvent(Channel); */
 963
 964         packetLen = desc.Length8 << 3;
 965         userLen = packetLen - (desc.DataOffset8 << 3);
 966         /* ASSERT(userLen > 0); */
 967
 968         DPRINT_DBG(VMBUS, "packet received on channel %p relid %d <type %d "
 969                    "flag %d tid %llx pktlen %d datalen %d> ",
 970                    Channel, Channel->OfferMsg.ChildRelId, desc.Type,
 971                    desc.Flags, desc.TransactionId, packetLen, userLen);
 972
 973         *BufferActualLen = userLen;
 974
 975         if (userLen > BufferLen) {
 976                 spin_unlock_irqrestore(&Channel->inbound_lock, flags);
 977
 978                 DPRINT_ERR(VMBUS, "buffer too small - got %d needs %d",
 979                            BufferLen, userLen);
 980                 DPRINT_EXIT(VMBUS);
 981
 982                 return -1;
 983         }
 984
 985         *RequestId = desc.TransactionId;
 986
 987         /* Copy over the packet to the user buffer */
 988         ret = RingBufferRead(&Channel->Inbound, Buffer, userLen,
 989                              (desc.DataOffset8 << 3));
 990
 991         spin_unlock_irqrestore(&Channel->inbound_lock, flags);
 992
 993         DPRINT_EXIT(VMBUS);
 994
 995         return 0;
 996 }
 997 EXPORT_SYMBOL(VmbusChannelRecvPacket);
 998
 999 /*
1000  * VmbusChannelRecvPacketRaw - Retrieve the raw packet on the specified channel
1001  */
1002 int VmbusChannelRecvPacketRaw(struct vmbus_channel *Channel, void *Buffer,
1003                               u32 BufferLen, u32 *BufferActualLen,
1004                               u64 *RequestId)
1005 {
1006         struct vmpacket_descriptor desc;
1007         u32 packetLen;
1008         u32 userLen;
1009         int ret;
1010         unsigned long flags;
1011
1012         DPRINT_ENTER(VMBUS);
1013
1014         *BufferActualLen = 0;
1015         *RequestId = 0;
1016
1017         spin_lock_irqsave(&Channel->inbound_lock, flags);
1018
1019         ret = RingBufferPeek(&Channel->Inbound, &desc,
1020                              sizeof(struct vmpacket_descriptor));
1021         if (ret != 0) {
1022                 spin_unlock_irqrestore(&Channel->inbound_lock, flags);
1023
1024                 /* DPRINT_DBG(VMBUS, "nothing to read!!"); */
1025                 DPRINT_EXIT(VMBUS);
1026                 return 0;
1027         }
1028
1029         /* VmbusChannelClearEvent(Channel); */
1030
1031         packetLen = desc.Length8 << 3;
1032         userLen = packetLen - (desc.DataOffset8 << 3);
1033
1034         DPRINT_DBG(VMBUS, "packet received on channel %p relid %d <type %d "
1035                    "flag %d tid %llx pktlen %d datalen %d> ",
1036                    Channel, Channel->OfferMsg.ChildRelId, desc.Type,
1037                    desc.Flags, desc.TransactionId, packetLen, userLen);
1038
1039         *BufferActualLen = packetLen;
1040
1041         if (packetLen > BufferLen) {
1042                 spin_unlock_irqrestore(&Channel->inbound_lock, flags);
1043
1044                 DPRINT_ERR(VMBUS, "buffer too small - needed %d bytes but "
1045                            "got space for only %d bytes", packetLen, BufferLen);
1046                 DPRINT_EXIT(VMBUS);
1047                 return -2;
1048         }
1049
1050         *RequestId = desc.TransactionId;
1051
1052         /* Copy over the entire packet to the user buffer */
1053         ret = RingBufferRead(&Channel->Inbound, Buffer, packetLen, 0);
1054
1055         spin_unlock_irqrestore(&Channel->inbound_lock, flags);
1056
1057         DPRINT_EXIT(VMBUS);
1058
1059         return 0;
1060 }
1061
1062 /*
1063  * VmbusChannelOnChannelEvent - Channel event callback
1064  */
1065 void VmbusChannelOnChannelEvent(struct vmbus_channel *Channel)
1066 {
1067         DumpVmbusChannel(Channel);
1068         /* ASSERT(Channel->OnChannelCallback); */
1069
1070         Channel->OnChannelCallback(Channel->ChannelCallbackContext);
1071
1072         mod_timer(&Channel->poll_timer, jiffies + usecs_to_jiffies(100));
1073 }
1074
1075 /*
1076  * VmbusChannelOnTimer - Timer event callback
1077  */
1078 void VmbusChannelOnTimer(unsigned long data)
1079 {
1080         struct vmbus_channel *channel = (struct vmbus_channel *)data;
1081
1082         if (channel->OnChannelCallback)
1083                 channel->OnChannelCallback(channel->ChannelCallbackContext);
1084 }
1085
1086 /*
1087  * DumpVmbusChannel - Dump vmbus channel info to the console
1088  */
1089 static void DumpVmbusChannel(struct vmbus_channel *Channel)
1090 {
1091         DPRINT_DBG(VMBUS, "Channel (%d)", Channel->OfferMsg.ChildRelId);
1092         DumpRingInfo(&Channel->Outbound, "Outbound ");
1093         DumpRingInfo(&Channel->Inbound, "Inbound ");
1094 }