drivers/bus/pcix/fdo.c

   1 /*
   2  * PROJECT:         ReactOS PCI Bus Driver
   3  * LICENSE:         BSD - See COPYING.ARM in the top level directory
   4  * FILE:            drivers/bus/pci/fdo.c
   5  * PURPOSE:         FDO Device Management
   6  * PROGRAMMERS:     ReactOS Portable Systems Group
   7  */
   8
   9 /* INCLUDES *******************************************************************/
  10
  11 #include <pci.h>
  12 #define NDEBUG
  13 #include <debug.h>
  14
  15 /* GLOBALS ********************************************************************/
  16
  17 SINGLE_LIST_ENTRY PciFdoExtensionListHead;
  18 BOOLEAN PciBreakOnDefault;
  19
  20 PCI_MN_DISPATCH_TABLE PciFdoDispatchPowerTable[] =
  21 {
  22     {IRP_DISPATCH, (PCI_DISPATCH_FUNCTION)PciFdoWaitWake},
  23     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported},
  24     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciFdoSetPowerState},
  25     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciFdoIrpQueryPower},
  26     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported}
  27 };
  28
  29 PCI_MN_DISPATCH_TABLE PciFdoDispatchPnpTable[] =
  30 {
  31     {IRP_UPWARD,   (PCI_DISPATCH_FUNCTION)PciFdoIrpStartDevice},
  32     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciFdoIrpQueryRemoveDevice},
  33     {IRP_DISPATCH, (PCI_DISPATCH_FUNCTION)PciFdoIrpRemoveDevice},
  34     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciFdoIrpCancelRemoveDevice},
  35     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciFdoIrpStopDevice},
  36     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciFdoIrpQueryStopDevice},
  37     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciFdoIrpCancelStopDevice},
  38     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciFdoIrpQueryDeviceRelations},
  39     {IRP_DISPATCH, (PCI_DISPATCH_FUNCTION)PciFdoIrpQueryInterface},
  40     {IRP_UPWARD,   (PCI_DISPATCH_FUNCTION)PciFdoIrpQueryCapabilities},
  41     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported},
  42     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported},
  43     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported},
  44     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported},
  45     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported},
  46     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported},
  47     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported},
  48     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported},
  49     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported},
  50     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported},
  51     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported},
  52     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported},
  53     {IRP_UPWARD,   (PCI_DISPATCH_FUNCTION)PciFdoIrpDeviceUsageNotification},
  54     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciFdoIrpSurpriseRemoval},
  55     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciFdoIrpQueryLegacyBusInformation},
  56     {IRP_DOWNWARD, (PCI_DISPATCH_FUNCTION)PciIrpNotSupported}
  57 };
  58
  59 PCI_MJ_DISPATCH_TABLE PciFdoDispatchTable =
  60 {
  61     IRP_MN_QUERY_LEGACY_BUS_INFORMATION,
  62     PciFdoDispatchPnpTable,
  63     IRP_MN_QUERY_POWER,
  64     PciFdoDispatchPowerTable,
  65     IRP_DOWNWARD,
  66     (PCI_DISPATCH_FUNCTION)PciIrpNotSupported,
  67     IRP_DOWNWARD,
  68     (PCI_DISPATCH_FUNCTION)PciIrpNotSupported
  69 };
  70
  71 /* FUNCTIONS ******************************************************************/
  72
  73 NTSTATUS
  74 NTAPI
  75 PciFdoIrpStartDevice(IN PIRP Irp,
  76                      IN PIO_STACK_LOCATION IoStackLocation,
  77                      IN PPCI_FDO_EXTENSION DeviceExtension)
  78 {
  79     NTSTATUS Status;
  80     PCM_RESOURCE_LIST Resources;
  81     PAGED_CODE();
  82
  83     /* The device stack must be starting the FDO in a success path */
  84     if (!NT_SUCCESS(Irp->IoStatus.Status)) return STATUS_NOT_SUPPORTED;
  85
  86     /* Attempt to switch the state machine to the started state */
  87     Status = PciBeginStateTransition(DeviceExtension, PciStarted);
  88     if (!NT_SUCCESS(Status)) return Status;
  89
  90     /* Check for any boot-provided resources */
  91     Resources = IoStackLocation->Parameters.StartDevice.AllocatedResources;
  92     DPRINT1("Resources: %p\n", Resources);
  93     if ((Resources) && !(PCI_IS_ROOT_FDO(DeviceExtension)))
  94     {
  95         /* These resources would only be for non-root FDOs, unhandled for now */
  96         ASSERT(Resources->Count == 1);
  97         UNIMPLEMENTED;
  98         while (TRUE);
  99     }
 100
 101     /* Initialize the arbiter for this FDO */
 102     Status = PciInitializeArbiterRanges(DeviceExtension, Resources);
 103     if (!NT_SUCCESS(Status))
 104     {
 105         /* Cancel the transition if this failed */
 106         PciCancelStateTransition(DeviceExtension, PciStarted);
 107         return Status;
 108     }
 109
 110     /* Again, check for boot-provided resources for non-root FDO */
 111     if ((Resources) && !(PCI_IS_ROOT_FDO(DeviceExtension)))
 112     {
 113         /* Unhandled for now */
 114         ASSERT(Resources->Count == 1);
 115         UNIMPLEMENTED;
 116         while (TRUE);
 117     }
 118
 119     /* Commit the transition to the started state */
 120     PciCommitStateTransition(DeviceExtension, PciStarted);
 121     return STATUS_SUCCESS;
 122 }
 123
 124 NTSTATUS
 125 NTAPI
 126 PciFdoIrpQueryRemoveDevice(IN PIRP Irp,
 127                            IN PIO_STACK_LOCATION IoStackLocation,
 128                            IN PPCI_FDO_EXTENSION DeviceExtension)
 129 {
 130     UNIMPLEMENTED;
 131     while (TRUE);
 132     return STATUS_NOT_SUPPORTED;
 133 }
 134
 135 NTSTATUS
 136 NTAPI
 137 PciFdoIrpRemoveDevice(IN PIRP Irp,
 138                       IN PIO_STACK_LOCATION IoStackLocation,
 139                       IN PPCI_FDO_EXTENSION DeviceExtension)
 140 {
 141     UNIMPLEMENTED;
 142     while (TRUE);
 143     return STATUS_NOT_SUPPORTED;
 144 }
 145
 146 NTSTATUS
 147 NTAPI
 148 PciFdoIrpCancelRemoveDevice(IN PIRP Irp,
 149                             IN PIO_STACK_LOCATION IoStackLocation,
 150                             IN PPCI_FDO_EXTENSION DeviceExtension)
 151 {
 152     UNIMPLEMENTED;
 153     while (TRUE);
 154     return STATUS_NOT_SUPPORTED;
 155 }
 156
 157 NTSTATUS
 158 NTAPI
 159 PciFdoIrpStopDevice(IN PIRP Irp,
 160                     IN PIO_STACK_LOCATION IoStackLocation,
 161                     IN PPCI_FDO_EXTENSION DeviceExtension)
 162 {
 163     UNIMPLEMENTED;
 164     while (TRUE);
 165     return STATUS_NOT_SUPPORTED;
 166 }
 167
 168 NTSTATUS
 169 NTAPI
 170 PciFdoIrpQueryStopDevice(IN PIRP Irp,
 171                          IN PIO_STACK_LOCATION IoStackLocation,
 172                          IN PPCI_FDO_EXTENSION DeviceExtension)
 173 {
 174     UNIMPLEMENTED;
 175     while (TRUE);
 176     return STATUS_NOT_SUPPORTED;
 177 }
 178
 179 NTSTATUS
 180 NTAPI
 181 PciFdoIrpCancelStopDevice(IN PIRP Irp,
 182                           IN PIO_STACK_LOCATION IoStackLocation,
 183                           IN PPCI_FDO_EXTENSION DeviceExtension)
 184 {
 185     UNIMPLEMENTED;
 186     while (TRUE);
 187     return STATUS_NOT_SUPPORTED;
 188 }
 189
 190 NTSTATUS
 191 NTAPI
 192 PciFdoIrpQueryDeviceRelations(IN PIRP Irp,
 193                               IN PIO_STACK_LOCATION IoStackLocation,
 194                               IN PPCI_FDO_EXTENSION DeviceExtension)
 195 {
 196     NTSTATUS Status;
 197     PAGED_CODE();
 198
 199     /* Are bus relations being queried? */
 200     if (IoStackLocation->Parameters.QueryDeviceRelations.Type != BusRelations)
 201     {
 202         /* The FDO is a bus, so only bus relations can be obtained */
 203         Status = STATUS_NOT_SUPPORTED;
 204     }
 205     else
 206     {
 207         /* Scan the PCI bus and build the device relations for the caller */
 208         Status = PciQueryDeviceRelations(DeviceExtension,
 209                                          (PDEVICE_RELATIONS*)
 210                                          &Irp->IoStatus.Information);
 211     }
 212
 213     /* Return the enumeration status back */
 214     return Status;
 215 }
 216
 217 NTSTATUS
 218 NTAPI
 219 PciFdoIrpQueryInterface(IN PIRP Irp,
 220                         IN PIO_STACK_LOCATION IoStackLocation,
 221                         IN PPCI_FDO_EXTENSION DeviceExtension)
 222 {
 223     NTSTATUS Status;
 224     PAGED_CODE();
 225     ASSERT(DeviceExtension->ExtensionType == PciFdoExtensionType);
 226
 227     /* Deleted extensions don't respond to IRPs */
 228     if (DeviceExtension->DeviceState == PciDeleted)
 229     {
 230         /* Hand it bacO try to deal with it */
 231         return PciPassIrpFromFdoToPdo(DeviceExtension, Irp);
 232     }
 233
 234     /* Query our driver for this interface */
 235     Status = PciQueryInterface(DeviceExtension,
 236                                IoStackLocation->Parameters.QueryInterface.
 237                                InterfaceType,
 238                                IoStackLocation->Parameters.QueryInterface.
 239                                Size,
 240                                IoStackLocation->Parameters.QueryInterface.
 241                                Version,
 242                                IoStackLocation->Parameters.QueryInterface.
 243                                InterfaceSpecificData,
 244                                IoStackLocation->Parameters.QueryInterface.
 245                                Interface,
 246                                FALSE);
 247     if (NT_SUCCESS(Status))
 248     {
 249         /* We found it, let the PDO handle it */
 250         Irp->IoStatus.Status = Status;
 251         return PciPassIrpFromFdoToPdo(DeviceExtension, Irp);
 252     }
 253     else if (Status == STATUS_NOT_SUPPORTED)
 254     {
 255         /* Otherwise, we can't handle it, let someone else down the stack try */
 256         Status = PciCallDownIrpStack(DeviceExtension, Irp);
 257         if (Status == STATUS_NOT_SUPPORTED)
 258         {
 259             /* They can't either, try a last-resort interface lookup */
 260             Status = PciQueryInterface(DeviceExtension,
 261                                        IoStackLocation->Parameters.QueryInterface.
 262                                        InterfaceType,
 263                                        IoStackLocation->Parameters.QueryInterface.
 264                                        Size,
 265                                        IoStackLocation->Parameters.QueryInterface.
 266                                        Version,
 267                                        IoStackLocation->Parameters.QueryInterface.
 268                                        InterfaceSpecificData,
 269                                        IoStackLocation->Parameters.QueryInterface.
 270                                        Interface,
 271                                        TRUE);
 272         }
 273     }
 274
 275     /* Has anyone claimed this interface yet? */
 276     if (Status == STATUS_NOT_SUPPORTED)
 277     {
 278         /* No, return the original IRP status */
 279         Status = Irp->IoStatus.Status;
 280     }
 281     else
 282     {
 283         /* Yes, set the new IRP status */
 284         Irp->IoStatus.Status = Status;
 285     }
 286
 287     /* Complete this IRP */
 288     IoCompleteRequest(Irp, IO_NO_INCREMENT);
 289     return Status;
 290 }
 291
 292 NTSTATUS
 293 NTAPI
 294 PciFdoIrpQueryCapabilities(IN PIRP Irp,
 295                            IN PIO_STACK_LOCATION IoStackLocation,
 296                            IN PPCI_FDO_EXTENSION DeviceExtension)
 297 {
 298     UNIMPLEMENTED;
 299     while (TRUE);
 300     return STATUS_NOT_SUPPORTED;
 301 }
 302
 303 NTSTATUS
 304 NTAPI
 305 PciFdoIrpDeviceUsageNotification(IN PIRP Irp,
 306                                  IN PIO_STACK_LOCATION IoStackLocation,
 307                                  IN PPCI_FDO_EXTENSION DeviceExtension)
 308 {
 309     UNIMPLEMENTED;
 310     while (TRUE);
 311     return STATUS_NOT_SUPPORTED;
 312 }
 313
 314 NTSTATUS
 315 NTAPI
 316 PciFdoIrpSurpriseRemoval(IN PIRP Irp,
 317                          IN PIO_STACK_LOCATION IoStackLocation,
 318                          IN PPCI_FDO_EXTENSION DeviceExtension)
 319 {
 320     UNIMPLEMENTED;
 321     while (TRUE);
 322     return STATUS_NOT_SUPPORTED;
 323 }
 324
 325 NTSTATUS
 326 NTAPI
 327 PciFdoIrpQueryLegacyBusInformation(IN PIRP Irp,
 328                                    IN PIO_STACK_LOCATION IoStackLocation,
 329                                    IN PPCI_FDO_EXTENSION DeviceExtension)
 330 {
 331     UNIMPLEMENTED;
 332     while (TRUE);
 333     return STATUS_NOT_SUPPORTED;
 334 }
 335
 336 VOID
 337 NTAPI
 338 PciGetHotPlugParameters(IN PPCI_FDO_EXTENSION FdoExtension)
 339 {
 340     ACPI_EVAL_INPUT_BUFFER InputBuffer;
 341     PACPI_EVAL_OUTPUT_BUFFER OutputBuffer;
 342     ULONG Length;
 343     NTSTATUS Status;
 344     PAGED_CODE();
 345
 346     /* We should receive 4 parameters, per the HPP specification */
 347     Length = sizeof(ACPI_EVAL_OUTPUT_BUFFER) + 4 * sizeof(ACPI_METHOD_ARGUMENT);
 348
 349     /* Allocate the buffer to hold the parameters */
 350     OutputBuffer = ExAllocatePoolWithTag(PagedPool, Length, PCI_POOL_TAG);
 351     if (!OutputBuffer) return;
 352
 353     /* Initialize the output and input buffers. The method is _HPP */
 354     RtlZeroMemory(OutputBuffer, Length);
 355     *(PULONG)InputBuffer.MethodName = 'PPH_';
 356     InputBuffer.Signature = ACPI_EVAL_INPUT_BUFFER_SIGNATURE;
 357     do
 358     {
 359         /* Send the IOCTL to the ACPI driver */
 360         Status = PciSendIoctl(FdoExtension->PhysicalDeviceObject,
 361                               IOCTL_ACPI_EVAL_METHOD,
 362                               &InputBuffer,
 363                               sizeof(InputBuffer),
 364                               OutputBuffer,
 365                               Length);
 366         if (!NT_SUCCESS(Status))
 367         {
 368             /* The method failed, check if we can salvage data from parent */
 369             if (!PCI_IS_ROOT_FDO(FdoExtension))
 370             {
 371                 /* Copy the root bus' hot plug parameters */
 372                 FdoExtension->HotPlugParameters = FdoExtension->ParentFdoExtension->HotPlugParameters;
 373             }
 374
 375             /* Nothing more to do on this path */
 376             break;
 377         }
 378
 379         /* ACPI sent back some data. 4 parameters are expected in the output */
 380         if (OutputBuffer->Count != 4) break;
 381
 382         /* HotPlug PCI Support not yet implemented */
 383         UNIMPLEMENTED;
 384         while (TRUE);
 385     } while (FALSE);
 386
 387     /* Free the buffer and return */
 388     ExFreePoolWithTag(OutputBuffer, 0);
 389 }
 390
 391 VOID
 392 NTAPI
 393 PciInitializeFdoExtensionCommonFields(PPCI_FDO_EXTENSION FdoExtension,
 394                                       IN PDEVICE_OBJECT DeviceObject,
 395                                       IN PDEVICE_OBJECT PhysicalDeviceObject)
 396 {
 397     /* Initialize the extension */
 398     RtlZeroMemory(FdoExtension, sizeof(PCI_FDO_EXTENSION));
 399
 400     /* Setup the common fields */
 401     FdoExtension->PhysicalDeviceObject = PhysicalDeviceObject;
 402     FdoExtension->FunctionalDeviceObject = DeviceObject;
 403     FdoExtension->ExtensionType = PciFdoExtensionType;
 404     FdoExtension->PowerState.CurrentSystemState = PowerSystemWorking;
 405     FdoExtension->PowerState.CurrentDeviceState = PowerDeviceD0;
 406     FdoExtension->IrpDispatchTable = &PciFdoDispatchTable;
 407
 408     /* Initialize the extension locks */
 409     KeInitializeEvent(&FdoExtension->SecondaryExtLock, SynchronizationEvent, TRUE);
 410     KeInitializeEvent(&FdoExtension->ChildListLock, SynchronizationEvent, TRUE);
 411
 412     /* Initialize the default state */
 413     PciInitializeState(FdoExtension);
 414 }
 415
 416 NTSTATUS
 417 NTAPI
 418 PciAddDevice(IN PDRIVER_OBJECT DriverObject,
 419              IN PDEVICE_OBJECT PhysicalDeviceObject)
 420 {
 421     PCM_RESOURCE_LIST Descriptor;
 422     PDEVICE_OBJECT AttachedTo;
 423     PPCI_FDO_EXTENSION FdoExtension;
 424     PPCI_FDO_EXTENSION ParentExtension;
 425     PDEVICE_OBJECT DeviceObject;
 426     UCHAR Buffer[sizeof(KEY_VALUE_PARTIAL_INFORMATION) + sizeof(ULONG)];
 427     PKEY_VALUE_PARTIAL_INFORMATION ValueInfo = (PKEY_VALUE_PARTIAL_INFORMATION)Buffer;
 428     NTSTATUS Status;
 429     HANDLE KeyHandle;
 430     UNICODE_STRING ValueName;
 431     ULONG ResultLength;
 432     PAGED_CODE();
 433     DPRINT1("PCI - AddDevice (a new bus). PDO: %p (Driver: %wZ)\n",
 434             PhysicalDeviceObject, &PhysicalDeviceObject->DriverObject->DriverName);
 435
 436     /* Zero out variables so failure path knows what to do */
 437     AttachedTo = NULL;
 438     do
 439     {
 440         /* Check if there's already a device extension for this bus */
 441         ParentExtension = PciFindParentPciFdoExtension(PhysicalDeviceObject,
 442                                                        &PciGlobalLock);
 443         if (ParentExtension)
 444         {
 445             /* More than one PCI bus, this is not expected yet */
 446             UNIMPLEMENTED;
 447             while (TRUE);
 448         }
 449
 450         /* Create the FDO for the bus */
 451         Status = IoCreateDevice(DriverObject,
 452                                 sizeof(PCI_FDO_EXTENSION),
 453                                 NULL,
 454                                 FILE_DEVICE_BUS_EXTENDER,
 455                                 0,
 456                                 0,
 457                                 &DeviceObject);
 458         if (!NT_SUCCESS(Status)) break;
 459
 460         /* Initialize the extension for the FDO */
 461         FdoExtension = DeviceObject->DeviceExtension;
 462         PciInitializeFdoExtensionCommonFields(DeviceObject->DeviceExtension,
 463                                               DeviceObject,
 464                                               PhysicalDeviceObject);
 465
 466         /* Attach to the root PDO */
 467         Status = STATUS_NO_SUCH_DEVICE;
 468         AttachedTo = IoAttachDeviceToDeviceStack(DeviceObject,
 469                                                  PhysicalDeviceObject);
 470         ASSERT(AttachedTo != NULL);
 471         if (!AttachedTo) break;
 472         FdoExtension->AttachedDeviceObject = AttachedTo;
 473         if (ParentExtension)
 474         {
 475             /* More than one PCI bus, this is not expected yet */
 476             UNIMPLEMENTED;
 477             while (TRUE);
 478         }
 479         else
 480         {
 481             /* Query the boot configuration */
 482             Status = PciGetDeviceProperty(PhysicalDeviceObject,
 483                                           DevicePropertyBootConfiguration,
 484                                           (PVOID*)&Descriptor);
 485             if (!NT_SUCCESS(Status))
 486             {
 487                 /* No configuration has been set */
 488                 Descriptor = NULL;
 489             }
 490             else
 491             {
 492                 /* Root PDO in ReactOS does not assign boot resources */
 493                 UNIMPLEMENTED;
 494                 while (TRUE);
 495             }
 496
 497             if (Descriptor)
 498             {
 499                 /* Root PDO in ReactOS does not assign boot resources */
 500                 UNIMPLEMENTED;
 501                 while (TRUE);
 502             }
 503             else
 504             {
 505                 /* Default configuration isn't the normal path on Windows */
 506                 if (PciBreakOnDefault)
 507                 {
 508                     /* If a second bus is found and there's still no data, crash */
 509                     #if 0 // ros bug?
 510                     KeBugCheckEx(PCI_BUS_DRIVER_INTERNAL,
 511                                  0xDEAD0010u,
 512                                  (ULONG_PTR)DeviceObject,
 513                                  0,
 514                                  0);
 515                     #else
 516                     DPRINT1("Windows would crash!\n");
 517                     #endif
 518                 }
 519
 520                 /* Warn that a default configuration will be used, and set bus 0 */
 521                 DPRINT1("PCI   Will use default configuration.\n");
 522                 PciBreakOnDefault = TRUE;
 523                 FdoExtension->BaseBus = 0;
 524             }
 525
 526             /* This is the root bus */
 527             FdoExtension->BusRootFdoExtension = FdoExtension;
 528         }
 529
 530         /* Get the HAL or ACPI Bus Handler Callbacks for Configuration Access */
 531         Status = PciGetConfigHandlers(FdoExtension);
 532         if (!NT_SUCCESS(Status)) break;
 533
 534         /* Initialize all the supported PCI arbiters */
 535         Status = PciInitializeArbiters(FdoExtension);
 536         if (!NT_SUCCESS(Status)) break;
 537
 538         /* This is a real FDO, insert it into the list */
 539         FdoExtension->Fake = FALSE;
 540         PciInsertEntryAtTail(&PciFdoExtensionListHead,
 541                              FdoExtension,
 542                              &PciGlobalLock);
 543
 544         /* Open the device registry key so that we can query the errata flags */
 545         IoOpenDeviceRegistryKey(DeviceObject,
 546                                 PLUGPLAY_REGKEY_DEVICE,
 547                                 KEY_ALL_ACCESS,
 548                                 &KeyHandle),
 549
 550         /* Open the value that contains errata flags for this bus instance */
 551         RtlInitUnicodeString(&ValueName, L"HackFlags");
 552         Status = ZwQueryValueKey(KeyHandle,
 553                                  &ValueName,
 554                                  KeyValuePartialInformation,
 555                                  ValueInfo,
 556                                  sizeof(Buffer),
 557                                  &ResultLength);
 558         ZwClose(KeyHandle);
 559         if (NT_SUCCESS(Status))
 560         {
 561             /* Make sure the data is of expected type and size */
 562             if ((ValueInfo->Type == REG_DWORD) &&
 563                 (ValueInfo->DataLength == sizeof(ULONG)))
 564             {
 565                 /* Read the flags for this bus */
 566                 FdoExtension->BusHackFlags = *(PULONG)&ValueInfo->Data;
 567             }
 568         }
 569
 570         /* Query ACPI for PCI HotPlug Support */
 571         PciGetHotPlugParameters(FdoExtension);
 572
 573         /* The Bus FDO is now initialized */
 574         DeviceObject->Flags &= ~DO_DEVICE_INITIALIZING;
 575         DPRINT1("PCI Root FDO Added: %p %p\n", DeviceObject, FdoExtension);
 576         return STATUS_SUCCESS;
 577     } while (FALSE);
 578
 579     /* This is the failure path */
 580     ASSERT(!NT_SUCCESS(Status));
 581     if (AttachedTo) IoDetachDevice(AttachedTo);
 582     if (DeviceObject) IoDeleteDevice(DeviceObject);
 583     return Status;
 584 }
 585
 586 /* EOF */