MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridge.h

   1 /** @file
   2
   3   The PCI Root Bridge header file.
   4
   5 Copyright (c) 1999 - 2016, Intel Corporation. All rights reserved.<BR>
   6 This program and the accompanying materials
   7 are licensed and made available under the terms and conditions of the BSD License
   8 which accompanies this distribution.  The full text of the license may be found at
   9 http://opensource.org/licenses/bsd-license.php
  10
  11 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #ifndef _PCI_ROOT_BRIDGE_H_
  17 #define _PCI_ROOT_BRIDGE_H_
  18
  19 #include <PiDxe.h>
  20 #include <IndustryStandard/Acpi.h>
  21 #include <IndustryStandard/Pci.h>
  22
  23 //
  24 // Driver Consumed Protocol Prototypes
  25 //
  26 #include <Protocol/Metronome.h>
  27 #include <Protocol/CpuIo2.h>
  28 #include <Protocol/DevicePath.h>
  29 #include <Protocol/PciRootBridgeIo.h>
  30 #include <Library/DebugLib.h>
  31 #include <Library/DevicePathLib.h>
  32 #include <Library/BaseMemoryLib.h>
  33 #include <Library/DxeServicesTableLib.h>
  34 #include <Library/UefiBootServicesTableLib.h>
  35 #include <Library/BaseLib.h>
  36 #include <Library/PciSegmentLib.h>
  37 #include "PciHostResource.h"
  38
  39
  40 typedef enum {
  41   IoOperation,
  42   MemOperation,
  43   PciOperation
  44 } OPERATION_TYPE;
  45
  46 #define MAP_INFO_SIGNATURE  SIGNATURE_32 ('_', 'm', 'a', 'p')
  47 typedef struct {
  48   UINT32                                    Signature;
  49   LIST_ENTRY                                Link;
  50   EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_OPERATION Operation;
  51   UINTN                                     NumberOfBytes;
  52   UINTN                                     NumberOfPages;
  53   EFI_PHYSICAL_ADDRESS                      HostAddress;
  54   EFI_PHYSICAL_ADDRESS                      MappedHostAddress;
  55 } MAP_INFO;
  56 #define MAP_INFO_FROM_LINK(a) CR (a, MAP_INFO, Link, MAP_INFO_SIGNATURE)
  57
  58 #define PCI_ROOT_BRIDGE_SIGNATURE SIGNATURE_32 ('_', 'p', 'r', 'b')
  59
  60 typedef struct {
  61   UINT32                            Signature;
  62   LIST_ENTRY                        Link;
  63   EFI_HANDLE                        Handle;
  64   UINT64                            AllocationAttributes;
  65   UINT64                            Attributes;
  66   UINT64                            Supports;
  67   PCI_RES_NODE                      ResAllocNode[TypeMax];
  68   PCI_ROOT_BRIDGE_APERTURE          Bus;
  69   PCI_ROOT_BRIDGE_APERTURE          Io;
  70   PCI_ROOT_BRIDGE_APERTURE          Mem;
  71   PCI_ROOT_BRIDGE_APERTURE          PMem;
  72   PCI_ROOT_BRIDGE_APERTURE          MemAbove4G;
  73   PCI_ROOT_BRIDGE_APERTURE          PMemAbove4G;
  74   BOOLEAN                           DmaAbove4G;
  75   VOID                              *ConfigBuffer;
  76   EFI_DEVICE_PATH_PROTOCOL          *DevicePath;
  77   CHAR16                            *DevicePathStr;
  78   EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL   RootBridgeIo;
  79
  80   BOOLEAN                           ResourceSubmitted;
  81   LIST_ENTRY                        Maps;
  82 } PCI_ROOT_BRIDGE_INSTANCE;
  83
  84 #define ROOT_BRIDGE_FROM_THIS(a) CR (a, PCI_ROOT_BRIDGE_INSTANCE, RootBridgeIo, PCI_ROOT_BRIDGE_SIGNATURE)
  85
  86 #define ROOT_BRIDGE_FROM_LINK(a) CR (a, PCI_ROOT_BRIDGE_INSTANCE, Link, PCI_ROOT_BRIDGE_SIGNATURE)
  87
  88 /**
  89
  90   Construct the Pci Root Bridge Io protocol.
  91
  92   @param Protocol          -  Protocol to initialize.
  93   @param HostBridgeHandle  -  Handle to the HostBridge.
  94
  95   @retval EFI_SUCCESS  -  Success.
  96   @retval Others       -  Fail.
  97
  98 **/
  99 PCI_ROOT_BRIDGE_INSTANCE *
 100 CreateRootBridge (
 101   IN PCI_ROOT_BRIDGE       *Bridge,
 102   IN EFI_HANDLE            HostBridgeHandle
 103   );
 104
 105 //
 106 // Protocol Member Function Prototypes
 107 //
 108 /**
 109
 110   Poll an address in memory mapped space until an exit condition is met
 111   or a timeout occurs.
 112
 113   @param This     -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
 114   @param Width    -  Width of the memory operation.
 115   @param Address  -  The base address of the memory operation.
 116   @param Mask     -  Mask used for polling criteria.
 117   @param Value    -  Comparison value used for polling exit criteria.
 118   @param Delay    -  Number of 100ns units to poll.
 119   @param Result   -  Pointer to the last value read from memory location.
 120
 121   @retval EFI_SUCCESS            -  Success.
 122   @retval EFI_INVALID_PARAMETER  -  Invalid parameter found.
 123   @retval EFI_TIMEOUT            -  Delay expired before a match occurred.
 124   @retval EFI_OUT_OF_RESOURCES   -  Fail due to lack of resources.
 125
 126 **/
 127 EFI_STATUS
 128 EFIAPI
 129 RootBridgeIoPollMem (
 130   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
 131   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
 132   IN  UINT64                                 Address,
 133   IN  UINT64                                 Mask,
 134   IN  UINT64                                 Value,
 135   IN  UINT64                                 Delay,
 136   OUT UINT64                                 *Result
 137   )
 138 ;
 139
 140 /**
 141
 142   Poll an address in I/O space until an exit condition is met
 143   or a timeout occurs.
 144
 145   @param This     -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
 146   @param Width    -  Width of I/O operation.
 147   @param Address  -  The base address of the I/O operation.
 148   @param Mask     -  Mask used for polling criteria.
 149   @param Value    -  Comparison value used for polling exit criteria.
 150   @param Delay    -  Number of 100ns units to poll.
 151   @param Result   -  Pointer to the last value read from memory location.
 152
 153   @retval EFI_SUCCESS            -  Success.
 154   @retval EFI_INVALID_PARAMETER  -  Invalid parameter found.
 155   @retval EFI_TIMEOUT            -  Delay expired before a match occurred.
 156   @retval EFI_OUT_OF_RESOURCES   -  Fail due to lack of resources.
 157
 158 **/
 159 EFI_STATUS
 160 EFIAPI
 161 RootBridgeIoPollIo (
 162   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
 163   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
 164   IN  UINT64                                 Address,
 165   IN  UINT64                                 Mask,
 166   IN  UINT64                                 Value,
 167   IN  UINT64                                 Delay,
 168   OUT UINT64                                 *Result
 169   )
 170 ;
 171
 172 /**
 173
 174   Allow read from memory mapped I/O space.
 175
 176   @param This     -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
 177   @param Width    -  The width of memory operation.
 178   @param Address  -  Base address of the memory operation.
 179   @param Count    -  Number of memory opeartion to perform.
 180   @param Buffer   -  The destination buffer to store data.
 181
 182   @retval EFI_SUCCESS            -  Success.
 183   @retval EFI_INVALID_PARAMETER  -  Invalid parameter found.
 184   @retval EFI_OUT_OF_RESOURCES   -  Fail due to lack of resources.
 185
 186 **/
 187 EFI_STATUS
 188 EFIAPI
 189 RootBridgeIoMemRead (
 190   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
 191   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
 192   IN     UINT64                                 Address,
 193   IN     UINTN                                  Count,
 194   IN OUT VOID                                   *Buffer
 195   )
 196 ;
 197
 198 /**
 199
 200   Allow write to memory mapped I/O space.
 201
 202   @param This     -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
 203   @param Width    -  The width of memory operation.
 204   @param Address  -  Base address of the memory operation.
 205   @param Count    -  Number of memory opeartion to perform.
 206   @param Buffer   -  The source buffer to write data from.
 207
 208   @retval EFI_SUCCESS            -  Success.
 209   @retval EFI_INVALID_PARAMETER  -  Invalid parameter found.
 210   @retval EFI_OUT_OF_RESOURCES   -  Fail due to lack of resources.
 211
 212 **/
 213 EFI_STATUS
 214 EFIAPI
 215 RootBridgeIoMemWrite (
 216   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
 217   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
 218   IN     UINT64                                 Address,
 219   IN     UINTN                                  Count,
 220   IN OUT VOID                                   *Buffer
 221   )
 222 ;
 223
 224 /**
 225
 226   Enable a PCI driver to read PCI controller registers in the
 227   PCI root bridge I/O space.
 228
 229   @param This         -  A pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
 230   @param Width        -  Signifies the width of the memory operation.
 231   @param UserAddress  -  The base address of the I/O operation.
 232   @param Count        -  The number of I/O operations to perform.
 233   @param UserBuffer   -  The destination buffer to store the results.
 234
 235   @retval EFI_SUCCESS            -  The data was read from the PCI root bridge.
 236   @retval EFI_INVALID_PARAMETER  -  Invalid parameters found.
 237   @retval EFI_OUT_OF_RESOURCES   -  The request could not be completed due to a lack of
 238                             @retval resources.
 239 **/
 240 EFI_STATUS
 241 EFIAPI
 242 RootBridgeIoIoRead (
 243   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
 244   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
 245   IN     UINT64                                 UserAddress,
 246   IN     UINTN                                  Count,
 247   IN OUT VOID                                   *UserBuffer
 248   )
 249 ;
 250
 251 /**
 252
 253   Enable a PCI driver to write to PCI controller registers in the
 254   PCI root bridge I/O space.
 255
 256   @param This         -  A pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
 257   @param Width        -  Signifies the width of the memory operation.
 258   @param UserAddress  -  The base address of the I/O operation.
 259   @param Count        -  The number of I/O operations to perform.
 260   @param UserBuffer   -  The source buffer to write data from.
 261
 262   @retval EFI_SUCCESS            -  The data was written to the PCI root bridge.
 263   @retval EFI_INVALID_PARAMETER  -  Invalid parameters found.
 264   @retval EFI_OUT_OF_RESOURCES   -  The request could not be completed due to a lack of
 265                             @retval resources.
 266 **/
 267 EFI_STATUS
 268 EFIAPI
 269 RootBridgeIoIoWrite (
 270   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
 271   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
 272   IN     UINT64                                 UserAddress,
 273   IN     UINTN                                  Count,
 274   IN OUT VOID                                   *UserBuffer
 275   )
 276 ;
 277
 278 /**
 279
 280   Copy one region of PCI root bridge memory space to be copied to
 281   another region of PCI root bridge memory space.
 282
 283   @param This         -  A pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
 284   @param Width        -  Signifies the width of the memory operation.
 285   @param DestAddress  -  Destination address of the memory operation.
 286   @param SrcAddress   -  Source address of the memory operation.
 287   @param Count        -  Number of memory operations to perform.
 288
 289   @retval EFI_SUCCESS            -  The data was copied successfully.
 290   @retval EFI_INVALID_PARAMETER  -  Invalid parameters found.
 291   @retval EFI_OUT_OF_RESOURCES   -  The request could not be completed due to a lack of
 292                             @retval resources.
 293 **/
 294 EFI_STATUS
 295 EFIAPI
 296 RootBridgeIoCopyMem (
 297   IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL          *This,
 298   IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH    Width,
 299   IN UINT64                                   DestAddress,
 300   IN UINT64                                   SrcAddress,
 301   IN UINTN                                    Count
 302   )
 303 ;
 304
 305 /**
 306
 307   Allows read from PCI configuration space.
 308
 309   @param This     -  A pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
 310   @param Width    -  Signifies the width of the memory operation.
 311   @param Address  -  The address within the PCI configuration space
 312                      for the PCI controller.
 313   @param Count    -  The number of PCI configuration operations
 314                      to perform.
 315   @param Buffer   -  The destination buffer to store the results.
 316
 317   @retval EFI_SUCCESS            -  The data was read from the PCI root bridge.
 318   @retval EFI_INVALID_PARAMETER  -  Invalid parameters found.
 319   @retval EFI_OUT_OF_RESOURCES   -  The request could not be completed due to a lack of
 320                             @retval resources.
 321 **/
 322 EFI_STATUS
 323 EFIAPI
 324 RootBridgeIoPciRead (
 325   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
 326   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
 327   IN     UINT64                                 Address,
 328   IN     UINTN                                  Count,
 329   IN OUT VOID                                   *Buffer
 330   )
 331 ;
 332
 333 /**
 334
 335   Allows write to PCI configuration space.
 336
 337   @param This     -  A pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
 338   @param Width    -  Signifies the width of the memory operation.
 339   @param Address  -  The address within the PCI configuration space
 340                      for the PCI controller.
 341   @param Count    -  The number of PCI configuration operations
 342                      to perform.
 343   @param Buffer   -  The source buffer to get the results.
 344
 345   @retval EFI_SUCCESS            -  The data was written to the PCI root bridge.
 346   @retval EFI_INVALID_PARAMETER  -  Invalid parameters found.
 347   @retval EFI_OUT_OF_RESOURCES   -  The request could not be completed due to a lack of
 348                             @retval resources.
 349 **/
 350 EFI_STATUS
 351 EFIAPI
 352 RootBridgeIoPciWrite (
 353   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
 354   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
 355   IN     UINT64                                 Address,
 356   IN     UINTN                                  Count,
 357   IN OUT VOID                                   *Buffer
 358   )
 359 ;
 360
 361 /**
 362
 363   Provides the PCI controller-specific address needed to access
 364   system memory for DMA.
 365
 366   @param This           -  A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
 367   @param Operation      -  Indicate if the bus master is going to read or write
 368                            to system memory.
 369   @param HostAddress    -  The system memory address to map on the PCI controller.
 370   @param NumberOfBytes  -  On input the number of bytes to map.
 371                            On output the number of bytes that were mapped.
 372   @param DeviceAddress  -  The resulting map address for the bus master PCI
 373                            controller to use to access the system memory's HostAddress.
 374   @param Mapping        -  The value to pass to Unmap() when the bus master DMA
 375                            operation is complete.
 376
 377   @retval EFI_SUCCESS            -  Success.
 378   @retval EFI_INVALID_PARAMETER  -  Invalid parameters found.
 379   @retval EFI_UNSUPPORTED        -  The HostAddress cannot be mapped as a common
 380                             @retval buffer.
 381   @retval EFI_DEVICE_ERROR       -  The System hardware could not map the requested
 382                             @retval address.
 383   @retval EFI_OUT_OF_RESOURCES   -  The request could not be completed due to
 384                             @retval lack of resources.
 385
 386 **/
 387 EFI_STATUS
 388 EFIAPI
 389 RootBridgeIoMap (
 390   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL            *This,
 391   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_OPERATION  Operation,
 392   IN     VOID                                       *HostAddress,
 393   IN OUT UINTN                                      *NumberOfBytes,
 394   OUT    EFI_PHYSICAL_ADDRESS                       *DeviceAddress,
 395   OUT    VOID                                       **Mapping
 396   )
 397 ;
 398
 399 /**
 400
 401   Completes the Map() operation and releases any corresponding resources.
 402
 403   @param This     -  Pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
 404   Mapping  -  The value returned from Map() operation.
 405
 406   @retval EFI_SUCCESS            -  The range was unmapped successfully.
 407   @retval EFI_INVALID_PARAMETER  -  Mapping is not a value that was returned
 408                             @retval by Map operation.
 409   @retval EFI_DEVICE_ERROR       -  The data was not committed to the target
 410                             @retval system memory.
 411
 412 **/
 413 EFI_STATUS
 414 EFIAPI
 415 RootBridgeIoUnmap (
 416   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
 417   IN  VOID                             *Mapping
 418   )
 419 ;
 420
 421 /**
 422
 423   Allocates pages that are suitable for a common buffer mapping.
 424
 425   @param This         -  Pointer to EFI_ROOT_BRIDGE_IO_PROTOCOL instance.
 426   @param Type         -  Not used and can be ignored.
 427   @param MemoryType   -  Type of memory to allocate.
 428   @param Pages        -  Number of pages to allocate.
 429   @param HostAddress  -  Pointer to store the base system memory address
 430                          of the allocated range.
 431   @param Attributes   -  Requested bit mask of attributes of the allocated
 432                          range.
 433
 434   @retval EFI_SUCCESS            -  The requested memory range were allocated.
 435   @retval EFI_INVALID_PARAMETER  -  Invalid parameter found.
 436   @retval EFI_UNSUPPORTED        -  Attributes is unsupported.
 437
 438 **/
 439 EFI_STATUS
 440 EFIAPI
 441 RootBridgeIoAllocateBuffer (
 442   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
 443   IN  EFI_ALLOCATE_TYPE                Type,
 444   IN  EFI_MEMORY_TYPE                  MemoryType,
 445   IN  UINTN                            Pages,
 446   OUT VOID                             **HostAddress,
 447   IN  UINT64                           Attributes
 448   )
 449 ;
 450
 451 /**
 452
 453   Free memory allocated in AllocateBuffer.
 454
 455   @param This         -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
 456                          instance.
 457   @param Pages        -  Number of pages to free.
 458   @param HostAddress  -  The base system memory address of the
 459                          allocated range.
 460
 461   @retval EFI_SUCCESS            -  Requested memory pages were freed.
 462   @retval EFI_INVALID_PARAMETER  -  Invalid parameter found.
 463
 464 **/
 465 EFI_STATUS
 466 EFIAPI
 467 RootBridgeIoFreeBuffer (
 468   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
 469   IN  UINTN                            Pages,
 470   OUT VOID                             *HostAddress
 471   )
 472 ;
 473
 474 /**
 475
 476   Flushes all PCI posted write transactions from a PCI host
 477   bridge to system memory.
 478
 479   @param This  - Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
 480
 481   @retval EFI_SUCCESS       -  PCI posted write transactions were flushed
 482                        @retval from PCI host bridge to system memory.
 483   @retval EFI_DEVICE_ERROR  -  Fail due to hardware error.
 484
 485 **/
 486 EFI_STATUS
 487 EFIAPI
 488 RootBridgeIoFlush (
 489   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This
 490   )
 491 ;
 492
 493 /**
 494
 495   Get the attributes that a PCI root bridge supports and
 496   the attributes the PCI root bridge is currently using.
 497
 498   @param This        -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
 499                         instance.
 500   @param Supports    -  A pointer to the mask of attributes that
 501                         this PCI root bridge supports.
 502   @param Attributes  -  A pointer to the mask of attributes that
 503                         this PCI root bridge is currently using.
 504   @retval EFI_SUCCESS            -  Success.
 505   @retval EFI_INVALID_PARAMETER  -  Invalid parameter found.
 506
 507 **/
 508 EFI_STATUS
 509 EFIAPI
 510 RootBridgeIoGetAttributes (
 511   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
 512   OUT UINT64                           *Supported,
 513   OUT UINT64                           *Attributes
 514   )
 515 ;
 516
 517 /**
 518
 519   Sets the attributes for a resource range on a PCI root bridge.
 520
 521   @param This            -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
 522   @param Attributes      -  The mask of attributes to set.
 523   @param ResourceBase    -  Pointer to the base address of the resource range
 524                             to be modified by the attributes specified by Attributes.
 525   @param ResourceLength  -  Pointer to the length of the resource range to be modified.
 526
 527   @retval EFI_SUCCESS            -  Success.
 528   @retval EFI_INVALID_PARAMETER  -  Invalid parameter found.
 529   @retval EFI_OUT_OF_RESOURCES   -  Not enough resources to set the attributes upon.
 530
 531 **/
 532 EFI_STATUS
 533 EFIAPI
 534 RootBridgeIoSetAttributes (
 535   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
 536   IN     UINT64                           Attributes,
 537   IN OUT UINT64                           *ResourceBase,
 538   IN OUT UINT64                           *ResourceLength
 539   )
 540 ;
 541
 542 /**
 543
 544   Retrieves the current resource settings of this PCI root bridge
 545   in the form of a set of ACPI 2.0 resource descriptor.
 546
 547   @param This       -  Pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
 548   @param Resources  -  Pointer to the ACPI 2.0 resource descriptor that
 549                        describe the current configuration of this PCI root
 550                        bridge.
 551
 552   @retval EFI_SUCCESS      -  Success.
 553   @retval EFI_UNSUPPORTED  -  Current configuration of the PCI root bridge
 554                       @retval could not be retrieved.
 555
 556 **/
 557 EFI_STATUS
 558 EFIAPI
 559 RootBridgeIoConfiguration (
 560   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
 561   OUT VOID                             **Resources
 562   )
 563 ;
 564
 565
 566 extern EFI_METRONOME_ARCH_PROTOCOL *mMetronome;
 567 extern EFI_CPU_IO2_PROTOCOL         *mCpuIo;
 568 #endif