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1 /** @file
2 The PCI Root Bridge header file.
3 
4 Copyright (c) 2013-2015 Intel Corporation.
5 
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 
17 #ifndef _PCI_ROOT_BRIDGE_H_
18 #define _PCI_ROOT_BRIDGE_H_
19 
20 #include <PiDxe.h>
21 #include <IndustryStandard/Acpi.h>
22 #include <IndustryStandard/Pci.h>
23 #include <PciHostResource.h>
24 
25 //
26 // Driver Consumed Protocol Prototypes
27 //
28 #include <Protocol/Metronome.h>
29 #include <Protocol/CpuIo2.h>
30 #include <Protocol/DevicePath.h>
31 #include <Protocol/Runtime.h>
32 #include <Protocol/PciRootBridgeIo.h>
33 #include <Library/UefiLib.h>
34 #include <Library/DebugLib.h>
35 #include <Library/DevicePathLib.h>
36 #include <Library/BaseMemoryLib.h>
37 #include <Library/DxeServicesTableLib.h>
38 #include <Library/UefiBootServicesTableLib.h>
39 #include <Library/BaseLib.h>
40 
41 
42 //
43 // Define the region of memory used for DMA memory
44 //
45 #define DMA_MEMORY_TOP          0x0000000001FFFFFFULL
46 
47 //
48 // The number of PCI root bridges
49 //
50 #define ROOT_BRIDGE_COUNT  1
51 
52 //
53 // The default latency for controllers
54 //
55 #define DEFAULT_PCI_LATENCY 0x20
56 
57 //
58 // Define resource status constant
59 //
60 typedef struct {
61   EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_OPERATION Operation;
62   UINTN                                     NumberOfBytes;
63   UINTN                                     NumberOfPages;
64   EFI_PHYSICAL_ADDRESS                      HostAddress;
65   EFI_PHYSICAL_ADDRESS                      MappedHostAddress;
66 } MAP_INFO;
67 
68 typedef struct {
69   ACPI_HID_DEVICE_PATH      AcpiDevicePath;
70   EFI_DEVICE_PATH_PROTOCOL  EndDevicePath;
71 } EFI_PCI_ROOT_BRIDGE_DEVICE_PATH;
72 
73 #define PCI_ROOT_BRIDGE_SIGNATURE SIGNATURE_32 ('e', '2', 'p', 'b')
74 
75 typedef struct {
76   UINT32                            Signature;
77   EFI_LIST_ENTRY                    Link;
78   EFI_HANDLE                        Handle;
79   UINT64                            RootBridgeAllocAttrib;
80   UINT64                            Attributes;
81   UINT64                            Supports;
82   PCI_RES_NODE                      ResAllocNode[6];
83   PCI_ROOT_BRIDGE_RESOURCE_APERTURE Aperture;
84   EFI_LOCK                          PciLock;
85   UINTN                             PciAddress;
86   UINTN                             PciData;
87   UINT32                            HecBase;
88   UINT32                            HecLen;
89   UINTN                             BusScanCount;
90   BOOLEAN                           BusNumberAssigned;
91   VOID                              *ConfigBuffer;
92   EFI_DEVICE_PATH_PROTOCOL          *DevicePath;
93   EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL   Io;
94 } PCI_ROOT_BRIDGE_INSTANCE;
95 
96 //
97 // Driver Instance Data Macros
98 //
99 #define DRIVER_INSTANCE_FROM_PCI_ROOT_BRIDGE_IO_THIS(a) CR (a, PCI_ROOT_BRIDGE_INSTANCE, Io, PCI_ROOT_BRIDGE_SIGNATURE)
100 
101 #define DRIVER_INSTANCE_FROM_LIST_ENTRY(a)              CR (a, PCI_ROOT_BRIDGE_INSTANCE, Link, PCI_ROOT_BRIDGE_SIGNATURE)
102 
103 EFI_STATUS
104 SimpleIioRootBridgeConstructor (
105   IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL    *Protocol,
106   IN EFI_HANDLE                         HostBridgeHandle,
107   IN PCI_ROOT_BRIDGE_RESOURCE_APERTURE  *ResAppeture,
108   IN UINT64                             AllocAttributes
109   )
110 /*++
111 
112 Routine Description:
113 
114   Construct the Pci Root Bridge Io protocol.
115 
116 Arguments:
117 
118   Protocol          -  Protocol to initialize.
119   HostBridgeHandle  -  Handle to the HostBridge.
120   ResAppeture       -  Resource apperture of the root bridge.
121   AllocAttributes   -  Attribute of resouce allocated.
122 
123 Returns:
124 
125   EFI_SUCCESS  -  Success.
126   Others       -  Fail.
127 
128 --*/
129 ;
130 
131 //
132 // Protocol Member Function Prototypes
133 //
134 EFI_STATUS
135 EFIAPI
136 RootBridgeIoPollMem (
137   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
138   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
139   IN  UINT64                                 Address,
140   IN  UINT64                                 Mask,
141   IN  UINT64                                 Value,
142   IN  UINT64                                 Delay,
143   OUT UINT64                                 *Result
144   )
145 /*++
146 
147 Routine Description:
148 
149   Poll an address in memory mapped space until an exit condition is met
150   or a timeout occurs.
151 
152 Arguments:
153 
154   This     -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
155   Width    -  Width of the memory operation.
156   Address  -  The base address of the memory operation.
157   Mask     -  Mask used for polling criteria.
158   Value    -  Comparison value used for polling exit criteria.
159   Delay    -  Number of 100ns units to poll.
160   Result   -  Pointer to the last value read from memory location.
161 
162 Returns:
163 
164   EFI_SUCCESS            -  Success.
165   EFI_INVALID_PARAMETER  -  Invalid parameter found.
166   EFI_TIMEOUT            -  Delay expired before a match occurred.
167   EFI_OUT_OF_RESOURCES   -  Fail due to lack of resources.
168 
169 --*/
170 ;
171 
172 EFI_STATUS
173 EFIAPI
174 RootBridgeIoPollIo (
175   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
176   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
177   IN  UINT64                                 Address,
178   IN  UINT64                                 Mask,
179   IN  UINT64                                 Value,
180   IN  UINT64                                 Delay,
181   OUT UINT64                                 *Result
182   )
183 /*++
184 
185 Routine Description:
186 
187   Poll an address in I/O space until an exit condition is met
188   or a timeout occurs.
189 
190 Arguments:
191 
192   This     -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
193   Width    -  Width of I/O operation.
194   Address  -  The base address of the I/O operation.
195   Mask     -  Mask used for polling criteria.
196   Value    -  Comparison value used for polling exit criteria.
197   Delay    -  Number of 100ns units to poll.
198   Result   -  Pointer to the last value read from memory location.
199 
200 Returns:
201 
202   EFI_SUCCESS            -  Success.
203   EFI_INVALID_PARAMETER  -  Invalid parameter found.
204   EFI_TIMEOUT            -  Delay expired before a match occurred.
205   EFI_OUT_OF_RESOURCES   -  Fail due to lack of resources.
206 
207 --*/
208 ;
209 
210 EFI_STATUS
211 EFIAPI
212 RootBridgeIoMemRead (
213   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
214   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
215   IN     UINT64                                 Address,
216   IN     UINTN                                  Count,
217   IN OUT VOID                                   *Buffer
218   )
219 /*++
220 
221 Routine Description:
222 
223   Allow read from memory mapped I/O space.
224 
225 Arguments:
226 
227   This     -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
228   Width    -  The width of memory operation.
229   Address  -  Base address of the memory operation.
230   Count    -  Number of memory opeartion to perform.
231   Buffer   -  The destination buffer to store data.
232 
233 Returns:
234 
235   EFI_SUCCESS            -  Success.
236   EFI_INVALID_PARAMETER  -  Invalid parameter found.
237   EFI_OUT_OF_RESOURCES   -  Fail due to lack of resources.
238 
239 --*/
240 ;
241 
242 EFI_STATUS
243 EFIAPI
244 RootBridgeIoMemWrite (
245   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
246   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
247   IN     UINT64                                 Address,
248   IN     UINTN                                  Count,
249   IN OUT VOID                                   *Buffer
250   )
251 /*++
252 
253 Routine Description:
254 
255   Allow write to memory mapped I/O space.
256 
257 Arguments:
258 
259   This     -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
260   Width    -  The width of memory operation.
261   Address  -  Base address of the memory operation.
262   Count    -  Number of memory opeartion to perform.
263   Buffer   -  The source buffer to write data from.
264 
265 Returns:
266 
267   EFI_SUCCESS            -  Success.
268   EFI_INVALID_PARAMETER  -  Invalid parameter found.
269   EFI_OUT_OF_RESOURCES   -  Fail due to lack of resources.
270 
271 --*/
272 ;
273 
274 EFI_STATUS
275 EFIAPI
276 RootBridgeIoIoRead (
277   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
278   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
279   IN     UINT64                                 UserAddress,
280   IN     UINTN                                  Count,
281   IN OUT VOID                                   *UserBuffer
282   )
283 /*++
284 
285 Routine Description:
286 
287   Enable a PCI driver to read PCI controller registers in the
288   PCI root bridge I/O space.
289 
290 Arguments:
291 
292   This         -  A pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
293   Width        -  Signifies the width of the memory operation.
294   UserAddress  -  The base address of the I/O operation.
295   Count        -  The number of I/O operations to perform.
296   UserBuffer   -  The destination buffer to store the results.
297 
298 Returns:
299 
300   EFI_SUCCESS            -  The data was read from the PCI root bridge.
301   EFI_INVALID_PARAMETER  -  Invalid parameters found.
302   EFI_OUT_OF_RESOURCES   -  The request could not be completed due to a lack of
303                             resources.
304 --*/
305 ;
306 
307 EFI_STATUS
308 EFIAPI
309 RootBridgeIoIoWrite (
310   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
311   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
312   IN     UINT64                                 UserAddress,
313   IN     UINTN                                  Count,
314   IN OUT VOID                                   *UserBuffer
315   )
316 /*++
317 
318 Routine Description:
319 
320   Enable a PCI driver to write to PCI controller registers in the
321   PCI root bridge I/O space.
322 
323 Arguments:
324 
325   This         -  A pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
326   Width        -  Signifies the width of the memory operation.
327   UserAddress  -  The base address of the I/O operation.
328   Count        -  The number of I/O operations to perform.
329   UserBuffer   -  The source buffer to write data from.
330 
331 Returns:
332 
333   EFI_SUCCESS            -  The data was written to the PCI root bridge.
334   EFI_INVALID_PARAMETER  -  Invalid parameters found.
335   EFI_OUT_OF_RESOURCES   -  The request could not be completed due to a lack of
336                             resources.
337 --*/
338 ;
339 
340 EFI_STATUS
341 EFIAPI
342 RootBridgeIoCopyMem (
343   IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL          *This,
344   IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH    Width,
345   IN UINT64                                   DestAddress,
346   IN UINT64                                   SrcAddress,
347   IN UINTN                                    Count
348   )
349 /*++
350 
351 Routine Description:
352 
353   Copy one region of PCI root bridge memory space to be copied to
354   another region of PCI root bridge memory space.
355 
356 Arguments:
357 
358   This         -  A pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
359   Width        -  Signifies the width of the memory operation.
360   DestAddress  -  Destination address of the memory operation.
361   SrcAddress   -  Source address of the memory operation.
362   Count        -  Number of memory operations to perform.
363 
364 Returns:
365 
366   EFI_SUCCESS            -  The data was copied successfully.
367   EFI_INVALID_PARAMETER  -  Invalid parameters found.
368   EFI_OUT_OF_RESOURCES   -  The request could not be completed due to a lack of
369                             resources.
370 --*/
371 ;
372 
373 EFI_STATUS
374 EFIAPI
375 RootBridgeIoPciRead (
376   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
377   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
378   IN     UINT64                                 Address,
379   IN     UINTN                                  Count,
380   IN OUT VOID                                   *Buffer
381   )
382 /*++
383 
384 Routine Description:
385 
386   Allows read from PCI configuration space.
387 
388 Arguments:
389 
390   This     -  A pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
391   Width    -  Signifies the width of the memory operation.
392   Address  -  The address within the PCI configuration space
393               for the PCI controller.
394   Count    -  The number of PCI configuration operations
395               to perform.
396   Buffer   -  The destination buffer to store the results.
397 
398 Returns:
399 
400   EFI_SUCCESS            -  The data was read from the PCI root bridge.
401   EFI_INVALID_PARAMETER  -  Invalid parameters found.
402   EFI_OUT_OF_RESOURCES   -  The request could not be completed due to a lack of
403                             resources.
404 --*/
405 ;
406 
407 EFI_STATUS
408 EFIAPI
409 RootBridgeIoPciWrite (
410   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
411   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
412   IN     UINT64                                 Address,
413   IN     UINTN                                  Count,
414   IN OUT VOID                                   *Buffer
415   )
416 /*++
417 
418 Routine Description:
419 
420   Allows write to PCI configuration space.
421 
422 Arguments:
423 
424   This     -  A pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
425   Width    -  Signifies the width of the memory operation.
426   Address  -  The address within the PCI configuration space
427               for the PCI controller.
428   Count    -  The number of PCI configuration operations
429               to perform.
430   Buffer   -  The source buffer to get the results.
431 
432 Returns:
433 
434   EFI_SUCCESS            -  The data was written to the PCI root bridge.
435   EFI_INVALID_PARAMETER  -  Invalid parameters found.
436   EFI_OUT_OF_RESOURCES   -  The request could not be completed due to a lack of
437                             resources.
438 --*/
439 ;
440 
441 EFI_STATUS
442 EFIAPI
443 RootBridgeIoMap (
444   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL            *This,
445   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_OPERATION  Operation,
446   IN     VOID                                       *HostAddress,
447   IN OUT UINTN                                      *NumberOfBytes,
448   OUT    EFI_PHYSICAL_ADDRESS                       *DeviceAddress,
449   OUT    VOID                                       **Mapping
450   )
451 /*++
452 
453 Routine Description:
454 
455   Provides the PCI controller-specific address needed to access
456   system memory for DMA.
457 
458 Arguments:
459 
460   This           -  A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.
461   Operation      -  Indicate if the bus master is going to read or write
462                     to system memory.
463   HostAddress    -  The system memory address to map on the PCI controller.
464   NumberOfBytes  -  On input the number of bytes to map.
465                     On output the number of bytes that were mapped.
466   DeviceAddress  -  The resulting map address for the bus master PCI
467                     controller to use to access the system memory's HostAddress.
468   Mapping        -  The value to pass to Unmap() when the bus master DMA
469                     operation is complete.
470 
471 Returns:
472 
473   EFI_SUCCESS            -  Success.
474   EFI_INVALID_PARAMETER  -  Invalid parameters found.
475   EFI_UNSUPPORTED        -  The HostAddress cannot be mapped as a common
476                             buffer.
477   EFI_DEVICE_ERROR       -  The System hardware could not map the requested
478                             address.
479   EFI_OUT_OF_RESOURCES   -  The request could not be completed due to
480                             lack of resources.
481 
482 --*/
483 ;
484 
485 EFI_STATUS
486 EFIAPI
487 RootBridgeIoUnmap (
488   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
489   IN  VOID                             *Mapping
490   )
491 /*++
492 
493 Routine Description:
494 
495   Completes the Map() operation and releases any corresponding resources.
496 
497 Arguments:
498 
499   This     -  Pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
500   Mapping  -  The value returned from Map() operation.
501 
502 Returns:
503 
504   EFI_SUCCESS            -  The range was unmapped successfully.
505   EFI_INVALID_PARAMETER  -  Mapping is not a value that was returned
506                             by Map operation.
507   EFI_DEVICE_ERROR       -  The data was not committed to the target
508                             system memory.
509 
510 --*/
511 ;
512 
513 EFI_STATUS
514 EFIAPI
515 RootBridgeIoAllocateBuffer (
516   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
517   IN  EFI_ALLOCATE_TYPE                Type,
518   IN  EFI_MEMORY_TYPE                  MemoryType,
519   IN  UINTN                            Pages,
520   OUT VOID                             **HostAddress,
521   IN  UINT64                           Attributes
522   )
523 /*++
524 
525 Routine Description:
526 
527   Allocates pages that are suitable for a common buffer mapping.
528 
529 Arguments:
530 
531   This         -  Pointer to EFI_ROOT_BRIDGE_IO_PROTOCOL instance.
532   Type         -  Not used and can be ignored.
533   MemoryType   -  Type of memory to allocate.
534   Pages        -  Number of pages to allocate.
535   HostAddress  -  Pointer to store the base system memory address
536                   of the allocated range.
537   Attributes   -  Requested bit mask of attributes of the allocated
538                   range.
539 
540 Returns:
541 
542   EFI_SUCCESS            -  The requested memory range were allocated.
543   EFI_INVALID_PARAMETER  -  Invalid parameter found.
544   EFI_UNSUPPORTED        -  Attributes is unsupported.
545 
546 --*/
547 ;
548 
549 EFI_STATUS
550 EFIAPI
551 RootBridgeIoFreeBuffer (
552   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
553   IN  UINTN                            Pages,
554   OUT VOID                             *HostAddress
555   )
556 /*++
557 
558 Routine Description:
559 
560   Free memory allocated in AllocateBuffer.
561 
562 Arguments:
563 
564   This         -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
565                   instance.
566   Pages        -  Number of pages to free.
567   HostAddress  -  The base system memory address of the
568                   allocated range.
569 
570 Returns:
571 
572   EFI_SUCCESS            -  Requested memory pages were freed.
573   EFI_INVALID_PARAMETER  -  Invalid parameter found.
574 
575 --*/
576 ;
577 
578 EFI_STATUS
579 EFIAPI
580 RootBridgeIoFlush (
581   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This
582   )
583 /*++
584 
585 Routine Description:
586 
587   Flushes all PCI posted write transactions from a PCI host
588   bridge to system memory.
589 
590 Arguments:
591 
592   This  - Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
593 
594 Returns:
595 
596   EFI_SUCCESS       -  PCI posted write transactions were flushed
597                        from PCI host bridge to system memory.
598   EFI_DEVICE_ERROR  -  Fail due to hardware error.
599 
600 --*/
601 ;
602 
603 EFI_STATUS
604 EFIAPI
605 RootBridgeIoGetAttributes (
606   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
607   OUT UINT64                           *Supported,
608   OUT UINT64                           *Attributes
609   )
610 /*++
611 
612 Routine Description:
613 
614   Get the attributes that a PCI root bridge supports and
615   the attributes the PCI root bridge is currently using.
616 
617 Arguments:
618 
619   This        -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
620                  instance.
621   Supports    -  A pointer to the mask of attributes that
622                  this PCI root bridge supports.
623   Attributes  -  A pointer to the mask of attributes that
624                  this PCI root bridge is currently using.
625 Returns:
626 
627   EFI_SUCCESS            -  Success.
628   EFI_INVALID_PARAMETER  -  Invalid parameter found.
629 
630 --*/
631 
632 // GC_TODO:    Supported - add argument and description to function comment
633 //
634 // GC_TODO:    Supported - add argument and description to function comment
635 //
636 // GC_TODO:    Supported - add argument and description to function comment
637 //
638 ;
639 
640 EFI_STATUS
641 EFIAPI
642 RootBridgeIoSetAttributes (
643   IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
644   IN     UINT64                           Attributes,
645   IN OUT UINT64                           *ResourceBase,
646   IN OUT UINT64                           *ResourceLength
647   )
648 /*++
649 
650 Routine Description:
651 
652   Sets the attributes for a resource range on a PCI root bridge.
653 
654 Arguments:
655 
656   This            -  Pointer to EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
657   Attributes      -  The mask of attributes to set.
658   ResourceBase    -  Pointer to the base address of the resource range
659                      to be modified by the attributes specified by Attributes.
660   ResourceLength  -  Pointer to the length of the resource range to be modified.
661 
662 Returns:
663   EFI_SUCCESS            -  Success.
664   EFI_INVALID_PARAMETER  -  Invalid parameter found.
665   EFI_OUT_OF_RESOURCES   -  Not enough resources to set the attributes upon.
666 
667 --*/
668 ;
669 
670 EFI_STATUS
671 EFIAPI
672 RootBridgeIoConfiguration (
673   IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
674   OUT VOID                             **Resources
675   )
676 /*++
677 
678 Routine Description:
679 
680   Retrieves the current resource settings of this PCI root bridge
681   in the form of a set of ACPI 2.0 resource descriptor.
682 
683 Arguments:
684 
685   This       -  Pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL instance.
686   Resources  -  Pointer to the ACPI 2.0 resource descriptor that
687                 describe the current configuration of this PCI root
688                 bridge.
689 
690 Returns:
691 
692   EFI_SUCCESS      -  Success.
693   EFI_UNSUPPORTED  -  Current configuration of the PCI root bridge
694                       could not be retrieved.
695 
696 --*/
697 ;
698 
699 #endif
700