EdkCompatibilityPkg/Compatibility/PciCfg2OnPciCfgThunk/PciCfg2OnPciCfgThunk.c - third_party/edk2 - Git at Google

 /** @file
  Module produces PciCfgPpi2 on top of PciCfgPpi. It also updates the
  PciCfg2Ppi pointer in the EFI_PEI_SERVICES upon a installation of
  EcpPeiPciCfgPpi.

  EcpPeiPciCfgPpi is installed by a framework module which
  produce PciCfgPpi originally. Such framework module is updated based on the
  following rule to install EcpPeiPciCfgPpi instead of updating the PciCfg pointer
  in the Framework PeiServicesTable:

  Search pattern:
  	   PeiServices->PciCfg = <*>;
  Replace pattern:
          {
            static EFI_PEI_PPI_DESCRIPTOR gEcpPeiPciCfgPpiList = {
              (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
              &gEcpPeiPciCfgPpiGuid,
              <*>
            };
            (**PeiServices).InstallPpi (PeiServices, gEcpPeiPciCfgPpiList);
          }

  In addition, the PeiServicesTable definition in PeiApi.h is updated to

  struct _EFI_PEI_SERVICES {
    EFI_TABLE_HEADER              Hdr;
    ...

    //
    // Pointer to PPI interface
    //
  if (PI_SPECIFICATION_VERSION < 0x00010000)

    PEI_CPU_IO_PPI                 *CpuIo;
    ECP_PEI_PCI_CFG_PPI        *PciCfg;  //Changed.
  else
  ...
  endif

  };

  This change enable the detection of code segment which invokes PeiServices->PciCfg->Modify.
  Such code causes a build break as ECP_PEI_PCI_CFG_PPI does not has "Modify" field.
  This should be updated to a call to PeiLibPciCfgModify as shown below:

  Search pattern:
  		*->Modify(<*>);
  Replace pattern:
  		PeiLibPciCfgModify(<*>);


 PIWG's PI specification replaces Inte's EFI Specification 1.10.
 EFI_PEI_PCI_CFG_PPI defined in Inte's EFI Specification 1.10 is replaced by
 EFI_PEI_PCI_CFG2_PPI in PI 1.0.
 This module produces PciCfgPpi on top of PciCfgPpi2. This module is used on platform when both of
 these two conditions are true:
 1) Framework module present that produces PCI CFG PPI  AND
 2) PI module that produces PCI CFG2 is not present

 Copyright (c) 2006 - 2008 Intel Corporation. <BR>
 All rights reserved. This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
 http://opensource.org/licenses/bsd-license.php

 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

 **/

 #include <PiPei.h>
 #include <Ppi/PciCfg.h>
 #include <Ppi/PciCfg2.h>
 #include <Ppi/EcpPciCfg.h>
 #include <Library/DebugLib.h>

 //
 // Function Prototypes
 //

 /**
   Notification service to be called when gEcpPeiPciCfgPpiGuid is installed.

   @param  PeiServices                 Indirect reference to the PEI Services Table.
   @param  NotifyDescriptor          Address of the notification descriptor data structure. Type
           EFI_PEI_NOTIFY_DESCRIPTOR is defined above.
   @param  Ppi                             Address of the PPI that was installed.

   @retval   EFI_STATUS                This function will install a PPI to PPI database. The status
                                                   code will be the code for (*PeiServices)->InstallPpi.

 **/
 EFI_STATUS
 EFIAPI
 EcpPciCfgPpiNotifyCallback (
   IN EFI_PEI_SERVICES              **PeiServices,
   IN EFI_PEI_NOTIFY_DESCRIPTOR     *NotifyDescriptor,
   IN VOID                          *Ppi
   );

 //
 // Function Prototypes
 //
 /**
   Reads from a given location in the PCI configuration space.

   @param  PeiServices                   An indirect pointer to the PEI Services Table published by the PEI Foundation.

   @param  This                              Pointer to local data for the interface.

   @param  Width                           The width of the access. Enumerated in bytes.
                                                    See EFI_PEI_PCI_CFG_PPI_WIDTH above.

   @param  Address                       The physical address of the access. The format of
                                                   the address is described by EFI_PEI_PCI_CFG_PPI_PCI_ADDRESS.

   @param  Buffer                           A pointer to the buffer of data..


   @retval EFI_SUCCESS                 The function completed successfully.

   @retval EFI_DEVICE_ERROR        There was a problem with the transaction.

   @retval EFI_DEVICE_NOT_READY  The device is not capable of supporting the operation at this
                                                     time.

 **/
 EFI_STATUS
 EFIAPI
 PciCfg2Read (
   IN CONST  EFI_PEI_SERVICES          **PeiServices,
   IN CONST  EFI_PEI_PCI_CFG2_PPI      *This,
   IN        EFI_PEI_PCI_CFG_PPI_WIDTH Width,
   IN        UINT64                    Address,
   IN OUT    VOID                      *Buffer
   );

 /**
   Write to a given location in the PCI configuration space.

   @param  PeiServices                   An indirect pointer to the PEI Services Table published by the PEI Foundation.

   @param  This                              Pointer to local data for the interface.

   @param  Width                            The width of the access. Enumerated in bytes.
                                                     See EFI_PEI_PCI_CFG_PPI_WIDTH above.

   @param  Address                         The physical address of the access. The format of
                                                     the address is described by EFI_PEI_PCI_CFG_PPI_PCI_ADDRESS.

   @param  Buffer                            A pointer to the buffer of data..


   @retval EFI_SUCCESS                   The function completed successfully.

   @retval EFI_DEVICE_ERROR          There was a problem with the transaction.

   @retval EFI_DEVICE_NOT_READY  The device is not capable of supporting the operation at this
                                                      time.

 **/
 EFI_STATUS
 EFIAPI
 PciCfg2Write (
   IN CONST  EFI_PEI_SERVICES          **PeiServices,
   IN CONST  EFI_PEI_PCI_CFG2_PPI      *This,
   IN        EFI_PEI_PCI_CFG_PPI_WIDTH Width,
   IN        UINT64                    Address,
   IN OUT    VOID                      *Buffer
   );

 /**
   PCI read-modify-write operation.

   @param  PeiServices                     An indirect pointer to the PEI Services Table
                                                       published by the PEI Foundation.

   @param  This                                Pointer to local data for the interface.

   @param  Width                             The width of the access. Enumerated in bytes. Type
                                                       EFI_PEI_PCI_CFG_PPI_WIDTH is defined in Read().

   @param  Address                           The physical address of the access.

   @param  SetBits                            Points to value to bitwise-OR with the read configuration value.
                                                       The size of the value is determined by Width.

   @param  ClearBits                         Points to the value to negate and bitwise-AND with the read configuration value.
                                                       The size of the value is determined by Width.


   @retval EFI_SUCCESS                   The function completed successfully.

   @retval EFI_DEVICE_ERROR          There was a problem with the transaction.

   @retval EFI_DEVICE_NOT_READY  The device is not capable of supporting
                                                     the operation at this time.

 **/
 EFI_STATUS
 EFIAPI
 PciCfg2Modify (
   IN CONST  EFI_PEI_SERVICES          **PeiServices,
   IN CONST  EFI_PEI_PCI_CFG2_PPI      *This,
   IN        EFI_PEI_PCI_CFG_PPI_WIDTH Width,
   IN        UINT64                    Address,
   IN        VOID                      *SetBits,
   IN        VOID                      *ClearBits
   );

 //
 // Module globals
 //
 EFI_PEI_NOTIFY_DESCRIPTOR mNotifyOnEcpPciCfgList = {
   (EFI_PEI_PPI_DESCRIPTOR_NOTIFY_CALLBACK | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
   &gEcpPeiPciCfgPpiGuid,
   EcpPciCfgPpiNotifyCallback
 };

 EFI_PEI_PCI_CFG2_PPI mPciCfg2Ppi = {
   PciCfg2Read,
   PciCfg2Write,
   PciCfg2Modify,
   0
 };

 EFI_PEI_PPI_DESCRIPTOR mPpiListPciCfg2 = {
   (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
   &gEfiPciCfg2PpiGuid,
   &mPciCfg2Ppi
 };


 /**

   Standard PEIM entry point.

   @param FfsHeadher   The FFS file header
   @param PeiServices   General purpose services available to every PEIM.


   @retval EFI_SUCCESS if the interface could be successfully
                                     installed

 --*/
 EFI_STATUS
 EFIAPI
 PeimInitializePciCfg2 (
   IN EFI_PEI_FILE_HANDLE     FfsHeader,
   IN CONST EFI_PEI_SERVICES  **PeiServices
   )
 {
   EFI_STATUS  Status;
   VOID        *Ppi;

   //
   // Make sure no other module has install the first instance of gEfiPciCfg2PpiGuid.
   //
   Status = (*PeiServices)->LocatePpi (PeiServices, &gEfiPciCfg2PpiGuid, 0, NULL, &Ppi);
   ASSERT (Status == EFI_NOT_FOUND);

   //
   // Register a notification for ECP PCI CFG PPI
   //
   Status = (*PeiServices)->NotifyPpi (PeiServices, &mNotifyOnEcpPciCfgList);
   ASSERT_EFI_ERROR (Status);
   return Status;
 }


 /**
   Notification service to be called when gEcpPeiPciCfgPpiGuid is installed.

   @param  PeiServices                 Indirect reference to the PEI Services Table.
   @param  NotifyDescriptor          Address of the notification descriptor data structure. Type
           EFI_PEI_NOTIFY_DESCRIPTOR is defined above.
   @param  Ppi                             Address of the PPI that was installed.

   @retval   EFI_STATUS                This function will install a PPI to PPI database. The status
                                                   code will be the code for (*PeiServices)->InstallPpi.

 **/
 EFI_STATUS
 EFIAPI
 EcpPciCfgPpiNotifyCallback (
   IN EFI_PEI_SERVICES              **PeiServices,
   IN EFI_PEI_NOTIFY_DESCRIPTOR     *NotifyDescriptor,
   IN VOID                          *Ppi
   )
 {
   //
   // When ECP PCI CFG PPI is installed, publish the PCI CFG2 PPI in the
   // PEI Services Table and the PPI database
   //
   (*PeiServices)->PciCfg = &mPciCfg2Ppi;
   return (*PeiServices)->InstallPpi ((CONST EFI_PEI_SERVICES **)PeiServices, &mPpiListPciCfg2);
 }

 /**
   Reads from a given location in the PCI configuration space.

   @param  PeiServices                   An indirect pointer to the PEI Services Table published by the PEI Foundation.

   @param  This                              Pointer to local data for the interface.

   @param  Width                           The width of the access. Enumerated in bytes.
                                                    See EFI_PEI_PCI_CFG_PPI_WIDTH above.

   @param  Address                       The physical address of the access. The format of
                                                   the address is described by EFI_PEI_PCI_CFG_PPI_PCI_ADDRESS.

   @param  Buffer                           A pointer to the buffer of data..


   @retval EFI_SUCCESS                 The function completed successfully.

   @retval EFI_DEVICE_ERROR        There was a problem with the transaction.

   @retval EFI_DEVICE_NOT_READY  The device is not capable of supporting the operation at this
                                                     time.

 **/
 EFI_STATUS
 EFIAPI
 PciCfg2Read (
   IN CONST  EFI_PEI_SERVICES          **PeiServices,
   IN CONST  EFI_PEI_PCI_CFG2_PPI      *This,
   IN        EFI_PEI_PCI_CFG_PPI_WIDTH Width,
   IN        UINT64                    Address,
   IN OUT    VOID                      *Buffer
   )
 {
   EFI_STATUS           Status;
   EFI_PEI_PCI_CFG_PPI  *PciCfg;

   Status = (*PeiServices)->LocatePpi (
              PeiServices,
              &gEcpPeiPciCfgPpiGuid,
              0,
              NULL,
              (VOID **)&PciCfg
              );
   ASSERT_EFI_ERROR (Status);

   return PciCfg->Read ((EFI_PEI_SERVICES **)PeiServices, PciCfg, Width, Address, Buffer);
 }

 /**
   Write to a given location in the PCI configuration space.

   @param  PeiServices                   An indirect pointer to the PEI Services Table published by the PEI Foundation.

   @param  This                              Pointer to local data for the interface.

   @param  Width                            The width of the access. Enumerated in bytes.
                                                     See EFI_PEI_PCI_CFG_PPI_WIDTH above.

   @param  Address                         The physical address of the access. The format of
                                                     the address is described by EFI_PEI_PCI_CFG_PPI_PCI_ADDRESS.

   @param  Buffer                            A pointer to the buffer of data..


   @retval EFI_SUCCESS                   The function completed successfully.

   @retval EFI_DEVICE_ERROR          There was a problem with the transaction.

   @retval EFI_DEVICE_NOT_READY  The device is not capable of supporting the operation at this
                                                      time.

 **/
 EFI_STATUS
 EFIAPI
 PciCfg2Write (
   IN CONST  EFI_PEI_SERVICES          **PeiServices,
   IN CONST  EFI_PEI_PCI_CFG2_PPI      *This,
   IN        EFI_PEI_PCI_CFG_PPI_WIDTH Width,
   IN        UINT64                    Address,
   IN OUT    VOID                      *Buffer
   )
 {
   EFI_STATUS           Status;
   EFI_PEI_PCI_CFG_PPI  *PciCfg;

   Status = (*PeiServices)->LocatePpi (
              PeiServices,
              &gEcpPeiPciCfgPpiGuid,
              0,
              NULL,
              (VOID **)&PciCfg
              );
   ASSERT_EFI_ERROR (Status);

   return PciCfg->Write ((EFI_PEI_SERVICES **)PeiServices, PciCfg, Width, Address, Buffer);
 }

 /**
   PCI read-modify-write operation.

   @param  PeiServices                     An indirect pointer to the PEI Services Table
                                                       published by the PEI Foundation.

   @param  This                                Pointer to local data for the interface.

   @param  Width                             The width of the access. Enumerated in bytes. Type
                                                       EFI_PEI_PCI_CFG_PPI_WIDTH is defined in Read().

   @param  Address                           The physical address of the access.

   @param  SetBits                            Points to value to bitwise-OR with the read configuration value.
                                                       The size of the value is determined by Width.

   @param  ClearBits                         Points to the value to negate and bitwise-AND with the read configuration value.
                                                       The size of the value is determined by Width.


   @retval EFI_SUCCESS                   The function completed successfully.

   @retval EFI_DEVICE_ERROR          There was a problem with the transaction.

   @retval EFI_DEVICE_NOT_READY  The device is not capable of supporting
                                                     the operation at this time.

 **/
 EFI_STATUS
 EFIAPI
 PciCfg2Modify (
   IN CONST  EFI_PEI_SERVICES          **PeiServices,
   IN CONST  EFI_PEI_PCI_CFG2_PPI      *This,
   IN        EFI_PEI_PCI_CFG_PPI_WIDTH Width,
   IN        UINT64                    Address,
   IN        VOID                      *SetBits,
   IN        VOID                      *ClearBits
   )
 {
   EFI_STATUS           Status;
   EFI_PEI_PCI_CFG_PPI  *PciCfg;

   Status = (*PeiServices)->LocatePpi (
              PeiServices,
              &gEfiPciCfgPpiInServiceTableGuid,
              0,
              NULL,
              (VOID **)&PciCfg
              );
   ASSERT_EFI_ERROR (Status);

   return PciCfg->Modify ((EFI_PEI_SERVICES **)PeiServices, PciCfg, Width, Address, *(UINTN *)SetBits, *(UINTN *)ClearBits);
 }
	/** @file
	Module produces PciCfgPpi2 on top of PciCfgPpi. It also updates the
	PciCfg2Ppi pointer in the EFI_PEI_SERVICES upon a installation of
	EcpPeiPciCfgPpi.

	EcpPeiPciCfgPpi is installed by a framework module which
	produce PciCfgPpi originally. Such framework module is updated based on the
	following rule to install EcpPeiPciCfgPpi instead of updating the PciCfg pointer
	in the Framework PeiServicesTable:

	Search pattern:
	PeiServices->PciCfg = <*>;
	Replace pattern:
	{
	static EFI_PEI_PPI_DESCRIPTOR gEcpPeiPciCfgPpiList = {
	(EFI_PEI_PPI_DESCRIPTOR_PPI \| EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
	&gEcpPeiPciCfgPpiGuid,
	<*>
	};
	(**PeiServices).InstallPpi (PeiServices, gEcpPeiPciCfgPpiList);
	}

	In addition, the PeiServicesTable definition in PeiApi.h is updated to

	struct _EFI_PEI_SERVICES {
	EFI_TABLE_HEADER Hdr;
	...

	//
	// Pointer to PPI interface
	//
	if (PI_SPECIFICATION_VERSION < 0x00010000)

	PEI_CPU_IO_PPI *CpuIo;
	ECP_PEI_PCI_CFG_PPI *PciCfg; //Changed.
	else
	...
	endif

	};

	This change enable the detection of code segment which invokes PeiServices->PciCfg->Modify.
	Such code causes a build break as ECP_PEI_PCI_CFG_PPI does not has "Modify" field.
	This should be updated to a call to PeiLibPciCfgModify as shown below:

	Search pattern:
	->Modify(<>);
	Replace pattern:
	PeiLibPciCfgModify(<*>);



	PIWG's PI specification replaces Inte's EFI Specification 1.10.
	EFI_PEI_PCI_CFG_PPI defined in Inte's EFI Specification 1.10 is replaced by
	EFI_PEI_PCI_CFG2_PPI in PI 1.0.
	This module produces PciCfgPpi on top of PciCfgPpi2. This module is used on platform when both of
	these two conditions are true:
	1) Framework module present that produces PCI CFG PPI AND
	2) PI module that produces PCI CFG2 is not present

	Copyright (c) 2006 - 2008 Intel Corporation. <BR>
	All rights reserved. This program and the accompanying materials
	are licensed and made available under the terms and conditions of the BSD License
	which accompanies this distribution. The full text of the license may be found at
	http://opensource.org/licenses/bsd-license.php

	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

	**/

	#include <PiPei.h>
	#include <Ppi/PciCfg.h>
	#include <Ppi/PciCfg2.h>
	#include <Ppi/EcpPciCfg.h>
	#include <Library/DebugLib.h>

	//
	// Function Prototypes
	//

	/**
	Notification service to be called when gEcpPeiPciCfgPpiGuid is installed.

	@param PeiServices Indirect reference to the PEI Services Table.
	@param NotifyDescriptor Address of the notification descriptor data structure. Type
	EFI_PEI_NOTIFY_DESCRIPTOR is defined above.
	@param Ppi Address of the PPI that was installed.

	@retval EFI_STATUS This function will install a PPI to PPI database. The status
	code will be the code for (*PeiServices)->InstallPpi.

	**/
	EFI_STATUS
	EFIAPI
	EcpPciCfgPpiNotifyCallback (
	IN EFI_PEI_SERVICES **PeiServices,
	IN EFI_PEI_NOTIFY_DESCRIPTOR *NotifyDescriptor,
	IN VOID *Ppi
	);

	//
	// Function Prototypes
	//
	/**
	Reads from a given location in the PCI configuration space.

	@param PeiServices An indirect pointer to the PEI Services Table published by the PEI Foundation.

	@param This Pointer to local data for the interface.

	@param Width The width of the access. Enumerated in bytes.
	See EFI_PEI_PCI_CFG_PPI_WIDTH above.

	@param Address The physical address of the access. The format of
	the address is described by EFI_PEI_PCI_CFG_PPI_PCI_ADDRESS.

	@param Buffer A pointer to the buffer of data..


	@retval EFI_SUCCESS The function completed successfully.

	@retval EFI_DEVICE_ERROR There was a problem with the transaction.

	@retval EFI_DEVICE_NOT_READY The device is not capable of supporting the operation at this
	time.

	**/
	EFI_STATUS
	EFIAPI
	PciCfg2Read (
	IN CONST EFI_PEI_SERVICES **PeiServices,
	IN CONST EFI_PEI_PCI_CFG2_PPI *This,
	IN EFI_PEI_PCI_CFG_PPI_WIDTH Width,
	IN UINT64 Address,
	IN OUT VOID *Buffer
	);

	/**
	Write to a given location in the PCI configuration space.

	@param PeiServices An indirect pointer to the PEI Services Table published by the PEI Foundation.

	@param This Pointer to local data for the interface.

	@param Width The width of the access. Enumerated in bytes.
	See EFI_PEI_PCI_CFG_PPI_WIDTH above.

	@param Address The physical address of the access. The format of
	the address is described by EFI_PEI_PCI_CFG_PPI_PCI_ADDRESS.

	@param Buffer A pointer to the buffer of data..


	@retval EFI_SUCCESS The function completed successfully.

	@retval EFI_DEVICE_ERROR There was a problem with the transaction.

	@retval EFI_DEVICE_NOT_READY The device is not capable of supporting the operation at this
	time.

	**/
	EFI_STATUS
	EFIAPI
	PciCfg2Write (
	IN CONST EFI_PEI_SERVICES **PeiServices,
	IN CONST EFI_PEI_PCI_CFG2_PPI *This,
	IN EFI_PEI_PCI_CFG_PPI_WIDTH Width,
	IN UINT64 Address,
	IN OUT VOID *Buffer
	);

	/**
	PCI read-modify-write operation.

	@param PeiServices An indirect pointer to the PEI Services Table
	published by the PEI Foundation.

	@param This Pointer to local data for the interface.

	@param Width The width of the access. Enumerated in bytes. Type
	EFI_PEI_PCI_CFG_PPI_WIDTH is defined in Read().

	@param Address The physical address of the access.

	@param SetBits Points to value to bitwise-OR with the read configuration value.
	The size of the value is determined by Width.

	@param ClearBits Points to the value to negate and bitwise-AND with the read configuration value.
	The size of the value is determined by Width.


	@retval EFI_SUCCESS The function completed successfully.

	@retval EFI_DEVICE_ERROR There was a problem with the transaction.

	@retval EFI_DEVICE_NOT_READY The device is not capable of supporting
	the operation at this time.

	**/
	EFI_STATUS
	EFIAPI
	PciCfg2Modify (
	IN CONST EFI_PEI_SERVICES **PeiServices,
	IN CONST EFI_PEI_PCI_CFG2_PPI *This,
	IN EFI_PEI_PCI_CFG_PPI_WIDTH Width,
	IN UINT64 Address,
	IN VOID *SetBits,
	IN VOID *ClearBits
	);

	//
	// Module globals
	//
	EFI_PEI_NOTIFY_DESCRIPTOR mNotifyOnEcpPciCfgList = {
	(EFI_PEI_PPI_DESCRIPTOR_NOTIFY_CALLBACK \| EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
	&gEcpPeiPciCfgPpiGuid,
	EcpPciCfgPpiNotifyCallback
	};

	EFI_PEI_PCI_CFG2_PPI mPciCfg2Ppi = {
	PciCfg2Read,
	PciCfg2Write,
	PciCfg2Modify,
	0
	};

	EFI_PEI_PPI_DESCRIPTOR mPpiListPciCfg2 = {
	(EFI_PEI_PPI_DESCRIPTOR_PPI \| EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
	&gEfiPciCfg2PpiGuid,
	&mPciCfg2Ppi
	};


	/**

	Standard PEIM entry point.

	@param FfsHeadher The FFS file header
	@param PeiServices General purpose services available to every PEIM.


	@retval EFI_SUCCESS if the interface could be successfully
	installed

	--*/
	EFI_STATUS
	EFIAPI
	PeimInitializePciCfg2 (
	IN EFI_PEI_FILE_HANDLE FfsHeader,
	IN CONST EFI_PEI_SERVICES **PeiServices
	)
	{
	EFI_STATUS Status;
	VOID *Ppi;

	//
	// Make sure no other module has install the first instance of gEfiPciCfg2PpiGuid.
	//
	Status = (*PeiServices)->LocatePpi (PeiServices, &gEfiPciCfg2PpiGuid, 0, NULL, &Ppi);
	ASSERT (Status == EFI_NOT_FOUND);

	//
	// Register a notification for ECP PCI CFG PPI
	//
	Status = (*PeiServices)->NotifyPpi (PeiServices, &mNotifyOnEcpPciCfgList);
	ASSERT_EFI_ERROR (Status);
	return Status;
	}


	/**
	Notification service to be called when gEcpPeiPciCfgPpiGuid is installed.

	@param PeiServices Indirect reference to the PEI Services Table.
	@param NotifyDescriptor Address of the notification descriptor data structure. Type
	EFI_PEI_NOTIFY_DESCRIPTOR is defined above.
	@param Ppi Address of the PPI that was installed.

	@retval EFI_STATUS This function will install a PPI to PPI database. The status
	code will be the code for (*PeiServices)->InstallPpi.

	**/
	EFI_STATUS
	EFIAPI
	EcpPciCfgPpiNotifyCallback (
	IN EFI_PEI_SERVICES **PeiServices,
	IN EFI_PEI_NOTIFY_DESCRIPTOR *NotifyDescriptor,
	IN VOID *Ppi
	)
	{
	//
	// When ECP PCI CFG PPI is installed, publish the PCI CFG2 PPI in the
	// PEI Services Table and the PPI database
	//
	(*PeiServices)->PciCfg = &mPciCfg2Ppi;
	return (PeiServices)->InstallPpi ((CONST EFI_PEI_SERVICES *)PeiServices, &mPpiListPciCfg2);
	}

	/**
	Reads from a given location in the PCI configuration space.

	@param PeiServices An indirect pointer to the PEI Services Table published by the PEI Foundation.

	@param This Pointer to local data for the interface.

	@param Width The width of the access. Enumerated in bytes.
	See EFI_PEI_PCI_CFG_PPI_WIDTH above.

	@param Address The physical address of the access. The format of
	the address is described by EFI_PEI_PCI_CFG_PPI_PCI_ADDRESS.

	@param Buffer A pointer to the buffer of data..


	@retval EFI_SUCCESS The function completed successfully.

	@retval EFI_DEVICE_ERROR There was a problem with the transaction.

	@retval EFI_DEVICE_NOT_READY The device is not capable of supporting the operation at this
	time.

	**/
	EFI_STATUS
	EFIAPI
	PciCfg2Read (
	IN CONST EFI_PEI_SERVICES **PeiServices,
	IN CONST EFI_PEI_PCI_CFG2_PPI *This,
	IN EFI_PEI_PCI_CFG_PPI_WIDTH Width,
	IN UINT64 Address,
	IN OUT VOID *Buffer
	)
	{
	EFI_STATUS Status;
	EFI_PEI_PCI_CFG_PPI *PciCfg;

	Status = (*PeiServices)->LocatePpi (
	PeiServices,
	&gEcpPeiPciCfgPpiGuid,
	0,
	NULL,
	(VOID **)&PciCfg
	);
	ASSERT_EFI_ERROR (Status);

	return PciCfg->Read ((EFI_PEI_SERVICES **)PeiServices, PciCfg, Width, Address, Buffer);
	}

	/**
	Write to a given location in the PCI configuration space.

	@param PeiServices An indirect pointer to the PEI Services Table published by the PEI Foundation.

	@param This Pointer to local data for the interface.

	@param Width The width of the access. Enumerated in bytes.
	See EFI_PEI_PCI_CFG_PPI_WIDTH above.

	@param Address The physical address of the access. The format of
	the address is described by EFI_PEI_PCI_CFG_PPI_PCI_ADDRESS.

	@param Buffer A pointer to the buffer of data..


	@retval EFI_SUCCESS The function completed successfully.

	@retval EFI_DEVICE_ERROR There was a problem with the transaction.

	@retval EFI_DEVICE_NOT_READY The device is not capable of supporting the operation at this
	time.

	**/
	EFI_STATUS
	EFIAPI
	PciCfg2Write (
	IN CONST EFI_PEI_SERVICES **PeiServices,
	IN CONST EFI_PEI_PCI_CFG2_PPI *This,
	IN EFI_PEI_PCI_CFG_PPI_WIDTH Width,
	IN UINT64 Address,
	IN OUT VOID *Buffer
	)
	{
	EFI_STATUS Status;
	EFI_PEI_PCI_CFG_PPI *PciCfg;

	Status = (*PeiServices)->LocatePpi (
	PeiServices,
	&gEcpPeiPciCfgPpiGuid,
	0,
	NULL,
	(VOID **)&PciCfg
	);
	ASSERT_EFI_ERROR (Status);

	return PciCfg->Write ((EFI_PEI_SERVICES **)PeiServices, PciCfg, Width, Address, Buffer);
	}

	/**
	PCI read-modify-write operation.

	@param PeiServices An indirect pointer to the PEI Services Table
	published by the PEI Foundation.

	@param This Pointer to local data for the interface.

	@param Width The width of the access. Enumerated in bytes. Type
	EFI_PEI_PCI_CFG_PPI_WIDTH is defined in Read().

	@param Address The physical address of the access.

	@param SetBits Points to value to bitwise-OR with the read configuration value.
	The size of the value is determined by Width.

	@param ClearBits Points to the value to negate and bitwise-AND with the read configuration value.
	The size of the value is determined by Width.


	@retval EFI_SUCCESS The function completed successfully.

	@retval EFI_DEVICE_ERROR There was a problem with the transaction.

	@retval EFI_DEVICE_NOT_READY The device is not capable of supporting
	the operation at this time.

	**/
	EFI_STATUS
	EFIAPI
	PciCfg2Modify (
	IN CONST EFI_PEI_SERVICES **PeiServices,
	IN CONST EFI_PEI_PCI_CFG2_PPI *This,
	IN EFI_PEI_PCI_CFG_PPI_WIDTH Width,
	IN UINT64 Address,
	IN VOID *SetBits,
	IN VOID *ClearBits
	)
	{
	EFI_STATUS Status;
	EFI_PEI_PCI_CFG_PPI *PciCfg;

	Status = (*PeiServices)->LocatePpi (
	PeiServices,
	&gEfiPciCfgPpiInServiceTableGuid,
	0,
	NULL,
	(VOID **)&PciCfg
	);
	ASSERT_EFI_ERROR (Status);

	return PciCfg->Modify ((EFI_PEI_SERVICES *)PeiServices, PciCfg, Width, Address, (UINTN )SetBits, (UINTN *)ClearBits);
	}