Re: [PATCH v3 15/28] Ampere: PCIe: Add PciSegmentLib library instance

["Ard Biesheuvel" <ardb@kernel.org>]

On Wed, 15 Sept 2021 at 18:00, Nhi Pham <nhi@os.amperecomputing.com> wrote:
>
> From: Vu Nguyen <vunguyen@os.amperecomputing.com>
>
> Provides wrapper calls to the Ac01PcieLib to handle the PCIe access.
> As Ampere Altra processor supports upto 16 PCIe Root Complexs, the
> target Root Complex will depend on the segment number parsed from the
> input address.
>
> Cc: Thang Nguyen <thang@os.amperecomputing.com>
> Cc: Chuong Tran <chuong@os.amperecomputing.com>
> Cc: Phong Vo <phong@os.amperecomputing.com>
> Cc: Leif Lindholm <leif@nuviainc.com>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
>
> Signed-off-by: Vu Nguyen <vunguyen@os.amperecomputing.com>

OK, this is not your fault, but this file is 99% boilerplate, with the
only platform specific piece being the calls to Ac01PcieConfigRW(),
right?

Leif, Michael, do you see any avenues here to improve this situation?
I don't think it should hold up this patch, but I have seen this
pattern a few times now (and I am responsible for at least one of
them)

For the change itself,

Acked-by: Ard Biesheuvel <ardb@kernel.org>

> ---
>  Silicon/Ampere/AmpereAltraPkg/AmpereAltraPkg.dsc.inc                        |    1 +
>  Silicon/Ampere/AmpereAltraPkg/Library/PciSegmentLibPci/PciSegmentLibPci.inf |   28 +
>  Silicon/Ampere/AmpereAltraPkg/Library/PciSegmentLibPci/PciSegmentLib.c      | 1189 ++++++++++++++++++++
>  3 files changed, 1218 insertions(+)
>
> diff --git a/Silicon/Ampere/AmpereAltraPkg/AmpereAltraPkg.dsc.inc b/Silicon/Ampere/AmpereAltraPkg/AmpereAltraPkg.dsc.inc
> index dc66b711aba8..dbcd1c9acaa2 100644
> --- a/Silicon/Ampere/AmpereAltraPkg/AmpereAltraPkg.dsc.inc
> +++ b/Silicon/Ampere/AmpereAltraPkg/AmpereAltraPkg.dsc.inc
> @@ -229,6 +229,7 @@ [LibraryClasses.common.DXE_DRIVER]
>    MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
>    FlashLib|Silicon/Ampere/AmpereAltraPkg/Library/FlashLib/FlashLib.inf
>    PciHostBridgeLib|Silicon/Ampere/AmpereAltraPkg/Library/PciHostBridgeLib/PciHostBridgeLib.inf
> +  PciSegmentLib|Silicon/Ampere/AmpereAltraPkg/Library/PciSegmentLibPci/PciSegmentLibPci.inf
>
>  [LibraryClasses.common.UEFI_APPLICATION]
>    UefiDecompressLib|MdePkg/Library/BaseUefiDecompressLib/BaseUefiTianoCustomDecompressLib.inf
> diff --git a/Silicon/Ampere/AmpereAltraPkg/Library/PciSegmentLibPci/PciSegmentLibPci.inf b/Silicon/Ampere/AmpereAltraPkg/Library/PciSegmentLibPci/PciSegmentLibPci.inf
> new file mode 100644
> index 000000000000..64897653e126
> --- /dev/null
> +++ b/Silicon/Ampere/AmpereAltraPkg/Library/PciSegmentLibPci/PciSegmentLibPci.inf
> @@ -0,0 +1,28 @@
> +## @file
> +#
> +# Copyright (c) 2021, Ampere Computing LLC. All rights reserved.<BR>
> +#
> +# SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> +  INF_VERSION                    = 0x0001001B
> +  BASE_NAME                      = PciSegmentLibPci
> +  FILE_GUID                      = 0AF5E76D-D31E-492B-AE69-A7B441FF62D9
> +  MODULE_TYPE                    = BASE
> +  VERSION_STRING                 = 1.0
> +  LIBRARY_CLASS                  = PciSegmentLib
> +
> +[Sources]
> +  PciSegmentLib.c
> +
> +[Packages]
> +  MdePkg/MdePkg.dec
> +  MdeModulePkg/MdeModulePkg.dec
> +  Silicon/Ampere/AmpereAltraPkg/AmpereAltraPkg.dec
> +
> +[LibraryClasses]
> +  Ac01PcieLib
> +  BaseLib
> +  DebugLib
> diff --git a/Silicon/Ampere/AmpereAltraPkg/Library/PciSegmentLibPci/PciSegmentLib.c b/Silicon/Ampere/AmpereAltraPkg/Library/PciSegmentLibPci/PciSegmentLib.c
> new file mode 100644
> index 000000000000..c893c56dfadf
> --- /dev/null
> +++ b/Silicon/Ampere/AmpereAltraPkg/Library/PciSegmentLibPci/PciSegmentLib.c
> @@ -0,0 +1,1189 @@
> +/** @file
> +
> +  Copyright (c) 2021, Ampere Computing LLC. All rights reserved.<BR>
> +
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#include <Uefi.h>
> +
> +#include <Library/Ac01PcieLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/DevicePathLib.h>
> +#include <Library/PciLib.h>
> +#include <Library/PciSegmentLib.h>
> +#include <Protocol/PciRootBridgeIo.h>
> +
> +#include <Ac01PcieCommon.h>
> +
> +/**
> +  Assert the validity of a PCI Segment address.
> +  A valid PCI Segment address should not contain 1's in bits 28..31 and 48..63
> +  and the segment should be 0.
> +
> +  @param  A The address to validate.
> +  @param  M Additional bits to assert to be zero.
> +
> +**/
> +#define ASSERT_INVALID_PCI_SEGMENT_ADDRESS(A,M) \
> +  ASSERT (((A) & (0xffff0000f0000000ULL | (M))) == 0)
> +
> +/**
> +  Convert the PCI Segment library address to PCI library address.
> +
> +  @param A The address to convert.
> +**/
> +#define PCI_SEGMENT_TO_PCI_ADDRESS(A) ((UINTN)(UINT32)A)
> +
> +/**
> +  Register a PCI device so PCI configuration registers may be accessed after
> +  SetVirtualAddressMap().
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +
> +  @param  Address The address that encodes the PCI Bus, Device, Function and
> +                  Register.
> +
> +  @retval RETURN_SUCCESS           The PCI device was registered for runtime access.
> +  @retval RETURN_UNSUPPORTED       An attempt was made to call this function
> +                                   after ExitBootServices().
> +  @retval RETURN_UNSUPPORTED       The resources required to access the PCI device
> +                                   at runtime could not be mapped.
> +  @retval RETURN_OUT_OF_RESOURCES  There are not enough resources available to
> +                                   complete the registration.
> +
> +**/
> +RETURN_STATUS
> +EFIAPI
> +PciSegmentRegisterForRuntimeAccess (
> +  IN UINTN  Address
> +  )
> +{
> +  ASSERT_INVALID_PCI_SEGMENT_ADDRESS (Address, 0);
> +  return PciRegisterForRuntimeAccess (PCI_SEGMENT_TO_PCI_ADDRESS (Address));
> +}
> +
> +/**
> +  Reads an 8-bit PCI configuration register.
> +
> +  Reads and returns the 8-bit PCI configuration register specified by Address.
> +  This function must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +
> +  @param  Address   Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +
> +  @return The 8-bit PCI configuration register specified by Address.
> +
> +**/
> +UINT8
> +EFIAPI
> +PciSegmentRead8 (
> +  IN UINT64                    Address
> +  )
> +{
> +  ASSERT_INVALID_PCI_SEGMENT_ADDRESS (Address, 0);
> +
> +  return PciRead8 (PCI_SEGMENT_TO_PCI_ADDRESS (Address));
> +}
> +
> +/**
> +  Writes an 8-bit PCI configuration register.
> +
> +  Writes the 8-bit PCI configuration register specified by Address with the value specified by Value.
> +  Value is returned.  This function must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +
> +  @param  Address     Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +  @param  Value       The value to write.
> +
> +  @return The value written to the PCI configuration register.
> +
> +**/
> +UINT8
> +EFIAPI
> +PciSegmentWrite8 (
> +  IN UINT64                    Address,
> +  IN UINT8                     Value
> +  )
> +{
> +  ASSERT_INVALID_PCI_SEGMENT_ADDRESS (Address, 0);
> +
> +  return PciWrite8 (PCI_SEGMENT_TO_PCI_ADDRESS (Address), Value);
> +}
> +
> +/**
> +  Performs a bitwise OR of an 8-bit PCI configuration register with an 8-bit value.
> +
> +  Reads the 8-bit PCI configuration register specified by Address,
> +  performs a bitwise OR between the read result and the value specified by OrData,
> +  and writes the result to the 8-bit PCI configuration register specified by Address.
> +  The value written to the PCI configuration register is returned.
> +  This function must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +
> +  @param  Address   Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +  @param  OrData    The value to OR with the PCI configuration register.
> +
> +  @return The value written to the PCI configuration register.
> +
> +**/
> +UINT8
> +EFIAPI
> +PciSegmentOr8 (
> +  IN UINT64                    Address,
> +  IN UINT8                     OrData
> +  )
> +{
> +  return PciWrite8 (PCI_SEGMENT_TO_PCI_ADDRESS (Address), (UINT8)(PciSegmentRead8 (Address) | OrData));
> +}
> +
> +/**
> +  Performs a bitwise AND of an 8-bit PCI configuration register with an 8-bit value.
> +
> +  Reads the 8-bit PCI configuration register specified by Address,
> +  performs a bitwise AND between the read result and the value specified by AndData,
> +  and writes the result to the 8-bit PCI configuration register specified by Address.
> +  The value written to the PCI configuration register is returned.
> +  This function must guarantee that all PCI read and write operations are serialized.
> +  If any reserved bits in Address are set, then ASSERT().
> +
> +  @param  Address   Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +  @param  AndData   The value to AND with the PCI configuration register.
> +
> +  @return The value written to the PCI configuration register.
> +
> +**/
> +UINT8
> +EFIAPI
> +PciSegmentAnd8 (
> +  IN UINT64                    Address,
> +  IN UINT8                     AndData
> +  )
> +{
> +  return PciSegmentWrite8 (Address, (UINT8)(PciSegmentRead8 (Address) & AndData));
> +}
> +
> +/**
> +  Performs a bitwise AND of an 8-bit PCI configuration register with an 8-bit value,
> +  followed a  bitwise OR with another 8-bit value.
> +
> +  Reads the 8-bit PCI configuration register specified by Address,
> +  performs a bitwise AND between the read result and the value specified by AndData,
> +  performs a bitwise OR between the result of the AND operation and the value specified by OrData,
> +  and writes the result to the 8-bit PCI configuration register specified by Address.
> +  The value written to the PCI configuration register is returned.
> +  This function must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +
> +  @param  Address   Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +  @param  AndData   The value to AND with the PCI configuration register.
> +  @param  OrData    The value to OR with the PCI configuration register.
> +
> +  @return The value written to the PCI configuration register.
> +
> +**/
> +UINT8
> +EFIAPI
> +PciSegmentAndThenOr8 (
> +  IN UINT64                    Address,
> +  IN UINT8                     AndData,
> +  IN UINT8                     OrData
> +  )
> +{
> +  return PciSegmentWrite8 (Address, (UINT8)((PciSegmentRead8 (Address) & AndData) | OrData));
> +}
> +
> +/**
> +  Reads a bit field of a PCI configuration register.
> +
> +  Reads the bit field in an 8-bit PCI configuration register. The bit field is
> +  specified by the StartBit and the EndBit. The value of the bit field is
> +  returned.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If StartBit is greater than 7, then ASSERT().
> +  If EndBit is greater than 7, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +
> +  @param  Address   PCI configuration register to read.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..7.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..7.
> +
> +  @return The value of the bit field read from the PCI configuration register.
> +
> +**/
> +UINT8
> +EFIAPI
> +PciSegmentBitFieldRead8 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit
> +  )
> +{
> +  return BitFieldRead8 (PciSegmentRead8 (Address), StartBit, EndBit);
> +}
> +
> +/**
> +  Writes a bit field to a PCI configuration register.
> +
> +  Writes Value to the bit field of the PCI configuration register. The bit
> +  field is specified by the StartBit and the EndBit. All other bits in the
> +  destination PCI configuration register are preserved. The new value of the
> +  8-bit register is returned.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If StartBit is greater than 7, then ASSERT().
> +  If EndBit is greater than 7, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +  If Value is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +
> +  @param  Address   PCI configuration register to write.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..7.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..7.
> +  @param  Value     New value of the bit field.
> +
> +  @return The value written back to the PCI configuration register.
> +
> +**/
> +UINT8
> +EFIAPI
> +PciSegmentBitFieldWrite8 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit,
> +  IN UINT8                     Value
> +  )
> +{
> +  return PciSegmentWrite8 (
> +           Address,
> +           BitFieldWrite8 (PciSegmentRead8 (Address), StartBit, EndBit, Value)
> +           );
> +}
> +
> +/**
> +  Reads a bit field in an 8-bit PCI configuration, performs a bitwise OR, and
> +  writes the result back to the bit field in the 8-bit port.
> +
> +  Reads the 8-bit PCI configuration register specified by Address, performs a
> +  bitwise OR between the read result and the value specified by
> +  OrData, and writes the result to the 8-bit PCI configuration register
> +  specified by Address. The value written to the PCI configuration register is
> +  returned. This function must guarantee that all PCI read and write operations
> +  are serialized. Extra left bits in OrData are stripped.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If StartBit is greater than 7, then ASSERT().
> +  If EndBit is greater than 7, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +  If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +
> +  @param  Address   PCI configuration register to write.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..7.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..7.
> +  @param  OrData    The value to OR with the PCI configuration register.
> +
> +  @return The value written back to the PCI configuration register.
> +
> +**/
> +UINT8
> +EFIAPI
> +PciSegmentBitFieldOr8 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit,
> +  IN UINT8                     OrData
> +  )
> +{
> +  return PciSegmentWrite8 (
> +           Address,
> +           BitFieldOr8 (PciSegmentRead8 (Address), StartBit, EndBit, OrData)
> +           );
> +}
> +
> +/**
> +  Reads a bit field in an 8-bit PCI configuration register, performs a bitwise
> +  AND, and writes the result back to the bit field in the 8-bit register.
> +
> +  Reads the 8-bit PCI configuration register specified by Address, performs a
> +  bitwise AND between the read result and the value specified by AndData, and
> +  writes the result to the 8-bit PCI configuration register specified by
> +  Address. The value written to the PCI configuration register is returned.
> +  This function must guarantee that all PCI read and write operations are
> +  serialized. Extra left bits in AndData are stripped.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If StartBit is greater than 7, then ASSERT().
> +  If EndBit is greater than 7, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +  If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +
> +  @param  Address   PCI configuration register to write.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..7.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..7.
> +  @param  AndData   The value to AND with the PCI configuration register.
> +
> +  @return The value written back to the PCI configuration register.
> +
> +**/
> +UINT8
> +EFIAPI
> +PciSegmentBitFieldAnd8 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit,
> +  IN UINT8                     AndData
> +  )
> +{
> +  return PciSegmentWrite8 (
> +           Address,
> +           BitFieldAnd8 (PciSegmentRead8 (Address), StartBit, EndBit, AndData)
> +           );
> +}
> +
> +/**
> +  Reads a bit field in an 8-bit port, performs a bitwise AND followed by a
> +  bitwise OR, and writes the result back to the bit field in the 8-bit port.
> +
> +  Reads the 8-bit PCI configuration register specified by Address, performs a
> +  bitwise AND followed by a bitwise OR between the read result and
> +  the value specified by AndData, and writes the result to the 8-bit PCI
> +  configuration register specified by Address. The value written to the PCI
> +  configuration register is returned. This function must guarantee that all PCI
> +  read and write operations are serialized. Extra left bits in both AndData and
> +  OrData are stripped.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If StartBit is greater than 7, then ASSERT().
> +  If EndBit is greater than 7, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +  If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +  If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +
> +  @param  Address   PCI configuration register to write.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..7.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..7.
> +  @param  AndData   The value to AND with the PCI configuration register.
> +  @param  OrData    The value to OR with the result of the AND operation.
> +
> +  @return The value written back to the PCI configuration register.
> +
> +**/
> +UINT8
> +EFIAPI
> +PciSegmentBitFieldAndThenOr8 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit,
> +  IN UINT8                     AndData,
> +  IN UINT8                     OrData
> +  )
> +{
> +  return PciSegmentWrite8 (
> +           Address,
> +           BitFieldAndThenOr8 (PciSegmentRead8 (Address), StartBit, EndBit, AndData, OrData)
> +           );
> +}
> +
> +/**
> +  Reads a 16-bit PCI configuration register.
> +
> +  Reads and returns the 16-bit PCI configuration register specified by Address.
> +  This function must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address   Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +
> +  @return The 16-bit PCI configuration register specified by Address.
> +
> +**/
> +UINT16
> +EFIAPI
> +PciSegmentRead16 (
> +  IN UINT64                    Address
> +  )
> +{
> +  ASSERT_INVALID_PCI_SEGMENT_ADDRESS (Address, 1);
> +
> +  return PciRead16 (PCI_SEGMENT_TO_PCI_ADDRESS (Address));
> +}
> +
> +/**
> +  Writes a 16-bit PCI configuration register.
> +
> +  Writes the 16-bit PCI configuration register specified by Address with the value specified by Value.
> +  Value is returned.  This function must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address     Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +  @param  Value       The value to write.
> +
> +  @return The parameter of Value.
> +
> +**/
> +UINT16
> +EFIAPI
> +PciSegmentWrite16 (
> +  IN UINT64                    Address,
> +  IN UINT16                    Value
> +  )
> +{
> +  ASSERT_INVALID_PCI_SEGMENT_ADDRESS (Address, 1);
> +
> +  return PciWrite16 (PCI_SEGMENT_TO_PCI_ADDRESS (Address), Value);
> +}
> +
> +/**
> +  Performs a bitwise OR of a 16-bit PCI configuration register with
> +  a 16-bit value.
> +
> +  Reads the 16-bit PCI configuration register specified by Address, performs a
> +  bitwise OR between the read result and the value specified by OrData, and
> +  writes the result to the 16-bit PCI configuration register specified by Address.
> +  The value written to the PCI configuration register is returned. This function
> +  must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address Address that encodes the PCI Segment, Bus, Device, Function and
> +                  Register.
> +  @param  OrData  The value to OR with the PCI configuration register.
> +
> +  @return The value written back to the PCI configuration register.
> +
> +**/
> +UINT16
> +EFIAPI
> +PciSegmentOr16 (
> +  IN UINT64                    Address,
> +  IN UINT16                    OrData
> +  )
> +{
> +  return PciSegmentWrite16 (Address, (UINT16) (PciSegmentRead16 (Address) | OrData));
> +}
> +
> +/**
> +  Performs a bitwise AND of a 16-bit PCI configuration register with a 16-bit value.
> +
> +  Reads the 16-bit PCI configuration register specified by Address,
> +  performs a bitwise AND between the read result and the value specified by AndData,
> +  and writes the result to the 16-bit PCI configuration register specified by Address.
> +  The value written to the PCI configuration register is returned.
> +  This function must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address   Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +  @param  AndData   The value to AND with the PCI configuration register.
> +
> +  @return The value written to the PCI configuration register.
> +
> +**/
> +UINT16
> +EFIAPI
> +PciSegmentAnd16 (
> +  IN UINT64                    Address,
> +  IN UINT16                    AndData
> +  )
> +{
> +  return PciSegmentWrite16 (Address, (UINT16) (PciSegmentRead16 (Address) & AndData));
> +}
> +
> +/**
> +  Performs a bitwise AND of a 16-bit PCI configuration register with a 16-bit value,
> +  followed a  bitwise OR with another 16-bit value.
> +
> +  Reads the 16-bit PCI configuration register specified by Address,
> +  performs a bitwise AND between the read result and the value specified by AndData,
> +  performs a bitwise OR between the result of the AND operation and the value specified by OrData,
> +  and writes the result to the 16-bit PCI configuration register specified by Address.
> +  The value written to the PCI configuration register is returned.
> +  This function must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address   Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +  @param  AndData   The value to AND with the PCI configuration register.
> +  @param  OrData    The value to OR with the PCI configuration register.
> +
> +  @return The value written to the PCI configuration register.
> +
> +**/
> +UINT16
> +EFIAPI
> +PciSegmentAndThenOr16 (
> +  IN UINT64                    Address,
> +  IN UINT16                    AndData,
> +  IN UINT16                    OrData
> +  )
> +{
> +  return PciSegmentWrite16 (Address, (UINT16) ((PciSegmentRead16 (Address) & AndData) | OrData));
> +}
> +
> +/**
> +  Reads a bit field of a PCI configuration register.
> +
> +  Reads the bit field in a 16-bit PCI configuration register. The bit field is
> +  specified by the StartBit and the EndBit. The value of the bit field is
> +  returned.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +  If StartBit is greater than 15, then ASSERT().
> +  If EndBit is greater than 15, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +
> +  @param  Address   PCI configuration register to read.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..15.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..15.
> +
> +  @return The value of the bit field read from the PCI configuration register.
> +
> +**/
> +UINT16
> +EFIAPI
> +PciSegmentBitFieldRead16 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit
> +  )
> +{
> +  return BitFieldRead16 (PciSegmentRead16 (Address), StartBit, EndBit);
> +}
> +
> +/**
> +  Writes a bit field to a PCI configuration register.
> +
> +  Writes Value to the bit field of the PCI configuration register. The bit
> +  field is specified by the StartBit and the EndBit. All other bits in the
> +  destination PCI configuration register are preserved. The new value of the
> +  16-bit register is returned.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +  If StartBit is greater than 15, then ASSERT().
> +  If EndBit is greater than 15, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +  If Value is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +
> +  @param  Address   PCI configuration register to write.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..15.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..15.
> +  @param  Value     New value of the bit field.
> +
> +  @return The value written back to the PCI configuration register.
> +
> +**/
> +UINT16
> +EFIAPI
> +PciSegmentBitFieldWrite16 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit,
> +  IN UINT16                    Value
> +  )
> +{
> +  return PciSegmentWrite16 (
> +           Address,
> +           BitFieldWrite16 (PciSegmentRead16 (Address), StartBit, EndBit, Value)
> +           );
> +}
> +
> +/**
> +  Reads a bit field in a 16-bit PCI configuration, performs a bitwise OR, writes
> +  the result back to the bit field in the 16-bit port.
> +
> +  Reads the 16-bit PCI configuration register specified by Address, performs a
> +  bitwise OR between the read result and the value specified by
> +  OrData, and writes the result to the 16-bit PCI configuration register
> +  specified by Address. The value written to the PCI configuration register is
> +  returned. This function must guarantee that all PCI read and write operations
> +  are serialized. Extra left bits in OrData are stripped.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +  If StartBit is greater than 15, then ASSERT().
> +  If EndBit is greater than 15, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +  If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +
> +  @param  Address   PCI configuration register to write.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..15.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..15.
> +  @param  OrData    The value to OR with the PCI configuration register.
> +
> +  @return The value written back to the PCI configuration register.
> +
> +**/
> +UINT16
> +EFIAPI
> +PciSegmentBitFieldOr16 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit,
> +  IN UINT16                    OrData
> +  )
> +{
> +  return PciSegmentWrite16 (
> +           Address,
> +           BitFieldOr16 (PciSegmentRead16 (Address), StartBit, EndBit, OrData)
> +           );
> +}
> +
> +/**
> +  Reads a bit field in a 16-bit PCI configuration register, performs a bitwise
> +  AND, writes the result back to the bit field in the 16-bit register.
> +
> +  Reads the 16-bit PCI configuration register specified by Address, performs a
> +  bitwise AND between the read result and the value specified by AndData, and
> +  writes the result to the 16-bit PCI configuration register specified by
> +  Address. The value written to the PCI configuration register is returned.
> +  This function must guarantee that all PCI read and write operations are
> +  serialized. Extra left bits in AndData are stripped.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +  If StartBit is greater than 15, then ASSERT().
> +  If EndBit is greater than 15, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +  If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +
> +  @param  Address   Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..15.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..15.
> +  @param  AndData   The value to AND with the PCI configuration register.
> +
> +  @return The value written back to the PCI configuration register.
> +
> +**/
> +UINT16
> +EFIAPI
> +PciSegmentBitFieldAnd16 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit,
> +  IN UINT16                    AndData
> +  )
> +{
> +  return PciSegmentWrite16 (
> +           Address,
> +           BitFieldAnd16 (PciSegmentRead16 (Address), StartBit, EndBit, AndData)
> +           );
> +}
> +
> +/**
> +  Reads a bit field in a 16-bit port, performs a bitwise AND followed by a
> +  bitwise OR, and writes the result back to the bit field in the
> +  16-bit port.
> +
> +  Reads the 16-bit PCI configuration register specified by Address, performs a
> +  bitwise AND followed by a bitwise OR between the read result and
> +  the value specified by AndData, and writes the result to the 16-bit PCI
> +  configuration register specified by Address. The value written to the PCI
> +  configuration register is returned. This function must guarantee that all PCI
> +  read and write operations are serialized. Extra left bits in both AndData and
> +  OrData are stripped.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If StartBit is greater than 15, then ASSERT().
> +  If EndBit is greater than 15, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +  If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +  If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +
> +  @param  Address   PCI configuration register to write.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..15.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..15.
> +  @param  AndData   The value to AND with the PCI configuration register.
> +  @param  OrData    The value to OR with the result of the AND operation.
> +
> +  @return The value written back to the PCI configuration register.
> +
> +**/
> +UINT16
> +EFIAPI
> +PciSegmentBitFieldAndThenOr16 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit,
> +  IN UINT16                    AndData,
> +  IN UINT16                    OrData
> +  )
> +{
> +  return PciSegmentWrite16 (
> +           Address,
> +           BitFieldAndThenOr16 (PciSegmentRead16 (Address), StartBit, EndBit, AndData, OrData)
> +           );
> +}
> +
> +/**
> +  Reads a 32-bit PCI configuration register.
> +
> +  Reads and returns the 32-bit PCI configuration register specified by Address.
> +  This function must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address   Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +
> +  @return The 32-bit PCI configuration register specified by Address.
> +
> +**/
> +UINT32
> +EFIAPI
> +PciSegmentRead32 (
> +  IN UINT64                    Address
> +  )
> +{
> +  ASSERT_INVALID_PCI_SEGMENT_ADDRESS (Address, 3);
> +
> +  return PciRead32 (PCI_SEGMENT_TO_PCI_ADDRESS (Address));
> +}
> +
> +/**
> +  Writes a 32-bit PCI configuration register.
> +
> +  Writes the 32-bit PCI configuration register specified by Address with the value specified by Value.
> +  Value is returned.  This function must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address     Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +  @param  Value       The value to write.
> +
> +  @return The parameter of Value.
> +
> +**/
> +UINT32
> +EFIAPI
> +PciSegmentWrite32 (
> +  IN UINT64                    Address,
> +  IN UINT32                    Value
> +  )
> +{
> +  ASSERT_INVALID_PCI_SEGMENT_ADDRESS (Address, 3);
> +
> +  return PciWrite32 (PCI_SEGMENT_TO_PCI_ADDRESS (Address), Value);
> +}
> +
> +/**
> +  Performs a bitwise OR of a 32-bit PCI configuration register with a 32-bit value.
> +
> +  Reads the 32-bit PCI configuration register specified by Address,
> +  performs a bitwise OR between the read result and the value specified by OrData,
> +  and writes the result to the 32-bit PCI configuration register specified by Address.
> +  The value written to the PCI configuration register is returned.
> +  This function must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address   Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +  @param  OrData    The value to OR with the PCI configuration register.
> +
> +  @return The value written to the PCI configuration register.
> +
> +**/
> +UINT32
> +EFIAPI
> +PciSegmentOr32 (
> +  IN UINT64                    Address,
> +  IN UINT32                    OrData
> +  )
> +{
> +  return PciSegmentWrite32 (Address, PciSegmentRead32 (Address) | OrData);
> +}
> +
> +/**
> +  Performs a bitwise AND of a 32-bit PCI configuration register with a 32-bit value.
> +
> +  Reads the 32-bit PCI configuration register specified by Address,
> +  performs a bitwise AND between the read result and the value specified by AndData,
> +  and writes the result to the 32-bit PCI configuration register specified by Address.
> +  The value written to the PCI configuration register is returned.
> +  This function must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address   Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +  @param  AndData   The value to AND with the PCI configuration register.
> +
> +  @return The value written to the PCI configuration register.
> +
> +**/
> +UINT32
> +EFIAPI
> +PciSegmentAnd32 (
> +  IN UINT64                    Address,
> +  IN UINT32                    AndData
> +  )
> +{
> +  return PciSegmentWrite32 (Address, PciSegmentRead32 (Address) & AndData);
> +}
> +
> +/**
> +  Performs a bitwise AND of a 32-bit PCI configuration register with a 32-bit value,
> +  followed a  bitwise OR with another 32-bit value.
> +
> +  Reads the 32-bit PCI configuration register specified by Address,
> +  performs a bitwise AND between the read result and the value specified by AndData,
> +  performs a bitwise OR between the result of the AND operation and the value specified by OrData,
> +  and writes the result to the 32-bit PCI configuration register specified by Address.
> +  The value written to the PCI configuration register is returned.
> +  This function must guarantee that all PCI read and write operations are serialized.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address   Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +  @param  AndData   The value to AND with the PCI configuration register.
> +  @param  OrData    The value to OR with the PCI configuration register.
> +
> +  @return The value written to the PCI configuration register.
> +
> +**/
> +UINT32
> +EFIAPI
> +PciSegmentAndThenOr32 (
> +  IN UINT64                    Address,
> +  IN UINT32                    AndData,
> +  IN UINT32                    OrData
> +  )
> +{
> +  return PciSegmentWrite32 (Address, (PciSegmentRead32 (Address) & AndData) | OrData);
> +}
> +
> +/**
> +  Reads a bit field of a PCI configuration register.
> +
> +  Reads the bit field in a 32-bit PCI configuration register. The bit field is
> +  specified by the StartBit and the EndBit. The value of the bit field is
> +  returned.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +  If StartBit is greater than 31, then ASSERT().
> +  If EndBit is greater than 31, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +
> +  @param  Address   PCI configuration register to read.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..31.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..31.
> +
> +  @return The value of the bit field read from the PCI configuration register.
> +
> +**/
> +UINT32
> +EFIAPI
> +PciSegmentBitFieldRead32 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit
> +  )
> +{
> +  return BitFieldRead32 (PciSegmentRead32 (Address), StartBit, EndBit);
> +}
> +
> +/**
> +  Writes a bit field to a PCI configuration register.
> +
> +  Writes Value to the bit field of the PCI configuration register. The bit
> +  field is specified by the StartBit and the EndBit. All other bits in the
> +  destination PCI configuration register are preserved. The new value of the
> +  32-bit register is returned.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +  If StartBit is greater than 31, then ASSERT().
> +  If EndBit is greater than 31, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +  If Value is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +
> +  @param  Address   PCI configuration register to write.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..31.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..31.
> +  @param  Value     New value of the bit field.
> +
> +  @return The value written back to the PCI configuration register.
> +
> +**/
> +UINT32
> +EFIAPI
> +PciSegmentBitFieldWrite32 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit,
> +  IN UINT32                    Value
> +  )
> +{
> +  return PciSegmentWrite32 (
> +           Address,
> +           BitFieldWrite32 (PciSegmentRead32 (Address), StartBit, EndBit, Value)
> +           );
> +}
> +
> +/**
> +  Reads a bit field in a 32-bit PCI configuration, performs a bitwise OR, and
> +  writes the result back to the bit field in the 32-bit port.
> +
> +  Reads the 32-bit PCI configuration register specified by Address, performs a
> +  bitwise OR between the read result and the value specified by
> +  OrData, and writes the result to the 32-bit PCI configuration register
> +  specified by Address. The value written to the PCI configuration register is
> +  returned. This function must guarantee that all PCI read and write operations
> +  are serialized. Extra left bits in OrData are stripped.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If StartBit is greater than 31, then ASSERT().
> +  If EndBit is greater than 31, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +  If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +
> +  @param  Address   PCI configuration register to write.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..31.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..31.
> +  @param  OrData    The value to OR with the PCI configuration register.
> +
> +  @return The value written back to the PCI configuration register.
> +
> +**/
> +UINT32
> +EFIAPI
> +PciSegmentBitFieldOr32 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit,
> +  IN UINT32                    OrData
> +  )
> +{
> +  return PciSegmentWrite32 (
> +           Address,
> +           BitFieldOr32 (PciSegmentRead32 (Address), StartBit, EndBit, OrData)
> +           );
> +}
> +
> +/**
> +  Reads a bit field in a 32-bit PCI configuration register, performs a bitwise
> +  AND, and writes the result back to the bit field in the 32-bit register.
> +
> +
> +  Reads the 32-bit PCI configuration register specified by Address, performs a bitwise
> +  AND between the read result and the value specified by AndData, and writes the result
> +  to the 32-bit PCI configuration register specified by Address. The value written to
> +  the PCI configuration register is returned.  This function must guarantee that all PCI
> +  read and write operations are serialized.  Extra left bits in AndData are stripped.
> +  If any reserved bits in Address are set, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +  If StartBit is greater than 31, then ASSERT().
> +  If EndBit is greater than 31, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +  If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +
> +  @param  Address   Address that encodes the PCI Segment, Bus, Device, Function, and Register.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..31.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..31.
> +  @param  AndData   The value to AND with the PCI configuration register.
> +
> +  @return The value written back to the PCI configuration register.
> +
> +**/
> +UINT32
> +EFIAPI
> +PciSegmentBitFieldAnd32 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit,
> +  IN UINT32                    AndData
> +  )
> +{
> +  return PciSegmentWrite32 (
> +           Address,
> +           BitFieldAnd32 (PciSegmentRead32 (Address), StartBit, EndBit, AndData)
> +           );
> +}
> +
> +/**
> +  Reads a bit field in a 32-bit port, performs a bitwise AND followed by a
> +  bitwise OR, and writes the result back to the bit field in the
> +  32-bit port.
> +
> +  Reads the 32-bit PCI configuration register specified by Address, performs a
> +  bitwise AND followed by a bitwise OR between the read result and
> +  the value specified by AndData, and writes the result to the 32-bit PCI
> +  configuration register specified by Address. The value written to the PCI
> +  configuration register is returned. This function must guarantee that all PCI
> +  read and write operations are serialized. Extra left bits in both AndData and
> +  OrData are stripped.
> +
> +  If any reserved bits in Address are set, then ASSERT().
> +  If StartBit is greater than 31, then ASSERT().
> +  If EndBit is greater than 31, then ASSERT().
> +  If EndBit is less than StartBit, then ASSERT().
> +  If AndData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +  If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().
> +
> +  @param  Address   PCI configuration register to write.
> +  @param  StartBit  The ordinal of the least significant bit in the bit field.
> +                    Range 0..31.
> +  @param  EndBit    The ordinal of the most significant bit in the bit field.
> +                    Range 0..31.
> +  @param  AndData   The value to AND with the PCI configuration register.
> +  @param  OrData    The value to OR with the result of the AND operation.
> +
> +  @return The value written back to the PCI configuration register.
> +
> +**/
> +UINT32
> +EFIAPI
> +PciSegmentBitFieldAndThenOr32 (
> +  IN UINT64                    Address,
> +  IN UINTN                     StartBit,
> +  IN UINTN                     EndBit,
> +  IN UINT32                    AndData,
> +  IN UINT32                    OrData
> +  )
> +{
> +  return PciSegmentWrite32 (
> +           Address,
> +           BitFieldAndThenOr32 (PciSegmentRead32 (Address), StartBit, EndBit, AndData, OrData)
> +           );
> +}
> +
> +/**
> +  Reads a range of PCI configuration registers into a caller supplied buffer.
> +
> +  Reads the range of PCI configuration registers specified by StartAddress and
> +  Size into the buffer specified by Buffer. This function only allows the PCI
> +  configuration registers from a single PCI function to be read. Size is
> +  returned. When possible 32-bit PCI configuration read cycles are used to read
> +  from StartAddress to StartAddress + Size. Due to alignment restrictions, 8-bit
> +  and 16-bit PCI configuration read cycles may be used at the beginning and the
> +  end of the range.
> +
> +  If any reserved bits in StartAddress are set, then ASSERT().
> +  If ((StartAddress & 0xFFF) + Size) > 0x1000, then ASSERT().
> +  If Size > 0 and Buffer is NULL, then ASSERT().
> +
> +  @param  StartAddress  Starting address that encodes the PCI Segment, Bus, Device,
> +                        Function and Register.
> +  @param  Size          Size in bytes of the transfer.
> +  @param  Buffer        Pointer to a buffer receiving the data read.
> +
> +  @return Size
> +
> +**/
> +UINTN
> +EFIAPI
> +PciSegmentReadBuffer (
> +  IN  UINT64                   StartAddress,
> +  IN  UINTN                    Size,
> +  OUT VOID                     *Buffer
> +  )
> +{
> +  EFI_STATUS Status;
> +
> +  ASSERT_INVALID_PCI_SEGMENT_ADDRESS (StartAddress, 0);
> +  ASSERT (((StartAddress & 0xFFF) + Size) <= SIZE_4KB);
> +
> +  if (Size == 0) {
> +    return Size;
> +  }
> +
> +  ASSERT (Buffer != NULL);
> +
> +  Status = Ac01PcieConfigRW (NULL, StartAddress, FALSE, Size, Buffer);
> +  ASSERT_EFI_ERROR (Status);
> +
> +  return Size;
> +}
> +
> +/**
> +  Copies the data in a caller supplied buffer to a specified range of PCI
> +  configuration space.
> +
> +  Writes the range of PCI configuration registers specified by StartAddress and
> +  Size from the buffer specified by Buffer. This function only allows the PCI
> +  configuration registers from a single PCI function to be written. Size is
> +  returned. When possible 32-bit PCI configuration write cycles are used to
> +  write from StartAddress to StartAddress + Size. Due to alignment restrictions,
> +  8-bit and 16-bit PCI configuration write cycles may be used at the beginning
> +  and the end of the range.
> +
> +  If any reserved bits in StartAddress are set, then ASSERT().
> +  If ((StartAddress & 0xFFF) + Size) > 0x1000, then ASSERT().
> +  If Size > 0 and Buffer is NULL, then ASSERT().
> +
> +  @param  StartAddress  Starting address that encodes the PCI Segment, Bus, Device,
> +                        Function and Register.
> +  @param  Size          Size in bytes of the transfer.
> +  @param  Buffer        Pointer to a buffer containing the data to write.
> +
> +  @return The parameter of Size.
> +
> +**/
> +UINTN
> +EFIAPI
> +PciSegmentWriteBuffer (
> +  IN UINT64                    StartAddress,
> +  IN UINTN                     Size,
> +  IN VOID                      *Buffer
> +  )
> +{
> +  EFI_STATUS Status;
> +
> +  ASSERT_INVALID_PCI_SEGMENT_ADDRESS (StartAddress, 0);
> +  ASSERT (((StartAddress & 0xFFF) + Size) <= SIZE_4KB);
> +
> +  if (Size == 0) {
> +    return Size;
> +  }
> +
> +  ASSERT (Buffer != NULL);
> +
> +  Status = Ac01PcieConfigRW (NULL, StartAddress, TRUE, Size, Buffer);
> +  ASSERT_EFI_ERROR (Status);
> +
> +  return Size;
> +}
> --
> 2.17.1
>