source: vbox/trunk/src/VBox/Devices/EFI/FirmwareNew/MdePkg/Library/SmmPciExpressLib/PciExpressLib.c@ 80721

/** @file
 Functions in this library instance make use of MMIO functions in IoLib to
 access memory mapped PCI configuration space.

 All assertions for I/O operations are handled in MMIO functions in the IoLib
 Library.

 Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.
 Portions copyright (c) 2016, American Megatrends, Inc. All rights reserved.
 SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include <PiDxe.h>

#include <Library/BaseLib.h>
#include <Library/PciExpressLib.h>
#include <Library/IoLib.h>
#include <Library/DebugLib.h>
#include <Library/PcdLib.h>

///
/// Module global that contains the base physical address of the PCI Express MMIO range.
///
UINTN mSmmPciExpressLibPciExpressBaseAddress = 0;

/**
 The constructor function caches the PCI Express Base Address

 @param ImageHandle The firmware allocated handle for the EFI image.
 @param SystemTable A pointer to the EFI System Table.

 @retval EFI_SUCCESS The constructor completed successfully.
**/
EFI_STATUS
EFIAPI
SmmPciExpressLibConstructor (
 IN EFI_HANDLE ImageHandle,
 IN EFI_SYSTEM_TABLE *SystemTable
 )
{
 //
 // Cache the physical address of the PCI Express MMIO range into a module global variable
 //
 mSmmPciExpressLibPciExpressBaseAddress = (UINTN) PcdGet64 (PcdPciExpressBaseAddress);

 return EFI_SUCCESS;
}

/**
 Assert the validity of a PCI address. A valid PCI address should contain 1's
 only in the low 28 bits.

 @param A The address to validate.

**/
#define ASSERT_INVALID_PCI_ADDRESS(A) \
 ASSERT (((A) & ~0xfffffff) == 0)

/**
 Registers a PCI device so PCI configuration registers may be accessed after
 SetVirtualAddressMap().

 Registers the PCI device specified by Address so all the PCI configuration
 registers associated with that PCI device may be accessed after SetVirtualAddressMap()
 is called.

 If Address > 0x0FFFFFFF, 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
PciExpressRegisterForRuntimeAccess (
 IN UINTN Address
 )
{
 ASSERT_INVALID_PCI_ADDRESS (Address);
 return RETURN_UNSUPPORTED;
}

/**
 Gets MMIO address that can be used to access PCI Express location defined by Address.

 This internal functions converts PCI Express address to a CPU MMIO address by adding
 PCI Express Base Address stored in a global variable mSmmPciExpressLibPciExpressBaseAddress.
 mSmmPciExpressLibPciExpressBaseAddress is initialized in the library constructor from PCD entry
 PcdPciExpressBaseAddress.

 @param Address The address that encodes the PCI Bus, Device, Function and Register.
 @return MMIO address corresponding to Address.

**/
UINTN
GetPciExpressAddress (
 IN UINTN Address
 )
{
 //
 // Make sure Address is valid
 //
 ASSERT_INVALID_PCI_ADDRESS (Address);
 return mSmmPciExpressLibPciExpressBaseAddress + 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 Address > 0x0FFFFFFF, then ASSERT().

 @param Address The address that encodes the PCI Bus, Device, Function and
 Register.

 @return The read value from the PCI configuration register.

**/
UINT8
EFIAPI
PciExpressRead8 (
 IN UINTN Address
 )
{
 return MmioRead8 (GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().

 @param Address The address that encodes the PCI Bus, Device, Function and
 Register.
 @param Value The value to write.

 @return The value written to the PCI configuration register.

**/
UINT8
EFIAPI
PciExpressWrite8 (
 IN UINTN Address,
 IN UINT8 Value
 )
{
 return MmioWrite8 (GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().

 @param Address The address that encodes the PCI 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.

**/
UINT8
EFIAPI
PciExpressOr8 (
 IN UINTN Address,
 IN UINT8 OrData
 )
{
 return MmioOr8 (GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().

 @param Address The address that encodes the PCI Bus, Device, Function and
 Register.
 @param AndData The value to AND with the PCI configuration register.

 @return The value written back to the PCI configuration register.

**/
UINT8
EFIAPI
PciExpressAnd8 (
 IN UINTN Address,
 IN UINT8 AndData
 )
{
 return MmioAnd8 (GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().

 @param Address The address that encodes the PCI Bus, Device, Function and
 Register.
 @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
PciExpressAndThenOr8 (
 IN UINTN Address,
 IN UINT8 AndData,
 IN UINT8 OrData
 )
{
 return MmioAndThenOr8 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, 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 The 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
PciExpressBitFieldRead8 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit
 )
{
 return MmioBitFieldRead8 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, 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 The 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 The new value of the bit field.

 @return The value written back to the PCI configuration register.

**/
UINT8
EFIAPI
PciExpressBitFieldWrite8 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit,
 IN UINT8 Value
 )
{
 return MmioBitFieldWrite8 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, 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 The 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
PciExpressBitFieldOr8 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit,
 IN UINT8 OrData
 )
{
 return MmioBitFieldOr8 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, 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 The 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
PciExpressBitFieldAnd8 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit,
 IN UINT8 AndData
 )
{
 return MmioBitFieldAnd8 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, 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 The 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
PciExpressBitFieldAndThenOr8 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit,
 IN UINT8 AndData,
 IN UINT8 OrData
 )
{
 return MmioBitFieldAndThenOr8 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().
 If Address is not aligned on a 16-bit boundary, then ASSERT().

 @param Address The address that encodes the PCI Bus, Device, Function and
 Register.

 @return The read value from the PCI configuration register.

**/
UINT16
EFIAPI
PciExpressRead16 (
 IN UINTN Address
 )
{
 return MmioRead16 (GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().
 If Address is not aligned on a 16-bit boundary, then ASSERT().

 @param Address The address that encodes the PCI Bus, Device, Function and
 Register.
 @param Value The value to write.

 @return The value written to the PCI configuration register.

**/
UINT16
EFIAPI
PciExpressWrite16 (
 IN UINTN Address,
 IN UINT16 Value
 )
{
 return MmioWrite16 (GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().
 If Address is not aligned on a 16-bit boundary, then ASSERT().

 @param Address The address that encodes the PCI 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
PciExpressOr16 (
 IN UINTN Address,
 IN UINT16 OrData
 )
{
 return MmioOr16 (GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().
 If Address is not aligned on a 16-bit boundary, then ASSERT().

 @param Address The address that encodes the PCI Bus, Device, Function and
 Register.
 @param AndData The value to AND with the PCI configuration register.

 @return The value written back to the PCI configuration register.

**/
UINT16
EFIAPI
PciExpressAnd16 (
 IN UINTN Address,
 IN UINT16 AndData
 )
{
 return MmioAnd16 (GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().
 If Address is not aligned on a 16-bit boundary, then ASSERT().

 @param Address The address that encodes the PCI Bus, Device, Function and
 Register.
 @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
PciExpressAndThenOr16 (
 IN UINTN Address,
 IN UINT16 AndData,
 IN UINT16 OrData
 )
{
 return MmioAndThenOr16 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, 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 The 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
PciExpressBitFieldRead16 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit
 )
{
 return MmioBitFieldRead16 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, 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 The 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 The new value of the bit field.

 @return The value written back to the PCI configuration register.

**/
UINT16
EFIAPI
PciExpressBitFieldWrite16 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit,
 IN UINT16 Value
 )
{
 return MmioBitFieldWrite16 (
 GetPciExpressAddress (Address),
 StartBit,
 EndBit,
 Value
 );
}

/**
 Reads a bit field in a 16-bit PCI configuration, performs 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 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 Address > 0x0FFFFFFF, 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 The 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
PciExpressBitFieldOr16 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit,
 IN UINT16 OrData
 )
{
 return MmioBitFieldOr16 (
 GetPciExpressAddress (Address),
 StartBit,
 EndBit,
 OrData
 );
}

/**
 Reads a bit field in a 16-bit PCI configuration register, performs a bitwise
 AND, 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 Address > 0x0FFFFFFF, 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 The 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.

 @return The value written back to the PCI configuration register.

**/
UINT16
EFIAPI
PciExpressBitFieldAnd16 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit,
 IN UINT16 AndData
 )
{
 return MmioBitFieldAnd16 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, 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().
 If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().

 @param Address The 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
PciExpressBitFieldAndThenOr16 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit,
 IN UINT16 AndData,
 IN UINT16 OrData
 )
{
 return MmioBitFieldAndThenOr16 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().
 If Address is not aligned on a 32-bit boundary, then ASSERT().

 @param Address The address that encodes the PCI Bus, Device, Function and
 Register.

 @return The read value from the PCI configuration register.

**/
UINT32
EFIAPI
PciExpressRead32 (
 IN UINTN Address
 )
{
 return MmioRead32 (GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().
 If Address is not aligned on a 32-bit boundary, then ASSERT().

 @param Address The address that encodes the PCI Bus, Device, Function and
 Register.
 @param Value The value to write.

 @return The value written to the PCI configuration register.

**/
UINT32
EFIAPI
PciExpressWrite32 (
 IN UINTN Address,
 IN UINT32 Value
 )
{
 return MmioWrite32 (GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().
 If Address is not aligned on a 32-bit boundary, then ASSERT().

 @param Address The address that encodes the PCI 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.

**/
UINT32
EFIAPI
PciExpressOr32 (
 IN UINTN Address,
 IN UINT32 OrData
 )
{
 return MmioOr32 (GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().
 If Address is not aligned on a 32-bit boundary, then ASSERT().

 @param Address The address that encodes the PCI Bus, Device, Function and
 Register.
 @param AndData The value to AND with the PCI configuration register.

 @return The value written back to the PCI configuration register.

**/
UINT32
EFIAPI
PciExpressAnd32 (
 IN UINTN Address,
 IN UINT32 AndData
 )
{
 return MmioAnd32 (GetPciExpressAddress (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 Address > 0x0FFFFFFF, then ASSERT().
 If Address is not aligned on a 32-bit boundary, then ASSERT().

 @param Address The address that encodes the PCI Bus, Device, Function and
 Register.
 @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
PciExpressAndThenOr32 (
 IN UINTN Address,
 IN UINT32 AndData,
 IN UINT32 OrData
 )
{
 return MmioAndThenOr32 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, 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 The 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
PciExpressBitFieldRead32 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit
 )
{
 return MmioBitFieldRead32 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, 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 The 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 The new value of the bit field.

 @return The value written back to the PCI configuration register.

**/
UINT32
EFIAPI
PciExpressBitFieldWrite32 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit,
 IN UINT32 Value
 )
{
 return MmioBitFieldWrite32 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, 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 OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().

 @param Address The 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
PciExpressBitFieldOr32 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit,
 IN UINT32 OrData
 )
{
 return MmioBitFieldOr32 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, 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 The 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.

 @return The value written back to the PCI configuration register.

**/
UINT32
EFIAPI
PciExpressBitFieldAnd32 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit,
 IN UINT32 AndData
 )
{
 return MmioBitFieldAnd32 (
 GetPciExpressAddress (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 Address > 0x0FFFFFFF, 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().
 If OrData is larger than the bitmask value range specified by StartBit and EndBit, then ASSERT().

 @param Address The 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
PciExpressBitFieldAndThenOr32 (
 IN UINTN Address,
 IN UINTN StartBit,
 IN UINTN EndBit,
 IN UINT32 AndData,
 IN UINT32 OrData
 )
{
 return MmioBitFieldAndThenOr32 (
 GetPciExpressAddress (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 StartAdress 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 StartAddress > 0x0FFFFFFF, then ASSERT().
 If ((StartAddress & 0xFFF) + Size) > 0x1000, then ASSERT().
 If Size > 0 and Buffer is NULL, then ASSERT().

 @param StartAddress The starting address that encodes the PCI Bus, Device,
 Function and Register.
 @param Size The size in bytes of the transfer.
 @param Buffer The pointer to a buffer receiving the data read.

 @return Size read data from StartAddress.

**/
UINTN
EFIAPI
PciExpressReadBuffer (
 IN UINTN StartAddress,
 IN UINTN Size,
 OUT VOID *Buffer
 )
{
 UINTN ReturnValue;

 //
 // Make sure Address is valid
 //
 ASSERT_INVALID_PCI_ADDRESS (StartAddress);
 ASSERT (((StartAddress & 0xFFF) + Size) <= 0x1000);

 if (Size == 0) {
 return Size;
 }

 ASSERT (Buffer != NULL);

 //
 // Save Size for return
 //
 ReturnValue = Size;

 if ((StartAddress & 1) != 0) {
 //
 // Read a byte if StartAddress is byte aligned
 //
 *(volatile UINT8 *)Buffer = PciExpressRead8 (StartAddress);
 StartAddress += sizeof (UINT8);
 Size -= sizeof (UINT8);
 Buffer = (UINT8*)Buffer + 1;
 }

 if (Size >= sizeof (UINT16) && (StartAddress & 2) != 0) {
 //
 // Read a word if StartAddress is word aligned
 //
 WriteUnaligned16 ((UINT16 *) Buffer, (UINT16) PciExpressRead16 (StartAddress));

 StartAddress += sizeof (UINT16);
 Size -= sizeof (UINT16);
 Buffer = (UINT16*)Buffer + 1;
 }

 while (Size >= sizeof (UINT32)) {
 //
 // Read as many double words as possible
 //
 WriteUnaligned32 ((UINT32 *) Buffer, (UINT32) PciExpressRead32 (StartAddress));

 StartAddress += sizeof (UINT32);
 Size -= sizeof (UINT32);
 Buffer = (UINT32*)Buffer + 1;
 }

 if (Size >= sizeof (UINT16)) {
 //
 // Read the last remaining word if exist
 //
 WriteUnaligned16 ((UINT16 *) Buffer, (UINT16) PciExpressRead16 (StartAddress));
 StartAddress += sizeof (UINT16);
 Size -= sizeof (UINT16);
 Buffer = (UINT16*)Buffer + 1;
 }

 if (Size >= sizeof (UINT8)) {
 //
 // Read the last remaining byte if exist
 //
 *(volatile UINT8 *)Buffer = PciExpressRead8 (StartAddress);
 }

 return ReturnValue;
}

/**
 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 StartAdress 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 StartAddress > 0x0FFFFFFF, then ASSERT().
 If ((StartAddress & 0xFFF) + Size) > 0x1000, then ASSERT().
 If Size > 0 and Buffer is NULL, then ASSERT().

 @param StartAddress The starting address that encodes the PCI Bus, Device,
 Function and Register.
 @param Size The size in bytes of the transfer.
 @param Buffer The pointer to a buffer containing the data to write.

 @return Size written to StartAddress.

**/
UINTN
EFIAPI
PciExpressWriteBuffer (
 IN UINTN StartAddress,
 IN UINTN Size,
 IN VOID *Buffer
 )
{
 UINTN ReturnValue;

 //
 // Make sure Address is valid
 //
 ASSERT_INVALID_PCI_ADDRESS (StartAddress);
 ASSERT (((StartAddress & 0xFFF) + Size) <= 0x1000);


 if (Size == 0) {
 return 0;
 }

 ASSERT (Buffer != NULL);

 //
 // Save Size for return
 //
 ReturnValue = Size;

 if ((StartAddress & 1) != 0) {
 //
 // Write a byte if StartAddress is byte aligned
 //
 PciExpressWrite8 (StartAddress, *(UINT8*)Buffer);
 StartAddress += sizeof (UINT8);
 Size -= sizeof (UINT8);
 Buffer = (UINT8*)Buffer + 1;
 }

 if (Size >= sizeof (UINT16) && (StartAddress & 2) != 0) {
 //
 // Write a word if StartAddress is word aligned
 //
 PciExpressWrite16 (StartAddress, ReadUnaligned16 ((UINT16*)Buffer));
 StartAddress += sizeof (UINT16);
 Size -= sizeof (UINT16);
 Buffer = (UINT16*)Buffer + 1;
 }

 while (Size >= sizeof (UINT32)) {
 //
 // Write as many double words as possible
 //
 PciExpressWrite32 (StartAddress, ReadUnaligned32 ((UINT32*)Buffer));
 StartAddress += sizeof (UINT32);
 Size -= sizeof (UINT32);
 Buffer = (UINT32*)Buffer + 1;
 }

 if (Size >= sizeof (UINT16)) {
 //
 // Write the last remaining word if exist
 //
 PciExpressWrite16 (StartAddress, ReadUnaligned16 ((UINT16*)Buffer));
 StartAddress += sizeof (UINT16);
 Size -= sizeof (UINT16);
 Buffer = (UINT16*)Buffer + 1;
 }

 if (Size >= sizeof (UINT8)) {
 //
 // Write the last remaining byte if exist
 //
 PciExpressWrite8 (StartAddress, *(UINT8*)Buffer);
 }

 return ReturnValue;
}