Re: [RFC PATCH] MdePkg: add byte-swapping MMIO BaseIoLibSwap

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 21 February 2018 at 15:25, Leif Lindholm <leif.lindholm@linaro.org> wrote:
> When performing MMIO to a destination of the opposite endianness to the
> executing processor, this library provides automatic byte order reversal
> on inputs and outputs.
>

As pointed out by Laszlo, 'opposite' is ill defined, as it is not a
property of the device nor is it a property of the CPU/platform (even
though UEFI is likely to remain little endian for the foreseeable
future)

So BigEndianIoLib seems more appropriate as a library class, and it
does need to be a separate class so that a single driver can perform
both LE and BE MMIO (which, as was pointed out, is the case for any
driver that drives a BE MMIO peripheral but uses LE MMIO for serial
port DEBUG output)



> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
> ---
>
> As promised in the dark and distant past:
> https://www.mail-archive.com/edk2-devel@lists.01.org/msg33447.html
>
> This starts out as a clone of MdePkg/Include/Library/IoLib.h,
> implementing simple wrappers that depend on an IoLib instance to perform
> any actual accesses.
>
> Comments are mostly nonsense, since they've not been changed from their
> originals in IoLib.h. If people feel this library is a sensible approach,
> I'll fix that up before I send a v1.
>
> I have explicitly excluded:
> - non-MMIO accesses (could you really end up with mixed endianness in
>   such a system?)
> - bitfields (would either require duplicating code or merging this all
>   into the BaseIoLibIntrinsic module, which is already a bit on the
>   bloated side)
> - buffers operations (let's avoid those until we find we need them)
>
> MdePkg/Include/Library/IoLibSwap.h             | 395 ++++++++++++++++++++

If you create a library class, please declare it in the .dec file

>  MdePkg/Library/BaseIoLibSwap/BaseIoLibSwap.inf |  44 +++
>  MdePkg/Library/BaseIoLibSwap/BaseIoLibSwap.uni |  23 ++
>  MdePkg/Library/BaseIoLibSwap/IoLibSwap.c       | 491 +++++++++++++++++++++++++
>  MdePkg/MdePkg.dec                              |   3 +
>  MdePkg/MdePkg.dsc                              |   1 +
>  6 files changed, 957 insertions(+)
>  create mode 100644 MdePkg/Include/Library/IoLibSwap.h
>  create mode 100644 MdePkg/Library/BaseIoLibSwap/BaseIoLibSwap.inf
>  create mode 100644 MdePkg/Library/BaseIoLibSwap/BaseIoLibSwap.uni
>  create mode 100644 MdePkg/Library/BaseIoLibSwap/IoLibSwap.c
>
> diff --git a/MdePkg/Include/Library/IoLibSwap.h b/MdePkg/Include/Library/IoLibSwap.h
> new file mode 100644
> index 0000000000..f13c8d86e7
> --- /dev/null
> +++ b/MdePkg/Include/Library/IoLibSwap.h
> @@ -0,0 +1,395 @@
> +/** @file
> +  Provide byte-swapping services to access MMIO registers.
> +
> +Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
> +Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
> +Copyright (c) 2018, Linaro ltd. All rights reserved.<BR>
> +
> +This program and the accompanying materials
> +are licensed and made available under the terms and conditions of the BSD License
> +which accompanies this distribution.  The full text of the license may be found at
> +http://opensource.org/licenses/bsd-license.php
> +
> +THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
> +WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
> +
> +**/
> +
> +#ifndef __IO_LIB_SWAP_H__
> +#define __IO_LIB_SWAP_H__
> +
> +/**
> +  Reads a 16-bit MMIO register.
> +
> +  Reads the 16-bit MMIO register specified by Address. The 16-bit read value is
> +  returned. This function must guarantee that all MMIO read and write
> +  operations are serialized.
> +
> +  If 16-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to read.
> +
> +  @return The value read.
> +
> +**/
> +UINT16
> +EFIAPI
> +SwapMmioRead16 (
> +  IN      UINTN                     Address
> +  );
> +
> +/**
> +  Writes a 16-bit MMIO register.
> +
> +  Writes the 16-bit MMIO register specified by Address with the value specified
> +  by Value and returns Value. This function must guarantee that all MMIO read
> +  and write operations are serialized.
> +
> +  If 16-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  Value   The value to write to the MMIO register.
> +
> +  @return Value.
> +
> +**/
> +UINT16
> +EFIAPI
> +SwapMmioWrite16 (
> +  IN      UINTN                     Address,
> +  IN      UINT16                    Value
> +  );
> +
> +/**
> +  Reads a 16-bit MMIO register, performs a bitwise OR, and writes the
> +  result back to the 16-bit MMIO register.
> +
> +  Reads the 16-bit MMIO 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 MMIO register specified by Address. The value
> +  written to the MMIO register is returned. This function must guarantee that
> +  all MMIO read and write operations are serialized.
> +
> +  If 16-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  OrData  The value to OR with the read value from the MMIO register.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT16
> +EFIAPI
> +SwapMmioOr16 (
> +  IN      UINTN                     Address,
> +  IN      UINT16                    OrData
> +  );
> +
> +/**
> +  Reads a 16-bit MMIO register, performs a bitwise AND, and writes the result
> +  back to the 16-bit MMIO register.
> +
> +  Reads the 16-bit MMIO 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 MMIO register specified by Address. The value written to
> +  the MMIO register is returned. This function must guarantee that all MMIO
> +  read and write operations are serialized.
> +
> +  If 16-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  AndData The value to AND with the read value from the MMIO register.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT16
> +EFIAPI
> +SwapMmioAnd16 (
> +  IN      UINTN                     Address,
> +  IN      UINT16                    AndData
> +  );
> +
> +/**
> +  Reads a 16-bit MMIO register, performs a bitwise AND followed by a bitwise
> +  OR, and writes the result back to the 16-bit MMIO register.
> +
> +  Reads the 16-bit MMIO 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 MMIO register specified by
> +  Address. The value written to the MMIO register is returned. This function
> +  must guarantee that all MMIO read and write operations are serialized.
> +
> +  If 16-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  AndData The value to AND with the read value from the MMIO register.
> +  @param  OrData  The value to OR with the result of the AND operation.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT16
> +EFIAPI
> +SwapMmioAndThenOr16 (
> +  IN      UINTN                     Address,
> +  IN      UINT16                    AndData,
> +  IN      UINT16                    OrData
> +  );
> +
> +/**
> +  Reads a 32-bit MMIO register.
> +
> +  Reads the 32-bit MMIO register specified by Address. The 32-bit read value is
> +  returned. This function must guarantee that all MMIO read and write
> +  operations are serialized.
> +
> +  If 32-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to read.
> +
> +  @return The value read.
> +
> +**/
> +UINT32
> +EFIAPI
> +SwapMmioRead32 (
> +  IN      UINTN                     Address
> +  );
> +
> +/**
> +  Writes a 32-bit MMIO register.
> +
> +  Writes the 32-bit MMIO register specified by Address with the value specified
> +  by Value and returns Value. This function must guarantee that all MMIO read
> +  and write operations are serialized.
> +
> +  If 32-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  Value   The value to write to the MMIO register.
> +
> +  @return Value.
> +
> +**/
> +UINT32
> +EFIAPI
> +SwapMmioWrite32 (
> +  IN      UINTN                     Address,
> +  IN      UINT32                    Value
> +  );
> +
> +/**
> +  Reads a 32-bit MMIO register, performs a bitwise OR, and writes the
> +  result back to the 32-bit MMIO register.
> +
> +  Reads the 32-bit MMIO 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 MMIO register specified by Address. The value
> +  written to the MMIO register is returned. This function must guarantee that
> +  all MMIO read and write operations are serialized.
> +
> +  If 32-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  OrData  The value to OR with the read value from the MMIO register.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT32
> +EFIAPI
> +SwapMmioOr32 (
> +  IN      UINTN                     Address,
> +  IN      UINT32                    OrData
> +  );
> +
> +/**
> +  Reads a 32-bit MMIO register, performs a bitwise AND, and writes the result
> +  back to the 32-bit MMIO register.
> +
> +  Reads the 32-bit MMIO 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 MMIO register specified by Address. The value written to
> +  the MMIO register is returned. This function must guarantee that all MMIO
> +  read and write operations are serialized.
> +
> +  If 32-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  AndData The value to AND with the read value from the MMIO register.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT32
> +EFIAPI
> +SwapMmioAnd32 (
> +  IN      UINTN                     Address,
> +  IN      UINT32                    AndData
> +  );
> +
> +/**
> +  Reads a 32-bit MMIO register, performs a bitwise AND followed by a bitwise
> +  OR, and writes the result back to the 32-bit MMIO register.
> +
> +  Reads the 32-bit MMIO 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 MMIO register specified by
> +  Address. The value written to the MMIO register is returned. This function
> +  must guarantee that all MMIO read and write operations are serialized.
> +
> +  If 32-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  AndData The value to AND with the read value from the MMIO register.
> +  @param  OrData  The value to OR with the result of the AND operation.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT32
> +EFIAPI
> +SwapMmioAndThenOr32 (
> +  IN      UINTN                     Address,
> +  IN      UINT32                    AndData,
> +  IN      UINT32                    OrData
> +  );
> +
> +/**
> +  Reads a 64-bit MMIO register.
> +
> +  Reads the 64-bit MMIO register specified by Address. The 64-bit read value is
> +  returned. This function must guarantee that all MMIO read and write
> +  operations are serialized.
> +
> +  If 64-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 64-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to read.
> +
> +  @return The value read.
> +
> +**/
> +UINT64
> +EFIAPI
> +SwapMmioRead64 (
> +  IN      UINTN                     Address
> +  );
> +
> +/**
> +  Writes a 64-bit MMIO register.
> +
> +  Writes the 64-bit MMIO register specified by Address with the value specified
> +  by Value and returns Value. This function must guarantee that all MMIO read
> +  and write operations are serialized.
> +
> +  If 64-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 64-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  Value   The value to write to the MMIO register.
> +
> +**/
> +UINT64
> +EFIAPI
> +SwapMmioWrite64 (
> +  IN      UINTN                     Address,
> +  IN      UINT64                    Value
> +  );
> +
> +/**
> +  Reads a 64-bit MMIO register, performs a bitwise OR, and writes the
> +  result back to the 64-bit MMIO register.
> +
> +  Reads the 64-bit MMIO register specified by Address, performs a bitwise
> +  OR between the read result and the value specified by OrData, and
> +  writes the result to the 64-bit MMIO register specified by Address. The value
> +  written to the MMIO register is returned. This function must guarantee that
> +  all MMIO read and write operations are serialized.
> +
> +  If 64-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 64-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  OrData  The value to OR with the read value from the MMIO register.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT64
> +EFIAPI
> +SwapMmioOr64 (
> +  IN      UINTN                     Address,
> +  IN      UINT64                    OrData
> +  );
> +
> +/**
> +  Reads a 64-bit MMIO register, performs a bitwise AND, and writes the result
> +  back to the 64-bit MMIO register.
> +
> +  Reads the 64-bit MMIO register specified by Address, performs a bitwise AND
> +  between the read result and the value specified by AndData, and writes the
> +  result to the 64-bit MMIO register specified by Address. The value written to
> +  the MMIO register is returned. This function must guarantee that all MMIO
> +  read and write operations are serialized.
> +
> +  If 64-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 64-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  AndData The value to AND with the read value from the MMIO register.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT64
> +EFIAPI
> +SwapMmioAnd64 (
> +  IN      UINTN                     Address,
> +  IN      UINT64                    AndData
> +  );
> +
> +/**
> +  Reads a 64-bit MMIO register, performs a bitwise AND followed by a bitwise
> +  OR, and writes the result back to the 64-bit MMIO register.
> +
> +  Reads the 64-bit MMIO 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 64-bit MMIO register specified by
> +  Address. The value written to the MMIO register is returned. This function
> +  must guarantee that all MMIO read and write operations are serialized.
> +
> +  If 64-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 64-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  AndData The value to AND with the read value from the MMIO register.
> +  @param  OrData  The value to OR with the result of the AND operation.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT64
> +EFIAPI
> +SwapMmioAndThenOr64 (
> +  IN      UINTN                     Address,
> +  IN      UINT64                    AndData,
> +  IN      UINT64                    OrData
> +  );
> +
> +#endif
> +
> diff --git a/MdePkg/Library/BaseIoLibSwap/BaseIoLibSwap.inf b/MdePkg/Library/BaseIoLibSwap/BaseIoLibSwap.inf
> new file mode 100644
> index 0000000000..59d774dc97
> --- /dev/null
> +++ b/MdePkg/Library/BaseIoLibSwap/BaseIoLibSwap.inf
> @@ -0,0 +1,44 @@
> +## @file
> +#  Byte swapping I/O Library.
> +#
> +#  Byte swapping I/O Library for all architectures. Only MMIO supported. I/O
> +#  accesses take place through the normal IoLib, but values read and written
> +#  are byte-reversed to interact with peripherals of non-native endianness.
> +#
> +#  Copyright (c) 2007 - 2015, Intel Corporation. All rights reserved.<BR>
> +#  Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
> +#  Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
> +#
> +#  This program and the accompanying materials
> +#  are licensed and made available under the terms and conditions of the BSD License
> +#  which accompanies this distribution. The full text of the license may be found at
> +#  http://opensource.org/licenses/bsd-license.php.
> +#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
> +#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
> +#
> +##
> +
> +[Defines]
> +  INF_VERSION                    = 0x0001001a
> +  BASE_NAME                      = BaseIoLibSwap
> +  MODULE_UNI_FILE                = BaseIoLibSwap.uni
> +  FILE_GUID                      = 073c3fbd-ff0d-41b6-a209-1e42fd2a3bab
> +  MODULE_TYPE                    = BASE
> +  VERSION_STRING                 = 1.0
> +  LIBRARY_CLASS                  = IoLibSwap
> +
> +
> +#
> +#  VALID_ARCHITECTURES           = IA32 X64 EBC IPF ARM AARCH64
> +#
> +
> +[Sources]
> +  IoLibSwap.c
> +
> +[Packages]
> +  MdePkg/MdePkg.dec
> +
> +[LibraryClasses]
> +  BaseLib
> +#  DebugLib
> +  IoLib
> diff --git a/MdePkg/Library/BaseIoLibSwap/BaseIoLibSwap.uni b/MdePkg/Library/BaseIoLibSwap/BaseIoLibSwap.uni
> new file mode 100644
> index 0000000000..e35b4abef7
> --- /dev/null
> +++ b/MdePkg/Library/BaseIoLibSwap/BaseIoLibSwap.uni
> @@ -0,0 +1,23 @@
> +// /** @file
> +// Byte swapping I/O Library.
> +//
> +// Byte swapping I/O Library for all architectures. Only MMIO supported. I/O
> +// accesses take place through the normal IoLib, but values read and written
> +// are byte-reversed to interact with peripherals of non-native endianness.
> +//
> +// Copyright (c) 2018, Linaro ltd. All rights reserved.<BR>
> +//
> +// This program and the accompanying materials
> +// are licensed and made available under the terms and conditions of the BSD License
> +// which accompanies this distribution. The full text of the license may be found at
> +// http://opensource.org/licenses/bsd-license.php.
> +// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
> +// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
> +//
> +// **/
> +
> +
> +#string STR_MODULE_ABSTRACT             #language en-US "Byte swapping I/O Library"
> +
> +#string STR_MODULE_DESCRIPTION          #language en-US "Byte swapping I/O Library for all architectures. Only MMIO supported. I/O accesses take place through the normal IoLib, but values read and written are byte-reversed to interact with peripherals of non-native endianness."
> +
> diff --git a/MdePkg/Library/BaseIoLibSwap/IoLibSwap.c b/MdePkg/Library/BaseIoLibSwap/IoLibSwap.c
> new file mode 100644
> index 0000000000..6eb675de20
> --- /dev/null
> +++ b/MdePkg/Library/BaseIoLibSwap/IoLibSwap.c
> @@ -0,0 +1,491 @@
> +/** @file
> +  Provide byte-swapping services to access MMIO registers.
> +
> +Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
> +Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
> +Copyright (c) 2018, Linaro ltd. All rights reserved.<BR>
> +
> +This program and the accompanying materials
> +are licensed and made available under the terms and conditions of the BSD License
> +which accompanies this distribution.  The full text of the license may be found at
> +http://opensource.org/licenses/bsd-license.php
> +
> +THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
> +WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
> +
> +**/
> +
> +#include <Library/BaseLib.h>
> +#include <Library/IoLib.h>
> +
> +/**
> +  Reads a 16-bit MMIO register.
> +
> +  Reads the 16-bit MMIO register specified by Address. The 16-bit read value is
> +  returned. This function must guarantee that all MMIO read and write
> +  operations are serialized.
> +
> +  If 16-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to read.
> +
> +  @return The value read.
> +
> +**/
> +UINT16
> +EFIAPI
> +SwapMmioRead16 (
> +  IN      UINTN                     Address
> +  )
> +{
> +  return SwapBytes16 (MmioRead16 (Address));
> +}
> +
> +/**
> +  Writes a 16-bit MMIO register.
> +
> +  Writes the 16-bit MMIO register specified by Address with the value specified
> +  by Value and returns Value. This function must guarantee that all MMIO read
> +  and write operations are serialized.
> +
> +  If 16-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  Value   The value to write to the MMIO register.
> +
> +  @return Value.
> +
> +**/
> +UINT16
> +EFIAPI
> +SwapMmioWrite16 (
> +  IN      UINTN                     Address,
> +  IN      UINT16                    Value
> +  )
> +{
> +  (VOID) MmioWrite16 (Address, SwapBytes16 (Value));
> +
> +  return Value;
> +}
> +
> +/**
> +  Reads a 16-bit MMIO register, performs a bitwise OR, and writes the
> +  result back to the 16-bit MMIO register.
> +
> +  Reads the 16-bit MMIO 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 MMIO register specified by Address. The value
> +  written to the MMIO register is returned. This function must guarantee that
> +  all MMIO read and write operations are serialized.
> +
> +  If 16-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  OrData  The value to OR with the read value from the MMIO register.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT16
> +EFIAPI
> +SwapMmioOr16 (
> +  IN      UINTN                     Address,
> +  IN      UINT16                    OrData
> +  )
> +{
> +  UINT16 Value;
> +
> +  Value = SwapMmioRead16 (Address);
> +  Value |= OrData;
> +
> +  return SwapMmioWrite16 (Address, Value);
> +}
> +
> +/**
> +  Reads a 16-bit MMIO register, performs a bitwise AND, and writes the result
> +  back to the 16-bit MMIO register.
> +
> +  Reads the 16-bit MMIO 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 MMIO register specified by Address. The value written to
> +  the MMIO register is returned. This function must guarantee that all MMIO
> +  read and write operations are serialized.
> +
> +  If 16-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  AndData The value to AND with the read value from the MMIO register.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT16
> +EFIAPI
> +SwapMmioAnd16 (
> +  IN      UINTN                     Address,
> +  IN      UINT16                    AndData
> +  )
> +{
> +  UINT16 Value;
> +
> +  Value = SwapMmioRead16 (Address);
> +  Value &= AndData;
> +
> +  return SwapMmioWrite16 (Address, Value);
> +}
> +
> +/**
> +  Reads a 16-bit MMIO register, performs a bitwise AND followed by a bitwise
> +  OR, and writes the result back to the 16-bit MMIO register.
> +
> +  Reads the 16-bit MMIO 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 MMIO register specified by
> +  Address. The value written to the MMIO register is returned. This function
> +  must guarantee that all MMIO read and write operations are serialized.
> +
> +  If 16-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 16-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  AndData The value to AND with the read value from the MMIO register.
> +  @param  OrData  The value to OR with the result of the AND operation.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT16
> +EFIAPI
> +SwapMmioAndThenOr16 (
> +  IN      UINTN                     Address,
> +  IN      UINT16                    AndData,
> +  IN      UINT16                    OrData
> +  )
> +{
> +  UINT16 Value;
> +
> +  Value = SwapMmioRead16 (Address);
> +  Value &= AndData;
> +  Value |= OrData;
> +
> +  return SwapMmioWrite16 (Address, Value);
> +}
> +
> +/**
> +  Reads a 32-bit MMIO register.
> +
> +  Reads the 32-bit MMIO register specified by Address. The 32-bit read value is
> +  returned. This function must guarantee that all MMIO read and write
> +  operations are serialized.
> +
> +  If 32-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to read.
> +
> +  @return The value read.
> +
> +**/
> +UINT32
> +EFIAPI
> +SwapMmioRead32 (
> +  IN      UINTN                     Address
> +  )
> +{
> +  return SwapBytes32 (MmioRead32 (Address));
> +}
> +
> +/**
> +  Writes a 32-bit MMIO register.
> +
> +  Writes the 32-bit MMIO register specified by Address with the value specified
> +  by Value and returns Value. This function must guarantee that all MMIO read
> +  and write operations are serialized.
> +
> +  If 32-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  Value   The value to write to the MMIO register.
> +
> +  @return Value.
> +
> +**/
> +UINT32
> +EFIAPI
> +SwapMmioWrite32 (
> +  IN      UINTN                     Address,
> +  IN      UINT32                    Value
> +  )
> +{
> +  (VOID) MmioWrite32 (Address, SwapBytes32 (Value));
> +
> +  return Value;
> +}
> +
> +/**
> +  Reads a 32-bit MMIO register, performs a bitwise OR, and writes the
> +  result back to the 32-bit MMIO register.
> +
> +  Reads the 32-bit MMIO 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 MMIO register specified by Address. The value
> +  written to the MMIO register is returned. This function must guarantee that
> +  all MMIO read and write operations are serialized.
> +
> +  If 32-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  OrData  The value to OR with the read value from the MMIO register.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT32
> +EFIAPI
> +SwapMmioOr32 (
> +  IN      UINTN                     Address,
> +  IN      UINT32                    OrData
> +  )
> +{
> +  UINT32 Value;
> +
> +  Value = SwapMmioRead32 (Address);
> +  Value |= OrData;
> +
> +  return SwapMmioWrite32 (Address, Value);
> +}
> +
> +/**
> +  Reads a 32-bit MMIO register, performs a bitwise AND, and writes the result
> +  back to the 32-bit MMIO register.
> +
> +  Reads the 32-bit MMIO 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 MMIO register specified by Address. The value written to
> +  the MMIO register is returned. This function must guarantee that all MMIO
> +  read and write operations are serialized.
> +
> +  If 32-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  AndData The value to AND with the read value from the MMIO register.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT32
> +EFIAPI
> +SwapMmioAnd32 (
> +  IN      UINTN                     Address,
> +  IN      UINT32                    AndData
> +  )
> +{
> +  UINT32 Value;
> +
> +  Value = SwapMmioRead32 (Address);
> +  Value &= AndData;
> +
> +  return SwapMmioWrite32 (Address, Value);
> +}
> +
> +/**
> +  Reads a 32-bit MMIO register, performs a bitwise AND followed by a bitwise
> +  OR, and writes the result back to the 32-bit MMIO register.
> +
> +  Reads the 32-bit MMIO 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 MMIO register specified by
> +  Address. The value written to the MMIO register is returned. This function
> +  must guarantee that all MMIO read and write operations are serialized.
> +
> +  If 32-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 32-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  AndData The value to AND with the read value from the MMIO register.
> +  @param  OrData  The value to OR with the result of the AND operation.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT32
> +EFIAPI
> +SwapMmioAndThenOr32 (
> +  IN      UINTN                     Address,
> +  IN      UINT32                    AndData,
> +  IN      UINT32                    OrData
> +  )
> +{
> +  UINT32 Value;
> +
> +  Value = SwapMmioRead32 (Address);
> +  Value &= AndData;
> +  Value |= OrData;
> +
> +  return SwapMmioWrite32 (Address, Value);
> +}
> +
> +/**
> +  Reads a 64-bit MMIO register.
> +
> +  Reads the 64-bit MMIO register specified by Address. The 64-bit read value is
> +  returned. This function must guarantee that all MMIO read and write
> +  operations are serialized.
> +
> +  If 64-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 64-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to read.
> +
> +  @return The value read.
> +
> +**/
> +UINT64
> +EFIAPI
> +SwapMmioRead64 (
> +  IN      UINTN                     Address
> +  )
> +{
> +  return SwapBytes64 (MmioRead64 (Address));
> +}
> +
> +/**
> +  Writes a 64-bit MMIO register.
> +
> +  Writes the 64-bit MMIO register specified by Address with the value specified
> +  by Value and returns Value. This function must guarantee that all MMIO read
> +  and write operations are serialized.
> +
> +  If 64-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 64-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  Value   The value to write to the MMIO register.
> +
> +**/
> +UINT64
> +EFIAPI
> +SwapMmioWrite64 (
> +  IN      UINTN                     Address,
> +  IN      UINT64                    Value
> +  )
> +{
> +  (VOID) MmioWrite64 (Address, SwapBytes64 (Value));
> +
> +  return Value;
> +}
> +
> +/**
> +  Reads a 64-bit MMIO register, performs a bitwise OR, and writes the
> +  result back to the 64-bit MMIO register.
> +
> +  Reads the 64-bit MMIO register specified by Address, performs a bitwise
> +  OR between the read result and the value specified by OrData, and
> +  writes the result to the 64-bit MMIO register specified by Address. The value
> +  written to the MMIO register is returned. This function must guarantee that
> +  all MMIO read and write operations are serialized.
> +
> +  If 64-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 64-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  OrData  The value to OR with the read value from the MMIO register.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT64
> +EFIAPI
> +SwapMmioOr64 (
> +  IN      UINTN                     Address,
> +  IN      UINT64                    OrData
> +  )
> +{
> +  UINT64 Value;
> +
> +  Value = SwapMmioRead64 (Address);
> +  Value |= OrData;
> +
> +  return SwapMmioWrite64 (Address, Value);
> +}
> +
> +/**
> +  Reads a 64-bit MMIO register, performs a bitwise AND, and writes the result
> +  back to the 64-bit MMIO register.
> +
> +  Reads the 64-bit MMIO register specified by Address, performs a bitwise AND
> +  between the read result and the value specified by AndData, and writes the
> +  result to the 64-bit MMIO register specified by Address. The value written to
> +  the MMIO register is returned. This function must guarantee that all MMIO
> +  read and write operations are serialized.
> +
> +  If 64-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 64-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  AndData The value to AND with the read value from the MMIO register.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT64
> +EFIAPI
> +SwapMmioAnd64 (
> +  IN      UINTN                     Address,
> +  IN      UINT64                    AndData
> +  )
> +{
> +  UINT64 Value;
> +
> +  Value = SwapMmioRead64 (Address);
> +  Value &= AndData;
> +
> +  return SwapMmioWrite64 (Address, Value);
> +}
> +
> +/**
> +  Reads a 64-bit MMIO register, performs a bitwise AND followed by a bitwise
> +  OR, and writes the result back to the 64-bit MMIO register.
> +
> +  Reads the 64-bit MMIO 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 64-bit MMIO register specified by
> +  Address. The value written to the MMIO register is returned. This function
> +  must guarantee that all MMIO read and write operations are serialized.
> +
> +  If 64-bit MMIO register operations are not supported, then ASSERT().
> +  If Address is not aligned on a 64-bit boundary, then ASSERT().
> +
> +  @param  Address The MMIO register to write.
> +  @param  AndData The value to AND with the read value from the MMIO register.
> +  @param  OrData  The value to OR with the result of the AND operation.
> +
> +  @return The value written back to the MMIO register.
> +
> +**/
> +UINT64
> +EFIAPI
> +SwapMmioAndThenOr64 (
> +  IN      UINTN                     Address,
> +  IN      UINT64                    AndData,
> +  IN      UINT64                    OrData
> +  )
> +{
> +  UINT64 Value;
> +
> +  Value = SwapMmioRead64 (Address);
> +  Value &= AndData;
> +  Value |= OrData;
> +
> +  return SwapMmioWrite64 (Address, Value);
> +}
> diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec
> index 0e64f22f4a..98016f47e9 100644
> --- a/MdePkg/MdePkg.dec
> +++ b/MdePkg/MdePkg.dec
> @@ -160,6 +160,9 @@ [LibraryClasses]
>    ##  @libraryclass  Provide services to access I/O Ports and MMIO registers.
>    IoLib|Include/Library/IoLib.h
>
> +  ##  @libraryclass  Provide byte-swapping services to access MMIO registers.
> +  IoLibSwap|Include/Library/IoLibSwap.h
> +
>    ##  @libraryclass  Provide services to create, get and update HSTI table in AIP protocol.
>    HstiLib|Include/Library/HstiLib.h
>
> diff --git a/MdePkg/MdePkg.dsc b/MdePkg/MdePkg.dsc
> index 60efd722e9..a2f2696394 100644
> --- a/MdePkg/MdePkg.dsc
> +++ b/MdePkg/MdePkg.dsc
> @@ -60,6 +60,7 @@ [Components]
>    MdePkg/Library/BaseDebugLibNull/BaseDebugLibNull.inf
>    MdePkg/Library/BaseDebugLibSerialPort/BaseDebugLibSerialPort.inf
>    MdePkg/Library/BaseDebugPrintErrorLevelLib/BaseDebugPrintErrorLevelLib.inf
> +  MdePkg/Library/BaseIoLibSwap/BaseIoLibSwap.inf
>    MdePkg/Library/BaseLib/BaseLib.inf
>    MdePkg/Library/BaseMemoryLib/BaseMemoryLib.inf
>    MdePkg/Library/BaseOrderedCollectionRedBlackTreeLib/BaseOrderedCollectionRedBlackTreeLib.inf
> --
> 2.11.0
>