Re: [PATCH v2 1/1] EmbeddedPkg/AcpiLib: Add more helper functions

["Leif Lindholm" <leif@nuviainc.com>]

Hi Nhi,

On Fri, Sep 03, 2021 at 22:44:23 +0700, Nhi Pham wrote:
> This adds more helper functions that assist in calculating the checksum,
> locating an ACPI table by signature, and updating an AML integer object.
> 
> Cc: Leif Lindholm <leif@nuviainc.com>
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Abner Chang <abner.chang@hpe.com>
> Cc: Daniel Schaefer <daniel.schaefer@hpe.com>
> Signed-off-by: Nhi Pham <nhi@os.amperecomputing.com>

Ideally, I'd like to have some code that makes use of these new
functions (even if in edk2-platforms) so that *someone* can verify
that these functions do what they're supposed to do before we merge
them.

Acked-by: Leif Lindholm <leif@nuviainc.com>

/
    Leif

> ---
> Changes since v1:
> + Add copyright [Abner]
> + Improve the AcpiLocateTableBySignature function to remove the caution
> for the usage of SSDT table. [Abner]
> + AcpiAmlObjectUpdateInteger: Use the AcpiSdtProtocol->SetOption to update
> the value of data object. [Abner]
> 
>  EmbeddedPkg/Library/AcpiLib/AcpiLib.inf |   3 +
>  EmbeddedPkg/Include/Library/AcpiLib.h   |  69 +++++++
>  EmbeddedPkg/Library/AcpiLib/AcpiLib.c   | 214 ++++++++++++++++++++
>  3 files changed, 286 insertions(+)
> 
> diff --git a/EmbeddedPkg/Library/AcpiLib/AcpiLib.inf b/EmbeddedPkg/Library/AcpiLib/AcpiLib.inf
> index 538fe09cca29..01b12c9423a9 100644
> --- a/EmbeddedPkg/Library/AcpiLib/AcpiLib.inf
> +++ b/EmbeddedPkg/Library/AcpiLib/AcpiLib.inf
> @@ -1,6 +1,7 @@
>  #/** @file
>  #
>  #  Copyright (c) 2014, ARM Ltd. All rights reserved.
> +#  Copyright (c) 2021, Ampere Computing LLC. All rights reserved.
>  #
>  #  SPDX-License-Identifier: BSD-2-Clause-Patent
>  #
> @@ -23,6 +24,8 @@ [Packages]
>    EmbeddedPkg/EmbeddedPkg.dec
>  
>  [LibraryClasses]
> +  BaseLib
> +  BaseMemoryLib
>    DebugLib
>    UefiBootServicesTableLib
>  
> diff --git a/EmbeddedPkg/Include/Library/AcpiLib.h b/EmbeddedPkg/Include/Library/AcpiLib.h
> index c142446d9d59..933582b7f607 100644
> --- a/EmbeddedPkg/Include/Library/AcpiLib.h
> +++ b/EmbeddedPkg/Include/Library/AcpiLib.h
> @@ -2,6 +2,7 @@
>    Helper Library for ACPI
>  
>    Copyright (c) 2014-2016, ARM Ltd. All rights reserved.
> +  Copyright (c) 2021, Ampere Computing LLC. All rights reserved.
>  
>    SPDX-License-Identifier: BSD-2-Clause-Patent
>  
> @@ -13,6 +14,7 @@
>  #include <Uefi.h>
>  
>  #include <IndustryStandard/Acpi10.h>
> +#include <Protocol/AcpiSystemDescriptionTable.h>
>  
>  //
>  // Macros for the Generic Address Space
> @@ -128,4 +130,71 @@ LocateAndInstallAcpiFromFv (
>    IN CONST EFI_GUID* AcpiFile
>    );
>  
> +/**
> +  This function calculates and updates a UINT8 checksum
> +  in an ACPI description table header.
> +
> +  @param  Buffer          Pointer to buffer to checksum
> +  @param  Size            Number of bytes to checksum
> +
> +  @retval EFI_SUCCESS             The function completed successfully.
> +  @retval EFI_INVALID_PARAMETER   Invalid parameter.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +AcpiUpdateChecksum (
> +  IN OUT  UINT8      *Buffer,
> +  IN      UINTN      Size
> +  );
> +
> +/**
> +  This function uses the ACPI SDT protocol to locate an ACPI table
> +  with a given signature that only have a single instance.
> +
> +  @param  AcpiTableSdtProtocol    Pointer to ACPI SDT protocol.
> +  @param  TableSignature          ACPI table signature.
> +  @param  Index                   The zero-based index of the table where to search the table.
> +  @param  Table                   Pointer to the table.
> +  @param  TableKey                Pointer to the table key.
> +
> +  @return EFI_SUCCESS             The function completed successfully.
> +  @return EFI_INVALID_PARAMETER   At least one of parameters is invalid.
> +  @retval EFI_NOT_FOUND           The requested index is too large and a table was not found.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +AcpiLocateTableBySignature (
> +  IN      EFI_ACPI_SDT_PROTOCOL           *AcpiSdtProtocol,
> +  IN      UINT32                          TableSignature,
> +  IN OUT  UINTN                           *Index,
> +  OUT     EFI_ACPI_DESCRIPTION_HEADER     **Table,
> +  OUT     UINTN                           *TableKey
> +  );
> +
> +/**
> +  This function updates the integer value of an AML Object.
> +
> +  @param  AcpiTableSdtProtocol    Pointer to ACPI SDT protocol.
> +  @param  TableHandle             Points to the table representing the starting point
> +                                  for the object path search.
> +  @param  AsciiObjectPath         Pointer to the ACPI path of the object being updated.
> +  @param  Value                   New value to write to the object.
> +
> +  @return EFI_SUCCESS             The function completed successfully.
> +  @return EFI_INVALID_PARAMETER   At least one of parameters is invalid or the data type
> +                                  of the ACPI object is not an integer value.
> +  @retval EFI_NOT_FOUND           The object is not found with the given path.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +AcpiAmlObjectUpdateInteger (
> +  IN  EFI_ACPI_SDT_PROTOCOL           *AcpiSdtProtocol,
> +  IN  EFI_ACPI_HANDLE                 TableHandle,
> +  IN  CHAR8                           *AsciiObjectPath,
> +  IN  UINTN                           Value
> +  );
> +
>  #endif // __ACPI_LIB_H__
> diff --git a/EmbeddedPkg/Library/AcpiLib/AcpiLib.c b/EmbeddedPkg/Library/AcpiLib/AcpiLib.c
> index ff7d678433d5..393133f54381 100644
> --- a/EmbeddedPkg/Library/AcpiLib/AcpiLib.c
> +++ b/EmbeddedPkg/Library/AcpiLib/AcpiLib.c
> @@ -1,6 +1,7 @@
>  /** @file
>  *
>  *  Copyright (c) 2014-2015, ARM Limited. All rights reserved.
> +*  Copyright (c) 2021, Ampere Computing LLC. All rights reserved.
>  *
>  *  SPDX-License-Identifier: BSD-2-Clause-Patent
>  *
> @@ -9,9 +10,12 @@
>  #include <Uefi.h>
>  
>  #include <Library/AcpiLib.h>
> +#include <Library/BaseLib.h>
> +#include <Library/BaseMemoryLib.h>
>  #include <Library/DebugLib.h>
>  #include <Library/UefiBootServicesTableLib.h>
>  
> +#include <Protocol/AcpiSystemDescriptionTable.h>
>  #include <Protocol/AcpiTable.h>
>  #include <Protocol/FirmwareVolume2.h>
>  
> @@ -170,3 +174,213 @@ LocateAndInstallAcpiFromFv (
>  {
>    return LocateAndInstallAcpiFromFvConditional (AcpiFile, NULL);
>  }
> +
> +/**
> +  This function calculates and updates a UINT8 checksum
> +  in an ACPI description table header.
> +
> +  @param  Buffer          Pointer to buffer to checksum
> +  @param  Size            Number of bytes to checksum
> +
> +  @retval EFI_SUCCESS             The function completed successfully.
> +  @retval EFI_INVALID_PARAMETER   Invalid parameter.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +AcpiUpdateChecksum (
> +  IN OUT  UINT8      *Buffer,
> +  IN      UINTN      Size
> +  )
> +{
> +  UINTN ChecksumOffset;
> +
> +  if (Buffer == NULL || Size == 0) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  ChecksumOffset = OFFSET_OF (EFI_ACPI_DESCRIPTION_HEADER, Checksum);
> +
> +  //
> +  // Set checksum to 0 first
> +  //
> +  Buffer[ChecksumOffset] = 0;
> +
> +  //
> +  // Update checksum value
> +  //
> +  Buffer[ChecksumOffset] = CalculateCheckSum8 (Buffer, Size);
> +
> +  return EFI_SUCCESS;
> +}
> +
> +/**
> +  This function uses the ACPI SDT protocol to locate an ACPI table
> +  with a given signature that only have a single instance.
> +
> +  @param  AcpiTableSdtProtocol    Pointer to ACPI SDT protocol.
> +  @param  TableSignature          ACPI table signature.
> +  @param  Index                   The zero-based index of the table where to search the table.
> +  @param  Table                   Pointer to the table.
> +  @param  TableKey                Pointer to the table key.
> +
> +  @return EFI_SUCCESS             The function completed successfully.
> +  @return EFI_INVALID_PARAMETER   At least one of parameters is invalid.
> +  @retval EFI_NOT_FOUND           The requested index is too large and a table was not found.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +AcpiLocateTableBySignature (
> +  IN      EFI_ACPI_SDT_PROTOCOL           *AcpiSdtProtocol,
> +  IN      UINT32                          TableSignature,
> +  IN OUT  UINTN                           *Index,
> +  OUT     EFI_ACPI_DESCRIPTION_HEADER     **Table,
> +  OUT     UINTN                           *TableKey
> +  )
> +{
> +  EFI_STATUS              Status;
> +  EFI_ACPI_SDT_HEADER     *TempTable;
> +  EFI_ACPI_TABLE_VERSION  TableVersion;
> +  UINTN                   TableIndex;
> +
> +  if (AcpiSdtProtocol == NULL
> +      || Table == NULL
> +      || TableKey == NULL) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  Status = EFI_SUCCESS;
> +
> +  //
> +  // Search for ACPI Table with matching signature
> +  //
> +  TableVersion = 0;
> +  TableIndex = *Index;
> +  while (!EFI_ERROR (Status)) {
> +    Status = AcpiSdtProtocol->GetAcpiTable (
> +                                TableIndex,
> +                                &TempTable,
> +                                &TableVersion,
> +                                TableKey
> +                                );
> +    if (!EFI_ERROR (Status)) {
> +      TableIndex++;
> +
> +      if (((EFI_ACPI_DESCRIPTION_HEADER *)TempTable)->Signature == TableSignature) {
> +        *Table = (EFI_ACPI_DESCRIPTION_HEADER *)TempTable;
> +        *Index = TableIndex;
> +        break;
> +      }
> +    }
> +  }
> +
> +  return Status;
> +}
> +
> +/**
> +  This function updates the integer value of an AML Object.
> +
> +  @param  AcpiTableSdtProtocol    Pointer to ACPI SDT protocol.
> +  @param  TableHandle             Points to the table representing the starting point
> +                                  for the object path search.
> +  @param  AsciiObjectPath         Pointer to the ACPI path of the object being updated.
> +  @param  Value                   New value to write to the object.
> +
> +  @return EFI_SUCCESS             The function completed successfully.
> +  @return EFI_INVALID_PARAMETER   At least one of parameters is invalid or the data type
> +                                  of the ACPI object is not an integer value.
> +  @retval EFI_NOT_FOUND           The object is not found with the given path.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +AcpiAmlObjectUpdateInteger (
> +  IN  EFI_ACPI_SDT_PROTOCOL           *AcpiSdtProtocol,
> +  IN  EFI_ACPI_HANDLE                 TableHandle,
> +  IN  CHAR8                           *AsciiObjectPath,
> +  IN  UINTN                           Value
> +  )
> +{
> +  EFI_STATUS            Status;
> +  EFI_ACPI_HANDLE       ObjectHandle;
> +  EFI_ACPI_HANDLE       DataHandle;
> +  EFI_ACPI_DATA_TYPE    DataType;
> +  UINT8                 *Buffer;
> +  UINTN                 BufferSize;
> +  UINTN                 DataSize;
> +
> +  if (AcpiSdtProtocol == NULL || AsciiObjectPath == NULL) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  ObjectHandle = NULL;
> +  Status = AcpiSdtProtocol->FindPath (TableHandle, AsciiObjectPath, &ObjectHandle);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  Status = AcpiSdtProtocol->GetOption (ObjectHandle, 0, &DataType, (VOID *)&Buffer, &BufferSize);
> +  if (EFI_ERROR (Status)) {
> +    Status = EFI_NOT_FOUND;
> +    goto Exit;
> +  }
> +  ASSERT (DataType == EFI_ACPI_DATA_TYPE_OPCODE);
> +  ASSERT (Buffer != NULL);
> +
> +  if (Buffer[0] != AML_NAME_OP) {
> +    Status = EFI_NOT_FOUND;
> +    goto Exit;
> +  }
> +
> +  //
> +  // Get handle of data object
> +  //
> +  DataHandle = NULL;
> +  Status = AcpiSdtProtocol->GetChild (ObjectHandle, &DataHandle);
> +  ASSERT_EFI_ERROR (Status);
> +
> +  Status = AcpiSdtProtocol->GetOption (DataHandle, 0, &DataType, (VOID *)&Buffer, &BufferSize);
> +  ASSERT (DataType == EFI_ACPI_DATA_TYPE_OPCODE);
> +  ASSERT (Buffer != NULL);
> +
> +  if (Buffer[0] == AML_ZERO_OP || Buffer[0] == AML_ONE_OP) {
> +    Status = AcpiSdtProtocol->SetOption (DataHandle, 0, (VOID *)&Value, sizeof (UINT8));
> +    ASSERT_EFI_ERROR (Status);
> +  } else {
> +    //
> +    // Check the size of data object
> +    //
> +    switch (Buffer[0]) {
> +    case AML_BYTE_PREFIX:
> +      DataSize = sizeof (UINT8);
> +      break;
> +
> +    case AML_WORD_PREFIX:
> +      DataSize = sizeof (UINT16);
> +      break;
> +
> +    case AML_DWORD_PREFIX:
> +      DataSize = sizeof (UINT32);
> +      break;
> +
> +    case AML_QWORD_PREFIX:
> +      DataSize = sizeof (UINT64);
> +      break;
> +
> +    default:
> +      // The data type of the ACPI object is not an integer
> +      Status = EFI_INVALID_PARAMETER;
> +      goto Exit;
> +    }
> +
> +    Status = AcpiSdtProtocol->SetOption (DataHandle, 1, (VOID *)&Value, DataSize);
> +    ASSERT_EFI_ERROR (Status);
> +  }
> +
> +Exit:
> +  AcpiSdtProtocol->Close (DataHandle);
> +  AcpiSdtProtocol->Close (ObjectHandle);
> +
> +  return Status;
> +}
> -- 
> 2.17.1
>