path: root/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c

/** @file
  It updates TPM2 items in ACPI table and registers SMI2 callback
  functions for Tcg2 physical presence, ClearMemory, and sample
  for dTPM StartMethod.

  Caution: This module requires additional review when modified.
  This driver will have external input - variable and ACPINvs data in SMM mode.
  This external input must be validated carefully to avoid security issue.

  PhysicalPresenceCallback() and MemoryClearCallback() will receive untrusted input and do some check.

Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "Tcg2Smm.h"

#pragma pack(1)

typedef struct {
  EFI_ACPI_DESCRIPTION_HEADER Header;
  // Flags field is replaced in version 4 and above
  //    BIT0~15:  PlatformClass      This field is only valid for version 4 and above
  //    BIT16~31: Reserved
  UINT32                      Flags;
  UINT64                      AddressOfControlArea;
  UINT32                      StartMethod;
  UINT8                       PlatformSpecificParameters[12];  // size up to 12
  UINT32                      Laml;                          // Optional
  UINT64                      Lasa;                          // Optional
} EFI_TPM2_ACPI_TABLE_V4;

#pragma pack()

EFI_TPM2_ACPI_TABLE_V4  mTpm2AcpiTemplate = {
  {
    EFI_ACPI_5_0_TRUSTED_COMPUTING_PLATFORM_2_TABLE_SIGNATURE,
    sizeof (mTpm2AcpiTemplate),
    EFI_TPM2_ACPI_TABLE_REVISION,
    //
    // Compiler initializes the remaining bytes to 0
    // These fields should be filled in in production
    //
  },
  0, // BIT0~15:  PlatformClass
     // BIT16~31: Reserved
  0, // Control Area
  EFI_TPM2_ACPI_TABLE_START_METHOD_TIS, // StartMethod
};

EFI_SMM_VARIABLE_PROTOCOL  *mSmmVariable;
TCG_NVS                    *mTcgNvs;

/**
  Software SMI callback for TPM physical presence which is called from ACPI method.

  Caution: This function may receive untrusted input.
  Variable and ACPINvs are external input, so this function will validate
  its data structure to be valid value.

  @param[in]      DispatchHandle  The unique handle assigned to this handler by SmiHandlerRegister().
  @param[in]      Context         Points to an optional handler context which was specified when the
                                  handler was registered.
  @param[in, out] CommBuffer      A pointer to a collection of data in memory that will
                                  be conveyed from a non-SMM environment into an SMM environment.
  @param[in, out] CommBufferSize  The size of the CommBuffer.

  @retval EFI_SUCCESS             The interrupt was handled successfully.

**/
EFI_STATUS
EFIAPI
PhysicalPresenceCallback (
  IN EFI_HANDLE                  DispatchHandle,
  IN CONST VOID                  *Context,
  IN OUT VOID                    *CommBuffer,
  IN OUT UINTN                   *CommBufferSize
  )
{
  UINT32                MostRecentRequest;
  UINT32                Response;
  UINT32                OperationRequest;
  UINT32                RequestParameter;


  if (mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_RETURN_REQUEST_RESPONSE_TO_OS) {
    mTcgNvs->PhysicalPresence.ReturnCode = Tcg2PhysicalPresenceLibReturnOperationResponseToOsFunction (
                                             &MostRecentRequest,
                                             &Response
                                             );
    mTcgNvs->PhysicalPresence.LastRequest = MostRecentRequest;
    mTcgNvs->PhysicalPresence.Response = Response;
    return EFI_SUCCESS;
  } else if ((mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_SUBMIT_REQUEST_TO_BIOS)
          || (mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_SUBMIT_REQUEST_TO_BIOS_2)) {

    OperationRequest = mTcgNvs->PhysicalPresence.Request;
    RequestParameter = mTcgNvs->PhysicalPresence.RequestParameter;
    mTcgNvs->PhysicalPresence.ReturnCode = Tcg2PhysicalPresenceLibSubmitRequestToPreOSFunctionEx (
                                             &OperationRequest,
                                             &RequestParameter
                                             );
    mTcgNvs->PhysicalPresence.Request = OperationRequest;
    mTcgNvs->PhysicalPresence.RequestParameter = RequestParameter;
  } else if (mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_GET_USER_CONFIRMATION_STATUS_FOR_REQUEST) {
    mTcgNvs->PhysicalPresence.ReturnCode = Tcg2PhysicalPresenceLibGetUserConfirmationStatusFunction (mTcgNvs->PPRequestUserConfirm);
  }

  return EFI_SUCCESS;
}


/**
  Software SMI callback for MemoryClear which is called from ACPI method.

  Caution: This function may receive untrusted input.
  Variable and ACPINvs are external input, so this function will validate
  its data structure to be valid value.

  @param[in]      DispatchHandle  The unique handle assigned to this handler by SmiHandlerRegister().
  @param[in]      Context         Points to an optional handler context which was specified when the
                                  handler was registered.
  @param[in, out] CommBuffer      A pointer to a collection of data in memory that will
                                  be conveyed from a non-SMM environment into an SMM environment.
  @param[in, out] CommBufferSize  The size of the CommBuffer.

  @retval EFI_SUCCESS             The interrupt was handled successfully.

**/
EFI_STATUS
EFIAPI
MemoryClearCallback (
  IN EFI_HANDLE                  DispatchHandle,
  IN CONST VOID                  *Context,
  IN OUT VOID                    *CommBuffer,
  IN OUT UINTN                   *CommBufferSize
  )
{
  EFI_STATUS                     Status;
  UINTN                          DataSize;
  UINT8                          MorControl;

  mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_SUCCESS;
  if (mTcgNvs->MemoryClear.Parameter == ACPI_FUNCTION_DSM_MEMORY_CLEAR_INTERFACE) {
    MorControl = (UINT8) mTcgNvs->MemoryClear.Request;
  } else if (mTcgNvs->MemoryClear.Parameter == ACPI_FUNCTION_PTS_CLEAR_MOR_BIT) {
    DataSize = sizeof (UINT8);
    Status = mSmmVariable->SmmGetVariable (
                             MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME,
                             &gEfiMemoryOverwriteControlDataGuid,
                             NULL,
                             &DataSize,
                             &MorControl
                             );
    if (EFI_ERROR (Status)) {
      mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_GENERAL_FAILURE;
      DEBUG ((EFI_D_ERROR, "[TPM] Get MOR variable failure! Status = %r\n", Status));
      return EFI_SUCCESS;
    }

    if (MOR_CLEAR_MEMORY_VALUE (MorControl) == 0x0) {
      return EFI_SUCCESS;
    }
    MorControl &= ~MOR_CLEAR_MEMORY_BIT_MASK;
  } else {
    mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_GENERAL_FAILURE;
    DEBUG ((EFI_D_ERROR, "[TPM] MOR Parameter error! Parameter = %x\n", mTcgNvs->MemoryClear.Parameter));
    return EFI_SUCCESS;
  }

  DataSize = sizeof (UINT8);
  Status = mSmmVariable->SmmSetVariable (
                           MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME,
                           &gEfiMemoryOverwriteControlDataGuid,
                           EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
                           DataSize,
                           &MorControl
                           );
  if (EFI_ERROR (Status)) {
    mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_GENERAL_FAILURE;
    DEBUG ((EFI_D_ERROR, "[TPM] Set MOR variable failure! Status = %r\n", Status));
  }

  return EFI_SUCCESS;
}

/**
  Find the operation region in TCG ACPI table by given Name and Size,
  and initialize it if the region is found.

  @param[in, out] Table          The TPM item in ACPI table.
  @param[in]      Name           The name string to find in TPM table.
  @param[in]      Size           The size of the region to find.

  @return                        The allocated address for the found region.

**/
VOID *
AssignOpRegion (
  EFI_ACPI_DESCRIPTION_HEADER    *Table,
  UINT32                         Name,
  UINT16                         Size
  )
{
  EFI_STATUS                     Status;
  AML_OP_REGION_32_8             *OpRegion;
  EFI_PHYSICAL_ADDRESS           MemoryAddress;

  MemoryAddress = SIZE_4GB - 1;

  //
  // Patch some pointers for the ASL code before loading the SSDT.
  //
  for (OpRegion  = (AML_OP_REGION_32_8 *) (Table + 1);
       OpRegion <= (AML_OP_REGION_32_8 *) ((UINT8 *) Table + Table->Length);
       OpRegion  = (AML_OP_REGION_32_8 *) ((UINT8 *) OpRegion + 1)) {
    if ((OpRegion->OpRegionOp  == AML_EXT_REGION_OP) &&
        (OpRegion->NameString  == Name) &&
        (OpRegion->DWordPrefix == AML_DWORD_PREFIX) &&
        (OpRegion->BytePrefix  == AML_BYTE_PREFIX)) {

      Status = gBS->AllocatePages(AllocateMaxAddress, EfiACPIMemoryNVS, EFI_SIZE_TO_PAGES (Size), &MemoryAddress);
      ASSERT_EFI_ERROR (Status);
      ZeroMem ((VOID *)(UINTN)MemoryAddress, Size);
      OpRegion->RegionOffset = (UINT32) (UINTN) MemoryAddress;
      OpRegion->RegionLen    = (UINT8) Size;
      break;
    }
  }

  return (VOID *) (UINTN) MemoryAddress;
}

/**
  Patch version string of Physical Presence interface supported by platform. The initial string tag in TPM
ACPI table is "$PV".

  @param[in, out] Table          The TPM item in ACPI table.
  @param[in]      PPVer          Version string of Physical Presence interface supported by platform.

  @return                        The allocated address for the found region.

**/
EFI_STATUS
UpdatePPVersion (
  EFI_ACPI_DESCRIPTION_HEADER    *Table,
  CHAR8                          *PPVer
  )
{
  EFI_STATUS  Status;
  UINT8       *DataPtr;

  //
  // Patch some pointers for the ASL code before loading the SSDT.
  //
  for (DataPtr  = (UINT8 *)(Table + 1);
       DataPtr <= (UINT8 *) ((UINT8 *) Table + Table->Length - PHYSICAL_PRESENCE_VERSION_SIZE);
       DataPtr += 1) {
    if (AsciiStrCmp((CHAR8 *)DataPtr,  PHYSICAL_PRESENCE_VERSION_TAG) == 0) {
      Status = AsciiStrCpyS((CHAR8 *)DataPtr, PHYSICAL_PRESENCE_VERSION_SIZE, PPVer);
      DEBUG((EFI_D_INFO, "TPM2 Physical Presence Interface Version update status 0x%x\n", Status));
      return Status;
    }
  }

  return EFI_NOT_FOUND;
}

/**
  Patch interrupt resources returned by TPM _PRS. ResourceTemplate to patch is determined by input
  interrupt buffer size. BufferSize, PkgLength and interrupt descriptor in ByteList need to be patched

  @param[in, out] Table            The TPM item in ACPI table.
  @param[in]      IrqBuffer        Input new IRQ buffer.
  @param[in]      IrqBuffserSize   Input new IRQ buffer size.
  @param[out]     IsShortFormPkgLength   If _PRS returns Short length Package(ACPI spec 20.2.4).

  @return                          patch status.

**/
EFI_STATUS
UpdatePossibleResource (
  IN OUT  EFI_ACPI_DESCRIPTION_HEADER    *Table,
  IN      UINT32                         *IrqBuffer,
  IN      UINT32                         IrqBuffserSize,
  OUT     BOOLEAN                        *IsShortFormPkgLength
  )
{
  UINT8       *DataPtr;
  UINT8       *DataEndPtr;
  UINT32      NewPkgLength;
  UINT32      OrignalPkgLength;

  NewPkgLength     = 0;
  OrignalPkgLength = 0;
  DataEndPtr       = NULL;

  //
  // Follow ACPI spec
  //           6.4.3   Extend Interrupt Descriptor.
  //           19.3.3 ASL Resource Template
  //           20      AML specification
  // to patch TPM ACPI object _PRS returned ResourceTemplate() containing 2 resource descriptors and an auto appended End Tag
  //
  //  AML data is organized by following rule.
  //  Code need to patch BufferSize and PkgLength and interrupt descriptor in ByteList
  //
  // =============  Buffer ====================
  //           DefBuffer := BufferOp PkgLength BufferSize ByteList
  //            BufferOp := 0x11
  //
  // ==============PkgLength==================
  //          PkgLength := PkgLeadByte |
  //                              <PkgLeadByte ByteData> |
  //                              <PkgLeadByte ByteData ByteData> |
  //                              <PkgLeadByte ByteData ByteData ByteData>
  //
  //       PkgLeadByte := <bit 7-6: ByteData count that follows (0-3)>
  //                               <bit 5-4: Only used if PkgLength <= 63 >
  //                               <bit 3-0: Least significant package length nybble>
  //
  //==============BufferSize==================
  //        BufferSize := Integer
  //           Integer := ByteConst|WordConst|DwordConst....
  //
  //           ByteConst := BytePrefix ByteData
  //
  //==============ByteList===================
  //          ByteList := ByteData ByteList
  //
  //=========================================

  //
  // 1. Check TPM_PRS_RESS with PkgLength <=63 can hold the input interrupt number buffer for patching
  //
  for (DataPtr  = (UINT8 *)(Table + 1);
       DataPtr < (UINT8 *) ((UINT8 *) Table + Table->Length - (TPM_PRS_RES_NAME_SIZE + TPM_POS_RES_TEMPLATE_MIN_SIZE));
       DataPtr += 1) {
    if (CompareMem(DataPtr, TPM_PRS_RESS, TPM_PRS_RES_NAME_SIZE) == 0) {
      //
      // Jump over object name & BufferOp
      //
      DataPtr += TPM_PRS_RES_NAME_SIZE + 1;

      if ((*DataPtr & (BIT7|BIT6)) == 0) {
        OrignalPkgLength = (UINT32)*DataPtr;
        DataEndPtr       = DataPtr + OrignalPkgLength;

        //
        // Jump over PkgLength = PkgLeadByte only
        //
        NewPkgLength++;

        //
        // Jump over BufferSize
        //
        if (*(DataPtr + 1) == AML_BYTE_PREFIX) {
          NewPkgLength += 2;
        } else if (*(DataPtr + 1) == AML_WORD_PREFIX) {
          NewPkgLength += 3;
        } else if (*(DataPtr + 1) == AML_DWORD_PREFIX) {
          NewPkgLength += 5;
        } else {
          ASSERT(FALSE);
          return EFI_UNSUPPORTED;
        }
      } else {
        ASSERT(FALSE);
        return EFI_UNSUPPORTED;
      }

      //
      // Include Memory32Fixed Descriptor (12 Bytes) + Interrupt Descriptor header(5 Bytes) + End Tag(2 Bytes)
      //
      NewPkgLength += 19 + IrqBuffserSize;
      if (NewPkgLength > 63) {
        break;
      }

      if (NewPkgLength > OrignalPkgLength) {
        ASSERT(FALSE);
        return EFI_INVALID_PARAMETER;
      }

      //
      // 1.1 Patch PkgLength
      //
      *DataPtr = (UINT8)NewPkgLength;

      //
      // 1.2 Patch BufferSize = sizeof(Memory32Fixed Descriptor + Interrupt Descriptor + End Tag).
      //      It is Little endian. So only patch lowest byte of BufferSize due to current interrupt number limit.
      //
      *(DataPtr + 2) = (UINT8)(IrqBuffserSize + 19);

      //
      // Notify _PRS to report short formed ResourceTemplate
      //
      *IsShortFormPkgLength = TRUE;

      break;
    }
  }

  //
  // 2. Use TPM_PRS_RESL with PkgLength > 63 to hold longer input interrupt number buffer for patching
  //
  if (NewPkgLength > 63) {
    NewPkgLength     = 0;
    OrignalPkgLength = 0;
    for (DataPtr  = (UINT8 *)(Table + 1);
         DataPtr < (UINT8 *) ((UINT8 *) Table + Table->Length - (TPM_PRS_RES_NAME_SIZE + TPM_POS_RES_TEMPLATE_MIN_SIZE));
         DataPtr += 1) {
      if (CompareMem(DataPtr, TPM_PRS_RESL, TPM_PRS_RES_NAME_SIZE) == 0) {
        //
        // Jump over object name & BufferOp
        //
        DataPtr += TPM_PRS_RES_NAME_SIZE + 1;

        if ((*DataPtr & (BIT7|BIT6)) != 0) {
          OrignalPkgLength = (UINT32)(*(DataPtr + 1) << 4) + (*DataPtr & 0x0F);
          DataEndPtr       = DataPtr + OrignalPkgLength;
          //
          // Jump over PkgLength = PkgLeadByte + ByteData length
          //
          NewPkgLength += 1 + ((*DataPtr & (BIT7|BIT6)) >> 6);

          //
          // Jump over BufferSize
          //
          if (*(DataPtr + NewPkgLength) == AML_BYTE_PREFIX) {
            NewPkgLength += 2;
          } else if (*(DataPtr + NewPkgLength) == AML_WORD_PREFIX) {
            NewPkgLength += 3;
          } else if (*(DataPtr + NewPkgLength) == AML_DWORD_PREFIX) {
            NewPkgLength += 5;
          } else {
            ASSERT(FALSE);
            return EFI_UNSUPPORTED;
          }
        } else {
          ASSERT(FALSE);
          return EFI_UNSUPPORTED;
        }

        //
        // Include Memory32Fixed Descriptor (12 Bytes) + Interrupt Descriptor header(5 Bytes) + End Tag(2  Bytes)
        //
        NewPkgLength += 19 + IrqBuffserSize;

        if (NewPkgLength > OrignalPkgLength) {
          ASSERT(FALSE);
          return EFI_INVALID_PARAMETER;
        }

        //
        // 2.1 Patch PkgLength. Only patch PkgLeadByte and first ByteData
        //
        *DataPtr = (UINT8)((*DataPtr) & 0xF0) | (NewPkgLength & 0x0F);
        *(DataPtr + 1) = (UINT8)((NewPkgLength & 0xFF0) >> 4);

        //
        // 2.2 Patch BufferSize = sizeof(Memory32Fixed Descriptor + Interrupt Descriptor + End Tag).
        //     It is Little endian. Only patch lowest byte of BufferSize due to current interrupt number limit.
        //
        *(DataPtr + 2 + ((*DataPtr & (BIT7|BIT6)) >> 6)) = (UINT8)(IrqBuffserSize + 19);

        //
        // Notify _PRS to report long formed ResourceTemplate
        //
        *IsShortFormPkgLength = FALSE;
        break;
      }
    }
  }

  if (DataPtr >= (UINT8 *) ((UINT8 *) Table + Table->Length - (TPM_PRS_RES_NAME_SIZE + TPM_POS_RES_TEMPLATE_MIN_SIZE))) {
    return EFI_NOT_FOUND;
  }

  //
  // 3. Move DataPtr to Interrupt descriptor header and patch interrupt descriptor.
  //     5 bytes for interrupt descriptor header, 2 bytes for End Tag
  //
  DataPtr += NewPkgLength - (5 + IrqBuffserSize + 2);
  //
  //   3.1 Patch Length bit[7:0] of Interrupt descriptor patch interrupt descriptor
  //
  *(DataPtr + 1) = (UINT8)(2 + IrqBuffserSize);
  //
  //   3.2 Patch Interrupt Table Length
  //
  *(DataPtr + 4) = (UINT8)(IrqBuffserSize / sizeof(UINT32));
  //
  //   3.3 Copy patched InterruptNumBuffer
  //
  CopyMem(DataPtr + 5, IrqBuffer, IrqBuffserSize);

  //
  // 4. Jump over Interrupt descriptor and Patch END Tag, set Checksum field to 0
  //
  DataPtr       += 5 + IrqBuffserSize;
  *DataPtr       = ACPI_END_TAG_DESCRIPTOR;
  *(DataPtr + 1) = 0;

  //
  // 5. Jump over new ResourceTemplate. Stuff rest bytes to NOOP
  //
  DataPtr += 2;
  if (DataPtr < DataEndPtr) {
    SetMem(DataPtr, (UINTN)DataEndPtr - (UINTN)DataPtr, AML_NOOP_OP);
  }

  return EFI_SUCCESS;
}

/**
  Patch TPM2 device HID string.  The initial string tag in TPM2 ACPI table is "NNN0000".

  @param[in, out] Table          The TPM2 SSDT ACPI table.

  @return                               HID Update status.

**/
EFI_STATUS
UpdateHID (
  EFI_ACPI_DESCRIPTION_HEADER    *Table
  )
{
  EFI_STATUS  Status;
  UINT8       *DataPtr;
  CHAR8       Hid[TPM_HID_ACPI_SIZE];
  UINT32      ManufacturerID;
  UINT32      FirmwareVersion1;
  UINT32      FirmwareVersion2;
  BOOLEAN     PnpHID;

  PnpHID = TRUE;

  //
  // Initialize HID with Default PNP string
  //
  ZeroMem(Hid, TPM_HID_ACPI_SIZE);

  //
  // Get Manufacturer ID
  //
  Status = Tpm2GetCapabilityManufactureID(&ManufacturerID);
  if (!EFI_ERROR(Status)) {
    DEBUG((EFI_D_INFO, "TPM_PT_MANUFACTURER 0x%08x\n", ManufacturerID));
    //
    // ManufacturerID defined in TCG Vendor ID Registry
    // may tailed with 0x00 or 0x20
    //
    if ((ManufacturerID >> 24) == 0x00 || ((ManufacturerID >> 24) == 0x20)) {
      //
      //  HID containing PNP ID "NNN####"
      //   NNN is uppercase letter for Vendor ID specified by manufacturer
      //
      CopyMem(Hid, &ManufacturerID, 3);
    } else {
      //
      //  HID containing ACP ID "NNNN####"
      //   NNNN is uppercase letter for Vendor ID specified by manufacturer
      //
      CopyMem(Hid, &ManufacturerID, 4);
      PnpHID = FALSE;
    }
  } else {
    DEBUG ((EFI_D_ERROR, "Get TPM_PT_MANUFACTURER failed %x!\n", Status));
    ASSERT(FALSE);
    return Status;
  }

  Status = Tpm2GetCapabilityFirmwareVersion(&FirmwareVersion1, &FirmwareVersion2);
  if (!EFI_ERROR(Status)) {
    DEBUG((EFI_D_INFO, "TPM_PT_FIRMWARE_VERSION_1 0x%x\n", FirmwareVersion1));
    DEBUG((EFI_D_INFO, "TPM_PT_FIRMWARE_VERSION_2 0x%x\n", FirmwareVersion2));
    //
    //   #### is Firmware Version 1
    //
    if (PnpHID) {
      AsciiSPrint(Hid + 3, TPM_HID_PNP_SIZE - 3, "%02d%02d", ((FirmwareVersion1 & 0xFFFF0000) >> 16), (FirmwareVersion1 & 0x0000FFFF));
    } else {
      AsciiSPrint(Hid + 4, TPM_HID_ACPI_SIZE - 4, "%02d%02d", ((FirmwareVersion1 & 0xFFFF0000) >> 16), (FirmwareVersion1 & 0x0000FFFF));
    }

  } else {
    DEBUG ((EFI_D_ERROR, "Get TPM_PT_FIRMWARE_VERSION_X failed %x!\n", Status));
    ASSERT(FALSE);
    return Status;
  }

  //
  // Patch HID in ASL code before loading the SSDT.
  //
  for (DataPtr  = (UINT8 *)(Table + 1);
       DataPtr <= (UINT8 *) ((UINT8 *) Table + Table->Length - TPM_HID_PNP_SIZE);
       DataPtr += 1) {
    if (AsciiStrCmp((CHAR8 *)DataPtr,  TPM_HID_TAG) == 0) {
      if (PnpHID) {
        CopyMem(DataPtr, Hid, TPM_HID_PNP_SIZE);
        //
        // if HID is PNP ID, patch the last byte in HID TAG to Noop
        //
        *(DataPtr + TPM_HID_PNP_SIZE) = AML_NOOP_OP;
      } else {

        CopyMem(DataPtr, Hid, TPM_HID_ACPI_SIZE);
      }
      DEBUG((DEBUG_INFO, "TPM2 ACPI _HID is patched to %a\n", DataPtr));

      return Status;
    }
  }

  DEBUG((EFI_D_ERROR, "TPM2 ACPI HID TAG for patch not found!\n"));
  return EFI_NOT_FOUND;
}

/**
  Initialize and publish TPM items in ACPI table.

  @retval   EFI_SUCCESS     The TCG ACPI table is published successfully.
  @retval   Others          The TCG ACPI table is not published.

**/
EFI_STATUS
PublishAcpiTable (
  VOID
  )
{
  EFI_STATUS                     Status;
  EFI_ACPI_TABLE_PROTOCOL        *AcpiTable;
  UINTN                          TableKey;
  EFI_ACPI_DESCRIPTION_HEADER    *Table;
  UINTN                          TableSize;
  UINT32                         *PossibleIrqNumBuf;
  UINT32                         PossibleIrqNumBufSize;
  BOOLEAN                        IsShortFormPkgLength;

  IsShortFormPkgLength = FALSE;

  Status = GetSectionFromFv (
             &gEfiCallerIdGuid,
             EFI_SECTION_RAW,
             0,
             (VOID **) &Table,
             &TableSize
             );
  ASSERT_EFI_ERROR (Status);

  //
  // Measure to PCR[0] with event EV_POST_CODE ACPI DATA.
  // The measurement has to be done before any update.
  // Otherwise, the PCR record would be different after TPM FW update
  // or the PCD configuration change.
  //
  TpmMeasureAndLogData(
    0,
    EV_POST_CODE,
    EV_POSTCODE_INFO_ACPI_DATA,
    ACPI_DATA_LEN,
    Table,
    TableSize
    );

  //
  // Update Table version before measuring it to PCR
  //
  Status = UpdatePPVersion(Table, (CHAR8 *)PcdGetPtr(PcdTcgPhysicalPresenceInterfaceVer));
  ASSERT_EFI_ERROR (Status);

  DEBUG ((
    DEBUG_INFO,
    "Current physical presence interface version - %a\n",
    (CHAR8 *) PcdGetPtr(PcdTcgPhysicalPresenceInterfaceVer)
    ));

  //
  // Update TPM2 HID after measuring it to PCR
  //
  Status = UpdateHID(Table);
  if (EFI_ERROR(Status)) {
    return Status;
  }

  if (PcdGet32(PcdTpm2CurrentIrqNum) != 0) {
    //
    // Patch _PRS interrupt resource only when TPM interrupt is supported
    //
    PossibleIrqNumBuf     = (UINT32 *)PcdGetPtr(PcdTpm2PossibleIrqNumBuf);
    PossibleIrqNumBufSize = (UINT32)PcdGetSize(PcdTpm2PossibleIrqNumBuf);

    if (PossibleIrqNumBufSize <= MAX_PRS_INT_BUF_SIZE && (PossibleIrqNumBufSize % sizeof(UINT32)) == 0) {
      Status = UpdatePossibleResource(Table, PossibleIrqNumBuf, PossibleIrqNumBufSize, &IsShortFormPkgLength);
      DEBUG ((
        DEBUG_INFO,
        "UpdatePossibleResource status - %x. TPM2 service may not ready in OS.\n",
        Status
        ));
    } else {
      DEBUG ((
        DEBUG_INFO,
        "PcdTpm2PossibleIrqNumBuf size %x is not correct. TPM2 service may not ready in OS.\n",
        PossibleIrqNumBufSize
      ));
    }
  }

  ASSERT (Table->OemTableId == SIGNATURE_64 ('T', 'p', 'm', '2', 'T', 'a', 'b', 'l'));
  CopyMem (Table->OemId, PcdGetPtr (PcdAcpiDefaultOemId), sizeof (Table->OemId) );
  mTcgNvs = AssignOpRegion (Table, SIGNATURE_32 ('T', 'N', 'V', 'S'), (UINT16) sizeof (TCG_NVS));
  ASSERT (mTcgNvs != NULL);
  mTcgNvs->TpmIrqNum            = PcdGet32(PcdTpm2CurrentIrqNum);
  mTcgNvs->IsShortFormPkgLength = IsShortFormPkgLength;

  //
  // Publish the TPM ACPI table. Table is re-checksummed.
  //
  Status = gBS->LocateProtocol (&gEfiAcpiTableProtocolGuid, NULL, (VOID **) &AcpiTable);
  ASSERT_EFI_ERROR (Status);

  TableKey = 0;
  Status = AcpiTable->InstallAcpiTable (
                        AcpiTable,
                        Table,
                        TableSize,
                        &TableKey
                        );
  ASSERT_EFI_ERROR (Status);

  return Status;
}

/**
  Publish TPM2 ACPI table

  @retval   EFI_SUCCESS     The TPM2 ACPI table is published successfully.
  @retval   Others          The TPM2 ACPI table is not published.

**/
EFI_STATUS
PublishTpm2 (
  VOID
  )
{
  EFI_STATUS                     Status;
  EFI_ACPI_TABLE_PROTOCOL        *AcpiTable;
  UINTN                          TableKey;
  UINT64                         OemTableId;
  EFI_TPM2_ACPI_CONTROL_AREA     *ControlArea;
  TPM2_PTP_INTERFACE_TYPE        InterfaceType;

  //
  // Measure to PCR[0] with event EV_POST_CODE ACPI DATA.
  // The measurement has to be done before any update.
  // Otherwise, the PCR record would be different after event log update
  // or the PCD configuration change.
  //
  TpmMeasureAndLogData(
    0,
    EV_POST_CODE,
    EV_POSTCODE_INFO_ACPI_DATA,
    ACPI_DATA_LEN,
    &mTpm2AcpiTemplate,
    mTpm2AcpiTemplate.Header.Length
    );

  mTpm2AcpiTemplate.Header.Revision = PcdGet8(PcdTpm2AcpiTableRev);
  DEBUG((DEBUG_INFO, "Tpm2 ACPI table revision is %d\n", mTpm2AcpiTemplate.Header.Revision));

  //
  // PlatformClass is only valid for version 4 and above
  //    BIT0~15:  PlatformClass
  //    BIT16~31: Reserved
  //
  if (mTpm2AcpiTemplate.Header.Revision >= EFI_TPM2_ACPI_TABLE_REVISION_4) {
    mTpm2AcpiTemplate.Flags = (mTpm2AcpiTemplate.Flags & 0xFFFF0000) | PcdGet8(PcdTpmPlatformClass);
    DEBUG((DEBUG_INFO, "Tpm2 ACPI table PlatformClass is %d\n", (mTpm2AcpiTemplate.Flags & 0x0000FFFF)));
  }

  mTpm2AcpiTemplate.Laml = PcdGet32(PcdTpm2AcpiTableLaml);
  mTpm2AcpiTemplate.Lasa = PcdGet64(PcdTpm2AcpiTableLasa);
  if ((mTpm2AcpiTemplate.Header.Revision < EFI_TPM2_ACPI_TABLE_REVISION_4) ||
      (mTpm2AcpiTemplate.Laml == 0) || (mTpm2AcpiTemplate.Lasa == 0)) {
    //
    // If version is smaller than 4 or Laml/Lasa is not valid, rollback to original Length.
    //
    mTpm2AcpiTemplate.Header.Length = sizeof(EFI_TPM2_ACPI_TABLE);
  }

  InterfaceType = PcdGet8(PcdActiveTpmInterfaceType);
  switch (InterfaceType) {
  case Tpm2PtpInterfaceCrb:
    mTpm2AcpiTemplate.StartMethod = EFI_TPM2_ACPI_TABLE_START_METHOD_COMMAND_RESPONSE_BUFFER_INTERFACE;
    mTpm2AcpiTemplate.AddressOfControlArea = PcdGet64 (PcdTpmBaseAddress) + 0x40;
    ControlArea = (EFI_TPM2_ACPI_CONTROL_AREA *)(UINTN)mTpm2AcpiTemplate.AddressOfControlArea;
    ControlArea->CommandSize  = 0xF80;
    ControlArea->ResponseSize = 0xF80;
    ControlArea->Command      = PcdGet64 (PcdTpmBaseAddress) + 0x80;
    ControlArea->Response     = PcdGet64 (PcdTpmBaseAddress) + 0x80;
    break;
  case Tpm2PtpInterfaceFifo:
  case Tpm2PtpInterfaceTis:
    break;
  default:
    DEBUG((EFI_D_ERROR, "TPM2 InterfaceType get error! %d\n", InterfaceType));
    break;
  }

  CopyMem (mTpm2AcpiTemplate.Header.OemId, PcdGetPtr (PcdAcpiDefaultOemId), sizeof (mTpm2AcpiTemplate.Header.OemId));
  OemTableId = PcdGet64 (PcdAcpiDefaultOemTableId);
  CopyMem (&mTpm2AcpiTemplate.Header.OemTableId, &OemTableId, sizeof (UINT64));
  mTpm2AcpiTemplate.Header.OemRevision      = PcdGet32 (PcdAcpiDefaultOemRevision);
  mTpm2AcpiTemplate.Header.CreatorId        = PcdGet32 (PcdAcpiDefaultCreatorId);
  mTpm2AcpiTemplate.Header.CreatorRevision  = PcdGet32 (PcdAcpiDefaultCreatorRevision);

  //
  // Construct ACPI table
  //
  Status = gBS->LocateProtocol (&gEfiAcpiTableProtocolGuid, NULL, (VOID **) &AcpiTable);
  ASSERT_EFI_ERROR (Status);

  Status = AcpiTable->InstallAcpiTable (
                        AcpiTable,
                        &mTpm2AcpiTemplate,
                        mTpm2AcpiTemplate.Header.Length,
                        &TableKey
                        );
  ASSERT_EFI_ERROR (Status);

  return Status;
}

/**
  The driver's entry point.

  It install callbacks for TPM physical presence and MemoryClear, and locate
  SMM variable to be used in the callback function.

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

  @retval EFI_SUCCESS     The entry point is executed successfully.
  @retval Others          Some error occurs when executing this entry point.

**/
EFI_STATUS
EFIAPI
InitializeTcgSmm (
  IN EFI_HANDLE                  ImageHandle,
  IN EFI_SYSTEM_TABLE            *SystemTable
  )
{
  EFI_STATUS                     Status;
  EFI_SMM_SW_DISPATCH2_PROTOCOL  *SwDispatch;
  EFI_SMM_SW_REGISTER_CONTEXT    SwContext;
  EFI_HANDLE                     SwHandle;

  if (!CompareGuid (PcdGetPtr(PcdTpmInstanceGuid), &gEfiTpmDeviceInstanceTpm20DtpmGuid)){
    DEBUG ((EFI_D_ERROR, "No TPM2 DTPM instance required!\n"));
    return EFI_UNSUPPORTED;
  }

  Status = PublishAcpiTable ();
  ASSERT_EFI_ERROR (Status);

  //
  // Get the Sw dispatch protocol and register SMI callback functions.
  //
  Status = gSmst->SmmLocateProtocol (&gEfiSmmSwDispatch2ProtocolGuid, NULL, (VOID**)&SwDispatch);
  ASSERT_EFI_ERROR (Status);
  SwContext.SwSmiInputValue = (UINTN) -1;
  Status = SwDispatch->Register (SwDispatch, PhysicalPresenceCallback, &SwContext, &SwHandle);
  ASSERT_EFI_ERROR (Status);
  if (EFI_ERROR (Status)) {
    return Status;
  }
  mTcgNvs->PhysicalPresence.SoftwareSmi = (UINT8) SwContext.SwSmiInputValue;

  SwContext.SwSmiInputValue = (UINTN) -1;
  Status = SwDispatch->Register (SwDispatch, MemoryClearCallback, &SwContext, &SwHandle);
  ASSERT_EFI_ERROR (Status);
  if (EFI_ERROR (Status)) {
    return Status;
  }
  mTcgNvs->MemoryClear.SoftwareSmi = (UINT8) SwContext.SwSmiInputValue;

  //
  // Locate SmmVariableProtocol.
  //
  Status = gSmst->SmmLocateProtocol (&gEfiSmmVariableProtocolGuid, NULL, (VOID**)&mSmmVariable);
  ASSERT_EFI_ERROR (Status);

  //
  // Set TPM2 ACPI table
  //
  Status = PublishTpm2 ();
  ASSERT_EFI_ERROR (Status);


  return EFI_SUCCESS;
}