SecurityPkg: Cache TPM interface type info

[mirror_edk2.git] / SecurityPkg / Library / Tpm2DeviceLibDTpm / Tpm2Ptp.c

/** @file\r
  PTP (Platform TPM Profile) CRB (Command Response Buffer) interface used by dTPM2.0 library.\r
\r
Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>\r
This program and the accompanying materials\r
are licensed and made available under the terms and conditions of the BSD License\r
which accompanies this distribution.  The full text of the license may be found at\r
http://opensource.org/licenses/bsd-license.php\r
\r
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
#include <IndustryStandard/Tpm20.h>\r
\r
#include <Library/BaseLib.h>\r
#include <Library/BaseMemoryLib.h>\r
#include <Library/IoLib.h>\r
#include <Library/TimerLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/Tpm2DeviceLib.h>\r
#include <Library/PcdLib.h>\r
\r
#include <IndustryStandard/TpmPtp.h>\r
#include <IndustryStandard/TpmTis.h>\r
\r
//\r
// Execution of the command may take from several seconds to minutes for certain\r
// commands, such as key generation.\r
//\r
#define PTP_TIMEOUT_MAX             (90000 * 1000)  // 90s\r
\r
//\r
// Max TPM command/reponse length\r
//\r
#define TPMCMDBUFLENGTH             0x500\r
\r
/**\r
  Check whether TPM PTP register exist.\r
\r
  @param[in] Reg  Pointer to PTP register.\r
\r
  @retval    TRUE    TPM PTP exists.\r
  @retval    FALSE   TPM PTP is not found.\r
**/\r
BOOLEAN\r
Tpm2IsPtpPresence (\r
  IN VOID *Reg\r
  )\r
{\r
  UINT8                             RegRead;\r
\r
  RegRead = MmioRead8 ((UINTN)Reg);\r
  if (RegRead == 0xFF) {\r
    //\r
    // No TPM chip\r
    //\r
    return FALSE;\r
  }\r
  return TRUE;\r
}\r
\r
/**\r
  Check whether the value of a TPM chip register satisfies the input BIT setting.\r
\r
  @param[in]  Register     Address port of register to be checked.\r
  @param[in]  BitSet       Check these data bits are set.\r
  @param[in]  BitClear     Check these data bits are clear.\r
  @param[in]  TimeOut      The max wait time (unit MicroSecond) when checking register.\r
\r
  @retval     EFI_SUCCESS  The register satisfies the check bit.\r
  @retval     EFI_TIMEOUT  The register can't run into the expected status in time.\r
**/\r
EFI_STATUS\r
PtpCrbWaitRegisterBits (\r
  IN      UINT32                    *Register,\r
  IN      UINT32                    BitSet,\r
  IN      UINT32                    BitClear,\r
  IN      UINT32                    TimeOut\r
  )\r
{\r
  UINT32                            RegRead;\r
  UINT32                            WaitTime;\r
\r
  for (WaitTime = 0; WaitTime < TimeOut; WaitTime += 30){\r
    RegRead = MmioRead32 ((UINTN)Register);\r
    if ((RegRead & BitSet) == BitSet && (RegRead & BitClear) == 0) {\r
      return EFI_SUCCESS;\r
    }\r
    MicroSecondDelay (30);\r
  }\r
  return EFI_TIMEOUT;\r
}\r
\r
/**\r
  Get the control of TPM chip.\r
\r
  @param[in] CrbReg                Pointer to CRB register.\r
\r
  @retval    EFI_SUCCESS           Get the control of TPM chip.\r
  @retval    EFI_INVALID_PARAMETER CrbReg is NULL.\r
  @retval    EFI_NOT_FOUND         TPM chip doesn't exit.\r
  @retval    EFI_TIMEOUT           Can't get the TPM control in time.\r
**/\r
EFI_STATUS\r
PtpCrbRequestUseTpm (\r
  IN      PTP_CRB_REGISTERS_PTR      CrbReg\r
  )\r
{\r
  EFI_STATUS                        Status;\r
\r
  if (!Tpm2IsPtpPresence (CrbReg)) {\r
    return EFI_NOT_FOUND;\r
  }\r
\r
  MmioWrite32((UINTN)&CrbReg->LocalityControl, PTP_CRB_LOCALITY_CONTROL_REQUEST_ACCESS);\r
  Status = PtpCrbWaitRegisterBits (\r
             &CrbReg->LocalityStatus,\r
             PTP_CRB_LOCALITY_STATUS_GRANTED,\r
             0,\r
             PTP_TIMEOUT_A\r
             );\r
  return Status;\r
}\r
\r
/**\r
  Send a command to TPM for execution and return response data.\r
\r
  @param[in]      CrbReg        TPM register space base address.\r
  @param[in]      BufferIn      Buffer for command data.\r
  @param[in]      SizeIn        Size of command data.\r
  @param[in, out] BufferOut     Buffer for response data.\r
  @param[in, out] SizeOut       Size of response data.\r
\r
  @retval EFI_SUCCESS           Operation completed successfully.\r
  @retval EFI_BUFFER_TOO_SMALL  Response data buffer is too small.\r
  @retval EFI_DEVICE_ERROR      Unexpected device behavior.\r
  @retval EFI_UNSUPPORTED       Unsupported TPM version\r
\r
**/\r
EFI_STATUS\r
PtpCrbTpmCommand (\r
  IN     PTP_CRB_REGISTERS_PTR      CrbReg,\r
  IN     UINT8                      *BufferIn,\r
  IN     UINT32                     SizeIn,\r
  IN OUT UINT8                      *BufferOut,\r
  IN OUT UINT32                     *SizeOut\r
  )\r
{\r
  EFI_STATUS                        Status;\r
  UINT32                            Index;\r
  UINT32                            TpmOutSize;\r
  UINT16                            Data16;\r
  UINT32                            Data32;\r
\r
  DEBUG_CODE (\r
    UINTN  DebugSize;\r
\r
    DEBUG ((EFI_D_VERBOSE, "PtpCrbTpmCommand Send - "));\r
    if (SizeIn > 0x100) {\r
      DebugSize = 0x40;\r
    } else {\r
      DebugSize = SizeIn;\r
    }\r
    for (Index = 0; Index < DebugSize; Index++) {\r
      DEBUG ((EFI_D_VERBOSE, "%02x ", BufferIn[Index]));\r
    }\r
    if (DebugSize != SizeIn) {\r
      DEBUG ((EFI_D_VERBOSE, "...... "));\r
      for (Index = SizeIn - 0x20; Index < SizeIn; Index++) {\r
        DEBUG ((EFI_D_VERBOSE, "%02x ", BufferIn[Index]));\r
      }\r
    }\r
    DEBUG ((EFI_D_VERBOSE, "\n"));\r
  );\r
  TpmOutSize = 0;\r
\r
  //\r
  // STEP 0:\r
  // Ready is any time the TPM is ready to receive a command, following a write\r
  // of 1 by software to Request.cmdReady, as indicated by the Status field\r
  // being cleared to 0.\r
  //\r
  MmioWrite32((UINTN)&CrbReg->CrbControlRequest, PTP_CRB_CONTROL_AREA_REQUEST_COMMAND_READY);\r
  Status = PtpCrbWaitRegisterBits (\r
             &CrbReg->CrbControlRequest,\r
             0,\r
             PTP_CRB_CONTROL_AREA_REQUEST_COMMAND_READY,\r
             PTP_TIMEOUT_C\r
             );\r
  if (EFI_ERROR (Status)) {\r
    Status = EFI_DEVICE_ERROR;\r
    goto Exit;\r
  }\r
  Status = PtpCrbWaitRegisterBits (\r
             &CrbReg->CrbControlStatus,\r
             0,\r
             PTP_CRB_CONTROL_AREA_STATUS_TPM_IDLE,\r
             PTP_TIMEOUT_C\r
             );\r
  if (EFI_ERROR (Status)) {\r
    Status = EFI_DEVICE_ERROR;\r
    goto Exit;\r
  }\r
\r
  //\r
  // STEP 1:\r
  // Command Reception occurs following a Ready state between the write of the\r
  // first byte of a command to the Command Buffer and the receipt of a write\r
  // of 1 to Start.\r
  //\r
  for (Index = 0; Index < SizeIn; Index++) {\r
    MmioWrite8 ((UINTN)&CrbReg->CrbDataBuffer[Index], BufferIn[Index]);\r
  }\r
  MmioWrite32 ((UINTN)&CrbReg->CrbControlCommandAddressHigh, (UINT32)RShiftU64 ((UINTN)CrbReg->CrbDataBuffer, 32));\r
  MmioWrite32 ((UINTN)&CrbReg->CrbControlCommandAddressLow, (UINT32)(UINTN)CrbReg->CrbDataBuffer);\r
  MmioWrite32 ((UINTN)&CrbReg->CrbControlCommandSize, sizeof(CrbReg->CrbDataBuffer));\r
\r
  MmioWrite64 ((UINTN)&CrbReg->CrbControlResponseAddrss, (UINT32)(UINTN)CrbReg->CrbDataBuffer);\r
  MmioWrite32 ((UINTN)&CrbReg->CrbControlResponseSize, sizeof(CrbReg->CrbDataBuffer));\r
\r
  //\r
  // STEP 2:\r
  // Command Execution occurs after receipt of a 1 to Start and the TPM\r
  // clearing Start to 0.\r
  //\r
  MmioWrite32((UINTN)&CrbReg->CrbControlStart, PTP_CRB_CONTROL_START);\r
  Status = PtpCrbWaitRegisterBits (\r
             &CrbReg->CrbControlStart,\r
             0,\r
             PTP_CRB_CONTROL_START,\r
             PTP_TIMEOUT_MAX\r
             );\r
  if (EFI_ERROR (Status)) {\r
    //\r
    // Command Completion check timeout. Cancel the currently executing command by writing TPM_CRB_CTRL_CANCEL,\r
    // Expect TPM_RC_CANCELLED or successfully completed response.\r
    //\r
    MmioWrite32((UINTN)&CrbReg->CrbControlCancel, PTP_CRB_CONTROL_CANCEL);\r
    Status = PtpCrbWaitRegisterBits (\r
               &CrbReg->CrbControlStart,\r
               0,\r
               PTP_CRB_CONTROL_START,\r
               PTP_TIMEOUT_B\r
               );\r
    MmioWrite32((UINTN)&CrbReg->CrbControlCancel, 0);\r
\r
    if (EFI_ERROR(Status)) {\r
      //\r
      // Still in Command Execution state. Try to goIdle, the behavior is agnostic.\r
      //\r
      Status = EFI_DEVICE_ERROR;\r
      goto Exit;\r
    }\r
  }\r
\r
  //\r
  // STEP 3:\r
  // Command Completion occurs after completion of a command (indicated by the\r
  // TPM clearing TPM_CRB_CTRL_Start_x to 0) and before a write of a 1 by the\r
  // software to Request.goIdle.\r
  //\r
\r
  //\r
  // Get response data header\r
  //\r
  for (Index = 0; Index < sizeof (TPM2_RESPONSE_HEADER); Index++) {\r
    BufferOut[Index] = MmioRead8 ((UINTN)&CrbReg->CrbDataBuffer[Index]);\r
  }\r
  DEBUG_CODE (\r
    DEBUG ((EFI_D_VERBOSE, "PtpCrbTpmCommand ReceiveHeader - "));\r
    for (Index = 0; Index < sizeof (TPM2_RESPONSE_HEADER); Index++) {\r
      DEBUG ((EFI_D_VERBOSE, "%02x ", BufferOut[Index]));\r
    }\r
    DEBUG ((EFI_D_VERBOSE, "\n"));\r
  );\r
  //\r
  // Check the reponse data header (tag, parasize and returncode)\r
  //\r
  CopyMem (&Data16, BufferOut, sizeof (UINT16));\r
  // TPM2 should not use this RSP_COMMAND\r
  if (SwapBytes16 (Data16) == TPM_ST_RSP_COMMAND) {\r
    DEBUG ((EFI_D_ERROR, "TPM2: TPM_ST_RSP error - %x\n", TPM_ST_RSP_COMMAND));\r
    Status = EFI_UNSUPPORTED;\r
    goto Exit;\r
  }\r
\r
  CopyMem (&Data32, (BufferOut + 2), sizeof (UINT32));\r
  TpmOutSize  = SwapBytes32 (Data32);\r
  if (*SizeOut < TpmOutSize) {\r
    Status = EFI_BUFFER_TOO_SMALL;\r
    goto Exit;\r
  }\r
  *SizeOut = TpmOutSize;\r
  //\r
  // Continue reading the remaining data\r
  //\r
  for (Index = sizeof (TPM2_RESPONSE_HEADER); Index < TpmOutSize; Index++) {\r
    BufferOut[Index] = MmioRead8 ((UINTN)&CrbReg->CrbDataBuffer[Index]);\r
  }\r
Exit:\r
  DEBUG_CODE (\r
    DEBUG ((EFI_D_VERBOSE, "PtpCrbTpmCommand Receive - "));\r
    for (Index = 0; Index < TpmOutSize; Index++) {\r
      DEBUG ((EFI_D_VERBOSE, "%02x ", BufferOut[Index]));\r
    }\r
    DEBUG ((EFI_D_VERBOSE, "\n"));\r
  );\r
\r
  //\r
  // STEP 4:\r
  // Idle is any time TPM_CRB_CTRL_STS_x.Status.goIdle is 1.\r
  //\r
  MmioWrite32((UINTN)&CrbReg->CrbControlRequest, PTP_CRB_CONTROL_AREA_REQUEST_GO_IDLE);\r
  return Status;\r
}\r
\r
/**\r
  Send a command to TPM for execution and return response data.\r
\r
  @param[in]      TisReg        TPM register space base address.\r
  @param[in]      BufferIn      Buffer for command data.\r
  @param[in]      SizeIn        Size of command data.\r
  @param[in, out] BufferOut     Buffer for response data.\r
  @param[in, out] SizeOut       Size of response data.\r
\r
  @retval EFI_SUCCESS           Operation completed successfully.\r
  @retval EFI_BUFFER_TOO_SMALL  Response data buffer is too small.\r
  @retval EFI_DEVICE_ERROR      Unexpected device behavior.\r
  @retval EFI_UNSUPPORTED       Unsupported TPM version\r
\r
**/\r
EFI_STATUS\r
Tpm2TisTpmCommand (\r
  IN     TIS_PC_REGISTERS_PTR       TisReg,\r
  IN     UINT8                      *BufferIn,\r
  IN     UINT32                     SizeIn,\r
  IN OUT UINT8                      *BufferOut,\r
  IN OUT UINT32                     *SizeOut\r
  );\r
\r
/**\r
  Get the control of TPM chip by sending requestUse command TIS_PC_ACC_RQUUSE\r
  to ACCESS Register in the time of default TIS_TIMEOUT_A.\r
\r
  @param[in] TisReg                Pointer to TIS register.\r
\r
  @retval    EFI_SUCCESS           Get the control of TPM chip.\r
  @retval    EFI_INVALID_PARAMETER TisReg is NULL.\r
  @retval    EFI_NOT_FOUND         TPM chip doesn't exit.\r
  @retval    EFI_TIMEOUT           Can't get the TPM control in time.\r
**/\r
EFI_STATUS\r
TisPcRequestUseTpm (\r
  IN     TIS_PC_REGISTERS_PTR       TisReg\r
  );\r
\r
/**\r
  Return PTP interface type.\r
\r
  @param[in] Register                Pointer to PTP register.\r
\r
  @return PTP interface type.\r
**/\r
TPM2_PTP_INTERFACE_TYPE\r
Tpm2GetPtpInterface (\r
  IN VOID *Register\r
  )\r
{\r
  PTP_CRB_INTERFACE_IDENTIFIER  InterfaceId;\r
  PTP_FIFO_INTERFACE_CAPABILITY InterfaceCapability;\r
\r
  if (!Tpm2IsPtpPresence (Register)) {\r
    return Tpm2PtpInterfaceMax;\r
  }\r
  //\r
  // Check interface id\r
  //\r
  InterfaceId.Uint32 = MmioRead32 ((UINTN)&((PTP_CRB_REGISTERS *)Register)->InterfaceId);\r
  InterfaceCapability.Uint32 = MmioRead32 ((UINTN)&((PTP_FIFO_REGISTERS *)Register)->InterfaceCapability);\r
\r
  if ((InterfaceId.Bits.InterfaceType == PTP_INTERFACE_IDENTIFIER_INTERFACE_TYPE_CRB) &&\r
      (InterfaceId.Bits.InterfaceVersion == PTP_INTERFACE_IDENTIFIER_INTERFACE_VERSION_CRB) &&\r
      (InterfaceId.Bits.CapCRB != 0)) {\r
    return Tpm2PtpInterfaceCrb;\r
  }\r
  if ((InterfaceId.Bits.InterfaceType == PTP_INTERFACE_IDENTIFIER_INTERFACE_TYPE_FIFO) &&\r
      (InterfaceId.Bits.InterfaceVersion == PTP_INTERFACE_IDENTIFIER_INTERFACE_VERSION_FIFO) &&\r
      (InterfaceId.Bits.CapFIFO != 0) &&\r
      (InterfaceCapability.Bits.InterfaceVersion == INTERFACE_CAPABILITY_INTERFACE_VERSION_PTP)) {\r
    return Tpm2PtpInterfaceFifo;\r
  }\r
  return Tpm2PtpInterfaceTis;\r
}\r
\r
/**\r
  Dump PTP register information.\r
\r
  @param[in] Register                Pointer to PTP register.\r
**/\r
VOID\r
DumpPtpInfo (\r
  IN VOID *Register\r
  )\r
{\r
  PTP_CRB_INTERFACE_IDENTIFIER  InterfaceId;\r
  PTP_FIFO_INTERFACE_CAPABILITY InterfaceCapability;\r
  UINT8                         StatusEx;\r
  UINT16                        Vid;\r
  UINT16                        Did;\r
  UINT8                         Rid;\r
  TPM2_PTP_INTERFACE_TYPE       PtpInterface;\r
\r
  if (!Tpm2IsPtpPresence (Register)) {\r
    return ;\r
  }\r
\r
  InterfaceId.Uint32 = MmioRead32 ((UINTN)&((PTP_CRB_REGISTERS *)Register)->InterfaceId);\r
  InterfaceCapability.Uint32 = MmioRead32 ((UINTN)&((PTP_FIFO_REGISTERS *)Register)->InterfaceCapability);\r
  StatusEx = MmioRead8 ((UINTN)&((PTP_FIFO_REGISTERS *)Register)->StatusEx);\r
\r
  //\r
  // Dump InterfaceId Register for PTP\r
  //\r
  DEBUG ((EFI_D_INFO, "InterfaceId - 0x%08x\n", InterfaceId.Uint32));\r
  DEBUG ((EFI_D_INFO, "  InterfaceType    - 0x%02x\n", InterfaceId.Bits.InterfaceType));\r
  if (InterfaceId.Bits.InterfaceType != PTP_INTERFACE_IDENTIFIER_INTERFACE_TYPE_TIS) {\r
    DEBUG ((EFI_D_INFO, "  InterfaceVersion - 0x%02x\n", InterfaceId.Bits.InterfaceVersion));\r
    DEBUG ((EFI_D_INFO, "  CapFIFO          - 0x%x\n", InterfaceId.Bits.CapFIFO));\r
    DEBUG ((EFI_D_INFO, "  CapCRB           - 0x%x\n", InterfaceId.Bits.CapCRB));\r
  }\r
\r
  //\r
  // Dump Capability Register for TIS and FIFO\r
  //\r
  DEBUG ((EFI_D_INFO, "InterfaceCapability - 0x%08x\n", InterfaceCapability.Uint32));\r
  if ((InterfaceId.Bits.InterfaceType == PTP_INTERFACE_IDENTIFIER_INTERFACE_TYPE_TIS) ||\r
      (InterfaceId.Bits.InterfaceType == PTP_INTERFACE_IDENTIFIER_INTERFACE_TYPE_FIFO)) {\r
    DEBUG ((EFI_D_INFO, "  InterfaceVersion - 0x%x\n", InterfaceCapability.Bits.InterfaceVersion));\r
  }\r
\r
  //\r
  // Dump StatusEx Register for PTP FIFO\r
  //\r
  DEBUG ((EFI_D_INFO, "StatusEx - 0x%02x\n", StatusEx));\r
  if (InterfaceCapability.Bits.InterfaceVersion == INTERFACE_CAPABILITY_INTERFACE_VERSION_PTP) {\r
    DEBUG ((EFI_D_INFO, "  TpmFamily - 0x%x\n", (StatusEx & PTP_FIFO_STS_EX_TPM_FAMILY) >> PTP_FIFO_STS_EX_TPM_FAMILY_OFFSET));\r
  }\r
\r
  Vid = 0xFFFF;\r
  Did = 0xFFFF;\r
  Rid = 0xFF;\r
  PtpInterface = PcdGet8(PcdActiveTpmInterfaceType);\r
  DEBUG ((EFI_D_INFO, "PtpInterface - %x\n", PtpInterface));\r
  switch (PtpInterface) {\r
  case Tpm2PtpInterfaceCrb:\r
    Vid = MmioRead16 ((UINTN)&((PTP_CRB_REGISTERS *)Register)->Vid);\r
    Did = MmioRead16 ((UINTN)&((PTP_CRB_REGISTERS *)Register)->Did);\r
    Rid = (UINT8)InterfaceId.Bits.Rid;\r
    break;\r
  case Tpm2PtpInterfaceFifo:\r
  case Tpm2PtpInterfaceTis:\r
    Vid = MmioRead16 ((UINTN)&((PTP_FIFO_REGISTERS *)Register)->Vid);\r
    Did = MmioRead16 ((UINTN)&((PTP_FIFO_REGISTERS *)Register)->Did);\r
    Rid = MmioRead8 ((UINTN)&((PTP_FIFO_REGISTERS *)Register)->Rid);\r
    break;\r
  default:\r
    break;\r
  }\r
  DEBUG ((EFI_D_INFO, "VID - 0x%04x\n", Vid));\r
  DEBUG ((EFI_D_INFO, "DID - 0x%04x\n", Did));\r
  DEBUG ((EFI_D_INFO, "RID - 0x%02x\n", Rid));\r
}\r
\r
/**\r
  This service enables the sending of commands to the TPM2.\r
\r
  @param[in]      InputParameterBlockSize  Size of the TPM2 input parameter block.\r
  @param[in]      InputParameterBlock      Pointer to the TPM2 input parameter block.\r
  @param[in,out]  OutputParameterBlockSize Size of the TPM2 output parameter block.\r
  @param[in]      OutputParameterBlock     Pointer to the TPM2 output parameter block.\r
\r
  @retval EFI_SUCCESS            The command byte stream was successfully sent to the device and a response was successfully received.\r
  @retval EFI_DEVICE_ERROR       The command was not successfully sent to the device or a response was not successfully received from the device.\r
  @retval EFI_BUFFER_TOO_SMALL   The output parameter block is too small.\r
**/\r
EFI_STATUS\r
EFIAPI\r
DTpm2SubmitCommand (\r
  IN UINT32            InputParameterBlockSize,\r
  IN UINT8             *InputParameterBlock,\r
  IN OUT UINT32        *OutputParameterBlockSize,\r
  IN UINT8             *OutputParameterBlock\r
  )\r
{\r
  TPM2_PTP_INTERFACE_TYPE  PtpInterface;\r
\r
  PtpInterface = PcdGet8(PcdActiveTpmInterfaceType);\r
  switch (PtpInterface) {\r
  case Tpm2PtpInterfaceCrb:\r
    return PtpCrbTpmCommand (\r
           (PTP_CRB_REGISTERS_PTR) (UINTN) PcdGet64 (PcdTpmBaseAddress),\r
           InputParameterBlock,\r
           InputParameterBlockSize,\r
           OutputParameterBlock,\r
           OutputParameterBlockSize\r
           );\r
  case Tpm2PtpInterfaceFifo:\r
  case Tpm2PtpInterfaceTis:\r
    return Tpm2TisTpmCommand (\r
           (TIS_PC_REGISTERS_PTR) (UINTN) PcdGet64 (PcdTpmBaseAddress),\r
           InputParameterBlock,\r
           InputParameterBlockSize,\r
           OutputParameterBlock,\r
           OutputParameterBlockSize\r
           );\r
  default:\r
    return EFI_NOT_FOUND;\r
  }\r
}\r
\r
/**\r
  This service requests use TPM2.\r
\r
  @retval EFI_SUCCESS      Get the control of TPM2 chip.\r
  @retval EFI_NOT_FOUND    TPM2 not found.\r
  @retval EFI_DEVICE_ERROR Unexpected device behavior.\r
**/\r
EFI_STATUS\r
EFIAPI\r
DTpm2RequestUseTpm (\r
  VOID\r
  )\r
{\r
  TPM2_PTP_INTERFACE_TYPE  PtpInterface;\r
\r
  PtpInterface = PcdGet8(PcdActiveTpmInterfaceType);\r
  switch (PtpInterface) {\r
  case Tpm2PtpInterfaceCrb:\r
    return PtpCrbRequestUseTpm ((PTP_CRB_REGISTERS_PTR) (UINTN) PcdGet64 (PcdTpmBaseAddress));\r
  case Tpm2PtpInterfaceFifo:\r
  case Tpm2PtpInterfaceTis:\r
    return TisPcRequestUseTpm ((TIS_PC_REGISTERS_PTR) (UINTN) PcdGet64 (PcdTpmBaseAddress));\r
  default:\r
    return EFI_NOT_FOUND;\r
  }\r
}\r