Re: [PATCH v3] SecurityPkg: Add retry mechanism for tpm command

["Yao, Jiewen" <jiewen.yao@intel.com>]

Hey
Please add the spec related info to the code as comments.

Thank you
Yao, Jiewen

> -----Original Message-----
> From: Zhang, Qi1 <qi1.zhang@intel.com>
> Sent: Thursday, July 28, 2022 4:51 PM
> To: devel@edk2.groups.io
> Cc: Zhang, Qi1 <qi1.zhang@intel.com>; Yao, Jiewen <jiewen.yao@intel.com>;
> Wang, Jian J <jian.j.wang@intel.com>; Patil, Swapnil
> <s.keshavrao.patil@dell.com>
> Subject: [PATCH v3] SecurityPkg: Add retry mechanism for tpm command
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3980
> 
> As per TCG PC Client Device Driver Design Principle document,
> if tpm commands fails due to timeout condition, then it should
> have retry mechanism (3 retry attempts).
> Existing implementation of PtpCrbTpmCommand does not have retry
> mechanism if it fails with EFI_TIMEOUT.
> 
> See TCG PC Client Device Driver Design Principles for TPM 2.0
> https://trustedcomputinggroup.org/wp-
> content/uploads/TCG_PCClient_Device_Driver_Design_Principles_TPM2p0_v1p1
> _r4_211104_final.pdf
> Vision 1.1, Revision 0.04
> Section 7.2.1
> 
> Signed-off-by: Qi Zhang <qi1.zhang@intel.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
> Tested-by: Swapnil Patil <S.Keshavrao.Patil@dell.com>
> ---
>  .../Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c       | 107 +++++++++++-------
>  1 file changed, 68 insertions(+), 39 deletions(-)
> 
> diff --git a/SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c
> b/SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c
> index 1d99beaa10..6b5994fde2 100644
> --- a/SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c
> +++ b/SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c
> @@ -33,6 +33,11 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
>  //
> 
>  #define TPMCMDBUFLENGTH  0x500
> 
> 
> 
> +//
> 
> +// Max retry count
> 
> +//
> 
> +#define RETRY_CNT_MAX  3
> 
> +
> 
>  /**
> 
>    Check whether TPM PTP register exist.
> 
> 
> 
> @@ -153,6 +158,7 @@ PtpCrbTpmCommand (
>    UINT32      TpmOutSize;
> 
>    UINT16      Data16;
> 
>    UINT32      Data32;
> 
> +  UINT8       RetryCnt;
> 
> 
> 
>    DEBUG_CODE_BEGIN ();
> 
>    UINTN  DebugSize;
> 
> @@ -179,53 +185,76 @@ PtpCrbTpmCommand (
>    DEBUG_CODE_END ();
> 
>    TpmOutSize = 0;
> 
> 
> 
> -  //
> 
> -  // STEP 0:
> 
> -  // if CapCRbIdelByPass == 0, enforce Idle state before sending command
> 
> -  //
> 
> -  if ((GetCachedIdleByPass () == 0) && ((MmioRead32 ((UINTN)&CrbReg-
> >CrbControlStatus) & PTP_CRB_CONTROL_AREA_STATUS_TPM_IDLE) == 0)) {
> 
> +  RetryCnt = 0;
> 
> +  while (TRUE) {
> 
> +    //
> 
> +    // STEP 0:
> 
> +    // if CapCRbIdelByPass == 0, enforce Idle state before sending command
> 
> +    //
> 
> +    if ((GetCachedIdleByPass () == 0) && ((MmioRead32 ((UINTN)&CrbReg-
> >CrbControlStatus) & PTP_CRB_CONTROL_AREA_STATUS_TPM_IDLE) == 0)) {
> 
> +      Status = PtpCrbWaitRegisterBits (
> 
> +                 &CrbReg->CrbControlStatus,
> 
> +                 PTP_CRB_CONTROL_AREA_STATUS_TPM_IDLE,
> 
> +                 0,
> 
> +                 PTP_TIMEOUT_C
> 
> +                 );
> 
> +      if (EFI_ERROR (Status)) {
> 
> +        RetryCnt++;
> 
> +        if (RetryCnt < RETRY_CNT_MAX) {
> 
> +          MmioWrite32 ((UINTN)&CrbReg->CrbControlRequest,
> PTP_CRB_CONTROL_AREA_REQUEST_GO_IDLE);
> 
> +          continue;
> 
> +        } else {
> 
> +          //
> 
> +          // Try to goIdle to recover TPM
> 
> +          //
> 
> +          Status = EFI_DEVICE_ERROR;
> 
> +          goto GoIdle_Exit;
> 
> +        }
> 
> +      }
> 
> +    }
> 
> +
> 
> +    //
> 
> +    // STEP 1:
> 
> +    // Ready is any time the TPM is ready to receive a command, following a
> write
> 
> +    // of 1 by software to Request.cmdReady, as indicated by the Status field
> 
> +    // being cleared to 0.
> 
> +    //
> 
> +    MmioWrite32 ((UINTN)&CrbReg->CrbControlRequest,
> PTP_CRB_CONTROL_AREA_REQUEST_COMMAND_READY);
> 
>      Status = PtpCrbWaitRegisterBits (
> 
> -               &CrbReg->CrbControlStatus,
> 
> -               PTP_CRB_CONTROL_AREA_STATUS_TPM_IDLE,
> 
> +               &CrbReg->CrbControlRequest,
> 
>                 0,
> 
> +               PTP_CRB_CONTROL_AREA_REQUEST_COMMAND_READY,
> 
>                 PTP_TIMEOUT_C
> 
>                 );
> 
>      if (EFI_ERROR (Status)) {
> 
> -      //
> 
> -      // Try to goIdle to recover TPM
> 
> -      //
> 
> -      Status = EFI_DEVICE_ERROR;
> 
> -      goto GoIdle_Exit;
> 
> +      RetryCnt++;
> 
> +      if (RetryCnt < RETRY_CNT_MAX) {
> 
> +        MmioWrite32 ((UINTN)&CrbReg->CrbControlRequest,
> PTP_CRB_CONTROL_AREA_REQUEST_GO_IDLE);
> 
> +        continue;
> 
> +      } else {
> 
> +        Status = EFI_DEVICE_ERROR;
> 
> +        goto GoIdle_Exit;
> 
> +      }
> 
>      }
> 
> -  }
> 
> 
> 
> -  //
> 
> -  // STEP 1:
> 
> -  // Ready is any time the TPM is ready to receive a command, following a write
> 
> -  // of 1 by software to Request.cmdReady, as indicated by the Status field
> 
> -  // being cleared to 0.
> 
> -  //
> 
> -  MmioWrite32 ((UINTN)&CrbReg->CrbControlRequest,
> PTP_CRB_CONTROL_AREA_REQUEST_COMMAND_READY);
> 
> -  Status = PtpCrbWaitRegisterBits (
> 
> -             &CrbReg->CrbControlRequest,
> 
> -             0,
> 
> -             PTP_CRB_CONTROL_AREA_REQUEST_COMMAND_READY,
> 
> -             PTP_TIMEOUT_C
> 
> -             );
> 
> -  if (EFI_ERROR (Status)) {
> 
> -    Status = EFI_DEVICE_ERROR;
> 
> -    goto GoIdle_Exit;
> 
> -  }
> 
> +    Status = PtpCrbWaitRegisterBits (
> 
> +               &CrbReg->CrbControlStatus,
> 
> +               0,
> 
> +               PTP_CRB_CONTROL_AREA_STATUS_TPM_IDLE,
> 
> +               PTP_TIMEOUT_C
> 
> +               );
> 
> +    if (EFI_ERROR (Status)) {
> 
> +      RetryCnt++;
> 
> +      if (RetryCnt < RETRY_CNT_MAX) {
> 
> +        MmioWrite32 ((UINTN)&CrbReg->CrbControlRequest,
> PTP_CRB_CONTROL_AREA_REQUEST_GO_IDLE);
> 
> +        continue;
> 
> +      } else {
> 
> +        Status = EFI_DEVICE_ERROR;
> 
> +        goto GoIdle_Exit;
> 
> +      }
> 
> +    }
> 
> 
> 
> -  Status = PtpCrbWaitRegisterBits (
> 
> -             &CrbReg->CrbControlStatus,
> 
> -             0,
> 
> -             PTP_CRB_CONTROL_AREA_STATUS_TPM_IDLE,
> 
> -             PTP_TIMEOUT_C
> 
> -             );
> 
> -  if (EFI_ERROR (Status)) {
> 
> -    Status = EFI_DEVICE_ERROR;
> 
> -    goto GoIdle_Exit;
> 
> +    break;
> 
>    }
> 
> 
> 
>    //
> 
> --
> 2.26.2.windows.1