SecurityPkg/Library/TpmCommLib/TisPc.c

   1 /** @file
   2   Basic TIS (TPM Interface Specification) functions.
   3
   4 Copyright (c) 2005 - 2018, Intel Corporation. All rights reserved.<BR>
   5 SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include "CommonHeader.h"
  10
  11 /**
  12   Check whether TPM chip exist.
  13
  14   @param[in] TisReg  Pointer to TIS register.
  15
  16   @retval    TRUE    TPM chip exists.
  17   @retval    FALSE   TPM chip is not found.
  18 **/
  19 BOOLEAN
  20 TisPcPresenceCheck (
  21   IN      TIS_PC_REGISTERS_PTR      TisReg
  22   )
  23 {
  24   UINT8                             RegRead;
  25
  26   RegRead = MmioRead8 ((UINTN)&TisReg->Access);
  27   return (BOOLEAN)(RegRead != (UINT8)-1);
  28 }
  29
  30 /**
  31   Check whether the value of a TPM chip register satisfies the input BIT setting.
  32
  33   @param[in]  Register     Address port of register to be checked.
  34   @param[in]  BitSet       Check these data bits are set.
  35   @param[in]  BitClear     Check these data bits are clear.
  36   @param[in]  TimeOut      The max wait time (unit MicroSecond) when checking register.
  37
  38   @retval     EFI_SUCCESS  The register satisfies the check bit.
  39   @retval     EFI_TIMEOUT  The register can't run into the expected status in time.
  40 **/
  41 EFI_STATUS
  42 EFIAPI
  43 TisPcWaitRegisterBits (
  44   IN      UINT8                     *Register,
  45   IN      UINT8                     BitSet,
  46   IN      UINT8                     BitClear,
  47   IN      UINT32                    TimeOut
  48   )
  49 {
  50   UINT8                             RegRead;
  51   UINT32                            WaitTime;
  52
  53   for (WaitTime = 0; WaitTime < TimeOut; WaitTime += 30){
  54     RegRead = MmioRead8 ((UINTN)Register);
  55     if ((RegRead & BitSet) == BitSet && (RegRead & BitClear) == 0)
  56       return EFI_SUCCESS;
  57     MicroSecondDelay (30);
  58   }
  59   return EFI_TIMEOUT;
  60 }
  61
  62 /**
  63   Get BurstCount by reading the burstCount field of a TIS regiger
  64   in the time of default TIS_TIMEOUT_D.
  65
  66   @param[in]  TisReg                Pointer to TIS register.
  67   @param[out] BurstCount            Pointer to a buffer to store the got BurstConut.
  68
  69   @retval     EFI_SUCCESS           Get BurstCount.
  70   @retval     EFI_INVALID_PARAMETER TisReg is NULL or BurstCount is NULL.
  71   @retval     EFI_TIMEOUT           BurstCount can't be got in time.
  72 **/
  73 EFI_STATUS
  74 EFIAPI
  75 TisPcReadBurstCount (
  76   IN      TIS_PC_REGISTERS_PTR      TisReg,
  77      OUT  UINT16                    *BurstCount
  78   )
  79 {
  80   UINT32                            WaitTime;
  81   UINT8                             DataByte0;
  82   UINT8                             DataByte1;
  83
  84   if (BurstCount == NULL || TisReg == NULL) {
  85     return EFI_INVALID_PARAMETER;
  86   }
  87
  88   WaitTime = 0;
  89   do {
  90     //
  91     // TIS_PC_REGISTERS_PTR->burstCount is UINT16, but it is not 2bytes aligned,
  92     // so it needs to use MmioRead8 to read two times
  93     //
  94     DataByte0   = MmioRead8 ((UINTN)&TisReg->BurstCount);
  95     DataByte1   = MmioRead8 ((UINTN)&TisReg->BurstCount + 1);
  96     *BurstCount = (UINT16)((DataByte1 << 8) + DataByte0);
  97     if (*BurstCount != 0) {
  98       return EFI_SUCCESS;
  99     }
 100     MicroSecondDelay (30);
 101     WaitTime += 30;
 102   } while (WaitTime < TIS_TIMEOUT_D);
 103
 104   return EFI_TIMEOUT;
 105 }
 106
 107 /**
 108   Set TPM chip to ready state by sending ready command TIS_PC_STS_READY
 109   to Status Register in time.
 110
 111   @param[in] TisReg                Pointer to TIS register.
 112
 113   @retval    EFI_SUCCESS           TPM chip enters into ready state.
 114   @retval    EFI_INVALID_PARAMETER TisReg is NULL.
 115   @retval    EFI_TIMEOUT           TPM chip can't be set to ready state in time.
 116 **/
 117 EFI_STATUS
 118 EFIAPI
 119 TisPcPrepareCommand (
 120   IN      TIS_PC_REGISTERS_PTR      TisReg
 121   )
 122 {
 123   EFI_STATUS                        Status;
 124
 125   if (TisReg == NULL) {
 126     return EFI_INVALID_PARAMETER;
 127   }
 128
 129   MmioWrite8((UINTN)&TisReg->Status, TIS_PC_STS_READY);
 130   Status = TisPcWaitRegisterBits (
 131              &TisReg->Status,
 132              TIS_PC_STS_READY,
 133              0,
 134              TIS_TIMEOUT_B
 135              );
 136   return Status;
 137 }
 138
 139 /**
 140   Get the control of TPM chip by sending requestUse command TIS_PC_ACC_RQUUSE
 141   to ACCESS Register in the time of default TIS_TIMEOUT_A.
 142
 143   @param[in] TisReg                Pointer to TIS register.
 144
 145   @retval    EFI_SUCCESS           Get the control of TPM chip.
 146   @retval    EFI_INVALID_PARAMETER TisReg is NULL.
 147   @retval    EFI_NOT_FOUND         TPM chip doesn't exit.
 148   @retval    EFI_TIMEOUT           Can't get the TPM control in time.
 149 **/
 150 EFI_STATUS
 151 EFIAPI
 152 TisPcRequestUseTpm (
 153   IN      TIS_PC_REGISTERS_PTR      TisReg
 154   )
 155 {
 156   EFI_STATUS                        Status;
 157
 158   if (TisReg == NULL) {
 159     return EFI_INVALID_PARAMETER;
 160   }
 161
 162   if (!TisPcPresenceCheck (TisReg)) {
 163     return EFI_NOT_FOUND;
 164   }
 165
 166   MmioWrite8((UINTN)&TisReg->Access, TIS_PC_ACC_RQUUSE);
 167   //
 168   // No locality set before, ACCESS_X.activeLocality MUST be valid within TIMEOUT_A
 169   //
 170   Status = TisPcWaitRegisterBits (
 171              &TisReg->Access,
 172              (UINT8)(TIS_PC_ACC_ACTIVE |TIS_PC_VALID),
 173              0,
 174              TIS_TIMEOUT_A
 175              );
 176   return Status;
 177 }