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     }
  58
  59     MicroSecondDelay (30);
  60   }
  61
  62   return EFI_TIMEOUT;
  63 }
  64
  65 /**
  66   Get BurstCount by reading the burstCount field of a TIS register
  67   in the time of default TIS_TIMEOUT_D.
  68
  69   @param[in]  TisReg                Pointer to TIS register.
  70   @param[out] BurstCount            Pointer to a buffer to store the got BurstCount.
  71
  72   @retval     EFI_SUCCESS           Get BurstCount.
  73   @retval     EFI_INVALID_PARAMETER TisReg is NULL or BurstCount is NULL.
  74   @retval     EFI_TIMEOUT           BurstCount can't be got in time.
  75 **/
  76 EFI_STATUS
  77 EFIAPI
  78 TisPcReadBurstCount (
  79   IN      TIS_PC_REGISTERS_PTR  TisReg,
  80   OUT  UINT16                   *BurstCount
  81   )
  82 {
  83   UINT32  WaitTime;
  84   UINT8   DataByte0;
  85   UINT8   DataByte1;
  86
  87   if ((BurstCount == NULL) || (TisReg == NULL)) {
  88     return EFI_INVALID_PARAMETER;
  89   }
  90
  91   WaitTime = 0;
  92   do {
  93     //
  94     // TIS_PC_REGISTERS_PTR->burstCount is UINT16, but it is not 2bytes aligned,
  95     // so it needs to use MmioRead8 to read two times
  96     //
  97     DataByte0   = MmioRead8 ((UINTN)&TisReg->BurstCount);
  98     DataByte1   = MmioRead8 ((UINTN)&TisReg->BurstCount + 1);
  99     *BurstCount = (UINT16)((DataByte1 << 8) + DataByte0);
 100     if (*BurstCount != 0) {
 101       return EFI_SUCCESS;
 102     }
 103
 104     MicroSecondDelay (30);
 105     WaitTime += 30;
 106   } while (WaitTime < TIS_TIMEOUT_D);
 107
 108   return EFI_TIMEOUT;
 109 }
 110
 111 /**
 112   Set TPM chip to ready state by sending ready command TIS_PC_STS_READY
 113   to Status Register in time.
 114
 115   @param[in] TisReg                Pointer to TIS register.
 116
 117   @retval    EFI_SUCCESS           TPM chip enters into ready state.
 118   @retval    EFI_INVALID_PARAMETER TisReg is NULL.
 119   @retval    EFI_TIMEOUT           TPM chip can't be set to ready state in time.
 120 **/
 121 EFI_STATUS
 122 EFIAPI
 123 TisPcPrepareCommand (
 124   IN      TIS_PC_REGISTERS_PTR  TisReg
 125   )
 126 {
 127   EFI_STATUS  Status;
 128
 129   if (TisReg == NULL) {
 130     return EFI_INVALID_PARAMETER;
 131   }
 132
 133   MmioWrite8 ((UINTN)&TisReg->Status, TIS_PC_STS_READY);
 134   Status = TisPcWaitRegisterBits (
 135              &TisReg->Status,
 136              TIS_PC_STS_READY,
 137              0,
 138              TIS_TIMEOUT_B
 139              );
 140   return Status;
 141 }
 142
 143 /**
 144   Get the control of TPM chip by sending requestUse command TIS_PC_ACC_RQUUSE
 145   to ACCESS Register in the time of default TIS_TIMEOUT_A.
 146
 147   @param[in] TisReg                Pointer to TIS register.
 148
 149   @retval    EFI_SUCCESS           Get the control of TPM chip.
 150   @retval    EFI_INVALID_PARAMETER TisReg is NULL.
 151   @retval    EFI_NOT_FOUND         TPM chip doesn't exit.
 152   @retval    EFI_TIMEOUT           Can't get the TPM control in time.
 153 **/
 154 EFI_STATUS
 155 EFIAPI
 156 TisPcRequestUseTpm (
 157   IN      TIS_PC_REGISTERS_PTR  TisReg
 158   )
 159 {
 160   EFI_STATUS  Status;
 161
 162   if (TisReg == NULL) {
 163     return EFI_INVALID_PARAMETER;
 164   }
 165
 166   if (!TisPcPresenceCheck (TisReg)) {
 167     return EFI_NOT_FOUND;
 168   }
 169
 170   MmioWrite8 ((UINTN)&TisReg->Access, TIS_PC_ACC_RQUUSE);
 171   //
 172   // No locality set before, ACCESS_X.activeLocality MUST be valid within TIMEOUT_A
 173   //
 174   Status = TisPcWaitRegisterBits (
 175              &TisReg->Access,
 176              (UINT8)(TIS_PC_ACC_ACTIVE |TIS_PC_VALID),
 177              0,
 178              TIS_TIMEOUT_A
 179              );
 180   return Status;
 181 }