SecurityPkg/Library/TpmCommLib/TisPc.c

   1 /** @file
   2   Basic TIS (TPM Interface Specification) functions.
   3
   4 Copyright (c) 2005 - 2011, Intel Corporation. All rights reserved.<BR>
   5 This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include "CommonHeader.h"
  16
  17 /**
  18   Check whether TPM chip exist.
  19
  20   @param[in] TisReg  Pointer to TIS register.
  21
  22   @retval    TRUE    TPM chip exists.
  23   @retval    FALSE   TPM chip is not found.
  24 **/
  25 BOOLEAN
  26 TisPcPresenceCheck (
  27   IN      TIS_PC_REGISTERS_PTR      TisReg
  28   )
  29 {
  30   UINT8                             RegRead;
  31
  32   RegRead = MmioRead8 ((UINTN)&TisReg->Access);
  33   return (BOOLEAN)(RegRead != (UINT8)-1);
  34 }
  35
  36 /**
  37   Check whether the value of a TPM chip register satisfies the input BIT setting.
  38
  39   @param[in]  Register     Address port of register to be checked.
  40   @param[in]  BitSet       Check these data bits are set.
  41   @param[in]  BitClear     Check these data bits are clear.
  42   @param[in]  TimeOut      The max wait time (unit MicroSecond) when checking register.
  43
  44   @retval     EFI_SUCCESS  The register satisfies the check bit.
  45   @retval     EFI_TIMEOUT  The register can't run into the expected status in time.
  46 **/
  47 EFI_STATUS
  48 EFIAPI
  49 TisPcWaitRegisterBits (
  50   IN      UINT8                     *Register,
  51   IN      UINT8                     BitSet,
  52   IN      UINT8                     BitClear,
  53   IN      UINT32                    TimeOut
  54   )
  55 {
  56   UINT8                             RegRead;
  57   UINT32                            WaitTime;
  58
  59   for (WaitTime = 0; WaitTime < TimeOut; WaitTime += 30){
  60     RegRead = MmioRead8 ((UINTN)Register);
  61     if ((RegRead & BitSet) == BitSet && (RegRead & BitClear) == 0)
  62       return EFI_SUCCESS;
  63     MicroSecondDelay (30);
  64   }
  65   return EFI_TIMEOUT;
  66 }
  67
  68 /**
  69   Get BurstCount by reading the burstCount field of a TIS regiger
  70   in the time of default TIS_TIMEOUT_D.
  71
  72   @param[in]  TisReg                Pointer to TIS register.
  73   @param[out] BurstCount            Pointer to a buffer to store the got BurstConut.
  74
  75   @retval     EFI_SUCCESS           Get BurstCount.
  76   @retval     EFI_INVALID_PARAMETER TisReg is NULL or BurstCount is NULL.
  77   @retval     EFI_TIMEOUT           BurstCount can't be got in time.
  78 **/
  79 EFI_STATUS
  80 EFIAPI
  81 TisPcReadBurstCount (
  82   IN      TIS_PC_REGISTERS_PTR      TisReg,
  83      OUT  UINT16                    *BurstCount
  84   )
  85 {
  86   UINT32                            WaitTime;
  87   UINT8                             DataByte0;
  88   UINT8                             DataByte1;
  89
  90   if (BurstCount == NULL || TisReg == NULL) {
  91     return EFI_INVALID_PARAMETER;
  92   }
  93
  94   WaitTime = 0;
  95   do {
  96     //
  97     // TIS_PC_REGISTERS_PTR->burstCount is UINT16, but it is not 2bytes aligned,
  98     // so it needs to use MmioRead8 to read two times
  99     //
 100     DataByte0   = MmioRead8 ((UINTN)&TisReg->BurstCount);
 101     DataByte1   = MmioRead8 ((UINTN)&TisReg->BurstCount + 1);
 102     *BurstCount = (UINT16)((DataByte1 << 8) + DataByte0);
 103     if (*BurstCount != 0) {
 104       return EFI_SUCCESS;
 105     }
 106     MicroSecondDelay (30);
 107     WaitTime += 30;
 108   } while (WaitTime < TIS_TIMEOUT_D);
 109
 110   return EFI_TIMEOUT;
 111 }
 112
 113 /**
 114   Set TPM chip to ready state by sending ready command TIS_PC_STS_READY
 115   to Status Register in time.
 116
 117   @param[in] TisReg                Pointer to TIS register.
 118
 119   @retval    EFI_SUCCESS           TPM chip enters into ready state.
 120   @retval    EFI_INVALID_PARAMETER TisReg is NULL.
 121   @retval    EFI_TIMEOUT           TPM chip can't be set to ready state in time.
 122 **/
 123 EFI_STATUS
 124 EFIAPI
 125 TisPcPrepareCommand (
 126   IN      TIS_PC_REGISTERS_PTR      TisReg
 127   )
 128 {
 129   EFI_STATUS                        Status;
 130
 131   if (TisReg == NULL) {
 132     return EFI_INVALID_PARAMETER;
 133   }
 134
 135   MmioWrite8((UINTN)&TisReg->Status, TIS_PC_STS_READY);
 136   Status = TisPcWaitRegisterBits (
 137              &TisReg->Status,
 138              TIS_PC_STS_READY,
 139              0,
 140              TIS_TIMEOUT_B
 141              );
 142   return Status;
 143 }
 144
 145 /**
 146   Get the control of TPM chip by sending requestUse command TIS_PC_ACC_RQUUSE
 147   to ACCESS Register in the time of default TIS_TIMEOUT_D.
 148
 149   @param[in] TisReg                Pointer to TIS register.
 150
 151   @retval    EFI_SUCCESS           Get the control of TPM chip.
 152   @retval    EFI_INVALID_PARAMETER TisReg is NULL.
 153   @retval    EFI_NOT_FOUND         TPM chip doesn't exit.
 154   @retval    EFI_TIMEOUT           Can't get the TPM control in time.
 155 **/
 156 EFI_STATUS
 157 EFIAPI
 158 TisPcRequestUseTpm (
 159   IN      TIS_PC_REGISTERS_PTR      TisReg
 160   )
 161 {
 162   EFI_STATUS                        Status;
 163
 164   if (TisReg == NULL) {
 165     return EFI_INVALID_PARAMETER;
 166   }
 167
 168   if (!TisPcPresenceCheck (TisReg)) {
 169     return EFI_NOT_FOUND;
 170   }
 171
 172   MmioWrite8((UINTN)&TisReg->Access, TIS_PC_ACC_RQUUSE);
 173   Status = TisPcWaitRegisterBits (
 174              &TisReg->Access,
 175              (UINT8)(TIS_PC_ACC_ACTIVE |TIS_PC_VALID),
 176              0,
 177              TIS_TIMEOUT_D
 178              );
 179   return Status;
 180 }