OvmfPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.c

   1 /** @file
   2   Provide constructor and GetTick for Base instance of ACPI Timer Library
   3
   4   Copyright (C) 2014, Gabriel L. Somlo <somlo@cmu.edu>
   5
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7 **/
   8
   9 #include <Library/DebugLib.h>
  10 #include <Library/IoLib.h>
  11 #include <Library/PciLib.h>
  12 #include <OvmfPlatforms.h>
  13
  14 //
  15 // Cached ACPI Timer IO Address
  16 //
  17 STATIC UINT32  mAcpiTimerIoAddr;
  18
  19 /**
  20   The constructor function caches the ACPI tick counter address, and,
  21   if necessary, enables ACPI IO space.
  22
  23   @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.
  24
  25 **/
  26 RETURN_STATUS
  27 EFIAPI
  28 AcpiTimerLibConstructor (
  29   VOID
  30   )
  31 {
  32   UINT16  HostBridgeDevId;
  33   UINTN   Pmba;
  34   UINT32  PmbaAndVal;
  35   UINT32  PmbaOrVal;
  36   UINTN   AcpiCtlReg;
  37   UINT8   AcpiEnBit;
  38
  39   //
  40   // Query Host Bridge DID to determine platform type
  41   //
  42   HostBridgeDevId = PciRead16 (OVMF_HOSTBRIDGE_DID);
  43   switch (HostBridgeDevId) {
  44     case INTEL_82441_DEVICE_ID:
  45       Pmba       = POWER_MGMT_REGISTER_PIIX4 (PIIX4_PMBA);
  46       PmbaAndVal = ~(UINT32)PIIX4_PMBA_MASK;
  47       PmbaOrVal  = PIIX4_PMBA_VALUE;
  48       AcpiCtlReg = POWER_MGMT_REGISTER_PIIX4 (PIIX4_PMREGMISC);
  49       AcpiEnBit  = PIIX4_PMREGMISC_PMIOSE;
  50       break;
  51     case INTEL_Q35_MCH_DEVICE_ID:
  52       Pmba       = POWER_MGMT_REGISTER_Q35 (ICH9_PMBASE);
  53       PmbaAndVal = ~(UINT32)ICH9_PMBASE_MASK;
  54       PmbaOrVal  = ICH9_PMBASE_VALUE;
  55       AcpiCtlReg = POWER_MGMT_REGISTER_Q35 (ICH9_ACPI_CNTL);
  56       AcpiEnBit  = ICH9_ACPI_CNTL_ACPI_EN;
  57       break;
  58     default:
  59       DEBUG ((
  60         DEBUG_ERROR,
  61         "%a: Unknown Host Bridge Device ID: 0x%04x\n",
  62         __FUNCTION__,
  63         HostBridgeDevId
  64         ));
  65       ASSERT (FALSE);
  66       return RETURN_UNSUPPORTED;
  67   }
  68
  69   //
  70   // Check to see if the Power Management Base Address is already enabled
  71   //
  72   if ((PciRead8 (AcpiCtlReg) & AcpiEnBit) == 0) {
  73     //
  74     // If the Power Management Base Address is not programmed,
  75     // then program it now.
  76     //
  77     PciAndThenOr32 (Pmba, PmbaAndVal, PmbaOrVal);
  78
  79     //
  80     // Enable PMBA I/O port decodes
  81     //
  82     PciOr8 (AcpiCtlReg, AcpiEnBit);
  83   }
  84
  85   mAcpiTimerIoAddr = (PciRead32 (Pmba) & ~PMBA_RTE) + ACPI_TIMER_OFFSET;
  86   return RETURN_SUCCESS;
  87 }
  88
  89 /**
  90   Internal function to read the current tick counter of ACPI.
  91
  92   Read the current ACPI tick counter using the counter address cached
  93   by this instance's constructor.
  94
  95   @return The tick counter read.
  96
  97 **/
  98 UINT32
  99 InternalAcpiGetTimerTick (
 100   VOID
 101   )
 102 {
 103   //
 104   //   Return the current ACPI timer value.
 105   //
 106   return IoRead32 (mAcpiTimerIoAddr);
 107 }