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 ((DEBUG_ERROR, "%a: Unknown Host Bridge Device ID: 0x%04x\n",
  60         __FUNCTION__, HostBridgeDevId));
  61       ASSERT (FALSE);
  62       return RETURN_UNSUPPORTED;
  63   }
  64
  65   //
  66   // Check to see if the Power Management Base Address is already enabled
  67   //
  68   if ((PciRead8 (AcpiCtlReg) & AcpiEnBit) == 0) {
  69     //
  70     // If the Power Management Base Address is not programmed,
  71     // then program it now.
  72     //
  73     PciAndThenOr32 (Pmba, PmbaAndVal, PmbaOrVal);
  74
  75     //
  76     // Enable PMBA I/O port decodes
  77     //
  78     PciOr8 (AcpiCtlReg, AcpiEnBit);
  79   }
  80
  81   mAcpiTimerIoAddr = (PciRead32 (Pmba) & ~PMBA_RTE) + ACPI_TIMER_OFFSET;
  82   return RETURN_SUCCESS;
  83 }
  84
  85 /**
  86   Internal function to read the current tick counter of ACPI.
  87
  88   Read the current ACPI tick counter using the counter address cached
  89   by this instance's constructor.
  90
  91   @return The tick counter read.
  92
  93 **/
  94 UINT32
  95 InternalAcpiGetTimerTick (
  96   VOID
  97   )
  98 {
  99   //
 100   //   Return the current ACPI timer value.
 101   //
 102   return IoRead32 (mAcpiTimerIoAddr);
 103 }