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   This program and the accompanying materials are licensed and made
   7   available under the terms and conditions of the BSD License which
   8   accompanies this distribution.   The full text of the license may
   9   be found at http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13 **/
  14
  15 #include <Library/DebugLib.h>
  16 #include <Library/IoLib.h>
  17 #include <Library/PciLib.h>
  18 #include <OvmfPlatforms.h>
  19
  20 //
  21 // Cached ACPI Timer IO Address
  22 //
  23 STATIC UINT32 mAcpiTimerIoAddr;
  24
  25 /**
  26   The constructor function caches the ACPI tick counter address, and,
  27   if necessary, enables ACPI IO space.
  28
  29   @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.
  30
  31 **/
  32 RETURN_STATUS
  33 EFIAPI
  34 AcpiTimerLibConstructor (
  35   VOID
  36   )
  37 {
  38   UINT16 HostBridgeDevId;
  39   UINTN Pmba;
  40   UINT32 PmbaAndVal;
  41   UINT32 PmbaOrVal;
  42   UINTN AcpiCtlReg;
  43   UINT8 AcpiEnBit;
  44
  45   //
  46   // Query Host Bridge DID to determine platform type
  47   //
  48   HostBridgeDevId = PciRead16 (OVMF_HOSTBRIDGE_DID);
  49   switch (HostBridgeDevId) {
  50     case INTEL_82441_DEVICE_ID:
  51       Pmba       = POWER_MGMT_REGISTER_PIIX4 (PIIX4_PMBA);
  52       PmbaAndVal = ~(UINT32)PIIX4_PMBA_MASK;
  53       PmbaOrVal  = PIIX4_PMBA_VALUE;
  54       AcpiCtlReg = POWER_MGMT_REGISTER_PIIX4 (PIIX4_PMREGMISC);
  55       AcpiEnBit  = PIIX4_PMREGMISC_PMIOSE;
  56       break;
  57     case INTEL_Q35_MCH_DEVICE_ID:
  58       Pmba       = POWER_MGMT_REGISTER_Q35 (ICH9_PMBASE);
  59       PmbaAndVal = ~(UINT32)ICH9_PMBASE_MASK;
  60       PmbaOrVal  = ICH9_PMBASE_VALUE;
  61       AcpiCtlReg = POWER_MGMT_REGISTER_Q35 (ICH9_ACPI_CNTL);
  62       AcpiEnBit  = ICH9_ACPI_CNTL_ACPI_EN;
  63       break;
  64     default:
  65       DEBUG ((EFI_D_ERROR, "%a: Unknown Host Bridge Device ID: 0x%04x\n",
  66         __FUNCTION__, HostBridgeDevId));
  67       ASSERT (FALSE);
  68       return RETURN_UNSUPPORTED;
  69   }
  70
  71   //
  72   // Check to see if the Power Management Base Address is already enabled
  73   //
  74   if ((PciRead8 (AcpiCtlReg) & AcpiEnBit) == 0) {
  75     //
  76     // If the Power Management Base Address is not programmed,
  77     // then program it now.
  78     //
  79     PciAndThenOr32 (Pmba, PmbaAndVal, PmbaOrVal);
  80
  81     //
  82     // Enable PMBA I/O port decodes
  83     //
  84     PciOr8 (AcpiCtlReg, AcpiEnBit);
  85   }
  86
  87   mAcpiTimerIoAddr = (PciRead32 (Pmba) & ~PMBA_RTE) + ACPI_TIMER_OFFSET;
  88   return RETURN_SUCCESS;
  89 }
  90
  91 /**
  92   Internal function to read the current tick counter of ACPI.
  93
  94   Read the current ACPI tick counter using the counter address cached
  95   by this instance's constructor.
  96
  97   @return The tick counter read.
  98
  99 **/
 100 UINT32
 101 InternalAcpiGetTimerTick (
 102   VOID
 103   )
 104 {
 105   //
 106   //   Return the current ACPI timer value.
 107   //
 108   return IoRead32 (mAcpiTimerIoAddr);
 109 }