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 <Library/PcdLib.h>
  19 #include <OvmfPlatforms.h>
  20
  21 //
  22 // Power Management PCI Configuration Register fields
  23 //
  24 #define PMBA_RTE      BIT0
  25
  26 //
  27 // Offset in the Power Management Base Address to the ACPI Timer
  28 //
  29 #define ACPI_TIMER_OFFSET  0x8
  30
  31 //
  32 // Cached ACPI Timer IO Address
  33 //
  34 STATIC UINT32 mAcpiTimerIoAddr;
  35
  36 /**
  37   The constructor function caches the ACPI tick counter address, and,
  38   if necessary, enables ACPI IO space.
  39
  40   @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.
  41
  42 **/
  43 RETURN_STATUS
  44 EFIAPI
  45 AcpiTimerLibConstructor (
  46   VOID
  47   )
  48 {
  49   UINT16 HostBridgeDevId;
  50   UINTN Pmba;
  51   UINTN AcpiCtlReg;
  52   UINT8 AcpiEnBit;
  53
  54   //
  55   // Query Host Bridge DID to determine platform type
  56   //
  57   HostBridgeDevId = PciRead16 (OVMF_HOSTBRIDGE_DID);
  58   switch (HostBridgeDevId) {
  59     case INTEL_82441_DEVICE_ID:
  60       Pmba       = POWER_MGMT_REGISTER_PIIX4 (PIIX4_PMBA);
  61       AcpiCtlReg = POWER_MGMT_REGISTER_PIIX4 (PIIX4_PMREGMISC);
  62       AcpiEnBit  = PIIX4_PMREGMISC_PMIOSE;
  63       break;
  64     case INTEL_Q35_MCH_DEVICE_ID:
  65       Pmba       = POWER_MGMT_REGISTER_Q35 (ICH9_PMBASE);
  66       AcpiCtlReg = POWER_MGMT_REGISTER_Q35 (ICH9_ACPI_CNTL);
  67       AcpiEnBit  = ICH9_ACPI_CNTL_ACPI_EN;
  68       break;
  69     default:
  70       DEBUG ((EFI_D_ERROR, "%a: Unknown Host Bridge Device ID: 0x%04x\n",
  71         __FUNCTION__, HostBridgeDevId));
  72       ASSERT (FALSE);
  73       return RETURN_UNSUPPORTED;
  74   }
  75
  76   mAcpiTimerIoAddr = (PciRead32 (Pmba) & ~PMBA_RTE) + ACPI_TIMER_OFFSET;
  77
  78   //
  79   // Check to see if the Power Management Base Address is already enabled
  80   //
  81   if ((PciRead8 (AcpiCtlReg) & AcpiEnBit) == 0) {
  82     //
  83     // If the Power Management Base Address is not programmed,
  84     // then program the Power Management Base Address from a PCD.
  85     //
  86     PciAndThenOr32 (Pmba, (UINT32) ~0xFFC0, PcdGet16 (PcdAcpiPmBaseAddress));
  87
  88     //
  89     // Enable PMBA I/O port decodes
  90     //
  91     PciOr8 (AcpiCtlReg, AcpiEnBit);
  92   }
  93
  94   return RETURN_SUCCESS;
  95 }
  96
  97 /**
  98   Internal function to read the current tick counter of ACPI.
  99
 100   Read the current ACPI tick counter using the counter address cached
 101   by this instance's constructor.
 102
 103   @return The tick counter read.
 104
 105 **/
 106 UINT32
 107 InternalAcpiGetTimerTick (
 108   VOID
 109   )
 110 {
 111   //
 112   //   Return the current ACPI timer value.
 113   //
 114   return IoRead32 (mAcpiTimerIoAddr);
 115 }