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 #define PIIX4_PMIOSE  BIT0
  26
  27 //
  28 // Offset in the Power Management Base Address to the ACPI Timer
  29 //
  30 #define ACPI_TIMER_OFFSET  0x8
  31
  32 //
  33 // Cached ACPI Timer IO Address
  34 //
  35 STATIC UINT32 mAcpiTimerIoAddr;
  36
  37 /**
  38   The constructor function caches the ACPI tick counter address, and,
  39   if necessary, enables ACPI IO space.
  40
  41   @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.
  42
  43 **/
  44 RETURN_STATUS
  45 EFIAPI
  46 AcpiTimerLibConstructor (
  47   VOID
  48   )
  49 {
  50   UINT16 HostBridgeDevId;
  51   UINTN Pmba;
  52   UINTN AcpiCtlReg;
  53   UINT8 AcpiEnBit;
  54
  55   //
  56   // Query Host Bridge DID to determine platform type
  57   //
  58   HostBridgeDevId = PciRead16 (OVMF_HOSTBRIDGE_DID);
  59   switch (HostBridgeDevId) {
  60     case INTEL_82441_DEVICE_ID:
  61       Pmba       = POWER_MGMT_REGISTER_PIIX4 (0x40);
  62       AcpiCtlReg = POWER_MGMT_REGISTER_PIIX4 (0x80); // PMREGMISC
  63       AcpiEnBit  = PIIX4_PMIOSE;
  64       break;
  65     case INTEL_Q35_MCH_DEVICE_ID:
  66       Pmba       = POWER_MGMT_REGISTER_Q35 (ICH9_PMBASE);
  67       AcpiCtlReg = POWER_MGMT_REGISTER_Q35 (ICH9_ACPI_CNTL);
  68       AcpiEnBit  = ICH9_ACPI_CNTL_ACPI_EN;
  69       break;
  70     default:
  71       DEBUG ((EFI_D_ERROR, "%a: Unknown Host Bridge Device ID: 0x%04x\n",
  72         __FUNCTION__, HostBridgeDevId));
  73       ASSERT (FALSE);
  74       return RETURN_UNSUPPORTED;
  75   }
  76
  77   mAcpiTimerIoAddr = (PciRead32 (Pmba) & ~PMBA_RTE) + ACPI_TIMER_OFFSET;
  78
  79   //
  80   // Check to see if the Power Management Base Address is already enabled
  81   //
  82   if ((PciRead8 (AcpiCtlReg) & AcpiEnBit) == 0) {
  83     //
  84     // If the Power Management Base Address is not programmed,
  85     // then program the Power Management Base Address from a PCD.
  86     //
  87     PciAndThenOr32 (Pmba, (UINT32) ~0xFFC0, PcdGet16 (PcdAcpiPmBaseAddress));
  88
  89     //
  90     // Enable PMBA I/O port decodes
  91     //
  92     PciOr8 (AcpiCtlReg, AcpiEnBit);
  93   }
  94
  95   return RETURN_SUCCESS;
  96 }
  97
  98 /**
  99   Internal function to read the current tick counter of ACPI.
 100
 101   Read the current ACPI tick counter using the counter address cached
 102   by this instance's constructor.
 103
 104   @return The tick counter read.
 105
 106 **/
 107 UINT32
 108 InternalAcpiGetTimerTick (
 109   VOID
 110   )
 111 {
 112   //
 113   //   Return the current ACPI timer value.
 114   //
 115   return IoRead32 (mAcpiTimerIoAddr);
 116 }