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 #define Q35_ACPI_EN   BIT7
  27
  28 //
  29 // Offset in the Power Management Base Address to the ACPI Timer
  30 //
  31 #define ACPI_TIMER_OFFSET  0x8
  32
  33 //
  34 // Cached ACPI Timer IO Address
  35 //
  36 STATIC UINT32 mAcpiTimerIoAddr;
  37
  38 /**
  39   The constructor function caches the ACPI tick counter address, and,
  40   if necessary, enables ACPI IO space.
  41
  42   @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.
  43
  44 **/
  45 RETURN_STATUS
  46 EFIAPI
  47 AcpiTimerLibConstructor (
  48   VOID
  49   )
  50 {
  51   UINT16 HostBridgeDevId;
  52   UINTN Pmba;
  53   UINTN AcpiCtlReg;
  54   UINT8 AcpiEnBit;
  55
  56   //
  57   // Query Host Bridge DID to determine platform type
  58   //
  59   HostBridgeDevId = PciRead16 (OVMF_HOSTBRIDGE_DID);
  60   switch (HostBridgeDevId) {
  61     case INTEL_82441_DEVICE_ID:
  62       Pmba       = POWER_MGMT_REGISTER_PIIX4 (0x40);
  63       AcpiCtlReg = POWER_MGMT_REGISTER_PIIX4 (0x80); // PMREGMISC
  64       AcpiEnBit  = PIIX4_PMIOSE;
  65       break;
  66     case INTEL_Q35_MCH_DEVICE_ID:
  67       Pmba       = POWER_MGMT_REGISTER_Q35 (0x40);
  68       AcpiCtlReg = POWER_MGMT_REGISTER_Q35 (0x44); // ACPI_CNTL
  69       AcpiEnBit  = Q35_ACPI_EN;
  70       break;
  71     default:
  72       DEBUG ((EFI_D_ERROR, "%a: Unknown Host Bridge Device ID: 0x%04x\n",
  73         __FUNCTION__, HostBridgeDevId));
  74       ASSERT (FALSE);
  75       return RETURN_UNSUPPORTED;
  76   }
  77
  78   mAcpiTimerIoAddr = (PciRead32 (Pmba) & ~PMBA_RTE) + ACPI_TIMER_OFFSET;
  79
  80   //
  81   // Check to see if the Power Management Base Address is already enabled
  82   //
  83   if ((PciRead8 (AcpiCtlReg) & AcpiEnBit) == 0) {
  84     //
  85     // If the Power Management Base Address is not programmed,
  86     // then program the Power Management Base Address from a PCD.
  87     //
  88     PciAndThenOr32 (Pmba, (UINT32) ~0xFFC0, PcdGet16 (PcdAcpiPmBaseAddress));
  89
  90     //
  91     // Enable PMBA I/O port decodes
  92     //
  93     PciOr8 (AcpiCtlReg, AcpiEnBit);
  94   }
  95
  96   return RETURN_SUCCESS;
  97 }
  98
  99 /**
 100   Internal function to read the current tick counter of ACPI.
 101
 102   Read the current ACPI tick counter using the counter address cached
 103   by this instance's constructor.
 104
 105   @return The tick counter read.
 106
 107 **/
 108 UINT32
 109 InternalAcpiGetTimerTick (
 110   VOID
 111   )
 112 {
 113   //
 114   //   Return the current ACPI timer value.
 115   //
 116   return IoRead32 (mAcpiTimerIoAddr);
 117 }