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      1 /** @file
      2   Provide constructor and GetTick for Base instance of ACPI Timer Library
      3 
      4   Copyright (C) 2014, Gabriel L. Somlo <somlo (at) 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 }
    110