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