projects / mirror_edk2.git / blame
| Commit | Line | Data |
|---|---|---|
| 170ef2d9 GS |
1 | /** @file\r |
| 2 | Provide constructor and GetTick for Dxe instance of ACPI Timer Library\r | |
| 3 | \r | |
| 4 | Copyright (C) 2014, Gabriel L. Somlo <somlo@cmu.edu>\r | |
| 5 | \r | |
| b26f0cf9 | 6 | SPDX-License-Identifier: BSD-2-Clause-Patent\r |
| 170ef2d9 GS |
7 | **/\r |
| 8 | \r | |
| 9 | #include <Library/DebugLib.h>\r | |
| 10 | #include <Library/IoLib.h>\r | |
| 11 | #include <Library/PcdLib.h>\r | |
| 12 | #include <Library/PciLib.h>\r | |
| 13 | #include <OvmfPlatforms.h>\r | |
| 14 | \r | |
| 170ef2d9 GS |
15 | //\r |
| 16 | // Cached ACPI Timer IO Address\r | |
| 17 | //\r | |
| 18 | STATIC UINT32 mAcpiTimerIoAddr;\r | |
| 19 | \r | |
| 20 | /**\r | |
| 21 | The constructor function caches the ACPI tick counter address\r | |
| 22 | \r | |
| 23 | At the time this constructor runs (DXE_CORE or later), ACPI IO space\r | |
| 24 | has already been enabled by either PlatformPei or by the "Base"\r | |
| 25 | instance of this library.\r | |
| 26 | In order to avoid querying the underlying platform type during each\r | |
| 27 | tick counter read operation, we cache the counter address during\r | |
| 28 | initialization of this instance of the Timer Library.\r | |
| 29 | \r | |
| 30 | @retval EFI_SUCCESS The constructor always returns RETURN_SUCCESS.\r | |
| 31 | \r | |
| 32 | **/\r | |
| 33 | RETURN_STATUS\r | |
| 34 | EFIAPI\r | |
| 35 | AcpiTimerLibConstructor (\r | |
| 36 | VOID\r | |
| 37 | )\r | |
| 38 | {\r | |
| 39 | UINT16 HostBridgeDevId;\r | |
| 40 | UINTN Pmba;\r | |
| 41 | \r | |
| 42 | //\r | |
| 43 | // Query Host Bridge DID to determine platform type\r | |
| 44 | //\r | |
| 45 | HostBridgeDevId = PcdGet16 (PcdOvmfHostBridgePciDevId);\r | |
| 46 | switch (HostBridgeDevId) {\r | |
| 47 | case INTEL_82441_DEVICE_ID:\r | |
| da372167 | 48 | Pmba = POWER_MGMT_REGISTER_PIIX4 (PIIX4_PMBA);\r |
| 170ef2d9 GS |
49 | break;\r |
| 50 | case INTEL_Q35_MCH_DEVICE_ID:\r | |
| bc9d05d6 | 51 | Pmba = POWER_MGMT_REGISTER_Q35 (ICH9_PMBASE);\r |
| 170ef2d9 GS |
52 | break;\r |
| 53 | default:\r | |
| 70d5086c | 54 | DEBUG ((DEBUG_ERROR, "%a: Unknown Host Bridge Device ID: 0x%04x\n",\r |
| 170ef2d9 GS |
55 | __FUNCTION__, HostBridgeDevId));\r |
| 56 | ASSERT (FALSE);\r | |
| 57 | return RETURN_UNSUPPORTED;\r | |
| 58 | }\r | |
| 59 | \r | |
| 60 | mAcpiTimerIoAddr = (PciRead32 (Pmba) & ~PMBA_RTE) + ACPI_TIMER_OFFSET;\r | |
| 61 | \r | |
| 62 | return RETURN_SUCCESS;\r | |
| 63 | }\r | |
| 64 | \r | |
| 65 | /**\r | |
| 66 | Internal function to read the current tick counter of ACPI.\r | |
| 67 | \r | |
| 68 | Read the current ACPI tick counter using the counter address cached\r | |
| 69 | by this instance's constructor.\r | |
| 70 | \r | |
| 71 | @return The tick counter read.\r | |
| 72 | \r | |
| 73 | **/\r | |
| 74 | UINT32\r | |
| 75 | InternalAcpiGetTimerTick (\r | |
| 76 | VOID\r | |
| 77 | )\r | |
| 78 | {\r | |
| 79 | //\r | |
| 80 | // Return the current ACPI timer value.\r | |
| 81 | //\r | |
| 82 | return IoRead32 (mAcpiTimerIoAddr);\r | |
| 83 | }\r |