2 Clock Modulation feature.
4 Copyright (c) 2017 - 2018, Intel Corporation. All rights reserved.<BR>
5 SPDX-License-Identifier: BSD-2-Clause-Patent
9 #include "CpuCommonFeatures.h"
12 Detects if Clock Modulation feature supported on current processor.
14 @param[in] ProcessorNumber The index of the CPU executing this function.
15 @param[in] CpuInfo A pointer to the REGISTER_CPU_FEATURE_INFORMATION
16 structure for the CPU executing this function.
17 @param[in] ConfigData A pointer to the configuration buffer returned
18 by CPU_FEATURE_GET_CONFIG_DATA. NULL if
19 CPU_FEATURE_GET_CONFIG_DATA was not provided in
22 @retval TRUE Clock Modulation feature is supported.
23 @retval FALSE Clock Modulation feature is not supported.
25 @note This service could be called by BSP/APs.
29 ClockModulationSupport (
30 IN UINTN ProcessorNumber
,
31 IN REGISTER_CPU_FEATURE_INFORMATION
*CpuInfo
,
32 IN VOID
*ConfigData OPTIONAL
35 return (CpuInfo
->CpuIdVersionInfoEdx
.Bits
.ACPI
== 1);
39 Initializes Clock Modulation feature to specific state.
41 @param[in] ProcessorNumber The index of the CPU executing this function.
42 @param[in] CpuInfo A pointer to the REGISTER_CPU_FEATURE_INFORMATION
43 structure for the CPU executing this function.
44 @param[in] ConfigData A pointer to the configuration buffer returned
45 by CPU_FEATURE_GET_CONFIG_DATA. NULL if
46 CPU_FEATURE_GET_CONFIG_DATA was not provided in
48 @param[in] State If TRUE, then the Clock Modulation feature must be enabled.
49 If FALSE, then the Clock Modulation feature must be disabled.
51 @retval RETURN_SUCCESS Clock Modulation feature is initialized.
53 @note This service could be called by BSP only.
57 ClockModulationInitialize (
58 IN UINTN ProcessorNumber
,
59 IN REGISTER_CPU_FEATURE_INFORMATION
*CpuInfo
,
60 IN VOID
*ConfigData
, OPTIONAL
64 CPUID_THERMAL_POWER_MANAGEMENT_EAX ThermalPowerManagementEax
;
65 AsmCpuid (CPUID_THERMAL_POWER_MANAGEMENT
, &ThermalPowerManagementEax
.Uint32
, NULL
, NULL
, NULL
);
67 CPU_REGISTER_TABLE_WRITE_FIELD (
70 MSR_IA32_CLOCK_MODULATION
,
71 MSR_IA32_CLOCK_MODULATION_REGISTER
,
72 Bits
.OnDemandClockModulationDutyCycle
,
73 PcdGet8 (PcdCpuClockModulationDutyCycle
) >> 1
75 if (ThermalPowerManagementEax
.Bits
.ECMD
== 1) {
76 CPU_REGISTER_TABLE_WRITE_FIELD (
79 MSR_IA32_CLOCK_MODULATION
,
80 MSR_IA32_CLOCK_MODULATION_REGISTER
,
81 Bits
.ExtendedOnDemandClockModulationDutyCycle
,
82 PcdGet8 (PcdCpuClockModulationDutyCycle
) & BIT0
85 CPU_REGISTER_TABLE_WRITE_FIELD (
88 MSR_IA32_CLOCK_MODULATION
,
89 MSR_IA32_CLOCK_MODULATION_REGISTER
,
90 Bits
.OnDemandClockModulationEnable
,
93 return RETURN_SUCCESS
;