2 Clock Modulation feature.
4 Copyright (c) 2017 - 2018, Intel Corporation. All rights reserved.<BR>
5 This program and the accompanying materials
6 are licensed and made available under the terms and conditions of the BSD License
7 which accompanies this distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
15 #include "CpuCommonFeatures.h"
18 Detects if Clock Modulation feature supported on current processor.
20 @param[in] ProcessorNumber The index of the CPU executing this function.
21 @param[in] CpuInfo A pointer to the REGISTER_CPU_FEATURE_INFORMATION
22 structure for the CPU executing this function.
23 @param[in] ConfigData A pointer to the configuration buffer returned
24 by CPU_FEATURE_GET_CONFIG_DATA. NULL if
25 CPU_FEATURE_GET_CONFIG_DATA was not provided in
28 @retval TRUE Clock Modulation feature is supported.
29 @retval FALSE Clock Modulation feature is not supported.
31 @note This service could be called by BSP/APs.
35 ClockModulationSupport (
36 IN UINTN ProcessorNumber
,
37 IN REGISTER_CPU_FEATURE_INFORMATION
*CpuInfo
,
38 IN VOID
*ConfigData OPTIONAL
41 return (CpuInfo
->CpuIdVersionInfoEdx
.Bits
.ACPI
== 1);
45 Initializes Clock Modulation feature to specific state.
47 @param[in] ProcessorNumber The index of the CPU executing this function.
48 @param[in] CpuInfo A pointer to the REGISTER_CPU_FEATURE_INFORMATION
49 structure for the CPU executing this function.
50 @param[in] ConfigData A pointer to the configuration buffer returned
51 by CPU_FEATURE_GET_CONFIG_DATA. NULL if
52 CPU_FEATURE_GET_CONFIG_DATA was not provided in
54 @param[in] State If TRUE, then the Clock Modulation feature must be enabled.
55 If FALSE, then the Clock Modulation feature must be disabled.
57 @retval RETURN_SUCCESS Clock Modulation feature is initialized.
59 @note This service could be called by BSP only.
63 ClockModulationInitialize (
64 IN UINTN ProcessorNumber
,
65 IN REGISTER_CPU_FEATURE_INFORMATION
*CpuInfo
,
66 IN VOID
*ConfigData
, OPTIONAL
70 CPUID_THERMAL_POWER_MANAGEMENT_EAX ThermalPowerManagementEax
;
71 AsmCpuid (CPUID_THERMAL_POWER_MANAGEMENT
, &ThermalPowerManagementEax
.Uint32
, NULL
, NULL
, NULL
);
73 CPU_REGISTER_TABLE_WRITE_FIELD (
76 MSR_IA32_CLOCK_MODULATION
,
77 MSR_IA32_CLOCK_MODULATION_REGISTER
,
78 Bits
.OnDemandClockModulationDutyCycle
,
79 PcdGet8 (PcdCpuClockModulationDutyCycle
) >> 1
81 if (ThermalPowerManagementEax
.Bits
.ECMD
== 1) {
82 CPU_REGISTER_TABLE_WRITE_FIELD (
85 MSR_IA32_CLOCK_MODULATION
,
86 MSR_IA32_CLOCK_MODULATION_REGISTER
,
87 Bits
.ExtendedOnDemandClockModulationDutyCycle
,
88 PcdGet8 (PcdCpuClockModulationDutyCycle
) & BIT0
91 CPU_REGISTER_TABLE_WRITE_FIELD (
94 MSR_IA32_CLOCK_MODULATION
,
95 MSR_IA32_CLOCK_MODULATION_REGISTER
,
96 Bits
.OnDemandClockModulationEnable
,
99 return RETURN_SUCCESS
;