audk/UefiCpuPkg/Library/CpuCommonFeaturesLib/Eist.c

89 lines
3.2 KiB
C

/** @file
Enhanced Intel SpeedStep feature.
Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "CpuCommonFeatures.h"
/**
Detects if Enhanced Intel SpeedStep feature supported on current processor.
@param[in] ProcessorNumber The index of the CPU executing this function.
@param[in] CpuInfo A pointer to the REGISTER_CPU_FEATURE_INFORMATION
structure for the CPU executing this function.
@param[in] ConfigData A pointer to the configuration buffer returned
by CPU_FEATURE_GET_CONFIG_DATA. NULL if
CPU_FEATURE_GET_CONFIG_DATA was not provided in
RegisterCpuFeature().
@retval TRUE Enhanced Intel SpeedStep feature is supported.
@retval FALSE Enhanced Intel SpeedStep feature is not supported.
@note This service could be called by BSP/APs.
**/
BOOLEAN
EFIAPI
EistSupport (
IN UINTN ProcessorNumber,
IN REGISTER_CPU_FEATURE_INFORMATION *CpuInfo,
IN VOID *ConfigData OPTIONAL
)
{
return (CpuInfo->CpuIdVersionInfoEcx.Bits.EIST == 1);
}
/**
Initializes Enhanced Intel SpeedStep feature to specific state.
@param[in] ProcessorNumber The index of the CPU executing this function.
@param[in] CpuInfo A pointer to the REGISTER_CPU_FEATURE_INFORMATION
structure for the CPU executing this function.
@param[in] ConfigData A pointer to the configuration buffer returned
by CPU_FEATURE_GET_CONFIG_DATA. NULL if
CPU_FEATURE_GET_CONFIG_DATA was not provided in
RegisterCpuFeature().
@param[in] State If TRUE, then the Enhanced Intel SpeedStep feature
must be enabled.
If FALSE, then the Enhanced Intel SpeedStep feature
must be disabled.
@retval RETURN_SUCCESS Enhanced Intel SpeedStep feature is initialized.
@note This service could be called by BSP only.
**/
RETURN_STATUS
EFIAPI
EistInitialize (
IN UINTN ProcessorNumber,
IN REGISTER_CPU_FEATURE_INFORMATION *CpuInfo,
IN VOID *ConfigData OPTIONAL,
IN BOOLEAN State
)
{
//
// The scope of the MSR_IA32_MISC_ENABLE is core for below processor type, only program
// MSR_IA32_MISC_ENABLE for thread 0 in each core.
//
if (IS_ATOM_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
IS_CORE_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
IS_CORE2_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel))
{
if (CpuInfo->ProcessorInfo.Location.Thread != 0) {
return RETURN_SUCCESS;
}
}
CPU_REGISTER_TABLE_WRITE_FIELD (
ProcessorNumber,
Msr,
MSR_IA32_MISC_ENABLE,
MSR_IA32_MISC_ENABLE_REGISTER,
Bits.EIST,
(State) ? 1 : 0
);
return RETURN_SUCCESS;
}