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Diffstat (limited to 'UefiCpuPkg/Library/CpuCommonFeaturesLib/Eist.c')
-rw-r--r-- | UefiCpuPkg/Library/CpuCommonFeaturesLib/Eist.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Eist.c b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Eist.c new file mode 100644 index 0000000000..e1d3d42d99 --- /dev/null +++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Eist.c @@ -0,0 +1,81 @@ +/** @file + Enhanced Intel SpeedStep feature. + + Copyright (c) 2017, Intel Corporation. All rights reserved.<BR> + This program and the accompanying materials + are licensed and made available under the terms and conditions of the BSD License + which accompanies this distribution. The full text of the license may be found at + http://opensource.org/licenses/bsd-license.php + + THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, + WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. + +**/ + +#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 + ) +{ + CPU_REGISTER_TABLE_WRITE_FIELD ( + ProcessorNumber, + Msr, + MSR_IA32_MISC_ENABLE, + MSR_IA32_MISC_ENABLE_REGISTER, + Bits.EIST, + (State) ? 1 : 0 + ); + return RETURN_SUCCESS; +} |