UefiCpuPkg/Library/CpuCommonFeaturesLib/ClockModulation.c

   1 /** @file
   2   Clock Modulation feature.
   3
   4   Copyright (c) 2017 - 2019, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include "CpuCommonFeatures.h"
  10
  11 typedef struct  {
  12   CPUID_THERMAL_POWER_MANAGEMENT_EAX    ThermalPowerManagementEax;
  13   MSR_IA32_CLOCK_MODULATION_REGISTER    ClockModulation;
  14 } CLOCK_MODULATION_CONFIG_DATA;
  15
  16 /**
  17   Prepares for the data used by CPU feature detection and initialization.
  18
  19   @param[in]  NumberOfProcessors  The number of CPUs in the platform.
  20
  21   @return  Pointer to a buffer of CPU related configuration data.
  22
  23   @note This service could be called by BSP only.
  24 **/
  25 VOID *
  26 EFIAPI
  27 ClockModulationGetConfigData (
  28   IN UINTN  NumberOfProcessors
  29   )
  30 {
  31   UINT32  *ConfigData;
  32
  33   ConfigData = AllocateZeroPool (sizeof (CLOCK_MODULATION_CONFIG_DATA) * NumberOfProcessors);
  34   ASSERT (ConfigData != NULL);
  35   return ConfigData;
  36 }
  37
  38 /**
  39   Detects if Clock Modulation feature supported on current processor.
  40
  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
  47                                RegisterCpuFeature().
  48
  49   @retval TRUE     Clock Modulation feature is supported.
  50   @retval FALSE    Clock Modulation feature is not supported.
  51
  52   @note This service could be called by BSP/APs.
  53 **/
  54 BOOLEAN
  55 EFIAPI
  56 ClockModulationSupport (
  57   IN UINTN                             ProcessorNumber,
  58   IN REGISTER_CPU_FEATURE_INFORMATION  *CpuInfo,
  59   IN VOID                              *ConfigData  OPTIONAL
  60   )
  61 {
  62   CLOCK_MODULATION_CONFIG_DATA  *CmConfigData;
  63
  64   if (CpuInfo->CpuIdVersionInfoEdx.Bits.ACPI == 1) {
  65     CmConfigData = (CLOCK_MODULATION_CONFIG_DATA *)ConfigData;
  66     ASSERT (CmConfigData != NULL);
  67     AsmCpuid (
  68       CPUID_THERMAL_POWER_MANAGEMENT,
  69       &CmConfigData[ProcessorNumber].ThermalPowerManagementEax.Uint32,
  70       NULL,
  71       NULL,
  72       NULL
  73       );
  74     CmConfigData[ProcessorNumber].ClockModulation.Uint64 = AsmReadMsr64 (MSR_IA32_CLOCK_MODULATION);
  75     return TRUE;
  76   }
  77
  78   return FALSE;
  79 }
  80
  81 /**
  82   Initializes Clock Modulation feature to specific state.
  83
  84   @param[in]  ProcessorNumber  The index of the CPU executing this function.
  85   @param[in]  CpuInfo          A pointer to the REGISTER_CPU_FEATURE_INFORMATION
  86                                structure for the CPU executing this function.
  87   @param[in]  ConfigData       A pointer to the configuration buffer returned
  88                                by CPU_FEATURE_GET_CONFIG_DATA.  NULL if
  89                                CPU_FEATURE_GET_CONFIG_DATA was not provided in
  90                                RegisterCpuFeature().
  91   @param[in]  State            If TRUE, then the Clock Modulation feature must be enabled.
  92                                If FALSE, then the Clock Modulation feature must be disabled.
  93
  94   @retval RETURN_SUCCESS       Clock Modulation feature is initialized.
  95
  96   @note This service could be called by BSP only.
  97 **/
  98 RETURN_STATUS
  99 EFIAPI
 100 ClockModulationInitialize (
 101   IN UINTN                             ProcessorNumber,
 102   IN REGISTER_CPU_FEATURE_INFORMATION  *CpuInfo,
 103   IN VOID                              *ConfigData   OPTIONAL,
 104   IN BOOLEAN                           State
 105   )
 106 {
 107   CLOCK_MODULATION_CONFIG_DATA        *CmConfigData;
 108   MSR_IA32_CLOCK_MODULATION_REGISTER  *ClockModulation;
 109
 110   CmConfigData = (CLOCK_MODULATION_CONFIG_DATA *)ConfigData;
 111   ASSERT (CmConfigData != NULL);
 112   ClockModulation = &CmConfigData[ProcessorNumber].ClockModulation;
 113
 114   if (State) {
 115     ClockModulation->Bits.OnDemandClockModulationEnable    = 1;
 116     ClockModulation->Bits.OnDemandClockModulationDutyCycle = PcdGet8 (PcdCpuClockModulationDutyCycle) >> 1;
 117     if (CmConfigData[ProcessorNumber].ThermalPowerManagementEax.Bits.ECMD == 1) {
 118       ClockModulation->Bits.ExtendedOnDemandClockModulationDutyCycle = PcdGet8 (PcdCpuClockModulationDutyCycle) & BIT0;
 119     }
 120   } else {
 121     ClockModulation->Bits.OnDemandClockModulationEnable = 0;
 122   }
 123
 124   CPU_REGISTER_TABLE_WRITE64 (
 125     ProcessorNumber,
 126     Msr,
 127     MSR_IA32_CLOCK_MODULATION,
 128     ClockModulation->Uint64
 129     );
 130
 131   return RETURN_SUCCESS;
 132 }