UefiCpuPkg/Library/CpuCommonFeaturesLib/MonitorMwait.c

   1 /** @file
   2   MonitorMwait feature.
   3
   4   Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include "CpuCommonFeatures.h"
  10
  11 /**
  12   Detects if MONITOR/MWAIT feature supported on current processor.
  13
  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
  20                                RegisterCpuFeature().
  21
  22   @retval TRUE     MONITOR/MWAIT feature is supported.
  23   @retval FALSE    MONITOR/MWAIT feature is not supported.
  24
  25   @note This service could be called by BSP/APs.
  26 **/
  27 BOOLEAN
  28 EFIAPI
  29 MonitorMwaitSupport (
  30   IN UINTN                             ProcessorNumber,
  31   IN REGISTER_CPU_FEATURE_INFORMATION  *CpuInfo,
  32   IN VOID                              *ConfigData  OPTIONAL
  33   )
  34 {
  35   return (CpuInfo->CpuIdVersionInfoEcx.Bits.MONITOR == 1);
  36 }
  37
  38 /**
  39   Initializes MONITOR/MWAIT feature to specific state.
  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   @param[in]  State            If TRUE, then the MONITOR/MWAIT feature must be enabled.
  49                                If FALSE, then the MONITOR/MWAIT feature must be disabled.
  50
  51   @retval RETURN_SUCCESS       MONITOR/MWAIT feature is initialized.
  52
  53   @note This service could be called by BSP only.
  54 **/
  55 RETURN_STATUS
  56 EFIAPI
  57 MonitorMwaitInitialize (
  58   IN UINTN                             ProcessorNumber,
  59   IN REGISTER_CPU_FEATURE_INFORMATION  *CpuInfo,
  60   IN VOID                              *ConfigData,  OPTIONAL
  61   IN BOOLEAN                           State
  62   )
  63 {
  64   //
  65   // The scope of the MSR_IA32_MISC_ENABLE is core for below processor type, only program
  66   // MSR_IA32_MISC_ENABLE for thread 0 in each core.
  67   //
  68   if (IS_CORE2_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
  69       IS_ATOM_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
  70       IS_GOLDMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
  71       IS_SILVERMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
  72       IS_PENTIUM_4_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
  73       IS_CORE_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel)) {
  74     if (CpuInfo->ProcessorInfo.Location.Thread != 0) {
  75       return RETURN_SUCCESS;
  76     }
  77   }
  78
  79   CPU_REGISTER_TABLE_WRITE_FIELD (
  80     ProcessorNumber,
  81     Msr,
  82     MSR_IA32_MISC_ENABLE,
  83     MSR_IA32_MISC_ENABLE_REGISTER,
  84     Bits.MONITOR,
  85     (State) ? 1 : 0
  86     );
  87   return RETURN_SUCCESS;
  88 }