UefiCpuPkg/Library/CpuCommonFeaturesLib/LimitCpuIdMaxval.c

   1 /** @file
   2   LimitCpuidMaxval Feature.
   3
   4   Copyright (c) 2017 - 2018, 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 LimitCpuidMaxval 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     LimitCpuidMaxval feature is supported.
  23   @retval FALSE    LimitCpuidMaxval feature is not supported.
  24
  25   @note This service could be called by BSP/APs.
  26 **/
  27 BOOLEAN
  28 EFIAPI
  29 LimitCpuidMaxvalSupport (
  30   IN UINTN                             ProcessorNumber,
  31   IN REGISTER_CPU_FEATURE_INFORMATION  *CpuInfo,
  32   IN VOID                              *ConfigData  OPTIONAL
  33   )
  34 {
  35   UINT32  Eax;
  36
  37   AsmCpuid (CPUID_SIGNATURE, &Eax, NULL, NULL, NULL);
  38   return (Eax > 2);
  39 }
  40
  41 /**
  42   Initializes LimitCpuidMaxval feature to specific state.
  43
  44   @param[in]  ProcessorNumber  The index of the CPU executing this function.
  45   @param[in]  CpuInfo          A pointer to the REGISTER_CPU_FEATURE_INFORMATION
  46                                structure for the CPU executing this function.
  47   @param[in]  ConfigData       A pointer to the configuration buffer returned
  48                                by CPU_FEATURE_GET_CONFIG_DATA.  NULL if
  49                                CPU_FEATURE_GET_CONFIG_DATA was not provided in
  50                                RegisterCpuFeature().
  51   @param[in]  State            If TRUE, then the LimitCpuidMaxval feature must be enabled.
  52                                If FALSE, then the LimitCpuidMaxval feature must be disabled.
  53
  54   @retval RETURN_SUCCESS       LimitCpuidMaxval feature is initialized.
  55
  56   @note This service could be called by BSP only.
  57 **/
  58 RETURN_STATUS
  59 EFIAPI
  60 LimitCpuidMaxvalInitialize (
  61   IN UINTN                             ProcessorNumber,
  62   IN REGISTER_CPU_FEATURE_INFORMATION  *CpuInfo,
  63   IN VOID                              *ConfigData   OPTIONAL,
  64   IN BOOLEAN                           State
  65   )
  66 {
  67   //
  68   // The scope of LimitCpuidMaxval bit in the MSR_IA32_MISC_ENABLE is core for below
  69   // processor type, only program MSR_IA32_MISC_ENABLE for thread 0 in each core.
  70   //
  71   if (IS_PENTIUM_4_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
  72       IS_SILVERMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
  73       IS_GOLDMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
  74       IS_CORE_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
  75       IS_CORE2_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel))
  76   {
  77     if (CpuInfo->ProcessorInfo.Location.Thread != 0) {
  78       return RETURN_SUCCESS;
  79     }
  80   }
  81
  82   CPU_REGISTER_TABLE_WRITE_FIELD (
  83     ProcessorNumber,
  84     Msr,
  85     MSR_IA32_MISC_ENABLE,
  86     MSR_IA32_MISC_ENABLE_REGISTER,
  87     Bits.LimitCpuidMaxval,
  88     (State) ? 1 : 0
  89     );
  90   return RETURN_SUCCESS;
  91 }