LimitCpuIdMaxval.c

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#include "CpuCommonFeatures.h"
 
BOOLEAN
EFIAPI
LimitCpuidMaxvalSupport (
  IN UINTN                             ProcessorNumber,
  IN REGISTER_CPU_FEATURE_INFORMATION  *CpuInfo,
  IN VOID                              *ConfigData  OPTIONAL
  )
{
  UINT32  Eax;
 
  AsmCpuid (CPUID_SIGNATURE, &Eax, NULL, NULL, NULL);
  return (Eax > 2);
}
 
RETURN_STATUS
EFIAPI
LimitCpuidMaxvalInitialize (
  IN UINTN                             ProcessorNumber,
  IN REGISTER_CPU_FEATURE_INFORMATION  *CpuInfo,
  IN VOID                              *ConfigData   OPTIONAL,
  IN BOOLEAN                           State
  )
{
  //
  // The scope of LimitCpuidMaxval bit in 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_PENTIUM_4_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
      IS_SILVERMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
      IS_GOLDMONT_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.LimitCpuidMaxval,
    (State) ? 1 : 0
    );
  return RETURN_SUCCESS;
}