source: vbox/trunk/src/VBox/Devices/EFI/FirmwareNew/UefiCpuPkg/Library/CpuCommonFeaturesLib/PendingBreak.c@ 85716

/** @file
  Pending Break feature.

  Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "CpuCommonFeatures.h"

/**
  Detects if Pending Break 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     Pending Break feature is supported.
  @retval FALSE    Pending Break feature is not supported.

  @note This service could be called by BSP/APs.
**/
BOOLEAN
EFIAPI
PendingBreakSupport (
  IN UINTN                             ProcessorNumber,
  IN REGISTER_CPU_FEATURE_INFORMATION  *CpuInfo,
  IN VOID                              *ConfigData  OPTIONAL
  )
{
  if (IS_ATOM_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
      IS_CORE2_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
      IS_CORE_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
      IS_PENTIUM_4_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
      IS_PENTIUM_M_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel)) {
    return (CpuInfo->CpuIdVersionInfoEdx.Bits.PBE == 1);
  }
  return FALSE;
}

/**
  Initializes Pending Break 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 Pending Break feature must be enabled.
                               If FALSE, then the Pending Break feature must be disabled.

  @retval RETURN_SUCCESS       Pending Break feature is initialized.

  @note This service could be called by BSP only.
**/
RETURN_STATUS
EFIAPI
PendingBreakInitialize (
  IN UINTN                             ProcessorNumber,
  IN REGISTER_CPU_FEATURE_INFORMATION  *CpuInfo,
  IN VOID                              *ConfigData,  OPTIONAL
  IN BOOLEAN                           State
  )
{
  //
  // The scope of the MSR_ATOM_IA32_MISC_ENABLE is core for below processor type, only program
  // MSR_ATOM_IA32_MISC_ENABLE for thread 0 in each core.
  //
  // Support function has check the processer type for this feature, no need to check again
  // here.
  //
  if (CpuInfo->ProcessorInfo.Location.Thread != 0) {
    return RETURN_SUCCESS;
  }

  //
  // ATOM, CORE2, CORE, PENTIUM_4 and IS_PENTIUM_M_PROCESSOR have the same MSR index,
  // Simply use MSR_ATOM_IA32_MISC_ENABLE here
  //
  CPU_REGISTER_TABLE_WRITE_FIELD (
    ProcessorNumber,
    Msr,
    MSR_ATOM_IA32_MISC_ENABLE,
    MSR_ATOM_IA32_MISC_ENABLE_REGISTER,
    Bits.FERR,
    (State) ? 1 : 0
    );
  return RETURN_SUCCESS;
}