audk/UefiCpuPkg/Library/CpuCommonFeaturesLib/ExecuteDisable.c

96 lines
3.2 KiB
C

/** @file
Execute Disable feature.
Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "CpuCommonFeatures.h"
/**
Detects if Execute Disable 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 Execute Disable feature is supported.
@retval FALSE Execute Disable feature is not supported.
@note This service could be called by BSP/APs.
**/
BOOLEAN
EFIAPI
ExecuteDisableSupport (
IN UINTN ProcessorNumber,
IN REGISTER_CPU_FEATURE_INFORMATION *CpuInfo,
IN VOID *ConfigData OPTIONAL
)
{
UINT32 Eax;
CPUID_EXTENDED_CPU_SIG_EDX Edx;
AsmCpuid (CPUID_EXTENDED_FUNCTION, &Eax, NULL, NULL, NULL);
if (Eax <= CPUID_EXTENDED_FUNCTION) {
//
// Extended CPUID functions are not supported on this processor.
//
return FALSE;
}
AsmCpuid (CPUID_EXTENDED_CPU_SIG, NULL, NULL, NULL, &Edx.Uint32);
return (Edx.Bits.NX != 0);
}
/**
Initializes Execute Disable 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 Execute Disable feature must be enabled.
If FALSE, then the Execute Disable feature must be disabled.
@retval RETURN_SUCCESS Execute Disable feature is initialized.
@note This service could be called by BSP only.
**/
RETURN_STATUS
EFIAPI
ExecuteDisableInitialize (
IN UINTN ProcessorNumber,
IN REGISTER_CPU_FEATURE_INFORMATION *CpuInfo,
IN VOID *ConfigData, OPTIONAL
IN BOOLEAN State
)
{
//
// The scope of the MSR_IA32_EFER is core for below processor type, only program
// MSR_IA32_EFER for thread 0 in each core.
//
if (IS_SILVERMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel)) {
if (CpuInfo->ProcessorInfo.Location.Thread != 0) {
return RETURN_SUCCESS;
}
}
CPU_REGISTER_TABLE_WRITE_FIELD (
ProcessorNumber,
Msr,
MSR_IA32_EFER,
MSR_IA32_EFER_REGISTER,
Bits.NXE,
(State) ? 1 : 0
);
return RETURN_SUCCESS;
}