audk/UefiCpuPkg/Library/CpuCommonFeaturesLib/ExecuteDisable.c

92 lines
3.3 KiB
C

/** @file
Execute Disable feature.
Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#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
)
{
CPU_REGISTER_TABLE_WRITE_FIELD (
ProcessorNumber,
Msr,
MSR_IA32_EFER,
MSR_IA32_EFER_REGISTER,
Bits.NXE,
(State) ? 1 : 0
);
return RETURN_SUCCESS;
}