/** @file | |
AsmReadMsr64 function | |
Copyright (c) 2006 - 2021, Intel Corporation. All rights reserved.<BR> | |
SPDX-License-Identifier: BSD-2-Clause-Patent | |
**/ | |
#include <Library/RegisterFilterLib.h> | |
/** | |
Returns a 64-bit Machine Specific Register(MSR). | |
Reads and returns the 64-bit MSR specified by Index. No parameter checking is | |
performed on Index, and some Index values may cause CPU exceptions. The | |
caller must either guarantee that Index is valid, or the caller must set up | |
exception handlers to catch the exceptions. This function is only available | |
on IA-32 and x64. | |
@param Index The 32-bit MSR index to read. | |
@return The value of the MSR identified by Index. | |
**/ | |
UINT64 | |
AsmReadMsr64Internal ( | |
IN UINT32 Index | |
) | |
{ | |
_asm { | |
mov ecx, Index | |
rdmsr | |
} | |
} | |
/** | |
Returns a 64-bit Machine Specific Register(MSR). | |
Reads and returns the 64-bit MSR specified by Index. No parameter checking is | |
performed on Index, and some Index values may cause CPU exceptions. The | |
caller must either guarantee that Index is valid, or the caller must set up | |
exception handlers to catch the exceptions. This function is only available | |
on IA-32 and x64. | |
@param Index The 32-bit MSR index to read. | |
@return The value of the MSR identified by Index. | |
**/ | |
UINT64 | |
EFIAPI | |
AsmReadMsr64 ( | |
IN UINT32 Index | |
) | |
{ | |
UINT64 Value; | |
BOOLEAN Flag; | |
Flag = FilterBeforeMsrRead (Index, &Value); | |
if (Flag) { | |
Value = AsmReadMsr64Internal (Index); | |
} | |
FilterAfterMsrRead (Index, &Value); | |
return Value; | |
} |