Source code of Windows XP (NT5)
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

101 lines
1.9 KiB

/*++
Copyright (c) 1999-2000 Microsoft Corporation. All Rights Reserved.
Module Name:
msr.c
Abstract:
This module contains global variables used to access x86 processor model specific registers
related to performance counters, as well as a function for writing to x86 model specific registers.
Author:
Joseph Ballantyne
Environment:
Kernel Mode
Revision History:
--*/
#include "common.h"
#include "msr.h"
#pragma LOCKED_DATA
// These variables are used when programming performance counter MSRs.
// The default values are for Intel PII/PIII/Celeron processors.
ULONG PerformanceCounter0=INTELPERFORMANCECOUNTER0;
ULONG PerformanceCounter1=INTELPERFORMANCECOUNTER1;
ULONG EventSelect0=INTELEVENTSELECT0;
ULONG EventSelect1=INTELEVENTSELECT1;
ULONGLONG PerformanceCounterMask=INTELPERFCOUNTMASK;
ULONG StopCounter=PERFCOUNTERENABLED;
ULONG StartCycleCounter=STARTPERFCOUNTERS|INTELCOUNTCYCLES;
ULONG StartInstructionCounter=STARTPERFCOUNTERS|INTELCOUNTINSTRUCTIONS;
ULONG StartInterruptsDisabledCounter=STARTPERFCOUNTERS|INTELINTSDISABLEDWHILEPENDING;
ULONG EnablePerfCounters=0;
#pragma PAGEABLE_DATA
#pragma LOCKED_CODE
// We disable stack frames so that our direct accessing of parameters based
// off of the stack pointer works properly.
#pragma optimize("y", on)
VOID
__fastcall
WriteIntelMSR (
ULONG index,
ULONGLONG value
)
/*++
Routine Description:
Writes the 64 bit data in value to the processor model specific register selected
by index.
Arguments:
index - Supplies the index of the model specific register (MSR) to be written.
Note that writing to an unsupported MSR will cause a GP (general protection)
fault.
value - Supplies the 64 bit data to write into the specified MSR.
Return Value:
None.
--*/
{
__asm {
mov eax, [esp + 0x4]
mov edx, [esp + 0x8]
wrmsr
}
}
#pragma optimize("", on)
#pragma PAGEABLE_CODE