UefiCpuPkg/CpuDxe: Fix hard code actual TimerPeriod value

Current CpuGetTimerValue() implementation return hard code TimerPeriod value. We
could calculate the actual TimerPeriod value over period of time (100us) at the
first time invoking CpuGetTimerValue() and save the TimerPeriod value into one
global variable to avoid delay at the next CpuGetTimerValue() invoking.

https://bugzilla.tianocore.org/show_bug.cgi?id=382

Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Feng Tian <feng.tian@Intel.com>
This commit is contained in:
Jeff Fan 2017-02-20 16:17:05 +08:00
parent 14f92ded90
commit 7537f8c09a
3 changed files with 25 additions and 3 deletions

View File

@ -27,6 +27,7 @@ EFI_HANDLE mCpuHandle = NULL;
BOOLEAN mIsFlushingGCD; BOOLEAN mIsFlushingGCD;
UINT64 mValidMtrrAddressMask = MTRR_LIB_CACHE_VALID_ADDRESS; UINT64 mValidMtrrAddressMask = MTRR_LIB_CACHE_VALID_ADDRESS;
UINT64 mValidMtrrBitsMask = MTRR_LIB_MSR_VALID_MASK; UINT64 mValidMtrrBitsMask = MTRR_LIB_MSR_VALID_MASK;
UINT64 mTimerPeriod = 0;
FIXED_MTRR mFixedMtrrTable[] = { FIXED_MTRR mFixedMtrrTable[] = {
{ {
@ -297,6 +298,9 @@ CpuGetTimerValue (
OUT UINT64 *TimerPeriod OPTIONAL OUT UINT64 *TimerPeriod OPTIONAL
) )
{ {
UINT64 BeginValue;
UINT64 EndValue;
if (TimerValue == NULL) { if (TimerValue == NULL) {
return EFI_INVALID_PARAMETER; return EFI_INVALID_PARAMETER;
} }
@ -308,10 +312,26 @@ CpuGetTimerValue (
*TimerValue = AsmReadTsc (); *TimerValue = AsmReadTsc ();
if (TimerPeriod != NULL) { if (TimerPeriod != NULL) {
if (mTimerPeriod == 0) {
// //
// BugBug: Hard coded. Don't know how to do this generically // Read time stamp counter before and after delay of 100 microseconds
// //
*TimerPeriod = 1000000000; BeginValue = AsmReadTsc ();
MicroSecondDelay (100);
EndValue = AsmReadTsc ();
//
// Calculate the actual frequency
//
mTimerPeriod = DivU64x64Remainder (
MultU64x32 (
1000 * 1000 * 1000,
100
),
EndValue - BeginValue,
NULL
);
}
*TimerPeriod = mTimerPeriod;
} }
return EFI_SUCCESS; return EFI_SUCCESS;

View File

@ -1,7 +1,7 @@
/** @file /** @file
CPU DXE Module to produce CPU ARCH Protocol and CPU MP Protocol. CPU DXE Module to produce CPU ARCH Protocol and CPU MP Protocol.
Copyright (c) 2008 - 2016, Intel Corporation. All rights reserved.<BR> Copyright (c) 2008 - 2017, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License 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 which accompanies this distribution. The full text of the license may be found at
@ -39,6 +39,7 @@
#include <Library/HobLib.h> #include <Library/HobLib.h>
#include <Library/ReportStatusCodeLib.h> #include <Library/ReportStatusCodeLib.h>
#include <Library/MpInitLib.h> #include <Library/MpInitLib.h>
#include <Library/TimerLib.h>
#include <Guid/IdleLoopEvent.h> #include <Guid/IdleLoopEvent.h>
#include <Guid/VectorHandoffTable.h> #include <Guid/VectorHandoffTable.h>

View File

@ -43,6 +43,7 @@
HobLib HobLib
ReportStatusCodeLib ReportStatusCodeLib
MpInitLib MpInitLib
TimerLib
[Sources] [Sources]
CpuDxe.c CpuDxe.c