audk/UefiCpuPkg/PiSmmCpuDxeSmm/SyncTimer.c

125 lines
2.6 KiB
C

/** @file
SMM Timer feature support
Copyright (c) 2009 - 2024, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "PiSmmCpuCommon.h"
UINT64 mTimeoutTicker = 0;
UINT64 mTimeoutTicker2 = 0;
//
// Number of counts in a roll-over cycle of the performance counter.
//
UINT64 mCycle = 0;
//
// Flag to indicate the performance counter is count-up or count-down.
//
BOOLEAN mCountDown;
/**
Initialize Timer for SMM AP Sync.
**/
VOID
InitializeSmmTimer (
VOID
)
{
UINT64 TimerFrequency;
UINT64 SyncTimeout;
UINT64 SyncTimeout2;
UINT64 Start;
UINT64 End;
SyncTimeout = 0;
SyncTimeout2 = 0;
GetSmmCpuSyncConfigData (NULL, &SyncTimeout, &SyncTimeout2);
TimerFrequency = GetPerformanceCounterProperties (&Start, &End);
mTimeoutTicker = DivU64x32 (
MultU64x64 (TimerFrequency, SyncTimeout),
1000 * 1000
);
mTimeoutTicker2 = DivU64x32 (
MultU64x64 (TimerFrequency, SyncTimeout2),
1000 * 1000
);
if (End < Start) {
mCountDown = TRUE;
mCycle = Start - End;
} else {
mCountDown = FALSE;
mCycle = End - Start;
}
}
/**
Start Timer for SMM AP Sync.
**/
UINT64
EFIAPI
StartSyncTimer (
VOID
)
{
return GetPerformanceCounter ();
}
/**
Check if the SMM AP Sync Timer is timeout specified by Timeout.
@param Timer The start timer from the begin.
@param Timeout The timeout ticker to wait.
**/
BOOLEAN
EFIAPI
IsSyncTimerTimeout (
IN UINT64 Timer,
IN UINT64 Timeout
)
{
UINT64 CurrentTimer;
UINT64 Delta;
CurrentTimer = GetPerformanceCounter ();
//
// We need to consider the case that CurrentTimer is equal to Timer
// when some timer runs too slow and CPU runs fast. We think roll over
// condition does not happen on this case.
//
if (mCountDown) {
//
// The performance counter counts down. Check for roll over condition.
//
if (CurrentTimer <= Timer) {
Delta = Timer - CurrentTimer;
} else {
//
// Handle one roll-over.
//
Delta = mCycle - (CurrentTimer - Timer) + 1;
}
} else {
//
// The performance counter counts up. Check for roll over condition.
//
if (CurrentTimer >= Timer) {
Delta = CurrentTimer - Timer;
} else {
//
// Handle one roll-over.
//
Delta = mCycle - (Timer - CurrentTimer) + 1;
}
}
return (BOOLEAN)(Delta >= Timeout);
}