diff options
Diffstat (limited to 'src/VBox/Devices/EFI/Firmware/UefiCpuPkg/PiSmmCpuDxeSmm/SyncTimer.c')
-rw-r--r-- | src/VBox/Devices/EFI/Firmware/UefiCpuPkg/PiSmmCpuDxeSmm/SyncTimer.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/src/VBox/Devices/EFI/Firmware/UefiCpuPkg/PiSmmCpuDxeSmm/SyncTimer.c b/src/VBox/Devices/EFI/Firmware/UefiCpuPkg/PiSmmCpuDxeSmm/SyncTimer.c new file mode 100644 index 00000000..1d79a50c --- /dev/null +++ b/src/VBox/Devices/EFI/Firmware/UefiCpuPkg/PiSmmCpuDxeSmm/SyncTimer.c @@ -0,0 +1,110 @@ +/** @file +SMM Timer feature support + +Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.<BR> +SPDX-License-Identifier: BSD-2-Clause-Patent + +**/ + +#include "PiSmmCpuDxeSmm.h" + +UINT64 mTimeoutTicker = 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 Start; + UINT64 End; + + TimerFrequency = GetPerformanceCounterProperties (&Start, &End); + mTimeoutTicker = DivU64x32 ( + MultU64x64(TimerFrequency, PcdGet64 (PcdCpuSmmApSyncTimeout)), + 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. + + @param Timer The start timer from the begin. + +**/ +BOOLEAN +EFIAPI +IsSyncTimerTimeout ( + IN UINT64 Timer + ) +{ + 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 >= mTimeoutTicker); +} |