Functions | |
UINTN EFIAPI | MicroSecondDelay (IN UINTN MicroSeconds) |
UINTN EFIAPI | NanoSecondDelay (IN UINTN NanoSeconds) |
UINT64 EFIAPI | GetPerformanceCounter (VOID) |
UINT64 EFIAPI | GetPerformanceCounterProperties (OUT UINT64 *StartValue, OUT UINT64 *EndValue) |
UINT64 EFIAPI | GetTimeInNanoSecond (IN UINT64 Ticks) |
Copyright (c) 2007 - 2011, Intel Corporation. All rights reserved.
This program and the accompanying materials 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 http://opensource.org/licenses/bsd-license.php.
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
Retrieves the current value of a 64-bit free running performance counter.
Retrieves the current value of a 64-bit free running performance counter. The counter can either count up by 1 or count down by 1. If the physical performance counter counts by a larger increment, then the counter values must be translated. The properties of the counter can be retrieved from GetPerformanceCounterProperties().
References AsmReadItc().
Retrieves the 64-bit frequency in Hz and the range of performance counter values.
If StartValue is not NULL, then the value that the performance counter starts with immediately after is it rolls over is returned in StartValue. If EndValue is not NULL, then the value that the performance counter end with immediately before it rolls over is returned in EndValue. The 64-bit frequency of the performance counter in Hz is always returned. If StartValue is less than EndValue, then the performance counter counts up. If StartValue is greater than EndValue, then the performance counter counts down. For example, a 64-bit free running counter that counts up would have a StartValue of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
StartValue | The value the performance counter starts with when it rolls over. | |
EndValue | The value that the performance counter ends with before it rolls over. |
References ASSERT, NULL, PAL_FREQ_BASE, PAL_FREQ_RATIOS, PalCall(), PAL_CALL_RETURN::r11, PAL_CALL_RETURN::r9, and PAL_CALL_RETURN::Status.
Converts elapsed ticks of performance counter to time in nanoseconds.
This function converts the elapsed ticks of running performance counter to time value in unit of nanoseconds.
Ticks | The number of elapsed ticks of running performance counter. |
References DivU64x64Remainder(), GetPerformanceCounterProperties(), HighBitSet64(), MAX, MultU64x32(), NULL, and RShiftU64().
UINTN EFIAPI MicroSecondDelay | ( | IN UINTN | MicroSeconds | ) |
Stalls the CPU for at least the given number of microseconds.
This function wraps EsalStall function of Extended SAL Stall Services Class. It stalls the CPU for the number of microseconds specified by MicroSeconds.
MicroSeconds | The minimum number of microseconds to delay. |
References EFI_EXTENDED_SAL_STALL_SERVICES_PROTOCOL_GUID_HI, EFI_EXTENDED_SAL_STALL_SERVICES_PROTOCOL_GUID_LO, EsalCall(), and StallFunctionId.
UINTN EFIAPI NanoSecondDelay | ( | IN UINTN | NanoSeconds | ) |
Stalls the CPU for at least the given number of nanoseconds.
This function wraps EsalStall function of Extended SAL Stall Services Class. It stalls the CPU for the number of nanoseconds specified by NanoSeconds.
NanoSeconds | The minimum number of nanoseconds to delay. |
References DivU64x32(), EFI_EXTENDED_SAL_STALL_SERVICES_PROTOCOL_GUID_HI, EFI_EXTENDED_SAL_STALL_SERVICES_PROTOCOL_GUID_LO, EsalCall(), and StallFunctionId.