| /** @file |
| Provides calibrated delay and performance counter services. |
| |
| Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR> |
| SPDX-License-Identifier: BSD-2-Clause-Patent |
| |
| **/ |
| |
| #ifndef __TIMER_LIB__ |
| #define __TIMER_LIB__ |
| |
| /** |
| Stalls the CPU for at least the given number of microseconds. |
| |
| Stalls the CPU for the number of microseconds specified by MicroSeconds. |
| |
| @param MicroSeconds The minimum number of microseconds to delay. |
| |
| @return The value of MicroSeconds inputted. |
| |
| **/ |
| UINTN |
| EFIAPI |
| MicroSecondDelay ( |
| IN UINTN MicroSeconds |
| ); |
| |
| /** |
| Stalls the CPU for at least the given number of nanoseconds. |
| |
| Stalls the CPU for the number of nanoseconds specified by NanoSeconds. |
| |
| @param NanoSeconds The minimum number of nanoseconds to delay. |
| |
| @return The value of NanoSeconds inputted. |
| |
| **/ |
| UINTN |
| EFIAPI |
| NanoSecondDelay ( |
| IN UINTN NanoSeconds |
| ); |
| |
| /** |
| 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(). |
| |
| @return The current value of the free running performance counter. |
| |
| **/ |
| UINT64 |
| EFIAPI |
| GetPerformanceCounter ( |
| VOID |
| ); |
| |
| /** |
| 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. |
| |
| @param StartValue The value the performance counter starts with when it |
| rolls over. |
| @param EndValue The value that the performance counter ends with before |
| it rolls over. |
| |
| @return The frequency in Hz. |
| |
| **/ |
| UINT64 |
| EFIAPI |
| GetPerformanceCounterProperties ( |
| OUT UINT64 *StartValue OPTIONAL, |
| OUT UINT64 *EndValue OPTIONAL |
| ); |
| |
| /** |
| 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. |
| |
| @param Ticks The number of elapsed ticks of running performance counter. |
| |
| @return The elapsed time in nanoseconds. |
| |
| **/ |
| UINT64 |
| EFIAPI |
| GetTimeInNanoSecond ( |
| IN UINT64 Ticks |
| ); |
| |
| #endif |