mirror of https://github.com/acidanthera/audk.git
43 lines
1.2 KiB
C
43 lines
1.2 KiB
C
/** @file
|
|
ACPI Timer implements one instance of Timer Library.
|
|
|
|
Copyright (c) 2013 - 2014, Intel Corporation. All rights reserved.<BR>
|
|
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.
|
|
|
|
**/
|
|
|
|
#include <Base.h>
|
|
#include <Library/TimerLib.h>
|
|
#include <Library/BaseLib.h>
|
|
|
|
/**
|
|
Internal function to retrieves the 64-bit frequency in Hz.
|
|
|
|
Internal function to retrieves the 64-bit frequency in Hz.
|
|
|
|
@return The frequency in Hz.
|
|
|
|
**/
|
|
UINT64
|
|
InternalGetPerformanceCounterFrequency (
|
|
VOID
|
|
)
|
|
{
|
|
BOOLEAN InterruptState;
|
|
UINT64 Count;
|
|
UINT64 Frequency;
|
|
|
|
InterruptState = SaveAndDisableInterrupts ();
|
|
Count = GetPerformanceCounter ();
|
|
MicroSecondDelay (100);
|
|
Frequency = MultU64x32 (GetPerformanceCounter () - Count, 10000);
|
|
SetInterruptState (InterruptState);
|
|
return Frequency;
|
|
}
|