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/** @file
CPUID Leaf 0x15 for Core Crystal Clock frequency instance as Base Timer Library.
Copyright (c) 2019 Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Base.h>
#include <Library/TimerLib.h>
#include <Library/BaseLib.h>
/**
CPUID Leaf 0x15 for Core Crystal Clock Frequency.
The TSC counting frequency is determined by using CPUID leaf 0x15. Frequency in MHz = Core XTAL frequency * EBX/EAX.
In newer flavors of the CPU, core xtal frequency is returned in ECX or 0 if not supported.
@return The number of TSC counts per second.
**/
UINT64
CpuidCoreClockCalculateTscFrequency (
VOID
);
/**
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
)
{
return CpuidCoreClockCalculateTscFrequency ();
}
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