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EmulatorPkg/TimerLib: Add missing GetTimeInNanoSecond function

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Add GetTimeInNanoSecond, already declared in the TimerLib API,
to EmulatorPkg implementations of TimerLib.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Andrew Fish <afish@apple.com>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Michael Johnson <michael.johnson@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
This commit is contained in:
Michael Johnson
2019-06-12 15:59:08 -07:00
committed by Liming Gao
parent 136dad0956
commit d652b458f5
3 changed files with 134 additions and 3 deletions
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47
EmulatorPkg/Library/PeiTimerLib/PeiTimerLib.c
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@@ -1,12 +1,13 @@
/** @file
A non-functional instance of the Timer Library.
Copyright (c) 2007 - 2010, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2007 - 2019, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <PiPei.h>
#include <Library/BaseLib.h>
#include <Library/TimerLib.h>
#include <Library/DebugLib.h>
#include <Library/PeiServicesLib.h>
@@ -166,3 +167,47 @@ GetPerformanceCounterProperties (
return 0;
}
/**
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
)
{
UINT64 Frequency;
UINT64 NanoSeconds;
UINT64 Remainder;
INTN Shift;
Frequency = GetPerformanceCounterProperties (NULL, NULL);
//
// Ticks
// Time = --------- x 1,000,000,000
// Frequency
//
NanoSeconds = MultU64x32 (DivU64x64Remainder (Ticks, Frequency, &Remainder), 1000000000u);
//
// Ensure (Remainder * 1,000,000,000) will not overflow 64-bit.
// Since 2^29 < 1,000,000,000 = 0x3B9ACA00 < 2^30, Remainder should < 2^(64-30) = 2^34,
// i.e. highest bit set in Remainder should <= 33.
//
Shift = MAX (0, HighBitSet64 (Remainder) - 33);
Remainder = RShiftU64 (Remainder, (UINTN) Shift);
Frequency = RShiftU64 (Frequency, (UINTN) Shift);
NanoSeconds += DivU64x64Remainder (MultU64x32 (Remainder, 1000000000u), Frequency, NULL);
return NanoSeconds;
}