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/** @file
This library implements the Timer Library using the Extended SAL Stall Services Class.
Copyright (c) 2007 - 2011, 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 <PiDxe.h>
#include <Protocol/ExtendedSalServiceClasses.h>
#include <Library/TimerLib.h>
#include <Library/BaseLib.h>
#include <Library/ExtendedSalLib.h>
#include <Library/DebugLib.h>
#include <Library/PalLib.h>
/**
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.
@param MicroSeconds The minimum number of microseconds to delay.
@return MicroSeconds
**/
UINTN
EFIAPI
MicroSecondDelay (
IN UINTN MicroSeconds
)
{
EsalCall (
EFI_EXTENDED_SAL_STALL_SERVICES_PROTOCOL_GUID_LO,
EFI_EXTENDED_SAL_STALL_SERVICES_PROTOCOL_GUID_HI,
StallFunctionId,
MicroSeconds,
0,
0,
0,
0,
0,
0
);
return MicroSeconds;
}
/**
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.
@param NanoSeconds The minimum number of nanoseconds to delay.
@return NanoSeconds
**/
UINTN
EFIAPI
NanoSecondDelay (
IN UINTN NanoSeconds
)
{
UINT64 MicroSeconds;
//
// The unit of ESAL Stall service is microsecond, so we turn the time interval
// from nanosecond to microsecond, using the ceiling value to ensure stalling
// at least the given number of nanoseconds.
//
MicroSeconds = DivU64x32 (NanoSeconds + 999, 1000);
EsalCall (
EFI_EXTENDED_SAL_STALL_SERVICES_PROTOCOL_GUID_LO,
EFI_EXTENDED_SAL_STALL_SERVICES_PROTOCOL_GUID_HI,
StallFunctionId,
MicroSeconds,
0,
0,
0,
0,
0,
0
);
return NanoSeconds;
}
/**
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().
@return The current value of the free running performance counter.
**/
UINT64
EFIAPI
GetPerformanceCounter (
VOID
)
{
return 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.
@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
)
{
PAL_CALL_RETURN PalRet;
UINT64 BaseFrequence;
//
// Get processor base frequency
//
PalRet = PalCall (PAL_FREQ_BASE, 0, 0, 0);
ASSERT (PalRet.Status == 0);
BaseFrequence = PalRet.r9;
//
// Get processor frequency ratio
//
PalRet = PalCall (PAL_FREQ_RATIOS, 0, 0, 0);
ASSERT (PalRet.Status == 0);
//
// Start value of counter is 0
//
if (StartValue != NULL) {
*StartValue = 0;
}
//
// End value of counter is 0xFFFFFFFFFFFFFFFF
//
if (EndValue != NULL) {
*EndValue = (UINT64)(-1);
}
return BaseFrequence * (PalRet.r11 >> 32) / (UINT32)PalRet.r11;
}
/**
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;
}
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