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/** @file
A non-functional instance of the Timer Library.
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/EmuThunkLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiLib.h>
#include <Protocol/Timer.h>
STATIC UINT64 gTimerPeriod = 0;
STATIC EFI_TIMER_ARCH_PROTOCOL *gTimerAp = NULL;
STATIC EFI_EVENT gTimerEvent = NULL;
STATIC VOID *gRegistration = NULL;
VOID
EFIAPI
RegisterTimerArchProtocol (
IN EFI_EVENT Event,
IN VOID *Context
)
{
EFI_STATUS Status;
Status = gBS->LocateProtocol (&gEfiTimerArchProtocolGuid, NULL, (VOID **)&gTimerAp);
if (!EFI_ERROR (Status)) {
Status = gTimerAp->GetTimerPeriod (gTimerAp, &gTimerPeriod);
ASSERT_EFI_ERROR (Status);
// Convert to Nanoseconds.
gTimerPeriod = MultU64x32 (gTimerPeriod, 100);
if (gTimerEvent == NULL) {
Status = gBS->CreateEvent (EVT_TIMER, 0, NULL, NULL, &gTimerEvent);
ASSERT_EFI_ERROR (Status);
}
}
}
/**
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
)
{
return NanoSecondDelay (MicroSeconds * 1000);
}
/**
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
)
{
EFI_STATUS Status;
UINT64 HundredNanoseconds;
UINTN Index;
if ((gTimerPeriod != 0) &&
((UINT64)NanoSeconds > gTimerPeriod) &&
(EfiGetCurrentTpl () == TPL_APPLICATION)) {
//
// This stall is long, so use gBS->WaitForEvent () to yield CPU to DXE Core
//
HundredNanoseconds = DivU64x32 (NanoSeconds, 100);
Status = gBS->SetTimer (gTimerEvent, TimerRelative, HundredNanoseconds);
ASSERT_EFI_ERROR (Status);
Status = gBS->WaitForEvent (sizeof (gTimerEvent)/sizeof (EFI_EVENT), &gTimerEvent, &Index);
ASSERT_EFI_ERROR (Status);
} else {
gEmuThunk->Sleep (NanoSeconds);
}
return 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
)
{
return gEmuThunk->QueryPerformanceCounter ();
}
/**
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
)
{
if (StartValue != NULL) {
*StartValue = 0ULL;
}
if (EndValue != NULL) {
*EndValue = (UINT64)-1LL;
}
return gEmuThunk->QueryPerformanceFrequency ();
}
/**
Register for the Timer AP protocol.
@param ImageHandle The firmware allocated handle for the EFI image.
@param SystemTable A pointer to the EFI System Table.
@retval EFI_SUCCESS The constructor always returns EFI_SUCCESS.
**/
EFI_STATUS
EFIAPI
DxeTimerLibConstructor (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EfiCreateProtocolNotifyEvent (
&gEfiTimerArchProtocolGuid,
TPL_CALLBACK,
RegisterTimerArchProtocol,
NULL,
&gRegistration
);
return EFI_SUCCESS;
}
/**
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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