mirror of https://github.com/acidanthera/audk.git
261 lines
9.8 KiB
C
261 lines
9.8 KiB
C
/** @file
|
|
|
|
Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
|
|
Copyright (c) 2011, ARM Limited. All rights reserved.
|
|
|
|
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/BaseLib.h>
|
|
#include <Library/TimerLib.h>
|
|
#include <Library/DebugLib.h>
|
|
#include <Library/PcdLib.h>
|
|
#include <Library/IoLib.h>
|
|
#include <Drivers/SP804Timer.h>
|
|
|
|
#define SP804_TIMER_METRONOME_BASE ((UINTN)PcdGet32 (PcdSP804TimerMetronomeBase))
|
|
#define SP804_TIMER_PERFORMANCE_BASE ((UINTN)PcdGet32 (PcdSP804TimerPerformanceBase))
|
|
|
|
// Setup SP810's Timer2 for managing delay functions. And Timer3 for Performance counter
|
|
// Note: ArmVE's Timer0 and Timer1 are used by TimerDxe.
|
|
RETURN_STATUS
|
|
EFIAPI
|
|
TimerConstructor (
|
|
VOID
|
|
)
|
|
{
|
|
// Check if the Metronome Timer is already initialized
|
|
if (MmioRead32(SP804_TIMER_METRONOME_BASE + SP804_TIMER_CONTROL_REG) & SP804_TIMER_CTRL_ENABLE) {
|
|
return RETURN_SUCCESS;
|
|
} else {
|
|
// Configure the Metronome Timer for free running operation, 32 bits, no prescaler, and interrupt disabled
|
|
MmioWrite32 (SP804_TIMER_METRONOME_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_32BIT | SP804_PRESCALE_DIV_1);
|
|
|
|
// Start the Metronome Timer ticking
|
|
MmioOr32 (SP804_TIMER_METRONOME_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ENABLE);
|
|
}
|
|
|
|
// Check if the Performance Timer is already initialized
|
|
if (MmioRead32(SP804_TIMER_PERFORMANCE_BASE + SP804_TIMER_CONTROL_REG) & SP804_TIMER_CTRL_ENABLE) {
|
|
return RETURN_SUCCESS;
|
|
} else {
|
|
// Configure the Performance timer for free running operation, 32 bits, no prescaler, interrupt disabled
|
|
MmioWrite32 (SP804_TIMER_PERFORMANCE_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_32BIT | SP804_PRESCALE_DIV_1);
|
|
|
|
// Start the Performance Timer ticking
|
|
MmioOr32 (SP804_TIMER_PERFORMANCE_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ENABLE);
|
|
}
|
|
|
|
return RETURN_SUCCESS;
|
|
}
|
|
|
|
/**
|
|
Stalls the CPU for at least the given number of microseconds.
|
|
|
|
Stalls the CPU for the number of microseconds specified by MicroSeconds.
|
|
The hardware timer is 32 bits.
|
|
The maximum possible delay is (0xFFFFFFFF / TimerFrequencyMHz), i.e. ([32bits] / FreqInMHz)
|
|
For example:
|
|
+----------------+------------+----------+----------+
|
|
| TimerFrequency | MaxDelay | MaxDelay | MaxDelay |
|
|
| (MHz) | (us) | (s) | (min) |
|
|
+----------------+------------+----------+----------+
|
|
| 1 | 0xFFFFFFFF | 4294 | 71.5 |
|
|
| 5 | 0x33333333 | 859 | 14.3 |
|
|
| 10 | 0x19999999 | 429 | 7.2 |
|
|
| 50 | 0x051EB851 | 86 | 1.4 |
|
|
+----------------+------------+----------+----------+
|
|
If it becomes necessary to support higher delays, then consider using the
|
|
real time clock.
|
|
|
|
During this delay, the cpu is not yielded to any other process, with one exception:
|
|
events that are triggered off a timer and which execute at a higher TPL than
|
|
this function. These events may call MicroSecondDelay (or NanoSecondDelay) to
|
|
fulfil their own needs.
|
|
Therefore, this function must be re-entrant, as it may be interrupted and re-started.
|
|
|
|
@param MicroSeconds The minimum number of microseconds to delay.
|
|
|
|
@return The value of MicroSeconds inputted.
|
|
|
|
**/
|
|
UINTN
|
|
EFIAPI
|
|
MicroSecondDelay (
|
|
IN UINTN MicroSeconds
|
|
)
|
|
{
|
|
UINT64 DelayTicks64; // Convert from microseconds to timer ticks, more bits to detect over-range conditions.
|
|
UINTN DelayTicks; // Convert from microseconds to timer ticks, native size for general calculations.
|
|
UINTN StartTicks; // Timer value snapshot at the start of the delay
|
|
UINTN TargetTicks; // Timer value to signal the end of the delay
|
|
UINTN CurrentTicks; // Current value of the 64-bit timer value at any given moment
|
|
|
|
// If we snapshot the timer at the start of the delay function then we minimise unaccounted overheads.
|
|
StartTicks = MmioRead32 (SP804_TIMER_METRONOME_BASE + SP804_TIMER_CURRENT_REG);
|
|
|
|
// We are operating at the limit of 32bits. For the range checking work in 64 bits to avoid overflows.
|
|
DelayTicks64 = MultU64x32((UINT64)MicroSeconds, PcdGet32(PcdSP804TimerFrequencyInMHz));
|
|
|
|
// We are limited to 32 bits.
|
|
// If the specified delay is exactly equal to the max range of the timer,
|
|
// then the start will be equal to the stop plus one timer overflow (wrap-around).
|
|
// To avoid having to check for that, reduce the maximum acceptable range by 1 tick,
|
|
// i.e. reject delays equal or greater than the max range of the timer.
|
|
if (DelayTicks64 >= (UINT64)SP804_MAX_TICKS) {
|
|
DEBUG((EFI_D_ERROR,"MicroSecondDelay: ERROR: MicroSeconds=%d exceed SP804 count range. Max MicroSeconds=%d\n",
|
|
MicroSeconds,
|
|
((UINTN)SP804_MAX_TICKS/PcdGet32(PcdSP804TimerFrequencyInMHz))));
|
|
}
|
|
ASSERT(DelayTicks64 < (UINT64)SP804_MAX_TICKS);
|
|
|
|
// From now on do calculations only in native bit size.
|
|
DelayTicks = (UINTN)DelayTicks64;
|
|
|
|
// Calculate the target value of the timer.
|
|
|
|
//Note: SP804 timer is counting down
|
|
if (StartTicks >= DelayTicks) {
|
|
// In this case we do not expect a wrap-around of the timer to occur.
|
|
// CurrentTicks must be less than StartTicks and higher than TargetTicks.
|
|
// If this is not the case, then the delay has been reached and may even have been exceeded if this
|
|
// function was suspended by a higher priority interrupt.
|
|
|
|
TargetTicks = StartTicks - DelayTicks;
|
|
|
|
do {
|
|
CurrentTicks = MmioRead32 (SP804_TIMER_METRONOME_BASE + SP804_TIMER_CURRENT_REG);
|
|
} while ((CurrentTicks > TargetTicks) && (CurrentTicks <= StartTicks));
|
|
|
|
} else {
|
|
// In this case TargetTicks is larger than StartTicks.
|
|
// This means we expect a wrap-around of the timer to occur and we must wait for it.
|
|
// Before the wrap-around, CurrentTicks must be less than StartTicks and less than TargetTicks.
|
|
// After the wrap-around, CurrentTicks must be larger than StartTicks and larger than TargetTicks.
|
|
// If this is not the case, then the delay has been reached and may even have been exceeded if this
|
|
// function was suspended by a higher priority interrupt.
|
|
|
|
// The order of operations is essential to avoid arithmetic overflow problems
|
|
TargetTicks = ((UINTN)SP804_MAX_TICKS - DelayTicks) + StartTicks;
|
|
|
|
// First wait for the wrap-around to occur
|
|
do {
|
|
CurrentTicks = MmioRead32 (SP804_TIMER_METRONOME_BASE + SP804_TIMER_CURRENT_REG);
|
|
} while (CurrentTicks <= StartTicks);
|
|
|
|
// Then wait for the target
|
|
do {
|
|
CurrentTicks = MmioRead32 (SP804_TIMER_METRONOME_BASE + SP804_TIMER_CURRENT_REG);
|
|
} while (CurrentTicks > TargetTicks);
|
|
}
|
|
|
|
return MicroSeconds;
|
|
}
|
|
|
|
/**
|
|
Stalls the CPU for at least the given number of nanoseconds.
|
|
|
|
Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
|
|
|
|
When the timer frequency is 1MHz, each tick corresponds to 1 microsecond.
|
|
Therefore, the nanosecond delay will be rounded up to the nearest 1 microsecond.
|
|
|
|
@param NanoSeconds The minimum number of nanoseconds to delay.
|
|
|
|
@return The value of NanoSeconds inputted.
|
|
|
|
**/
|
|
UINTN
|
|
EFIAPI
|
|
NanoSecondDelay (
|
|
IN UINTN NanoSeconds
|
|
)
|
|
{
|
|
UINTN MicroSeconds;
|
|
|
|
// Round up to 1us Tick Number
|
|
MicroSeconds = NanoSeconds / 1000;
|
|
MicroSeconds += ((NanoSeconds % 1000) == 0) ? 0 : 1;
|
|
|
|
MicroSecondDelay (MicroSeconds);
|
|
|
|
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
|
|
)
|
|
{
|
|
// Free running 64-bit/32-bit counter is needed here.
|
|
// Don't think we need this to boot, just to do performance profile
|
|
UINT64 Value;
|
|
Value = MmioRead32 (SP804_TIMER_PERFORMANCE_BASE + SP804_TIMER_CURRENT_REG);
|
|
return Value;
|
|
}
|
|
|
|
|
|
/**
|
|
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) {
|
|
// Timer starts with the reload value
|
|
*StartValue = 0xFFFFFFFF;
|
|
}
|
|
|
|
if (EndValue != NULL) {
|
|
// Timer counts down to 0x0
|
|
*EndValue = (UINT64)0ULL;
|
|
}
|
|
|
|
return PcdGet64 (PcdEmbeddedPerformanceCounterFrequencyInHz);
|
|
}
|