forked from Imagelibrary/rtems
87 lines
3.4 KiB
C
87 lines
3.4 KiB
C
/* SPDX-License-Identifier: BSD-2-Clause */
|
|
|
|
/*
|
|
* This file implements a benchmark timer using a TX39 timer.
|
|
*
|
|
* NOTE: On the simulator, the count directly reflects instructions.
|
|
*
|
|
* COPYRIGHT (c) 1989-2000.
|
|
* On-Line Applications Research Corporation (OAR).
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <assert.h>
|
|
|
|
#include <bsp.h>
|
|
#include <rtems/btimer.h>
|
|
|
|
bool benchmark_timer_find_average_overhead;
|
|
|
|
void benchmark_timer_initialize(void)
|
|
{
|
|
/*
|
|
* Programming the compare register as the maximum value should let
|
|
* it run long enough and accurate enough not to require an interrupt.
|
|
* but if it ever does generate an interrupt, we will simply fault.
|
|
*
|
|
* NOTE: This is similar to the clock driver initialization
|
|
* with the exception that the divider is disabled and
|
|
* the compare register is set to the maximum value.
|
|
*/
|
|
|
|
TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_TCR, 0x20 );
|
|
TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_CCDR, 0x3 );
|
|
TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_TRR, 0x0 );
|
|
TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_CPRA, 0xFFFFFFFF );
|
|
TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_TISR, 0x00 );
|
|
TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_ITMR, 0x0001 );
|
|
TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_TCR, 0xe0 );
|
|
}
|
|
|
|
#define AVG_OVERHEAD 0 /* It typically takes N instructions */
|
|
/* to start/stop the timer. */
|
|
#define LEAST_VALID 1 /* Don't trust a value lower than this */
|
|
/* tx39 simulator can count instructions. :) */
|
|
|
|
benchmark_timer_t benchmark_timer_read(void)
|
|
{
|
|
uint32_t total;
|
|
|
|
total = TX3904_TIMER_READ( TX3904_TIMER1_BASE, TX3904_TIMER_TRR );
|
|
|
|
if ( benchmark_timer_find_average_overhead == true )
|
|
return total; /* in one microsecond units */
|
|
|
|
if ( total < LEAST_VALID )
|
|
return 0; /* below timer resolution */
|
|
|
|
return total - AVG_OVERHEAD;
|
|
}
|
|
|
|
void benchmark_timer_disable_subtracting_average_overhead(
|
|
bool find_flag
|
|
)
|
|
{
|
|
benchmark_timer_find_average_overhead = find_flag;
|
|
}
|