mirror of
https://gitlab.rtems.org/rtems/rtos/rtems.git
synced 2025-12-05 23:23:13 +00:00
3f71ac151b
* include/bsp.h, shmsupp/getcfg.c, startup/bspstart.c, timer/timer.c: Convert to using c99 fixed size types.
71 lines
1.5 KiB
C
71 lines
1.5 KiB
C
/*
|
|
* This file implements a benchmark timer using the PPC decrement register.
|
|
*
|
|
* COPYRIGHT (c) 1989-2000.
|
|
* On-Line Applications Research Corporation (OAR).
|
|
*
|
|
*
|
|
* $Id$
|
|
*/
|
|
|
|
#include <assert.h>
|
|
|
|
#include <bsp.h>
|
|
|
|
uint64_t Timer_driver_Start_time;
|
|
|
|
rtems_boolean Timer_driver_Find_average_overhead;
|
|
|
|
void Timer_initialize()
|
|
{
|
|
/*
|
|
* Timer runs long and accurate enough not to require an interrupt.
|
|
*/
|
|
|
|
Timer_driver_Start_time = PPC_Get_timebase_register();
|
|
}
|
|
|
|
#define AVG_OVERHEAD 24 /* It typically takes 24 instructions */
|
|
/* to start/stop the timer. */
|
|
#define LEAST_VALID 1 /* Don't trust a value lower than this */
|
|
/* psim can count instructions. :) */
|
|
|
|
int Read_timer()
|
|
{
|
|
uint64_t clicks;
|
|
uint64_t total64;
|
|
uint32_t total;
|
|
|
|
/* approximately CLOCK_SPEED clicks per microsecond */
|
|
|
|
clicks = PPC_Get_timebase_register();
|
|
|
|
assert( clicks > Timer_driver_Start_time );
|
|
|
|
total64 = clicks - Timer_driver_Start_time;
|
|
|
|
assert( total64 <= 0xffffffff ); /* fits into a uint32_t */
|
|
|
|
total = (uint32_t) total64;
|
|
|
|
if ( Timer_driver_Find_average_overhead == 1 )
|
|
return total; /* in one microsecond units */
|
|
|
|
if ( total < LEAST_VALID )
|
|
return 0; /* below timer resolution */
|
|
|
|
return total - AVG_OVERHEAD;
|
|
}
|
|
|
|
rtems_status_code Empty_function( void )
|
|
{
|
|
return RTEMS_SUCCESSFUL;
|
|
}
|
|
|
|
void Set_find_average_overhead(
|
|
rtems_boolean find_flag
|
|
)
|
|
{
|
|
Timer_driver_Find_average_overhead = find_flag;
|
|
}
|