diff options
Diffstat (limited to 'c/src/lib/libbsp/or1k/or1ksim/timer/timer.c')
-rw-r--r-- | c/src/lib/libbsp/or1k/or1ksim/timer/timer.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/or1k/or1ksim/timer/timer.c b/c/src/lib/libbsp/or1k/or1ksim/timer/timer.c new file mode 100644 index 0000000000..ec3c33ed0f --- /dev/null +++ b/c/src/lib/libbsp/or1k/or1ksim/timer/timer.c @@ -0,0 +1,64 @@ +/** + * @file + * + * @ingroup or1ksim + * + * @brief Benchmark timer support. + */ + +/* + * Copyright (c) 2014 by Hesham ALMatary + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE + */ + +#include <rtems.h> +#include <rtems/btimer.h> +#include <bsp/or1ksim.h> +#include <rtems/score/or1k-utility.h> + +#define OR1KSIM_NANOSECONDS_PER_CLK_CYCLE 10 + +static bool benchmark_timer_find_average_overhead = false; +static uint64_t benchmark_timer_base; + +void benchmark_timer_initialize(void) +{ + benchmark_timer_base = _OR1K_mfspr(CPU_OR1K_SPR_TTCR); +} + +#define AVG_OVERHEAD 0 +#define LEAST_VALID 1 + +uint32_t benchmark_timer_read( void ) +{ + uint64_t clicks; + uint64_t total; + uint64_t delta; + /* + * Read the timer and see how many clicks (clock cycles) + * has passed since timer initialization. + */ + clicks = _OR1K_mfspr(CPU_OR1K_SPR_TTCR); + + delta = clicks - benchmark_timer_base; + + /* total in nanoseconds */ + total = OR1KSIM_NANOSECONDS_PER_CLK_CYCLE * (delta); + + if ( benchmark_timer_find_average_overhead == true ) + return total; /* in nanoseconds microsecond units */ + else { + 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; +} |