Subversion Repositories c0or1k

/*

 * Test cpu cycles using platform timer

 * ticks.

 *

 * Copyright (C) 2010 B Labs Ltd.

 *

 * Author: Bahadir Balban

 */

#include <l4lib/macros.h>

#include L4LIB_INC_ARCH(syslib.h)

#include L4LIB_INC_ARCH(syscalls.h)

#include <l4lib/lib/thread.h>

#include <l4lib/perfmon.h>

#include <perf.h>

#include <tests.h>

#include <string.h>

#include <timer.h>

void platform_measure_cpu_cycles()

{

        /* Initialize the timer */

        const int load_value = 1000;

        int mhz_top, mhz_bot, temp;

        int cyccnt;

        /* Make sure timer is disabled */

        timer_stop(timer_base);

        /* Load the timer with ticks value */

        timer_load(load_value, timer_base);

        /* One shot, 32 bits, no irqs */

        timer_init_oneshot(timer_base);

        /* Start the timer */

        timer_start(timer_base);

        /* Start counter */

        perfmon_reset_start_cyccnt();

        /* Wait until 0 */

        while (timer_read(timer_base) != 0)

                ;

        cyccnt = perfmon_read_cyccnt();

        /* Fixed-point accuracy on bottom digit */

        temp = cyccnt * 64 * 10 / load_value;

        mhz_top = temp / 10;

        mhz_bot = temp - mhz_top * 10;

        //printk("Perfmon: %u cycles/%dMhz\n",

        //       cyccnt * 64, timer_load);

        printk("%s: %d.%d MHz CPU speed measured by timer REFCLK at 1MHz\n",

               __KERNELNAME__, mhz_top, mhz_bot);

}