/* * Periodic timing measurement for RTLinux. * * Copyright (C) 1999 FSM Labs (http://www.fsmlabs.com/) *  Written by Cort Dougan <cort@fsmlabs.com> */#include <linux/module.h>#include <linux/kernel.h>#include <asm/ptrace.h>#include <rtl_core.h>#include <asm/io.h>#include <rtl_sync.h>#include <rtl_fifo.h>#include <rtl_time.h>#include <rtl_core.h>clockid_t clock;void shutdown(void);static int shutdown_flag = 0;hrtime_t last_time;#define FIFO_NUM 0struct samp{	hrtime_t min, max, total;	hrtime_t period;	int cnt;};struct samp sm;int period_cnt = 0;hrtime_t period;void handler(struct pt_regs *p){	hrtime_t x, y;	switch( shutdown_flag )	{		case 0:			if ( last_time )			{				y = x = gethrtime();				if ( last_time > x )					goto out;				x = x - last_time;				if ( (ulong)sm.max < (ulong)x )					sm.max = x;				if ( (ulong)sm.min > (ulong)x )					sm.min = x;				sm.total += x;				if( sm.cnt++ > 100 )				{					sm.period = period;					rtf_put( FIFO_NUM, &sm, sizeof(sm) );					sm.cnt = 0;					sm.max = 0;					sm.min = HRTIME_INFINITY;					sm.total = 0;				}			}			else			{				last_time = gethrtime();				return;			}out:			last_time = y;			break;		case 1: 			shutdown_flag = 2;			break;		default: /* do nothing */			break;	}	return;}int fifo_size=4000;int init_module(void){	rtl_irqstate_t old_irq_state;	int fifo_status; 	rtf_destroy(FIFO_NUM); /* just in case someone else is using!*/	fifo_status = rtf_create(FIFO_NUM, fifo_size);	if (fifo_status) {		rtl_printf("RTLinux measurement test fail. fifo_status=%d\n",fifo_status);		return -1;	}        rtl_printf ("Starting Timer measurement module\n");	rtl_no_interrupts(old_irq_state);	clock = rtl_getbestclock(rtl_getcpuid());	if (!clock || rtl_setclockhandler(clock, handler)) {		rtl_printf("Can't get clock\n");		rtf_destroy(FIFO_NUM); 		goto out;	}		sm.cnt = 0;	sm.max = 0;	sm.min = HRTIME_INFINITY;	sm.total = 0;	last_time = 0;		clock->init(clock);	clock->settimermode(clock, RTL_CLOCK_MODE_PERIODIC);	period = 1000000;	clock->settimer(clock, period);	rtl_restore_interrupts(old_irq_state);	return 0; out:	rtl_restore_interrupts(old_irq_state);	return -1;}void shutdown(){	rtl_irqstate_t old_irq_state;	rtl_no_interrupts(old_irq_state);	clock->uninit(clock);	rtl_restore_interrupts(old_irq_state);	rtf_destroy(FIFO_NUM);}void cleanup_module(void){	int timeout = 100000;	shutdown_flag = 1;	while((shutdown_flag==1) && timeout--);	/* so it's kinda sloppy, wait for timeout or for 	   interrupt routine to ack shutdown, whatever comes	   first */	shutdown();}