coreboot-kgpe-d16/src/lib/timer.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright 2014 Google Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <console/console.h>
#include <timer.h>
#include <delay.h>
#include <thread.h>

void udelay(unsigned usec)
{
	struct stopwatch sw;

	/*
	 * As the timer granularity is in microseconds pad the
	 * requested delay by one to get at least >= requested usec delay.
	 */
	usec += 1;

	if (!thread_yield_microseconds(usec))
		return;

	stopwatch_init_usecs_expire(&sw, usec);

	while (!stopwatch_expired(&sw))
		;
}