/*
 * Copyright 1996 Massachusetts Institute of Technology
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby
 * granted, provided that both the above copyright notice and this
 * permission notice appear in all copies, that both the above
 * copyright notice and this permission notice appear in all
 * supporting documentation, and that the name of M.I.T. not be used
 * in advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.  M.I.T. makes
 * no representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied
 * warranty.
 * 
 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: releng/9.2/share/examples/perfmon/perfmon.c 209455 2010-06-23 04:42:47Z kevlo $
 */

#include <sys/types.h>
#include <sys/ioctl.h>

#include <machine/cpu.h>
#include <machine/perfmon.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>
#include <unistd.h>
#include <fcntl.h>
#include <limits.h>
#include <errno.h>

static int getnum(const char *, int, int);
static void usage(const char *) __dead2;

int
main(int argc, char **argv)
{
	int c, fd, num;
	int loops, i, sleeptime;
	char *cmd;
	struct pmc pmc;
	struct pmc_tstamp then, now;
	struct pmc_data value;
	quad_t *buf;
	double total;

	pmc.pmc_num = 0;
	pmc.pmc_event = 0;
	pmc.pmc_unit = 0;
	pmc.pmc_flags = 0;
	pmc.pmc_mask = 0;
	cmd = NULL;
	loops = 50;
	sleeptime = 0;

	while ((c = getopt(argc, argv, "s:l:uoeiU:m:c:")) != -1) {
		switch(c) {
		case 'u':
			pmc.pmc_flags |= PMCF_USR;
			break;
		case 'o':
			pmc.pmc_flags |= PMCF_OS;
			break;
		case 'e':
			pmc.pmc_flags |= PMCF_E;
			break;
		case 'i':
			pmc.pmc_flags |= PMCF_INV;
			break;
		case 'U':
			pmc.pmc_unit = getnum(optarg, 0, 256);
			break;
		case 'm':
			pmc.pmc_mask = getnum(optarg, 0, 256);
			break;
		case 'l':
			loops = getnum(optarg, 1, INT_MAX - 1);
			break;
		case 's':
			sleeptime = getnum(optarg, 0, INT_MAX - 1);
			break;
		case 'c':
			cmd = optarg;
			break;
		default:
			usage(argv[0]);
		}
	}

	if (argc - optind != 1)
		usage(argv[0]);

	pmc.pmc_event = getnum(argv[optind], 0, 255);

	buf = malloc((loops + 1) * sizeof *buf);
	if (!buf)
		err(1, "malloc(%lu)", (unsigned long)(loops +1) * sizeof *buf);

	fd = open(_PATH_PERFMON, O_RDWR, 0);
	if (fd < 0)
		err(1, "open: " _PATH_PERFMON);

	if (ioctl(fd, PMIOSETUP, &pmc) < 0)
		err(1, "ioctl(PMIOSETUP)");

	if (ioctl(fd, PMIOTSTAMP, &then) < 0)
		err(1, "ioctl(PMIOTSTAMP)");

	num = 0;
	if (ioctl(fd, PMIOSTART, &num) < 0)
		err(1, "ioctl(PMIOSTART)");

	value.pmcd_num = 0;
	for (i = 0; i < loops; i++) {
		if (ioctl(fd, PMIOSTOP, &num) < 0)
			err(1, "ioctl(PMIOSTOP)");
		if (ioctl(fd, PMIOREAD, &value) < 0)
			err(1, "ioctl(PMIOREAD)");
		buf[i] = value.pmcd_value;
		if (ioctl(fd, PMIORESET, &value.pmcd_num) < 0)
			err(1, "ioctl(PMIORESET)");
		if (ioctl(fd, PMIOSTART, &num) < 0)
			err(1, "ioctl(PMIOSTART)");
		if (sleeptime)
			sleep(sleeptime);
		if (cmd)
			system(cmd);
	}

	if (ioctl(fd, PMIOSTOP, &num) < 0)
		err(1, "ioctl(PMIOSTOP)");
	if (ioctl(fd, PMIOREAD, &value) < 0)
		err(1, "ioctl(PMIOREAD)");
	buf[i] = value.pmcd_value;
	if (ioctl(fd, PMIOTSTAMP, &now) < 0)
		err(1, "ioctl(PMIOTSTAMP)");

	total = 0;
	for (i = 1; i <= loops; i++) {
		printf("%d: %qd\n", i, buf[i]);
		total += buf[i];
	}
	printf("total: %f\nmean: %f\n", total, total / loops);

	printf("clocks (at %d-MHz): %qd\n", now.pmct_rate,
	       now.pmct_value - then.pmct_value);

	return 0;
}

static int
getnum(const char *buf, int min, int max)
{
	char *ep;
	long l;

	errno = 0;
	l = strtol(buf, &ep, 0);
	if (*buf && !*ep && !errno) {
		if (l < min || l > max) {
			errx(1, "%s: must be between %d and %d", 
			     buf, min, max);
		}
		return (int)l;
	} 

	errx(1, "%s: parameter must be an integer", buf);
}

static void
usage(const char *pname)
{
	fprintf(stderr, 
	"usage: %s [-eiou] [-c command] [-l nloops] [-m mask] [-s sleeptime]\n"
	"       [-U unit] counter\n",
		pname);
	exit(1);
}
