/*
 * 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.
 */

#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);
}