root/lib/libc/arch/powerpc64/gen/usertc.c
/*      $OpenBSD: usertc.c,v 1.2 2022/11/05 16:23:02 cheloha Exp $      */
/*
 * Copyright (c) 2020 Paul Irofti <paul@irofti.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

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

static u_int
mftbl(void)
{
        uint64_t value;
        __asm volatile ("mftb %0" : "=r"(value));
        return value;
}

static int
tc_get_timecount(struct timekeep *tk, u_int *tc)
{
        switch (tk->tk_user) {
        case TC_TB:
                *tc = mftbl();
                return 0;
        }
        return -1;
}

int (*const _tc_get_timecount)(struct timekeep *, u_int *) = tc_get_timecount;