/*      $OpenBSD: usertc.c,v 1.2 2020/07/08 09:20:28 kettenis Exp $     */
/*
 * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
 *
 * 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 inline u_int
tick_get_timecount(struct timecounter *tc)
{
        u_int64_t tick;

        __asm volatile("rd %%tick, %0" : "=r" (tick));

        return (tick & ~0u);
}

static inline u_int
sys_tick_get_timecount(struct timecounter *tc)
{
        u_int64_t tick;

        __asm volatile("rd %%sys_tick, %0" : "=r" (tick));

        return (tick & ~0u);
}

static int
tc_get_timecount(struct timekeep *tk, u_int *tc)
{
        switch (tk->tk_user) {
        case TC_TICK:
                *tc = tick_get_timecount(NULL);
                return 0;
        case TC_SYS_TICK:
                *tc = sys_tick_get_timecount(NULL);
                return 0;
        }

        return -1;
}

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