1/*	$OpenBSD: usertc.c,v 1.3 2021/07/25 22:58:39 jca Exp $	*/
2/*
3 * Copyright (c) 2020 Visa Hankala
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#include <sys/types.h>
19#include <sys/timetc.h>
20
21static inline u_int
22get_cp0_count(void)
23{
24	uint32_t count;
25
26	__asm volatile (
27	"	.set	push\n"
28	"	.set	mips64r2\n"
29	"	rdhwr	%0, $2\n"
30	"	.set	pop\n"
31	: "=r" (count));
32
33	return count;
34}
35
36static int
37tc_get_timecount(struct timekeep *tk, u_int *tc)
38{
39	switch (tk->tk_user) {
40	case TC_CP0_COUNT:
41		*tc = get_cp0_count();
42		return 0;
43	}
44
45	return -1;
46}
47
48int (*const _tc_get_timecount)(struct timekeep *, u_int *) = tc_get_timecount;
49