xref: /openbsd/lib/libc/arch/riscv64/gen/usertc.c (revision 73471bf0)
1 /*	$OpenBSD: usertc.c,v 1.2 2021/07/24 22:41:09 jca Exp $	*/
2 /*
3  * Copyright (c) 2020 Paul Irofti <paul@irofti.net>
4  * Copyright (c) 2021 Jeremie Courreges-Anglas <jca@wxcvbn.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/timetc.h>
21 
22 static inline u_int
23 rdtime(void)
24 {
25 	uint64_t ret;
26 
27 	__asm volatile("rdtime %0" : "=r"(ret));
28 
29 	return ret;
30 }
31 
32 static int
33 tc_get_timecount(struct timekeep *tk, u_int *tc)
34 {
35 	switch (tk->tk_user) {
36 	case TC_TB:
37 		*tc = rdtime();
38 		return 0;
39 	}
40 
41 	return -1;
42 }
43 
44 int (*const _tc_get_timecount)(struct timekeep *, u_int *) = tc_get_timecount;
45