xref: /freebsd/lib/libsys/riscv/__vdso_gettc.c (revision e1c4c8dd8d2d10b6104f06856a77bd5b4813a801)
1 /*-
2  * Copyright (c) 2021 Jessica Clarke
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 #include <sys/types.h>
27 #include <sys/elf.h>
28 #include <sys/time.h>
29 #include <sys/vdso.h>
30 
31 #include <machine/riscvreg.h>
32 
33 #include <errno.h>
34 
35 #include "libc_private.h"
36 
37 #pragma weak __vdso_gettc
38 int
39 __vdso_gettc(const struct vdso_timehands *th, u_int *tc)
40 {
41 	if (th->th_algo != VDSO_TH_ALGO_RISCV_RDTIME)
42 		return (ENOSYS);
43 
44 	*tc = csr_read(time);
45 	return (0);
46 }
47 
48 #pragma weak __vdso_gettimekeep
49 int
50 __vdso_gettimekeep(struct vdso_timekeep **tk)
51 {
52 	return (_elf_aux_info(AT_TIMEKEEP, tk, sizeof(*tk)));
53 }
54