xref: /freebsd/lib/libsys/powerpc/__vdso_gettc.c (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2020 Brandon Bergren <bdragon@FreeBSD.org>
5  *
6  * This software was developed by Konstantin Belousov
7  * under sponsorship from the FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/types.h>
32 #include <sys/elf.h>
33 #include <sys/time.h>
34 #include <sys/vdso.h>
35 
36 #include <machine/cpufunc.h>
37 #include <machine/spr.h>
38 
39 #include <errno.h>
40 
41 #include "libc_private.h"
42 
43 #pragma weak __vdso_gettc
44 int
45 __vdso_gettc(const struct vdso_timehands *th, u_int *tc)
46 {
47 
48 	if (__predict_false(th->th_algo != VDSO_TH_ALGO_PPC_TB))
49 	    return (ENOSYS);
50 	/*
51 	 * While the timebase is a 64 bit quantity, we are only interested
52 	 * in the lower 32 bits of it.
53 	 */
54 	*tc = mfspr(TBR_TBL);
55 
56 	return (0);
57 }
58 
59 #pragma weak __vdso_gettimekeep
60 int
61 __vdso_gettimekeep(struct vdso_timekeep **tk)
62 {
63 
64 	return (_elf_aux_info(AT_TIMEKEEP, tk, sizeof(*tk)));
65 }
66