1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2015 The FreeBSD Foundation
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#include <machine/cpufunc.h>
36#include <machine/acle-compat.h>
37#include <errno.h>
38#include "libc_private.h"
39
40static inline uint64_t
41cp15_cntvct_get(void)
42{
43	uint64_t reg;
44
45	__asm __volatile("mrrc\tp15, 1, %Q0, %R0, c14" : "=r" (reg));
46	return (reg);
47}
48
49static inline uint64_t
50cp15_cntpct_get(void)
51{
52	uint64_t reg;
53
54	__asm __volatile("mrrc\tp15, 0, %Q0, %R0, c14" : "=r" (reg));
55	return (reg);
56}
57
58#pragma weak __vdso_gettc
59int
60__vdso_gettc(const struct vdso_timehands *th, u_int *tc)
61{
62
63	if (th->th_algo != VDSO_TH_ALGO_ARM_GENTIM)
64		return (ENOSYS);
65	/*
66	 * Userspace gettimeofday() is only enabled on ARMv7 CPUs, but
67	 * libc is compiled for ARMv6.  Due to clang issues, .arch
68	 * armv7-a directive does not work.
69	 */
70	__asm __volatile(".word\t0xf57ff06f" : : : "memory"); /* isb */
71	*tc = th->th_physical == 0 ? cp15_cntvct_get() : cp15_cntpct_get();
72	return (0);
73}
74
75#pragma weak __vdso_gettimekeep
76int
77__vdso_gettimekeep(struct vdso_timekeep **tk)
78{
79
80	return (_elf_aux_info(AT_TIMEKEEP, tk, sizeof(*tk)));
81}
82