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
40 static inline uint64_t
cp15_cntvct_get(void)41 cp15_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
49 static inline uint64_t
cp15_cntpct_get(void)50 cp15_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
59 int
__vdso_gettc(const struct vdso_timehands * th,u_int * tc)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
76 int
__vdso_gettimekeep(struct vdso_timekeep ** tk)77 __vdso_gettimekeep(struct vdso_timekeep **tk)
78 {
79
80 return (_elf_aux_info(AT_TIMEKEEP, tk, sizeof(*tk)));
81 }
82