1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
5 * Copyright (c) 2021 Dmitry Chagin <dchagin@FreeBSD.org>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/elf.h>
30#include <sys/errno.h>
31#include <sys/proc.h>
32#include <sys/stddef.h>
33#define	_KERNEL
34#include <sys/vdso.h>
35#undef	_KERNEL
36#include <stdbool.h>
37
38#include <machine/atomic.h>
39#include <machine/stdarg.h>
40
41#include <arm64/linux/linux.h>
42#include <arm64/linux/linux_syscall.h>
43#include <compat/linux/linux_errno.h>
44#include <compat/linux/linux_time.h>
45
46/* The kernel fixup this at vDSO install */
47uintptr_t *kern_timekeep_base = NULL;
48uint32_t kern_tsc_selector = 0;
49
50static int
51write(int lfd, const void *lbuf, size_t lsize)
52{
53	register long svc asm("x8") = LINUX_SYS_linux_write;
54	register int fd asm("x0") = lfd;
55	register const char *buf asm("x1") = lbuf;
56	register long size asm("x2") = lsize;
57	register long res asm ("x0");
58
59	asm volatile(
60	"       svc #0\n"
61	: "=r" (res)
62	: "r" (fd), "r" (buf), "r" (size), "r" (svc)
63	: "memory");
64	return (res);
65}
66
67static int
68__vdso_clock_gettime_fallback(clockid_t clock_id, struct l_timespec *lts)
69{
70	register long svc asm("x8") = LINUX_SYS_linux_clock_gettime;
71	register clockid_t clockid asm("x0") = clock_id;
72	register struct l_timespec *ts asm("x1") = lts;
73	register long res asm ("x0");
74
75	asm volatile(
76	"       svc #0\n"
77	: "=r" (res)
78	: "r" (clockid), "r" (ts), "r" (svc)
79	: "memory");
80	return (res);
81}
82
83static int
84__vdso_gettimeofday_fallback(l_timeval *ltv, struct timezone *ltz)
85{
86	register long svc asm("x8") = LINUX_SYS_gettimeofday;
87	register l_timeval *tv asm("x0") = ltv;
88	register struct timezone *tz asm("x1") = ltz;
89	register long res asm ("x0");
90
91	asm volatile(
92	"       svc #0\n"
93	: "=r" (res)
94	: "r" (tv), "r" (tz), "r" (svc)
95	: "memory");
96	return (res);
97}
98
99static int
100__vdso_clock_getres_fallback(clockid_t clock_id, struct l_timespec *lts)
101{
102	register long svc asm("x8") = LINUX_SYS_linux_clock_getres;
103	register clockid_t clockid asm("x0") = clock_id;
104	register struct l_timespec *ts asm("x1") = lts;
105	register long res asm ("x0");
106
107	asm volatile(
108	"       svc #0\n"
109	: "=r" (res)
110	: "r" (clockid), "r" (ts), "r" (svc)
111	: "memory");
112	return (res);
113}
114
115/*
116 * copied from lib/libc/aarch64/sys/__vdso_gettc.c
117 */
118
119static inline uint64_t
120cp15_cntvct_get(void)
121{
122	uint64_t reg;
123
124	__asm __volatile("mrs %0, cntvct_el0" : "=r" (reg));
125	return (reg);
126}
127
128static inline uint64_t
129cp15_cntpct_get(void)
130{
131	uint64_t reg;
132
133	__asm __volatile("mrs %0, cntpct_el0" : "=r" (reg));
134	return (reg);
135}
136
137int
138__vdso_gettc(const struct vdso_timehands *th, u_int *tc)
139{
140
141	if (th->th_algo != VDSO_TH_ALGO_ARM_GENTIM)
142		return (ENOSYS);
143	__asm __volatile("isb" : : : "memory");
144	*tc = th->th_physical == 0 ? cp15_cntvct_get() : cp15_cntpct_get();
145	return (0);
146}
147
148#include <compat/linux/linux_vdso_gtod.inc>
149