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 */
47 uintptr_t *kern_timekeep_base = NULL;
48 uint32_t kern_tsc_selector = 0;
49
50 static int
write(int lfd,const void * lbuf,size_t lsize)51 write(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
67 static int
__vdso_clock_gettime_fallback(clockid_t clock_id,struct l_timespec * lts)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
83 static int
__vdso_gettimeofday_fallback(l_timeval * ltv,struct timezone * ltz)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
99 static int
__vdso_clock_getres_fallback(clockid_t clock_id,struct l_timespec * lts)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
119 static inline uint64_t
cp15_cntvct_get(void)120 cp15_cntvct_get(void)
121 {
122 uint64_t reg;
123
124 __asm __volatile("mrs %0, cntvct_el0" : "=r" (reg));
125 return (reg);
126 }
127
128 static inline uint64_t
cp15_cntpct_get(void)129 cp15_cntpct_get(void)
130 {
131 uint64_t reg;
132
133 __asm __volatile("mrs %0, cntpct_el0" : "=r" (reg));
134 return (reg);
135 }
136
137 int
__vdso_gettc(const struct vdso_timehands * th,u_int * tc)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