xref: /freebsd/sys/amd64/linux/linux_vdso_gtod.c (revision 1349891a0eed79625faafa5ad354d65ff9ea6012)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2021 Dmitry Chagin <dchagin@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/elf.h>
32 #include <sys/errno.h>
33 #include <sys/proc.h>
34 #include <sys/stddef.h>
35 #define	_KERNEL
36 #include <sys/vdso.h>
37 #undef	_KERNEL
38 #include <stdbool.h>
39 
40 #include <machine/atomic.h>
41 #include <machine/stdarg.h>
42 
43 #include <amd64/linux/linux.h>
44 #include <amd64/linux/linux_syscall.h>
45 #include <compat/linux/linux_errno.h>
46 #include <compat/linux/linux_timer.h>
47 
48 /* The kernel fixup this at vDSO install */
49 uintptr_t *kern_timekeep_base = NULL;
50 uint32_t kern_tsc_selector = 0;
51 
52 #include <x86/linux/linux_vdso_gettc_x86.inc>
53 
54 /* for debug purpose */
55 static int
56 write(int fd, const void *buf, size_t size)
57 {
58 	int res;
59 
60 	__asm__ __volatile__
61 	(
62 	    "syscall"
63 	    : "=a"(res)
64 	    : "a"(LINUX_SYS_write), "D"(fd), "S"(buf), "d"(size)
65 	    : "cc", "rcx", "r11", "memory"
66 	);
67 	return (res);
68 }
69 
70 static int
71 __vdso_clock_gettime_fallback(clockid_t clock_id, struct l_timespec *ts)
72 {
73 	int res;
74 
75 	__asm__ __volatile__
76 	(
77 	    "syscall"
78 	    : "=a"(res)
79 	    : "a"(LINUX_SYS_linux_clock_gettime), "D"(clock_id), "S"(ts)
80 	    : "cc", "rcx", "r11", "memory"
81 	);
82 	return (res);
83 }
84 
85 static int
86 __vdso_gettimeofday_fallback(l_timeval *tv, struct timezone *tz)
87 {
88 	int res;
89 
90 	__asm__ __volatile__
91 	(
92 	    "syscall"
93 	    : "=a"(res)
94 	    : "a"(LINUX_SYS_gettimeofday), "D"(tv), "S"(tz)
95 	    : "cc", "rcx", "r11", "memory"
96 	);
97 	return (res);
98 }
99 
100 static int
101 __vdso_clock_getres_fallback(clockid_t clock_id, struct l_timespec *ts)
102 {
103 	int res;
104 
105 	__asm__ __volatile__
106 	(
107 	    "syscall"
108 	    : "=a"(res)
109 	    : "a"(LINUX_SYS_linux_clock_getres), "D"(clock_id), "S"(ts)
110 	    : "cc", "rcx", "r11", "memory"
111 	);
112 	return (res);
113 }
114 
115 static int
116 __vdso_getcpu_fallback(uint32_t *cpu, uint32_t *node, void *cache)
117 {
118 	int res;
119 
120 	__asm__ __volatile__
121 	(
122 	    "syscall"
123 	    : "=a"(res)
124 	    : "a"(LINUX_SYS_linux_getcpu), "D"(cpu), "S"(node), "d"(cache)
125 	    : "cc", "rcx", "r11", "memory"
126 	);
127 	return (res);
128 }
129 
130 static int
131 __vdso_time_fallback(long *tm)
132 {
133 	int res;
134 
135 	__asm__ __volatile__
136 	(
137 	    "syscall"
138 	    : "=a"(res)
139 	    : "a"(LINUX_SYS_linux_time), "D"(tm)
140 	    : "cc", "rcx", "r11", "memory"
141 	);
142 	return (res);
143 }
144 
145 #include <compat/linux/linux_vdso_gtod.inc>
146