xref: /freebsd/lib/libsys/aarch64/SYS.h (revision 8269e7673cf033aba67dab8264fe719920c70f87)
1 /*-
2  * Copyright (c) 2014 Andrew Turner
3  * Copyright (c) 2015 The FreeBSD Foundation
4  *
5  * This software was developed by Andrew Turner under
6  * sponsorship from the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/syscall.h>
31 #include <machine/asm.h>
32 
33 #define	_SYSCALL(name)						\
34 	mov	x8, SYS_ ## name;				\
35 	svc	0
36 
37 /*
38  * Conditional jumps can only go up to one megabyte in either
39  * direction, and cerror can be located anywhere, so we have
40  * to jump around to use more capable unconditional branch
41  * instruction.
42  */
43 #define	_SYSCALL_BODY(name)					\
44 	_SYSCALL(name);						\
45 	b.cs	1f;						\
46 	ret;							\
47 1:	b	cerror
48 
49 #define	PSEUDO(name)						\
50 ENTRY(__sys_##name);						\
51 	WEAK_REFERENCE(__sys_##name, _##name);			\
52 	_SYSCALL_BODY(name);					\
53 END(__sys_##name)
54 
55 #define	RSYSCALL(name)						\
56 ENTRY(__sys_##name);						\
57 	WEAK_REFERENCE(__sys_##name, name);			\
58 	WEAK_REFERENCE(__sys_##name, _##name);			\
59 	_SYSCALL_BODY(name);					\
60 END(__sys_##name)
61