xref: /netbsd-src/lib/libc/arch/riscv/SYS.h (revision 6d1cc151b5409c4fabb542849c4a02c9c5012a16)
1 /*	$NetBSD: SYS.h,v 1.5 2023/05/19 06:41:41 skrll Exp $ */
2 
3 /*-
4  * Copyright (c) 2014,2022 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Matt Thomas of 3am Software Foundry, and Nick Hudson.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/syscall.h>
33 #include <machine/asm.h>
34 
35 #define SYSTRAP(x)							\
36 	li	t6, SYS_ ## x;						\
37 	ecall
38 
39 #define	JUMP_TO_CERROR()						\
40 	.option push							;\
41 	.option norelax							;\
42 	tail	_C_LABEL(__cerror)					;\
43 	.option pop
44 
45 #define	SYSTRAP_NOERROR(x)						\
46 	SYSTRAP(x)							;\
47 	nop; nop		/* size of ... 			*/	;\
48 	nop; nop		/*     JUMP_TO_CERROR		*/	;\
49 
50 /*
51  * Do a syscall that cannot fail (sync, get{p,u,g,eu,eg)id)
52  */
53 #define RSYSCALL_NOERROR(x)						\
54 	PSEUDO_NOERROR(x,x)
55 
56 /*
57  * Do a normal syscall.
58  */
59 #define RSYSCALL(x)							\
60 	PSEUDO(x,x)
61 
62 /*
63  * Do a syscall that has an internal name and a weak external alias.
64  */
65 #define	WSYSCALL(weak,strong)						\
66 	WEAK_ALIAS(weak,strong)						;\
67 	PSEUDO(strong,weak)
68 
69 /*
70  * Do a renamed or pseudo syscall (e.g., _exit()), where the entrypoint
71  * and syscall name are not the same.
72  */
73 #define PSEUDO_NOERROR(x,y)						\
74 ENTRY(x)								;\
75 	SYSTRAP_NOERROR(y)						;\
76 	ret			/* success */				;\
77 END(x)
78 
79 #define PSEUDO(x,y)							\
80 ENTRY(x)								;\
81 	SYSTRAP(y)							;\
82 	JUMP_TO_CERROR()	/* error */				;\
83 	ret			/* success */				;\
84 END(x)
85