xref: /openbmc/linux/arch/arc/include/asm/syscall.h (revision e3b9f1e8)
1 /*
2  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #ifndef _ASM_ARC_SYSCALL_H
10 #define _ASM_ARC_SYSCALL_H  1
11 
12 #include <linux/err.h>
13 #include <linux/sched.h>
14 #include <asm/unistd.h>
15 #include <asm/ptrace.h>		/* in_syscall() */
16 
17 static inline long
18 syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
19 {
20 	if (user_mode(regs) && in_syscall(regs))
21 		return regs->r8;
22 	else
23 		return -1;
24 }
25 
26 static inline void
27 syscall_rollback(struct task_struct *task, struct pt_regs *regs)
28 {
29 	regs->r0 = regs->orig_r0;
30 }
31 
32 static inline long
33 syscall_get_error(struct task_struct *task, struct pt_regs *regs)
34 {
35 	/* 0 if syscall succeeded, otherwise -Errorcode */
36 	return IS_ERR_VALUE(regs->r0) ? regs->r0 : 0;
37 }
38 
39 static inline long
40 syscall_get_return_value(struct task_struct *task, struct pt_regs *regs)
41 {
42 	return regs->r0;
43 }
44 
45 static inline void
46 syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
47 			 int error, long val)
48 {
49 	regs->r0 = (long) error ?: val;
50 }
51 
52 /*
53  * @i:      argument index [0,5]
54  * @n:      number of arguments; n+i must be [1,6].
55  */
56 static inline void
57 syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
58 		      unsigned int i, unsigned int n, unsigned long *args)
59 {
60 	unsigned long *inside_ptregs = &(regs->r0);
61 	inside_ptregs -= i;
62 
63 	BUG_ON((i + n) > 6);
64 
65 	while (n--) {
66 		args[i++] = (*inside_ptregs);
67 		inside_ptregs--;
68 	}
69 }
70 
71 #endif
72