1/* Access to user system call parameters and results
2 *
3 * See asm-generic/syscall.h for function descriptions.
4 *
5 * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved.
6 * Written by David Howells (dhowells@redhat.com)
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public Licence
10 * as published by the Free Software Foundation; either version
11 * 2 of the Licence, or (at your option) any later version.
12 */
13
14#ifndef _ASM_SYSCALL_H
15#define _ASM_SYSCALL_H
16
17#include <linux/sched.h>
18#include <linux/err.h>
19
20extern const unsigned long sys_call_table[];
21
22static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
23{
24	return regs->orig_d0;
25}
26
27static inline void syscall_rollback(struct task_struct *task,
28				    struct pt_regs *regs)
29{
30	regs->d0 = regs->orig_d0;
31}
32
33static inline long syscall_get_error(struct task_struct *task,
34				     struct pt_regs *regs)
35{
36	unsigned long error = regs->d0;
37	return IS_ERR_VALUE(error) ? error : 0;
38}
39
40static inline long syscall_get_return_value(struct task_struct *task,
41					    struct pt_regs *regs)
42{
43	return regs->d0;
44}
45
46static inline void syscall_set_return_value(struct task_struct *task,
47					    struct pt_regs *regs,
48					    int error, long val)
49{
50	regs->d0 = (long) error ?: val;
51}
52
53static inline void syscall_get_arguments(struct task_struct *task,
54					 struct pt_regs *regs,
55					 unsigned int i, unsigned int n,
56					 unsigned long *args)
57{
58	switch (i) {
59	case 0:
60		if (!n--) break;
61		*args++ = regs->a0;
62	case 1:
63		if (!n--) break;
64		*args++ = regs->d1;
65	case 2:
66		if (!n--) break;
67		*args++ = regs->a3;
68	case 3:
69		if (!n--) break;
70		*args++ = regs->a2;
71	case 4:
72		if (!n--) break;
73		*args++ = regs->d3;
74	case 5:
75		if (!n--) break;
76		*args++ = regs->d2;
77	case 6:
78		if (!n--) break;
79	default:
80		BUG();
81		break;
82	}
83}
84
85static inline void syscall_set_arguments(struct task_struct *task,
86					 struct pt_regs *regs,
87					 unsigned int i, unsigned int n,
88					 const unsigned long *args)
89{
90	switch (i) {
91	case 0:
92		if (!n--) break;
93		regs->a0 = *args++;
94	case 1:
95		if (!n--) break;
96		regs->d1 = *args++;
97	case 2:
98		if (!n--) break;
99		regs->a3 = *args++;
100	case 3:
101		if (!n--) break;
102		regs->a2 = *args++;
103	case 4:
104		if (!n--) break;
105		regs->d3 = *args++;
106	case 5:
107		if (!n--) break;
108		regs->d2 = *args++;
109	case 6:
110		if (!n--) break;
111	default:
112		BUG();
113		break;
114	}
115}
116
117#endif /* _ASM_SYSCALL_H */
118