1/*
 2 * Access to user system call parameters and results
 3 *
 4 * See asm-generic/syscall.h for descriptions of what we must do here.
 5 */
 6
 7#ifndef _ASM_ARM_SYSCALL_H
 8#define _ASM_ARM_SYSCALL_H
 9
10#include <linux/err.h>
11
12extern const unsigned long sys_call_table[];
13
14static inline int syscall_get_nr(struct task_struct *task,
15				 struct pt_regs *regs)
16{
17	return task_thread_info(task)->syscall;
18}
19
20static inline void syscall_rollback(struct task_struct *task,
21				    struct pt_regs *regs)
22{
23	regs->ARM_r0 = regs->ARM_ORIG_r0;
24}
25
26static inline long syscall_get_error(struct task_struct *task,
27				     struct pt_regs *regs)
28{
29	unsigned long error = regs->ARM_r0;
30	return IS_ERR_VALUE(error) ? error : 0;
31}
32
33static inline long syscall_get_return_value(struct task_struct *task,
34					    struct pt_regs *regs)
35{
36	return regs->ARM_r0;
37}
38
39static inline void syscall_set_return_value(struct task_struct *task,
40					    struct pt_regs *regs,
41					    int error, long val)
42{
43	regs->ARM_r0 = (long) error ? error : val;
44}
45
46#define SYSCALL_MAX_ARGS 7
47
48static inline void syscall_get_arguments(struct task_struct *task,
49					 struct pt_regs *regs,
50					 unsigned int i, unsigned int n,
51					 unsigned long *args)
52{
53	if (i + n > SYSCALL_MAX_ARGS) {
54		unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i;
55		unsigned int n_bad = n + i - SYSCALL_MAX_ARGS;
56		pr_warning("%s called with max args %d, handling only %d\n",
57			   __func__, i + n, SYSCALL_MAX_ARGS);
58		memset(args_bad, 0, n_bad * sizeof(args[0]));
59		n = SYSCALL_MAX_ARGS - i;
60	}
61
62	if (i == 0) {
63		args[0] = regs->ARM_ORIG_r0;
64		args++;
65		i++;
66		n--;
67	}
68
69	memcpy(args, &regs->ARM_r0 + i, n * sizeof(args[0]));
70}
71
72static inline void syscall_set_arguments(struct task_struct *task,
73					 struct pt_regs *regs,
74					 unsigned int i, unsigned int n,
75					 const unsigned long *args)
76{
77	if (i + n > SYSCALL_MAX_ARGS) {
78		pr_warning("%s called with max args %d, handling only %d\n",
79			   __func__, i + n, SYSCALL_MAX_ARGS);
80		n = SYSCALL_MAX_ARGS - i;
81	}
82
83	if (i == 0) {
84		regs->ARM_ORIG_r0 = args[0];
85		args++;
86		i++;
87		n--;
88	}
89
90	memcpy(&regs->ARM_r0 + i, args, n * sizeof(args[0]));
91}
92
93#endif /* _ASM_ARM_SYSCALL_H */