xref: /openbmc/linux/arch/mips/include/asm/syscall.h (revision c0ff3c53d4f99f5e0ac5fc30ad77f26159b347e0)
119e2e172SRalf Baechle /*
2*c0ff3c53SRalf Baechle  * Access to user system call parameters and results
3*c0ff3c53SRalf Baechle  *
419e2e172SRalf Baechle  * This file is subject to the terms and conditions of the GNU General Public
519e2e172SRalf Baechle  * License.  See the file "COPYING" in the main directory of this archive
619e2e172SRalf Baechle  * for more details.
719e2e172SRalf Baechle  *
8*c0ff3c53SRalf Baechle  * See asm-generic/syscall.h for descriptions of what we must do here.
9*c0ff3c53SRalf Baechle  *
1019e2e172SRalf Baechle  * Copyright (C) 2012 Ralf Baechle <ralf@linux-mips.org>
1119e2e172SRalf Baechle  */
1219e2e172SRalf Baechle 
1319e2e172SRalf Baechle #ifndef __ASM_MIPS_SYSCALL_H
1419e2e172SRalf Baechle #define __ASM_MIPS_SYSCALL_H
1519e2e172SRalf Baechle 
16*c0ff3c53SRalf Baechle #include <linux/kernel.h>
17*c0ff3c53SRalf Baechle #include <linux/sched.h>
18*c0ff3c53SRalf Baechle #include <linux/uaccess.h>
19*c0ff3c53SRalf Baechle #include <asm/ptrace.h>
20*c0ff3c53SRalf Baechle 
21*c0ff3c53SRalf Baechle static inline long syscall_get_nr(struct task_struct *task,
22*c0ff3c53SRalf Baechle 				  struct pt_regs *regs)
23*c0ff3c53SRalf Baechle {
24*c0ff3c53SRalf Baechle 	return regs->regs[2];
25*c0ff3c53SRalf Baechle }
26*c0ff3c53SRalf Baechle 
27*c0ff3c53SRalf Baechle static inline unsigned long mips_get_syscall_arg(unsigned long *arg,
28*c0ff3c53SRalf Baechle 	struct task_struct *task, struct pt_regs *regs, unsigned int n)
29*c0ff3c53SRalf Baechle {
30*c0ff3c53SRalf Baechle 	unsigned long usp = regs->regs[29];
31*c0ff3c53SRalf Baechle 
32*c0ff3c53SRalf Baechle 	switch (n) {
33*c0ff3c53SRalf Baechle 	case 0: case 1: case 2: case 3:
34*c0ff3c53SRalf Baechle 		*arg = regs->regs[4 + n];
35*c0ff3c53SRalf Baechle 
36*c0ff3c53SRalf Baechle 		return 0;
37*c0ff3c53SRalf Baechle 
38*c0ff3c53SRalf Baechle #ifdef CONFIG_32BIT
39*c0ff3c53SRalf Baechle 	case 4: case 5: case 6: case 7:
40*c0ff3c53SRalf Baechle 		return get_user(*arg, (int *)usp + 4 * n);
41*c0ff3c53SRalf Baechle #endif
42*c0ff3c53SRalf Baechle 
43*c0ff3c53SRalf Baechle #ifdef CONFIG_64BIT
44*c0ff3c53SRalf Baechle 	case 4: case 5: case 6: case 7:
45*c0ff3c53SRalf Baechle #ifdef CONFIG_MIPS32_O32
46*c0ff3c53SRalf Baechle 		if (test_thread_flag(TIF_32BIT_REGS))
47*c0ff3c53SRalf Baechle 			return get_user(*arg, (int *)usp + 4 * n);
48*c0ff3c53SRalf Baechle 		else
49*c0ff3c53SRalf Baechle #endif
50*c0ff3c53SRalf Baechle 			*arg = regs->regs[4 + n];
51*c0ff3c53SRalf Baechle 
52*c0ff3c53SRalf Baechle 		return 0;
53*c0ff3c53SRalf Baechle #endif
54*c0ff3c53SRalf Baechle 
55*c0ff3c53SRalf Baechle 	default:
56*c0ff3c53SRalf Baechle 		BUG();
57*c0ff3c53SRalf Baechle 	}
58*c0ff3c53SRalf Baechle }
59*c0ff3c53SRalf Baechle 
60*c0ff3c53SRalf Baechle static inline void syscall_get_arguments(struct task_struct *task,
61*c0ff3c53SRalf Baechle 					 struct pt_regs *regs,
62*c0ff3c53SRalf Baechle 					 unsigned int i, unsigned int n,
63*c0ff3c53SRalf Baechle 					 unsigned long *args)
64*c0ff3c53SRalf Baechle {
65*c0ff3c53SRalf Baechle 	unsigned long arg;
66*c0ff3c53SRalf Baechle 	int ret;
67*c0ff3c53SRalf Baechle 
68*c0ff3c53SRalf Baechle 	while (n--)
69*c0ff3c53SRalf Baechle 		ret |= mips_get_syscall_arg(&arg, task, regs, i++);
70*c0ff3c53SRalf Baechle 
71*c0ff3c53SRalf Baechle 	/*
72*c0ff3c53SRalf Baechle 	 * No way to communicate an error because this is a void function.
73*c0ff3c53SRalf Baechle 	 */
74*c0ff3c53SRalf Baechle #if 0
75*c0ff3c53SRalf Baechle 	return ret;
76*c0ff3c53SRalf Baechle #endif
77*c0ff3c53SRalf Baechle }
78*c0ff3c53SRalf Baechle 
7919e2e172SRalf Baechle extern const unsigned long sys_call_table[];
8019e2e172SRalf Baechle extern const unsigned long sys32_call_table[];
8119e2e172SRalf Baechle extern const unsigned long sysn32_call_table[];
8219e2e172SRalf Baechle 
8319e2e172SRalf Baechle #endif	/* __ASM_MIPS_SYSCALL_H */
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