xref: /openbmc/linux/arch/s390/include/asm/syscall.h (revision 9ac8d3fb)
1 /*
2  * Access to user system call parameters and results
3  *
4  *  Copyright IBM Corp. 2008
5  *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License (version 2 only)
9  * as published by the Free Software Foundation.
10  */
11 
12 #ifndef _ASM_SYSCALL_H
13 #define _ASM_SYSCALL_H	1
14 
15 #include <asm/ptrace.h>
16 
17 static inline long syscall_get_nr(struct task_struct *task,
18 				  struct pt_regs *regs)
19 {
20 	if (regs->trap != __LC_SVC_OLD_PSW)
21 		return -1;
22 	return regs->gprs[2];
23 }
24 
25 static inline void syscall_rollback(struct task_struct *task,
26 				    struct pt_regs *regs)
27 {
28 	regs->gprs[2] = regs->orig_gpr2;
29 }
30 
31 static inline long syscall_get_error(struct task_struct *task,
32 				     struct pt_regs *regs)
33 {
34 	return (regs->gprs[2] >= -4096UL) ? -regs->gprs[2] : 0;
35 }
36 
37 static inline long syscall_get_return_value(struct task_struct *task,
38 					    struct pt_regs *regs)
39 {
40 	return regs->gprs[2];
41 }
42 
43 static inline void syscall_set_return_value(struct task_struct *task,
44 					    struct pt_regs *regs,
45 					    int error, long val)
46 {
47 	regs->gprs[2] = error ? -error : val;
48 }
49 
50 static inline void syscall_get_arguments(struct task_struct *task,
51 					 struct pt_regs *regs,
52 					 unsigned int i, unsigned int n,
53 					 unsigned long *args)
54 {
55 	BUG_ON(i + n > 6);
56 #ifdef CONFIG_COMPAT
57 	if (test_tsk_thread_flag(task, TIF_31BIT)) {
58 		if (i + n == 6)
59 			args[--n] = (u32) regs->args[0];
60 		while (n-- > 0)
61 			args[n] = (u32) regs->gprs[2 + i + n];
62 	}
63 #endif
64 	if (i + n == 6)
65 		args[--n] = regs->args[0];
66 	memcpy(args, &regs->gprs[2 + i], n * sizeof(args[0]));
67 }
68 
69 static inline void syscall_set_arguments(struct task_struct *task,
70 					 struct pt_regs *regs,
71 					 unsigned int i, unsigned int n,
72 					 const unsigned long *args)
73 {
74 	BUG_ON(i + n > 6);
75 	if (i + n == 6)
76 		regs->args[0] = args[--n];
77 	memcpy(&regs->gprs[2 + i], args, n * sizeof(args[0]));
78 }
79 
80 #endif	/* _ASM_SYSCALL_H */
81