1 /*
2 * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved.
3 * Copyright 2010 Tilera Corporation. All Rights Reserved.
4 * Copyright 2015 Regents of the University of California, Berkeley
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation, version 2.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * See asm-generic/syscall.h for descriptions of what we must do here.
16 */
17
18 #ifndef _ASM_RISCV_SYSCALL_H
19 #define _ASM_RISCV_SYSCALL_H
20
21 #include <linux/sched.h>
22 #include <linux/err.h>
23
24 /* The array of function pointers for syscalls. */
25 extern void *sys_call_table[];
26
27 /*
28 * Only the low 32 bits of orig_r0 are meaningful, so we return int.
29 * This importantly ignores the high bits on 64-bit, so comparisons
30 * sign-extend the low 32 bits.
31 */
syscall_get_nr(struct task_struct * task,struct pt_regs * regs)32 static inline int syscall_get_nr(struct task_struct *task,
33 struct pt_regs *regs)
34 {
35 return regs->a7;
36 }
37
syscall_set_nr(struct task_struct * task,struct pt_regs * regs,int sysno)38 static inline void syscall_set_nr(struct task_struct *task,
39 struct pt_regs *regs,
40 int sysno)
41 {
42 regs->a7 = sysno;
43 }
44
syscall_rollback(struct task_struct * task,struct pt_regs * regs)45 static inline void syscall_rollback(struct task_struct *task,
46 struct pt_regs *regs)
47 {
48 regs->a0 = regs->orig_a0;
49 }
50
syscall_get_error(struct task_struct * task,struct pt_regs * regs)51 static inline long syscall_get_error(struct task_struct *task,
52 struct pt_regs *regs)
53 {
54 unsigned long error = regs->a0;
55
56 return IS_ERR_VALUE(error) ? error : 0;
57 }
58
syscall_get_return_value(struct task_struct * task,struct pt_regs * regs)59 static inline long syscall_get_return_value(struct task_struct *task,
60 struct pt_regs *regs)
61 {
62 return regs->a0;
63 }
64
syscall_set_return_value(struct task_struct * task,struct pt_regs * regs,int error,long val)65 static inline void syscall_set_return_value(struct task_struct *task,
66 struct pt_regs *regs,
67 int error, long val)
68 {
69 regs->a0 = (long) error ?: val;
70 }
71
syscall_get_arguments(struct task_struct * task,struct pt_regs * regs,unsigned int i,unsigned int n,unsigned long * args)72 static inline void syscall_get_arguments(struct task_struct *task,
73 struct pt_regs *regs,
74 unsigned int i, unsigned int n,
75 unsigned long *args)
76 {
77 BUG_ON(i + n > 6);
78 if (i == 0) {
79 args[0] = regs->orig_a0;
80 args++;
81 i++;
82 n--;
83 }
84 memcpy(args, ®s->a1 + i * sizeof(regs->a1), n * sizeof(args[0]));
85 }
86
syscall_set_arguments(struct task_struct * task,struct pt_regs * regs,unsigned int i,unsigned int n,const unsigned long * args)87 static inline void syscall_set_arguments(struct task_struct *task,
88 struct pt_regs *regs,
89 unsigned int i, unsigned int n,
90 const unsigned long *args)
91 {
92 BUG_ON(i + n > 6);
93 if (i == 0) {
94 regs->orig_a0 = args[0];
95 args++;
96 i++;
97 n--;
98 }
99 memcpy(®s->a1 + i * sizeof(regs->a1), args, n * sizeof(regs->a0));
100 }
101
102 #endif /* _ASM_RISCV_SYSCALL_H */
103
