xref: /openbmc/linux/arch/riscv/include/asm/syscall.h (revision 3d37ef41)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2008-2009 Red Hat, Inc.  All rights reserved.
4  * Copyright 2010 Tilera Corporation. All Rights Reserved.
5  * Copyright 2015 Regents of the University of California, Berkeley
6  *
7  * See asm-generic/syscall.h for descriptions of what we must do here.
8  */
9 
10 #ifndef _ASM_RISCV_SYSCALL_H
11 #define _ASM_RISCV_SYSCALL_H
12 
13 #include <uapi/linux/audit.h>
14 #include <linux/sched.h>
15 #include <linux/err.h>
16 
17 /* The array of function pointers for syscalls. */
18 extern void * const sys_call_table[];
19 
20 /*
21  * Only the low 32 bits of orig_r0 are meaningful, so we return int.
22  * This importantly ignores the high bits on 64-bit, so comparisons
23  * sign-extend the low 32 bits.
24  */
25 static inline int syscall_get_nr(struct task_struct *task,
26 				 struct pt_regs *regs)
27 {
28 	return regs->a7;
29 }
30 
31 static inline void syscall_rollback(struct task_struct *task,
32 				    struct pt_regs *regs)
33 {
34         regs->a0 = regs->orig_a0;
35 }
36 
37 static inline long syscall_get_error(struct task_struct *task,
38 				     struct pt_regs *regs)
39 {
40 	unsigned long error = regs->a0;
41 
42 	return IS_ERR_VALUE(error) ? error : 0;
43 }
44 
45 static inline long syscall_get_return_value(struct task_struct *task,
46 					    struct pt_regs *regs)
47 {
48 	return regs->a0;
49 }
50 
51 static inline void syscall_set_return_value(struct task_struct *task,
52 					    struct pt_regs *regs,
53 					    int error, long val)
54 {
55 	regs->a0 = (long) error ?: val;
56 }
57 
58 static inline void syscall_get_arguments(struct task_struct *task,
59 					 struct pt_regs *regs,
60 					 unsigned long *args)
61 {
62 	args[0] = regs->orig_a0;
63 	args++;
64 	memcpy(args, &regs->a1, 5 * sizeof(args[0]));
65 }
66 
67 static inline void syscall_set_arguments(struct task_struct *task,
68 					 struct pt_regs *regs,
69 					 const unsigned long *args)
70 {
71 	regs->orig_a0 = args[0];
72 	args++;
73 	memcpy(&regs->a1, args, 5 * sizeof(regs->a1));
74 }
75 
76 static inline int syscall_get_arch(struct task_struct *task)
77 {
78 #ifdef CONFIG_64BIT
79 	return AUDIT_ARCH_RISCV64;
80 #else
81 	return AUDIT_ARCH_RISCV32;
82 #endif
83 }
84 
85 #endif	/* _ASM_RISCV_SYSCALL_H */
86