xref: /openbmc/linux/arch/riscv/include/asm/syscall.h (revision ecd25094)
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 *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_set_nr(struct task_struct *task,
32 				  struct pt_regs *regs,
33 				  int sysno)
34 {
35 	regs->a7 = sysno;
36 }
37 
38 static inline void syscall_rollback(struct task_struct *task,
39 				    struct pt_regs *regs)
40 {
41         regs->a0 = regs->orig_a0;
42 }
43 
44 static inline long syscall_get_error(struct task_struct *task,
45 				     struct pt_regs *regs)
46 {
47 	unsigned long error = regs->a0;
48 
49 	return IS_ERR_VALUE(error) ? error : 0;
50 }
51 
52 static inline long syscall_get_return_value(struct task_struct *task,
53 					    struct pt_regs *regs)
54 {
55 	return regs->a0;
56 }
57 
58 static inline void syscall_set_return_value(struct task_struct *task,
59 					    struct pt_regs *regs,
60 					    int error, long val)
61 {
62 	regs->a0 = (long) error ?: val;
63 }
64 
65 static inline void syscall_get_arguments(struct task_struct *task,
66 					 struct pt_regs *regs,
67 					 unsigned long *args)
68 {
69 	args[0] = regs->orig_a0;
70 	args++;
71 	memcpy(args, &regs->a1, 5 * sizeof(args[0]));
72 }
73 
74 static inline void syscall_set_arguments(struct task_struct *task,
75 					 struct pt_regs *regs,
76 					 const unsigned long *args)
77 {
78 	regs->orig_a0 = args[0];
79 	args++;
80 	memcpy(&regs->a1, args, 5 * sizeof(regs->a1));
81 }
82 
83 static inline int syscall_get_arch(struct task_struct *task)
84 {
85 #ifdef CONFIG_64BIT
86 	return AUDIT_ARCH_RISCV64;
87 #else
88 	return AUDIT_ARCH_RISCV32;
89 #endif
90 }
91 
92 #endif	/* _ASM_RISCV_SYSCALL_H */
93