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 <asm/hwprobe.h>
14#include <uapi/linux/audit.h>
15#include <linux/sched.h>
16#include <linux/err.h>
17
18/* The array of function pointers for syscalls. */
19extern void * const sys_call_table[];
20extern void * const compat_sys_call_table[];
21
22/*
23 * Only the low 32 bits of orig_r0 are meaningful, so we return int.
24 * This importantly ignores the high bits on 64-bit, so comparisons
25 * sign-extend the low 32 bits.
26 */
27static inline int syscall_get_nr(struct task_struct *task,
28				 struct pt_regs *regs)
29{
30	return regs->a7;
31}
32
33static inline void syscall_rollback(struct task_struct *task,
34				    struct pt_regs *regs)
35{
36        regs->a0 = regs->orig_a0;
37}
38
39static inline long syscall_get_error(struct task_struct *task,
40				     struct pt_regs *regs)
41{
42	unsigned long error = regs->a0;
43
44	return IS_ERR_VALUE(error) ? error : 0;
45}
46
47static inline long syscall_get_return_value(struct task_struct *task,
48					    struct pt_regs *regs)
49{
50	return regs->a0;
51}
52
53static inline void syscall_set_return_value(struct task_struct *task,
54					    struct pt_regs *regs,
55					    int error, long val)
56{
57	regs->a0 = (long) error ?: val;
58}
59
60static inline void syscall_get_arguments(struct task_struct *task,
61					 struct pt_regs *regs,
62					 unsigned long *args)
63{
64	args[0] = regs->orig_a0;
65	args++;
66	memcpy(args, &regs->a1, 5 * sizeof(args[0]));
67}
68
69static inline int syscall_get_arch(struct task_struct *task)
70{
71#ifdef CONFIG_64BIT
72	return AUDIT_ARCH_RISCV64;
73#else
74	return AUDIT_ARCH_RISCV32;
75#endif
76}
77
78typedef long (*syscall_t)(const struct pt_regs *);
79static inline void syscall_handler(struct pt_regs *regs, ulong syscall)
80{
81	syscall_t fn;
82
83#ifdef CONFIG_COMPAT
84	if ((regs->status & SR_UXL) == SR_UXL_32)
85		fn = compat_sys_call_table[syscall];
86	else
87#endif
88		fn = sys_call_table[syscall];
89
90	regs->a0 = fn(regs);
91}
92
93static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
94{
95	return false;
96}
97
98asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);
99
100asmlinkage long sys_riscv_hwprobe(struct riscv_hwprobe *, size_t, size_t,
101				  unsigned long *, unsigned int);
102#endif	/* _ASM_RISCV_SYSCALL_H */
103