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. */
19 extern void * const sys_call_table[];
20 extern 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 */
27 static inline int syscall_get_nr(struct task_struct *task,
28 struct pt_regs *regs)
29 {
30 return regs->a7;
31 }
32
33 static inline void syscall_rollback(struct task_struct *task,
34 struct pt_regs *regs)
35 {
36 regs->a0 = regs->orig_a0;
37 }
38
39 static 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
47 static inline long syscall_get_return_value(struct task_struct *task,
48 struct pt_regs *regs)
49 {
50 return regs->a0;
51 }
52
53 static 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
60 static 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, ®s->a1, 5 * sizeof(args[0]));
67 }
68
69 static 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
78 typedef long (*syscall_t)(const struct pt_regs *);
79 static 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
93 static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
94 {
95 return false;
96 }
97
98 asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);
99
100 asmlinkage long sys_riscv_hwprobe(struct riscv_hwprobe *, size_t, size_t,
101 unsigned long *, unsigned int);
102 #endif /* _ASM_RISCV_SYSCALL_H */
103
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