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 */