/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2008-2009 Red Hat, Inc.  All rights reserved.
 * Copyright 2010 Tilera Corporation. All Rights Reserved.
 * Copyright 2015 Regents of the University of California, Berkeley
 *
 * See asm-generic/syscall.h for descriptions of what we must do here.
 */

#ifndef _ASM_RISCV_SYSCALL_H
#define _ASM_RISCV_SYSCALL_H

#include <asm/hwprobe.h>
#include <uapi/linux/audit.h>
#include <linux/sched.h>
#include <linux/err.h>

/* The array of function pointers for syscalls. */
extern void * const sys_call_table[];
extern void * const compat_sys_call_table[];

/*
 * Only the low 32 bits of orig_r0 are meaningful, so we return int.
 * This importantly ignores the high bits on 64-bit, so comparisons
 * sign-extend the low 32 bits.
 */
static inline int syscall_get_nr(struct task_struct *task,
                 struct pt_regs *regs)
{
    return regs->a7;
}

static inline void syscall_rollback(struct task_struct *task,
                    struct pt_regs *regs)
{
        regs->a0 = regs->orig_a0;
}

static inline long syscall_get_error(struct task_struct *task,
                     struct pt_regs *regs)
{
    unsigned long error = regs->a0;

    return IS_ERR_VALUE(error) ? error : 0;
}

static inline long syscall_get_return_value(struct task_struct *task,
                        struct pt_regs *regs)
{
    return regs->a0;
}

static inline void syscall_set_return_value(struct task_struct *task,
                        struct pt_regs *regs,
                        int error, long val)
{
    regs->a0 = (long) error ?: val;
}

static inline void syscall_get_arguments(struct task_struct *task,
                     struct pt_regs *regs,
                     unsigned long *args)
{
    args[0] = regs->orig_a0;
    args++;
    memcpy(args, &regs->a1, 5 * sizeof(args[0]));
}

static inline int syscall_get_arch(struct task_struct *task)
{
#ifdef CONFIG_64BIT
    return AUDIT_ARCH_RISCV64;
#else
    return AUDIT_ARCH_RISCV32;
#endif
}

typedef long (*syscall_t)(ulong, ulong, ulong, ulong, ulong, ulong, ulong);
static inline void syscall_handler(struct pt_regs *regs, ulong syscall)
{
    syscall_t fn;

#ifdef CONFIG_COMPAT
    if ((regs->status & SR_UXL) == SR_UXL_32)
        fn = compat_sys_call_table[syscall];
    else
#endif
        fn = sys_call_table[syscall];

    regs->a0 = fn(regs->orig_a0, regs->a1, regs->a2,
              regs->a3, regs->a4, regs->a5, regs->a6);
}

static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
{
    return false;
}

asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);

asmlinkage long sys_riscv_hwprobe(struct riscv_hwprobe *, size_t, size_t,
                  unsigned long *, unsigned int);
#endif    /* _ASM_RISCV_SYSCALL_H */