1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Author: Hanlu Li <lihanlu@loongson.cn>
4 * Huacai Chen <chenhuacai@loongson.cn>
5 *
6 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
7 */
8#include <linux/capability.h>
9#include <linux/entry-common.h>
10#include <linux/errno.h>
11#include <linux/linkage.h>
12#include <linux/syscalls.h>
13#include <linux/unistd.h>
14
15#include <asm/asm.h>
16#include <asm/exception.h>
17#include <asm/signal.h>
18#include <asm/switch_to.h>
19#include <asm-generic/syscalls.h>
20
21#undef __SYSCALL
22#define __SYSCALL(nr, call) [nr] = (call),
23
24SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, unsigned long,
25 prot, unsigned long, flags, unsigned long, fd, off_t, offset)
26{
27 if (offset & ~PAGE_MASK)
28 return -EINVAL;
29
30 return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff: offset >> PAGE_SHIFT);
31}
32
33void *sys_call_table[__NR_syscalls] = {
34 [0 ... __NR_syscalls - 1] = sys_ni_syscall,
35#include <asm/unistd.h>
36};
37
38typedef long (*sys_call_fn)(unsigned long, unsigned long,
39 unsigned long, unsigned long, unsigned long, unsigned long);
40
41void noinstr do_syscall(struct pt_regs *regs)
42{
43 unsigned long nr;
44 sys_call_fn syscall_fn;
45
46 nr = regs->regs[11];
47 /* Set for syscall restarting */
48 if (nr < NR_syscalls)
49 regs->regs[0] = nr + 1;
50
51 regs->csr_era += 4;
52 regs->orig_a0 = regs->regs[4];
53 regs->regs[4] = -ENOSYS;
54
55 nr = syscall_enter_from_user_mode(regs, syscall: nr);
56
57 if (nr < NR_syscalls) {
58 syscall_fn = sys_call_table[nr];
59 regs->regs[4] = syscall_fn(regs->orig_a0, regs->regs[5], regs->regs[6],
60 regs->regs[7], regs->regs[8], regs->regs[9]);
61 }
62
63 syscall_exit_to_user_mode(regs);
64}
65

source code of linux/arch/loongarch/kernel/syscall.c