arch/loongarch/kernel/syscall.c

   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
  24 SYSCALL_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, offset >> PAGE_SHIFT);
  31 }
  32
  33 void *sys_call_table[__NR_syscalls] = {
  34         [0 ... __NR_syscalls - 1] = sys_ni_syscall,
  35 #include <asm/unistd.h>
  36 };
  37
  38 typedef long (*sys_call_fn)(unsigned long, unsigned long,
  39         unsigned long, unsigned long, unsigned long, unsigned long);
  40
  41 void 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, 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 }