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/signal.h>
  17 #include <asm/switch_to.h>
  18 #include <asm-generic/syscalls.h>
  19
  20 #undef __SYSCALL
  21 #define __SYSCALL(nr, call)     [nr] = (call),
  22
  23 SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, unsigned long,
  24                 prot, unsigned long, flags, unsigned long, fd, off_t, offset)
  25 {
  26         if (offset & ~PAGE_MASK)
  27                 return -EINVAL;
  28
  29         return ksys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
  30 }
  31
  32 void *sys_call_table[__NR_syscalls] = {
  33         [0 ... __NR_syscalls - 1] = sys_ni_syscall,
  34 #include <asm/unistd.h>
  35 };
  36
  37 typedef long (*sys_call_fn)(unsigned long, unsigned long,
  38         unsigned long, unsigned long, unsigned long, unsigned long);
  39
  40 void noinstr do_syscall(struct pt_regs *regs)
  41 {
  42         unsigned long nr;
  43         sys_call_fn syscall_fn;
  44
  45         nr = regs->regs[11];
  46         /* Set for syscall restarting */
  47         if (nr < NR_syscalls)
  48                 regs->regs[0] = nr + 1;
  49
  50         regs->csr_era += 4;
  51         regs->orig_a0 = regs->regs[4];
  52         regs->regs[4] = -ENOSYS;
  53
  54         nr = syscall_enter_from_user_mode(regs, nr);
  55
  56         if (nr < NR_syscalls) {
  57                 syscall_fn = sys_call_table[nr];
  58                 regs->regs[4] = syscall_fn(regs->orig_a0, regs->regs[5], regs->regs[6],
  59                                            regs->regs[7], regs->regs[8], regs->regs[9]);
  60         }
  61
  62         syscall_exit_to_user_mode(regs);
  63 }