arch/mips/include/asm/syscall.h

   1 /*
   2  * Access to user system call parameters and results
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * See asm-generic/syscall.h for descriptions of what we must do here.
   9  *
  10  * Copyright (C) 2012 Ralf Baechle <ralf@linux-mips.org>
  11  */
  12
  13 #ifndef __ASM_MIPS_SYSCALL_H
  14 #define __ASM_MIPS_SYSCALL_H
  15
  16 #include <linux/kernel.h>
  17 #include <linux/sched.h>
  18 #include <linux/uaccess.h>
  19 #include <asm/ptrace.h>
  20
  21 static inline long syscall_get_nr(struct task_struct *task,
  22                                   struct pt_regs *regs)
  23 {
  24         return regs->regs[2];
  25 }
  26
  27 static inline unsigned long mips_get_syscall_arg(unsigned long *arg,
  28         struct task_struct *task, struct pt_regs *regs, unsigned int n)
  29 {
  30         unsigned long usp = regs->regs[29];
  31
  32         switch (n) {
  33         case 0: case 1: case 2: case 3:
  34                 *arg = regs->regs[4 + n];
  35
  36                 return 0;
  37
  38 #ifdef CONFIG_32BIT
  39         case 4: case 5: case 6: case 7:
  40                 return get_user(*arg, (int *)usp + 4 * n);
  41 #endif
  42
  43 #ifdef CONFIG_64BIT
  44         case 4: case 5: case 6: case 7:
  45 #ifdef CONFIG_MIPS32_O32
  46                 if (test_thread_flag(TIF_32BIT_REGS))
  47                         return get_user(*arg, (int *)usp + 4 * n);
  48                 else
  49 #endif
  50                         *arg = regs->regs[4 + n];
  51
  52                 return 0;
  53 #endif
  54
  55         default:
  56                 BUG();
  57         }
  58 }
  59
  60 static inline void syscall_get_arguments(struct task_struct *task,
  61                                          struct pt_regs *regs,
  62                                          unsigned int i, unsigned int n,
  63                                          unsigned long *args)
  64 {
  65         unsigned long arg;
  66         int ret;
  67
  68         while (n--)
  69                 ret |= mips_get_syscall_arg(&arg, task, regs, i++);
  70
  71         /*
  72          * No way to communicate an error because this is a void function.
  73          */
  74 #if 0
  75         return ret;
  76 #endif
  77 }
  78
  79 extern const unsigned long sys_call_table[];
  80 extern const unsigned long sys32_call_table[];
  81 extern const unsigned long sysn32_call_table[];
  82
  83 #endif  /* __ASM_MIPS_SYSCALL_H */