arch/arc/include/asm/syscall.h

   1 /*
   2  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #ifndef _ASM_ARC_SYSCALL_H
  10 #define _ASM_ARC_SYSCALL_H  1
  11
  12 #include <linux/err.h>
  13 #include <linux/sched.h>
  14 #include <asm/unistd.h>
  15 #include <asm/ptrace.h>         /* in_syscall() */
  16
  17 static inline long
  18 syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
  19 {
  20         if (user_mode(regs) && in_syscall(regs))
  21                 return regs->r8;
  22         else
  23                 return -1;
  24 }
  25
  26 static inline void
  27 syscall_rollback(struct task_struct *task, struct pt_regs *regs)
  28 {
  29         regs->r0 = regs->orig_r0;
  30 }
  31
  32 static inline long
  33 syscall_get_error(struct task_struct *task, struct pt_regs *regs)
  34 {
  35         /* 0 if syscall succeeded, otherwise -Errorcode */
  36         return IS_ERR_VALUE(regs->r0) ? regs->r0 : 0;
  37 }
  38
  39 static inline long
  40 syscall_get_return_value(struct task_struct *task, struct pt_regs *regs)
  41 {
  42         return regs->r0;
  43 }
  44
  45 static inline void
  46 syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
  47                          int error, long val)
  48 {
  49         regs->r0 = (long) error ?: val;
  50 }
  51
  52 /*
  53  * @i:      argument index [0,5]
  54  * @n:      number of arguments; n+i must be [1,6].
  55  */
  56 static inline void
  57 syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
  58                       unsigned int i, unsigned int n, unsigned long *args)
  59 {
  60         unsigned long *inside_ptregs = &(regs->r0);
  61         inside_ptregs -= i;
  62
  63         BUG_ON((i + n) > 6);
  64
  65         while (n--) {
  66                 args[i++] = (*inside_ptregs);
  67                 inside_ptregs--;
  68         }
  69 }
  70
  71 #endif