arch/tile/include/asm/syscall.h

   1 /*
   2  * Copyright (C) 2008-2009 Red Hat, Inc.  All rights reserved.
   3  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   4  *
   5  *   This program is free software; you can redistribute it and/or
   6  *   modify it under the terms of the GNU General Public License
   7  *   as published by the Free Software Foundation, version 2.
   8  *
   9  *   This program is distributed in the hope that it will be useful, but
  10  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  12  *   NON INFRINGEMENT.  See the GNU General Public License for
  13  *   more details.
  14  *
  15  * See asm-generic/syscall.h for descriptions of what we must do here.
  16  */
  17
  18 #ifndef _ASM_TILE_SYSCALL_H
  19 #define _ASM_TILE_SYSCALL_H
  20
  21 #include <linux/sched.h>
  22 #include <linux/err.h>
  23 #include <arch/abi.h>
  24
  25 /* The array of function pointers for syscalls. */
  26 extern void *sys_call_table[];
  27 #ifdef CONFIG_COMPAT
  28 extern void *compat_sys_call_table[];
  29 #endif
  30
  31 /*
  32  * Only the low 32 bits of orig_r0 are meaningful, so we return int.
  33  * This importantly ignores the high bits on 64-bit, so comparisons
  34  * sign-extend the low 32 bits.
  35  */
  36 static inline int syscall_get_nr(struct task_struct *t, struct pt_regs *regs)
  37 {
  38         return regs->regs[TREG_SYSCALL_NR];
  39 }
  40
  41 static inline void syscall_rollback(struct task_struct *task,
  42                                     struct pt_regs *regs)
  43 {
  44         regs->regs[0] = regs->orig_r0;
  45 }
  46
  47 static inline long syscall_get_error(struct task_struct *task,
  48                                      struct pt_regs *regs)
  49 {
  50         unsigned long error = regs->regs[0];
  51         return IS_ERR_VALUE(error) ? error : 0;
  52 }
  53
  54 static inline long syscall_get_return_value(struct task_struct *task,
  55                                             struct pt_regs *regs)
  56 {
  57         return regs->regs[0];
  58 }
  59
  60 static inline void syscall_set_return_value(struct task_struct *task,
  61                                             struct pt_regs *regs,
  62                                             int error, long val)
  63 {
  64         regs->regs[0] = (long) error ?: val;
  65 }
  66
  67 static inline void syscall_get_arguments(struct task_struct *task,
  68                                          struct pt_regs *regs,
  69                                          unsigned int i, unsigned int n,
  70                                          unsigned long *args)
  71 {
  72         BUG_ON(i + n > 6);
  73         memcpy(args, &regs[i], n * sizeof(args[0]));
  74 }
  75
  76 static inline void syscall_set_arguments(struct task_struct *task,
  77                                          struct pt_regs *regs,
  78                                          unsigned int i, unsigned int n,
  79                                          const unsigned long *args)
  80 {
  81         BUG_ON(i + n > 6);
  82         memcpy(&regs[i], args, n * sizeof(args[0]));
  83 }
  84
  85 #endif  /* _ASM_TILE_SYSCALL_H */