LXR linux/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 <linux/audit.h>
  24#include <linux/compat.h>
  25#include <arch/abi.h>
  26
  27/* The array of function pointers for syscalls. */
  28extern void *sys_call_table[];
  29#ifdef CONFIG_COMPAT
  30extern void *compat_sys_call_table[];
  31#endif
  32
  33/*
  34 * Only the low 32 bits of orig_r0 are meaningful, so we return int.
  35 * This importantly ignores the high bits on 64-bit, so comparisons
  36 * sign-extend the low 32 bits.
  37 */
  38static inline int syscall_get_nr(struct task_struct *t, struct pt_regs *regs)
  39{
  40        return regs->regs[TREG_SYSCALL_NR];
  41}
  42
  43static inline void syscall_rollback(struct task_struct *task,
  44                                    struct pt_regs *regs)
  45{
  46        regs->regs[0] = regs->orig_r0;
  47}
  48
  49static inline long syscall_get_error(struct task_struct *task,
  50                                     struct pt_regs *regs)
  51{
  52        unsigned long error = regs->regs[0];
  53        return IS_ERR_VALUE(error) ? error : 0;
  54}
  55
  56static inline long syscall_get_return_value(struct task_struct *task,
  57                                            struct pt_regs *regs)
  58{
  59        return regs->regs[0];
  60}
  61
  62static inline void syscall_set_return_value(struct task_struct *task,
  63                                            struct pt_regs *regs,
  64                                            int error, long val)
  65{
  66        if (error) {
  67                /* R0 is the passed-in negative error, R1 is positive. */
  68                regs->regs[0] = error;
  69                regs->regs[1] = -error;
  70        } else {
  71                /* R1 set to zero to indicate no error. */
  72                regs->regs[0] = val;
  73                regs->regs[1] = 0;
  74        }
  75}
  76
  77static inline void syscall_get_arguments(struct task_struct *task,
  78                                         struct pt_regs *regs,
  79                                         unsigned int i, unsigned int n,
  80                                         unsigned long *args)
  81{
  82        BUG_ON(i + n > 6);
  83        memcpy(args, &regs[i], n * sizeof(args[0]));
  84}
  85
  86static inline void syscall_set_arguments(struct task_struct *task,
  87                                         struct pt_regs *regs,
  88                                         unsigned int i, unsigned int n,
  89                                         const unsigned long *args)
  90{
  91        BUG_ON(i + n > 6);
  92        memcpy(&regs[i], args, n * sizeof(args[0]));
  93}
  94
  95/*
  96 * We don't care about endianness (__AUDIT_ARCH_LE bit) here because
  97 * tile has the same system calls both on little- and big- endian.
  98 */
  99static inline int syscall_get_arch(void)
 100{
 101        if (is_compat_task())
 102                return AUDIT_ARCH_TILEGX32;
 103
 104#ifdef CONFIG_TILEGX
 105        return AUDIT_ARCH_TILEGX;
 106#else
 107        return AUDIT_ARCH_TILEPRO;
 108#endif
 109}
 110
 111#endif  /* _ASM_TILE_SYSCALL_H */
 112