LXR linux/arch/powerpc/include/asm/syscall.h

   1/*
   2 * Access to user system call parameters and results
   3 *
   4 * Copyright (C) 2008 Red Hat, Inc.  All rights reserved.
   5 *
   6 * This copyrighted material is made available to anyone wishing to use,
   7 * modify, copy, or redistribute it subject to the terms and conditions
   8 * of the GNU General Public License v.2.
   9 *
  10 * See asm-generic/syscall.h for descriptions of what we must do here.
  11 */
  12
  13#ifndef _ASM_SYSCALL_H
  14#define _ASM_SYSCALL_H  1
  15
  16#include <linux/sched.h>
  17
  18static inline long syscall_get_nr(struct task_struct *task,
  19                                  struct pt_regs *regs)
  20{
  21        return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1L;
  22}
  23
  24static inline void syscall_rollback(struct task_struct *task,
  25                                    struct pt_regs *regs)
  26{
  27        regs->gpr[3] = regs->orig_gpr3;
  28}
  29
  30static inline long syscall_get_error(struct task_struct *task,
  31                                     struct pt_regs *regs)
  32{
  33        return (regs->ccr & 0x1000) ? -regs->gpr[3] : 0;
  34}
  35
  36static inline long syscall_get_return_value(struct task_struct *task,
  37                                            struct pt_regs *regs)
  38{
  39        return regs->gpr[3];
  40}
  41
  42static inline void syscall_set_return_value(struct task_struct *task,
  43                                            struct pt_regs *regs,
  44                                            int error, long val)
  45{
  46        if (error) {
  47                regs->ccr |= 0x1000L;
  48                regs->gpr[3] = -error;
  49        } else {
  50                regs->ccr &= ~0x1000L;
  51                regs->gpr[3] = val;
  52        }
  53}
  54
  55static inline void syscall_get_arguments(struct task_struct *task,
  56                                         struct pt_regs *regs,
  57                                         unsigned int i, unsigned int n,
  58                                         unsigned long *args)
  59{
  60        BUG_ON(i + n > 6);
  61#ifdef CONFIG_PPC64
  62        if (test_tsk_thread_flag(task, TIF_32BIT)) {
  63                /*
  64                 * Zero-extend 32-bit argument values.  The high bits are
  65                 * garbage ignored by the actual syscall dispatch.
  66                 */
  67                while (n-- > 0)
  68                        args[n] = (u32) regs->gpr[3 + i + n];
  69                return;
  70        }
  71#endif
  72        memcpy(args, &regs->gpr[3 + i], n * sizeof(args[0]));
  73}
  74
  75static inline void syscall_set_arguments(struct task_struct *task,
  76                                         struct pt_regs *regs,
  77                                         unsigned int i, unsigned int n,
  78                                         const unsigned long *args)
  79{
  80        BUG_ON(i + n > 6);
  81        memcpy(&regs->gpr[3 + i], args, n * sizeof(args[0]));
  82}
  83
  84#endif  /* _ASM_SYSCALL_H */
  85