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
  18/* ftrace syscalls requires exporting the sys_call_table */
  19#ifdef CONFIG_FTRACE_SYSCALLS
  20extern const unsigned long *sys_call_table;
  21#endif /* CONFIG_FTRACE_SYSCALLS */
  22
  23static inline long syscall_get_nr(struct task_struct *task,
  24                                  struct pt_regs *regs)
  25{
  26        return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1L;
  27}
  28
  29static inline void syscall_rollback(struct task_struct *task,
  30                                    struct pt_regs *regs)
  31{
  32        regs->gpr[3] = regs->orig_gpr3;
  33}
  34
  35static inline long syscall_get_error(struct task_struct *task,
  36                                     struct pt_regs *regs)
  37{
  38        return (regs->ccr & 0x10000000) ? -regs->gpr[3] : 0;
  39}
  40
  41static inline long syscall_get_return_value(struct task_struct *task,
  42                                            struct pt_regs *regs)
  43{
  44        return regs->gpr[3];
  45}
  46
  47static inline void syscall_set_return_value(struct task_struct *task,
  48                                            struct pt_regs *regs,
  49                                            int error, long val)
  50{
  51        if (error) {
  52                regs->ccr |= 0x10000000L;
  53                regs->gpr[3] = -error;
  54        } else {
  55                regs->ccr &= ~0x10000000L;
  56                regs->gpr[3] = val;
  57        }
  58}
  59
  60static 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        BUG_ON(i + n > 6);
  66#ifdef CONFIG_PPC64
  67        if (test_tsk_thread_flag(task, TIF_32BIT)) {
  68                /*
  69                 * Zero-extend 32-bit argument values.  The high bits are
  70                 * garbage ignored by the actual syscall dispatch.
  71                 */
  72                while (n-- > 0)
  73                        args[n] = (u32) regs->gpr[3 + i + n];
  74                return;
  75        }
  76#endif
  77        memcpy(args, &regs->gpr[3 + i], n * sizeof(args[0]));
  78}
  79
  80static inline void syscall_set_arguments(struct task_struct *task,
  81                                         struct pt_regs *regs,
  82                                         unsigned int i, unsigned int n,
  83                                         const unsigned long *args)
  84{
  85        BUG_ON(i + n > 6);
  86        memcpy(&regs->gpr[3 + i], args, n * sizeof(args[0]));
  87}
  88
  89#endif  /* _ASM_SYSCALL_H */
  90