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 static 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
  24 static inline void syscall_rollback(struct task_struct *task,
  25                                     struct pt_regs *regs)
  26 {
  27         regs->gpr[3] = regs->orig_gpr3;
  28 }
  29
  30 static 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
  36 static inline long syscall_get_return_value(struct task_struct *task,
  37                                             struct pt_regs *regs)
  38 {
  39         return regs->gpr[3];
  40 }
  41
  42 static 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
  55 static 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
  75 static 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 */