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
  20 extern const unsigned long *sys_call_table;
  21 #endif /* CONFIG_FTRACE_SYSCALLS */
  22
  23 static 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
  29 static inline void syscall_rollback(struct task_struct *task,
  30                                     struct pt_regs *regs)
  31 {
  32         regs->gpr[3] = regs->orig_gpr3;
  33 }
  34
  35 static 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
  41 static inline long syscall_get_return_value(struct task_struct *task,
  42                                             struct pt_regs *regs)
  43 {
  44         return regs->gpr[3];
  45 }
  46
  47 static 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
  60 static 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
  80 static 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 */