arch/s390/include/asm/syscall.h

   1 /*
   2  * Access to user system call parameters and results
   3  *
   4  *  Copyright IBM Corp. 2008
   5  *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License (version 2 only)
   9  * as published by the Free Software Foundation.
  10  */
  11
  12 #ifndef _ASM_SYSCALL_H
  13 #define _ASM_SYSCALL_H  1
  14
  15 #include <asm/ptrace.h>
  16
  17 static inline long syscall_get_nr(struct task_struct *task,
  18                                   struct pt_regs *regs)
  19 {
  20         if (regs->trap != __LC_SVC_OLD_PSW)
  21                 return -1;
  22         return regs->gprs[2];
  23 }
  24
  25 static inline void syscall_rollback(struct task_struct *task,
  26                                     struct pt_regs *regs)
  27 {
  28         regs->gprs[2] = regs->orig_gpr2;
  29 }
  30
  31 static inline long syscall_get_error(struct task_struct *task,
  32                                      struct pt_regs *regs)
  33 {
  34         return (regs->gprs[2] >= -4096UL) ? -regs->gprs[2] : 0;
  35 }
  36
  37 static inline long syscall_get_return_value(struct task_struct *task,
  38                                             struct pt_regs *regs)
  39 {
  40         return regs->gprs[2];
  41 }
  42
  43 static inline void syscall_set_return_value(struct task_struct *task,
  44                                             struct pt_regs *regs,
  45                                             int error, long val)
  46 {
  47         regs->gprs[2] = error ? -error : val;
  48 }
  49
  50 static inline void syscall_get_arguments(struct task_struct *task,
  51                                          struct pt_regs *regs,
  52                                          unsigned int i, unsigned int n,
  53                                          unsigned long *args)
  54 {
  55         BUG_ON(i + n > 6);
  56 #ifdef CONFIG_COMPAT
  57         if (test_tsk_thread_flag(task, TIF_31BIT)) {
  58                 if (i + n == 6)
  59                         args[--n] = (u32) regs->args[0];
  60                 while (n-- > 0)
  61                         args[n] = (u32) regs->gprs[2 + i + n];
  62         }
  63 #endif
  64         if (i + n == 6)
  65                 args[--n] = regs->args[0];
  66         memcpy(args, &regs->gprs[2 + i], n * sizeof(args[0]));
  67 }
  68
  69 static inline void syscall_set_arguments(struct task_struct *task,
  70                                          struct pt_regs *regs,
  71                                          unsigned int i, unsigned int n,
  72                                          const unsigned long *args)
  73 {
  74         BUG_ON(i + n > 6);
  75         if (i + n == 6)
  76                 regs->args[0] = args[--n];
  77         memcpy(&regs->gprs[2 + i], args, n * sizeof(args[0]));
  78 }
  79
  80 #endif  /* _ASM_SYSCALL_H */