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         return regs->svcnr ? regs->svcnr : -1;
  21 }
  22
  23 static inline void syscall_rollback(struct task_struct *task,
  24                                     struct pt_regs *regs)
  25 {
  26         regs->gprs[2] = regs->orig_gpr2;
  27 }
  28
  29 static inline long syscall_get_error(struct task_struct *task,
  30                                      struct pt_regs *regs)
  31 {
  32         return (regs->gprs[2] >= -4096UL) ? -regs->gprs[2] : 0;
  33 }
  34
  35 static inline long syscall_get_return_value(struct task_struct *task,
  36                                             struct pt_regs *regs)
  37 {
  38         return regs->gprs[2];
  39 }
  40
  41 static inline void syscall_set_return_value(struct task_struct *task,
  42                                             struct pt_regs *regs,
  43                                             int error, long val)
  44 {
  45         regs->gprs[2] = error ? -error : val;
  46 }
  47
  48 static inline void syscall_get_arguments(struct task_struct *task,
  49                                          struct pt_regs *regs,
  50                                          unsigned int i, unsigned int n,
  51                                          unsigned long *args)
  52 {
  53         unsigned long mask = -1UL;
  54
  55         BUG_ON(i + n > 6);
  56 #ifdef CONFIG_COMPAT
  57         if (test_tsk_thread_flag(task, TIF_31BIT))
  58                 mask = 0xffffffff;
  59 #endif
  60         if (i + n == 6)
  61                 args[--n] = regs->args[0] & mask;
  62         while (n-- > 0)
  63                 if (i + n > 0)
  64                         args[n] = regs->gprs[2 + i + n] & mask;
  65         if (i == 0)
  66                 args[0] = regs->orig_gpr2 & mask;
  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         while (n-- > 0)
  78                 if (i + n > 0)
  79                         regs->gprs[2 + i + n] = args[n];
  80         if (i == 0)
  81                 regs->orig_gpr2 = args[0];
  82 }
  83
  84 #endif  /* _ASM_SYSCALL_H */