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 <linux/sched.h>
  16 #include <linux/err.h>
  17 #include <asm/ptrace.h>
  18
  19 /*
  20  * The syscall table always contains 32 bit pointers since we know that the
  21  * address of the function to be called is (way) below 4GB.  So the "int"
  22  * type here is what we want [need] for both 32 bit and 64 bit systems.
  23  */
  24 extern const unsigned int sys_call_table[];
  25
  26 static inline long syscall_get_nr(struct task_struct *task,
  27                                   struct pt_regs *regs)
  28 {
  29         return test_tsk_thread_flag(task, TIF_SYSCALL) ?
  30                 (regs->svc_code & 0xffff) : -1;
  31 }
  32
  33 static inline void syscall_rollback(struct task_struct *task,
  34                                     struct pt_regs *regs)
  35 {
  36         regs->gprs[2] = regs->orig_gpr2;
  37 }
  38
  39 static inline long syscall_get_error(struct task_struct *task,
  40                                      struct pt_regs *regs)
  41 {
  42         return IS_ERR_VALUE(regs->gprs[2]) ? regs->gprs[2] : 0;
  43 }
  44
  45 static inline long syscall_get_return_value(struct task_struct *task,
  46                                             struct pt_regs *regs)
  47 {
  48         return regs->gprs[2];
  49 }
  50
  51 static inline void syscall_set_return_value(struct task_struct *task,
  52                                             struct pt_regs *regs,
  53                                             int error, long val)
  54 {
  55         regs->gprs[2] = error ? -error : val;
  56 }
  57
  58 static inline void syscall_get_arguments(struct task_struct *task,
  59                                          struct pt_regs *regs,
  60                                          unsigned int i, unsigned int n,
  61                                          unsigned long *args)
  62 {
  63         unsigned long mask = -1UL;
  64
  65         BUG_ON(i + n > 6);
  66 #ifdef CONFIG_COMPAT
  67         if (test_tsk_thread_flag(task, TIF_31BIT))
  68                 mask = 0xffffffff;
  69 #endif
  70         while (n-- > 0)
  71                 if (i + n > 0)
  72                         args[n] = regs->gprs[2 + i + n] & mask;
  73         if (i == 0)
  74                 args[0] = regs->orig_gpr2 & mask;
  75 }
  76
  77 static inline void syscall_set_arguments(struct task_struct *task,
  78                                          struct pt_regs *regs,
  79                                          unsigned int i, unsigned int n,
  80                                          const unsigned long *args)
  81 {
  82         BUG_ON(i + n > 6);
  83         while (n-- > 0)
  84                 if (i + n > 0)
  85                         regs->gprs[2 + i + n] = args[n];
  86         if (i == 0)
  87                 regs->orig_gpr2 = args[0];
  88 }
  89
  90 #endif  /* _ASM_SYSCALL_H */