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 <asm/ptrace.h>
  17
  18 /*
  19  * The syscall table always contains 32 bit pointers since we know that the
  20  * address of the function to be called is (way) below 4GB.  So the "int"
  21  * type here is what we want [need] for both 32 bit and 64 bit systems.
  22  */
  23 extern const unsigned int sys_call_table[];
  24
  25 static inline long syscall_get_nr(struct task_struct *task,
  26                                   struct pt_regs *regs)
  27 {
  28         return regs->svcnr ? regs->svcnr : -1;
  29 }
  30
  31 static inline void syscall_rollback(struct task_struct *task,
  32                                     struct pt_regs *regs)
  33 {
  34         regs->gprs[2] = regs->orig_gpr2;
  35 }
  36
  37 static inline long syscall_get_error(struct task_struct *task,
  38                                      struct pt_regs *regs)
  39 {
  40         return (regs->gprs[2] >= -4096UL) ? -regs->gprs[2] : 0;
  41 }
  42
  43 static inline long syscall_get_return_value(struct task_struct *task,
  44                                             struct pt_regs *regs)
  45 {
  46         return regs->gprs[2];
  47 }
  48
  49 static inline void syscall_set_return_value(struct task_struct *task,
  50                                             struct pt_regs *regs,
  51                                             int error, long val)
  52 {
  53         regs->gprs[2] = error ? -error : val;
  54 }
  55
  56 static inline void syscall_get_arguments(struct task_struct *task,
  57                                          struct pt_regs *regs,
  58                                          unsigned int i, unsigned int n,
  59                                          unsigned long *args)
  60 {
  61         unsigned long mask = -1UL;
  62
  63         BUG_ON(i + n > 6);
  64 #ifdef CONFIG_COMPAT
  65         if (test_tsk_thread_flag(task, TIF_31BIT))
  66                 mask = 0xffffffff;
  67 #endif
  68         while (n-- > 0)
  69                 if (i + n > 0)
  70                         args[n] = regs->gprs[2 + i + n] & mask;
  71         if (i == 0)
  72                 args[0] = regs->orig_gpr2 & mask;
  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         while (n-- > 0)
  82                 if (i + n > 0)
  83                         regs->gprs[2 + i + n] = args[n];
  84         if (i == 0)
  85                 regs->orig_gpr2 = args[0];
  86 }
  87
  88 #endif  /* _ASM_SYSCALL_H */