LXR linux/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 */
  24extern const unsigned int sys_call_table[];
  25
  26static 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
  33static inline void syscall_rollback(struct task_struct *task,
  34                                    struct pt_regs *regs)
  35{
  36        regs->gprs[2] = regs->orig_gpr2;
  37}
  38
  39static 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
  45static inline long syscall_get_return_value(struct task_struct *task,
  46                                            struct pt_regs *regs)
  47{
  48        return regs->gprs[2];
  49}
  50
  51static 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
  58static 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
  77static 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 */
  91