arch/s390/include/asm/io.h

   1 /*
   2  *  include/asm-s390/io.h
   3  *
   4  *  S390 version
   5  *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
   7  *
   8  *  Derived from "include/asm-i386/io.h"
   9  */
  10
  11 #ifndef _S390_IO_H
  12 #define _S390_IO_H
  13
  14 #ifdef __KERNEL__
  15
  16 #include <asm/page.h>
  17
  18 #define IO_SPACE_LIMIT 0xffffffff
  19
  20 /*
  21  * Change virtual addresses to physical addresses and vv.
  22  * These are pretty trivial
  23  */
  24 static inline unsigned long virt_to_phys(volatile void * address)
  25 {
  26         unsigned long real_address;
  27         asm volatile(
  28                  "      lra     %0,0(%1)\n"
  29                  "      jz      0f\n"
  30                  "      la      %0,0\n"
  31                  "0:"
  32                  : "=a" (real_address) : "a" (address) : "cc");
  33         return real_address;
  34 }
  35
  36 static inline void * phys_to_virt(unsigned long address)
  37 {
  38         return (void *) address;
  39 }
  40
  41 /*
  42  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
  43  * access
  44  */
  45 #define xlate_dev_mem_ptr(p)    __va(p)
  46
  47 /*
  48  * Convert a virtual cached pointer to an uncached pointer
  49  */
  50 #define xlate_dev_kmem_ptr(p)   p
  51
  52 #endif /* __KERNEL__ */
  53
  54 #endif