1 /* virtconvert.h: virtual/physical/page address conversion
2  *
3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 #ifndef _ASM_VIRTCONVERT_H
12 #define _ASM_VIRTCONVERT_H
13 
14 /*
15  * Macros used for converting between virtual and physical mappings.
16  */
17 
18 #ifdef __KERNEL__
19 
20 #include <asm/setup.h>
21 
22 #ifdef CONFIG_MMU
23 
24 #define phys_to_virt(vaddr)	((void *) ((unsigned long)(vaddr) + PAGE_OFFSET))
25 #define virt_to_phys(vaddr)	((unsigned long) (vaddr) - PAGE_OFFSET)
26 
27 #else
28 
29 #define phys_to_virt(vaddr)	((void *) (vaddr))
30 #define virt_to_phys(vaddr)	((unsigned long) (vaddr))
31 
32 #endif
33 
34 #define virt_to_bus virt_to_phys
35 #define bus_to_virt phys_to_virt
36 
37 #define __page_address(page)	(PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT))
38 #define page_to_phys(page)	virt_to_phys((void *)__page_address(page))
39 
40 #endif
41 #endif
42