virtconvert.h

来自「linux 内核源代码」· C头文件 代码 · 共 42 行

/* virtconvert.h: virtual/physical/page address convertion
 *
 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([e-mail])
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */
#ifndef _ASM_VIRTCONVERT_H
#define _ASM_VIRTCONVERT_H

/*
 * Macros used for converting between virtual and physical mappings.
 */

#ifdef __KERNEL__

#include <asm/setup.h>

#ifdef CONFIG_MMU

#define phys_to_virt(vaddr)	((void *) ((unsigned long)(vaddr) + PAGE_OFFSET))
#define virt_to_phys(vaddr)	((unsigned long) (vaddr) - PAGE_OFFSET)

#else

#define phys_to_virt(vaddr)	((void *) (vaddr))
#define virt_to_phys(vaddr)	((unsigned long) (vaddr))

#endif

#define virt_to_bus virt_to_phys
#define bus_to_virt phys_to_virt

#define __page_address(page)	(PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT))
#define page_to_phys(page)	virt_to_phys((void *)__page_address(page))

#endif
#endif