1. 根目录:
2. arch
3. xtensa
4. include
5. asm
6. io.h

/*
 * include/asm-xtensa/io.h
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2001 - 2005 Tensilica Inc.
 */

#ifndef _XTENSA_IO_H
#define _XTENSA_IO_H

#ifdef __KERNEL__
#include <asm/byteorder.h>
#include <asm/page.h>
#include <linux/bug.h>
#include <linux/kernel.h>

#include <linux/types.h>

#define XCHAL_KIO_CACHED_VADDR	0xe0000000
#define XCHAL_KIO_BYPASS_VADDR	0xf0000000
#define XCHAL_KIO_PADDR		0xf0000000
#define XCHAL_KIO_SIZE		0x10000000

#define IOADDR(x)		(XCHAL_KIO_BYPASS_VADDR + (x))
#define IO_SPACE_LIMIT ~0

#ifdef CONFIG_MMU
/*
 * Return the virtual address for the specified bus memory.
 * Note that we currently don't support any address outside the KIO segment.
 */
static inline void __iomem *ioremap_nocache(unsigned long offset,
		unsigned long size)
{
	if (offset >= XCHAL_KIO_PADDR
	    && offset - XCHAL_KIO_PADDR < XCHAL_KIO_SIZE)
		return (void*)(offset-XCHAL_KIO_PADDR+XCHAL_KIO_BYPASS_VADDR);
	else
		BUG();
}

static inline void __iomem *ioremap_cache(unsigned long offset,
		unsigned long size)
{
	if (offset >= XCHAL_KIO_PADDR
	    && offset - XCHAL_KIO_PADDR < XCHAL_KIO_SIZE)
		return (void*)(offset-XCHAL_KIO_PADDR+XCHAL_KIO_CACHED_VADDR);
	else
		BUG();
}

#define ioremap_wc ioremap_nocache

static inline void __iomem *ioremap(unsigned long offset, unsigned long size)
{
	return ioremap_nocache(offset, size);
}

static inline void iounmap(volatile void __iomem *addr)
{
}

#define virt_to_bus     virt_to_phys
#define bus_to_virt     phys_to_virt

#endif /* CONFIG_MMU */

/*
 * Generic I/O
 */
#define readb_relaxed readb
#define readw_relaxed readw
#define readl_relaxed readl

#endif	/* __KERNEL__ */

#include <asm-generic/io.h>

#endif	/* _XTENSA_IO_H */