/*
 *  arch/arm/include/asm/io.h
 *
 *  Copyright (C) 1996-2000 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Modifications:
 *  16-Sep-1996	RMK	Inlined the inx/outx functions & optimised for both
 *			constant addresses and variable addresses.
 *  04-Dec-1997	RMK	Moved a lot of this stuff to the new architecture
 *			specific IO header files.
 *  27-Mar-1999	PJB	Second parameter of memcpy_toio is const..
 *  04-Apr-1999	PJB	Added check_signature.
 *  12-Dec-1999	RMK	More cleanups
 *  18-Jun-2000 RMK	Removed virt_to_* and friends definitions
 *  05-Oct-2004 BJD     Moved memory string functions to use void __iomem
 */
#ifndef __ASM_ARM_IO_H
#define __ASM_ARM_IO_H

#ifdef __KERNEL__

#include <linux/types.h>
#include <asm/byteorder.h>
#include <asm/memory.h>
#include <asm-generic/pci_iomap.h>

/*
 * ISA I/O bus memory addresses are 1:1 with the physical address.
 */
#define isa_virt_to_bus virt_to_phys
#define isa_page_to_bus page_to_phys
#define isa_bus_to_virt phys_to_virt

/*
 * Generic IO read/write.  These perform native-endian accesses.  Note
 * that some architectures will want to re-define __raw_{read,write}w.
 */
extern void __raw_writesb(void __iomem *addr, const void *data, int bytelen);
extern void __raw_writesw(void __iomem *addr, const void *data, int wordlen);
extern void __raw_writesl(void __iomem *addr, const void *data, int longlen);

extern void __raw_readsb(const void __iomem *addr, void *data, int bytelen);
extern void __raw_readsw(const void __iomem *addr, void *data, int wordlen);
extern void __raw_readsl(const void __iomem *addr, void *data, int longlen);

#if __LINUX_ARM_ARCH__ < 6
/*
 * Half-word accesses are problematic with RiscPC due to limitations of
 * the bus. Rather than special-case the machine, just let the compiler
 * generate the access for CPUs prior to ARMv6.
 */
#define __raw_readw(a)         (__chk_io_ptr(a), *(volatile unsigned short __force *)(a))
#define __raw_writew(v,a)      ((void)(__chk_io_ptr(a), *(volatile unsigned short __force *)(a) = (v)))
#else
/*
 * When running under a hypervisor, we want to avoid I/O accesses with
 * writeback addressing modes as these incur a significant performance
 * overhead (the address generation must be emulated in software).
 */
static inline void __raw_writew(u16 val, volatile void __iomem *addr)
{
	asm volatile("strh %1, %0"
		     : "+Q" (*(volatile u16 __force *)addr)
		     : "r" (val));
}

static inline u16 __raw_readw(const volatile void __iomem *addr)
{
	u16 val;
	asm volatile("ldrh %1, %0"
		     : "+Q" (*(volatile u16 __force *)addr),
		       "=r" (val));
	return val;
}
#endif

static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
{
	asm volatile("strb %1, %0"
		     : "+Qo" (*(volatile u8 __force *)addr)
		     : "r" (val));
}

static inline void __raw_writel(u32 val, volatile void __iomem *addr)