#ifndef __ALPHA_IO_H
#define __ALPHA_IO_H

#ifdef __KERNEL__

#include <linux/kernel.h>
#include <linux/mm.h>
#include <asm/compiler.h>
#include <asm/pgtable.h>
#include <asm/machvec.h>
#include <asm/hwrpb.h>

/* The generic header contains only prototypes.  Including it ensures that
   the implementation we have here matches that interface.  */
#include <asm-generic/iomap.h>

/* We don't use IO slowdowns on the Alpha, but.. */
#define __SLOW_DOWN_IO	do { } while (0)
#define SLOW_DOWN_IO	do { } while (0)

/*
 * Virtual -> physical identity mapping starts at this offset
 */
#ifdef USE_48_BIT_KSEG
#define IDENT_ADDR     0xffff800000000000UL
#else
#define IDENT_ADDR     0xfffffc0000000000UL
#endif

/*
 * We try to avoid hae updates (thus the cache), but when we
 * do need to update the hae, we need to do it atomically, so
 * that any interrupts wouldn't get confused with the hae
 * register not being up-to-date with respect to the hardware
 * value.
 */
extern inline void __set_hae(unsigned long new_hae)
{
	unsigned long flags = swpipl(IPL_MAX);

	barrier();

	alpha_mv.hae_cache = new_hae;
	*alpha_mv.hae_register = new_hae;
	mb();
	/* Re-read to make sure it was written.  */
	new_hae = *alpha_mv.hae_register;

	setipl(flags);
	barrier();
}

extern inline void set_hae(unsigned long new_hae)
{
	if (new_hae != alpha_mv.hae_cache)
		__set_hae(new_hae);
}

/*
 * Change virtual addresses to physical addresses and vv.
 */
#ifdef USE_48_BIT_KSEG
static inline unsigned long virt_to_phys(void *address)
{
	return (unsigned long)address - IDENT_ADDR;
}

static inline void * phys_to_virt(unsigned long address)
{
	return (void *) (address + IDENT_ADDR);
}
#else
static inline unsigned long virt_to_phys(void *address)
{
        unsigned long phys = (unsigned long)address;

	/* Sign-extend from bit 41.  */
	phys <<= (64 - 41);
	phys = (long)phys >> (64 - 41);

	/* Crop to the physical address width of the processor.  */
        phys &= (1ul << hwrpb->pa_bits) - 1;

        return phys;
}

static inline void * phys_to_virt(unsigned long address)
{
        return (void *)(IDENT_ADDR + (address & ((1ul << 41) - 1)));
}
#endif

#define page_to_phys(page)	page_to_pa(page)

static inline dma_addr_t __deprecated isa_page_to_bus(struct page *page)
{
	return page_to_phys(page);
}

/* Maximum PIO space address supported?  */
#define IO_SPACE_LIMIT 0xffff

/*
 * Change addresses as seen by the kernel (virtual) to addresses as
 * seen by a device (bus), and vice versa.
 *
 * Note that this only works for a limited range of kernel addresses,
 * and very well may not span all memory.  Consider this interface 
 * deprecated in favour of the DMA-mapping API.
 */
extern unsigned long __direct_map_base;
extern unsigned long __direct_map_size;

static inline unsigned long __deprecated virt_to_bus(void *address)
{
	unsigned long phys = virt_to_phys(address);
	unsigned long bus = phys + __direct_map_base;
	return phys <= __direct_map_size ? bus : 0;
}
#define isa_virt_to_bus virt_to_bus

static inline void * __deprecated bus_to_virt(unsigned long address)
{
	void *virt;

	/* This check is a sanity check but also ensures that bus address 0
	   maps to virtual address 0 which is useful to detect null pointers
	   (the NCR driver is much simpler if NULL pointers are preserved).  */
	address -= __direct_map_base;
	virt = phys_to_virt(address);
	return (long)address <= 0 ? NULL : virt;
}
#define isa_bus_to_virt bus_to_virt

/*
 * There are different chipsets to interface the Alpha CPUs to the world.
 */

#define IO_CONCAT(a,b)	_IO_CONCAT(a,b)
#define _IO_CONCAT(a,b)	a ## _ ## b

#ifdef CONFIG_ALPHA_GENERIC

/* In a generic kernel, we always go through the machine vector.  */

#define REMAP1(TYPE, NAME, QUAL)					\
static inline TYPE generic_##NAME(QUAL void __iomem *addr)		\
{									\
	return alpha_mv.mv_##NAME(addr);				\
}

#define REMAP2(TYPE, NAME, QUAL)					\
static inline void generic_##NAME(TYPE b, QUAL void __iomem *addr)	\
{									\
	alpha_mv.mv_##NAME(b, addr);					\
}

REMAP1(unsigned int, ioread8, /**/)
REMAP1(unsigned int, ioread16, /**/)
REMAP1(unsigned int, ioread32, /**/)
REMAP1(u8, readb, const volatile)
REMAP1(u16, readw, const volatile)
REMAP1(u32, readl, const volatile)
REMAP1(u64, readq, const volatile)

REMAP2(u8, iowrite8, /**/)
REMAP2(u16, iowrite16, /**/)
REMAP2(u32, iowrite32, /**/)
REMAP2(u8, writeb, volatile)
REMAP2(u16, writew, volatile)
REMAP2(u32, writel, volatile)
REMAP2(u64, writeq, volatile)

#undef REMAP1
#undef REMAP2

extern inline void __iomem *generic_ioportmap(unsigned long a)
{
	return alpha_mv.mv_ioportmap(a);
}

static inline void __iomem *generic_ioremap(unsigned long a, unsigned long s)
{
	return alpha_mv.mv_ioremap(a, s);
}

static inline void generic_iounmap(volatile void __iomem *a)