/*	$OpenBSD: pio.h,v 1.10 2011/03/23 16:54:35 pirofti Exp $	*/
/*	$NetBSD: pio.h,v 1.13 1996/03/08 20:15:23 cgd Exp $	*/

/*
 * Copyright (c) 1993, 1995 Charles M. Hannum.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Charles M. Hannum.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _MACHINE_PIO_H_
#define _MACHINE_PIO_H_

/*
 * Functions to provide access to i386 programmed I/O instructions.
 *
 * The in[bwl]() and out[bwl]() functions are split into two varieties: one to
 * use a small, constant, 8-bit port number, and another to use a large or
 * variable port number.  The former can be compiled as a smaller instruction.
 */


#ifdef __OPTIMIZE__

#define	__use_immediate_port(port) \
	(__builtin_constant_p((port)) && (port) < 0x100)

#else

#define	__use_immediate_port(port)	0

#endif


#define	inb(port) \
	(__use_immediate_port(port) ? __inbc(port) : __inb(port))

static __inline u_int8_t
__inbc(int port)
{
	u_int8_t data;
	__asm __volatile("inb %w1,%0" : "=a" (data) : "id" (port));
	return data;
}

static __inline u_int8_t
__inb(int port)
{
	u_int8_t data;
	__asm __volatile("inb %w1,%0" : "=a" (data) : "d" (port));
	return data;
}

static __inline void
insb(int port, void *addr, int cnt)
{
	__asm __volatile("cld\n\trepne\n\tinsb"
	    : "+D" (addr), "+c" (cnt) : "d" (port) : "memory", "cc");
}

#define	inw(port) \
	(__use_immediate_port(port) ? __inwc(port) : __inw(port))

static __inline u_int16_t
__inwc(int port)
{
	u_int16_t data;
	__asm __volatile("inw %w1,%0" : "=a" (data) : "id" (port));
	return data;
}

static __inline u_int16_t
__inw(int port)
{
	u_int16_t data;
	__asm __volatile("inw %w1,%0" : "=a" (data) : "d" (port));
	return data;
}

static __inline void
insw(int port, void *addr, int cnt)
{
	__asm __volatile("cld\n\trepne\n\tinsw"
	    : "+D" (addr), "+c" (cnt) : "d" (port) : "memory", "cc");
}

#define	inl(port) \
	(__use_immediate_port(port) ? __inlc(port) : __inl(port))

static __inline u_int32_t
__inlc(int port)
{
	u_int32_t data;
	__asm __volatile("inl %w1,%0" : "=a" (data) : "id" (port));
	return data;
}

static __inline u_int32_t
__inl(int port)
{
	u_int32_t data;
	__asm __volatile("inl %w1,%0" : "=a" (data) : "d" (port));
	return data;
}

static __inline void
insl(int port, void *addr, int cnt)
{
	__asm __volatile("cld\n\trepne\n\tinsl"
	    : "+D" (addr), "+c" (cnt) : "d" (port) : "memory", "cc");
}

#define	outb(port, data) \
	(__use_immediate_port(port) ? __outbc(port, data) : __outb(port, data))

static __inline void
__outbc(int port, u_int8_t data)
{
	__asm __volatile("outb %0,%w1" : : "a" (data), "id" (port));
}

static __inline void
__outb(int port, u_int8_t data)
{
	__asm __volatile("outb %0,%w1" : : "a" (data), "d" (port));
}

static __inline void
outsb(int port, const void *addr, int cnt)
{
	__asm __volatile("cld\n\trepne\n\toutsb"
	    : "+S" (addr), "+c" (cnt) : "d" (port) : "cc");
}

#define	outw(port, data) \
	(__use_immediate_port(port) ? __outwc(port, data) : __outw(port, data))

static __inline void
__outwc(int port, u_int16_t data)
{
	__asm __volatile("outw %0,%w1" : : "a" (data), "id" (port));
}

static __inline void
__outw(int port, u_int16_t data)
{
	__asm __volatile("outw %0,%w1" : : "a" (data), "d" (port));
}

static __inline void
outsw(int port, const void *addr, int cnt)
{
	__asm __volatile("cld\n\trepne\n\toutsw"
	    : "+S" (addr), "+c" (cnt) : "d" (port) : "cc");
}

#define	outl(port, data) \
	(__use_immediate_port(port) ? __outlc(port, data) : __outl(port, data))

static __inline void
__outlc(int port, u_int32_t data)
{
	__asm __volatile("outl %0,%w1" : : "a" (data), "id" (port));
}

static __inline void
__outl(int port, u_int32_t data)
{
	__asm __volatile("outl %0,%w1" : : "a" (data), "d" (port));
}

static __inline void
outsl(int port, const void *addr, int cnt)
{
	__asm __volatile("cld\n\trepne\n\toutsl"
	    : "+S" (addr), "+c" (cnt) : "d" (port) : "cc");
}

#endif /* _MACHINE_PIO_H_ */