xnu-344.23.tar.gz

[apple/xnu.git] / bsd / i386 / param.h

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/*-
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * 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 the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 *
 *	@(#)param.h	8.1 (Berkeley) 4/4/95
 */

/*
 * Machine dependent constants for Intel 386.
 */

#ifndef _I386_PARAM_H_
#define _I386_PARAM_H_

/*
 * Round p (pointer or byte index) up to a correctly-aligned value for all
 * data types (int, long, ...).   The result is u_int and must be cast to
 * any desired pointer type.
 */
#define	ALIGNBYTES	3
#define	ALIGN(p)	(((u_int)(p) + ALIGNBYTES) &~ ALIGNBYTES)

#define	NBPG		4096		/* bytes/page */
#define	PGOFSET		(NBPG-1)	/* byte offset into page */
#define	PGSHIFT		12		/* LOG2(NBPG) */

#define	DEV_BSIZE	512
#define	DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
#define BLKDEV_IOSIZE	2048
#define	MAXPHYS		(64 * 1024)	/* max raw I/O transfer size */

#define	STACK_GROWS_UP	0		/* stack grows to lower addresses */

#define	CLSIZE		1
#define	CLSIZELOG2	0

/*
 * Constants related to network buffer management.
 * MCLBYTES must be no larger than CLBYTES (the software page size), and,
 * on machines that exchange pages of input or output buffers with mbuf
 * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
 * of the hardware page size.
 */
#define	MSIZE		256		/* size of an mbuf */
#define	MCLBYTES	2048		/* large enough for ether MTU */
#define	MCLSHIFT	11
#define	MCLOFSET	(MCLBYTES - 1)
#ifndef NMBCLUSTERS
#ifdef GATEWAY
#define	NMBCLUSTERS	((1024 * 1024) / MCLBYTES)	/* cl map size: 1MB */
#else
#define	NMBCLUSTERS	((1024 * 512) / MCLBYTES)	/* cl map size: 0.5MB */
#endif
#endif

/*
 * Some macros for units conversion
 */
/* Core clicks (NeXT_page_size bytes) to segments and vice versa */
#define	ctos(x)	(x)
#define	stoc(x)	(x)

/* Core clicks (4096 bytes) to disk blocks */
#define	ctod(x)	((x)<<(PGSHIFT-DEV_BSHIFT))
#define	dtoc(x)	((x)>>(PGSHIFT-DEV_BSHIFT))
#define	dtob(x)	((x)<<DEV_BSHIFT)

/* clicks to bytes */
#define	ctob(x)	((x)<<PGSHIFT)

/* bytes to clicks */
#define	btoc(x)	(((unsigned)(x)+(NBPG-1))>>PGSHIFT)

#ifdef __APPLE__
#define  btodb(bytes, devBlockSize)         \
        ((unsigned)(bytes) / devBlockSize)
#define  dbtob(db, devBlockSize)            \
        ((unsigned)(db) * devBlockSize)
#else
#define	btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
	((unsigned)(bytes) >> DEV_BSHIFT)
#define	dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
	((unsigned)(db) << DEV_BSHIFT)
#endif

/*
 * Map a ``block device block'' to a file system block.
 * This should be device dependent, and will be if we
 * add an entry to cdevsw/bdevsw for that purpose.
 * For now though just use DEV_BSIZE.
 */
#define	bdbtofsb(bn)	((bn) / (BLKDEV_IOSIZE/DEV_BSIZE))

/*
 * Macros to decode (and encode) processor status word.
 */
#define STATUS_WORD(rpl, ipl)	(((ipl) << 8) | (rpl))
#define	USERMODE(x)		(((x) & 3) == 3)
#define	BASEPRI(x)		(((x) & (255 << 8)) == 0)


#if	defined(KERNEL) || defined(STANDALONE)
#define	DELAY(n) delay(n)

#else	/* defined(KERNEL) || defined(STANDALONE) */
#define	DELAY(n)	{ register int N = (n); while (--N > 0); }
#endif	/* defined(KERNEL) || defined(STANDALONE) */

#endif /* _I386_PARAM_H_ */