freebsd/sys/i386/include/param.h

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * 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	5.8 (Berkeley) 6/28/91
 *
 * PATCHES MAGIC                LEVEL   PATCH THAT GOT US HERE
 * --------------------         -----   ----------------------
 * CURRENT PATCH LEVEL:         2       00166
 * --------------------         -----   ----------------------
 *
 * 08 Apr 93	Andrew Herbert		Fixes for kmem_alloc panics
 *		Rodney W. Grimes	Tuneable mbuf sizes
 * 04 Jun 93	Rodney W. Grimes	Change default mbuf size to 2048 via
 *					MCLSHIFT.
 */

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

#define MACHINE "i386"

/*
 * 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	(sizeof(int) - 1)
#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	NPTEPG		(NBPG/(sizeof (struct pte)))

#define NBPDR		(1024*NBPG)	/* bytes/page dir */
#define	PDROFSET	(NBPDR-1)	/* byte offset into page dir */
#define	PDRSHIFT	22		/* LOG2(NBPDR) */

#define	KERNBASE	0xFE000000	/* start of kernel virtual */
#define	BTOPKERNBASE	((u_long)KERNBASE >> PGSHIFT)

#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	CLSIZE		1
#define	CLSIZELOG2	0

/* NOTE: SSIZE, SINCR and UPAGES must be multiples of CLSIZE */
#define	SSIZE	1		/* initial stack size/NBPG */
#define	SINCR	1		/* increment of stack/NBPG */

#define	UPAGES	2		/* pages of u-area */

/*
 * 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.
 */
#ifndef	MSIZE
#define	MSIZE		128		/* size of an mbuf */
#endif	/* MSIZE */

#ifndef	MCLSHIFT
#define	MCLSHIFT	11		/* convert bytes to m_buf clusters */
#endif	/* MCLSHIFT */
#define	MCLBYTES	(1 << MCLSHIFT)	/* size of an m_buf cluster */
#define	MCLOFSET	(MCLBYTES - 1)	/* offset within an m_buf cluster */

#ifndef NMBCLUSTERS
#ifdef GATEWAY
#define	NMBCLUSTERS	512		/* map size, max cluster allocation */
#else
#define	NMBCLUSTERS	256		/* map size, max cluster allocation */
#endif	/* GATEWAY */
#endif	/* NMBCLUSTERS */

/*
 * Size of kernel malloc arena in CLBYTES-sized logical pages
 */ 
#ifndef NKMEMCLUSTERS
#define	NKMEMCLUSTERS	(3072*1024/CLBYTES)
#endif
/*
 * Some macros for units conversion
 */
/* Core clicks (4096 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)

#define	btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
	((unsigned)(bytes) >> DEV_BSHIFT)
#define	dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
	((unsigned)(db) << DEV_BSHIFT)

/*
 * 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))

/*
 * Mach derived conversion macros
 */
#define i386_round_pdr(x)	((((unsigned)(x)) + NBPDR - 1) & ~(NBPDR-1))
#define i386_trunc_pdr(x)	((unsigned)(x) & ~(NBPDR-1))
#define i386_round_page(x)	((((unsigned)(x)) + NBPG - 1) & ~(NBPG-1))
#define i386_trunc_page(x)	((unsigned)(x) & ~(NBPG-1))
#define i386_btod(x)		((unsigned)(x) >> PDRSHIFT)
#define i386_dtob(x)		((unsigned)(x) << PDRSHIFT)
#define i386_btop(x)		((unsigned)(x) >> PGSHIFT)
#define i386_ptob(x)		((unsigned)(x) << PGSHIFT)

#ifndef KERNEL
#define	DELAY(n)	{ volatile int N = (n); while (--N > 0); }
#endif