xref: /netbsd-src/sys/arch/i386/include/param.h (revision 4b30c543a0b21e3ba94f2c569e9a82b4fdb2075f)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * William Jolitz.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	from: @(#)param.h	5.8 (Berkeley) 6/28/91
37  *	$Id: param.h,v 1.8 1993/08/03 21:51:10 mycroft Exp $
38  */
39 
40 /*
41  * Machine dependent constants for Intel 386.
42  */
43 
44 #define MACHINE		"i386"
45 #define MID_MACHINE	MID_I386
46 
47 /*
48  * Round p (pointer or byte index) up to a correctly-aligned value
49  * for all data types (int, long, ...).   The result is u_int and
50  * must be cast to any desired pointer type.
51  */
52 #define ALIGNBYTES	(sizeof(int) - 1)
53 #define ALIGN(p)	(((u_int)(p) + ALIGNBYTES) &~ ALIGNBYTES)
54 
55 #define	NBPG		4096		/* bytes/page */
56 #define	PGOFSET		(NBPG-1)	/* byte offset into page */
57 #define	PGSHIFT		12		/* LOG2(NBPG) */
58 #define	NPTEPG		(NBPG/(sizeof (struct pte)))
59 
60 #define NBPDR		(1024*NBPG)	/* bytes/page dir */
61 #define	PDROFSET	(NBPDR-1)	/* byte offset into page dir */
62 #define	PDRSHIFT	22		/* LOG2(NBPDR) */
63 
64 #define	KERNBASE	0xFE000000	/* start of kernel virtual */
65 #define	BTOPKERNBASE	((u_long)KERNBASE >> PGSHIFT)
66 
67 #define	DEV_BSIZE	512
68 #define	DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
69 #define BLKDEV_IOSIZE	2048
70 #define	MAXPHYS		(64 * 1024)	/* max raw I/O transfer size */
71 
72 #define	CLSIZE		1
73 #define	CLSIZELOG2	0
74 
75 /* NOTE: SSIZE, SINCR and UPAGES must be multiples of CLSIZE */
76 #define	SSIZE	1		/* initial stack size/NBPG */
77 #define	SINCR	1		/* increment of stack/NBPG */
78 
79 #define	UPAGES	2		/* pages of u-area */
80 
81 /*
82  * Constants related to network buffer management.
83  * MCLBYTES must be no larger than CLBYTES (the software page size), and,
84  * on machines that exchange pages of input or output buffers with mbuf
85  * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
86  * of the hardware page size.
87  */
88 #ifndef	MSIZE
89 #define	MSIZE		128		/* size of an mbuf */
90 #endif	/* MSIZE */
91 
92 #ifndef	MCLSHIFT
93 #define	MCLSHIFT	11		/* convert bytes to m_buf clusters */
94 #endif	/* MCLSHIFT */
95 #define	MCLBYTES	(1 << MCLSHIFT)	/* size of a m_buf cluster */
96 #define	MCLOFSET	(MCLBYTES - 1)	/* offset within a m_buf cluster */
97 
98 #ifndef NMBCLUSTERS
99 #ifdef GATEWAY
100 #define	NMBCLUSTERS	512		/* map size, max cluster allocation */
101 #else
102 #define	NMBCLUSTERS	256		/* map size, max cluster allocation */
103 #endif	/* GATEWAY */
104 #endif	/* NMBCLUSTERS */
105 
106 /*
107  * Size of kernel malloc arena in CLBYTES-sized logical pages
108  */
109 #ifndef NKMEMCLUSTERS
110 #define	NKMEMCLUSTERS	(3072*1024/CLBYTES)
111 #endif
112 /*
113  * Some macros for units conversion
114  */
115 /* Core clicks (4096 bytes) to segments and vice versa */
116 #define	ctos(x)	(x)
117 #define	stoc(x)	(x)
118 
119 /* Core clicks (4096 bytes) to disk blocks */
120 #define	ctod(x)	((x)<<(PGSHIFT-DEV_BSHIFT))
121 #define	dtoc(x)	((x)>>(PGSHIFT-DEV_BSHIFT))
122 #define	dtob(x)	((x)<<DEV_BSHIFT)
123 
124 /* clicks to bytes */
125 #define	ctob(x)	((x)<<PGSHIFT)
126 
127 /* bytes to clicks */
128 #define	btoc(x)	(((unsigned)(x)+(NBPG-1))>>PGSHIFT)
129 
130 #define	btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
131 	((unsigned)(bytes) >> DEV_BSHIFT)
132 #define	dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
133 	((unsigned)(db) << DEV_BSHIFT)
134 
135 /*
136  * Map a ``block device block'' to a file system block.
137  * This should be device dependent, and will be if we
138  * add an entry to cdevsw/bdevsw for that purpose.
139  * For now though just use DEV_BSIZE.
140  */
141 #define	bdbtofsb(bn)	((bn) / (BLKDEV_IOSIZE/DEV_BSIZE))
142 
143 /*
144  * Mach derived conversion macros
145  */
146 #define i386_round_pdr(x)	((((unsigned)(x)) + NBPDR - 1) & ~(NBPDR-1))
147 #define i386_trunc_pdr(x)	((unsigned)(x) & ~(NBPDR-1))
148 #define i386_round_page(x)	((((unsigned)(x)) + NBPG - 1) & ~(NBPG-1))
149 #define i386_trunc_page(x)	((unsigned)(x) & ~(NBPG-1))
150 #define i386_btod(x)		((unsigned)(x) >> PDRSHIFT)
151 #define i386_dtob(x)		((unsigned)(x) << PDRSHIFT)
152 #define i386_btop(x)		((unsigned)(x) >> PGSHIFT)
153 #define i386_ptob(x)		((unsigned)(x) << PGSHIFT)
154