xref: /netbsd-src/sys/arch/i386/include/param.h (revision ce63d6c20fc4ec8ddc95c84bb229e3c4ecf82b69)
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 1.5 1993/06/05 23:11:10 cgd Exp $
38  */
39 
40 /*
41  * Machine dependent constants for Intel 386.
42  */
43 
44 #define MACHINE "i386"
45 
46 /*
47  * Round p (pointer or byte index) up to a correctly-aligned value
48  * for all data types (int, long, ...).   The result is u_int and
49  * must be cast to any desired pointer type.
50  */
51 #define	ALIGN(p)	(((u_int)(p) + (sizeof(int) - 1)) &~ (sizeof(int) - 1))
52 
53 #define	NBPG		4096		/* bytes/page */
54 #define	PGOFSET		(NBPG-1)	/* byte offset into page */
55 #define	PGSHIFT		12		/* LOG2(NBPG) */
56 #define	NPTEPG		(NBPG/(sizeof (struct pte)))
57 
58 #define NBPDR		(1024*NBPG)	/* bytes/page dir */
59 #define	PDROFSET	(NBPDR-1)	/* byte offset into page dir */
60 #define	PDRSHIFT	22		/* LOG2(NBPDR) */
61 
62 #define	KERNBASE	0xFE000000	/* start of kernel virtual */
63 #define	BTOPKERNBASE	((u_long)KERNBASE >> PGSHIFT)
64 
65 #define	DEV_BSIZE	512
66 #define	DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
67 #define BLKDEV_IOSIZE	2048
68 #define	MAXPHYS		(64 * 1024)	/* max raw I/O transfer size */
69 
70 #define	CLSIZE		1
71 #define	CLSIZELOG2	0
72 
73 /* NOTE: SSIZE, SINCR and UPAGES must be multiples of CLSIZE */
74 #define	SSIZE	1		/* initial stack size/NBPG */
75 #define	SINCR	1		/* increment of stack/NBPG */
76 
77 #define	UPAGES	2		/* pages of u-area */
78 
79 /*
80  * Constants related to network buffer management.
81  * MCLBYTES must be no larger than CLBYTES (the software page size), and,
82  * on machines that exchange pages of input or output buffers with mbuf
83  * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
84  * of the hardware page size.
85  */
86 #ifndef	MSIZE
87 #define	MSIZE		128		/* size of an mbuf */
88 #endif
89 #ifndef	MCLSHIFT
90 #define	MCLSHIFT	11		/* convert bytes to m_buf clusters */
91 #endif
92 #define	MCLBYTES	(1 << MCLSHIFT)	/* size of a m_buf cluster */
93 #define	MCLOFSET	(MCLBYTES - 1)	/* offset within a m_buf cluster */
94 #ifndef NMBCLUSTERS
95 #ifdef GATEWAY
96 #define	NMBCLUSTERS	512		/* map size, max cluster allocation */
97 #else
98 #define	NMBCLUSTERS	256		/* map size, max cluster allocation */
99 #endif
100 #endif
101 
102 /*
103  * Size of kernel malloc arena in CLBYTES-sized logical pages
104  */
105 #ifndef NKMEMCLUSTERS
106 #define	NKMEMCLUSTERS	(3072*1024/CLBYTES)
107 #endif
108 /*
109  * Some macros for units conversion
110  */
111 /* Core clicks (4096 bytes) to segments and vice versa */
112 #define	ctos(x)	(x)
113 #define	stoc(x)	(x)
114 
115 /* Core clicks (4096 bytes) to disk blocks */
116 #define	ctod(x)	((x)<<(PGSHIFT-DEV_BSHIFT))
117 #define	dtoc(x)	((x)>>(PGSHIFT-DEV_BSHIFT))
118 #define	dtob(x)	((x)<<DEV_BSHIFT)
119 
120 /* clicks to bytes */
121 #define	ctob(x)	((x)<<PGSHIFT)
122 
123 /* bytes to clicks */
124 #define	btoc(x)	(((unsigned)(x)+(NBPG-1))>>PGSHIFT)
125 
126 #define	btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
127 	((unsigned)(bytes) >> DEV_BSHIFT)
128 #define	dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
129 	((unsigned)(db) << DEV_BSHIFT)
130 
131 /*
132  * Map a ``block device block'' to a file system block.
133  * This should be device dependent, and will be if we
134  * add an entry to cdevsw/bdevsw for that purpose.
135  * For now though just use DEV_BSIZE.
136  */
137 #define	bdbtofsb(bn)	((bn) / (BLKDEV_IOSIZE/DEV_BSIZE))
138 
139 /*
140  * Mach derived conversion macros
141  */
142 #define i386_round_pdr(x)	((((unsigned)(x)) + NBPDR - 1) & ~(NBPDR-1))
143 #define i386_trunc_pdr(x)	((unsigned)(x) & ~(NBPDR-1))
144 #define i386_round_page(x)	((((unsigned)(x)) + NBPG - 1) & ~(NBPG-1))
145 #define i386_trunc_page(x)	((unsigned)(x) & ~(NBPG-1))
146 #define i386_btod(x)		((unsigned)(x) >> PDRSHIFT)
147 #define i386_dtob(x)		((unsigned)(x) << PDRSHIFT)
148 #define i386_btop(x)		((unsigned)(x) >> PGSHIFT)
149 #define i386_ptob(x)		((unsigned)(x) << PGSHIFT)
150 
151 #ifndef KERNEL
152 #define	DELAY(n)	{ volatile int N = (n); while (--N > 0); }
153 #endif
154