xref: /netbsd-src/sys/arch/i386/include/param.h (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: param.h,v 1.33 1997/10/20 00:45:04 fvdl Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * William Jolitz.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)param.h	5.8 (Berkeley) 6/28/91
39  */
40 
41 /*
42  * Machine dependent constants for Intel 386.
43  */
44 
45 #ifdef _KERNEL
46 #ifdef _LOCORE
47 #include <machine/psl.h>
48 #else
49 #include <machine/cpu.h>
50 #endif
51 #endif
52 
53 #define	_MACHINE	i386
54 #define	MACHINE		"i386"
55 #define	_MACHINE_ARCH	i386
56 #define	MACHINE_ARCH	"i386"
57 #define	MID_MACHINE	MID_I386
58 
59 /*
60  * Round p (pointer or byte index) up to a correctly-aligned value
61  * for all data types (int, long, ...).   The result is u_int and
62  * must be cast to any desired pointer type.
63  *
64  * ALIGNED_POINTER is a boolean macro that checks whether an address
65  * is valid to fetch data elements of type t from on this architecture.
66  * This does not reflect the optimal alignment, just the possibility
67  * (within reasonable limits).
68  *
69  */
70 #define ALIGNBYTES		(sizeof(int) - 1)
71 #define ALIGN(p)		(((u_int)(p) + ALIGNBYTES) &~ ALIGNBYTES)
72 #define ALIGNED_POINTER(p,t)	1
73 
74 #define	PGSHIFT		12		/* LOG2(NBPG) */
75 #define	NBPG		(1 << PGSHIFT)	/* bytes/page */
76 #define	PGOFSET		(NBPG-1)	/* byte offset into page */
77 #define	NPTEPG		(NBPG/(sizeof (pt_entry_t)))
78 
79 #define	KERNBASE	0xf0000000	/* start of kernel virtual space */
80 #define	KERNSIZE	0x01800000	/* size of kernel virtual space */
81 #define	KERNTEXTOFF	0xf0100000	/* start of kernel text */
82 #define	BTOPKERNBASE	((u_long)KERNBASE >> PGSHIFT)
83 
84 #define	DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
85 #define	DEV_BSIZE	(1 << DEV_BSHIFT)
86 #define	BLKDEV_IOSIZE	2048
87 #define	MAXPHYS		(64 * 1024)	/* max raw I/O transfer size */
88 
89 #define	CLSIZELOG2	0
90 #define	CLSIZE		(1 << CLSIZELOG2)
91 
92 /* NOTE: SSIZE, SINCR and UPAGES must be multiples of CLSIZE */
93 #define	SSIZE		1		/* initial stack size/NBPG */
94 #define	SINCR		1		/* increment of stack/NBPG */
95 #define	UPAGES		2		/* pages of u-area */
96 #define	USPACE		(UPAGES * NBPG)	/* total size of u-area */
97 
98 #ifndef MSGBUFSIZE
99 #define MSGBUFSIZE	NBPG		/* default message buffer size */
100 #endif
101 
102 /*
103  * Constants related to network buffer management.
104  * MCLBYTES must be no larger than CLBYTES (the software page size), and,
105  * on machines that exchange pages of input or output buffers with mbuf
106  * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
107  * of the hardware page size.
108  */
109 #define	MSIZE		128		/* size of an mbuf */
110 
111 #ifndef MCLSHIFT
112 # define	MCLSHIFT	11	/* convert bytes to m_buf clusters */
113 #endif	/* MCLSHIFT */
114 
115 #define	MCLBYTES	(1 << MCLSHIFT)	/* size of a m_buf cluster */
116 #define	MCLOFSET	(MCLBYTES - 1)	/* offset within a m_buf cluster */
117 
118 #ifndef NMBCLUSTERS
119 #ifdef GATEWAY
120 #define	NMBCLUSTERS	512		/* map size, max cluster allocation */
121 #else
122 #define	NMBCLUSTERS	256		/* map size, max cluster allocation */
123 #endif
124 #endif
125 
126 /*
127  * Size of kernel malloc arena in CLBYTES-sized logical pages
128  */
129 #ifndef NKMEMCLUSTERS
130 #define	NKMEMCLUSTERS	(6 * 1024 * 1024 / CLBYTES)
131 #endif
132 
133 /* pages ("clicks") to disk blocks */
134 #define	ctod(x)		((x) << (PGSHIFT - DEV_BSHIFT))
135 #define	dtoc(x)		((x) >> (PGSHIFT - DEV_BSHIFT))
136 
137 /* bytes to pages */
138 #define	ctob(x)		((x) << PGSHIFT)
139 #define	btoc(x)		(((x) + PGOFSET) >> PGSHIFT)
140 
141 /* bytes to disk blocks */
142 #define	dbtob(x)	((x) << DEV_BSHIFT)
143 #define	btodb(x)	((x) >> DEV_BSHIFT)
144 
145 /*
146  * Map a ``block device block'' to a file system block.
147  * This should be device dependent, and should use the bsize
148  * field from the disk label.
149  * For now though just use DEV_BSIZE.
150  */
151 #define	bdbtofsb(bn)	((bn) / (BLKDEV_IOSIZE / DEV_BSIZE))
152 
153 /*
154  * Mach derived conversion macros
155  */
156 #define	i386_round_pdr(x)	((((unsigned)(x)) + PDOFSET) & ~PDOFSET)
157 #define	i386_trunc_pdr(x)	((unsigned)(x) & ~PDOFSET)
158 #define	i386_btod(x)		((unsigned)(x) >> PDSHIFT)
159 #define	i386_dtob(x)		((unsigned)(x) << PDSHIFT)
160 #define	i386_round_page(x)	((((unsigned)(x)) + PGOFSET) & ~PGOFSET)
161 #define	i386_trunc_page(x)	((unsigned)(x) & ~PGOFSET)
162 #define	i386_btop(x)		((unsigned)(x) >> PGSHIFT)
163 #define	i386_ptob(x)		((unsigned)(x) << PGSHIFT)
164