xref: /freebsd/sys/i386/include/param.h (revision 17ee9d00bc1ae1e598c38f25826f861e4bc6c3ce)
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 1.17 1995/01/23 19:21:49 davidg Exp $
38  */
39 
40 #ifndef _MACHINE_PARAM_H_
41 #define	_MACHINE_PARAM_H_
42 
43 /*
44  * Machine dependent constants for Intel 386.
45  */
46 
47 #define MACHINE		"i386"
48 #define MID_MACHINE	MID_I386
49 
50 /*
51  * Round p (pointer or byte index) up to a correctly-aligned value
52  * for all data types (int, long, ...).   The result is unsigned int
53  * and must be cast to any desired pointer type.
54  */
55 #define ALIGNBYTES	(sizeof(int) - 1)
56 #define ALIGN(p)	(((unsigned)(p) + ALIGNBYTES) & ~ALIGNBYTES)
57 
58 /* XXX PGSHIFT and PG_SHIFT are two names for the same thing */
59 #define PGSHIFT		12		/* LOG2(NBPG) */
60 #define PAGE_SHIFT	12
61 #define NBPG		(1 << PAGE_SHIFT)	/* bytes/page */
62 #define PAGE_SIZE	(1 << PAGE_SHIFT)
63 #define PAGE_MASK	(PAGE_SIZE-1)
64 #define PGOFSET		(NBPG-1)	/* byte offset into page */
65 #define NPTEPG		(NBPG/(sizeof (pt_entry_t)))
66 
67 /* XXX PDRSHIFT and PD_SHIFT are two names for the same thing */
68 #define PDRSHIFT	22		/* LOG2(NBPDR) */
69 #define NBPDR		(1 << PDRSHIFT)	/* bytes/page dir */
70 #define PDROFSET	(NBPDR-1)	/* byte offset into page dir */
71 
72 /*
73  * XXX This should really be KPTDPTDI << PDRSHIFT, but since KPTDPTDI is
74  * defined in pmap.h which is included after this we can't do that
75  * (YET!)
76  */
77 #define BTOPKERNBASE	(KERNBASE >> PGSHIFT)
78 
79 #define DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
80 #define DEV_BSIZE	(1 << DEV_BSHIFT)
81 
82 #define BLKDEV_IOSIZE	2048
83 #define MAXPHYS		(64 * 1024)	/* max raw I/O transfer size */
84 
85 #define CLSIZELOG2	0
86 #define CLSIZE		(1 << CLSIZELOG2)
87 
88 /* NOTE: SSIZE, SINCR and UPAGES must be multiples of CLSIZE */
89 #define SSIZE	1		/* initial stack size/NBPG */
90 #define SINCR	1		/* increment of stack/NBPG */
91 
92 #define UPAGES	2		/* pages of u-area */
93 
94 /*
95  * Constants related to network buffer management.
96  * MCLBYTES must be no larger than CLBYTES (the software page size), and,
97  * on machines that exchange pages of input or output buffers with mbuf
98  * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
99  * of the hardware page size.
100  */
101 #ifndef	MSIZE
102 #define MSIZE		128		/* size of an mbuf */
103 #endif	/* MSIZE */
104 
105 #ifndef	MCLSHIFT
106 #define MCLSHIFT	11		/* convert bytes to m_buf clusters */
107 #endif	/* MCLSHIFT */
108 #define MCLBYTES	(1 << MCLSHIFT)	/* size of an m_buf cluster */
109 #define MCLOFSET	(MCLBYTES - 1)	/* offset within an m_buf cluster */
110 
111 #ifndef NMBCLUSTERS
112 #ifdef GATEWAY
113 #define NMBCLUSTERS	512		/* map size, max cluster allocation */
114 #else
115 #define NMBCLUSTERS	256		/* map size, max cluster allocation */
116 #endif	/* GATEWAY */
117 #endif	/* NMBCLUSTERS */
118 
119 /*
120  * Some macros for units conversion
121  */
122 /* Core clicks (4096 bytes) to segments and vice versa */
123 #define ctos(x)	(x)
124 #define stoc(x)	(x)
125 
126 /* Core clicks (4096 bytes) to disk blocks */
127 #define ctod(x)	((x)<<(PGSHIFT-DEV_BSHIFT))
128 #define dtoc(x)	((x)>>(PGSHIFT-DEV_BSHIFT))
129 #define dtob(x)	((x)<<DEV_BSHIFT)
130 
131 /* clicks to bytes */
132 #define ctob(x)	((x)<<PGSHIFT)
133 
134 /* bytes to clicks */
135 #define btoc(x)	(((unsigned)(x)+(NBPG-1))>>PGSHIFT)
136 
137 /*
138  * This is messy and perhaps slow because `bytes' may be an off_t.  We
139  * have to shift an unsigned type to avoid sign extension and we don't
140  * want to widen `bytes' unnecessarily.  Assume that off_t is long long
141  * and daddr_t is unsigned long.
142  */
143 #define btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
144 	(sizeof (bytes) > sizeof(long) \
145 	 ? (unsigned long)((unsigned long long)(bytes) >> DEV_BSHIFT) \
146 	 : (unsigned long)((unsigned long)(bytes) >> DEV_BSHIFT))
147 #define dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
148 	((unsigned long long)(db) << DEV_BSHIFT)
149 
150 /*
151  * Mach derived conversion macros
152  */
153 #define trunc_page(x)		((unsigned)(x) & ~(NBPG-1))
154 #define round_page(x)		((((unsigned)(x)) + NBPG - 1) & ~(NBPG-1))
155 
156 #define atop(x)			((unsigned)(x) >> PG_SHIFT)
157 #define ptoa(x)			((unsigned)(x) << PG_SHIFT)
158 
159 #define i386_round_pdr(x)	((((unsigned)(x)) + NBPDR - 1) & ~(NBPDR-1))
160 #define i386_trunc_pdr(x)	((unsigned)(x) & ~(NBPDR-1))
161 #define i386_round_page(x)	((((unsigned)(x)) + NBPG - 1) & ~(NBPG-1))
162 #define i386_trunc_page(x)	((unsigned)(x) & ~(NBPG-1))
163 #define i386_btod(x)		((unsigned)(x) >> PDRSHIFT)
164 #define i386_dtob(x)		((unsigned)(x) << PDRSHIFT)
165 #define i386_btop(x)		((unsigned)(x) >> PGSHIFT)
166 #define i386_ptob(x)		((unsigned)(x) << PGSHIFT)
167 
168 #endif /* !_MACHINE_PARAM_H_ */
169