xref: /freebsd/sys/i386/include/param.h (revision f798d060)
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  *	@(#)param.h	5.8 (Berkeley) 6/28/91
37  *
38  * PATCHES MAGIC                LEVEL   PATCH THAT GOT US HERE
39  * --------------------         -----   ----------------------
40  * CURRENT PATCH LEVEL:         2       00166
41  * --------------------         -----   ----------------------
42  *
43  * 08 Apr 93	Andrew Herbert		Fixes for kmem_alloc panics
44  *		Rodney W. Grimes	Tuneable mbuf sizes
45  * 04 Jun 93	Rodney W. Grimes	Change default mbuf size to 2048 via
46  *					MCLSHIFT.
47  */
48 
49 /*
50  * Machine dependent constants for Intel 386.
51  */
52 
53 #define MACHINE "i386"
54 
55 /*
56  * Round p (pointer or byte index) up to a correctly-aligned value
57  * for all data types (int, long, ...).   The result is u_int and
58  * must be cast to any desired pointer type.
59  */
60 #define ALIGNBYTES	(sizeof(int) - 1)
61 #define ALIGN(p)	(((u_int)(p) + ALIGNBYTES) &~ ALIGNBYTES)
62 
63 
64 #define	NBPG		4096		/* bytes/page */
65 #define	PGOFSET		(NBPG-1)	/* byte offset into page */
66 #define	PGSHIFT		12		/* LOG2(NBPG) */
67 #define	NPTEPG		(NBPG/(sizeof (struct pte)))
68 
69 #define NBPDR		(1024*NBPG)	/* bytes/page dir */
70 #define	PDROFSET	(NBPDR-1)	/* byte offset into page dir */
71 #define	PDRSHIFT	22		/* LOG2(NBPDR) */
72 
73 #define	KERNBASE	0xFE000000	/* start of kernel virtual */
74 #define	BTOPKERNBASE	((u_long)KERNBASE >> PGSHIFT)
75 
76 #define	DEV_BSIZE	512
77 #define	DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
78 #define BLKDEV_IOSIZE	2048
79 #define	MAXPHYS		(64 * 1024)	/* max raw I/O transfer size */
80 
81 #define	CLSIZE		1
82 #define	CLSIZELOG2	0
83 
84 /* NOTE: SSIZE, SINCR and UPAGES must be multiples of CLSIZE */
85 #define	SSIZE	1		/* initial stack size/NBPG */
86 #define	SINCR	1		/* increment of stack/NBPG */
87 
88 #define	UPAGES	2		/* pages of u-area */
89 
90 /*
91  * Constants related to network buffer management.
92  * MCLBYTES must be no larger than CLBYTES (the software page size), and,
93  * on machines that exchange pages of input or output buffers with mbuf
94  * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
95  * of the hardware page size.
96  */
97 #ifndef	MSIZE
98 #define	MSIZE		128		/* size of an mbuf */
99 #endif	/* MSIZE */
100 
101 #ifndef	MCLSHIFT
102 #define	MCLSHIFT	11		/* convert bytes to m_buf clusters */
103 #endif	/* MCLSHIFT */
104 #define	MCLBYTES	(1 << MCLSHIFT)	/* size of an m_buf cluster */
105 #define	MCLOFSET	(MCLBYTES - 1)	/* offset within an m_buf cluster */
106 
107 #ifndef NMBCLUSTERS
108 #ifdef GATEWAY
109 #define	NMBCLUSTERS	512		/* map size, max cluster allocation */
110 #else
111 #define	NMBCLUSTERS	256		/* map size, max cluster allocation */
112 #endif	/* GATEWAY */
113 #endif	/* NMBCLUSTERS */
114 
115 /*
116  * Size of kernel malloc arena in CLBYTES-sized logical pages
117  */
118 #ifndef NKMEMCLUSTERS
119 #define	NKMEMCLUSTERS	(3072*1024/CLBYTES)
120 #endif
121 /*
122  * Some macros for units conversion
123  */
124 /* Core clicks (4096 bytes) to segments and vice versa */
125 #define	ctos(x)	(x)
126 #define	stoc(x)	(x)
127 
128 /* Core clicks (4096 bytes) to disk blocks */
129 #define	ctod(x)	((x)<<(PGSHIFT-DEV_BSHIFT))
130 #define	dtoc(x)	((x)>>(PGSHIFT-DEV_BSHIFT))
131 #define	dtob(x)	((x)<<DEV_BSHIFT)
132 
133 /* clicks to bytes */
134 #define	ctob(x)	((x)<<PGSHIFT)
135 
136 /* bytes to clicks */
137 #define	btoc(x)	(((unsigned)(x)+(NBPG-1))>>PGSHIFT)
138 
139 #define	btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
140 	((unsigned)(bytes) >> DEV_BSHIFT)
141 #define	dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
142 	((unsigned)(db) << DEV_BSHIFT)
143 
144 /*
145  * Map a ``block device block'' to a file system block.
146  * This should be device dependent, and will be if we
147  * add an entry to cdevsw/bdevsw for that purpose.
148  * For now though just use DEV_BSIZE.
149  */
150 #define	bdbtofsb(bn)	((bn) / (BLKDEV_IOSIZE/DEV_BSIZE))
151 
152 /*
153  * Mach derived conversion macros
154  */
155 #define i386_round_pdr(x)	((((unsigned)(x)) + NBPDR - 1) & ~(NBPDR-1))
156 #define i386_trunc_pdr(x)	((unsigned)(x) & ~(NBPDR-1))
157 #define i386_round_page(x)	((((unsigned)(x)) + NBPG - 1) & ~(NBPG-1))
158 #define i386_trunc_page(x)	((unsigned)(x) & ~(NBPG-1))
159 #define i386_btod(x)		((unsigned)(x) >> PDRSHIFT)
160 #define i386_dtob(x)		((unsigned)(x) << PDRSHIFT)
161 #define i386_btop(x)		((unsigned)(x) >> PGSHIFT)
162 #define i386_ptob(x)		((unsigned)(x) << PGSHIFT)
163 
164 #ifndef KERNEL
165 #define	DELAY(n)	{ volatile int N = (n); while (--N > 0); }
166 #endif
167