param.h revision 27617 
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 1.27 1997/04/07 09:27:21 peter 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 NCPUS		1
49#define MID_MACHINE	MID_I386
50
51/*
52 * Round p (pointer or byte index) up to a correctly-aligned value
53 * for all data types (int, long, ...).   The result is unsigned int
54 * and must be cast to any desired pointer type.
55 */
56#define ALIGNBYTES	(sizeof(int) - 1)
57#define ALIGN(p)	(((unsigned)(p) + ALIGNBYTES) & ~ALIGNBYTES)
58
59#define PAGE_SHIFT	12		/* LOG2(PAGE_SIZE) */
60#define PAGE_SIZE	(1<<PAGE_SHIFT)	/* bytes/page */
61#define PAGE_MASK	(PAGE_SIZE-1)
62#define NPTEPG		(PAGE_SIZE/(sizeof (pt_entry_t)))
63
64#define NPDEPG		(PAGE_SIZE/(sizeof (pd_entry_t)))
65#define PDRSHIFT	22		/* LOG2(NBPDR) */
66#define NBPDR		(1<<PDRSHIFT)	/* bytes/page dir */
67
68#define DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
69#define DEV_BSIZE	(1<<DEV_BSHIFT)
70
71#define BLKDEV_IOSIZE	2048
72#define MAXPHYS		(64 * 1024)	/* max raw I/O transfer size */
73
74#define UPAGES	2		/* pages of u-area */
75#define UPAGES_HOLE	2	/* pages of "hole" at top of user space where */
76				/* the upages used to be. DO NOT CHANGE! */
77
78/*
79 * Constants related to network buffer management.
80 * MCLBYTES must be no larger than CLBYTES (the software page size), and,
81 * on machines that exchange pages of input or output buffers with mbuf
82 * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
83 * of the hardware page size.
84 */
85#ifndef	MSIZE
86#define MSIZE		128		/* size of an mbuf */
87#endif	/* MSIZE */
88
89#ifndef	MCLSHIFT
90#define MCLSHIFT	11		/* convert bytes to m_buf clusters */
91#endif	/* MCLSHIFT */
92#define MCLBYTES	(1 << MCLSHIFT)	/* size of an m_buf cluster */
93#define MCLOFSET	(MCLBYTES - 1)	/* offset within an m_buf cluster */
94
95/*
96 * Some macros for units conversion
97 */
98
99/* clicks to bytes */
100#define ctob(x)	((x)<<PAGE_SHIFT)
101
102/* bytes to clicks */
103#define btoc(x)	(((unsigned)(x)+PAGE_MASK)>>PAGE_SHIFT)
104
105/*
106 * btodb() is messy and perhaps slow because `bytes' may be an off_t.  We
107 * want to shift an unsigned type to avoid sign extension and we don't
108 * want to widen `bytes' unnecessarily.  Assume that the result fits in
109 * a daddr_t.
110 */
111#define btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
112	(sizeof (bytes) > sizeof(long) \
113	 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
114	 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
115
116#define dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
117	((off_t)(db) << DEV_BSHIFT)
118
119/*
120 * Mach derived conversion macros
121 */
122#define trunc_page(x)		((unsigned)(x) & ~PAGE_MASK)
123#define round_page(x)		((((unsigned)(x)) + PAGE_MASK) & ~PAGE_MASK)
124
125#define atop(x)			((unsigned)(x) >> PAGE_SHIFT)
126#define ptoa(x)			((unsigned)(x) << PAGE_SHIFT)
127
128#define i386_btop(x)		((unsigned)(x) >> PAGE_SHIFT)
129#define i386_ptob(x)		((unsigned)(x) << PAGE_SHIFT)
130
131#ifndef _SIMPLELOCK_H_
132#define _SIMPLELOCK_H_
133/*
134 * A simple spin lock.
135 *
136 * This structure only sets one bit of data, but is sized based on the
137 * minimum word size that can be operated on by the hardware test-and-set
138 * instruction. It is only needed for multiprocessors, as uniprocessors
139 * will always run to completion or a sleep. It is an error to hold one
140 * of these locks while a process is sleeping.
141 */
142struct simplelock {
143	int	lock_data;
144};
145
146#if !defined(SIMPLELOCK_DEBUG) && NCPUS > 1
147/*
148 * The simple-lock routines are the primitives out of which the lock
149 * package is built. The machine-dependent code must implement an
150 * atomic test_and_set operation that indivisibly sets the simple lock
151 * to non-zero and returns its old value. It also assumes that the
152 * setting of the lock to zero below is indivisible. Simple locks may
153 * only be used for exclusive locks.
154 */
155static __inline void
156simple_lock_init(struct simplelock *lkp)
157{
158
159	lkp->lock_data = 0;
160}
161
162static __inline void
163simple_lock(__volatile struct simplelock *lkp)
164{
165
166	while (test_and_set(&lkp->lock_data))
167		continue;
168}
169
170static __inline int
171simple_lock_try(__volatile struct simplelock *lkp)
172{
173
174	return (!test_and_set(&lkp->lock_data));
175}
176
177static __inline void
178simple_unlock(__volatile struct simplelock *lkp)
179{
180
181	lkp->lock_data = 0;
182}
183#endif /* NCPUS > 1 */
184#endif /* !_SIMPLELOCK_H_ */
185
186#endif /* !_MACHINE_PARAM_H_ */
187