xref: /freebsd/sys/i386/include/param.h (revision ce834215a70ff69e7e222827437116eee2f9ac6f)
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 1.26 1997/02/22 09:34:54 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  */
142 struct 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  */
155 static __inline void
156 simple_lock_init(lkp)
157 	struct simplelock *lkp;
158 {
159 
160 	lkp->lock_data = 0;
161 }
162 
163 static __inline void
164 simple_lock(lkp)
165 	__volatile struct simplelock *lkp;
166 {
167 
168 	while (test_and_set(&lkp->lock_data))
169 		continue;
170 }
171 
172 static __inline int
173 simple_lock_try(lkp)
174 	__volatile struct simplelock *lkp;
175 {
176 
177 	return (!test_and_set(&lkp->lock_data))
178 }
179 
180 static __inline void
181 simple_unlock(lkp)
182 	__volatile struct simplelock *lkp;
183 {
184 
185 	lkp->lock_data = 0;
186 }
187 #endif /* NCPUS > 1 */
188 #endif /* !_SIMPLELOCK_H_ */
189 
190 #endif /* !_MACHINE_PARAM_H_ */
191