xref: /freebsd/sys/i386/include/param.h (revision 48a09cf2760da35e089ae3e2d56578b730fc7047)
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 1.32 1997/08/07 05:15:52 dyson 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 #define PDRMASK		(NBPDR-1)
68 
69 #define DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
70 #define DEV_BSIZE	(1<<DEV_BSHIFT)
71 
72 #define BLKDEV_IOSIZE	2048
73 #define MAXPHYS		(64 * 1024)	/* max raw I/O transfer size */
74 
75 #define IOPAGES	2		/* pages of i/o permission bitmap */
76 #define UPAGES	2		/* pages of u-area */
77 #define UPAGES_HOLE	2	/* pages of "hole" at top of user space where */
78 				/* the upages used to be. DO NOT CHANGE! */
79 
80 /*
81  * Constants related to network buffer management.
82  * MCLBYTES must be no larger than CLBYTES (the software page size), and,
83  * on machines that exchange pages of input or output buffers with mbuf
84  * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
85  * of the hardware page size.
86  */
87 #ifndef	MSIZE
88 #define MSIZE		128		/* size of an mbuf */
89 #endif	/* MSIZE */
90 
91 #ifndef	MCLSHIFT
92 #define MCLSHIFT	11		/* convert bytes to m_buf clusters */
93 #endif	/* MCLSHIFT */
94 #define MCLBYTES	(1 << MCLSHIFT)	/* size of an m_buf cluster */
95 #define MCLOFSET	(MCLBYTES - 1)	/* offset within an m_buf cluster */
96 
97 /*
98  * Some macros for units conversion
99  */
100 
101 /* clicks to bytes */
102 #define ctob(x)	((x)<<PAGE_SHIFT)
103 
104 /* bytes to clicks */
105 #define btoc(x)	(((unsigned)(x)+PAGE_MASK)>>PAGE_SHIFT)
106 
107 /*
108  * btodb() is messy and perhaps slow because `bytes' may be an off_t.  We
109  * want to shift an unsigned type to avoid sign extension and we don't
110  * want to widen `bytes' unnecessarily.  Assume that the result fits in
111  * a daddr_t.
112  */
113 #define btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
114 	(sizeof (bytes) > sizeof(long) \
115 	 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
116 	 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
117 
118 #define dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
119 	((off_t)(db) << DEV_BSHIFT)
120 
121 /*
122  * Mach derived conversion macros
123  */
124 #define trunc_page(x)		((unsigned)(x) & ~PAGE_MASK)
125 #define round_page(x)		((((unsigned)(x)) + PAGE_MASK) & ~PAGE_MASK)
126 #define trunc_4mpage(x)		((unsigned)(x) & ~PDRMASK)
127 #define round_4mpage(x)		((((unsigned)(x)) + PDRMASK) & ~PDRMASK)
128 
129 #define atop(x)			((unsigned)(x) >> PAGE_SHIFT)
130 #define ptoa(x)			((unsigned)(x) << PAGE_SHIFT)
131 
132 #define i386_btop(x)		((unsigned)(x) >> PAGE_SHIFT)
133 #define i386_ptob(x)		((unsigned)(x) << PAGE_SHIFT)
134 
135 #ifndef _SIMPLELOCK_H_
136 #define _SIMPLELOCK_H_
137 /*
138  * A simple spin lock.
139  *
140  * This structure only sets one bit of data, but is sized based on the
141  * minimum word size that can be operated on by the hardware test-and-set
142  * instruction. It is only needed for multiprocessors, as uniprocessors
143  * will always run to completion or a sleep. It is an error to hold one
144  * of these locks while a process is sleeping.
145  */
146 struct simplelock {
147 	volatile int	lock_data;
148 };
149 
150 #if !defined(SIMPLELOCK_DEBUG) && NCPUS > 1
151 /*
152  * The simple-lock routines are the primitives out of which the lock
153  * package is built. The machine-dependent code must implement an
154  * atomic test_and_set operation that indivisibly sets the simple lock
155  * to non-zero and returns its old value. It also assumes that the
156  * setting of the lock to zero below is indivisible. Simple locks may
157  * only be used for exclusive locks.
158  */
159 
160 #ifdef the_original_code
161 
162 static __inline void
163 simple_lock_init(struct simplelock *lkp)
164 {
165 
166 	lkp->lock_data = 0;
167 }
168 
169 static __inline void
170 simple_lock(struct simplelock *lkp)
171 {
172 
173 	while (test_and_set(&lkp->lock_data))
174 		continue;
175 }
176 
177 static __inline int
178 simple_lock_try(struct simplelock *lkp)
179 {
180 
181 	return (!test_and_set(&lkp->lock_data));
182 }
183 
184 static __inline void
185 simple_unlock(struct simplelock *lkp)
186 {
187 
188 	lkp->lock_data = 0;
189 }
190 
191 #else /* the_original_code */
192 
193 /*
194  * This set of defines turns on the real functions in i386/isa/apic_ipl.s.
195  * It has never actually been tested.
196  */
197 #define	simple_lock_init(alp)	s_lock_init(alp)
198 #define	simple_lock(alp)	s_lock(alp)
199 #define	simple_lock_try(alp)	s_lock_try(alp)
200 #define	simple_unlock(alp)	s_unlock(alp)
201 
202 #endif /* the_original_code */
203 
204 #endif /* NCPUS > 1 */
205 #endif /* !_SIMPLELOCK_H_ */
206 
207 #endif /* !_MACHINE_PARAM_H_ */
208