xref: /freebsd/sys/i386/include/param.h (revision 75d23f5f)
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 1.33 1997/08/09 00:03:16 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 #ifdef SMP
49 #define NCPUS		2
50 #else
51 #define NCPUS		1
52 #endif
53 #define MID_MACHINE	MID_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 unsigned int
58  * and must be cast to any desired pointer type.
59  */
60 #define ALIGNBYTES	(sizeof(int) - 1)
61 #define ALIGN(p)	(((unsigned)(p) + ALIGNBYTES) & ~ALIGNBYTES)
62 
63 #define PAGE_SHIFT	12		/* LOG2(PAGE_SIZE) */
64 #define PAGE_SIZE	(1<<PAGE_SHIFT)	/* bytes/page */
65 #define PAGE_MASK	(PAGE_SIZE-1)
66 #define NPTEPG		(PAGE_SIZE/(sizeof (pt_entry_t)))
67 
68 #define NPDEPG		(PAGE_SIZE/(sizeof (pd_entry_t)))
69 #define PDRSHIFT	22		/* LOG2(NBPDR) */
70 #define NBPDR		(1<<PDRSHIFT)	/* bytes/page dir */
71 #define PDRMASK		(NBPDR-1)
72 
73 #define DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
74 #define DEV_BSIZE	(1<<DEV_BSHIFT)
75 
76 #define BLKDEV_IOSIZE	2048
77 #define MAXPHYS		(64 * 1024)	/* max raw I/O transfer size */
78 
79 #define IOPAGES	2		/* pages of i/o permission bitmap */
80 #define UPAGES	2		/* pages of u-area */
81 #define UPAGES_HOLE	2	/* pages of "hole" at top of user space where */
82 				/* the upages used to be. DO NOT CHANGE! */
83 
84 /*
85  * Constants related to network buffer management.
86  * MCLBYTES must be no larger than CLBYTES (the software page size), and,
87  * on machines that exchange pages of input or output buffers with mbuf
88  * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
89  * of the hardware page size.
90  */
91 #ifndef	MSIZE
92 #define MSIZE		128		/* size of an mbuf */
93 #endif	/* MSIZE */
94 
95 #ifndef	MCLSHIFT
96 #define MCLSHIFT	11		/* convert bytes to m_buf clusters */
97 #endif	/* MCLSHIFT */
98 #define MCLBYTES	(1 << MCLSHIFT)	/* size of an m_buf cluster */
99 #define MCLOFSET	(MCLBYTES - 1)	/* offset within an m_buf cluster */
100 
101 /*
102  * Some macros for units conversion
103  */
104 
105 /* clicks to bytes */
106 #define ctob(x)	((x)<<PAGE_SHIFT)
107 
108 /* bytes to clicks */
109 #define btoc(x)	(((unsigned)(x)+PAGE_MASK)>>PAGE_SHIFT)
110 
111 /*
112  * btodb() is messy and perhaps slow because `bytes' may be an off_t.  We
113  * want to shift an unsigned type to avoid sign extension and we don't
114  * want to widen `bytes' unnecessarily.  Assume that the result fits in
115  * a daddr_t.
116  */
117 #define btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
118 	(sizeof (bytes) > sizeof(long) \
119 	 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
120 	 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
121 
122 #define dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
123 	((off_t)(db) << DEV_BSHIFT)
124 
125 /*
126  * Mach derived conversion macros
127  */
128 #define trunc_page(x)		((unsigned)(x) & ~PAGE_MASK)
129 #define round_page(x)		((((unsigned)(x)) + PAGE_MASK) & ~PAGE_MASK)
130 #define trunc_4mpage(x)		((unsigned)(x) & ~PDRMASK)
131 #define round_4mpage(x)		((((unsigned)(x)) + PDRMASK) & ~PDRMASK)
132 
133 #define atop(x)			((unsigned)(x) >> PAGE_SHIFT)
134 #define ptoa(x)			((unsigned)(x) << PAGE_SHIFT)
135 
136 #define i386_btop(x)		((unsigned)(x) >> PAGE_SHIFT)
137 #define i386_ptob(x)		((unsigned)(x) << PAGE_SHIFT)
138 
139 #ifndef _SIMPLELOCK_H_
140 #define _SIMPLELOCK_H_
141 /*
142  * A simple spin lock.
143  *
144  * This structure only sets one bit of data, but is sized based on the
145  * minimum word size that can be operated on by the hardware test-and-set
146  * instruction. It is only needed for multiprocessors, as uniprocessors
147  * will always run to completion or a sleep. It is an error to hold one
148  * of these locks while a process is sleeping.
149  */
150 struct simplelock {
151 	volatile int	lock_data;
152 };
153 
154 #if !defined(SIMPLELOCK_DEBUG) && NCPUS > 1
155 /*
156  * The simple-lock routines are the primitives out of which the lock
157  * package is built. The machine-dependent code must implement an
158  * atomic test_and_set operation that indivisibly sets the simple lock
159  * to non-zero and returns its old value. It also assumes that the
160  * setting of the lock to zero below is indivisible. Simple locks may
161  * only be used for exclusive locks.
162  */
163 
164 #ifdef the_original_code
165 
166 static __inline void
167 simple_lock_init(struct simplelock *lkp)
168 {
169 
170 	lkp->lock_data = 0;
171 }
172 
173 static __inline void
174 simple_lock(struct simplelock *lkp)
175 {
176 
177 	while (test_and_set(&lkp->lock_data))
178 		continue;
179 }
180 
181 static __inline int
182 simple_lock_try(struct simplelock *lkp)
183 {
184 
185 	return (!test_and_set(&lkp->lock_data));
186 }
187 
188 static __inline void
189 simple_unlock(struct simplelock *lkp)
190 {
191 
192 	lkp->lock_data = 0;
193 }
194 
195 #else /* the_original_code */
196 
197 /*
198  * This set of defines turns on the real functions in i386/isa/apic_ipl.s.
199  * It has never actually been tested.
200  */
201 #define	simple_lock_init(alp)	s_lock_init(alp)
202 #define	simple_lock(alp)	s_lock(alp)
203 #define	simple_lock_try(alp)	s_lock_try(alp)
204 #define	simple_unlock(alp)	s_unlock(alp)
205 
206 #endif /* the_original_code */
207 
208 #endif /* NCPUS > 1 */
209 #endif /* !_SIMPLELOCK_H_ */
210 
211 #endif /* !_MACHINE_PARAM_H_ */
212