xref: /original-bsd/sys/i386/include/param.h (revision 0ac4996f)
1 /*-
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * William Jolitz.
7  *
8  * %sccs.include.redist.c%
9  *
10  *	@(#)param.h	8.3 (Berkeley) 05/14/95
11  */
12 
13 /*
14  * Machine dependent constants for Intel 386.
15  */
16 
17 #define MACHINE "i386"
18 #define NCPUS 1
19 
20 /*
21  * Round p (pointer or byte index) up to a correctly-aligned value for all
22  * data types (int, long, ...).   The result is u_int and must be cast to
23  * any desired pointer type.
24  */
25 #define	ALIGNBYTES	3
26 #define	ALIGN(p)	(((u_int)(p) + ALIGNBYTES) &~ ALIGNBYTES)
27 
28 #define	NBPG		4096		/* bytes/page */
29 #define	PGOFSET		(NBPG-1)	/* byte offset into page */
30 #define	PGSHIFT		12		/* LOG2(NBPG) */
31 #define	NPTEPG		(NBPG/(sizeof (struct pte)))
32 
33 #define NBPDR		(1024*NBPG)	/* bytes/page dir */
34 #define	PDROFSET	(NBPDR-1)	/* byte offset into page dir */
35 #define	PDRSHIFT	22		/* LOG2(NBPDR) */
36 
37 #define	KERNBASE	0xFE000000	/* start of kernel virtual */
38 #define	BTOPKERNBASE	((u_long)KERNBASE >> PGSHIFT)
39 
40 #define	DEV_BSIZE	512
41 #define	DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
42 #define BLKDEV_IOSIZE	2048
43 #define	MAXPHYS		(64 * 1024)	/* max raw I/O transfer size */
44 
45 #define	CLSIZE		1
46 #define	CLSIZELOG2	0
47 
48 /* NOTE: SSIZE, SINCR and UPAGES must be multiples of CLSIZE */
49 #define	SSIZE	1		/* initial stack size/NBPG */
50 #define	SINCR	1		/* increment of stack/NBPG */
51 
52 #define	UPAGES	2		/* pages of u-area */
53 
54 /*
55  * Constants related to network buffer management.
56  * MCLBYTES must be no larger than CLBYTES (the software page size), and,
57  * on machines that exchange pages of input or output buffers with mbuf
58  * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
59  * of the hardware page size.
60  */
61 #define	MSIZE		128		/* size of an mbuf */
62 #define	MCLBYTES	1024
63 #define	MCLSHIFT	10
64 #define	MCLOFSET	(MCLBYTES - 1)
65 #ifndef NMBCLUSTERS
66 #ifdef GATEWAY
67 #define	NMBCLUSTERS	512		/* map size, max cluster allocation */
68 #else
69 #define	NMBCLUSTERS	256		/* map size, max cluster allocation */
70 #endif
71 #endif
72 
73 /*
74  * Size of kernel malloc arena in CLBYTES-sized logical pages
75  */
76 #ifndef NKMEMCLUSTERS
77 #define	NKMEMCLUSTERS	(2048*1024/CLBYTES)
78 #endif
79 /*
80  * Some macros for units conversion
81  */
82 /* Core clicks (4096 bytes) to segments and vice versa */
83 #define	ctos(x)	(x)
84 #define	stoc(x)	(x)
85 
86 /* Core clicks (4096 bytes) to disk blocks */
87 #define	ctod(x)	((x)<<(PGSHIFT-DEV_BSHIFT))
88 #define	dtoc(x)	((x)>>(PGSHIFT-DEV_BSHIFT))
89 #define	dtob(x)	((x)<<DEV_BSHIFT)
90 
91 /* clicks to bytes */
92 #define	ctob(x)	((x)<<PGSHIFT)
93 
94 /* bytes to clicks */
95 #define	btoc(x)	(((unsigned)(x)+(NBPG-1))>>PGSHIFT)
96 
97 #define	btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
98 	((bytes) >> DEV_BSHIFT)
99 #define	dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
100 	((db) << DEV_BSHIFT)
101 
102 /*
103  * Map a ``block device block'' to a file system block.
104  * This should be device dependent, and will be if we
105  * add an entry to cdevsw/bdevsw for that purpose.
106  * For now though just use DEV_BSIZE.
107  */
108 #define	bdbtofsb(bn)	((bn) / (BLKDEV_IOSIZE/DEV_BSIZE))
109 
110 /*
111  * Mach derived conversion macros
112  */
113 #define i386_round_pdr(x)	((((unsigned)(x)) + NBPDR - 1) & ~(NBPDR-1))
114 #define i386_trunc_pdr(x)	((unsigned)(x) & ~(NBPDR-1))
115 #define i386_round_page(x)	((((unsigned)(x)) + NBPG - 1) & ~(NBPG-1))
116 #define i386_trunc_page(x)	((unsigned)(x) & ~(NBPG-1))
117 #define i386_btod(x)		((unsigned)(x) >> PDRSHIFT)
118 #define i386_dtob(x)		((unsigned)(x) << PDRSHIFT)
119 #define i386_btop(x)		((unsigned)(x) >> PGSHIFT)
120 #define i386_ptob(x)		((unsigned)(x) << PGSHIFT)
121 
122 #ifndef KERNEL
123 /* DELAY is in locore.s for the kernel */
124 #define	DELAY(n)	{ register int N = (n); while (--N > 0); }
125 #endif
126 
127 #ifndef _SIMPLELOCK_H_
128 #define _SIMPLELOCK_H_
129 /*
130  * A simple spin lock.
131  *
132  * This structure only sets one bit of data, but is sized based on the
133  * minimum word size that can be operated on by the hardware test-and-set
134  * instruction. It is only needed for multiprocessors, as uniprocessors
135  * will always run to completion or a sleep. It is an error to hold one
136  * of these locks while a process is sleeping.
137  */
138 struct simplelock {
139 	int	lock_data;
140 };
141 
142 #if !defined(DEBUG) && NCPUS > 1
143 /*
144  * The simple-lock routines are the primitives out of which the lock
145  * package is built. The machine-dependent code must implement an
146  * atomic test_and_set operation that indivisibly sets the simple lock
147  * to non-zero and returns its old value. It also assumes that the
148  * setting of the lock to zero below is indivisible. Simple locks may
149  * only be used for exclusive locks.
150  */
151 static __inline void
152 simple_lock_init(lkp)
153 	struct simplelock *lkp;
154 {
155 
156 	lkp->lock_data = 0;
157 }
158 
159 static __inline void
160 simple_lock(lkp)
161 	__volatile struct simplelock *lkp;
162 {
163 
164 	while (test_and_set(&lkp->lock_data))
165 		continue;
166 }
167 
168 static __inline int
169 simple_lock_try(lkp)
170 	__volatile struct simplelock *lkp;
171 {
172 
173 	return (!test_and_set(&lkp->lock_data))
174 }
175 
176 static __inline void
177 simple_unlock(lkp)
178 	__volatile struct simplelock *lkp;
179 {
180 
181 	lkp->lock_data = 0;
182 }
183 #endif /* NCPUS > 1 */
184 #endif /* !_SIMPLELOCK_H_ */
185