xref: /freebsd/sys/sys/param.h (revision aa0a1e58)
1 /*-
2  * Copyright (c) 1982, 1986, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * (c) UNIX System Laboratories, Inc.
5  * All or some portions of this file are derived from material licensed
6  * to the University of California by American Telephone and Telegraph
7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8  * the permission of UNIX System Laboratories, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)param.h	8.3 (Berkeley) 4/4/95
35  * $FreeBSD$
36  */
37 
38 #ifndef _SYS_PARAM_H_
39 #define _SYS_PARAM_H_
40 
41 #include <sys/_null.h>
42 
43 #define	BSD	199506		/* System version (year & month). */
44 #define BSD4_3	1
45 #define BSD4_4	1
46 
47 /*
48  * __FreeBSD_version numbers are documented in the Porter's Handbook.
49  * If you bump the version for any reason, you should update the documentation
50  * there.
51  * Currently this lives here:
52  *
53  *	doc/en_US.ISO8859-1/books/porters-handbook/book.sgml
54  *
55  * scheme is:  <major><two digit minor>Rxx
56  *		'R' is in the range 0 to 4 if this is a release branch or
57  *		x.0-CURRENT before RELENG_*_0 is created, otherwise 'R' is
58  *		in the range 5 to 9.
59  */
60 #undef __FreeBSD_version
61 #define __FreeBSD_version 900034	/* Master, propagated to newvers */
62 
63 #ifdef _KERNEL
64 #define	P_OSREL_SIGSEGV		700004
65 #define	P_OSREL_MAP_ANON	800104
66 #endif
67 
68 #ifndef LOCORE
69 #include <sys/types.h>
70 #endif
71 
72 /*
73  * Machine-independent constants (some used in following include files).
74  * Redefined constants are from POSIX 1003.1 limits file.
75  *
76  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
77  */
78 #include <sys/syslimits.h>
79 
80 #define	MAXCOMLEN	19		/* max command name remembered */
81 #define	MAXINTERP	PATH_MAX	/* max interpreter file name length */
82 #define	MAXLOGNAME	17		/* max login name length (incl. NUL) */
83 #define	MAXUPRC		CHILD_MAX	/* max simultaneous processes */
84 #define	NCARGS		ARG_MAX		/* max bytes for an exec function */
85 #define	NGROUPS		(NGROUPS_MAX+1)	/* max number groups */
86 #define	NOFILE		OPEN_MAX	/* max open files per process */
87 #define	NOGROUP		65535		/* marker for empty group set member */
88 #define MAXHOSTNAMELEN	256		/* max hostname size */
89 #define SPECNAMELEN	63		/* max length of devicename */
90 
91 /* More types and definitions used throughout the kernel. */
92 #ifdef _KERNEL
93 #include <sys/cdefs.h>
94 #include <sys/errno.h>
95 #ifndef LOCORE
96 #include <sys/time.h>
97 #include <sys/priority.h>
98 #endif
99 
100 #ifndef FALSE
101 #define	FALSE	0
102 #endif
103 #ifndef TRUE
104 #define	TRUE	1
105 #endif
106 #endif
107 
108 #ifndef _KERNEL
109 /* Signals. */
110 #include <sys/signal.h>
111 #endif
112 
113 /* Machine type dependent parameters. */
114 #include <machine/param.h>
115 #ifndef _KERNEL
116 #include <sys/limits.h>
117 #endif
118 
119 #ifndef DEV_BSHIFT
120 #define	DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
121 #endif
122 #define	DEV_BSIZE	(1<<DEV_BSHIFT)
123 
124 #ifndef BLKDEV_IOSIZE
125 #define BLKDEV_IOSIZE  PAGE_SIZE	/* default block device I/O size */
126 #endif
127 #ifndef DFLTPHYS
128 #define DFLTPHYS	(64 * 1024)	/* default max raw I/O transfer size */
129 #endif
130 #ifndef MAXPHYS
131 #define MAXPHYS		(128 * 1024)	/* max raw I/O transfer size */
132 #endif
133 #ifndef MAXDUMPPGS
134 #define MAXDUMPPGS	(DFLTPHYS/PAGE_SIZE)
135 #endif
136 
137 /*
138  * Constants related to network buffer management.
139  * MCLBYTES must be no larger than PAGE_SIZE.
140  */
141 #ifndef	MSIZE
142 #define MSIZE		256		/* size of an mbuf */
143 #endif	/* MSIZE */
144 
145 #ifndef	MCLSHIFT
146 #define MCLSHIFT	11		/* convert bytes to mbuf clusters */
147 #endif	/* MCLSHIFT */
148 
149 #define MCLBYTES	(1 << MCLSHIFT)	/* size of an mbuf cluster */
150 
151 #if PAGE_SIZE < 2048
152 #define	MJUMPAGESIZE	MCLBYTES
153 #elif PAGE_SIZE <= 8192
154 #define	MJUMPAGESIZE	PAGE_SIZE
155 #else
156 #define	MJUMPAGESIZE	(8 * 1024)
157 #endif
158 
159 #define	MJUM9BYTES	(9 * 1024)	/* jumbo cluster 9k */
160 #define	MJUM16BYTES	(16 * 1024)	/* jumbo cluster 16k */
161 
162 /*
163  * Some macros for units conversion
164  */
165 
166 /* clicks to bytes */
167 #ifndef ctob
168 #define ctob(x)	((x)<<PAGE_SHIFT)
169 #endif
170 
171 /* bytes to clicks */
172 #ifndef btoc
173 #define btoc(x)	(((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
174 #endif
175 
176 /*
177  * btodb() is messy and perhaps slow because `bytes' may be an off_t.  We
178  * want to shift an unsigned type to avoid sign extension and we don't
179  * want to widen `bytes' unnecessarily.  Assume that the result fits in
180  * a daddr_t.
181  */
182 #ifndef btodb
183 #define btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
184 	(sizeof (bytes) > sizeof(long) \
185 	 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
186 	 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
187 #endif
188 
189 #ifndef dbtob
190 #define dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
191 	((off_t)(db) << DEV_BSHIFT)
192 #endif
193 
194 #define	PRIMASK	0x0ff
195 #define	PCATCH	0x100		/* OR'd with pri for tsleep to check signals */
196 #define	PDROP	0x200	/* OR'd with pri to stop re-entry of interlock mutex */
197 #define	PBDRY	0x400	/* for PCATCH stop is done on the user boundary */
198 
199 #define	NZERO	0		/* default "nice" */
200 
201 #define	NBBY	8		/* number of bits in a byte */
202 #define	NBPW	sizeof(int)	/* number of bytes per word (integer) */
203 
204 #define	CMASK	022		/* default file mask: S_IWGRP|S_IWOTH */
205 
206 #define	NODEV	(dev_t)(-1)	/* non-existent device */
207 
208 /*
209  * File system parameters and macros.
210  *
211  * MAXBSIZE -	Filesystems are made out of blocks of at most MAXBSIZE bytes
212  *		per block.  MAXBSIZE may be made larger without effecting
213  *		any existing filesystems as long as it does not exceed MAXPHYS,
214  *		and may be made smaller at the risk of not being able to use
215  *		filesystems which require a block size exceeding MAXBSIZE.
216  *
217  * BKVASIZE -	Nominal buffer space per buffer, in bytes.  BKVASIZE is the
218  *		minimum KVM memory reservation the kernel is willing to make.
219  *		Filesystems can of course request smaller chunks.  Actual
220  *		backing memory uses a chunk size of a page (PAGE_SIZE).
221  *
222  *		If you make BKVASIZE too small you risk seriously fragmenting
223  *		the buffer KVM map which may slow things down a bit.  If you
224  *		make it too big the kernel will not be able to optimally use
225  *		the KVM memory reserved for the buffer cache and will wind
226  *		up with too-few buffers.
227  *
228  *		The default is 16384, roughly 2x the block size used by a
229  *		normal UFS filesystem.
230  */
231 #define MAXBSIZE	65536	/* must be power of 2 */
232 #define BKVASIZE	16384	/* must be power of 2 */
233 #define BKVAMASK	(BKVASIZE-1)
234 
235 /*
236  * MAXPATHLEN defines the longest permissible path length after expanding
237  * symbolic links. It is used to allocate a temporary buffer from the buffer
238  * pool in which to do the name expansion, hence should be a power of two,
239  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
240  * maximum number of symbolic links that may be expanded in a path name.
241  * It should be set high enough to allow all legitimate uses, but halt
242  * infinite loops reasonably quickly.
243  */
244 #define	MAXPATHLEN	PATH_MAX
245 #define MAXSYMLINKS	32
246 
247 /* Bit map related macros. */
248 #define	setbit(a,i)	(((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
249 #define	clrbit(a,i)	(((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
250 #define	isset(a,i)							\
251 	(((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
252 #define	isclr(a,i)							\
253 	((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
254 
255 /* Macros for counting and rounding. */
256 #ifndef howmany
257 #define	howmany(x, y)	(((x)+((y)-1))/(y))
258 #endif
259 #define	rounddown(x, y)	(((x)/(y))*(y))
260 #define	roundup(x, y)	((((x)+((y)-1))/(y))*(y))  /* to any y */
261 #define	roundup2(x, y)	(((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
262 #define powerof2(x)	((((x)-1)&(x))==0)
263 
264 /* Macros for min/max. */
265 #define	MIN(a,b) (((a)<(b))?(a):(b))
266 #define	MAX(a,b) (((a)>(b))?(a):(b))
267 
268 #ifdef _KERNEL
269 /*
270  * Basic byte order function prototypes for non-inline functions.
271  */
272 #ifndef LOCORE
273 #ifndef _BYTEORDER_PROTOTYPED
274 #define	_BYTEORDER_PROTOTYPED
275 __BEGIN_DECLS
276 __uint32_t	 htonl(__uint32_t);
277 __uint16_t	 htons(__uint16_t);
278 __uint32_t	 ntohl(__uint32_t);
279 __uint16_t	 ntohs(__uint16_t);
280 __END_DECLS
281 #endif
282 #endif
283 
284 #ifndef lint
285 #ifndef _BYTEORDER_FUNC_DEFINED
286 #define	_BYTEORDER_FUNC_DEFINED
287 #define	htonl(x)	__htonl(x)
288 #define	htons(x)	__htons(x)
289 #define	ntohl(x)	__ntohl(x)
290 #define	ntohs(x)	__ntohs(x)
291 #endif /* !_BYTEORDER_FUNC_DEFINED */
292 #endif /* lint */
293 #endif /* _KERNEL */
294 
295 /*
296  * Scale factor for scaled integers used to count %cpu time and load avgs.
297  *
298  * The number of CPU `tick's that map to a unique `%age' can be expressed
299  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
300  * can be calculated (assuming 32 bits) can be closely approximated using
301  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
302  *
303  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
304  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
305  */
306 #define	FSHIFT	11		/* bits to right of fixed binary point */
307 #define FSCALE	(1<<FSHIFT)
308 
309 #define dbtoc(db)			/* calculates devblks to pages */ \
310 	((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
311 
312 #define ctodb(db)			/* calculates pages to devblks */ \
313 	((db) << (PAGE_SHIFT - DEV_BSHIFT))
314 
315 /*
316  * Given the pointer x to the member m of the struct s, return
317  * a pointer to the containing structure.
318  */
319 #define	member2struct(s, m, x)						\
320 	((struct s *)(void *)((char *)(x) - offsetof(struct s, m)))
321 
322 #endif	/* _SYS_PARAM_H_ */
323