xref: /illumos-gate/usr/src/boot/sys/sys/param.h (revision 55fea89d)
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 in the doc/ repository:
52  *
53  *	head/en_US.ISO8859-1/books/porters-handbook/versions/chapter.xml
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 1100100	/* Master, propagated to newvers */
62 
63 /*
64  * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,
65  * which by definition is always true on FreeBSD. This macro is also defined
66  * on other systems that use the kernel of FreeBSD, such as GNU/kFreeBSD.
67  *
68  * It is tempting to use this macro in userland code when we want to enable
69  * kernel-specific routines, and in fact it's fine to do this in code that
70  * is part of FreeBSD itself.  However, be aware that as presence of this
71  * macro is still not widespread (e.g. older FreeBSD versions, 3rd party
72  * compilers, etc), it is STRONGLY DISCOURAGED to check for this macro in
73  * external applications without also checking for __FreeBSD__ as an
74  * alternative.
75  */
76 #undef __FreeBSD_kernel__
77 #define __FreeBSD_kernel__
78 
79 #ifdef _KERNEL
80 #define	P_OSREL_SIGWAIT			700000
81 #define	P_OSREL_SIGSEGV			700004
82 #define	P_OSREL_MAP_ANON		800104
83 #define	P_OSREL_MAP_FSTRICT		1100036
84 #define	P_OSREL_SHUTDOWN_ENOTCONN	1100077
85 
86 #define	P_OSREL_MAJOR(x)		((x) / 100000)
87 #endif
88 
89 #ifndef LOCORE
90 #include <sys/types.h>
91 #endif
92 
93 /*
94  * Machine-independent constants (some used in following include files).
95  * Redefined constants are from POSIX 1003.1 limits file.
96  *
97  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
98  */
99 #include <sys/syslimits.h>
100 
101 #define	MAXCOMLEN	19		/* max command name remembered */
102 #define	MAXINTERP	PATH_MAX	/* max interpreter file name length */
103 #define	MAXLOGNAME	33		/* max login name length (incl. NUL) */
104 #define	MAXUPRC		CHILD_MAX	/* max simultaneous processes */
105 #define	NCARGS		ARG_MAX		/* max bytes for an exec function */
106 #define	NGROUPS		(NGROUPS_MAX+1)	/* max number groups */
107 #define	NOFILE		OPEN_MAX	/* max open files per process */
108 #define	NOGROUP		65535		/* marker for empty group set member */
109 #define MAXHOSTNAMELEN	256		/* max hostname size */
110 #define SPECNAMELEN	63		/* max length of devicename */
111 
112 /* More types and definitions used throughout the kernel. */
113 #ifdef _KERNEL
114 #include <sys/cdefs.h>
115 #include <sys/errno.h>
116 #ifndef LOCORE
117 #include <sys/time.h>
118 #include <sys/priority.h>
119 #endif
120 
121 #ifndef FALSE
122 #define	FALSE	0
123 #endif
124 #ifndef TRUE
125 #define	TRUE	1
126 #endif
127 #endif
128 
129 #ifndef _KERNEL
130 /* Signals. */
131 #include <sys/signal.h>
132 #endif
133 
134 /* Machine type dependent parameters. */
135 #include <machine/param.h>
136 #ifndef _KERNEL
137 #include <sys/limits.h>
138 #endif
139 
140 #ifndef DEV_BSHIFT
141 #define	DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
142 #endif
143 #define	DEV_BSIZE	(1<<DEV_BSHIFT)
144 
145 #ifndef BLKDEV_IOSIZE
146 #define BLKDEV_IOSIZE  PAGE_SIZE	/* default block device I/O size */
147 #endif
148 #ifndef DFLTPHYS
149 #define DFLTPHYS	(64 * 1024)	/* default max raw I/O transfer size */
150 #endif
151 #ifndef MAXPHYS
152 #define MAXPHYS		(128 * 1024)	/* max raw I/O transfer size */
153 #endif
154 #ifndef MAXDUMPPGS
155 #define MAXDUMPPGS	(DFLTPHYS/PAGE_SIZE)
156 #endif
157 
158 /*
159  * Constants related to network buffer management.
160  * MCLBYTES must be no larger than PAGE_SIZE.
161  */
162 #ifndef	MSIZE
163 #define	MSIZE		256		/* size of an mbuf */
164 #endif
165 
166 #ifndef	MCLSHIFT
167 #define MCLSHIFT	11		/* convert bytes to mbuf clusters */
168 #endif	/* MCLSHIFT */
169 
170 #define MCLBYTES	(1 << MCLSHIFT)	/* size of an mbuf cluster */
171 
172 #if PAGE_SIZE < 2048
173 #define	MJUMPAGESIZE	MCLBYTES
174 #elif PAGE_SIZE <= 8192
175 #define	MJUMPAGESIZE	PAGE_SIZE
176 #else
177 #define	MJUMPAGESIZE	(8 * 1024)
178 #endif
179 
180 #define	MJUM9BYTES	(9 * 1024)	/* jumbo cluster 9k */
181 #define	MJUM16BYTES	(16 * 1024)	/* jumbo cluster 16k */
182 
183 /*
184  * Some macros for units conversion
185  */
186 
187 /* clicks to bytes */
188 #ifndef ctob
189 #define ctob(x)	((x)<<PAGE_SHIFT)
190 #endif
191 
192 /* bytes to clicks */
193 #ifndef btoc
194 #define btoc(x)	(((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
195 #endif
196 
197 /*
198  * btodb() is messy and perhaps slow because `bytes' may be an off_t.  We
199  * want to shift an unsigned type to avoid sign extension and we don't
200  * want to widen `bytes' unnecessarily.  Assume that the result fits in
201  * a daddr_t.
202  */
203 #ifndef btodb
204 #define btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
205 	(sizeof (bytes) > sizeof(long) \
206 	 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
207 	 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
208 #endif
209 
210 #ifndef dbtob
211 #define dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
212 	((off_t)(db) << DEV_BSHIFT)
213 #endif
214 
215 #define	PRIMASK	0x0ff
216 #define	PCATCH	0x100		/* OR'd with pri for tsleep to check signals */
217 #define	PDROP	0x200	/* OR'd with pri to stop re-entry of interlock mutex */
218 
219 #define	NZERO	0		/* default "nice" */
220 
221 #define	NBBY	8		/* number of bits in a byte */
222 #define	NBPW	sizeof(int)	/* number of bytes per word (integer) */
223 
224 #define	CMASK	022		/* default file mask: S_IWGRP|S_IWOTH */
225 
226 #define	NODEV	(dev_t)(-1)	/* non-existent device */
227 
228 /*
229  * File system parameters and macros.
230  *
231  * MAXBSIZE -	Filesystems are made out of blocks of at most MAXBSIZE bytes
232  *		per block.  MAXBSIZE may be made larger without effecting
233  *		any existing filesystems as long as it does not exceed MAXPHYS,
234  *		and may be made smaller at the risk of not being able to use
235  *		filesystems which require a block size exceeding MAXBSIZE.
236  *
237  * MAXBCACHEBUF - Maximum size of a buffer in the buffer cache.  This must
238  *		be >= MAXBSIZE and can be set differently for different
239  *		architectures by defining it in <machine/param.h>.
240  *		Making this larger allows NFS to do larger reads/writes.
241  *
242  * BKVASIZE -	Nominal buffer space per buffer, in bytes.  BKVASIZE is the
243  *		minimum KVM memory reservation the kernel is willing to make.
244  *		Filesystems can of course request smaller chunks.  Actual
245  *		backing memory uses a chunk size of a page (PAGE_SIZE).
246  *		The default value here can be overridden on a per-architecture
247  *		basis by defining it in <machine/param.h>.  This should
248  *		probably be done to increase its value, when MAXBCACHEBUF is
249  *		defined as a larger value in <machine/param.h>.
250  *
251  *		If you make BKVASIZE too small you risk seriously fragmenting
252  *		the buffer KVM map which may slow things down a bit.  If you
253  *		make it too big the kernel will not be able to optimally use
254  *		the KVM memory reserved for the buffer cache and will wind
255  *		up with too-few buffers.
256  *
257  *		The default is 16384, roughly 2x the block size used by a
258  *		normal UFS filesystem.
259  */
260 #define MAXBSIZE	65536	/* must be power of 2 */
261 #ifndef	MAXBCACHEBUF
262 #define	MAXBCACHEBUF	MAXBSIZE /* must be a power of 2 >= MAXBSIZE */
263 #endif
264 #ifndef	BKVASIZE
265 #define BKVASIZE	16384	/* must be power of 2 */
266 #endif
267 #define BKVAMASK	(BKVASIZE-1)
268 
269 /*
270  * MAXPATHLEN defines the longest permissible path length after expanding
271  * symbolic links. It is used to allocate a temporary buffer from the buffer
272  * pool in which to do the name expansion, hence should be a power of two,
273  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
274  * maximum number of symbolic links that may be expanded in a path name.
275  * It should be set high enough to allow all legitimate uses, but halt
276  * infinite loops reasonably quickly.
277  */
278 #define	MAXPATHLEN	PATH_MAX
279 #define MAXSYMLINKS	32
280 
281 /* Bit map related macros. */
282 #define	setbit(a,i)	(((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
283 #define	clrbit(a,i)	(((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
284 #define	isset(a,i)							\
285 	(((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
286 #define	isclr(a,i)							\
287 	((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
288 
289 /* Macros for counting and rounding. */
290 #ifndef howmany
291 #define	howmany(x, y)	(((x)+((y)-1))/(y))
292 #endif
293 #define	nitems(x)	(sizeof((x)) / sizeof((x)[0]))
294 #define	rounddown(x, y)	(((x)/(y))*(y))
295 #define	rounddown2(x, y) ((x)&(~((y)-1)))          /* if y is power of two */
296 #define	roundup(x, y)	((((x)+((y)-1))/(y))*(y))  /* to any y */
297 #define	roundup2(x, y)	(((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
298 #define powerof2(x)	((((x)-1)&(x))==0)
299 
300 /* Macros for min/max. */
301 #define	MIN(a,b) (((a)<(b))?(a):(b))
302 #define	MAX(a,b) (((a)>(b))?(a):(b))
303 
304 #ifdef _KERNEL
305 /*
306  * Basic byte order function prototypes for non-inline functions.
307  */
308 #ifndef LOCORE
309 #ifndef _BYTEORDER_PROTOTYPED
310 #define	_BYTEORDER_PROTOTYPED
311 __BEGIN_DECLS
312 __uint32_t	 htonl(__uint32_t);
313 __uint16_t	 htons(__uint16_t);
314 __uint32_t	 ntohl(__uint32_t);
315 __uint16_t	 ntohs(__uint16_t);
316 __END_DECLS
317 #endif
318 #endif
319 
320 #ifndef lint
321 #ifndef _BYTEORDER_FUNC_DEFINED
322 #define	_BYTEORDER_FUNC_DEFINED
323 #define	htonl(x)	__htonl(x)
324 #define	htons(x)	__htons(x)
325 #define	ntohl(x)	__ntohl(x)
326 #define	ntohs(x)	__ntohs(x)
327 #endif /* !_BYTEORDER_FUNC_DEFINED */
328 #endif /* lint */
329 #endif /* _KERNEL */
330 
331 /*
332  * Scale factor for scaled integers used to count %cpu time and load avgs.
333  *
334  * The number of CPU `tick's that map to a unique `%age' can be expressed
335  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
336  * can be calculated (assuming 32 bits) can be closely approximated using
337  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
338  *
339  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
340  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
341  */
342 #define	FSHIFT	11		/* bits to right of fixed binary point */
343 #define FSCALE	(1<<FSHIFT)
344 
345 #define dbtoc(db)			/* calculates devblks to pages */ \
346 	((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
347 
348 #define ctodb(db)			/* calculates pages to devblks */ \
349 	((db) << (PAGE_SHIFT - DEV_BSHIFT))
350 
351 /*
352  * Old spelling of __containerof().
353  */
354 #define	member2struct(s, m, x)						\
355 	((struct s *)(void *)((char *)(x) - offsetof(struct s, m)))
356 
357 /*
358  * Access a variable length array that has been declared as a fixed
359  * length array.
360  */
361 #define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset])
362 
363 #endif	/* _SYS_PARAM_H_ */
364