FreeBSD/Linux Kernel Cross Reference
sys/sys/param.h
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: releng/8.2/sys/sys/param.h 216639 2010-12-22 04:51:05Z kensmith $
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 802000 /* 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 * MAXLOGNAME should be == UT_NAMESIZE+1 (see <utmp.h>)
78 */
79 #include <sys/syslimits.h>
80
81 #define MAXCOMLEN 19 /* max command name remembered */
82 #define MAXINTERP 32 /* max interpreter file name length */
83 #define MAXLOGNAME 17 /* max login name length (incl. NUL) */
84 #define MAXUPRC CHILD_MAX /* max simultaneous processes */
85 #define NCARGS ARG_MAX /* max bytes for an exec function */
86 #define NGROUPS (NGROUPS_MAX+1) /* max number groups */
87 #define NOFILE OPEN_MAX /* max open files per process */
88 #define NOGROUP 65535 /* marker for empty group set member */
89 #define MAXHOSTNAMELEN 256 /* max hostname size */
90 #define SPECNAMELEN 63 /* max length of devicename */
91
92 /* More types and definitions used throughout the kernel. */
93 #ifdef _KERNEL
94 #include <sys/cdefs.h>
95 #include <sys/errno.h>
96 #ifndef LOCORE
97 #include <sys/time.h>
98 #include <sys/priority.h>
99 #endif
100
101 #ifndef FALSE
102 #define FALSE 0
103 #endif
104 #ifndef TRUE
105 #define TRUE 1
106 #endif
107 #endif
108
109 #ifndef _KERNEL
110 /* Signals. */
111 #include <sys/signal.h>
112 #endif
113
114 /* Machine type dependent parameters. */
115 #include <machine/param.h>
116 #ifndef _KERNEL
117 #include <sys/limits.h>
118 #endif
119
120 #ifndef _NO_NAMESPACE_POLLUTION
121
122 #ifndef DEV_BSHIFT
123 #define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */
124 #endif
125 #define DEV_BSIZE (1<<DEV_BSHIFT)
126
127 #ifndef BLKDEV_IOSIZE
128 #define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */
129 #endif
130 #ifndef DFLTPHYS
131 #define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */
132 #endif
133 #ifndef MAXPHYS
134 #define MAXPHYS (128 * 1024) /* max raw I/O transfer size */
135 #endif
136 #ifndef MAXDUMPPGS
137 #define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE)
138 #endif
139
140 /*
141 * Constants related to network buffer management.
142 * MCLBYTES must be no larger than PAGE_SIZE.
143 */
144 #ifndef MSIZE
145 #define MSIZE 256 /* size of an mbuf */
146 #endif /* MSIZE */
147
148 #ifndef MCLSHIFT
149 #define MCLSHIFT 11 /* convert bytes to mbuf clusters */
150 #endif /* MCLSHIFT */
151
152 #define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */
153
154 #define MJUMPAGESIZE PAGE_SIZE /* jumbo cluster 4k */
155 #define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */
156 #define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */
157
158 /*
159 * Some macros for units conversion
160 */
161
162 /* clicks to bytes */
163 #ifndef ctob
164 #define ctob(x) ((x)<<PAGE_SHIFT)
165 #endif
166
167 /* bytes to clicks */
168 #ifndef btoc
169 #define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
170 #endif
171
172 /*
173 * btodb() is messy and perhaps slow because `bytes' may be an off_t. We
174 * want to shift an unsigned type to avoid sign extension and we don't
175 * want to widen `bytes' unnecessarily. Assume that the result fits in
176 * a daddr_t.
177 */
178 #ifndef btodb
179 #define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \
180 (sizeof (bytes) > sizeof(long) \
181 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
182 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
183 #endif
184
185 #ifndef dbtob
186 #define dbtob(db) /* calculates (db * DEV_BSIZE) */ \
187 ((off_t)(db) << DEV_BSHIFT)
188 #endif
189
190 #endif /* _NO_NAMESPACE_POLLUTION */
191
192 #define PRIMASK 0x0ff
193 #define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */
194 #define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */
195 #define PBDRY 0x400 /* for PCATCH stop is done on the user boundary */
196
197 #define NZERO 0 /* default "nice" */
198
199 #define NBBY 8 /* number of bits in a byte */
200 #define NBPW sizeof(int) /* number of bytes per word (integer) */
201
202 #define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
203
204 #define NODEV (dev_t)(-1) /* non-existent device */
205
206 /*
207 * File system parameters and macros.
208 *
209 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes
210 * per block. MAXBSIZE may be made larger without effecting
211 * any existing filesystems as long as it does not exceed MAXPHYS,
212 * and may be made smaller at the risk of not being able to use
213 * filesystems which require a block size exceeding MAXBSIZE.
214 *
215 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the
216 * minimum KVM memory reservation the kernel is willing to make.
217 * Filesystems can of course request smaller chunks. Actual
218 * backing memory uses a chunk size of a page (PAGE_SIZE).
219 *
220 * If you make BKVASIZE too small you risk seriously fragmenting
221 * the buffer KVM map which may slow things down a bit. If you
222 * make it too big the kernel will not be able to optimally use
223 * the KVM memory reserved for the buffer cache and will wind
224 * up with too-few buffers.
225 *
226 * The default is 16384, roughly 2x the block size used by a
227 * normal UFS filesystem.
228 */
229 #define MAXBSIZE 65536 /* must be power of 2 */
230 #define BKVASIZE 16384 /* must be power of 2 */
231 #define BKVAMASK (BKVASIZE-1)
232
233 /*
234 * MAXPATHLEN defines the longest permissible path length after expanding
235 * symbolic links. It is used to allocate a temporary buffer from the buffer
236 * pool in which to do the name expansion, hence should be a power of two,
237 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the
238 * maximum number of symbolic links that may be expanded in a path name.
239 * It should be set high enough to allow all legitimate uses, but halt
240 * infinite loops reasonably quickly.
241 */
242 #define MAXPATHLEN PATH_MAX
243 #define MAXSYMLINKS 32
244
245 /* Bit map related macros. */
246 #define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
247 #define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
248 #define isset(a,i) \
249 (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
250 #define isclr(a,i) \
251 ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
252
253 /* Macros for counting and rounding. */
254 #ifndef howmany
255 #define howmany(x, y) (((x)+((y)-1))/(y))
256 #endif
257 #define rounddown(x, y) (((x)/(y))*(y))
258 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
259 #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
260 #define powerof2(x) ((((x)-1)&(x))==0)
261
262 /* Macros for min/max. */
263 #define MIN(a,b) (((a)<(b))?(a):(b))
264 #define MAX(a,b) (((a)>(b))?(a):(b))
265
266 #ifdef _KERNEL
267 /*
268 * Basic byte order function prototypes for non-inline functions.
269 */
270 #ifndef LOCORE
271 #ifndef _BYTEORDER_PROTOTYPED
272 #define _BYTEORDER_PROTOTYPED
273 __BEGIN_DECLS
274 __uint32_t htonl(__uint32_t);
275 __uint16_t htons(__uint16_t);
276 __uint32_t ntohl(__uint32_t);
277 __uint16_t ntohs(__uint16_t);
278 __END_DECLS
279 #endif
280 #endif
281
282 #ifndef lint
283 #ifndef _BYTEORDER_FUNC_DEFINED
284 #define _BYTEORDER_FUNC_DEFINED
285 #define htonl(x) __htonl(x)
286 #define htons(x) __htons(x)
287 #define ntohl(x) __ntohl(x)
288 #define ntohs(x) __ntohs(x)
289 #endif /* !_BYTEORDER_FUNC_DEFINED */
290 #endif /* lint */
291 #endif /* _KERNEL */
292
293 /*
294 * Scale factor for scaled integers used to count %cpu time and load avgs.
295 *
296 * The number of CPU `tick's that map to a unique `%age' can be expressed
297 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
298 * can be calculated (assuming 32 bits) can be closely approximated using
299 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
300 *
301 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
302 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
303 */
304 #define FSHIFT 11 /* bits to right of fixed binary point */
305 #define FSCALE (1<<FSHIFT)
306
307 #define dbtoc(db) /* calculates devblks to pages */ \
308 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
309
310 #define ctodb(db) /* calculates pages to devblks */ \
311 ((db) << (PAGE_SHIFT - DEV_BSHIFT))
312
313 /*
314 * Given the pointer x to the member m of the struct s, return
315 * a pointer to the containing structure.
316 */
317 #define member2struct(s, m, x) \
318 ((struct s *)(void *)((char *)(x) - offsetof(struct s, m)))
319
320 #endif /* _SYS_PARAM_H_ */
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