2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1982, 1986, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. 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.
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
36 * @(#)param.h 8.3 (Berkeley) 4/4/95
43 #include <sys/_null.h>
45 #define BSD 199506 /* System version (year & month). */
50 * __FreeBSD_version numbers are documented in the Porter's Handbook.
51 * If you bump the version for any reason, you should update the documentation
53 * Currently this lives here in the doc/ repository:
55 * head/en_US.ISO8859-1/books/porters-handbook/versions/chapter.xml
57 * scheme is: <major><two digit minor>Rxx
58 * 'R' is in the range 0 to 4 if this is a release branch or
59 * X.0-CURRENT before releng/X.0 is created, otherwise 'R' is
60 * in the range 5 to 9.
62 #undef __FreeBSD_version
63 #define __FreeBSD_version 1201525 /* Master, propagated to newvers */
66 * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,
67 * which by definition is always true on FreeBSD. This macro is also defined
68 * on other systems that use the kernel of FreeBSD, such as GNU/kFreeBSD.
70 * It is tempting to use this macro in userland code when we want to enable
71 * kernel-specific routines, and in fact it's fine to do this in code that
72 * is part of FreeBSD itself. However, be aware that as presence of this
73 * macro is still not widespread (e.g. older FreeBSD versions, 3rd party
74 * compilers, etc), it is STRONGLY DISCOURAGED to check for this macro in
75 * external applications without also checking for __FreeBSD__ as an
78 #undef __FreeBSD_kernel__
79 #define __FreeBSD_kernel__
81 #if defined(_KERNEL) || defined(IN_RTLD)
82 #define P_OSREL_SIGWAIT 700000
83 #define P_OSREL_SIGSEGV 700004
84 #define P_OSREL_MAP_ANON 800104
85 #define P_OSREL_MAP_FSTRICT 1100036
86 #define P_OSREL_SHUTDOWN_ENOTCONN 1100077
87 #define P_OSREL_MAP_GUARD 1200035
88 #define P_OSREL_WRFSBASE 1200041
89 #define P_OSREL_CK_CYLGRP 1200046
90 #define P_OSREL_VMTOTAL64 1200054
92 #define P_OSREL_MAJOR(x) ((x) / 100000)
96 #include <sys/types.h>
100 * Machine-independent constants (some used in following include files).
101 * Redefined constants are from POSIX 1003.1 limits file.
103 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
105 #include <sys/syslimits.h>
107 #define MAXCOMLEN 19 /* max command name remembered */
108 #define MAXINTERP PATH_MAX /* max interpreter file name length */
109 #define MAXLOGNAME 33 /* max login name length (incl. NUL) */
110 #define MAXUPRC CHILD_MAX /* max simultaneous processes */
111 #define NCARGS ARG_MAX /* max bytes for an exec function */
112 #define NGROUPS (NGROUPS_MAX+1) /* max number groups */
113 #define NOFILE OPEN_MAX /* max open files per process */
114 #define NOGROUP 65535 /* marker for empty group set member */
115 #define MAXHOSTNAMELEN 256 /* max hostname size */
116 #define SPECNAMELEN 63 /* max length of devicename */
118 /* More types and definitions used throughout the kernel. */
120 #include <sys/cdefs.h>
121 #include <sys/errno.h>
123 #include <sys/time.h>
124 #include <sys/priority.h>
137 #include <sys/signal.h>
140 /* Machine type dependent parameters. */
141 #include <machine/param.h>
143 #include <sys/limits.h>
147 #define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */
149 #define DEV_BSIZE (1<<DEV_BSHIFT)
151 #ifndef BLKDEV_IOSIZE
152 #define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */
155 #define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */
158 #define MAXPHYS (128 * 1024) /* max raw I/O transfer size */
161 #define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE)
165 * Constants related to network buffer management.
166 * MCLBYTES must be no larger than PAGE_SIZE.
169 #define MSIZE 256 /* size of an mbuf */
173 #define MCLSHIFT 11 /* convert bytes to mbuf clusters */
174 #endif /* MCLSHIFT */
176 #define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */
179 #define MJUMPAGESIZE MCLBYTES
180 #elif PAGE_SIZE <= 8192
181 #define MJUMPAGESIZE PAGE_SIZE
183 #define MJUMPAGESIZE (8 * 1024)
186 #define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */
187 #define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */
190 * Some macros for units conversion
193 /* clicks to bytes */
195 #define ctob(x) ((x)<<PAGE_SHIFT)
198 /* bytes to clicks */
200 #define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
204 * btodb() is messy and perhaps slow because `bytes' may be an off_t. We
205 * want to shift an unsigned type to avoid sign extension and we don't
206 * want to widen `bytes' unnecessarily. Assume that the result fits in
210 #define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \
211 (sizeof (bytes) > sizeof(long) \
212 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
213 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
217 #define dbtob(db) /* calculates (db * DEV_BSIZE) */ \
218 ((off_t)(db) << DEV_BSHIFT)
221 #define PRIMASK 0x0ff
222 #define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */
223 #define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */
225 #define NZERO 0 /* default "nice" */
227 #define NBBY 8 /* number of bits in a byte */
228 #define NBPW sizeof(int) /* number of bytes per word (integer) */
230 #define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
232 #define NODEV (dev_t)(-1) /* non-existent device */
235 * File system parameters and macros.
237 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes
238 * per block. MAXBSIZE may be made larger without effecting
239 * any existing filesystems as long as it does not exceed MAXPHYS,
240 * and may be made smaller at the risk of not being able to use
241 * filesystems which require a block size exceeding MAXBSIZE.
243 * MAXBCACHEBUF - Maximum size of a buffer in the buffer cache. This must
244 * be >= MAXBSIZE and can be set differently for different
245 * architectures by defining it in <machine/param.h>.
246 * Making this larger allows NFS to do larger reads/writes.
248 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the
249 * minimum KVM memory reservation the kernel is willing to make.
250 * Filesystems can of course request smaller chunks. Actual
251 * backing memory uses a chunk size of a page (PAGE_SIZE).
252 * The default value here can be overridden on a per-architecture
253 * basis by defining it in <machine/param.h>.
255 * If you make BKVASIZE too small you risk seriously fragmenting
256 * the buffer KVM map which may slow things down a bit. If you
257 * make it too big the kernel will not be able to optimally use
258 * the KVM memory reserved for the buffer cache and will wind
259 * up with too-few buffers.
261 * The default is 16384, roughly 2x the block size used by a
262 * normal UFS filesystem.
264 #define MAXBSIZE 65536 /* must be power of 2 */
266 #define MAXBCACHEBUF MAXBSIZE /* must be a power of 2 >= MAXBSIZE */
269 #define BKVASIZE 16384 /* must be power of 2 */
271 #define BKVAMASK (BKVASIZE-1)
274 * MAXPATHLEN defines the longest permissible path length after expanding
275 * symbolic links. It is used to allocate a temporary buffer from the buffer
276 * pool in which to do the name expansion, hence should be a power of two,
277 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the
278 * maximum number of symbolic links that may be expanded in a path name.
279 * It should be set high enough to allow all legitimate uses, but halt
280 * infinite loops reasonably quickly.
282 #define MAXPATHLEN PATH_MAX
283 #define MAXSYMLINKS 32
285 /* Bit map related macros. */
286 #define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
287 #define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
289 (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
291 ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
293 /* Macros for counting and rounding. */
295 #define howmany(x, y) (((x)+((y)-1))/(y))
297 #define nitems(x) (sizeof((x)) / sizeof((x)[0]))
298 #define rounddown(x, y) (((x)/(y))*(y))
299 #define rounddown2(x, y) ((x)&(~((y)-1))) /* if y is power of two */
300 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
301 #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
302 #define powerof2(x) ((((x)-1)&(x))==0)
304 /* Macros for min/max. */
305 #define MIN(a,b) (((a)<(b))?(a):(b))
306 #define MAX(a,b) (((a)>(b))?(a):(b))
310 * Basic byte order function prototypes for non-inline functions.
313 #ifndef _BYTEORDER_PROTOTYPED
314 #define _BYTEORDER_PROTOTYPED
316 __uint32_t htonl(__uint32_t);
317 __uint16_t htons(__uint16_t);
318 __uint32_t ntohl(__uint32_t);
319 __uint16_t ntohs(__uint16_t);
324 #ifndef _BYTEORDER_FUNC_DEFINED
325 #define _BYTEORDER_FUNC_DEFINED
326 #define htonl(x) __htonl(x)
327 #define htons(x) __htons(x)
328 #define ntohl(x) __ntohl(x)
329 #define ntohs(x) __ntohs(x)
330 #endif /* !_BYTEORDER_FUNC_DEFINED */
334 * Scale factor for scaled integers used to count %cpu time and load avgs.
336 * The number of CPU `tick's that map to a unique `%age' can be expressed
337 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
338 * can be calculated (assuming 32 bits) can be closely approximated using
339 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
341 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
342 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
344 #define FSHIFT 11 /* bits to right of fixed binary point */
345 #define FSCALE (1<<FSHIFT)
347 #define dbtoc(db) /* calculates devblks to pages */ \
348 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
350 #define ctodb(db) /* calculates pages to devblks */ \
351 ((db) << (PAGE_SHIFT - DEV_BSHIFT))
354 * Old spelling of __containerof().
356 #define member2struct(s, m, x) \
357 ((struct s *)(void *)((char *)(x) - offsetof(struct s, m)))
360 * Access a variable length array that has been declared as a fixed
363 #define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset])
365 #endif /* _SYS_PARAM_H_ */