2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1982, 1986, 1989, 1993
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6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
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9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
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15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
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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 1300131 /* 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
91 #define P_OSREL_CK_SUPERBLOCK 1300000
92 #define P_OSREL_CK_INODE 1300005
93 #define P_OSREL_POWERPC_NEW_AUX_ARGS 1300070
95 #define P_OSREL_MAJOR(x) ((x) / 100000)
99 #include <sys/types.h>
103 * Machine-independent constants (some used in following include files).
104 * Redefined constants are from POSIX 1003.1 limits file.
106 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
108 #include <sys/syslimits.h>
110 #define MAXCOMLEN 19 /* max command name remembered */
111 #define MAXINTERP PATH_MAX /* max interpreter file name length */
112 #define MAXLOGNAME 33 /* max login name length (incl. NUL) */
113 #define MAXUPRC CHILD_MAX /* max simultaneous processes */
114 #define NCARGS ARG_MAX /* max bytes for an exec function */
115 #define NGROUPS (NGROUPS_MAX+1) /* max number groups */
116 #define NOFILE OPEN_MAX /* max open files per process */
117 #define NOGROUP 65535 /* marker for empty group set member */
118 #define MAXHOSTNAMELEN 256 /* max hostname size */
119 #define SPECNAMELEN 255 /* max length of devicename */
121 /* More types and definitions used throughout the kernel. */
123 #include <sys/cdefs.h>
124 #include <sys/errno.h>
126 #include <sys/time.h>
127 #include <sys/priority.h>
141 #include <sys/signal.h>
145 /* Machine type dependent parameters. */
146 #include <machine/param.h>
148 #include <sys/limits.h>
152 #define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */
154 #define DEV_BSIZE (1<<DEV_BSHIFT)
156 #ifndef BLKDEV_IOSIZE
157 #define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */
160 #define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */
162 #ifndef MAXPHYS /* max raw I/O transfer size */
164 #define MAXPHYS (128 * 1024)
166 #define MAXPHYS (1024 * 1024)
170 #define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE)
174 * Constants related to network buffer management.
175 * MCLBYTES must be no larger than PAGE_SIZE.
178 #define MSIZE 256 /* size of an mbuf */
182 #define MCLSHIFT 11 /* convert bytes to mbuf clusters */
183 #endif /* MCLSHIFT */
185 #define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */
188 #define MJUMPAGESIZE MCLBYTES
189 #elif PAGE_SIZE <= 8192
190 #define MJUMPAGESIZE PAGE_SIZE
192 #define MJUMPAGESIZE (8 * 1024)
195 #define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */
196 #define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */
199 * Some macros for units conversion
202 /* clicks to bytes */
204 #define ctob(x) ((x)<<PAGE_SHIFT)
207 /* bytes to clicks */
209 #define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
213 * btodb() is messy and perhaps slow because `bytes' may be an off_t. We
214 * want to shift an unsigned type to avoid sign extension and we don't
215 * want to widen `bytes' unnecessarily. Assume that the result fits in
219 #define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \
220 (sizeof (bytes) > sizeof(long) \
221 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
222 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
226 #define dbtob(db) /* calculates (db * DEV_BSIZE) */ \
227 ((off_t)(db) << DEV_BSHIFT)
230 #define PRIMASK 0x0ff
231 #define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */
232 #define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */
234 #define NZERO 0 /* default "nice" */
236 #define NBBY 8 /* number of bits in a byte */
237 #define NBPW sizeof(int) /* number of bytes per word (integer) */
239 #define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
241 #define NODEV (dev_t)(-1) /* non-existent device */
244 * File system parameters and macros.
246 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes
247 * per block. MAXBSIZE may be made larger without effecting
248 * any existing filesystems as long as it does not exceed MAXPHYS,
249 * and may be made smaller at the risk of not being able to use
250 * filesystems which require a block size exceeding MAXBSIZE.
252 * MAXBCACHEBUF - Maximum size of a buffer in the buffer cache. This must
253 * be >= MAXBSIZE and can be set differently for different
254 * architectures by defining it in <machine/param.h>.
255 * Making this larger allows NFS to do larger reads/writes.
257 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the
258 * minimum KVM memory reservation the kernel is willing to make.
259 * Filesystems can of course request smaller chunks. Actual
260 * backing memory uses a chunk size of a page (PAGE_SIZE).
261 * The default value here can be overridden on a per-architecture
262 * basis by defining it in <machine/param.h>.
264 * If you make BKVASIZE too small you risk seriously fragmenting
265 * the buffer KVM map which may slow things down a bit. If you
266 * make it too big the kernel will not be able to optimally use
267 * the KVM memory reserved for the buffer cache and will wind
268 * up with too-few buffers.
270 * The default is 16384, roughly 2x the block size used by a
271 * normal UFS filesystem.
273 #define MAXBSIZE 65536 /* must be power of 2 */
275 #define MAXBCACHEBUF MAXBSIZE /* must be a power of 2 >= MAXBSIZE */
278 #define BKVASIZE 16384 /* must be power of 2 */
280 #define BKVAMASK (BKVASIZE-1)
283 * MAXPATHLEN defines the longest permissible path length after expanding
284 * symbolic links. It is used to allocate a temporary buffer from the buffer
285 * pool in which to do the name expansion, hence should be a power of two,
286 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the
287 * maximum number of symbolic links that may be expanded in a path name.
288 * It should be set high enough to allow all legitimate uses, but halt
289 * infinite loops reasonably quickly.
291 #define MAXPATHLEN PATH_MAX
292 #define MAXSYMLINKS 32
294 /* Bit map related macros. */
295 #define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
296 #define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
298 (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
300 ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
302 /* Macros for counting and rounding. */
304 #define howmany(x, y) (((x)+((y)-1))/(y))
306 #define nitems(x) (sizeof((x)) / sizeof((x)[0]))
307 #define rounddown(x, y) (((x)/(y))*(y))
308 #define rounddown2(x, y) ((x)&(~((y)-1))) /* if y is power of two */
309 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
310 #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
311 #define powerof2(x) ((((x)-1)&(x))==0)
313 /* Macros for min/max. */
314 #define MIN(a,b) (((a)<(b))?(a):(b))
315 #define MAX(a,b) (((a)>(b))?(a):(b))
319 * Basic byte order function prototypes for non-inline functions.
322 #ifndef _BYTEORDER_PROTOTYPED
323 #define _BYTEORDER_PROTOTYPED
325 __uint32_t htonl(__uint32_t);
326 __uint16_t htons(__uint16_t);
327 __uint32_t ntohl(__uint32_t);
328 __uint16_t ntohs(__uint16_t);
333 #ifndef _BYTEORDER_FUNC_DEFINED
334 #define _BYTEORDER_FUNC_DEFINED
335 #define htonl(x) __htonl(x)
336 #define htons(x) __htons(x)
337 #define ntohl(x) __ntohl(x)
338 #define ntohs(x) __ntohs(x)
339 #endif /* !_BYTEORDER_FUNC_DEFINED */
343 * Scale factor for scaled integers used to count %cpu time and load avgs.
345 * The number of CPU `tick's that map to a unique `%age' can be expressed
346 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
347 * can be calculated (assuming 32 bits) can be closely approximated using
348 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
350 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
351 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
353 #define FSHIFT 11 /* bits to right of fixed binary point */
354 #define FSCALE (1<<FSHIFT)
356 #define dbtoc(db) /* calculates devblks to pages */ \
357 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
359 #define ctodb(db) /* calculates pages to devblks */ \
360 ((db) << (PAGE_SHIFT - DEV_BSHIFT))
363 * Old spelling of __containerof().
365 #define member2struct(s, m, x) \
366 ((struct s *)(void *)((char *)(x) - offsetof(struct s, m)))
369 * Access a variable length array that has been declared as a fixed
372 #define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset])
374 #endif /* _SYS_PARAM_H_ */