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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10 * the permission of UNIX System Laboratories, Inc.
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15 * 1. Redistributions of source code must retain the above copyright
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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 * documentation/content/en/books/porters-handbook/versions/_index.adoc
57 * Encoding: <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.
63 * __FreeBSD_version is bumped every time there's a change in the base system
64 * that's noteworthy. A noteworthy change is any change which changes the
65 * kernel's KBI in -CURRENT, one that changes some detail about the system that
66 * external software (or the ports system) would want to know about, one that
67 * adds a system call, one that adds or deletes a shipped library, a security
68 * fix, or similar change not specifically noted here. Bumps should be limited
69 * to one per day / a couple per week except for security fixes.
71 * The approved way to obtain this from a shell script is:
72 * awk '/^\#define[[:space:]]*__FreeBSD_version/ {print $3}'
73 * Other methods to parse this file may work, but are not guaranteed against
74 * future changes. The above script works back to FreeBSD 3.x when this macro
75 * was introduced. This number is propagated to other places needing it that
76 * cannot include sys/param.h and should only be updated here.
78 #undef __FreeBSD_version
79 #define __FreeBSD_version 1400043
82 * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,
83 * which by definition is always true on FreeBSD. This macro is also defined
84 * on other systems that use the kernel of FreeBSD, such as GNU/kFreeBSD.
86 * It is tempting to use this macro in userland code when we want to enable
87 * kernel-specific routines, and in fact it's fine to do this in code that
88 * is part of FreeBSD itself. However, be aware that as presence of this
89 * macro is still not widespread (e.g. older FreeBSD versions, 3rd party
90 * compilers, etc), it is STRONGLY DISCOURAGED to check for this macro in
91 * external applications without also checking for __FreeBSD__ as an
94 #undef __FreeBSD_kernel__
95 #define __FreeBSD_kernel__
97 #if defined(_KERNEL) || defined(IN_RTLD)
98 #define P_OSREL_SIGWAIT 700000
99 #define P_OSREL_SIGSEGV 700004
100 #define P_OSREL_MAP_ANON 800104
101 #define P_OSREL_MAP_FSTRICT 1100036
102 #define P_OSREL_SHUTDOWN_ENOTCONN 1100077
103 #define P_OSREL_MAP_GUARD 1200035
104 #define P_OSREL_WRFSBASE 1200041
105 #define P_OSREL_CK_CYLGRP 1200046
106 #define P_OSREL_VMTOTAL64 1200054
107 #define P_OSREL_CK_SUPERBLOCK 1300000
108 #define P_OSREL_CK_INODE 1300005
109 #define P_OSREL_POWERPC_NEW_AUX_ARGS 1300070
111 #define P_OSREL_MAJOR(x) ((x) / 100000)
115 #include <sys/types.h>
119 * Machine-independent constants (some used in following include files).
120 * Redefined constants are from POSIX 1003.1 limits file.
122 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
124 #include <sys/syslimits.h>
126 #define MAXCOMLEN 19 /* max command name remembered */
127 #define MAXINTERP PATH_MAX /* max interpreter file name length */
128 #define MAXLOGNAME 33 /* max login name length (incl. NUL) */
129 #define MAXUPRC CHILD_MAX /* max simultaneous processes */
130 #define NCARGS ARG_MAX /* max bytes for an exec function */
131 #define NGROUPS (NGROUPS_MAX+1) /* max number groups */
132 #define NOFILE OPEN_MAX /* max open files per process */
133 #define NOGROUP 65535 /* marker for empty group set member */
134 #define MAXHOSTNAMELEN 256 /* max hostname size */
135 #define SPECNAMELEN 255 /* max length of devicename */
137 /* More types and definitions used throughout the kernel. */
139 #include <sys/cdefs.h>
140 #include <sys/errno.h>
142 #include <sys/time.h>
143 #include <sys/priority.h>
157 #include <sys/signal.h>
161 /* Machine type dependent parameters. */
162 #include <machine/param.h>
164 #include <sys/limits.h>
168 #define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */
170 #define DEV_BSIZE (1<<DEV_BSHIFT)
172 #ifndef BLKDEV_IOSIZE
173 #define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */
176 #define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */
178 #ifndef MAXPHYS /* max raw I/O transfer size */
180 #define MAXPHYS (128 * 1024)
182 #define MAXPHYS (1024 * 1024)
186 #define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE)
190 * Constants related to network buffer management.
191 * MCLBYTES must be no larger than PAGE_SIZE.
194 #define MSIZE 256 /* size of an mbuf */
198 #define MCLSHIFT 11 /* convert bytes to mbuf clusters */
199 #endif /* MCLSHIFT */
201 #define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */
204 #define MJUMPAGESIZE MCLBYTES
205 #elif PAGE_SIZE <= 8192
206 #define MJUMPAGESIZE PAGE_SIZE
208 #define MJUMPAGESIZE (8 * 1024)
211 #define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */
212 #define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */
215 * Some macros for units conversion
218 /* clicks to bytes */
220 #define ctob(x) ((x)<<PAGE_SHIFT)
223 /* bytes to clicks */
225 #define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
229 * btodb() is messy and perhaps slow because `bytes' may be an off_t. We
230 * want to shift an unsigned type to avoid sign extension and we don't
231 * want to widen `bytes' unnecessarily. Assume that the result fits in
235 #define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \
236 (sizeof (bytes) > sizeof(long) \
237 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
238 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
242 #define dbtob(db) /* calculates (db * DEV_BSIZE) */ \
243 ((off_t)(db) << DEV_BSHIFT)
246 #define PRIMASK 0x0ff
247 #define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */
248 #define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */
249 #define PNOLOCK 0x400 /* OR'd with pri to allow sleeping w/o a lock */
250 #define PRILASTFLAG 0x400 /* Last flag defined above */
252 #define NZERO 0 /* default "nice" */
254 #define NBBY 8 /* number of bits in a byte */
255 #define NBPW sizeof(int) /* number of bytes per word (integer) */
257 #define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
259 #define NODEV (dev_t)(-1) /* non-existent device */
262 * File system parameters and macros.
264 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes
265 * per block. MAXBSIZE may be made larger without effecting
266 * any existing filesystems as long as it does not exceed MAXPHYS,
267 * and may be made smaller at the risk of not being able to use
268 * filesystems which require a block size exceeding MAXBSIZE.
270 * MAXBCACHEBUF - Maximum size of a buffer in the buffer cache. This must
271 * be >= MAXBSIZE and can be set differently for different
272 * architectures by defining it in <machine/param.h>.
273 * Making this larger allows NFS to do larger reads/writes.
275 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the
276 * minimum KVM memory reservation the kernel is willing to make.
277 * Filesystems can of course request smaller chunks. Actual
278 * backing memory uses a chunk size of a page (PAGE_SIZE).
279 * The default value here can be overridden on a per-architecture
280 * basis by defining it in <machine/param.h>.
282 * If you make BKVASIZE too small you risk seriously fragmenting
283 * the buffer KVM map which may slow things down a bit. If you
284 * make it too big the kernel will not be able to optimally use
285 * the KVM memory reserved for the buffer cache and will wind
286 * up with too-few buffers.
288 * The default is 16384, roughly 2x the block size used by a
289 * normal UFS filesystem.
291 #define MAXBSIZE 65536 /* must be power of 2 */
293 #define MAXBCACHEBUF MAXBSIZE /* must be a power of 2 >= MAXBSIZE */
296 #define BKVASIZE 16384 /* must be power of 2 */
298 #define BKVAMASK (BKVASIZE-1)
301 * MAXPATHLEN defines the longest permissible path length after expanding
302 * symbolic links. It is used to allocate a temporary buffer from the buffer
303 * pool in which to do the name expansion, hence should be a power of two,
304 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the
305 * maximum number of symbolic links that may be expanded in a path name.
306 * It should be set high enough to allow all legitimate uses, but halt
307 * infinite loops reasonably quickly.
309 #define MAXPATHLEN PATH_MAX
310 #define MAXSYMLINKS 32
312 /* Bit map related macros. */
313 #define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
314 #define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
316 (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
318 ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
320 /* Macros for counting and rounding. */
322 #define howmany(x, y) (((x)+((y)-1))/(y))
324 #define nitems(x) (sizeof((x)) / sizeof((x)[0]))
325 #define rounddown(x, y) (((x)/(y))*(y))
326 #define rounddown2(x, y) __align_down(x, y) /* if y is power of two */
327 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
328 #define roundup2(x, y) __align_up(x, y) /* if y is powers of two */
329 #define powerof2(x) ((((x)-1)&(x))==0)
331 /* Macros for min/max. */
332 #define MIN(a,b) (((a)<(b))?(a):(b))
333 #define MAX(a,b) (((a)>(b))?(a):(b))
337 * Basic byte order function prototypes for non-inline functions.
340 #ifndef _BYTEORDER_PROTOTYPED
341 #define _BYTEORDER_PROTOTYPED
343 __uint32_t htonl(__uint32_t);
344 __uint16_t htons(__uint16_t);
345 __uint32_t ntohl(__uint32_t);
346 __uint16_t ntohs(__uint16_t);
351 #ifndef _BYTEORDER_FUNC_DEFINED
352 #define _BYTEORDER_FUNC_DEFINED
353 #define htonl(x) __htonl(x)
354 #define htons(x) __htons(x)
355 #define ntohl(x) __ntohl(x)
356 #define ntohs(x) __ntohs(x)
357 #endif /* !_BYTEORDER_FUNC_DEFINED */
361 * Scale factor for scaled integers used to count %cpu time and load avgs.
363 * The number of CPU `tick's that map to a unique `%age' can be expressed
364 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
365 * can be calculated (assuming 32 bits) can be closely approximated using
366 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
368 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
369 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
371 #define FSHIFT 11 /* bits to right of fixed binary point */
372 #define FSCALE (1<<FSHIFT)
374 #define dbtoc(db) /* calculates devblks to pages */ \
375 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
377 #define ctodb(db) /* calculates pages to devblks */ \
378 ((db) << (PAGE_SHIFT - DEV_BSHIFT))
381 * Old spelling of __containerof().
383 #define member2struct(s, m, x) \
384 ((struct s *)(void *)((char *)(x) - offsetof(struct s, m)))
387 * Access a variable length array that has been declared as a fixed
390 #define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset])
392 #endif /* _SYS_PARAM_H_ */