xref: /freebsd/sys/sys/param.h (revision 6275cd73aca7f31cbb3b9da2d031f6664814d58c)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
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.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
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.
23  *
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
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef _SYS_PARAM_H_
38 #define _SYS_PARAM_H_
39 
40 #include <sys/_null.h>
41 #include <sys/_param.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  *	documentation/content/en/books/porters-handbook/versions/_index.adoc
54  *
55  * Encoding:	<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/X.0 is created, otherwise 'R' is
58  *		in the range 5 to 9.
59  * Short hand: MMmmXXX
60  *
61  * __FreeBSD_version is bumped every time there's a change in the base system
62  * that's noteworthy. A noteworthy change is any change which changes the
63  * kernel's KBI in -CURRENT, one that changes some detail about the system that
64  * external software (or the ports system) would want to know about, one that
65  * adds a system call, one that adds or deletes a shipped library, a security
66  * fix, or similar change not specifically noted here. Bumps should be limited
67  * to one per day / a couple per week except for security fixes.
68  *
69  * The approved way to obtain this from a shell script is:
70  *	awk '/^\#define[[:space:]]*__FreeBSD_version/ {print $3}'
71  * Other methods to parse this file may work, but are not guaranteed against
72  * future changes. The above script works back to FreeBSD 3.x when this macro
73  * was introduced. This number is propagated to other places needing it that
74  * cannot include sys/param.h and should only be updated here.
75  */
76 #undef __FreeBSD_version
77 #define __FreeBSD_version 1600014
78 
79 /*
80  * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,
81  * which by definition is always true on FreeBSD. This macro is also defined
82  * on other systems that use the kernel of FreeBSD, such as GNU/kFreeBSD.
83  *
84  * It is tempting to use this macro in userland code when we want to enable
85  * kernel-specific routines, and in fact it's fine to do this in code that
86  * is part of FreeBSD itself.  However, be aware that as presence of this
87  * macro is still not widespread (e.g. older FreeBSD versions, 3rd party
88  * compilers, etc), it is STRONGLY DISCOURAGED to check for this macro in
89  * external applications without also checking for __FreeBSD__ as an
90  * alternative.
91  */
92 #undef __FreeBSD_kernel__
93 #define __FreeBSD_kernel__
94 
95 #if defined(_KERNEL) || defined(_WANT_P_OSREL)
96 #define	P_OSREL_SIGWAIT			700000
97 #define	P_OSREL_SIGSEGV			700004
98 #define	P_OSREL_MAP_ANON		800104
99 #define	P_OSREL_MAP_FSTRICT		1100036
100 #define	P_OSREL_SHUTDOWN_ENOTCONN	1100077
101 #define	P_OSREL_MAP_GUARD		1200035
102 #define	P_OSREL_WRFSBASE		1200041
103 #define	P_OSREL_CK_CYLGRP		1200046
104 #define	P_OSREL_VMTOTAL64		1200054
105 #define	P_OSREL_CK_SUPERBLOCK		1300000
106 #define	P_OSREL_CK_INODE		1300005
107 #define	P_OSREL_POWERPC_NEW_AUX_ARGS	1300070
108 #define	P_OSREL_TIDPID			1400079
109 #define	P_OSREL_ARM64_SPSR		1400084
110 #define	P_OSREL_TLSBASE			1500044
111 #define	P_OSREL_EXTERRCTL		1500045
112 #define	P_OSREL_AMD64_TF_FRED		1600014
113 
114 #define	P_OSREL_MAJOR(x)		((x) / 100000)
115 #endif
116 
117 #ifndef LOCORE
118 #include <sys/types.h>
119 #endif
120 
121 /*
122  * Machine-independent constants (some used in following include files).
123  * Redefined constants are from POSIX 1003.1 limits file.
124  *
125  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
126  */
127 #include <sys/syslimits.h>
128 
129 #define	MAXCOMLEN	19		/* max command name remembered */
130 #define	MAXINTERP	PATH_MAX	/* max interpreter file name length */
131 #define	MAXLOGNAME	33		/* max login name length (incl. NUL) */
132 #define	MAXUPRC		CHILD_MAX	/* max simultaneous processes */
133 #define	NCARGS		ARG_MAX		/* max bytes for an exec function */
134 #define	NGROUPS		(NGROUPS_MAX+1)	/* max number groups */
135 #define	NOFILE		OPEN_MAX	/* max open files per process */
136 #define	NOGROUP		65535		/* marker for empty group set member */
137 #define MAXHOSTNAMELEN	256		/* max hostname size */
138 #define SPECNAMELEN	255		/* max length of devicename */
139 
140 /* More types and definitions used throughout the kernel. */
141 #ifdef _KERNEL
142 #include <sys/cdefs.h>
143 #include <sys/errno.h>
144 #ifndef LOCORE
145 #include <sys/time.h>
146 #include <sys/priority.h>
147 #endif
148 
149 #ifndef FALSE
150 #define	FALSE	0
151 #endif
152 #ifndef TRUE
153 #define	TRUE	1
154 #endif
155 #endif
156 
157 #if !defined(_KERNEL) && !defined(_STANDALONE) && !defined(LOCORE)
158 /* Signals. */
159 #include <sys/signal.h>
160 #endif
161 
162 /* Machine type dependent parameters. */
163 #include <machine/param.h>
164 #ifndef _KERNEL
165 #include <sys/limits.h>
166 #include <sys/_maxphys.h>
167 #endif
168 
169 #ifndef DEV_BSHIFT
170 #define	DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
171 #endif
172 #define	DEV_BSIZE	(1<<DEV_BSHIFT)
173 
174 #ifndef BLKDEV_IOSIZE
175 #define BLKDEV_IOSIZE  PAGE_SIZE	/* default block device I/O size */
176 #endif
177 #ifndef DFLTPHYS
178 #define DFLTPHYS	(64 * 1024)	/* default max raw I/O transfer size */
179 #endif
180 #ifndef MAXDUMPPGS
181 #define MAXDUMPPGS	(DFLTPHYS/PAGE_SIZE)
182 #endif
183 #ifdef STACKALIGNBYTES
184 #define	STACKALIGN(p)	(__align_down(p, STACKALIGNBYTES + 1))
185 #endif
186 
187 /*
188  * Constants related to network buffer management.
189  * MCLBYTES must be no larger than PAGE_SIZE.
190  */
191 #ifndef	MSIZE
192 #define	MSIZE		256		/* size of an mbuf */
193 #endif
194 
195 #ifndef	MCLSHIFT
196 #define MCLSHIFT	11		/* convert bytes to mbuf clusters */
197 #endif	/* MCLSHIFT */
198 
199 #define MCLBYTES	(1 << MCLSHIFT)	/* size of an mbuf cluster */
200 
201 #if PAGE_SIZE <= 8192
202 #define	MJUMPAGESIZE	PAGE_SIZE
203 #else
204 #define	MJUMPAGESIZE	(8 * 1024)
205 #endif
206 
207 #define	MJUM9BYTES	(9 * 1024)	/* jumbo cluster 9k */
208 #define	MJUM16BYTES	(16 * 1024)	/* jumbo cluster 16k */
209 
210 /*
211  * Mach derived conversion macros
212  */
213 #define	round_page(x)	roundup2(x, PAGE_SIZE)
214 #define	trunc_page(x)	rounddown2(x, PAGE_SIZE)
215 
216 #define	atop(x)		((x) >> PAGE_SHIFT)
217 #define	ptoa(x)		((x) << PAGE_SHIFT)
218 
219 #define	pgtok(x)	((x) * (PAGE_SIZE / 1024))
220 
221 /*
222  * Some macros for units conversion
223  */
224 
225 /* clicks to bytes */
226 #ifndef ctob
227 #define ctob(x)	((x)<<PAGE_SHIFT)
228 #endif
229 
230 /* bytes to clicks */
231 #ifndef btoc
232 #define btoc(x)	(((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
233 #endif
234 
235 /*
236  * btodb() is messy and perhaps slow because `bytes' may be an off_t.  We
237  * want to shift an unsigned type to avoid sign extension and we don't
238  * want to widen `bytes' unnecessarily.  Assume that the result fits in
239  * a daddr_t.
240  */
241 #ifndef btodb
242 #define btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
243 	(sizeof (bytes) > sizeof(long) \
244 	 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
245 	 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
246 #endif
247 
248 #ifndef dbtob
249 #define dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
250 	((off_t)(db) << DEV_BSHIFT)
251 #endif
252 
253 #define	PRIMASK		0x0ff
254 #define	PCATCH		0x100	/* OR'd with pri for tsleep to check signals */
255 #define	PDROP		0x200	/* OR'd with pri to stop re-entry of interlock mutex */
256 #define	PNOLOCK		0x400	/* OR'd with pri to allow sleeping w/o a lock */
257 #define	PRILASTFLAG	0x400	/* Last flag defined above */
258 
259 #define	NZERO	0		/* default "nice" */
260 
261 #define	CMASK	022		/* default file mask: S_IWGRP|S_IWOTH */
262 
263 #define	NODEV	(dev_t)(-1)	/* non-existent device */
264 
265 /*
266  * File system parameters and macros.
267  *
268  * MAXBSIZE -	Filesystems are made out of blocks of at most MAXBSIZE bytes
269  *		per block.  MAXBSIZE may be made larger without effecting
270  *		any existing filesystems as long as it does not exceed MAXPHYS,
271  *		and may be made smaller at the risk of not being able to use
272  *		filesystems which require a block size exceeding MAXBSIZE.
273  *
274  * MAXBCACHEBUF - Maximum size of a buffer in the buffer cache.  This must
275  *		be >= MAXBSIZE and can be set differently for different
276  *		architectures by defining it in <machine/param.h>.
277  *		Making this larger allows NFS to do larger reads/writes.
278  *
279  * BKVASIZE -	Nominal buffer space per buffer, in bytes.  BKVASIZE is the
280  *		minimum KVM memory reservation the kernel is willing to make.
281  *		Filesystems can of course request smaller chunks.  Actual
282  *		backing memory uses a chunk size of a page (PAGE_SIZE).
283  *		The default value here can be overridden on a per-architecture
284  *		basis by defining it in <machine/param.h>.
285  *
286  *		If you make BKVASIZE too small you risk seriously fragmenting
287  *		the buffer KVM map which may slow things down a bit.  If you
288  *		make it too big the kernel will not be able to optimally use
289  *		the KVM memory reserved for the buffer cache and will wind
290  *		up with too-few buffers.
291  *
292  *		The default is 16384, roughly 2x the block size used by a
293  *		normal UFS filesystem.
294  */
295 #define MAXBSIZE	65536	/* must be power of 2 */
296 #ifndef	MAXBCACHEBUF
297 #define	MAXBCACHEBUF	MAXBSIZE /* must be a power of 2 >= MAXBSIZE */
298 #endif
299 #ifndef	BKVASIZE
300 #define BKVASIZE	16384	/* must be power of 2 */
301 #endif
302 #define BKVAMASK	(BKVASIZE-1)
303 
304 /*
305  * MAXPATHLEN defines the longest permissible path length after expanding
306  * symbolic links. It is used to allocate a temporary buffer from the buffer
307  * pool in which to do the name expansion, hence should be a power of two,
308  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
309  * maximum number of symbolic links that may be expanded in a path name.
310  * It should be set high enough to allow all legitimate uses, but halt
311  * infinite loops reasonably quickly.
312  */
313 #define	MAXPATHLEN	PATH_MAX
314 #define MAXSYMLINKS	32
315 
316 /* Bit map related macros. */
317 #define	setbit(a,i)	(((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
318 #define	clrbit(a,i)	(((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
319 #define	isset(a,i)							\
320 	(((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
321 #define	isclr(a,i)							\
322 	((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
323 
324 /* Macros for counting and rounding provided by <sys/_param.h>. */
325 
326 /* Macros for min/max. */
327 #define	MIN(a,b) (((a)<(b))?(a):(b))
328 #define	MAX(a,b) (((a)>(b))?(a):(b))
329 
330 #ifdef _KERNEL
331 /*
332  * Basic byte order function prototypes for non-inline functions.
333  */
334 #ifndef LOCORE
335 #ifndef _BYTEORDER_PROTOTYPED
336 #define	_BYTEORDER_PROTOTYPED
337 __BEGIN_DECLS
338 __uint32_t	 htonl(__uint32_t);
339 __uint16_t	 htons(__uint16_t);
340 __uint32_t	 ntohl(__uint32_t);
341 __uint16_t	 ntohs(__uint16_t);
342 __END_DECLS
343 #endif
344 #endif
345 
346 #ifndef _BYTEORDER_FUNC_DEFINED
347 #define	_BYTEORDER_FUNC_DEFINED
348 #define	htonl(x)	__htonl(x)
349 #define	htons(x)	__htons(x)
350 #define	ntohl(x)	__ntohl(x)
351 #define	ntohs(x)	__ntohs(x)
352 #endif /* !_BYTEORDER_FUNC_DEFINED */
353 #endif /* _KERNEL */
354 
355 /*
356  * Scale factor for scaled integers used to count %cpu time and load avgs.
357  *
358  * The number of CPU `tick's that map to a unique `%age' can be expressed
359  * by the formula (1 / (2 ^ (FSHIFT - 11))).  Since the intermediate
360  * calculation is done with 64-bit precision, the maximum load average that can
361  * be calculated is approximately 2^32 / FSCALE.
362  *
363  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
364  * FSHIFT must be at least 11.  This gives a maximum load avg of 2 million.
365  */
366 #define	FSHIFT	11		/* bits to right of fixed binary point */
367 #define FSCALE	(1<<FSHIFT)
368 
369 #define dbtoc(db)			/* calculates devblks to pages */ \
370 	((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
371 
372 #define ctodb(db)			/* calculates pages to devblks */ \
373 	((db) << (PAGE_SHIFT - DEV_BSHIFT))
374 
375 /*
376  * Old spelling of __containerof().
377  */
378 #define	member2struct(s, m, x)						\
379 	((struct s *)(void *)((char *)(x) - offsetof(struct s, m)))
380 
381 /*
382  * Access a variable length array that has been declared as a fixed
383  * length array.
384  */
385 #define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset])
386 
387 #endif	/* _SYS_PARAM_H_ */
388