2 * Copyright (c) 1982, 1986, 1989, 1993
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4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
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8 * the permission of UNIX System Laboratories, Inc.
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34 * @(#)param.h 8.3 (Berkeley) 4/4/95
41 #include <sys/_null.h>
43 #define BSD 199506 /* System version (year & month). */
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
51 * Currently this lives here in the doc/ repository:
53 * head/en_US.ISO8859-1/books/porters-handbook/book.xml
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.
60 #undef __FreeBSD_version
61 #define __FreeBSD_version 1002000 /* Master, propagated to newvers */
64 * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,
65 * which by definition is always true on FreeBSD. This macro is also defined
66 * on other systems that use the kernel of FreeBSD, such as GNU/kFreeBSD.
68 * It is tempting to use this macro in userland code when we want to enable
69 * kernel-specific routines, and in fact it's fine to do this in code that
70 * is part of FreeBSD itself. However, be aware that as presence of this
71 * macro is still not widespread (e.g. older FreeBSD versions, 3rd party
72 * compilers, etc), it is STRONGLY DISCOURAGED to check for this macro in
73 * external applications without also checking for __FreeBSD__ as an
76 #undef __FreeBSD_kernel__
77 #define __FreeBSD_kernel__
80 #define P_OSREL_SIGWAIT 700000
81 #define P_OSREL_SIGSEGV 700004
82 #define P_OSREL_MAP_ANON 800104
84 #define P_OSREL_MAJOR(x) ((x) / 100000)
88 #include <sys/types.h>
92 * Machine-independent constants (some used in following include files).
93 * Redefined constants are from POSIX 1003.1 limits file.
95 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
97 #include <sys/syslimits.h>
99 #define MAXCOMLEN 19 /* max command name remembered */
100 #define MAXINTERP PATH_MAX /* max interpreter file name length */
101 #define MAXLOGNAME 33 /* max login name length (incl. NUL) */
102 #define MAXUPRC CHILD_MAX /* max simultaneous processes */
103 #define NCARGS ARG_MAX /* max bytes for an exec function */
104 #define NGROUPS (NGROUPS_MAX+1) /* max number groups */
105 #define NOFILE OPEN_MAX /* max open files per process */
106 #define NOGROUP 65535 /* marker for empty group set member */
107 #define MAXHOSTNAMELEN 256 /* max hostname size */
108 #define SPECNAMELEN 63 /* max length of devicename */
110 /* More types and definitions used throughout the kernel. */
112 #include <sys/cdefs.h>
113 #include <sys/errno.h>
115 #include <sys/time.h>
116 #include <sys/priority.h>
129 #include <sys/signal.h>
132 /* Machine type dependent parameters. */
133 #include <machine/param.h>
135 #include <sys/limits.h>
139 #define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */
141 #define DEV_BSIZE (1<<DEV_BSHIFT)
143 #ifndef BLKDEV_IOSIZE
144 #define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */
147 #define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */
150 #define MAXPHYS (128 * 1024) /* max raw I/O transfer size */
153 #define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE)
157 * Constants related to network buffer management.
158 * MCLBYTES must be no larger than PAGE_SIZE.
161 #define MSIZE 256 /* size of an mbuf */
165 #define MCLSHIFT 11 /* convert bytes to mbuf clusters */
166 #endif /* MCLSHIFT */
168 #define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */
171 #define MJUMPAGESIZE MCLBYTES
172 #elif PAGE_SIZE <= 8192
173 #define MJUMPAGESIZE PAGE_SIZE
175 #define MJUMPAGESIZE (8 * 1024)
178 #define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */
179 #define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */
182 * Some macros for units conversion
185 /* clicks to bytes */
187 #define ctob(x) ((x)<<PAGE_SHIFT)
190 /* bytes to clicks */
192 #define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
196 * btodb() is messy and perhaps slow because `bytes' may be an off_t. We
197 * want to shift an unsigned type to avoid sign extension and we don't
198 * want to widen `bytes' unnecessarily. Assume that the result fits in
202 #define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \
203 (sizeof (bytes) > sizeof(long) \
204 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
205 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
209 #define dbtob(db) /* calculates (db * DEV_BSIZE) */ \
210 ((off_t)(db) << DEV_BSHIFT)
213 #define PRIMASK 0x0ff
214 #define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */
215 #define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */
217 #define NZERO 0 /* default "nice" */
219 #define NBBY 8 /* number of bits in a byte */
220 #define NBPW sizeof(int) /* number of bytes per word (integer) */
222 #define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
224 #define NODEV (dev_t)(-1) /* non-existent device */
227 * File system parameters and macros.
229 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes
230 * per block. MAXBSIZE may be made larger without effecting
231 * any existing filesystems as long as it does not exceed MAXPHYS,
232 * and may be made smaller at the risk of not being able to use
233 * filesystems which require a block size exceeding MAXBSIZE.
235 * MAXBCACHEBUF - Maximum size of a buffer in the buffer cache. This must
236 * be >= MAXBSIZE and can be set differently for different
237 * architectures by defining it in <machine/param.h>.
238 * Making this larger allows NFS to do larger reads/writes.
240 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the
241 * minimum KVM memory reservation the kernel is willing to make.
242 * Filesystems can of course request smaller chunks. Actual
243 * backing memory uses a chunk size of a page (PAGE_SIZE).
244 * The default value here can be overridden on a per-architecture
245 * basis by defining it in <machine/param.h>. This should
246 * probably be done to increase its value, when MAXBCACHEBUF is
247 * defined as a larger value in <machine/param.h>.
249 * If you make BKVASIZE too small you risk seriously fragmenting
250 * the buffer KVM map which may slow things down a bit. If you
251 * make it too big the kernel will not be able to optimally use
252 * the KVM memory reserved for the buffer cache and will wind
253 * up with too-few buffers.
255 * The default is 16384, roughly 2x the block size used by a
256 * normal UFS filesystem.
258 #define MAXBSIZE 65536 /* must be power of 2 */
260 #define MAXBCACHEBUF MAXBSIZE /* must be a power of 2 >= MAXBSIZE */
263 #define BKVASIZE 16384 /* must be power of 2 */
265 #define BKVAMASK (BKVASIZE-1)
268 * MAXPATHLEN defines the longest permissible path length after expanding
269 * symbolic links. It is used to allocate a temporary buffer from the buffer
270 * pool in which to do the name expansion, hence should be a power of two,
271 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the
272 * maximum number of symbolic links that may be expanded in a path name.
273 * It should be set high enough to allow all legitimate uses, but halt
274 * infinite loops reasonably quickly.
276 #define MAXPATHLEN PATH_MAX
277 #define MAXSYMLINKS 32
279 /* Bit map related macros. */
280 #define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
281 #define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
283 (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
285 ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
287 /* Macros for counting and rounding. */
289 #define howmany(x, y) (((x)+((y)-1))/(y))
291 #define nitems(x) (sizeof((x)) / sizeof((x)[0]))
292 #define rounddown(x, y) (((x)/(y))*(y))
293 #define rounddown2(x, y) ((x)&(~((y)-1))) /* if y is power of two */
294 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
295 #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
296 #define powerof2(x) ((((x)-1)&(x))==0)
298 /* Macros for min/max. */
299 #define MIN(a,b) (((a)<(b))?(a):(b))
300 #define MAX(a,b) (((a)>(b))?(a):(b))
304 * Basic byte order function prototypes for non-inline functions.
307 #ifndef _BYTEORDER_PROTOTYPED
308 #define _BYTEORDER_PROTOTYPED
310 __uint32_t htonl(__uint32_t);
311 __uint16_t htons(__uint16_t);
312 __uint32_t ntohl(__uint32_t);
313 __uint16_t ntohs(__uint16_t);
319 #ifndef _BYTEORDER_FUNC_DEFINED
320 #define _BYTEORDER_FUNC_DEFINED
321 #define htonl(x) __htonl(x)
322 #define htons(x) __htons(x)
323 #define ntohl(x) __ntohl(x)
324 #define ntohs(x) __ntohs(x)
325 #endif /* !_BYTEORDER_FUNC_DEFINED */
330 * Scale factor for scaled integers used to count %cpu time and load avgs.
332 * The number of CPU `tick's that map to a unique `%age' can be expressed
333 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
334 * can be calculated (assuming 32 bits) can be closely approximated using
335 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
337 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
338 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
340 #define FSHIFT 11 /* bits to right of fixed binary point */
341 #define FSCALE (1<<FSHIFT)
343 #define dbtoc(db) /* calculates devblks to pages */ \
344 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
346 #define ctodb(db) /* calculates pages to devblks */ \
347 ((db) << (PAGE_SHIFT - DEV_BSHIFT))
350 * Old spelling of __containerof().
352 #define member2struct(s, m, x) \
353 ((struct s *)(void *)((char *)(x) - offsetof(struct s, m)))
356 * Access a variable length array that has been declared as a fixed
359 #define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset])
361 #endif /* _SYS_PARAM_H_ */