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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:
53 * doc/en_US.ISO8859-1/books/porters-handbook/book.sgml
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 802500 /* Master, propagated to newvers */
64 #define P_OSREL_SIGSEGV 700004
65 #define P_OSREL_MAP_ANON 800104
69 #include <sys/types.h>
73 * Machine-independent constants (some used in following include files).
74 * Redefined constants are from POSIX 1003.1 limits file.
76 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
77 * MAXLOGNAME should be == UT_NAMESIZE+1 (see <utmp.h>)
79 #include <sys/syslimits.h>
81 #define MAXCOMLEN 19 /* max command name remembered */
82 #define MAXINTERP 32 /* max interpreter file name length */
83 #define MAXLOGNAME 17 /* max login name length (incl. NUL) */
84 #define MAXUPRC CHILD_MAX /* max simultaneous processes */
85 #define NCARGS ARG_MAX /* max bytes for an exec function */
86 #define NGROUPS (NGROUPS_MAX+1) /* max number groups */
87 #define NOFILE OPEN_MAX /* max open files per process */
88 #define NOGROUP 65535 /* marker for empty group set member */
89 #define MAXHOSTNAMELEN 256 /* max hostname size */
90 #define SPECNAMELEN 63 /* max length of devicename */
92 /* More types and definitions used throughout the kernel. */
94 #include <sys/cdefs.h>
95 #include <sys/errno.h>
98 #include <sys/priority.h>
111 #include <sys/signal.h>
114 /* Machine type dependent parameters. */
115 #include <machine/param.h>
117 #include <sys/limits.h>
120 #ifndef _NO_NAMESPACE_POLLUTION
123 #define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */
125 #define DEV_BSIZE (1<<DEV_BSHIFT)
127 #ifndef BLKDEV_IOSIZE
128 #define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */
131 #define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */
134 #define MAXPHYS (128 * 1024) /* max raw I/O transfer size */
137 #define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE)
141 * Constants related to network buffer management.
142 * MCLBYTES must be no larger than PAGE_SIZE.
145 #define MSIZE 256 /* size of an mbuf */
149 #define MCLSHIFT 11 /* convert bytes to mbuf clusters */
150 #endif /* MCLSHIFT */
152 #define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */
154 #define MJUMPAGESIZE PAGE_SIZE /* jumbo cluster 4k */
155 #define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */
156 #define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */
159 * Some macros for units conversion
162 /* clicks to bytes */
164 #define ctob(x) ((x)<<PAGE_SHIFT)
167 /* bytes to clicks */
169 #define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
173 * btodb() is messy and perhaps slow because `bytes' may be an off_t. We
174 * want to shift an unsigned type to avoid sign extension and we don't
175 * want to widen `bytes' unnecessarily. Assume that the result fits in
179 #define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \
180 (sizeof (bytes) > sizeof(long) \
181 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
182 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
186 #define dbtob(db) /* calculates (db * DEV_BSIZE) */ \
187 ((off_t)(db) << DEV_BSHIFT)
190 #endif /* _NO_NAMESPACE_POLLUTION */
192 #define PRIMASK 0x0ff
193 #define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */
194 #define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */
195 #define PBDRY 0x400 /* for PCATCH stop is done on the user boundary */
197 #define NZERO 0 /* default "nice" */
199 #define NBBY 8 /* number of bits in a byte */
200 #define NBPW sizeof(int) /* number of bytes per word (integer) */
202 #define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
204 #define NODEV (dev_t)(-1) /* non-existent device */
207 * File system parameters and macros.
209 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes
210 * per block. MAXBSIZE may be made larger without effecting
211 * any existing filesystems as long as it does not exceed MAXPHYS,
212 * and may be made smaller at the risk of not being able to use
213 * filesystems which require a block size exceeding MAXBSIZE.
215 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the
216 * minimum KVM memory reservation the kernel is willing to make.
217 * Filesystems can of course request smaller chunks. Actual
218 * backing memory uses a chunk size of a page (PAGE_SIZE).
220 * If you make BKVASIZE too small you risk seriously fragmenting
221 * the buffer KVM map which may slow things down a bit. If you
222 * make it too big the kernel will not be able to optimally use
223 * the KVM memory reserved for the buffer cache and will wind
224 * up with too-few buffers.
226 * The default is 16384, roughly 2x the block size used by a
227 * normal UFS filesystem.
229 #define MAXBSIZE 65536 /* must be power of 2 */
230 #define BKVASIZE 16384 /* must be power of 2 */
231 #define BKVAMASK (BKVASIZE-1)
234 * MAXPATHLEN defines the longest permissible path length after expanding
235 * symbolic links. It is used to allocate a temporary buffer from the buffer
236 * pool in which to do the name expansion, hence should be a power of two,
237 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the
238 * maximum number of symbolic links that may be expanded in a path name.
239 * It should be set high enough to allow all legitimate uses, but halt
240 * infinite loops reasonably quickly.
242 #define MAXPATHLEN PATH_MAX
243 #define MAXSYMLINKS 32
245 /* Bit map related macros. */
246 #define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
247 #define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
249 (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
251 ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
253 /* Macros for counting and rounding. */
255 #define howmany(x, y) (((x)+((y)-1))/(y))
257 #define rounddown(x, y) (((x)/(y))*(y))
258 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
259 #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
260 #define powerof2(x) ((((x)-1)&(x))==0)
262 /* Macros for min/max. */
263 #define MIN(a,b) (((a)<(b))?(a):(b))
264 #define MAX(a,b) (((a)>(b))?(a):(b))
268 * Basic byte order function prototypes for non-inline functions.
271 #ifndef _BYTEORDER_PROTOTYPED
272 #define _BYTEORDER_PROTOTYPED
274 __uint32_t htonl(__uint32_t);
275 __uint16_t htons(__uint16_t);
276 __uint32_t ntohl(__uint32_t);
277 __uint16_t ntohs(__uint16_t);
283 #ifndef _BYTEORDER_FUNC_DEFINED
284 #define _BYTEORDER_FUNC_DEFINED
285 #define htonl(x) __htonl(x)
286 #define htons(x) __htons(x)
287 #define ntohl(x) __ntohl(x)
288 #define ntohs(x) __ntohs(x)
289 #endif /* !_BYTEORDER_FUNC_DEFINED */
294 * Scale factor for scaled integers used to count %cpu time and load avgs.
296 * The number of CPU `tick's that map to a unique `%age' can be expressed
297 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
298 * can be calculated (assuming 32 bits) can be closely approximated using
299 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
301 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
302 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
304 #define FSHIFT 11 /* bits to right of fixed binary point */
305 #define FSCALE (1<<FSHIFT)
307 #define dbtoc(db) /* calculates devblks to pages */ \
308 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
310 #define ctodb(db) /* calculates pages to devblks */ \
311 ((db) << (PAGE_SHIFT - DEV_BSHIFT))
314 * Given the pointer x to the member m of the struct s, return
315 * a pointer to the containing structure.
317 #define member2struct(s, m, x) \
318 ((struct s *)(void *)((char *)(x) - offsetof(struct s, m)))
320 #endif /* _SYS_PARAM_H_ */