usr/src/boot/sys/sys/param.h

   1 /*-
   2  * Copyright (c) 1982, 1986, 1989, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  * (c) UNIX System Laboratories, Inc.
   5  * All or some portions of this file are derived from material licensed
   6  * to the University of California by American Telephone and Telegraph
   7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
   8  * the permission of UNIX System Laboratories, Inc.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)param.h     8.3 (Berkeley) 4/4/95
  35  * $FreeBSD$
  36  */
  37
  38 #ifndef _SYS_PARAM_H_
  39 #define _SYS_PARAM_H_
  40
  41 #include <sys/_null.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  *      head/en_US.ISO8859-1/books/porters-handbook/versions/chapter.xml
  54  *
  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.
  59  */
  60 #undef __FreeBSD_version
  61 #define __FreeBSD_version 1100100       /* Master, propagated to newvers */
  62
  63 /*
  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.
  67  *
  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
  74  * alternative.
  75  */
  76 #undef __FreeBSD_kernel__
  77 #define __FreeBSD_kernel__
  78
  79 #ifdef _KERNEL
  80 #define P_OSREL_SIGWAIT                 700000
  81 #define P_OSREL_SIGSEGV                 700004
  82 #define P_OSREL_MAP_ANON                800104
  83 #define P_OSREL_MAP_FSTRICT             1100036
  84 #define P_OSREL_SHUTDOWN_ENOTCONN       1100077
  85
  86 #define P_OSREL_MAJOR(x)                ((x) / 100000)
  87 #endif
  88
  89 #ifndef LOCORE
  90 #include <sys/types.h>
  91 #endif
  92
  93 /*
  94  * Machine-independent constants (some used in following include files).
  95  * Redefined constants are from POSIX 1003.1 limits file.
  96  *
  97  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
  98  */
  99 #include <sys/syslimits.h>
 100
 101 #define MAXCOMLEN       19              /* max command name remembered */
 102 #define MAXINTERP       PATH_MAX        /* max interpreter file name length */
 103 #define MAXLOGNAME      33              /* max login name length (incl. NUL) */
 104 #define MAXUPRC         CHILD_MAX       /* max simultaneous processes */
 105 #define NCARGS          ARG_MAX         /* max bytes for an exec function */
 106 #define NGROUPS         (NGROUPS_MAX+1) /* max number groups */
 107 #define NOFILE          OPEN_MAX        /* max open files per process */
 108 #define NOGROUP         65535           /* marker for empty group set member */
 109 #define MAXHOSTNAMELEN  256             /* max hostname size */
 110 #define SPECNAMELEN     63              /* max length of devicename */
 111
 112 /* More types and definitions used throughout the kernel. */
 113 #ifdef _KERNEL
 114 #include <sys/cdefs.h>
 115 #include <sys/errno.h>
 116 #ifndef LOCORE
 117 #include <sys/time.h>
 118 #include <sys/priority.h>
 119 #endif
 120
 121 #ifndef FALSE
 122 #define FALSE   0
 123 #endif
 124 #ifndef TRUE
 125 #define TRUE    1
 126 #endif
 127 #endif
 128
 129 #ifndef _KERNEL
 130 /* Signals. */
 131 #include <sys/signal.h>
 132 #endif
 133
 134 /* Machine type dependent parameters. */
 135 #include <machine/param.h>
 136 #ifndef _KERNEL
 137 #include <sys/limits.h>
 138 #endif
 139
 140 #ifndef DEV_BSHIFT
 141 #define DEV_BSHIFT      9               /* log2(DEV_BSIZE) */
 142 #endif
 143 #define DEV_BSIZE       (1<<DEV_BSHIFT)
 144
 145 #ifndef BLKDEV_IOSIZE
 146 #define BLKDEV_IOSIZE  PAGE_SIZE        /* default block device I/O size */
 147 #endif
 148 #ifndef DFLTPHYS
 149 #define DFLTPHYS        (64 * 1024)     /* default max raw I/O transfer size */
 150 #endif
 151 #ifndef MAXPHYS
 152 #define MAXPHYS         (128 * 1024)    /* max raw I/O transfer size */
 153 #endif
 154 #ifndef MAXDUMPPGS
 155 #define MAXDUMPPGS      (DFLTPHYS/PAGE_SIZE)
 156 #endif
 157
 158 /*
 159  * Constants related to network buffer management.
 160  * MCLBYTES must be no larger than PAGE_SIZE.
 161  */
 162 #ifndef MSIZE
 163 #define MSIZE           256             /* size of an mbuf */
 164 #endif
 165
 166 #ifndef MCLSHIFT
 167 #define MCLSHIFT        11              /* convert bytes to mbuf clusters */
 168 #endif  /* MCLSHIFT */
 169
 170 #define MCLBYTES        (1 << MCLSHIFT) /* size of an mbuf cluster */
 171
 172 #if PAGE_SIZE < 2048
 173 #define MJUMPAGESIZE    MCLBYTES
 174 #elif PAGE_SIZE <= 8192
 175 #define MJUMPAGESIZE    PAGE_SIZE
 176 #else
 177 #define MJUMPAGESIZE    (8 * 1024)
 178 #endif
 179
 180 #define MJUM9BYTES      (9 * 1024)      /* jumbo cluster 9k */
 181 #define MJUM16BYTES     (16 * 1024)     /* jumbo cluster 16k */
 182
 183 /*
 184  * Some macros for units conversion
 185  */
 186
 187 /* clicks to bytes */
 188 #ifndef ctob
 189 #define ctob(x) ((x)<<PAGE_SHIFT)
 190 #endif
 191
 192 /* bytes to clicks */
 193 #ifndef btoc
 194 #define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
 195 #endif
 196
 197 /*
 198  * btodb() is messy and perhaps slow because `bytes' may be an off_t.  We
 199  * want to shift an unsigned type to avoid sign extension and we don't
 200  * want to widen `bytes' unnecessarily.  Assume that the result fits in
 201  * a daddr_t.
 202  */
 203 #ifndef btodb
 204 #define btodb(bytes)                    /* calculates (bytes / DEV_BSIZE) */ \
 205         (sizeof (bytes) > sizeof(long) \
 206          ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
 207          : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
 208 #endif
 209
 210 #ifndef dbtob
 211 #define dbtob(db)                       /* calculates (db * DEV_BSIZE) */ \
 212         ((off_t)(db) << DEV_BSHIFT)
 213 #endif
 214
 215 #define PRIMASK 0x0ff
 216 #define PCATCH  0x100           /* OR'd with pri for tsleep to check signals */
 217 #define PDROP   0x200   /* OR'd with pri to stop re-entry of interlock mutex */
 218
 219 #define NZERO   0               /* default "nice" */
 220
 221 #define NBBY    8               /* number of bits in a byte */
 222 #define NBPW    sizeof(int)     /* number of bytes per word (integer) */
 223
 224 #define CMASK   022             /* default file mask: S_IWGRP|S_IWOTH */
 225
 226 #define NODEV   (dev_t)(-1)     /* non-existent device */
 227
 228 /*
 229  * File system parameters and macros.
 230  *
 231  * MAXBSIZE -   Filesystems are made out of blocks of at most MAXBSIZE bytes
 232  *              per block.  MAXBSIZE may be made larger without effecting
 233  *              any existing filesystems as long as it does not exceed MAXPHYS,
 234  *              and may be made smaller at the risk of not being able to use
 235  *              filesystems which require a block size exceeding MAXBSIZE.
 236  *
 237  * MAXBCACHEBUF - Maximum size of a buffer in the buffer cache.  This must
 238  *              be >= MAXBSIZE and can be set differently for different
 239  *              architectures by defining it in <machine/param.h>.
 240  *              Making this larger allows NFS to do larger reads/writes.
 241  *
 242  * BKVASIZE -   Nominal buffer space per buffer, in bytes.  BKVASIZE is the
 243  *              minimum KVM memory reservation the kernel is willing to make.
 244  *              Filesystems can of course request smaller chunks.  Actual
 245  *              backing memory uses a chunk size of a page (PAGE_SIZE).
 246  *              The default value here can be overridden on a per-architecture
 247  *              basis by defining it in <machine/param.h>.  This should
 248  *              probably be done to increase its value, when MAXBCACHEBUF is
 249  *              defined as a larger value in <machine/param.h>.
 250  *
 251  *              If you make BKVASIZE too small you risk seriously fragmenting
 252  *              the buffer KVM map which may slow things down a bit.  If you
 253  *              make it too big the kernel will not be able to optimally use
 254  *              the KVM memory reserved for the buffer cache and will wind
 255  *              up with too-few buffers.
 256  *
 257  *              The default is 16384, roughly 2x the block size used by a
 258  *              normal UFS filesystem.
 259  */
 260 #define MAXBSIZE        65536   /* must be power of 2 */
 261 #ifndef MAXBCACHEBUF
 262 #define MAXBCACHEBUF    MAXBSIZE /* must be a power of 2 >= MAXBSIZE */
 263 #endif
 264 #ifndef BKVASIZE
 265 #define BKVASIZE        16384   /* must be power of 2 */
 266 #endif
 267 #define BKVAMASK        (BKVASIZE-1)
 268
 269 /*
 270  * MAXPATHLEN defines the longest permissible path length after expanding
 271  * symbolic links. It is used to allocate a temporary buffer from the buffer
 272  * pool in which to do the name expansion, hence should be a power of two,
 273  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
 274  * maximum number of symbolic links that may be expanded in a path name.
 275  * It should be set high enough to allow all legitimate uses, but halt
 276  * infinite loops reasonably quickly.
 277  */
 278 #define MAXPATHLEN      PATH_MAX
 279 #define MAXSYMLINKS     32
 280
 281 /* Bit map related macros. */
 282 #define setbit(a,i)     (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
 283 #define clrbit(a,i)     (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
 284 #define isset(a,i)                                                      \
 285         (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
 286 #define isclr(a,i)                                                      \
 287         ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
 288
 289 /* Macros for counting and rounding. */
 290 #ifndef howmany
 291 #define howmany(x, y)   (((x)+((y)-1))/(y))
 292 #endif
 293 #define nitems(x)       (sizeof((x)) / sizeof((x)[0]))
 294 #define rounddown(x, y) (((x)/(y))*(y))
 295 #define rounddown2(x, y) ((x)&(~((y)-1)))          /* if y is power of two */
 296 #define roundup(x, y)   ((((x)+((y)-1))/(y))*(y))  /* to any y */
 297 #define roundup2(x, y)  (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
 298 #define powerof2(x)     ((((x)-1)&(x))==0)
 299
 300 /* Macros for min/max. */
 301 #define MIN(a,b) (((a)<(b))?(a):(b))
 302 #define MAX(a,b) (((a)>(b))?(a):(b))
 303
 304 #ifdef _KERNEL
 305 /*
 306  * Basic byte order function prototypes for non-inline functions.
 307  */
 308 #ifndef LOCORE
 309 #ifndef _BYTEORDER_PROTOTYPED
 310 #define _BYTEORDER_PROTOTYPED
 311 __BEGIN_DECLS
 312 __uint32_t       htonl(__uint32_t);
 313 __uint16_t       htons(__uint16_t);
 314 __uint32_t       ntohl(__uint32_t);
 315 __uint16_t       ntohs(__uint16_t);
 316 __END_DECLS
 317 #endif
 318 #endif
 319
 320 #ifndef lint
 321 #ifndef _BYTEORDER_FUNC_DEFINED
 322 #define _BYTEORDER_FUNC_DEFINED
 323 #define htonl(x)        __htonl(x)
 324 #define htons(x)        __htons(x)
 325 #define ntohl(x)        __ntohl(x)
 326 #define ntohs(x)        __ntohs(x)
 327 #endif /* !_BYTEORDER_FUNC_DEFINED */
 328 #endif /* lint */
 329 #endif /* _KERNEL */
 330
 331 /*
 332  * Scale factor for scaled integers used to count %cpu time and load avgs.
 333  *
 334  * The number of CPU `tick's that map to a unique `%age' can be expressed
 335  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
 336  * can be calculated (assuming 32 bits) can be closely approximated using
 337  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
 338  *
 339  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
 340  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
 341  */
 342 #define FSHIFT  11              /* bits to right of fixed binary point */
 343 #define FSCALE  (1<<FSHIFT)
 344
 345 #define dbtoc(db)                       /* calculates devblks to pages */ \
 346         ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
 347
 348 #define ctodb(db)                       /* calculates pages to devblks */ \
 349         ((db) << (PAGE_SHIFT - DEV_BSHIFT))
 350
 351 /*
 352  * Old spelling of __containerof().
 353  */
 354 #define member2struct(s, m, x)                                          \
 355         ((struct s *)(void *)((char *)(x) - offsetof(struct s, m)))
 356
 357 /*
 358  * Access a variable length array that has been declared as a fixed
 359  * length array.
 360  */
 361 #define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset])
 362
 363 #endif  /* _SYS_PARAM_H_ */