bsd/sys/param.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
  26 /*-
  27  * Copyright (c) 1982, 1986, 1989, 1993
  28  *      The Regents of the University of California.  All rights reserved.
  29  * (c) UNIX System Laboratories, Inc.
  30  * All or some portions of this file are derived from material licensed
  31  * to the University of California by American Telephone and Telegraph
  32  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  33  * the permission of UNIX System Laboratories, Inc.
  34  *
  35  * Redistribution and use in source and binary forms, with or without
  36  * modification, are permitted provided that the following conditions
  37  * are met:
  38  * 1. Redistributions of source code must retain the above copyright
  39  *    notice, this list of conditions and the following disclaimer.
  40  * 2. Redistributions in binary form must reproduce the above copyright
  41  *    notice, this list of conditions and the following disclaimer in the
  42  *    documentation and/or other materials provided with the distribution.
  43  * 3. All advertising materials mentioning features or use of this software
  44  *    must display the following acknowledgement:
  45  *      This product includes software developed by the University of
  46  *      California, Berkeley and its contributors.
  47  * 4. Neither the name of the University nor the names of its contributors
  48  *    may be used to endorse or promote products derived from this software
  49  *    without specific prior written permission.
  50  *
  51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  61  * SUCH DAMAGE.
  62  *
  63  *      @(#)param.h     8.3 (Berkeley) 4/4/95
  64  */
  65
  66 #ifndef _SYS_PARAM_H_
  67 #define _SYS_PARAM_H_
  68
  69 #define BSD     199506          /* System version (year & month). */
  70 #define BSD4_3  1
  71 #define BSD4_4  1
  72
  73 #define NeXTBSD 1995064         /* NeXTBSD version (year, month, release) */
  74 #define NeXTBSD4_0 0            /* NeXTBSD 4.0 */
  75
  76 #ifndef NULL
  77 #define NULL    0
  78 #endif
  79
  80 #ifndef LOCORE
  81 #include <sys/types.h>
  82 #endif
  83
  84 /*
  85  * Machine-independent constants (some used in following include files).
  86  * Redefined constants are from POSIX 1003.1 limits file.
  87  *
  88  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
  89  * MAXLOGNAME should be >= UT_NAMESIZE (see <utmp.h>)
  90  */
  91 #include <sys/syslimits.h>
  92
  93 #define MAXCOMLEN       16              /* max command name remembered */
  94 #define MAXINTERP       64              /* max interpreter file name length */
  95 #define MAXLOGNAME      255             /* max login name length */
  96 #define MAXUPRC         CHILD_MAX       /* max simultaneous processes */
  97 #define NCARGS          ARG_MAX         /* max bytes for an exec function */
  98 #define NGROUPS         NGROUPS_MAX     /* max number groups */
  99 #define NOFILE          256             /* default max open files per process */
 100 #define NOGROUP         65535           /* marker for empty group set member */
 101 #define MAXHOSTNAMELEN  256             /* max hostname size */
 102 #define MAXDOMNAMELEN   256             /* maximum domain name length */
 103
 104 /* Machine type dependent parameters. */
 105 #include <machine/param.h>
 106
 107 /* More types and definitions used throughout the kernel. */
 108 #ifdef KERNEL
 109 #include <machine/limits.h>
 110 #include <sys/cdefs.h>
 111 #include <sys/errno.h>
 112 #include <sys/time.h>
 113 #include <sys/resource.h>
 114 #include <sys/ucred.h>
 115 #include <sys/uio.h>
 116 #else
 117 #include <limits.h>
 118 #endif
 119
 120 /* Signals. */
 121 #include <sys/signal.h>
 122
 123 /*
 124  * Priorities.  Note that with 32 run queues, differences less than 4 are
 125  * insignificant.
 126  */
 127 #define PSWP    0
 128 #define PVM     4
 129 #define PINOD   8
 130 #define PRIBIO  16
 131 #define PVFS    20
 132 #define PZERO   22              /* No longer magic, shouldn't be here.  XXX */
 133 #define PSOCK   24
 134 #define PWAIT   32
 135 #define PLOCK   36
 136 #define PPAUSE  40
 137 #define PUSER   50
 138 #define MAXPRI  127             /* Priorities range from 0 through MAXPRI. */
 139
 140 #define PRIMASK 0x0ff
 141 #define PCATCH  0x100           /* OR'd with pri for tsleep to check signals */
 142 #define PTTYBLOCK 0x200         /* for tty SIGTTOU and SIGTTIN blocking */
 143
 144 #define NZERO   0               /* default "nice" */
 145
 146 #define NBPW    sizeof(int)     /* number of bytes per word (integer) */
 147
 148 #define CMASK   022             /* default file mask: S_IWGRP|S_IWOTH */
 149 #define NODEV   (dev_t)(-1)     /* non-existent device */
 150
 151 /*
 152  * Clustering of hardware pages on machines with ridiculously small
 153  * page sizes is done here.  The paging subsystem deals with units of
 154  * CLSIZE pte's describing NBPG (from machine/param.h) pages each.
 155  */
 156 #define CLBYTES         (CLSIZE*NBPG)
 157 #define CLOFSET         (CLSIZE*NBPG-1) /* for clusters, like PGOFSET */
 158 #define claligned(x)    ((((int)(x))&CLOFSET)==0)
 159 #define CLOFF           CLOFSET
 160 #define CLSHIFT         (PGSHIFT+CLSIZELOG2)
 161
 162 #if CLSIZE==1
 163 #define clbase(i)       (i)
 164 #define clrnd(i)        (i)
 165 #else
 166 /* Give the base virtual address (first of CLSIZE). */
 167 #define clbase(i)       ((i) &~ (CLSIZE-1))
 168 /* Round a number of clicks up to a whole cluster. */
 169 #define clrnd(i)        (((i) + (CLSIZE-1)) &~ (CLSIZE-1))
 170 #endif
 171
 172 #define CBLOCK  64              /* Clist block size, must be a power of 2. */
 173 #define CBQSIZE (CBLOCK/NBBY)   /* Quote bytes/cblock - can do better. */
 174                                 /* Data chars/clist. */
 175 #define CBSIZE  (CBLOCK - sizeof(struct cblock *) - CBQSIZE)
 176 #define CROUND  (CBLOCK - 1)    /* Clist rounding. */
 177
 178 /*
 179  * File system parameters and macros.
 180  *
 181  * The file system is made out of blocks of at most MAXBSIZE units, with
 182  * smaller units (fragments) only in the last direct block.  MAXBSIZE
 183  * primarily determines the size of buffers in the buffer pool.  It may be
 184  * made larger without any effect on existing file systems; however making
 185  * it smaller make make some file systems unmountable.
 186  */
 187 #define MAXBSIZE        MAXPHYS
 188 #define MAXPHYSIO       MAXPHYS
 189 #define MAXFRAG         8
 190
 191 /*
 192  * MAXPATHLEN defines the longest permissable path length after expanding
 193  * symbolic links. It is used to allocate a temporary buffer from the buffer
 194  * pool in which to do the name expansion, hence should be a power of two,
 195  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
 196  * maximum number of symbolic links that may be expanded in a path name.
 197  * It should be set high enough to allow all legitimate uses, but halt
 198  * infinite loops reasonably quickly.
 199  */
 200 #define MAXPATHLEN      PATH_MAX
 201 #define MAXSYMLINKS     32
 202
 203 /* Bit map related macros. */
 204 #define setbit(a,i)     (((char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
 205 #define clrbit(a,i)     (((char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
 206 #define isset(a,i)      (((char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
 207 #define isclr(a,i)      ((((char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
 208
 209 /* Macros for counting and rounding. */
 210 #ifndef howmany
 211 #define howmany(x, y)   (((x)+((y)-1))/(y))
 212 #endif
 213 #define roundup(x, y)   ((((x)+((y)-1))/(y))*(y))
 214 #define powerof2(x)     ((((x)-1)&(x))==0)
 215
 216 /* Macros for min/max. */
 217 #ifndef MIN
 218 #define MIN(a,b) (((a)<(b))?(a):(b))
 219 #endif /* MIN */
 220 #ifndef MAX
 221 #define MAX(a,b) (((a)>(b))?(a):(b))
 222 #endif  /* MAX */
 223
 224 /*
 225  * Constants for setting the parameters of the kernel memory allocator.
 226  *
 227  * 2 ** MINBUCKET is the smallest unit of memory that will be
 228  * allocated. It must be at least large enough to hold a pointer.
 229  *
 230  * Units of memory less or equal to MAXALLOCSAVE will permanently
 231  * allocate physical memory; requests for these size pieces of
 232  * memory are quite fast. Allocations greater than MAXALLOCSAVE must
 233  * always allocate and free physical memory; requests for these
 234  * size allocations should be done infrequently as they will be slow.
 235  *
 236  * Constraints: CLBYTES <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
 237  * MAXALLOCSIZE must be a power of two.
 238  */
 239 #define MINBUCKET       4               /* 4 => min allocation of 16 bytes */
 240 #define MAXALLOCSAVE    (2 * CLBYTES)
 241
 242 /*
 243  * Scale factor for scaled integers used to count %cpu time and load avgs.
 244  *
 245  * The number of CPU `tick's that map to a unique `%age' can be expressed
 246  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
 247  * can be calculated (assuming 32 bits) can be closely approximated using
 248  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
 249  *
 250  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
 251  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
 252  */
 253 #define FSHIFT  11              /* bits to right of fixed binary point */
 254 #define FSCALE  (1<<FSHIFT)
 255
 256 #endif  /* _SYS_PARAM_H_ */