bsd/sys/param.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
  23 /*-
  24  * Copyright (c) 1982, 1986, 1989, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  * (c) UNIX System Laboratories, Inc.
  27  * All or some portions of this file are derived from material licensed
  28  * to the University of California by American Telephone and Telegraph
  29  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  30  * the permission of UNIX System Laboratories, Inc.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)param.h     8.3 (Berkeley) 4/4/95
  61  */
  62
  63 #ifndef _SYS_PARAM_H_
  64 #define _SYS_PARAM_H_
  65
  66 #define BSD     199506          /* System version (year & month). */
  67 #define BSD4_3  1
  68 #define BSD4_4  1
  69
  70 #define NeXTBSD 1995064         /* NeXTBSD version (year, month, release) */
  71 #define NeXTBSD4_0 0            /* NeXTBSD 4.0 */
  72
  73 #ifndef NULL
  74 #define NULL    0
  75 #endif
  76
  77 #ifndef LOCORE
  78 #include <sys/types.h>
  79 #endif
  80
  81 /*
  82  * Machine-independent constants (some used in following include files).
  83  * Redefined constants are from POSIX 1003.1 limits file.
  84  *
  85  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
  86  * MAXLOGNAME should be >= UT_NAMESIZE (see <utmp.h>)
  87  */
  88 #include <sys/syslimits.h>
  89
  90 #define MAXCOMLEN       16              /* max command name remembered */
  91 #define MAXINTERP       64              /* max interpreter file name length */
  92 #define MAXLOGNAME      12              /* max login name length */
  93 #define MAXUPRC         CHILD_MAX       /* max simultaneous processes */
  94 #define NCARGS          ARG_MAX         /* max bytes for an exec function */
  95 #define NGROUPS         NGROUPS_MAX     /* max number groups */
  96 #define NOFILE          256             /* default max open files per process */
  97 #define NOGROUP         65535           /* marker for empty group set member */
  98 #define MAXHOSTNAMELEN  256             /* max hostname size */
  99 #define MAXDOMNAMELEN   256             /* maximum domain name length */
 100
 101 /* Machine type dependent parameters. */
 102 #include <machine/param.h>
 103 #include <machine/limits.h>
 104
 105 /* More types and definitions used throughout the kernel. */
 106 #ifdef KERNEL
 107 #include <sys/cdefs.h>
 108 #include <sys/errno.h>
 109 #include <sys/time.h>
 110 #include <sys/resource.h>
 111 #include <sys/ucred.h>
 112 #include <sys/uio.h>
 113 #endif
 114
 115 /* Signals. */
 116 #include <sys/signal.h>
 117
 118 /*
 119  * Priorities.  Note that with 32 run queues, differences less than 4 are
 120  * insignificant.
 121  */
 122 #define PSWP    0
 123 #define PVM     4
 124 #define PINOD   8
 125 #define PRIBIO  16
 126 #define PVFS    20
 127 #define PZERO   22              /* No longer magic, shouldn't be here.  XXX */
 128 #define PSOCK   24
 129 #define PWAIT   32
 130 #define PLOCK   36
 131 #define PPAUSE  40
 132 #define PUSER   50
 133 #define MAXPRI  127             /* Priorities range from 0 through MAXPRI. */
 134
 135 #define PRIMASK 0x0ff
 136 #define PCATCH  0x100           /* OR'd with pri for tsleep to check signals */
 137 #define PTTYBLOCK 0x200         /* for tty SIGTTOU and SIGTTIN blocking */
 138
 139 #define NZERO   0               /* default "nice" */
 140
 141 #define NBPW    sizeof(int)     /* number of bytes per word (integer) */
 142
 143 #define CMASK   022             /* default file mask: S_IWGRP|S_IWOTH */
 144 #define NODEV   (dev_t)(-1)     /* non-existent device */
 145
 146 /*
 147  * Clustering of hardware pages on machines with ridiculously small
 148  * page sizes is done here.  The paging subsystem deals with units of
 149  * CLSIZE pte's describing NBPG (from machine/param.h) pages each.
 150  */
 151 #define CLBYTES         (CLSIZE*NBPG)
 152 #define CLOFSET         (CLSIZE*NBPG-1) /* for clusters, like PGOFSET */
 153 #define claligned(x)    ((((int)(x))&CLOFSET)==0)
 154 #define CLOFF           CLOFSET
 155 #define CLSHIFT         (PGSHIFT+CLSIZELOG2)
 156
 157 #if CLSIZE==1
 158 #define clbase(i)       (i)
 159 #define clrnd(i)        (i)
 160 #else
 161 /* Give the base virtual address (first of CLSIZE). */
 162 #define clbase(i)       ((i) &~ (CLSIZE-1))
 163 /* Round a number of clicks up to a whole cluster. */
 164 #define clrnd(i)        (((i) + (CLSIZE-1)) &~ (CLSIZE-1))
 165 #endif
 166
 167 #define CBLOCK  64              /* Clist block size, must be a power of 2. */
 168 #define CBQSIZE (CBLOCK/NBBY)   /* Quote bytes/cblock - can do better. */
 169                                 /* Data chars/clist. */
 170 #define CBSIZE  (CBLOCK - sizeof(struct cblock *) - CBQSIZE)
 171 #define CROUND  (CBLOCK - 1)    /* Clist rounding. */
 172
 173 /*
 174  * File system parameters and macros.
 175  *
 176  * The file system is made out of blocks of at most MAXBSIZE units, with
 177  * smaller units (fragments) only in the last direct block.  MAXBSIZE
 178  * primarily determines the size of buffers in the buffer pool.  It may be
 179  * made larger without any effect on existing file systems; however making
 180  * it smaller make make some file systems unmountable.
 181  */
 182 #define MAXBSIZE        MAXPHYS
 183 #define MAXPHYSIO       MAXPHYS
 184 #define MAXFRAG         8
 185
 186 /*
 187  * MAXPATHLEN defines the longest permissable path length after expanding
 188  * symbolic links. It is used to allocate a temporary buffer from the buffer
 189  * pool in which to do the name expansion, hence should be a power of two,
 190  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
 191  * maximum number of symbolic links that may be expanded in a path name.
 192  * It should be set high enough to allow all legitimate uses, but halt
 193  * infinite loops reasonably quickly.
 194  */
 195 #define MAXPATHLEN      PATH_MAX
 196 #define MAXSYMLINKS     32
 197
 198 /* Bit map related macros. */
 199 #define setbit(a,i)     (((char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
 200 #define clrbit(a,i)     (((char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
 201 #define isset(a,i)      (((char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
 202 #define isclr(a,i)      ((((char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
 203
 204 /* Macros for counting and rounding. */
 205 #ifndef howmany
 206 #define howmany(x, y)   (((x)+((y)-1))/(y))
 207 #endif
 208 #define roundup(x, y)   ((((x)+((y)-1))/(y))*(y))
 209 #define powerof2(x)     ((((x)-1)&(x))==0)
 210
 211 /* Macros for min/max. */
 212 #ifndef MIN
 213 #define MIN(a,b) (((a)<(b))?(a):(b))
 214 #endif /* MIN */
 215 #ifndef MAX
 216 #define MAX(a,b) (((a)>(b))?(a):(b))
 217 #endif  /* MAX */
 218
 219 /*
 220  * Constants for setting the parameters of the kernel memory allocator.
 221  *
 222  * 2 ** MINBUCKET is the smallest unit of memory that will be
 223  * allocated. It must be at least large enough to hold a pointer.
 224  *
 225  * Units of memory less or equal to MAXALLOCSAVE will permanently
 226  * allocate physical memory; requests for these size pieces of
 227  * memory are quite fast. Allocations greater than MAXALLOCSAVE must
 228  * always allocate and free physical memory; requests for these
 229  * size allocations should be done infrequently as they will be slow.
 230  *
 231  * Constraints: CLBYTES <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
 232  * MAXALLOCSIZE must be a power of two.
 233  */
 234 #define MINBUCKET       4               /* 4 => min allocation of 16 bytes */
 235 #define MAXALLOCSAVE    (2 * CLBYTES)
 236
 237 /*
 238  * Scale factor for scaled integers used to count %cpu time and load avgs.
 239  *
 240  * The number of CPU `tick's that map to a unique `%age' can be expressed
 241  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
 242  * can be calculated (assuming 32 bits) can be closely approximated using
 243  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
 244  *
 245  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
 246  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
 247  */
 248 #define FSHIFT  11              /* bits to right of fixed binary point */
 249 #define FSCALE  (1<<FSHIFT)
 250
 251 #endif  /* _SYS_PARAM_H_ */