bsd/sys/param.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
  29 /*-
  30  * Copyright (c) 1982, 1986, 1989, 1993
  31  *      The Regents of the University of California.  All rights reserved.
  32  * (c) UNIX System Laboratories, Inc.
  33  * All or some portions of this file are derived from material licensed
  34  * to the University of California by American Telephone and Telegraph
  35  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  36  * the permission of UNIX System Laboratories, Inc.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  * 1. Redistributions of source code must retain the above copyright
  42  *    notice, this list of conditions and the following disclaimer.
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in the
  45  *    documentation and/or other materials provided with the distribution.
  46  * 3. All advertising materials mentioning features or use of this software
  47  *    must display the following acknowledgement:
  48  *      This product includes software developed by the University of
  49  *      California, Berkeley and its contributors.
  50  * 4. Neither the name of the University nor the names of its contributors
  51  *    may be used to endorse or promote products derived from this software
  52  *    without specific prior written permission.
  53  *
  54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  64  * SUCH DAMAGE.
  65  *
  66  *      @(#)param.h     8.3 (Berkeley) 4/4/95
  67  */
  68
  69 #ifndef _SYS_PARAM_H_
  70 #define _SYS_PARAM_H_
  71
  72 #define BSD     199506          /* System version (year & month). */
  73 #define BSD4_3  1
  74 #define BSD4_4  1
  75
  76 #define NeXTBSD 1995064         /* NeXTBSD version (year, month, release) */
  77 #define NeXTBSD4_0 0            /* NeXTBSD 4.0 */
  78
  79 #include <sys/_types.h>
  80 #include <sys/_types/_null.h>
  81
  82 #ifndef LOCORE
  83 #include <sys/types.h>
  84 #endif
  85
  86 /*
  87  * Machine-independent constants (some used in following include files).
  88  * Redefined constants are from POSIX 1003.1 limits file.
  89  *
  90  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
  91  * MAXLOGNAME should be >= UT_NAMESIZE (see <utmp.h>)
  92  */
  93 #include <sys/syslimits.h>
  94
  95 #define MAXCOMLEN       16              /* max command name remembered */
  96 #define MAXINTERP       64              /* max interpreter file name length */
  97 #define MAXLOGNAME      255             /* max login name length */
  98 #define MAXUPRC         CHILD_MAX       /* max simultaneous processes */
  99 #define NCARGS          ARG_MAX         /* max bytes for an exec function */
 100 #define NGROUPS         NGROUPS_MAX     /* max number groups */
 101 #define NOFILE          256             /* default max open files per process */
 102 #define NOGROUP         65535           /* marker for empty group set member */
 103 #define MAXHOSTNAMELEN  256             /* max hostname size */
 104 #define MAXDOMNAMELEN   256             /* maximum domain name length */
 105
 106 /* Machine type dependent parameters. */
 107 #include <machine/param.h>
 108
 109 /* More types and definitions used throughout the kernel. */
 110 #ifdef KERNEL
 111 #include <machine/limits.h>
 112 #include <sys/cdefs.h>
 113 #include <sys/errno.h>
 114 #include <sys/time.h>
 115 #include <sys/resource.h>
 116 #include <sys/ucred.h>
 117 #include <sys/uio.h>
 118 #else
 119 #include <limits.h>
 120 #endif
 121
 122 /* Signals. */
 123 #include <sys/signal.h>
 124
 125 /*
 126  * Priorities.  Note that with 32 run queues, differences less than 4 are
 127  * insignificant.
 128  */
 129 #define PSWP    0
 130 #define PVM     4
 131 #define PINOD   8
 132 #define PRIBIO  16
 133 #define PVFS    20
 134 #define PZERO   22              /* No longer magic, shouldn't be here.  XXX */
 135 #define PSOCK   24
 136 #define PWAIT   32
 137 #define PLOCK   36
 138 #define PPAUSE  40
 139 #define PUSER   50
 140 #define MAXPRI  127             /* Priorities range from 0 through MAXPRI. */
 141
 142 #define PRIMASK 0x0ff
 143 #define PCATCH  0x100           /* OR'd with pri for tsleep to check signals */
 144 #define PTTYBLOCK 0x200         /* for tty SIGTTOU and SIGTTIN blocking */
 145 #define PDROP   0x400           /* OR'd with pri to stop re-aquistion of mutex upon wakeup */
 146 #define PSPIN   0x800           /* OR'd with pri to require mutex in spin mode upon wakeup */
 147
 148 #define NBPW    sizeof(int)     /* number of bytes per word (integer) */
 149
 150 #define CMASK   022             /* default file mask: S_IWGRP|S_IWOTH */
 151 #define NODEV   (dev_t)(-1)     /* non-existent device */
 152
 153 /*
 154  * Clustering of hardware pages on machines with ridiculously small
 155  * page sizes is done here.  The paging subsystem deals with units of
 156  * CLSIZE pte's describing NBPG (from machine/param.h) pages each.
 157  */
 158 #define CLBYTES         (CLSIZE*NBPG)
 159 #define CLOFSET         (CLSIZE*NBPG-1) /* for clusters, like PGOFSET */
 160 #define claligned(x)    ((((int)(x))&CLOFSET)==0)
 161 #define CLOFF           CLOFSET
 162 #define CLSHIFT         (PGSHIFT+CLSIZELOG2)
 163
 164 #if CLSIZE == 1
 165 #define clbase(i)       (i)
 166 #define clrnd(i)        (i)
 167 #else
 168 /* Give the base virtual address (first of CLSIZE). */
 169 #define clbase(i)       ((i) &~ (CLSIZE-1))
 170 /* Round a number of clicks up to a whole cluster. */
 171 #define clrnd(i)        (((i) + (CLSIZE-1)) &~ (CLSIZE-1))
 172 #endif
 173
 174 #define CBLOCK  64              /* Clist block size, must be a power of 2. */
 175 #define CBQSIZE (CBLOCK/NBBY)   /* Quote bytes/cblock - can do better. */
 176                                 /* Data chars/clist. */
 177 #define CBSIZE  (CBLOCK - sizeof(struct cblock *) - CBQSIZE)
 178 #define CROUND  (CBLOCK - 1)    /* Clist rounding. */
 179
 180 /*
 181  * File system parameters and macros.
 182  *
 183  * The file system is made out of blocks of at most MAXPHYS units, with
 184  * smaller units (fragments) only in the last direct block.  MAXBSIZE
 185  * primarily determines the size of buffers in the buffer pool.  It may be
 186  * made larger than MAXPHYS without any effect on existing file systems;
 187  * however making it smaller may make some file systems unmountable.
 188  * We set this to track the value of MAX_UPL_TRANSFER_BYTES from
 189  * osfmk/mach/memory_object_types.h to bound it at the maximum UPL size.
 190  */
 191 #define MAXBSIZE        (256 * 4096)
 192 #define MAXPHYSIO       MAXPHYS
 193 #define MAXFRAG         8
 194
 195 #define MAXPHYSIO_WIRED (16 * 1024 * 1024)
 196
 197 /*
 198  * MAXPATHLEN defines the longest permissable path length after expanding
 199  * symbolic links. It is used to allocate a temporary buffer from the buffer
 200  * pool in which to do the name expansion, hence should be a power of two,
 201  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
 202  * maximum number of symbolic links that may be expanded in a path name.
 203  * It should be set high enough to allow all legitimate uses, but halt
 204  * infinite loops reasonably quickly.
 205  */
 206 #define MAXPATHLEN      PATH_MAX
 207 #define MAXSYMLINKS     32
 208
 209 /* Bit map related macros. */
 210 #define setbit(a, i)     (((char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
 211 #define clrbit(a, i)     (((char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
 212 #define isset(a, i)      (((char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
 213 #define isclr(a, i)      ((((char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
 214
 215 /* Macros for counting and rounding. */
 216 #ifndef howmany
 217 #define howmany(x, y)   ((((x) % (y)) == 0) ? ((x) / (y)) : (((x) / (y)) + 1))
 218 #endif
 219 #define roundup(x, y)   ((((x) % (y)) == 0) ? \
 220                         (x) : ((x) + ((y) - ((x) % (y)))))
 221 #define powerof2(x)     ((((x)-1)&(x))==0)
 222
 223 /* Macros for min/max. */
 224 #ifndef MIN
 225 #define MIN(a, b) (((a)<(b))?(a):(b))
 226 #endif /* MIN */
 227 #ifndef MAX
 228 #define MAX(a, b) (((a)>(b))?(a):(b))
 229 #endif  /* MAX */
 230
 231 /*
 232  * Constants for setting the parameters of the kernel memory allocator.
 233  *
 234  * 2 ** MINBUCKET is the smallest unit of memory that will be
 235  * allocated. It must be at least large enough to hold a pointer.
 236  *
 237  * Units of memory less or equal to MAXALLOCSAVE will permanently
 238  * allocate physical memory; requests for these size pieces of
 239  * memory are quite fast. Allocations greater than MAXALLOCSAVE must
 240  * always allocate and free physical memory; requests for these
 241  * size allocations should be done infrequently as they will be slow.
 242  *
 243  * Constraints: CLBYTES <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
 244  * MAXALLOCSIZE must be a power of two.
 245  */
 246 #define MINBUCKET       4               /* 4 => min allocation of 16 bytes */
 247 #define MAXALLOCSAVE    (2 * CLBYTES)
 248
 249 /*
 250  * Scale factor for scaled integers used to count %cpu time and load avgs.
 251  *
 252  * The number of CPU `tick's that map to a unique `%age' can be expressed
 253  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
 254  * can be calculated (assuming 32 bits) can be closely approximated using
 255  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
 256  *
 257  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
 258  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
 259  */
 260 #define FSHIFT  11              /* bits to right of fixed binary point */
 261 #define FSCALE  (1<<FSHIFT)
 262
 263 #endif  /* _SYS_PARAM_H_ */