bsd/sys/param.h

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
  31 /*-
  32  * Copyright (c) 1982, 1986, 1989, 1993
  33  *      The Regents of the University of California.  All rights reserved.
  34  * (c) UNIX System Laboratories, Inc.
  35  * All or some portions of this file are derived from material licensed
  36  * to the University of California by American Telephone and Telegraph
  37  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  38  * the permission of UNIX System Laboratories, Inc.
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  * 3. All advertising materials mentioning features or use of this software
  49  *    must display the following acknowledgement:
  50  *      This product includes software developed by the University of
  51  *      California, Berkeley and its contributors.
  52  * 4. Neither the name of the University nor the names of its contributors
  53  *    may be used to endorse or promote products derived from this software
  54  *    without specific prior written permission.
  55  *
  56  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  57  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  58  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  59  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  60  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  61  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  62  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  63  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  64  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  65  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  66  * SUCH DAMAGE.
  67  *
  68  *      @(#)param.h     8.3 (Berkeley) 4/4/95
  69  */
  70
  71 #ifndef _SYS_PARAM_H_
  72 #define _SYS_PARAM_H_
  73
  74 #define BSD     199506          /* System version (year & month). */
  75 #define BSD4_3  1
  76 #define BSD4_4  1
  77
  78 #define NeXTBSD 1995064         /* NeXTBSD version (year, month, release) */
  79 #define NeXTBSD4_0 0            /* NeXTBSD 4.0 */
  80
  81 #include <sys/_types.h>
  82
  83 #ifndef NULL
  84 #define NULL    __DARWIN_NULL
  85 #endif /* ! NULL */
  86
  87 #ifndef LOCORE
  88 #include <sys/types.h>
  89 #endif
  90
  91 /*
  92  * Machine-independent constants (some used in following include files).
  93  * Redefined constants are from POSIX 1003.1 limits file.
  94  *
  95  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
  96  * MAXLOGNAME should be >= UT_NAMESIZE (see <utmp.h>)
  97  */
  98 #include <sys/syslimits.h>
  99
 100 #define MAXCOMLEN       16              /* max command name remembered */
 101 #define MAXINTERP       64              /* max interpreter file name length */
 102 #define MAXLOGNAME      255             /* max login name length */
 103 #define MAXUPRC         CHILD_MAX       /* max simultaneous processes */
 104 #define NCARGS          ARG_MAX         /* max bytes for an exec function */
 105 #define NGROUPS         NGROUPS_MAX     /* max number groups */
 106 #define NOFILE          256             /* default max open files per process */
 107 #define NOGROUP         65535           /* marker for empty group set member */
 108 #define MAXHOSTNAMELEN  256             /* max hostname size */
 109 #define MAXDOMNAMELEN   256             /* maximum domain name length */
 110
 111 /* Machine type dependent parameters. */
 112 #include <machine/param.h>
 113
 114 /* More types and definitions used throughout the kernel. */
 115 #ifdef KERNEL
 116 #include <machine/limits.h>
 117 #include <sys/cdefs.h>
 118 #include <sys/errno.h>
 119 #include <sys/time.h>
 120 #include <sys/resource.h>
 121 #include <sys/ucred.h>
 122 #include <sys/uio.h>
 123 #else
 124 #include <limits.h>
 125 #endif
 126
 127 /* Signals. */
 128 #include <sys/signal.h>
 129
 130 /*
 131  * Priorities.  Note that with 32 run queues, differences less than 4 are
 132  * insignificant.
 133  */
 134 #define PSWP    0
 135 #define PVM     4
 136 #define PINOD   8
 137 #define PRIBIO  16
 138 #define PVFS    20
 139 #define PZERO   22              /* No longer magic, shouldn't be here.  XXX */
 140 #define PSOCK   24
 141 #define PWAIT   32
 142 #define PLOCK   36
 143 #define PPAUSE  40
 144 #define PUSER   50
 145 #define MAXPRI  127             /* Priorities range from 0 through MAXPRI. */
 146
 147 #define PRIMASK 0x0ff
 148 #define PCATCH  0x100           /* OR'd with pri for tsleep to check signals */
 149 #define PTTYBLOCK 0x200         /* for tty SIGTTOU and SIGTTIN blocking */
 150 #define PDROP   0x400           /* OR'd with pri to stop re-entry of interlock mutex */
 151
 152 #define NZERO   0               /* default "nice" */
 153
 154 #define NBPW    sizeof(int)     /* number of bytes per word (integer) */
 155
 156 #define CMASK   022             /* default file mask: S_IWGRP|S_IWOTH */
 157 #define NODEV   (dev_t)(-1)     /* non-existent device */
 158
 159 /*
 160  * Clustering of hardware pages on machines with ridiculously small
 161  * page sizes is done here.  The paging subsystem deals with units of
 162  * CLSIZE pte's describing NBPG (from machine/param.h) pages each.
 163  */
 164 #define CLBYTES         (CLSIZE*NBPG)
 165 #define CLOFSET         (CLSIZE*NBPG-1) /* for clusters, like PGOFSET */
 166 #define claligned(x)    ((((int)(x))&CLOFSET)==0)
 167 #define CLOFF           CLOFSET
 168 #define CLSHIFT         (PGSHIFT+CLSIZELOG2)
 169
 170 #if CLSIZE==1
 171 #define clbase(i)       (i)
 172 #define clrnd(i)        (i)
 173 #else
 174 /* Give the base virtual address (first of CLSIZE). */
 175 #define clbase(i)       ((i) &~ (CLSIZE-1))
 176 /* Round a number of clicks up to a whole cluster. */
 177 #define clrnd(i)        (((i) + (CLSIZE-1)) &~ (CLSIZE-1))
 178 #endif
 179
 180 #define CBLOCK  64              /* Clist block size, must be a power of 2. */
 181 #define CBQSIZE (CBLOCK/NBBY)   /* Quote bytes/cblock - can do better. */
 182                                 /* Data chars/clist. */
 183 #define CBSIZE  (CBLOCK - sizeof(struct cblock *) - CBQSIZE)
 184 #define CROUND  (CBLOCK - 1)    /* Clist rounding. */
 185
 186 /*
 187  * File system parameters and macros.
 188  *
 189  * The file system is made out of blocks of at most MAXPHYS units, with
 190  * smaller units (fragments) only in the last direct block.  MAXBSIZE
 191  * primarily determines the size of buffers in the buffer pool.  It may be
 192  * made larger than MAXPHYS without any effect on existing file systems;
 193  * however making it smaller may make some file systems unmountable.
 194  * We set this to track the value of (MAX_UPL_TRANSFER*PAGE_SIZE) from
 195  * osfmk/mach/memory_object_types.h to bound it at the maximum UPL size.
 196  */
 197 #define MAXBSIZE        (256 * 4096)
 198 #define MAXPHYSIO       MAXPHYS
 199 #define MAXFRAG         8
 200
 201 #define MAXPHYSIO_WIRED (16 * 1024 * 1024)
 202
 203 /*
 204  * MAXPATHLEN defines the longest permissable path length after expanding
 205  * symbolic links. It is used to allocate a temporary buffer from the buffer
 206  * pool in which to do the name expansion, hence should be a power of two,
 207  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
 208  * maximum number of symbolic links that may be expanded in a path name.
 209  * It should be set high enough to allow all legitimate uses, but halt
 210  * infinite loops reasonably quickly.
 211  */
 212 #define MAXPATHLEN      PATH_MAX
 213 #define MAXSYMLINKS     32
 214
 215 /* Bit map related macros. */
 216 #define setbit(a,i)     (((char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
 217 #define clrbit(a,i)     (((char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
 218 #define isset(a,i)      (((char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
 219 #define isclr(a,i)      ((((char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
 220
 221 /* Macros for counting and rounding. */
 222 #ifndef howmany
 223 #define howmany(x, y)   (((x)+((y)-1))/(y))
 224 #endif
 225 #define roundup(x, y)   ((((x)+((y)-1))/(y))*(y))
 226 #define powerof2(x)     ((((x)-1)&(x))==0)
 227
 228 /* Macros for min/max. */
 229 #ifndef MIN
 230 #define MIN(a,b) (((a)<(b))?(a):(b))
 231 #endif /* MIN */
 232 #ifndef MAX
 233 #define MAX(a,b) (((a)>(b))?(a):(b))
 234 #endif  /* MAX */
 235
 236 /*
 237  * Constants for setting the parameters of the kernel memory allocator.
 238  *
 239  * 2 ** MINBUCKET is the smallest unit of memory that will be
 240  * allocated. It must be at least large enough to hold a pointer.
 241  *
 242  * Units of memory less or equal to MAXALLOCSAVE will permanently
 243  * allocate physical memory; requests for these size pieces of
 244  * memory are quite fast. Allocations greater than MAXALLOCSAVE must
 245  * always allocate and free physical memory; requests for these
 246  * size allocations should be done infrequently as they will be slow.
 247  *
 248  * Constraints: CLBYTES <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
 249  * MAXALLOCSIZE must be a power of two.
 250  */
 251 #define MINBUCKET       4               /* 4 => min allocation of 16 bytes */
 252 #define MAXALLOCSAVE    (2 * CLBYTES)
 253
 254 /*
 255  * Scale factor for scaled integers used to count %cpu time and load avgs.
 256  *
 257  * The number of CPU `tick's that map to a unique `%age' can be expressed
 258  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
 259  * can be calculated (assuming 32 bits) can be closely approximated using
 260  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
 261  *
 262  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
 263  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
 264  */
 265 #define FSHIFT  11              /* bits to right of fixed binary point */
 266 #define FSCALE  (1<<FSHIFT)
 267
 268 #endif  /* _SYS_PARAM_H_ */