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 #include <sys/_types.h>
  74
  75 #ifndef NULL
  76 #define NULL    __DARWIN_NULL
  77 #endif /* ! NULL */
  78
  79 #ifndef LOCORE
  80 #include <sys/types.h>
  81 #endif
  82
  83 /*
  84  * Machine-independent constants (some used in following include files).
  85  * Redefined constants are from POSIX 1003.1 limits file.
  86  *
  87  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
  88  * MAXLOGNAME should be >= UT_NAMESIZE (see <utmp.h>)
  89  */
  90 #include <sys/syslimits.h>
  91
  92 #define MAXCOMLEN       16              /* max command name remembered */
  93 #define MAXINTERP       64              /* max interpreter file name length */
  94 #define MAXLOGNAME      255             /* max login name length */
  95 #define MAXUPRC         CHILD_MAX       /* max simultaneous processes */
  96 #define NCARGS          ARG_MAX         /* max bytes for an exec function */
  97 #define NGROUPS         NGROUPS_MAX     /* max number groups */
  98 #define NOFILE          256             /* default max open files per process */
  99 #define NOGROUP         65535           /* marker for empty group set member */
 100 #define MAXHOSTNAMELEN  256             /* max hostname size */
 101 #define MAXDOMNAMELEN   256             /* maximum domain name length */
 102
 103 /* Machine type dependent parameters. */
 104 #include <machine/param.h>
 105
 106 /* More types and definitions used throughout the kernel. */
 107 #ifdef KERNEL
 108 #include <machine/limits.h>
 109 #include <sys/cdefs.h>
 110 #include <sys/errno.h>
 111 #include <sys/time.h>
 112 #include <sys/resource.h>
 113 #include <sys/ucred.h>
 114 #include <sys/uio.h>
 115 #else
 116 #include <limits.h>
 117 #endif
 118
 119 /* Signals. */
 120 #include <sys/signal.h>
 121
 122 /*
 123  * Priorities.  Note that with 32 run queues, differences less than 4 are
 124  * insignificant.
 125  */
 126 #define PSWP    0
 127 #define PVM     4
 128 #define PINOD   8
 129 #define PRIBIO  16
 130 #define PVFS    20
 131 #define PZERO   22              /* No longer magic, shouldn't be here.  XXX */
 132 #define PSOCK   24
 133 #define PWAIT   32
 134 #define PLOCK   36
 135 #define PPAUSE  40
 136 #define PUSER   50
 137 #define MAXPRI  127             /* Priorities range from 0 through MAXPRI. */
 138
 139 #define PRIMASK 0x0ff
 140 #define PCATCH  0x100           /* OR'd with pri for tsleep to check signals */
 141 #define PTTYBLOCK 0x200         /* for tty SIGTTOU and SIGTTIN blocking */
 142 #define PDROP   0x400           /* OR'd with pri to stop re-entry of interlock mutex */
 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 MAXPHYS 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 than MAXPHYS without any effect on existing file systems;
 185  * however making it smaller may make some file systems unmountable.
 186  * We set this to track the value of (MAX_UPL_TRANSFER*PAGE_SIZE) from
 187  * osfmk/mach/memory_object_types.h to bound it at the maximum UPL size.
 188  */
 189 #define MAXBSIZE        (256 * 4096)
 190 #define MAXPHYSIO       MAXPHYS
 191 #define MAXFRAG         8
 192
 193 #define MAXPHYSIO_WIRED (16 * 1024 * 1024)
 194
 195 /*
 196  * MAXPATHLEN defines the longest permissable path length after expanding
 197  * symbolic links. It is used to allocate a temporary buffer from the buffer
 198  * pool in which to do the name expansion, hence should be a power of two,
 199  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
 200  * maximum number of symbolic links that may be expanded in a path name.
 201  * It should be set high enough to allow all legitimate uses, but halt
 202  * infinite loops reasonably quickly.
 203  */
 204 #define MAXPATHLEN      PATH_MAX
 205 #define MAXSYMLINKS     32
 206
 207 /* Bit map related macros. */
 208 #define setbit(a,i)     (((char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
 209 #define clrbit(a,i)     (((char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
 210 #define isset(a,i)      (((char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
 211 #define isclr(a,i)      ((((char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
 212
 213 /* Macros for counting and rounding. */
 214 #ifndef howmany
 215 #define howmany(x, y)   (((x)+((y)-1))/(y))
 216 #endif
 217 #define roundup(x, y)   ((((x)+((y)-1))/(y))*(y))
 218 #define powerof2(x)     ((((x)-1)&(x))==0)
 219
 220 /* Macros for min/max. */
 221 #ifndef MIN
 222 #define MIN(a,b) (((a)<(b))?(a):(b))
 223 #endif /* MIN */
 224 #ifndef MAX
 225 #define MAX(a,b) (((a)>(b))?(a):(b))
 226 #endif  /* MAX */
 227
 228 /*
 229  * Constants for setting the parameters of the kernel memory allocator.
 230  *
 231  * 2 ** MINBUCKET is the smallest unit of memory that will be
 232  * allocated. It must be at least large enough to hold a pointer.
 233  *
 234  * Units of memory less or equal to MAXALLOCSAVE will permanently
 235  * allocate physical memory; requests for these size pieces of
 236  * memory are quite fast. Allocations greater than MAXALLOCSAVE must
 237  * always allocate and free physical memory; requests for these
 238  * size allocations should be done infrequently as they will be slow.
 239  *
 240  * Constraints: CLBYTES <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
 241  * MAXALLOCSIZE must be a power of two.
 242  */
 243 #define MINBUCKET       4               /* 4 => min allocation of 16 bytes */
 244 #define MAXALLOCSAVE    (2 * CLBYTES)
 245
 246 /*
 247  * Scale factor for scaled integers used to count %cpu time and load avgs.
 248  *
 249  * The number of CPU `tick's that map to a unique `%age' can be expressed
 250  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
 251  * can be calculated (assuming 32 bits) can be closely approximated using
 252  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
 253  *
 254  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
 255  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
 256  */
 257 #define FSHIFT  11              /* bits to right of fixed binary point */
 258 #define FSCALE  (1<<FSHIFT)
 259
 260 #endif  /* _SYS_PARAM_H_ */