StdLib/Include/sys/param.h

   1 /*  $NetBSD: param.h,v 1.244.2.9.2.2 2008/10/05 08:44:03 bouyer Exp $ */
   2
   3 /*-
   4  * Copyright (c) 1982, 1986, 1989, 1993
   5  *  The Regents of the University of California.  All rights reserved.
   6  * (c) UNIX System Laboratories, Inc.
   7  * All or some portions of this file are derived from material licensed
   8  * to the University of California by American Telephone and Telegraph
   9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  10  * the permission of UNIX System Laboratories, Inc.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  *  @(#)param.h 8.3 (Berkeley) 4/4/95
  37  */
  38
  39 #ifndef _SYS_PARAM_H_
  40 #define _SYS_PARAM_H_
  41
  42 /*
  43  * Historic BSD #defines -- probably will remain untouched for all time.
  44  */
  45 #define BSD 199506    /* System version (year & month). */
  46 #define BSD4_3  1
  47 #define BSD4_4  1
  48
  49 /*
  50  *  #define __NetBSD_Version__ MMmmrrpp00
  51  *
  52  *  M = major version
  53  *  m = minor version; a minor number of 99 indicates current.
  54  *  r = 0 (*)
  55  *  p = patchlevel
  56  *
  57  * When new releases are made, src/gnu/usr.bin/groff/tmac/mdoc.local
  58  * needs to be updated and the changes sent back to the groff maintainers.
  59  *
  60  * (*)  Up to 2.0I "release" used to be "",A-Z,Z[A-Z] but numeric
  61  *        e.g. NetBSD-1.2D  = 102040000 ('D' == 4)
  62  *  NetBSD-2.0H   (200080000) was changed on 20041001 to:
  63  *  2.99.9    (299000900)
  64  */
  65
  66 #define __NetBSD_Version__  400000003 /* NetBSD 4.0.1 */
  67
  68 #define __NetBSD_Prereq__(M,m,p) (((((M) * 100000000) + \
  69     (m) * 1000000) + (p) * 100) <= __NetBSD_Version__)
  70
  71 /*
  72  * Historical NetBSD #define
  73  *
  74  * NetBSD 1.4 was the last release for which this value was incremented.
  75  * The value is now permanently fixed at 199905. It will never be
  76  * changed again.
  77  *
  78  * New code must use __NetBSD_Version__ instead, and should not even
  79  * count on NetBSD being defined.
  80  *
  81  */
  82
  83 #define NetBSD  199905    /* NetBSD version (year & month). */
  84
  85 #ifndef _LOCORE
  86 //#include <sys/inttypes.h>
  87 #include <sys/types.h>
  88 #endif
  89
  90 /*
  91  * Machine-independent constants (some used in following include files).
  92  * Redefined constants are from POSIX 1003.1 limits file.
  93  *
  94  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
  95  * MAXLOGNAME should be >= UT_NAMESIZE (see <utmp.h>)
  96  */
  97 #include <sys/syslimits.h>
  98
  99 #define MAXCOMLEN 16    /* max command name remembered */
 100 #define MAXINTERP PATH_MAX  /* max interpreter file name length */
 101 /* DEPRECATED: use LOGIN_NAME_MAX instead. */
 102 #define MAXLOGNAME  (LOGIN_NAME_MAX - 1) /* max login name length */
 103 #define NCARGS    ARG_MAX   /* max bytes for an exec function */
 104 #define NGROUPS   NGROUPS_MAX /* max number groups */
 105 #define NOGROUP   65535   /* marker for empty group set member */
 106 #define MAXHOSTNAMELEN  256   /* max hostname size */
 107
 108 #ifndef NOFILE
 109 #define NOFILE    OPEN_MAX  /* max open files per process */
 110 #endif
 111 #ifndef MAXUPRC       /* max simultaneous processes */
 112 #define MAXUPRC   CHILD_MAX /* POSIX 1003.1-compliant default */
 113 #else
 114 #if (MAXUPRC - 0) < CHILD_MAX
 115 #error MAXUPRC less than CHILD_MAX.  See options(4) for details.
 116 #endif /* (MAXUPRC - 0) < CHILD_MAX */
 117 #endif /* !defined(MAXUPRC) */
 118
 119 /* Signals. */
 120 #include <sys/signal.h>
 121
 122 /* Machine type dependent parameters. */
 123 #include <machine/param.h>
 124 #include <machine/limits.h>
 125
 126 /* pages ("clicks") to disk blocks */
 127 #define ctod(x)   ((x) << (PGSHIFT - DEV_BSHIFT))
 128 #define dtoc(x)   ((x) >> (PGSHIFT - DEV_BSHIFT))
 129
 130 /* bytes to pages */
 131 #define ctob(x)   ((x) << PGSHIFT)
 132 #define btoc(x)   (((x) + PGOFSET) >> PGSHIFT)
 133
 134 /* bytes to disk blocks */
 135 #define dbtob(x)  ((x) << DEV_BSHIFT)
 136 #define btodb(x)  ((x) >> DEV_BSHIFT)
 137
 138 /*
 139  * Stack macros.  On most architectures, the stack grows down,
 140  * towards lower addresses; it is the rare architecture where
 141  * it grows up, towards higher addresses.
 142  *
 143  * STACK_GROW and STACK_SHRINK adjust a stack pointer by some
 144  * size, no questions asked.  STACK_ALIGN aligns a stack pointer.
 145  *
 146  * STACK_ALLOC returns a pointer to allocated stack space of
 147  * some size; given such a pointer and a size, STACK_MAX gives
 148  * the maximum (in the "maxsaddr" sense) stack address of the
 149  * allocated memory.
 150  */
 151 #if defined(_KERNEL) || defined(__EXPOSE_STACK)
 152 #ifdef __MACHINE_STACK_GROWS_UP
 153 #define STACK_GROW(sp, _size)   (((caddr_t)(sp)) + (_size))
 154 #define STACK_SHRINK(sp, _size)   (((caddr_t)(sp)) - (_size))
 155 #define STACK_ALIGN(sp, bytes)  \
 156   ((caddr_t)((((unsigned long)(sp)) + (bytes)) & ~(bytes)))
 157 #define STACK_ALLOC(sp, _size)    ((caddr_t)(sp))
 158 #define STACK_MAX(p, _size)   (((caddr_t)(p)) + (_size))
 159 #else
 160 #define STACK_GROW(sp, _size)   (((caddr_t)(sp)) - (_size))
 161 #define STACK_SHRINK(sp, _size)   (((caddr_t)(sp)) + (_size))
 162 #define STACK_ALIGN(sp, bytes)  \
 163   ((caddr_t)(((unsigned long)(sp)) & ~(bytes)))
 164 #define STACK_ALLOC(sp, _size)    (((caddr_t)(sp)) - (_size))
 165 #define STACK_MAX(p, _size)   ((caddr_t)(p))
 166 #endif
 167 #endif /* defined(_KERNEL) || defined(__EXPOSE_STACK) */
 168
 169 /*
 170  * Priorities.  Note that with 32 run queues, differences less than 4 are
 171  * insignificant.
 172  */
 173 #define PSWP  0
 174 #define PVM 4
 175 #define PINOD 8
 176 #define PRIBIO  16
 177 #define PVFS  20
 178 #define PZERO 22    /* No longer magic, shouldn't be here.  XXX */
 179 #define PSOCK 24
 180 #define PWAIT 32
 181 #define PLOCK 36
 182 #define PPAUSE  40
 183 #define PUSER 50
 184 #define MAXPRI  127   /* Priorities range from 0 through MAXPRI. */
 185
 186 #define PRIMASK   0x0ff
 187 #define PCATCH    0x100 /* OR'd with pri for tsleep to check signals */
 188 #define PNORELOCK 0x200 /* OR'd with pri for cond_wait() to not relock
 189            the interlock */
 190 #define PNOEXITERR      0x400   /* OR'd with pri for tsleep to not exit
 191            with an error code when LWPs are exiting */
 192 #define NBPW  sizeof(int) /* number of bytes per word (integer) */
 193
 194 #define CMASK 022   /* default file mask: S_IWGRP|S_IWOTH */
 195 #define NODEV (dev_t)(-1) /* non-existent device */
 196
 197 #define CBLOCK  64    /* Clist block size, must be a power of 2. */
 198 #define CBQSIZE (CBLOCK/NBBY) /* Quote bytes/cblock - can do better. */
 199         /* Data chars/clist. */
 200 #define CBSIZE  (CBLOCK - (int)sizeof(struct cblock *) - CBQSIZE)
 201 #define CROUND  (CBLOCK - 1)  /* Clist rounding. */
 202
 203 /*
 204  * File system parameters and macros.
 205  *
 206  * The file system is made out of blocks of at most MAXBSIZE units, with
 207  * smaller units (fragments) only in the last direct block.  MAXBSIZE
 208  * primarily determines the size of buffers in the buffer pool.  It may be
 209  * made larger without any effect on existing file systems; however making
 210  * it smaller may make some file systems unmountable.
 211  */
 212 #ifndef MAXBSIZE        /* XXX */
 213 #define MAXBSIZE  MAXPHYS
 214 #endif
 215 #define MAXFRAG   8
 216
 217 /*
 218  * MAXPATHLEN defines the longest permissible path length after expanding
 219  * symbolic links. It is used to allocate a temporary buffer from the buffer
 220  * pool in which to do the name expansion, hence should be a power of two,
 221  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
 222  * maximum number of symbolic links that may be expanded in a path name.
 223  * It should be set high enough to allow all legitimate uses, but halt
 224  * infinite loops reasonably quickly.
 225  */
 226 #define MAXPATHLEN  PATH_MAX
 227 #define MAXSYMLINKS 32
 228
 229 /* Bit map related macros. */
 230 #define setbit(a,i) ((a)[(i)/NBBY] |= 1<<((i)%NBBY))
 231 #define clrbit(a,i) ((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
 232 #define isset(a,i)  ((a)[(i)/NBBY] & (1<<((i)%NBBY)))
 233 #define isclr(a,i)  (((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
 234
 235 /* Macros for counting and rounding. */
 236 #ifndef howmany
 237 #define howmany(x, y) (((x)+((y)-1))/(y))
 238 #endif
 239 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y))
 240 #define rounddown(x,y)  (((x)/(y))*(y))
 241 #define powerof2(x) ((((x)-1)&(x))==0)
 242
 243 ///* Macros for min/max. */
 244 //#define MIN(a,b)  (((a)<(b))?(a):(b))
 245 //#define MAX(a,b)  (((a)>(b))?(a):(b))
 246
 247 /*
 248  * Constants for setting the parameters of the kernel memory allocator.
 249  *
 250  * 2 ** MINBUCKET is the smallest unit of memory that will be
 251  * allocated. It must be at least large enough to hold a pointer.
 252  *
 253  * Units of memory less or equal to MAXALLOCSAVE will permanently
 254  * allocate physical memory; requests for these size pieces of
 255  * memory are quite fast. Allocations greater than MAXALLOCSAVE must
 256  * always allocate and free physical memory; requests for these
 257  * size allocations should be done infrequently as they will be slow.
 258  *
 259  * Constraints: NBPG <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
 260  * MAXALLOCSAVE must be a power of two.
 261  */
 262 #ifdef _LP64
 263 #define MINBUCKET 5   /* 5 => min allocation of 32 bytes */
 264 #else
 265 #define MINBUCKET 4   /* 4 => min allocation of 16 bytes */
 266 #endif
 267 #define MAXALLOCSAVE  (2 * NBPG)
 268
 269 /*
 270  * Scale factor for scaled integers used to count %cpu time and load avgs.
 271  *
 272  * The number of CPU `tick's that map to a unique `%age' can be expressed
 273  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
 274  * can be calculated (assuming 32 bits) can be closely approximated using
 275  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
 276  *
 277  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
 278  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
 279  */
 280 #define FSHIFT  11    /* bits to right of fixed binary point */
 281 #define FSCALE  (1<<FSHIFT)
 282
 283 /*
 284  * The time for a process to be blocked before being very swappable.
 285  * This is a number of seconds which the system takes as being a non-trivial
 286  * amount of real time.  You probably shouldn't change this;
 287  * it is used in subtle ways (fractions and multiples of it are, that is, like
 288  * half of a ``long time'', almost a long time, etc.)
 289  * It is related to human patience and other factors which don't really
 290  * change over time.
 291  */
 292 #define        MAXSLP          20
 293
 294 /*
 295  * Defaults for Unified Buffer Cache parameters.
 296  * These may be overridden in <machine/param.h>.
 297  */
 298
 299 #ifndef UBC_WINSHIFT
 300 #define UBC_WINSHIFT  13
 301 #endif
 302 #ifndef UBC_NWINS
 303 #define UBC_NWINS 1024
 304 #endif
 305
 306 #ifdef _KERNEL
 307 /*
 308  * macro to convert from milliseconds to hz without integer overflow
 309  * Default version using only 32bits arithmetics.
 310  * 64bit port can define 64bit version in their <machine/param.h>
 311  * 0x20000 is safe for hz < 20000
 312  */
 313 #ifndef mstohz
 314 #define mstohz(ms) \
 315   (__predict_false((ms) >= 0x20000) ? \
 316       ((ms +0u) / 1000u) * hz : \
 317       ((ms +0u) * hz) / 1000u)
 318 #endif
 319 #endif /* _KERNEL */
 320
 321 #endif /* !_SYS_PARAM_H_ */