sys/param.h

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00001 /*-
00002  * Copyright (c) 1982, 1986, 1989, 1993
00003  *      The Regents of the University of California.  All rights reserved.
00004  * (c) UNIX System Laboratories, Inc.
00005  * All or some portions of this file are derived from material licensed
00006  * to the University of California by American Telephone and Telegraph
00007  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
00008  * the permission of UNIX System Laboratories, Inc.
00009  *
00010  * Redistribution and use in source and binary forms, with or without
00011  * modification, are permitted provided that the following conditions
00012  * are met:
00013  * 1. Redistributions of source code must retain the above copyright
00014  *    notice, this list of conditions and the following disclaimer.
00015  * 2. Redistributions in binary form must reproduce the above copyright
00016  *    notice, this list of conditions and the following disclaimer in the
00017  *    documentation and/or other materials provided with the distribution.
00018  * 4. Neither the name of the University nor the names of its contributors
00019  *    may be used to endorse or promote products derived from this software
00020  *    without specific prior written permission.
00021  *
00022  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
00023  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00024  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00025  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
00026  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00027  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
00028  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
00029  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00030  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
00031  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00032  * SUCH DAMAGE.
00033  *
00034  *      @(#)param.h     8.3 (Berkeley) 4/4/95
00035  * $FreeBSD: src/sys/sys/param.h,v 1.244.2.2 2005/08/13 21:27:58 rwatson Exp $
00036  */
00037 
00038 #ifndef _SYS_PARAM_H_
00039 #define _SYS_PARAM_H_
00040 
00041 #include <sys/_null.h>
00042 
00043 #define BSD     199506          /* System version (year & month). */
00044 #define BSD4_3  1
00045 #define BSD4_4  1
00046 
00047 /* 
00048  * __FreeBSD_version numbers are documented in the Porter's Handbook.
00049  * If you bump the version for any reason, you should update the documentation
00050  * there.
00051  * Currently this lives here:
00052  *
00053  *      doc/en_US.ISO8859-1/books/porters-handbook/book.sgml
00054  *
00055  * scheme is:  <major><two digit minor>Rxx
00056  *              'R' is 0 if release branch or x.0-CURRENT before RELENG_*_0
00057  *              is created, otherwise 1.
00058  */
00059 #undef __FreeBSD_version
00060 #define __FreeBSD_version 600034        /* Master, propagated to newvers */
00061 
00062 #ifndef LOCORE
00063 #include <sys/types.h>
00064 #endif
00065 
00066 /*
00067  * Machine-independent constants (some used in following include files).
00068  * Redefined constants are from POSIX 1003.1 limits file.
00069  *
00070  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
00071  * MAXLOGNAME should be == UT_NAMESIZE+1 (see <utmp.h>)
00072  */
00073 #include <sys/syslimits.h>
00074 
00075 #define MAXCOMLEN       19              /* max command name remembered */
00076 #define MAXINTERP       32              /* max interpreter file name length */
00077 #define MAXLOGNAME      17              /* max login name length (incl. NUL) */
00078 #define MAXUPRC         CHILD_MAX       /* max simultaneous processes */
00079 #define NCARGS          ARG_MAX         /* max bytes for an exec function */
00080 #define NGROUPS         NGROUPS_MAX     /* max number groups */
00081 #define NOFILE          OPEN_MAX        /* max open files per process */
00082 #define NOGROUP         65535           /* marker for empty group set member */
00083 #define MAXHOSTNAMELEN  256             /* max hostname size */
00084 #define SPECNAMELEN     63              /* max length of devicename */
00085 
00086 /* More types and definitions used throughout the kernel. */
00087 #ifdef _KERNEL
00088 #if 0
00089 #if (defined(BURN_BRIDGES) || __FreeBSD_version >= 600000) \
00090         && defined(OBSOLETE_IN_6)
00091 #error "This file contains obsolete code to be removed in 6.0-current"
00092 #endif
00093 #endif
00094 #include <sys/cdefs.h>
00095 #include <sys/errno.h>
00096 #include <sys/time.h>
00097 
00098 #ifndef __SYMBIAN32__
00099 #include <sys/priority.h>
00100 //__SYMBIAN32__
00101 #endif
00102 
00103 #define FALSE   0
00104 #define TRUE    1
00105 #endif
00106 
00107 #ifndef _KERNEL
00108 /* Signals. */
00109 #ifndef __SYMBIAN32__
00110 #include <sys/signal.h>
00111 //__SYMBIAN32__
00112 #endif
00113 #endif
00114 
00115 /* Machine type dependent parameters. */
00116 #include <machine/param.h>
00117 #ifndef _KERNEL
00118 #include <sys/limits.h>
00119 #endif
00120 
00121 #ifndef _NO_NAMESPACE_POLLUTION
00122 
00123 #ifndef DEV_BSHIFT
00124 #define DEV_BSHIFT      9               /* log2(DEV_BSIZE) */
00125 #endif
00126 #define DEV_BSIZE       (1<<DEV_BSHIFT)
00127 
00128 #ifndef BLKDEV_IOSIZE
00129 #define BLKDEV_IOSIZE  PAGE_SIZE        /* default block device I/O size */
00130 #endif
00131 #ifndef DFLTPHYS
00132 #define DFLTPHYS        (64 * 1024)     /* default max raw I/O transfer size */
00133 #endif
00134 #ifndef MAXPHYS
00135 #define MAXPHYS         (128 * 1024)    /* max raw I/O transfer size */
00136 #endif
00137 #ifndef MAXDUMPPGS
00138 #define MAXDUMPPGS      (DFLTPHYS/PAGE_SIZE)
00139 #endif
00140 
00141 /*
00142  * Constants related to network buffer management.
00143  * MCLBYTES must be no larger than PAGE_SIZE.
00144  */
00145 #ifndef MSIZE
00146 #define MSIZE           256             /* size of an mbuf */
00147 #endif  /* MSIZE */
00148 
00149 #ifndef MCLSHIFT
00150 #define MCLSHIFT        11              /* convert bytes to mbuf clusters */
00151 #endif  /* MCLSHIFT */
00152 
00153 #define MCLBYTES        (1 << MCLSHIFT) /* size of an mbuf cluster */
00154 
00155 /*
00156  * Some macros for units conversion
00157  */
00158 
00159 /* clicks to bytes */
00160 #ifndef ctob
00161 #define ctob(x) ((x)<<PAGE_SHIFT)
00162 #endif
00163 
00164 /* bytes to clicks */
00165 #ifndef btoc
00166 #define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
00167 #endif
00168 
00169 /*
00170  * btodb() is messy and perhaps slow because `bytes' may be an off_t.  We
00171  * want to shift an unsigned type to avoid sign extension and we don't
00172  * want to widen `bytes' unnecessarily.  Assume that the result fits in
00173  * a daddr_t.
00174  */
00175 #ifndef btodb
00176 #define btodb(bytes)                    /* calculates (bytes / DEV_BSIZE) */ \
00177         (sizeof (bytes) > sizeof(long) \
00178          ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
00179          : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
00180 #endif
00181 
00182 #ifndef dbtob
00183 #define dbtob(db)                       /* calculates (db * DEV_BSIZE) */ \
00184         ((off_t)(db) << DEV_BSHIFT)
00185 #endif
00186 
00187 #endif /* _NO_NAMESPACE_POLLUTION */
00188 
00189 #define PRIMASK 0x0ff
00190 #define PCATCH  0x100           /* OR'd with pri for tsleep to check signals */
00191 #define PDROP   0x200   /* OR'd with pri to stop re-entry of interlock mutex */
00192 
00193 #define NZERO   0               /* default "nice" */
00194 
00195 #define NBBY    8               /* number of bits in a byte */
00196 #define NBPW    sizeof(int)     /* number of bytes per word (integer) */
00197 
00198 #define CMASK   022             /* default file mask: S_IWGRP|S_IWOTH */
00199 
00200 #define NODEV   (dev_t)(-1)     /* non-existent device */
00201 
00202 #define CBLOCK  128             /* Clist block size, must be a power of 2. */
00203 #define CBQSIZE (CBLOCK/NBBY)   /* Quote bytes/cblock - can do better. */
00204                                 /* Data chars/clist. */
00205 #define CBSIZE  (CBLOCK - sizeof(struct cblock *) - CBQSIZE)
00206 #define CROUND  (CBLOCK - 1)    /* Clist rounding. */
00207 
00208 /*
00209  * File system parameters and macros.
00210  *
00211  * MAXBSIZE -   Filesystems are made out of blocks of at most MAXBSIZE bytes
00212  *              per block.  MAXBSIZE may be made larger without effecting
00213  *              any existing filesystems as long as it does not exceed MAXPHYS,
00214  *              and may be made smaller at the risk of not being able to use
00215  *              filesystems which require a block size exceeding MAXBSIZE.
00216  *
00217  * BKVASIZE -   Nominal buffer space per buffer, in bytes.  BKVASIZE is the
00218  *              minimum KVM memory reservation the kernel is willing to make.
00219  *              Filesystems can of course request smaller chunks.  Actual 
00220  *              backing memory uses a chunk size of a page (PAGE_SIZE).
00221  *
00222  *              If you make BKVASIZE too small you risk seriously fragmenting
00223  *              the buffer KVM map which may slow things down a bit.  If you
00224  *              make it too big the kernel will not be able to optimally use 
00225  *              the KVM memory reserved for the buffer cache and will wind 
00226  *              up with too-few buffers.
00227  *
00228  *              The default is 16384, roughly 2x the block size used by a
00229  *              normal UFS filesystem.
00230  */
00231 #define MAXBSIZE        65536   /* must be power of 2 */
00232 #define BKVASIZE        16384   /* must be power of 2 */
00233 #define BKVAMASK        (BKVASIZE-1)
00234 
00235 /*
00236  * MAXPATHLEN defines the longest permissible path length after expanding
00237  * symbolic links. It is used to allocate a temporary buffer from the buffer
00238  * pool in which to do the name expansion, hence should be a power of two,
00239  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
00240  * maximum number of symbolic links that may be expanded in a path name.
00241  * It should be set high enough to allow all legitimate uses, but halt
00242  * infinite loops reasonably quickly.
00243  */
00244 #define MAXPATHLEN      PATH_MAX
00245 #define MAXSYMLINKS     32
00246 
00247 /* Bit map related macros. */
00248 #define setbit(a,i)     ((a)[(i)/NBBY] |= 1<<((i)%NBBY))
00249 #define clrbit(a,i)     ((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
00250 #define isset(a,i)      ((a)[(i)/NBBY] & (1<<((i)%NBBY)))
00251 #define isclr(a,i)      (((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
00252 
00253 /* Macros for counting and rounding. */
00254 #ifndef howmany
00255 #define howmany(x, y)   (((x)+((y)-1))/(y))
00256 #endif
00257 #define rounddown(x, y) (((x)/(y))*(y))
00258 #define roundup(x, y)   ((((x)+((y)-1))/(y))*(y))  /* to any y */
00259 #define roundup2(x, y)  (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
00260 #define powerof2(x)     ((((x)-1)&(x))==0)
00261 
00262 /* Macros for min/max. */
00263 #define MIN(a,b) (((a)<(b))?(a):(b))
00264 #define MAX(a,b) (((a)>(b))?(a):(b))
00265 
00266 #ifdef _KERNEL
00267 /*
00268  * Basic byte order function prototypes for non-inline functions.
00269  */
00270 #ifndef _BYTEORDER_PROTOTYPED
00271 #define _BYTEORDER_PROTOTYPED
00272 __BEGIN_DECLS
00273 __uint32_t       htonl(__uint32_t);
00274 __uint16_t       htons(__uint16_t);
00275 __uint32_t       ntohl(__uint32_t);
00276 __uint16_t       ntohs(__uint16_t);
00277 __END_DECLS
00278 #endif
00279 
00280 #ifndef lint
00281 #ifndef _BYTEORDER_FUNC_DEFINED
00282 #define _BYTEORDER_FUNC_DEFINED
00283 #define htonl(x)        __htonl(x)
00284 #define htons(x)        __htons(x)
00285 #define ntohl(x)        __ntohl(x)
00286 #define ntohs(x)        __ntohs(x)
00287 #endif /* !_BYTEORDER_FUNC_DEFINED */
00288 #endif /* lint */
00289 #endif /* _KERNEL */
00290 
00291 /*
00292  * Constants for setting the parameters of the kernel memory allocator.
00293  *
00294  * 2 ** MINBUCKET is the smallest unit of memory that will be
00295  * allocated. It must be at least large enough to hold a pointer.
00296  *
00297  * Units of memory less or equal to MAXALLOCSAVE will permanently
00298  * allocate physical memory; requests for these size pieces of
00299  * memory are quite fast. Allocations greater than MAXALLOCSAVE must
00300  * always allocate and free physical memory; requests for these
00301  * size allocations should be done infrequently as they will be slow.
00302  *
00303  * Constraints: PAGE_SIZE <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
00304  * MAXALLOCSIZE must be a power of two.
00305  */
00306 #if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__)
00307 #define MINBUCKET       5               /* 5 => min allocation of 32 bytes */
00308 #else
00309 #define MINBUCKET       4               /* 4 => min allocation of 16 bytes */
00310 #endif
00311 #define MAXALLOCSAVE    (2 * PAGE_SIZE)
00312 
00313 /*
00314  * Scale factor for scaled integers used to count %cpu time and load avgs.
00315  *
00316  * The number of CPU `tick's that map to a unique `%age' can be expressed
00317  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
00318  * can be calculated (assuming 32 bits) can be closely approximated using
00319  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
00320  *
00321  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
00322  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
00323  */
00324 #define FSHIFT  11              /* bits to right of fixed binary point */
00325 #define FSCALE  (1<<FSHIFT)
00326 
00327 #define dbtoc(db)                       /* calculates devblks to pages */ \
00328         ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
00329  
00330 #define ctodb(db)                       /* calculates pages to devblks */ \
00331         ((db) << (PAGE_SHIFT - DEV_BSHIFT))
00332 
00333 #endif  /* _SYS_PARAM_H_ */

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