param.h revision 256283
1/*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)param.h 8.3 (Berkeley) 4/4/95 35 * $FreeBSD: stable/10/sys/sys/param.h 256283 2013-10-10 17:59:44Z gjb $ 36 */ 37 38#ifndef _SYS_PARAM_H_ 39#define _SYS_PARAM_H_ 40 41#include <sys/_null.h> 42 43#define BSD 199506 /* System version (year & month). */ 44#define BSD4_3 1 45#define BSD4_4 1 46 47/* 48 * __FreeBSD_version numbers are documented in the Porter's Handbook. 49 * If you bump the version for any reason, you should update the documentation 50 * there. 51 * Currently this lives here in the doc/ repository: 52 * 53 * head/en_US.ISO8859-1/books/porters-handbook/book.xml 54 * 55 * scheme is: <major><two digit minor>Rxx 56 * 'R' is in the range 0 to 4 if this is a release branch or 57 * x.0-CURRENT before RELENG_*_0 is created, otherwise 'R' is 58 * in the range 5 to 9. 59 */ 60#undef __FreeBSD_version 61#define __FreeBSD_version 1000500 /* Master, propagated to newvers */ 62 63/* 64 * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD, 65 * which by definition is always true on FreeBSD. This macro is also defined 66 * on other systems that use the kernel of FreeBSD, such as GNU/kFreeBSD. 67 * 68 * It is tempting to use this macro in userland code when we want to enable 69 * kernel-specific routines, and in fact it's fine to do this in code that 70 * is part of FreeBSD itself. However, be aware that as presence of this 71 * macro is still not widespread (e.g. older FreeBSD versions, 3rd party 72 * compilers, etc), it is STRONGLY DISCOURAGED to check for this macro in 73 * external applications without also checking for __FreeBSD__ as an 74 * alternative. 75 */ 76#undef __FreeBSD_kernel__ 77#define __FreeBSD_kernel__ 78 79#ifdef _KERNEL 80#define P_OSREL_SIGWAIT 700000 81#define P_OSREL_SIGSEGV 700004 82#define P_OSREL_MAP_ANON 800104 83#endif 84 85#ifndef LOCORE 86#include <sys/types.h> 87#endif 88 89/* 90 * Machine-independent constants (some used in following include files). 91 * Redefined constants are from POSIX 1003.1 limits file. 92 * 93 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>) 94 */ 95#include <sys/syslimits.h> 96 97#define MAXCOMLEN 19 /* max command name remembered */ 98#define MAXINTERP PATH_MAX /* max interpreter file name length */ 99#define MAXLOGNAME 33 /* max login name length (incl. NUL) */ 100#define MAXUPRC CHILD_MAX /* max simultaneous processes */ 101#define NCARGS ARG_MAX /* max bytes for an exec function */ 102#define NGROUPS (NGROUPS_MAX+1) /* max number groups */ 103#define NOFILE OPEN_MAX /* max open files per process */ 104#define NOGROUP 65535 /* marker for empty group set member */ 105#define MAXHOSTNAMELEN 256 /* max hostname size */ 106#define SPECNAMELEN 63 /* max length of devicename */ 107 108/* More types and definitions used throughout the kernel. */ 109#ifdef _KERNEL 110#include <sys/cdefs.h> 111#include <sys/errno.h> 112#ifndef LOCORE 113#include <sys/time.h> 114#include <sys/priority.h> 115#endif 116 117#ifndef FALSE 118#define FALSE 0 119#endif 120#ifndef TRUE 121#define TRUE 1 122#endif 123#endif 124 125#ifndef _KERNEL 126/* Signals. */ 127#include <sys/signal.h> 128#endif 129 130/* Machine type dependent parameters. */ 131#include <machine/param.h> 132#ifndef _KERNEL 133#include <sys/limits.h> 134#endif 135 136#ifndef DEV_BSHIFT 137#define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */ 138#endif 139#define DEV_BSIZE (1<<DEV_BSHIFT) 140 141#ifndef BLKDEV_IOSIZE 142#define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */ 143#endif 144#ifndef DFLTPHYS 145#define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */ 146#endif 147#ifndef MAXPHYS 148#define MAXPHYS (128 * 1024) /* max raw I/O transfer size */ 149#endif 150#ifndef MAXDUMPPGS 151#define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE) 152#endif 153 154/* 155 * Constants related to network buffer management. 156 * MCLBYTES must be no larger than PAGE_SIZE. 157 */ 158#ifndef MSIZE 159#define MSIZE 256 /* size of an mbuf */ 160#endif 161 162#ifndef MCLSHIFT 163#define MCLSHIFT 11 /* convert bytes to mbuf clusters */ 164#endif /* MCLSHIFT */ 165 166#define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */ 167 168#if PAGE_SIZE < 2048 169#define MJUMPAGESIZE MCLBYTES 170#elif PAGE_SIZE <= 8192 171#define MJUMPAGESIZE PAGE_SIZE 172#else 173#define MJUMPAGESIZE (8 * 1024) 174#endif 175 176#define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */ 177#define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */ 178 179/* 180 * Some macros for units conversion 181 */ 182 183/* clicks to bytes */ 184#ifndef ctob 185#define ctob(x) ((x)<<PAGE_SHIFT) 186#endif 187 188/* bytes to clicks */ 189#ifndef btoc 190#define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT) 191#endif 192 193/* 194 * btodb() is messy and perhaps slow because `bytes' may be an off_t. We 195 * want to shift an unsigned type to avoid sign extension and we don't 196 * want to widen `bytes' unnecessarily. Assume that the result fits in 197 * a daddr_t. 198 */ 199#ifndef btodb 200#define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \ 201 (sizeof (bytes) > sizeof(long) \ 202 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \ 203 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT)) 204#endif 205 206#ifndef dbtob 207#define dbtob(db) /* calculates (db * DEV_BSIZE) */ \ 208 ((off_t)(db) << DEV_BSHIFT) 209#endif 210 211#define PRIMASK 0x0ff 212#define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */ 213#define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */ 214 215#define NZERO 0 /* default "nice" */ 216 217#define NBBY 8 /* number of bits in a byte */ 218#define NBPW sizeof(int) /* number of bytes per word (integer) */ 219 220#define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */ 221 222#define NODEV (dev_t)(-1) /* non-existent device */ 223 224/* 225 * File system parameters and macros. 226 * 227 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes 228 * per block. MAXBSIZE may be made larger without effecting 229 * any existing filesystems as long as it does not exceed MAXPHYS, 230 * and may be made smaller at the risk of not being able to use 231 * filesystems which require a block size exceeding MAXBSIZE. 232 * 233 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the 234 * minimum KVM memory reservation the kernel is willing to make. 235 * Filesystems can of course request smaller chunks. Actual 236 * backing memory uses a chunk size of a page (PAGE_SIZE). 237 * 238 * If you make BKVASIZE too small you risk seriously fragmenting 239 * the buffer KVM map which may slow things down a bit. If you 240 * make it too big the kernel will not be able to optimally use 241 * the KVM memory reserved for the buffer cache and will wind 242 * up with too-few buffers. 243 * 244 * The default is 16384, roughly 2x the block size used by a 245 * normal UFS filesystem. 246 */ 247#define MAXBSIZE 65536 /* must be power of 2 */ 248#define BKVASIZE 16384 /* must be power of 2 */ 249#define BKVAMASK (BKVASIZE-1) 250 251/* 252 * MAXPATHLEN defines the longest permissible path length after expanding 253 * symbolic links. It is used to allocate a temporary buffer from the buffer 254 * pool in which to do the name expansion, hence should be a power of two, 255 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the 256 * maximum number of symbolic links that may be expanded in a path name. 257 * It should be set high enough to allow all legitimate uses, but halt 258 * infinite loops reasonably quickly. 259 */ 260#define MAXPATHLEN PATH_MAX 261#define MAXSYMLINKS 32 262 263/* Bit map related macros. */ 264#define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY)) 265#define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY))) 266#define isset(a,i) \ 267 (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) 268#define isclr(a,i) \ 269 ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0) 270 271/* Macros for counting and rounding. */ 272#ifndef howmany 273#define howmany(x, y) (((x)+((y)-1))/(y)) 274#endif 275#define nitems(x) (sizeof((x)) / sizeof((x)[0])) 276#define rounddown(x, y) (((x)/(y))*(y)) 277#define rounddown2(x, y) ((x)&(~((y)-1))) /* if y is power of two */ 278#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ 279#define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */ 280#define powerof2(x) ((((x)-1)&(x))==0) 281 282/* Macros for min/max. */ 283#define MIN(a,b) (((a)<(b))?(a):(b)) 284#define MAX(a,b) (((a)>(b))?(a):(b)) 285 286#ifdef _KERNEL 287/* 288 * Basic byte order function prototypes for non-inline functions. 289 */ 290#ifndef LOCORE 291#ifndef _BYTEORDER_PROTOTYPED 292#define _BYTEORDER_PROTOTYPED 293__BEGIN_DECLS 294__uint32_t htonl(__uint32_t); 295__uint16_t htons(__uint16_t); 296__uint32_t ntohl(__uint32_t); 297__uint16_t ntohs(__uint16_t); 298__END_DECLS 299#endif 300#endif 301 302#ifndef lint 303#ifndef _BYTEORDER_FUNC_DEFINED 304#define _BYTEORDER_FUNC_DEFINED 305#define htonl(x) __htonl(x) 306#define htons(x) __htons(x) 307#define ntohl(x) __ntohl(x) 308#define ntohs(x) __ntohs(x) 309#endif /* !_BYTEORDER_FUNC_DEFINED */ 310#endif /* lint */ 311#endif /* _KERNEL */ 312 313/* 314 * Scale factor for scaled integers used to count %cpu time and load avgs. 315 * 316 * The number of CPU `tick's that map to a unique `%age' can be expressed 317 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that 318 * can be calculated (assuming 32 bits) can be closely approximated using 319 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15). 320 * 321 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age', 322 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024. 323 */ 324#define FSHIFT 11 /* bits to right of fixed binary point */ 325#define FSCALE (1<<FSHIFT) 326 327#define dbtoc(db) /* calculates devblks to pages */ \ 328 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT)) 329 330#define ctodb(db) /* calculates pages to devblks */ \ 331 ((db) << (PAGE_SHIFT - DEV_BSHIFT)) 332 333/* 334 * Old spelling of __containerof(). 335 */ 336#define member2struct(s, m, x) \ 337 ((struct s *)(void *)((char *)(x) - offsetof(struct s, m))) 338 339/* 340 * Access a variable length array that has been declared as a fixed 341 * length array. 342 */ 343#define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset]) 344 345#endif /* _SYS_PARAM_H_ */ 346