param.h revision 363792
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/11/sys/sys/param.h 363792 2020-08-03 09:15:38Z hselasky $ 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/versions/chapter.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/X.0 is created, otherwise 'R' is 58 * in the range 5 to 9. 59 */ 60#undef __FreeBSD_version 61#define __FreeBSD_version 1104504 /* 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#if defined(_KERNEL) || defined(IN_RTLD) 80#define P_OSREL_SIGWAIT 700000 81#define P_OSREL_SIGSEGV 700004 82#define P_OSREL_MAP_ANON 800104 83#define P_OSREL_MAP_FSTRICT 1100036 84#define P_OSREL_SHUTDOWN_ENOTCONN 1100077 85#define P_OSREL_MAP_GUARD 1200035 86#define P_OSREL_MAP_GUARD_11 1101501 87#define P_OSREL_WRFSBASE 1200041 88#define P_OSREL_WRFSBASE_11 1101503 89 90#define P_OSREL_MAJOR(x) ((x) / 100000) 91#endif 92 93#ifndef LOCORE 94#include <sys/types.h> 95#endif 96 97/* 98 * Machine-independent constants (some used in following include files). 99 * Redefined constants are from POSIX 1003.1 limits file. 100 * 101 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>) 102 */ 103#include <sys/syslimits.h> 104 105#define MAXCOMLEN 19 /* max command name remembered */ 106#define MAXINTERP PATH_MAX /* max interpreter file name length */ 107#define MAXLOGNAME 33 /* max login name length (incl. NUL) */ 108#define MAXUPRC CHILD_MAX /* max simultaneous processes */ 109#define NCARGS ARG_MAX /* max bytes for an exec function */ 110#define NGROUPS (NGROUPS_MAX+1) /* max number groups */ 111#define NOFILE OPEN_MAX /* max open files per process */ 112#define NOGROUP 65535 /* marker for empty group set member */ 113#define MAXHOSTNAMELEN 256 /* max hostname size */ 114#define SPECNAMELEN 63 /* max length of devicename */ 115 116/* More types and definitions used throughout the kernel. */ 117#ifdef _KERNEL 118#include <sys/cdefs.h> 119#include <sys/errno.h> 120#ifndef LOCORE 121#include <sys/time.h> 122#include <sys/priority.h> 123#endif 124 125#ifndef FALSE 126#define FALSE 0 127#endif 128#ifndef TRUE 129#define TRUE 1 130#endif 131#endif 132 133#ifndef _KERNEL 134/* Signals. */ 135#include <sys/signal.h> 136#endif 137 138/* Machine type dependent parameters. */ 139#include <machine/param.h> 140#ifndef _KERNEL 141#include <sys/limits.h> 142#endif 143 144#ifndef DEV_BSHIFT 145#define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */ 146#endif 147#define DEV_BSIZE (1<<DEV_BSHIFT) 148 149#ifndef BLKDEV_IOSIZE 150#define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */ 151#endif 152#ifndef DFLTPHYS 153#define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */ 154#endif 155#ifndef MAXPHYS 156#define MAXPHYS (128 * 1024) /* max raw I/O transfer size */ 157#endif 158#ifndef MAXDUMPPGS 159#define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE) 160#endif 161 162/* 163 * Constants related to network buffer management. 164 * MCLBYTES must be no larger than PAGE_SIZE. 165 */ 166#ifndef MSIZE 167#define MSIZE 256 /* size of an mbuf */ 168#endif 169 170#ifndef MCLSHIFT 171#define MCLSHIFT 11 /* convert bytes to mbuf clusters */ 172#endif /* MCLSHIFT */ 173 174#define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */ 175 176#if PAGE_SIZE < 2048 177#define MJUMPAGESIZE MCLBYTES 178#elif PAGE_SIZE <= 8192 179#define MJUMPAGESIZE PAGE_SIZE 180#else 181#define MJUMPAGESIZE (8 * 1024) 182#endif 183 184#define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */ 185#define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */ 186 187/* 188 * Some macros for units conversion 189 */ 190 191/* clicks to bytes */ 192#ifndef ctob 193#define ctob(x) ((x)<<PAGE_SHIFT) 194#endif 195 196/* bytes to clicks */ 197#ifndef btoc 198#define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT) 199#endif 200 201/* 202 * btodb() is messy and perhaps slow because `bytes' may be an off_t. We 203 * want to shift an unsigned type to avoid sign extension and we don't 204 * want to widen `bytes' unnecessarily. Assume that the result fits in 205 * a daddr_t. 206 */ 207#ifndef btodb 208#define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \ 209 (sizeof (bytes) > sizeof(long) \ 210 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \ 211 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT)) 212#endif 213 214#ifndef dbtob 215#define dbtob(db) /* calculates (db * DEV_BSIZE) */ \ 216 ((off_t)(db) << DEV_BSHIFT) 217#endif 218 219#define PRIMASK 0x0ff 220#define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */ 221#define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */ 222 223#define NZERO 0 /* default "nice" */ 224 225#define NBBY 8 /* number of bits in a byte */ 226#define NBPW sizeof(int) /* number of bytes per word (integer) */ 227 228#define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */ 229 230#define NODEV (dev_t)(-1) /* non-existent device */ 231 232/* 233 * File system parameters and macros. 234 * 235 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes 236 * per block. MAXBSIZE may be made larger without effecting 237 * any existing filesystems as long as it does not exceed MAXPHYS, 238 * and may be made smaller at the risk of not being able to use 239 * filesystems which require a block size exceeding MAXBSIZE. 240 * 241 * MAXBCACHEBUF - Maximum size of a buffer in the buffer cache. This must 242 * be >= MAXBSIZE and can be set differently for different 243 * architectures by defining it in <machine/param.h>. 244 * Making this larger allows NFS to do larger reads/writes. 245 * 246 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the 247 * minimum KVM memory reservation the kernel is willing to make. 248 * Filesystems can of course request smaller chunks. Actual 249 * backing memory uses a chunk size of a page (PAGE_SIZE). 250 * The default value here can be overridden on a per-architecture 251 * basis by defining it in <machine/param.h>. 252 * 253 * If you make BKVASIZE too small you risk seriously fragmenting 254 * the buffer KVM map which may slow things down a bit. If you 255 * make it too big the kernel will not be able to optimally use 256 * the KVM memory reserved for the buffer cache and will wind 257 * up with too-few buffers. 258 * 259 * The default is 16384, roughly 2x the block size used by a 260 * normal UFS filesystem. 261 */ 262#define MAXBSIZE 65536 /* must be power of 2 */ 263#ifndef MAXBCACHEBUF 264#define MAXBCACHEBUF MAXBSIZE /* must be a power of 2 >= MAXBSIZE */ 265#endif 266#ifndef BKVASIZE 267#define BKVASIZE 16384 /* must be power of 2 */ 268#endif 269#define BKVAMASK (BKVASIZE-1) 270 271/* 272 * MAXPATHLEN defines the longest permissible path length after expanding 273 * symbolic links. It is used to allocate a temporary buffer from the buffer 274 * pool in which to do the name expansion, hence should be a power of two, 275 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the 276 * maximum number of symbolic links that may be expanded in a path name. 277 * It should be set high enough to allow all legitimate uses, but halt 278 * infinite loops reasonably quickly. 279 */ 280#define MAXPATHLEN PATH_MAX 281#define MAXSYMLINKS 32 282 283/* Bit map related macros. */ 284#define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY)) 285#define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY))) 286#define isset(a,i) \ 287 (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) 288#define isclr(a,i) \ 289 ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0) 290 291/* Macros for counting and rounding. */ 292#ifndef howmany 293#define howmany(x, y) (((x)+((y)-1))/(y)) 294#endif 295#define nitems(x) (sizeof((x)) / sizeof((x)[0])) 296#define rounddown(x, y) (((x)/(y))*(y)) 297#define rounddown2(x, y) ((x)&(~((y)-1))) /* if y is power of two */ 298#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ 299#define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */ 300#define powerof2(x) ((((x)-1)&(x))==0) 301 302/* Macros for min/max. */ 303#define MIN(a,b) (((a)<(b))?(a):(b)) 304#define MAX(a,b) (((a)>(b))?(a):(b)) 305 306#ifdef _KERNEL 307/* 308 * Basic byte order function prototypes for non-inline functions. 309 */ 310#ifndef LOCORE 311#ifndef _BYTEORDER_PROTOTYPED 312#define _BYTEORDER_PROTOTYPED 313__BEGIN_DECLS 314__uint32_t htonl(__uint32_t); 315__uint16_t htons(__uint16_t); 316__uint32_t ntohl(__uint32_t); 317__uint16_t ntohs(__uint16_t); 318__END_DECLS 319#endif 320#endif 321 322#ifndef lint 323#ifndef _BYTEORDER_FUNC_DEFINED 324#define _BYTEORDER_FUNC_DEFINED 325#define htonl(x) __htonl(x) 326#define htons(x) __htons(x) 327#define ntohl(x) __ntohl(x) 328#define ntohs(x) __ntohs(x) 329#endif /* !_BYTEORDER_FUNC_DEFINED */ 330#endif /* lint */ 331#endif /* _KERNEL */ 332 333/* 334 * Scale factor for scaled integers used to count %cpu time and load avgs. 335 * 336 * The number of CPU `tick's that map to a unique `%age' can be expressed 337 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that 338 * can be calculated (assuming 32 bits) can be closely approximated using 339 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15). 340 * 341 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age', 342 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024. 343 */ 344#define FSHIFT 11 /* bits to right of fixed binary point */ 345#define FSCALE (1<<FSHIFT) 346 347#define dbtoc(db) /* calculates devblks to pages */ \ 348 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT)) 349 350#define ctodb(db) /* calculates pages to devblks */ \ 351 ((db) << (PAGE_SHIFT - DEV_BSHIFT)) 352 353/* 354 * Old spelling of __containerof(). 355 */ 356#define member2struct(s, m, x) \ 357 ((struct s *)(void *)((char *)(x) - offsetof(struct s, m))) 358 359/* 360 * Access a variable length array that has been declared as a fixed 361 * length array. 362 */ 363#define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset]) 364 365#endif /* _SYS_PARAM_H_ */ 366