param.h revision 310618
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 310618 2016-12-26 20:36:37Z dim $ 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_*_0 is created, otherwise 'R' is 58 * in the range 5 to 9. 59 */ 60#undef __FreeBSD_version 61#define __FreeBSD_version 1100508 /* 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#define P_OSREL_MAP_FSTRICT 1100036 84#define P_OSREL_SHUTDOWN_ENOTCONN 1100077 85 86#define P_OSREL_MAJOR(x) ((x) / 100000) 87#endif 88 89#ifndef LOCORE 90#include <sys/types.h> 91#endif 92 93/* 94 * Machine-independent constants (some used in following include files). 95 * Redefined constants are from POSIX 1003.1 limits file. 96 * 97 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>) 98 */ 99#include <sys/syslimits.h> 100 101#define MAXCOMLEN 19 /* max command name remembered */ 102#define MAXINTERP PATH_MAX /* max interpreter file name length */ 103#define MAXLOGNAME 33 /* max login name length (incl. NUL) */ 104#define MAXUPRC CHILD_MAX /* max simultaneous processes */ 105#define NCARGS ARG_MAX /* max bytes for an exec function */ 106#define NGROUPS (NGROUPS_MAX+1) /* max number groups */ 107#define NOFILE OPEN_MAX /* max open files per process */ 108#define NOGROUP 65535 /* marker for empty group set member */ 109#define MAXHOSTNAMELEN 256 /* max hostname size */ 110#define SPECNAMELEN 63 /* max length of devicename */ 111 112/* More types and definitions used throughout the kernel. */ 113#ifdef _KERNEL 114#include <sys/cdefs.h> 115#include <sys/errno.h> 116#ifndef LOCORE 117#include <sys/time.h> 118#include <sys/priority.h> 119#endif 120 121#ifndef FALSE 122#define FALSE 0 123#endif 124#ifndef TRUE 125#define TRUE 1 126#endif 127#endif 128 129#ifndef _KERNEL 130/* Signals. */ 131#include <sys/signal.h> 132#endif 133 134/* Machine type dependent parameters. */ 135#include <machine/param.h> 136#ifndef _KERNEL 137#include <sys/limits.h> 138#endif 139 140#ifndef DEV_BSHIFT 141#define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */ 142#endif 143#define DEV_BSIZE (1<<DEV_BSHIFT) 144 145#ifndef BLKDEV_IOSIZE 146#define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */ 147#endif 148#ifndef DFLTPHYS 149#define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */ 150#endif 151#ifndef MAXPHYS 152#define MAXPHYS (128 * 1024) /* max raw I/O transfer size */ 153#endif 154#ifndef MAXDUMPPGS 155#define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE) 156#endif 157 158/* 159 * Constants related to network buffer management. 160 * MCLBYTES must be no larger than PAGE_SIZE. 161 */ 162#ifndef MSIZE 163#define MSIZE 256 /* size of an mbuf */ 164#endif 165 166#ifndef MCLSHIFT 167#define MCLSHIFT 11 /* convert bytes to mbuf clusters */ 168#endif /* MCLSHIFT */ 169 170#define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */ 171 172#if PAGE_SIZE < 2048 173#define MJUMPAGESIZE MCLBYTES 174#elif PAGE_SIZE <= 8192 175#define MJUMPAGESIZE PAGE_SIZE 176#else 177#define MJUMPAGESIZE (8 * 1024) 178#endif 179 180#define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */ 181#define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */ 182 183/* 184 * Some macros for units conversion 185 */ 186 187/* clicks to bytes */ 188#ifndef ctob 189#define ctob(x) ((x)<<PAGE_SHIFT) 190#endif 191 192/* bytes to clicks */ 193#ifndef btoc 194#define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT) 195#endif 196 197/* 198 * btodb() is messy and perhaps slow because `bytes' may be an off_t. We 199 * want to shift an unsigned type to avoid sign extension and we don't 200 * want to widen `bytes' unnecessarily. Assume that the result fits in 201 * a daddr_t. 202 */ 203#ifndef btodb 204#define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \ 205 (sizeof (bytes) > sizeof(long) \ 206 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \ 207 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT)) 208#endif 209 210#ifndef dbtob 211#define dbtob(db) /* calculates (db * DEV_BSIZE) */ \ 212 ((off_t)(db) << DEV_BSHIFT) 213#endif 214 215#define PRIMASK 0x0ff 216#define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */ 217#define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */ 218 219#define NZERO 0 /* default "nice" */ 220 221#define NBBY 8 /* number of bits in a byte */ 222#define NBPW sizeof(int) /* number of bytes per word (integer) */ 223 224#define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */ 225 226#define NODEV (dev_t)(-1) /* non-existent device */ 227 228/* 229 * File system parameters and macros. 230 * 231 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes 232 * per block. MAXBSIZE may be made larger without effecting 233 * any existing filesystems as long as it does not exceed MAXPHYS, 234 * and may be made smaller at the risk of not being able to use 235 * filesystems which require a block size exceeding MAXBSIZE. 236 * 237 * MAXBCACHEBUF - Maximum size of a buffer in the buffer cache. This must 238 * be >= MAXBSIZE and can be set differently for different 239 * architectures by defining it in <machine/param.h>. 240 * Making this larger allows NFS to do larger reads/writes. 241 * 242 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the 243 * minimum KVM memory reservation the kernel is willing to make. 244 * Filesystems can of course request smaller chunks. Actual 245 * backing memory uses a chunk size of a page (PAGE_SIZE). 246 * The default value here can be overridden on a per-architecture 247 * basis by defining it in <machine/param.h>. This should 248 * probably be done to increase its value, when MAXBCACHEBUF is 249 * defined as a larger value in <machine/param.h>. 250 * 251 * If you make BKVASIZE too small you risk seriously fragmenting 252 * the buffer KVM map which may slow things down a bit. If you 253 * make it too big the kernel will not be able to optimally use 254 * the KVM memory reserved for the buffer cache and will wind 255 * up with too-few buffers. 256 * 257 * The default is 16384, roughly 2x the block size used by a 258 * normal UFS filesystem. 259 */ 260#define MAXBSIZE 65536 /* must be power of 2 */ 261#ifndef MAXBCACHEBUF 262#define MAXBCACHEBUF MAXBSIZE /* must be a power of 2 >= MAXBSIZE */ 263#endif 264#ifndef BKVASIZE 265#define BKVASIZE 16384 /* must be power of 2 */ 266#endif 267#define BKVAMASK (BKVASIZE-1) 268 269/* 270 * MAXPATHLEN defines the longest permissible path length after expanding 271 * symbolic links. It is used to allocate a temporary buffer from the buffer 272 * pool in which to do the name expansion, hence should be a power of two, 273 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the 274 * maximum number of symbolic links that may be expanded in a path name. 275 * It should be set high enough to allow all legitimate uses, but halt 276 * infinite loops reasonably quickly. 277 */ 278#define MAXPATHLEN PATH_MAX 279#define MAXSYMLINKS 32 280 281/* Bit map related macros. */ 282#define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY)) 283#define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY))) 284#define isset(a,i) \ 285 (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) 286#define isclr(a,i) \ 287 ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0) 288 289/* Macros for counting and rounding. */ 290#ifndef howmany 291#define howmany(x, y) (((x)+((y)-1))/(y)) 292#endif 293#define nitems(x) (sizeof((x)) / sizeof((x)[0])) 294#define rounddown(x, y) (((x)/(y))*(y)) 295#define rounddown2(x, y) ((x)&(~((y)-1))) /* if y is power of two */ 296#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ 297#define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */ 298#define powerof2(x) ((((x)-1)&(x))==0) 299 300/* Macros for min/max. */ 301#define MIN(a,b) (((a)<(b))?(a):(b)) 302#define MAX(a,b) (((a)>(b))?(a):(b)) 303 304#ifdef _KERNEL 305/* 306 * Basic byte order function prototypes for non-inline functions. 307 */ 308#ifndef LOCORE 309#ifndef _BYTEORDER_PROTOTYPED 310#define _BYTEORDER_PROTOTYPED 311__BEGIN_DECLS 312__uint32_t htonl(__uint32_t); 313__uint16_t htons(__uint16_t); 314__uint32_t ntohl(__uint32_t); 315__uint16_t ntohs(__uint16_t); 316__END_DECLS 317#endif 318#endif 319 320#ifndef lint 321#ifndef _BYTEORDER_FUNC_DEFINED 322#define _BYTEORDER_FUNC_DEFINED 323#define htonl(x) __htonl(x) 324#define htons(x) __htons(x) 325#define ntohl(x) __ntohl(x) 326#define ntohs(x) __ntohs(x) 327#endif /* !_BYTEORDER_FUNC_DEFINED */ 328#endif /* lint */ 329#endif /* _KERNEL */ 330 331/* 332 * Scale factor for scaled integers used to count %cpu time and load avgs. 333 * 334 * The number of CPU `tick's that map to a unique `%age' can be expressed 335 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that 336 * can be calculated (assuming 32 bits) can be closely approximated using 337 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15). 338 * 339 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age', 340 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024. 341 */ 342#define FSHIFT 11 /* bits to right of fixed binary point */ 343#define FSCALE (1<<FSHIFT) 344 345#define dbtoc(db) /* calculates devblks to pages */ \ 346 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT)) 347 348#define ctodb(db) /* calculates pages to devblks */ \ 349 ((db) << (PAGE_SHIFT - DEV_BSHIFT)) 350 351/* 352 * Old spelling of __containerof(). 353 */ 354#define member2struct(s, m, x) \ 355 ((struct s *)(void *)((char *)(x) - offsetof(struct s, m))) 356 357/* 358 * Access a variable length array that has been declared as a fixed 359 * length array. 360 */ 361#define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset]) 362 363#endif /* _SYS_PARAM_H_ */ 364