param.h revision 328379
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 328379 2018-01-24 21:48:39Z jhb $ 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/X.0 is created, otherwise 'R' is 58 * in the range 5 to 9. 59 */ 60#undef __FreeBSD_version 61#define __FreeBSD_version 1004501 /* 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_GUARD 1200035 84 85#define P_OSREL_MAJOR(x) ((x) / 100000) 86#endif 87 88#ifndef LOCORE 89#include <sys/types.h> 90#endif 91 92/* 93 * Machine-independent constants (some used in following include files). 94 * Redefined constants are from POSIX 1003.1 limits file. 95 * 96 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>) 97 */ 98#include <sys/syslimits.h> 99 100#define MAXCOMLEN 19 /* max command name remembered */ 101#define MAXINTERP PATH_MAX /* max interpreter file name length */ 102#define MAXLOGNAME 33 /* max login name length (incl. NUL) */ 103#define MAXUPRC CHILD_MAX /* max simultaneous processes */ 104#define NCARGS ARG_MAX /* max bytes for an exec function */ 105#define NGROUPS (NGROUPS_MAX+1) /* max number groups */ 106#define NOFILE OPEN_MAX /* max open files per process */ 107#define NOGROUP 65535 /* marker for empty group set member */ 108#define MAXHOSTNAMELEN 256 /* max hostname size */ 109#define SPECNAMELEN 63 /* max length of devicename */ 110 111/* More types and definitions used throughout the kernel. */ 112#ifdef _KERNEL 113#include <sys/cdefs.h> 114#include <sys/errno.h> 115#ifndef LOCORE 116#include <sys/time.h> 117#include <sys/priority.h> 118#endif 119 120#ifndef FALSE 121#define FALSE 0 122#endif 123#ifndef TRUE 124#define TRUE 1 125#endif 126#endif 127 128#ifndef _KERNEL 129/* Signals. */ 130#include <sys/signal.h> 131#endif 132 133/* Machine type dependent parameters. */ 134#include <machine/param.h> 135#ifndef _KERNEL 136#include <sys/limits.h> 137#endif 138 139#ifndef DEV_BSHIFT 140#define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */ 141#endif 142#define DEV_BSIZE (1<<DEV_BSHIFT) 143 144#ifndef BLKDEV_IOSIZE 145#define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */ 146#endif 147#ifndef DFLTPHYS 148#define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */ 149#endif 150#ifndef MAXPHYS 151#define MAXPHYS (128 * 1024) /* max raw I/O transfer size */ 152#endif 153#ifndef MAXDUMPPGS 154#define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE) 155#endif 156 157/* 158 * Constants related to network buffer management. 159 * MCLBYTES must be no larger than PAGE_SIZE. 160 */ 161#ifndef MSIZE 162#define MSIZE 256 /* size of an mbuf */ 163#endif 164 165#ifndef MCLSHIFT 166#define MCLSHIFT 11 /* convert bytes to mbuf clusters */ 167#endif /* MCLSHIFT */ 168 169#define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */ 170 171#if PAGE_SIZE < 2048 172#define MJUMPAGESIZE MCLBYTES 173#elif PAGE_SIZE <= 8192 174#define MJUMPAGESIZE PAGE_SIZE 175#else 176#define MJUMPAGESIZE (8 * 1024) 177#endif 178 179#define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */ 180#define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */ 181 182/* 183 * Some macros for units conversion 184 */ 185 186/* clicks to bytes */ 187#ifndef ctob 188#define ctob(x) ((x)<<PAGE_SHIFT) 189#endif 190 191/* bytes to clicks */ 192#ifndef btoc 193#define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT) 194#endif 195 196/* 197 * btodb() is messy and perhaps slow because `bytes' may be an off_t. We 198 * want to shift an unsigned type to avoid sign extension and we don't 199 * want to widen `bytes' unnecessarily. Assume that the result fits in 200 * a daddr_t. 201 */ 202#ifndef btodb 203#define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \ 204 (sizeof (bytes) > sizeof(long) \ 205 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \ 206 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT)) 207#endif 208 209#ifndef dbtob 210#define dbtob(db) /* calculates (db * DEV_BSIZE) */ \ 211 ((off_t)(db) << DEV_BSHIFT) 212#endif 213 214#define PRIMASK 0x0ff 215#define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */ 216#define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */ 217 218#define NZERO 0 /* default "nice" */ 219 220#define NBBY 8 /* number of bits in a byte */ 221#define NBPW sizeof(int) /* number of bytes per word (integer) */ 222 223#define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */ 224 225#define NODEV (dev_t)(-1) /* non-existent device */ 226 227/* 228 * File system parameters and macros. 229 * 230 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes 231 * per block. MAXBSIZE may be made larger without effecting 232 * any existing filesystems as long as it does not exceed MAXPHYS, 233 * and may be made smaller at the risk of not being able to use 234 * filesystems which require a block size exceeding MAXBSIZE. 235 * 236 * MAXBCACHEBUF - Maximum size of a buffer in the buffer cache. This must 237 * be >= MAXBSIZE and can be set differently for different 238 * architectures by defining it in <machine/param.h>. 239 * Making this larger allows NFS to do larger reads/writes. 240 * 241 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the 242 * minimum KVM memory reservation the kernel is willing to make. 243 * Filesystems can of course request smaller chunks. Actual 244 * backing memory uses a chunk size of a page (PAGE_SIZE). 245 * The default value here can be overridden on a per-architecture 246 * basis by defining it in <machine/param.h>. 247 * 248 * If you make BKVASIZE too small you risk seriously fragmenting 249 * the buffer KVM map which may slow things down a bit. If you 250 * make it too big the kernel will not be able to optimally use 251 * the KVM memory reserved for the buffer cache and will wind 252 * up with too-few buffers. 253 * 254 * The default is 16384, roughly 2x the block size used by a 255 * normal UFS filesystem. 256 */ 257#define MAXBSIZE 65536 /* must be power of 2 */ 258#ifndef MAXBCACHEBUF 259#define MAXBCACHEBUF MAXBSIZE /* must be a power of 2 >= MAXBSIZE */ 260#endif 261#ifndef BKVASIZE 262#define BKVASIZE 16384 /* must be power of 2 */ 263#endif 264#define BKVAMASK (BKVASIZE-1) 265 266/* 267 * MAXPATHLEN defines the longest permissible path length after expanding 268 * symbolic links. It is used to allocate a temporary buffer from the buffer 269 * pool in which to do the name expansion, hence should be a power of two, 270 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the 271 * maximum number of symbolic links that may be expanded in a path name. 272 * It should be set high enough to allow all legitimate uses, but halt 273 * infinite loops reasonably quickly. 274 */ 275#define MAXPATHLEN PATH_MAX 276#define MAXSYMLINKS 32 277 278/* Bit map related macros. */ 279#define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY)) 280#define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY))) 281#define isset(a,i) \ 282 (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) 283#define isclr(a,i) \ 284 ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0) 285 286/* Macros for counting and rounding. */ 287#ifndef howmany 288#define howmany(x, y) (((x)+((y)-1))/(y)) 289#endif 290#define nitems(x) (sizeof((x)) / sizeof((x)[0])) 291#define rounddown(x, y) (((x)/(y))*(y)) 292#define rounddown2(x, y) ((x)&(~((y)-1))) /* if y is power of two */ 293#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ 294#define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */ 295#define powerof2(x) ((((x)-1)&(x))==0) 296 297/* Macros for min/max. */ 298#define MIN(a,b) (((a)<(b))?(a):(b)) 299#define MAX(a,b) (((a)>(b))?(a):(b)) 300 301#ifdef _KERNEL 302/* 303 * Basic byte order function prototypes for non-inline functions. 304 */ 305#ifndef LOCORE 306#ifndef _BYTEORDER_PROTOTYPED 307#define _BYTEORDER_PROTOTYPED 308__BEGIN_DECLS 309__uint32_t htonl(__uint32_t); 310__uint16_t htons(__uint16_t); 311__uint32_t ntohl(__uint32_t); 312__uint16_t ntohs(__uint16_t); 313__END_DECLS 314#endif 315#endif 316 317#ifndef lint 318#ifndef _BYTEORDER_FUNC_DEFINED 319#define _BYTEORDER_FUNC_DEFINED 320#define htonl(x) __htonl(x) 321#define htons(x) __htons(x) 322#define ntohl(x) __ntohl(x) 323#define ntohs(x) __ntohs(x) 324#endif /* !_BYTEORDER_FUNC_DEFINED */ 325#endif /* lint */ 326#endif /* _KERNEL */ 327 328/* 329 * Scale factor for scaled integers used to count %cpu time and load avgs. 330 * 331 * The number of CPU `tick's that map to a unique `%age' can be expressed 332 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that 333 * can be calculated (assuming 32 bits) can be closely approximated using 334 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15). 335 * 336 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age', 337 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024. 338 */ 339#define FSHIFT 11 /* bits to right of fixed binary point */ 340#define FSCALE (1<<FSHIFT) 341 342#define dbtoc(db) /* calculates devblks to pages */ \ 343 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT)) 344 345#define ctodb(db) /* calculates pages to devblks */ \ 346 ((db) << (PAGE_SHIFT - DEV_BSHIFT)) 347 348/* 349 * Old spelling of __containerof(). 350 */ 351#define member2struct(s, m, x) \ 352 ((struct s *)(void *)((char *)(x) - offsetof(struct s, m))) 353 354/* 355 * Access a variable length array that has been declared as a fixed 356 * length array. 357 */ 358#define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset]) 359 360#endif /* _SYS_PARAM_H_ */ 361