param.h revision 280438
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 280438 2015-03-24 14:36:10Z ken $ 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 1001512 /* 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 84#define P_OSREL_MAJOR(x) ((x) / 100000) 85#endif 86 87#ifndef LOCORE 88#include <sys/types.h> 89#endif 90 91/* 92 * Machine-independent constants (some used in following include files). 93 * Redefined constants are from POSIX 1003.1 limits file. 94 * 95 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>) 96 */ 97#include <sys/syslimits.h> 98 99#define MAXCOMLEN 19 /* max command name remembered */ 100#define MAXINTERP PATH_MAX /* max interpreter file name length */ 101#define MAXLOGNAME 33 /* max login name length (incl. NUL) */ 102#define MAXUPRC CHILD_MAX /* max simultaneous processes */ 103#define NCARGS ARG_MAX /* max bytes for an exec function */ 104#define NGROUPS (NGROUPS_MAX+1) /* max number groups */ 105#define NOFILE OPEN_MAX /* max open files per process */ 106#define NOGROUP 65535 /* marker for empty group set member */ 107#define MAXHOSTNAMELEN 256 /* max hostname size */ 108#define SPECNAMELEN 63 /* max length of devicename */ 109 110/* More types and definitions used throughout the kernel. */ 111#ifdef _KERNEL 112#include <sys/cdefs.h> 113#include <sys/errno.h> 114#ifndef LOCORE 115#include <sys/time.h> 116#include <sys/priority.h> 117#endif 118 119#ifndef FALSE 120#define FALSE 0 121#endif 122#ifndef TRUE 123#define TRUE 1 124#endif 125#endif 126 127#ifndef _KERNEL 128/* Signals. */ 129#include <sys/signal.h> 130#endif 131 132/* Machine type dependent parameters. */ 133#include <machine/param.h> 134#ifndef _KERNEL 135#include <sys/limits.h> 136#endif 137 138#ifndef DEV_BSHIFT 139#define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */ 140#endif 141#define DEV_BSIZE (1<<DEV_BSHIFT) 142 143#ifndef BLKDEV_IOSIZE 144#define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */ 145#endif 146#ifndef DFLTPHYS 147#define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */ 148#endif 149#ifndef MAXPHYS 150#define MAXPHYS (128 * 1024) /* max raw I/O transfer size */ 151#endif 152#ifndef MAXDUMPPGS 153#define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE) 154#endif 155 156/* 157 * Constants related to network buffer management. 158 * MCLBYTES must be no larger than PAGE_SIZE. 159 */ 160#ifndef MSIZE 161#define MSIZE 256 /* size of an mbuf */ 162#endif 163 164#ifndef MCLSHIFT 165#define MCLSHIFT 11 /* convert bytes to mbuf clusters */ 166#endif /* MCLSHIFT */ 167 168#define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */ 169 170#if PAGE_SIZE < 2048 171#define MJUMPAGESIZE MCLBYTES 172#elif PAGE_SIZE <= 8192 173#define MJUMPAGESIZE PAGE_SIZE 174#else 175#define MJUMPAGESIZE (8 * 1024) 176#endif 177 178#define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */ 179#define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */ 180 181/* 182 * Some macros for units conversion 183 */ 184 185/* clicks to bytes */ 186#ifndef ctob 187#define ctob(x) ((x)<<PAGE_SHIFT) 188#endif 189 190/* bytes to clicks */ 191#ifndef btoc 192#define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT) 193#endif 194 195/* 196 * btodb() is messy and perhaps slow because `bytes' may be an off_t. We 197 * want to shift an unsigned type to avoid sign extension and we don't 198 * want to widen `bytes' unnecessarily. Assume that the result fits in 199 * a daddr_t. 200 */ 201#ifndef btodb 202#define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \ 203 (sizeof (bytes) > sizeof(long) \ 204 ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \ 205 : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT)) 206#endif 207 208#ifndef dbtob 209#define dbtob(db) /* calculates (db * DEV_BSIZE) */ \ 210 ((off_t)(db) << DEV_BSHIFT) 211#endif 212 213#define PRIMASK 0x0ff 214#define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */ 215#define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */ 216 217#define NZERO 0 /* default "nice" */ 218 219#define NBBY 8 /* number of bits in a byte */ 220#define NBPW sizeof(int) /* number of bytes per word (integer) */ 221 222#define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */ 223 224#define NODEV (dev_t)(-1) /* non-existent device */ 225 226/* 227 * File system parameters and macros. 228 * 229 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes 230 * per block. MAXBSIZE may be made larger without effecting 231 * any existing filesystems as long as it does not exceed MAXPHYS, 232 * and may be made smaller at the risk of not being able to use 233 * filesystems which require a block size exceeding MAXBSIZE. 234 * 235 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the 236 * minimum KVM memory reservation the kernel is willing to make. 237 * Filesystems can of course request smaller chunks. Actual 238 * backing memory uses a chunk size of a page (PAGE_SIZE). 239 * 240 * If you make BKVASIZE too small you risk seriously fragmenting 241 * the buffer KVM map which may slow things down a bit. If you 242 * make it too big the kernel will not be able to optimally use 243 * the KVM memory reserved for the buffer cache and will wind 244 * up with too-few buffers. 245 * 246 * The default is 16384, roughly 2x the block size used by a 247 * normal UFS filesystem. 248 */ 249#define MAXBSIZE 65536 /* must be power of 2 */ 250#define BKVASIZE 16384 /* must be power of 2 */ 251#define BKVAMASK (BKVASIZE-1) 252 253/* 254 * MAXPATHLEN defines the longest permissible path length after expanding 255 * symbolic links. It is used to allocate a temporary buffer from the buffer 256 * pool in which to do the name expansion, hence should be a power of two, 257 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the 258 * maximum number of symbolic links that may be expanded in a path name. 259 * It should be set high enough to allow all legitimate uses, but halt 260 * infinite loops reasonably quickly. 261 */ 262#define MAXPATHLEN PATH_MAX 263#define MAXSYMLINKS 32 264 265/* Bit map related macros. */ 266#define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY)) 267#define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY))) 268#define isset(a,i) \ 269 (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) 270#define isclr(a,i) \ 271 ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0) 272 273/* Macros for counting and rounding. */ 274#ifndef howmany 275#define howmany(x, y) (((x)+((y)-1))/(y)) 276#endif 277#define nitems(x) (sizeof((x)) / sizeof((x)[0])) 278#define rounddown(x, y) (((x)/(y))*(y)) 279#define rounddown2(x, y) ((x)&(~((y)-1))) /* if y is power of two */ 280#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ 281#define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */ 282#define powerof2(x) ((((x)-1)&(x))==0) 283 284/* Macros for min/max. */ 285#define MIN(a,b) (((a)<(b))?(a):(b)) 286#define MAX(a,b) (((a)>(b))?(a):(b)) 287 288#ifdef _KERNEL 289/* 290 * Basic byte order function prototypes for non-inline functions. 291 */ 292#ifndef LOCORE 293#ifndef _BYTEORDER_PROTOTYPED 294#define _BYTEORDER_PROTOTYPED 295__BEGIN_DECLS 296__uint32_t htonl(__uint32_t); 297__uint16_t htons(__uint16_t); 298__uint32_t ntohl(__uint32_t); 299__uint16_t ntohs(__uint16_t); 300__END_DECLS 301#endif 302#endif 303 304#ifndef lint 305#ifndef _BYTEORDER_FUNC_DEFINED 306#define _BYTEORDER_FUNC_DEFINED 307#define htonl(x) __htonl(x) 308#define htons(x) __htons(x) 309#define ntohl(x) __ntohl(x) 310#define ntohs(x) __ntohs(x) 311#endif /* !_BYTEORDER_FUNC_DEFINED */ 312#endif /* lint */ 313#endif /* _KERNEL */ 314 315/* 316 * Scale factor for scaled integers used to count %cpu time and load avgs. 317 * 318 * The number of CPU `tick's that map to a unique `%age' can be expressed 319 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that 320 * can be calculated (assuming 32 bits) can be closely approximated using 321 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15). 322 * 323 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age', 324 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024. 325 */ 326#define FSHIFT 11 /* bits to right of fixed binary point */ 327#define FSCALE (1<<FSHIFT) 328 329#define dbtoc(db) /* calculates devblks to pages */ \ 330 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT)) 331 332#define ctodb(db) /* calculates pages to devblks */ \ 333 ((db) << (PAGE_SHIFT - DEV_BSHIFT)) 334 335/* 336 * Old spelling of __containerof(). 337 */ 338#define member2struct(s, m, x) \ 339 ((struct s *)(void *)((char *)(x) - offsetof(struct s, m))) 340 341/* 342 * Access a variable length array that has been declared as a fixed 343 * length array. 344 */ 345#define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset]) 346 347#endif /* _SYS_PARAM_H_ */ 348