1199767f8SToomas Soome /*- 2199767f8SToomas Soome * Copyright (c) 1982, 1986, 1989, 1993 3199767f8SToomas Soome * The Regents of the University of California. All rights reserved. 4199767f8SToomas Soome * (c) UNIX System Laboratories, Inc. 5199767f8SToomas Soome * All or some portions of this file are derived from material licensed 6199767f8SToomas Soome * to the University of California by American Telephone and Telegraph 7199767f8SToomas Soome * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8199767f8SToomas Soome * the permission of UNIX System Laboratories, Inc. 9199767f8SToomas Soome * 10199767f8SToomas Soome * Redistribution and use in source and binary forms, with or without 11199767f8SToomas Soome * modification, are permitted provided that the following conditions 12199767f8SToomas Soome * are met: 13199767f8SToomas Soome * 1. Redistributions of source code must retain the above copyright 14199767f8SToomas Soome * notice, this list of conditions and the following disclaimer. 15199767f8SToomas Soome * 2. Redistributions in binary form must reproduce the above copyright 16199767f8SToomas Soome * notice, this list of conditions and the following disclaimer in the 17199767f8SToomas Soome * documentation and/or other materials provided with the distribution. 18199767f8SToomas Soome * 4. Neither the name of the University nor the names of its contributors 19199767f8SToomas Soome * may be used to endorse or promote products derived from this software 20199767f8SToomas Soome * without specific prior written permission. 21199767f8SToomas Soome * 22199767f8SToomas Soome * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23199767f8SToomas Soome * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24199767f8SToomas Soome * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25199767f8SToomas Soome * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26199767f8SToomas Soome * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27199767f8SToomas Soome * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28199767f8SToomas Soome * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29199767f8SToomas Soome * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30199767f8SToomas Soome * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31199767f8SToomas Soome * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32199767f8SToomas Soome * SUCH DAMAGE. 33199767f8SToomas Soome * 34199767f8SToomas Soome * @(#)param.h 8.3 (Berkeley) 4/4/95 35199767f8SToomas Soome * $FreeBSD$ 36199767f8SToomas Soome */ 37199767f8SToomas Soome 38199767f8SToomas Soome #ifndef _SYS_PARAM_H_ 39199767f8SToomas Soome #define _SYS_PARAM_H_ 40199767f8SToomas Soome 41199767f8SToomas Soome #include <sys/_null.h> 42199767f8SToomas Soome 43199767f8SToomas Soome #define BSD 199506 /* System version (year & month). */ 44199767f8SToomas Soome #define BSD4_3 1 45199767f8SToomas Soome #define BSD4_4 1 46199767f8SToomas Soome 47*55fea89dSDan Cross /* 48199767f8SToomas Soome * __FreeBSD_version numbers are documented in the Porter's Handbook. 49199767f8SToomas Soome * If you bump the version for any reason, you should update the documentation 50199767f8SToomas Soome * there. 51199767f8SToomas Soome * Currently this lives here in the doc/ repository: 52199767f8SToomas Soome * 53199767f8SToomas Soome * head/en_US.ISO8859-1/books/porters-handbook/versions/chapter.xml 54199767f8SToomas Soome * 55199767f8SToomas Soome * scheme is: <major><two digit minor>Rxx 56199767f8SToomas Soome * 'R' is in the range 0 to 4 if this is a release branch or 57199767f8SToomas Soome * x.0-CURRENT before RELENG_*_0 is created, otherwise 'R' is 58199767f8SToomas Soome * in the range 5 to 9. 59199767f8SToomas Soome */ 60199767f8SToomas Soome #undef __FreeBSD_version 61199767f8SToomas Soome #define __FreeBSD_version 1100100 /* Master, propagated to newvers */ 62199767f8SToomas Soome 63199767f8SToomas Soome /* 64199767f8SToomas Soome * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD, 65199767f8SToomas Soome * which by definition is always true on FreeBSD. This macro is also defined 66199767f8SToomas Soome * on other systems that use the kernel of FreeBSD, such as GNU/kFreeBSD. 67199767f8SToomas Soome * 68199767f8SToomas Soome * It is tempting to use this macro in userland code when we want to enable 69199767f8SToomas Soome * kernel-specific routines, and in fact it's fine to do this in code that 70199767f8SToomas Soome * is part of FreeBSD itself. However, be aware that as presence of this 71199767f8SToomas Soome * macro is still not widespread (e.g. older FreeBSD versions, 3rd party 72199767f8SToomas Soome * compilers, etc), it is STRONGLY DISCOURAGED to check for this macro in 73199767f8SToomas Soome * external applications without also checking for __FreeBSD__ as an 74199767f8SToomas Soome * alternative. 75199767f8SToomas Soome */ 76199767f8SToomas Soome #undef __FreeBSD_kernel__ 77199767f8SToomas Soome #define __FreeBSD_kernel__ 78199767f8SToomas Soome 79199767f8SToomas Soome #ifdef _KERNEL 80199767f8SToomas Soome #define P_OSREL_SIGWAIT 700000 81199767f8SToomas Soome #define P_OSREL_SIGSEGV 700004 82199767f8SToomas Soome #define P_OSREL_MAP_ANON 800104 83199767f8SToomas Soome #define P_OSREL_MAP_FSTRICT 1100036 84199767f8SToomas Soome #define P_OSREL_SHUTDOWN_ENOTCONN 1100077 85199767f8SToomas Soome 86199767f8SToomas Soome #define P_OSREL_MAJOR(x) ((x) / 100000) 87199767f8SToomas Soome #endif 88199767f8SToomas Soome 89199767f8SToomas Soome #ifndef LOCORE 90199767f8SToomas Soome #include <sys/types.h> 91199767f8SToomas Soome #endif 92199767f8SToomas Soome 93199767f8SToomas Soome /* 94199767f8SToomas Soome * Machine-independent constants (some used in following include files). 95199767f8SToomas Soome * Redefined constants are from POSIX 1003.1 limits file. 96199767f8SToomas Soome * 97199767f8SToomas Soome * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>) 98199767f8SToomas Soome */ 99199767f8SToomas Soome #include <sys/syslimits.h> 100199767f8SToomas Soome 101199767f8SToomas Soome #define MAXCOMLEN 19 /* max command name remembered */ 102199767f8SToomas Soome #define MAXINTERP PATH_MAX /* max interpreter file name length */ 103199767f8SToomas Soome #define MAXLOGNAME 33 /* max login name length (incl. NUL) */ 104199767f8SToomas Soome #define MAXUPRC CHILD_MAX /* max simultaneous processes */ 105199767f8SToomas Soome #define NCARGS ARG_MAX /* max bytes for an exec function */ 106199767f8SToomas Soome #define NGROUPS (NGROUPS_MAX+1) /* max number groups */ 107199767f8SToomas Soome #define NOFILE OPEN_MAX /* max open files per process */ 108199767f8SToomas Soome #define NOGROUP 65535 /* marker for empty group set member */ 109199767f8SToomas Soome #define MAXHOSTNAMELEN 256 /* max hostname size */ 110199767f8SToomas Soome #define SPECNAMELEN 63 /* max length of devicename */ 111199767f8SToomas Soome 112199767f8SToomas Soome /* More types and definitions used throughout the kernel. */ 113199767f8SToomas Soome #ifdef _KERNEL 114199767f8SToomas Soome #include <sys/cdefs.h> 115199767f8SToomas Soome #include <sys/errno.h> 116199767f8SToomas Soome #ifndef LOCORE 117199767f8SToomas Soome #include <sys/time.h> 118199767f8SToomas Soome #include <sys/priority.h> 119199767f8SToomas Soome #endif 120199767f8SToomas Soome 121199767f8SToomas Soome #ifndef FALSE 122199767f8SToomas Soome #define FALSE 0 123199767f8SToomas Soome #endif 124199767f8SToomas Soome #ifndef TRUE 125199767f8SToomas Soome #define TRUE 1 126199767f8SToomas Soome #endif 127199767f8SToomas Soome #endif 128199767f8SToomas Soome 129199767f8SToomas Soome #ifndef _KERNEL 130199767f8SToomas Soome /* Signals. */ 131199767f8SToomas Soome #include <sys/signal.h> 132199767f8SToomas Soome #endif 133199767f8SToomas Soome 134199767f8SToomas Soome /* Machine type dependent parameters. */ 135199767f8SToomas Soome #include <machine/param.h> 136199767f8SToomas Soome #ifndef _KERNEL 137199767f8SToomas Soome #include <sys/limits.h> 138199767f8SToomas Soome #endif 139199767f8SToomas Soome 140199767f8SToomas Soome #ifndef DEV_BSHIFT 141199767f8SToomas Soome #define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */ 142199767f8SToomas Soome #endif 143199767f8SToomas Soome #define DEV_BSIZE (1<<DEV_BSHIFT) 144199767f8SToomas Soome 145199767f8SToomas Soome #ifndef BLKDEV_IOSIZE 146199767f8SToomas Soome #define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */ 147199767f8SToomas Soome #endif 148199767f8SToomas Soome #ifndef DFLTPHYS 149199767f8SToomas Soome #define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */ 150199767f8SToomas Soome #endif 151199767f8SToomas Soome #ifndef MAXPHYS 152199767f8SToomas Soome #define MAXPHYS (128 * 1024) /* max raw I/O transfer size */ 153199767f8SToomas Soome #endif 154199767f8SToomas Soome #ifndef MAXDUMPPGS 155199767f8SToomas Soome #define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE) 156199767f8SToomas Soome #endif 157199767f8SToomas Soome 158199767f8SToomas Soome /* 159199767f8SToomas Soome * Constants related to network buffer management. 160199767f8SToomas Soome * MCLBYTES must be no larger than PAGE_SIZE. 161199767f8SToomas Soome */ 162199767f8SToomas Soome #ifndef MSIZE 163199767f8SToomas Soome #define MSIZE 256 /* size of an mbuf */ 164199767f8SToomas Soome #endif 165199767f8SToomas Soome 166199767f8SToomas Soome #ifndef MCLSHIFT 167199767f8SToomas Soome #define MCLSHIFT 11 /* convert bytes to mbuf clusters */ 168199767f8SToomas Soome #endif /* MCLSHIFT */ 169199767f8SToomas Soome 170199767f8SToomas Soome #define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */ 171199767f8SToomas Soome 172199767f8SToomas Soome #if PAGE_SIZE < 2048 173199767f8SToomas Soome #define MJUMPAGESIZE MCLBYTES 174199767f8SToomas Soome #elif PAGE_SIZE <= 8192 175199767f8SToomas Soome #define MJUMPAGESIZE PAGE_SIZE 176199767f8SToomas Soome #else 177199767f8SToomas Soome #define MJUMPAGESIZE (8 * 1024) 178199767f8SToomas Soome #endif 179199767f8SToomas Soome 180199767f8SToomas Soome #define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */ 181199767f8SToomas Soome #define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */ 182199767f8SToomas Soome 183199767f8SToomas Soome /* 184199767f8SToomas Soome * Some macros for units conversion 185199767f8SToomas Soome */ 186199767f8SToomas Soome 187199767f8SToomas Soome /* clicks to bytes */ 188199767f8SToomas Soome #ifndef ctob 189199767f8SToomas Soome #define ctob(x) ((x)<<PAGE_SHIFT) 190199767f8SToomas Soome #endif 191199767f8SToomas Soome 192199767f8SToomas Soome /* bytes to clicks */ 193199767f8SToomas Soome #ifndef btoc 194199767f8SToomas Soome #define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT) 195199767f8SToomas Soome #endif 196199767f8SToomas Soome 197199767f8SToomas Soome /* 198199767f8SToomas Soome * btodb() is messy and perhaps slow because `bytes' may be an off_t. We 199199767f8SToomas Soome * want to shift an unsigned type to avoid sign extension and we don't 200199767f8SToomas Soome * want to widen `bytes' unnecessarily. Assume that the result fits in 201199767f8SToomas Soome * a daddr_t. 202199767f8SToomas Soome */ 203199767f8SToomas Soome #ifndef btodb 204199767f8SToomas Soome #define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \ 205199767f8SToomas Soome (sizeof (bytes) > sizeof(long) \ 206199767f8SToomas Soome ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \ 207199767f8SToomas Soome : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT)) 208199767f8SToomas Soome #endif 209199767f8SToomas Soome 210199767f8SToomas Soome #ifndef dbtob 211199767f8SToomas Soome #define dbtob(db) /* calculates (db * DEV_BSIZE) */ \ 212199767f8SToomas Soome ((off_t)(db) << DEV_BSHIFT) 213199767f8SToomas Soome #endif 214199767f8SToomas Soome 215199767f8SToomas Soome #define PRIMASK 0x0ff 216199767f8SToomas Soome #define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */ 217199767f8SToomas Soome #define PDROP 0x200 /* OR'd with pri to stop re-entry of interlock mutex */ 218199767f8SToomas Soome 219199767f8SToomas Soome #define NZERO 0 /* default "nice" */ 220199767f8SToomas Soome 221199767f8SToomas Soome #define NBBY 8 /* number of bits in a byte */ 222199767f8SToomas Soome #define NBPW sizeof(int) /* number of bytes per word (integer) */ 223199767f8SToomas Soome 224199767f8SToomas Soome #define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */ 225199767f8SToomas Soome 226199767f8SToomas Soome #define NODEV (dev_t)(-1) /* non-existent device */ 227199767f8SToomas Soome 228199767f8SToomas Soome /* 229199767f8SToomas Soome * File system parameters and macros. 230199767f8SToomas Soome * 231199767f8SToomas Soome * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes 232199767f8SToomas Soome * per block. MAXBSIZE may be made larger without effecting 233199767f8SToomas Soome * any existing filesystems as long as it does not exceed MAXPHYS, 234199767f8SToomas Soome * and may be made smaller at the risk of not being able to use 235199767f8SToomas Soome * filesystems which require a block size exceeding MAXBSIZE. 236199767f8SToomas Soome * 237199767f8SToomas Soome * MAXBCACHEBUF - Maximum size of a buffer in the buffer cache. This must 238199767f8SToomas Soome * be >= MAXBSIZE and can be set differently for different 239199767f8SToomas Soome * architectures by defining it in <machine/param.h>. 240199767f8SToomas Soome * Making this larger allows NFS to do larger reads/writes. 241199767f8SToomas Soome * 242199767f8SToomas Soome * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the 243199767f8SToomas Soome * minimum KVM memory reservation the kernel is willing to make. 244*55fea89dSDan Cross * Filesystems can of course request smaller chunks. Actual 245199767f8SToomas Soome * backing memory uses a chunk size of a page (PAGE_SIZE). 246199767f8SToomas Soome * The default value here can be overridden on a per-architecture 247199767f8SToomas Soome * basis by defining it in <machine/param.h>. This should 248199767f8SToomas Soome * probably be done to increase its value, when MAXBCACHEBUF is 249199767f8SToomas Soome * defined as a larger value in <machine/param.h>. 250199767f8SToomas Soome * 251199767f8SToomas Soome * If you make BKVASIZE too small you risk seriously fragmenting 252199767f8SToomas Soome * the buffer KVM map which may slow things down a bit. If you 253*55fea89dSDan Cross * make it too big the kernel will not be able to optimally use 254*55fea89dSDan Cross * the KVM memory reserved for the buffer cache and will wind 255199767f8SToomas Soome * up with too-few buffers. 256199767f8SToomas Soome * 257199767f8SToomas Soome * The default is 16384, roughly 2x the block size used by a 258199767f8SToomas Soome * normal UFS filesystem. 259199767f8SToomas Soome */ 260199767f8SToomas Soome #define MAXBSIZE 65536 /* must be power of 2 */ 261199767f8SToomas Soome #ifndef MAXBCACHEBUF 262199767f8SToomas Soome #define MAXBCACHEBUF MAXBSIZE /* must be a power of 2 >= MAXBSIZE */ 263199767f8SToomas Soome #endif 264199767f8SToomas Soome #ifndef BKVASIZE 265199767f8SToomas Soome #define BKVASIZE 16384 /* must be power of 2 */ 266199767f8SToomas Soome #endif 267199767f8SToomas Soome #define BKVAMASK (BKVASIZE-1) 268199767f8SToomas Soome 269199767f8SToomas Soome /* 270199767f8SToomas Soome * MAXPATHLEN defines the longest permissible path length after expanding 271199767f8SToomas Soome * symbolic links. It is used to allocate a temporary buffer from the buffer 272199767f8SToomas Soome * pool in which to do the name expansion, hence should be a power of two, 273199767f8SToomas Soome * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the 274199767f8SToomas Soome * maximum number of symbolic links that may be expanded in a path name. 275199767f8SToomas Soome * It should be set high enough to allow all legitimate uses, but halt 276199767f8SToomas Soome * infinite loops reasonably quickly. 277199767f8SToomas Soome */ 278199767f8SToomas Soome #define MAXPATHLEN PATH_MAX 279199767f8SToomas Soome #define MAXSYMLINKS 32 280199767f8SToomas Soome 281199767f8SToomas Soome /* Bit map related macros. */ 282199767f8SToomas Soome #define setbit(a,i) (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY)) 283199767f8SToomas Soome #define clrbit(a,i) (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY))) 284199767f8SToomas Soome #define isset(a,i) \ 285199767f8SToomas Soome (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) 286199767f8SToomas Soome #define isclr(a,i) \ 287199767f8SToomas Soome ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0) 288199767f8SToomas Soome 289199767f8SToomas Soome /* Macros for counting and rounding. */ 290199767f8SToomas Soome #ifndef howmany 291199767f8SToomas Soome #define howmany(x, y) (((x)+((y)-1))/(y)) 292199767f8SToomas Soome #endif 293199767f8SToomas Soome #define nitems(x) (sizeof((x)) / sizeof((x)[0])) 294199767f8SToomas Soome #define rounddown(x, y) (((x)/(y))*(y)) 295199767f8SToomas Soome #define rounddown2(x, y) ((x)&(~((y)-1))) /* if y is power of two */ 296199767f8SToomas Soome #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ 297199767f8SToomas Soome #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */ 298199767f8SToomas Soome #define powerof2(x) ((((x)-1)&(x))==0) 299199767f8SToomas Soome 300199767f8SToomas Soome /* Macros for min/max. */ 301199767f8SToomas Soome #define MIN(a,b) (((a)<(b))?(a):(b)) 302199767f8SToomas Soome #define MAX(a,b) (((a)>(b))?(a):(b)) 303199767f8SToomas Soome 304199767f8SToomas Soome #ifdef _KERNEL 305199767f8SToomas Soome /* 306199767f8SToomas Soome * Basic byte order function prototypes for non-inline functions. 307199767f8SToomas Soome */ 308199767f8SToomas Soome #ifndef LOCORE 309199767f8SToomas Soome #ifndef _BYTEORDER_PROTOTYPED 310199767f8SToomas Soome #define _BYTEORDER_PROTOTYPED 311199767f8SToomas Soome __BEGIN_DECLS 312199767f8SToomas Soome __uint32_t htonl(__uint32_t); 313199767f8SToomas Soome __uint16_t htons(__uint16_t); 314199767f8SToomas Soome __uint32_t ntohl(__uint32_t); 315199767f8SToomas Soome __uint16_t ntohs(__uint16_t); 316199767f8SToomas Soome __END_DECLS 317199767f8SToomas Soome #endif 318199767f8SToomas Soome #endif 319199767f8SToomas Soome 320199767f8SToomas Soome #ifndef lint 321199767f8SToomas Soome #ifndef _BYTEORDER_FUNC_DEFINED 322199767f8SToomas Soome #define _BYTEORDER_FUNC_DEFINED 323199767f8SToomas Soome #define htonl(x) __htonl(x) 324199767f8SToomas Soome #define htons(x) __htons(x) 325199767f8SToomas Soome #define ntohl(x) __ntohl(x) 326199767f8SToomas Soome #define ntohs(x) __ntohs(x) 327199767f8SToomas Soome #endif /* !_BYTEORDER_FUNC_DEFINED */ 328199767f8SToomas Soome #endif /* lint */ 329199767f8SToomas Soome #endif /* _KERNEL */ 330199767f8SToomas Soome 331199767f8SToomas Soome /* 332199767f8SToomas Soome * Scale factor for scaled integers used to count %cpu time and load avgs. 333199767f8SToomas Soome * 334199767f8SToomas Soome * The number of CPU `tick's that map to a unique `%age' can be expressed 335199767f8SToomas Soome * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that 336199767f8SToomas Soome * can be calculated (assuming 32 bits) can be closely approximated using 337199767f8SToomas Soome * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15). 338199767f8SToomas Soome * 339199767f8SToomas Soome * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age', 340199767f8SToomas Soome * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024. 341199767f8SToomas Soome */ 342199767f8SToomas Soome #define FSHIFT 11 /* bits to right of fixed binary point */ 343199767f8SToomas Soome #define FSCALE (1<<FSHIFT) 344199767f8SToomas Soome 345199767f8SToomas Soome #define dbtoc(db) /* calculates devblks to pages */ \ 346199767f8SToomas Soome ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT)) 347*55fea89dSDan Cross 348199767f8SToomas Soome #define ctodb(db) /* calculates pages to devblks */ \ 349199767f8SToomas Soome ((db) << (PAGE_SHIFT - DEV_BSHIFT)) 350199767f8SToomas Soome 351199767f8SToomas Soome /* 352199767f8SToomas Soome * Old spelling of __containerof(). 353199767f8SToomas Soome */ 354199767f8SToomas Soome #define member2struct(s, m, x) \ 355199767f8SToomas Soome ((struct s *)(void *)((char *)(x) - offsetof(struct s, m))) 356199767f8SToomas Soome 357199767f8SToomas Soome /* 358199767f8SToomas Soome * Access a variable length array that has been declared as a fixed 359199767f8SToomas Soome * length array. 360199767f8SToomas Soome */ 361199767f8SToomas Soome #define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset]) 362199767f8SToomas Soome 363199767f8SToomas Soome #endif /* _SYS_PARAM_H_ */ 364