root/sys/sys/param.h
/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1982, 1986, 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef _SYS_PARAM_H_
#define _SYS_PARAM_H_

#include <sys/_null.h>
#include <sys/_param.h>

#define BSD     199506          /* System version (year & month). */
#define BSD4_3  1
#define BSD4_4  1

/*
 * __FreeBSD_version numbers are documented in the Porter's Handbook.
 * If you bump the version for any reason, you should update the documentation
 * there.
 * Currently this lives here in the doc/ repository:
 *
 *      documentation/content/en/books/porters-handbook/versions/_index.adoc
 *
 * Encoding:    <major><two digit minor>Rxx
 *              'R' is in the range 0 to 4 if this is a release branch or
 *              X.0-CURRENT before releng/X.0 is created, otherwise 'R' is
 *              in the range 5 to 9.
 * Short hand: MMmmXXX
 *
 * __FreeBSD_version is bumped every time there's a change in the base system
 * that's noteworthy. A noteworthy change is any change which changes the
 * kernel's KBI in -CURRENT, one that changes some detail about the system that
 * external software (or the ports system) would want to know about, one that
 * adds a system call, one that adds or deletes a shipped library, a security
 * fix, or similar change not specifically noted here. Bumps should be limited
 * to one per day / a couple per week except for security fixes.
 *
 * The approved way to obtain this from a shell script is:
 *      awk '/^\#define[[:space:]]*__FreeBSD_version/ {print $3}'
 * Other methods to parse this file may work, but are not guaranteed against
 * future changes. The above script works back to FreeBSD 3.x when this macro
 * was introduced. This number is propagated to other places needing it that
 * cannot include sys/param.h and should only be updated here.
 */
#undef __FreeBSD_version
#define __FreeBSD_version 1600015

/*
 * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,
 * which by definition is always true on FreeBSD. This macro is also defined
 * on other systems that use the kernel of FreeBSD, such as GNU/kFreeBSD.
 *
 * It is tempting to use this macro in userland code when we want to enable
 * kernel-specific routines, and in fact it's fine to do this in code that
 * is part of FreeBSD itself.  However, be aware that as presence of this
 * macro is still not widespread (e.g. older FreeBSD versions, 3rd party
 * compilers, etc), it is STRONGLY DISCOURAGED to check for this macro in
 * external applications without also checking for __FreeBSD__ as an
 * alternative.
 */
#undef __FreeBSD_kernel__
#define __FreeBSD_kernel__

#if defined(_KERNEL) || defined(_WANT_P_OSREL)
#define P_OSREL_SIGWAIT                 700000
#define P_OSREL_SIGSEGV                 700004
#define P_OSREL_MAP_ANON                800104
#define P_OSREL_MAP_FSTRICT             1100036
#define P_OSREL_SHUTDOWN_ENOTCONN       1100077
#define P_OSREL_MAP_GUARD               1200035
#define P_OSREL_WRFSBASE                1200041
#define P_OSREL_CK_CYLGRP               1200046
#define P_OSREL_VMTOTAL64               1200054
#define P_OSREL_CK_SUPERBLOCK           1300000
#define P_OSREL_CK_INODE                1300005
#define P_OSREL_POWERPC_NEW_AUX_ARGS    1300070
#define P_OSREL_TIDPID                  1400079
#define P_OSREL_ARM64_SPSR              1400084
#define P_OSREL_TLSBASE                 1500044
#define P_OSREL_EXTERRCTL               1500045
#define P_OSREL_AMD64_TF_FRED           1600014

#define P_OSREL_MAJOR(x)                ((x) / 100000)
#endif

#ifndef LOCORE
#include <sys/types.h>
#endif

/*
 * Machine-independent constants (some used in following include files).
 * Redefined constants are from POSIX 1003.1 limits file.
 *
 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
 */
#include <sys/syslimits.h>

#define MAXCOMLEN       19              /* max command name remembered */
#define MAXINTERP       PATH_MAX        /* max interpreter file name length */
#define MAXLOGNAME      33              /* max login name length (incl. NUL) */
#define MAXUPRC         CHILD_MAX       /* max simultaneous processes */
#define NCARGS          ARG_MAX         /* max bytes for an exec function */
#define NGROUPS         (NGROUPS_MAX+1) /* max number groups */
#define NOFILE          OPEN_MAX        /* max open files per process */
#define NOGROUP         65535           /* marker for empty group set member */
#define MAXHOSTNAMELEN  256             /* max hostname size */
#define SPECNAMELEN     255             /* max length of devicename */

/* More types and definitions used throughout the kernel. */
#ifdef _KERNEL
#include <sys/cdefs.h>
#include <sys/errno.h>
#ifndef LOCORE
#include <sys/time.h>
#include <sys/priority.h>
#endif

#ifndef FALSE
#define FALSE   0
#endif
#ifndef TRUE
#define TRUE    1
#endif
#endif

#if !defined(_KERNEL) && !defined(_STANDALONE) && !defined(LOCORE)
/* Signals. */
#include <sys/signal.h>
#endif

/* Machine type dependent parameters. */
#include <machine/param.h>
#ifndef _KERNEL
#include <sys/limits.h>
#include <sys/_maxphys.h>
#endif

#ifndef DEV_BSHIFT
#define DEV_BSHIFT      9               /* log2(DEV_BSIZE) */
#endif
#define DEV_BSIZE       (1<<DEV_BSHIFT)

#ifndef BLKDEV_IOSIZE
#define BLKDEV_IOSIZE  PAGE_SIZE        /* default block device I/O size */
#endif
#ifndef DFLTPHYS
#define DFLTPHYS        (64 * 1024)     /* default max raw I/O transfer size */
#endif
#ifndef MAXDUMPPGS
#define MAXDUMPPGS      (DFLTPHYS/PAGE_SIZE)
#endif
#ifdef STACKALIGNBYTES
#define STACKALIGN(p)   (__align_down(p, STACKALIGNBYTES + 1))
#endif

/*
 * Constants related to network buffer management.
 * MCLBYTES must be no larger than PAGE_SIZE.
 */
#ifndef MSIZE
#define MSIZE           256             /* size of an mbuf */
#endif

#ifndef MCLSHIFT
#define MCLSHIFT        11              /* convert bytes to mbuf clusters */
#endif  /* MCLSHIFT */

#define MCLBYTES        (1 << MCLSHIFT) /* size of an mbuf cluster */

#if PAGE_SIZE <= 8192
#define MJUMPAGESIZE    PAGE_SIZE
#else
#define MJUMPAGESIZE    (8 * 1024)
#endif

#define MJUM9BYTES      (9 * 1024)      /* jumbo cluster 9k */
#define MJUM16BYTES     (16 * 1024)     /* jumbo cluster 16k */

/*
 * Mach derived conversion macros
 */
#define round_page(x)   roundup2(x, PAGE_SIZE)
#define trunc_page(x)   rounddown2(x, PAGE_SIZE)

#define atop(x)         ((x) >> PAGE_SHIFT)
#define ptoa(x)         ((x) << PAGE_SHIFT)

#define pgtok(x)        ((x) * (PAGE_SIZE / 1024))

/*
 * Some macros for units conversion
 */

/* clicks to bytes */
#ifndef ctob
#define ctob(x) ((x)<<PAGE_SHIFT)
#endif

/* bytes to clicks */
#ifndef btoc
#define btoc(x) (((vm_offset_t)(x)+PAGE_MASK)>>PAGE_SHIFT)
#endif

/*
 * btodb() is messy and perhaps slow because `bytes' may be an off_t.  We
 * want to shift an unsigned type to avoid sign extension and we don't
 * want to widen `bytes' unnecessarily.  Assume that the result fits in
 * a daddr_t.
 */
#ifndef btodb
#define btodb(bytes)                    /* calculates (bytes / DEV_BSIZE) */ \
        (sizeof (bytes) > sizeof(long) \
         ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
         : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
#endif

#ifndef dbtob
#define dbtob(db)                       /* calculates (db * DEV_BSIZE) */ \
        ((off_t)(db) << DEV_BSHIFT)
#endif

#define PRIMASK         0x0ff
#define PCATCH          0x100   /* OR'd with pri for tsleep to check signals */
#define PDROP           0x200   /* OR'd with pri to stop re-entry of interlock mutex */
#define PNOLOCK         0x400   /* OR'd with pri to allow sleeping w/o a lock */
#define PRILASTFLAG     0x400   /* Last flag defined above */

#define NZERO   0               /* default "nice" */

#define CMASK   022             /* default file mask: S_IWGRP|S_IWOTH */

#define NODEV   (dev_t)(-1)     /* non-existent device */

/*
 * File system parameters and macros.
 *
 * MAXBSIZE -   Filesystems are made out of blocks of at most MAXBSIZE bytes
 *              per block.  MAXBSIZE may be made larger without effecting
 *              any existing filesystems as long as it does not exceed MAXPHYS,
 *              and may be made smaller at the risk of not being able to use
 *              filesystems which require a block size exceeding MAXBSIZE.
 *
 * MAXBCACHEBUF - Maximum size of a buffer in the buffer cache.  This must
 *              be >= MAXBSIZE and can be set differently for different
 *              architectures by defining it in <machine/param.h>.
 *              Making this larger allows NFS to do larger reads/writes.
 *
 * BKVASIZE -   Nominal buffer space per buffer, in bytes.  BKVASIZE is the
 *              minimum KVM memory reservation the kernel is willing to make.
 *              Filesystems can of course request smaller chunks.  Actual
 *              backing memory uses a chunk size of a page (PAGE_SIZE).
 *              The default value here can be overridden on a per-architecture
 *              basis by defining it in <machine/param.h>.
 *
 *              If you make BKVASIZE too small you risk seriously fragmenting
 *              the buffer KVM map which may slow things down a bit.  If you
 *              make it too big the kernel will not be able to optimally use
 *              the KVM memory reserved for the buffer cache and will wind
 *              up with too-few buffers.
 *
 *              The default is 16384, roughly 2x the block size used by a
 *              normal UFS filesystem.
 */
#define MAXBSIZE        65536   /* must be power of 2 */
#ifndef MAXBCACHEBUF
#define MAXBCACHEBUF    MAXBSIZE /* must be a power of 2 >= MAXBSIZE */
#endif
#ifndef BKVASIZE
#define BKVASIZE        16384   /* must be power of 2 */
#endif
#define BKVAMASK        (BKVASIZE-1)

/*
 * MAXPATHLEN defines the longest permissible path length after expanding
 * symbolic links. It is used to allocate a temporary buffer from the buffer
 * pool in which to do the name expansion, hence should be a power of two,
 * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
 * maximum number of symbolic links that may be expanded in a path name.
 * It should be set high enough to allow all legitimate uses, but halt
 * infinite loops reasonably quickly.
 */
#define MAXPATHLEN      PATH_MAX
#define MAXSYMLINKS     32

/* Bit map related macros. */
#define setbit(a,i)     (((unsigned char *)(a))[(i)/NBBY] |= 1<<((i)%NBBY))
#define clrbit(a,i)     (((unsigned char *)(a))[(i)/NBBY] &= ~(1<<((i)%NBBY)))
#define isset(a,i)                                                      \
        (((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY)))
#define isclr(a,i)                                                      \
        ((((const unsigned char *)(a))[(i)/NBBY] & (1<<((i)%NBBY))) == 0)

/* Macros for counting and rounding provided by <sys/_param.h>. */

/* Macros for min/max. */
#define MIN(a,b) (((a)<(b))?(a):(b))
#define MAX(a,b) (((a)>(b))?(a):(b))

#ifdef _KERNEL
/*
 * Basic byte order function prototypes for non-inline functions.
 */
#ifndef LOCORE
#ifndef _BYTEORDER_PROTOTYPED
#define _BYTEORDER_PROTOTYPED
__BEGIN_DECLS
__uint32_t       htonl(__uint32_t);
__uint16_t       htons(__uint16_t);
__uint32_t       ntohl(__uint32_t);
__uint16_t       ntohs(__uint16_t);
__END_DECLS
#endif
#endif

#ifndef _BYTEORDER_FUNC_DEFINED
#define _BYTEORDER_FUNC_DEFINED
#define htonl(x)        __htonl(x)
#define htons(x)        __htons(x)
#define ntohl(x)        __ntohl(x)
#define ntohs(x)        __ntohs(x)
#endif /* !_BYTEORDER_FUNC_DEFINED */
#endif /* _KERNEL */

/*
 * Scale factor for scaled integers used to count %cpu time and load avgs.
 *
 * The number of CPU `tick's that map to a unique `%age' can be expressed
 * by the formula (1 / (2 ^ (FSHIFT - 11))).  Since the intermediate
 * calculation is done with 64-bit precision, the maximum load average that can
 * be calculated is approximately 2^32 / FSCALE.
 *
 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
 * FSHIFT must be at least 11.  This gives a maximum load avg of 2 million.
 */
#define FSHIFT  11              /* bits to right of fixed binary point */
#define FSCALE  (1<<FSHIFT)

#define dbtoc(db)                       /* calculates devblks to pages */ \
        ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))

#define ctodb(db)                       /* calculates pages to devblks */ \
        ((db) << (PAGE_SHIFT - DEV_BSHIFT))

/*
 * Old spelling of __containerof().
 */
#define member2struct(s, m, x)                                          \
        ((struct s *)(void *)((char *)(x) - offsetof(struct s, m)))

/*
 * Access a variable length array that has been declared as a fixed
 * length array.
 */
#define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset])

#endif  /* _SYS_PARAM_H_ */