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freebsd/sys/sys/param.h

327 lines
11 KiB
C

/*-
* 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.
* 4. 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.
*
* @(#)param.h 8.3 (Berkeley) 4/4/95
* $FreeBSD$
*/
#ifndef _SYS_PARAM_H_
#define _SYS_PARAM_H_
#include <sys/_null.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:
*
* doc/en_US.ISO8859-1/books/porters-handbook/book.sgml
*
* scheme is: <major><two digit minor>Rxx
* 'R' is 0 if release branch or x.0-CURRENT before RELENG_*_0
* is created, otherwise 1.
*/
#undef __FreeBSD_version
#define __FreeBSD_version 600022 /* Master, propagated to newvers */
#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>)
* MAXLOGNAME should be == UT_NAMESIZE+1 (see <utmp.h>)
*/
#include <sys/syslimits.h>
#define MAXCOMLEN 19 /* max command name remembered */
#define MAXINTERP 32 /* max interpreter file name length */
#define MAXLOGNAME 17 /* 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 /* 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 63 /* max length of devicename */
/* More types and definitions used throughout the kernel. */
#ifdef _KERNEL
#if 0
#if (defined(BURN_BRIDGES) || __FreeBSD_version >= 600000) \
&& defined(OBSOLETE_IN_6)
#error "This file contains obsolete code to be removed in 6.0-current"
#endif
#endif
#include <sys/cdefs.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/priority.h>
#define FALSE 0
#define TRUE 1
#endif
#ifndef _KERNEL
/* Signals. */
#include <sys/signal.h>
#endif
/* Machine type dependent parameters. */
#include <machine/param.h>
#ifndef _KERNEL
#include <sys/limits.h>
#endif
#ifndef _NO_NAMESPACE_POLLUTION
#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 MAXPHYS
#define MAXPHYS (128 * 1024) /* max raw I/O transfer size */
#endif
#ifndef MAXDUMPPGS
#define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE)
#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 /* MSIZE */
#ifndef MCLSHIFT
#define MCLSHIFT 11 /* convert bytes to mbuf clusters */
#endif /* MCLSHIFT */
#define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */
/*
* 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
#endif /* _NO_NAMESPACE_POLLUTION */
#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 NZERO 0 /* default "nice" */
#define NBBY 8 /* number of bits in a byte */
#define NBPW sizeof(int) /* number of bytes per word (integer) */
#define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
#define NODEV (dev_t)(-1) /* non-existent device */
#define CBLOCK 128 /* Clist block size, must be a power of 2. */
#define CBQSIZE (CBLOCK/NBBY) /* Quote bytes/cblock - can do better. */
/* Data chars/clist. */
#define CBSIZE (CBLOCK - sizeof(struct cblock *) - CBQSIZE)
#define CROUND (CBLOCK - 1) /* Clist rounding. */
/*
* 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.
*
* 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).
*
* 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 */
#define BKVASIZE 16384 /* must be power of 2 */
#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) ((a)[(i)/NBBY] |= 1<<((i)%NBBY))
#define clrbit(a,i) ((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
#define isset(a,i) ((a)[(i)/NBBY] & (1<<((i)%NBBY)))
#define isclr(a,i) (((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
/* Macros for counting and rounding. */
#ifndef howmany
#define howmany(x, y) (((x)+((y)-1))/(y))
#endif
#define rounddown(x, y) (((x)/(y))*(y))
#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
#define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
#define powerof2(x) ((((x)-1)&(x))==0)
/* 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 _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
#ifndef lint
#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 /* lint */
#endif /* _KERNEL */
/*
* Constants for setting the parameters of the kernel memory allocator.
*
* 2 ** MINBUCKET is the smallest unit of memory that will be
* allocated. It must be at least large enough to hold a pointer.
*
* Units of memory less or equal to MAXALLOCSAVE will permanently
* allocate physical memory; requests for these size pieces of
* memory are quite fast. Allocations greater than MAXALLOCSAVE must
* always allocate and free physical memory; requests for these
* size allocations should be done infrequently as they will be slow.
*
* Constraints: PAGE_SIZE <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
* MAXALLOCSIZE must be a power of two.
*/
#if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__)
#define MINBUCKET 5 /* 5 => min allocation of 32 bytes */
#else
#define MINBUCKET 4 /* 4 => min allocation of 16 bytes */
#endif
#define MAXALLOCSAVE (2 * PAGE_SIZE)
/*
* 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))). The maximum load average that
* can be calculated (assuming 32 bits) can be closely approximated using
* the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
*
* For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
* FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
*/
#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))
#endif /* _SYS_PARAM_H_ */