usr/src/sys/h/param.h

/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *      @(#)param.h     7.1 (Berkeley) 6/4/86
 */

#define BSD     43              /* 4.3 * 10, as cpp doesn't do floats */
#define BSD4_3  1

/*
 * Machine type dependent parameters.
 */
#ifdef KERNEL
#include "../machine/machparam.h"
#else
#include <machine/machparam.h>
#endif

#define NPTEPG          (NBPG/(sizeof (struct pte)))

/*
 * Machine-independent constants
 */
#define NMOUNT  20              /* number of mountable file systems */
/* NMOUNT must be <= 255 unless c_mdev (cmap.h) is expanded */
#define MSWAPX  NMOUNT          /* pseudo mount table index for swapdev */
#define MAXUPRC 40              /* max processes per user */
#define NOFILE  64              /* max open files per process */
#define CANBSIZ 256             /* max size of typewriter line */
#define NCARGS  20480           /* # characters in exec arglist */
#define NGROUPS 16              /* max number groups */

#define NOGROUP 65535           /* marker for empty group set member */

/*
 * Priorities
 */
#define PSWP    0
#define PINOD   10
#define PRIBIO  20
#define PRIUBA  24
#define PZERO   25
#define PPIPE   26
#define PWAIT   30
#define PLOCK   35
#define PSLEP   40
#define PUSER   50

#define NZERO   0

/*
 * Signals
 */
#ifdef KERNEL
#include "signal.h"
#else
#include <signal.h>
#endif

#define ISSIG(p) \
        ((p)->p_sig && ((p)->p_flag&STRC || \
         ((p)->p_sig &~ ((p)->p_sigignore | (p)->p_sigmask))) && issig())

#define NBPW    sizeof(int)     /* number of bytes in an integer */

#define NULL    0
#define CMASK   022             /* default mask for file creation */
#define NODEV   (dev_t)(-1)

/*
 * Clustering of hardware pages on machines with ridiculously small
 * page sizes is done here.  The paging subsystem deals with units of
 * CLSIZE pte's describing NBPG (from vm.h) pages each.
 *
 * NOTE: SSIZE, SINCR and UPAGES must be multiples of CLSIZE
 */
#define CLBYTES         (CLSIZE*NBPG)
#define CLOFSET         (CLSIZE*NBPG-1) /* for clusters, like PGOFSET */
#define claligned(x)    ((((int)(x))&CLOFSET)==0)
#define CLOFF           CLOFSET
#define CLSHIFT         (PGSHIFT+CLSIZELOG2)

#if CLSIZE==1
#define clbase(i)       (i)
#define clrnd(i)        (i)
#else
/* give the base virtual address (first of CLSIZE) */
#define clbase(i)       ((i) &~ (CLSIZE-1))
/* round a number of clicks up to a whole cluster */
#define clrnd(i)        (((i) + (CLSIZE-1)) &~ (CLSIZE-1))
#endif

/* CBLOCK is the size of a clist block, must be power of 2 */
#define CBLOCK  64
#define CBSIZE  (CBLOCK - sizeof(struct cblock *))      /* data chars/clist */
#define CROUND  (CBLOCK - 1)                            /* clist rounding */

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

/*
 * File system parameters and macros.
 *
 * The file system is made out of blocks of at most MAXBSIZE units,
 * with smaller units (fragments) only in the last direct block.
 * MAXBSIZE primarily determines the size of buffers in the buffer
 * pool. It may be made larger without any effect on existing
 * file systems; however making it smaller make make some file
 * systems unmountable.
 *
 * Note that the blocked devices are assumed to have DEV_BSIZE
 * "sectors" and that fragments must be some multiple of this size.
 * Block devices are read in BLKDEV_IOSIZE units. This number must
 * be a power of two and in the range of
 *      DEV_BSIZE <= BLKDEV_IOSIZE <= MAXBSIZE
 * This size has no effect upon the file system, but is usually set
 * to the block size of the root file system, so as to maximize the
 * speed of ``fsck''.
 */
#define MAXBSIZE        8192
#define DEV_BSIZE       512
#define DEV_BSHIFT      9               /* log2(DEV_BSIZE) */
#define BLKDEV_IOSIZE   2048
#define MAXFRAG         8

#define btodb(bytes)                    /* calculates (bytes / DEV_BSIZE) */ \
        ((unsigned)(bytes) >> DEV_BSHIFT)
#define dbtob(db)                       /* calculates (db * DEV_BSIZE) */ \
        ((unsigned)(db) << DEV_BSHIFT)

/*
 * Map a ``block device block'' to a file system block.
 * This should be device dependent, and will be after we
 * add an entry to cdevsw for that purpose.  For now though
 * just use DEV_BSIZE.
 */
#define bdbtofsb(bn)    ((bn) / (BLKDEV_IOSIZE/DEV_BSIZE))

/*
 * MAXPATHLEN defines the longest permissable 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      1024
#define MAXSYMLINKS     8

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

/*
 * Macros for counting and rounding.
 */
#ifndef howmany
#define howmany(x, y)   (((x)+((y)-1))/(y))
#endif
#define roundup(x, y)   ((((x)+((y)-1))/(y))*(y))

/*
 * Maximum size of hostname recognized and stored in the kernel.
 */
#define MAXHOSTNAMELEN  64