Annotation of 42BSD/sys/h/param.h, revision 1.1

1.1     ! root        1: /*     param.h 6.1     83/07/29        */
        !             2: 
        !             3: /*
        !             4:  * Machine type dependent parameters.
        !             5:  */
        !             6: #ifdef KERNEL
        !             7: #include "../machine/param.h"
        !             8: #else
        !             9: #include <machine/param.h>
        !            10: #endif
        !            11: 
        !            12: #define        NPTEPG          (NBPG/(sizeof (struct pte)))
        !            13: 
        !            14: /*
        !            15:  * Machine-independent constants
        !            16:  */
        !            17: #define        NMOUNT  15              /* number of mountable file systems */
        !            18: #define        MSWAPX  15              /* pseudo mount table index for swapdev */
        !            19: #define        MAXUPRC 25              /* max processes per user */
        !            20: #define        NOFILE  20              /* max open files per process */
        !            21: /* NOFILE MUST NOT BE >= 31; SEE pte.h */
        !            22: #define        CANBSIZ 256             /* max size of typewriter line */
        !            23: #define        NCARGS  10240           /* # characters in exec arglist */
        !            24: #define        NGROUPS 8               /* max number groups */
        !            25: 
        !            26: #define        NOGROUP -1              /* marker for empty group set member */
        !            27: 
        !            28: /*
        !            29:  * Priorities
        !            30:  */
        !            31: #define        PSWP    0
        !            32: #define        PINOD   10
        !            33: #define        PRIBIO  20
        !            34: #define        PRIUBA  24
        !            35: #define        PZERO   25
        !            36: #define        PPIPE   26
        !            37: #define        PWAIT   30
        !            38: #define        PLOCK   35
        !            39: #define        PSLEP   40
        !            40: #define        PUSER   50
        !            41: 
        !            42: #define        NZERO   20
        !            43: 
        !            44: /*
        !            45:  * Signals
        !            46:  */
        !            47: #ifdef KERNEL
        !            48: #include "../h/signal.h"
        !            49: #else
        !            50: #include <signal.h>
        !            51: #endif
        !            52: 
        !            53: #define        ISSIG(p) \
        !            54:        ((p)->p_sig && ((p)->p_flag&STRC || \
        !            55:         ((p)->p_sig &~ ((p)->p_sigignore | (p)->p_sigmask))) && issig())
        !            56: 
        !            57: /*
        !            58:  * Fundamental constants of the implementation.
        !            59:  */
        !            60: #define        NBBY    8               /* number of bits in a byte */
        !            61: #define        NBPW    sizeof(int)     /* number of bytes in an integer */
        !            62: 
        !            63: #define        NULL    0
        !            64: #define        CMASK   0               /* default mask for file creation */
        !            65: #define        NODEV   (dev_t)(-1)
        !            66: 
        !            67: /*
        !            68:  * Clustering of hardware pages on machines with ridiculously small
        !            69:  * page sizes is done here.  The paging subsystem deals with units of
        !            70:  * CLSIZE pte's describing NBPG (from vm.h) pages each... BSIZE must
        !            71:  * be CLSIZE*NBPG in the current implementation, that is the paging subsystem
        !            72:  * deals with the same size blocks that the file system uses.
        !            73:  *
        !            74:  * NOTE: SSIZE, SINCR and UPAGES must be multiples of CLSIZE
        !            75:  */
        !            76: #define        CLBYTES         (CLSIZE*NBPG)
        !            77: #define        CLOFSET         (CLSIZE*NBPG-1) /* for clusters, like PGOFSET */
        !            78: #define        claligned(x)    ((((int)(x))&CLOFSET)==0)
        !            79: #define        CLOFF           CLOFSET
        !            80: #define        CLSHIFT         (PGSHIFT+CLSIZELOG2)
        !            81: 
        !            82: #if CLSIZE==1
        !            83: #define        clbase(i)       (i)
        !            84: #define        clrnd(i)        (i)
        !            85: #else
        !            86: /* give the base virtual address (first of CLSIZE) */
        !            87: #define        clbase(i)       ((i) &~ (CLSIZE-1))
        !            88: /* round a number of clicks up to a whole cluster */
        !            89: #define        clrnd(i)        (((i) + (CLSIZE-1)) &~ (CLSIZE-1))
        !            90: #endif
        !            91: 
        !            92: #ifndef INTRLVE
        !            93: /* macros replacing interleaving functions */
        !            94: #define        dkblock(bp)     ((bp)->b_blkno)
        !            95: #define        dkunit(bp)      (minor((bp)->b_dev) >> 3)
        !            96: #endif
        !            97: 
        !            98: #define        CBSIZE  28              /* number of chars in a clist block */
        !            99: #define        CROUND  0x1F            /* clist rounding; sizeof(int *) + CBSIZE -1*/
        !           100: 
        !           101: #ifndef KERNEL
        !           102: #include       <sys/types.h>
        !           103: #else
        !           104: #ifndef LOCORE
        !           105: #include       "../h/types.h"
        !           106: #endif
        !           107: #endif
        !           108: 
        !           109: /*
        !           110:  * File system parameters and macros.
        !           111:  *
        !           112:  * The file system is made out of blocks of at most MAXBSIZE units,
        !           113:  * with smaller units (fragments) only in the last direct block.
        !           114:  * MAXBSIZE primarily determines the size of buffers in the buffer
        !           115:  * pool. It may be made larger without any effect on existing
        !           116:  * file systems; however making it smaller make make some file
        !           117:  * systems unmountable.
        !           118:  *
        !           119:  * Note that the blocked devices are assumed to have DEV_BSIZE
        !           120:  * "sectors" and that fragments must be some multiple of this size.
        !           121:  * Block devices are read in BLKDEV_IOSIZE units. This number must
        !           122:  * be a power of two and in the range of
        !           123:  *     DEV_BSIZE <= BLKDEV_IOSIZE <= MAXBSIZE
        !           124:  * This size has no effect upon the file system, but is usually set
        !           125:  * to the block size of the root file system, so as to maximize the
        !           126:  * speed of ``fsck''.
        !           127:  */
        !           128: #define        MAXBSIZE        8192
        !           129: #define        DEV_BSIZE       512
        !           130: #define        DEV_BSHIFT      9               /* log2(DEV_BSIZE) */
        !           131: #define BLKDEV_IOSIZE  2048
        !           132: #define MAXFRAG        8
        !           133: 
        !           134: #define        btodb(bytes)                    /* calculates (bytes / DEV_BSIZE) */ \
        !           135:        ((unsigned)(bytes) >> DEV_BSHIFT)
        !           136: #define        dbtob(db)                       /* calculates (db * DEV_BSIZE) */ \
        !           137:        ((unsigned)(db) << DEV_BSHIFT)
        !           138: 
        !           139: /*
        !           140:  * Map a ``block device block'' to a file system block.
        !           141:  * This should be device dependent, and will be after we
        !           142:  * add an entry to cdevsw for that purpose.  For now though
        !           143:  * just use DEV_BSIZE.
        !           144:  */
        !           145: #define        bdbtofsb(bn)    ((bn) / (BLKDEV_IOSIZE/DEV_BSIZE))
        !           146: 
        !           147: /*
        !           148:  * MAXPATHLEN defines the longest permissable path length
        !           149:  * after expanding symbolic links. It is used to allocate
        !           150:  * a temporary buffer from the buffer pool in which to do the
        !           151:  * name expansion, hence should be a power of two, and must
        !           152:  * be less than or equal to MAXBSIZE.
        !           153:  * MAXSYMLINKS defines the maximum number of symbolic links
        !           154:  * that may be expanded in a path name. It should be set high
        !           155:  * enough to allow all legitimate uses, but halt infinite loops
        !           156:  * reasonably quickly.
        !           157:  */
        !           158: #define MAXPATHLEN     1024
        !           159: #define MAXSYMLINKS    8
        !           160: 
        !           161: /*
        !           162:  * bit map related macros
        !           163:  */
        !           164: #define        setbit(a,i)     ((a)[(i)/NBBY] |= 1<<((i)%NBBY))
        !           165: #define        clrbit(a,i)     ((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
        !           166: #define        isset(a,i)      ((a)[(i)/NBBY] & (1<<((i)%NBBY)))
        !           167: #define        isclr(a,i)      (((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
        !           168: 
        !           169: /*
        !           170:  * Macros for fast min/max.
        !           171:  */
        !           172: #define        MIN(a,b) (((a)<(b))?(a):(b))
        !           173: #define        MAX(a,b) (((a)>(b))?(a):(b))
        !           174: 
        !           175: /*
        !           176:  * Macros for counting and rounding.
        !           177:  */
        !           178: #define        howmany(x, y)   (((x)+((y)-1))/(y))
        !           179: #define        roundup(x, y)   ((((x)+((y)-1))/(y))*(y))

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