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mips_param.h revision 1.13 
      1 /*	$NetBSD: mips_param.h,v 1.13 1999/04/24 08:10:36 simonb Exp $	*/
      2 
      3 /*
      4  * NOTE: SSIZE, SINCR and UPAGES must be multiples of CLSIZE.
      5  * On mips, UPAGES is fixed by sys/arch/mips/mips/locore code
      6  * to be the number of per-process-wired kernel-stack pages/PTES.
      7  */
      8 
      9 #define	SSIZE		1		/* initial stack size/NBPG */
     10 #define	SINCR		1		/* increment of stack/NBPG */
     11 
     12 #define	UPAGES		2		/* pages of u-area */
     13 #define USPACE          (UPAGES*NBPG)   /* size of u-area in bytes */
     14 
     15 #ifndef MSGBUFSIZE
     16 #define MSGBUFSIZE	NBPG		/* default message buffer size */
     17 #endif
     18 
     19 /*
     20  * Round p (pointer or byte index) up to a correctly-aligned value for all
     21  * data types (int, long, ...).   The result is u_int and must be cast to
     22  * any desired pointer type.
     23  *
     24  * ALIGNED_POINTER is a boolean macro that checks whether an address
     25  * is valid to fetch data elements of type t from on this architecture.
     26  * This does not reflect the optimal alignment, just the possibility
     27  * (within reasonable limits).
     28  *
     29  */
     30 #define	ALIGNBYTES	7
     31 #define	ALIGN(p)	(((u_int)(p) + ALIGNBYTES) & ~ALIGNBYTES)
     32 #define ALIGNED_POINTER(p,t)	((((u_long)(p)) & (sizeof(t)-1)) == 0)
     33 
     34 #define	NBPG		4096		/* bytes/page */
     35 #define	PGOFSET		(NBPG-1)	/* byte offset into page */
     36 #define	PGSHIFT		12		/* LOG2(NBPG) */
     37 #define	NPTEPG		(NBPG/4)
     38 
     39 #define NBSEG		0x400000	/* bytes/segment */
     40 #define	SEGOFSET	(NBSEG-1)	/* byte offset into segment */
     41 #define	SEGSHIFT	22		/* LOG2(NBSEG) */
     42 
     43 /*
     44  * Size of kernel malloc arena in CLBYTES-sized logical pages
     45  */
     46 #ifndef NKMEMCLUSTERS
     47 #define	NKMEMCLUSTERS	(6 * 1024 * 1024 / CLBYTES)
     48 #endif
     49 
     50 /* pages ("clicks") (4096 bytes) to disk blocks */
     51 #define	ctod(x)		((x) << (PGSHIFT - DEV_BSHIFT))
     52 #define	dtoc(x)		((x) >> (PGSHIFT - DEV_BSHIFT))
     53 
     54 /* pages to bytes */
     55 #define	ctob(x)		((x) << PGSHIFT)
     56 #define btoc(x)		(((x) + PGOFSET) >> PGSHIFT)
     57 
     58 /* bytes to disk blocks */
     59 #define	btodb(x)	((x) >> DEV_BSHIFT)
     60 #define dbtob(x)	((x) << DEV_BSHIFT)
     61 
     62 /*
     63  * Map a ``block device block'' to a file system block.
     64  * This should be device dependent, and should use the bsize
     65  * field from the disk label.
     66  * For now though just use DEV_BSIZE.
     67  */
     68 #define	bdbtofsb(bn)	((bn) / (BLKDEV_IOSIZE/DEV_BSIZE))
     69 
     70 /*
     71  * Mach derived conversion macros
     72  */
     73 #define mips_round_page(x)	((((unsigned)(x)) + NBPG - 1) & ~(NBPG-1))
     74 #define mips_trunc_page(x)	((unsigned)(x) & ~(NBPG-1))
     75 #define mips_btop(x)		((unsigned)(x) >> PGSHIFT)
     76 #define mips_ptob(x)		((unsigned)(x) << PGSHIFT)
     77