xref: /netbsd-src/sys/arch/mips/include/mips_param.h (revision dc306354b0b29af51801a7632f1e95265a68cd81)
1 /*	$NetBSD: mips_param.h,v 1.11 1999/01/14 18:45:45 castor Exp $	*/
2 
3 /*
4  * Architecture name.
5  */
6 #define	_MACHINE_ARCH	mips
7 #define	MACHINE_ARCH	"mips"
8 
9 /*
10  * NOTE: SSIZE, SINCR and UPAGES must be multiples of CLSIZE.
11  * On mips, UPAGES is fixed by sys/arch/mips/mips/locore code
12  * to be the number of per-process-wired kernel-stack pages/PTES.
13  */
14 
15 #define	SSIZE		1		/* initial stack size/NBPG */
16 #define	SINCR		1		/* increment of stack/NBPG */
17 
18 #define	UPAGES		2		/* pages of u-area */
19 #define USPACE          (UPAGES*NBPG)   /* size of u-area in bytes */
20 
21 #ifndef MSGBUFSIZE
22 #define MSGBUFSIZE	NBPG		/* default message buffer size */
23 #endif
24 
25 /*
26  * Round p (pointer or byte index) up to a correctly-aligned value for all
27  * data types (int, long, ...).   The result is u_int and must be cast to
28  * any desired pointer type.
29  *
30  * ALIGNED_POINTER is a boolean macro that checks whether an address
31  * is valid to fetch data elements of type t from on this architecture.
32  * This does not reflect the optimal alignment, just the possibility
33  * (within reasonable limits).
34  *
35  */
36 #define	ALIGNBYTES	7
37 #define	ALIGN(p)	(((u_int)(p) + ALIGNBYTES) & ~ALIGNBYTES)
38 #define ALIGNED_POINTER(p,t)	((((u_long)(p)) & (sizeof(t)-1)) == 0)
39 
40 #define	NBPG		4096		/* bytes/page */
41 #define	PGOFSET		(NBPG-1)	/* byte offset into page */
42 #define	PGSHIFT		12		/* LOG2(NBPG) */
43 #define	NPTEPG		(NBPG/4)
44 
45 #define NBSEG		0x400000	/* bytes/segment */
46 #define	SEGOFSET	(NBSEG-1)	/* byte offset into segment */
47 #define	SEGSHIFT	22		/* LOG2(NBSEG) */
48 
49 /*
50  * Size of kernel malloc arena in CLBYTES-sized logical pages
51  */
52 #ifndef NKMEMCLUSTERS
53 #define	NKMEMCLUSTERS	(6 * 1024 * 1024 / CLBYTES)
54 #endif
55 
56 /* pages ("clicks") (4096 bytes) to disk blocks */
57 #define	ctod(x)		((x) << (PGSHIFT - DEV_BSHIFT))
58 #define	dtoc(x)		((x) >> (PGSHIFT - DEV_BSHIFT))
59 
60 /* pages to bytes */
61 #define	ctob(x)		((x) << PGSHIFT)
62 #define btoc(x)		(((x) + PGOFSET) >> PGSHIFT)
63 
64 /* bytes to disk blocks */
65 #define	btodb(x)	((x) >> DEV_BSHIFT)
66 #define dbtob(x)	((x) << DEV_BSHIFT)
67 
68 /*
69  * Map a ``block device block'' to a file system block.
70  * This should be device dependent, and should use the bsize
71  * field from the disk label.
72  * For now though just use DEV_BSIZE.
73  */
74 #define	bdbtofsb(bn)	((bn) / (BLKDEV_IOSIZE/DEV_BSIZE))
75 
76 /*
77  * Mach derived conversion macros
78  */
79 #define mips_round_page(x)	((((unsigned)(x)) + NBPG - 1) & ~(NBPG-1))
80 #define mips_trunc_page(x)	((unsigned)(x) & ~(NBPG-1))
81 #define mips_btop(x)		((unsigned)(x) >> PGSHIFT)
82 #define mips_ptob(x)		((unsigned)(x) << PGSHIFT)
83