xref: /netbsd-src/sys/arch/mips/include/mips_param.h (revision 5e4c038a45edbc7d63b7c2daa76e29f88b64a4e3)
1 /*	$NetBSD: mips_param.h,v 1.21 2000/12/11 15:38:43 tsutsui Exp $	*/
2 
3 #ifdef _KERNEL
4 #include <machine/cpu.h>
5 #endif
6 
7 /*
8  * On mips, UPAGES is fixed by sys/arch/mips/mips/locore code
9  * to be the number of per-process-wired kernel-stack pages/PTES.
10  */
11 
12 #define	SSIZE		1		/* initial stack size/NBPG */
13 #define	SINCR		1		/* increment of stack/NBPG */
14 
15 #define	UPAGES		2		/* pages of u-area */
16 #define	USPACE		(UPAGES*NBPG)	/* size of u-area in bytes */
17 
18 #ifndef MSGBUFSIZE
19 #define MSGBUFSIZE	NBPG		/* default message buffer size */
20 #endif
21 
22 /*
23  * Round p (pointer or byte index) up to a correctly-aligned value for all
24  * data types (int, long, ...).   The result is u_int and must be cast to
25  * any desired pointer type.
26  *
27  * ALIGNED_POINTER is a boolean macro that checks whether an address
28  * is valid to fetch data elements of type t from on this architecture.
29  * This does not reflect the optimal alignment, just the possibility
30  * (within reasonable limits).
31  *
32  */
33 #define	ALIGNBYTES	7
34 #define	ALIGN(p)	(((u_int)(p) + ALIGNBYTES) & ~ALIGNBYTES)
35 #define ALIGNED_POINTER(p,t)	((((u_long)(p)) & (sizeof(t)-1)) == 0)
36 
37 #define	NBPG		4096		/* bytes/page */
38 #define	PGOFSET		(NBPG-1)	/* byte offset into page */
39 #define	PGSHIFT		12		/* LOG2(NBPG) */
40 #define	NPTEPG		(NBPG/4)
41 
42 #define NBSEG		0x400000	/* bytes/segment */
43 #define	SEGOFSET	(NBSEG-1)	/* byte offset into segment */
44 #define	SEGSHIFT	22		/* LOG2(NBSEG) */
45 
46 /*
47  * Minimum and maximum sizes of the kernel malloc arena in PAGE_SIZE-sized
48  * logical pages.
49  */
50 #define	NKMEMPAGES_MIN_DEFAULT	((8 * 1024 * 1024) >> PAGE_SHIFT)
51 #define	NKMEMPAGES_MAX_DEFAULT	((128 * 1024 * 1024) >> PAGE_SHIFT)
52 
53 /* pages ("clicks") (4096 bytes) to disk blocks */
54 #define	ctod(x)		((x) << (PGSHIFT - DEV_BSHIFT))
55 #define	dtoc(x)		((x) >> (PGSHIFT - DEV_BSHIFT))
56 
57 /* pages to bytes */
58 #define	ctob(x)		((x) << PGSHIFT)
59 #define btoc(x)		(((x) + PGOFSET) >> PGSHIFT)
60 
61 /* bytes to disk blocks */
62 #define	btodb(x)	((x) >> DEV_BSHIFT)
63 #define dbtob(x)	((x) << DEV_BSHIFT)
64 
65 /*
66  * Map a ``block device block'' to a file system block.
67  * This should be device dependent, and should use the bsize
68  * field from the disk label.
69  * For now though just use DEV_BSIZE.
70  */
71 #define	bdbtofsb(bn)	((bn) / (BLKDEV_IOSIZE/DEV_BSIZE))
72 
73 /*
74  * Mach derived conversion macros
75  */
76 #define mips_round_page(x)	((((unsigned)(x)) + NBPG - 1) & ~(NBPG-1))
77 #define mips_trunc_page(x)	((unsigned)(x) & ~(NBPG-1))
78 #define mips_btop(x)		((paddr_t)(x) >> PGSHIFT)
79 #define mips_ptob(x)		((paddr_t)(x) << PGSHIFT)
80