xref: /netbsd-src/sys/arch/i386/include/pte.h (revision ae9172d6cd9432a6a1a56760d86b32c57a66c39c)
1 /*	$NetBSD: pte.h,v 1.7 1994/10/27 04:16:21 cgd Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * William Jolitz.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)pte.h	5.5 (Berkeley) 5/9/91
39  */
40 
41 /*
42  * 386 page table entry and page table directory
43  * W.Jolitz, 8/89
44  *
45  * There are two major kinds of pte's: those which have ever existed (and are
46  * thus either now in core or on the swap device), and those which have
47  * never existed, but which will be filled on demand at first reference.
48  * There is a structure describing each.  There is also an ancillary
49  * structure used in page clustering.
50  */
51 
52 #ifndef _I386_PTE_H_
53 #define _I386_PTE_H_
54 
55 #define	PDSHIFT		22		/* LOG2(NBPDR) */
56 #define	NBPD		(1 << PDSHIFT)	/* bytes/page dir */
57 #define	PDOFSET		(NBPD-1)	/* byte offset into page dir */
58 #define	NPTEPD		(NBPD / NBPG)
59 
60 #ifndef LOCORE
61 typedef int	pd_entry_t;		/* page directory entry */
62 typedef int	pt_entry_t;		/* Mach page table entry */
63 #endif
64 
65 #define	PD_MASK		0xffc00000	/* page directory address bits */
66 #define	PT_MASK		0x003ff000	/* page table address bits */
67 
68 #define	PG_V		0x00000001	/* present */
69 #define	PG_RO		0x00000000	/* read-only by user (and kernel if 486) */
70 #define	PG_RW		0x00000002	/* read-write by user */
71 #define	PG_u		0x00000004	/* accessible by user */
72 #define	PG_PROT		0x00000006	/* all protection bits */
73 #define	PG_N		0x00000018	/* non-cacheable */
74 #define	PG_U		0x00000020	/* has been used */
75 #define	PG_M		0x00000040	/* has been modified */
76 #define	PG_W            0x00000200	/* page is wired */
77 #define	PG_FRAME	0xfffff000	/* page frame mask */
78 
79 #define	PG_FZERO	0
80 #define	PG_FTEXT	1
81 #define	PG_FMAX		(PG_FTEXT)
82 
83 #define	PG_NOACC	0
84 #define	PG_KR		0x00000000
85 #define	PG_KW		0x00000002
86 #define	PG_URKR		0x00000004
87 #define	PG_URKW		0x00000004
88 #define	PG_UW		0x00000006
89 
90 /*
91  * Page Protection Exception bits
92  */
93 #define PGEX_P		0x01	/* Protection violation vs. not present */
94 #define PGEX_W		0x02	/* during a Write cycle */
95 #define PGEX_U		0x04	/* access from User mode (UPL) */
96 
97 #ifndef LOCORE
98 #ifdef KERNEL
99 /* utilities defined in pmap.c */
100 extern	pt_entry_t *Sysmap;
101 #endif
102 #endif
103 
104 #endif /* _I386_PTE_H_ */
105