xref: /netbsd-src/sys/arch/i386/include/pte.h (revision cda4f8f6ee55684e8d311b86c99ea59191e6b74f)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * William Jolitz.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	from: @(#)pte.h	5.5 (Berkeley) 5/9/91
37  *	$Id: pte.h,v 1.3 1993/06/27 04:50:14 andrew Exp $
38  */
39 
40 /*
41  * 386 page table entry and page table directory
42  * W.Jolitz, 8/89
43  *
44  * There are two major kinds of pte's: those which have ever existed (and are
45  * thus either now in core or on the swap device), and those which have
46  * never existed, but which will be filled on demand at first reference.
47  * There is a structure describing each.  There is also an ancillary
48  * structure used in page clustering.
49  */
50 
51 #ifndef _I386_PTE_H_
52 #define _I386_PTE_H_
53 
54 #ifndef LOCORE
55 struct pde
56 {
57 unsigned int
58 		pd_v:1,			/* valid bit */
59 		pd_prot:2,		/* access control */
60 		pd_mbz1:2,		/* reserved, must be zero */
61 		pd_u:1,			/* hardware maintained 'used' bit */
62 		:1,			/* not used */
63 		pd_mbz2:2,		/* reserved, must be zero */
64 		:3,			/* reserved for software */
65 		pd_pfnum:20;		/* physical page frame number of pte's*/
66 };
67 struct pte
68 {
69 unsigned int
70 		pg_v:1,			/* valid bit */
71 		pg_prot:2,		/* access control */
72 		pg_mbz1:2,		/* reserved, must be zero */
73 		pg_u:1,			/* hardware maintained 'used' bit */
74 		pg_m:1,			/* hardware maintained modified bit */
75 		pg_mbz2:2,		/* reserved, must be zero */
76 		pg_fod:1,		/* is fill on demand (=0) */
77 		:1,			/* must write back to swap (unused) */
78 		pg_nc:1,		/* 'uncacheable page' bit */
79 		pg_pfnum:20;		/* physical page frame number */
80 };
81 struct hpte
82 {
83 unsigned int
84 		pg_high:12,		/* special for clustering */
85 		pg_pfnum:20;
86 };
87 struct fpte
88 {
89 unsigned int
90 		pg_v:1,			/* valid bit */
91 		pg_prot:2,		/* access control */
92 		:5,
93 		pg_fileno:1,		/* file mapped from or TEXT or ZERO */
94 		pg_fod:1,		/* is fill on demand (=1) */
95 		pg_blkno:22;		/* file system block number */
96 };
97 #endif
98 
99 #define	PD_MASK		0xffc00000	/* page directory address bits */
100 #define	PD_SHIFT	22		/* page directory address bits */
101 
102 #define	PG_V		0x00000001
103 #define	PG_PROT		0x00000006 /* all protection bits . */
104 #define	PG_FOD		0x00000200
105 #define	PG_SWAPM	0x00000400
106 #define PG_N		0x00000800 /* Non-cacheable */
107 #define	PG_M		0x00000040
108 #define PG_U		0x00000020 /* not currently used */
109 #define	PG_FRAME	0xfffff000
110 
111 #define	PG_FZERO	0
112 #define	PG_FTEXT	1
113 #define	PG_FMAX		(PG_FTEXT)
114 
115 #define	PG_NOACC	0
116 #define	PG_KR		0x00000000
117 #define	PG_KW		0x00000002
118 #define	PG_URKR		0x00000004
119 #define	PG_URKW		0x00000004
120 #define	PG_UW		0x00000006
121 
122 /*
123  * Page Protection Exception bits
124  */
125 
126 #define PGEX_P		0x01	/* Protection violation vs. not present */
127 #define PGEX_W		0x02	/* during a Write cycle */
128 #define PGEX_U		0x04	/* access from User mode (UPL) */
129 
130 /*
131  * Pte related macros
132  */
133 #define	dirty(pte)	((pte)->pg_m)
134 
135 #ifndef LOCORE
136 #ifdef KERNEL
137 /* utilities defined in pmap.c */
138 extern	struct pte *Sysmap;
139 #endif
140 #endif
141 
142 #endif /* _I386_PTE_H_ */
143