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pte.h revision 1.2 
      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 1.2 1993/05/22 08:00:34 cgd 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 LOCORE
     52 struct pde
     53 {
     54 unsigned int
     55 		pd_v:1,			/* valid bit */
     56 		pd_prot:2,		/* access control */
     57 		pd_mbz1:2,		/* reserved, must be zero */
     58 		pd_u:1,			/* hardware maintained 'used' bit */
     59 		:1,			/* not used */
     60 		pd_mbz2:2,		/* reserved, must be zero */
     61 		:3,			/* reserved for software */
     62 		pd_pfnum:20;		/* physical page frame number of pte's*/
     63 };
     64 struct pte
     65 {
     66 unsigned int
     67 		pg_v:1,			/* valid bit */
     68 		pg_prot:2,		/* access control */
     69 		pg_mbz1:2,		/* reserved, must be zero */
     70 		pg_u:1,			/* hardware maintained 'used' bit */
     71 		pg_m:1,			/* hardware maintained modified bit */
     72 		pg_mbz2:2,		/* reserved, must be zero */
     73 		pg_fod:1,		/* is fill on demand (=0) */
     74 		:1,			/* must write back to swap (unused) */
     75 		pg_nc:1,		/* 'uncacheable page' bit */
     76 		pg_pfnum:20;		/* physical page frame number */
     77 };
     78 struct hpte
     79 {
     80 unsigned int
     81 		pg_high:12,		/* special for clustering */
     82 		pg_pfnum:20;
     83 };
     84 struct fpte
     85 {
     86 unsigned int
     87 		pg_v:1,			/* valid bit */
     88 		pg_prot:2,		/* access control */
     89 		:5,
     90 		pg_fileno:1,		/* file mapped from or TEXT or ZERO */
     91 		pg_fod:1,		/* is fill on demand (=1) */
     92 		pg_blkno:22;		/* file system block number */
     93 };
     94 #endif
     95 
     96 #define	PD_MASK		0xffc00000	/* page directory address bits */
     97 #define	PD_SHIFT	22		/* page directory address bits */
     98 
     99 #define	PG_V		0x00000001
    100 #define	PG_PROT		0x00000006 /* all protection bits . */
    101 #define	PG_FOD		0x00000200
    102 #define	PG_SWAPM	0x00000400
    103 #define PG_N		0x00000800 /* Non-cacheable */
    104 #define	PG_M		0x00000040
    105 #define PG_U		0x00000020 /* not currently used */
    106 #define	PG_FRAME	0xfffff000
    107 
    108 #define	PG_FZERO	0
    109 #define	PG_FTEXT	1
    110 #define	PG_FMAX		(PG_FTEXT)
    111 
    112 #define	PG_NOACC	0
    113 #define	PG_KR		0x00000000
    114 #define	PG_KW		0x00000002
    115 #define	PG_URKR		0x00000004
    116 #define	PG_URKW		0x00000004
    117 #define	PG_UW		0x00000006
    118 
    119 /*
    120  * Page Protection Exception bits
    121  */
    122 
    123 #define PGEX_P		0x01	/* Protection violation vs. not present */
    124 #define PGEX_W		0x02	/* during a Write cycle */
    125 #define PGEX_U		0x04	/* access from User mode (UPL) */
    126 
    127 /*
    128  * Pte related macros
    129  */
    130 #define	dirty(pte)	((pte)->pg_m)
    131 
    132 #ifndef LOCORE
    133 #ifdef KERNEL
    134 /* utilities defined in pmap.c */
    135 extern	struct pte *Sysmap;
    136 #endif
    137 #endif
    138