Home | History | Annotate | Line # | Download | only in include
pte.h revision 1.4 
      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 1.4 1993/12/14 05:31:40 mycroft 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 #define	PDSHIFT		22		/* LOG2(NBPDR) */
     55 #define	NBPD		(1 << PDSHIFT)	/* bytes/page dir */
     56 #define	PDOFSET		(NBPD-1)	/* byte offset into page dir */
     57 #define	NPTEPD		(NBPD / NBPG)
     58 
     59 #ifndef LOCORE
     60 
     61 struct pde {
     62 	unsigned int
     63 		pd_v:1,			/* valid bit */
     64 		pd_prot:2,		/* access control */
     65 		pg_nc:2,		/* cache disable and write-through */
     66 		pd_u:1,			/* hardware maintained 'used' bit */
     67 		pd_mbz:3,		/* reserved, must be zero */
     68 		pg_w:1,			/* is wired */
     69 		:2,			/* reserved for software */
     70 		pd_pfnum:20;		/* physical page frame number of pte's*/
     71 };
     72 
     73 struct pte {
     74 	unsigned int
     75 		pg_v:1,			/* valid bit */
     76 		pg_prot:2,		/* access control */
     77 		pg_nc:2,		/* cache disable and write-through */
     78 		pg_u:1,			/* hardware maintained 'used' bit */
     79 		pg_m:1,			/* hardware maintained modified bit */
     80 		pg_mbz:2,		/* reserved, must be zero */
     81 		pg_w:1,			/* is wired */
     82 		:2,			/* must write back to swap (unused) */
     83 		pg_pfnum:20;		/* physical page frame number */
     84 };
     85 
     86 typedef struct pde	pd_entry_t;	/* page directory entry */
     87 typedef struct pte	pt_entry_t;	/* Mach page table entry */
     88 
     89 #endif
     90 
     91 #define	PD_MASK		0xffc00000	/* page directory address bits */
     92 #define	PT_MASK		0x003ff000	/* page table address bits */
     93 
     94 #define	PG_V		0x00000001	/* present */
     95 #define	PG_RO		0x00000000	/* read-only by user (and kernel if 486) */
     96 #define	PG_RW		0x00000002	/* read-write by user */
     97 #define	PG_u		0x00000004	/* accessible by user */
     98 #define	PG_PROT		0x00000006	/* all protection bits */
     99 #define	PG_N		0x00000018	/* non-cacheable */
    100 #define	PG_U		0x00000020	/* has been used */
    101 #define	PG_M		0x00000040	/* has been modified */
    102 #define	PG_W            0x00000200	/* page is wired */
    103 #define	PG_FRAME	0xfffff000	/* page frame mask */
    104 
    105 #define	PG_FZERO	0
    106 #define	PG_FTEXT	1
    107 #define	PG_FMAX		(PG_FTEXT)
    108 
    109 #define	PG_NOACC	0
    110 #define	PG_KR		0x00000000
    111 #define	PG_KW		0x00000002
    112 #define	PG_URKR		0x00000004
    113 #define	PG_URKW		0x00000004
    114 #define	PG_UW		0x00000006
    115 
    116 /*
    117  * Page Protection Exception bits
    118  */
    119 #define PGEX_P		0x01	/* Protection violation vs. not present */
    120 #define PGEX_W		0x02	/* during a Write cycle */
    121 #define PGEX_U		0x04	/* access from User mode (UPL) */
    122 
    123 /*
    124  * Pte related macros
    125  */
    126 #define	dirty(pte)	((pte)->pg_m)
    127 
    128 #ifndef LOCORE
    129 #ifdef KERNEL
    130 /* utilities defined in pmap.c */
    131 extern	struct pte *Sysmap;
    132 #endif
    133 #endif
    134 
    135 #endif /* _I386_PTE_H_ */
    136