sys/i386/include/pte.h

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      from: @(#)pte.h 5.5 (Berkeley) 5/9/91
 *      $Id$
 */

/*
 * 386 page table entry and page table directory
 * W.Jolitz, 8/89
 *
 * There are two major kinds of pte's: those which have ever existed (and are
 * thus either now in core or on the swap device), and those which have
 * never existed, but which will be filled on demand at first reference.
 * There is a structure describing each.  There is also an ancillary
 * structure used in page clustering.
 */

#ifndef LOCORE
struct pde
{
unsigned int
                pd_v:1,                 /* valid bit */
                pd_prot:2,              /* access control */
                pd_mbz1:2,              /* reserved, must be zero */
                pd_u:1,                 /* hardware maintained 'used' bit */
                :1,                     /* not used */
                pd_mbz2:2,              /* reserved, must be zero */
                :3,                     /* reserved for software */
                pd_pfnum:20;            /* physical page frame number of pte's*/
};
struct pte
{
unsigned int
                pg_v:1,                 /* valid bit */
                pg_prot:2,              /* access control */
                pg_mbz1:2,              /* reserved, must be zero */
                pg_u:1,                 /* hardware maintained 'used' bit */
                pg_m:1,                 /* hardware maintained modified bit */
                pg_mbz2:2,              /* reserved, must be zero */
                pg_fod:1,               /* is fill on demand (=0) */
                :1,                     /* must write back to swap (unused) */
                pg_nc:1,                /* 'uncacheable page' bit */
                pg_pfnum:20;            /* physical page frame number */
};
struct hpte
{
unsigned int
                pg_high:12,             /* special for clustering */
                pg_pfnum:20;
};
struct fpte
{
unsigned int
                pg_v:1,                 /* valid bit */
                pg_prot:2,              /* access control */
                :5,
                pg_fileno:1,            /* file mapped from or TEXT or ZERO */
                pg_fod:1,               /* is fill on demand (=1) */
                pg_blkno:22;            /* file system block number */
};
#endif

#define PD_MASK         0xffc00000      /* page directory address bits */
#define PD_SHIFT        22              /* page directory address bits */

#define PG_V            0x00000001
#define PG_PROT         0x00000006 /* all protection bits . */
#define PG_FOD          0x00000200
#define PG_SWAPM        0x00000400
#define PG_N            0x00000800 /* Non-cacheable */
#define PG_M            0x00000040
#define PG_U            0x00000020 /* not currently used */
#define PG_FRAME        0xfffff000

#define PG_FZERO        0
#define PG_FTEXT        1
#define PG_FMAX         (PG_FTEXT)

#define PG_NOACC        0
#define PG_KR           0x00000000
#define PG_KW           0x00000002
#define PG_URKR         0x00000004
#define PG_URKW         0x00000004
#define PG_UW           0x00000006

/*
 * Page Protection Exception bits
 */

#define PGEX_P          0x01    /* Protection violation vs. not present */
#define PGEX_W          0x02    /* during a Write cycle */
#define PGEX_U          0x04    /* access from User mode (UPL) */

/*
 * Pte related macros
 */
#define dirty(pte)      ((pte)->pg_m)

#ifndef LOCORE
#ifdef KERNEL
/* utilities defined in pmap.c */
extern  struct pte *Sysmap;
#endif
#endif