sys/cpu/i386/include/pmap.h

   1 /*
   2  * Copyright (c) 1991 Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * the Systems Programming Group of the University of Utah Computer
   7  * Science Department and William Jolitz of UUNET Technologies Inc.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed by the University of
  20  *      California, Berkeley and its contributors.
  21  * 4. Neither the name of the University nor the names of its contributors
  22  *    may be used to endorse or promote products derived from this software
  23  *    without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  *
  37  * Derived from hp300 version by Mike Hibler, this version by William
  38  * Jolitz uses a recursive map [a pde points to the page directory] to
  39  * map the page tables using the pagetables themselves. This is done to
  40  * reduce the impact on kernel virtual memory for lots of sparse address
  41  * space, and to reduce the cost of memory to each process.
  42  *
  43  *      from: hp300: @(#)pmap.h 7.2 (Berkeley) 12/16/90
  44  *      from: @(#)pmap.h        7.4 (Berkeley) 5/12/91
  45  * $FreeBSD: src/sys/i386/include/pmap.h,v 1.65.2.3 2001/10/03 07:15:37 peter Exp $
  46  * $DragonFly: src/sys/cpu/i386/include/pmap.h,v 1.14 2007/01/14 20:07:11 dillon Exp $
  47  */
  48
  49 #ifndef _CPU_PMAP_H_
  50 #define _CPU_PMAP_H_
  51
  52 /*
  53  * Page-directory and page-table entires follow this format, with a few
  54  * of the fields not present here and there, depending on a lot of things.
  55  */
  56                                 /* ---- Intel Nomenclature ---- */
  57 #define PG_V            0x001   /* P    Valid                   */
  58 #define PG_RW           0x002   /* R/W  Read/Write              */
  59 #define PG_U            0x004   /* U/S  User/Supervisor         */
  60 #define PG_NC_PWT       0x008   /* PWT  Write through           */
  61 #define PG_NC_PCD       0x010   /* PCD  Cache disable           */
  62 #define PG_A            0x020   /* A    Accessed                */
  63 #define PG_M            0x040   /* D    Dirty                   */
  64 #define PG_PS           0x080   /* PS   Page size (0=4k,1=4M)   */
  65 #define PG_G            0x100   /* G    Global                  */
  66 #define PG_AVAIL1       0x200   /*    / Available for system    */
  67 #define PG_AVAIL2       0x400   /*   <  programmers use         */
  68 #define PG_AVAIL3       0x800   /*    \                         */
  69
  70
  71 /* Our various interpretations of the above */
  72 #define PG_W            PG_AVAIL1       /* "Wired" pseudoflag */
  73 #define PG_MANAGED      PG_AVAIL2
  74 #define PG_FRAME        (~((vm_paddr_t)PAGE_MASK))
  75 #define PG_PROT         (PG_RW|PG_U)    /* all protection bits . */
  76 #define PG_N            (PG_NC_PWT|PG_NC_PCD)   /* Non-cacheable */
  77
  78 /*
  79  * Page Protection Exception bits, stored in tf_err on a real fault
  80  * and in tf_xflags on a signal frame or virtual kernel's trap frame.
  81  * These only apply to T_PAGEFLT faults.
  82  *
  83  * PGEX_U is also used internally by the virtual kernel to indicate
  84  * whether the frame is a userland frame or a supervisor frame.
  85  */
  86 #define PGEX_P          0x01    /* Protection violation vs. not present */
  87 #define PGEX_W          0x02    /* during a Write cycle */
  88 #define PGEX_U          0x04    /* access from User mode (UPL) */
  89
  90 /*
  91  * Virtual kernel bits, managed by software.  Stored in tf_xflags.
  92  *
  93  * PGEX_FPFAULT - Force the FP unit to generate a T_DNA fault if an
  94  *                emulated user process tried to use it.  This bit is
  95  *                only used by vmspace_ctl().
  96  *
  97  * PGEX_MAILBOX - Set in xflags by signal code to indicate that a mailbox
  98  *                signal was pending.  Remerged on signal return.  This
  99  *                bit is only used in a signal vector frame.
 100  */
 101 #define PGEX_MAILBOX    0x40
 102 #define PGEX_FPFAULT    0x80
 103
 104 #endif /* !_CPU_PMAP_H_ */