/**************************************************************************************
 Copyright (c) 2002
      The UbixOS Project

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions, the following disclaimer and the list of authors.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions, the following disclaimer and the list of authors
in the documentation and/or other materials provided with the distribution. Neither the name of the UbixOS Project 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.

 $Id: unmappage.c,v 1.1 2003/04/19 11:31:35 reddawg Exp $
**************************************************************************************/

#include <vmm/paging.h>

/************************************************************************

Function: void unmapPage(uLong pageAddr,int flags);
Description: This Function Will Unmap A Page From The Kernel VM Space
             The Flags Variable Decides If Its To Free The Page Or Not
             A Flag Of 0 Will Free It And A Flag Of 1 Will Keep It
Notes:

07/30/02 - I Have Decided That This Should Free The Physical Page There
           Is No Reason To Keep It Marked As Not Available

07/30/02 - Ok A Found A Reason To Keep It Marked As Available I Admit
           Even I Am Not Perfect Ok The Case Where You Wouldn't Want To
           Free It Would Be On Something Like Where I Allocated A Page
           To Create A New Virtual Space So Now It Has A Flag

************************************************************************/
void unmapPage(uLong pageAddr,int flags) {
  int pageDirectoryIndex=0,pageTableIndex=0;
  uLong *pageTable = 0x0;
  //Get The Index To The Page Directory
  pageDirectoryIndex = (pageAddr/(1024*4096));
  //Get The Index To The Page Table
  pageTableIndex = ((pageAddr-(pageDirectoryIndex*(1024*4096)))/4096);
  //Set pageTable To The Virtual Address Of Table
  pageTable = (uLong *)(tablesBaseAddress + (4096 * pageDirectoryIndex));
  //Free The Physical Page If Flags Is 0
  if (flags == 0) {
    //This is temp i think its still an issue
    //clearVirtualPage(pageAddr);
    //freePage((uLong)(pageTable[pageTableIndex] & 0xFFFFF000));
    }
  //Unmap The Page
  pageTable[pageTableIndex] = 0x0;
  //Rehash The Page Directory
  asm(
    "movl %cr3,%eax\n"
    "movl %eax,%cr3\n"
    );
  //Return
  return;
  }