pk_pagekey.cxx

C++ 编写的EROS RTOS

/*
 * Copyright (C) 1998, 1999, Jonathan S. Shapiro.
 *
 * This file is part of the EROS Operating System.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2,
 * or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <kerninc/kernel.hxx>
#include <kerninc/Key.hxx>
#include <kerninc/Invocation.hxx>
#include <kerninc/ObjectCache.hxx>
#include <kerninc/Thread.hxx>
#include <eros/Invoke.h>
#include <eros/StdKeyType.h>
#include <eros/PageKey.h>
#include <eros/memory.h>

void
PageKey(Invocation& inv)
{
  kva_t pageAddress =
    ObjectCache::ObHdrToPage(inv.key->GetObjectPtr());

  /* First handle the Read and Write order codes */

  /* There are too many page write OC's to put them all in the switch
   * statment. Consistency, remember, is the hobgoblin of little minds.
   */

  switch(inv.entry.code) {
  case OC_KeyType:
    COMMIT_POINT();

    inv.exit.code = RC_OK;
    inv.exit.w1 = AKT_Page;
    inv.exit.w2 = inv.key->keyData;
    return;

  case OC_Page_MakeReadOnly:	/* Make RO page key */
    COMMIT_POINT();

    /* No problem with overwriting original key, since in that event
     * we would be overwriting it with itself anyway.
     */

    inv.SetExitKey(0, *inv.key);
    if (inv.exit.pKey[0])
      inv.exit.pKey[0]->SetReadOnly();
    
    inv.exit.code = RC_OK;
    return;

  case OC_Page_Zero:		/* zero page */
    if (inv.key->IsReadOnly()) {
      inv.exit.code = RC_NoAccess;
      return;
    }

    /* Mark the object dirty. */
    inv.key->GetObjectPtr()->MakeObjectDirty();

    COMMIT_POINT();

    bzero((void*)pageAddress, EROS_PAGE_SIZE);

    inv.exit.code = RC_OK;
    return;
    
  case OC_Page_Clone:
    {
      /* copy content of page key in arg0 to current page */

      if (inv.key->IsReadOnly()) {
	COMMIT_POINT();
	inv.exit.code = RC_NoAccess;
	return;
      }

      /* FIX: This is now wrong: phys pages, time page */
      if (inv.entry.key[0]->IsType(KT_Page) == false) {
	COMMIT_POINT();
	inv.exit.code = RC_RequestError;
	return;
      }

      /* Mark the object dirty. */
      inv.key->GetObjectPtr()->MakeObjectDirty();

      inv.entry.key[0]->Prepare();
      assert(inv.key->IsPrepared());

      COMMIT_POINT();

      kva_t invokedPage = ObjectCache::ObHdrToPage(inv.key->GetObjectPtr());
      kva_t copiedPage = ObjectCache::ObHdrToPage(inv.entry.key[0]->GetObjectPtr());

      bcopy((void *) copiedPage, (void *) invokedPage, EROS_PAGE_SIZE);
						    
      inv.exit.code = RC_OK;
      return;
    }

  default:
    COMMIT_POINT();

    break;
  }

  inv.exit.code = RC_UnknownRequest;
  return;
}