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/*

 *  Dual Port Memory Manager

 *

 *  COPYRIGHT (c) 1989-1999.

 *  On-Line Applications Research Corporation (OAR).

 *

 *  The license and distribution terms for this file may be

 *  found in the file LICENSE in this distribution or at

 *  http://www.OARcorp.com/rtems/license.html.

 *

 *  $Id: dpmemexternal2internal.c,v 1.2 2001-09-27 11:59:19 chris Exp $

 */

#include <rtems/system.h>

#include <rtems/rtems/status.h>

#include <rtems/rtems/support.h>

#include <rtems/score/address.h>

#include <rtems/rtems/dpmem.h>

#include <rtems/score/object.h>

#include <rtems/score/thread.h>

#include <rtems/rtems/dpmem.h>

/*PAGE

 *

 *  rtems_port_external_to_internal

 *

 *  This directive converts an external dual-ported memory address to an

 *  internal dual-ported memory address.  If the given external address

 *  is an invalid dual-ported address, then the internal address is set

 *  to the given external address.

 *

 *  Input parameters:

 *    id       - id of dp memory object

 *    external - external address

 *    internal - pointer of internal address to set

 *

 *  Output parameters:

 *    internal          - internal address

 *    RTEMS_SUCCESSFUL - always succeeds

 */

rtems_status_code rtems_port_external_to_internal(

  Objects_Id   id,

  void        *external,

  void       **internal

)

{

  register Dual_ported_memory_Control *the_port;

  Objects_Locations                    location;

  unsigned32                           ending;

  the_port = _Dual_ported_memory_Get( id, &location );

  switch ( location ) {

    case OBJECTS_REMOTE:        /* this error cannot be returned */

      return RTEMS_INTERNAL_ERROR;

    case OBJECTS_ERROR:

      return RTEMS_INVALID_ID;

    case OBJECTS_LOCAL:

      ending = _Addresses_Subtract( external, the_port->external_base );

      if ( ending > the_port->length )

        *internal = external;

      else

        *internal = _Addresses_Add_offset( the_port->internal_base,

                                           ending );

      _Thread_Enable_dispatch();

      return RTEMS_SUCCESSFUL;

  }

  return RTEMS_INTERNAL_ERROR;   /* unreached - only to remove warnings */

}