source: rtems/cpukit/rtems/src/dpmemexternal2internal.c @ 66cb142

5
Last change on this file since 66cb142 was 9c3bae11, checked in by Sebastian Huber <sebastian.huber@…>, on 04/21/16 at 05:52:19

rtems: Avoid Giant lock for dual ported memory

There is no need for an ISR lock since the Dual_ported_memory_Control is
immutable after initialization. ISR disable is enough for deletion
safety on uni-processor configurations.

Update #2555.

  • Property mode set to 100644
File size: 1.2 KB
RevLine 
[205dbb9d]1/**
2 *  @file
[1dc030f]3 *
[205dbb9d]4 *  @brief RTEMS Port External to Internal
5 *  @ingroup ClassicDPMEM
6 */
7
8/*
[3a638ce]9 *  COPYRIGHT (c) 1989-2014.
[1dc030f]10 *  On-Line Applications Research Corporation (OAR).
11 *
12 *  The license and distribution terms for this file may be
13 *  found in the file LICENSE in this distribution or at
[c499856]14 *  http://www.rtems.org/license/LICENSE.
[1dc030f]15 */
16
[1095ec1]17#if HAVE_CONFIG_H
18#include "config.h"
19#endif
20
[562815c]21#include <rtems/rtems/dpmemimpl.h>
[9c3bae11]22#include <rtems/score/address.h>
[1dc030f]23
24rtems_status_code rtems_port_external_to_internal(
[d3b72ca3]25  rtems_id   id,
26  void      *external,
27  void     **internal
[1dc030f]28)
29{
[9c3bae11]30  Dual_ported_memory_Control *the_port;
31  ISR_lock_Context            lock_context;
32  uint32_t                    ending;
[1dc030f]33
[9c3bae11]34  if ( internal == NULL ) {
[e980b219]35    return RTEMS_INVALID_ADDRESS;
[9c3bae11]36  }
[e980b219]37
[9c3bae11]38  the_port = _Dual_ported_memory_Get( id, &lock_context );
39
40  if ( the_port == NULL ) {
41    return RTEMS_INVALID_ID;
42  }
43
44  ending = _Addresses_Subtract( external, the_port->external_base );
45
46  if ( ending > the_port->length ) {
47    *internal = external;
48  } else {
49    *internal = _Addresses_Add_offset( the_port->internal_base, ending );
[1dc030f]50  }
51
[9c3bae11]52  _ISR_lock_ISR_enable( &lock_context );
53  return RTEMS_SUCCESSFUL;
[1dc030f]54}
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