src/mem/mport.hh

   1 /*
   2  * Copyright (c) 2008 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Authors: Gabe Black
  29  */
  30
  31 #ifndef __MEM_MPORT_HH__
  32 #define __MEM_MPORT_HH__
  33
  34 #include "mem/tport.hh"
  35
  36 /*
  37  * This file defines a port class which is used for sending and receiving
  38  * messages. These messages are atomic units which don't interact and
  39  * should be smaller than a cache block. This class is based on
  40  * the underpinnings of SimpleTimingPort, but it tweaks some of the external
  41  * functions.
  42  */
  43
  44 class MessagePort : public SimpleTimingPort
  45 {
  46   public:
  47     MessagePort(std::string pname, MemObject *_owner = NULL) :
  48         SimpleTimingPort(pname, _owner)
  49     {}
  50
  51     virtual ~MessagePort()
  52     {}
  53
  54     void
  55     recvFunctional(PacketPtr pkt)
  56     {
  57         recvAtomic(pkt);
  58     }
  59
  60     Tick recvAtomic(PacketPtr pkt);
  61
  62     virtual Tick recvMessage(PacketPtr pkt) = 0;
  63
  64     // Accept and ignore responses.
  65     virtual Tick recvResponse(PacketPtr pkt)
  66     {
  67         return 0;
  68     }
  69
  70     // Since by default we're assuming everything we send is accepted, panic.
  71     virtual Tick recvNack(PacketPtr pkt)
  72     {
  73         panic("Unhandled message nack.\n");
  74     }
  75
  76     void sendMessageTiming(PacketPtr pkt, Tick latency);
  77     Tick sendMessageAtomic(PacketPtr pkt);
  78 };
  79
  80 #endif