gem5/src/mem/protocol/MESI_CMP_directory-mem.sm

/*
 * Copyright (c) 1999-2005 Mark D. Hill and David A. Wood
 * All rights reserved.
 *
 * 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 and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders 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: MOESI_CMP_token-dir.sm 1.6 05/01/19 15:48:35-06:00 mikem@royal16.cs.wisc.edu $
 */


machine(Directory, "Token protocol") {

  MessageBuffer requestToDir, network="From", virtual_network="2", ordered="false";
  MessageBuffer responseToDir, network="From", virtual_network="3", ordered="false";
  MessageBuffer responseFromDir, network="To", virtual_network="3", ordered="false";

  // STATES
  enumeration(State, desc="Directory states", default="Directory_State_I") {
    // Base states
    I, desc="Owner";
  }

  // Events
  enumeration(Event, desc="Directory events") {
    Fetch, desc="A GETX arrives";
    Data, desc="A GETS arrives";
  }

  // TYPES

  // DirectoryEntry
  structure(Entry, desc="...") {
    DataBlock DataBlk,             desc="data for the block";
  }

  external_type(DirectoryMemory) {
    Entry lookup(Address);
    bool isPresent(Address);
  }


  // ** OBJECTS **

  DirectoryMemory directory, constructor_hack="i";

  State getState(Address addr) {
    return State:I;
  }

  void setState(Address addr, State state) {
  }

  // ** OUT_PORTS **
  out_port(responseNetwork_out, ResponseMsg, responseFromDir);

  // ** IN_PORTS **

  in_port(requestNetwork_in, RequestMsg, requestToDir) {
    if (requestNetwork_in.isReady()) {
      peek(requestNetwork_in, RequestMsg) {
        assert(in_msg.Destination.isElement(machineID));
        if (in_msg.Type == CoherenceRequestType:GETS) {
          trigger(Event:Fetch, in_msg.Address);
        } else if (in_msg.Type == CoherenceRequestType:GETX) {
          trigger(Event:Fetch, in_msg.Address);
        } else {
          error("Invalid message");
        }
      }
    }
  }

  in_port(responseNetwork_in, ResponseMsg, responseToDir) {
    if (responseNetwork_in.isReady()) {
      peek(responseNetwork_in, ResponseMsg) {
        assert(in_msg.Destination.isElement(machineID));
        if (in_msg.Type == CoherenceResponseType:MEMORY_DATA) {
          trigger(Event:Data, in_msg.Address);
        } else {
          DEBUG_EXPR(in_msg.Type);
          error("Invalid message");
        }
      }
    }
  }

  // Actions
  action(a_sendAck, "a", desc="Send ack to L2") {
    peek(responseNetwork_in, ResponseMsg) {
      enqueue(responseNetwork_out, ResponseMsg, latency="MEMORY_LATENCY") {
        out_msg.Address := address;
        out_msg.Type := CoherenceResponseType:MEMORY_ACK;
        out_msg.Sender := machineID;
        out_msg.Destination.add(in_msg.Sender);
        out_msg.MessageSize := MessageSizeType:Response_Control;
      }
    }
  }

  action(d_sendData, "d", desc="Send data to requestor") {
    peek(requestNetwork_in, RequestMsg) {
      enqueue(responseNetwork_out, ResponseMsg, latency="MEMORY_LATENCY") {
        out_msg.Address := address;
        out_msg.Type := CoherenceResponseType:MEMORY_DATA;
        out_msg.Sender := machineID;
        out_msg.Destination.add(in_msg.Requestor);
        out_msg.DataBlk := directory[in_msg.Address].DataBlk;
        out_msg.Dirty := false;
        out_msg.MessageSize := MessageSizeType:Response_Data;
      }
    }
  }

  action(j_popIncomingRequestQueue, "j", desc="Pop incoming request queue") {
    requestNetwork_in.dequeue();
  }

  action(k_popIncomingResponseQueue, "k", desc="Pop incoming request queue") {
    responseNetwork_in.dequeue();
  }

  action(m_writeDataToMemory, "m", desc="Write dirty writeback to memory") {
    peek(responseNetwork_in, ResponseMsg) {
      directory[in_msg.Address].DataBlk := in_msg.DataBlk;
      DEBUG_EXPR(in_msg.Address);
      DEBUG_EXPR(in_msg.DataBlk);
    }
  }

  // TRANSITIONS

  transition(I, Fetch) {
    d_sendData;
    j_popIncomingRequestQueue;
  }

  transition(I, Data) {
    m_writeDataToMemory;
    a_sendAck;
    k_popIncomingResponseQueue;
  }
}