path: root/src/mem/protocol/MOESI_hammer-cache.sm

/*
 * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
 * Copyright (c) 2009 Advanced Micro Devices, Inc.
 * 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.
 *
 * AMD's contributions to the MOESI hammer protocol do not constitute an 
 * endorsement of its similarity to any AMD products.
 *
 * Authors: Milo Martin
 *          Brad Beckmann
 */

machine(L1Cache, "AMD Hammer-like protocol") 
: int cache_response_latency,
  int issue_latency
{

  // NETWORK BUFFERS
  MessageBuffer requestFromCache, network="To", virtual_network="3", ordered="false";
  MessageBuffer responseFromCache, network="To", virtual_network="1", ordered="false";
  MessageBuffer unblockFromCache, network="To", virtual_network="0", ordered="false";

  MessageBuffer forwardToCache, network="From", virtual_network="2", ordered="false";
  MessageBuffer responseToCache, network="From", virtual_network="1", ordered="false";


  // STATES
  enumeration(State, desc="Cache states", default="L1Cache_State_I") {
    // Base states
    I, desc="Idle";
    S, desc="Shared";
    O, desc="Owned";
    M, desc="Modified (dirty)";
    MM, desc="Modified (dirty and locally modified)";

    // Transient States
    IM, "IM", desc="Issued GetX";
    SM, "SM", desc="Issued GetX, we still have an old copy of the line";
    OM, "OM", desc="Issued GetX, received data";
    ISM, "ISM", desc="Issued GetX, received data, waiting for all acks";
    M_W, "M^W", desc="Issued GetS, received exclusive data";
    MM_W, "MM^W", desc="Issued GetX, received exclusive data";
    IS, "IS", desc="Issued GetS";
    SS, "SS", desc="Issued GetS, received data, waiting for all acks";
    OI, "OI", desc="Issued PutO, waiting for ack";
    MI, "MI", desc="Issued PutX, waiting for ack";
    II, "II", desc="Issued PutX/O, saw Other_GETS or Other_GETX, waiting for ack";
  }

  // EVENTS
  enumeration(Event, desc="Cache events") {
    Load,            desc="Load request from the processor";
    Ifetch,          desc="I-fetch request from the processor";
    Store,           desc="Store request from the processor";
    L2_Replacement,  desc="L2 Replacement";
    L1_to_L2,        desc="L1 to L2 transfer";
    L2_to_L1D,       desc="L2 to L1-Data transfer";
    L2_to_L1I,       desc="L2 to L1-Instruction transfer";

    // Requests
    Other_GETX,      desc="A GetX from another processor";
    Other_GETS,      desc="A GetS from another processor";

    // Responses
    Ack,             desc="Received an ack message";
    Shared_Ack,      desc="Received an ack message, responder has a shared copy";
    Data,            desc="Received a data message";
    Shared_Data,     desc="Received a data message, responder has a shared copy";
    Exclusive_Data,  desc="Received a data message, responder had an exclusive copy, they gave it to us";

    Writeback_Ack,   desc="Writeback O.K. from directory";
    Writeback_Nack,  desc="Writeback not O.K. from directory";

    // Triggers
    All_acks,                  desc="Received all required data and message acks";
    All_acks_no_sharers,        desc="Received all acks and no other processor has a shared copy";
  }

  // TYPES

  // STRUCTURE DEFINITIONS

  MessageBuffer mandatoryQueue, ordered="false";
  Sequencer sequencer, factory='RubySystem::getSequencer(m_cfg["sequencer"])';

  // CacheEntry
  structure(Entry, desc="...", interface="AbstractCacheEntry") {
    State CacheState,        desc="cache state";
    bool Dirty,              desc="Is the data dirty (different than memory)?";
    DataBlock DataBlk,       desc="data for the block";
  }

  // TBE fields
  structure(TBE, desc="...") {
    State TBEState,          desc="Transient state";
    DataBlock DataBlk,       desc="data for the block, required for concurrent writebacks";
    bool Dirty,              desc="Is the data dirty (different than memory)?";
    int NumPendingMsgs,      desc="Number of acks/data messages that this processor is waiting for";
    bool Sharers,            desc="On a GetS, did we find any other sharers in the system";
  }

  external_type(CacheMemory) {
    bool cacheAvail(Address);
    Address cacheProbe(Address);
    void allocate(Address, Entry);
    void deallocate(Address);
    Entry lookup(Address);
    void changePermission(Address, AccessPermission);
    bool isTagPresent(Address);
    void profileMiss(CacheMsg);
  }

  external_type(TBETable) {
    TBE lookup(Address);
    void allocate(Address);
    void deallocate(Address);
    bool isPresent(Address);
  }

  TBETable TBEs, template_hack="<L1Cache_TBE>";
  CacheMemory L1IcacheMemory, factory='RubySystem::getCache(m_cfg["icache"])';
  CacheMemory L1DcacheMemory, factory='RubySystem::getCache(m_cfg["dcache"])';
  CacheMemory L2cacheMemory, factory='RubySystem::getCache(m_cfg["l2cache"])';

  Entry getCacheEntry(Address addr), return_by_ref="yes" {
    if (L2cacheMemory.isTagPresent(addr)) {
      return L2cacheMemory[addr];
    } else if (L1DcacheMemory.isTagPresent(addr)) {
      return L1DcacheMemory[addr];
    } else {
      return L1IcacheMemory[addr];
    }
  }

  void changePermission(Address addr, AccessPermission permission) {
    if (L2cacheMemory.isTagPresent(addr)) {
      return L2cacheMemory.changePermission(addr, permission);
    } else if (L1DcacheMemory.isTagPresent(addr)) {
      return L1DcacheMemory.changePermission(addr, permission);
    } else {
      return L1IcacheMemory.changePermission(addr, permission);
    }
  }

  bool isCacheTagPresent(Address addr) {
    return (L2cacheMemory.isTagPresent(addr) || L1DcacheMemory.isTagPresent(addr) || L1IcacheMemory.isTagPresent(addr));
  }

  State getState(Address addr) {
    assert((L1DcacheMemory.isTagPresent(addr) && L1IcacheMemory.isTagPresent(addr)) == false);
    assert((L1IcacheMemory.isTagPresent(addr) && L2cacheMemory.isTagPresent(addr)) == false);
    assert((L1DcacheMemory.isTagPresent(addr) && L2cacheMemory.isTagPresent(addr)) == false);

    if(TBEs.isPresent(addr)) { 
      return TBEs[addr].TBEState;
    } else if (isCacheTagPresent(addr)) {
      return getCacheEntry(addr).CacheState;
    }
    return State:I;
  }

  void setState(Address addr, State state) {
    assert((L1DcacheMemory.isTagPresent(addr) && L1IcacheMemory.isTagPresent(addr)) == false);
    assert((L1IcacheMemory.isTagPresent(addr) && L2cacheMemory.isTagPresent(addr)) == false);
    assert((L1DcacheMemory.isTagPresent(addr) && L2cacheMemory.isTagPresent(addr)) == false);

    if (TBEs.isPresent(addr)) {
      TBEs[addr].TBEState := state;
    }

    if (isCacheTagPresent(addr)) {
      getCacheEntry(addr).CacheState := state;
    
      // Set permission
      if ((state == State:MM) || 
          (state == State:MM_W)) {
        changePermission(addr, AccessPermission:Read_Write);
      } else if (state == State:S || 
                 state == State:O || 
                 state == State:M || 
                 state == State:M_W || 
                 state == State:SM || 
                 state == State:ISM || 
                 state == State:OM || 
                 state == State:SS) {
        changePermission(addr, AccessPermission:Read_Only);
      } else {
        changePermission(addr, AccessPermission:Invalid);
      }
    }
  }

  Event mandatory_request_type_to_event(CacheRequestType type) {
    if (type == CacheRequestType:LD) {
      return Event:Load;
    } else if (type == CacheRequestType:IFETCH) {
      return Event:Ifetch;
    } else if ((type == CacheRequestType:ST) || (type == CacheRequestType:ATOMIC)) {
      return Event:Store;
    } else {
      error("Invalid CacheRequestType");
    }
  }

  MessageBuffer triggerQueue, ordered="true";

  // ** OUT_PORTS **

  out_port(requestNetwork_out, RequestMsg, requestFromCache);
  out_port(responseNetwork_out, ResponseMsg, responseFromCache);
  out_port(unblockNetwork_out, ResponseMsg, unblockFromCache);
  out_port(triggerQueue_out, TriggerMsg, triggerQueue);

  // ** IN_PORTS **

  // Trigger Queue
  in_port(triggerQueue_in, TriggerMsg, triggerQueue) {
    if (triggerQueue_in.isReady()) {
      peek(triggerQueue_in, TriggerMsg) {
        if (in_msg.Type == TriggerType:ALL_ACKS) {
          trigger(Event:All_acks, in_msg.Address);
        } else if (in_msg.Type == TriggerType:ALL_ACKS_NO_SHARERS) {
          trigger(Event:All_acks_no_sharers, in_msg.Address);
        } else {
          error("Unexpected message");
        }
      }
    }
  }

  // Nothing from the request network

  // Forward Network
  in_port(forwardToCache_in, RequestMsg, forwardToCache) {
    if (forwardToCache_in.isReady()) {
      peek(forwardToCache_in, RequestMsg) {
        if (in_msg.Type == CoherenceRequestType:GETX) {
          trigger(Event:Other_GETX, in_msg.Address);
        } else if (in_msg.Type == CoherenceRequestType:GETS) {
          trigger(Event:Other_GETS, in_msg.Address);
        } else if (in_msg.Type == CoherenceRequestType:WB_ACK) {
          trigger(Event:Writeback_Ack, in_msg.Address);
        } else if (in_msg.Type == CoherenceRequestType:WB_NACK) {
          trigger(Event:Writeback_Nack, in_msg.Address);
        } else {
          error("Unexpected message");
        }
      }
    }
  }

  // Response Network
  in_port(responseToCache_in, ResponseMsg, responseToCache) {
    if (responseToCache_in.isReady()) {
      peek(responseToCache_in, ResponseMsg) {
        if (in_msg.Type == CoherenceResponseType:ACK) {
          trigger(Event:Ack, in_msg.Address);
        } else if (in_msg.Type == CoherenceResponseType:ACK_SHARED) {
          trigger(Event:Shared_Ack, in_msg.Address);
        } else if (in_msg.Type == CoherenceResponseType:DATA) {
          trigger(Event:Data, in_msg.Address);
        } else if (in_msg.Type == CoherenceResponseType:DATA_SHARED) {
          trigger(Event:Shared_Data, in_msg.Address);
        } else if (in_msg.Type == CoherenceResponseType:DATA_EXCLUSIVE) {
          trigger(Event:Exclusive_Data, in_msg.Address);
        } else {
          error("Unexpected message");
        }
      }
    }
  }

  // Nothing from the unblock network

  // Mandatory Queue
  in_port(mandatoryQueue_in, CacheMsg, mandatoryQueue, desc="...") {
    if (mandatoryQueue_in.isReady()) {
      peek(mandatoryQueue_in, CacheMsg) {

        // Check for data access to blocks in I-cache and ifetchs to blocks in D-cache

        if (in_msg.Type == CacheRequestType:IFETCH) {
          // ** INSTRUCTION ACCESS ***

          // Check to see if it is in the OTHER L1
          if (L1DcacheMemory.isTagPresent(in_msg.LineAddress)) {
            // The block is in the wrong L1, try to write it to the L2
            if (L2cacheMemory.cacheAvail(in_msg.LineAddress)) {
              trigger(Event:L1_to_L2, in_msg.LineAddress);
            } else {
              trigger(Event:L2_Replacement, L2cacheMemory.cacheProbe(in_msg.LineAddress));
            }
          }

          if (L1IcacheMemory.isTagPresent(in_msg.LineAddress)) { 
            // The tag matches for the L1, so the L1 fetches the line.  We know it can't be in the L2 due to exclusion
            trigger(mandatory_request_type_to_event(in_msg.Type), in_msg.LineAddress);
          } else {
            if (L1IcacheMemory.cacheAvail(in_msg.LineAddress)) {
              // L1 does't have the line, but we have space for it in the L1
              if (L2cacheMemory.isTagPresent(in_msg.LineAddress)) {
                // L2 has it (maybe not with the right permissions)
                trigger(Event:L2_to_L1I, in_msg.LineAddress);
              } else {
                // We have room, the L2 doesn't have it, so the L1 fetches the line
                trigger(mandatory_request_type_to_event(in_msg.Type), in_msg.LineAddress);
              }
            } else {
              // No room in the L1, so we need to make room
              if (L2cacheMemory.cacheAvail(L1IcacheMemory.cacheProbe(in_msg.LineAddress))) {
                // The L2 has room, so we move the line from the L1 to the L2
                trigger(Event:L1_to_L2, L1IcacheMemory.cacheProbe(in_msg.LineAddress));
              } else {
                // The L2 does not have room, so we replace a line from the L2
                trigger(Event:L2_Replacement, L2cacheMemory.cacheProbe(L1IcacheMemory.cacheProbe(in_msg.LineAddress)));
              }
            }
          }
        } else {
          // *** DATA ACCESS ***

          // Check to see if it is in the OTHER L1
          if (L1IcacheMemory.isTagPresent(in_msg.LineAddress)) {
            // The block is in the wrong L1, try to write it to the L2
            if (L2cacheMemory.cacheAvail(in_msg.LineAddress)) {
              trigger(Event:L1_to_L2, in_msg.LineAddress);
            } else {
              trigger(Event:L2_Replacement, L2cacheMemory.cacheProbe(in_msg.LineAddress));
            }
          }

          if (L1DcacheMemory.isTagPresent(in_msg.LineAddress)) { 
            // The tag matches for the L1, so the L1 fetches the line.  We know it can't be in the L2 due to exclusion
            trigger(mandatory_request_type_to_event(in_msg.Type), in_msg.LineAddress);
          } else {
            if (L1DcacheMemory.cacheAvail(in_msg.LineAddress)) {
              // L1 does't have the line, but we have space for it in the L1
              if (L2cacheMemory.isTagPresent(in_msg.LineAddress)) {
                // L2 has it (maybe not with the right permissions)
                trigger(Event:L2_to_L1D, in_msg.LineAddress);
              } else {
                // We have room, the L2 doesn't have it, so the L1 fetches the line
                trigger(mandatory_request_type_to_event(in_msg.Type), in_msg.LineAddress);
              }
            } else {
              // No room in the L1, so we need to make room
              if (L2cacheMemory.cacheAvail(L1DcacheMemory.cacheProbe(in_msg.LineAddress))) {
                // The L2 has room, so we move the line from the L1 to the L2
                trigger(Event:L1_to_L2, L1DcacheMemory.cacheProbe(in_msg.LineAddress));
              } else {
                // The L2 does not have room, so we replace a line from the L2
                trigger(Event:L2_Replacement, L2cacheMemory.cacheProbe(L1DcacheMemory.cacheProbe(in_msg.LineAddress)));
              }
            }
          }
        }
      }
    }
  }
  
  // ACTIONS

  action(a_issueGETS, "a", desc="Issue GETS") {
    enqueue(requestNetwork_out, RequestMsg, latency=issue_latency) {
      out_msg.Address := address;
      out_msg.Type := CoherenceRequestType:GETS;
      out_msg.Requestor := machineID;
      out_msg.Destination.add(map_Address_to_Directory(address));
      out_msg.MessageSize := MessageSizeType:Request_Control;
      TBEs[address].NumPendingMsgs := getNumberOfLastLevelCaches(); // One from each other cache (n-1) plus the memory (+1)
    }
  }

  action(b_issueGETX, "b", desc="Issue GETX") {
    enqueue(requestNetwork_out, RequestMsg, latency=issue_latency) {
      out_msg.Address := address;
      out_msg.Type := CoherenceRequestType:GETX;
      out_msg.Requestor := machineID;
      out_msg.Destination.add(map_Address_to_Directory(address));
      out_msg.MessageSize := MessageSizeType:Request_Control;
      TBEs[address].NumPendingMsgs := getNumberOfLastLevelCaches(); // One from each other cache (n-1) plus the memory (+1)
    }
  }

  action(c_sendExclusiveData, "c", desc="Send exclusive data from cache to requestor") {
    peek(forwardToCache_in, RequestMsg) {
      enqueue(responseNetwork_out, ResponseMsg, latency=cache_response_latency) {
        out_msg.Address := address;
        out_msg.Type := CoherenceResponseType:DATA_EXCLUSIVE;
        out_msg.Sender := machineID;
        out_msg.Destination.add(in_msg.Requestor);
        out_msg.DataBlk := getCacheEntry(address).DataBlk;
        out_msg.Dirty := getCacheEntry(address).Dirty;
        out_msg.Acks := 2;
        out_msg.MessageSize := MessageSizeType:Response_Data;
      }
    }
  }

  action(d_issuePUT, "d", desc="Issue PUT") {
    enqueue(requestNetwork_out, RequestMsg, latency=issue_latency) {
      out_msg.Address := address;
      out_msg.Type := CoherenceRequestType:PUT;
      out_msg.Requestor := machineID;
      out_msg.Destination.add(map_Address_to_Directory(address));
      out_msg.MessageSize := MessageSizeType:Writeback_Control;
    }
  }

  action(e_sendData, "e", desc="Send data from cache to requestor") {
    peek(forwardToCache_in, RequestMsg) {
      enqueue(responseNetwork_out, ResponseMsg, latency=cache_response_latency) {
        out_msg.Address := address;
        out_msg.Type := CoherenceResponseType:DATA;
        out_msg.Sender := machineID;
        out_msg.Destination.add(in_msg.Requestor);
        out_msg.DataBlk := getCacheEntry(address).DataBlk;
        out_msg.Dirty := getCacheEntry(address).Dirty;
        out_msg.Acks := 2;
        out_msg.MessageSize := MessageSizeType:Response_Data;
      }
    }
  }

  action(ee_sendDataShared, "\e", desc="Send data from cache to requestor, keep a shared copy") {
    peek(forwardToCache_in, RequestMsg) {
      enqueue(responseNetwork_out, ResponseMsg, latency=cache_response_latency) {
        out_msg.Address := address;
        out_msg.Type := CoherenceResponseType:DATA_SHARED;
        out_msg.Sender := machineID;
        out_msg.Destination.add(in_msg.Requestor);
        out_msg.DataBlk := getCacheEntry(address).DataBlk;
        out_msg.Dirty := getCacheEntry(address).Dirty;
        out_msg.Acks := 2;
        out_msg.MessageSize := MessageSizeType:Response_Data;
      }
    }
  }
  
  action(f_sendAck, "f", desc="Send ack from cache to requestor") {
    peek(forwardToCache_in, RequestMsg) {
      enqueue(responseNetwork_out, ResponseMsg, latency=cache_response_latency) {
        out_msg.Address := address;
        out_msg.Type := CoherenceResponseType:ACK;
        out_msg.Sender := machineID;
        out_msg.Destination.add(in_msg.Requestor);
        out_msg.Acks := 1;
        out_msg.MessageSize := MessageSizeType:Response_Control;
      }
    }
  }

  action(ff_sendAckShared, "\f", desc="Send shared ack from cache to requestor") {
    peek(forwardToCache_in, RequestMsg) {
      enqueue(responseNetwork_out, ResponseMsg, latency=cache_response_latency) {
        out_msg.Address := address;
        out_msg.Type := CoherenceResponseType:ACK_SHARED;
        out_msg.Sender := machineID;
        out_msg.Destination.add(in_msg.Requestor);
        out_msg.Acks := 1;
        out_msg.MessageSize := MessageSizeType:Response_Control;
      }
    }
  }

  action(g_sendUnblock, "g", desc="Send unblock to memory") {
    enqueue(unblockNetwork_out, ResponseMsg, latency=cache_response_latency) {
      out_msg.Address := address;
      out_msg.Type := CoherenceResponseType:UNBLOCK;
      out_msg.Sender := machineID;
      out_msg.Destination.add(map_Address_to_Directory(address));
      out_msg.MessageSize := MessageSizeType:Unblock_Control;
    }
  }

  action(h_load_hit, "h", desc="Notify sequencer the load completed.") {
    DEBUG_EXPR(getCacheEntry(address).DataBlk);
    sequencer.readCallback(address, getCacheEntry(address).DataBlk);
  }

  action(hh_store_hit, "\h", desc="Notify sequencer that store completed.") {
    DEBUG_EXPR(getCacheEntry(address).DataBlk);
    sequencer.writeCallback(address, getCacheEntry(address).DataBlk);
    getCacheEntry(address).Dirty := true;
  }

  action(i_allocateTBE, "i", desc="Allocate TBE") {
    check_allocate(TBEs);
    TBEs.allocate(address);
    TBEs[address].DataBlk := getCacheEntry(address).DataBlk; // Data only used for writebacks
    TBEs[address].Dirty := getCacheEntry(address).Dirty;
    TBEs[address].Sharers := false;
  }

  action(j_popTriggerQueue, "j", desc="Pop trigger queue.") {
    triggerQueue_in.dequeue();
  }

  action(k_popMandatoryQueue, "k", desc="Pop mandatory queue.") {
    mandatoryQueue_in.dequeue();
  }
  
  action(l_popForwardQueue, "l", desc="Pop forwareded request queue.") {
    forwardToCache_in.dequeue();
  }

  action(m_decrementNumberOfMessages, "m", desc="Decrement the number of messages for which we're waiting") {
    peek(responseToCache_in, ResponseMsg) {
      assert(in_msg.Acks > 0);
      DEBUG_EXPR(TBEs[address].NumPendingMsgs);
      TBEs[address].NumPendingMsgs := TBEs[address].NumPendingMsgs - in_msg.Acks;
      DEBUG_EXPR(TBEs[address].NumPendingMsgs);
    }
  }

  action(n_popResponseQueue, "n", desc="Pop response queue") {
    responseToCache_in.dequeue();
  }

  action(o_checkForCompletion, "o", desc="Check if we have received all the messages required for completion") {
    if (TBEs[address].NumPendingMsgs == 0) {
      enqueue(triggerQueue_out, TriggerMsg) {
        out_msg.Address := address;
        if (TBEs[address].Sharers) {
          out_msg.Type := TriggerType:ALL_ACKS;
        } else {
          out_msg.Type := TriggerType:ALL_ACKS_NO_SHARERS;
        }
      }
    }
  }

  action(p_decrementNumberOfMessagesByOne, "p", desc="Decrement the number of messages for which we're waiting by one") {
    TBEs[address].NumPendingMsgs := TBEs[address].NumPendingMsgs - 1;
  }

  action(pp_incrementNumberOfMessagesByOne, "\p", desc="Increment the number of messages for which we're waiting by one") {
    TBEs[address].NumPendingMsgs := TBEs[address].NumPendingMsgs + 1;
  }

  action(q_sendDataFromTBEToCache, "q", desc="Send data from TBE to cache") {
    peek(forwardToCache_in, RequestMsg) {
      enqueue(responseNetwork_out, ResponseMsg, latency=cache_response_latency) {
        out_msg.Address := address;
        out_msg.Type := CoherenceResponseType:DATA;
        out_msg.Sender := machineID;
        out_msg.Destination.add(in_msg.Requestor);
        out_msg.DataBlk := TBEs[address].DataBlk;
        out_msg.Dirty := TBEs[address].Dirty;
        out_msg.Acks := 2;
        out_msg.MessageSize := MessageSizeType:Response_Data;
      }
    }
  }

  action(qq_sendDataFromTBEToMemory, "\q", desc="Send data from TBE to memory") {
    enqueue(unblockNetwork_out, ResponseMsg, latency=cache_response_latency) {
      out_msg.Address := address;
      out_msg.Sender := machineID;
      out_msg.Destination.add(map_Address_to_Directory(address));
      out_msg.Dirty := TBEs[address].Dirty;
      if (TBEs[address].Dirty) {
        out_msg.Type := CoherenceResponseType:WB_DIRTY;
        out_msg.DataBlk := TBEs[address].DataBlk;
        out_msg.MessageSize := MessageSizeType:Writeback_Data;
      } else {
        out_msg.Type := CoherenceResponseType:WB_CLEAN;
        // NOTE: in a real system this would not send data.  We send
        // data here only so we can check it at the memory
        out_msg.DataBlk := TBEs[address].DataBlk; 
        out_msg.MessageSize := MessageSizeType:Writeback_Control;
      }
    }
  }

  action(r_setSharerBit, "r", desc="We saw other sharers") {
    TBEs[address].Sharers := true;
  }

  action(s_deallocateTBE, "s", desc="Deallocate TBE") {
    TBEs.deallocate(address);
  }

  action(t_sendExclusiveDataFromTBEToMemory, "t", desc="Send exclusive data from TBE to memory") {
    enqueue(unblockNetwork_out, ResponseMsg, latency=cache_response_latency) {
      out_msg.Address := address;
      out_msg.Sender := machineID;
      out_msg.Destination.add(map_Address_to_Directory(address));
      out_msg.DataBlk := TBEs[address].DataBlk; 
      out_msg.Dirty := TBEs[address].Dirty;
      if (TBEs[address].Dirty) {
        out_msg.Type := CoherenceResponseType:WB_EXCLUSIVE_DIRTY;
        out_msg.DataBlk := TBEs[address].DataBlk;
        out_msg.MessageSize := MessageSizeType:Writeback_Data;
      } else {
        out_msg.Type := CoherenceResponseType:WB_EXCLUSIVE_CLEAN;
        // NOTE: in a real system this would not send data.  We send
        // data here only so we can check it at the memory
        out_msg.DataBlk := TBEs[address].DataBlk;
        out_msg.MessageSize := MessageSizeType:Writeback_Control;
      }
    }
  }

  action(u_writeDataToCache, "u", desc="Write data to cache") {
    peek(responseToCache_in, ResponseMsg) {
      getCacheEntry(address).DataBlk := in_msg.DataBlk;
      getCacheEntry(address).Dirty := in_msg.Dirty;
    }
  }

  action(v_writeDataToCacheVerify, "v", desc="Write data to cache, assert it was same as before") {
    peek(responseToCache_in, ResponseMsg) {
      assert(getCacheEntry(address).DataBlk == in_msg.DataBlk);
      getCacheEntry(address).DataBlk := in_msg.DataBlk;
      getCacheEntry(address).Dirty := in_msg.Dirty;
    }
  }
  
  action(gg_deallocateL1CacheBlock, "\g", desc="Deallocate cache block.  Sets the cache to invalid, allowing a replacement in parallel with a fetch.") {
    if (L1DcacheMemory.isTagPresent(address)) {
      L1DcacheMemory.deallocate(address);
    } else {
      L1IcacheMemory.deallocate(address);
    }
  }
  
  action(ii_allocateL1DCacheBlock, "\i", desc="Set L1 D-cache tag equal to tag of block B.") {
    if (L1DcacheMemory.isTagPresent(address) == false) {
      L1DcacheMemory.allocate(address, new Entry);
    }
  }

  action(jj_allocateL1ICacheBlock, "\j", desc="Set L1 I-cache tag equal to tag of block B.") {
    if (L1IcacheMemory.isTagPresent(address) == false) {
      L1IcacheMemory.allocate(address, new Entry);
    }
  }

  action(vv_allocateL2CacheBlock, "\v", desc="Set L2 cache tag equal to tag of block B.") {
    L2cacheMemory.allocate(address, new Entry);
  }

  action(rr_deallocateL2CacheBlock, "\r", desc="Deallocate L2 cache block.  Sets the cache to not present, allowing a replacement in parallel with a fetch.") {
    L2cacheMemory.deallocate(address);
  }

  action(ss_copyFromL1toL2, "\s", desc="Copy data block from L1 (I or D) to L2") {
    if (L1DcacheMemory.isTagPresent(address)) {
      L2cacheMemory[address] := L1DcacheMemory[address];
    } else {
      L2cacheMemory[address] := L1IcacheMemory[address];
    }
  }
  
  action(tt_copyFromL2toL1, "\t", desc="Copy data block from L2 to L1 (I or D)") {
    if (L1DcacheMemory.isTagPresent(address)) {
      L1DcacheMemory[address] := L2cacheMemory[address];
    } else {
      L1IcacheMemory[address] := L2cacheMemory[address];
    }
  }

  action(uu_profileMiss, "\u", desc="Profile the demand miss") {
    peek(mandatoryQueue_in, CacheMsg) {
      if (L1IcacheMemory.isTagPresent(address)) {
        L1IcacheMemory.profileMiss(in_msg);
      } else if (L1DcacheMemory.isTagPresent(address)) {
        L1DcacheMemory.profileMiss(in_msg);
      } else {
        L2cacheMemory.profileMiss(in_msg);
      }
    }
  }

  action(zz_recycleMandatoryQueue, "\z", desc="Send the head of the mandatory queue to the back of the queue.") {
    mandatoryQueue_in.recycle();
  }

  //*****************************************************
  // TRANSITIONS
  //*****************************************************

  // Transitions for Load/Store/L2_Replacement from transient states
  transition({IM, SM, ISM, OM, IS, SS, OI, MI, II}, {Store, L2_Replacement}) {
    zz_recycleMandatoryQueue;
  }

  transition({M_W, MM_W}, {L2_Replacement}) {
    zz_recycleMandatoryQueue;
  }

  transition({IM, IS, OI, MI, II}, {Load, Ifetch}) {
    zz_recycleMandatoryQueue;
  }

  transition({IM, SM, ISM, OM, IS, SS, MM_W, M_W, OI, MI, II}, L1_to_L2) {
    zz_recycleMandatoryQueue;
  }

  // Transitions moving data between the L1 and L2 caches
  transition({I, S, O, M, MM}, L1_to_L2) {
    vv_allocateL2CacheBlock;
    ss_copyFromL1toL2; // Not really needed for state I
    gg_deallocateL1CacheBlock;
  }
  
  transition({I, S, O, M, MM}, L2_to_L1D) {
    ii_allocateL1DCacheBlock;
    tt_copyFromL2toL1; // Not really needed for state I
    rr_deallocateL2CacheBlock;
  }

  transition({I, S, O, M, MM}, L2_to_L1I) {
    jj_allocateL1ICacheBlock;
    tt_copyFromL2toL1; // Not really needed for state I
    rr_deallocateL2CacheBlock;
  }

  // Transitions from Idle
  transition(I, Load, IS) {
    ii_allocateL1DCacheBlock;
    i_allocateTBE;
    a_issueGETS;
    uu_profileMiss;
    k_popMandatoryQueue;
  }

  transition(I, Ifetch, IS) {
    jj_allocateL1ICacheBlock;
    i_allocateTBE;
    a_issueGETS;
    uu_profileMiss;
    k_popMandatoryQueue;
  }

  transition(I, Store, IM) {
    ii_allocateL1DCacheBlock;
    i_allocateTBE;
    b_issueGETX;
    uu_profileMiss;
    k_popMandatoryQueue;
  }

  transition(I, L2_Replacement) {
    rr_deallocateL2CacheBlock;
  }

  transition(I, {Other_GETX, Other_GETS}) {
    f_sendAck;
    l_popForwardQueue;
  }

  // Transitions from Shared
  transition({S, SM, ISM}, {Load, Ifetch}) {
    h_load_hit;
    k_popMandatoryQueue;
  }

  transition(S, Store, SM) {
    i_allocateTBE;
    b_issueGETX;
    uu_profileMiss;
    k_popMandatoryQueue;
  }

  transition(S, L2_Replacement, I) {
    rr_deallocateL2CacheBlock;
  }

  transition(S, Other_GETX, I) {
    f_sendAck;
    l_popForwardQueue;
  }

  transition(S, Other_GETS) {
    ff_sendAckShared;
    l_popForwardQueue;
  }

  // Transitions from Owned
  transition({O, OM, SS, MM_W, M_W}, {Load, Ifetch}) {
    h_load_hit;
    k_popMandatoryQueue;
  }

  transition(O, Store, OM) {
    i_allocateTBE;
    b_issueGETX;
    p_decrementNumberOfMessagesByOne;
    uu_profileMiss;
    k_popMandatoryQueue;
  }

  transition(O, L2_Replacement, OI) {
    i_allocateTBE;
    d_issuePUT;
    rr_deallocateL2CacheBlock;
  }

  transition(O, Other_GETX, I) {
    e_sendData;
    l_popForwardQueue;
  }

  transition(O, Other_GETS) {
    ee_sendDataShared;
    l_popForwardQueue;
  }

  // Transitions from Modified
  transition(MM, {Load, Ifetch}) {
    h_load_hit;
    k_popMandatoryQueue;
  }

  transition(MM, Store) {
    hh_store_hit;
    k_popMandatoryQueue;
  }

  transition(MM, L2_Replacement, MI) {
    i_allocateTBE;
    d_issuePUT;
    rr_deallocateL2CacheBlock;
  }

  transition(MM, Other_GETX, I) {
    c_sendExclusiveData;
    l_popForwardQueue;
  }

  transition(MM, Other_GETS, I) {
    c_sendExclusiveData;
    l_popForwardQueue;
  }
  
  // Transitions from Dirty Exclusive
  transition(M, {Load, Ifetch}) {
    h_load_hit;
    k_popMandatoryQueue;
  }

  transition(M, Store, MM) {
    hh_store_hit;
    k_popMandatoryQueue;
  }

  transition(M, L2_Replacement, MI) {
    i_allocateTBE;
    d_issuePUT;
    rr_deallocateL2CacheBlock;
  }

  transition(M, Other_GETX, I) {
    c_sendExclusiveData;
    l_popForwardQueue;
  }

  transition(M, Other_GETS, O) {
    ee_sendDataShared;
    l_popForwardQueue;
  }

  // Transitions from IM

  transition(IM, {Other_GETX, Other_GETS}) {
    f_sendAck;
    l_popForwardQueue;
  }

  transition(IM, Ack) {
    m_decrementNumberOfMessages;
    o_checkForCompletion;
    n_popResponseQueue;
  }

  transition(IM, Data, ISM) {
    u_writeDataToCache;
    m_decrementNumberOfMessages; 
    o_checkForCompletion;
    n_popResponseQueue;
  }

  transition(IM, Exclusive_Data, MM_W) {
    u_writeDataToCache;
    m_decrementNumberOfMessages; 
    o_checkForCompletion;
    hh_store_hit;
    n_popResponseQueue;
  }

  // Transitions from SM
  transition(SM, Other_GETS) {
    ff_sendAckShared;
    l_popForwardQueue;
  }

  transition(SM, Other_GETX, IM) {
    f_sendAck;
    l_popForwardQueue;
  }

  transition(SM, Ack) {
    m_decrementNumberOfMessages;
    o_checkForCompletion;
    n_popResponseQueue;
  }

  transition(SM, Data, ISM) {
    v_writeDataToCacheVerify;
    m_decrementNumberOfMessages; 
    o_checkForCompletion;
    n_popResponseQueue;
  }

  // Transitions from ISM
  transition(ISM, Ack) {
    m_decrementNumberOfMessages;
    o_checkForCompletion;
    n_popResponseQueue;
  }

  transition(ISM, All_acks_no_sharers, MM) {
    hh_store_hit;
    g_sendUnblock;
    s_deallocateTBE;
    j_popTriggerQueue;
  }

  // Transitions from OM

  transition(OM, Other_GETX, IM) {
    e_sendData;
    pp_incrementNumberOfMessagesByOne;
    l_popForwardQueue;
  }

  transition(OM, Other_GETS) {
    ee_sendDataShared;
    l_popForwardQueue;
  }

  transition(OM, Ack) {
    m_decrementNumberOfMessages;
    o_checkForCompletion;
    n_popResponseQueue;
  }

  transition(OM, {All_acks, All_acks_no_sharers}, MM) {
    hh_store_hit;
    g_sendUnblock;
    s_deallocateTBE;
    j_popTriggerQueue;
  }

  // Transitions from IS

  transition(IS, {Other_GETX, Other_GETS}) {
    f_sendAck;
    l_popForwardQueue;
  }

  transition(IS, Ack) {  
    m_decrementNumberOfMessages;
    o_checkForCompletion;
    n_popResponseQueue;
  }

  transition(IS, Shared_Ack) {  
    m_decrementNumberOfMessages;
    r_setSharerBit;
    o_checkForCompletion;
    n_popResponseQueue;
  }

  transition(IS, Data, SS) {
    u_writeDataToCache;
    m_decrementNumberOfMessages;
    o_checkForCompletion;
    h_load_hit;
    n_popResponseQueue;
  }

  transition(IS, Exclusive_Data, M_W) {
    u_writeDataToCache;
    m_decrementNumberOfMessages;
    o_checkForCompletion;
    h_load_hit;
    n_popResponseQueue;
  }

  transition(IS, Shared_Data, SS) {
    u_writeDataToCache;
    r_setSharerBit;
    m_decrementNumberOfMessages;
    o_checkForCompletion;
    h_load_hit;
    n_popResponseQueue;
  }

  // Transitions from SS

  transition(SS, Ack) {  
    m_decrementNumberOfMessages;
    o_checkForCompletion;
    n_popResponseQueue;
  }

  transition(SS, Shared_Ack) {  
    m_decrementNumberOfMessages;
    r_setSharerBit;
    o_checkForCompletion;
    n_popResponseQueue;
  }

  transition(SS, All_acks, S) {
    g_sendUnblock;
    s_deallocateTBE;
    j_popTriggerQueue;
  }

  transition(SS, All_acks_no_sharers, S) {
    // Note: The directory might still be the owner, so that is why we go to S
    g_sendUnblock;
    s_deallocateTBE;
    j_popTriggerQueue;
  }

  // Transitions from MM_W

  transition(MM_W, Store) {
    hh_store_hit;
    k_popMandatoryQueue;
  }

  transition(MM_W, Ack) {  
    m_decrementNumberOfMessages;
    o_checkForCompletion;
    n_popResponseQueue;
  }

  transition(MM_W, All_acks_no_sharers, MM) {
    g_sendUnblock;
    s_deallocateTBE;
    j_popTriggerQueue;
  }

  // Transitions from M_W

  transition(M_W, Store, MM_W) {
    hh_store_hit;
    k_popMandatoryQueue;
  }

  transition(M_W, Ack) {  
    m_decrementNumberOfMessages;
    o_checkForCompletion;
    n_popResponseQueue;
  }

  transition(M_W, All_acks_no_sharers, M) {
    g_sendUnblock;
    s_deallocateTBE;
    j_popTriggerQueue;
  }

  // Transitions from OI/MI

  transition({OI, MI}, Other_GETX, II) {
    q_sendDataFromTBEToCache;
    l_popForwardQueue;
  }

  transition({OI, MI}, Other_GETS, OI) {
    q_sendDataFromTBEToCache;
    l_popForwardQueue;
  }

  transition(MI, Writeback_Ack, I) {
    t_sendExclusiveDataFromTBEToMemory;
    s_deallocateTBE;
    l_popForwardQueue;
  }

  transition(OI, Writeback_Ack, I) {
    qq_sendDataFromTBEToMemory;
    s_deallocateTBE;
    l_popForwardQueue;
  }

  // Transitions from II
  transition(II, {Other_GETS, Other_GETX}, II) {
    f_sendAck;
    l_popForwardQueue;
  }

  transition(II, Writeback_Ack, I) {
    g_sendUnblock;
    s_deallocateTBE;
    l_popForwardQueue;
  }

  transition(II, Writeback_Nack, I) {
    s_deallocateTBE;
    l_popForwardQueue;
  }
}