path: root/src/mem/protocol/GPU_RfO-SQC.sm

/*
 * Copyright (c) 2011-2015 Advanced Micro Devices, Inc.
 * All rights reserved.
 *
 * For use for simulation and test purposes only
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * 3. Neither the name of the copyright holder 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 HOLDER 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.
 *
 * Author: Lisa Hsu
 */

machine(MachineType:SQC, "GPU SQC (L1 I Cache)")
 : Sequencer* sequencer;
   CacheMemory * L1cache;
   int TCC_select_num_bits;
   Cycles issue_latency := 80;  // time to send data down to TCC
   Cycles l2_hit_latency := 18;

  MessageBuffer * requestFromSQC, network="To", virtual_network="1", vnet_type="request";
  MessageBuffer * responseFromSQC, network="To", virtual_network="3", vnet_type="response";
  MessageBuffer * unblockFromCore, network="To", virtual_network="5", vnet_type="unblock";

  MessageBuffer * probeToSQC, network="From", virtual_network="1", vnet_type="request";
  MessageBuffer * responseToSQC, network="From", virtual_network="3", vnet_type="response";

  MessageBuffer * mandatoryQueue;
{
  state_declaration(State, desc="SQC Cache States", default="SQC_State_I") {
    I, AccessPermission:Invalid, desc="Invalid";
    S, AccessPermission:Read_Only, desc="Shared";

    I_S, AccessPermission:Busy, desc="Invalid, issued RdBlkS, have not seen response yet";
    S_I, AccessPermission:Read_Only, desc="L1 replacement, waiting for clean WB ack";
    I_C, AccessPermission:Invalid, desc="Invalid, waiting for WBAck from TCCdir for canceled WB";
  }

  enumeration(Event, desc="SQC Events") {
    // Core initiated
    Fetch,          desc="Fetch";

    //TCC initiated
    TCC_AckS,        desc="TCC Ack to Core Request";
    TCC_AckWB,       desc="TCC Ack for WB";
    TCC_NackWB,       desc="TCC Nack for WB";

    // Mem sys initiated
    Repl,           desc="Replacing block from cache";

    // Probe Events
    PrbInvData,         desc="probe, return M data";
    PrbInv,             desc="probe, no need for data";
    PrbShrData,         desc="probe downgrade, return data";
  }

  enumeration(RequestType, desc="To communicate stats from transitions to recordStats") {
    DataArrayRead,    desc="Read the data array";
    DataArrayWrite,   desc="Write the data array";
    TagArrayRead,     desc="Read the data array";
    TagArrayWrite,    desc="Write the data array";
  }


  structure(Entry, desc="...", interface="AbstractCacheEntry") {
    State CacheState,           desc="cache state";
    bool Dirty,                 desc="Is the data dirty (diff than memory)?";
    DataBlock DataBlk,          desc="data for the block";
    bool FromL2, default="false", desc="block just moved from L2";
  }

  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 Shared,             desc="Victim hit by shared probe";
   }

  structure(TBETable, external="yes") {
    TBE lookup(Addr);
    void allocate(Addr);
    void deallocate(Addr);
    bool isPresent(Addr);
  }

  TBETable TBEs, template="<SQC_TBE>", constructor="m_number_of_TBEs";
  int TCC_select_low_bit, default="RubySystem::getBlockSizeBits()";

  Tick clockEdge();
  Tick cyclesToTicks(Cycles c);

  void set_cache_entry(AbstractCacheEntry b);
  void unset_cache_entry();
  void set_tbe(TBE b);
  void unset_tbe();
  void wakeUpAllBuffers();
  void wakeUpBuffers(Addr a);
  Cycles curCycle();

  // Internal functions
  Entry getCacheEntry(Addr address), return_by_pointer="yes" {
    Entry cache_entry := static_cast(Entry, "pointer", L1cache.lookup(address));
    return cache_entry;
  }

  DataBlock getDataBlock(Addr addr), return_by_ref="yes" {
    TBE tbe := TBEs.lookup(addr);
    if(is_valid(tbe)) {
      return tbe.DataBlk;
    } else {
      return getCacheEntry(addr).DataBlk;
    }
  }

  State getState(TBE tbe, Entry cache_entry, Addr addr) {
    if(is_valid(tbe)) {
      return tbe.TBEState;
    } else if (is_valid(cache_entry)) {
      return cache_entry.CacheState;
    }
    return State:I;
  }

  void setState(TBE tbe, Entry cache_entry, Addr addr, State state) {
    if (is_valid(tbe)) {
      tbe.TBEState := state;
    }

    if (is_valid(cache_entry)) {
      cache_entry.CacheState := state;
    }
  }

  AccessPermission getAccessPermission(Addr addr) {
    TBE tbe := TBEs.lookup(addr);
    if(is_valid(tbe)) {
      return SQC_State_to_permission(tbe.TBEState);
    }

    Entry cache_entry := getCacheEntry(addr);
    if(is_valid(cache_entry)) {
      return SQC_State_to_permission(cache_entry.CacheState);
    }

    return AccessPermission:NotPresent;
  }

  void setAccessPermission(Entry cache_entry, Addr addr, State state) {
    if (is_valid(cache_entry)) {
      cache_entry.changePermission(SQC_State_to_permission(state));
    }
  }

  void functionalRead(Addr addr, Packet *pkt) {
    TBE tbe := TBEs.lookup(addr);
    if(is_valid(tbe)) {
      testAndRead(addr, tbe.DataBlk, pkt);
    } else {
      functionalMemoryRead(pkt);
    }
  }

  int functionalWrite(Addr addr, Packet *pkt) {
    int num_functional_writes := 0;

    TBE tbe := TBEs.lookup(addr);
    if(is_valid(tbe)) {
      num_functional_writes := num_functional_writes +
            testAndWrite(addr, tbe.DataBlk, pkt);
    }

    num_functional_writes := num_functional_writes + functionalMemoryWrite(pkt);
    return num_functional_writes;
  }

  void recordRequestType(RequestType request_type, Addr addr) {
    if (request_type == RequestType:DataArrayRead) {
        L1cache.recordRequestType(CacheRequestType:DataArrayRead, addr);
    } else if (request_type == RequestType:DataArrayWrite) {
        L1cache.recordRequestType(CacheRequestType:DataArrayWrite, addr);
    } else if (request_type == RequestType:TagArrayRead) {
        L1cache.recordRequestType(CacheRequestType:TagArrayRead, addr);
    } else if (request_type == RequestType:TagArrayWrite) {
        L1cache.recordRequestType(CacheRequestType:TagArrayWrite, addr);
    }
  }

  bool checkResourceAvailable(RequestType request_type, Addr addr) {
    if (request_type == RequestType:DataArrayRead) {
      return L1cache.checkResourceAvailable(CacheResourceType:DataArray, addr);
    } else if (request_type == RequestType:DataArrayWrite) {
      return L1cache.checkResourceAvailable(CacheResourceType:DataArray, addr);
    } else if (request_type == RequestType:TagArrayRead) {
      return L1cache.checkResourceAvailable(CacheResourceType:TagArray, addr);
    } else if (request_type == RequestType:TagArrayWrite) {
      return L1cache.checkResourceAvailable(CacheResourceType:TagArray, addr);
    } else {
      error("Invalid RequestType type in checkResourceAvailable");
      return true;
    }
  }

  // Out Ports

  out_port(requestNetwork_out, CPURequestMsg, requestFromSQC);
  out_port(responseNetwork_out, ResponseMsg, responseFromSQC);
  out_port(unblockNetwork_out, UnblockMsg, unblockFromCore);

  // In Ports

  in_port(probeNetwork_in, TDProbeRequestMsg, probeToSQC) {
    if (probeNetwork_in.isReady(clockEdge())) {
      peek(probeNetwork_in, TDProbeRequestMsg, block_on="addr") {
        Entry cache_entry := getCacheEntry(in_msg.addr);
        TBE tbe := TBEs.lookup(in_msg.addr);

        if (in_msg.Type == ProbeRequestType:PrbInv) {
          if (in_msg.ReturnData) {
            trigger(Event:PrbInvData, in_msg.addr, cache_entry, tbe);
          } else {
            trigger(Event:PrbInv, in_msg.addr, cache_entry, tbe);
          }
        } else if (in_msg.Type == ProbeRequestType:PrbDowngrade) {
          assert(in_msg.ReturnData);
          trigger(Event:PrbShrData, in_msg.addr, cache_entry, tbe);
        }
      }
    }
  }

  in_port(responseToSQC_in, ResponseMsg, responseToSQC) {
    if (responseToSQC_in.isReady(clockEdge())) {
      peek(responseToSQC_in, ResponseMsg, block_on="addr") {

        Entry cache_entry := getCacheEntry(in_msg.addr);
        TBE tbe := TBEs.lookup(in_msg.addr);

        if (in_msg.Type == CoherenceResponseType:TDSysResp) {
          if (in_msg.State == CoherenceState:Shared) {
            trigger(Event:TCC_AckS, in_msg.addr, cache_entry, tbe);
          } else {
            error("SQC should not receive TDSysResp other than CoherenceState:Shared");
          }
        } else if (in_msg.Type == CoherenceResponseType:TDSysWBAck) {
          trigger(Event:TCC_AckWB, in_msg.addr, cache_entry, tbe);
        } else if (in_msg.Type == CoherenceResponseType:TDSysWBNack) {
          trigger(Event:TCC_NackWB, in_msg.addr, cache_entry, tbe);
        } else {
          error("Unexpected Response Message to Core");
        }
      }
    }
  }

  in_port(mandatoryQueue_in, RubyRequest, mandatoryQueue, desc="...") {
    if (mandatoryQueue_in.isReady(clockEdge())) {
      peek(mandatoryQueue_in, RubyRequest, block_on="LineAddress") {
        Entry cache_entry := getCacheEntry(in_msg.LineAddress);
        TBE tbe := TBEs.lookup(in_msg.LineAddress);

        assert(in_msg.Type == RubyRequestType:IFETCH);
        if (is_valid(cache_entry) || L1cache.cacheAvail(in_msg.LineAddress)) {
          trigger(Event:Fetch, in_msg.LineAddress, cache_entry, tbe);
        } else {
          Addr victim := L1cache.cacheProbe(in_msg.LineAddress);
          trigger(Event:Repl, victim, getCacheEntry(victim), TBEs.lookup(victim));
        }
      }
    }
  }

  // Actions

  action(ic_invCache, "ic", desc="invalidate cache") {
    if(is_valid(cache_entry)) {
      L1cache.deallocate(address);
    }
    unset_cache_entry();
  }

  action(nS_issueRdBlkS, "nS", desc="Issue RdBlkS") {
    enqueue(requestNetwork_out, CPURequestMsg, issue_latency) {
      out_msg.addr := address;
      out_msg.Type := CoherenceRequestType:RdBlkS;
      out_msg.Requestor := machineID;
      out_msg.Destination.add(mapAddressToRange(address,MachineType:TCCdir,
                              TCC_select_low_bit, TCC_select_num_bits));
      out_msg.MessageSize := MessageSizeType:Request_Control;
      out_msg.InitialRequestTime := curCycle();
    }
  }

  action(vc_victim, "vc", desc="Victimize E/S Data") {
    enqueue(requestNetwork_out, CPURequestMsg, issue_latency) {
      out_msg.addr := address;
      out_msg.Requestor := machineID;
      out_msg.Destination.add(mapAddressToRange(address,MachineType:TCCdir,
                              TCC_select_low_bit, TCC_select_num_bits));
      out_msg.MessageSize := MessageSizeType:Request_Control;
      out_msg.Type := CoherenceRequestType:VicClean;
      out_msg.InitialRequestTime := curCycle();
      if (cache_entry.CacheState == State:S) {
        out_msg.Shared := true;
      } else {
        out_msg.Shared := false;
      }
      out_msg.InitialRequestTime := curCycle();
    }
  }

  action(a_allocate, "a", desc="allocate block") {
    if (is_invalid(cache_entry)) {
      set_cache_entry(L1cache.allocate(address, new Entry));
    }
  }

  action(t_allocateTBE, "t", desc="allocate TBE Entry") {
    check_allocate(TBEs);
    assert(is_valid(cache_entry));
    TBEs.allocate(address);
    set_tbe(TBEs.lookup(address));
    tbe.DataBlk := cache_entry.DataBlk;  // Data only used for WBs
    tbe.Dirty := cache_entry.Dirty;
    tbe.Shared := false;
  }

  action(d_deallocateTBE, "d", desc="Deallocate TBE") {
    TBEs.deallocate(address);
    unset_tbe();
  }

  action(p_popMandatoryQueue, "pm", desc="Pop Mandatory Queue") {
    mandatoryQueue_in.dequeue(clockEdge());
  }

  action(pr_popResponseQueue, "pr", desc="Pop Response Queue") {
    responseToSQC_in.dequeue(clockEdge());
  }

  action(pp_popProbeQueue, "pp", desc="pop probe queue") {
    probeNetwork_in.dequeue(clockEdge());
  }

  action(l_loadDone, "l", desc="local load done") {
    assert(is_valid(cache_entry));
    sequencer.readCallback(address, cache_entry.DataBlk,
                           false, MachineType:L1Cache);
    APPEND_TRANSITION_COMMENT(cache_entry.DataBlk);
  }

  action(xl_loadDone, "xl", desc="remote load done") {
    peek(responseToSQC_in, ResponseMsg) {
      assert(is_valid(cache_entry));
      sequencer.readCallback(address,
                             cache_entry.DataBlk,
                             false,
                             machineIDToMachineType(in_msg.Sender),
                             in_msg.InitialRequestTime,
                             in_msg.ForwardRequestTime,
                             in_msg.ProbeRequestStartTime);
      APPEND_TRANSITION_COMMENT(cache_entry.DataBlk);
    }
  }

  action(w_writeCache, "w", desc="write data to cache") {
    peek(responseToSQC_in, ResponseMsg) {
      assert(is_valid(cache_entry));
      cache_entry.DataBlk := in_msg.DataBlk;
      cache_entry.Dirty := in_msg.Dirty;
    }
  }

  action(ss_sendStaleNotification, "ss", desc="stale data; nothing to writeback") {
    peek(responseToSQC_in, ResponseMsg) {
      enqueue(responseNetwork_out, ResponseMsg, issue_latency) {
        out_msg.addr := address;
        out_msg.Type := CoherenceResponseType:StaleNotif;
        out_msg.Sender := machineID;
        out_msg.Destination.add(mapAddressToRange(address,MachineType:TCC,
                                TCC_select_low_bit, TCC_select_num_bits));
        out_msg.MessageSize := MessageSizeType:Response_Control;
        DPRINTF(RubySlicc, "%s\n", out_msg);
      }
    }
  }

  action(wb_data, "wb", desc="write back data") {
    peek(responseToSQC_in, ResponseMsg) {
      enqueue(responseNetwork_out, ResponseMsg, issue_latency) {
        out_msg.addr := address;
        out_msg.Type := CoherenceResponseType:CPUData;
        out_msg.Sender := machineID;
        out_msg.Destination.add(mapAddressToRange(address,MachineType:TCC,
                                TCC_select_low_bit, TCC_select_num_bits));
        out_msg.DataBlk := tbe.DataBlk;
        out_msg.Dirty := tbe.Dirty;
        if (tbe.Shared) {
          out_msg.NbReqShared := true;
        } else {
          out_msg.NbReqShared := false;
        }
        out_msg.State := CoherenceState:Shared; // faux info
        out_msg.MessageSize := MessageSizeType:Writeback_Data;
        DPRINTF(RubySlicc, "%s\n", out_msg);
      }
    }
  }

  action(pi_sendProbeResponseInv, "pi", desc="send probe ack inv, no data") {
    enqueue(responseNetwork_out, ResponseMsg, issue_latency) {
      out_msg.addr := address;
      out_msg.Type := CoherenceResponseType:CPUPrbResp;  // L3 and CPUs respond in same way to probes
      out_msg.Sender := machineID;
      // will this always be ok? probably not for multisocket
      out_msg.Destination.add(mapAddressToRange(address,MachineType:TCCdir,
                              TCC_select_low_bit, TCC_select_num_bits));
      out_msg.Dirty := false;
      out_msg.Hit := false;
      out_msg.Ntsl := true;
      out_msg.State := CoherenceState:NA;
      out_msg.MessageSize := MessageSizeType:Response_Control;
    }
  }

  action(pim_sendProbeResponseInvMs, "pim", desc="send probe ack inv, no data") {
    enqueue(responseNetwork_out, ResponseMsg, issue_latency) {
      out_msg.addr := address;
      out_msg.Type := CoherenceResponseType:CPUPrbResp;  // L3 and CPUs respond in same way to probes
      out_msg.Sender := machineID;
      // will this always be ok? probably not for multisocket
      out_msg.Destination.add(mapAddressToRange(address,MachineType:TCCdir,
                              TCC_select_low_bit, TCC_select_num_bits));
      out_msg.Dirty := false;
      out_msg.Ntsl := true;
      out_msg.Hit := false;
      out_msg.State := CoherenceState:NA;
      out_msg.MessageSize := MessageSizeType:Response_Control;
    }
  }

  action(prm_sendProbeResponseMiss, "prm", desc="send probe ack PrbShrData, no data") {
    enqueue(responseNetwork_out, ResponseMsg, issue_latency) {
      out_msg.addr := address;
      out_msg.Type := CoherenceResponseType:CPUPrbResp;  // L3 and CPUs respond in same way to probes
      out_msg.Sender := machineID;
      // will this always be ok? probably not for multisocket
      out_msg.Destination.add(mapAddressToRange(address,MachineType:TCCdir,
                              TCC_select_low_bit, TCC_select_num_bits));
      out_msg.Dirty := false;  // only true if sending back data i think
      out_msg.Hit := false;
      out_msg.Ntsl := false;
      out_msg.State := CoherenceState:NA;
      out_msg.MessageSize := MessageSizeType:Response_Control;
    }
  }

  action(pd_sendProbeResponseData, "pd", desc="send probe ack, with data") {
    enqueue(responseNetwork_out, ResponseMsg, issue_latency) {
      assert(is_valid(cache_entry) || is_valid(tbe));
      out_msg.addr := address;
      out_msg.Type := CoherenceResponseType:CPUPrbResp;
      out_msg.Sender := machineID;
      // will this always be ok? probably not for multisocket
      out_msg.Destination.add(mapAddressToRange(address,MachineType:TCCdir,
                              TCC_select_low_bit, TCC_select_num_bits));
      out_msg.DataBlk := getDataBlock(address);
      if (is_valid(tbe)) {
        out_msg.Dirty := tbe.Dirty;
      } else {
        out_msg.Dirty := cache_entry.Dirty;
      }
      out_msg.Hit := true;
      out_msg.State := CoherenceState:NA;
      out_msg.MessageSize := MessageSizeType:Response_Data;
    }
  }

  action(pdm_sendProbeResponseDataMs, "pdm", desc="send probe ack, with data") {
    enqueue(responseNetwork_out, ResponseMsg, issue_latency) {
      assert(is_valid(cache_entry) || is_valid(tbe));
      assert(is_valid(cache_entry));
      out_msg.addr := address;
      out_msg.Type := CoherenceResponseType:CPUPrbResp;
      out_msg.Sender := machineID;
      // will this always be ok? probably not for multisocket
      out_msg.Destination.add(mapAddressToRange(address,MachineType:TCCdir,
                              TCC_select_low_bit, TCC_select_num_bits));
      out_msg.DataBlk := getDataBlock(address);
      if (is_valid(tbe)) {
        out_msg.Dirty := tbe.Dirty;
      } else {
        out_msg.Dirty := cache_entry.Dirty;
      }
      out_msg.Hit := true;
      out_msg.State := CoherenceState:NA;
      out_msg.MessageSize := MessageSizeType:Response_Data;
    }
  }

  action(sf_setSharedFlip, "sf", desc="hit by shared probe, status may be different") {
    assert(is_valid(tbe));
    tbe.Shared := true;
  }

  action(uu_sendUnblock, "uu", desc="state changed, unblock") {
    enqueue(unblockNetwork_out, UnblockMsg, issue_latency) {
      out_msg.addr := address;
      out_msg.Sender := machineID;
      out_msg.Destination.add(mapAddressToRange(address,MachineType:TCCdir,
                              TCC_select_low_bit, TCC_select_num_bits));
      out_msg.MessageSize := MessageSizeType:Unblock_Control;
      DPRINTF(RubySlicc, "%s\n", out_msg);
    }
  }

  action(yy_recycleProbeQueue, "yy", desc="recycle probe queue") {
    probeNetwork_in.recycle(clockEdge(), cyclesToTicks(recycle_latency));
  }

  action(zz_recycleMandatoryQueue, "\z", desc="recycle mandatory queue") {
    mandatoryQueue_in.recycle(clockEdge(), cyclesToTicks(recycle_latency));
  }

  // Transitions

  // transitions from base
  transition(I, Fetch, I_S) {TagArrayRead, TagArrayWrite} {
    a_allocate;
    nS_issueRdBlkS;
    p_popMandatoryQueue;
  }

  // simple hit transitions
  transition(S, Fetch) {TagArrayRead, DataArrayRead} {
    l_loadDone;
    p_popMandatoryQueue;
  }

  // recycles from transients
  transition({I_S, S_I, I_C}, {Fetch, Repl}) {} {
    zz_recycleMandatoryQueue;
  }

  transition(S, Repl, S_I) {TagArrayRead} {
    t_allocateTBE;
    vc_victim;
    ic_invCache;
  }

  // TCC event
  transition(I_S, TCC_AckS, S) {DataArrayRead, DataArrayWrite} {
    w_writeCache;
    xl_loadDone;
    uu_sendUnblock;
    pr_popResponseQueue;
  }

  transition(S_I, TCC_NackWB, I){TagArrayWrite} {
    d_deallocateTBE;
    pr_popResponseQueue;
  }

  transition(S_I, TCC_AckWB, I) {TagArrayWrite} {
    wb_data;
    d_deallocateTBE;
    pr_popResponseQueue;
  }

  transition(I_C, TCC_AckWB, I){TagArrayWrite} {
    ss_sendStaleNotification;
    d_deallocateTBE;
    pr_popResponseQueue;
  }

  transition(I_C, TCC_NackWB, I) {TagArrayWrite} {
    d_deallocateTBE;
    pr_popResponseQueue;
  }

  // Probe transitions
  transition({S, I}, PrbInvData, I) {TagArrayRead, TagArrayWrite} {
    pd_sendProbeResponseData;
    ic_invCache;
    pp_popProbeQueue;
  }

  transition(I_C, PrbInvData, I_C) {
    pi_sendProbeResponseInv;
    ic_invCache;
    pp_popProbeQueue;
  }

  transition({S, I}, PrbInv, I) {TagArrayRead, TagArrayWrite} {
    pi_sendProbeResponseInv;
    ic_invCache;
    pp_popProbeQueue;
  }

  transition({S}, PrbShrData, S) {DataArrayRead} {
    pd_sendProbeResponseData;
    pp_popProbeQueue;
  }

  transition({I, I_C}, PrbShrData) {TagArrayRead} {
    prm_sendProbeResponseMiss;
    pp_popProbeQueue;
  }

  transition(I_C, PrbInv, I_C){
    pi_sendProbeResponseInv;
    ic_invCache;
    pp_popProbeQueue;
  }

  transition(I_S, {PrbInv, PrbInvData}) {} {
    pi_sendProbeResponseInv;
    ic_invCache;
    a_allocate;  // but make sure there is room for incoming data when it arrives
    pp_popProbeQueue;
  }

  transition(I_S, PrbShrData) {} {
    prm_sendProbeResponseMiss;
    pp_popProbeQueue;
  }

  transition(S_I, PrbInvData, I_C) {TagArrayWrite} {
    pi_sendProbeResponseInv;
    ic_invCache;
    pp_popProbeQueue;
  }

  transition(S_I, PrbInv, I_C) {TagArrayWrite} {
    pi_sendProbeResponseInv;
    ic_invCache;
    pp_popProbeQueue;
  }

  transition(S_I, PrbShrData) {DataArrayRead} {
    pd_sendProbeResponseData;
    sf_setSharedFlip;
    pp_popProbeQueue;
  }
}