/*
 * Copyright (c) 2009-2013 Mark D. Hill and David A. Wood
 * Copyright (c) 2010-2011 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.
 */

machine(MachineType:DMA, "DMA Controller")
    : DMASequencer * dma_sequencer;
      Cycles request_latency := 14;
      Cycles response_latency := 14;

      MessageBuffer * responseFromDir, network="From", virtual_network="2",
            vnet_type="response";

      MessageBuffer * reqToDir, network="To", virtual_network="1",
            vnet_type="request";
      MessageBuffer * respToDir, network="To", virtual_network="2",
            vnet_type="dmaresponse";

      MessageBuffer * mandatoryQueue;
      MessageBuffer * triggerQueue;
{
  state_declaration(State, desc="DMA states", default="DMA_State_READY") {
    READY, AccessPermission:Invalid, desc="Ready to accept a new request";
    BUSY_RD, AccessPermission:Busy, desc="Busy: currently processing a request";
    BUSY_WR, AccessPermission:Busy, desc="Busy: currently processing a request";
  }

  enumeration(Event, desc="DMA events") {
    ReadRequest,  desc="A new read request";
    WriteRequest, desc="A new write request";
    Data,         desc="Data from a DMA memory read";
    DMA_Ack,      desc="DMA write to memory completed";
    Inv_Ack,      desc="Invalidation Ack from a sharer";
    All_Acks,     desc="All acks received";
  }

  structure(TBE, desc="...") {
    Addr address, desc="Physical address";
    int NumAcks, default="0", desc="Number of Acks pending";
    DataBlock DataBlk, desc="Data";
  }

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

  TBETable TBEs, template="<DMA_TBE>", constructor="m_number_of_TBEs";
  State cur_state;

  Tick clockEdge();
  void set_tbe(TBE b);
  void unset_tbe();
  void wakeUpAllBuffers();
  MachineID mapAddressToMachine(Addr addr, MachineType mtype);

  State getState(TBE tbe, Addr addr) {
    return cur_state;
  }
  void setState(TBE tbe, Addr addr, State state) {
  cur_state := state;
  }

  AccessPermission getAccessPermission(Addr addr) {
    return AccessPermission:NotPresent;
  }

  void setAccessPermission(Addr addr, State state) {
  }

  void functionalRead(Addr addr, Packet *pkt) {
    error("DMA does not support functional read.");
  }

  int functionalWrite(Addr addr, Packet *pkt) {
    error("DMA does not support functional write.");
  }

  out_port(reqToDirectory_out, RequestMsg, reqToDir, desc="...");
  out_port(respToDirectory_out, ResponseMsg, respToDir, desc="...");
  out_port(triggerQueue_out, TriggerMsg, triggerQueue, desc="...");

  in_port(dmaRequestQueue_in, SequencerMsg, mandatoryQueue, desc="...") {
    if (dmaRequestQueue_in.isReady(clockEdge())) {
      peek(dmaRequestQueue_in, SequencerMsg) {
        if (in_msg.Type == SequencerRequestType:LD ) {
          trigger(Event:ReadRequest, in_msg.LineAddress,
                  TBEs[in_msg.LineAddress]);
        } else if (in_msg.Type == SequencerRequestType:ST) {
          trigger(Event:WriteRequest, in_msg.LineAddress,
                  TBEs[in_msg.LineAddress]);
        } else {
          error("Invalid request type");
        }
      }
    }
  }

  in_port(dmaResponseQueue_in, ResponseMsg, responseFromDir, desc="...") {
    if (dmaResponseQueue_in.isReady(clockEdge())) {
      peek( dmaResponseQueue_in, ResponseMsg) {
        if (in_msg.Type == CoherenceResponseType:DMA_ACK) {
          trigger(Event:DMA_Ack, makeLineAddress(in_msg.addr),
                  TBEs[makeLineAddress(in_msg.addr)]);
        } else if (in_msg.Type == CoherenceResponseType:DATA_EXCLUSIVE ||
       in_msg.Type == CoherenceResponseType:DATA) {
          trigger(Event:Data, makeLineAddress(in_msg.addr),
                  TBEs[makeLineAddress(in_msg.addr)]);
        } else if (in_msg.Type == CoherenceResponseType:ACK) {
          trigger(Event:Inv_Ack, makeLineAddress(in_msg.addr),
                  TBEs[makeLineAddress(in_msg.addr)]);
        } else {
          error("Invalid response type");
        }
      }
    }
  }

  // Trigger Queue
  in_port(triggerQueue_in, TriggerMsg, triggerQueue) {
    if (triggerQueue_in.isReady(clockEdge())) {
      peek(triggerQueue_in, TriggerMsg) {
        if (in_msg.Type == TriggerType:ALL_ACKS) {
          trigger(Event:All_Acks, in_msg.addr, TBEs[in_msg.addr]);
        } else {
          error("Unexpected message");
        }
      }
    }
  }

  action(s_sendReadRequest, "s", desc="Send a DMA read request to memory") {
    peek(dmaRequestQueue_in, SequencerMsg) {
      enqueue(reqToDirectory_out, RequestMsg, request_latency) {
        out_msg.addr := in_msg.PhysicalAddress;
        out_msg.Type := CoherenceRequestType:DMA_READ;
        out_msg.DataBlk := in_msg.DataBlk;
        out_msg.Len := in_msg.Len;
        out_msg.Destination.add(mapAddressToMachine(address, MachineType:Directory));
        out_msg.Requestor := machineID;
        out_msg.RequestorMachine := MachineType:DMA;
        out_msg.MessageSize := MessageSizeType:Writeback_Control;
      }
    }
  }

  action(s_sendWriteRequest, "\s", desc="Send a DMA write request to memory") {
    peek(dmaRequestQueue_in, SequencerMsg) {
      enqueue(reqToDirectory_out, RequestMsg, request_latency) {
          out_msg.addr := in_msg.PhysicalAddress;
          out_msg.Type := CoherenceRequestType:DMA_WRITE;
          out_msg.DataBlk := in_msg.DataBlk;
          out_msg.Len := in_msg.Len;
          out_msg.Destination.add(mapAddressToMachine(address, MachineType:Directory));
          out_msg.Requestor := machineID;
          out_msg.RequestorMachine := MachineType:DMA;
          out_msg.MessageSize := MessageSizeType:Writeback_Control;
        }
      }
  }

  action(a_ackCallback, "a", desc="Notify dma controller that write request completed") {
      dma_sequencer.ackCallback(address);
  }

  action(o_checkForCompletion, "o", desc="Check if we have received all the messages required for completion") {
    assert(is_valid(tbe));
    if (tbe.NumAcks == 0) {
      enqueue(triggerQueue_out, TriggerMsg) {
        out_msg.addr := address;
        out_msg.Type := TriggerType:ALL_ACKS;
      }
    }
  }

  action(u_updateAckCount, "u", desc="Update ack count") {
    peek(dmaResponseQueue_in, ResponseMsg) {
      assert(is_valid(tbe));
      tbe.NumAcks := tbe.NumAcks - in_msg.Acks;
    }
  }

  action( u_sendExclusiveUnblockToDir, "\u", desc="send exclusive unblock to directory") {
    enqueue(respToDirectory_out, ResponseMsg, response_latency) {
      out_msg.addr := address;
      out_msg.Type := CoherenceResponseType:UNBLOCK_EXCLUSIVE;
      out_msg.Destination.add(mapAddressToMachine(address, MachineType:Directory));
      out_msg.Sender := machineID;
      out_msg.SenderMachine := MachineType:DMA;
      out_msg.MessageSize := MessageSizeType:Writeback_Control;
    }
  }

  action(p_popRequestQueue, "p", desc="Pop request queue") {
    dmaRequestQueue_in.dequeue(clockEdge());
  }

  action(p_popResponseQueue, "\p", desc="Pop request queue") {
    dmaResponseQueue_in.dequeue(clockEdge());
  }

  action(p_popTriggerQueue, "pp", desc="Pop trigger queue") {
    triggerQueue_in.dequeue(clockEdge());
  }

  action(t_updateTBEData, "t", desc="Update TBE Data") {
    peek(dmaResponseQueue_in, ResponseMsg) {
      assert(is_valid(tbe));
      tbe.DataBlk := in_msg.DataBlk;
    }
  }

  action(d_dataCallbackFromTBE, "/d", desc="data callback with data from TBE") {
    assert(is_valid(tbe));
    dma_sequencer.dataCallback(tbe.DataBlk, address);
  }

  action(v_allocateTBE, "v", desc="Allocate TBE entry") {
    TBEs.allocate(address);
    set_tbe(TBEs[address]);
  }

  action(w_deallocateTBE, "w", desc="Deallocate TBE entry") {
    TBEs.deallocate(address);
    unset_tbe();
  }

  action(zz_stallAndWaitRequestQueue, "zz", desc="...") {
    stall_and_wait(dmaRequestQueue_in, address);
  }

  action(wkad_wakeUpAllDependents, "wkad", desc="wake-up all dependents") {
    wakeUpAllBuffers();
  }

  transition(READY, ReadRequest, BUSY_RD) {
    s_sendReadRequest;
    v_allocateTBE;
    p_popRequestQueue;
  }

  transition(BUSY_RD, Inv_Ack) {
    u_updateAckCount;
    o_checkForCompletion;
    p_popResponseQueue;
  }

  transition(BUSY_RD, Data, READY) {
    t_updateTBEData;
    d_dataCallbackFromTBE;
    w_deallocateTBE;
    //u_updateAckCount;
    //o_checkForCompletion;
    p_popResponseQueue;
    wkad_wakeUpAllDependents;
  }

  transition(BUSY_RD, All_Acks, READY) {
    d_dataCallbackFromTBE;
    //u_sendExclusiveUnblockToDir;
    w_deallocateTBE;
    p_popTriggerQueue;
    wkad_wakeUpAllDependents;
  }

  transition(READY, WriteRequest, BUSY_WR) {
    s_sendWriteRequest;
    v_allocateTBE;
    p_popRequestQueue;
  }

  transition(BUSY_WR, Inv_Ack) {
    u_updateAckCount;
    o_checkForCompletion;
    p_popResponseQueue;
  }

  transition(BUSY_WR, DMA_Ack) {
    u_updateAckCount; // actually increases
    o_checkForCompletion;
    p_popResponseQueue;
  }

  transition(BUSY_WR, All_Acks, READY) {
    a_ackCallback;
    u_sendExclusiveUnblockToDir;
    w_deallocateTBE;
    p_popTriggerQueue;
    wkad_wakeUpAllDependents;
  }

  transition({BUSY_RD,BUSY_WR}, {ReadRequest,WriteRequest}) {
    zz_stallAndWaitRequestQueue;
  }
}