src/systemc/tlm_bridge/tlm_to_gem5.cc - public/gem5 - Git at Google

 /*
  * Copyright 2019 Google, Inc.
  *
  * 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.
  *
  * Copyright (c) 2016, Dresden University of Technology (TU Dresden)
  * All rights reserved.
  *
  * 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.
  */

 #include "systemc/tlm_bridge/tlm_to_gem5.hh"

 #include <utility>

 #include "base/trace.hh"
 #include "debug/TlmBridge.hh"
 #include "params/TlmToGem5Bridge128.hh"
 #include "params/TlmToGem5Bridge256.hh"
 #include "params/TlmToGem5Bridge32.hh"
 #include "params/TlmToGem5Bridge512.hh"
 #include "params/TlmToGem5Bridge64.hh"
 #include "sim/core.hh"
 #include "sim/system.hh"
 #include "systemc/ext/core/sc_module_name.hh"
 #include "systemc/ext/core/sc_time.hh"

 using namespace gem5;

 namespace sc_gem5
 {

 namespace
 {
 /**
  * Hold all the callbacks necessary to convert a tlm payload to gem5 packet.
  */
 std::vector<PayloadToPacketConversionStep> extraPayloadToPacketSteps;
 }  // namespace

 /**
  * Notify the Tlm2Gem5 bridge that we need an extra step to properly convert a
  * tlm payload to gem5 packet. This can be useful when there exists a SystemC
  * extension that carries extra information. For example, SystemC user might
  * define an extension to store stream_id, the user may then add an extra step
  * to set the generated request's stream_id accordingly. Steps should be
  * idempotent.
  */
 void
 addPayloadToPacketConversionStep(PayloadToPacketConversionStep step)
 {
     extraPayloadToPacketSteps.push_back(std::move(step));
 }

 /**
  * Convert a TLM payload to gem5 packet by copying all the relevant information
  * to new packet. If the transaction is initiated by gem5 model, we would use
  * the original packet.
  * The first return value is the packet pointer.
  * The second return value is if the packet is newly created.
  */
 std::pair<PacketPtr, bool>
 payload2packet(RequestorID _id, tlm::tlm_generic_payload &trans)
 {
     Gem5SystemC::Gem5Extension *extension = nullptr;
     trans.get_extension(extension);

     // If there is an extension, this transaction was initiated by the gem5
     // world and we can pipe through the original packet. Otherwise, we
     // generate a new packet based on the transaction.
     if (extension != nullptr) {
         auto pkt = extension->getPacket();
         // Sync the address which could have changed.
         pkt->setAddr(trans.get_address());
         // Apply all conversion steps necessary in this specific setup.
         for (auto &step : extraPayloadToPacketSteps) {
             step(pkt, trans);
         }
         return std::make_pair(pkt, false);
     }

     MemCmd cmd;
     RequestPtr req;

     Gem5SystemC::AtomicExtension *atomic_ex = nullptr;
     trans.get_extension(atomic_ex);
     if (atomic_ex) {
         cmd = MemCmd::SwapReq;
         Request::Flags flags = (atomic_ex->isReturnRequired() ?
                                 Request::ATOMIC_RETURN_OP :
                                 Request::ATOMIC_NO_RETURN_OP);
         AtomicOpFunctorPtr amo_op = AtomicOpFunctorPtr(
             atomic_ex->getAtomicOpFunctor()->clone());
         // FIXME: correct the context_id and pc state.
         req = std::make_shared<Request>(
             trans.get_address(), trans.get_data_length(), flags, _id,
             0, 0, std::move(amo_op));
         req->setPaddr(trans.get_address());
     } else {
         switch (trans.get_command()) {
           case tlm::TLM_READ_COMMAND:
             cmd = MemCmd::ReadReq;
             break;
           case tlm::TLM_WRITE_COMMAND:
             cmd = MemCmd::WriteReq;
             break;
           case tlm::TLM_IGNORE_COMMAND:
             return std::make_pair(nullptr, false);
           default:
             SC_REPORT_FATAL("TlmToGem5Bridge",
                             "received transaction with unsupported "
                             "command");
         }
         Request::Flags flags;
         req = std::make_shared<Request>(
             trans.get_address(), trans.get_data_length(), flags, _id);
     }


     /*
      * Allocate a new Packet. The packet will be deleted when it returns from
      * the gem5 world as a response.
      */
     auto pkt = new Packet(req, cmd);
     pkt->dataStatic(trans.get_data_ptr());

     // Apply all conversion steps necessary in this specific setup.
     for (auto &step : extraPayloadToPacketSteps) {
         step(pkt, trans);
     }

     return std::make_pair(pkt, true);
 }

 template <unsigned int BITWIDTH>
 void
 TlmToGem5Bridge<BITWIDTH>::sendEndReq(tlm::tlm_generic_payload &trans)
 {
     tlm::tlm_phase phase = tlm::END_REQ;
     auto delay = sc_core::SC_ZERO_TIME;

     auto status = socket->nb_transport_bw(trans, phase, delay);
     panic_if(status != tlm::TLM_ACCEPTED,
              "Unexpected status after sending END_REQ");
 }

 template <unsigned int BITWIDTH>
 void
 TlmToGem5Bridge<BITWIDTH>::sendBeginResp(tlm::tlm_generic_payload &trans,
                                          sc_core::sc_time &delay)
 {
     tlm::tlm_phase phase = tlm::BEGIN_RESP;

     trans.set_response_status(tlm::TLM_OK_RESPONSE);

     auto status = socket->nb_transport_bw(trans, phase, delay);

     if (status == tlm::TLM_COMPLETED ||
         (status == tlm::TLM_UPDATED && phase == tlm::END_RESP)) {
         // transaction completed -> no need to wait for tlm::END_RESP
         responseInProgress = false;
     } else if (status == tlm::TLM_ACCEPTED) {
         // we need to wait for tlm::END_RESP
         responseInProgress = true;
     } else {
         panic("Unexpected status after sending BEGIN_RESP");
     }
 }

 template <unsigned int BITWIDTH>
 void
 TlmToGem5Bridge<BITWIDTH>::handleBeginReq(tlm::tlm_generic_payload &trans)
 {
     sc_assert(!waitForRetry);
     sc_assert(pendingRequest == nullptr);
     sc_assert(pendingPacket == nullptr);

     trans.acquire();

     auto res = payload2packet(_id, trans);
     auto pkt = res.first;
     pkt->pushSenderState(new Gem5SystemC::TlmSenderState(trans));

     // If the packet doesn't need a response, we should send BEGIN_RESP by
     // ourselves.
     bool needsResponse = pkt->needsResponse();
     if (bmp.sendTimingReq(pkt)) { // port is free -> send END_REQ immediately
         sendEndReq(trans);
         if (!needsResponse) {
             auto delay = sc_core::SC_ZERO_TIME;
             sendBeginResp(trans, delay);
         }
         trans.release();
     } else { // port is blocked -> wait for retry before sending END_REQ
         waitForRetry = true;
         pendingRequest = &trans;
         pendingPacket = pkt;
     }
 }

 template <unsigned int BITWIDTH>
 void
 TlmToGem5Bridge<BITWIDTH>::handleEndResp(tlm::tlm_generic_payload &trans)
 {
     sc_assert(responseInProgress);

     responseInProgress = false;

     checkTransaction(trans);

     if (needToSendRetry) {
         bmp.sendRetryResp();
         needToSendRetry = false;
     }
 }

 template <unsigned int BITWIDTH>
 void
 TlmToGem5Bridge<BITWIDTH>::destroyPacket(PacketPtr pkt)
 {
     delete pkt;
 }

 template <unsigned int BITWIDTH>
 void
 TlmToGem5Bridge<BITWIDTH>::checkTransaction(tlm::tlm_generic_payload &trans)
 {
     if (trans.is_response_error()) {
         std::stringstream ss;
         ss << "Transaction returned with error, response status = "
            << trans.get_response_string();
         SC_REPORT_ERROR("TLM-2", ss.str().c_str());
     }
 }

 template <unsigned int BITWIDTH>
 void
 TlmToGem5Bridge<BITWIDTH>::invalidateDmi(const gem5::MemBackdoor &backdoor)
 {
     socket->invalidate_direct_mem_ptr(
             backdoor.range().start(), backdoor.range().end());
     requestedBackdoors.erase(const_cast<gem5::MemBackdoorPtr>(&backdoor));
 }

 template <unsigned int BITWIDTH>
 void
 TlmToGem5Bridge<BITWIDTH>::peq_cb(tlm::tlm_generic_payload &trans,
                                   const tlm::tlm_phase &phase)
 {
     switch (phase) {
         case tlm::BEGIN_REQ:
             handleBeginReq(trans);
             break;
         case tlm::END_RESP:
             handleEndResp(trans);
             break;
         default:
             panic("unimplemented phase in callback");
     }
 }

 template <unsigned int BITWIDTH>
 tlm::tlm_sync_enum
 TlmToGem5Bridge<BITWIDTH>::nb_transport_fw(
         tlm::tlm_generic_payload &trans, tlm::tlm_phase &phase,
         sc_core::sc_time &delay)
 {
     unsigned len = trans.get_data_length();
     unsigned char *byteEnable = trans.get_byte_enable_ptr();
     unsigned width = trans.get_streaming_width();

     // check the transaction attributes for unsupported features ...
     if (byteEnable != 0) {
         trans.set_response_status(tlm::TLM_BYTE_ENABLE_ERROR_RESPONSE);
         return tlm::TLM_COMPLETED;
     }
     if (width < len) { // is this a burst request?
         trans.set_response_status(tlm::TLM_BURST_ERROR_RESPONSE);
         return tlm::TLM_COMPLETED;
     }

     // ... and queue the valid transaction
     trans.acquire();
     peq.notify(trans, phase, delay);
     return tlm::TLM_ACCEPTED;
 }

 template <unsigned int BITWIDTH>
 void
 TlmToGem5Bridge<BITWIDTH>::b_transport(tlm::tlm_generic_payload &trans,
                                        sc_core::sc_time &t)
 {
     auto [pkt, pkt_created] = payload2packet(_id, trans);
     pkt->pushSenderState(new Gem5SystemC::TlmSenderState(trans));

     MemBackdoorPtr backdoor = nullptr;
     Tick ticks = bmp.sendAtomicBackdoor(pkt, backdoor);
     if (backdoor)
         trans.set_dmi_allowed(true);

     // send an atomic request to gem5
     panic_if(pkt->needsResponse() && !pkt->isResponse(),
              "Packet sending failed!\n");

     auto delay =
       sc_core::sc_time((double)(ticks / sim_clock::as_int::ps),
         sc_core::SC_PS);

     // update time
     t += delay;

     gem5::Packet::SenderState *senderState = pkt->popSenderState();
     sc_assert(
         nullptr != dynamic_cast<Gem5SystemC::TlmSenderState*>(senderState));

     // clean up
     delete senderState;

     if (pkt_created)
         destroyPacket(pkt);

     trans.set_response_status(tlm::TLM_OK_RESPONSE);
 }

 template <unsigned int BITWIDTH>
 unsigned int
 TlmToGem5Bridge<BITWIDTH>::transport_dbg(tlm::tlm_generic_payload &trans)
 {
     auto [pkt, pkt_created] = payload2packet(_id, trans);
     if (pkt != nullptr) {
         pkt->pushSenderState(new Gem5SystemC::TlmSenderState(trans));

         bmp.sendFunctional(pkt);

         gem5::Packet::SenderState *senderState = pkt->popSenderState();
         sc_assert(
             nullptr != dynamic_cast<Gem5SystemC::TlmSenderState*>(senderState));

         // clean up
         delete senderState;

         if (pkt_created)
             destroyPacket(pkt);
     }

     return trans.get_data_length();
 }

 template <unsigned int BITWIDTH>
 bool
 TlmToGem5Bridge<BITWIDTH>::get_direct_mem_ptr(tlm::tlm_generic_payload &trans,
                                               tlm::tlm_dmi &dmi_data)
 {
     auto [pkt, pkt_created] = payload2packet(_id, trans);
     pkt->pushSenderState(new Gem5SystemC::TlmSenderState(trans));
     if (pkt_created)
         pkt->req->setFlags(Request::NO_ACCESS);

     MemBackdoorPtr backdoor = nullptr;
     bmp.sendAtomicBackdoor(pkt, backdoor);
     if (backdoor) {
         trans.set_dmi_allowed(true);
         dmi_data.set_dmi_ptr(backdoor->ptr());
         dmi_data.set_start_address(backdoor->range().start());
         dmi_data.set_end_address(backdoor->range().end());

         typedef tlm::tlm_dmi::dmi_access_e access_t;
         access_t access = tlm::tlm_dmi::DMI_ACCESS_NONE;
         if (backdoor->readable())
             access = (access_t)(access | tlm::tlm_dmi::DMI_ACCESS_READ);
         if (backdoor->writeable())
             access = (access_t)(access | tlm::tlm_dmi::DMI_ACCESS_WRITE);
         dmi_data.set_granted_access(access);

         // We only need to register the callback at the first time.
         if (requestedBackdoors.find(backdoor) == requestedBackdoors.end()) {
             backdoor->addInvalidationCallback(
                 [this](const MemBackdoor &backdoor)
                 {
                     invalidateDmi(backdoor);
                 }
             );
             requestedBackdoors.emplace(backdoor);
         }
     }

     gem5::Packet::SenderState *senderState = pkt->popSenderState();
     sc_assert(
         nullptr != dynamic_cast<Gem5SystemC::TlmSenderState*>(senderState));

     // clean up
     delete senderState;

     if (pkt_created)
         destroyPacket(pkt);

     trans.set_response_status(tlm::TLM_OK_RESPONSE);

     return backdoor != nullptr;
 }

 template <unsigned int BITWIDTH>
 bool
 TlmToGem5Bridge<BITWIDTH>::recvTimingResp(PacketPtr pkt)
 {
     // exclusion rule
     // We need to Wait for END_RESP before sending next BEGIN_RESP
     if (responseInProgress) {
         sc_assert(!needToSendRetry);
         needToSendRetry = true;
         return false;
     }

     sc_assert(pkt->isResponse());

     /*
      * Pay for annotated transport delays.
      *
      * See recvTimingReq in sc_slave_port.cc for a detailed description.
      */
     auto delay = sc_core::sc_time::from_value(pkt->payloadDelay);
     // reset the delays
     pkt->payloadDelay = 0;
     pkt->headerDelay = 0;

     auto *tlmSenderState =
         dynamic_cast<Gem5SystemC::TlmSenderState*>(pkt->popSenderState());
     sc_assert(tlmSenderState != nullptr);

     auto &trans = tlmSenderState->trans;

     Gem5SystemC::Gem5Extension *extension = nullptr;
     trans.get_extension(extension);

     // clean up
     delete tlmSenderState;

     // If there is an extension the packet was piped through and we must not
     // delete it. The packet travels back with the transaction.
     if (extension == nullptr)
         destroyPacket(pkt);

     sendBeginResp(trans, delay);
     trans.release();

     return true;
 }

 template <unsigned int BITWIDTH>
 void
 TlmToGem5Bridge<BITWIDTH>::recvReqRetry()
 {
     sc_assert(waitForRetry);
     sc_assert(pendingRequest != nullptr);
     sc_assert(pendingPacket != nullptr);

     // If the packet doesn't need a response, we should send BEGIN_RESP by
     // ourselves.
     bool needsResponse = pendingPacket->needsResponse();
     if (bmp.sendTimingReq(pendingPacket)) {
         waitForRetry = false;
         pendingPacket = nullptr;

         auto &trans = *pendingRequest;
         sendEndReq(trans);
         if (!needsResponse) {
             auto delay = sc_core::SC_ZERO_TIME;
             sendBeginResp(trans, delay);
         }
         trans.release();

         pendingRequest = nullptr;
     }
 }

 template <unsigned int BITWIDTH>
 void
 TlmToGem5Bridge<BITWIDTH>::recvRangeChange()
 {
     DPRINTF(TlmBridge,
             "received address range change but ignored it");
 }

 template <unsigned int BITWIDTH>
 gem5::Port &
 TlmToGem5Bridge<BITWIDTH>::gem5_getPort(const std::string &if_name, int idx)
 {
     if (if_name == "gem5")
         return bmp;
     else if (if_name == "tlm")
         return wrapper;

     return sc_core::sc_module::gem5_getPort(if_name, idx);
 }

 template <unsigned int BITWIDTH>
 TlmToGem5Bridge<BITWIDTH>::TlmToGem5Bridge(
         const Params &params, const sc_core::sc_module_name &mn) :
     TlmToGem5BridgeBase(mn), peq(this, &TlmToGem5Bridge<BITWIDTH>::peq_cb),
     waitForRetry(false), pendingRequest(nullptr), pendingPacket(nullptr),
     needToSendRetry(false), responseInProgress(false),
     bmp(std::string(name()) + "master", *this), socket("tlm_socket"),
     wrapper(socket, std::string(name()) + ".tlm", InvalidPortID),
     system(params.system),
     _id(params.system->getGlobalRequestorId(
                 std::string("[systemc].") + name()))
 {
 }

 template <unsigned int BITWIDTH>
 void
 TlmToGem5Bridge<BITWIDTH>::before_end_of_elaboration()
 {
     /*
      * Register the TLM non-blocking interface when using gem5 Timing mode and
      * the TLM blocking interface when using the gem5 Atomic mode.
      * Then the magic (TM) in simple_target_socket automatically transforms
      * non-blocking in blocking transactions and vice versa.
      *
      * NOTE: The mode may change during execution.
      */
     if (system->isTimingMode()) {
         DPRINTF(TlmBridge, "register non-blocking interface");
         socket.register_nb_transport_fw(
                 this, &TlmToGem5Bridge<BITWIDTH>::nb_transport_fw);
     } else if (system->isAtomicMode()) {
         DPRINTF(TlmBridge, "register blocking interface");
         socket.register_b_transport(
                 this, &TlmToGem5Bridge<BITWIDTH>::b_transport);
         socket.register_get_direct_mem_ptr(
                 this, &TlmToGem5Bridge<BITWIDTH>::get_direct_mem_ptr);
     } else {
         panic("gem5 operates neither in Timing nor in Atomic mode");
     }

     socket.register_transport_dbg(
             this, &TlmToGem5Bridge<BITWIDTH>::transport_dbg);

     sc_core::sc_module::before_end_of_elaboration();
 }

 } // namespace sc_gem5

 sc_gem5::TlmToGem5Bridge<32> *
 gem5::TlmToGem5Bridge32Params::create() const
 {
     return new sc_gem5::TlmToGem5Bridge<32>(
             *this, sc_core::sc_module_name(name.c_str()));
 }

 sc_gem5::TlmToGem5Bridge<64> *
 gem5::TlmToGem5Bridge64Params::create() const
 {
     return new sc_gem5::TlmToGem5Bridge<64>(
             *this, sc_core::sc_module_name(name.c_str()));
 }

 sc_gem5::TlmToGem5Bridge<128> *
 gem5::TlmToGem5Bridge128Params::create() const
 {
     return new sc_gem5::TlmToGem5Bridge<128>(
             *this, sc_core::sc_module_name(name.c_str()));
 }

 sc_gem5::TlmToGem5Bridge<256> *
 gem5::TlmToGem5Bridge256Params::create() const
 {
     return new sc_gem5::TlmToGem5Bridge<256>(
             *this, sc_core::sc_module_name(name.c_str()));
 }

 sc_gem5::TlmToGem5Bridge<512> *
 gem5::TlmToGem5Bridge512Params::create() const
 {
     return new sc_gem5::TlmToGem5Bridge<512>(
             *this, sc_core::sc_module_name(name.c_str()));
 }
	/*
	* Copyright 2019 Google, Inc.
	*
	* 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.
	*
	* Copyright (c) 2016, Dresden University of Technology (TU Dresden)
	* All rights reserved.
	*
	* 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.
	*/

	#include "systemc/tlm_bridge/tlm_to_gem5.hh"

	#include <utility>

	#include "base/trace.hh"
	#include "debug/TlmBridge.hh"
	#include "params/TlmToGem5Bridge128.hh"
	#include "params/TlmToGem5Bridge256.hh"
	#include "params/TlmToGem5Bridge32.hh"
	#include "params/TlmToGem5Bridge512.hh"
	#include "params/TlmToGem5Bridge64.hh"
	#include "sim/core.hh"
	#include "sim/system.hh"
	#include "systemc/ext/core/sc_module_name.hh"
	#include "systemc/ext/core/sc_time.hh"

	using namespace gem5;

	namespace sc_gem5
	{

	namespace
	{
	/**
	* Hold all the callbacks necessary to convert a tlm payload to gem5 packet.
	*/
	std::vector<PayloadToPacketConversionStep> extraPayloadToPacketSteps;
	} // namespace

	/**
	* Notify the Tlm2Gem5 bridge that we need an extra step to properly convert a
	* tlm payload to gem5 packet. This can be useful when there exists a SystemC
	* extension that carries extra information. For example, SystemC user might
	* define an extension to store stream_id, the user may then add an extra step
	* to set the generated request's stream_id accordingly. Steps should be
	* idempotent.
	*/
	void
	addPayloadToPacketConversionStep(PayloadToPacketConversionStep step)
	{
	extraPayloadToPacketSteps.push_back(std::move(step));
	}

	/**
	* Convert a TLM payload to gem5 packet by copying all the relevant information
	* to new packet. If the transaction is initiated by gem5 model, we would use
	* the original packet.
	* The first return value is the packet pointer.
	* The second return value is if the packet is newly created.
	*/
	std::pair<PacketPtr, bool>
	payload2packet(RequestorID _id, tlm::tlm_generic_payload &trans)
	{
	Gem5SystemC::Gem5Extension *extension = nullptr;
	trans.get_extension(extension);

	// If there is an extension, this transaction was initiated by the gem5
	// world and we can pipe through the original packet. Otherwise, we
	// generate a new packet based on the transaction.
	if (extension != nullptr) {
	auto pkt = extension->getPacket();
	// Sync the address which could have changed.
	pkt->setAddr(trans.get_address());
	// Apply all conversion steps necessary in this specific setup.
	for (auto &step : extraPayloadToPacketSteps) {
	step(pkt, trans);
	}
	return std::make_pair(pkt, false);
	}

	MemCmd cmd;
	RequestPtr req;

	Gem5SystemC::AtomicExtension *atomic_ex = nullptr;
	trans.get_extension(atomic_ex);
	if (atomic_ex) {
	cmd = MemCmd::SwapReq;
	Request::Flags flags = (atomic_ex->isReturnRequired() ?
	Request::ATOMIC_RETURN_OP :
	Request::ATOMIC_NO_RETURN_OP);
	AtomicOpFunctorPtr amo_op = AtomicOpFunctorPtr(
	atomic_ex->getAtomicOpFunctor()->clone());
	// FIXME: correct the context_id and pc state.
	req = std::make_shared<Request>(
	trans.get_address(), trans.get_data_length(), flags, _id,
	0, 0, std::move(amo_op));
	req->setPaddr(trans.get_address());
	} else {
	switch (trans.get_command()) {
	case tlm::TLM_READ_COMMAND:
	cmd = MemCmd::ReadReq;
	break;
	case tlm::TLM_WRITE_COMMAND:
	cmd = MemCmd::WriteReq;
	break;
	case tlm::TLM_IGNORE_COMMAND:
	return std::make_pair(nullptr, false);
	default:
	SC_REPORT_FATAL("TlmToGem5Bridge",
	"received transaction with unsupported "
	"command");
	}
	Request::Flags flags;
	req = std::make_shared<Request>(
	trans.get_address(), trans.get_data_length(), flags, _id);
	}


	/*
	* Allocate a new Packet. The packet will be deleted when it returns from
	* the gem5 world as a response.
	*/
	auto pkt = new Packet(req, cmd);
	pkt->dataStatic(trans.get_data_ptr());

	// Apply all conversion steps necessary in this specific setup.
	for (auto &step : extraPayloadToPacketSteps) {
	step(pkt, trans);
	}

	return std::make_pair(pkt, true);
	}

	template <unsigned int BITWIDTH>
	void
	TlmToGem5Bridge<BITWIDTH>::sendEndReq(tlm::tlm_generic_payload &trans)
	{
	tlm::tlm_phase phase = tlm::END_REQ;
	auto delay = sc_core::SC_ZERO_TIME;

	auto status = socket->nb_transport_bw(trans, phase, delay);
	panic_if(status != tlm::TLM_ACCEPTED,
	"Unexpected status after sending END_REQ");
	}

	template <unsigned int BITWIDTH>
	void
	TlmToGem5Bridge<BITWIDTH>::sendBeginResp(tlm::tlm_generic_payload &trans,
	sc_core::sc_time &delay)
	{
	tlm::tlm_phase phase = tlm::BEGIN_RESP;

	trans.set_response_status(tlm::TLM_OK_RESPONSE);

	auto status = socket->nb_transport_bw(trans, phase, delay);

	if (status == tlm::TLM_COMPLETED \|\|
	(status == tlm::TLM_UPDATED && phase == tlm::END_RESP)) {
	// transaction completed -> no need to wait for tlm::END_RESP
	responseInProgress = false;
	} else if (status == tlm::TLM_ACCEPTED) {
	// we need to wait for tlm::END_RESP
	responseInProgress = true;
	} else {
	panic("Unexpected status after sending BEGIN_RESP");
	}
	}

	template <unsigned int BITWIDTH>
	void
	TlmToGem5Bridge<BITWIDTH>::handleBeginReq(tlm::tlm_generic_payload &trans)
	{
	sc_assert(!waitForRetry);
	sc_assert(pendingRequest == nullptr);
	sc_assert(pendingPacket == nullptr);

	trans.acquire();

	auto res = payload2packet(_id, trans);
	auto pkt = res.first;
	pkt->pushSenderState(new Gem5SystemC::TlmSenderState(trans));

	// If the packet doesn't need a response, we should send BEGIN_RESP by
	// ourselves.
	bool needsResponse = pkt->needsResponse();
	if (bmp.sendTimingReq(pkt)) { // port is free -> send END_REQ immediately
	sendEndReq(trans);
	if (!needsResponse) {
	auto delay = sc_core::SC_ZERO_TIME;
	sendBeginResp(trans, delay);
	}
	trans.release();
	} else { // port is blocked -> wait for retry before sending END_REQ
	waitForRetry = true;
	pendingRequest = &trans;
	pendingPacket = pkt;
	}
	}

	template <unsigned int BITWIDTH>
	void
	TlmToGem5Bridge<BITWIDTH>::handleEndResp(tlm::tlm_generic_payload &trans)
	{
	sc_assert(responseInProgress);

	responseInProgress = false;

	checkTransaction(trans);

	if (needToSendRetry) {
	bmp.sendRetryResp();
	needToSendRetry = false;
	}
	}

	template <unsigned int BITWIDTH>
	void
	TlmToGem5Bridge<BITWIDTH>::destroyPacket(PacketPtr pkt)
	{
	delete pkt;
	}

	template <unsigned int BITWIDTH>
	void
	TlmToGem5Bridge<BITWIDTH>::checkTransaction(tlm::tlm_generic_payload &trans)
	{
	if (trans.is_response_error()) {
	std::stringstream ss;
	ss << "Transaction returned with error, response status = "
	<< trans.get_response_string();
	SC_REPORT_ERROR("TLM-2", ss.str().c_str());
	}
	}

	template <unsigned int BITWIDTH>
	void
	TlmToGem5Bridge<BITWIDTH>::invalidateDmi(const gem5::MemBackdoor &backdoor)
	{
	socket->invalidate_direct_mem_ptr(
	backdoor.range().start(), backdoor.range().end());
	requestedBackdoors.erase(const_cast<gem5::MemBackdoorPtr>(&backdoor));
	}

	template <unsigned int BITWIDTH>
	void
	TlmToGem5Bridge<BITWIDTH>::peq_cb(tlm::tlm_generic_payload &trans,
	const tlm::tlm_phase &phase)
	{
	switch (phase) {
	case tlm::BEGIN_REQ:
	handleBeginReq(trans);
	break;
	case tlm::END_RESP:
	handleEndResp(trans);
	break;
	default:
	panic("unimplemented phase in callback");
	}
	}

	template <unsigned int BITWIDTH>
	tlm::tlm_sync_enum
	TlmToGem5Bridge<BITWIDTH>::nb_transport_fw(
	tlm::tlm_generic_payload &trans, tlm::tlm_phase &phase,
	sc_core::sc_time &delay)
	{
	unsigned len = trans.get_data_length();
	unsigned char *byteEnable = trans.get_byte_enable_ptr();
	unsigned width = trans.get_streaming_width();

	// check the transaction attributes for unsupported features ...
	if (byteEnable != 0) {
	trans.set_response_status(tlm::TLM_BYTE_ENABLE_ERROR_RESPONSE);
	return tlm::TLM_COMPLETED;
	}
	if (width < len) { // is this a burst request?
	trans.set_response_status(tlm::TLM_BURST_ERROR_RESPONSE);
	return tlm::TLM_COMPLETED;
	}

	// ... and queue the valid transaction
	trans.acquire();
	peq.notify(trans, phase, delay);
	return tlm::TLM_ACCEPTED;
	}

	template <unsigned int BITWIDTH>
	void
	TlmToGem5Bridge<BITWIDTH>::b_transport(tlm::tlm_generic_payload &trans,
	sc_core::sc_time &t)
	{
	auto [pkt, pkt_created] = payload2packet(_id, trans);
	pkt->pushSenderState(new Gem5SystemC::TlmSenderState(trans));

	MemBackdoorPtr backdoor = nullptr;
	Tick ticks = bmp.sendAtomicBackdoor(pkt, backdoor);
	if (backdoor)
	trans.set_dmi_allowed(true);

	// send an atomic request to gem5
	panic_if(pkt->needsResponse() && !pkt->isResponse(),
	"Packet sending failed!\n");

	auto delay =
	sc_core::sc_time((double)(ticks / sim_clock::as_int::ps),
	sc_core::SC_PS);

	// update time
	t += delay;

	gem5::Packet::SenderState *senderState = pkt->popSenderState();
	sc_assert(
	nullptr != dynamic_cast<Gem5SystemC::TlmSenderState*>(senderState));

	// clean up
	delete senderState;

	if (pkt_created)
	destroyPacket(pkt);

	trans.set_response_status(tlm::TLM_OK_RESPONSE);
	}

	template <unsigned int BITWIDTH>
	unsigned int
	TlmToGem5Bridge<BITWIDTH>::transport_dbg(tlm::tlm_generic_payload &trans)
	{
	auto [pkt, pkt_created] = payload2packet(_id, trans);
	if (pkt != nullptr) {
	pkt->pushSenderState(new Gem5SystemC::TlmSenderState(trans));

	bmp.sendFunctional(pkt);

	gem5::Packet::SenderState *senderState = pkt->popSenderState();
	sc_assert(
	nullptr != dynamic_cast<Gem5SystemC::TlmSenderState*>(senderState));

	// clean up
	delete senderState;

	if (pkt_created)
	destroyPacket(pkt);
	}

	return trans.get_data_length();
	}

	template <unsigned int BITWIDTH>
	bool
	TlmToGem5Bridge<BITWIDTH>::get_direct_mem_ptr(tlm::tlm_generic_payload &trans,
	tlm::tlm_dmi &dmi_data)
	{
	auto [pkt, pkt_created] = payload2packet(_id, trans);
	pkt->pushSenderState(new Gem5SystemC::TlmSenderState(trans));
	if (pkt_created)
	pkt->req->setFlags(Request::NO_ACCESS);

	MemBackdoorPtr backdoor = nullptr;
	bmp.sendAtomicBackdoor(pkt, backdoor);
	if (backdoor) {
	trans.set_dmi_allowed(true);
	dmi_data.set_dmi_ptr(backdoor->ptr());
	dmi_data.set_start_address(backdoor->range().start());
	dmi_data.set_end_address(backdoor->range().end());

	typedef tlm::tlm_dmi::dmi_access_e access_t;
	access_t access = tlm::tlm_dmi::DMI_ACCESS_NONE;
	if (backdoor->readable())
	access = (access_t)(access \| tlm::tlm_dmi::DMI_ACCESS_READ);
	if (backdoor->writeable())
	access = (access_t)(access \| tlm::tlm_dmi::DMI_ACCESS_WRITE);
	dmi_data.set_granted_access(access);

	// We only need to register the callback at the first time.
	if (requestedBackdoors.find(backdoor) == requestedBackdoors.end()) {
	backdoor->addInvalidationCallback(
	[this](const MemBackdoor &backdoor)
	{
	invalidateDmi(backdoor);
	}
	);
	requestedBackdoors.emplace(backdoor);
	}
	}

	gem5::Packet::SenderState *senderState = pkt->popSenderState();
	sc_assert(
	nullptr != dynamic_cast<Gem5SystemC::TlmSenderState*>(senderState));

	// clean up
	delete senderState;

	if (pkt_created)
	destroyPacket(pkt);

	trans.set_response_status(tlm::TLM_OK_RESPONSE);

	return backdoor != nullptr;
	}

	template <unsigned int BITWIDTH>
	bool
	TlmToGem5Bridge<BITWIDTH>::recvTimingResp(PacketPtr pkt)
	{
	// exclusion rule
	// We need to Wait for END_RESP before sending next BEGIN_RESP
	if (responseInProgress) {
	sc_assert(!needToSendRetry);
	needToSendRetry = true;
	return false;
	}

	sc_assert(pkt->isResponse());

	/*
	* Pay for annotated transport delays.
	*
	* See recvTimingReq in sc_slave_port.cc for a detailed description.
	*/
	auto delay = sc_core::sc_time::from_value(pkt->payloadDelay);
	// reset the delays
	pkt->payloadDelay = 0;
	pkt->headerDelay = 0;

	auto *tlmSenderState =
	dynamic_cast<Gem5SystemC::TlmSenderState*>(pkt->popSenderState());
	sc_assert(tlmSenderState != nullptr);

	auto &trans = tlmSenderState->trans;

	Gem5SystemC::Gem5Extension *extension = nullptr;
	trans.get_extension(extension);

	// clean up
	delete tlmSenderState;

	// If there is an extension the packet was piped through and we must not
	// delete it. The packet travels back with the transaction.
	if (extension == nullptr)
	destroyPacket(pkt);

	sendBeginResp(trans, delay);
	trans.release();

	return true;
	}

	template <unsigned int BITWIDTH>
	void
	TlmToGem5Bridge<BITWIDTH>::recvReqRetry()
	{
	sc_assert(waitForRetry);
	sc_assert(pendingRequest != nullptr);
	sc_assert(pendingPacket != nullptr);

	// If the packet doesn't need a response, we should send BEGIN_RESP by
	// ourselves.
	bool needsResponse = pendingPacket->needsResponse();
	if (bmp.sendTimingReq(pendingPacket)) {
	waitForRetry = false;
	pendingPacket = nullptr;

	auto &trans = *pendingRequest;
	sendEndReq(trans);
	if (!needsResponse) {
	auto delay = sc_core::SC_ZERO_TIME;
	sendBeginResp(trans, delay);
	}
	trans.release();

	pendingRequest = nullptr;
	}
	}

	template <unsigned int BITWIDTH>
	void
	TlmToGem5Bridge<BITWIDTH>::recvRangeChange()
	{
	DPRINTF(TlmBridge,
	"received address range change but ignored it");
	}

	template <unsigned int BITWIDTH>
	gem5::Port &
	TlmToGem5Bridge<BITWIDTH>::gem5_getPort(const std::string &if_name, int idx)
	{
	if (if_name == "gem5")
	return bmp;
	else if (if_name == "tlm")
	return wrapper;

	return sc_core::sc_module::gem5_getPort(if_name, idx);
	}

	template <unsigned int BITWIDTH>
	TlmToGem5Bridge<BITWIDTH>::TlmToGem5Bridge(
	const Params &params, const sc_core::sc_module_name &mn) :
	TlmToGem5BridgeBase(mn), peq(this, &TlmToGem5Bridge<BITWIDTH>::peq_cb),
	waitForRetry(false), pendingRequest(nullptr), pendingPacket(nullptr),
	needToSendRetry(false), responseInProgress(false),
	bmp(std::string(name()) + "master", *this), socket("tlm_socket"),
	wrapper(socket, std::string(name()) + ".tlm", InvalidPortID),
	system(params.system),
	_id(params.system->getGlobalRequestorId(
	std::string("[systemc].") + name()))
	{
	}

	template <unsigned int BITWIDTH>
	void
	TlmToGem5Bridge<BITWIDTH>::before_end_of_elaboration()
	{
	/*
	* Register the TLM non-blocking interface when using gem5 Timing mode and
	* the TLM blocking interface when using the gem5 Atomic mode.
	* Then the magic (TM) in simple_target_socket automatically transforms
	* non-blocking in blocking transactions and vice versa.
	*
	* NOTE: The mode may change during execution.
	*/
	if (system->isTimingMode()) {
	DPRINTF(TlmBridge, "register non-blocking interface");
	socket.register_nb_transport_fw(
	this, &TlmToGem5Bridge<BITWIDTH>::nb_transport_fw);
	} else if (system->isAtomicMode()) {
	DPRINTF(TlmBridge, "register blocking interface");
	socket.register_b_transport(
	this, &TlmToGem5Bridge<BITWIDTH>::b_transport);
	socket.register_get_direct_mem_ptr(
	this, &TlmToGem5Bridge<BITWIDTH>::get_direct_mem_ptr);
	} else {
	panic("gem5 operates neither in Timing nor in Atomic mode");
	}

	socket.register_transport_dbg(
	this, &TlmToGem5Bridge<BITWIDTH>::transport_dbg);

	sc_core::sc_module::before_end_of_elaboration();
	}

	} // namespace sc_gem5

	sc_gem5::TlmToGem5Bridge<32> *
	gem5::TlmToGem5Bridge32Params::create() const
	{
	return new sc_gem5::TlmToGem5Bridge<32>(
	*this, sc_core::sc_module_name(name.c_str()));
	}

	sc_gem5::TlmToGem5Bridge<64> *
	gem5::TlmToGem5Bridge64Params::create() const
	{
	return new sc_gem5::TlmToGem5Bridge<64>(
	*this, sc_core::sc_module_name(name.c_str()));
	}

	sc_gem5::TlmToGem5Bridge<128> *
	gem5::TlmToGem5Bridge128Params::create() const
	{
	return new sc_gem5::TlmToGem5Bridge<128>(
	*this, sc_core::sc_module_name(name.c_str()));
	}

	sc_gem5::TlmToGem5Bridge<256> *
	gem5::TlmToGem5Bridge256Params::create() const
	{
	return new sc_gem5::TlmToGem5Bridge<256>(
	*this, sc_core::sc_module_name(name.c_str()));
	}

	sc_gem5::TlmToGem5Bridge<512> *
	gem5::TlmToGem5Bridge512Params::create() const
	{
	return new sc_gem5::TlmToGem5Bridge<512>(
	*this, sc_core::sc_module_name(name.c_str()));
	}