util/tlm/src/sc_slave_port.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2015, University of Kaiserslautern
  * 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 "sc_ext.hh"
 #include "sc_mm.hh"
 #include "sc_slave_port.hh"
 #include "slave_transactor.hh"

 namespace Gem5SystemC
 {

 /**
  * Instantiate a tlm memory manager that takes care about all the
  * tlm transactions in the system
  */
 MemoryManager mm;

 /**
  * Convert a gem5 packet to a TLM payload by copying all the relevant
  * information to a previously allocated tlm payload
  */
 void
 packet2payload(gem5::PacketPtr packet, tlm::tlm_generic_payload &trans)
 {
     trans.set_address(packet->getAddr());

     /* Check if this transaction was allocated by mm */
     sc_assert(trans.has_mm());

     unsigned int size = packet->getSize();
     unsigned char *data = packet->getPtr<unsigned char>();

     trans.set_data_length(size);
     trans.set_streaming_width(size);
     trans.set_data_ptr(data);

     if (packet->isRead()) {
         trans.set_command(tlm::TLM_READ_COMMAND);
     }
     else if (packet->isInvalidate()) {
         /* Do nothing */
     } else if (packet->isWrite()) {
         trans.set_command(tlm::TLM_WRITE_COMMAND);
     } else {
         SC_REPORT_FATAL("SCSlavePort", "No R/W packet");
     }
 }

 /**
  * Similar to TLM's blocking transport (LT)
  */
 gem5::Tick
 SCSlavePort::recvAtomic(gem5::PacketPtr packet)
 {
     CAUGHT_UP;
     SC_REPORT_INFO("SCSlavePort", "recvAtomic hasn't been tested much");

     panic_if(packet->cacheResponding(), "Should not see packets where cache "
              "is responding");

     panic_if(!(packet->isRead() || packet->isWrite()),
              "Should only see read and writes at TLM memory\n");


     sc_core::sc_time delay = sc_core::SC_ZERO_TIME;


     /* Prepare the transaction */
     tlm::tlm_generic_payload * trans = mm.allocate();
     trans->acquire();
     packet2payload(packet, *trans);

     /* Attach the packet pointer to the TLM transaction to keep track */
     Gem5Extension* extension = new Gem5Extension(packet);
     trans->set_auto_extension(extension);

     /* Execute b_transport: */
     if (packet->cmd == gem5::MemCmd::SwapReq) {
         SC_REPORT_FATAL("SCSlavePort", "SwapReq not supported");
     } else if (packet->isRead()) {
         transactor->socket->b_transport(*trans, delay);
     } else if (packet->isInvalidate()) {
         // do nothing
     } else if (packet->isWrite()) {
         transactor->socket->b_transport(*trans, delay);
     } else {
         SC_REPORT_FATAL("SCSlavePort", "Typo of request not supported");
     }

     if (packet->needsResponse()) {
         packet->makeResponse();
     }

     trans->release();

     return delay.value();
 }

 /**
  * Similar to TLM's debug transport
  */
 void
 SCSlavePort::recvFunctional(gem5::PacketPtr packet)
 {
     /* Prepare the transaction */
     tlm::tlm_generic_payload * trans = mm.allocate();
     trans->acquire();
     packet2payload(packet, *trans);

     /* Attach the packet pointer to the TLM transaction to keep track */
     Gem5Extension* extension = new Gem5Extension(packet);
     trans->set_auto_extension(extension);

     /* Execute Debug Transport: */
     unsigned int bytes = transactor->socket->transport_dbg(*trans);
     if (bytes != trans->get_data_length()) {
         SC_REPORT_FATAL("SCSlavePort","debug transport was not completed");
     }

     trans->release();
 }

 bool
 SCSlavePort::recvTimingSnoopResp(gem5::PacketPtr packet)
 {
     /* Snooping should be implemented with tlm_dbg_transport */
     SC_REPORT_FATAL("SCSlavePort","unimplemented func.: recvTimingSnoopResp");
     return false;
 }

 void
 SCSlavePort::recvFunctionalSnoop(gem5::PacketPtr packet)
 {
     /* Snooping should be implemented with tlm_dbg_transport */
     SC_REPORT_FATAL("SCSlavePort","unimplemented func.: recvFunctionalSnoop");
 }

 /**
  *  Similar to TLM's non-blocking transport (AT)
  */
 bool
 SCSlavePort::recvTimingReq(gem5::PacketPtr packet)
 {
     CAUGHT_UP;

     panic_if(packet->cacheResponding(), "Should not see packets where cache "
              "is responding");

     panic_if(!(packet->isRead() || packet->isWrite()),
              "Should only see read and writes at TLM memory\n");


     /* We should never get a second request after noting that a retry is
      * required */
     sc_assert(!needToSendRequestRetry);

     /* Remember if a request comes in while we're blocked so that a retry
      * can be sent to gem5 */
     if (blockingRequest) {
         needToSendRequestRetry = true;
         return false;
     }

     /*  NOTE: normal tlm is blocking here. But in our case we return false
      *  and tell gem5 when a retry can be done. This is the main difference
      *  in the protocol:
      *  if (requestInProgress)
      *  {
      *      wait(endRequestEvent);
      *  }
      *  requestInProgress = trans;
     */

     /* Prepare the transaction */
     tlm::tlm_generic_payload * trans = mm.allocate();
     trans->acquire();
     packet2payload(packet, *trans);

     /* Attach the packet pointer to the TLM transaction to keep track */
     Gem5Extension* extension = new Gem5Extension(packet);
     trans->set_auto_extension(extension);

     /*
      * Pay for annotated transport delays.
      *
      * The header delay marks the point in time, when the packet first is seen
      * by the transactor. This is the point int time, when the transactor needs
      * to send the BEGIN_REQ to the SystemC world.
      *
      * NOTE: We drop the payload delay here. Normally, the receiver would be
      *       responsible for handling the payload delay. In this case, however,
      *       the receiver is a SystemC module and has no notion of the gem5
      *       transport protocol and we cannot simply forward the
      *       payload delay to the receiving module. Instead, we expect the
      *       receiving SystemC module to model the payload delay by deferring
      *       the END_REQ. This could lead to incorrect delays, if the XBar
      *       payload delay is longer than the time the receiver needs to accept
      *       the request (time between BEGIN_REQ and END_REQ).
      *
      * TODO: We could detect the case described above by remembering the
      *       payload delay and comparing it to the time between BEGIN_REQ and
      *       END_REQ. Then, a warning should be printed.
      */
     auto delay = sc_core::sc_time::from_value(packet->payloadDelay);
     // reset the delays
     packet->payloadDelay = 0;
     packet->headerDelay = 0;

     /* Starting TLM non-blocking sequence (AT) Refer to IEEE1666-2011 SystemC
      * Standard Page 507 for a visualisation of the procedure */
     tlm::tlm_phase phase = tlm::BEGIN_REQ;
     tlm::tlm_sync_enum status;
     status = transactor->socket->nb_transport_fw(*trans, phase, delay);
     /* Check returned value: */
     if (status == tlm::TLM_ACCEPTED) {
         sc_assert(phase == tlm::BEGIN_REQ);
         /* Accepted but is now blocking until END_REQ (exclusion rule)*/
         blockingRequest = trans;
     } else if (status == tlm::TLM_UPDATED) {
         /* The Timing annotation must be honored: */
         sc_assert(phase == tlm::END_REQ || phase == tlm::BEGIN_RESP);

         PayloadEvent<SCSlavePort> * pe;
         pe = new PayloadEvent<SCSlavePort>(*this,
             &SCSlavePort::pec, "PEQ");
         pe->notify(*trans, phase, delay);
     } else if (status == tlm::TLM_COMPLETED) {
         /* Transaction is over nothing has do be done. */
         sc_assert(phase == tlm::END_RESP);
         trans->release();
     }

     return true;
 }

 void
 SCSlavePort::pec(
     PayloadEvent<SCSlavePort> * pe,
     tlm::tlm_generic_payload& trans,
     const tlm::tlm_phase& phase)
 {
     sc_time delay;

     if (phase == tlm::END_REQ ||
             &trans == blockingRequest && phase == tlm::BEGIN_RESP) {
         sc_assert(&trans == blockingRequest);
         blockingRequest = NULL;

         /* Did another request arrive while blocked, schedule a retry */
         if (needToSendRequestRetry) {
             needToSendRequestRetry = false;
             sendRetryReq();
         }
     }
     if (phase == tlm::BEGIN_RESP)
     {
         CAUGHT_UP;

         auto& extension = Gem5Extension::getExtension(trans);
         auto packet = extension.getPacket();

         sc_assert(!blockingResponse);

         bool need_retry = false;

         // If there is another gem5 model under the receiver side, and already
         // make a response packet back, we can simply send it back. Otherwise,
         // we make a response packet before sending it back to the initiator
         // side gem5 module.
         if (packet->needsResponse()) {
             packet->makeResponse();
         }
         if (packet->isResponse()) {
             need_retry = !sendTimingResp(packet);
         }

         if (need_retry) {
             blockingResponse = &trans;
         } else {
             if (phase == tlm::BEGIN_RESP) {
                 /* Send END_RESP and we're finished: */
                 tlm::tlm_phase fw_phase = tlm::END_RESP;
                 sc_time delay = SC_ZERO_TIME;
                 transactor->socket->nb_transport_fw(trans, fw_phase, delay);
                 /* Release the transaction with all the extensions */
                 trans.release();
             }
         }
     }
     delete pe;
 }

 void
 SCSlavePort::recvRespRetry()
 {
     CAUGHT_UP;

     /* Retry a response */
     sc_assert(blockingResponse);

     tlm::tlm_generic_payload *trans = blockingResponse;
     blockingResponse = NULL;
     gem5::PacketPtr packet = Gem5Extension::getExtension(trans).getPacket();

     bool need_retry = !sendTimingResp(packet);

     sc_assert(!need_retry);

     sc_core::sc_time delay = sc_core::SC_ZERO_TIME;
     tlm::tlm_phase phase = tlm::END_RESP;
     transactor->socket->nb_transport_fw(*trans, phase, delay);
     // Release transaction with all the extensions
     trans->release();
 }

 tlm::tlm_sync_enum
 SCSlavePort::nb_transport_bw(tlm::tlm_generic_payload& trans,
     tlm::tlm_phase& phase,
     sc_core::sc_time& delay)
 {
     PayloadEvent<SCSlavePort> * pe;
     pe = new PayloadEvent<SCSlavePort>(*this, &SCSlavePort::pec, "PE");
     pe->notify(trans, phase, delay);
     return tlm::TLM_ACCEPTED;
 }

 SCSlavePort::SCSlavePort(const std::string &name_,
     const std::string &systemc_name,
     gem5::ExternalSlave &owner_) :
     gem5::ExternalSlave::ExternalPort(name_, owner_),
     blockingRequest(NULL),
     needToSendRequestRetry(false),
     blockingResponse(NULL),
     transactor(nullptr)
 {
 }

 void
 SCSlavePort::bindToTransactor(Gem5SlaveTransactor* transactor)
 {
     sc_assert(this->transactor == nullptr);

     this->transactor = transactor;

     transactor->socket.register_nb_transport_bw(this,
                                                 &SCSlavePort::nb_transport_bw);
 }

 gem5::ExternalSlave::ExternalPort*
 SCSlavePortHandler::getExternalPort(const std::string &name,
                                     gem5::ExternalSlave &owner,
                                     const std::string &port_data)
 {
     // Create and register a new SystemC slave port
     auto* port = new SCSlavePort(name, port_data, owner);

     control.registerSlavePort(port_data, port);

     return port;
 }

 }
	/*
	* Copyright (c) 2015, University of Kaiserslautern
	* 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 "sc_ext.hh"
	#include "sc_mm.hh"
	#include "sc_slave_port.hh"
	#include "slave_transactor.hh"

	namespace Gem5SystemC
	{

	/**
	* Instantiate a tlm memory manager that takes care about all the
	* tlm transactions in the system
	*/
	MemoryManager mm;

	/**
	* Convert a gem5 packet to a TLM payload by copying all the relevant
	* information to a previously allocated tlm payload
	*/
	void
	packet2payload(gem5::PacketPtr packet, tlm::tlm_generic_payload &trans)
	{
	trans.set_address(packet->getAddr());

	/* Check if this transaction was allocated by mm */
	sc_assert(trans.has_mm());

	unsigned int size = packet->getSize();
	unsigned char *data = packet->getPtr<unsigned char>();

	trans.set_data_length(size);
	trans.set_streaming_width(size);
	trans.set_data_ptr(data);

	if (packet->isRead()) {
	trans.set_command(tlm::TLM_READ_COMMAND);
	}
	else if (packet->isInvalidate()) {
	/* Do nothing */
	} else if (packet->isWrite()) {
	trans.set_command(tlm::TLM_WRITE_COMMAND);
	} else {
	SC_REPORT_FATAL("SCSlavePort", "No R/W packet");
	}
	}

	/**
	* Similar to TLM's blocking transport (LT)
	*/
	gem5::Tick
	SCSlavePort::recvAtomic(gem5::PacketPtr packet)
	{
	CAUGHT_UP;
	SC_REPORT_INFO("SCSlavePort", "recvAtomic hasn't been tested much");

	panic_if(packet->cacheResponding(), "Should not see packets where cache "
	"is responding");

	panic_if(!(packet->isRead() \|\| packet->isWrite()),
	"Should only see read and writes at TLM memory\n");


	sc_core::sc_time delay = sc_core::SC_ZERO_TIME;


	/* Prepare the transaction */
	tlm::tlm_generic_payload * trans = mm.allocate();
	trans->acquire();
	packet2payload(packet, *trans);

	/* Attach the packet pointer to the TLM transaction to keep track */
	Gem5Extension* extension = new Gem5Extension(packet);
	trans->set_auto_extension(extension);

	/* Execute b_transport: */
	if (packet->cmd == gem5::MemCmd::SwapReq) {
	SC_REPORT_FATAL("SCSlavePort", "SwapReq not supported");
	} else if (packet->isRead()) {
	transactor->socket->b_transport(*trans, delay);
	} else if (packet->isInvalidate()) {
	// do nothing
	} else if (packet->isWrite()) {
	transactor->socket->b_transport(*trans, delay);
	} else {
	SC_REPORT_FATAL("SCSlavePort", "Typo of request not supported");
	}

	if (packet->needsResponse()) {
	packet->makeResponse();
	}

	trans->release();

	return delay.value();
	}

	/**
	* Similar to TLM's debug transport
	*/
	void
	SCSlavePort::recvFunctional(gem5::PacketPtr packet)
	{
	/* Prepare the transaction */
	tlm::tlm_generic_payload * trans = mm.allocate();
	trans->acquire();
	packet2payload(packet, *trans);

	/* Attach the packet pointer to the TLM transaction to keep track */
	Gem5Extension* extension = new Gem5Extension(packet);
	trans->set_auto_extension(extension);

	/* Execute Debug Transport: */
	unsigned int bytes = transactor->socket->transport_dbg(*trans);
	if (bytes != trans->get_data_length()) {
	SC_REPORT_FATAL("SCSlavePort","debug transport was not completed");
	}

	trans->release();
	}

	bool
	SCSlavePort::recvTimingSnoopResp(gem5::PacketPtr packet)
	{
	/* Snooping should be implemented with tlm_dbg_transport */
	SC_REPORT_FATAL("SCSlavePort","unimplemented func.: recvTimingSnoopResp");
	return false;
	}

	void
	SCSlavePort::recvFunctionalSnoop(gem5::PacketPtr packet)
	{
	/* Snooping should be implemented with tlm_dbg_transport */
	SC_REPORT_FATAL("SCSlavePort","unimplemented func.: recvFunctionalSnoop");
	}

	/**
	* Similar to TLM's non-blocking transport (AT)
	*/
	bool
	SCSlavePort::recvTimingReq(gem5::PacketPtr packet)
	{
	CAUGHT_UP;

	panic_if(packet->cacheResponding(), "Should not see packets where cache "
	"is responding");

	panic_if(!(packet->isRead() \|\| packet->isWrite()),
	"Should only see read and writes at TLM memory\n");


	/* We should never get a second request after noting that a retry is
	* required */
	sc_assert(!needToSendRequestRetry);

	/* Remember if a request comes in while we're blocked so that a retry
	* can be sent to gem5 */
	if (blockingRequest) {
	needToSendRequestRetry = true;
	return false;
	}

	/* NOTE: normal tlm is blocking here. But in our case we return false
	* and tell gem5 when a retry can be done. This is the main difference
	* in the protocol:
	* if (requestInProgress)
	* {
	* wait(endRequestEvent);
	* }
	* requestInProgress = trans;
	*/

	/* Prepare the transaction */
	tlm::tlm_generic_payload * trans = mm.allocate();
	trans->acquire();
	packet2payload(packet, *trans);

	/* Attach the packet pointer to the TLM transaction to keep track */
	Gem5Extension* extension = new Gem5Extension(packet);
	trans->set_auto_extension(extension);

	/*
	* Pay for annotated transport delays.
	*
	* The header delay marks the point in time, when the packet first is seen
	* by the transactor. This is the point int time, when the transactor needs
	* to send the BEGIN_REQ to the SystemC world.
	*
	* NOTE: We drop the payload delay here. Normally, the receiver would be
	* responsible for handling the payload delay. In this case, however,
	* the receiver is a SystemC module and has no notion of the gem5
	* transport protocol and we cannot simply forward the
	* payload delay to the receiving module. Instead, we expect the
	* receiving SystemC module to model the payload delay by deferring
	* the END_REQ. This could lead to incorrect delays, if the XBar
	* payload delay is longer than the time the receiver needs to accept
	* the request (time between BEGIN_REQ and END_REQ).
	*
	* TODO: We could detect the case described above by remembering the
	* payload delay and comparing it to the time between BEGIN_REQ and
	* END_REQ. Then, a warning should be printed.
	*/
	auto delay = sc_core::sc_time::from_value(packet->payloadDelay);
	// reset the delays
	packet->payloadDelay = 0;
	packet->headerDelay = 0;

	/* Starting TLM non-blocking sequence (AT) Refer to IEEE1666-2011 SystemC
	* Standard Page 507 for a visualisation of the procedure */
	tlm::tlm_phase phase = tlm::BEGIN_REQ;
	tlm::tlm_sync_enum status;
	status = transactor->socket->nb_transport_fw(*trans, phase, delay);
	/* Check returned value: */
	if (status == tlm::TLM_ACCEPTED) {
	sc_assert(phase == tlm::BEGIN_REQ);
	/* Accepted but is now blocking until END_REQ (exclusion rule)*/
	blockingRequest = trans;
	} else if (status == tlm::TLM_UPDATED) {
	/* The Timing annotation must be honored: */
	sc_assert(phase == tlm::END_REQ \|\| phase == tlm::BEGIN_RESP);

	PayloadEvent<SCSlavePort> * pe;
	pe = new PayloadEvent<SCSlavePort>(*this,
	&SCSlavePort::pec, "PEQ");
	pe->notify(*trans, phase, delay);
	} else if (status == tlm::TLM_COMPLETED) {
	/* Transaction is over nothing has do be done. */
	sc_assert(phase == tlm::END_RESP);
	trans->release();
	}

	return true;
	}

	void
	SCSlavePort::pec(
	PayloadEvent<SCSlavePort> * pe,
	tlm::tlm_generic_payload& trans,
	const tlm::tlm_phase& phase)
	{
	sc_time delay;

	if (phase == tlm::END_REQ \|\|
	&trans == blockingRequest && phase == tlm::BEGIN_RESP) {
	sc_assert(&trans == blockingRequest);
	blockingRequest = NULL;

	/* Did another request arrive while blocked, schedule a retry */
	if (needToSendRequestRetry) {
	needToSendRequestRetry = false;
	sendRetryReq();
	}
	}
	if (phase == tlm::BEGIN_RESP)
	{
	CAUGHT_UP;

	auto& extension = Gem5Extension::getExtension(trans);
	auto packet = extension.getPacket();

	sc_assert(!blockingResponse);

	bool need_retry = false;

	// If there is another gem5 model under the receiver side, and already
	// make a response packet back, we can simply send it back. Otherwise,
	// we make a response packet before sending it back to the initiator
	// side gem5 module.
	if (packet->needsResponse()) {
	packet->makeResponse();
	}
	if (packet->isResponse()) {
	need_retry = !sendTimingResp(packet);
	}

	if (need_retry) {
	blockingResponse = &trans;
	} else {
	if (phase == tlm::BEGIN_RESP) {
	/* Send END_RESP and we're finished: */
	tlm::tlm_phase fw_phase = tlm::END_RESP;
	sc_time delay = SC_ZERO_TIME;
	transactor->socket->nb_transport_fw(trans, fw_phase, delay);
	/* Release the transaction with all the extensions */
	trans.release();
	}
	}
	}
	delete pe;
	}

	void
	SCSlavePort::recvRespRetry()
	{
	CAUGHT_UP;

	/* Retry a response */
	sc_assert(blockingResponse);

	tlm::tlm_generic_payload *trans = blockingResponse;
	blockingResponse = NULL;
	gem5::PacketPtr packet = Gem5Extension::getExtension(trans).getPacket();

	bool need_retry = !sendTimingResp(packet);

	sc_assert(!need_retry);

	sc_core::sc_time delay = sc_core::SC_ZERO_TIME;
	tlm::tlm_phase phase = tlm::END_RESP;
	transactor->socket->nb_transport_fw(*trans, phase, delay);
	// Release transaction with all the extensions
	trans->release();
	}

	tlm::tlm_sync_enum
	SCSlavePort::nb_transport_bw(tlm::tlm_generic_payload& trans,
	tlm::tlm_phase& phase,
	sc_core::sc_time& delay)
	{
	PayloadEvent<SCSlavePort> * pe;
	pe = new PayloadEvent<SCSlavePort>(*this, &SCSlavePort::pec, "PE");
	pe->notify(trans, phase, delay);
	return tlm::TLM_ACCEPTED;
	}

	SCSlavePort::SCSlavePort(const std::string &name_,
	const std::string &systemc_name,
	gem5::ExternalSlave &owner_) :
	gem5::ExternalSlave::ExternalPort(name_, owner_),
	blockingRequest(NULL),
	needToSendRequestRetry(false),
	blockingResponse(NULL),
	transactor(nullptr)
	{
	}

	void
	SCSlavePort::bindToTransactor(Gem5SlaveTransactor* transactor)
	{
	sc_assert(this->transactor == nullptr);

	this->transactor = transactor;

	transactor->socket.register_nb_transport_bw(this,
	&SCSlavePort::nb_transport_bw);
	}

	gem5::ExternalSlave::ExternalPort*
	SCSlavePortHandler::getExternalPort(const std::string &name,
	gem5::ExternalSlave &owner,
	const std::string &port_data)
	{
	// Create and register a new SystemC slave port
	auto* port = new SCSlavePort(name, port_data, owner);

	control.registerSlavePort(port_data, port);

	return port;
	}

	}