-/*
- * 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.
- *
- * Authors: Matthias Jung
- * Abdul Mutaal Ahmad
- * Christian Menard
- */
-
-#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(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)
- */
-Tick
-SCSlavePort::recvAtomic(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 == 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(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(PacketPtr packet)
-{
- /* Snooping should be implemented with tlm_dbg_transport */
- SC_REPORT_FATAL("SCSlavePort","unimplemented func.: recvTimingSnoopResp");
- return false;
-}
-
-void
-SCSlavePort::recvFunctionalSnoop(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(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 the packet was piped through and needs a response, we don't need
- * to touch the packet and can forward it directly as a response.
- * Otherwise, we need to make a response and send the transformed
- * packet.
- */
- if (extension.isPipeThrough()) {
- if (packet->isResponse()) {
- need_retry = !sendTimingResp(packet);
- }
- } else if (packet->needsResponse()) {
- packet->makeResponse();
- 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;
- 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,
- ExternalSlave &owner_) :
- ExternalSlave::Port(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);
-}
-
-ExternalSlave::Port*
-SCSlavePortHandler::getExternalPort(const std::string &name,
- 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;
-}
-
-}
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