gem5/util/tlm/sc_port.cc

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/*
* Copyright (c) 2015, University of Kaiserslautern
* 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
*/
#include <cctype>
#include <iomanip>
#include <sstream>
#include "debug/ExternalPort.hh"
#include "sc_ext.hh"
#include "sc_mm.hh"
#include "sc_port.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("transactor", "No R/W packet");
}
}
/**
* Similar to TLM's blocking transport (LT)
*/
Tick
sc_transactor::recvAtomic(PacketPtr packet)
{
CAUGHT_UP;
SC_REPORT_INFO("transactor", "recvAtomic hasn't been tested much");
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("transactor", "SwapReq not supported");
} else if (packet->isRead()) {
iSocket->b_transport(*trans, delay);
} else if (packet->isInvalidate()) {
// do nothing
} else if (packet->isWrite()) {
iSocket->b_transport(*trans, delay);
} else {
SC_REPORT_FATAL("transactor", "Typo of request not supported");
}
if (packet->needsResponse()) {
packet->makeResponse();
}
trans->release();
return delay.value();
}
/**
* Similar to TLM's debug transport
*/
void
sc_transactor::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 = iSocket->transport_dbg(*trans);
if (bytes != trans->get_data_length()) {
SC_REPORT_FATAL("transactor","debug transport was not completed");
}
trans->release();
}
bool
sc_transactor::recvTimingSnoopResp(PacketPtr packet)
{
/* Snooping should be implemented with tlm_dbg_transport */
SC_REPORT_FATAL("transactor","unimplemented func.: recvTimingSnoopResp");
return false;
}
void
sc_transactor::recvFunctionalSnoop(PacketPtr packet)
{
/* Snooping should be implemented with tlm_dbg_transport */
SC_REPORT_FATAL("transactor","unimplemented func.: recvFunctionalSnoop");
}
/**
* Similar to TLM's non-blocking transport (AT)
*/
bool
sc_transactor::recvTimingReq(PacketPtr packet)
{
CAUGHT_UP;
/* We should never get a second request after noting that a retry is
* required */
sc_assert(!needToSendRequestRetry);
// simply drop inhibited packets and clean evictions
if (packet->memInhibitAsserted() ||
packet->cmd == MemCmd::CleanEvict)
return true;
/* 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);
/* Starting TLM non-blocking sequence (AT) Refer to IEEE1666-2011 SystemC
* Standard Page 507 for a visualisation of the procedure */
sc_core::sc_time delay = sc_core::SC_ZERO_TIME;
tlm::tlm_phase phase = tlm::BEGIN_REQ;
tlm::tlm_sync_enum status;
status = iSocket->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<sc_transactor> * pe;
pe = new payloadEvent<sc_transactor>(*this,
&sc_transactor::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
sc_transactor::pec(
sc_transactor::payloadEvent<sc_transactor> * 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;
iSocket.sendRetryReq();
}
}
else if (phase == tlm::BEGIN_RESP)
{
CAUGHT_UP;
PacketPtr packet = gem5Extension::getExtension(trans).getPacket();
sc_assert(!blockingResponse);
bool need_retry;
if (packet->needsResponse()) {
packet->makeResponse();
need_retry = !iSocket.sendTimingResp(packet);
} else {
need_retry = false;
}
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;
iSocket->nb_transport_fw(trans, fw_phase, delay);
/* Release the transaction with all the extensions */
trans.release();
}
}
} else {
SC_REPORT_FATAL("transactor", "Invalid protocol phase in pec");
}
delete pe;
}
void
sc_transactor::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 = !iSocket.sendTimingResp(packet);
sc_assert(!need_retry);
sc_core::sc_time delay = sc_core::SC_ZERO_TIME;
tlm::tlm_phase phase = tlm::END_RESP;
iSocket->nb_transport_fw(*trans, phase, delay);
// Release transaction with all the extensions
trans->release();
}
tlm::tlm_sync_enum
sc_transactor::nb_transport_bw(tlm::tlm_generic_payload& trans,
tlm::tlm_phase& phase,
sc_core::sc_time& delay)
{
payloadEvent<sc_transactor> * pe;
pe = new payloadEvent<sc_transactor>(*this, &sc_transactor::pec, "PE");
pe->notify(trans, phase, delay);
return tlm::TLM_ACCEPTED;
}
void
sc_transactor::invalidate_direct_mem_ptr(sc_dt::uint64 start_range,
sc_dt::uint64 end_range)
{
SC_REPORT_FATAL("transactor", "unimpl. func: invalidate_direct_mem_ptr");
}
sc_transactor::sc_transactor(const std::string &name_,
const std::string &systemc_name,
ExternalSlave &owner_) :
tlm::tlm_initiator_socket<>(systemc_name.c_str()),
ExternalSlave::Port(name_, owner_),
iSocket(*this),
blockingRequest(NULL),
needToSendRequestRetry(false),
blockingResponse(NULL)
{
m_export.bind(*this);
}
class sc_transactorHandler : public ExternalSlave::Handler
{
public:
ExternalSlave::Port *getExternalPort(const std::string &name,
ExternalSlave &owner,
const std::string &port_data)
{
// This will make a new initiatiator port
return new sc_transactor(name, port_data, owner);
}
};
void
registerSCPorts()
{
ExternalSlave::registerHandler("tlm", new sc_transactorHandler);
}
}