gem5/ext/sst/ExtSlave.cc
Curtis Dunham f05cb84ed1 ext: Add SST connector
This patch adds a connector that allows gem5 to be used as a component
in SST (Structural Simulation Toolkit, sst-simulator.org). At a high
level, this allows memory traffic to pass between the two simulators.
SST Links are roughly analogous to gem5 Ports, although Links do not
have a notion of master and slave. This distinction is important to
gem5, so when connecting a gem5 CPU to an SST cache, an ExternalSlave
must be used, and similarly when connecting the memory side of SST cache
to a gem5 port (for memory <-> I/O), an ExternalMaster must be used.

These connectors handle the administrative aspects of gem5
(initialization, simulation, shutdown) as well as translating SST's
MemEvents into gem5 Packets and vice-versa.
2015-04-08 15:56:06 -05:00

203 lines
7.1 KiB
C++

// Copyright (c) 2015 ARM Limited
// All rights reserved.
//
// The license below extends only to copyright in the software and shall
// not be construed as granting a license to any other intellectual
// property including but not limited to intellectual property relating
// to a hardware implementation of the functionality of the software
// licensed hereunder. You may use the software subject to the license
// terms below provided that you ensure that this notice is replicated
// unmodified and in its entirety in all distributions of the software,
// modified or unmodified, in source code or in binary form.
//
// 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 2009-2014 Sandia Coporation. Under the terms
// of Contract DE-AC04-94AL85000 with Sandia Corporation, the U.S.
// Government retains certain rights in this software.
//
// Copyright (c) 2009-2014, Sandia Corporation
// All rights reserved.
//
// For license information, see the LICENSE file in the current directory.
#include "gem5.hh"
#include <sst_config.h>
#include <sst/core/serialization.h>
#include <sst/core/params.h>
#include <sst/core/output.h>
#include <sst/core/link.h>
#ifdef fatal // gem5 sets this
#undef fatal
#endif
using namespace SST;
using namespace SST::gem5;
using namespace SST::MemHierarchy;
ExtSlave::ExtSlave(gem5Component *g5c, Output &out,
::ExternalSlave& port, std::string &name) :
Port(name, port),
comp(g5c), out(out), simPhase(CONSTRUCTION), initPackets(NULL),
link(comp->configureLink(name, new Event::Handler<ExtSlave>(this,
&ExtSlave::handleEvent)))
{
if (!link) {
out.fatal(CALL_INFO, 1, "Failed to configure link %s\n", name.c_str());
}
}
void ExtSlave::init(unsigned phase)
{
simPhase = INIT;
if (initPackets) {
while (!initPackets->empty()) {
link->sendInitData(initPackets->front());
initPackets->pop_front();
}
delete initPackets;
initPackets = NULL;
}
}
void
ExtSlave::recvFunctional(PacketPtr pkt)
{
if (simPhase == CONSTRUCTION) {
if (initPackets == NULL) {
initPackets = new std::list<MemEvent*>;
}
::MemCmd::Command pktCmd = (::MemCmd::Command)pkt->cmd.toInt();
assert(pktCmd == ::MemCmd::WriteReq || pktCmd == ::MemCmd::Writeback);
Addr a = pkt->getAddr();
MemEvent* ev = new MemEvent(comp, a, a, GetX);
ev->setPayload(pkt->getSize(), pkt->getPtr<uint8_t>());
initPackets->push_back(ev);
} else {
panic("Functional accesses not allowed after construction phase");
}
}
bool
ExtSlave::recvTimingReq(PacketPtr pkt)
{
Command cmd;
switch ((::MemCmd::Command)pkt->cmd.toInt()) {
case ::MemCmd::HardPFReq:
case ::MemCmd::SoftPFReq:
case ::MemCmd::LoadLockedReq:
case ::MemCmd::ReadExReq:
case ::MemCmd::ReadReq: cmd = GetS; break;
case ::MemCmd::StoreCondReq:
case ::MemCmd::WriteReq: cmd = GetX; break;
default:
out.fatal(CALL_INFO, 1, "Don't know how to convert gem5 packet "
"command %s to SST\n", pkt->cmd.toString().c_str());
}
auto ev = new MemEvent(comp, pkt->getAddr(), pkt->getAddr(), cmd);
ev->setPayload(pkt->getSize(), pkt->getPtr<uint8_t>());
if ((::MemCmd::Command)pkt->cmd.toInt() == ::MemCmd::LoadLockedReq)
ev->setLoadLink();
else if ((::MemCmd::Command)pkt->cmd.toInt() == ::MemCmd::StoreCondReq)
ev->setStoreConditional();
if (pkt->req->isLocked()) ev->setFlag(MemEvent::F_LOCKED);
if (pkt->req->isUncacheable()) ev->setFlag(MemEvent::F_NONCACHEABLE);
if (pkt->req->hasContextId()) ev->setGroupId(pkt->req->contextId());
// Prefetches not working with SST; it maybe be dropping them, treating them
// as not deserving of responses, or something else -- not sure yet.
// ev->setPrefetchFlag(pkt->req->isPrefetch());
if (simPhase == INIT) {
link->sendInitData(ev);
delete pkt->req;
delete pkt;
} else {
if (pkt->needsResponse()) {
PacketMap[ev->getID()] = pkt;
}
link->send(ev);
}
return true;
}
void
ExtSlave::handleEvent(Event* ev)
{
MemEvent* event = dynamic_cast<MemEvent*>(ev);
if (!event) {
out.fatal(CALL_INFO, 1, "ExtSlave handleEvent received non-MemEvent\n");
delete ev;
return;
}
Event::id_type id = event->getID();
PacketMap_t::iterator mi = PacketMap.find(id);
if (mi != PacketMap.end()) { // replying to prior request
PacketPtr pkt = mi->second;
PacketMap.erase(mi);
pkt->makeResponse(); // Convert to a response packet
pkt->setData(event->getPayload().data());
// Resolve the success of Store Conditionals
if (pkt->isLLSC() && pkt->isWrite()) {
pkt->req->setExtraData(event->isAtomic());
}
// Clear out bus delay notifications
pkt->headerDelay = pkt->payloadDelay = 0;
if (blocked() || !sendTimingResp(pkt)) {
respQ.push_back(pkt);
}
} else { // we can handle unexpected invalidates, but nothing else.
Command cmd = event->getCmd();
assert(cmd == Inv);
// make Req/Pkt for Snoop/no response needed
// presently no consideration for masterId, packet type, flags...
RequestPtr req = new Request(event->getAddr(), event->getSize(), 0, 0);
auto pkt = new Packet(req, ::MemCmd::InvalidationReq);
// Clear out bus delay notifications
pkt->headerDelay = pkt->payloadDelay = 0;
sendTimingSnoopReq(pkt);
}
delete event;
}
void
ExtSlave::recvRespRetry()
{
while (blocked() && sendTimingResp(respQ.front())) {
respQ.pop_front();
}
}