port.cc

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#include "mem/port.hh"
 
#include "base/trace.hh"
#include "debug/PortTrace.hh"
#include "debug/ResponsePort.hh"
#include "sim/sim_object.hh"
 
namespace gem5
{
 
namespace
{
 
class DefaultRequestPort : public RequestPort
{
  protected:
    [[noreturn]] void
    blowUp() const
    {
        throw UnboundPortException();
    }
 
  public:
    DefaultRequestPort() : RequestPort("default_request_port") {}
 
    // Atomic protocol.
    Tick recvAtomicSnoop(PacketPtr) override { blowUp(); }
 
    // Timing protocol.
    bool recvTimingResp(PacketPtr) override { blowUp(); }
    void recvTimingSnoopReq(PacketPtr) override { blowUp(); }
    void recvReqRetry() override { blowUp(); }
    void recvRetrySnoopResp() override { blowUp(); }
 
    // Functional protocol.
    void recvFunctionalSnoop(PacketPtr) override { blowUp(); }
};
 
class DefaultResponsePort : public ResponsePort
{
  protected:
    [[noreturn]] void
    blowUp() const
    {
        throw UnboundPortException();
    }
 
  public:
    DefaultResponsePort() : ResponsePort("default_response_port") {}
 
    // Atomic protocol.
    Tick recvAtomic(PacketPtr) override { blowUp(); }
 
    // Timing protocol.
    bool recvTimingReq(PacketPtr) override { blowUp(); }
    bool tryTiming(PacketPtr) override { blowUp(); }
    bool recvTimingSnoopResp(PacketPtr) override { blowUp(); }
    void recvRespRetry() override { blowUp(); }
 
    // Functional protocol.
    void recvFunctional(PacketPtr) override { blowUp(); }
    void
    recvMemBackdoorReq(const MemBackdoorReq &, MemBackdoorPtr &) override
    {
        blowUp();
    }
 
    // General.
    AddrRangeList getAddrRanges() const override { return AddrRangeList(); }
};
 
DefaultRequestPort defaultRequestPort;
DefaultResponsePort defaultResponsePort;
 
} // anonymous namespace
 
[[deprecated]]
RequestPort::RequestPort(const std::string& name,
                         SimObject* _owner,
                         PortID _id):
    Port(name, _id), _responsePort(&defaultResponsePort), owner{*_owner}
{
}
 
/*** FIXME:
 * The owner reference member is going through a deprecation path. In the
 * meantime, it must be initialized but no valid reference is available here.
 * Using 1 instead of nullptr prevents warning upon dereference. It should be
 * OK until definitive removal of owner.
 */
RequestPort::RequestPort(const std::string& name, PortID _id) :
    Port(name, _id), _responsePort(&defaultResponsePort),
    owner{*reinterpret_cast<SimObject*>(1)}
{
}
 
RequestPort::~RequestPort()
{
}
 
void
RequestPort::bind(Port &peer)
{
    auto *response_port = dynamic_cast<ResponsePort *>(&peer);
    fatal_if(!response_port, "Can't bind port %s to non-response port %s.",
             name(), peer.name());
    // request port keeps track of the response port
    _responsePort = response_port;
    Port::bind(peer);
    // response port also keeps track of request port
    _responsePort->responderBind(*this);
}
 
void
RequestPort::unbind()
{
    panic_if(!isConnected(), "Can't unbind request port %s which is "
    "not bound.", name());
    _responsePort->responderUnbind();
    _responsePort = &defaultResponsePort;
    Port::unbind();
}
 
AddrRangeList
RequestPort::getAddrRanges() const
{
    return _responsePort->getAddrRanges();
}
 
void
RequestPort::printAddr(Addr a)
{
    auto req = std::make_shared<Request>(
        a, 1, 0, Request::funcRequestorId);
 
    Packet pkt(req, MemCmd::PrintReq);
    Packet::PrintReqState prs(std::cerr);
    pkt.senderState = &prs;
 
    sendFunctional(&pkt);
}
 
void
RequestPort::addTrace(PacketPtr pkt) const
{
    if (!gem5::debug::PortTrace || !pkt)
        return;
    auto ext = pkt->getExtension<TracingExtension>();
    if (!ext) {
        ext = std::make_shared<TracingExtension>();
        pkt->setExtension(ext);
    }
    ext->add(name(), _responsePort->name());
}
 
void
RequestPort::removeTrace(PacketPtr pkt) const
{
    if (!gem5::debug::PortTrace || !pkt)
        return;
    auto ext = pkt->getExtension<TracingExtension>();
    panic_if(!ext, "There is no TracingExtension in the packet.");
    ext->remove();
}
 
[[deprecated]]
ResponsePort::ResponsePort(const std::string& name,
                           SimObject* _owner,
                           PortID _id):
    Port(name, _id),
    _requestPort(&defaultRequestPort),
    defaultBackdoorWarned(false),
    owner{*_owner}
{
}
 
 
/*** FIXME:
 * The owner reference member is going through a deprecation path. In the
 * meantime, it must be initialized but no valid reference is available here.
 * Using 1 instead of nullptr prevents warning upon dereference. It should be
 * OK until definitive removal of owner.
 */
ResponsePort::ResponsePort(const std::string& name, PortID id) :
    Port(name, id),
    _requestPort(&defaultRequestPort),
    defaultBackdoorWarned(false),
    owner{*reinterpret_cast<SimObject*>(1)}
{
}
 
ResponsePort::~ResponsePort()
{
}
 
void
ResponsePort::responderUnbind()
{
    _requestPort = &defaultRequestPort;
    Port::unbind();
}
 
void
ResponsePort::responderBind(RequestPort& request_port)
{
    _requestPort = &request_port;
    Port::bind(request_port);
}
 
Tick
ResponsePort::recvAtomicBackdoor(PacketPtr pkt, MemBackdoorPtr &backdoor)
{
    if (!defaultBackdoorWarned) {
        DPRINTF(ResponsePort,
                "Port %s doesn't support requesting a back door.", name());
        defaultBackdoorWarned = true;
    }
    return recvAtomic(pkt);
}
 
void
ResponsePort::recvMemBackdoorReq(const MemBackdoorReq &req,
        MemBackdoorPtr &backdoor)
{
    if (!defaultBackdoorWarned) {
        DPRINTF(ResponsePort,
                "Port %s doesn't support requesting a back door.", name());
        defaultBackdoorWarned = true;
    }
}
 
} // namespace gem5