{
assert(pkt->isResponse());
+ // all header delay should be paid for by the crossbar, unless
+ // this is a prefetch response from above
+ panic_if(pkt->headerDelay != 0 && pkt->cmd != MemCmd::HardPFResp,
+ "%s saw a non-zero packet delay\n", name());
+
MSHR *mshr = dynamic_cast<MSHR*>(pkt->senderState);
bool is_error = pkt->isError();
// create the slave ports, once again starting at zero
for (int i = 0; i < p->port_slave_connection_count; ++i) {
std::string portName = csprintf("%s.slave[%d]", name(), i);
- SlavePort* bp = new CoherentXBarSlavePort(portName, *this, i);
+ QueuedSlavePort* bp = new CoherentXBarSlavePort(portName, *this, i);
slavePorts.push_back(bp);
respLayers.push_back(new RespLayer(*bp, *this,
csprintf(".respLayer%d", i)));
snoopFilter->updateResponse(pkt, *slavePorts[slave_port_id]);
}
- // send the packet through the destination slave port
- bool success M5_VAR_USED = slavePorts[slave_port_id]->sendTimingResp(pkt);
-
- // currently it is illegal to block responses... can lead to
- // deadlock
- assert(success);
+ // send the packet through the destination slave port and pay for
+ // any outstanding header delay
+ Tick latency = pkt->headerDelay;
+ pkt->headerDelay = 0;
+ slavePorts[slave_port_id]->schedTimingResp(pkt, curTick() + latency);
// remove the request from the routing table
routeTo.erase(route_lookup);
pkt->getAddr());
// as a normal response, it should go back to a master through
- // one of our slave ports, at this point we are ignoring the
- // fact that the response layer could be busy and do not touch
- // its state
- bool success M5_VAR_USED =
- slavePorts[dest_port_id]->sendTimingResp(pkt);
-
- // @todo Put the response in an internal FIFO and pass it on
- // to the response layer from there
-
- // currently it is illegal to block responses... can lead
- // to deadlock
- assert(success);
+ // one of our slave ports, we also pay for any outstanding
+ // header latency
+ Tick latency = pkt->headerDelay;
+ pkt->headerDelay = 0;
+ slavePorts[dest_port_id]->schedTimingResp(pkt, curTick() + latency);
respLayers[dest_port_id]->succeededTiming(packetFinishTime);
}
void
CoherentXBar::forwardTiming(PacketPtr pkt, PortID exclude_slave_port_id,
- const std::vector<SlavePort*>& dests)
+ const std::vector<QueuedSlavePort*>& dests)
{
DPRINTF(CoherentXBar, "%s for %s address %x size %d\n", __func__,
pkt->cmdString(), pkt->getAddr(), pkt->getSize());
std::pair<MemCmd, Tick>
CoherentXBar::forwardAtomic(PacketPtr pkt, PortID exclude_slave_port_id,
PortID source_master_port_id,
- const std::vector<SlavePort*>& dests)
+ const std::vector<QueuedSlavePort*>& dests)
{
// the packet may be changed on snoops, record the original
// command to enable us to restore it between snoops so that
// there is no need to continue if the snooping has found what we
// were looking for and the packet is already a response
if (!pkt->isResponse()) {
+ // since our slave ports are queued ports we need to check them as well
+ for (const auto& p : slavePorts) {
+ // if we find a response that has the data, then the
+ // downstream caches/memories may be out of date, so simply stop
+ // here
+ if (p->checkFunctional(pkt)) {
+ if (pkt->needsResponse())
+ pkt->makeResponse();
+ return;
+ }
+ }
+
PortID dest_id = findPort(pkt->getAddr());
masterPorts[dest_id]->sendFunctional(pkt);
* be instantiated for each of the master ports connecting to the
* crossbar.
*/
- class CoherentXBarSlavePort : public SlavePort
+ class CoherentXBarSlavePort : public QueuedSlavePort
{
private:
/** A reference to the crossbar to which this port belongs. */
CoherentXBar &xbar;
+ /** A normal packet queue used to store responses. */
+ RespPacketQueue queue;
+
public:
CoherentXBarSlavePort(const std::string &_name,
CoherentXBar &_xbar, PortID _id)
- : SlavePort(_name, &_xbar, _id), xbar(_xbar)
+ : QueuedSlavePort(_name, &_xbar, queue, _id), xbar(_xbar),
+ queue(_xbar, *this)
{ }
protected:
virtual void recvFunctional(PacketPtr pkt)
{ xbar.recvFunctional(pkt, id); }
- /**
- * When receiving a retry, pass it to the crossbar.
- */
- virtual void recvRespRetry()
- { panic("Crossbar slave ports should never retry.\n"); }
-
/**
* Return the union of all adress ranges seen by this crossbar.
*/
private:
/** The port which we mirror internally. */
- SlavePort& slavePort;
+ QueuedSlavePort& slavePort;
public:
/**
* Create a snoop response port that mirrors a given slave port.
*/
- SnoopRespPort(SlavePort& slave_port, CoherentXBar& _xbar) :
+ SnoopRespPort(QueuedSlavePort& slave_port, CoherentXBar& _xbar) :
MasterPort(slave_port.name() + ".snoopRespPort", &_xbar),
slavePort(slave_port) { }
std::vector<SnoopRespPort*> snoopRespPorts;
- std::vector<SlavePort*> snoopPorts;
+ std::vector<QueuedSlavePort*> snoopPorts;
/**
* Store the outstanding requests that we are expecting snoop
* @param dests Vector of destination ports for the forwarded pkt
*/
void forwardTiming(PacketPtr pkt, PortID exclude_slave_port_id,
- const std::vector<SlavePort*>& dests);
+ const std::vector<QueuedSlavePort*>& dests);
/** Function called by the port when the crossbar is recieving a Atomic
transaction.*/
std::pair<MemCmd, Tick> forwardAtomic(PacketPtr pkt,
PortID exclude_slave_port_id)
{
- return forwardAtomic(pkt, exclude_slave_port_id, InvalidPortID, snoopPorts);
+ return forwardAtomic(pkt, exclude_slave_port_id, InvalidPortID,
+ snoopPorts);
}
/**
std::pair<MemCmd, Tick> forwardAtomic(PacketPtr pkt,
PortID exclude_slave_port_id,
PortID source_master_port_id,
- const std::vector<SlavePort*>& dests);
+ const std::vector<QueuedSlavePort*>&
+ dests);
/** Function called by the port when the crossbar is recieving a Functional
transaction.*/
// create the slave ports, once again starting at zero
for (int i = 0; i < p->port_slave_connection_count; ++i) {
std::string portName = csprintf("%s.slave[%d]", name(), i);
- SlavePort* bp = new NoncoherentXBarSlavePort(portName, *this, i);
+ QueuedSlavePort* bp = new NoncoherentXBarSlavePort(portName, *this, i);
slavePorts.push_back(bp);
respLayers.push_back(new RespLayer(*bp, *this,
csprintf(".respLayer%d", i)));
// determine how long to be crossbar layer is busy
Tick packetFinishTime = clockEdge(Cycles(1)) + pkt->payloadDelay;
- // send the packet through the destination slave port
- bool success M5_VAR_USED = slavePorts[slave_port_id]->sendTimingResp(pkt);
-
- // currently it is illegal to block responses... can lead to
- // deadlock
- assert(success);
+ // send the packet through the destination slave port, and pay for
+ // any outstanding latency
+ Tick latency = pkt->headerDelay;
+ pkt->headerDelay = 0;
+ slavePorts[slave_port_id]->schedTimingResp(pkt, curTick() + latency);
// remove the request from the routing table
routeTo.erase(route_lookup);
pkt->cmdString());
}
+ // since our slave ports are queued ports we need to check them as well
+ for (const auto& p : slavePorts) {
+ // if we find a response that has the data, then the
+ // downstream caches/memories may be out of date, so simply stop
+ // here
+ if (p->checkFunctional(pkt)) {
+ if (pkt->needsResponse())
+ pkt->makeResponse();
+ return;
+ }
+ }
+
// determine the destination port
PortID dest_id = findPort(pkt->getAddr());
* will be instantiated for each of the master ports connecting to
* the crossbar.
*/
- class NoncoherentXBarSlavePort : public SlavePort
+ class NoncoherentXBarSlavePort : public QueuedSlavePort
{
private:
/** A reference to the crossbar to which this port belongs. */
NoncoherentXBar &xbar;
+ /** A normal packet queue used to store responses. */
+ RespPacketQueue queue;
+
public:
NoncoherentXBarSlavePort(const std::string &_name,
NoncoherentXBar &_xbar, PortID _id)
- : SlavePort(_name, &_xbar, _id), xbar(_xbar)
+ : QueuedSlavePort(_name, &_xbar, queue, _id), xbar(_xbar),
+ queue(_xbar, *this)
{ }
protected:
virtual void recvFunctional(PacketPtr pkt)
{ xbar.recvFunctional(pkt, id); }
- /**
- * When receiving a retry, pass it to the crossbar.
- */
- virtual void recvRespRetry()
- { panic("Crossbar slave ports should never retry.\n"); }
-
/**
* Return the union of all adress ranges seen by this crossbar.
*/
#include "base/hashmap.hh"
#include "mem/packet.hh"
#include "mem/port.hh"
+#include "mem/qport.hh"
#include "params/SnoopFilter.hh"
#include "sim/sim_object.hh"
#include "sim/system.hh"
*/
class SnoopFilter : public SimObject {
public:
- typedef std::vector<SlavePort*> SnoopList;
+ typedef std::vector<QueuedSlavePort*> SnoopList;
SnoopFilter (const SnoopFilterParams *p) : SimObject(p),
linesize(p->system->cacheLineSize()), lookupLatency(p->lookup_latency)
*
* @param bus_slave_ports Vector of slave ports that the bus is attached to.
*/
- void setSlavePorts(const std::vector<SlavePort*>& bus_slave_ports) {
+ void setSlavePorts(const SnoopList& bus_slave_ports) {
slavePorts = bus_slave_ports;
}
#include "base/hashmap.hh"
#include "base/types.hh"
#include "mem/mem_object.hh"
+#include "mem/qport.hh"
#include "params/BaseXBar.hh"
#include "sim/stats.hh"
bool gotAllAddrRanges;
/** The master and slave ports of the crossbar */
- std::vector<SlavePort*> slavePorts;
+ std::vector<QueuedSlavePort*> slavePorts;
std::vector<MasterPort*> masterPorts;
/** Port that handles requests that don't match any of the interfaces.*/
projects / gem5.git / commitdiff