* Authors: Ali Saidi
*/
+#include "debug/Bus.hh"
#include "mem/tport.hh"
-void
-SimpleTimingPort::recvFunctional(PacketPtr pkt)
+using namespace std;
+
+SimpleTimingPort::SimpleTimingPort(string pname, MemObject *_owner)
+ : Port(pname, _owner), sendEvent(0), drainEvent(NULL),
+ waitingOnRetry(false)
+{
+ sendEvent = new EventWrapper<SimpleTimingPort,
+ &SimpleTimingPort::processSendEvent>(this);
+}
+
+SimpleTimingPort::~SimpleTimingPort()
+{
+ delete sendEvent;
+}
+
+bool
+SimpleTimingPort::checkFunctional(PacketPtr pkt)
{
- std::list<std::pair<Tick,PacketPtr> >::iterator i = transmitList.begin();
- std::list<std::pair<Tick,PacketPtr> >::iterator end = transmitList.end();
- bool notDone = true;
+ DeferredPacketIterator i = transmitList.begin();
+ DeferredPacketIterator end = transmitList.end();
- while (i != end && notDone) {
- PacketPtr target = i->second;
+ for (; i != end; ++i) {
+ PacketPtr target = i->pkt;
// If the target contains data, and it overlaps the
// probed request, need to update data
- if (target->intersect(pkt))
- notDone = fixPacket(pkt, target);
-
- i++;
+ if (pkt->checkFunctional(target)) {
+ return true;
+ }
}
- //Then just do an atomic access and throw away the returned latency
- if (pkt->result != Packet::Success)
+ return false;
+}
+
+void
+SimpleTimingPort::recvFunctional(PacketPtr pkt)
+{
+ if (!checkFunctional(pkt)) {
+ // Just do an atomic access and throw away the returned latency
recvAtomic(pkt);
+ }
}
bool
// code to hanldle nacks here, but I'm pretty sure it didn't work
// correctly with the drain code, so that would need to be fixed
// if we ever added it back.
- assert(pkt->result != Packet::Nacked);
+
+ if (pkt->memInhibitAsserted()) {
+ // snooper will supply based on copy of packet
+ // still target's responsibility to delete packet
+ delete pkt;
+ return true;
+ }
+
+ bool needsResponse = pkt->needsResponse();
Tick latency = recvAtomic(pkt);
// turn packet around to go back to requester if response expected
- if (pkt->needsResponse()) {
- pkt->makeTimingResponse();
- sendTiming(pkt, latency);
- }
- else {
- if (pkt->cmd != Packet::UpgradeReq)
- {
- delete pkt->req;
- delete pkt;
- }
+ if (needsResponse) {
+ // recvAtomic() should already have turned packet into
+ // atomic response
+ assert(pkt->isResponse());
+ schedSendTiming(pkt, curTick() + latency);
+ } else {
+ delete pkt;
}
+
return true;
}
-void
-SimpleTimingPort::recvRetry()
-{
- assert(!transmitList.empty());
- if (Port::sendTiming(transmitList.front().second)) {
- transmitList.pop_front();
- DPRINTF(Bus, "No Longer waiting on retry\n");
- if (!transmitList.empty()) {
- Tick time = transmitList.front().first;
- sendEvent.schedule(time <= curTick ? curTick+1 : time);
- }
- }
-
- if (transmitList.empty() && drainEvent) {
- drainEvent->process();
- drainEvent = NULL;
- }
-}
void
-SimpleTimingPort::sendTiming(PacketPtr pkt, Tick time)
+SimpleTimingPort::schedSendTiming(PacketPtr pkt, Tick when)
{
+ assert(when > curTick());
+ assert(when < curTick() + SimClock::Int::ms);
+
// Nothing is on the list: add it and schedule an event
- if (transmitList.empty()) {
- assert(!sendEvent.scheduled());
- sendEvent.schedule(curTick+time);
- transmitList.push_back(std::pair<Tick,PacketPtr>(time+curTick,pkt));
+ if (transmitList.empty() || when < transmitList.front().tick) {
+ transmitList.push_front(DeferredPacket(when, pkt));
+ schedSendEvent(when);
return;
}
- // something is on the list and this belongs at the end
- if (time+curTick >= transmitList.back().first) {
- transmitList.push_back(std::pair<Tick,PacketPtr>(time+curTick,pkt));
+ // list is non-empty & this belongs at the end
+ if (when >= transmitList.back().tick) {
+ transmitList.push_back(DeferredPacket(when, pkt));
return;
}
- // Something is on the list and this belongs somewhere else
- std::list<std::pair<Tick,PacketPtr> >::iterator i = transmitList.begin();
- std::list<std::pair<Tick,PacketPtr> >::iterator end = transmitList.end();
- bool done = false;
-
- while (i != end && !done) {
- if (time+curTick < i->first) {
- if (i == transmitList.begin()) {
- //Inserting at begining, reschedule
- sendEvent.reschedule(time+curTick);
- }
- transmitList.insert(i,std::pair<Tick,PacketPtr>(time+curTick,pkt));
- done = true;
+
+ // this belongs in the middle somewhere
+ DeferredPacketIterator i = transmitList.begin();
+ i++; // already checked for insertion at front
+ DeferredPacketIterator end = transmitList.end();
+
+ for (; i != end; ++i) {
+ if (when < i->tick) {
+ transmitList.insert(i, DeferredPacket(when, pkt));
+ return;
}
- i++;
}
+ assert(false); // should never get here
}
+
void
-SimpleTimingPort::SendEvent::process()
+SimpleTimingPort::sendDeferredPacket()
{
- assert(port->transmitList.size());
- assert(port->transmitList.front().first <= curTick);
- if (port->Port::sendTiming(port->transmitList.front().second)) {
- //send successful, remove packet
- port->transmitList.pop_front();
- if (!port->transmitList.empty()) {
- Tick time = port->transmitList.front().first;
- schedule(time <= curTick ? curTick+1 : time);
+ assert(deferredPacketReady());
+ // take packet off list here; if recvTiming() on the other side
+ // calls sendTiming() back on us (like SimpleTimingCpu does), then
+ // we get confused by having a non-active packet on transmitList
+ DeferredPacket dp = transmitList.front();
+ transmitList.pop_front();
+ bool success = sendTiming(dp.pkt);
+
+ if (success) {
+ if (!transmitList.empty() && !sendEvent->scheduled()) {
+ Tick time = transmitList.front().tick;
+ schedule(sendEvent, time <= curTick() ? curTick()+1 : time);
}
- if (port->transmitList.empty() && port->drainEvent) {
- port->drainEvent->process();
- port->drainEvent = NULL;
+
+ if (transmitList.empty() && drainEvent && !sendEvent->scheduled()) {
+ drainEvent->process();
+ drainEvent = NULL;
}
- return;
+ } else {
+ // Unsuccessful, need to put back on transmitList. Callee
+ // should not have messed with it (since it didn't accept that
+ // packet), so we can just push it back on the front.
+ assert(!sendEvent->scheduled());
+ transmitList.push_front(dp);
+ }
+
+ waitingOnRetry = !success;
+
+ if (waitingOnRetry) {
+ DPRINTF(Bus, "Send failed, waiting on retry\n");
}
- // send unsuccessful (due to flow control). Will get retry
- // callback later; save for then if not already
- DPRINTF(Bus, "Waiting on retry\n");
+}
+
+
+void
+SimpleTimingPort::recvRetry()
+{
+ DPRINTF(Bus, "Received retry\n");
+ assert(waitingOnRetry);
+ sendDeferredPacket();
+}
+
+
+void
+SimpleTimingPort::processSendEvent()
+{
+ assert(!waitingOnRetry);
+ sendDeferredPacket();
}
unsigned int
SimpleTimingPort::drain(Event *de)
{
- if (transmitList.size() == 0)
+ if (transmitList.size() == 0 && !sendEvent->scheduled())
return 0;
drainEvent = de;
return 1;
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