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44 #include "debug/Bus.hh"
45 #include "mem/mem_object.hh"
46 #include "mem/tport.hh"
50 SimpleTimingPort::SimpleTimingPort(const string
&_name
, MemObject
*_owner
,
52 : Port(_name
, _owner
), label(_label
), sendEvent(this), drainEvent(NULL
),
57 SimpleTimingPort::~SimpleTimingPort()
62 SimpleTimingPort::checkFunctional(PacketPtr pkt
)
64 pkt
->pushLabel(label
);
66 DeferredPacketIterator i
= transmitList
.begin();
67 DeferredPacketIterator end
= transmitList
.end();
70 while (!found
&& i
!= end
) {
71 // If the buffered packet contains data, and it overlaps the
72 // current packet, then update data
73 found
= pkt
->checkFunctional(i
->pkt
);
83 SimpleTimingPort::recvFunctional(PacketPtr pkt
)
85 if (!checkFunctional(pkt
)) {
86 // Just do an atomic access and throw away the returned latency
92 SimpleTimingPort::recvTiming(PacketPtr pkt
)
94 // If the device is only a slave, it should only be sending
95 // responses, which should never get nacked. There used to be
96 // code to hanldle nacks here, but I'm pretty sure it didn't work
97 // correctly with the drain code, so that would need to be fixed
98 // if we ever added it back.
100 if (pkt
->memInhibitAsserted()) {
101 // snooper will supply based on copy of packet
102 // still target's responsibility to delete packet
107 bool needsResponse
= pkt
->needsResponse();
108 Tick latency
= recvAtomic(pkt
);
109 // turn packet around to go back to requester if response expected
111 // recvAtomic() should already have turned packet into
113 assert(pkt
->isResponse());
114 schedSendTiming(pkt
, curTick() + latency
);
123 SimpleTimingPort::schedSendEvent(Tick when
)
125 // if we are waiting on a retry, do not schedule a send event, and
126 // instead rely on retry being called
127 if (waitingOnRetry
) {
128 assert(!sendEvent
.scheduled());
132 if (!sendEvent
.scheduled()) {
133 owner
->schedule(&sendEvent
, when
);
134 } else if (sendEvent
.when() > when
) {
135 owner
->reschedule(&sendEvent
, when
);
140 SimpleTimingPort::schedSendTiming(PacketPtr pkt
, Tick when
)
142 assert(when
> curTick());
143 assert(when
< curTick() + SimClock::Int::ms
);
145 // Nothing is on the list: add it and schedule an event
146 if (transmitList
.empty() || when
< transmitList
.front().tick
) {
147 transmitList
.push_front(DeferredPacket(when
, pkt
));
148 schedSendEvent(when
);
152 // list is non-empty & this belongs at the end
153 if (when
>= transmitList
.back().tick
) {
154 transmitList
.push_back(DeferredPacket(when
, pkt
));
158 // this belongs in the middle somewhere
159 DeferredPacketIterator i
= transmitList
.begin();
160 i
++; // already checked for insertion at front
161 DeferredPacketIterator end
= transmitList
.end();
163 for (; i
!= end
; ++i
) {
164 if (when
< i
->tick
) {
165 transmitList
.insert(i
, DeferredPacket(when
, pkt
));
169 assert(false); // should never get here
172 void SimpleTimingPort::trySendTiming()
174 assert(deferredPacketReady());
175 // take the next packet off the list here, as we might return to
176 // ourselves through the sendTiming call below
177 DeferredPacket dp
= transmitList
.front();
178 transmitList
.pop_front();
180 // attempt to send the packet and remember the outcome
181 waitingOnRetry
= !sendTiming(dp
.pkt
);
183 if (waitingOnRetry
) {
184 // put the packet back at the front of the list (packet should
185 // not have changed since it wasn't accepted)
186 assert(!sendEvent
.scheduled());
187 transmitList
.push_front(dp
);
192 SimpleTimingPort::scheduleSend(Tick time
)
194 // the next ready time is either determined by the next deferred packet,
195 // or in the cache through the MSHR ready time
196 Tick nextReady
= std::min(deferredPacketReadyTime(), time
);
197 if (nextReady
!= MaxTick
) {
198 // if the sendTiming caused someone else to call our
199 // recvTiming we could already have an event scheduled, check
200 if (!sendEvent
.scheduled())
201 owner
->schedule(&sendEvent
, std::max(nextReady
, curTick() + 1));
203 // no more to send, so if we're draining, we may be done
204 if (drainEvent
&& !sendEvent
.scheduled()) {
205 drainEvent
->process();
212 SimpleTimingPort::sendDeferredPacket()
214 // try to send what is on the list
217 // if we succeeded and are not waiting for a retry, schedule the
219 if (!waitingOnRetry
) {
226 SimpleTimingPort::recvRetry()
228 DPRINTF(Bus
, "Received retry\n");
229 // note that in the cache we get a retry even though we may not
230 // have a packet to retry (we could potentially decide on a new
231 // packet every time we retry)
232 assert(waitingOnRetry
);
233 sendDeferredPacket();
238 SimpleTimingPort::processSendEvent()
240 assert(!waitingOnRetry
);
241 sendDeferredPacket();
246 SimpleTimingPort::drain(Event
*de
)
248 if (transmitList
.empty() && !sendEvent
.scheduled())