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/*
* Copyright (c) 2006 The Regents of The University of Michigan
* All rights reserved.
*
* 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.
*
* Authors: Ali Saidi
*/
#include "mem/tport.hh"
void
SimpleTimingPort::recvFunctional(Packet *pkt)
{
// just do an atomic access and throw away the returned latency
recvAtomic(pkt);
}
bool
SimpleTimingPort::recvTiming(Packet *pkt)
{
// If the device is only a slave, it should only be sending
// responses, which should never get nacked. There used to be
// 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);
Tick latency = recvAtomic(pkt);
// turn packet around to go back to requester if response expected
if (pkt->needsResponse()) {
pkt->makeTimingResponse();
sendTimingLater(pkt, latency);
}
return true;
}
void
SimpleTimingPort::recvRetry()
{
bool result = true;
assert(transmitList.size());
while (result && transmitList.size()) {
result = sendTiming(transmitList.front());
if (result)
transmitList.pop_front();
}
if (transmitList.size() == 0 && drainEvent) {
drainEvent->process();
drainEvent = NULL;
}
}
void
SimpleTimingPort::SendEvent::process()
{
port->outTiming--;
assert(port->outTiming >= 0);
if (port->transmitList.size()) {
port->transmitList.push_back(packet);
} else if (port->sendTiming(packet)) {
// send successful
if (port->transmitList.size() == 0 && port->drainEvent) {
port->drainEvent->process();
port->drainEvent = NULL;
}
} else {
// send unsuccessful (due to flow control). Will get retry
// callback later; save for then.
port->transmitList.push_back(packet);
}
}
unsigned int
SimpleTimingPort::drain(Event *de)
{
if (outTiming == 0 && transmitList.size() == 0)
return 0;
drainEvent = de;
return 1;
}
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