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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(PacketPtr pkt)
{
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) {
PacketPtr target = i->second;
// If the target contains data, and it overlaps the
// probed request, need to update data
if (target->intersect(pkt))
done = fixPacket(pkt, target);
i++;
}
//Then just do an atomic access and throw away the returned latency
if (pkt->result != Packet::Success)
recvAtomic(pkt);
}
bool
SimpleTimingPort::recvTiming(PacketPtr 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();
sendTiming(pkt, latency);
}
else {
if (pkt->cmd != Packet::UpgradeReq)
{
delete pkt->req;
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)
{
// 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));
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));
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)
transmitList.insert(i,std::pair<Tick,PacketPtr>(time+curTick,pkt));
i++;
}
}
void
SimpleTimingPort::SendEvent::process()
{
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);
}
if (port->transmitList.empty() && port->drainEvent) {
port->drainEvent->process();
port->drainEvent = NULL;
}
return;
}
// send unsuccessful (due to flow control). Will get retry
// callback later; save for then if not already
DPRINTF(Bus, "Waiting on retry\n");
}
unsigned int
SimpleTimingPort::drain(Event *de)
{
if (transmitList.size() == 0)
return 0;
drainEvent = de;
return 1;
}
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