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authorGabe Black <gblack@eecs.umich.edu>2007-08-04 20:27:23 -0700
committerGabe Black <gblack@eecs.umich.edu>2007-08-04 20:27:23 -0700
commitcae8d20633c0f43fdae23576adfb894284a7ee86 (patch)
treee9e232684d7fc024900d8a07d6b8a3add1f52e92 /src/mem/tport.cc
parent30e777a5d3829975266ecccac965d2297a5f4985 (diff)
parentdf015f17a45b18302565c43d3790d787e1b54c42 (diff)
downloadgem5-cae8d20633c0f43fdae23576adfb894284a7ee86.tar.xz
Merge with head.
--HG-- extra : convert_revision : 3edb9f03353b18b4c9f062bccf11e79cfb3c15f2
Diffstat (limited to 'src/mem/tport.cc')
-rw-r--r--src/mem/tport.cc78
1 files changed, 49 insertions, 29 deletions
diff --git a/src/mem/tport.cc b/src/mem/tport.cc
index ed4c0c172..b1a6a4813 100644
--- a/src/mem/tport.cc
+++ b/src/mem/tport.cc
@@ -30,7 +30,7 @@
#include "mem/tport.hh"
-void
+bool
SimpleTimingPort::checkFunctional(PacketPtr pkt)
{
DeferredPacketIterator i = transmitList.begin();
@@ -40,23 +40,21 @@ SimpleTimingPort::checkFunctional(PacketPtr pkt)
PacketPtr target = i->pkt;
// If the target contains data, and it overlaps the
// probed request, need to update data
- if (target->intersect(pkt)) {
- if (!fixPacket(pkt, target)) {
- // fixPacket returns true for continue, false for done
- return;
- }
+ if (pkt->checkFunctional(target)) {
+ return true;
}
}
+
+ return false;
}
void
SimpleTimingPort::recvFunctional(PacketPtr pkt)
{
- checkFunctional(pkt);
-
- // Just do an atomic access and throw away the returned latency
- if (pkt->result != Packet::Success)
+ if (!checkFunctional(pkt)) {
+ // Just do an atomic access and throw away the returned latency
recvAtomic(pkt);
+ }
}
bool
@@ -67,17 +65,28 @@ SimpleTimingPort::recvTiming(PacketPtr pkt)
// 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);
+ assert(pkt->isRequest());
+
+ 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();
+ if (needsResponse) {
+ // recvAtomic() should already have turned packet into
+ // atomic response
+ assert(pkt->isResponse());
schedSendTiming(pkt, curTick + latency);
- }
- else if (pkt->cmd != MemCmd::UpgradeReq) {
+ } else {
delete pkt->req;
delete pkt;
}
+
return true;
}
@@ -88,28 +97,30 @@ SimpleTimingPort::schedSendTiming(PacketPtr pkt, Tick when)
assert(when > curTick);
// Nothing is on the list: add it and schedule an event
- if (transmitList.empty()) {
- assert(!sendEvent->scheduled());
- sendEvent->schedule(when);
- transmitList.push_back(DeferredPacket(when, 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
+ // list is non-empty and this is not the head, so event should
+ // already be scheduled
+ assert(waitingOnRetry ||
+ (sendEvent->scheduled() && sendEvent->when() <= when));
+
+ // 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
+
+ // 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) {
- if (i == transmitList.begin()) {
- //Inserting at begining, reschedule
- sendEvent->reschedule(when);
- }
transmitList.insert(i, DeferredPacket(when, pkt));
return;
}
@@ -122,12 +133,15 @@ void
SimpleTimingPort::sendDeferredPacket()
{
assert(deferredPacketReady());
- bool success = sendTiming(transmitList.front().pkt);
+ // 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) {
- //send successful, remove packet
- transmitList.pop_front();
- if (!transmitList.empty()) {
+ if (!transmitList.empty() && !sendEvent->scheduled()) {
Tick time = transmitList.front().tick;
sendEvent->schedule(time <= curTick ? curTick+1 : time);
}
@@ -136,6 +150,12 @@ SimpleTimingPort::sendDeferredPacket()
drainEvent->process();
drainEvent = NULL;
}
+ } 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;