add a backoff algorithm when nacks are received by devices

add seperate response buffers and request queue sizes in bus bridge
add delay to respond to a nack in the bus bridge

src/dev/i8254xGBe.cc:
src/dev/ide_ctrl.cc:
src/dev/ns_gige.cc:
src/dev/pcidev.hh:
src/dev/sinic.cc:
    add backoff delay parameters
src/dev/io_device.cc:
src/dev/io_device.hh:
    add a backoff algorithm when nacks are received.
src/mem/bridge.cc:
src/mem/bridge.hh:
    add seperate response buffers and request queue sizes
    add a new parameters to specify how long before a nack in ready to go after a packet that needs to be nacked is received
src/mem/cache/cache_impl.hh:
    assert on the
src/mem/tport.cc:
    add a friendly assert to make sure the packet was inserted into the list

--HG--
extra : convert_revision : 3595ad932015a4ce2bb72772da7850ad91bd09b1

src/mem/cache/cache_impl.hh

@@ -1192,6 +1192,8 @@ template<class TagStore, class Coherence>
 bool
 Cache<TagStore,Coherence>::CpuSidePort::recvTiming(PacketPtr pkt)
 {
+    assert(pkt->result != Packet::Nacked);
+
     if (!pkt->req->isUncacheable()
         && pkt->isInvalidate()
         && !pkt->isRead() && !pkt->isWrite()) {
@@ -1249,6 +1251,12 @@ template<class TagStore, class Coherence>
 bool
 Cache<TagStore,Coherence>::MemSidePort::recvTiming(PacketPtr pkt)
 {
+    // this needs to be fixed so that the cache updates the mshr and sends the
+    // packet back out on the link, but it probably won't happen so until this
+    // gets fixed, just panic when it does
+    if (pkt->result == Packet::Nacked)
+        panic("Need to implement cache resending nacked packets!\n");
+
     if (pkt->isRequest() && blocked)
     {
         DPRINTF(Cache,"Scheduling a retry while blocked\n");