mem: Clarification of packet crossbar timings

This patch clarifies the packet timings annotated
when going through a crossbar.

The old 'firstWordDelay' is replaced by 'headerDelay' that represents
the delay associated to the delivery of the header of the packet.

The old 'lastWordDelay' is replaced by 'payloadDelay' that represents
the delay needed to processing the payload of the packet.

For now the uses and values remain identical. However, going forward
the payloadDelay will be additive, and not include the
headerDelay. Follow-on patches will make the headerDelay capture the
pipeline latency incurred in the crossbar, whereas the payloadDelay
will capture the additional serialisation delay.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/mem/bridge.cc b/src/mem/bridge.cc
index a21d123a1..c003677ba 100644
--- a/src/mem/bridge.cc
+++ b/src/mem/bridge.cc
@@ -137,7 +137,7 @@ Bridge::BridgeMasterPort::recvTimingResp(PacketPtr pkt)
     DPRINTF(Bridge, "Request queue size: %d\n", transmitList.size());
 
     // @todo: We need to pay for this and not just zero it out
-    pkt->firstWordDelay = pkt->lastWordDelay = 0;
+    pkt->headerDelay = pkt->payloadDelay = 0;
 
     slavePort.schedTimingResp(pkt, bridge.clockEdge(delay));
 
@@ -181,7 +181,7 @@ Bridge::BridgeSlavePort::recvTimingReq(PacketPtr pkt)
 
         if (!retryReq) {
             // @todo: We need to pay for this and not just zero it out
-            pkt->firstWordDelay = pkt->lastWordDelay = 0;
+            pkt->headerDelay = pkt->payloadDelay = 0;
 
             masterPort.schedTimingReq(pkt, bridge.clockEdge(delay));
         }