From e65f0cef3ca70edf37ff74920def4ac899f6c7e3 Mon Sep 17 00:00:00 2001
From: Ron Dreslinski <rdreslin@umich.edu>
Date: Sun, 8 Oct 2006 19:05:48 -0400
Subject: [PATCH] Only respond if the pkt needs a response. Fix an issue with
 memory handling writebacks.

src/mem/cache/base_cache.hh:
src/mem/tport.cc:
    Only respond if the pkt needs a response.
src/mem/physical.cc:
    Make physical memory respond to writebacks, set satisfied for invalidates/upgrades.

--HG--
extra : convert_revision : 7601987a7923e54a6d1a168def4f8133d8de19fd
---
 src/mem/cache/base_cache.hh | 13 +++++++++----
 src/mem/physical.cc         | 15 +++++++++------
 src/mem/tport.cc            |  8 +++++---
 3 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/src/mem/cache/base_cache.hh b/src/mem/cache/base_cache.hh
index 4b0e114b9..2e92e7730 100644
--- a/src/mem/cache/base_cache.hh
+++ b/src/mem/cache/base_cache.hh
@@ -516,8 +516,10 @@ class BaseCache : public MemObject
      */
     void respond(Packet *pkt, Tick time)
     {
-        CacheEvent *reqCpu = new CacheEvent(cpuSidePort, pkt);
-        reqCpu->schedule(time);
+        if (pkt->needsResponse()) {
+            CacheEvent *reqCpu = new CacheEvent(cpuSidePort, pkt);
+            reqCpu->schedule(time);
+        }
     }
 
     /**
@@ -530,8 +532,10 @@ class BaseCache : public MemObject
         if (!pkt->req->isUncacheable()) {
             missLatency[pkt->cmdToIndex()][0/*pkt->req->getThreadNum()*/] += time - pkt->time;
         }
-        CacheEvent *reqCpu = new CacheEvent(cpuSidePort, pkt);
-        reqCpu->schedule(time);
+        if (pkt->needsResponse()) {
+            CacheEvent *reqCpu = new CacheEvent(cpuSidePort, pkt);
+            reqCpu->schedule(time);
+        }
     }
 
     /**
@@ -542,6 +546,7 @@ class BaseCache : public MemObject
     {
 //        assert("Implement\n" && 0);
 //	mi->respond(pkt,curTick + hitLatency);
+        assert (pkt->needsResponse());
         CacheEvent *reqMem = new CacheEvent(memSidePort, pkt);
         reqMem->schedule(time);
     }
diff --git a/src/mem/physical.cc b/src/mem/physical.cc
index 23b1d5ffc..070693442 100644
--- a/src/mem/physical.cc
+++ b/src/mem/physical.cc
@@ -197,22 +197,25 @@ PhysicalMemory::doFunctionalAccess(Packet *pkt)
 {
     assert(pkt->getAddr() + pkt->getSize() < params()->addrRange.size());
 
-    switch (pkt->cmd) {
-      case Packet::ReadReq:
+    if (pkt->isRead()) {
         if (pkt->req->isLocked()) {
             trackLoadLocked(pkt->req);
         }
         memcpy(pkt->getPtr<uint8_t>(),
                pmemAddr + pkt->getAddr() - params()->addrRange.start,
                pkt->getSize());
-        break;
-      case Packet::WriteReq:
+    }
+    else if (pkt->isWrite()) {
         if (writeOK(pkt->req)) {
             memcpy(pmemAddr + pkt->getAddr() - params()->addrRange.start,
                    pkt->getPtr<uint8_t>(), pkt->getSize());
         }
-        break;
-      default:
+    }
+    else if (pkt->isInvalidate()) {
+        //upgrade or invalidate
+        pkt->flags |= SATISFIED;
+    }
+    else {
         panic("unimplemented");
     }
 
diff --git a/src/mem/tport.cc b/src/mem/tport.cc
index 55c301c87..cef7a2a5b 100644
--- a/src/mem/tport.cc
+++ b/src/mem/tport.cc
@@ -47,9 +47,11 @@ SimpleTimingPort::recvTiming(Packet *pkt)
     // if we ever added it back.
     assert(pkt->result != Packet::Nacked);
     Tick latency = recvAtomic(pkt);
-    // turn packet around to go back to requester
-    pkt->makeTimingResponse();
-    sendTimingLater(pkt, latency);
+    // turn packet around to go back to requester if response expected
+    if (pkt->needsResponse()) {
+        pkt->makeTimingResponse();
+        sendTimingLater(pkt, latency);
+    }
     return true;
 }
 
-- 
2.30.2