4 files changed, 20 insertions, 7 deletions

diff --git a/src/mem/cache/cache_impl.hh b/src/mem/cache/cache_impl.hh
index 3f3dc6877..4f4d720b6 100644
--- a/src/mem/cache/cache_impl.hh
+++ b/src/mem/cache/cache_impl.hh
@@ -900,9 +900,10 @@ Cache<TagStore>::handleResponse(PacketPtr pkt)
                 assert(!target->pkt->req->isUncacheable());
                 missLatency[target->pkt->cmdToIndex()][0/*pkt->req->threadId()*/] +=
                     completion_time - target->recvTime;
-            } else if (target->pkt->cmd == MemCmd::StoreCondReq &&
-                       pkt->cmd == MemCmd::UpgradeFailResp) {
+            } else if (pkt->cmd == MemCmd::UpgradeFailResp) {
                 // failed StoreCond upgrade
+                assert(target->pkt->cmd == MemCmd::StoreCondReq ||
+                       target->pkt->cmd == MemCmd::StoreCondFailReq);
                 completion_time = tags->getHitLatency() + pkt->finishTime;
                 target->pkt->req->setExtraData(0);
             } else {
@@ -1443,10 +1444,11 @@ Cache<TagStore>::getTimingPacket()
     PacketPtr tgt_pkt = mshr->getTarget()->pkt;
     PacketPtr pkt = NULL;
 
-    if (tgt_pkt->cmd == MemCmd::SCUpgradeFailReq) {
-        // SCUpgradeReq saw invalidation while queued in MSHR, so now
-        // that we are getting around to processing it, just treat it
-        // as if we got a failure response
+    if (tgt_pkt->cmd == MemCmd::SCUpgradeFailReq ||
+        tgt_pkt->cmd == MemCmd::StoreCondFailReq) {
+        // SCUpgradeReq or StoreCondReq saw invalidation while queued
+        // in MSHR, so now that we are getting around to processing
+        // it, just treat it as if we got a failure response
         pkt = new Packet(tgt_pkt);
         pkt->cmd = MemCmd::UpgradeFailResp;
         pkt->senderState = mshr;
diff --git a/src/mem/cache/mshr.cc b/src/mem/cache/mshr.cc
index bbddf2aee..54977346f 100644
--- a/src/mem/cache/mshr.cc
+++ b/src/mem/cache/mshr.cc
@@ -72,7 +72,10 @@ MSHR::TargetList::add(PacketPtr pkt, Tick readyTime,
             needsExclusive = true;
         }
 
-        if (pkt->isUpgrade()) {
+        // StoreCondReq is effectively an upgrade if it's in an MSHR
+        // since it would have been failed already if we didn't have a
+        // read-only copy
+        if (pkt->isUpgrade() || pkt->cmd == MemCmd::StoreCondReq) {
             hasUpgrade = true;
         }
     }
@@ -98,6 +101,9 @@ replaceUpgrade(PacketPtr pkt)
     } else if (pkt->cmd == MemCmd::SCUpgradeReq) {
         pkt->cmd = MemCmd::SCUpgradeFailReq;
         DPRINTF(Cache, "Replacing SCUpgradeReq with SCUpgradeFailReq\n");
+    } else if (pkt->cmd == MemCmd::StoreCondReq) {
+        pkt->cmd = MemCmd::StoreCondFailReq;
+        DPRINTF(Cache, "Replacing StoreCondReq with StoreCondFailReq\n");
     }
 }
 
diff --git a/src/mem/packet.cc b/src/mem/packet.cc
index 5eb2ecc4b..d0b1fed83 100644
--- a/src/mem/packet.cc
+++ b/src/mem/packet.cc
@@ -123,6 +123,10 @@ MemCmd::commandInfo[] =
     { SET6(IsWrite, NeedsExclusive, IsLlsc,
            IsRequest, NeedsResponse, HasData),
             StoreCondResp, "StoreCondReq" },
+    /* StoreCondFailReq: generates failing StoreCondResp ASAP */
+    { SET6(IsWrite, NeedsExclusive, IsLlsc,
+           IsRequest, NeedsResponse, HasData),
+            StoreCondResp, "StoreCondFailReq" },
     /* StoreCondResp */
     { SET4(IsWrite, NeedsExclusive, IsLlsc, IsResponse),
             InvalidCmd, "StoreCondResp" },
diff --git a/src/mem/packet.hh b/src/mem/packet.hh
index cc2a39d0e..cefb7c2ed 100644
--- a/src/mem/packet.hh
+++ b/src/mem/packet.hh
@@ -90,6 +90,7 @@ class MemCmd
         ReadExResp,
         LoadLockedReq,
         StoreCondReq,
+        StoreCondFailReq,       // Failed StoreCondReq in MSHR (never sent)
         StoreCondResp,
         SwapReq,
         SwapResp,