cache: fail SC when invalidated while waiting for bus

Corrects an oversight in cset f97b62be544f.  The fix there only
failed queued SCUpgradeReq packets that encountered an
invalidation, which meant that the upgrade had to reach the L2
cache.  To handle pending requests in the L1 we must similarly
fail StoreCondReq packets too.

1 files changed, 7 insertions, 1 deletions

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");
     }
 }