cpu: Fix LLSC atomic CPU wakeup

Writes to locked memory addresses (LLSC) did not wake up the locking
CPU. This can lead to deadlocks on multi-core runs. In AtomicSimpleCPU,
recvAtomicSnoop was checking if the incoming packet was an invalidation
(isInvalidate) and only then handled a locked snoop. But, writes are
seen instead of invalidates when running without caches (fast-forward
configurations). As as simple fix, now handleLockedSnoop is also called
even if the incoming snoop packet are from writes.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/cpu/minor/lsq.cc b/src/cpu/minor/lsq.cc
index e644951f8..e0c5796c8 100644
--- a/src/cpu/minor/lsq.cc
+++ b/src/cpu/minor/lsq.cc
@@ -1617,7 +1617,9 @@ LSQ::recvTimingSnoopReq(PacketPtr pkt)
      * this action on snoops. */
 
     /* THREAD */
-    TheISA::handleLockedSnoop(cpu.getContext(0), pkt, cacheBlockMask);
+    if (pkt->isInvalidate() || pkt->isWrite()) {
+        TheISA::handleLockedSnoop(cpu.getContext(0), pkt, cacheBlockMask);
+    }
 }
 
 }