mem-cache: Fix MSHR handling of cache clean requests
Previously satisfied clean requests would not snoop in-service
MSHRs. This is a problem when a clean request is also invalidating, in
which case we have to post-invalidate or post-downgrade outstanding
requests. This changes fixes this bug.
Change-Id: I31e42aa94dd3637b2818e00fbaae68c810145eaf
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17728
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
diff --git a/src/mem/cache/cache.cc b/src/mem/cache/cache.cc
index 89e40f3..938b6f4 100644
--- a/src/mem/cache/cache.cc
+++ b/src/mem/cache/cache.cc
@@ -1180,13 +1180,6 @@
return;
}
- // Bypass any existing cache maintenance requests if the request
- // has been satisfied already (i.e., the dirty block has been
- // found).
- if (mshr && pkt->req->isCacheMaintenance() && pkt->satisfied()) {
- return;
- }
-
// Let the MSHR itself track the snoop and decide whether we want
// to go ahead and do the regular cache snoop
if (mshr && mshr->handleSnoop(pkt, order++)) {
diff --git a/src/mem/cache/mshr.cc b/src/mem/cache/mshr.cc
index 5b93029..8db7c29 100644
--- a/src/mem/cache/mshr.cc
+++ b/src/mem/cache/mshr.cc
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2012-2013, 2015-2018 ARM Limited
+ * Copyright (c) 2012-2013, 2015-2019 ARM Limited
* All rights reserved.
*
* The license below extends only to copyright in the software and shall
@@ -459,7 +459,14 @@
// in the case of an uncacheable request there is no need
// to set the responderHadWritable flag, but since the
// recipient does not care there is no harm in doing so
+ } else if (isPendingModified() && pkt->isClean()) {
+ // this cache doesn't respond to the clean request, a
+ // destination xbar will respond to this request, but to
+ // do so it needs to know if it should wait for the
+ // WriteCleanReq
+ pkt->setSatisfied();
}
+
targets.add(cp_pkt, curTick(), _order, Target::FromSnoop,
downstreamPending && targets.needsWritable, false);
@@ -467,10 +474,6 @@
// This transaction will take away our pending copy
postInvalidate = true;
}
-
- if (isPendingModified() && pkt->isClean()) {
- pkt->setSatisfied();
- }
}
if (!pkt->needsWritable() && !pkt->req->isUncacheable()) {