ruby: improved support for functional accesses

This patch adds support to different entities in the ruby memory system
for more reliable functional read/write accesses. Only the simple network
has been augmented as of now. Later on Garnet will also support functional
accesses.
The patch adds functional access code to all the different types of messages
that protocols can send around. These messages are functionally accessed
by going through the buffers maintained by the network entities.
The patch also rectifies some of the bugs found in coherence protocols while
testing the patch.

With this patch applied, functional writes always succeed. But functional
reads can still fail.

1 files changed, 11 insertions, 1 deletions

diff --git a/src/mem/protocol/MOESI_CMP_directory-L1cache.sm b/src/mem/protocol/MOESI_CMP_directory-L1cache.sm
index 43c2def2e..6295f90fd 100644
--- a/src/mem/protocol/MOESI_CMP_directory-L1cache.sm
+++ b/src/mem/protocol/MOESI_CMP_directory-L1cache.sm
@@ -219,7 +219,17 @@ machine(L1Cache, "Directory protocol")
   }
 
   DataBlock getDataBlock(Address addr), return_by_ref="yes" {
-    return getCacheEntry(addr).DataBlk;
+    Entry cache_entry := getCacheEntry(addr);
+    if(is_valid(cache_entry)) {
+        return cache_entry.DataBlk;
+    }
+
+    TBE tbe := TBEs[addr];
+    if(is_valid(tbe)) {
+      return tbe.DataBlk;
+    }
+
+    error("Data block missing!");
   }
 
   Event mandatory_request_type_to_event(RubyRequestType type) {