Several more fixes for multi-level timing coherence.

- Add "deferred snoop" flag to Packet so upper-level caches
  can distinguish whether lower-level cache request was
  in-service or not at the time of the original snoop.
- Revamp response handling to properly handle deferred snoops
  on non-cache-fill requests (i.e. upgrades).
- Make sure forwarded writebacks are kept in write buffer at
  lower-level caches so they get snooped properly.

--HG--
extra : convert_revision : 17f8a3772a1ae31a16991a53f8225ddf54d31fc9

1 files changed, 3 insertions, 0 deletions

diff --git a/src/mem/packet.hh b/src/mem/packet.hh
index 036bd3fd7..8063c7ae7 100644
--- a/src/mem/packet.hh
+++ b/src/mem/packet.hh
@@ -257,6 +257,7 @@ class Packet : public FastAlloc
         Shared,
         // Special control flags
         ExpressSnoop,
+        DeferredSnoop,
         NUM_PACKET_FLAGS
     };
 
@@ -322,6 +323,8 @@ class Packet : public FastAlloc
     // Special control flags
     void setExpressSnoop()      { flags[ExpressSnoop] = true; }
     bool isExpressSnoop()       { return flags[ExpressSnoop]; }
+    void setDeferredSnoop()     { flags[DeferredSnoop] = true; }
+    bool isDeferredSnoop()      { return flags[DeferredSnoop]; }
 
     // Network error conditions... encapsulate them as methods since
     // their encoding keeps changing (from result field to command