mem-ruby: add CHI SnpRespData_SD_Fwded_SC message

This snoop reponse is not generated internally by the SLICC
implementation, but is required for compatibility with classic caches
which may remain in SD state while returning SC data upon receiving
a converted SnpShared.

Change-Id: I5270b29c8863c7afd8abc39b3c7978b95330c183

src/mem/ruby/protocol/chi/CHI-cache-actions.sm

@@ -1950,6 +1950,7 @@ action(Send_SnpSharedFwd_ToOwner, desc="") {
     if (retToSrc) {
       tbe.expected_snp_resp.addExpectedDataType(CHIDataType:SnpRespData_SC_Fwded_SC);
       tbe.expected_snp_resp.addExpectedDataType(CHIDataType:SnpRespData_SC_Fwded_SD_PD);
+      tbe.expected_snp_resp.addExpectedDataType(CHIDataType:SnpRespData_SD_Fwded_SC);
       tbe.expected_snp_resp.addExpectedDataType(CHIDataType:SnpRespData_I_Fwded_SC);
       tbe.expected_snp_resp.addExpectedDataType(CHIDataType:SnpRespData_I_Fwded_SD_PD);
     } else {
@@ -1964,6 +1965,7 @@ action(Send_SnpSharedFwd_ToOwner, desc="") {
       tbe.expected_snp_resp.addExpectedRespType(CHIResponseType:SnpResp_SC_Fwded_SC);
     }
     tbe.expected_snp_resp.addExpectedDataType(CHIDataType:SnpRespData_SC_PD_Fwded_SC);
+    tbe.expected_snp_resp.addExpectedDataType(CHIDataType:SnpRespData_SD_Fwded_SC);
     tbe.expected_snp_resp.addExpectedDataType(CHIDataType:SnpRespData_I_PD_Fwded_SC);
   }
   tbe.expected_snp_resp.addExpectedCount(1);
@@ -2304,7 +2306,8 @@ action(UpdateDirState_FromSnpDataResp, desc="") {
                  (in_msg.type == CHIDataType:SnpRespData_SC) ||
                  (in_msg.type == CHIDataType:SnpRespData_SC_Fwded_SC) ||
                  (in_msg.type == CHIDataType:SnpRespData_SC_Fwded_SD_PD) ||
-                 (in_msg.type == CHIDataType:SnpRespData_SC_PD_Fwded_SC)) {
+                 (in_msg.type == CHIDataType:SnpRespData_SC_PD_Fwded_SC) ||
+                 (in_msg.type == CHIDataType:SnpRespData_SD_Fwded_SC)) {
         // the owner must have been the responder, if there was one
         assert((tbe.dir_ownerExists == false) ||
              (tbe.dir_ownerExists && (tbe.dir_owner == in_msg.responder)));
@@ -2313,12 +2316,16 @@ action(UpdateDirState_FromSnpDataResp, desc="") {
         tbe.dir_ownerIsExcl := false;
         if ((in_msg.type == CHIDataType:SnpRespData_SC_Fwded_SC) ||
             (in_msg.type == CHIDataType:SnpRespData_SC_PD_Fwded_SC) ||
-            (in_msg.type == CHIDataType:SnpRespData_SC_Fwded_SD_PD)) {
+            (in_msg.type == CHIDataType:SnpRespData_SC_Fwded_SD_PD) ||
+            (in_msg.type == CHIDataType:SnpRespData_SD_Fwded_SC)) {
           tbe.dir_sharers.add(tbe.requestor);
         }
         if (in_msg.type == CHIDataType:SnpRespData_SC_Fwded_SD_PD) {
           tbe.dir_ownerExists := true;
           tbe.dir_owner := tbe.requestor;
+        } else if (in_msg.type == CHIDataType:SnpRespData_SD_Fwded_SC) {
+          tbe.dir_ownerExists := true;
+          tbe.dir_owner := in_msg.responder;
         }
 
       } else if ((in_msg.type == CHIDataType:SnpRespData_I_Fwded_SD_PD) ||
@@ -2507,7 +2514,8 @@ action(UpdateDataState_FromSnpDataResp, desc="") {
 
       } else if ((in_msg.type == CHIDataType:SnpRespData_SD) ||
                  (in_msg.type == CHIDataType:SnpRespData_SC_Fwded_SD_PD) ||
-                 (in_msg.type == CHIDataType:SnpRespData_I_Fwded_SD_PD)) {
+                 (in_msg.type == CHIDataType:SnpRespData_I_Fwded_SD_PD) ||
+                 (in_msg.type == CHIDataType:SnpRespData_SD_Fwded_SC)) {
         tbe.dataDirty := true;
         tbe.dataValid := true;
         tbe.dataMaybeDirtyUpstream := true;

src/mem/ruby/protocol/chi/CHI-cache-funcs.sm

@@ -229,6 +229,7 @@ void functionalRead(Addr addr, Packet *pkt, WriteMask &mask) {
             tbe.expected_snp_resp.receivedDataType(CHIDataType:SnpRespData_UD) ||
             tbe.expected_snp_resp.receivedDataType(CHIDataType:SnpRespData_SC_Fwded_SD_PD) ||
             tbe.expected_snp_resp.receivedDataType(CHIDataType:SnpRespData_SC_PD_Fwded_SC) ||
+            tbe.expected_snp_resp.receivedDataType(CHIDataType:SnpRespData_SD_Fwded_SC) ||
             tbe.expected_snp_resp.receivedDataType(CHIDataType:SnpRespData_I_Fwded_SD_PD) ||
             tbe.expected_snp_resp.receivedDataType(CHIDataType:SnpRespData_I_PD_Fwded_SC);
     }
@@ -1420,6 +1421,8 @@ Event dataToEvent (CHIDataType type) {
     return Event:SnpRespData_SC_Fwded_SC;
   } else if (type == CHIDataType:SnpRespData_SC_Fwded_SD_PD) {
     return Event:SnpRespData_SC_Fwded_SD_PD;
+  } else if (type == CHIDataType:SnpRespData_SD_Fwded_SC) {
+    return Event:SnpRespData_SD_Fwded_SC;
   } else if (type == CHIDataType:SnpRespData_SC_PD_Fwded_SC) {
     return Event:SnpRespData_SC_PD_Fwded_SC;
   } else if (type == CHIDataType:SnpRespData_I_Fwded_SD_PD) {

src/mem/ruby/protocol/chi/CHI-cache-transitions.sm

@@ -1426,6 +1426,7 @@ transition(BUSY_BLKD,
            {SnpRespData_I_PD,SnpRespData_I,SnpRespData_SC_PD,
             SnpRespData_SC,SnpRespData_SD,SnpRespData_UC,SnpRespData_UD,
             SnpRespData_SC_Fwded_SC,SnpRespData_SC_Fwded_SD_PD,
+            SnpRespData_SD_Fwded_SC,
             SnpRespData_SC_PD_Fwded_SC,SnpRespData_I_Fwded_SD_PD,
             SnpRespData_I_PD_Fwded_SC,SnpRespData_I_Fwded_SC}) {
   Receive_SnpDataResp;

src/mem/ruby/protocol/chi/CHI-cache.sm

@@ -406,6 +406,7 @@ machine(MachineType:Cache, "Cache coherency protocol") :
     SnpRespData_UD,                desc="";
     SnpRespData_SC_Fwded_SC,       desc="";
     SnpRespData_SC_Fwded_SD_PD,    desc="";
+    SnpRespData_SD_Fwded_SC,       desc="";
     SnpRespData_SC_PD_Fwded_SC,    desc="";
     SnpRespData_I_Fwded_SD_PD,     desc="";
     SnpRespData_I_PD_Fwded_SC,     desc="";

src/mem/ruby/protocol/chi/CHI-msg.sm

@@ -205,6 +205,7 @@ enumeration(CHIDataType, desc="...") {
   SnpRespData_SC_Fwded_SC;
   SnpRespData_SC_Fwded_SD_PD;
   SnpRespData_SC_PD_Fwded_SC;
+  SnpRespData_SD_Fwded_SC;
   SnpRespData_I_Fwded_SD_PD;
   SnpRespData_I_PD_Fwded_SC;
   SnpRespData_I_Fwded_SC;
@@ -243,6 +244,7 @@ structure(CHIDataMsg, desc="", interface="Message") {
                     (type == CHIDataType:SnpRespData_SD) ||
                     (type == CHIDataType:SnpRespData_UD) ||
                     (type == CHIDataType:SnpRespData_SC_Fwded_SD_PD) ||
+                    (type == CHIDataType:SnpRespData_SD_Fwded_SC) ||
                     (type == CHIDataType:SnpRespData_SC_PD_Fwded_SC) ||
                     (type == CHIDataType:SnpRespData_I_Fwded_SD_PD) ||
                     (type == CHIDataType:SnpRespData_I_PD_Fwded_SC);