mem: Explicitly check MSHR snoops for cases not dealt with

[gem5.git] / src / mem / bridge.cc

diff --git a/src/mem/bridge.cc b/src/mem/bridge.cc
index a21d123a18fb3e80327859bb4cc33d7e614e15c2..1f7d1d43a02e8eb972a45ca3e638848d7dbe9ddc 100644 (file)
--- a/src/mem/bridge.cc
+++ b/src/mem/bridge.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011-2013 ARM Limited
+ * Copyright (c) 2011-2013, 2015 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -136,10 +136,14 @@ Bridge::BridgeMasterPort::recvTimingResp(PacketPtr pkt)
 
     DPRINTF(Bridge, "Request queue size: %d\n", transmitList.size());
 
-    // @todo: We need to pay for this and not just zero it out
-    pkt->firstWordDelay = pkt->lastWordDelay = 0;
+    // technically the packet only reaches us after the header delay,
+    // and typically we also need to deserialise any payload (unless
+    // the two sides of the bridge are synchronous)
+    Tick receive_delay = pkt->headerDelay + pkt->payloadDelay;
+    pkt->headerDelay = pkt->payloadDelay = 0;
 
-    slavePort.schedTimingResp(pkt, bridge.clockEdge(delay));
+    slavePort.schedTimingResp(pkt, bridge.clockEdge(delay) +
+                              receive_delay);
 
     return true;
 }
@@ -150,8 +154,20 @@ Bridge::BridgeSlavePort::recvTimingReq(PacketPtr pkt)
     DPRINTF(Bridge, "recvTimingReq: %s addr 0x%x\n",
             pkt->cmdString(), pkt->getAddr());
 
-    // we should not see a timing request if we are already in a retry
-    assert(!retryReq);
+    // sink inhibited packets without further action, also discard any
+    // packet that is not a read or a write
+    if (pkt->memInhibitAsserted() ||
+        !(pkt->isWrite() || pkt->isRead())) {
+        assert(!pkt->needsResponse());
+        pendingDelete.reset(pkt);
+        return true;
+    }
+
+    // we should not get a new request after committing to retry the
+    // current one, but unfortunately the CPU violates this rule, so
+    // simply ignore it for now
+    if (retryReq)
+        return false;
 
     DPRINTF(Bridge, "Response queue size: %d outresp: %d\n",
             transmitList.size(), outstandingResponses);
@@ -162,8 +178,7 @@ Bridge::BridgeSlavePort::recvTimingReq(PacketPtr pkt)
         retryReq = true;
     } else {
         // look at the response queue if we expect to see a response
-        bool expects_response = pkt->needsResponse() &&
-            !pkt->memInhibitAsserted();
+        bool expects_response = pkt->needsResponse();
         if (expects_response) {
             if (respQueueFull()) {
                 DPRINTF(Bridge, "Response queue full\n");
@@ -180,10 +195,15 @@ Bridge::BridgeSlavePort::recvTimingReq(PacketPtr pkt)
         }
 
         if (!retryReq) {
-            // @todo: We need to pay for this and not just zero it out
-            pkt->firstWordDelay = pkt->lastWordDelay = 0;
-
-            masterPort.schedTimingReq(pkt, bridge.clockEdge(delay));
+            // technically the packet only reaches us after the header
+            // delay, and typically we also need to deserialise any
+            // payload (unless the two sides of the bridge are
+            // synchronous)
+            Tick receive_delay = pkt->headerDelay + pkt->payloadDelay;
+            pkt->headerDelay = pkt->payloadDelay = 0;
+
+            masterPort.schedTimingReq(pkt, bridge.clockEdge(delay) +
+                                      receive_delay);
         }
     }
 
@@ -200,7 +220,7 @@ Bridge::BridgeSlavePort::retryStalledReq()
     if (retryReq) {
         DPRINTF(Bridge, "Request waiting for retry, now retrying\n");
         retryReq = false;
-        sendRetry();
+        sendRetryReq();
     }
 }
 
@@ -217,7 +237,7 @@ Bridge::BridgeMasterPort::schedTimingReq(PacketPtr pkt, Tick when)
 
     assert(transmitList.size() != reqQueueLimit);
 
-    transmitList.push_back(DeferredPacket(pkt, when));
+    transmitList.emplace_back(pkt, when);
 }
 
 
@@ -232,7 +252,7 @@ Bridge::BridgeSlavePort::schedTimingResp(PacketPtr pkt, Tick when)
         bridge.schedule(sendEvent, when);
     }
 
-    transmitList.push_back(DeferredPacket(pkt, when));
+    transmitList.emplace_back(pkt, when);
 }
 
 void
@@ -309,7 +329,7 @@ Bridge::BridgeSlavePort::trySendTiming()
         if (!masterPort.reqQueueFull() && retryReq) {
             DPRINTF(Bridge, "Request waiting for retry, now retrying\n");
             retryReq = false;
-            sendRetry();
+            sendRetryReq();
         }
     }
 
@@ -318,13 +338,13 @@ Bridge::BridgeSlavePort::trySendTiming()
 }
 
 void
-Bridge::BridgeMasterPort::recvRetry()
+Bridge::BridgeMasterPort::recvReqRetry()
 {
     trySendTiming();
 }
 
 void
-Bridge::BridgeSlavePort::recvRetry()
+Bridge::BridgeSlavePort::recvRespRetry()
 {
     trySendTiming();
 }