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, 13 insertions, 7 deletions

diff --git a/src/mem/ruby/buffers/MessageBuffer.hh b/src/mem/ruby/buffers/MessageBuffer.hh
index cf7e77c2d..c4fd7165d 100644
--- a/src/mem/ruby/buffers/MessageBuffer.hh
+++ b/src/mem/ruby/buffers/MessageBuffer.hh
@@ -41,10 +41,10 @@
 #include <string>
 #include <vector>
 
+#include "mem/packet.hh"
 #include "mem/ruby/buffers/MessageBufferNode.hh"
 #include "mem/ruby/common/Address.hh"
 #include "mem/ruby/common/Consumer.hh"
-#include "mem/ruby/common/Global.hh"
 #include "mem/ruby/slicc_interface/Message.hh"
 
 class MessageBuffer
@@ -65,12 +65,7 @@ class MessageBuffer
     void stallMessage(const Address& addr);
 
     // TRUE if head of queue timestamp <= SystemTime
-    bool
-    isReady() const
-    {
-        return ((m_prio_heap.size() > 0) &&
-                (m_prio_heap.front().m_time <= g_system_ptr->getTime()));
-    }
+    bool isReady() const;
 
     void
     delayHead()
@@ -145,6 +140,17 @@ class MessageBuffer
     void setIncomingLink(int link_id) { m_input_link_id = link_id; }
     void setVnet(int net) { m_vnet_id = net; }
 
+    // Function for figuring out if any of the messages in the buffer can
+    // satisfy the read request for the address in the packet.
+    // Return value, if true, indicates that the request was fulfilled.
+    bool functionalRead(Packet *pkt);
+
+    // Function for figuring out if any of the messages in the buffer need
+    // to be updated with the data from the packet.
+    // Return value indicates the number of messages that were updated.
+    // This required for debugging the code.
+    uint32_t functionalWrite(Packet *pkt);
+
   private:
     //added by SS
     int m_recycle_latency;