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, 38 insertions, 0 deletions

diff --git a/src/mem/ruby/network/simple/SimpleNetwork.cc b/src/mem/ruby/network/simple/SimpleNetwork.cc
index 7aa8e62f9..9df9ed3a5 100644
--- a/src/mem/ruby/network/simple/SimpleNetwork.cc
+++ b/src/mem/ruby/network/simple/SimpleNetwork.cc
@@ -327,3 +327,41 @@ SimpleNetworkParams::create()
 {
     return new SimpleNetwork(this);
 }
+
+/*
+ * The simple network has an array of switches. These switches have buffers
+ * that need to be accessed for functional reads and writes. Also the links
+ * between different switches have buffers that need to be accessed.
+ */
+bool
+SimpleNetwork::functionalRead(Packet *pkt)
+{
+    for (unsigned int i = 0; i < m_switch_ptr_vector.size(); i++) {
+        if (m_switch_ptr_vector[i]->functionalRead(pkt)) {
+            return true;
+        }
+    }
+
+    for (unsigned int i = 0; i < m_buffers_to_free.size(); ++i) {
+        if (m_buffers_to_free[i]->functionalRead(pkt)) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+uint32_t
+SimpleNetwork::functionalWrite(Packet *pkt)
+{
+    uint32_t num_functional_writes = 0;
+
+    for (unsigned int i = 0; i < m_switch_ptr_vector.size(); i++) {
+        num_functional_writes += m_switch_ptr_vector[i]->functionalWrite(pkt);
+    }
+
+    for (unsigned int i = 0; i < m_buffers_to_free.size(); ++i) {
+        num_functional_writes += m_buffers_to_free[i]->functionalWrite(pkt);
+    }
+    return num_functional_writes;
+}