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, 22 insertions, 0 deletions

diff --git a/src/mem/ruby/network/simple/Switch.cc b/src/mem/ruby/network/simple/Switch.cc
index 5c2f5a717..a0a27f758 100644
--- a/src/mem/ruby/network/simple/Switch.cc
+++ b/src/mem/ruby/network/simple/Switch.cc
@@ -217,6 +217,28 @@ Switch::print(std::ostream& out) const
     // FIXME printing
     out << "[Switch]";
 }
+bool
+Switch::functionalRead(Packet *pkt)
+{
+    // Access the buffers in the switch for performing a functional read
+    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
+Switch::functionalWrite(Packet *pkt)
+{
+    // Access the buffers in the switch for performing a functional write
+    uint32_t num_functional_writes = 0;
+    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;
+}
 
 Switch *
 SwitchParams::create()