Port: Add protocol-agnostic ports in the port hierarchy

This patch adds an additional level of ports in the inheritance
hierarchy, separating out the protocol-specific and protocl-agnostic
parts. All the functionality related to the binding of ports is now
confined to use BaseMaster/BaseSlavePorts, and all the
protocol-specific parts stay in the Master/SlavePort. In the future it
will be possible to add other protocol-specific implementations.

The functions used in the binding of ports, i.e. getMaster/SlavePort
now use the base classes, and the index parameter is updated to use
the PortID typedef with the symbolic InvalidPortID as the default.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/mem/bus.hh b/src/mem/bus.hh
index 26729f7cc..f3cbc9d24 100644
--- a/src/mem/bus.hh
+++ b/src/mem/bus.hh
@@ -361,8 +361,10 @@ class BaseBus : public MemObject
     virtual void init();
 
     /** A function used to return the port associated with this bus object. */
-    virtual MasterPort& getMasterPort(const std::string& if_name, int idx = -1);
-    virtual SlavePort& getSlavePort(const std::string& if_name, int idx = -1);
+    BaseMasterPort& getMasterPort(const std::string& if_name,
+                                  PortID idx = InvalidPortID);
+    BaseSlavePort& getSlavePort(const std::string& if_name,
+                                PortID idx = InvalidPortID);
 
     virtual unsigned int drain(Event *de) = 0;