mem, sim, systemc: Reorganize Port and co.s bind, unbind slightly.

The base Port class can keep track of its peer, and also whether it's
connected. This is partially delegated away from the port subclasses
which still keep track of a cast version of their peer pointer for
their own conveneince, so that it can be used by generic code. Even
with the Port mechanism's new flexibility, each port still has
exactly one peer and is either connected or not based on whether there
is a peer currently.

Change-Id: Id3228617dd1604d196814254a1aadeac5ade7cde
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20232
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>

1 files changed, 37 insertions, 11 deletions

diff --git a/src/mem/port.cc b/src/mem/port.cc
index 40481b0bb..303d1bc41 100644
--- a/src/mem/port.cc
+++ b/src/mem/port.cc
@@ -70,6 +70,22 @@ BaseMasterPort::getSlavePort() const
     return *_baseSlavePort;
 }
 
+void
+BaseMasterPort::bind(Port &peer)
+{
+    _baseSlavePort = dynamic_cast<BaseSlavePort *>(&peer);
+    fatal_if(!_baseSlavePort, "Attempt to bind port %s to non-master port %s.",
+             name(), peer.name());
+    Port::bind(peer);
+}
+
+void
+BaseMasterPort::unbind()
+{
+    _baseSlavePort = nullptr;
+    Port::unbind();
+}
+
 BaseSlavePort::BaseSlavePort(const std::string &name, PortID _id)
     : Port(name, _id), _baseMasterPort(NULL)
 {
@@ -89,6 +105,22 @@ BaseSlavePort::getMasterPort() const
     return *_baseMasterPort;
 }
 
+void
+BaseSlavePort::bind(Port &peer)
+{
+    _baseMasterPort = dynamic_cast<BaseMasterPort *>(&peer);
+    fatal_if(!_baseMasterPort, "Attempt to bind port %s to non-slave port %s.",
+             name(), peer.name());
+    Port::bind(peer);
+}
+
+void
+BaseSlavePort::unbind()
+{
+    _baseMasterPort = nullptr;
+    Port::unbind();
+}
+
 /**
  * Master port
  */
@@ -109,12 +141,9 @@ MasterPort::bind(Port &peer)
         fatal("Attempt to bind port %s to non-slave port %s.",
                 name(), peer.name());
     }
-    // bind on the level of the base ports
-    _baseSlavePort = slave_port;
-
     // master port keeps track of the slave port
     _slavePort = slave_port;
-    _connected = true;
+    BaseMasterPort::bind(peer);
     // slave port also keeps track of master port
     _slavePort->slaveBind(*this);
 }
@@ -126,9 +155,8 @@ MasterPort::unbind()
         panic("Attempting to unbind master port %s that is not connected\n",
               name());
     _slavePort->slaveUnbind();
-    _slavePort = NULL;
-    _connected = false;
-    _baseSlavePort = NULL;
+    _slavePort = nullptr;
+    BaseMasterPort::unbind();
 }
 
 AddrRangeList
@@ -166,17 +194,15 @@ SlavePort::~SlavePort()
 void
 SlavePort::slaveUnbind()
 {
-    _baseMasterPort = NULL;
     _masterPort = NULL;
-    _connected = false;
+    BaseSlavePort::unbind();
 }
 
 void
 SlavePort::slaveBind(MasterPort& master_port)
 {
-    _baseMasterPort = &master_port;
     _masterPort = &master_port;
-    _connected = true;
+    BaseSlavePort::bind(master_port);
 }
 
 Tick