Port: Stricter port bind/unbind semantics

This patch tightens up the semantics around port binding and checks
that the ports that are being bound are currently not connected, and
similarly connected before unbind is called.

The patch consequently also changes the order of the unbind and bind
for the switching of CPUs to ensure that the rules are adhered
to. Previously the ports would be "over-written" without any check.

There are no changes in behaviour due to this patch, and the only
place where the unbind functionality is used is in the CPU.

1 files changed, 10 insertions, 2 deletions

diff --git a/src/mem/port.cc b/src/mem/port.cc
index 3827994fb..9b65da756 100644
--- a/src/mem/port.cc
+++ b/src/mem/port.cc
@@ -82,14 +82,22 @@ MasterPort::getSlavePort() const
 }
 
 void
-MasterPort::unBind()
+MasterPort::unbind()
 {
+    if (_slavePort == NULL)
+        panic("Attempting to unbind master port %s that is not connected\n",
+              name());
+    _slavePort->unbind();
     _slavePort = NULL;
 }
 
 void
 MasterPort::bind(SlavePort& slave_port)
 {
+    if (_slavePort != NULL)
+        panic("Attempting to bind master port %s that is already connected\n",
+              name());
+
     // master port keeps track of the slave port
     _slavePort = &slave_port;
 
@@ -173,7 +181,7 @@ SlavePort::~SlavePort()
 }
 
 void
-SlavePort::unBind()
+SlavePort::unbind()
 {
     _masterPort = NULL;
 }