MEM: Move port creation to the memory object(s) construction

This patch moves all port creation from the getPort method to be
consistently done in the MemObject's constructor. This is possible
thanks to the Swig interface passing the length of the vector ports.
Previously there was a mix of: 1) creating the ports as members (at
object construction time) and using getPort for the name resolution,
or 2) dynamically creating the ports in the getPort call. This is now
uniform. Furthermore, objects that would not be complete without a
port have these ports as members rather than having pointers to
dynamically allocated ports.

This patch also enables an elaboration-time enumeration of all the
ports in the system which can be used to determine the masterId.

1 files changed, 42 insertions, 13 deletions

diff --git a/src/mem/bus.cc b/src/mem/bus.cc
index e37449b6e..827adc78e 100644
--- a/src/mem/bus.cc
+++ b/src/mem/bus.cc
@@ -57,6 +57,7 @@ Bus::Bus(const BusParams *p)
     : MemObject(p), busId(p->bus_id), clock(p->clock),
       headerCycles(p->header_cycles), width(p->width), tickNextIdle(0),
       drainEvent(NULL), busIdle(this), inRetry(false),
+      nbrMasterPorts(p->port_master_connection_count),
       defaultPortId(INVALID_PORT_ID), useDefaultRange(p->use_default_range),
       defaultBlockSize(p->block_size),
       cachedBlockSize(0), cachedBlockSizeValid(false)
@@ -68,27 +69,55 @@ Bus::Bus(const BusParams *p)
         fatal("Bus clock period must be positive\n");
     if (headerCycles <= 0)
         fatal("Number of header cycles must be positive\n");
+
+    // create the ports based on the size of the master and slave
+    // vector ports, and the presence of the default master
+
+    // id used to index into interfaces which is a flat vector of all
+    // ports
+    int id = 0;
+    for (int i = 0; i < p->port_master_connection_count; ++i) {
+        std::string portName = csprintf("%s-p%d", name(), id);
+        interfaces.push_back(new BusPort(portName, this, id));
+        ++id;
+    }
+
+    // note that the first slave port is now stored on index
+    // nbrMasterPorts in the vector
+    for (int i = 0; i < p->port_slave_connection_count; ++i) {
+        std::string portName = csprintf("%s-p%d", name(), id);
+        interfaces.push_back(new BusPort(portName, this, id));
+        ++id;
+    }
+
+    // see if we have a default master connected and if so add the
+    // port at the end
+    if (p->port_default_connection_count) {
+        defaultPortId = id;
+        std::string portName = csprintf("%s-default", name());
+        interfaces.push_back(new BusPort(portName, this, id));
+        ++id;
+    }
+
     clearPortCache();
 }
 
 Port *
 Bus::getPort(const std::string &if_name, int idx)
 {
-    std::string portName;
-    int id = interfaces.size();
-    if (if_name == "default") {
-        if (defaultPortId == INVALID_PORT_ID) {
-            defaultPortId = id;
-            portName = csprintf("%s-default", name());
-        } else
-            fatal("Default port already set on %s\n", name());
+    if (if_name == "master") {
+        // the master index translates directly to the interfaces
+        // vector as they are stored first
+        return interfaces[idx];
+    } else if (if_name == "slave") {
+        // the slaves are stored after the masters and we must thus
+        // offset the slave index with the number of master ports
+        return interfaces[nbrMasterPorts + idx];
+    } else  if (if_name == "default") {
+        return interfaces[defaultPortId];
     } else {
-        portName = csprintf("%s-p%d", name(), id);
+        panic("No port %s %d on bus %s\n", if_name, idx, name());
     }
-    BusPort *bp = new BusPort(portName, this, id);
-    interfaces.push_back(bp);
-    cachedBlockSizeValid = false;
-    return bp;
 }
 
 void