MEM: Introduce the master/slave port roles in the Python classes

This patch classifies all ports in Python as either Master or Slave
and enforces a binding of master to slave. Conceptually, a master (such
as a CPU or DMA port) issues requests, and receives responses, and
conversely, a slave (such as a memory or a PIO device) receives
requests and sends back responses. Currently there is no
differentiation between coherent and non-coherent masters and slaves.

The classification as master/slave also involves splitting the dual
role port of the bus into a master and slave port and updating all the
system assembly scripts to use the appropriate port. Similarly, the
interrupt devices have to have their int_port split into a master and
slave port. The intdev and its children have minimal changes to
facilitate the extra port.

Note that this patch does not enforce any port typing in the C++
world, it merely ensures that the Python objects have a notion of the
port roles and are connected in an appropriate manner. This check is
carried when two ports are connected, e.g. bus.master =
memory.port. The following patches will make use of the
classifications and specialise the C++ ports into masters and slaves.

1 files changed, 12 insertions, 12 deletions

diff --git a/src/dev/x86/SouthBridge.py b/src/dev/x86/SouthBridge.py
index baff35e0b..9f7070e96 100644
--- a/src/dev/x86/SouthBridge.py
+++ b/src/dev/x86/SouthBridge.py
@@ -102,15 +102,15 @@ class SouthBridge(SimObject):
         self.speaker.i8254 = self.pit
         self.io_apic.external_int_pic = self.pic1
         # Connect to the bus
-        self.cmos.pio = bus.port
-        self.dma1.pio = bus.port
-        self.ide.pio = bus.port
-        self.ide.config = bus.port
-        self.ide.dma = bus.port
-        self.keyboard.pio = bus.port
-        self.pic1.pio = bus.port
-        self.pic2.pio = bus.port
-        self.pit.pio = bus.port
-        self.speaker.pio = bus.port
-        self.io_apic.pio = bus.port
-        self.io_apic.int_port = bus.port
+        self.cmos.pio = bus.master
+        self.dma1.pio = bus.master
+        self.ide.pio = bus.master
+        self.ide.config = bus.master
+        self.ide.dma = bus.slave
+        self.keyboard.pio = bus.master
+        self.pic1.pio = bus.master
+        self.pic2.pio = bus.master
+        self.pit.pio = bus.master
+        self.speaker.pio = bus.master
+        self.io_apic.pio = bus.master
+        self.io_apic.int_master = bus.slave