configs: fix CHI mem buffers

Disabling randomization for the memory request and response buffers.
CHI requires that memory responses for the same address arrive in
the same order the request was sent.

Change-Id: Ia4236188679beaf2969978675414a870ccd9f94a
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/63673
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>

configs/ruby/CHI_config.py

@@ -183,6 +183,16 @@ class OrderedTriggerMessageBuffer(TriggerMessageBuffer):
     ordered = True
 
 
+class MemCtrlMessageBuffer(MessageBuffer):
+    """
+    MessageBuffer exchanging messages with the memory
+    These buffers should also not be affected by the Ruby tester randomization.
+    """
+
+    randomization = "disabled"
+    ordered = True
+
+
 class CHI_Cache_Controller(Cache_Controller):
     """
     Default parameters for a Cache controller
@@ -667,8 +677,8 @@ class CHI_SNF_Base(CHI_Node):
             version=Versions.getVersion(Memory_Controller),
             ruby_system=ruby_system,
             triggerQueue=TriggerMessageBuffer(),
-            responseFromMemory=MessageBuffer(),
-            requestToMemory=MessageBuffer(ordered=True),
+            responseFromMemory=MemCtrlMessageBuffer(),
+            requestToMemory=MemCtrlMessageBuffer(),
             reqRdy=TriggerMessageBuffer(),
             transitions_per_cycle=1024,
         )