mem-cache: Adopt a more sensible cache class hierarchy

This patch changes what goes into the BaseCache and what goes into the
Cache, to make it easier to add a NoncoherentCache with as much re-use
as possible. A number of redundant members and definitions are also
removed in the process.

This is a modified version of a changeset put together by Andreas
Hansson <andreas.hansson@arm.com>

Change-Id: Ie9dd73c4ec07732e778e7416b712dad8b4bd5d4b
Reviewed-on: https://gem5-review.googlesource.com/10431
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

1 files changed, 17 insertions, 14 deletions

diff --git a/src/mem/cache/Cache.py b/src/mem/cache/Cache.py
index faee0925b..a2fa4e90f 100644
--- a/src/mem/cache/Cache.py
+++ b/src/mem/cache/Cache.py
@@ -46,6 +46,12 @@ from Prefetcher import BasePrefetcher
 from ReplacementPolicies import *
 from Tags import *
 
+
+# Enum for cache clusivity, currently mostly inclusive or mostly
+# exclusive.
+class Clusivity(Enum): vals = ['mostly_incl', 'mostly_excl']
+
+
 class BaseCache(MemObject):
     type = 'BaseCache'
     abstract = True
@@ -90,13 +96,13 @@ class BaseCache(MemObject):
 
     system = Param.System(Parent.any, "System we belong to")
 
-# Enum for cache clusivity, currently mostly inclusive or mostly
-# exclusive.
-class Clusivity(Enum): vals = ['mostly_incl', 'mostly_excl']
-
-class Cache(BaseCache):
-    type = 'Cache'
-    cxx_header = 'mem/cache/cache.hh'
+    # Determine if this cache sends out writebacks for clean lines, or
+    # simply clean evicts. In cases where a downstream cache is mostly
+    # exclusive with respect to this cache (acting as a victim cache),
+    # the clean writebacks are essential for performance. In general
+    # this should be set to True for anything but the last-level
+    # cache.
+    writeback_clean = Param.Bool(False, "Writeback clean lines")
 
     # Control whether this cache should be mostly inclusive or mostly
     # exclusive with respect to upstream caches. The behaviour on a
@@ -110,10 +116,7 @@ class Cache(BaseCache):
     clusivity = Param.Clusivity('mostly_incl',
                                 "Clusivity with upstream cache")
 
-    # Determine if this cache sends out writebacks for clean lines, or
-    # simply clean evicts. In cases where a downstream cache is mostly
-    # exclusive with respect to this cache (acting as a victim cache),
-    # the clean writebacks are essential for performance. In general
-    # this should be set to True for anything but the last-level
-    # cache.
-    writeback_clean = Param.Bool(False, "Writeback clean lines")
+
+class Cache(BaseCache):
+    type = 'Cache'
+    cxx_header = 'mem/cache/cache.hh'