stdlib,ruby: Enable resetting version numbers (#1649)

Ruby requires each machine type to have a continuous set of version
numbers starting at 0. We were hiding this from users/developers by
using a Python class variable in the stdlib. Unfortunately, with
multiple ruby systems this doesn't work anymore.

As a stop-gap this change adds "resetting" these versions to the
beginning of `incorporate_caches`. It would be better to fix this in the
C++ code (and assign these numbers in C++ probably via the RubySystem),
but that's a bigger change than is needed right now.

---------

Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

src/python/gem5/components/cachehierarchies/chi/private_l1_cache_hierarchy.py

@@ -82,6 +82,7 @@ class PrivateL1CacheHierarchy(AbstractRubyCacheHierarchy):
 
     @overrides(AbstractCacheHierarchy)
     def incorporate_cache(self, board: AbstractBoard) -> None:
+        super().incorporate_cache(board)
         self.ruby_system = RubySystem()
 
         # Ruby's global network.
@@ -244,3 +245,10 @@ class PrivateL1CacheHierarchy(AbstractRubyCacheHierarchy):
             dma_controllers.append(ctrl)
 
         return dma_controllers
+
+    @overrides(AbstractRubyCacheHierarchy)
+    def _reset_version_numbers(self):
+        from .nodes.abstract_node import AbstractNode
+
+        AbstractNode._version = 0
+        MemoryController._version = 0

src/python/gem5/components/cachehierarchies/ruby/abstract_ruby_cache_hierarchy.py

@@ -37,6 +37,18 @@ class AbstractRubyCacheHierarchy(AbstractCacheHierarchy):
     def __init__(self):
         super().__init__()
 
+    def _reset_version_numbers(self):
+        """Needed for multiple ruby systems so that each system starts at 0.
+
+        Note: This needs to be overridden by the protocol since we don't know
+        the machine classes at this point.
+        """
+        raise NotImplementedError
+
+    @overrides(AbstractCacheHierarchy)
+    def incorporate_cache(self, board):
+        self._reset_version_numbers()
+
     @overrides(AbstractCacheHierarchy)
     def is_ruby(self) -> bool:
         return True

src/python/gem5/components/cachehierarchies/ruby/caches/prebuilt/octopi_cache/octopi.py

@@ -38,6 +38,7 @@ from ......components.cachehierarchies.ruby.caches.mesi_three_level.directory im
 from ......components.cachehierarchies.ruby.caches.mesi_three_level.dma_controller import (
     DMAController,
 )
+from ......utils.override import overrides
 from ......utils.requires import requires
 from ....abstract_three_level_cache_hierarchy import (
     AbstractThreeLevelCacheHierarchy,
@@ -95,6 +96,7 @@ class OctopiCache(
         requires(
             coherence_protocol_required=CoherenceProtocol.MESI_THREE_LEVEL
         )
+        super().incorporate_cache(board)
 
         cache_line_size = board.get_cache_line_size()
 
@@ -267,3 +269,15 @@ class OctopiCache(
             ]
             for link in self.dma_int_links:
                 self.ruby_system.network._add_int_link(link)
+
+    @overrides(AbstractRubyCacheHierarchy)
+    def _reset_version_numbers(self):
+        from ....caches.mesi_three_level.l1_cache import L1Cache
+        from ....caches.mesi_three_level.l2_cache import L2Cache
+        from ....caches.mesi_three_level.l3_cache import L3Cache
+
+        Directory._version = 0
+        L1Cache._version = 0
+        L2Cache._version = 0
+        L3Cache._version = 0
+        DMAController._version = 0

src/python/gem5/components/cachehierarchies/ruby/mesi_three_level_cache_hierarchy.py

@@ -33,6 +33,7 @@ from m5.objects import (
 )
 
 from ....coherence_protocol import CoherenceProtocol
+from ....utils.override import overrides
 from ....utils.requires import requires
 
 requires(coherence_protocol_required=CoherenceProtocol.MESI_THREE_LEVEL)
@@ -87,6 +88,7 @@ class MESIThreeLevelCacheHierarchy(
         self._num_l3_banks = num_l3_banks
 
     def incorporate_cache(self, board: AbstractBoard) -> None:
+        super().incorporate_cache(board)
         cache_line_size = board.get_cache_line_size()
 
         self.ruby_system = RubySystem()
@@ -233,3 +235,11 @@ class MESIThreeLevelCacheHierarchy(
             ruby_system=self.ruby_system
         )
         board.connect_system_port(self.ruby_system.sys_port_proxy.in_ports)
+
+    @overrides(AbstractRubyCacheHierarchy)
+    def _reset_version_numbers(self):
+        Directory._version = 0
+        L1Cache._version = 0
+        L2Cache._version = 0
+        L3Cache._version = 0
+        DMAController._version = 0

src/python/gem5/components/cachehierarchies/ruby/mesi_two_level_cache_hierarchy.py

@@ -33,6 +33,7 @@ from m5.objects import (
 )
 
 from ....coherence_protocol import CoherenceProtocol
+from ....utils.override import overrides
 from ....utils.requires import requires
 
 requires(coherence_protocol_required=CoherenceProtocol.MESI_TWO_LEVEL)
@@ -83,6 +84,7 @@ class MESITwoLevelCacheHierarchy(
         self._num_l2_banks = num_l2_banks
 
     def incorporate_cache(self, board: AbstractBoard) -> None:
+        super().incorporate_cache(board)
         cache_line_size = board.get_cache_line_size()
 
         self.ruby_system = RubySystem()
@@ -199,3 +201,10 @@ class MESITwoLevelCacheHierarchy(
             ruby_system=self.ruby_system
         )
         board.connect_system_port(self.ruby_system.sys_port_proxy.in_ports)
+
+    @overrides(AbstractRubyCacheHierarchy)
+    def _reset_version_numbers(self):
+        Directory._version = 0
+        L1Cache._version = 0
+        L2Cache._version = 0
+        DMAController._version = 0

src/python/gem5/components/cachehierarchies/ruby/mi_example_cache_hierarchy.py

@@ -32,6 +32,7 @@ from m5.objects import (
 )
 
 from ....coherence_protocol import CoherenceProtocol
+from ....utils.override import overrides
 from ....utils.requires import requires
 
 requires(coherence_protocol_required=CoherenceProtocol.MI_EXAMPLE)
@@ -65,6 +66,7 @@ class MIExampleCacheHierarchy(AbstractRubyCacheHierarchy):
 
     @overrides(AbstractCacheHierarchy)
     def incorporate_cache(self, board: AbstractBoard) -> None:
+        super().incorporate_cache(board)
         self.ruby_system = RubySystem()
 
         # Ruby's global network.
@@ -176,3 +178,9 @@ class MIExampleCacheHierarchy(AbstractRubyCacheHierarchy):
             ruby_system=self.ruby_system
         )
         board.connect_system_port(self.ruby_system.sys_port_proxy.in_ports)
+
+    @overrides(AbstractRubyCacheHierarchy)
+    def _reset_version_numbers(self):
+        Directory._version = 0
+        L1Cache._version = 0
+        DMAController._version = 0