Regression: Use CPU clock and 32-byte width for L1-L2 bus

This patch changes the CoherentBus between the L1s and L2 to use the
CPU clock and also four times the width compared to the default
bus. The parameters are not intending to fit every single scenario,
but rather serve as a better startingpoint than what we previously
had.

Note that the scripts that do not use the addTwoLevelCacheHiearchy are
not affected by this change.

A separate patch will update the stats.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/cpu/BaseCPU.py b/src/cpu/BaseCPU.py
index 6e5f6ff1a..331957749 100644
--- a/src/cpu/BaseCPU.py
+++ b/src/cpu/BaseCPU.py
@@ -236,7 +236,10 @@ class BaseCPU(MemObject):
 
     def addTwoLevelCacheHierarchy(self, ic, dc, l2c, iwc = None, dwc = None):
         self.addPrivateSplitL1Caches(ic, dc, iwc, dwc)
-        self.toL2Bus = CoherentBus()
+        # Override the default bus clock of 1 GHz and uses the CPU
+        # clock for the L1-to-L2 bus, and also set a width of 32 bytes
+        # (256-bits), which is four times that of the default bus.
+        self.toL2Bus = CoherentBus(clock = Parent.clock, width = 32)
         self.connectCachedPorts(self.toL2Bus)
         self.l2cache = l2c
         self.toL2Bus.master = self.l2cache.cpu_side