mem: Redesign the stack distance calculator as a probe

This changeset removes the stack distance calculator hooks from the
CommMonitor class and implements a stack distance calculator as a
memory system probe instead. The probe can be hooked up to any
component that exports probe points of the type ProbePoints::Packet.

src/mem/probes/StackDistProbe.py

@@ -0,0 +1,64 @@
+# Copyright (c) 2014-2015 ARM Limited
+# All rights reserved.
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Authors: Andreas Hansson
+#          Andreas Sandberg
+
+from m5.params import *
+from m5.proxy import *
+from BaseMemProbe import BaseMemProbe
+
+class StackDistProbe(BaseMemProbe):
+    type = 'StackDistProbe'
+    cxx_header = "mem/probes/stack_dist.hh"
+
+    system = Param.System(Parent.any,
+                          "System to use when determining system cache "
+                          "line size")
+
+    line_size = Param.Unsigned(Parent.cache_line_size,
+                               "Cache line size in bytes (must be larger or "
+                               "equal to the system's line size)")
+
+    # enable verification stack
+    verify = Param.Bool(False, "Verify behaviuor with reference implementation")
+
+    # linear histogram bins and enable/disable
+    linear_hist_bins = Param.Unsigned('16', "Bins in linear histograms")
+    disable_linear_hists = Param.Bool(False, "Disable linear histograms")
+
+    # logarithmic histogram bins and enable/disable
+    log_hist_bins = Param.Unsigned('32', "Bins in logarithmic histograms")
+    disable_log_hists = Param.Bool(False, "Disable logarithmic histograms")