mem: DRAMPower trace formatting script

This patch adds a first version of a script that processes the debug
output and generates a command trace for DRAMPower. This is work in
progress and is intended as a snapshot of ongoing work at this point.

The longer term plan is to link in DRAMPower as a library and have one
instance of the model per rank, and instantiate it based on a struct
passed from gem5. Each command will then be a call to the model and no
parsing of traces will be necessary.

diff --git a/util/drampower_trace.py b/util/drampower_trace.py
new file mode 100755 (executable)
index 0000000..3369228
--- /dev/null
+++ b/util/drampower_trace.py
@@ -0,0 +1,109 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2014 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
+
+import sys
+import re
+import math
+
+# This utility script parses through the debug output looking for
+# lines printed by the DRAMPowerTrace debug flag. For all such lines,
+# it sorts the entries based on the timestamp and outputs it to a new
+# file in a format that DRAMPower accepts.
+def main():
+    if len(sys.argv) != 4:
+        print "Usage: ", sys.argv[0], " <simout> <rank> <command output>"
+        exit(-1)
+
+    try:
+        sim_in = open(sys.argv[1], 'r')
+    except IOError:
+        print "Failed to open ", sys.argv[1], " for reading"
+        exit(-1)
+
+    try:
+        rank = int(sys.argv[2])
+    except ValueError:
+        print "Failed to determine rank from ", sys.argv[2]
+        exit(-1)
+
+    try:
+        cmd_out = open(sys.argv[3], 'w')
+    except IOError:
+        print "Failed to open ", sys.argv[3], " for writing"
+        exit(-1)
+
+    # Due to the out-of-order printing from the event-based DRAM
+    # controller model, we need to sort the commands by time stamp. We
+    # use the refresh as the ordering point
+    history = []
+
+    # For each line in the debug trace output
+    for line in sim_in:
+        # Search for a line with the right format. At the moment this
+        # is rather dangerous, and could be made more robust.
+        if re.search('\d+: .*: \d+,[A-Z]+,\d+,\d+', line):
+            cmd = line.split(' ')[-1]
+            cmd_cycle, cmd_name, cmd_bank, cmd_rank = cmd.split(',')
+
+            # only look at the commands for the specific rank
+            if (int(cmd_rank) == rank):
+
+                # Do the conversion to clock cycles so we can use it to
+                # sort
+                cmd_cycle = int(cmd_cycle)
+
+                # Append this to the history
+                history.append((cmd_cycle, cmd_name, cmd_bank))
+
+                # If we are refreshing, print the history and flush it
+                if cmd_name == "REF":
+                    history.sort(key = lambda tup: tup[0])
+                    for (c, n, b) in history:
+                        cmd_entry = "%d,%s,%s\n" % (c, n, b)
+                        cmd_out.write(cmd_entry)
+
+                    history = []
+
+    # We're done
+    sim_in.close()
+    cmd_out.close()
+
+if __name__ == "__main__":
+    main()
+