config, arm: Add an example power model

Add a script to demonstrate how power models can be wired to gem5
models. The script is meant as an example only and does not correlate
with any realistic implementation.

Change-Id: Ib95a74b2cb4af77a7816e3e8e89c89f3460775a1
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2721
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

configs/example/arm/fs_power.py

@@ -0,0 +1,105 @@
+# Copyright (c) 2017 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 Sandberg
+#          Stephan Diestelhorst
+
+# This configuration file extends the example ARM big.LITTLE(tm)
+# with example power models.
+
+import argparse
+import os
+
+import m5
+from m5.objects import MathExprPowerModel, PowerModel
+
+import fs_bigLITTLE as bL
+
+
+class CpuPowerOn(MathExprPowerModel):
+    # 2A per IPC, 3pA per cache miss
+    # and then convert to Watt
+    dyn = "voltage * (2 * ipc + " \
+            "3 * 0.000000001 * dcache.overall_misses / sim_seconds)"
+    st = "4 * temp"
+
+class CpuPowerOff(MathExprPowerModel):
+    dyn = "0"
+    st = "0"
+
+class CpuPowerModel(PowerModel):
+    pm = [
+        CpuPowerOn(), # ON
+        CpuPowerOff(), # CLK_GATED
+        CpuPowerOff(), # SRAM_RETENTION
+        CpuPowerOff(), # OFF
+    ]
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Generic ARM big.LITTLE configuration with "\
+        "example power models")
+    bL.addOptions(parser)
+    options = parser.parse_args()
+
+    if options.cpu_type != "timing":
+        m5.fatal("The power example script requires 'timing' CPUs.")
+
+    root = bL.build(options)
+
+    # Wire up some example power models to the CPUs
+    for cpu in root.system.descendants():
+        if not isinstance(cpu, m5.objects.BaseCPU):
+            continue
+
+        cpu.default_p_state = "ON"
+        cpu.power_model = CpuPowerModel()
+
+    bL.instantiate(options)
+
+    print "*" * 70
+    print "WARNING: The power numbers generated by this script are " \
+        "examples. They are not representative of any particular " \
+        "implementation or process."
+    print "*" * 70
+
+    # Dumping stats periodically
+    m5.stats.periodicStatDump(m5.ticks.fromSeconds(0.1E-3))
+    bL.run()
+
+
+if __name__ == "__m5_main__":
+    main()