config: Add an Energy param type.

This type expects values in joules (J).

Change-Id: I77a3a4f1c19443f573d5fe7a84d5abd954ce1603
Reviewed-on: https://gem5-review.googlesource.com/5625
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
diff --git a/src/python/m5/params.py b/src/python/m5/params.py
index c241b05..11a55e5 100644
--- a/src/python/m5/params.py
+++ b/src/python/m5/params.py
@@ -1563,6 +1563,17 @@
         value = convert.toCurrent(value)
         super(Current, self).__init__(value)
 
+class Energy(Float):
+    ex_str = "1pJ"
+
+    def __new__(cls, value):
+        value = convert.toEnergy(value)
+        return super(cls, Energy).__new__(cls, value)
+
+    def __init__(self, value):
+        value = convert.toEnergy(value)
+        super(Energy, self).__init__(value)
+
 class NetworkBandwidth(float,ParamValue):
     cxx_type = 'float'
     ex_str = "1Gbps"
@@ -2035,7 +2046,7 @@
            'TcpPort', 'UdpPort', 'EthernetAddr',
            'IpAddress', 'IpNetmask', 'IpWithPort',
            'MemorySize', 'MemorySize32',
-           'Latency', 'Frequency', 'Clock', 'Voltage', 'Current',
+           'Latency', 'Frequency', 'Clock', 'Voltage', 'Current', 'Energy',
            'NetworkBandwidth', 'MemoryBandwidth',
            'AddrRange',
            'MaxAddr', 'MaxTick', 'AllMemory',