python: Add Python 3 workarounds for long

Python 3 doesn't have a separate long type. Make long an alias for int
where needed to maintain compatibility.

Change-Id: I4c0861302bc3a2fa5226b3041803ef975d29b2fd
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15988
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>

config: Make parameter conversion handle integers in other bases.

Python's float() function/type can't handle hexadecimal notation, but
int() can. Since there are also cases where converting to a float and
then back to an int (or long) can cause rounding error, this change
splits toFloat and toInteger apart and makes them call a worker
function which accepts a conversion function which does the work of
converting a numeric string into an actual number.

in the case of toFloat, it still uses the standard float(), and in the
case of toInteger it uses a lambda which wraps int(x, 0).

Change-Id: Ic46cf4ae86b7eba6f55d731d1b25e3f84b8bb64c
Reviewed-on: https://gem5-review.googlesource.com/c/16504
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

python: Make exception handling Python 3 safe

Change-Id: I9c2cdfad20deb1ddfa224320cf93f2105d126652
Reviewed-on: https://gem5-review.googlesource.com/c/15980
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>

util: Add a "toEnergy" function to the convert module.

Change-Id: I7299af0e2a6ce9bd2272d6ccb898997336e95e51
Reviewed-on: https://gem5-review.googlesource.com/5623
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

util: Simplify/consolidate the python conversion module.

The python conversion module was really repetitive and fragmented,
where some types of conversions use common code, and some use hand
written case statements which did something very similar. Also, some
types like Voltage could only handle V and mV but no other scaling
prefix.

This change restructures the module to centralize a lot of the unit
handling code into toFloat, and makes the various other functions use
it.

Change-Id: Ic8529203cc226c9b551b8535a444e3f2f25ad1eb
Reviewed-on: https://gem5-review.googlesource.com/5621
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

config: Add Current as a parameter type

This patch adds the Python parameter type Current, which is used for
the DRAM power modelling (to start with). With this addition we avoid
implicit unit assumptions.

power: Add voltage domains to the clock domains

This patch adds the notion of voltage domains, and groups clock
domains that operate under the same voltage (i.e. power supply) into
domains. Each clock domain is required to be associated with a voltage
domain, and the latter requires the voltage to be explicitly set.

A voltage domain is an independently controllable voltage supply being
provided to section of the design. Thus, if you wish to perform
dynamic voltage scaling on a CPU, its clock domain should be
associated with a separate voltage domain.

The current implementation of the voltage domain does not take into
consideration cases where there are derived voltage domains running at
ratio of native voltage domains, as with the case where there can be
on-chip buck/boost (charge pumps) voltage regulation logic.

The regression and configuration scripts are updated with a generic
voltage domain for the system, and one for the CPUs.

Copyright: Add AMD copyright to the param changes I just made.

Params: Add parameter types for IP addresses in various forms.

New parameter forms are:
IP address in the format "a.b.c.d" where a-d are from decimal 0 to 255.
IP address with netmask which is an IP followed by "/n" where n is a netmask
length in bits from decimal 0 to 32 or by "/e.f.g.h" where e-h are from
decimal 0 to 255 and which is all 1 bits followed by all 0 bits when
represented in binary. These can also be specified as an integral IP and
netmask passed in separately.
IP address with port which is an IP followed by ":p" where p is a port index
from decimal 0 to 65535. These can also be specified as an integral IP and
port value passed in separately.

python: Move more code into m5.util allow SCons to use that code.
Get rid of misc.py and just stick misc things in __init__.py
Move utility functions out of SCons files and into m5.util
Move utility type stuff from m5/__init__.py to m5/util/__init__.py
Remove buildEnv from m5 and allow access only from m5.defines
Rename AddToPath to addToPath while we're moving it to m5.util
Rename read_command to readCommand while we're moving it
Rename compare_versions to compareVersions while we're moving it.