The only difference between GIC-500 and GIC-600 relevant to TF-A is the
differing power management sequence.
A certain GIC implementation is detectable at runtime, for instance by
checking the IIDR register. Let's add that test before initiating the
GIC-600 specific sequence, so the code can be used on both GIC-600 and
GIC-500 chips alike, without deciding on a GIC chip at compile time.

This means that the GIC-500 "driver" is now redundant. To allow minimal
platform support, add a switch to disable GIC-600 support.

Change-Id: I17ea97d9fb05874772ebaa13e6678b4ba3415557
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

This patch adds support for GICv4 extension.
New `GIC_ENABLE_V4_EXTN` option passed to gicv3.mk makefile
was added, and enables GICv4 related changes when set to 1.
This option defaults to 0.

Change-Id: I30ebe1b7a98d3a54863900f37eda4589c707a288
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

This patch provides support for GICv3.1 extended PPI and SPI
range. The option is enabled by setting to 1 and passing
`GIC_EXT_INTID` build flag to gicv3.mk makefile.
This option defaults to 0 with no extended range support.

Change-Id: I7d09086fe22ea531c5df51a8a1efd8928458d394
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

This patch moves all GICv3 driver files into new added
'gicv3.mk' makefile for the benefit of the generic driver
which can evolve in the future without affecting platforms.
The patch adds GICv3 driver configuration flags
'GICV3_IMPL', 'GICV3_IMPL_GIC600_MULTICHIP' and
'GICV3_OVERRIDE_DISTIF_PWR_OPS' described in
'GICv3 driver options' section of 'build-option.rst'
document.

NOTE: Platforms with GICv3 driver need to be modified to
include 'drivers/arm/gic/v3/gicv3.mk' in their makefiles.

Change-Id: If055f6770ff20f5dee5a3c99ae7ced7cdcac5c44
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>