The sunxi_mc_smp_lookback function is modeled after the mcpm_loopback
function in the MCPM framework. "lookback" was a typo introduced when
the new function was added.
Acked-by: NMaxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: NChen-Yu Tsai <wens@csie.org>

The BROM has a branch that checks if the primary core is hotplugging.
If the magic flag is set, execution jumps to the address set in the
software entry register. (Secondary cores always branch to the that
address.)

This patch sets the flags that makes BROM jump execution on the
primary core (cpu0) to the SMP software entry code when the core is
powered back up. After it is re-integrated into the system, the flag
is cleared.

A custom .cpu_can_disable callback that returns true for all cpus,
so that cpu0 can really be brought down.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>

This patch adds common code used to power down all cores and clusters.
The code was previously based on the MCPM framework. It has now been
adapted to hook into struct smp_operations directly, but the code
structure still shows signs of prior work.

The primary core (cpu0) requires setting flags to have the BROM bounce
execution to the SMP software entry code. This is done in a subsequent
patch to keep the changes cleanly separated. By default the ARM SMP code
blocks cpu0 from being turned off, so splitting this out is safe.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>

The A80 is a big.LITTLE SoC with 1 cluster of 4 Cortex-A7s and
1 cluster of 4 Cortex-A15s.

This patch adds support to bring up the second cluster and thus all
cores using custom platform SMP code. Core/cluster power down has not
been implemented, thus CPU hotplugging is not supported.

Parts of the trampoline and re-entry code for the boot cpu was adapted
from the MCPM framework.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>