feat(cm): support for asymmetric feature among cores

TF-A assumes that all the cores in a platform has architecture feature
parity, this is evident by the fact that primary sets up the
Non-secure context of secondary cores.

With changing landscape of platforms (e.g. big/little/mid cores), we are
seeing more and more platforms which has feature asymmetry among cores.
There is also a scenario where certain CPU erratum only applies to one
type of cores and requires a feature to be disabled even it supports
the feature.

To handle these scenarios, introduce a hook in warmboot path which would
be called on the running CPU to override any feature disparity in the
NS context stashed up by primary. Note that, re-checking of feature for
Secure/Realm context is not required as the context is created on
running core itself.

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I5a01dbda528fa8481a00fdd098b58a7463ed0e22
2 files changed