feat(psci): check that CPUs handled a pabandon
Up to now PSCI assumed that if a pabandon happened then the CPU driver
will have handled it. This patch adds a simple protocol to make sure
that this is indeed the case. The chosen method is with a return value
that is highly unlikely on cores that are unaware of pabandon (x0 will
be primed with 1 and if used should be overwritten with the value of
CPUPWRCTLR_EL1 which should have its last bit set to power off and its
top bits RES0; the ACK value is chosen to be the exact opposite). An
alternative method would have been to add a field in cpu_ops, however
that would have required more major refactoring across many cpus and
would have taken up more memory on older platforms, so it was not
chosen.
Change-Id: I5826c0e4802e104d295c4ecbd80b5f676d2cd871
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
5 files changed