tree cbcfee29b995a73d7135acde6ef040696f59eadc
parent da2c9e15a654baa4bf62995fcefb372505fc122c
author Marc Bonnici <marc.bonnici@arm.com> 1638206249 +0000
committer Marc Bonnici <marc.bonnici@arm.com> 1650480031 +0100

feat(spmc): add function to determine the return path from the SPMC

Use knowledge of the target partition ID and source security state
to determine which route should be used to exit the SPMC.

There are 3 exit paths:
1) Return to the normal world via the SPMD, this will take care of
   switching contexts if required.
2) Return to the secure world when the call originated in the normal
   world and therefore switch contexts.
3) Return to the secure world when the call originated in the secure
   world, therefore we can return directly.

Signed-off-by: Marc Bonnici <marc.bonnici@arm.com>
Change-Id: I4037f3a8a8519e2c9f1876be92806d2c41d0d154