tree 342f465e06b8546ca5b420b091139baddf181ba2
parent e828ec4fc58af67d915e89f4339d64d240ac1e48
author Olivier Deprez <olivier.deprez@arm.com> 1624261633 +0200
committer Olivier Deprez <olivier.deprez@arm.com> 1631199077 +0200

refactor(spmd): boot interface and pass core id

This change refactors the SPMD to setup SPMC CPU contexts once and early
from spmd_spmc_init (single call to cm_setup_context rather than on each
and every warm boot).
Pass the core linear ID through a GP register as an implementation
defined behavior helping FF-A adoption to legacy TOSes (essentially
when secure virtualization is not used).

A first version of this change was originally submitted by Lukas [1].
Pasting below the original justification:

Our TEE, Kinibi, is used to receive the core linear ID in the x3
register of booting secondary cores.
This patch is necessary to bring up secondary cores with Kinibi as an
SPMC in SEL1.

In Kinibi, the TEE is mostly platform-independent and all platform-
specifics like topology is concentrated in TF-A of our customers.
That is why we don't have the MPIDR - linear ID mapping in Kinibi.
We need the correct linear ID to program the GICv2 target register,
for example in power management case.
It is not needed on GICv3/v4, because of using a fixed mapping from
MPIDR to ICDIPTR/GICD_ITARGETSRn register.

For debug and power management purpose, we also want a unified view to
linear id between Linux and the TEE.
E.g. to disable a core, to see what cores are printing a trace /
an event.

In the past, Kinibi had several other designs, but the complexity was
getting out of control:
* Platform-specific assembler macros in the kernel.
* A per-core SMC from Linux to tell the linear ID after the boot.
* With DynamiQ, it seems SIPs were playing with MPIDR register values,
  reusing them between cores and changing them during boot.

[1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/10235

Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Signed-off-by: Lukas Hanel <lukas.hanel@trustonic.com>
Change-Id: Ifa8fa208e9b8eb1642c80b5f7b54152dadafa75e