Due to their interrelationship in the architecture the SVE and SME
features in TF-A are mutually exclusive. This means that a single binary
can't be shared between systems with and without SME if the system
without SME does support SVE, SVE will not be initialised so lower ELs
will run into trouble trying to use it. This unusual behaviour for TF-A
which normally gracefully handles situations where features are enabled
but not supported on the current hardware.
Address this by calling the SVE enable and disable functions if SME is
not supported rather than immediately exiting, these perform their own
feature checks so if neither SVE nor SME is supported behaviour is
unchanged.
Signed-off-by: Mark Brown <broonie@kernel.org>
Change-Id: I2c606202fa6c040069f44e29d36b5abb48391874
This patch adds two new compile time options to enable SME in TF-A:
ENABLE_SME_FOR_NS and ENABLE_SME_FOR_SWD for use in non-secure and
secure worlds respectively. Setting ENABLE_SME_FOR_NS=1 will enable
SME for non-secure worlds and trap SME, SVE, and FPU/SIMD instructions
in secure context. Setting ENABLE_SME_FOR_SWD=1 will disable these
traps, but support for SME context management does not yet exist in
SPM so building with SPD=spmd will fail.
The existing ENABLE_SVE_FOR_NS and ENABLE_SVE_FOR_SWD options cannot
be used with SME as it is a superset of SVE and will enable SVE and
FPU/SIMD along with SME.
Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: Iaaac9d22fe37b4a92315207891da848a8fd0ed73
