On Fri, 19 Dec 2025 15:52:36 +0000
Sascha Bischoff [off-list ref] wrote:

From: Marc Zyngier <maz@kernel.org>

None of the registers we manage in the feature dependency infrastructure
so far has any RES1 bit. This is about to change, as VTCR_EL2 has
its bit 31 being RES1.

Oh goody.

In order to not fail the consistency checks by not describing a bit,
add RES1 bits to the set of immutable bits. This requires some extra
surgery for the FGT handling, as we now need to track RES1 bits there
as well.

There are no RES1 FGT bits *yet*. Watch this space.

Signed-off-by: Marc Zyngier <maz@kernel.org>

FWIW it seems correct.  The only thing I wondered about is
the assumption that if there is an error best thing to do is
to assume it was res0 that was wrong and paper over it.
I guess we can't do anything better if that does happen.

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>

Process thing though: before anyone can merge this, Sasha
please take a look at submitting patches documentation.

When you 'post' a patch that was written by someone else you have
handled the patch and for the Developer Certificate of origin stuff
to work you have to add your Signed-off-by after theirs.

Jonathan