Commit 73839798af7ebc6c8d0c9271ebbbc148700e521f upstream.

When setting a dummy iwmmxt context, create a local instance and
use __copy_to_user both cases whether iwmmxt is being used or not.
This has the benefit of disabling/enabling PAN once for the whole copy
intead of once per write.
Signed-off-by: NJulien Thierry <julien.thierry@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid A. Long <dave.long@linaro.org>
Reviewed-by: NJulien Thierry <julien.thierry@arm.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>