commit 147b9635e6347104b91f48ca9dca61eb0fbf2a54 upstream.
If CTR_EL0.{CWG,ERG} are 0b0000 then they must be interpreted to have
their architecturally maximum values, which defeats the use of
FTR_HIGHER_SAFE when sanitising CPU ID registers on heterogeneous
machines.
Introduce FTR_HIGHER_OR_ZERO_SAFE so that these fields effectively
saturate at zero.
Fixes: 3c739b5710 ("arm64: Keep track of CPU feature registers")
Cc: <stable@vger.kernel.org> # 4.4.y only
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ebb9ffd10a