We've had bugs in the cache code with handling of register numbers with the top bit set before, add some test cases for this. It's not really worth fixing up all the individual tests to support a base address, instead write a specific test that reproduces a bunch of the coverge. Run this on the rbtree and maple caches which are the only ones that can reasonably support this case. Link: https://patch.msgid.link/20260818-regmap-kunit-cache-high-bit-v1-2-7e790676dea3@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org>