Use the vendor CSRs for enabling/disabling the caches, and the ISA
extension for cache maintenance.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Enable the T-HEAD ISA extensions, as these are required to use the cache
maintenance instructions. Enable the branch predictor and BTB to improve
performance. Some bits are only available on specific CPU models, so
provide Kconfig symbols for selecting the right model.
Signed-off-by: Samuel Holland <samuel@sholland.org>
T-HEAD C9xx and E9xx CPUs contain some extra CSRs which control the
branch predictor and cache-related functionality.
Signed-off-by: Samuel Holland <samuel@sholland.org>
