Use CONFIG_MEMMAP_CACHEATTR to initialize MPU as described in the Xtensa
LSP RM document. Coalesce adjacent regions with the same cacheattr.
Update Kconfig help text.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Implement atomic primitives using exclusive access opcodes available in
the recent xtensa cores.
Since l32ex/s32ex don't have any memory ordering guarantees don't define
__smp_mb__before_atomic/__smp_mb__after_atomic to make them use memw.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Introduce the header arch/xtensa/include/asm/core.h that provides
definitions for XCHAL macros missing in older xtensa releases. Use this
header instead of variant/core.h
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
