xtensa: SMP: fix secondary CPU initialization
- add missing memory barriers to the secondary CPU synchronization spin
loops; add comment to the matching memory barrier in the boot_secondary
and __cpu_die functions;
- use READ_ONCE/WRITE_ONCE to access cpu_start_id/cpu_start_ccount
instead of reading/writing them directly;
- re-initialize cpu_running every time before starting secondary CPU to
flush possible previous CPU startup results.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2 files changed