Fix regression introduced with d435d862ba
("cpu hotplug: mce: fix cpu hotplug error handling").
A CPU which was not brought up during boot (using maxcpus and
additional_cpus parameters) couldn't be onlined anymore. For such a CPU it
seemed that MCE was not supported during CPU_UP_PREPARE-time which caused
mce_cpu_callback to return NOTIFY_BAD to notifier_call_chain. To fix this
we:
- call mce_create_device for CPU_ONLINE event (instead of CPU_UP_PREPARE),
- avoid mce_remove_device() for the CPU that is not correctly initialized
by mce_create_device() failure,
- make mce_cpu_callback always return NOTIFY_OK for CPU_ONLINE event.
Because CPU_ONLINE callback return value is always ignored.
[akinobu.mita@gmail.com: avoid mce_remove_device() for not initialized device]
[akinobu.mita@gmail.com: make mce_cpu_callback always return NOTIFY_OK]
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bae19fe033