x86: apic: Cleanup and simplify setup_local_APIC()

setup_local_APIC() is used to setup local APIC early during CPU
initialization and already assumes that preemption is disabled on
entry. However, The function unnecessarily disables and enables
preemption and uses smp_processor_id() multiple times in and out of
the nested preemption disabled section. This gives the wrong
impression that the function might be able to handle being called with
preemption enabled and/or migrated to another processor in the middle.

Make it clear that the function is always called with preemption
disabled, drop the confusing preemption disable block and call
smp_processor_id() once at the beginning of the function.

Signed-off-by: Tejun Heo <[email protected]>
Acked-by: Cyrill Gorcunov <[email protected]>
Reviewed-by: Pekka Enberg <[email protected]>
Cc: Yinghai Lu <[email protected]>
Cc: [email protected]
LKML-Reference: <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>

0 files changed, 0 insertions, 0 deletions