Subject: Re: [PATCH] powerpc/64e: drop stale call to smp_processor_id() which hangs SMP startup

From: Michael Ellerman <[email-masked]>
Date: Mon, 12 Aug 2019 23:15:05 +1000 (AEST)

On Thu, 2019-08-08 at 12:48:26 UTC, Christophe Leroy wrote:
> Santa commit ebb9d30a6a74 ("powerpc/mm: any thread in one core can be
> the first to setup TLB1") removed the need to know the cpu_id in
> early_init_this_mmu(), but the call to smp_processor_id() which was
> marked __maybe_used remained.
> 
> Since commit ed1cd6deb013 ("powerpc: Activate
> CONFIG_THREAD_INFO_IN_TASK") thread_info cannot be reached before mmu
> is properly set up.
> 
> Drop this stale call to smp_processor_id() which make SMP hang
> when CONFIG_PREEMPT is set.
> 
> Reported-by: Chris Packham <[email-masked]>
> Fixes: ebb9d30a6a74 ("powerpc/mm: any thread in one core can be the first to setup TLB1")
> Link: https://github.com/linuxppc/issues/issues/264
> Signed-off-by: Christophe Leroy <[email-masked]>
> Cc: [email-masked]

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/b9ee5e04fd77898208c51b1395fa0b5e8536f9b6

cheers