FAILED: patch "[PATCH] powerpc/64e: Drop stale call to smp_processor_id() which" failed to apply to 4.9-stable tree

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b9ee5e04fd77898208c51b1395fa0b5e8536f9b6 Mon Sep 17 00:00:00 2001
From: Christophe Leroy <[email protected]>
Date: Thu, 8 Aug 2019 12:48:26 +0000
Subject: [PATCH] powerpc/64e: Drop stale call to smp_processor_id() which
hangs SMP startup

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 makes SMP hang when CONFIG_PREEMPT is set.

index d4acf6fa0596..bf60983a58c7 100644
@@ -630,7 +630,6 @@ static void early_init_this_mmu(void)
 #ifdef CONFIG_PPC_FSL_BOOK3E
 	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
 		unsigned int num_cams;
-		int __maybe_unused cpu = smp_processor_id();
 		bool map = true;
 
 		/* use a quarter of the TLBCAM for bolted linear map */