[PATCH 5.13 018/113] powerpc: Re-enable ARCH_ENABLE_SPLIT_PMD_PTLOCK

From: Greg Kroah-Hartman
Date: Wed Sep 01 2021 - 08:47:11 EST


From: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx>

commit 310d2e83cb9b7f1e7232319880e3fcb57592fa10 upstream.

Commit 66f24fa766e3 ("mm: drop redundant ARCH_ENABLE_SPLIT_PMD_PTLOCK")
broke PMD split page table lock for powerpc.

It selects the non-existent config ARCH_ENABLE_PMD_SPLIT_PTLOCK in
arch/powerpc/platforms/Kconfig.cputype, but clearly intended to
select ARCH_ENABLE_SPLIT_PMD_PTLOCK (notice the word swapping!), as
that commit did for all other architectures.

Fix it by selecting the correct symbol ARCH_ENABLE_SPLIT_PMD_PTLOCK.

Fixes: 66f24fa766e3 ("mm: drop redundant ARCH_ENABLE_SPLIT_PMD_PTLOCK")
Cc: stable@xxxxxxxxxxxxxxx # v5.13+
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx>
Reviewed-by: Daniel Axtens <dja@xxxxxxxxxx>
[mpe: Reword change log to make it clear this is a bug fix]
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210819113954.17515-3-lukas.bulwahn@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/platforms/Kconfig.cputype | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -97,7 +97,7 @@ config PPC_BOOK3S_64
select PPC_HAVE_PMU_SUPPORT
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
- select ARCH_ENABLE_PMD_SPLIT_PTLOCK
+ select ARCH_ENABLE_SPLIT_PMD_PTLOCK
select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
select ARCH_SUPPORTS_HUGETLBFS
select ARCH_SUPPORTS_NUMA_BALANCING