ARM64: mm: THP support.

Bring Transparent HugePage support to ARM. The size of a
transparent huge page depends on the normal page size. A
transparent huge page is always represented as a pmd.

If PAGE_SIZE is 4KB, THPs are 2MB.
If PAGE_SIZE is 64KB, THPs are 512MB.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 10607d63b945..308a55636f76 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -189,6 +189,9 @@ config ARCH_WANT_GENERAL_HUGETLB
 config ARCH_WANT_HUGE_PMD_SHARE
         def_bool y if !ARM64_64K_PAGES
 
+config HAVE_ARCH_TRANSPARENT_HUGEPAGE
+        def_bool y
+
 source "mm/Kconfig"
 
 config FORCE_MAX_ZONEORDER