[PATCH 3/3] mm: Introduce HAVE_ARCH_TRANSPARENT_HUGEPAGE

[Will Deacon <will.deacon@arm.com>]

From: Steve Capper <steve.capper@arm.com>

Different architectures have slightly different pre-requisites for supporting
Transparent Huge Pages. To simplify the layout of mm/Kconfig, a new option
HAVE_ARCH_TRANSPARENT_HUGEPAGE is introduced and set in each architecture's
Kconfig file (at the moment x86, with ARM being set in a future patch).

Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 arch/x86/Kconfig |    4 ++++
 mm/Kconfig       |    2 +-
 2 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 8ec3a1a..7decdcf 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1297,6 +1297,10 @@ config ILLEGAL_POINTER_VALUE
        default 0 if X86_32
        default 0xdead000000000000 if X86_64
 
+config HAVE_ARCH_TRANSPARENT_HUGEPAGE
+       def_bool y
+       depends on MMU
+
 source "mm/Kconfig"
 
 config HIGHPTE
diff --git a/mm/Kconfig b/mm/Kconfig
index d5c8019..3322342 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -318,7 +318,7 @@ config NOMMU_INITIAL_TRIM_EXCESS
 
 config TRANSPARENT_HUGEPAGE
 	bool "Transparent Hugepage Support"
-	depends on X86 && MMU
+	depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE
 	select COMPACTION
 	help
 	  Transparent Hugepages allows the kernel to use huge pages and
-- 
1.7.4.1