mm/hugetlb: introduce ARCH_HAS_GIGANTIC_PAGE

Avoid making ifdef get pretty unwieldy if many ARCHs support gigantic
page.  No functional change with this patch.

Link: http://lkml.kernel.org/r/1475227569-63446-2-git-send-email-xieyisheng1@huawei.com
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 6 insertions, 1 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index deeadfa291ba..fb538031569a 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -71,6 +71,7 @@ config S390
         select ARCH_HAS_DEVMEM_IS_ALLOWED
         select ARCH_HAS_ELF_RANDOMIZE
         select ARCH_HAS_GCOV_PROFILE_ALL
+        select ARCH_HAS_GIGANTIC_PAGE
         select ARCH_HAS_KCOV
         select ARCH_HAS_SG_CHAIN
         select ARCH_HAS_UBSAN_SANITIZE_ALL
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 58bec8f9641a..827273c56ae9 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -28,6 +28,7 @@ config X86
         select ARCH_HAS_ELF_RANDOMIZE
         select ARCH_HAS_FAST_MULTIPLIER
         select ARCH_HAS_GCOV_PROFILE_ALL
+        select ARCH_HAS_GIGANTIC_PAGE           if X86_64
         select ARCH_HAS_KCOV                    if X86_64
         select ARCH_HAS_PMEM_API                if X86_64
         select ARCH_HAS_MMIO_FLUSH
diff --git a/fs/Kconfig b/fs/Kconfig
index 3ef62bad8f2b..4bd03a2b0518 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -200,6 +200,9 @@ config HUGETLBFS
 config HUGETLB_PAGE
         def_bool HUGETLBFS
 
+config ARCH_HAS_GIGANTIC_PAGE
+        bool
+
 source "fs/configfs/Kconfig"
 source "fs/efivarfs/Kconfig"
 
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 770d83eb3f48..e4a4500758f2 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1022,7 +1022,7 @@ static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed)
                 ((node = hstate_next_node_to_free(hs, mask)) || 1);     \
                 nr_nodes--)
 
-#if (defined(CONFIG_X86_64) || defined(CONFIG_S390)) && \
+#if defined(CONFIG_ARCH_HAS_GIGANTIC_PAGE) && \
         ((defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || \
         defined(CONFIG_CMA))
 static void destroy_compound_gigantic_page(struct page *page,