hugetlb: add an inline helper for finding hstate index

Add an inline helper and use it in the code.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index d5d6bbe2259e..217f52859fa7 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -302,6 +302,11 @@ static inline unsigned hstate_index_to_shift(unsigned index)
         return hstates[index].order + PAGE_SHIFT;
 }
 
+static inline int hstate_index(struct hstate *h)
+{
+        return h - hstates;
+}
+
 #else
 struct hstate {};
 #define alloc_huge_page_node(h, nid) NULL
@@ -320,6 +325,7 @@ static inline unsigned int pages_per_huge_page(struct hstate *h)
         return 1;
 }
 #define hstate_index_to_shift(index) 0
+#define hstate_index(h) 0
 #endif
 
 #endif /* _LINUX_HUGETLB_H */