diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index 3485c58cfd1c..9a5eafb7145b 100644
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -104,4 +104,17 @@ static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
 		return object;
 }
 
+/*
+ * We want to avoid an expensive divide : (offset / cache->size)
+ *   Using the fact that size is a constant for a particular cache,
+ *   we can replace (offset / cache->size) by
+ *   reciprocal_divide(offset, cache->reciprocal_buffer_size)
+ */
+static inline unsigned int obj_to_index(const struct kmem_cache *cache,
+					const struct page *page, void *obj)
+{
+	u32 offset = (obj - page->s_mem);
+	return reciprocal_divide(offset, cache->reciprocal_buffer_size);
+}
+
 #endif	/* _LINUX_SLAB_DEF_H */
diff --git a/mm/slab.c b/mm/slab.c
index 15e53cef0378..a80beb543678 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -406,19 +406,6 @@ static inline void *index_to_obj(struct kmem_cache *cache, struct page *page,
 	return page->s_mem + cache->size * idx;
 }
 
-/*
- * We want to avoid an expensive divide : (offset / cache->size)
- *   Using the fact that size is a constant for a particular cache,
- *   we can replace (offset / cache->size) by
- *   reciprocal_divide(offset, cache->reciprocal_buffer_size)
- */
-static inline unsigned int obj_to_index(const struct kmem_cache *cache,
-					const struct page *page, void *obj)
-{
-	u32 offset = (obj - page->s_mem);
-	return reciprocal_divide(offset, cache->reciprocal_buffer_size);
-}
-
 #define BOOT_CPUCACHE_ENTRIES	1
 /* internal cache of cache description objs */
 static struct kmem_cache kmem_cache_boot = {