mm/dynamic_hugetlb: fix kabi broken when enable CONFIG_DYNAMIC_HUGETLB on arm64

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I6XOIE
CVE: NA

--------------------------------

When enable dynamic hugetlb on arm64, the new member struct dhugetlb_pool*
will be added to mem_cgroup. We need to use a KABI_RESERVE to fix broken
of kabi. The previous struct dhugetlb_pool* is only used on x86_64.
Signed-off-by: NLiu Shixin <liushixin2@huawei.com>
(cherry picked from commit fc47477c)

include/linux/memcontrol.h

@@ -372,7 +372,7 @@ struct mem_cgroup {
 	struct deferred_split deferred_split_queue;
 #endif
 
-#ifdef CONFIG_DYNAMIC_HUGETLB
+#if defined(CONFIG_DYNAMIC_HUGETLB) && defined(CONFIG_X86_64)
 	struct dhugetlb_pool *hpool;
 #endif
 #ifndef __GENKSYMS__
@@ -397,7 +397,11 @@ struct mem_cgroup {
 #else
 	KABI_RESERVE(5)
 #endif
+#if defined(CONFIG_DYNAMIC_HUGETLB) && defined(CONFIG_ARM64)
+	KABI_USE(6, struct dhugetlb_pool *hpool)
+#else
 	KABI_RESERVE(6)
+#endif
 	KABI_RESERVE(7)
 	KABI_RESERVE(8)