mm/dynamic_hugetlb: support dynamic hugetlb on arm64

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

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

To support dynamic hugetlb on arm64, we need to do two more things. The
first one is to fix kabi broken in mem_cgroup, we use kabi_reserve_5 to
fix it in previous patch. The second one is to check cont-bit hugetlb
since this feature only support for PMD-size and PUD-size hugepage.

This feature only support for 4KB pagesize, not support for 16KB and 64KB.
Signed-off-by: NLiu Shixin <liushixin2@huawei.com>

fs/Kconfig

@@ -262,7 +262,7 @@ config HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON
 
 config DYNAMIC_HUGETLB
 	bool "Dynamic HugeTLB"
-	depends on X86_64
+	depends on X86_64 || (ARM64 && ARM64_4K_PAGES)
 	depends on HUGETLBFS
 	depends on MEMCG && CGROUP_HUGETLB
 	help

fs/hugetlbfs/inode.c

@@ -1202,7 +1202,7 @@ static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
 	 */
 	mpol_shared_policy_init(&p->policy, NULL);
 	/* Initialize hpool here in case of a quick call to destroy */
-	link_hpool(p);
+	link_hpool(p, sbinfo->hstate);
 
 	return &p->vfs_inode;
 }

include/linux/dynamic_hugetlb.h

@@ -97,7 +97,7 @@ bool free_page_to_dhugetlb_pool(struct page *page);
 void free_page_list_to_dhugetlb_pool(struct list_head *list);
 int task_has_mem_in_hpool(struct task_struct *tsk);
 
-void link_hpool(struct hugetlbfs_inode_info *p);
+void link_hpool(struct hugetlbfs_inode_info *p, struct hstate *h);
 void unlink_hpool(struct hugetlbfs_inode_info *p);
 bool file_has_mem_in_hpool(struct hugetlbfs_inode_info *p);
 int dhugetlb_acct_memory(struct hstate *h, long delta, struct hugetlbfs_inode_info *p);
@@ -147,7 +147,7 @@ static inline int task_has_mem_in_hpool(struct task_struct *tsk)
 }
 
 #ifdef CONFIG_HUGETLBFS
-static inline void link_hpool(struct hugetlbfs_inode_info *p)
+static inline void link_hpool(struct hugetlbfs_inode_info *p, struct hstate *h)
 {
 }
 static inline void unlink_hpool(struct hugetlbfs_inode_info *p)

mm/dynamic_hugetlb.c

@@ -5,6 +5,7 @@
 
 #include <linux/rmap.h>
 #include <linux/migrate.h>
+#include <linux/memblock.h>
 #include <linux/memory_hotplug.h>
 #include <linux/dynamic_hugetlb.h>
 
@@ -618,13 +619,19 @@ void free_page_list_to_dhugetlb_pool(struct list_head *list)
 	}
 }
 
-void link_hpool(struct hugetlbfs_inode_info *p)
+void link_hpool(struct hugetlbfs_inode_info *p, struct hstate *h)
 {
+	unsigned long size;
+
 	if (!dhugetlb_enabled || !p)
 		return;
 
-	p->hpool = find_hpool_by_task(current);
-	if (!get_hpool_unless_zero(p->hpool))
+	size = huge_page_size(h);
+	if (size == PMD_SIZE || size == PUD_SIZE) {
+		p->hpool = find_hpool_by_task(current);
+		if (!get_hpool_unless_zero(p->hpool))
+			p->hpool = NULL;
+	} else
 		p->hpool = NULL;
 }