arm64/hugetlb: Use ptep_get() to get the pte value of a huge page

The original huge_ptep_get() on ARM64 is just a wrapper of ptep_get(),
which will not take into account any contig-PTEs dirty and access bits.
Meanwhile we will implement a new ARM64-specific huge_ptep_get()
interface in following patch, which will take into account any contig-PTEs
dirty and access bits. To keep the same efficient logic to get the pte
value, change to use ptep_get() as a preparation.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/5113ed6e103f995e1d0f0c9fda0373b761bbcad2.1652496622.git.baolin.wang@linux.alibaba.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Author: Baolin Wang

arch/arm64/mm/hugetlbpage.c

@@ -172,7 +172,7 @@ static pte_t get_clear_contig(struct mm_struct *mm,
 			     unsigned long pgsize,
 			     unsigned long ncontig)
 {
-	pte_t orig_pte = huge_ptep_get(ptep);
+	pte_t orig_pte = ptep_get(ptep);
 	unsigned long i;
 
 	for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) {
@@ -379,7 +379,7 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
 {
 	int ncontig;
 	size_t pgsize;
-	pte_t orig_pte = huge_ptep_get(ptep);
+	pte_t orig_pte = ptep_get(ptep);
 
 	if (!pte_cont(orig_pte))
 		return ptep_get_and_clear(mm, addr, ptep);
@@ -402,11 +402,11 @@ static int __cont_access_flags_changed(pte_t *ptep, pte_t pte, int ncontig)
 {
 	int i;
 
-	if (pte_write(pte) != pte_write(huge_ptep_get(ptep)))
+	if (pte_write(pte) != pte_write(ptep_get(ptep)))
 		return 1;
 
 	for (i = 0; i < ncontig; i++) {
-		pte_t orig_pte = huge_ptep_get(ptep + i);
+		pte_t orig_pte = ptep_get(ptep + i);
 
 		if (pte_dirty(pte) != pte_dirty(orig_pte))
 			return 1;