mm: huge_memory: use a folio in change_huge_pmd()

Use a folio in change_huge_pmd(), which helps to remove last
xchg_page_access_time() caller.

Link: https://lkml.kernel.org/r/20231018140806.2783514-11-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/huge_memory.c

@@ -1856,7 +1856,7 @@ int change_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
 	if (is_swap_pmd(*pmd)) {
 		swp_entry_t entry = pmd_to_swp_entry(*pmd);
-		struct page *page = pfn_swap_entry_to_page(entry);
+		struct folio *folio = page_folio(pfn_swap_entry_to_page(entry));
 		pmd_t newpmd;
 
 		VM_BUG_ON(!is_pmd_migration_entry(*pmd));
@@ -1865,7 +1865,7 @@ int change_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 			 * A protection check is difficult so
 			 * just be safe and disable write
 			 */
-			if (PageAnon(page))
+			if (folio_test_anon(folio))
 				entry = make_readable_exclusive_migration_entry(swp_offset(entry));
 			else
 				entry = make_readable_migration_entry(swp_offset(entry));
@@ -1887,7 +1887,7 @@ int change_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 #endif
 
 	if (prot_numa) {
-		struct page *page;
+		struct folio *folio;
 		bool toptier;
 		/*
 		 * Avoid trapping faults against the zero page. The read-only
@@ -1900,8 +1900,8 @@ int change_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		if (pmd_protnone(*pmd))
 			goto unlock;
 
-		page = pmd_page(*pmd);
-		toptier = node_is_toptier(page_to_nid(page));
+		folio = page_folio(pmd_page(*pmd));
+		toptier = node_is_toptier(folio_nid(folio));
 		/*
 		 * Skip scanning top tier node if normal numa
 		 * balancing is disabled
@@ -1912,7 +1912,8 @@ int change_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 
 		if (sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING &&
 		    !toptier)
-			xchg_page_access_time(page, jiffies_to_msecs(jiffies));
+			folio_xchg_access_time(folio,
+					       jiffies_to_msecs(jiffies));
 	}
 	/*
 	 * In case prot_numa, we are under mmap_read_lock(mm). It's critical