mm: memory: make numa_migrate_prep() to take a folio

In preparation for large folio numa balancing, make numa_migrate_prep() to
take a folio, no functional change intended.

Link: https://lkml.kernel.org/r/20230921074417.24004-5-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: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/huge_memory.c

@@ -1556,7 +1556,7 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf)
 	 */
 	if (node_is_toptier(nid))
 		last_cpupid = page_cpupid_last(&folio->page);
-	target_nid = numa_migrate_prep(&folio->page, vma, haddr, nid, &flags);
+	target_nid = numa_migrate_prep(folio, vma, haddr, nid, &flags);
 	if (target_nid == NUMA_NO_NODE) {
 		folio_put(folio);
 		goto out_map;

mm/internal.h

@@ -983,7 +983,7 @@ void vunmap_range_noflush(unsigned long start, unsigned long end);
 
 void __vunmap_range_noflush(unsigned long start, unsigned long end);
 
-int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
+int numa_migrate_prep(struct folio *folio, struct vm_area_struct *vma,
 		      unsigned long addr, int page_nid, int *flags);
 
 void free_zone_device_page(struct page *page);

mm/memory.c

@@ -4724,10 +4724,10 @@ static vm_fault_t do_fault(struct vm_fault *vmf)
 	return ret;
 }
 
-int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
+int numa_migrate_prep(struct folio *folio, struct vm_area_struct *vma,
 		      unsigned long addr, int page_nid, int *flags)
 {
-	get_page(page);
+	folio_get(folio);
 
 	/* Record the current PID acceesing VMA */
 	vma_set_access_pid_bit(vma);
@@ -4738,7 +4738,7 @@ int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
 		*flags |= TNF_FAULT_LOCAL;
 	}
 
-	return mpol_misplaced(page, vma, addr);
+	return mpol_misplaced(&folio->page, vma, addr);
 }
 
 static vm_fault_t do_numa_page(struct vm_fault *vmf)
@@ -4812,8 +4812,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf)
 		last_cpupid = (-1 & LAST_CPUPID_MASK);
 	else
 		last_cpupid = page_cpupid_last(&folio->page);
-	target_nid = numa_migrate_prep(&folio->page, vma, vmf->address, nid,
-				       &flags);
+	target_nid = numa_migrate_prep(folio, vma, vmf->address, nid, &flags);
 	if (target_nid == NUMA_NO_NODE) {
 		folio_put(folio);
 		goto out_map;