mm: convert free_zone_device_page to free_zone_device_folio

Both callers already have a folio; pass it in and save a few calls to
compound_head().

Link: https://lkml.kernel.org/r/20240405153228.2563754-6-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/internal.h

@@ -1165,7 +1165,7 @@ void __vunmap_range_noflush(unsigned long start, unsigned long end);
 int numa_migrate_prep(struct folio *folio, struct vm_fault *vmf,
 		      unsigned long addr, int page_nid, int *flags);
 
-void free_zone_device_page(struct page *page);
+void free_zone_device_folio(struct folio *folio);
 int migrate_device_coherent_page(struct page *page);
 
 /*

mm/memremap.c

@@ -456,21 +456,23 @@ struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
 }
 EXPORT_SYMBOL_GPL(get_dev_pagemap);
 
-void free_zone_device_page(struct page *page)
+void free_zone_device_folio(struct folio *folio)
 {
-	if (WARN_ON_ONCE(!page->pgmap->ops || !page->pgmap->ops->page_free))
+	if (WARN_ON_ONCE(!folio->page.pgmap->ops ||
+			!folio->page.pgmap->ops->page_free))
 		return;
 
-	mem_cgroup_uncharge(page_folio(page));
+	mem_cgroup_uncharge(folio);
 
 	/*
 	 * Note: we don't expect anonymous compound pages yet. Once supported
 	 * and we could PTE-map them similar to THP, we'd have to clear
 	 * PG_anon_exclusive on all tail pages.
 	 */
-	VM_BUG_ON_PAGE(PageAnon(page) && PageCompound(page), page);
-	if (PageAnon(page))
-		__ClearPageAnonExclusive(page);
+	if (folio_test_anon(folio)) {
+		VM_BUG_ON_FOLIO(folio_test_large(folio), folio);
+		__ClearPageAnonExclusive(folio_page(folio, 0));
+	}
 
 	/*
 	 * When a device managed page is freed, the folio->mapping field
@@ -481,20 +483,20 @@ void free_zone_device_page(struct page *page)
 	 *
 	 * For other types of ZONE_DEVICE pages, migration is either
 	 * handled differently or not done at all, so there is no need
-	 * to clear page->mapping.
+	 * to clear folio->mapping.
 	 */
-	page->mapping = NULL;
-	page->pgmap->ops->page_free(page);
+	folio->mapping = NULL;
+	folio->page.pgmap->ops->page_free(folio_page(folio, 0));
 
-	if (page->pgmap->type != MEMORY_DEVICE_PRIVATE &&
-	    page->pgmap->type != MEMORY_DEVICE_COHERENT)
+	if (folio->page.pgmap->type != MEMORY_DEVICE_PRIVATE &&
+	    folio->page.pgmap->type != MEMORY_DEVICE_COHERENT)
 		/*
-		 * Reset the page count to 1 to prepare for handing out the page
+		 * Reset the refcount to 1 to prepare for handing out the page
 		 * again.
 		 */
-		set_page_count(page, 1);
+		folio_set_count(folio, 1);
 	else
-		put_dev_pagemap(page->pgmap);
+		put_dev_pagemap(folio->page.pgmap);
 }
 
 void zone_device_page_init(struct page *page)

mm/swap.c

@@ -115,7 +115,7 @@ static void page_cache_release(struct folio *folio)
 void __folio_put(struct folio *folio)
 {
 	if (unlikely(folio_is_zone_device(folio))) {
-		free_zone_device_page(&folio->page);
+		free_zone_device_folio(folio);
 		return;
 	} else if (folio_test_hugetlb(folio)) {
 		free_huge_folio(folio);
@@ -983,7 +983,7 @@ void folios_put_refs(struct folio_batch *folios, unsigned int *refs)
 			if (put_devmap_managed_page_refs(&folio->page, nr_refs))
 				continue;
 			if (folio_ref_sub_and_test(folio, nr_refs))
-				free_zone_device_page(&folio->page);
+				free_zone_device_folio(folio);
 			continue;
 		}