s390/mm: Convert make_page_secure to use a folio

These page APIs are deprecated, so convert the incoming page to a folio
and use the folio APIs instead.  The ultravisor API cannot handle large
folios, so return -EINVAL if one has slipped through.
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240322161149.2327518-2-willy@infradead.orgSigned-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

arch/s390/kernel/uv.c

@@ -182,21 +182,21 @@ int uv_convert_owned_from_secure(unsigned long paddr)
 }
 
 /*
- * Calculate the expected ref_count for a page that would otherwise have no
+ * Calculate the expected ref_count for a folio that would otherwise have no
  * further pins. This was cribbed from similar functions in other places in
  * the kernel, but with some slight modifications. We know that a secure
- * page can not be a huge page for example.
+ * folio can not be a large folio, for example.
  */
-static int expected_page_refs(struct page *page)
+static int expected_folio_refs(struct folio *folio)
 {
 	int res;
 
-	res = page_mapcount(page);
-	if (PageSwapCache(page)) {
+	res = folio_mapcount(folio);
+	if (folio_test_swapcache(folio)) {
 		res++;
-	} else if (page_mapping(page)) {
+	} else if (folio_mapping(folio)) {
 		res++;
-		if (page_has_private(page))
+		if (folio->private)
 			res++;
 	}
 	return res;
@@ -204,14 +204,17 @@ static int expected_page_refs(struct page *page)
 
 static int make_page_secure(struct page *page, struct uv_cb_header *uvcb)
 {
+	struct folio *folio = page_folio(page);
 	int expected, cc = 0;
 
-	if (PageWriteback(page))
+	if (folio_test_large(folio))
+		return -EINVAL;
+	if (folio_test_writeback(folio))
 		return -EAGAIN;
-	expected = expected_page_refs(page);
-	if (!page_ref_freeze(page, expected))
+	expected = expected_folio_refs(folio);
+	if (!folio_ref_freeze(folio, expected))
 		return -EBUSY;
-	set_bit(PG_arch_1, &page->flags);
+	set_bit(PG_arch_1, &folio->flags);
 	/*
 	 * If the UVC does not succeed or fail immediately, we don't want to
 	 * loop for long, or we might get stall notifications.
@@ -221,9 +224,9 @@ static int make_page_secure(struct page *page, struct uv_cb_header *uvcb)
 	 * -EAGAIN and we let the callers deal with it.
 	 */
 	cc = __uv_call(0, (u64)uvcb);
-	page_ref_unfreeze(page, expected);
+	folio_ref_unfreeze(folio, expected);
 	/*
-	 * Return -ENXIO if the page was not mapped, -EINVAL for other errors.
+	 * Return -ENXIO if the folio was not mapped, -EINVAL for other errors.
 	 * If busy or partially completed, return -EAGAIN.
 	 */
 	if (cc == UVC_CC_OK)