1 files changed, 36 insertions, 23 deletions

diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index fc07bc39e6..016993e9eb 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -21,6 +21,7 @@
 /* the bootdata_preserved fields come from ones in arch/s390/boot/uv.c */
 #ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
 int __bootdata_preserved(prot_virt_guest);
+EXPORT_SYMBOL(prot_virt_guest);
 #endif
 
 /*
@@ -181,36 +182,36 @@ 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;
 }
 
-static int make_page_secure(struct page *page, struct uv_cb_header *uvcb)
+static int make_folio_secure(struct folio *folio, struct uv_cb_header *uvcb)
 {
 	int expected, cc = 0;
 
-	if (PageWriteback(page))
+	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.
@@ -220,9 +221,9 @@ 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)
@@ -277,7 +278,7 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb)
 	bool local_drain = false;
 	spinlock_t *ptelock;
 	unsigned long uaddr;
-	struct page *page;
+	struct folio *folio;
 	pte_t *ptep;
 	int rc;
 
@@ -306,15 +307,26 @@ again:
 	if (!ptep)
 		goto out;
 	if (pte_present(*ptep) && !(pte_val(*ptep) & _PAGE_INVALID) && pte_write(*ptep)) {
-		page = pte_page(*ptep);
+		folio = page_folio(pte_page(*ptep));
+		rc = -EINVAL;
+		if (folio_test_large(folio))
+			goto unlock;
 		rc = -EAGAIN;
-		if (trylock_page(page)) {
+		if (folio_trylock(folio)) {
 			if (should_export_before_import(uvcb, gmap->mm))
-				uv_convert_from_secure(page_to_phys(page));
-			rc = make_page_secure(page, uvcb);
-			unlock_page(page);
+				uv_convert_from_secure(PFN_PHYS(folio_pfn(folio)));
+			rc = make_folio_secure(folio, uvcb);
+			folio_unlock(folio);
 		}
+
+		/*
+		 * Once we drop the PTL, the folio may get unmapped and
+		 * freed immediately. We need a temporary reference.
+		 */
+		if (rc == -EAGAIN)
+			folio_get(folio);
 	}
+unlock:
 	pte_unmap_unlock(ptep, ptelock);
 out:
 	mmap_read_unlock(gmap->mm);
@@ -324,10 +336,11 @@ out:
 		 * If we are here because the UVC returned busy or partial
 		 * completion, this is just a useless check, but it is safe.
 		 */
-		wait_on_page_writeback(page);
+		folio_wait_writeback(folio);
+		folio_put(folio);
 	} else if (rc == -EBUSY) {
 		/*
-		 * If we have tried a local drain and the page refcount
+		 * If we have tried a local drain and the folio refcount
 		 * still does not match our expected safe value, try with a
 		 * system wide drain. This is needed if the pagevecs holding
 		 * the page are on a different CPU.
@@ -338,7 +351,7 @@ out:
 			return -EAGAIN;
 		}
 		/*
-		 * We are here if the page refcount does not match the
+		 * We are here if the folio refcount does not match the
 		 * expected safe value. The main culprits are usually
 		 * pagevecs. With lru_add_drain() we drain the pagevecs
 		 * on the local CPU so that hopefully the refcount will