s390/uv: Implement HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE

Let's also implement HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE, so we can convert
arch_make_page_accessible() to be a simple wrapper around
arch_make_folio_accessible(). Unfortunately, we cannot do that in the
header.

There are only two arch_make_page_accessible() calls remaining in gup.c.
We can now drop HAVE_ARCH_MAKE_PAGE_ACCESSIBLE completely form core-MM.
We'll handle that separately, once the s390x part landed.
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20240508182955.358628-10-david@redhat.comSigned-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

arch/s390/include/asm/page.h

@@ -162,6 +162,7 @@ static inline int page_reset_referenced(unsigned long addr)
 #define _PAGE_ACC_BITS		0xf0	/* HW access control bits	*/
 
 struct page;
+struct folio;
 void arch_free_page(struct page *page, int order);
 void arch_alloc_page(struct page *page, int order);
 
@@ -174,6 +175,8 @@ static inline int devmem_is_allowed(unsigned long pfn)
 #define HAVE_ARCH_ALLOC_PAGE
 
 #if IS_ENABLED(CONFIG_PGSTE)
+int arch_make_folio_accessible(struct folio *folio);
+#define HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE
 int arch_make_page_accessible(struct page *page);
 #define HAVE_ARCH_MAKE_PAGE_ACCESSIBLE
 #endif

arch/s390/kernel/uv.c

@@ -498,14 +498,13 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
 EXPORT_SYMBOL_GPL(gmap_destroy_page);
 
 /*
- * To be called with the page locked or with an extra reference! This will
- * prevent gmap_make_secure from touching the page concurrently. Having 2
- * parallel make_page_accessible is fine, as the UV calls will become a
- * no-op if the page is already exported.
+ * To be called with the folio locked or with an extra reference! This will
+ * prevent gmap_make_secure from touching the folio concurrently. Having 2
+ * parallel arch_make_folio_accessible is fine, as the UV calls will become a
+ * no-op if the folio is already exported.
  */
-int arch_make_page_accessible(struct page *page)
+int arch_make_folio_accessible(struct folio *folio)
 {
-	struct folio *folio = page_folio(page);
 	int rc = 0;
 
 	/* See gmap_make_secure(): large folios cannot be secure */
@@ -537,8 +536,13 @@ int arch_make_page_accessible(struct page *page)
 
 	return rc;
 }
-EXPORT_SYMBOL_GPL(arch_make_page_accessible);
+EXPORT_SYMBOL_GPL(arch_make_folio_accessible);
 
+int arch_make_page_accessible(struct page *page)
+{
+	return arch_make_folio_accessible(page_folio(page));
+}
+EXPORT_SYMBOL_GPL(arch_make_page_accessible);
 #endif
 
 #if defined(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) || IS_ENABLED(CONFIG_KVM)

arch/s390/mm/fault.c

@@ -492,6 +492,7 @@ void do_secure_storage_access(struct pt_regs *regs)
 	unsigned long addr = get_fault_address(regs);
 	struct vm_area_struct *vma;
 	struct mm_struct *mm;
+	struct folio *folio;
 	struct page *page;
 	struct gmap *gmap;
 	int rc;
@@ -539,17 +540,18 @@ void do_secure_storage_access(struct pt_regs *regs)
 			mmap_read_unlock(mm);
 			break;
 		}
-		if (arch_make_page_accessible(page))
+		folio = page_folio(page);
+		if (arch_make_folio_accessible(folio))
 			send_sig(SIGSEGV, current, 0);
-		put_page(page);
+		folio_put(folio);
 		mmap_read_unlock(mm);
 		break;
 	case KERNEL_FAULT:
-		page = phys_to_page(addr);
-		if (unlikely(!try_get_page(page)))
+		folio = phys_to_folio(addr);
+		if (unlikely(!folio_try_get(folio)))
 			break;
-		rc = arch_make_page_accessible(page);
-		put_page(page);
+		rc = arch_make_folio_accessible(folio);
+		folio_put(folio);
 		if (rc)
 			BUG();
 		break;