+#define __S100 PAGE_EX_RO
+#define __S101 PAGE_EX_RO
+#define __S110 PAGE_EX_RW
+#define __S111 PAGE_EX_RW
+
+#ifndef __s390x__
+# define PMD_SHADOW_SHIFT 1
+# define PGD_SHADOW_SHIFT 1
+#else /* __s390x__ */
+# define PMD_SHADOW_SHIFT 2
+# define PGD_SHADOW_SHIFT 2
+#endif /* __s390x__ */
+
+static inline struct page *get_shadow_page(struct page *page)
+{
+ if (s390_noexec && !list_empty(&page->lru))
+ return virt_to_page(page->lru.next);
+ return NULL;
+}
+
+static inline pte_t *get_shadow_pte(pte_t *ptep)
+{
+ unsigned long pteptr = (unsigned long) (ptep);
+
+ if (s390_noexec) {
+ unsigned long offset = pteptr & (PAGE_SIZE - 1);
+ void *addr = (void *) (pteptr ^ offset);
+ struct page *page = virt_to_page(addr);
+ if (!list_empty(&page->lru))
+ return (pte_t *) ((unsigned long) page->lru.next |
+ offset);
+ }
+ return NULL;
+}
+
+static inline pmd_t *get_shadow_pmd(pmd_t *pmdp)
+{
+ unsigned long pmdptr = (unsigned long) (pmdp);
+
+ if (s390_noexec) {
+ unsigned long offset = pmdptr &
+ ((PAGE_SIZE << PMD_SHADOW_SHIFT) - 1);
+ void *addr = (void *) (pmdptr ^ offset);
+ struct page *page = virt_to_page(addr);
+ if (!list_empty(&page->lru))
+ return (pmd_t *) ((unsigned long) page->lru.next |
+ offset);
+ }
+ return NULL;
+}
+
+static inline pgd_t *get_shadow_pgd(pgd_t *pgdp)
+{
+ unsigned long pgdptr = (unsigned long) (pgdp);
+
+ if (s390_noexec) {
+ unsigned long offset = pgdptr &
+ ((PAGE_SIZE << PGD_SHADOW_SHIFT) - 1);
+ void *addr = (void *) (pgdptr ^ offset);
+ struct page *page = virt_to_page(addr);
+ if (!list_empty(&page->lru))
+ return (pgd_t *) ((unsigned long) page->lru.next |
+ offset);
+ }
+ return NULL;
+}