1 files changed, 56 insertions, 0 deletions
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
new file mode 100644
index 00000000000..0607e4b14b2
--- /dev/null
+++ b/arch/s390/mm/pageattr.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright IBM Corp. 2011
+ * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
+ */
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <asm/pgtable.h>
+
+static void change_page_attr(unsigned long addr, int numpages,
+			     pte_t (*set) (pte_t))
+{
+	pte_t *ptep, pte;
+	pmd_t *pmdp;
+	pud_t *pudp;
+	pgd_t *pgdp;
+	int i;
+
+	for (i = 0; i < numpages; i++) {
+		pgdp = pgd_offset(&init_mm, addr);
+		pudp = pud_offset(pgdp, addr);
+		pmdp = pmd_offset(pudp, addr);
+		if (pmd_huge(*pmdp)) {
+			WARN_ON_ONCE(1);
+			continue;
+		}
+		ptep = pte_offset_kernel(pmdp, addr);
+
+		pte = *ptep;
+		pte = set(pte);
+		ptep_invalidate(&init_mm, addr, ptep);
+		*ptep = pte;
+		addr += PAGE_SIZE;
+	}
+}
+
+int set_memory_ro(unsigned long addr, int numpages)
+{
+	change_page_attr(addr, numpages, pte_wrprotect);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(set_memory_ro);
+
+int set_memory_rw(unsigned long addr, int numpages)
+{
+	change_page_attr(addr, numpages, pte_mkwrite);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(set_memory_rw);
+
+/* not possible */
+int set_memory_nx(unsigned long addr, int numpages)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(set_memory_nx);