+static inline int page_reset_referenced(unsigned long addr)
+{
+ unsigned int ipm;
+
+ asm volatile(
+ " rrbe 0,%1\n"
+ " ipm %0\n"
+ : "=d" (ipm) : "a" (addr) : "cc");
+ return !!(ipm & 0x20000000);
+}
+
+/* Bits int the storage key */
+#define _PAGE_CHANGED 0x02 /* HW changed bit */
+#define _PAGE_REFERENCED 0x04 /* HW referenced bit */
+#define _PAGE_FP_BIT 0x08 /* HW fetch protection bit */
+#define _PAGE_ACC_BITS 0xf0 /* HW access control bits */
+
+/*
+ * Test and clear dirty bit in storage key.
+ * We can't clear the changed bit atomically. This is a potential
+ * race against modification of the referenced bit. This function
+ * should therefore only be called if it is not mapped in any
+ * address space.
+ */
+#define __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
+static inline int page_test_and_clear_dirty(unsigned long pfn, int mapped)
+{
+ unsigned char skey;
+
+ skey = page_get_storage_key(pfn << PAGE_SHIFT);
+ if (!(skey & _PAGE_CHANGED))
+ return 0;
+ page_set_storage_key(pfn << PAGE_SHIFT, skey & ~_PAGE_CHANGED, mapped);
+ return 1;
+}
+
+/*
+ * Test and clear referenced bit in storage key.
+ */
+#define __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
+static inline int page_test_and_clear_young(unsigned long pfn)
+{
+ return page_reset_referenced(pfn << PAGE_SHIFT);
+}
+