diff --git a/arch/powerpc/mm/pageattr.c b/arch/powerpc/mm/pageattr.c
index edea388e9d3f..8812454e70ff 100644
--- a/arch/powerpc/mm/pageattr.c
+++ b/arch/powerpc/mm/pageattr.c
@@ -15,12 +15,14 @@
 #include <asm/pgtable.h>
 
 
+static pte_basic_t pte_update_delta(pte_t *ptep, unsigned long addr,
+				    unsigned long old, unsigned long new)
+{
+	return pte_update(&init_mm, addr, ptep, old & ~new, new & ~old, 0);
+}
+
 /*
- * Updates the attributes of a page in three steps:
- *
- * 1. take the page_table_lock
- * 2. install the new entry with the updated attributes
- * 3. flush the TLB
+ * Updates the attributes of a page atomically.
  *
  * This sequence is safe against concurrent updates, and also allows updating the
  * attributes of a page currently being executed or accessed.
@@ -28,41 +30,33 @@
 static int change_page_attr(pte_t *ptep, unsigned long addr, void *data)
 {
 	long action = (long)data;
-	pte_t pte;
 
-	spin_lock(&init_mm.page_table_lock);
-
-	pte = ptep_get(ptep);
-
-	/* modify the PTE bits as desired, then apply */
+	/* modify the PTE bits as desired */
 	switch (action) {
 	case SET_MEMORY_RO:
-		pte = pte_wrprotect(pte);
+		/* Don't clear DIRTY bit */
+		pte_update_delta(ptep, addr, _PAGE_KERNEL_RW & ~_PAGE_DIRTY, _PAGE_KERNEL_RO);
 		break;
 	case SET_MEMORY_RW:
-		pte = pte_mkwrite(pte_mkdirty(pte));
+		pte_update_delta(ptep, addr, _PAGE_KERNEL_RO, _PAGE_KERNEL_RW);
 		break;
 	case SET_MEMORY_NX:
-		pte = pte_exprotect(pte);
+		pte_update_delta(ptep, addr, _PAGE_KERNEL_ROX, _PAGE_KERNEL_RO);
 		break;
 	case SET_MEMORY_X:
-		pte = pte_mkexec(pte);
+		pte_update_delta(ptep, addr, _PAGE_KERNEL_RO, _PAGE_KERNEL_ROX);
 		break;
 	default:
 		WARN_ON_ONCE(1);
 		break;
 	}
 
-	pte_update(&init_mm, addr, ptep, ~0UL, pte_val(pte), 0);
-
 	/* See ptesync comment in radix__set_pte_at() */
 	if (radix_enabled())
 		asm volatile("ptesync": : :"memory");
 
 	flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
 
-	spin_unlock(&init_mm.page_table_lock);
-
 	return 0;
 }