powerpc/mm: Move WIMG update to helper.

Only difference here is, we apply the WIMG mapping early, so rflags
passed to updatepp will also be changed.

Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 6c67bd0..4233dcc 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -182,7 +182,18 @@
 	/*
 	 * Always add "C" bit for perf. Memory coherence is always enabled
 	 */
-	return rflags | HPTE_R_C | HPTE_R_M;
+	rflags |=  HPTE_R_C | HPTE_R_M;
+	/*
+	 * Add in WIG bits
+	 */
+	if (pteflags & _PAGE_WRITETHRU)
+		rflags |= HPTE_R_W;
+	if (pteflags & _PAGE_NO_CACHE)
+		rflags |= HPTE_R_I;
+	if (pteflags & _PAGE_GUARDED)
+		rflags |= HPTE_R_G;
+
+	return rflags;
 }
 
 int htab_bolt_mapping(unsigned long vstart, unsigned long vend,