diff --git a/arch/powerpc/sysdev/cpm_common.c b/arch/powerpc/sysdev/cpm_common.c
index 4f7869571290..e2ea51961979 100644
--- a/arch/powerpc/sysdev/cpm_common.c
+++ b/arch/powerpc/sysdev/cpm_common.c
@@ -147,7 +147,7 @@ unsigned long cpm_muram_alloc(unsigned long size, unsigned long align)
 	spin_lock_irqsave(&cpm_muram_lock, flags);
 	cpm_muram_info.alignment = align;
 	start = rh_alloc(&cpm_muram_info, size, "commproc");
-	memset(cpm_muram_addr(start), 0, size);
+	memset_io(cpm_muram_addr(start), 0, size);
 	spin_unlock_irqrestore(&cpm_muram_lock, flags);
 
 	return start;