iommu: dmar: Provide helper to copy shared irte fields

Instead of open coding, provide a helper function to copy the shared
irte fields.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jiang.liu@linux.intel.com
Cc: iommu@lists.linux-foundation.org
Cc: joro@8bytes.org
Cc: dwmw2@infradead.org
Link: http://lkml.kernel.org/r/1433827237-3382-4-git-send-email-feng.wu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/linux/dmar.h

@@ -249,6 +249,18 @@ struct irte {
 	};
 };
 
+static inline void dmar_copy_shared_irte(struct irte *dst, struct irte *src)
+{
+	dst->present	= src->present;
+	dst->fpd	= src->fpd;
+	dst->avail	= src->avail;
+	dst->pst	= src->pst;
+	dst->vector	= src->vector;
+	dst->sid	= src->sid;
+	dst->sq		= src->sq;
+	dst->svt	= src->svt;
+}
+
 #define PDA_LOW_BIT    26
 #define PDA_HIGH_BIT   32