x86: implement mapping_error in pci-nommu_64.c

This patch implements mapping_error for pci-nommu_64.c.
It takes care to keep the same compatible behaviour it already
had. Although this file is not (yet) used for i386, we introduce
the i386 version here. Again, care is taken, even at the expense of
an ifdef, to keep the same behaviour inconditionally.
Signed-off-by: NGlauber Costa <gcosta@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/pci-nommu_64.c

@@ -67,9 +67,21 @@ static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg,
 	return nents;
 }
 
+/* Make sure we keep the same behaviour */
+static int nommu_mapping_error(dma_addr_t dma_addr)
+{
+#ifdef CONFIG_X86_32
+	return 0;
+#else
+	return (dma_addr == bad_dma_address);
+#endif
+}
+
+
 const struct dma_mapping_ops nommu_dma_ops = {
 	.map_single = nommu_map_single,
 	.map_sg = nommu_map_sg,
+	.mapping_error = nommu_mapping_error,
 	.is_phys = 1,
 };