pasemi_mac: enable iommu support

pasemi_mac: enable iommu support

Enable IOMMU support for pasemi_mac, but avoid using it on non-partitioned
systems for performance reasons.

The user can override this by selecting the PPC_PASEMI_IOMMU_DMA_FORCE
configuration option.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/arch/powerpc/platforms/pasemi/Kconfig b/arch/powerpc/platforms/pasemi/Kconfig
index 95cd90f..e95261e 100644
--- a/arch/powerpc/platforms/pasemi/Kconfig
+++ b/arch/powerpc/platforms/pasemi/Kconfig
@@ -18,6 +18,16 @@
 	help
 	  IOMMU support for PA6T-1682M
 
+config PPC_PASEMI_IOMMU_DMA_FORCE
+	bool "Force DMA engine to use IOMMU"
+	depends on PPC_PASEMI_IOMMU
+	help
+	  This option forces the use of the IOMMU also for the
+	  DMA engine. Otherwise the kernel will use it only when
+	  running under a hypervisor.
+
+	  If in doubt, say "N".
+
 config PPC_PASEMI_MDIO
 	depends on PHYLIB
 	tristate "MDIO support via GPIO"