iommu/mediatek: Add mt8173 IOMMU driver

This patch adds support for mediatek m4u (MultiMedia Memory Management
Unit).
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/Kconfig

@@ -337,4 +337,20 @@ config S390_IOMMU
 	help
 	  Support for the IOMMU API for s390 PCI devices.
 
+config MTK_IOMMU
+	bool "MTK IOMMU Support"
+	depends on ARM || ARM64
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	select IOMMU_API
+	select IOMMU_DMA
+	select IOMMU_IO_PGTABLE_ARMV7S
+	select MEMORY
+	select MTK_SMI
+	help
+	  Support for the M4U on certain Mediatek SOCs. M4U is MultiMedia
+	  Memory Management Unit. This option enables remapping of DMA memory
+	  accesses for the multimedia subsystem.
+
+	  If unsure, say N here.
+
 endif # IOMMU_SUPPORT

drivers/iommu/Makefile

@@ -17,6 +17,7 @@ obj-$(CONFIG_INTEL_IOMMU) += intel-iommu.o
 obj-$(CONFIG_INTEL_IOMMU_SVM) += intel-svm.o
 obj-$(CONFIG_IPMMU_VMSA) += ipmmu-vmsa.o
 obj-$(CONFIG_IRQ_REMAP) += intel_irq_remapping.o irq_remapping.o
+obj-$(CONFIG_MTK_IOMMU) += mtk_iommu.o
 obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o
 obj-$(CONFIG_OMAP_IOMMU_DEBUG) += omap-iommu-debug.o
 obj-$(CONFIG_ROCKCHIP_IOMMU) += rockchip-iommu.o