iommu/io-pgtable: Add ARMv7 short descriptor support

Add a nearly-complete ARMv7 short descriptor implementation, omitting
only a few legacy and CPU-centric aspects which shouldn't be necessary
for IOMMU API use anyway.

Reviewed-by: Yong Wu <yong.wu@mediatek.com>
Tested-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index a1e75cb..dc1aaa5 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -39,6 +39,25 @@
 
 	  If unsure, say N here.
 
+config IOMMU_IO_PGTABLE_ARMV7S
+	bool "ARMv7/v8 Short Descriptor Format"
+	select IOMMU_IO_PGTABLE
+	depends on HAS_DMA && (ARM || ARM64 || COMPILE_TEST)
+	help
+	  Enable support for the ARM Short-descriptor pagetable format.
+	  This supports 32-bit virtual and physical addresses mapped using
+	  2-level tables with 4KB pages/1MB sections, and contiguous entries
+	  for 64KB pages/16MB supersections if indicated by the IOMMU driver.
+
+config IOMMU_IO_PGTABLE_ARMV7S_SELFTEST
+	bool "ARMv7s selftests"
+	depends on IOMMU_IO_PGTABLE_ARMV7S
+	help
+	  Enable self-tests for ARMv7s page table allocator. This performs
+	  a series of page-table consistency checks during boot.
+
+	  If unsure, say N here.
+
 endmenu
 
 config IOMMU_IOVA