Re: [PATCH v2 7/7] iommu/arm-smmu: Support non-PCI devices with SMMUv3

With the device <-> stream ID relationship suitably abstracted and
of_xlate() hooked up, we no longer have any PCI-specifics in play,
so adding support for the simpler kinds of platform device (a single
unique stream ID each) becomes trivial; let's do it!

Signed-off-by: Robin Murphy <redacted>
---

v2: New. Consider this one "extra bonus material" as I'm not sure there
    are even any suitable devices on our model to test it with (it
    _should_ be OK, given that I know the basic infrastructure on either
    side works...)

 drivers/iommu/Kconfig       |  2 +-
 drivers/iommu/arm-smmu-v3.c | 36 ++++++++++++++++++++++++++++++------
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index ad0860383cb3..d1c66afefeed 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig

@@ -308,7 +308,7 @@ config ARM_SMMU
 
 config ARM_SMMU_V3
 	bool "ARM Ltd. System MMU Version 3 (SMMUv3) Support"
-	depends on ARM64 && PCI
+	depends on ARM64
 	select IOMMU_API
 	select IOMMU_IO_PGTABLE_LPAE
 	select GENERIC_MSI_IRQ_DOMAIN

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 28dcc5ca237e..6379f0ab24fc 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c

@@ -35,6 +35,8 @@
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 
+#include <linux/amba/bus.h>
+
 #include "io-pgtable.h"
 
 /* MMIO registers */

@@ -1773,6 +1775,22 @@ static void arm_smmu_remove_device(struct device *dev)
 	iommu_group_remove_device(dev);
 }
 
+static struct iommu_group *arm_smmu_device_group(struct device *dev)
+{
+	struct iommu_group *group;
+
+	/*
+	 * We've currently no means of grouping non-PCI masters, so
+	 * there'd better not be any non-unique stream IDs in the DT...
+	 */