[RFC PATCH 5/8] iommu/arm-smmu: Attach to host1x context device bus

From: Mikko Perttunen
Date: Mon Feb 08 2021 - 13:42:10 EST


Set itself as the IOMMU for the host1x context device bus, containing
"dummy" devices used for Host1x context isolation.

Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
---
drivers/iommu/arm/arm-smmu/arm-smmu.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index d8c6bfde6a61..ec746c2a08ae 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -40,6 +40,7 @@

#include <linux/amba/bus.h>
#include <linux/fsl/mc.h>
+#include <linux/host1x_context_bus.h>

#include "arm-smmu.h"

@@ -2087,8 +2088,20 @@ static int arm_smmu_bus_init(struct iommu_ops *ops)
goto err_reset_pci_ops;
}
#endif
+#ifdef CONFIG_TEGRA_HOST1X_CONTEXT_BUS
+ if (!iommu_present(&host1x_context_device_bus_type)) {
+ err = bus_set_iommu(&host1x_context_device_bus_type, ops);
+ if (err)
+ goto err_reset_fsl_mc_ops;
+ }
+#endif
+
return 0;

+err_reset_fsl_mc_ops: __maybe_unused;
+#ifdef CONFIG_FSL_MC_BUS
+ bus_set_iommu(&fsl_mc_bus_type, NULL);
+#endif
err_reset_pci_ops: __maybe_unused;
#ifdef CONFIG_PCI
bus_set_iommu(&pci_bus_type, NULL);
--
2.30.0