iommu/arm-smmu: Add support for the fsl-mc bus

Implement bus specific support for the fsl-mc bus including
registering arm_smmu_ops and bus specific device add operations.

Signed-off-by: Nipun Gupta <[e-mail]>
Reviewed-by: Robin Murphy <[e-mail]>
Signed-off-by: Joerg Roedel <[e-mail]>

drivers/iommu/arm-smmu.c

···
 #include <linux/spinlock.h>
 
 #include <linux/amba/bus.h>
+#include <linux/fsl/mc.h>
 
 #include "io-pgtable.h"
 #include "arm-smmu-regs.h"
···
 
 	if (dev_is_pci(dev))
 		group = pci_device_group(dev);
+	else if (dev_is_fsl_mc(dev))
+		group = fsl_mc_device_group(dev);
 	else
 		group = generic_device_group(dev);
 
···
 		pci_request_acs();
 		bus_set_iommu(&pci_bus_type, &arm_smmu_ops);
 	}
+#endif
+#ifdef CONFIG_FSL_MC_BUS
+	if (!iommu_present(&fsl_mc_bus_type))
+		bus_set_iommu(&fsl_mc_bus_type, &arm_smmu_ops);
 #endif
 }
 

drivers/iommu/iommu.c

···
 #include <linux/pci.h>
 #include <linux/bitops.h>
 #include <linux/property.h>
+#include <linux/fsl/mc.h>
 #include <trace/events/iommu.h>
 
 static struct kset *iommu_group_kset;
···
 
 	/* No shared group found, allocate new */
 	return iommu_group_alloc();
+}
+
+/* Get the IOMMU group for device on fsl-mc bus */
+struct iommu_group *fsl_mc_device_group(struct device *dev)
+{
+	struct device *cont_dev = fsl_mc_cont_dev(dev);
+	struct iommu_group *group;
+
+	group = iommu_group_get(cont_dev);
+	if (!group)
+		group = iommu_group_alloc();
+	return group;
 }
 
 /**

include/linux/fsl/mc.h

···
 #define dev_is_fsl_mc(_dev) (0)
 #endif
 
+/* Macro to check if a device is a container device */
+#define fsl_mc_is_cont_dev(_dev) (to_fsl_mc_device(_dev)->flags & \
+	FSL_MC_IS_DPRC)
+
+/* Macro to get the container device of a MC device */
+#define fsl_mc_cont_dev(_dev) (fsl_mc_is_cont_dev(_dev) ? \
+	(_dev) : (_dev)->parent)
+
 /*
  * module_fsl_mc_driver() - Helper macro for drivers that don't do
  * anything special in module init/exit.  This eliminates a lot of

include/linux/iommu.h

···
 extern struct iommu_group *pci_device_group(struct device *dev);
 /* Generic device grouping function */
 extern struct iommu_group *generic_device_group(struct device *dev);
+/* FSL-MC device grouping function */
+struct iommu_group *fsl_mc_device_group(struct device *dev);
 
 /**
  * struct iommu_fwspec - per-device IOMMU instance data