[PATCH kernel] powerpc/powernv/sriov: Register IOMMU groups for VFs

[Alexey Kardashevskiy <aik@ozlabs.ru>]

The compound IOMMU group rework moved iommu_register_group() together in
pnv_pci_ioda_setup_iommu_api() (which is a part of ppc_md.pcibios_fixup).
As the result, pnv_ioda_setup_bus_iommu_group() does not create groups
any more, it only adds devices to groups.

This works fine for boot time devices. However IOMMU groups for SRIOV's
VFs were added by pnv_ioda_setup_bus_iommu_group() so this got broken:
pnv_tce_iommu_bus_notifier() expects a group to be registered for VF
and it is not.

This adds missing group registration and adds a NULL pointer check into
the bus notifier so we won't stop in xmon if there is no group, although
it is not expected to happen now.

Fixes: 0bd971676e68 "powerpc/powernv/npu: Add compound IOMMU groups"
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---

Fixes https://bugzilla.linux.ibm.com/show_bug.cgi?id=175550
"Kernel Oops while creating SRIOV VF's."


---
 arch/powerpc/platforms/powernv/pci-ioda.c | 2 ++
 arch/powerpc/platforms/powernv/pci.c      | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 7db3119..145373f 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1593,6 +1593,8 @@ static void pnv_ioda_setup_vf_PE(struct pci_dev *pdev, u16 num_vfs)
 
 		pnv_pci_ioda2_setup_dma_pe(phb, pe);
 #ifdef CONFIG_IOMMU_API
+		iommu_register_group(&pe->table_group,
+				pe->phb->hose->global_number, pe->pe_number);
 		pnv_ioda_setup_bus_iommu_group(pe, &pe->table_group, NULL);
 #endif
 	}
diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index 45fb70b..ef9448a 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -1147,6 +1147,8 @@ static int pnv_tce_iommu_bus_notifier(struct notifier_block *nb,
 			return 0;
 
 		pe = &phb->ioda.pe_array[pdn->pe_number];
+		if (!pe->table_group.group)
+			return 0;
 		iommu_add_device(&pe->table_group, dev);
 		return 0;
 	case BUS_NOTIFY_DEL_DEVICE:
-- 
2.17.1