powerpc/eeh/ioda2: Use device::iommu_group to check IOMMU group

This relies on the fact that a PCI device always has an IOMMU table
which may not be the case when we get dynamic DMA windows so
let's use more reliable check for IOMMU group here.

As we do not rely on the table presence here, remove the workaround
from pnv_pci_ioda2_set_bypass(); also remove the @add_to_iommu_group
parameter from pnv_ioda_setup_bus_dma().

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/eeh.c

@@ -1410,13 +1410,11 @@ static int dev_has_iommu_table(struct device *dev, void *data)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct pci_dev **ppdev = data;
-	struct iommu_table *tbl;
 
 	if (!dev)
 		return 0;
 
-	tbl = get_iommu_table_base(dev);
-	if (tbl && tbl->it_group) {
+	if (dev->iommu_group) {
 		*ppdev = pdev;
 		return 1;
 	}

arch/powerpc/platforms/powernv/pci-ioda.c

@@ -1655,21 +1655,15 @@ static u64 pnv_pci_ioda_dma_get_required_mask(struct pnv_phb *phb,
 }
 
 static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe,
-				   struct pci_bus *bus,
-				   bool add_to_iommu_group)
+				   struct pci_bus *bus)
 {
 	struct pci_dev *dev;
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
-		if (add_to_iommu_group)
-			set_iommu_table_base_and_group(&dev->dev,
-						       pe->tce32_table);
-		else
-			set_iommu_table_base(&dev->dev, pe->tce32_table);
+		set_iommu_table_base_and_group(&dev->dev, pe->tce32_table);
 
 		if (dev->subordinate)
-			pnv_ioda_setup_bus_dma(pe, dev->subordinate,
-					       add_to_iommu_group);
+			pnv_ioda_setup_bus_dma(pe, dev->subordinate);
 	}
 }
 
@@ -1846,7 +1840,7 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
 	} else if (pe->flags & (PNV_IODA_PE_BUS | PNV_IODA_PE_BUS_ALL)) {
 		iommu_register_group(tbl, phb->hose->global_number,
 				     pe->pe_number);
-		pnv_ioda_setup_bus_dma(pe, pe->pbus, true);
+		pnv_ioda_setup_bus_dma(pe, pe->pbus);
 	} else if (pe->flags & PNV_IODA_PE_VF) {
 		iommu_register_group(tbl, phb->hose->global_number,
 				     pe->pe_number);
@@ -1883,17 +1877,6 @@ static void pnv_pci_ioda2_set_bypass(struct iommu_table *tbl, bool enable)
 						     window_id,
 						     pe->tce_bypass_base,
 						     0);
-
-		/*
-		 * EEH needs the mapping between IOMMU table and group
-		 * of those VFIO/KVM pass-through devices. We can postpone
-		 * resetting DMA ops until the DMA mask is configured in
-		 * host side.
-		 */
-		if (pe->pdev)
-			set_iommu_table_base(&pe->pdev->dev, tbl);
-		else
-			pnv_ioda_setup_bus_dma(pe, pe->pbus, false);
 	}
 	if (rc)
 		pe_err(pe, "OPAL error %lld configuring bypass window\n", rc);
@@ -1985,7 +1968,7 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
 	} else if (pe->flags & (PNV_IODA_PE_BUS | PNV_IODA_PE_BUS_ALL)) {
 		iommu_register_group(tbl, phb->hose->global_number,
 				     pe->pe_number);
-		pnv_ioda_setup_bus_dma(pe, pe->pbus, true);
+		pnv_ioda_setup_bus_dma(pe, pe->pbus);
 	} else if (pe->flags & PNV_IODA_PE_VF) {
 		iommu_register_group(tbl, phb->hose->global_number,
 				     pe->pe_number);