[PATCH] powerpc/pseries: Add a null judgment after iommu_pseries_alloc_group

[Deming Wang <wangdeming@inspur.com>]

We should avoid use the return value directly after  call
iommu_pseries_alloc_group. Because it_may return a null.

Signed-off-by: Deming Wang <wangdeming@inspur.com>
---
 arch/powerpc/platforms/pseries/iommu.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index fba64304e859..801eb9d4bdca 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -649,6 +649,9 @@ static void pci_dma_bus_setup_pSeries(struct pci_bus *bus)
 	pci->phb->dma_window_base_cur = 0x8000000ul;
 
 	pci->table_group = iommu_pseries_alloc_group(pci->phb->node);
+	if (!pci->table_group)
+		return;
+
 	tbl = pci->table_group->tables[0];
 
 	iommu_table_setparms(pci->phb, dn, tbl);
@@ -734,6 +737,9 @@ static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus)
 
 	if (!ppci->table_group) {
 		ppci->table_group = iommu_pseries_alloc_group(ppci->phb->node);
+		if (!ppci->table_group)
+			return;
+
 		tbl = ppci->table_group->tables[0];
 		iommu_table_setparms_lpar(ppci->phb, pdn, tbl,
 				ppci->table_group, dma_window);
@@ -765,6 +771,9 @@ static void pci_dma_dev_setup_pSeries(struct pci_dev *dev)
 
 		pr_debug(" --> first child, no bridge. Allocating iommu table.\n");
 		PCI_DN(dn)->table_group = iommu_pseries_alloc_group(phb->node);
+		if (!PCI_DN(dn)->table_group)
+			return;
+
 		tbl = PCI_DN(dn)->table_group->tables[0];
 		iommu_table_setparms(phb, dn, tbl);
 
@@ -1521,6 +1530,9 @@ static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
 	pci = PCI_DN(pdn);
 	if (!pci->table_group) {
 		pci->table_group = iommu_pseries_alloc_group(pci->phb->node);
+		if (!pci->table_group)
+			return;
+
 		tbl = pci->table_group->tables[0];
 		iommu_table_setparms_lpar(pci->phb, pdn, tbl,
 				pci->table_group, dma_window);
-- 
2.27.0