From efca4885b5dea6af906d27b3516f68e0bc1ff9c3 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 25 Nov 2016 14:01:32 +0300 Subject: [PATCH] sparc64: move dereference after check for NULL We shouldn't dereference "iommu" until after we have checked that it is non-NULL. Fixes: f08978b0fdbf ("sparc64: Enable sun4v dma ops to use IOMMU v2 APIs") Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller --- arch/sparc/kernel/pci_sun4v.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c index 06981cc716b6..cabb609fedcc 100644 --- a/arch/sparc/kernel/pci_sun4v.c +++ b/arch/sparc/kernel/pci_sun4v.c @@ -478,11 +478,10 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist, BUG_ON(direction == DMA_NONE); iommu = dev->archdata.iommu; - atu = iommu->atu; - if (nelems == 0 || !iommu) return 0; - + atu = iommu->atu; + prot = HV_PCI_MAP_ATTR_READ; if (direction != DMA_TO_DEVICE) prot |= HV_PCI_MAP_ATTR_WRITE; -- 2.20.1