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Diffstat (limited to 'arch/powerpc/platforms/powernv/pci-ioda.c')
-rw-r--r--arch/powerpc/platforms/powernv/pci-ioda.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 026a06c51458..48de308224d6 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1851,6 +1851,14 @@ static int pnv_pci_ioda_dma_set_mask(struct pci_dev *pdev, u64 dma_mask)
/* 4GB offset bypasses 32-bit space */
set_dma_offset(&pdev->dev, (1ULL << 32));
set_dma_ops(&pdev->dev, &dma_direct_ops);
+ } else if (dma_mask >> 32 && dma_mask != DMA_BIT_MASK(64)) {
+ /*
+ * Fail the request if a DMA mask between 32 and 64 bits
+ * was requested but couldn't be fulfilled. Ideally we
+ * would do this for 64-bits but historically we have
+ * always fallen back to 32-bits.
+ */
+ return -ENOMEM;
} else {
dev_info(&pdev->dev, "Using 32-bit DMA via iommu\n");
set_dma_ops(&pdev->dev, &dma_iommu_ops);