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authorTushar Dave <tushar.n.dave@oracle.com>2017-07-11 14:34:47 -0700
committerDavid S. Miller <davem@davemloft.net>2017-07-12 08:13:04 -0700
commit2ad67141f1e47dc063b202993835361a06239aaa (patch)
tree72e0552f4322006d4474f46637e8ff55cee2b1f3 /arch/sparc
parent3b06b1a7448ee4e8e51dae3938774735404e51fb (diff)
SPARC64: Fix sun4v DMA panic
64bit DMA only supported on sun4v equipped with ATU IOMMU HW. 'Commit b02c2b0bfd7ae ("sparc: remove arch specific dma_supported implementations")' introduced a code that incorrectly allow dma_supported() to succeed for 64bit dma mask even if system doesn't have ATU IOMMU. This results into panic. Fix it. Reported-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Tushar Dave <tushar.n.dave@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc')
-rw-r--r--arch/sparc/kernel/pci_sun4v.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c
index 24f21c726dfa..f10e2f712394 100644
--- a/arch/sparc/kernel/pci_sun4v.c
+++ b/arch/sparc/kernel/pci_sun4v.c
@@ -673,12 +673,14 @@ static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist,
static int dma_4v_supported(struct device *dev, u64 device_mask)
{
struct iommu *iommu = dev->archdata.iommu;
- u64 dma_addr_mask;
+ u64 dma_addr_mask = iommu->dma_addr_mask;
- if (device_mask > DMA_BIT_MASK(32) && iommu->atu)
- dma_addr_mask = iommu->atu->dma_addr_mask;
- else
- dma_addr_mask = iommu->dma_addr_mask;
+ if (device_mask > DMA_BIT_MASK(32)) {
+ if (iommu->atu)
+ dma_addr_mask = iommu->atu->dma_addr_mask;
+ else
+ return 0;
+ }
if ((device_mask & dma_addr_mask) == dma_addr_mask)
return 1;