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SPARC64: Fix sun4v DMA panic 

64bit DMA only supported on sun4v equipped with ATU IOMMU HW.
'Commit b02c2b0bfd ("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>
This commit is contained in:
Tushar Dave 2017-07-11 14:34:47 -07:00 committed by David S. Miller
parent 3b06b1a744
commit 2ad67141f1
1 changed files with 7 additions and 5 deletions
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12
arch/sparc/kernel/pci_sun4v.c
View File

@ -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;