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 <mr...@linux.ee>
Signed-off-by: Tushar Dave <tushar.n.d...@oracle.com>
---
arch/sparc/kernel/pci_sun4v.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c
index 24f21c7..f10e2f7 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;
--
1.9.1
