| Message ID | 1499808887-31483-1-git-send-email-tushar.n.dave@oracle.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
On Tue, Jul 11, 2017 at 02:34:47PM -0700, Tushar Dave wrote: > 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> > --- > 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; > + } This would be more readable as: if (device_mask > DMA_BIT_MASK(32)) { if (!iommu->atu) return 0; dma_addr_mask = iommu->atu->dma_addr_mask; } But except for that it looks fine to me: Reviewed-by: Christoph Hellwig <hch@lst.de> -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Tushar Dave <tushar.n.dave@oracle.com> Date: Tue, 11 Jul 2017 14:34:47 -0700 > 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> Applied to the 'sparc' tree, thanks. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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;
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> --- arch/sparc/kernel/pci_sun4v.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)