| Message ID | 20230310-dma_iommu-v9-1-65bb8edd2beb@linux.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | iommu/dma: s390 DMA API conversion and optimized IOTLB flushing | expand |
On 5/15/23 11:15, Niklas Schnelle wrote: > A future change will convert the DMA API implementation from the > architecture specific arch/s390/pci/pci_dma.c to using the common code > drivers/iommu/dma-iommu.c which the utilizes the same IOMMU hardware > through the s390-iommu driver. Unlike the s390 specific DMA API this > requires devices to correctly call set the coherent mask to be allowed s/call// > to use IOVAs >2^32 in dma_alloc_coherent(). This was however not done > for ISM devices. ISM requires such addresses since currently the DMA > aperture for PCI devices starts at 2^32 and all calls to > dma_alloc_coherent() would thus fail. > > Reviewed-by: Alexandra Winter <wintera@linux.ibm.com> > Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> > Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> > --- > drivers/s390/net/ism_drv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/s390/net/ism_drv.c b/drivers/s390/net/ism_drv.c > index 8acb9eba691b..1399b5dc646c 100644 > --- a/drivers/s390/net/ism_drv.c > +++ b/drivers/s390/net/ism_drv.c > @@ -660,7 +660,7 @@ static int ism_probe(struct pci_dev *pdev, const struct pci_device_id *id) > if (ret) > goto err_disable; > > - ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)); > + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); > if (ret) > goto err_resource; > > Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
On Mon, 15 May 2023 11:15:51 +0200 Niklas Schnelle <schnelle@linux.ibm.com> wrote: > A future change will convert the DMA API implementation from the > architecture specific arch/s390/pci/pci_dma.c to using the common code > drivers/iommu/dma-iommu.c which the utilizes the same IOMMU hardware > through the s390-iommu driver. Unlike the s390 specific DMA API this > requires devices to correctly call set the coherent mask to be allowed > to use IOVAs >2^32 in dma_alloc_coherent(). This was however not done > for ISM devices. ISM requires such addresses since currently the DMA > aperture for PCI devices starts at 2^32 and all calls to > dma_alloc_coherent() would thus fail. > > Reviewed-by: Alexandra Winter <wintera@linux.ibm.com> > Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> > Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> > --- > drivers/s390/net/ism_drv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/s390/net/ism_drv.c b/drivers/s390/net/ism_drv.c > index 8acb9eba691b..1399b5dc646c 100644 > --- a/drivers/s390/net/ism_drv.c > +++ b/drivers/s390/net/ism_drv.c > @@ -660,7 +660,7 @@ static int ism_probe(struct pci_dev *pdev, const struct pci_device_id *id) > if (ret) > goto err_disable; > > - ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)); > + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); Ah. I love this change. I have already wondered a few times if the coherent DMA mask for this device may actually be different from dma_mask. Now I know. ;-) Thanks! Petr T
diff --git a/drivers/s390/net/ism_drv.c b/drivers/s390/net/ism_drv.c index 8acb9eba691b..1399b5dc646c 100644 --- a/drivers/s390/net/ism_drv.c +++ b/drivers/s390/net/ism_drv.c @@ -660,7 +660,7 @@ static int ism_probe(struct pci_dev *pdev, const struct pci_device_id *id) if (ret) goto err_disable; - ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)); + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); if (ret) goto err_resource;