Re: [PATCH v9 1/6] s390/ism: Set DMA coherent mask

Pierre Morel
2023-05-16T07:40:18Z

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>