[PATCH net-next] s390/ism: Set DMA coherent mask

From: Niklas Schnelle
Date: Wed May 24 2023 - 03:54:27 EST

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 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.

Link: https://lore.kernel.org/all/20230310-dma_iommu-v9-1-65bb8edd2beb@xxxxxxxxxxxxx/
Reviewed-by: Alexandra Winter <wintera@xxxxxxxxxxxxx>
Reviewed-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
Reviewed-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
Note: This was previously sent and reviewed as part of multiple versions of the
s390 DMA API conversion series which requires this change as a pre-requisite
with the latest version at the Link. Sending separately to add the net-next
prefix so this can be integrated.

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;