[PATCH v8 1/6] s390/ism: Set DMA coherent mask

From: Niklas Schnelle
Date: Fri Mar 10 2023 - 11:12:39 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 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@xxxxxxxxxxxxx>
Reviewed-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
---
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 eb7e13486087..a40e3afeaaa8 100644
--- a/drivers/s390/net/ism_drv.c
+++ b/drivers/s390/net/ism_drv.c
@@ -661,7 +661,7 @@ 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;


--
2.37.2