On 2/15/23 7:03 AM, Niklas Schnelle wrote: > While s390 already has a standard IOMMU driver and previous changes have > added I/O TLB flushing operations this driver is currently only used for > user-space PCI access such as vfio-pci. For the DMA API s390 instead > utilizes its own implementation in arch/s390/pci/pci_dma.c which drives > the same hardware and shares some code but requires a complex and > fragile hand over between DMA API and IOMMU API use of a device and > despite code sharing still leads to significant duplication and > maintenance effort. Let's utilize the common code DMAP API > implementation from drivers/iommu/dma-iommu.c instead allowing us to > get rid of arch/s390/pci/pci_dma.c. > > Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> > --- FYI, this patch doesn't fit on top of iommu-next, I'd guess at least due to baolu's 'Retire detach_dev callback' series, which removed .detach_dev and added .set_platform_dma_ops for s390-iommu. That's relevant here, because now that this patch enables dma-iommu for s390 and removes the platform DMA ops it must now remove .set_platform_dma_ops/s390_iommu_set_platform_dma for s390-iommu. Matt
