Re: [PATCH v7 4/6] s390/pci: Use dma-iommu layer

[Matthew Rosato]

On 2/20/23 10:22 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>

Reviewed-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>