> dma_direct_unmap_sg(dev, sglist, nelems, direction, attrs);
> }
>
> +static dma_addr_t dma_iommu_map_resource(struct device *dev,
> + phys_addr_t phys_addr, size_t size,
> + enum dma_data_direction dir,
> + unsigned long attrs)
> +{
> + struct pci_dev *pdev = to_pci_dev(dev);
> + struct pci_controller *phb = pci_bus_to_host(pdev->bus);
> +
> + if (dma_iommu_map_bypass(dev, attrs)) {
> + if (phb->controller_ops.dma_map_resource &&
> + phb->controller_ops.dma_map_resource(pdev, phys_addr, size,
> + dir))
> + return DMA_MAPPING_ERROR;
> + return dma_direct_map_resource(dev, phys_addr, size,
> + dir, attrs);
> + }
> + return DMA_MAPPING_ERROR;
Just a nitpick, but to the return errors early would be a much more
logical flow. Also if the callback just decides if the mapping is
possible in bypass mode it should have that in the name:
struct pci_controller_ops *ops = &phb->controller_ops;
if (!dma_iommu_map_bypass(dev, attrs) ||
!ops->dma_can_direct_map_resource ||
!ops->dma_can_direct_map_resource(pdev, phys_addr, size, dir)
return DMA_MAPPING_ERROR;
return dma_direct_map_resource(dev, phys_addr, size, dir, attrs);
> + if (dma_iommu_map_bypass(dev, attrs)) {
> + if (phb->controller_ops.dma_unmap_resource)
> + phb->controller_ops.dma_unmap_resource(pdev, dma_handle,
> + size, dir);
> + }
This can do a little early return as well, coupled with a WARN_ON_ONCE
as we should never end up in the unmap path for a setup where the map didn't
work.
