On Thu, Mar 11, 2021 at 04:31:34PM -0700, Logan Gunthorpe wrote: > Introduce pci_p2pdma_should_map_bus() which is meant to be called by ^^^^^^^^^^^^^^^^^^^^^^^^^ pci_p2pdma_dma_map_type() ???
FWIW I find this name confusing with pci_p2pdma_map_type() and looking at the implementation I'm not clear why pci_p2pdma_dma_map_type() needs to exist? Ira [snip] > + > +/** > + * pci_p2pdma_dma_map_type - determine if a DMA mapping should use the > + * bus address, be mapped normally or fail > + * @dev: device doing the DMA request > + * @pgmap: dev_pagemap structure for the mapping > + * > + * Returns: > + * 1 - if the page should be mapped with a bus address, > + * 0 - if the page should be mapped normally through an IOMMU mapping or > + * physical address; or > + * -1 - if the device should not map the pages and an error should be > + * returned > + */ > +int pci_p2pdma_dma_map_type(struct device *dev, struct dev_pagemap *pgmap) > +{ > + struct pci_p2pdma_pagemap *p2p_pgmap = to_p2p_pgmap(pgmap); > + struct pci_dev *client; > + > + if (!dev_is_pci(dev)) > + return -1; > + > + client = to_pci_dev(dev); > + > + switch (pci_p2pdma_map_type(p2p_pgmap->provider, client)) { > + case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE: > + return 0; > + case PCI_P2PDMA_MAP_BUS_ADDR: > + return 1; > + default: > + return -1; > + } > +} > +EXPORT_SYMBOL_GPL(pci_p2pdma_dma_map_type); I guess the main point here is to export this to the DMA layer? Ira _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu