On Sat, Nov 02, 2024 at 01:26:46PM -0400, Frank Li wrote: [...] > > > + > > > + target = NULL; > > > + err_i = of_map_id(dev->of_node, rid, "iommu-map", "iommu-map-mask", &target, &sid_i); > > > + target = NULL; > > > > What is the point in passing 'target' here? > > See https://lore.kernel.org/imx/b479cad6-e0c5-48fb-bb8f-a70f7582cfd5@xxxxxxx/ > Marc Zyngier's comments: > > "Perhaps it is reasonable to assume that i.MX95 will never have SMMU/ITS > mappings for low-numbered devices on bus 0, but in general this isn't > very robust, and either way it's certainly not all that clear at first > glance what assmuption is actually being made here. If it's significant > whether a mapping actually exists or not for the given ID then you > should really use the "target" argument of of_map_id() to determine that." > > See v4 https://lore.kernel.org/imx/20241101-imx95_lut-v4-2-0fdf9a2fe754@xxxxxxx/ > Okay, thanks! I was confused by the fact that you never used 'target' in this version. But v4 clears it up. - Mani > + target = NULL; > + err_m = of_map_id(dev->of_node, rid, "msi-map", "msi-map-mask", &target, &sid_m); > + > + /* > + * Return failure if msi-map exist and no entry for rid because dwc common > + * driver will skip setting up built-in MSI controller if msi-map existed. > + * > + * err_m target > + * 0 NULL Return failure, function not work. > + * !0 NULL msi-map not exist, use built-in MSI. > + * 0 !NULL Find one entry. > + * !0 !NULL Invalidate case. > + */ > > > > > > > + err_m = of_map_id(dev->of_node, rid, "msi-map", "msi-map-mask", &target, &sid_m); > > > + > > > + > > > + /* > > > + * msi-map iommu-map > > > + * Y Y ITS + SMMU, require the same sid > > > + * Y N ITS > > > + * N Y DWC MSI Ctrl + SMMU > > > + * N N DWC MSI Ctrl > > > + */ > > > + if (!err_i && !err_m) > > > + if ((sid_i & IMX95_SID_MASK) != (sid_m & IMX95_SID_MASK)) { > > > + dev_err(dev, "its and iommu stream id miss match, please check dts file\n"); > > > > "iommu-map and msi-map entries mismatch!" > > > > - Mani > > > > -- > > மணிவண்ணன் சதாசிவம் -- மணிவண்ணன் சதாசிவம்
