On 07/07/17 16:22, Scott Branden wrote: > Hi Robin, > > On 17-07-07 07:55 AM, Robin Murphy wrote: >> On 07/07/17 14:30, Mark Rutland wrote: [...] >>> Your mapping can be expressed today using a number of msi-map entries, >>> which you can easily generate programmatically with a trivial perl >>> script, without requiring a new binding or any new kernel code. >>> >>> Please do that instead. >> Indeed. The systems I'm aware of which need to express non-trivial RID >> to SID mappings tend to have the bootloader probe PCI and dynamically >> generate map entries per discovered RID, but even if you wanted to >> statically generate the whole lot for the worst-case bus range that's >> still only 512 entries, which is not unmanageable. Notably, it's also >> what would have to be done (in equivalent) for IORT, although I assume >> this is an embedded platform for which nobody cares about ACPI. > Actually we will care about ACPI and need to add it (doesn't need to be > in this patchet unless easy to do so...) Ah, OK, that's an even stronger argument for not adding anything new then - DT "iommu-map" is already marginally more expressive than IORT ID mappings can be, so there doesn't seem to be much justification for diverging them further. Robin. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
