Messages in this thread | | | Date | Thu, 7 Jul 2022 11:58:18 +0100 | Subject | Re: [PATCH v3 04/15] iommu: Move bus setup to IOMMU device registration | From | Robin Murphy <> |
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On 2022-07-07 07:51, Tian, Kevin wrote: >> From: Robin Murphy <robin.murphy@arm.com> >> Sent: Wednesday, July 6, 2022 1:08 AM >> >> @@ -202,12 +210,32 @@ int iommu_device_register(struct iommu_device >> *iommu, >> spin_lock(&iommu_device_lock); >> list_add_tail(&iommu->list, &iommu_device_list); >> spin_unlock(&iommu_device_lock); >> + >> + for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) { >> + struct bus_type *bus = iommu_buses[i]; >> + int err; >> + >> + if (bus->iommu_ops && bus->iommu_ops != ops) { >> + err = -EBUSY; >> + } else { >> + bus->iommu_ops = ops; >> + err = bus_iommu_probe(bus); >> + } >> + if (err) { >> + iommu_device_unregister(iommu); >> + return err; >> + } >> + } >> + > > Probably move above into a new function bus_iommu_probe_all(): > > /* probe all buses for devices associated with this iommu */ > err = bus_iommu_probe_all(); > if (err) { > iommu_device_unregister(iommu); > return err; > } > > Just my personal preference on leaving logic in iommu_device_register() > more relevant to the iommu instance itself.
On reflection I think it makes sense to pull the iommu_device_unregister() out of the loop anyway - I think that's really a left-over from between v1 and v2 when that error case briefly jumped to another cleanup loop, before I realised it was actually trivial for iommu_device_unregister() to clean up for itself.
However I now see I've also missed another opportunity, and the -EBUSY case should be hoisted out of the loop as well, since checking iommu_buses[0] is sufficient. Then it's hopefully much clearer that once the bus ops go away we'll be left with just a single extra line for the loop, as in iommu_device_unregister(). Does that sound reasonable?
> Apart from that: > > Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Thanks! (and for the others as well)
Robin.
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