Messages in this thread | | | Date | Tue, 19 Apr 2022 08:20:22 +0100 | Subject | Re: [PATCH 02/13] iommu: Move bus setup to IOMMU device registration | From | Robin Murphy <> |
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On 2022-04-19 00:37, Lu Baolu wrote: > On 2022/4/19 6:09, Robin Murphy wrote: >> On 2022-04-16 01:04, Lu Baolu wrote: >>> On 2022/4/14 20:42, Robin Murphy wrote: >>>> @@ -1883,27 +1900,12 @@ static int iommu_bus_init(struct bus_type *bus) >>>> */ >>>> int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops) >>>> { >>>> - int err; >>>> - >>>> - if (ops == NULL) { >>>> - bus->iommu_ops = NULL; >>>> - return 0; >>>> - } >>>> - >>>> - if (bus->iommu_ops != NULL) >>>> + if (bus->iommu_ops && ops && bus->iommu_ops != ops) >>>> return -EBUSY; >>>> bus->iommu_ops = ops; >>> >>> Do we still need to keep above lines in bus_set_iommu()? >> >> It preserves the existing behaviour until each callsite and its >> associated error handling are removed later on, which seems like as >> good a thing to do as any. Since I'm already relaxing >> iommu_device_register() to a warn-but-continue behaviour while it >> keeps the bus ops on life-support internally, I figured not changing >> too much at once would make it easier to bisect any potential issues >> arising from this first step. > > Fair enough. Thank you for the explanation. > > Do you have a public tree that I could pull these patches and try them > on an Intel hardware? Or perhaps you have done this? I like the whole > idea of this series, but it's better to try it with a real hardware.
I haven't bothered with separate branches since there's so many different pieces in-flight, but my complete (unstable) development branch can be found here:
https://gitlab.arm.com/linux-arm/linux-rm/-/commits/iommu/bus
For now I'd recommend winding the head back to "iommu: Clean up bus_set_iommu()" for testing - some of the patches above that have already been posted and picked up by their respective subsystems, but others are incomplete and barely compile-tested. I'll probably rearrange it later this week to better reflect what's happened so far.
Cheers, Robin.
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