Messages in this thread | | | Date | Tue, 29 Nov 2022 19:58:22 +0800 | Subject | Re: [PATCH v3 06/20] iommu/mtk: Remove detach_dev callback | From | Baolu Lu <> |
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On 2022/11/29 19:45, Robin Murphy wrote: > On 2022-11-29 02:07, Baolu Lu wrote: >> On 11/28/22 9:59 PM, Robin Murphy wrote: >>> On 2022-11-28 13:49, Jason Gunthorpe wrote: >>>> On Mon, Nov 28, 2022 at 02:46:34PM +0800, Lu Baolu wrote: >>>>> The IOMMU driver supports default domain, so the detach_dev op will >>>>> never >>>>> be called. Remove it to avoid dead code. >>>>> >>>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> >>>>> --- >>>>> drivers/iommu/mtk_iommu.c | 9 --------- >>>>> 1 file changed, 9 deletions(-) >>>> >>>> I listed this driver as not supporting default domains: >>>> >>>> https://lore.kernel.org/linux-iommu/20220516135741.GV1343366@nvidia.com/ >>>> >>>> ? >>>> >>>> Has something changed? Did I get it wrong? >>> >>> static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type) >>> { >>> struct mtk_iommu_domain *dom; >>> >>> if (type != IOMMU_DOMAIN_DMA && type != IOMMU_DOMAIN_UNMANAGED) >>> return NULL; >>> ... >>> >>> >>> This one runs on arm64, so has always supported default domains for >>> iommu-dma to work. >> >> This, together with several other ones, only support IOMMU_DOMAIN_DMA >> type of default domain. The iommu core handle this by falling back to >> IOMMU_DOMAIN_DMA if other types fail. >> >> dom = __iommu_domain_alloc(bus, type); >> if (!dom && type != IOMMU_DOMAIN_DMA) { >> dom = __iommu_domain_alloc(bus, IOMMU_DOMAIN_DMA); >> if (dom) >> pr_warn("Failed to allocate default IOMMU >> domain of type %u for group %s - Falling back to IOMMU_DOMAIN_DMA", >> type, group->name); >> } >> >> I have another cleanup series: >> >> https://github.com/LuBaolu/intel-iommu/commits/iommu-use-def_default_type-wip >> >> which adds IOMMU_DOMAIN_DMA default domain type requirement in the >> def_domain_type callback. I planed to bring that to discussion after >> this one. > > Per the discussion over on the s390 thread, I think that would be a step > in the wrong direction. I'd prefer to keep .def_domain_type for > device-specific requirements and express general driver domain support a > different way. If the IOMMU_DOMAIN_DMA fallback is worth removing then > the one for IOMMU_DOMAIN_BLOCKED is as well - no point doing half the > job ;)
Get you. Thanks for pointing this out. Sure, let's keep the code.
Best regards, baolu
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