Messages in this thread | | | Date | Fri, 4 Aug 2017 21:09:29 +0800 | From | Baoquan He <> | Subject | Re: [PATCH v9 06/13] iommu/amd: copy old trans table from old kernel |
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On 08/04/17 at 02:21pm, Joerg Roedel wrote: > On Tue, Aug 01, 2017 at 07:37:22PM +0800, Baoquan He wrote: > > static void init_device_table_dma(void) > > { > > @@ -2137,9 +2140,49 @@ static void early_enable_iommu(struct amd_iommu *iommu) > > static void early_enable_iommus(void) > > { > > struct amd_iommu *iommu; > > + bool is_pre_disabled = false; > > > > - for_each_iommu(iommu) > > - early_enable_iommu(iommu); > > + for_each_iommu(iommu) { > > + if (!translation_pre_enabled(iommu)) { > > + is_pre_disabled = true; > > + break; > > + } > > + } > > I think this could be easier if you make 'is_pre_disabled' a global state > bool variable with reversed meaning and initialize it with 'true'. > Basically > > static bool __init amd_iommu_pre_enabled = true; > > And set this variable to 'false' when you find a already disabled IOMMU > during initialization. Then you can remove the code above.
Great idea, will change as you suggested. Thanks.
> > > + > > + if (is_pre_disabled) { > > + for_each_iommu(iommu) > > + early_enable_iommu(iommu); > > return > } > > > + } else { > > And remove this to get rid of one indendation level for the code below. > > > + pr_warn("Translation is already enabled - trying to copy translation structures\n"); > > + if (copy_device_table()) { > > Seeing how the return value of copy_device_table() is used, it makes > sense to change its return-type to bool. This way it is also easier to > see which one is the sucess and which one the failure case. >
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