Re: [PATCH] powerpc/iommu: Fix multiple issues with IOMMU pools code

From: Alexander Graf
Date: Thu Oct 04 2012 - 06:54:51 EST


Hi Anton,

On 04.10.2012, at 06:57, Anton Blanchard wrote:

>
> Hi Alex,
>
> Looks to be a preempt issue with the iommu pools code. I did find a
> couple more bugs along the way too.
>
> Anton
> --
>
> There are a number of issues in the recent IOMMU pools code:
>
> - On a preempt kernel we might switch CPUs in the middle of building
> a scatter gather list. When this happens the handle hint passed in
> no longer falls within the local CPU's pool. Check for this and
> fall back to the pool hint.
>
> - We were missing a spin_unlock/spin_lock in one spot where we
> switch pools.
>
> - We need to provide locking around dart_tlb_invalidate_all and
> dart_tlb_invalidate_one now that the global lock is gone.
>
> Reported-by: Alexander Graf <agraf@xxxxxxx>
> Signed-off-by: Anton Blanchard <anton@xxxxxxxxx>
> ---
>
> There is still an issue with the lazy u3 flushing, but I wanted
> to get this out for testing.

Yup. It fixes the nfs problem on my U4 based machine.

Tested-by: Alexander Graf <agraf@xxxxxxx>

Alex

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