Re: [PATCH v4 5/7] iommu/dma: Make limit checks self-contained

Jon Hunter
2024-05-20T18:11:19Z

Hi Robin,

On 17/05/2024 16:03, Robin Murphy wrote:

...

> Thanks. From staring at the code I think I've spotted one subtlety which
> may not be quite as intended - can you see if the diff below helps? It
> occurs to me that suspend and CPU hotplug may not *cause* the symptom,
> but they could certainly stall if one or more relevant CPUs is *already*
> stuck in a loop somewhere...
>
> Thanks,
> Robin.
>
> ----->8-----
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index 89a53c2f2cf9..85eb1846c637 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -686,6 +686,7 @@ static int iommu_dma_init_domain(struct iommu_domain
> *domain, struct device *dev
>      /* Check the domain allows at least some access to the device... */
>      if (map) {
>          dma_addr_t base = dma_range_map_min(map);
> +        base = max(base, (dma_addr_t)1 << order);
>          if (base > domain->geometry.aperture_end ||
>              dma_range_map_max(map) < domain->geometry.aperture_start) {
>              pr_warn("specified DMA range outside IOMMU capability\n");

That fixes it for me!

Tested-by: Jon Hunter <jonathanh@nvidia.com>

Thanks!
Jon

--
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