Re: [RFC PATCH v6 04/20] iommu/arm-smmu: add capability IOMMU_CAP_INTR_REMAP

Christoffer Dall
2014-06-08T10:31:29Z

On Thu, Jun 05, 2014 at 07:03:12PM +0200, Antonios Motakis wrote:
> With an ARM SMMU, interrupt remapping should always be safe from the
> SMMU's point of view, as it is properly handled by the GIC.
>
> Signed-off-by: Antonios Motakis <a.motakis-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org>
> ---
> drivers/iommu/arm-smmu.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index 15ab2af..ff29402 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -1544,7 +1544,7 @@ static int arm_smmu_domain_has_cap(struct iommu_domain *domain,
> if (smmu_domain->root_cfg.smmu->features & ARM_SMMU_FEAT_COHERENT_WALK)
> caps |= IOMMU_CAP_CACHE_COHERENCY;
>
> - caps |= IOMMU_CAP_NOEXEC;
> + caps |= IOMMU_CAP_NOEXEC | IOMMU_CAP_INTR_REMAP;
>
> return !!(cap & caps);
> }
> --
> 1.8.3.2
>
What does IOMMU_CAP_INTR_REMAP signify exactly? Is there docs/examples
somewhere I can look at? (A quick scan of the Linux souce code doesn't
reveal much, and I'm not sure if this is purely MSI related or what...)

Thanks,
-Christoffer