Re: [PATCH rfcv2 2/8] iommu/arm-smmu-v3: Explicitly set smmu_domain->stage for SVA

[Balbir Singh <balbirs@nvidia.com>]

On 9/9/25 09:26, Nicolin Chen wrote:
> Both the ARM_SMMU_DOMAIN_S1 case and the SVA case use ASID, requiring ASID
> based invalidation commands to flush the TLB.
> 
> Define an ARM_SMMU_DOMAIN_SVA to make the SVA case clear to share the same
> path with the ARM_SMMU_DOMAIN_S1 case, which will be a part of the routine
> to build a new per-domain invalidation array.
> 
> There is no function change.
> 
> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> ---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h     | 1 +
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 1 +
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c     | 3 +++
>  3 files changed, 5 insertions(+)
> 
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> index ae23aacc38402..5c0b38595d209 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> @@ -858,6 +858,7 @@ struct arm_smmu_master {
>  enum arm_smmu_domain_stage {
>  	ARM_SMMU_DOMAIN_S1 = 0,
>  	ARM_SMMU_DOMAIN_S2,
> +	ARM_SMMU_DOMAIN_SVA,
>  };
>  
>  struct arm_smmu_domain {
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
> index 59a480974d80f..6097f1f540d87 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
> @@ -346,6 +346,7 @@ struct iommu_domain *arm_smmu_sva_domain_alloc(struct device *dev,
>  	 * ARM_SMMU_FEAT_RANGE_INV is present
>  	 */
>  	smmu_domain->domain.pgsize_bitmap = PAGE_SIZE;
> +	smmu_domain->stage = ARM_SMMU_DOMAIN_SVA;
>  	smmu_domain->smmu = smmu;
>  
>  	ret = xa_alloc(&arm_smmu_asid_xa, &asid, smmu_domain,
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index cccf8f52ee0d5..0016ec699acfe 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -3070,6 +3070,9 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
>  		arm_smmu_install_ste_for_dev(master, &target);
>  		arm_smmu_clear_cd(master, IOMMU_NO_PASID);
>  		break;
> +	default:
> +		WARN_ON(true);

WARN_ONCE_ONCE() and shoudn't ret be set to -EINVAL?

> +		break;
>  	}
>  
>  	arm_smmu_attach_commit(&state);

Balbir