Re: [PATCH v13 06/10] iommu/arm-smmu-v3: Add acpi_smmu_acpi_probe_model for impl

[Will Deacon <will@kernel.org>]

On Fri, Aug 23, 2024 at 05:10:40PM -0700, Nicolin Chen wrote:
> For model-specific implementation, repurpose the acpi_smmu_get_options()
> to a wider acpi_smmu_acpi_probe_model(). A new model can add to the list
> in this new function.
> 
> Suggested-by: Will Deacon <will@kernel.org>
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> ---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> 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 afdb8a76a72a..ceb31d63f79b 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -4341,18 +4341,28 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
>  }
>  
>  #ifdef CONFIG_ACPI
> -static void acpi_smmu_get_options(u32 model, struct arm_smmu_device *smmu)
> +static int acpi_smmu_iort_probe_model(struct acpi_iort_node *node,
> +				      struct arm_smmu_device *smmu)
>  {
> -	switch (model) {
> +	struct acpi_iort_smmu_v3 *iort_smmu =
> +		(struct acpi_iort_smmu_v3 *)node->node_data;
> +
> +	switch (iort_smmu->model) {
>  	case ACPI_IORT_SMMU_V3_CAVIUM_CN99XX:
>  		smmu->options |= ARM_SMMU_OPT_PAGE0_REGS_ONLY;
>  		break;
>  	case ACPI_IORT_SMMU_V3_HISILICON_HI161X:
>  		smmu->options |= ARM_SMMU_OPT_SKIP_PREFETCH;
>  		break;
> +	case ACPI_IORT_SMMU_V3_GENERIC:
> +		break;
> +	default:
> +		dev_err(smmu->dev, "Unknown/unsupported IORT model!\n");
> +		return -ENXIO;

We probably don't want this 'default' case, otherwise the driver will
need to be updated every time there's a new model.

If you agree, then I can just drop this bit when applying.

Will