Re: [PATCH V10 05/12] ACPI/IORT: Add function to check SMMUs drivers presence

[Robin Murphy]

On 04/04/17 11:18, Sricharan R wrote:
> From: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> 
> The IOMMU probe deferral implementation requires a mechanism to detect
> if drivers for SMMU components are built-in in the kernel to detect
> whether IOMMU configuration for a given device should be deferred (ie
> SMMU drivers present but still not probed) or not (drivers not present).
> 
> Add a simple function to IORT to detect if SMMU drivers for SMMU
> components managed by IORT are built-in in the kernel.

Ah, if only DT could be this neat and tidy :D

Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>

> Tested-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Cc: Robin Murphy <robin.murphy@xxxxxxx>
> Cc: Sricharan R <sricharan@xxxxxxxxxxxxxx>
> ---
>  drivers/acpi/arm64/iort.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 4a5bb96..3dd9ec3 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -523,6 +523,19 @@ static int arm_smmu_iort_xlate(struct device *dev, u32 streamid,
>  	return ret;
>  }
>  
> +static inline bool iort_iommu_driver_enabled(u8 type)
> +{
> +	switch (type) {
> +	case ACPI_IORT_NODE_SMMU_V3:
> +		return IS_BUILTIN(CONFIG_ARM_SMMU_V3);
> +	case ACPI_IORT_NODE_SMMU:
> +		return IS_BUILTIN(CONFIG_ARM_SMMU);
> +	default:
> +		pr_warn("IORT node type %u does not describe an SMMU\n", type);
> +		return false;
> +	}
> +}
> +
>  static const struct iommu_ops *iort_iommu_xlate(struct device *dev,
>  					struct acpi_iort_node *node,
>  					u32 streamid)
>