[PATCH v3 08/10] iommu/arm-smmu-v3: Reserve any RMR regions associated with a dev

[Robin Murphy]

On 2021-04-20 09:27, Shameer Kolothum wrote:
> Get RMR regions associated with a dev reserved so that there is
> a unity mapping for them in SMMU.
> 
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi at huawei.com>
> ---
>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 29 +++++++++++++++++++++
>   1 file changed, 29 insertions(+)
> 
> 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 14e9c7034c04..8bacedf7bb34 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -2531,6 +2531,34 @@ static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args)
>   	return iommu_fwspec_add_ids(dev, args->args, 1);
>   }
>   
> +static bool arm_smmu_dev_has_rmr(struct arm_smmu_master *master,
> +				 struct iommu_rmr *e)
> +{
> +	int i;
> +
> +	for (i = 0; i < master->num_sids; i++) {
> +		if (e->sid == master->sids[i])
> +			return true;
> +	}
> +
> +	return false;
> +}
> +
> +static void arm_smmu_rmr_get_resv_regions(struct device *dev,
> +					  struct list_head *head)
> +{
> +	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
> +	struct arm_smmu_device *smmu = master->smmu;
> +	struct iommu_rmr *rmr;
> +
> +	list_for_each_entry(rmr, &smmu->rmr_list, list) {
> +		if (!arm_smmu_dev_has_rmr(master, rmr))
> +			continue;
> +
> +		iommu_dma_get_rmr_resv_regions(dev, rmr, head);
> +	}
> +}
> +

TBH I wouldn't have thought we need a driver-specific hook for this, or 
is it too painful to correlate fwspec->iommu_fwnode back to the relevant 
IORT node generically?

Robin.

>   static void arm_smmu_get_resv_regions(struct device *dev,
>   				      struct list_head *head)
>   {
> @@ -2545,6 +2573,7 @@ static void arm_smmu_get_resv_regions(struct device *dev,
>   	list_add_tail(&region->list, head);
>   
>   	iommu_dma_get_resv_regions(dev, head);
> +	arm_smmu_rmr_get_resv_regions(dev, head);
>   }
>   
>   static bool arm_smmu_dev_has_feature(struct device *dev,
>