Subject: [PATCH v2 5/7] iommu/arm-smmu: Implement of_xlate() for SMMUv3

From: [email-masked] (Will Deacon)
Date: Tue, 14 Jun 2016 16:07:59 +0100

On Fri, Jun 03, 2016 at 06:15:40PM +0100, Robin Murphy wrote:
> Now that we can properly describe the mapping between PCI RIDs and
> stream IDs via "iommu-map", and have it fed it to the driver
> automatically via of_xlate(), rework the SMMUv3 driver to benefit from
> that. Initially, this just gets rid of the misuse of the "iommus"
> binding without changing the driver's existing level of functionality,
> but does at least pave the way to extending it more easily in future.
> 
> Signed-off-by: Robin Murphy <[email-masked]>
> ---
> 
> v2: New.
> 
>  drivers/iommu/arm-smmu-v3.c | 119 +++++++++++++++++++++++++++-----------------
>  1 file changed, 73 insertions(+), 46 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 94b68213c50d..7631639cc209 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -30,6 +30,7 @@
>  #include <linux/msi.h>
>  #include <linux/of.h>
>  #include <linux/of_address.h>
> +#include <linux/of_iommu.h>
>  #include <linux/of_platform.h>
>  #include <linux/pci.h>
>  #include <linux/platform_device.h>
> @@ -638,6 +639,12 @@ struct arm_smmu_domain {
>  	struct iommu_domain		domain;
>  };
>  
> +/* SMMU private data for each master */
> +struct arm_smmu_master_data {
> +	struct arm_smmu_device		*smmu;
> +	u32				sid;
> +};

Hmm, we already have this information in arm_smmu_group so I'd rather
avoid the duplication if we can.

> @@ -1804,23 +1790,41 @@ static int arm_smmu_add_device(struct device *dev)
>  {
>  	int i, ret;
>  	u32 sid, *sids;
> -	struct pci_dev *pdev;
>  	struct iommu_group *group;
> +	struct device_node *np;
>  	struct arm_smmu_group *smmu_group;
> -	struct arm_smmu_device *smmu;
> +	struct arm_smmu_device *smmu = NULL;
> +	struct arm_smmu_master_data *data = dev->archdata.iommu;
>  
> -	/* We only support PCI, for now */
> -	if (!dev_is_pci(dev))
> +	if (!data)
>  		return -ENODEV;
>  
> -	pdev = to_pci_dev(dev);
> +	np = (struct device_node *)data->smmu;
> +	smmu = data->smmu = arm_smmu_get_by_node(np);
> +	of_node_put(np);
> +	if (!smmu)
> +		return -ENODEV;

Why can't we continue to use the group here?

Will