[PATCH v2 13/22] iommu/tegra: smmu: Create default IOVA maps

[Hiroshi Doyu]

Stephen Warren <swarren at wwwdotorg.org> wrote @ Thu, 18 Jul 2013 22:10:29 +0200:

> On 07/05/2013 04:44 AM, Hiroshi Doyu wrote:
> > Create default IOVA maps at boot-up which can be attached to devices.
> 
> > diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
> 
> >  static int tegra_smmu_probe(struct platform_device *pdev)
> >  {
> >  	struct smmu_device *smmu;
> 
> > @@ -1160,13 +1182,15 @@ static int tegra_smmu_probe(struct platform_device *pdev)
> >  	if (of_property_read_u32(dev->of_node, "nvidia,#asids", &asids))
> >  		return -ENODEV;
> >  
> > -	bytes = sizeof(*smmu) + asids * sizeof(*smmu->as);
> > +	bytes = sizeof(*smmu) + asids * (sizeof(*smmu->as) +
> > +					 sizeof(struct dma_iommu_mapping *));
> >  	smmu = devm_kzalloc(dev, bytes, GFP_KERNEL);
> >  	if (!smmu) {
> >  		dev_err(dev, "failed to allocate smmu_device\n");
> >  		return -ENOMEM;
> >  	}
> >  
> > +	smmu->map = (struct dma_iommu_mapping **)(smmu->as + asids);
> 
> Shouldn't "+ asids" be "+ asids * sizeof(*smmu->as)" to match the
> calculation of "bytes" above?

The structure is:

smmu {
     ....
     struct dma_iommu_mapping **map;
     ....	
     struct smmu_as	as[0];
};

I think that this is correct, but is the following better?

+ smmu->map = (struct dma_iommu_mapping **)&smmu->as[asids];