Re: [PATCHv2 3/6] iommu/arm-smmu: Implement iommu_ops->def_domain_type call-back

[Sai Prakash Ranjan]

Hi Robin,

On 2020-04-20 20:56, Robin Murphy wrote:
> On 2020-04-20 3:37 pm, Sai Prakash Ranjan wrote:
> > Implement the new def_domain_type call-back for the ARM
> > SMMU driver. We need this to support requesting the domain
> > type by the client devices.
> >
> > Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>
> > ---
> >   drivers/iommu/arm-smmu.c | 20 ++++++++++++++++++++
> >   1 file changed, 20 insertions(+)
> >
> > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> > index e622f4e33379..b5d1d52dfbb8 100644
> > --- a/drivers/iommu/arm-smmu.c
> > +++ b/drivers/iommu/arm-smmu.c
> > @@ -1609,6 +1609,25 @@ static void arm_smmu_get_resv_regions(struct 
> > device *dev,
> >   	iommu_dma_get_resv_regions(dev, head);
> >   }
> >   +static int arm_smmu_def_domain_type(struct device *dev)
> > +{
> > +	struct iommu_fwspec *fwspec;
> > +	struct arm_smmu_device *smmu;
> > +
> > +	fwspec = dev_iommu_fwspec_get(dev);
> > +	if (!fwspec || fwspec->ops != &arm_smmu_ops)
> > +		return -ENODEV;
> > +
> > +	smmu = arm_smmu_get_by_fwnode(fwspec->iommu_fwnode);
> > +	if (!smmu)
> > +		return -ENODEV;
> > +
>
> AFAICS this should only ever be called for a device in a group, which
> means an initial ->probe_device has succeeded and rather than
> defensively going the long way round, we can safely assume this:
>
> 	struct arm_smmu_master_cfg = dev_iommu_priv_get(dev);
> 	struct arm_smmu_impl *impl = cfg->smmu->impl;
>
> 	if (impl && impl->req_domain)
> 		return impl->req_domain(dev);

Yes you are right, will use this.

Thanks,
Sai
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a 
member
of Code Aurora Forum, hosted by The Linux Foundation