[Freedreno] [PATCH v2 5/5] drm/msm: switch msm_kms_init_aspace() to use device_iommu_mapped()

[Dmitry Baryshkov]

On Thu, 5 May 2022 at 13:27, Robin Murphy <robin.murphy at arm.com> wrote:
>
> On 2022-05-05 01:16, Dmitry Baryshkov wrote:
> > Change msm_kms_init_aspace() to use generic function
> > device_iommu_mapped() instead of the fwnode-specific interface
> > dev_iommu_fwspec_get(). While we are at it, stop referencing
> > platform_bus_type directly and use the bus of the IOMMU device.
>
> FWIW, I'd have squashed these changes across the previous patches, such
> that the dodgy fwspec calls are never introduced in the first place, but
> it's your driver, and if that's the way you want to work it and Rob's
> happy with it too, then fine by me.

I thought about this. But as the calls were already there (in the
mdp5), it was easier for me to merge the code and to update it
afterwards.

>
> For the end result,
>
> Reviewed-by: Robin Murphy <robin.murphy at arm.com>
>
> I'm guessing MDP4 could probably use msm_kms_init_aspace() now as well,
> but unless there's any other reason to respin this series, that's
> something we could do as a follow-up. Thanks for sorting this out!

Not really. MDP4 doesn't have the parent MDSS device, so it doesn't
need all these troubles.

>
> Robin.
>
> > Suggested-by: Robin Murphy <robin.murphy at arm.com>
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> > ---
> >   drivers/gpu/drm/msm/msm_drv.c | 14 +++++++-------
> >   1 file changed, 7 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> > index 98ae0036ab57..2fc3f820cd59 100644
> > --- a/drivers/gpu/drm/msm/msm_drv.c
> > +++ b/drivers/gpu/drm/msm/msm_drv.c
> > @@ -272,21 +272,21 @@ struct msm_gem_address_space *msm_kms_init_aspace(struct drm_device *dev)
> >       struct device *mdss_dev = mdp_dev->parent;
> >       struct device *iommu_dev;
> >
> > -     domain = iommu_domain_alloc(&platform_bus_type);
> > -     if (!domain) {
> > -             drm_info(dev, "no IOMMU, fallback to phys contig buffers for scanout\n");
> > -             return NULL;
> > -     }
> > -
> >       /*
> >        * IOMMUs can be a part of MDSS device tree binding, or the
> >        * MDP/DPU device.
> >        */
> > -     if (dev_iommu_fwspec_get(mdp_dev))
> > +     if (device_iommu_mapped(mdp_dev))
> >               iommu_dev = mdp_dev;
> >       else
> >               iommu_dev = mdss_dev;
> >
> > +     domain = iommu_domain_alloc(iommu_dev->bus);
> > +     if (!domain) {
> > +             drm_info(dev, "no IOMMU, fallback to phys contig buffers for scanout\n");
> > +             return NULL;
> > +     }
> > +
> >       mmu = msm_iommu_new(iommu_dev, domain);
> >       if (IS_ERR(mmu)) {
> >               iommu_domain_free(domain);



-- 
With best wishes
Dmitry