On Fri, 22 Jan 2021 09:51:20 +0100
Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx> wrote:
> On Thu, Jan 21, 2021 at 07:12:36PM +0000, Jonathan Cameron wrote:
> > > @@ -2502,6 +2647,7 @@ static void arm_smmu_release_device(struct device *dev)
> > >
> > > master = dev_iommu_priv_get(dev);
> > > WARN_ON(arm_smmu_master_sva_enabled(master));
> > > + iopf_queue_remove_device(master->smmu->evtq.iopf, dev);
> > > arm_smmu_detach_dev(master);
> > > arm_smmu_disable_pasid(master);
> > > arm_smmu_remove_master(master);
> >
> > The lack of symmetry here bothers me a bit, but it's already true, so I guess
> > this case is fine as well.
>
> Normally the device driver calls iommu_dev_feat_disable(SVA) which does
> iopf_queue_remove_device(). This is just a safety net in case the device
> gets removed without the driver properly cleaning up (which will WARN as
> well)
Ah makes sense. Maybe it's worth a comment in the code for future generations
of tired code readers?
>
> >
> > ...
> > >
> > > @@ -2785,6 +2946,7 @@ static int arm_smmu_cmdq_init(struct arm_smmu_device *smmu)
> > > static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
> > > {
> > > int ret;
> > > + bool sva = smmu->features & ARM_SMMU_FEAT_STALLS;
> >
> > FEAT_SVA?
>
> Ugh yes, thanks. I left this as a bool instead of moving into the test
> below because the PRI patch reuses it, but I think I'll just move it down
> when resending.
Makes sense.
>
> Thanks,
> Jean
>
> >
> > >
> > > /* cmdq */
> > > ret = arm_smmu_init_one_queue(smmu, &smmu->cmdq.q, ARM_SMMU_CMDQ_PROD,
> > > @@ -2804,6 +2966,12 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
> > > if (ret)
> > > return ret;
> > >
> > > + if (sva && smmu->features & ARM_SMMU_FEAT_STALLS) {
> >
> > Isn't this checking same thing twice?
> >
> > > + smmu->evtq.iopf = iopf_queue_alloc(dev_name(smmu->dev));
> > > + if (!smmu->evtq.iopf)
> > > + return -ENOMEM;
> > > + }
> > > +
> > > /* priq */
> > > if (!(smmu->features & ARM_SMMU_FEAT_PRI))
> > > return 0;
> > > @@ -3718,6 +3886,7 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
> > > iommu_device_unregister(&smmu->iommu);
> > > iommu_device_sysfs_remove(&smmu->iommu);
> > > arm_smmu_device_disable(smmu);
> > > + iopf_queue_free(smmu->evtq.iopf);
> > >
> > > return 0;
> > > }
> >
