[PATCH v2 5/8] iommu/arm-smmu-v3: Report IOMMU_CAP_ENFORCE_CACHE_COHERENCY for CANWBS

[Jason Gunthorpe]

On Tue, Aug 27, 2024 at 01:12:27PM -0700, Nicolin Chen wrote:
> > @@ -2693,6 +2718,15 @@ static int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state,
> >  		 * one of them.
> >  		 */
> >  		spin_lock_irqsave(&smmu_domain->devices_lock, flags);
> > +		if (smmu_domain->enforce_cache_coherency &&
> > +		    !(dev_iommu_fwspec_get(master->dev)->flags &
> > +		      IOMMU_FWSPEC_PCI_RC_CANWBS)) {
> 
> How about a small dev_enforce_cache_coherency() helper?

I added a

+static bool arm_smmu_master_canwbs(struct arm_smmu_master *master)
+{
+       return dev_iommu_fwspec_get(master->dev)->flags &
+              IOMMU_FWSPEC_PCI_RC_CANWBS;
+}
+

> > +			kfree(master_domain);
> > +			spin_unlock_irqrestore(&smmu_domain->devices_lock,
> > +					       flags);
> > +			return -EINVAL;
> 
> kfree() doesn't need to be locked.

Yep

Thanks,
Jason