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

Jason Gunthorpe
2024-08-28T19:13:43Z

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