Re: [PATCH v7 3/5] iommu/arm-smmu: introduction of ACTLR for custom prefetcher settings

[Konrad Dybcio]

On 1/10/24 13:55, Bibek Kumar Patro wrote:
> On 1/10/2024 4:46 PM, Bibek Kumar Patro wrote:
> > On 1/10/2024 9:36 AM, Pavan Kondeti wrote:
>
> [...]
>
> > > > @@ -274,6 +321,21 @@ static const struct of_device_id qcom_smmu_client_of_match[] __maybe_unused = {
> > > >   static int qcom_smmu_init_context(struct arm_smmu_domain *smmu_domain,
> > > >           struct io_pgtable_cfg *pgtbl_cfg, struct device *dev)
> > > >   {
> > > > +    struct arm_smmu_device *smmu = smmu_domain->smmu;
> > > > +    struct qcom_smmu *qsmmu = to_qcom_smmu(smmu);
> > > > +    const struct actlr_variant *actlrvar;
> > > > +    int cbndx = smmu_domain->cfg.cbndx;
> > > > +
> > > > +    if (qsmmu->data->actlrvar) {
> > > > +        actlrvar = qsmmu->data->actlrvar;
> > > > +        for (; actlrvar->io_start; actlrvar++) {
> > > > +            if (actlrvar->io_start == smmu->ioaddr) {
> > > > +                qcom_smmu_set_actlr(dev, smmu, cbndx, actlrvar->actlrcfg);
> > > > +                break;
> > > > +            }
> > > > +        }
> > > > +    }
> > > > +
> > >
> > > This block and the one in qcom_adreno_smmu_init_context() are exactly
> > > the same. Possible to do some refactoring?
> >
> > I will check if this repeated blocks can be accomodated this into qcom_smmu_set_actlr function if that would be fine.
>
> Also adding to this, this might increase the number of indentation inside qcom_smmu_set_actlr as well, to around 5. So wouldn't this
> be an issue?

By the way, we can refactor this:

if (qsmmu->data->actlrvar) {
	actlrvar = qsmmu->data->actlrvar;
	for (; actlrvar->io_start; actlrvar++) {
		if (actlrvar->io_start == smmu->ioaddr) {
			qcom_smmu_set_actlr(dev, smmu, cbndx, actlrvar->actlrcfg);
			break;
		}
	}
}

into

// add const u8 num_actlrcfgs to struct actrl_variant to
// save on sentinel space:
//   sizeof(u8) < sizeof(ptr) + sizeof(resource_size_t)


[declarations]
const struct actlr_variant *actlrvar = qsmmu->data->actlrvar;
int i;

[rest of the functions]

if (!actlrvar)
	return 0;

for (i = 0; i < actrlvar->num_actrlcfgs; i++) {
	if (actlrvar[i].io_start == smmu->ioaddr) {
		qcom_smmu_set_actlr(dev, smmu, cbndx, actlrvar->actlrcfg);
		break;
	}
}

Saving both on .TEXT size and indentation levels :)

Konrad