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

From: Konrad Dybcio
Date: Wed Jan 10 2024 - 12:57:18 EST




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