OPP: pstate is only valid for genpd OPP tables

It is not very clear right now that the `pstate` field is only valid for
genpd OPP tables and not consumer tables. And there is no checking for
the same at various places.

Add checks in place to verify that and make it clear to the reader.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Tested-by: Bjorn Andersson <quic_bjorande@quicinc.com>

drivers/opp/core.c

@@ -227,16 +227,24 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_level);
 unsigned int dev_pm_opp_get_required_pstate(struct dev_pm_opp *opp,
 					    unsigned int index)
 {
+	struct opp_table *opp_table = opp->opp_table;
+
 	if (IS_ERR_OR_NULL(opp) || !opp->available ||
-	    index >= opp->opp_table->required_opp_count) {
+	    index >= opp_table->required_opp_count) {
 		pr_err("%s: Invalid parameters\n", __func__);
 		return 0;
 	}
 
 	/* required-opps not fully initialized yet */
-	if (lazy_linking_pending(opp->opp_table))
+	if (lazy_linking_pending(opp_table))
 		return 0;
 
+	/* The required OPP table must belong to a genpd */
+	if (unlikely(!opp_table->required_opp_tables[index]->is_genpd)) {
+		pr_err("%s: Performance state is only valid for genpds.\n", __func__);
+		return 0;
+	}
+
 	return opp->required_opps[index]->pstate;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_required_pstate);
@@ -2696,6 +2704,12 @@ int dev_pm_opp_xlate_performance_state(struct opp_table *src_table,
 	if (!src_table || !src_table->required_opp_count)
 		return pstate;
 
+	/* Both OPP tables must belong to genpds */
+	if (unlikely(!src_table->is_genpd || !dst_table->is_genpd)) {
+		pr_err("%s: Performance state is only valid for genpds.\n", __func__);
+		return -EINVAL;
+	}
+
 	/* required-opps not fully initialized yet */
 	if (lazy_linking_pending(src_table))
 		return -EBUSY;

drivers/opp/debugfs.c

@@ -152,11 +152,13 @@ void opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
 	debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic);
 	debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo);
 	debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend);
-	debugfs_create_u32("performance_state", S_IRUGO, d, &opp->pstate);
 	debugfs_create_u32("level", S_IRUGO, d, &opp->level);
 	debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
 			     &opp->clock_latency_ns);
 
+	if (opp_table->is_genpd)
+		debugfs_create_u32("performance_state", S_IRUGO, d, &opp->pstate);
+
 	opp->of_name = of_node_full_name(opp->np);
 	debugfs_create_str("of_name", S_IRUGO, d, (char **)&opp->of_name);
 

drivers/opp/of.c

@@ -1392,6 +1392,12 @@ int of_get_required_opp_performance_state(struct device_node *np, int index)
 		goto put_required_np;
 	}
 
+	/* The OPP tables must belong to a genpd */
+	if (unlikely(!opp_table->is_genpd)) {
+		pr_err("%s: Performance state is only valid for genpds.\n", __func__);
+		goto put_required_np;
+	}
+
 	opp = _find_opp_of_np(opp_table, required_np);
 	if (opp) {
 		pstate = opp->pstate;