opp: Add sanity checks in _read_opp_key()

When we read the OPP keys, it would be nice to do some sanity checks
of the values we get from DT and see if they match with the information
that is populated in the OPP table. Let's pass a pointer of the table,
so that we can do some validation.

Signed-off-by: Georgi Djakov <[email protected]>
Reviewed-by: Matthias Kaehlcke <[email protected]>
Reviewed-by: Sibi Sankar <[email protected]>
[ Viresh: Fix rebase conflicts ]
Signed-off-by: Viresh Kumar <[email protected]>

Author: Georgi Djakov

drivers/opp/of.c

@@ -577,8 +577,8 @@ void dev_pm_opp_of_remove_table(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
 
-static int _read_bw(struct dev_pm_opp *new_opp, struct device_node *np,
-		    bool peak)
+static int _read_bw(struct dev_pm_opp *new_opp, struct opp_table *table,
+		    struct device_node *np, bool peak)
 {
 	const char *name = peak ? "opp-peak-kBps" : "opp-avg-kBps";
 	struct property *prop;
@@ -590,6 +590,12 @@ static int _read_bw(struct dev_pm_opp *new_opp, struct device_node *np,
 		return -ENODEV;
 
 	count = prop->length / sizeof(u32);
+	if (table->path_count != count) {
+		pr_err("%s: Mismatch between %s and paths (%d %d)\n",
+				__func__, name, count, table->path_count);
+		return -EINVAL;
+	}
+
 	bw = kmalloc_array(count, sizeof(*bw), GFP_KERNEL);
 	if (!bw)
 		return -ENOMEM;
@@ -612,8 +618,8 @@ static int _read_bw(struct dev_pm_opp *new_opp, struct device_node *np,
 	return ret;
 }
 
-static int _read_opp_key(struct dev_pm_opp *new_opp, struct device_node *np,
-			 bool *rate_not_available)
+static int _read_opp_key(struct dev_pm_opp *new_opp, struct opp_table *table,
+			 struct device_node *np, bool *rate_not_available)
 {
 	bool found = false;
 	u64 rate;
@@ -636,10 +642,10 @@ static int _read_opp_key(struct dev_pm_opp *new_opp, struct device_node *np,
 	 * opp-peak-kBps = <path1_value path2_value>;
 	 * opp-avg-kBps = <path1_value path2_value>;
 	 */
-	ret = _read_bw(new_opp, np, true);
+	ret = _read_bw(new_opp, table, np, true);
 	if (!ret) {
 		found = true;
-		ret = _read_bw(new_opp, np, false);
+		ret = _read_bw(new_opp, table, np, false);
 	}
 
 	/* The properties were found but we failed to parse them */
@@ -692,7 +698,7 @@ static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
 	if (!new_opp)
 		return ERR_PTR(-ENOMEM);
 
-	ret = _read_opp_key(new_opp, np, &rate_not_available);
+	ret = _read_opp_key(new_opp, opp_table, np, &rate_not_available);
 	if (ret < 0 && !opp_table->is_genpd) {
 		dev_err(dev, "%s: opp key field not found\n", __func__);
 		goto free_opp;