linux-kernel - [PATCH 7/8] OPP: Assert clk_count == 1 for single clk helpers

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Date:   Fri, 10 Jun 2022 13:50:51 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
        Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
        Stephen Boyd <sboyd@...nel.org>
Cc:     Viresh Kumar <viresh.kumar@...aro.org>, linux-pm@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        linux-kernel@...r.kernel.org
Subject: [PATCH 7/8] OPP: Assert clk_count == 1 for single clk helpers

Many helpers can be safely called only for devices that have a single
clk associated with them. Assert the same for those routines.

Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 drivers/opp/core.c | 39 +++++++++++++++++++++++++++++++++------
 1 file changed, 33 insertions(+), 6 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index b8e6dc0a9b36..5635f4ad6d59 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -93,6 +93,12 @@ struct opp_table *_find_opp_table(struct device *dev)
 	return opp_table;
 }
 
+/* Returns true for single clock, false with WARN otherwise */
+bool assert_single_clk(struct opp_table *opp_table)
+{
+	return !WARN_ON(opp_table->clk_count != 1);
+}
+
 /**
  * dev_pm_opp_get_voltage() - Gets the voltage corresponding to an opp
  * @opp:	opp for which voltage has to be returned for
@@ -177,6 +183,9 @@ unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp)
 		return 0;
 	}
 
+	if (!assert_single_clk(opp->opp_table))
+		return 0;
+
 	return opp->rates[0];
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
@@ -597,7 +606,8 @@ static struct dev_pm_opp *_find_key_floor(struct device *dev,
 struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
 		unsigned long freq, bool available)
 {
-	return _find_key_exact(dev, freq, 0, available, _read_freq, NULL);
+	return _find_key_exact(dev, freq, 0, available, _read_freq,
+			       assert_single_clk);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact);
 
@@ -605,7 +615,7 @@ static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,
 						   unsigned long *freq)
 {
 	return _opp_table_find_key_ceil(opp_table, freq, 0, true, _read_freq,
-					NULL);
+					assert_single_clk);
 }
 
 /**
@@ -629,7 +639,7 @@ static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,
 struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
 					     unsigned long *freq)
 {
-	return _find_key_ceil(dev, freq, 0, true, _read_freq, NULL);
+	return _find_key_ceil(dev, freq, 0, true, _read_freq, assert_single_clk);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil);
 
@@ -654,7 +664,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil);
 struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
 					      unsigned long *freq)
 {
-	return _find_key_floor(dev, freq, 0, true, _read_freq, NULL);
+	return _find_key_floor(dev, freq, 0, true, _read_freq, assert_single_clk);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
 
@@ -1507,6 +1517,9 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq)
 	if (IS_ERR(opp_table))
 		return;
 
+	if (!assert_single_clk(opp_table))
+		goto put_table;
+
 	mutex_lock(&opp_table->lock);
 
 	list_for_each_entry(iter, &opp_table->opp_list, node) {
@@ -1528,6 +1541,7 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq)
 			 __func__, freq);
 	}
 
+put_table:
 	/* Drop the reference taken by _find_opp_table() */
 	dev_pm_opp_put_opp_table(opp_table);
 }
@@ -1819,6 +1833,9 @@ int _opp_add_v1(struct opp_table *opp_table, struct device *dev,
 	unsigned long tol;
 	int ret;
 
+	if (!assert_single_clk(opp_table))
+		return -EINVAL;
+
 	new_opp = _opp_allocate(opp_table);
 	if (!new_opp)
 		return -ENOMEM;
@@ -2600,6 +2617,11 @@ static int _opp_set_availability(struct device *dev, unsigned long freq,
 		return r;
 	}
 
+	if (!assert_single_clk(opp_table)) {
+		r = -EINVAL;
+		goto put_table;
+	}
+
 	mutex_lock(&opp_table->lock);
 
 	/* Do we have the frequency? */
@@ -2671,6 +2693,11 @@ int dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq,
 		return r;
 	}
 
+	if (!assert_single_clk(opp_table)) {
+		r = -EINVAL;
+		goto put_table;
+	}
+
 	mutex_lock(&opp_table->lock);
 
 	/* Do we have the frequency? */
@@ -2702,11 +2729,11 @@ int dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq,
 				     opp);
 
 	dev_pm_opp_put(opp);
-	goto adjust_put_table;
+	goto put_table;
 
 adjust_unlock:
 	mutex_unlock(&opp_table->lock);
-adjust_put_table:
+put_table:
 	dev_pm_opp_put_opp_table(opp_table);
 	return r;
 }
-- 
2.31.1.272.g89b43f80a514