[SRU][F/J][PATCH 1/3] clk: Add a devm variant of clk_rate_exclusive_get()

[Massimiliano Pellizzer]

From: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>

This allows to simplify drivers that use clk_rate_exclusive_get()
in their probe routine as calling clk_rate_exclusive_put() is cared for
automatically.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
Link: https://lore.kernel.org/r/20240104225512.1124519-2-u.kleine-koenig@pengutronix.de
Acked-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>
Signed-off-by: Stephen Boyd <sboyd at kernel.org>
(cherry picked from commit b0cde62e4c548b2e7cb535caa6eb0df135888601)
CVE-2024-40965
Signed-off-by: Massimiliano Pellizzer <massimiliano.pellizzer at canonical.com>
---
 drivers/clk/clk.c   | 19 +++++++++++++++++++
 include/linux/clk.h | 12 ++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 56be3f97c265..aec20a8cc888 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -926,6 +926,25 @@ int clk_rate_exclusive_get(struct clk *clk)
 }
 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
 
+static void devm_clk_rate_exclusive_put(void *data)
+{
+	struct clk *clk = data;
+
+	clk_rate_exclusive_put(clk);
+}
+
+int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk)
+{
+	int ret;
+
+	ret = clk_rate_exclusive_get(clk);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev, devm_clk_rate_exclusive_put, clk);
+}
+EXPORT_SYMBOL_GPL(devm_clk_rate_exclusive_get);
+
 static void clk_core_unprepare(struct clk_core *core)
 {
 	lockdep_assert_held(&prepare_lock);
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 562859ee24f4..0b41d78f8e01 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -190,6 +190,18 @@ bool clk_is_match(const struct clk *p, const struct clk *q);
  */
 int clk_rate_exclusive_get(struct clk *clk);
 
+/**
+ * devm_clk_rate_exclusive_get - devm variant of clk_rate_exclusive_get
+ * @dev: device the exclusivity is bound to
+ * @clk: clock source
+ *
+ * Calls clk_rate_exclusive_get() on @clk and registers a devm cleanup handler
+ * on @dev to call clk_rate_exclusive_put().
+ *
+ * Must not be called from within atomic context.
+ */
+int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk);
+
 /**
  * clk_rate_exclusive_put - release exclusivity over the rate control of a
  *                          producer
-- 
2.43.0