Let's add a data pointer to the genpd_power_state struct, to allow a genpd
backend driver to store per state specific data. To introduce the pointer,
we need to change the way genpd deals with freeing of the corresponding
allocated data.

More precisely, let's clarify the responsibility of whom that shall free
the data, by adding a ->free_states() callback to the struct
generic_pm_domain. The one allocating the data shall assign the callback,
to allow genpd to invoke it from genpd_remove().

Cc: Lina Iyer <redacted>
Co-developed-by: Lina Iyer <redacted>
Signed-off-by: Ulf Hansson <redacted>
---

Changes in v12:
	- None.

---
 drivers/base/power/domain.c | 12 ++++++++++--
 include/linux/pm_domain.h   |  4 +++-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 2c334c01fc43..03885c003c6a 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c

@@ -1685,6 +1685,12 @@ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
 }
 EXPORT_SYMBOL_GPL(pm_genpd_remove_subdomain);
 
+static void genpd_free_default_power_state(struct genpd_power_state *states,
+					   unsigned int state_count)
+{
+	kfree(states);
+}
+
 static int genpd_set_default_power_state(struct generic_pm_domain *genpd)
 {
 	struct genpd_power_state *state;

@@ -1695,7 +1701,7 @@ static int genpd_set_default_power_state(struct generic_pm_domain *genpd)
 
 	genpd->states = state;
 	genpd->state_count = 1;
-	genpd->free = state;
+	genpd->free_states = genpd_free_default_power_state;
 
 	return 0;
 }

@@ -1811,7 +1817,9 @@ static int genpd_remove(struct generic_pm_domain *genpd)
 	list_del(&genpd->gpd_list_node);
 	genpd_unlock(genpd);
 	cancel_work_sync(&genpd->power_off_work);
-	kfree(genpd->free);
+	if (genpd->free_states)

+		genpd->free_states(genpd->states, genpd->state_count);
+
 	pr_debug("%s: removed %s\n", __func__, genpd->name);
 
 	return 0;

diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 1ed5874bcee0..8e1399231753 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h

@@ -69,6 +69,7 @@ struct genpd_power_state {
 	s64 residency_ns;
 	struct fwnode_handle *fwnode;
 	ktime_t idle_time;
+	void *data;
 };
 
 struct genpd_lock_ops;

@@ -110,9 +111,10 @@ struct generic_pm_domain {
 			   struct device *dev);
 	unsigned int flags;		/* Bit field of configs for genpd */
 	struct genpd_power_state *states;
+	void (*free_states)(struct genpd_power_state *states,
+			    unsigned int state_count);
 	unsigned int state_count; /* number of states */
 	unsigned int state_idx; /* state that genpd will go to when off */
-	void *free; /* Free the state that was allocated for default */
 	ktime_t on_time;
 	ktime_t accounting_time;
 	const struct genpd_lock_ops *lock_ops;