PM / OPP: Add dev_pm_opp_get_sharing_cpus()
OPP core allows a platform to mark OPP table as shared, when the
platform isn't using operating-points-v2 bindings.
And, so there should be a non DT way of finding out if the OPP table is
shared or not.
This patch adds dev_pm_opp_get_sharing_cpus(), which first tries to get
OPP sharing information from the opp-table (in case it is already marked
as shared), otherwise it uses the existing DT way of finding sharing
information.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/base/power/opp/cpu.c b/drivers/base/power/opp/cpu.c
index 5469e77..3428380 100644
--- a/drivers/base/power/opp/cpu.c
+++ b/drivers/base/power/opp/cpu.c
@@ -330,3 +330,48 @@
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus);
+
+/**
+ * dev_pm_opp_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with @cpu_dev
+ * @cpu_dev: CPU device for which we do this operation
+ * @cpumask: cpumask to update with information of sharing CPUs
+ *
+ * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
+ *
+ * Returns -ENODEV if OPP table isn't already present.
+ *
+ * Locking: The internal opp_table and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, cpumask_var_t cpumask)
+{
+ struct opp_device *opp_dev;
+ struct opp_table *opp_table;
+ int ret = 0;
+
+ mutex_lock(&opp_table_lock);
+
+ opp_table = _find_opp_table(cpu_dev);
+ if (IS_ERR(opp_table)) {
+ ret = PTR_ERR(opp_table);
+ goto unlock;
+ }
+
+ cpumask_clear(cpumask);
+
+ if (opp_table->shared_opp) {
+ list_for_each_entry(opp_dev, &opp_table->dev_list, node)
+ cpumask_set_cpu(opp_dev->dev->id, cpumask);
+ } else {
+ cpumask_set_cpu(cpu_dev->id, cpumask);
+ }
+
+unlock:
+ mutex_unlock(&opp_table_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_sharing_cpus);