PM / OPP: add some lockdep annotations

Certain OPP APIs need to be called under RCU lock; let's add a few rcu_lockdep_assert() calls to warn about potential misuse.

Signed-off-by Dmitry Torokhov <[email protected]>

---
 drivers/base/power/opp.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

drivers/base/power/opp.c +15 -0

index d24dd614a..852eebf 100644
@@ -218,6 +218,11 @@ int dev_pm_opp_get_opp_count(struct device *dev)
        struct dev_pm_opp *temp_opp;
        int count = 0;
 
+       rcu_lockdep_assert(rcu_read_lock_held() ||
+                               lockdep_is_held(&dev_opp_list_lock),
+                          "dev_pm_opp_get_opp_count() needs rcu_read_lock() "
+                          "or dev_opp_list_lock protection");
+
        dev_opp = find_device_opp(dev);
        if (IS_ERR(dev_opp)) {
                int r = PTR_ERR(dev_opp);

@@ -267,6 +272,11 @@ struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
        struct device_opp *dev_opp;
        struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
 
+       rcu_lockdep_assert(rcu_read_lock_held() ||
+                               lockdep_is_held(&dev_opp_list_lock),
+                          "dev_pm_opp_find_freq_exact() needs rcu_read_lock() "
+                          "or dev_opp_list_lock protection");
+
        dev_opp = find_device_opp(dev);
        if (IS_ERR(dev_opp)) {
                int r = PTR_ERR(dev_opp);

@@ -313,6 +323,11 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
        struct device_opp *dev_opp;
        struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
 
+       rcu_lockdep_assert(rcu_read_lock_held() ||
+                               lockdep_is_held(&dev_opp_list_lock),
+                          "dev_pm_opp_find_freq_ceil() needs rcu_read_lock() "
+                          "or dev_opp_list_lock protection");
+
        if (!dev || !freq) {
                dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
                return ERR_PTR(-EINVAL);