1 files changed, 30 insertions, 14 deletions

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index d5c1149ff123..5e4b1d82b2f8 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -11,6 +11,8 @@
  * published by the Free Software Foundation.
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/slab.h>
@@ -27,7 +29,7 @@
  */
 static LIST_HEAD(dev_opp_list);
 /* Lock to allow exclusive modification to the device and opp lists */
-static DEFINE_MUTEX(dev_opp_list_lock);
+DEFINE_MUTEX(dev_opp_list_lock);
 
 #define opp_rcu_lockdep_assert()                                        \
 do {                                                                    \
@@ -79,14 +81,18 @@ static struct device_opp *_managed_opp(const struct device_node *np)
  * Return: pointer to 'struct device_opp' if found, otherwise -ENODEV or
  * -EINVAL based on type of error.
  *
- * Locking: This function must be called under rcu_read_lock(). device_opp
- * is a RCU protected pointer. This means that device_opp is valid as long
- * as we are under RCU lock.
+ * Locking: For readers, this function must be called under rcu_read_lock().
+ * device_opp is a RCU protected pointer, which means that device_opp is valid
+ * as long as we are under RCU lock.
+ *
+ * For Writers, this function must be called with dev_opp_list_lock held.
  */
 struct device_opp *_find_device_opp(struct device *dev)
 {
         struct device_opp *dev_opp;
 
+        opp_rcu_lockdep_assert();
+
         if (IS_ERR_OR_NULL(dev)) {
                 pr_err("%s: Invalid parameters\n", __func__);
                 return ERR_PTR(-EINVAL);
@@ -701,7 +707,7 @@ static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
 }
 
 /**
- * _opp_add_dynamic() - Allocate a dynamic OPP.
+ * _opp_add_v1() - Allocate a OPP based on v1 bindings.
  * @dev:        device for which we do this operation
  * @freq:       Frequency in Hz for this OPP
  * @u_volt:     Voltage in uVolts for this OPP
@@ -727,8 +733,8 @@ static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
  *              Duplicate OPPs (both freq and volt are same) and !opp->available
  * -ENOMEM      Memory allocation failure
  */
-static int _opp_add_dynamic(struct device *dev, unsigned long freq,
-                            long u_volt, bool dynamic)
+static int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,
+                       bool dynamic)
 {
         struct device_opp *dev_opp;
         struct dev_pm_opp *new_opp;
@@ -770,9 +776,10 @@ unlock:
 }
 
 /* TODO: Support multiple regulators */
-static int opp_get_microvolt(struct dev_pm_opp *opp, struct device *dev)
+static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
 {
         u32 microvolt[3] = {0};
+        u32 val;
         int count, ret;
 
         /* Missing property isn't a problem, but an invalid entry is */
@@ -805,6 +812,9 @@ static int opp_get_microvolt(struct dev_pm_opp *opp, struct device *dev)
         opp->u_volt_min = microvolt[1];
         opp->u_volt_max = microvolt[2];
 
+        if (!of_property_read_u32(opp->np, "opp-microamp", &val))
+                opp->u_amp = val;
+
         return 0;
 }
 
@@ -869,13 +879,10 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
         if (!of_property_read_u32(np, "clock-latency-ns", &val))
                 new_opp->clock_latency_ns = val;
 
-        ret = opp_get_microvolt(new_opp, dev);
+        ret = opp_parse_supplies(new_opp, dev);
         if (ret)
                 goto free_opp;
 
-        if (!of_property_read_u32(new_opp->np, "opp-microamp", &val))
-                new_opp->u_amp = val;
-
         ret = _opp_add(dev, new_opp, dev_opp);
         if (ret)
                 goto free_opp;
@@ -939,7 +946,7 @@ unlock:
  */
 int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
 {
-        return _opp_add_dynamic(dev, freq, u_volt, true);
+        return _opp_add_v1(dev, freq, u_volt, true);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_add);
 
@@ -1172,13 +1179,17 @@ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np)
         struct device_opp *dev_opp;
         int ret = 0, count = 0;
 
+        mutex_lock(&dev_opp_list_lock);
+
         dev_opp = _managed_opp(opp_np);
         if (dev_opp) {
                 /* OPPs are already managed */
                 if (!_add_list_dev(dev, dev_opp))
                         ret = -ENOMEM;
+                mutex_unlock(&dev_opp_list_lock);
                 return ret;
         }
+        mutex_unlock(&dev_opp_list_lock);
 
         /* We have opp-list node now, iterate over it and add OPPs */
         for_each_available_child_of_node(opp_np, np) {
@@ -1196,15 +1207,20 @@ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np)
         if (WARN_ON(!count))
                 return -ENOENT;
 
+        mutex_lock(&dev_opp_list_lock);
+
         dev_opp = _find_device_opp(dev);
         if (WARN_ON(IS_ERR(dev_opp))) {
                 ret = PTR_ERR(dev_opp);
+                mutex_unlock(&dev_opp_list_lock);
                 goto free_table;
         }
 
         dev_opp->np = opp_np;
         dev_opp->shared_opp = of_property_read_bool(opp_np, "opp-shared");
 
+        mutex_unlock(&dev_opp_list_lock);
+
         return 0;
 
 free_table:
@@ -1241,7 +1257,7 @@ static int _of_add_opp_table_v1(struct device *dev)
                 unsigned long freq = be32_to_cpup(val++) * 1000;
                 unsigned long volt = be32_to_cpup(val++);
 
-                if (_opp_add_dynamic(dev, freq, volt, false))
+                if (_opp_add_v1(dev, freq, volt, false))
                         dev_warn(dev, "%s: Failed to add OPP %ld\n",
                                  __func__, freq);
                 nr -= 2;