MAINTAINERS: Add entry for MediaTek PMIC LED driver

[tomoyo/tomoyo-test1.git] / kernel / jump_label.c

diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index d11c506..0bf2e8f 100644 (file)
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -79,29 +79,7 @@ int static_key_count(struct static_key *key)
 }
 EXPORT_SYMBOL_GPL(static_key_count);
 
-void static_key_enable(struct static_key *key)
-{
-       int count = static_key_count(key);
-
-       WARN_ON_ONCE(count < 0 || count > 1);
-
-       if (!count)
-               static_key_slow_inc(key);
-}
-EXPORT_SYMBOL_GPL(static_key_enable);
-
-void static_key_disable(struct static_key *key)
-{
-       int count = static_key_count(key);
-
-       WARN_ON_ONCE(count < 0 || count > 1);
-
-       if (count)
-               static_key_slow_dec(key);
-}
-EXPORT_SYMBOL_GPL(static_key_disable);
-
-void static_key_slow_inc(struct static_key *key)
+static void static_key_slow_inc_cpuslocked(struct static_key *key)
 {
        int v, v1;
 
@@ -125,24 +103,87 @@ void static_key_slow_inc(struct static_key *key)
                        return;
        }
 
-       cpus_read_lock();
        jump_label_lock();
        if (atomic_read(&key->enabled) == 0) {
                atomic_set(&key->enabled, -1);
                jump_label_update(key);
-               atomic_set(&key->enabled, 1);
+               /*
+                * Ensure that if the above cmpxchg loop observes our positive
+                * value, it must also observe all the text changes.
+                */
+               atomic_set_release(&key->enabled, 1);
        } else {
                atomic_inc(&key->enabled);
        }
        jump_label_unlock();
+}
+
+void static_key_slow_inc(struct static_key *key)
+{
+       cpus_read_lock();
+       static_key_slow_inc_cpuslocked(key);
        cpus_read_unlock();
 }
 EXPORT_SYMBOL_GPL(static_key_slow_inc);
 
-static void __static_key_slow_dec(struct static_key *key,
-               unsigned long rate_limit, struct delayed_work *work)
+void static_key_enable_cpuslocked(struct static_key *key)
+{
+       STATIC_KEY_CHECK_USE();
+
+       if (atomic_read(&key->enabled) > 0) {
+               WARN_ON_ONCE(atomic_read(&key->enabled) != 1);
+               return;
+       }
+
+       jump_label_lock();
+       if (atomic_read(&key->enabled) == 0) {
+               atomic_set(&key->enabled, -1);
+               jump_label_update(key);
+               /*
+                * See static_key_slow_inc().
+                */
+               atomic_set_release(&key->enabled, 1);
+       }
+       jump_label_unlock();
+}
+EXPORT_SYMBOL_GPL(static_key_enable_cpuslocked);
+
+void static_key_enable(struct static_key *key)
+{
+       cpus_read_lock();
+       static_key_enable_cpuslocked(key);
+       cpus_read_unlock();
+}
+EXPORT_SYMBOL_GPL(static_key_enable);
+
+void static_key_disable_cpuslocked(struct static_key *key)
+{
+       STATIC_KEY_CHECK_USE();
+
+       if (atomic_read(&key->enabled) != 1) {
+               WARN_ON_ONCE(atomic_read(&key->enabled) != 0);
+               return;
+       }
+
+       jump_label_lock();
+       if (atomic_cmpxchg(&key->enabled, 1, 0))
+               jump_label_update(key);
+       jump_label_unlock();
+}
+EXPORT_SYMBOL_GPL(static_key_disable_cpuslocked);
+
+void static_key_disable(struct static_key *key)
 {
        cpus_read_lock();
+       static_key_disable_cpuslocked(key);
+       cpus_read_unlock();
+}
+EXPORT_SYMBOL_GPL(static_key_disable);
+
+static void static_key_slow_dec_cpuslocked(struct static_key *key,
+                                          unsigned long rate_limit,
+                                          struct delayed_work *work)
+{
        /*
         * The negative count check is valid even when a negative
         * key->enabled is in use by static_key_slow_inc(); a
@@ -153,7 +194,6 @@ static void __static_key_slow_dec(struct static_key *key,
        if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) {
                WARN(atomic_read(&key->enabled) < 0,
                     "jump label: negative count!\n");
-               cpus_read_unlock();
                return;
        }
 
@@ -164,6 +204,14 @@ static void __static_key_slow_dec(struct static_key *key,
                jump_label_update(key);
        }
        jump_label_unlock();
+}
+
+static void __static_key_slow_dec(struct static_key *key,
+                                 unsigned long rate_limit,
+                                 struct delayed_work *work)
+{
+       cpus_read_lock();
+       static_key_slow_dec_cpuslocked(key, rate_limit, work);
        cpus_read_unlock();
 }