Merge branch 'acpi-battery'

[cascardo/linux.git] / kernel / locking / rwsem-xadd.c

diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index a4d4de0..09e30c6 100644 (file)
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -433,12 +433,13 @@ static inline bool rwsem_has_spinner(struct rw_semaphore *sem)
 /*
  * Wait until we successfully acquire the write lock
  */
-__visible
-struct rw_semaphore __sched *rwsem_down_write_failed(struct rw_semaphore *sem)
+static inline struct rw_semaphore *
+__rwsem_down_write_failed_common(struct rw_semaphore *sem, int state)
 {
        long count;
        bool waiting = true; /* any queued threads before us */
        struct rwsem_waiter waiter;
+       struct rw_semaphore *ret = sem;
 
        /* undo write bias from down_write operation, stop active locking */
        count = rwsem_atomic_update(-RWSEM_ACTIVE_WRITE_BIAS, sem);
@@ -478,7 +479,7 @@ struct rw_semaphore __sched *rwsem_down_write_failed(struct rw_semaphore *sem)
                count = rwsem_atomic_update(RWSEM_WAITING_BIAS, sem);
 
        /* wait until we successfully acquire the lock */
-       set_current_state(TASK_UNINTERRUPTIBLE);
+       set_current_state(state);
        while (true) {
                if (rwsem_try_write_lock(count, sem))
                        break;
@@ -486,21 +487,48 @@ struct rw_semaphore __sched *rwsem_down_write_failed(struct rw_semaphore *sem)
 
                /* Block until there are no active lockers. */
                do {
+                       if (signal_pending_state(state, current))
+                               goto out_nolock;
+
                        schedule();
-                       set_current_state(TASK_UNINTERRUPTIBLE);
+                       set_current_state(state);
                } while ((count = sem->count) & RWSEM_ACTIVE_MASK);
 
                raw_spin_lock_irq(&sem->wait_lock);
        }
        __set_current_state(TASK_RUNNING);
+       list_del(&waiter.list);
+       raw_spin_unlock_irq(&sem->wait_lock);
 
+       return ret;
+
+out_nolock:
+       __set_current_state(TASK_RUNNING);
+       raw_spin_lock_irq(&sem->wait_lock);
        list_del(&waiter.list);
+       if (list_empty(&sem->wait_list))
+               rwsem_atomic_update(-RWSEM_WAITING_BIAS, sem);
+       else
+               __rwsem_do_wake(sem, RWSEM_WAKE_ANY);
        raw_spin_unlock_irq(&sem->wait_lock);
 
-       return sem;
+       return ERR_PTR(-EINTR);
+}
+
+__visible struct rw_semaphore * __sched
+rwsem_down_write_failed(struct rw_semaphore *sem)
+{
+       return __rwsem_down_write_failed_common(sem, TASK_UNINTERRUPTIBLE);
 }
 EXPORT_SYMBOL(rwsem_down_write_failed);
 
+__visible struct rw_semaphore * __sched
+rwsem_down_write_failed_killable(struct rw_semaphore *sem)
+{
+       return __rwsem_down_write_failed_common(sem, TASK_KILLABLE);
+}
+EXPORT_SYMBOL(rwsem_down_write_failed_killable);
+
 /*
  * handle waking up a waiter on the semaphore
  * - up_read/up_write has decremented the active part of count if we come here