Merge commit 'v2.6.32-rc5' into for-2.6.33
[safe/jmp/linux-2.6] / lib / rwsem-spinlock.c
index 21f0db2..9df3ca5 100644 (file)
@@ -17,27 +17,22 @@ struct rwsem_waiter {
 #define RWSEM_WAITING_FOR_WRITE        0x00000002
 };
 
-#if RWSEM_DEBUG
-void rwsemtrace(struct rw_semaphore *sem, const char *str)
-{
-       if (sem->debug)
-               printk("[%d] %s({%d,%d})\n",
-                      current->pid, str, sem->activity,
-                      list_empty(&sem->wait_list) ? 0 : 1);
-}
-#endif
-
 /*
  * initialise the semaphore
  */
-void fastcall init_rwsem(struct rw_semaphore *sem)
+void __init_rwsem(struct rw_semaphore *sem, const char *name,
+                 struct lock_class_key *key)
 {
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+       /*
+        * Make sure we are not reinitializing a held semaphore:
+        */
+       debug_check_no_locks_freed((void *)sem, sizeof(*sem));
+       lockdep_init_map(&sem->dep_map, name, key, 0);
+#endif
        sem->activity = 0;
        spin_lock_init(&sem->wait_lock);
        INIT_LIST_HEAD(&sem->wait_list);
-#if RWSEM_DEBUG
-       sem->debug = 0;
-#endif
 }
 
 /*
@@ -56,8 +51,6 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite)
        struct task_struct *tsk;
        int woken;
 
-       rwsemtrace(sem, "Entering __rwsem_do_wake");
-
        waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);
 
        if (!wakewrite) {
@@ -76,7 +69,7 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite)
                list_del(&waiter->list);
                tsk = waiter->task;
                /* Don't touch waiter after ->task has been NULLed */
-               mb();
+               smp_mb();
                waiter->task = NULL;
                wake_up_process(tsk);
                put_task_struct(tsk);
@@ -91,7 +84,7 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite)
 
                list_del(&waiter->list);
                tsk = waiter->task;
-               mb();
+               smp_mb();
                waiter->task = NULL;
                wake_up_process(tsk);
                put_task_struct(tsk);
@@ -104,7 +97,6 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite)
        sem->activity += woken;
 
  out:
-       rwsemtrace(sem, "Leaving __rwsem_do_wake");
        return sem;
 }
 
@@ -123,7 +115,7 @@ __rwsem_wake_one_writer(struct rw_semaphore *sem)
        list_del(&waiter->list);
 
        tsk = waiter->task;
-       mb();
+       smp_mb();
        waiter->task = NULL;
        wake_up_process(tsk);
        put_task_struct(tsk);
@@ -133,13 +125,11 @@ __rwsem_wake_one_writer(struct rw_semaphore *sem)
 /*
  * get a read lock on the semaphore
  */
-void fastcall __sched __down_read(struct rw_semaphore *sem)
+void __sched __down_read(struct rw_semaphore *sem)
 {
        struct rwsem_waiter waiter;
        struct task_struct *tsk;
 
-       rwsemtrace(sem, "Entering __down_read");
-
        spin_lock_irq(&sem->wait_lock);
 
        if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
@@ -171,20 +161,18 @@ void fastcall __sched __down_read(struct rw_semaphore *sem)
        }
 
        tsk->state = TASK_RUNNING;
-
  out:
-       rwsemtrace(sem, "Leaving __down_read");
+       ;
 }
 
 /*
  * trylock for reading -- returns 1 if successful, 0 if contention
  */
-int fastcall __down_read_trylock(struct rw_semaphore *sem)
+int __down_read_trylock(struct rw_semaphore *sem)
 {
        unsigned long flags;
        int ret = 0;
 
-       rwsemtrace(sem, "Entering __down_read_trylock");
 
        spin_lock_irqsave(&sem->wait_lock, flags);
 
@@ -196,7 +184,6 @@ int fastcall __down_read_trylock(struct rw_semaphore *sem)
 
        spin_unlock_irqrestore(&sem->wait_lock, flags);
 
-       rwsemtrace(sem, "Leaving __down_read_trylock");
        return ret;
 }
 
@@ -204,13 +191,11 @@ int fastcall __down_read_trylock(struct rw_semaphore *sem)
  * get a write lock on the semaphore
  * - we increment the waiting count anyway to indicate an exclusive lock
  */
-void fastcall __sched __down_write(struct rw_semaphore *sem)
+void __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
 {
        struct rwsem_waiter waiter;
        struct task_struct *tsk;
 
-       rwsemtrace(sem, "Entering __down_write");
-
        spin_lock_irq(&sem->wait_lock);
 
        if (sem->activity == 0 && list_empty(&sem->wait_list)) {
@@ -242,21 +227,23 @@ void fastcall __sched __down_write(struct rw_semaphore *sem)
        }
 
        tsk->state = TASK_RUNNING;
-
  out:
-       rwsemtrace(sem, "Leaving __down_write");
+       ;
+}
+
+void __sched __down_write(struct rw_semaphore *sem)
+{
+       __down_write_nested(sem, 0);
 }
 
 /*
  * trylock for writing -- returns 1 if successful, 0 if contention
  */
-int fastcall __down_write_trylock(struct rw_semaphore *sem)
+int __down_write_trylock(struct rw_semaphore *sem)
 {
        unsigned long flags;
        int ret = 0;
 
-       rwsemtrace(sem, "Entering __down_write_trylock");
-
        spin_lock_irqsave(&sem->wait_lock, flags);
 
        if (sem->activity == 0 && list_empty(&sem->wait_list)) {
@@ -267,38 +254,31 @@ int fastcall __down_write_trylock(struct rw_semaphore *sem)
 
        spin_unlock_irqrestore(&sem->wait_lock, flags);
 
-       rwsemtrace(sem, "Leaving __down_write_trylock");
        return ret;
 }
 
 /*
  * release a read lock on the semaphore
  */
-void fastcall __up_read(struct rw_semaphore *sem)
+void __up_read(struct rw_semaphore *sem)
 {
        unsigned long flags;
 
-       rwsemtrace(sem, "Entering __up_read");
-
        spin_lock_irqsave(&sem->wait_lock, flags);
 
        if (--sem->activity == 0 && !list_empty(&sem->wait_list))
                sem = __rwsem_wake_one_writer(sem);
 
        spin_unlock_irqrestore(&sem->wait_lock, flags);
-
-       rwsemtrace(sem, "Leaving __up_read");
 }
 
 /*
  * release a write lock on the semaphore
  */
-void fastcall __up_write(struct rw_semaphore *sem)
+void __up_write(struct rw_semaphore *sem)
 {
        unsigned long flags;
 
-       rwsemtrace(sem, "Entering __up_write");
-
        spin_lock_irqsave(&sem->wait_lock, flags);
 
        sem->activity = 0;
@@ -306,20 +286,16 @@ void fastcall __up_write(struct rw_semaphore *sem)
                sem = __rwsem_do_wake(sem, 1);
 
        spin_unlock_irqrestore(&sem->wait_lock, flags);
-
-       rwsemtrace(sem, "Leaving __up_write");
 }
 
 /*
  * downgrade a write lock into a read lock
  * - just wake up any readers at the front of the queue
  */
-void fastcall __downgrade_write(struct rw_semaphore *sem)
+void __downgrade_write(struct rw_semaphore *sem)
 {
        unsigned long flags;
 
-       rwsemtrace(sem, "Entering __downgrade_write");
-
        spin_lock_irqsave(&sem->wait_lock, flags);
 
        sem->activity = 1;
@@ -327,18 +303,14 @@ void fastcall __downgrade_write(struct rw_semaphore *sem)
                sem = __rwsem_do_wake(sem, 0);
 
        spin_unlock_irqrestore(&sem->wait_lock, flags);
-
-       rwsemtrace(sem, "Leaving __downgrade_write");
 }
 
-EXPORT_SYMBOL(init_rwsem);
+EXPORT_SYMBOL(__init_rwsem);
 EXPORT_SYMBOL(__down_read);
 EXPORT_SYMBOL(__down_read_trylock);
+EXPORT_SYMBOL(__down_write_nested);
 EXPORT_SYMBOL(__down_write);
 EXPORT_SYMBOL(__down_write_trylock);
 EXPORT_SYMBOL(__up_read);
 EXPORT_SYMBOL(__up_write);
 EXPORT_SYMBOL(__downgrade_write);
-#if RWSEM_DEBUG
-EXPORT_SYMBOL(rwsemtrace);
-#endif