Merge to Fedora kernel-2.6.18-1.2224_FC5 patched with stable patch-2.6.18.1-vs2.0...

[linux-2.6.git] / lib / rwsem.c

diff --git a/lib/rwsem.c b/lib/rwsem.c
index 465ec72..a2d725f 100644 (file)
--- a/lib/rwsem.c
+++ b/lib/rwsem.c
@@ -8,6 +8,26 @@
 #include <linux/init.h>
 #include <linux/module.h>
 
+/*
+ * Initialize an rwsem:
+ */
+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->count = RWSEM_UNLOCKED_VALUE;
+       spin_lock_init(&sem->wait_lock);
+       INIT_LIST_HEAD(&sem->wait_list);
+}
+
+EXPORT_SYMBOL(__init_rwsem);
+
 struct rwsem_waiter {
        struct list_head list;
        struct task_struct *task;
@@ -16,17 +36,6 @@ struct rwsem_waiter {
 #define RWSEM_WAITING_FOR_WRITE        0x00000002
 };
 
-#if RWSEM_DEBUG
-#undef rwsemtrace
-void rwsemtrace(struct rw_semaphore *sem, const char *str)
-{
-       printk("sem=%p\n", sem);
-       printk("(sem)=%08lx\n", sem->count);
-       if (sem->debug)
-               printk("[%d] %s({%08lx})\n", current->pid, str, sem->count);
-}
-#endif
-
 /*
  * handle the lock release when processes blocked on it that can now run
  * - if we come here from up_xxxx(), then:
@@ -45,8 +54,6 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
        struct list_head *next;
        signed long oldcount, woken, loop;
 
-       rwsemtrace(sem, "Entering __rwsem_do_wake");
-
        if (downgrading)
                goto dont_wake_writers;
 
@@ -74,7 +81,7 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
         */
        list_del(&waiter->list);
        tsk = waiter->task;
-       mb();
+       smp_mb();
        waiter->task = NULL;
        wake_up_process(tsk);
        put_task_struct(tsk);
@@ -117,7 +124,7 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
                waiter = list_entry(next, struct rwsem_waiter, list);
                next = waiter->list.next;
                tsk = waiter->task;
-               mb();
+               smp_mb();
                waiter->task = NULL;
                wake_up_process(tsk);
                put_task_struct(tsk);
@@ -127,7 +134,6 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
        next->prev = &sem->wait_list;
 
  out:
-       rwsemtrace(sem, "Leaving __rwsem_do_wake");
        return sem;
 
        /* undo the change to count, but check for a transition 1->0 */
@@ -150,7 +156,7 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
        set_task_state(tsk, TASK_UNINTERRUPTIBLE);
 
        /* set up my own style of waitqueue */
-       spin_lock(&sem->wait_lock);
+       spin_lock_irq(&sem->wait_lock);
        waiter->task = tsk;
        get_task_struct(tsk);
 
@@ -163,7 +169,7 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
        if (!(count & RWSEM_ACTIVE_MASK))
                sem = __rwsem_do_wake(sem, 0);
 
-       spin_unlock(&sem->wait_lock);
+       spin_unlock_irq(&sem->wait_lock);
 
        /* wait to be given the lock */
        for (;;) {
@@ -186,13 +192,9 @@ rwsem_down_read_failed(struct rw_semaphore *sem)
 {
        struct rwsem_waiter waiter;
 
-       rwsemtrace(sem, "Entering rwsem_down_read_failed");
-
        waiter.flags = RWSEM_WAITING_FOR_READ;
        rwsem_down_failed_common(sem, &waiter,
                                RWSEM_WAITING_BIAS - RWSEM_ACTIVE_BIAS);
-
-       rwsemtrace(sem, "Leaving rwsem_down_read_failed");
        return sem;
 }
 
@@ -204,12 +206,9 @@ rwsem_down_write_failed(struct rw_semaphore *sem)
 {
        struct rwsem_waiter waiter;
 
-       rwsemtrace(sem, "Entering rwsem_down_write_failed");
-
        waiter.flags = RWSEM_WAITING_FOR_WRITE;
        rwsem_down_failed_common(sem, &waiter, -RWSEM_ACTIVE_BIAS);
 
-       rwsemtrace(sem, "Leaving rwsem_down_write_failed");
        return sem;
 }
 
@@ -219,17 +218,15 @@ rwsem_down_write_failed(struct rw_semaphore *sem)
  */
 struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem)
 {
-       rwsemtrace(sem, "Entering rwsem_wake");
+       unsigned long flags;
 
-       spin_lock(&sem->wait_lock);
+       spin_lock_irqsave(&sem->wait_lock, flags);
 
        /* do nothing if list empty */
        if (!list_empty(&sem->wait_list))
                sem = __rwsem_do_wake(sem, 0);
 
-       spin_unlock(&sem->wait_lock);
-
-       rwsemtrace(sem, "Leaving rwsem_wake");
+       spin_unlock_irqrestore(&sem->wait_lock, flags);
 
        return sem;
 }
@@ -241,24 +238,20 @@ struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem)
  */
 struct rw_semaphore fastcall *rwsem_downgrade_wake(struct rw_semaphore *sem)
 {
-       rwsemtrace(sem, "Entering rwsem_downgrade_wake");
+       unsigned long flags;
 
-       spin_lock(&sem->wait_lock);
+       spin_lock_irqsave(&sem->wait_lock, flags);
 
        /* do nothing if list empty */
        if (!list_empty(&sem->wait_list))
                sem = __rwsem_do_wake(sem, 1);
 
-       spin_unlock(&sem->wait_lock);
+       spin_unlock_irqrestore(&sem->wait_lock, flags);
 
-       rwsemtrace(sem, "Leaving rwsem_downgrade_wake");
        return sem;
 }
 
-EXPORT_SYMBOL_NOVERS(rwsem_down_read_failed);
-EXPORT_SYMBOL_NOVERS(rwsem_down_write_failed);
-EXPORT_SYMBOL_NOVERS(rwsem_wake);
-EXPORT_SYMBOL_NOVERS(rwsem_downgrade_wake);
-#if RWSEM_DEBUG
-EXPORT_SYMBOL(rwsemtrace);
-#endif
+EXPORT_SYMBOL(rwsem_down_read_failed);
+EXPORT_SYMBOL(rwsem_down_write_failed);
+EXPORT_SYMBOL(rwsem_wake);
+EXPORT_SYMBOL(rwsem_downgrade_wake);