1 files changed, 125 insertions, 0 deletions

diff --git a/kernel/mutex.c b/kernel/mutex.c
index d607ed5dd441..2f363b9bfc1f 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -498,3 +498,128 @@ int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock)
         return 1;
 }
 EXPORT_SYMBOL(atomic_dec_and_mutex_lock);
+
+
+
+
+void mutex_lock_sfx(struct mutex *lock,
+                                   side_effect_t pre, unsigned long pre_arg,
+                                   side_effect_t post, unsigned long post_arg)
+{
+        long state = TASK_UNINTERRUPTIBLE;
+
+        struct task_struct *task = current;
+        struct mutex_waiter waiter;
+        unsigned long flags;
+        
+        preempt_disable();
+        mutex_acquire(&lock->dep_map, subclass, 0, ip);
+
+        spin_lock_mutex(&lock->wait_lock, flags);
+        
+        if(pre)
+        {
+                if(unlikely(pre(pre_arg)))
+                {
+                        // this will fuck with lockdep's CONFIG_PROVE_LOCKING...
+                        spin_unlock_mutex(&lock->wait_lock, flags);
+                        preempt_enable();
+                        return;
+                }
+        }
+
+        debug_mutex_lock_common(lock, &waiter);
+        debug_mutex_add_waiter(lock, &waiter, task_thread_info(task));
+        
+        /* add waiting tasks to the end of the waitqueue (FIFO): */
+        list_add_tail(&waiter.list, &lock->wait_list);
+        waiter.task = task;
+        
+        if (atomic_xchg(&lock->count, -1) == 1)
+                goto done;
+        
+        lock_contended(&lock->dep_map, ip);
+        
+        for (;;) {
+                /*
+                 * Lets try to take the lock again - this is needed even if
+                 * we get here for the first time (shortly after failing to
+                 * acquire the lock), to make sure that we get a wakeup once
+                 * it's unlocked. Later on, if we sleep, this is the
+                 * operation that gives us the lock. We xchg it to -1, so
+                 * that when we release the lock, we properly wake up the
+                 * other waiters:
+                 */
+                if (atomic_xchg(&lock->count, -1) == 1)
+                        break;
+                
+                __set_task_state(task, state);
+                
+                /* didnt get the lock, go to sleep: */
+                spin_unlock_mutex(&lock->wait_lock, flags);
+                preempt_enable_no_resched();
+                schedule();
+                preempt_disable();
+                spin_lock_mutex(&lock->wait_lock, flags);
+        }
+        
+done:
+        lock_acquired(&lock->dep_map, ip);
+        /* got the lock - rejoice! */
+        mutex_remove_waiter(lock, &waiter, current_thread_info());
+        mutex_set_owner(lock);
+        
+        /* set it to 0 if there are no waiters left: */
+        if (likely(list_empty(&lock->wait_list)))
+                atomic_set(&lock->count, 0);
+        
+        if(post)
+                post(post_arg); 
+        
+        spin_unlock_mutex(&lock->wait_lock, flags);
+        
+        debug_mutex_free_waiter(&waiter);
+        preempt_enable();
+}
+EXPORT_SYMBOL(mutex_lock_sfx);
+
+void mutex_unlock_sfx(struct mutex *lock,
+                                        side_effect_t pre, unsigned long pre_arg,
+                                        side_effect_t post, unsigned long post_arg)
+{
+        unsigned long flags;
+        
+        spin_lock_mutex(&lock->wait_lock, flags);
+        
+        if(pre)
+                pre(pre_arg);
+        
+        //mutex_release(&lock->dep_map, nested, _RET_IP_);
+        mutex_release(&lock->dep_map, 1, _RET_IP_);
+        debug_mutex_unlock(lock);
+        
+        /*
+         * some architectures leave the lock unlocked in the fastpath failure
+         * case, others need to leave it locked. In the later case we have to
+         * unlock it here
+         */
+        if (__mutex_slowpath_needs_to_unlock())
+                atomic_set(&lock->count, 1);
+        
+        if (!list_empty(&lock->wait_list)) {
+                /* get the first entry from the wait-list: */
+                struct mutex_waiter *waiter =
+                list_entry(lock->wait_list.next,
+                                   struct mutex_waiter, list);
+                
+                debug_mutex_wake_waiter(lock, waiter);
+                
+                wake_up_process(waiter->task);
+        }
+        
+        if(post)
+                post(post_arg);
+        
+        spin_unlock_mutex(&lock->wait_lock, flags);     
+}
+EXPORT_SYMBOL(mutex_unlock_sfx);