MAINTAINERS: fix a few pinctrl related entries

[pandora-kernel.git] / kernel / task_work.c

diff --git a/kernel/task_work.c b/kernel/task_work.c
index 82d1c79..91d4e17 100644 (file)
--- a/kernel/task_work.c
+++ b/kernel/task_work.c
@@ -3,82 +3,78 @@
 #include <linux/tracehook.h>
 
 int
-task_work_add(struct task_struct *task, struct task_work *twork, bool notify)
+task_work_add(struct task_struct *task, struct callback_head *twork, bool notify)
 {
+       struct callback_head *last, *first;
        unsigned long flags;
-       int err = -ESRCH;
 
-#ifndef TIF_NOTIFY_RESUME
-       if (notify)
-               return -ENOTSUPP;
-#endif
        /*
-        * We must not insert the new work if the task has already passed
-        * exit_task_work(). We rely on do_exit()->raw_spin_unlock_wait()
-        * and check PF_EXITING under pi_lock.
+        * Not inserting the new work if the task has already passed
+        * exit_task_work() is the responisbility of callers.
         */
        raw_spin_lock_irqsave(&task->pi_lock, flags);
-       if (likely(!(task->flags & PF_EXITING))) {
-               hlist_add_head(&twork->hlist, &task->task_works);
-               err = 0;
-       }
+       last = task->task_works;
+       first = last ? last->next : twork;
+       twork->next = first;
+       if (last)
+               last->next = twork;
+       task->task_works = twork;
        raw_spin_unlock_irqrestore(&task->pi_lock, flags);
 
        /* test_and_set_bit() implies mb(), see tracehook_notify_resume(). */
-       if (likely(!err) && notify)
+       if (notify)
                set_notify_resume(task);
-       return err;
+       return 0;
 }
 
-struct task_work *
+struct callback_head *
 task_work_cancel(struct task_struct *task, task_work_func_t func)
 {
        unsigned long flags;
-       struct task_work *twork;
-       struct hlist_node *pos;
+       struct callback_head *last, *res = NULL;
 
        raw_spin_lock_irqsave(&task->pi_lock, flags);
-       hlist_for_each_entry(twork, pos, &task->task_works, hlist) {
-               if (twork->func == func) {
-                       hlist_del(&twork->hlist);
-                       goto found;
+       last = task->task_works;
+       if (last) {
+               struct callback_head *q = last, *p = q->next;
+               while (1) {
+                       if (p->func == func) {
+                               q->next = p->next;
+                               if (p == last)
+                                       task->task_works = q == p ? NULL : q;
+                               res = p;
+                               break;
+                       }
+                       if (p == last)
+                               break;
+                       q = p;
+                       p = q->next;
                }
        }
-       twork = NULL;
- found:
        raw_spin_unlock_irqrestore(&task->pi_lock, flags);
-
-       return twork;
+       return res;
 }
 
 void task_work_run(void)
 {
        struct task_struct *task = current;
-       struct hlist_head task_works;
-       struct hlist_node *pos;
+       struct callback_head *p, *q;
 
-       raw_spin_lock_irq(&task->pi_lock);
-       hlist_move_list(&task->task_works, &task_works);
-       raw_spin_unlock_irq(&task->pi_lock);
+       while (1) {
+               raw_spin_lock_irq(&task->pi_lock);
+               p = task->task_works;
+               task->task_works = NULL;
+               raw_spin_unlock_irq(&task->pi_lock);
 
-       if (unlikely(hlist_empty(&task_works)))
-               return;
-       /*
-        * We use hlist to save the space in task_struct, but we want fifo.
-        * Find the last entry, the list should be short, then process them
-        * in reverse order.
-        */
-       for (pos = task_works.first; pos->next; pos = pos->next)
-               ;
+               if (unlikely(!p))
+                       return;
 
-       for (;;) {
-               struct hlist_node **pprev = pos->pprev;
-               struct task_work *twork = container_of(pos, struct task_work,
-                                                       hlist);
-               twork->func(twork);
-
-               if (pprev == &task_works.first)
-                       break;
-               pos = container_of(pprev, struct hlist_node, next);
+               q = p->next; /* head */
+               p->next = NULL; /* cut it */
+               while (q) {
+                       p = q->next;
+                       q->func(q);
+                       q = p;
+               }
        }
 }