cpumask: introduce new API, without changing anything

[linux-2.6-omap-h63xx.git] / kernel / workqueue.c

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index f928f2a87b9b365a8e1d8684902a3ad6f917d6b0..d4dc69ddebd7276684e2564737618859e96fbd1c 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -970,6 +970,51 @@ undo:
        return ret;
 }
 
+#ifdef CONFIG_SMP
+struct work_for_cpu {
+       struct work_struct work;
+       long (*fn)(void *);
+       void *arg;
+       long ret;
+};
+
+static void do_work_for_cpu(struct work_struct *w)
+{
+       struct work_for_cpu *wfc = container_of(w, struct work_for_cpu, work);
+
+       wfc->ret = wfc->fn(wfc->arg);
+}
+
+/**
+ * work_on_cpu - run a function in user context on a particular cpu
+ * @cpu: the cpu to run on
+ * @fn: the function to run
+ * @arg: the function arg
+ *
+ * This will return -EINVAL in the cpu is not online, or the return value
+ * of @fn otherwise.
+ */
+long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
+{
+       struct work_for_cpu wfc;
+
+       INIT_WORK(&wfc.work, do_work_for_cpu);
+       wfc.fn = fn;
+       wfc.arg = arg;
+       get_online_cpus();
+       if (unlikely(!cpu_online(cpu)))
+               wfc.ret = -EINVAL;
+       else {
+               schedule_work_on(cpu, &wfc.work);
+               flush_work(&wfc.work);
+       }
+       put_online_cpus();
+
+       return wfc.ret;
+}
+EXPORT_SYMBOL_GPL(work_on_cpu);
+#endif /* CONFIG_SMP */
+
 void __init init_workqueues(void)
 {
        cpu_populated_map = cpu_online_map;