2 files changed, 35 insertions, 0 deletions

diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 86b111300231..957c21c16d62 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -20,6 +20,10 @@ struct work_struct {
         struct timer_list timer;
 };
 
+struct execute_work {
+        struct work_struct work;
+};
+
 #define __WORK_INITIALIZER(n, f, d) {                           \
         .entry  = { &(n).entry, &(n).entry },                   \
         .func = (f),                                            \
@@ -74,6 +78,8 @@ extern void init_workqueues(void);
 void cancel_rearming_delayed_work(struct work_struct *work);
 void cancel_rearming_delayed_workqueue(struct workqueue_struct *,
                                        struct work_struct *);
+int execute_in_process_context(void (*fn)(void *), void *,
+                               struct execute_work *);
 
 /*
  * Kill off a pending schedule_delayed_work().  Note that the work callback
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index b052e2c4c710..e9e464a90376 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -27,6 +27,7 @@
 #include <linux/cpu.h>
 #include <linux/notifier.h>
 #include <linux/kthread.h>
+#include <linux/hardirq.h>
 
 /*
  * The per-CPU workqueue (if single thread, we always use the first
@@ -476,6 +477,34 @@ void cancel_rearming_delayed_work(struct work_struct *work)
 }
 EXPORT_SYMBOL(cancel_rearming_delayed_work);
 
+/**
+ * execute_in_process_context - reliably execute the routine with user context
+ * @fn:         the function to execute
+ * @data:       data to pass to the function
+ * @ew:         guaranteed storage for the execute work structure (must
+ *              be available when the work executes)
+ *
+ * Executes the function immediately if process context is available,
+ * otherwise schedules the function for delayed execution.
+ *
+ * Returns:     0 - function was executed
+ *              1 - function was scheduled for execution
+ */
+int execute_in_process_context(void (*fn)(void *data), void *data,
+                               struct execute_work *ew)
+{
+        if (!in_interrupt()) {
+                fn(data);
+                return 0;
+        }
+
+        INIT_WORK(&ew->work, fn, data);
+        schedule_work(&ew->work);
+
+        return 1;
+}
+EXPORT_SYMBOL_GPL(execute_in_process_context);
+
 int keventd_up(void)
 {
         return keventd_wq != NULL;