Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:
 "This adds a new timer wheel function which is required for the
  conversion of the timer callback function from the 'unsigned long
  data' argument to 'struct timer_list *timer'. This conversion has two
  benefits:

   1) It makes struct timer_list smaller

   2) Many callers hand in a pointer to the timer or to the structure
      containing the timer, which happens via type casting both at setup
      and in the callback. This change gets rid of the typecasts.

  Once the conversion is complete, which is planned for 4.15, the old
  setup function and the intermediate typecast in the new setup function
  go away along with the data field in struct timer_list.

  Merging this now into mainline allows a smooth queueing of the actual
  conversion in the affected maintainer trees without creating
  dependencies"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  um/time: Fixup namespace collision
  timer: Prepare to change timer callback argument type

Author: torvalds

arch/um/kernel/time.c

@@ -98,7 +98,7 @@ static struct clocksource timer_clocksource = {
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
-static void __init timer_setup(void)
+static void __init um_timer_setup(void)
 {
 	int err;
 
@@ -132,5 +132,5 @@ void read_persistent_clock(struct timespec *ts)
 void __init time_init(void)
 {
 	timer_set_signal_handler();
-	late_time_init = timer_setup;
+	late_time_init = um_timer_setup;
 }

include/linux/timer.h

@@ -168,6 +168,20 @@ static inline void init_timer_on_stack_key(struct timer_list *timer,
 #define setup_pinned_deferrable_timer_on_stack(timer, fn, data)		\
 	__setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
 
+#define TIMER_DATA_TYPE		unsigned long
+#define TIMER_FUNC_TYPE		void (*)(TIMER_DATA_TYPE)
+
+static inline void timer_setup(struct timer_list *timer,
+			       void (*callback)(struct timer_list *),
+			       unsigned int flags)
+{
+	__setup_timer(timer, (TIMER_FUNC_TYPE)callback,
+		      (TIMER_DATA_TYPE)timer, flags);
+}
+
+#define from_timer(var, callback_timer, timer_fieldname) \
+	container_of(callback_timer, typeof(*var), timer_fieldname)
+
 /**
  * timer_pending - is a timer pending?
  * @timer: the timer in question