Commit 908a1d77 authored by Nam Cao's avatar Nam Cao Committed by Thomas Gleixner
Browse files

hrtimers: Introduce hrtimer_setup() to replace hrtimer_init() 



To initialize hrtimer, hrtimer_init() needs to be called and also
hrtimer::function must be set. This is error-prone and awkward to use.

Introduce hrtimer_setup() which does both of these things, so that users of
hrtimer can be simplified.

The new setup function also has a sanity check for the provided function
pointer. If NULL, a warning is emitted and a dummy callback installed.

hrtimer_init() will be removed as soon as all of its users have been
converted to the new function.

Signed-off-by: default avatarNam Cao <namcao@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/5057c1ddbfd4b92033cd93d37fe38e6b069d5ba6.1730386209.git.namcao@linutronix.de
parent c95d3658

include/linux/hrtimer.h

+2 −0
Original line number Diff line number Diff line
@@ -228,6 +228,8 @@ static inline void hrtimer_cancel_wait_running(struct hrtimer *timer) 
/* Initialize timers: */

extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,

			 enum hrtimer_mode mode);

extern void hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*function)(struct hrtimer *),

			  clockid_t clock_id, enum hrtimer_mode mode);

extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,

				  enum hrtimer_mode mode);

extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,

kernel/time/hrtimer.c

+38 −0
Original line number Diff line number Diff line
@@ -1535,6 +1535,11 @@ static inline int hrtimer_clockid_to_base(clockid_t clock_id) 
	return HRTIMER_BASE_MONOTONIC;

}



static enum hrtimer_restart hrtimer_dummy_timeout(struct hrtimer *unused)

{

	return HRTIMER_NORESTART;

}



static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,

			   enum hrtimer_mode mode)

{
@@ -1571,6 +1576,18 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, 
	timerqueue_init(&timer->node);

}



static void __hrtimer_setup(struct hrtimer *timer,

			    enum hrtimer_restart (*function)(struct hrtimer *),

			    clockid_t clock_id, enum hrtimer_mode mode)

{

	__hrtimer_init(timer, clock_id, mode);



	if (WARN_ON_ONCE(!function))

		timer->function = hrtimer_dummy_timeout;

	else

		timer->function = function;

}



/**

 * hrtimer_init - initialize a timer to the given clock

 * @timer:	the timer to be initialized
@@ -1591,6 +1608,27 @@ void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, 
}

EXPORT_SYMBOL_GPL(hrtimer_init);



/**

 * hrtimer_setup - initialize a timer to the given clock

 * @timer:	the timer to be initialized

 * @function:	the callback function

 * @clock_id:	the clock to be used

 * @mode:       The modes which are relevant for initialization:

 *              HRTIMER_MODE_ABS, HRTIMER_MODE_REL, HRTIMER_MODE_ABS_SOFT,

 *              HRTIMER_MODE_REL_SOFT

 *

 *              The PINNED variants of the above can be handed in,

 *              but the PINNED bit is ignored as pinning happens

 *              when the hrtimer is started

 */

void hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*function)(struct hrtimer *),

		   clockid_t clock_id, enum hrtimer_mode mode)

{

	debug_init(timer, clock_id, mode);

	__hrtimer_setup(timer, function, clock_id, mode);

}

EXPORT_SYMBOL_GPL(hrtimer_setup);



/**

 * hrtimer_init_on_stack - initialize a timer in stack memory

 * @timer:	The timer to be initialized