Commit 444cb7db authored by Nam Cao's avatar Nam Cao Committed by Thomas Gleixner
Browse files

hrtimers: Introduce hrtimer_setup_on_stack() 



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

Introduce hrtimer_setup_on_stack() 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_on_stack() 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/4b05e2ab3a82c517adf67fabc0f0cd8fe118b97c.1730386209.git.namcao@linutronix.de
parent 908a1d77

include/linux/hrtimer.h

+3 −0
Original line number Diff line number Diff line
@@ -232,6 +232,9 @@ extern void hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*function 
			  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_setup_on_stack(struct hrtimer *timer,

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

				   clockid_t clock_id, enum hrtimer_mode mode);

extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,

					  clockid_t clock_id,

					  enum hrtimer_mode mode);

kernel/time/hrtimer.c

+19 −0
Original line number Diff line number Diff line
@@ -1646,6 +1646,25 @@ void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id, 
}

EXPORT_SYMBOL_GPL(hrtimer_init_on_stack);



/**

 * hrtimer_setup_on_stack - initialize a timer on stack memory

 * @timer:	The timer to be initialized

 * @function:	the callback function

 * @clock_id:	The clock to be used

 * @mode:       The timer mode

 *

 * Similar to hrtimer_setup(), except that this one must be used if struct hrtimer is in stack

 * memory.

 */

void hrtimer_setup_on_stack(struct hrtimer *timer,

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

			    clockid_t clock_id, enum hrtimer_mode mode)

{

	debug_init_on_stack(timer, clock_id, mode);

	__hrtimer_setup(timer, function, clock_id, mode);

}

EXPORT_SYMBOL_GPL(hrtimer_setup_on_stack);



/*

 * A timer is active, when it is enqueued into the rbtree or the

 * callback function is running or it's in the state of being migrated