Commit 606424bf authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

timekeeping: Add minimal posix-timers support for auxiliary clocks 



Provide clock_getres(2) and clock_gettime(2) for auxiliary clocks.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarJohn Stultz <jstultz@google.com>
Link: https://lore.kernel.org/all/20250625183757.932220594@linutronix.de
parent 05bc6e62

kernel/time/posix-timers.c

+3 −0
Original line number Diff line number Diff line
@@ -1526,6 +1526,9 @@ static const struct k_clock * const posix_clocks[] = { 
	[CLOCK_REALTIME_ALARM]		= &alarm_clock,

	[CLOCK_BOOTTIME_ALARM]		= &alarm_clock,

	[CLOCK_TAI]			= &clock_tai,

#ifdef CONFIG_POSIX_AUX_CLOCKS

	[CLOCK_AUX ... CLOCK_AUX_LAST]	= &clock_aux,

#endif

};



static const struct k_clock *clockid_to_kclock(const clockid_t id)

kernel/time/posix-timers.h

+1 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ extern const struct k_clock clock_posix_dynamic; 
extern const struct k_clock clock_process;

extern const struct k_clock clock_thread;

extern const struct k_clock alarm_clock;

extern const struct k_clock clock_aux;



void posix_timer_queue_signal(struct k_itimer *timr);

kernel/time/timekeeping.c

+21 −0
Original line number Diff line number Diff line
@@ -2655,6 +2655,7 @@ EXPORT_SYMBOL(hardpps); 
#endif /* CONFIG_NTP_PPS */



#ifdef CONFIG_POSIX_AUX_CLOCKS

#include "posix-timers.h"



/*

 * Bitmap for the activated auxiliary timekeepers to allow lockless quick
@@ -2749,6 +2750,26 @@ bool ktime_get_aux_ts64(clockid_t id, struct timespec64 *ts) 
}

EXPORT_SYMBOL_GPL(ktime_get_aux_ts64);



static int aux_get_res(clockid_t id, struct timespec64 *tp)

{

	if (!clockid_aux_valid(id))

		return -ENODEV;



	tp->tv_sec = 0;

	tp->tv_nsec = 1;

	return 0;

}



static int aux_get_timespec(clockid_t id, struct timespec64 *tp)

{

	return ktime_get_aux_ts64(id, tp) ? 0 : -ENODEV;

}



const struct k_clock clock_aux = {

	.clock_getres		= aux_get_res,

	.clock_get_timespec	= aux_get_timespec,

};



static __init void tk_aux_setup(void)

{

	for (int i = TIMEKEEPER_AUX_FIRST; i <= TIMEKEEPER_AUX_LAST; i++)