Commit 33e62e83 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

ntp, rtc: Move rtc_set_ntp_time() to ntp code 



rtc_set_ntp_time() is not really RTC functionality as the code is just a
user of RTC. Move it into the NTP code which allows further cleanups.

Requested-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Acked-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220542.166871172@linutronix.de
parent c9e6189f

drivers/rtc/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -6,7 +6,6 @@ 
ccflags-$(CONFIG_RTC_DEBUG)	:= -DDEBUG



obj-$(CONFIG_RTC_LIB)		+= lib.o

obj-$(CONFIG_RTC_SYSTOHC)	+= systohc.o

obj-$(CONFIG_RTC_CLASS)		+= rtc-core.o

obj-$(CONFIG_RTC_MC146818_LIB)	+= rtc-mc146818-lib.o

rtc-core-y			:= class.o interface.o

drivers/rtc/systohc.c

deleted100644 → 0
+0 −61
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <linux/rtc.h>

#include <linux/time.h>



/**

 * rtc_set_ntp_time - Save NTP synchronized time to the RTC

 * @now: Current time of day

 * @target_nsec: pointer for desired now->tv_nsec value

 *

 * Replacement for the NTP platform function update_persistent_clock64

 * that stores time for later retrieval by rtc_hctosys.

 *

 * Returns 0 on successful RTC update, -ENODEV if a RTC update is not

 * possible at all, and various other -errno for specific temporary failure

 * cases.

 *

 * -EPROTO is returned if now.tv_nsec is not close enough to *target_nsec.

 *

 * If temporary failure is indicated the caller should try again 'soon'

 */

int rtc_set_ntp_time(struct timespec64 now, unsigned long *target_nsec)

{

	struct rtc_device *rtc;

	struct rtc_time tm;

	struct timespec64 to_set;

	int err = -ENODEV;

	bool ok;



	rtc = rtc_class_open(CONFIG_RTC_SYSTOHC_DEVICE);

	if (!rtc)

		goto out_err;



	if (!rtc->ops || !rtc->ops->set_time)

		goto out_close;



	/* Compute the value of tv_nsec we require the caller to supply in

	 * now.tv_nsec.  This is the value such that (now +

	 * set_offset_nsec).tv_nsec == 0.

	 */

	set_normalized_timespec64(&to_set, 0, -rtc->set_offset_nsec);

	*target_nsec = to_set.tv_nsec;



	/* The ntp code must call this with the correct value in tv_nsec, if

	 * it does not we update target_nsec and return EPROTO to make the ntp

	 * code try again later.

	 */

	ok = rtc_tv_nsec_ok(rtc->set_offset_nsec, &to_set, &now);

	if (!ok) {

		err = -EPROTO;

		goto out_close;

	}



	rtc_time64_to_tm(to_set.tv_sec, &tm);



	err = rtc_set_time(rtc, &tm);



out_close:

	rtc_class_close(rtc);

out_err:

	return err;

}

include/linux/rtc.h

+0 −34
Original line number Diff line number Diff line
@@ -165,7 +165,6 @@ int __rtc_register_device(struct module *owner, struct rtc_device *rtc); 


extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);

extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);

extern int rtc_set_ntp_time(struct timespec64 now, unsigned long *target_nsec);

int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);

extern int rtc_read_alarm(struct rtc_device *rtc,

			struct rtc_wkalrm *alrm);
@@ -205,39 +204,6 @@ static inline bool is_leap_year(unsigned int year) 
	return (!(year % 4) && (year % 100)) || !(year % 400);

}



/* Determine if we can call to driver to set the time. Drivers can only be

 * called to set a second aligned time value, and the field set_offset_nsec

 * specifies how far away from the second aligned time to call the driver.

 *

 * This also computes 'to_set' which is the time we are trying to set, and has

 * a zero in tv_nsecs, such that:

 *    to_set - set_delay_nsec == now +/- FUZZ

 *

 */

static inline bool rtc_tv_nsec_ok(s64 set_offset_nsec,

				  struct timespec64 *to_set,

				  const struct timespec64 *now)

{

	/* Allowed error in tv_nsec, arbitarily set to 5 jiffies in ns. */

	const unsigned long TIME_SET_NSEC_FUZZ = TICK_NSEC * 5;

	struct timespec64 delay = {.tv_sec = 0,

				   .tv_nsec = set_offset_nsec};



	*to_set = timespec64_add(*now, delay);



	if (to_set->tv_nsec < TIME_SET_NSEC_FUZZ) {

		to_set->tv_nsec = 0;

		return true;

	}



	if (to_set->tv_nsec > NSEC_PER_SEC - TIME_SET_NSEC_FUZZ) {

		to_set->tv_sec++;

		to_set->tv_nsec = 0;

		return true;

	}

	return false;

}



#define rtc_register_device(device) \

	__rtc_register_device(THIS_MODULE, device)

kernel/time/ntp.c

+85 −3
Original line number Diff line number Diff line
@@ -519,15 +519,94 @@ static void sched_sync_hw_clock(unsigned long offset_nsec, bool retry) 
	hrtimer_start(&sync_hrtimer, exp, HRTIMER_MODE_ABS);

}



/*

 * Determine if we can call to driver to set the time. Drivers can only be

 * called to set a second aligned time value, and the field set_offset_nsec

 * specifies how far away from the second aligned time to call the driver.

 *

 * This also computes 'to_set' which is the time we are trying to set, and has

 * a zero in tv_nsecs, such that:

 *    to_set - set_delay_nsec == now +/- FUZZ

 *

 */

static inline bool rtc_tv_nsec_ok(long set_offset_nsec,

				  struct timespec64 *to_set,

				  const struct timespec64 *now)

{

	/* Allowed error in tv_nsec, arbitarily set to 5 jiffies in ns. */

	const unsigned long TIME_SET_NSEC_FUZZ = TICK_NSEC * 5;

	struct timespec64 delay = {.tv_sec = 0,

				   .tv_nsec = set_offset_nsec};



	*to_set = timespec64_add(*now, delay);



	if (to_set->tv_nsec < TIME_SET_NSEC_FUZZ) {

		to_set->tv_nsec = 0;

		return true;

	}



	if (to_set->tv_nsec > NSEC_PER_SEC - TIME_SET_NSEC_FUZZ) {

		to_set->tv_sec++;

		to_set->tv_nsec = 0;

		return true;

	}

	return false;

}



#ifdef CONFIG_RTC_SYSTOHC

/*

 * rtc_set_ntp_time - Save NTP synchronized time to the RTC

 */

static int rtc_set_ntp_time(struct timespec64 now, unsigned long *target_nsec)

{

	struct rtc_device *rtc;

	struct rtc_time tm;

	struct timespec64 to_set;

	int err = -ENODEV;

	bool ok;



	rtc = rtc_class_open(CONFIG_RTC_SYSTOHC_DEVICE);

	if (!rtc)

		goto out_err;



	if (!rtc->ops || !rtc->ops->set_time)

		goto out_close;



	/*

	 * Compute the value of tv_nsec we require the caller to supply in

	 * now.tv_nsec.  This is the value such that (now +

	 * set_offset_nsec).tv_nsec == 0.

	 */

	set_normalized_timespec64(&to_set, 0, -rtc->set_offset_nsec);

	*target_nsec = to_set.tv_nsec;



	/*

	 * The ntp code must call this with the correct value in tv_nsec, if

	 * it does not we update target_nsec and return EPROTO to make the ntp

	 * code try again later.

	 */

	ok = rtc_tv_nsec_ok(rtc->set_offset_nsec, &to_set, &now);

	if (!ok) {

		err = -EPROTO;

		goto out_close;

	}



	rtc_time64_to_tm(to_set.tv_sec, &tm);



	err = rtc_set_time(rtc, &tm);



out_close:

	rtc_class_close(rtc);

out_err:

	return err;

}



static void sync_rtc_clock(void)

{

	unsigned long offset_nsec;

	struct timespec64 adjust;

	int rc;



	if (!IS_ENABLED(CONFIG_RTC_SYSTOHC))

		return;



	ktime_get_real_ts64(&adjust);



	if (persistent_clock_is_local)
@@ -544,6 +623,9 @@ static void sync_rtc_clock(void) 


	sched_sync_hw_clock(offset_nsec, rc != 0);

}

#else

static inline void sync_rtc_clock(void) { }

#endif



#ifdef CONFIG_GENERIC_CMOS_UPDATE

int __weak update_persistent_clock64(struct timespec64 now64)