Commit 68f66f97 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

ntp: Introduce struct ntp_data 



All NTP data is held in static variables. That prevents the NTP code from
being reuasble for non-system time timekeepers, e.g. per PTP clock
timekeeping.

Introduce struct ntp_data and move tick_usec into it for a start.

No functional change.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarAnna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarJohn Stultz <jstultz@google.com>
Link: https://lore.kernel.org/all/20240911-devel-anna-maria-b4-timers-ptp-ntp-v1-7-2d52f4e13476@linutronix.de
parent 136bccbc

kernel/time/ntp.c

+36 −29
Original line number Diff line number Diff line
@@ -22,16 +22,19 @@ 
#include "ntp_internal.h"

#include "timekeeping_internal.h"





/*

 * NTP timekeeping variables:

/**

 * struct ntp_data - Structure holding all NTP related state

 * @tick_usec:		USER_HZ period in microseconds

 *

 * Note: All of the NTP state is protected by the timekeeping locks.

 * Protected by the timekeeping locks.

 */

struct ntp_data {

	unsigned long		tick_usec;

};





/* USER_HZ period (usecs): */

static unsigned long		tick_usec = USER_TICK_USEC;

static struct ntp_data tk_ntp_data = {

	.tick_usec		= USER_TICK_USEC,

};



static u64			tick_length;

static u64			tick_length_base;
@@ -245,13 +248,11 @@ static inline void pps_fill_timex(struct __kernel_timex *txc) 
 * Update tick_length and tick_length_base, based on tick_usec, ntp_tick_adj and

 * time_freq:

 */

static void ntp_update_frequency(void)

static void ntp_update_frequency(struct ntp_data *ntpdata)

{

	u64 second_length;

	u64 new_base;

	u64 second_length, new_base, tick_usec = (u64)ntpdata->tick_usec;



	second_length		 = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)

						<< NTP_SCALE_SHIFT;

	second_length		 = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ) << NTP_SCALE_SHIFT;



	second_length		+= ntp_tick_adj;

	second_length		+= time_freq;
@@ -330,10 +331,7 @@ static void ntp_update_offset(long offset) 
	time_offset = div_s64(offset64 << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ);

}



/**

 * ntp_clear - Clears the NTP state variables

 */

void ntp_clear(void)

static void __ntp_clear(struct ntp_data *ntpdata)

{

	/* Stop active adjtime() */

	time_adjust	= 0;
@@ -341,7 +339,7 @@ void ntp_clear(void) 
	time_maxerror	= NTP_PHASE_LIMIT;

	time_esterror	= NTP_PHASE_LIMIT;



	ntp_update_frequency();

	ntp_update_frequency(ntpdata);



	tick_length	= tick_length_base;

	time_offset	= 0;
@@ -351,6 +349,14 @@ void ntp_clear(void) 
	pps_clear();

}



/**

 * ntp_clear - Clears the NTP state variables

 */

void ntp_clear(void)

{

	__ntp_clear(&tk_ntp_data);

}





u64 ntp_tick_length(void)

{
@@ -706,7 +712,7 @@ static inline void process_adj_status(const struct __kernel_timex *txc) 
}





static inline void process_adjtimex_modes(const struct __kernel_timex *txc,

static inline void process_adjtimex_modes(struct ntp_data *ntpdata, const struct __kernel_timex *txc,

					  s32 *time_tai)

{

	if (txc->modes & ADJ_STATUS)
@@ -747,13 +753,12 @@ static inline void process_adjtimex_modes(const struct __kernel_timex *txc, 
		ntp_update_offset(txc->offset);



	if (txc->modes & ADJ_TICK)

		tick_usec = txc->tick;

		ntpdata->tick_usec = txc->tick;



	if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))

		ntp_update_frequency();

		ntp_update_frequency(ntpdata);

}





/*

 * adjtimex() mainly allows reading (and writing, if superuser) of

 * kernel time-keeping variables. used by xntpd.
@@ -761,6 +766,7 @@ static inline void process_adjtimex_modes(const struct __kernel_timex *txc, 
int __do_adjtimex(struct __kernel_timex *txc, const struct timespec64 *ts,

		  s32 *time_tai, struct audit_ntp_data *ad)

{

	struct ntp_data *ntpdata = &tk_ntp_data;

	int result;



	if (txc->modes & ADJ_ADJTIME) {
@@ -769,7 +775,7 @@ int __do_adjtimex(struct __kernel_timex *txc, const struct timespec64 *ts, 
		if (!(txc->modes & ADJ_OFFSET_READONLY)) {

			/* adjtime() is independent from ntp_adjtime() */

			time_adjust = txc->offset;

			ntp_update_frequency();

			ntp_update_frequency(ntpdata);



			audit_ntp_set_old(ad, AUDIT_NTP_ADJUST,	save_adjust);

			audit_ntp_set_new(ad, AUDIT_NTP_ADJUST,	time_adjust);
@@ -782,15 +788,15 @@ int __do_adjtimex(struct __kernel_timex *txc, const struct timespec64 *ts, 
			audit_ntp_set_old(ad, AUDIT_NTP_FREQ,	time_freq);

			audit_ntp_set_old(ad, AUDIT_NTP_STATUS,	time_status);

			audit_ntp_set_old(ad, AUDIT_NTP_TAI,	*time_tai);

			audit_ntp_set_old(ad, AUDIT_NTP_TICK,	tick_usec);

			audit_ntp_set_old(ad, AUDIT_NTP_TICK,	ntpdata->tick_usec);



			process_adjtimex_modes(txc, time_tai);

			process_adjtimex_modes(ntpdata, txc, time_tai);



			audit_ntp_set_new(ad, AUDIT_NTP_OFFSET,	time_offset);

			audit_ntp_set_new(ad, AUDIT_NTP_FREQ,	time_freq);

			audit_ntp_set_new(ad, AUDIT_NTP_STATUS,	time_status);

			audit_ntp_set_new(ad, AUDIT_NTP_TAI,	*time_tai);

			audit_ntp_set_new(ad, AUDIT_NTP_TICK,	tick_usec);

			audit_ntp_set_new(ad, AUDIT_NTP_TICK,	ntpdata->tick_usec);

		}



		txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
@@ -811,7 +817,7 @@ int __do_adjtimex(struct __kernel_timex *txc, const struct timespec64 *ts, 
	txc->constant	   = time_constant;

	txc->precision	   = 1;

	txc->tolerance	   = MAXFREQ_SCALED / PPM_SCALE;

	txc->tick	   = tick_usec;

	txc->tick	   = ntpdata->tick_usec;

	txc->tai	   = *time_tai;



	/* Fill PPS status fields */
@@ -932,7 +938,7 @@ static inline void pps_inc_freq_interval(void) 
 * too long, the data are discarded.

 * Returns the difference between old and new frequency values.

 */

static long hardpps_update_freq(struct pps_normtime freq_norm)

static long hardpps_update_freq(struct ntp_data *ntpdata, struct pps_normtime freq_norm)

{

	long delta, delta_mod;

	s64 ftemp;
@@ -979,7 +985,7 @@ static long hardpps_update_freq(struct pps_normtime freq_norm) 
	/* If enabled, the system clock frequency is updated */

	if ((time_status & STA_PPSFREQ) && !(time_status & STA_FREQHOLD)) {

		time_freq = pps_freq;

		ntp_update_frequency();

		ntp_update_frequency(ntpdata);

	}



	return delta;
@@ -1030,6 +1036,7 @@ static void hardpps_update_phase(long error) 
void __hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts)

{

	struct pps_normtime pts_norm, freq_norm;

	struct ntp_data *ntpdata = &tk_ntp_data;



	pts_norm = pps_normalize_ts(*phase_ts);
@@ -1070,7 +1077,7 @@ void __hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_t 
		pps_calcnt++;

		/* Restart the frequency calibration interval */

		pps_fbase = *raw_ts;

		hardpps_update_freq(freq_norm);

		hardpps_update_freq(ntpdata, freq_norm);

	}



	hardpps_update_phase(pts_norm.nsec);