[PATCH 07/21] ntp: Introduce struct ntp_data
From: Anna-Maria Behnsen
Date: Wed Sep 11 2024 - 09:20:07 EST
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
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: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx>
---
kernel/time/ntp.c | 65 ++++++++++++++++++++++++++++++-------------------------
1 file changed, 36 insertions(+), 29 deletions(-)
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 477cb08062bc..0222f8e46081 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -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)
{
@@ -698,7 +704,7 @@ 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)
@@ -739,13 +745,12 @@ 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.
@@ -753,6 +758,7 @@ 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) {
@@ -761,7 +767,7 @@ 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);
@@ -774,15 +780,15 @@ 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,
@@ -803,7 +809,7 @@ 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 */
@@ -924,7 +930,7 @@ 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;
@@ -971,7 +977,7 @@ 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;
@@ -1022,6 +1028,7 @@ 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);
@@ -1062,7 +1069,7 @@ 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);
--
2.39.2