Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
timekeeping: Provide time getters for auxiliary clocks
Provide interfaces similar to the ktime_get*() family which provide access
to the auxiliary clocks.
These interfaces have a boolean return value, which indicates whether the
accessed clock is valid or not.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/all/20250625183757.868342628@linutronix.de
+81
+5
include/linux/posix-timers.h
+5
include/linux/posix-timers.h
+11
include/linux/timekeeping.h
+11
include/linux/timekeeping.h
···
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extern void timekeeping_inject_sleeptime64(const struct timespec64 *delta);
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/*
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* Auxiliary clock interfaces
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*/
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#ifdef CONFIG_POSIX_AUX_CLOCKS
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extern bool ktime_get_aux(clockid_t id, ktime_t *kt);
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extern bool ktime_get_aux_ts64(clockid_t id, struct timespec64 *kt);
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#else
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static inline bool ktime_get_aux(clockid_t id, ktime_t *kt) { return false; }
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static inline bool ktime_get_aux_ts64(clockid_t id, struct timespec64 *kt) { return false; }
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#endif
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/**
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* struct system_time_snapshot - simultaneous raw/real time capture with
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* counter value
+65
kernel/time/timekeeping.c
+65
kernel/time/timekeeping.c
···
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*/
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static unsigned long aux_timekeepers;
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static inline unsigned int clockid_to_tkid(unsigned int id)
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{
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return TIMEKEEPER_AUX_FIRST + id - CLOCK_AUX;
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}
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+
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static inline struct tk_data *aux_get_tk_data(clockid_t id)
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{
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if (!clockid_aux_valid(id))
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return NULL;
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return &timekeeper_data[clockid_to_tkid(id)];
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}
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/* Invoked from timekeeping after a clocksource change */
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static void tk_aux_update_clocksource(void)
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{
···
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timekeeping_update_from_shadow(tkd, TK_UPDATE_ALL);
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}
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}
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+
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/**
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* ktime_get_aux - Get time for a AUX clock
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* @id: ID of the clock to read (CLOCK_AUX...)
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* @kt: Pointer to ktime_t to store the time stamp
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*
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* Returns: True if the timestamp is valid, false otherwise
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*/
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bool ktime_get_aux(clockid_t id, ktime_t *kt)
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{
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struct tk_data *aux_tkd = aux_get_tk_data(id);
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struct timekeeper *aux_tk;
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unsigned int seq;
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ktime_t base;
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u64 nsecs;
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WARN_ON(timekeeping_suspended);
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if (!aux_tkd)
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return false;
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+
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aux_tk = &aux_tkd->timekeeper;
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do {
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seq = read_seqcount_begin(&aux_tkd->seq);
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if (!aux_tk->clock_valid)
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return false;
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+
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base = ktime_add(aux_tk->tkr_mono.base, aux_tk->offs_aux);
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nsecs = timekeeping_get_ns(&aux_tk->tkr_mono);
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} while (read_seqcount_retry(&aux_tkd->seq, seq));
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+
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*kt = ktime_add_ns(base, nsecs);
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return true;
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}
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EXPORT_SYMBOL_GPL(ktime_get_aux);
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+
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/**
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* ktime_get_aux_ts64 - Get time for a AUX clock
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* @id: ID of the clock to read (CLOCK_AUX...)
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* @ts: Pointer to timespec64 to store the time stamp
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*
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* Returns: True if the timestamp is valid, false otherwise
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*/
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bool ktime_get_aux_ts64(clockid_t id, struct timespec64 *ts)
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{
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ktime_t now;
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+
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if (!ktime_get_aux(id, &now))
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return false;
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*ts = ktime_to_timespec64(now);
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return true;
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}
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EXPORT_SYMBOL_GPL(ktime_get_aux_ts64);
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static __init void tk_aux_setup(void)
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{