@@ -318,6 +318,10 @@ struct system_counterval_t {
bool use_nsecs;
};
+extern bool ktime_real_to_base_clock(ktime_t treal,
+ enum clocksource_ids base_id, u64 *cycles);
+extern bool timekeeping_clocksource_has_base(enum clocksource_ids id);
+
/*
* Get cross timestamp between system clock and device clock
*/
@@ -1229,6 +1229,64 @@ static bool convert_base_to_cs(struct system_counterval_t *scv)
return true;
}
+static bool convert_cs_to_base(u64 *cycles, enum clocksource_ids base_id)
+{
+ struct clocksource *cs = tk_core.timekeeper.tkr_mono.clock;
+ struct clocksource_base *base = cs->base;
+
+ /* Check whether base_id matches the base clock */
+ if (!base || base->id != base_id)
+ return false;
+
+ *cycles -= base->offset;
+ if (!convert_clock(cycles, base->denominator, base->numerator))
+ return false;
+ return true;
+}
+
+static bool convert_ns_to_cs(u64 *delta)
+{
+ struct tk_read_base *tkr = &tk_core.timekeeper.tkr_mono;
+
+ if (BITS_TO_BYTES(fls64(*delta) + tkr->shift) >= sizeof(*delta))
+ return false;
+
+ *delta = div_u64((*delta << tkr->shift) - tkr->xtime_nsec, tkr->mult);
+ return true;
+}
+
+/**
+ * ktime_real_to_base_clock() - Convert CLOCK_REALTIME timestamp to a base clock timestamp
+ * @treal: CLOCK_REALTIME timestamp to convert
+ * @base_id: base clocksource id
+ * @cycles: pointer to store the converted base clock timestamp
+ *
+ * Converts a supplied, future realtime clock value to the corresponding base clock value.
+ *
+ * Return: true if the conversion is successful, false otherwise.
+ */
+bool ktime_real_to_base_clock(ktime_t treal, enum clocksource_ids base_id, u64 *cycles)
+{
+ struct timekeeper *tk = &tk_core.timekeeper;
+ unsigned int seq;
+ u64 delta;
+
+ do {
+ seq = read_seqcount_begin(&tk_core.seq);
+ if ((u64)treal < tk->tkr_mono.base_real)
+ return false;
+ delta = (u64)treal - tk->tkr_mono.base_real;
+ if (!convert_ns_to_cs(&delta))
+ return false;
+ *cycles = tk->tkr_mono.cycle_last + delta;
+ if (!convert_cs_to_base(cycles, base_id))
+ return false;
+ } while (read_seqcount_retry(&tk_core.seq, seq));
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(ktime_real_to_base_clock);
+
/**
* get_device_system_crosststamp - Synchronously capture system/device timestamp
* @get_time_fn: Callback to get simultaneous device time and
@@ -1340,6 +1398,34 @@ int get_device_system_crosststamp(int (*get_time_fn)
}
EXPORT_SYMBOL_GPL(get_device_system_crosststamp);
+/**
+ * timekeeping_clocksource_has_base - Check whether the current clocksource
+ * is based on given a base clock
+ * @id: base clocksource ID
+ *
+ * Note: The return value is a snapshot which can become invalid right
+ * after the function returns.
+ *
+ * Return: true if the timekeeper clocksource has a base clock with @id,
+ * false otherwise
+ */
+bool timekeeping_clocksource_has_base(enum clocksource_ids id)
+{
+ unsigned int seq;
+ bool ret;
+
+ do {
+ seq = read_seqcount_begin(&tk_core.seq);
+ if (tk_core.timekeeper.tkr_mono.clock->base)
+ ret = (tk_core.timekeeper.tkr_mono.clock->base->id == id);
+ else
+ ret = false;
+ } while (read_seqcount_retry(&tk_core.seq, seq));
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(timekeeping_clocksource_has_base);
+
/**
* do_settimeofday64 - Sets the time of day.
* @ts: pointer to the timespec64 variable containing the new time