timekeeping: Make __timekeeping_advance() reusable

In __timekeeping_advance() the pointer to struct tk_data is hardcoded by the
use of &tk_core. As long as there is only a single timekeeper (tk_core),
this is not a problem. But when __timekeeping_advance() will be reused for
per auxiliary timekeepers, __timekeeping_advance() needs to be generalized.

Add a pointer to struct tk_data as function argument of
__timekeeping_advance() and adapt all call sites.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/all/20250519083026.160967312@linutronix.de

Author: anna-marialx

kernel/time/timekeeping.c

@@ -2196,10 +2196,10 @@ static u64 logarithmic_accumulation(struct timekeeper *tk, u64 offset,
  * timekeeping_advance - Updates the timekeeper to the current time and
  * current NTP tick length
  */
-static bool __timekeeping_advance(enum timekeeping_adv_mode mode)
+static bool __timekeeping_advance(struct tk_data *tkd, enum timekeeping_adv_mode mode)
 {
-	struct timekeeper *tk = &tk_core.shadow_timekeeper;
-	struct timekeeper *real_tk = &tk_core.timekeeper;
+	struct timekeeper *tk = &tkd->shadow_timekeeper;
+	struct timekeeper *real_tk = &tkd->timekeeper;
 	unsigned int clock_set = 0;
 	int shift = 0, maxshift;
 	u64 offset, orig_offset;
@@ -2252,15 +2252,15 @@ static bool __timekeeping_advance(enum timekeeping_adv_mode mode)
 	if (orig_offset != offset)
 		tk_update_coarse_nsecs(tk);
 
-	timekeeping_update_from_shadow(&tk_core, clock_set);
+	timekeeping_update_from_shadow(tkd, clock_set);
 
 	return !!clock_set;
 }
 
 static bool timekeeping_advance(enum timekeeping_adv_mode mode)
 {
 	guard(raw_spinlock_irqsave)(&tk_core.lock);
-	return __timekeeping_advance(mode);
+	return __timekeeping_advance(&tk_core, mode);
 }
 
 /**
@@ -2598,7 +2598,7 @@ int do_adjtimex(struct __kernel_timex *txc)
 
 		/* Update the multiplier immediately if frequency was set directly */
 		if (txc->modes & (ADJ_FREQUENCY | ADJ_TICK))
-			clock_set |= __timekeeping_advance(TK_ADV_FREQ);
+			clock_set |= __timekeeping_advance(&tk_core, TK_ADV_FREQ);
 	}
 
 	if (txc->modes & ADJ_SETOFFSET)