Merge tag 'timers-cleanups-2025-04-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer cleanups from Thomas Gleixner:
 "A set of final cleanups for the timer subsystem:

   - Convert all del_timer[_sync]() instances over to the new
     timer_delete[_sync]() API and remove the legacy wrappers.

     Conversion was done with coccinelle plus some manual fixups as
     coccinelle chokes on scoped_guard().

   - The final cleanup of the hrtimer_init() to hrtimer_setup()
     conversion.

     This has been delayed to the end of the merge window, so that all
     patches which have been merged through other trees are in mainline
     and all new users are catched.

  Doing this right before rc1 ensures that new code which is merged post
  rc1 is not introducing new instances of the original functionality"

* tag 'timers-cleanups-2025-04-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tracing/timers: Rename the hrtimer_init event to hrtimer_setup
  hrtimers: Rename debug_init_on_stack() to debug_setup_on_stack()
  hrtimers: Rename debug_init() to debug_setup()
  hrtimers: Rename __hrtimer_init_sleeper() to __hrtimer_setup_sleeper()
  hrtimers: Remove unnecessary NULL check in hrtimer_start_range_ns()
  hrtimers: Make callback function pointer private
  hrtimers: Merge __hrtimer_init() into __hrtimer_setup()
  hrtimers: Switch to use __htimer_setup()
  hrtimers: Delete hrtimer_init()
  treewide: Convert new and leftover hrtimer_init() users
  treewide: Switch/rename to timer_delete[_sync]()

5 files changed, 27 insertions, 58 deletions

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index e0eeacbe2521..bb48498ebb5a 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -619,7 +619,7 @@ static inline void clocksource_stop_watchdog(void)
 {
 	if (!watchdog_running || (watchdog && !list_empty(&watchdog_list)))
 		return;
-	del_timer(&watchdog_timer);
+	timer_delete(&watchdog_timer);
 	watchdog_running = 0;
 }
 
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 22376a1a75b9..517ee2590a29 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -465,19 +465,17 @@ static inline void debug_hrtimer_activate(struct hrtimer *timer,
 static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { }
 #endif
 
-static inline void
-debug_init(struct hrtimer *timer, clockid_t clockid,
-	   enum hrtimer_mode mode)
+static inline void debug_setup(struct hrtimer *timer, clockid_t clockid, enum hrtimer_mode mode)
 {
 	debug_hrtimer_init(timer);
-	trace_hrtimer_init(timer, clockid, mode);
+	trace_hrtimer_setup(timer, clockid, mode);
 }
 
-static inline void debug_init_on_stack(struct hrtimer *timer, clockid_t clockid,
-				       enum hrtimer_mode mode)
+static inline void debug_setup_on_stack(struct hrtimer *timer, clockid_t clockid,
+					enum hrtimer_mode mode)
 {
 	debug_hrtimer_init_on_stack(timer);
-	trace_hrtimer_init(timer, clockid, mode);
+	trace_hrtimer_setup(timer, clockid, mode);
 }
 
 static inline void debug_activate(struct hrtimer *timer,
@@ -1316,8 +1314,6 @@ void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
 	struct hrtimer_clock_base *base;
 	unsigned long flags;
 
-	if (WARN_ON_ONCE(!timer->function))
-		return;
 	/*
 	 * Check whether the HRTIMER_MODE_SOFT bit and hrtimer.is_soft
 	 * match on CONFIG_PREEMPT_RT = n. With PREEMPT_RT check the hard
@@ -1429,7 +1425,7 @@ static __always_inline bool is_migration_base(struct hrtimer_clock_base *base)
  * running.
  *
  * This prevents priority inversion: if the soft irq thread is preempted
- * in the middle of a timer callback, then calling del_timer_sync() can
+ * in the middle of a timer callback, then calling hrtimer_cancel() can
  * lead to two issues:
  *
  *  - If the caller is on a remote CPU then it has to spin wait for the timer
@@ -1592,8 +1588,9 @@ static inline int hrtimer_clockid_to_base(clockid_t clock_id)
 	}
 }
 
-static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
-			   enum hrtimer_mode mode)
+static void __hrtimer_setup(struct hrtimer *timer,
+			    enum hrtimer_restart (*function)(struct hrtimer *),
+			    clockid_t clock_id, enum hrtimer_mode mode)
 {
 	bool softtimer = !!(mode & HRTIMER_MODE_SOFT);
 	struct hrtimer_cpu_base *cpu_base;
@@ -1626,39 +1623,12 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
 	timer->is_hard = !!(mode & HRTIMER_MODE_HARD);
 	timer->base = &cpu_base->clock_base[base];
 	timerqueue_init(&timer->node);
-}
-
-static void __hrtimer_setup(struct hrtimer *timer,
-			    enum hrtimer_restart (*function)(struct hrtimer *),
-			    clockid_t clock_id, enum hrtimer_mode mode)
-{
-	__hrtimer_init(timer, clock_id, mode);
 
 	if (WARN_ON_ONCE(!function))
-		timer->function = hrtimer_dummy_timeout;
+		ACCESS_PRIVATE(timer, function) = hrtimer_dummy_timeout;
 	else
-		timer->function = function;
-}
-
-/**
- * hrtimer_init - initialize a timer to the given clock
- * @timer:	the timer to be initialized
- * @clock_id:	the clock to be used
- * @mode:       The modes which are relevant for initialization:
- *              HRTIMER_MODE_ABS, HRTIMER_MODE_REL, HRTIMER_MODE_ABS_SOFT,
- *              HRTIMER_MODE_REL_SOFT
- *
- *              The PINNED variants of the above can be handed in,
- *              but the PINNED bit is ignored as pinning happens
- *              when the hrtimer is started
- */
-void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
-		  enum hrtimer_mode mode)
-{
-	debug_init(timer, clock_id, mode);
-	__hrtimer_init(timer, clock_id, mode);
+		ACCESS_PRIVATE(timer, function) = function;
 }
-EXPORT_SYMBOL_GPL(hrtimer_init);
 
 /**
  * hrtimer_setup - initialize a timer to the given clock
@@ -1676,7 +1646,7 @@ EXPORT_SYMBOL_GPL(hrtimer_init);
 void hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*function)(struct hrtimer *),
 		   clockid_t clock_id, enum hrtimer_mode mode)
 {
-	debug_init(timer, clock_id, mode);
+	debug_setup(timer, clock_id, mode);
 	__hrtimer_setup(timer, function, clock_id, mode);
 }
 EXPORT_SYMBOL_GPL(hrtimer_setup);
@@ -1695,7 +1665,7 @@ void hrtimer_setup_on_stack(struct hrtimer *timer,
 			    enum hrtimer_restart (*function)(struct hrtimer *),
 			    clockid_t clock_id, enum hrtimer_mode mode)
 {
-	debug_init_on_stack(timer, clock_id, mode);
+	debug_setup_on_stack(timer, clock_id, mode);
 	__hrtimer_setup(timer, function, clock_id, mode);
 }
 EXPORT_SYMBOL_GPL(hrtimer_setup_on_stack);
@@ -1769,7 +1739,7 @@ static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base,
 	raw_write_seqcount_barrier(&base->seq);
 
 	__remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE, 0);
-	fn = timer->function;
+	fn = ACCESS_PRIVATE(timer, function);
 
 	/*
 	 * Clear the 'is relative' flag for the TIME_LOW_RES case. If the
@@ -2044,7 +2014,7 @@ void hrtimer_sleeper_start_expires(struct hrtimer_sleeper *sl,
 	 * Make the enqueue delivery mode check work on RT. If the sleeper
 	 * was initialized for hard interrupt delivery, force the mode bit.
 	 * This is a special case for hrtimer_sleepers because
-	 * __hrtimer_init_sleeper() determines the delivery mode on RT so the
+	 * __hrtimer_setup_sleeper() determines the delivery mode on RT so the
 	 * fiddling with this decision is avoided at the call sites.
 	 */
 	if (IS_ENABLED(CONFIG_PREEMPT_RT) && sl->timer.is_hard)
@@ -2054,8 +2024,8 @@ void hrtimer_sleeper_start_expires(struct hrtimer_sleeper *sl,
 }
 EXPORT_SYMBOL_GPL(hrtimer_sleeper_start_expires);
 
-static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
-				   clockid_t clock_id, enum hrtimer_mode mode)
+static void __hrtimer_setup_sleeper(struct hrtimer_sleeper *sl,
+				    clockid_t clock_id, enum hrtimer_mode mode)
 {
 	/*
 	 * On PREEMPT_RT enabled kernels hrtimers which are not explicitly
@@ -2081,8 +2051,7 @@ static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
 			mode |= HRTIMER_MODE_HARD;
 	}
 
-	__hrtimer_init(&sl->timer, clock_id, mode);
-	sl->timer.function = hrtimer_wakeup;
+	__hrtimer_setup(&sl->timer, hrtimer_wakeup, clock_id, mode);
 	sl->task = current;
 }
 
@@ -2095,8 +2064,8 @@ static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
 void hrtimer_setup_sleeper_on_stack(struct hrtimer_sleeper *sl,
 				    clockid_t clock_id, enum hrtimer_mode mode)
 {
-	debug_init_on_stack(&sl->timer, clock_id, mode);
-	__hrtimer_init_sleeper(sl, clock_id, mode);
+	debug_setup_on_stack(&sl->timer, clock_id, mode);
+	__hrtimer_setup_sleeper(sl, clock_id, mode);
 }
 EXPORT_SYMBOL_GPL(hrtimer_setup_sleeper_on_stack);
 
diff --git a/kernel/time/sleep_timeout.c b/kernel/time/sleep_timeout.c
index dfe939f6e4ec..c0e960a5de39 100644
--- a/kernel/time/sleep_timeout.c
+++ b/kernel/time/sleep_timeout.c
@@ -97,7 +97,7 @@ signed long __sched schedule_timeout(signed long timeout)
 	timer.timer.expires = expire;
 	add_timer(&timer.timer);
 	schedule();
-	del_timer_sync(&timer.timer);
+	timer_delete_sync(&timer.timer);
 
 	/* Remove the timer from the object tracker */
 	destroy_timer_on_stack(&timer.timer);
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index c8f776dc6ee0..4d915c0a263c 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -744,7 +744,7 @@ static bool timer_fixup_init(void *addr, enum debug_obj_state state)
 
 	switch (state) {
 	case ODEBUG_STATE_ACTIVE:
-		del_timer_sync(timer);
+		timer_delete_sync(timer);
 		debug_object_init(timer, &timer_debug_descr);
 		return true;
 	default:
@@ -790,7 +790,7 @@ static bool timer_fixup_free(void *addr, enum debug_obj_state state)
 
 	switch (state) {
 	case ODEBUG_STATE_ACTIVE:
-		del_timer_sync(timer);
+		timer_delete_sync(timer);
 		debug_object_free(timer, &timer_debug_descr);
 		return true;
 	default:
@@ -1212,10 +1212,10 @@ EXPORT_SYMBOL(mod_timer_pending);
  *
  * mod_timer(timer, expires) is equivalent to:
  *
- *     del_timer(timer); timer->expires = expires; add_timer(timer);
+ *     timer_delete(timer); timer->expires = expires; add_timer(timer);
  *
  * mod_timer() is more efficient than the above open coded sequence. In
- * case that the timer is inactive, the del_timer() part is a NOP. The
+ * case that the timer is inactive, the timer_delete() part is a NOP. The
  * timer is in any case activated with the new expiry time @expires.
  *
  * Note that if there are multiple unserialized concurrent users of the
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index cfbb46cc4e76..b03d0ada6469 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -46,7 +46,7 @@ static void
 print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
 	    int idx, u64 now)
 {
-	SEQ_printf(m, " #%d: <%p>, %ps", idx, taddr, timer->function);
+	SEQ_printf(m, " #%d: <%p>, %ps", idx, taddr, ACCESS_PRIVATE(timer, function));
 	SEQ_printf(m, ", S:%02x", timer->state);
 	SEQ_printf(m, "\n");
 	SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",