Merge tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer cleanups from Thomas Gleixner:
 "A treewide hrtimer timer cleanup

  hrtimers are initialized with hrtimer_init() and a subsequent store to
  the callback pointer. This turned out to be suboptimal for the
  upcoming Rust integration and is obviously a silly implementation to
  begin with.

  This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
  with hrtimer_setup(T, cb);

  The conversion was done with Coccinelle and a few manual fixups.

  Once the conversion has completely landed in mainline, hrtimer_init()
  will be removed and the hrtimer::function becomes a private member"

* tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits)
  wifi: rt2x00: Switch to use hrtimer_update_function()
  io_uring: Use helper function hrtimer_update_function()
  serial: xilinx_uartps: Use helper function hrtimer_update_function()
  ASoC: fsl: imx-pcm-fiq: Switch to use hrtimer_setup()
  RDMA: Switch to use hrtimer_setup()
  virtio: mem: Switch to use hrtimer_setup()
  drm/vmwgfx: Switch to use hrtimer_setup()
  drm/xe/oa: Switch to use hrtimer_setup()
  drm/vkms: Switch to use hrtimer_setup()
  drm/msm: Switch to use hrtimer_setup()
  drm/i915/request: Switch to use hrtimer_setup()
  drm/i915/uncore: Switch to use hrtimer_setup()
  drm/i915/pmu: Switch to use hrtimer_setup()
  drm/i915/perf: Switch to use hrtimer_setup()
  drm/i915/gvt: Switch to use hrtimer_setup()
  drm/i915/huc: Switch to use hrtimer_setup()
  drm/amdgpu: Switch to use hrtimer_setup()
  stm class: heartbeat: Switch to use hrtimer_setup()
  i2c: Switch to use hrtimer_setup()
  iio: Switch to use hrtimer_setup()
  ...

15 files changed, 25 insertions, 46 deletions

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index f27ce162427ab..672abe1112824 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -1284,8 +1284,7 @@ static int __bpf_async_init(struct bpf_async_kern *async, struct bpf_map *map, u
 
 		atomic_set(&t->cancelling, 0);
 		INIT_WORK(&t->cb.delete_work, bpf_timer_delete_work);
-		hrtimer_init(&t->timer, clockid, HRTIMER_MODE_REL_SOFT);
-		t->timer.function = bpf_timer_cb;
+		hrtimer_setup(&t->timer, bpf_timer_cb, clockid, HRTIMER_MODE_REL_SOFT);
 		cb->value = (void *)async - map->record->timer_off;
 		break;
 	case BPF_ASYNC_TYPE_WQ:
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 4ce9795e5519e..5d2221ec6d7c0 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1193,8 +1193,8 @@ static void __perf_mux_hrtimer_init(struct perf_cpu_pmu_context *cpc, int cpu)
 	cpc->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval);
 
 	raw_spin_lock_init(&cpc->hrtimer_lock);
-	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD);
-	timer->function = perf_mux_hrtimer_handler;
+	hrtimer_setup(timer, perf_mux_hrtimer_handler, CLOCK_MONOTONIC,
+		      HRTIMER_MODE_ABS_PINNED_HARD);
 }
 
 static int perf_mux_hrtimer_restart(struct perf_cpu_pmu_context *cpc)
@@ -11679,8 +11679,7 @@ static void perf_swevent_init_hrtimer(struct perf_event *event)
 	if (!is_sampling_event(event))
 		return;
 
-	hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
-	hwc->hrtimer.function = perf_swevent_hrtimer;
+	hrtimer_setup(&hwc->hrtimer, perf_swevent_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 
 	/*
 	 * Since hrtimers have a fixed rate, we can do a static freq->period
diff --git a/kernel/fork.c b/kernel/fork.c
index f11ac96b75876..a61a4407ebdf2 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1891,8 +1891,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 #ifdef CONFIG_POSIX_TIMERS
 	INIT_HLIST_HEAD(&sig->posix_timers);
 	INIT_HLIST_HEAD(&sig->ignored_posix_timers);
-	hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-	sig->real_timer.function = it_real_fn;
+	hrtimer_setup(&sig->real_timer, it_real_fn, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 #endif
 
 	task_lock(current->group_leader);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5bd8d7e7347d1..87540217fc098 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -912,8 +912,7 @@ static void hrtick_rq_init(struct rq *rq)
 #ifdef CONFIG_SMP
 	INIT_CSD(&rq->hrtick_csd, __hrtick_start, rq);
 #endif
-	hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
-	rq->hrtick_timer.function = hrtick;
+	hrtimer_setup(&rq->hrtick_timer, hrtick, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 }
 #else	/* CONFIG_SCHED_HRTICK */
 static inline void hrtick_clear(struct rq *rq)
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 03a33b5977685..ad45a8fea245e 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1382,8 +1382,7 @@ static void init_dl_task_timer(struct sched_dl_entity *dl_se)
 {
 	struct hrtimer *timer = &dl_se->dl_timer;
 
-	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
-	timer->function = dl_task_timer;
+	hrtimer_setup(timer, dl_task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 }
 
 /*
@@ -1839,8 +1838,7 @@ static void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se)
 {
 	struct hrtimer *timer = &dl_se->inactive_timer;
 
-	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
-	timer->function = inactive_task_timer;
+	hrtimer_setup(timer, inactive_task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 }
 
 #define __node_2_dle(node) \
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index a0c4cd26ee078..e43993a4e5807 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6552,14 +6552,14 @@ void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b, struct cfs_bandwidth *paren
 	cfs_b->hierarchical_quota = parent ? parent->hierarchical_quota : RUNTIME_INF;
 
 	INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq);
-	hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
-	cfs_b->period_timer.function = sched_cfs_period_timer;
+	hrtimer_setup(&cfs_b->period_timer, sched_cfs_period_timer, CLOCK_MONOTONIC,
+		      HRTIMER_MODE_ABS_PINNED);
 
 	/* Add a random offset so that timers interleave */
 	hrtimer_set_expires(&cfs_b->period_timer,
 			    get_random_u32_below(cfs_b->period));
-	hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-	cfs_b->slack_timer.function = sched_cfs_slack_timer;
+	hrtimer_setup(&cfs_b->slack_timer, sched_cfs_slack_timer, CLOCK_MONOTONIC,
+		      HRTIMER_MODE_REL);
 	cfs_b->slack_started = false;
 }
 
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index a4774155ae121..fa03ec3ed56a2 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -127,9 +127,8 @@ void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
 
 	raw_spin_lock_init(&rt_b->rt_runtime_lock);
 
-	hrtimer_init(&rt_b->rt_period_timer, CLOCK_MONOTONIC,
-		     HRTIMER_MODE_REL_HARD);
-	rt_b->rt_period_timer.function = sched_rt_period_timer;
+	hrtimer_setup(&rt_b->rt_period_timer, sched_rt_period_timer, CLOCK_MONOTONIC,
+		      HRTIMER_MODE_REL_HARD);
 }
 
 static inline void do_start_rt_bandwidth(struct rt_bandwidth *rt_b)
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 453dc76c93484..22376a1a75b9f 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1592,11 +1592,6 @@ static inline int hrtimer_clockid_to_base(clockid_t clock_id)
 	}
 }
 
-static enum hrtimer_restart hrtimer_dummy_timeout(struct hrtimer *unused)
-{
-	return HRTIMER_NORESTART;
-}
-
 static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
 			   enum hrtimer_mode mode)
 {
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 163e7a2033b62..b837d3d9d3253 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -678,8 +678,7 @@ void ntp_notify_cmos_timer(bool offset_set)
 
 static void __init ntp_init_cmos_sync(void)
 {
-	hrtimer_init(&sync_hrtimer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
-	sync_hrtimer.function = sync_timer_callback;
+	hrtimer_setup(&sync_hrtimer, sync_timer_callback, CLOCK_REALTIME, HRTIMER_MODE_ABS);
 }
 #else /* CONFIG_GENERIC_CMOS_UPDATE) || defined(CONFIG_RTC_SYSTOHC) */
 static inline void __init ntp_init_cmos_sync(void) { }
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index bc0bdf40eb505..6222112533a7b 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -466,7 +466,7 @@ static void posix_timer_unhash_and_free(struct k_itimer *tmr)
 
 static int common_timer_create(struct k_itimer *new_timer)
 {
-	hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
+	hrtimer_setup(&new_timer->it.real.timer, posix_timer_fn, new_timer->it_clock, 0);
 	return 0;
 }
 
@@ -821,7 +821,7 @@ static void common_hrtimer_arm(struct k_itimer *timr, ktime_t expires,
 	/*
 	 * Posix magic: Relative CLOCK_REALTIME timers are not affected by
 	 * clock modifications, so they become CLOCK_MONOTONIC based under the
-	 * hood. See hrtimer_init(). Update timr->kclock, so the generic
+	 * hood. See hrtimer_setup(). Update timr->kclock, so the generic
 	 * functions which use timr->kclock->clock_get_*() work.
 	 *
 	 * Note: it_clock stays unmodified, because the next timer_set() might
@@ -830,8 +830,7 @@ static void common_hrtimer_arm(struct k_itimer *timr, ktime_t expires,
 	if (timr->it_clock == CLOCK_REALTIME)
 		timr->kclock = absolute ? &clock_realtime : &clock_monotonic;
 
-	hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
-	timr->it.real.timer.function = posix_timer_fn;
+	hrtimer_setup(&timr->it.real.timer, posix_timer_fn, timr->it_clock, mode);
 
 	if (!absolute)
 		expires = ktime_add_safe(expires, timer->base->get_time());
diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index fcca4e72f1efa..cc15fe293719f 100644
--- a/kernel/time/sched_clock.c
+++ b/kernel/time/sched_clock.c
@@ -263,8 +263,7 @@ void __init generic_sched_clock_init(void)
 	 * Start the timer to keep sched_clock() properly updated and
 	 * sets the initial epoch.
 	 */
-	hrtimer_init(&sched_clock_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
-	sched_clock_timer.function = sched_clock_poll;
+	hrtimer_setup(&sched_clock_timer, sched_clock_poll, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 	hrtimer_start(&sched_clock_timer, cd.wrap_kt, HRTIMER_MODE_REL_HARD);
 }
 
diff --git a/kernel/time/tick-broadcast-hrtimer.c b/kernel/time/tick-broadcast-hrtimer.c
index e28f9210f8a15..a88b72b0f35ee 100644
--- a/kernel/time/tick-broadcast-hrtimer.c
+++ b/kernel/time/tick-broadcast-hrtimer.c
@@ -100,7 +100,6 @@ static enum hrtimer_restart bc_handler(struct hrtimer *t)
 
 void tick_setup_hrtimer_broadcast(void)
 {
-	hrtimer_init(&bctimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
-	bctimer.function = bc_handler;
+	hrtimer_setup(&bctimer, bc_handler, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 	clockevents_register_device(&ce_broadcast_hrtimer);
 }
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index fa058510af9c1..c527b421c8652 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -1573,12 +1573,10 @@ void tick_setup_sched_timer(bool hrtimer)
 	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 
 	/* Emulate tick processing via per-CPU hrtimers: */
-	hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
+	hrtimer_setup(&ts->sched_timer, tick_nohz_handler, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 
-	if (IS_ENABLED(CONFIG_HIGH_RES_TIMERS) && hrtimer) {
+	if (IS_ENABLED(CONFIG_HIGH_RES_TIMERS) && hrtimer)
 		tick_sched_flag_set(ts, TS_FLAG_HIGHRES);
-		ts->sched_timer.function = tick_nohz_handler;
-	}
 
 	/* Get the next period (per-CPU) */
 	hrtimer_set_expires(&ts->sched_timer, tick_init_jiffy_update());
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 512034e365ad2..92e16f03fa4ef 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -1899,8 +1899,7 @@ static int timerlat_main(void *data)
 	tlat->count = 0;
 	tlat->tracing_thread = false;
 
-	hrtimer_init(&tlat->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD);
-	tlat->timer.function = timerlat_irq;
+	hrtimer_setup(&tlat->timer, timerlat_irq, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD);
 	tlat->kthread = current;
 	osn_var->pid = current->pid;
 	/*
@@ -2454,8 +2453,7 @@ static int timerlat_fd_open(struct inode *inode, struct file *file)
 	tlat = this_cpu_tmr_var();
 	tlat->count = 0;
 
-	hrtimer_init(&tlat->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD);
-	tlat->timer.function = timerlat_irq;
+	hrtimer_setup(&tlat->timer, timerlat_irq, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD);
 
 	migrate_enable();
 	return 0;
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 18156023e4614..9fa2af9dbf2ce 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -795,8 +795,7 @@ static void watchdog_enable(unsigned int cpu)
 	 * Start the timer first to prevent the hardlockup watchdog triggering
 	 * before the timer has a chance to fire.
 	 */
-	hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
-	hrtimer->function = watchdog_timer_fn;
+	hrtimer_setup(hrtimer, watchdog_timer_fn, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 	hrtimer_start(hrtimer, ns_to_ktime(sample_period),
 		      HRTIMER_MODE_REL_PINNED_HARD);