hrtimer: Consolidate hrtimer_init() + hrtimer_init_sleeper() calls

hrtimer_init_sleeper() calls require prior initialisation of the hrtimer
object which is embedded into the hrtimer_sleeper.

Combine the initialization and spare a function call. Fixup all call sites.

This is also a preparatory change for PREEMPT_RT to do hrtimer sleeper
specific initializations of the embedded hrtimer without modifying any of
the call sites.

No functional change.

[ anna-maria: Minor cleanups ]
[ tglx: Adopted to the removal of the task argument of
  	hrtimer_init_sleeper() and trivial polishing.
	Folded a fix from Stephen Rothwell for the vsoc code ]

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190726185752.887468908@linutronix.de

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 5f647cb..df3fafb 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3415,10 +3415,9 @@ static bool blk_mq_poll_hybrid_sleep(struct request_queue *q,
 	kt = nsecs;
 
 	mode = HRTIMER_MODE_REL;
-	hrtimer_init_on_stack(&hs.timer, CLOCK_MONOTONIC, mode);
+	hrtimer_init_sleeper_on_stack(&hs, CLOCK_MONOTONIC, mode);
 	hrtimer_set_expires(&hs.timer, kt);
 
-	hrtimer_init_sleeper(&hs);
 	do {
 		if (blk_mq_rq_state(rq) == MQ_RQ_COMPLETE)
 			break;
diff --git a/drivers/staging/android/vsoc.c b/drivers/staging/android/vsoc.c
index ce480bc..2d6b398 100644
--- a/drivers/staging/android/vsoc.c
+++ b/drivers/staging/android/vsoc.c
@@ -437,12 +437,10 @@ static int handle_vsoc_cond_wait(struct file *filp, struct vsoc_cond_wait *arg)
 			return -EINVAL;
 		wake_time = ktime_set(arg->wake_time_sec, arg->wake_time_nsec);
 
-		hrtimer_init_on_stack(&to->timer, CLOCK_MONOTONIC,
-				      HRTIMER_MODE_ABS);
+		hrtimer_init_sleeper_on_stack(to, CLOCK_MONOTONIC,
+					      HRTIMER_MODE_ABS);
 		hrtimer_set_expires_range_ns(&to->timer, wake_time,
 					     current->timer_slack_ns);
-
-		hrtimer_init_sleeper(to);
 	}
 
 	while (1) {
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 3c74f89..0df373b 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -347,10 +347,15 @@ DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
 /* Initialize timers: */
 extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
 			 enum hrtimer_mode mode);
+extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id,
+				 enum hrtimer_mode mode);
 
 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
 extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,
 				  enum hrtimer_mode mode);
+extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
+					  clockid_t clock_id,
+					  enum hrtimer_mode mode);
 
 extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
 #else
@@ -360,6 +365,14 @@ static inline void hrtimer_init_on_stack(struct hrtimer *timer,
 {
 	hrtimer_init(timer, which_clock, mode);
 }
+
+static inline void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
+						 clockid_t clock_id,
+						 enum hrtimer_mode mode)
+{
+	hrtimer_init_sleeper(sl, clock_id, mode);
+}
+
 static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
 #endif
 
@@ -463,10 +476,8 @@ extern long hrtimer_nanosleep(const struct timespec64 *rqtp,
 			      const enum hrtimer_mode mode,
 			      const clockid_t clockid);
 
-extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl);
-
 extern int schedule_hrtimeout_range(ktime_t *expires, u64 delta,
-						const enum hrtimer_mode mode);
+				    const enum hrtimer_mode mode);
 extern int schedule_hrtimeout_range_clock(ktime_t *expires,
 					  u64 delta,
 					  const enum hrtimer_mode mode,
diff --git a/include/linux/wait.h b/include/linux/wait.h
index d578327..4707543 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -488,8 +488,8 @@ do {										\
 	int __ret = 0;								\
 	struct hrtimer_sleeper __t;						\
 										\
-	hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);	\
-	hrtimer_init_sleeper(&__t);						\
+	hrtimer_init_sleeper_on_stack(&__t, CLOCK_MONOTONIC,			\
+				      HRTIMER_MODE_REL);			\
 	if ((timeout) != KTIME_MAX)						\
 		hrtimer_start_range_ns(&__t.timer, timeout,			\
 				       current->timer_slack_ns,			\
diff --git a/kernel/futex.c b/kernel/futex.c
index 5e9842e..c8561aa 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -487,11 +487,9 @@ futex_setup_timer(ktime_t *time, struct hrtimer_sleeper *timeout,
 	if (!time)
 		return NULL;
 
-	hrtimer_init_on_stack(&timeout->timer, (flags & FLAGS_CLOCKRT) ?
-			      CLOCK_REALTIME : CLOCK_MONOTONIC,
-			      HRTIMER_MODE_ABS);
-	hrtimer_init_sleeper(timeout);
-
+	hrtimer_init_sleeper_on_stack(timeout, (flags & FLAGS_CLOCKRT) ?
+				      CLOCK_REALTIME : CLOCK_MONOTONIC,
+				      HRTIMER_MODE_ABS);
 	/*
 	 * If range_ns is 0, calling hrtimer_set_expires_range_ns() is
 	 * effectively the same as calling hrtimer_set_expires().
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index de895d8..bb55d62 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -427,6 +427,17 @@ void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id,
 }
 EXPORT_SYMBOL_GPL(hrtimer_init_on_stack);
 
+static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
+				   clockid_t clock_id, enum hrtimer_mode mode);
+
+void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
+				   clockid_t clock_id, enum hrtimer_mode mode)
+{
+	debug_object_init_on_stack(&sl->timer, &hrtimer_debug_descr);
+	__hrtimer_init_sleeper(sl, clock_id, mode);
+}
+EXPORT_SYMBOL_GPL(hrtimer_init_sleeper_on_stack);
+
 void destroy_hrtimer_on_stack(struct hrtimer *timer)
 {
 	debug_object_free(timer, &hrtimer_debug_descr);
@@ -1639,11 +1650,27 @@ static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer)
 	return HRTIMER_NORESTART;
 }
 
-void hrtimer_init_sleeper(struct hrtimer_sleeper *sl)
+static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
+				   clockid_t clock_id, enum hrtimer_mode mode)
 {
+	__hrtimer_init(&sl->timer, clock_id, mode);
 	sl->timer.function = hrtimer_wakeup;
 	sl->task = current;
 }
+
+/**
+ * hrtimer_init_sleeper - initialize sleeper to the given clock
+ * @sl:		sleeper to be initialized
+ * @clock_id:	the clock to be used
+ * @mode:	timer mode abs/rel
+ */
+void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id,
+			  enum hrtimer_mode mode)
+{
+	debug_init(&sl->timer, clock_id, mode);
+	__hrtimer_init_sleeper(sl, clock_id, mode);
+
+}
 EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
 
 int nanosleep_copyout(struct restart_block *restart, struct timespec64 *ts)
@@ -1669,8 +1696,6 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod
 {
 	struct restart_block *restart;
 
-	hrtimer_init_sleeper(t);
-
 	do {
 		set_current_state(TASK_INTERRUPTIBLE);
 		hrtimer_start_expires(&t->timer, mode);
@@ -1707,10 +1732,9 @@ static long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
 	struct hrtimer_sleeper t;
 	int ret;
 
-	hrtimer_init_on_stack(&t.timer, restart->nanosleep.clockid,
-				HRTIMER_MODE_ABS);
+	hrtimer_init_sleeper_on_stack(&t, restart->nanosleep.clockid,
+				      HRTIMER_MODE_ABS);
 	hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
-
 	ret = do_nanosleep(&t, HRTIMER_MODE_ABS);
 	destroy_hrtimer_on_stack(&t.timer);
 	return ret;
@@ -1728,7 +1752,7 @@ long hrtimer_nanosleep(const struct timespec64 *rqtp,
 	if (dl_task(current) || rt_task(current))
 		slack = 0;
 
-	hrtimer_init_on_stack(&t.timer, clockid, mode);
+	hrtimer_init_sleeper_on_stack(&t, clockid, mode);
 	hrtimer_set_expires_range_ns(&t.timer, timespec64_to_ktime(*rqtp), slack);
 	ret = do_nanosleep(&t, mode);
 	if (ret != -ERESTART_RESTARTBLOCK)
@@ -1927,11 +1951,8 @@ schedule_hrtimeout_range_clock(ktime_t *expires, u64 delta,
 		return -EINTR;
 	}
 
-	hrtimer_init_on_stack(&t.timer, clock_id, mode);
+	hrtimer_init_sleeper_on_stack(&t, clock_id, mode);
 	hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
-
-	hrtimer_init_sleeper(&t);
-
 	hrtimer_start_expires(&t.timer, mode);
 
 	if (likely(t.task))
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 7f3cf23..a590597 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2156,7 +2156,7 @@ static void spin(struct pktgen_dev *pkt_dev, ktime_t spin_until)
 	s64 remaining;
 	struct hrtimer_sleeper t;
 
-	hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+	hrtimer_init_sleeper_on_stack(&t, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 	hrtimer_set_expires(&t.timer, spin_until);
 
 	remaining = ktime_to_ns(hrtimer_expires_remaining(&t.timer));
@@ -2170,8 +2170,6 @@ static void spin(struct pktgen_dev *pkt_dev, ktime_t spin_until)
 			end_time = ktime_get();
 		} while (ktime_compare(end_time, spin_until) < 0);
 	} else {
-		/* see do_nanosleep */
-		hrtimer_init_sleeper(&t);
 		do {
 			set_current_state(TASK_INTERRUPTIBLE);
 			hrtimer_start_expires(&t.timer, HRTIMER_MODE_ABS);