hrtimer: Convert state and properties to boolean

All 'u8' flags are true booleans, so make it entirely clear that these can
only contain true or false.

This is especially true for hrtimer::state, which has a historical leftover
of using the state with bitwise operations. That was used in the early
hrtimer implementation with several bits, but then converted to a boolean
state. But that conversion missed to replace the bit OR and bit check
operations all over the place, which creates suboptimal code. As of today
'state' is a misnomer because it's only purpose is to reflect whether the
timer is enqueued into the RB-tree or not. Rename it to 'is_queued' and
make all operations on it boolean.

This reduces text size from 8926 to 8732 bytes.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260224163430.542427240@kernel.org

2 files changed, 8 insertions, 35 deletions

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index c924bb2498db..4ad4a454b4c5 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -63,33 +63,6 @@ enum hrtimer_mode {
 	HRTIMER_MODE_REL_PINNED_HARD = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_HARD,
 };
 
-/*
- * Values to track state of the timer
- *
- * Possible states:
- *
- * 0x00		inactive
- * 0x01		enqueued into rbtree
- *
- * The callback state is not part of the timer->state because clearing it would
- * mean touching the timer after the callback, this makes it impossible to free
- * the timer from the callback function.
- *
- * Therefore we track the callback state in:
- *
- *	timer->base->cpu_base->running == timer
- *
- * On SMP it is possible to have a "callback function running and enqueued"
- * status. It happens for example when a posix timer expired and the callback
- * queued a signal. Between dropping the lock which protects the posix timer
- * and reacquiring the base lock of the hrtimer, another CPU can deliver the
- * signal and rearm the timer.
- *
- * All state transitions are protected by cpu_base->lock.
- */
-#define HRTIMER_STATE_INACTIVE	0x00
-#define HRTIMER_STATE_ENQUEUED	0x01
-
 /**
  * struct hrtimer_sleeper - simple sleeper structure
  * @timer:	embedded timer structure
@@ -300,8 +273,8 @@ extern bool hrtimer_active(const struct hrtimer *timer);
  */
 static inline bool hrtimer_is_queued(struct hrtimer *timer)
 {
-	/* The READ_ONCE pairs with the update functions of timer->state */
-	return !!(READ_ONCE(timer->state) & HRTIMER_STATE_ENQUEUED);
+	/* The READ_ONCE pairs with the update functions of timer->is_queued */
+	return READ_ONCE(timer->is_queued);
 }
 
 /*
diff --git a/include/linux/hrtimer_types.h b/include/linux/hrtimer_types.h
index 64381c64cdbd..0e22bc91d00f 100644
--- a/include/linux/hrtimer_types.h
+++ b/include/linux/hrtimer_types.h
@@ -28,7 +28,7 @@ enum hrtimer_restart {
  *		was armed.
  * @function:	timer expiry callback function
  * @base:	pointer to the timer base (per cpu and per clock)
- * @state:	state information (See bit values above)
+ * @is_queued:	Indicates whether a timer is enqueued or not
  * @is_rel:	Set if the timer was armed relative
  * @is_soft:	Set if hrtimer will be expired in soft interrupt context.
  * @is_hard:	Set if hrtimer will be expired in hard interrupt context
@@ -43,11 +43,11 @@ struct hrtimer {
 	ktime_t				_softexpires;
 	enum hrtimer_restart		(*__private function)(struct hrtimer *);
 	struct hrtimer_clock_base	*base;
-	u8				state;
-	u8				is_rel;
-	u8				is_soft;
-	u8				is_hard;
-	u8				is_lazy;
+	bool				is_queued;
+	bool				is_rel;
+	bool				is_soft;
+	bool				is_hard;
+	bool				is_lazy;
 };
 
 #endif /* _LINUX_HRTIMER_TYPES_H */