Using guard/scoped_guard() to simplify code. Using guard() to remove
'goto unlock' label is neater especially.

[ tglx: Brought back the scoped_guard()'s which were dropped in v2 and
  	simplified alarmtimer_rtc_add_device() ]

Signed-off-by: Su Hui <suhui@nfschina.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/all/20250430032734.2079290-4-suhui@nfschina.com

'clockid' can only be ALARM_REALTIME and ALARM_BOOTTIME. It's impossible to
return -1 and callers never check the return value.

Only alarm_clock_get_timespec(), alarm_clock_get_ktime(),
alarm_timer_create() and alarm_timer_nsleep() call clock2alarm(). These
callers use clockid_to_kclock() to get 'struct k_clock', which ensures
that clock2alarm() never returns -1.

Remove the impossible -1 return value, and add a warning to notify about any
future misuse of this function.

Signed-off-by: Su Hui <suhui@nfschina.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250430032734.2079290-3-suhui@nfschina.com

hrtimer_setup() and hrtimer_setup_on_stack() take the callback function
pointer as argument and initialize the timer completely.

Replace the hrtimer_init*() variants and the open coded initialization of
hrtimer::function with the new setup mechanism.

Switch to use the new functions.

Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/2bae912336103405adcdab96b88d3ea0353b4228.1730386209.git.namcao@linutronix.de

Now that the SIG_IGN problem is solved in the core code, the alarmtimer
callbacks do not require a return value anymore.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241105064214.318837272@linutronix.de

Now that ignored posix timer signals are requeued and the timers are
rearmed on signal delivery the workaround to keep such timers alive and
self rearm them is not longer required.

Remove the unused alarm timer parts.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20241105064214.252443020@linutronix.de

Now that ignored posix timer signals are requeued and the timers are
rearmed on signal delivery the workaround to keep such timers alive and
self rearm them is not longer required.

Remove the relevant hacks and the not longer required return values from
the related functions. The alarm timer workarounds will be cleaned up in a
separate step.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20241105064214.187239060@linutronix.de

Right now the state tracking is done by two struct members:

 - it_active:
     A boolean which tracks armed/disarmed state

 - it_signal_seq:
     A sequence counter which is used to invalidate settings
     and prevent rearming

Replace it_active with it_status and keep properly track about the states
in one place.

This allows to reuse it_signal_seq to track reprogramming, disarm and
delete operations in order to drop signals which are related to the state
previous of those operations.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20241001083835.670337048@linutronix.de

Prepare for using this struct member to do a proper reprogramming and
deletion accounting so that stale signals can be dropped.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20241001083835.611997737@linutronix.de

There are several comments all over the place, which uses a wrong singular
form of jiffies.

Replace 'jiffie' by 'jiffy'. No functional change.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Link: https://lore.kernel.org/all/20240904-devel-anna-maria-b4-timers-flseep-v1-3-e98760256370@linutronix.de

Rename posix_timer_event() to posix_timer_queue_signal() as this is what
the function is about.

Consolidate the requeue pending and deactivation updates into that function
as there is no point in doing this in all incarnations of posix timers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>