posix-cpu-timers: Replace old expiry retrieval in posix_cpu_timer_set()

Reuse the split out __posix_cpu_timer_get() function which does already the
right thing.

No functional change.

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

diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index cf8904423cba3c0653e84d954ca1c46a35fb02c4..040d5c36184e64f0275498d08fd027cfd7084825 100644 (file)
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -614,6 +614,8 @@ static void cpu_timer_fire(struct k_itimer *timer)
        }
 }
 
+static void __posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec64 *itp, u64 now);
+
 /*
  * Guts of sys_timer_settime for CPU timers.
  * This is called with the timer locked and interrupts disabled.
@@ -623,7 +625,6 @@ static void cpu_timer_fire(struct k_itimer *timer)
 static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
                               struct itimerspec64 *new, struct itimerspec64 *old)
 {
-       bool sigev_none = timer->it_sigev_notify == SIGEV_NONE;
        clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
        u64 old_expires, new_expires, old_incr, val;
        struct cpu_timer *ctmr = &timer->it.cpu;
@@ -689,37 +690,11 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
        else
                val = cpu_clock_sample_group(clkid, p, true);
 
+       /* Retrieve the previous expiry value if requested. */
        if (old) {
-               if (old_expires == 0) {
-                       old->it_value.tv_sec = 0;
-                       old->it_value.tv_nsec = 0;
-               } else {
-                       /*
-                        * Update the timer in case it has overrun already.
-                        * If it has, we'll report it as having overrun and
-                        * with the next reloaded timer already ticking,
-                        * though we are swallowing that pending
-                        * notification here to install the new setting.
-                        */
-                       u64 exp = bump_cpu_timer(timer, val);
-
-                       if (val < exp) {
-                               old_expires = exp - val;
-                               old->it_value = ns_to_timespec64(old_expires);
-                       } else {
-                               /*
-                                * A single shot SIGEV_NONE timer must return 0, when it is
-                                * expired! Timers which have a real signal delivery mode
-                                * must return a remaining time greater than 0 because the
-                                * signal has not yet been delivered.
-                                */
-                               if (sigev_none)
-                                       old->it_value.tv_nsec = 0;
-                               else
-                                       old->it_value.tv_nsec = 1;
-                               old->it_value.tv_sec = 0;
-                       }
-               }
+               old->it_value = (struct timespec64){ };
+               if (old_expires)
+                       __posix_cpu_timer_get(timer, old, val);
        }
 
        if (unlikely(ret)) {