DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
{
+ .lock = __RAW_SPIN_LOCK_UNLOCKED(hrtimer_bases.lock),
.clock_base =
{
{
goto again;
}
timer->base = new_base;
+ } else {
+ if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) {
+ cpu = this_cpu;
+ goto again;
+ }
}
return new_base;
}
} else {
unsigned long rem = do_div(nsec, NSEC_PER_SEC);
+ /* Make sure nsec fits into long */
+ if (unlikely(nsec > KTIME_SEC_MAX))
+ return (ktime_t){ .tv64 = KTIME_MAX };
+
tmp = ktime_set((long)nsec, rem);
}
cpu_base->expires_next.tv64 = expires_next.tv64;
+ /*
+ * If a hang was detected in the last timer interrupt then we
+ * leave the hang delay active in the hardware. We want the
+ * system to make progress. That also prevents the following
+ * scenario:
+ * T1 expires 50ms from now
+ * T2 expires 5s from now
+ *
+ * T1 is removed, so this code is called and would reprogram
+ * the hardware to 5s from now. Any hrtimer_start after that
+ * will not reprogram the hardware due to hang_detected being
+ * set. So we'd effectivly block all timers until the T2 event
+ * fires.
+ */
+ if (cpu_base->hang_detected)
+ return;
+
if (cpu_base->expires_next.tv64 != KTIME_MAX)
tick_program_event(cpu_base->expires_next, 1);
}
* and expiry check is done in the hrtimer_interrupt or in the softirq.
*/
static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
- struct hrtimer_clock_base *base,
- int wakeup)
+ struct hrtimer_clock_base *base)
{
- if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) {
- if (wakeup) {
- raw_spin_unlock(&base->cpu_base->lock);
- raise_softirq_irqoff(HRTIMER_SOFTIRQ);
- raw_spin_lock(&base->cpu_base->lock);
- } else
- __raise_softirq_irqoff(HRTIMER_SOFTIRQ);
-
- return 1;
- }
-
- return 0;
+ return base->cpu_base->hres_active && hrtimer_reprogram(timer, base);
}
static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
static inline void
hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
- struct hrtimer_clock_base *base,
- int wakeup)
+ struct hrtimer_clock_base *base)
{
return 0;
}
if (delta.tv64 < 0)
return 0;
+ if (WARN_ON(timer->state & HRTIMER_STATE_ENQUEUED))
+ return 0;
+
if (interval.tv64 < timer->base->resolution.tv64)
interval.tv64 = timer->base->resolution.tv64;
*/
static void __remove_hrtimer(struct hrtimer *timer,
struct hrtimer_clock_base *base,
- unsigned long newstate, int reprogram)
+ u8 newstate, int reprogram)
{
struct timerqueue_node *next_timer;
if (!(timer->state & HRTIMER_STATE_ENQUEUED))
remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
{
if (hrtimer_is_queued(timer)) {
- unsigned long state;
+ u8 state;
int reprogram;
/*
return 0;
}
+static inline ktime_t hrtimer_update_lowres(struct hrtimer *timer, ktime_t tim,
+ const enum hrtimer_mode mode)
+{
+#ifdef CONFIG_TIME_LOW_RES
+ /*
+ * CONFIG_TIME_LOW_RES indicates that the system has no way to return
+ * granular time values. For relative timers we add KTIME_LOW_RES
+ * (i.e. one jiffie) to prevent short timeouts.
+ */
+ timer->is_rel = mode & HRTIMER_MODE_REL;
+ if (timer->is_rel)
+ tim = ktime_add_safe(tim, KTIME_LOW_RES);
+#endif
+ return tim;
+}
+
int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
unsigned long delta_ns, const enum hrtimer_mode mode,
int wakeup)
/* Remove an active timer from the queue: */
ret = remove_hrtimer(timer, base);
- /* Switch the timer base, if necessary: */
- new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
+ if (mode & HRTIMER_MODE_REL)
+ tim = ktime_add_safe(tim, base->get_time());
- if (mode & HRTIMER_MODE_REL) {
- tim = ktime_add_safe(tim, new_base->get_time());
- /*
- * CONFIG_TIME_LOW_RES is a temporary way for architectures
- * to signal that they simply return xtime in
- * do_gettimeoffset(). In this case we want to round up by
- * resolution when starting a relative timer, to avoid short
- * timeouts. This will go away with the GTOD framework.
- */
-#ifdef CONFIG_TIME_LOW_RES
- tim = ktime_add_safe(tim, base->resolution);
-#endif
- }
+ tim = hrtimer_update_lowres(timer, tim, mode);
hrtimer_set_expires_range_ns(timer, tim, delta_ns);
+ /* Switch the timer base, if necessary: */
+ new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
+
timer_stats_hrtimer_set_start_info(timer);
leftmost = enqueue_hrtimer(timer, new_base);
*
* XXX send_remote_softirq() ?
*/
- if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases))
- hrtimer_enqueue_reprogram(timer, new_base, wakeup);
+ if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases)
+ && hrtimer_enqueue_reprogram(timer, new_base)) {
+ if (wakeup) {
+ /*
+ * We need to drop cpu_base->lock to avoid a
+ * lock ordering issue vs. rq->lock.
+ */
+ raw_spin_unlock(&new_base->cpu_base->lock);
+ raise_softirq_irqoff(HRTIMER_SOFTIRQ);
+ local_irq_restore(flags);
+ return ret;
+ } else {
+ __raise_softirq_irqoff(HRTIMER_SOFTIRQ);
+ }
+ }
unlock_hrtimer_base(timer, &flags);
/**
* hrtimer_get_remaining - get remaining time for the timer
* @timer: the timer to read
+ * @adjust: adjust relative timers when CONFIG_TIME_LOW_RES=y
*/
-ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
+ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust)
{
unsigned long flags;
ktime_t rem;
lock_hrtimer_base(timer, &flags);
- rem = hrtimer_expires_remaining(timer);
+#ifdef CONFIG_TIME_LOW_RES
+ if (adjust)
+ rem = hrtimer_expires_remaining_adjusted(timer);
+ else
+#endif
+ rem = hrtimer_expires_remaining(timer);
unlock_hrtimer_base(timer, &flags);
return rem;
}
-EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
+EXPORT_SYMBOL_GPL(__hrtimer_get_remaining);
#ifdef CONFIG_NO_HZ
/**
timer_stats_account_hrtimer(timer);
fn = timer->function;
+ /*
+ * Clear the 'is relative' flag for the TIME_LOW_RES case. If the
+ * timer is restarted with a period then it becomes an absolute
+ * timer. If its not restarted it does not matter.
+ */
+#ifdef CONFIG_TIME_LOW_RES
+ timer->is_rel = false;
+#endif
+
/*
* Because we run timers from hardirq context, there is no chance
* they get migrated to another cpu, therefore its safe to unlock
* Note: We clear the CALLBACK bit after enqueue_hrtimer and
* we do not reprogramm the event hardware. Happens either in
* hrtimer_start_range_ns() or in hrtimer_interrupt()
+ *
+ * Note: Because we dropped the cpu_base->lock above,
+ * hrtimer_start_range_ns() can have popped in and enqueued the timer
+ * for us already.
*/
- if (restart != HRTIMER_NORESTART) {
- BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
+ if (restart != HRTIMER_NORESTART &&
+ !(timer->state & HRTIMER_STATE_ENQUEUED))
enqueue_hrtimer(timer, base);
- }
WARN_ON_ONCE(!(timer->state & HRTIMER_STATE_CALLBACK));
expires = ktime_sub(hrtimer_get_expires(timer),
base->offset);
+ if (expires.tv64 < 0)
+ expires.tv64 = KTIME_MAX;
if (expires.tv64 < expires_next.tv64)
expires_next = expires;
break;
struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
int i;
- raw_spin_lock_init(&cpu_base->lock);
-
for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
cpu_base->clock_base[i].cpu_base = cpu_base;
timerqueue_init_head(&cpu_base->clock_base[i].active);