diff options
Diffstat (limited to 'kernel/time/tick-broadcast.c')
| -rw-r--r-- | kernel/time/tick-broadcast.c | 97 |
1 files changed, 43 insertions, 54 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 7e8ca4f448a8..d39f32cdd1b5 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -255,18 +255,18 @@ int tick_receive_broadcast(void) /* * Broadcast the event to the cpus, which are set in the mask (mangled). */ -static void tick_do_broadcast(struct cpumask *mask) +static bool tick_do_broadcast(struct cpumask *mask) { int cpu = smp_processor_id(); struct tick_device *td; + bool local = false; /* * Check, if the current cpu is in the mask */ if (cpumask_test_cpu(cpu, mask)) { cpumask_clear_cpu(cpu, mask); - td = &per_cpu(tick_cpu_device, cpu); - td->evtdev->event_handler(td->evtdev); + local = true; } if (!cpumask_empty(mask)) { @@ -279,16 +279,17 @@ static void tick_do_broadcast(struct cpumask *mask) td = &per_cpu(tick_cpu_device, cpumask_first(mask)); td->evtdev->broadcast(mask); } + return local; } /* * Periodic broadcast: * - invoke the broadcast handlers */ -static void tick_do_periodic_broadcast(void) +static bool tick_do_periodic_broadcast(void) { cpumask_and(tmpmask, cpu_online_mask, tick_broadcast_mask); - tick_do_broadcast(tmpmask); + return tick_do_broadcast(tmpmask); } /* @@ -296,34 +297,26 @@ static void tick_do_periodic_broadcast(void) */ static void tick_handle_periodic_broadcast(struct clock_event_device *dev) { - ktime_t next; + struct tick_device *td = this_cpu_ptr(&tick_cpu_device); + bool bc_local; raw_spin_lock(&tick_broadcast_lock); + bc_local = tick_do_periodic_broadcast(); - tick_do_periodic_broadcast(); + if (clockevent_state_oneshot(dev)) { + ktime_t next = ktime_add(dev->next_event, tick_period); - /* - * The device is in periodic mode. No reprogramming necessary: - */ - if (dev->state == CLOCK_EVT_STATE_PERIODIC) - goto unlock; + clockevents_program_event(dev, next, true); + } + raw_spin_unlock(&tick_broadcast_lock); /* - * Setup the next period for devices, which do not have - * periodic mode. We read dev->next_event first and add to it - * when the event already expired. clockevents_program_event() - * sets dev->next_event only when the event is really - * programmed to the device. + * We run the handler of the local cpu after dropping + * tick_broadcast_lock because the handler might deadlock when + * trying to switch to oneshot mode. */ - for (next = dev->next_event; ;) { - next = ktime_add(next, tick_period); - - if (!clockevents_program_event(dev, next, false)) - goto unlock; - tick_do_periodic_broadcast(); - } -unlock: - raw_spin_unlock(&tick_broadcast_lock); + if (bc_local) + td->evtdev->event_handler(td->evtdev); } /** @@ -532,23 +525,19 @@ static void tick_broadcast_set_affinity(struct clock_event_device *bc, irq_set_affinity(bc->irq, bc->cpumask); } -static int tick_broadcast_set_event(struct clock_event_device *bc, int cpu, - ktime_t expires, int force) +static void tick_broadcast_set_event(struct clock_event_device *bc, int cpu, + ktime_t expires) { - int ret; - - if (bc->state != CLOCK_EVT_STATE_ONESHOT) - clockevents_set_state(bc, CLOCK_EVT_STATE_ONESHOT); + if (!clockevent_state_oneshot(bc)) + clockevents_switch_state(bc, CLOCK_EVT_STATE_ONESHOT); - ret = clockevents_program_event(bc, expires, force); - if (!ret) - tick_broadcast_set_affinity(bc, cpumask_of(cpu)); - return ret; + clockevents_program_event(bc, expires, 1); + tick_broadcast_set_affinity(bc, cpumask_of(cpu)); } static void tick_resume_broadcast_oneshot(struct clock_event_device *bc) { - clockevents_set_state(bc, CLOCK_EVT_STATE_ONESHOT); + clockevents_switch_state(bc, CLOCK_EVT_STATE_ONESHOT); } /* @@ -566,7 +555,7 @@ void tick_check_oneshot_broadcast_this_cpu(void) * switched over, leave the device alone. */ if (td->mode == TICKDEV_MODE_ONESHOT) { - clockevents_set_state(td->evtdev, + clockevents_switch_state(td->evtdev, CLOCK_EVT_STATE_ONESHOT); } } @@ -580,9 +569,9 @@ static void tick_handle_oneshot_broadcast(struct clock_event_device *dev) struct tick_device *td; ktime_t now, next_event; int cpu, next_cpu = 0; + bool bc_local; raw_spin_lock(&tick_broadcast_lock); -again: dev->next_event.tv64 = KTIME_MAX; next_event.tv64 = KTIME_MAX; cpumask_clear(tmpmask); @@ -624,7 +613,7 @@ again: /* * Wakeup the cpus which have an expired event. */ - tick_do_broadcast(tmpmask); + bc_local = tick_do_broadcast(tmpmask); /* * Two reasons for reprogram: @@ -636,15 +625,15 @@ again: * - There are pending events on sleeping CPUs which were not * in the event mask */ - if (next_event.tv64 != KTIME_MAX) { - /* - * Rearm the broadcast device. If event expired, - * repeat the above - */ - if (tick_broadcast_set_event(dev, next_cpu, next_event, 0)) - goto again; - } + if (next_event.tv64 != KTIME_MAX) + tick_broadcast_set_event(dev, next_cpu, next_event); + raw_spin_unlock(&tick_broadcast_lock); + + if (bc_local) { + td = this_cpu_ptr(&tick_cpu_device); + td->evtdev->event_handler(td->evtdev); + } } static int broadcast_needs_cpu(struct clock_event_device *bc, int cpu) @@ -670,7 +659,7 @@ static void broadcast_shutdown_local(struct clock_event_device *bc, if (dev->next_event.tv64 < bc->next_event.tv64) return; } - clockevents_set_state(dev, CLOCK_EVT_STATE_SHUTDOWN); + clockevents_switch_state(dev, CLOCK_EVT_STATE_SHUTDOWN); } /** @@ -726,7 +715,7 @@ int tick_broadcast_oneshot_control(enum tick_broadcast_state state) */ if (!cpumask_test_cpu(cpu, tick_broadcast_force_mask) && dev->next_event.tv64 < bc->next_event.tv64) - tick_broadcast_set_event(bc, cpu, dev->next_event, 1); + tick_broadcast_set_event(bc, cpu, dev->next_event); } /* * If the current CPU owns the hrtimer broadcast @@ -740,7 +729,7 @@ int tick_broadcast_oneshot_control(enum tick_broadcast_state state) cpumask_clear_cpu(cpu, tick_broadcast_oneshot_mask); } else { if (cpumask_test_and_clear_cpu(cpu, tick_broadcast_oneshot_mask)) { - clockevents_set_state(dev, CLOCK_EVT_STATE_ONESHOT); + clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT); /* * The cpu which was handling the broadcast * timer marked this cpu in the broadcast @@ -842,7 +831,7 @@ void tick_broadcast_setup_oneshot(struct clock_event_device *bc) /* Set it up only once ! */ if (bc->event_handler != tick_handle_oneshot_broadcast) { - int was_periodic = bc->state == CLOCK_EVT_STATE_PERIODIC; + int was_periodic = clockevent_state_periodic(bc); bc->event_handler = tick_handle_oneshot_broadcast; @@ -858,10 +847,10 @@ void tick_broadcast_setup_oneshot(struct clock_event_device *bc) tick_broadcast_oneshot_mask, tmpmask); if (was_periodic && !cpumask_empty(tmpmask)) { - clockevents_set_state(bc, CLOCK_EVT_STATE_ONESHOT); + clockevents_switch_state(bc, CLOCK_EVT_STATE_ONESHOT); tick_broadcast_init_next_event(tmpmask, tick_next_period); - tick_broadcast_set_event(bc, cpu, tick_next_period, 1); + tick_broadcast_set_event(bc, cpu, tick_next_period); } else bc->next_event.tv64 = KTIME_MAX; } else { |