/* * linux/kernel/time/tick-broadcast.c * * This file contains functions which emulate a local clock-event * device via a broadcast event source. * * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de> * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner * * This code is licenced under the GPL version 2. For details see * kernel-base/COPYING. */#include <linux/cpu.h>#include <linux/err.h>#include <linux/hrtimer.h>#include <linux/interrupt.h>#include <linux/percpu.h>#include <linux/profile.h>#include <linux/sched.h> #include "tick-internal.h" /* * Broadcast support for broken x86 hardware, where the local apic * timer stops in C3 state. */ static struct tick_device tick_broadcast_device;/* FIXME: Use cpumask_var_t. */static DECLARE_BITMAP(tick_broadcast_mask, NR_CPUS);static DECLARE_BITMAP(tmpmask, NR_CPUS);static DEFINE_RAW_SPINLOCK(tick_broadcast_lock);static int tick_broadcast_force; #ifdef CONFIG_TICK_ONESHOTstatic void tick_broadcast_clear_oneshot(int cpu);#elsestatic inline void tick_broadcast_clear_oneshot(int cpu) { }#endif /* * Debugging: see timer_list.c */struct tick_device *tick_get_broadcast_device(void){ return &tick_broadcast_device;} struct cpumask *tick_get_broadcast_mask(void){ return to_cpumask(tick_broadcast_mask);} /* * Start the device in periodic mode */static void tick_broadcast_start_periodic(struct clock_event_device *bc){ if (bc) tick_setup_periodic(bc, 1);} /* * Check, if the device can be utilized as broadcast device: */int tick_check_broadcast_device(struct clock_event_device *dev){ if ((tick_broadcast_device.evtdev && tick_broadcast_device.evtdev->rating >= dev->rating) || (dev->features & CLOCK_EVT_FEAT_C3STOP)) return 0; clockevents_exchange_device(tick_broadcast_device.evtdev, dev); tick_broadcast_device.evtdev = dev; if (!cpumask_empty(tick_get_broadcast_mask())) tick_broadcast_start_periodic(dev); return 1;} /* * Check, if the device is the broadcast device */int tick_is_broadcast_device(struct clock_event_device *dev){ return (dev && tick_broadcast_device.evtdev == dev);} /* * Check, if the device is disfunctional and a place holder, which * needs to be handled by the broadcast device. */int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu){ unsigned long flags; int ret = 0; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); /* * Devices might be registered with both periodic and oneshot * mode disabled. This signals, that the device needs to be * operated from the broadcast device and is a placeholder for * the cpu local device. */ if (!tick_device_is_functional(dev)) { dev->event_handler = tick_handle_periodic; cpumask_set_cpu(cpu, tick_get_broadcast_mask()); tick_broadcast_start_periodic(tick_broadcast_device.evtdev); ret = 1; } else { /* * When the new device is not affected by the stop * feature and the cpu is marked in the broadcast mask * then clear the broadcast bit. */ if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) { int cpu = smp_processor_id(); cpumask_clear_cpu(cpu, tick_get_broadcast_mask()); tick_broadcast_clear_oneshot(cpu); } } raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); return ret;} /* * Broadcast the event to the cpus, which are set in the mask (mangled). */static void tick_do_broadcast(struct cpumask *mask){ int cpu = smp_processor_id(); struct tick_device *td; /* * 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); } if (!cpumask_empty(mask)) { /* * It might be necessary to actually check whether the devices * have different broadcast functions. For now, just use the * one of the first device. This works as long as we have this * misfeature only on x86 (lapic) */ td = &per_cpu(tick_cpu_device, cpumask_first(mask)); td->evtdev->broadcast(mask); }} /* * Periodic broadcast: * - invoke the broadcast handlers */static void tick_do_periodic_broadcast(void){ raw_spin_lock(&tick_broadcast_lock); cpumask_and(to_cpumask(tmpmask), cpu_online_mask, tick_get_broadcast_mask()); tick_do_broadcast(to_cpumask(tmpmask)); raw_spin_unlock(&tick_broadcast_lock);} /* * Event handler for periodic broadcast ticks */static void tick_handle_periodic_broadcast(struct clock_event_device *dev){ ktime_t next; tick_do_periodic_broadcast(); /* * The device is in periodic mode. No reprogramming necessary: */ if (dev->mode == CLOCK_EVT_MODE_PERIODIC) return; /* * 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. */ for (next = dev->next_event; ;) { next = ktime_add(next, tick_period); if (!clockevents_program_event(dev, next, false)) return; tick_do_periodic_broadcast(); }} /* * Powerstate information: The system enters/leaves a state, where * affected devices might stop */static void tick_do_broadcast_on_off(unsigned long *reason){ struct clock_event_device *bc, *dev; struct tick_device *td; unsigned long flags; int cpu, bc_stopped; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); cpu = smp_processor_id(); td = &per_cpu(tick_cpu_device, cpu); dev = td->evtdev; bc = tick_broadcast_device.evtdev; /* * Is the device not affected by the powerstate ? */ if (!dev || !(dev->features & CLOCK_EVT_FEAT_C3STOP)) goto out; if (!tick_device_is_functional(dev)) goto out; bc_stopped = cpumask_empty(tick_get_broadcast_mask()); switch (*reason) { case CLOCK_EVT_NOTIFY_BROADCAST_ON: case CLOCK_EVT_NOTIFY_BROADCAST_FORCE: if (!cpumask_test_cpu(cpu, tick_get_broadcast_mask())) { cpumask_set_cpu(cpu, tick_get_broadcast_mask()); if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) clockevents_shutdown(dev); } if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_FORCE) tick_broadcast_force = 1; break; case CLOCK_EVT_NOTIFY_BROADCAST_OFF: if (!tick_broadcast_force && cpumask_test_cpu(cpu, tick_get_broadcast_mask())) { cpumask_clear_cpu(cpu, tick_get_broadcast_mask()); if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) tick_setup_periodic(dev, 0); } break; } if (cpumask_empty(tick_get_broadcast_mask())) { if (!bc_stopped) clockevents_shutdown(bc); } else if (bc_stopped) { if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) tick_broadcast_start_periodic(bc); else tick_broadcast_setup_oneshot(bc); }out: raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);} /* * Powerstate information: The system enters/leaves a state, where * affected devices might stop. */void tick_broadcast_on_off(unsigned long reason, int *oncpu){ if (!cpumask_test_cpu(*oncpu, cpu_online_mask)) printk(KERN_ERR "tick-broadcast: ignoring broadcast for " "offline CPU #%d\n", *oncpu); else tick_do_broadcast_on_off(&reason);} /* * Set the periodic handler depending on broadcast on/off */void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast){ if (!broadcast) dev->event_handler = tick_handle_periodic; else dev->event_handler = tick_handle_periodic_broadcast;} /* * Remove a CPU from broadcasting */void tick_shutdown_broadcast(unsigned int *cpup){ struct clock_event_device *bc; unsigned long flags; unsigned int cpu = *cpup; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); bc = tick_broadcast_device.evtdev; cpumask_clear_cpu(cpu, tick_get_broadcast_mask()); if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) { if (bc && cpumask_empty(tick_get_broadcast_mask())) clockevents_shutdown(bc); } raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);} void tick_suspend_broadcast(void){ struct clock_event_device *bc; unsigned long flags; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); bc = tick_broadcast_device.evtdev; if (bc) clockevents_shutdown(bc); raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);} int tick_resume_broadcast(void){ struct clock_event_device *bc; unsigned long flags; int broadcast = 0; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); bc = tick_broadcast_device.evtdev; if (bc) { clockevents_set_mode(bc, CLOCK_EVT_MODE_RESUME); switch (tick_broadcast_device.mode) { case TICKDEV_MODE_PERIODIC: if (!cpumask_empty(tick_get_broadcast_mask())) tick_broadcast_start_periodic(bc); broadcast = cpumask_test_cpu(smp_processor_id(), tick_get_broadcast_mask()); break; case TICKDEV_MODE_ONESHOT: if (!cpumask_empty(tick_get_broadcast_mask())) broadcast = tick_resume_broadcast_oneshot(bc); break; } } raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); return broadcast;} #ifdef CONFIG_TICK_ONESHOT /* FIXME: use cpumask_var_t. */static DECLARE_BITMAP(tick_broadcast_oneshot_mask, NR_CPUS); /* * Exposed for debugging: see timer_list.c */struct cpumask *tick_get_broadcast_oneshot_mask(void){ return to_cpumask(tick_broadcast_oneshot_mask);} static int tick_broadcast_set_event(ktime_t expires, int force){ struct clock_event_device *bc = tick_broadcast_device.evtdev; if (bc->mode != CLOCK_EVT_MODE_ONESHOT) clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT); return clockevents_program_event(bc, expires, force);} int tick_resume_broadcast_oneshot(struct clock_event_device *bc){ clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT); return 0;} /* * Called from irq_enter() when idle was interrupted to reenable the * per cpu device. */void tick_check_oneshot_broadcast(int cpu){ if (cpumask_test_cpu(cpu, to_cpumask(tick_broadcast_oneshot_mask))) { struct tick_device *td = &per_cpu(tick_cpu_device, cpu); clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_ONESHOT); }} /* * Handle oneshot mode broadcasting */static void tick_handle_oneshot_broadcast(struct clock_event_device *dev){ struct tick_device *td; ktime_t now, next_event; int cpu; raw_spin_lock(&tick_broadcast_lock);again: dev->next_event.tv64 = KTIME_MAX; next_event.tv64 = KTIME_MAX; cpumask_clear(to_cpumask(tmpmask)); now = ktime_get(); /* Find all expired events */ for_each_cpu(cpu, tick_get_broadcast_oneshot_mask()) { td = &per_cpu(tick_cpu_device, cpu); if (td->evtdev->next_event.tv64 <= now.tv64) cpumask_set_cpu(cpu, to_cpumask(tmpmask)); else if (td->evtdev->next_event.tv64 < next_event.tv64) next_event.tv64 = td->evtdev->next_event.tv64; } /* * Wakeup the cpus which have an expired event. */ tick_do_broadcast(to_cpumask(tmpmask)); /* * Two reasons for reprogram: * * - The global event did not expire any CPU local * events. This happens in dyntick mode, as the maximum PIT * delta is quite small. * * - 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(next_event, 0)) goto again; } raw_spin_unlock(&tick_broadcast_lock);} /* * Powerstate information: The system enters/leaves a state, where * affected devices might stop */void tick_broadcast_oneshot_control(unsigned long reason){ struct clock_event_device *bc, *dev; struct tick_device *td; unsigned long flags; int cpu; /* * Periodic mode does not care about the enter/exit of power * states */ if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) return; /* * We are called with preemtion disabled from the depth of the * idle code, so we can't be moved away. */ cpu = smp_processor_id(); td = &per_cpu(tick_cpu_device, cpu); dev = td->evtdev; if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) return; bc = tick_broadcast_device.evtdev; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); if (reason == CLOCK_EVT_NOTIFY_BROADCAST_ENTER) { if (!cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) { cpumask_set_cpu(cpu, tick_get_broadcast_oneshot_mask()); clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN); if (dev->next_event.tv64 < bc->next_event.tv64) tick_broadcast_set_event(dev->next_event, 1); } } else { if (cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) { cpumask_clear_cpu(cpu, tick_get_broadcast_oneshot_mask()); clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT); if (dev->next_event.tv64 != KTIME_MAX) tick_program_event(dev->next_event, 1); } } raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);Lines 1–500 of 629. 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/* * linux/kernel/time/tick-broadcast.c * * This file contains functions which emulate a local clock-event * device via a broadcast event source. * * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de> * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner * * This code is licenced under the GPL version 2. For details see * kernel-base/COPYING. */ #include <linux/cpu.h> #include <linux/err.h> #include <linux/hrtimer.h> #include <linux/interrupt.h> #include <linux/percpu.h> #include <linux/profile.h> #include <linux/sched.h> #include "tick-internal.h" /* * Broadcast support for broken x86 hardware, where the local apic * timer stops in C3 state. */ static struct tick_device tick_broadcast_device; /* FIXME: Use cpumask_var_t. */ static DECLARE_BITMAP(tick_broadcast_mask, NR_CPUS); static DECLARE_BITMAP(tmpmask, NR_CPUS); static DEFINE_RAW_SPINLOCK(tick_broadcast_lock); static int tick_broadcast_force; #ifdef CONFIG_TICK_ONESHOT static void tick_broadcast_clear_oneshot(int cpu); #else static inline void tick_broadcast_clear_oneshot(int cpu) { } #endif /* * Debugging: see timer_list.c */ struct tick_device *tick_get_broadcast_device(void) { return &tick_broadcast_device; } struct cpumask *tick_get_broadcast_mask(void) { return to_cpumask(tick_broadcast_mask); } /* * Start the device in periodic mode */ static void tick_broadcast_start_periodic(struct clock_event_device *bc) { if (bc) tick_setup_periodic(bc, 1); } /* * Check, if the device can be utilized as broadcast device: */ int tick_check_broadcast_device(struct clock_event_device *dev) { if ((tick_broadcast_device.evtdev && tick_broadcast_device.evtdev->rating >= dev->rating) || (dev->features & CLOCK_EVT_FEAT_C3STOP)) return 0; clockevents_exchange_device(tick_broadcast_device.evtdev, dev); tick_broadcast_device.evtdev = dev; if (!cpumask_empty(tick_get_broadcast_mask())) tick_broadcast_start_periodic(dev); return 1; } /* * Check, if the device is the broadcast device */ int tick_is_broadcast_device(struct clock_event_device *dev) { return (dev && tick_broadcast_device.evtdev == dev); } /* * Check, if the device is disfunctional and a place holder, which * needs to be handled by the broadcast device. */ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { unsigned long flags; int ret = 0; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); /* * Devices might be registered with both periodic and oneshot * mode disabled. This signals, that the device needs to be * operated from the broadcast device and is a placeholder for * the cpu local device. */ if (!tick_device_is_functional(dev)) { dev->event_handler = tick_handle_periodic; cpumask_set_cpu(cpu, tick_get_broadcast_mask()); tick_broadcast_start_periodic(tick_broadcast_device.evtdev); ret = 1; } else { /* * When the new device is not affected by the stop * feature and the cpu is marked in the broadcast mask * then clear the broadcast bit. */ if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) { int cpu = smp_processor_id(); cpumask_clear_cpu(cpu, tick_get_broadcast_mask()); tick_broadcast_clear_oneshot(cpu); } } raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); return ret; } /* * Broadcast the event to the cpus, which are set in the mask (mangled). */ static void tick_do_broadcast(struct cpumask *mask) { int cpu = smp_processor_id(); struct tick_device *td; /* * 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); } if (!cpumask_empty(mask)) { /* * It might be necessary to actually check whether the devices * have different broadcast functions. For now, just use the * one of the first device. This works as long as we have this * misfeature only on x86 (lapic) */ td = &per_cpu(tick_cpu_device, cpumask_first(mask)); td->evtdev->broadcast(mask); } } /* * Periodic broadcast: * - invoke the broadcast handlers */ static void tick_do_periodic_broadcast(void) { raw_spin_lock(&tick_broadcast_lock); cpumask_and(to_cpumask(tmpmask), cpu_online_mask, tick_get_broadcast_mask()); tick_do_broadcast(to_cpumask(tmpmask)); raw_spin_unlock(&tick_broadcast_lock); } /* * Event handler for periodic broadcast ticks */ static void tick_handle_periodic_broadcast(struct clock_event_device *dev) { ktime_t next; tick_do_periodic_broadcast(); /* * The device is in periodic mode. No reprogramming necessary: */ if (dev->mode == CLOCK_EVT_MODE_PERIODIC) return; /* * 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. */ for (next = dev->next_event; ;) { next = ktime_add(next, tick_period); if (!clockevents_program_event(dev, next, false)) return; tick_do_periodic_broadcast(); } } /* * Powerstate information: The system enters/leaves a state, where * affected devices might stop */ static void tick_do_broadcast_on_off(unsigned long *reason) { struct clock_event_device *bc, *dev; struct tick_device *td; unsigned long flags; int cpu, bc_stopped; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); cpu = smp_processor_id(); td = &per_cpu(tick_cpu_device, cpu); dev = td->evtdev; bc = tick_broadcast_device.evtdev; /* * Is the device not affected by the powerstate ? */ if (!dev || !(dev->features & CLOCK_EVT_FEAT_C3STOP)) goto out; if (!tick_device_is_functional(dev)) goto out; bc_stopped = cpumask_empty(tick_get_broadcast_mask()); switch (*reason) { case CLOCK_EVT_NOTIFY_BROADCAST_ON: case CLOCK_EVT_NOTIFY_BROADCAST_FORCE: if (!cpumask_test_cpu(cpu, tick_get_broadcast_mask())) { cpumask_set_cpu(cpu, tick_get_broadcast_mask()); if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) clockevents_shutdown(dev); } if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_FORCE) tick_broadcast_force = 1; break; case CLOCK_EVT_NOTIFY_BROADCAST_OFF: if (!tick_broadcast_force && cpumask_test_cpu(cpu, tick_get_broadcast_mask())) { cpumask_clear_cpu(cpu, tick_get_broadcast_mask()); if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) tick_setup_periodic(dev, 0); } break; } if (cpumask_empty(tick_get_broadcast_mask())) { if (!bc_stopped) clockevents_shutdown(bc); } else if (bc_stopped) { if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) tick_broadcast_start_periodic(bc); else tick_broadcast_setup_oneshot(bc); } out: raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); } /* * Powerstate information: The system enters/leaves a state, where * affected devices might stop. */ void tick_broadcast_on_off(unsigned long reason, int *oncpu) { if (!cpumask_test_cpu(*oncpu, cpu_online_mask)) printk(KERN_ERR "tick-broadcast: ignoring broadcast for " "offline CPU #%d\n", *oncpu); else tick_do_broadcast_on_off(&reason); } /* * Set the periodic handler depending on broadcast on/off */ void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast) { if (!broadcast) dev->event_handler = tick_handle_periodic; else dev->event_handler = tick_handle_periodic_broadcast; } /* * Remove a CPU from broadcasting */ void tick_shutdown_broadcast(unsigned int *cpup) { struct clock_event_device *bc; unsigned long flags; unsigned int cpu = *cpup; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); bc = tick_broadcast_device.evtdev; cpumask_clear_cpu(cpu, tick_get_broadcast_mask()); if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) { if (bc && cpumask_empty(tick_get_broadcast_mask())) clockevents_shutdown(bc); } raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); } void tick_suspend_broadcast(void) { struct clock_event_device *bc; unsigned long flags; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); bc = tick_broadcast_device.evtdev; if (bc) clockevents_shutdown(bc); raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); } int tick_resume_broadcast(void) { struct clock_event_device *bc; unsigned long flags; int broadcast = 0; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); bc = tick_broadcast_device.evtdev; if (bc) { clockevents_set_mode(bc, CLOCK_EVT_MODE_RESUME); switch (tick_broadcast_device.mode) { case TICKDEV_MODE_PERIODIC: if (!cpumask_empty(tick_get_broadcast_mask())) tick_broadcast_start_periodic(bc); broadcast = cpumask_test_cpu(smp_processor_id(), tick_get_broadcast_mask()); break; case TICKDEV_MODE_ONESHOT: if (!cpumask_empty(tick_get_broadcast_mask())) broadcast = tick_resume_broadcast_oneshot(bc); break; } } raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); return broadcast; } #ifdef CONFIG_TICK_ONESHOT /* FIXME: use cpumask_var_t. */ static DECLARE_BITMAP(tick_broadcast_oneshot_mask, NR_CPUS); /* * Exposed for debugging: see timer_list.c */ struct cpumask *tick_get_broadcast_oneshot_mask(void) { return to_cpumask(tick_broadcast_oneshot_mask); } static int tick_broadcast_set_event(ktime_t expires, int force) { struct clock_event_device *bc = tick_broadcast_device.evtdev; if (bc->mode != CLOCK_EVT_MODE_ONESHOT) clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT); return clockevents_program_event(bc, expires, force); } int tick_resume_broadcast_oneshot(struct clock_event_device *bc) { clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT); return 0; } /* * Called from irq_enter() when idle was interrupted to reenable the * per cpu device. */ void tick_check_oneshot_broadcast(int cpu) { if (cpumask_test_cpu(cpu, to_cpumask(tick_broadcast_oneshot_mask))) { struct tick_device *td = &per_cpu(tick_cpu_device, cpu); clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_ONESHOT); } } /* * Handle oneshot mode broadcasting */ static void tick_handle_oneshot_broadcast(struct clock_event_device *dev) { struct tick_device *td; ktime_t now, next_event; int cpu; raw_spin_lock(&tick_broadcast_lock); again: dev->next_event.tv64 = KTIME_MAX; next_event.tv64 = KTIME_MAX; cpumask_clear(to_cpumask(tmpmask)); now = ktime_get(); /* Find all expired events */ for_each_cpu(cpu, tick_get_broadcast_oneshot_mask()) { td = &per_cpu(tick_cpu_device, cpu); if (td->evtdev->next_event.tv64 <= now.tv64) cpumask_set_cpu(cpu, to_cpumask(tmpmask)); else if (td->evtdev->next_event.tv64 < next_event.tv64) next_event.tv64 = td->evtdev->next_event.tv64; } /* * Wakeup the cpus which have an expired event. */ tick_do_broadcast(to_cpumask(tmpmask)); /* * Two reasons for reprogram: * * - The global event did not expire any CPU local * events. This happens in dyntick mode, as the maximum PIT * delta is quite small. * * - 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(next_event, 0)) goto again; } raw_spin_unlock(&tick_broadcast_lock); } /* * Powerstate information: The system enters/leaves a state, where * affected devices might stop */ void tick_broadcast_oneshot_control(unsigned long reason) { struct clock_event_device *bc, *dev; struct tick_device *td; unsigned long flags; int cpu; /* * Periodic mode does not care about the enter/exit of power * states */ if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) return; /* * We are called with preemtion disabled from the depth of the * idle code, so we can't be moved away. */ cpu = smp_processor_id(); td = &per_cpu(tick_cpu_device, cpu); dev = td->evtdev; if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) return; bc = tick_broadcast_device.evtdev; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); if (reason == CLOCK_EVT_NOTIFY_BROADCAST_ENTER) { if (!cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) { cpumask_set_cpu(cpu, tick_get_broadcast_oneshot_mask()); clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN); if (dev->next_event.tv64 < bc->next_event.tv64) tick_broadcast_set_event(dev->next_event, 1); } } else { if (cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) { cpumask_clear_cpu(cpu, tick_get_broadcast_oneshot_mask()); clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT); if (dev->next_event.tv64 != KTIME_MAX) tick_program_event(dev->next_event, 1); } } raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);