/* * 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 <linux/smp.h>#include <linux/module.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;static cpumask_var_t tick_broadcast_mask;static cpumask_var_t tick_broadcast_on;static cpumask_var_t tmpmask;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 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: */static bool tick_check_broadcast_device(struct clock_event_device *curdev, struct clock_event_device *newdev){ if ((newdev->features & CLOCK_EVT_FEAT_DUMMY) || (newdev->features & CLOCK_EVT_FEAT_PERCPU) || (newdev->features & CLOCK_EVT_FEAT_C3STOP)) return false; if (tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT && !(newdev->features & CLOCK_EVT_FEAT_ONESHOT)) return false; return !curdev || newdev->rating > curdev->rating;} /* * Conditionally install/replace broadcast device */void tick_install_broadcast_device(struct clock_event_device *dev){ struct clock_event_device *cur = tick_broadcast_device.evtdev; if (!tick_check_broadcast_device(cur, dev)) return; if (!try_module_get(dev->owner)) return; clockevents_exchange_device(cur, dev); if (cur) cur->event_handler = clockevents_handle_noop; tick_broadcast_device.evtdev = dev; if (!cpumask_empty(tick_broadcast_mask)) tick_broadcast_start_periodic(dev); /* * Inform all cpus about this. We might be in a situation * where we did not switch to oneshot mode because the per cpu * devices are affected by CLOCK_EVT_FEAT_C3STOP and the lack * of a oneshot capable broadcast device. Without that * notification the systems stays stuck in periodic mode * forever. */ if (dev->features & CLOCK_EVT_FEAT_ONESHOT) tick_clock_notify();} /* * 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);} static void err_broadcast(const struct cpumask *mask){ pr_crit_once("Failed to broadcast timer tick. Some CPUs may be unresponsive.\n");} static void tick_device_setup_broadcast_func(struct clock_event_device *dev){ if (!dev->broadcast) dev->broadcast = tick_broadcast; if (!dev->broadcast) { pr_warn_once("%s depends on broadcast, but no broadcast function available\n", dev->name); dev->broadcast = err_broadcast; }} /* * 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){ struct clock_event_device *bc = tick_broadcast_device.evtdev; unsigned long flags; int ret; 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; tick_device_setup_broadcast_func(dev); cpumask_set_cpu(cpu, tick_broadcast_mask); if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) tick_broadcast_start_periodic(bc); else tick_broadcast_setup_oneshot(bc); ret = 1; } else { /* * Clear the broadcast bit for this cpu if the * device is not power state affected. */ if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) cpumask_clear_cpu(cpu, tick_broadcast_mask); else tick_device_setup_broadcast_func(dev); /* * Clear the broadcast bit if the CPU is not in * periodic broadcast on state. */ if (!cpumask_test_cpu(cpu, tick_broadcast_on)) cpumask_clear_cpu(cpu, tick_broadcast_mask); switch (tick_broadcast_device.mode) { case TICKDEV_MODE_ONESHOT: /* * If the system is in oneshot mode we can * unconditionally clear the oneshot mask bit, * because the CPU is running and therefore * not in an idle state which causes the power * state affected device to stop. Let the * caller initialize the device. */ tick_broadcast_clear_oneshot(cpu); ret = 0; break; case TICKDEV_MODE_PERIODIC: /* * If the system is in periodic mode, check * whether the broadcast device can be * switched off now. */ if (cpumask_empty(tick_broadcast_mask) && bc) clockevents_shutdown(bc); /* * If we kept the cpu in the broadcast mask, * tell the caller to leave the per cpu device * in shutdown state. The periodic interrupt * is delivered by the broadcast device. */ ret = cpumask_test_cpu(cpu, tick_broadcast_mask); break; default: /* Nothing to do */ ret = 0; break; } } raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); return ret;} #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCASTint tick_receive_broadcast(void){ struct tick_device *td = this_cpu_ptr(&tick_cpu_device); struct clock_event_device *evt = td->evtdev; if (!evt) return -ENODEV; if (!evt->event_handler) return -EINVAL; evt->event_handler(evt); return 0;}#endif /* * 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(tmpmask, cpu_online_mask, tick_broadcast_mask); tick_do_broadcast(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_broadcast_mask); switch (*reason) { case CLOCK_EVT_NOTIFY_BROADCAST_ON: case CLOCK_EVT_NOTIFY_BROADCAST_FORCE: cpumask_set_cpu(cpu, tick_broadcast_on); if (!cpumask_test_and_set_cpu(cpu, tick_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) break; cpumask_clear_cpu(cpu, tick_broadcast_on); if (!tick_device_is_functional(dev)) break; if (cpumask_test_and_clear_cpu(cpu, tick_broadcast_mask)) { if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) tick_setup_periodic(dev, 0); } break; } if (cpumask_empty(tick_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_broadcast_mask); cpumask_clear_cpu(cpu, tick_broadcast_on); if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) { if (bc && cpumask_empty(tick_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_broadcast_mask)) tick_broadcast_start_periodic(bc); broadcast = cpumask_test_cpu(smp_processor_id(), tick_broadcast_mask); break; case TICKDEV_MODE_ONESHOT: if (!cpumask_empty(tick_broadcast_mask)) broadcast = tick_resume_broadcast_oneshot(bc); break; } } raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); return broadcast;} #ifdef CONFIG_TICK_ONESHOT static cpumask_var_t tick_broadcast_oneshot_mask;static cpumask_var_t tick_broadcast_pending_mask;static cpumask_var_t tick_broadcast_force_mask; /* * Exposed for debugging: see timer_list.c */struct cpumask *tick_get_broadcast_oneshot_mask(void){ return tick_broadcast_oneshot_mask;} /* * Called before going idle with interrupts disabled. Checks whether a * broadcast event from the other core is about to happen. We detected * that in tick_broadcast_oneshot_control(). The callsite can use this * to avoid a deep idle transition as we are about to get the * broadcast IPI right away. */int tick_check_broadcast_expired(void){ return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask);} Lines 1–500 of 887. Load more
/* * 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 <linux/smp.h> #include <linux/module.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; static cpumask_var_t tick_broadcast_mask; static cpumask_var_t tick_broadcast_on; static cpumask_var_t tmpmask; 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 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: */ static bool tick_check_broadcast_device(struct clock_event_device *curdev, struct clock_event_device *newdev) { if ((newdev->features & CLOCK_EVT_FEAT_DUMMY) || (newdev->features & CLOCK_EVT_FEAT_PERCPU) || (newdev->features & CLOCK_EVT_FEAT_C3STOP)) return false; if (tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT && !(newdev->features & CLOCK_EVT_FEAT_ONESHOT)) return false; return !curdev || newdev->rating > curdev->rating; } /* * Conditionally install/replace broadcast device */ void tick_install_broadcast_device(struct clock_event_device *dev) { struct clock_event_device *cur = tick_broadcast_device.evtdev; if (!tick_check_broadcast_device(cur, dev)) return; if (!try_module_get(dev->owner)) return; clockevents_exchange_device(cur, dev); if (cur) cur->event_handler = clockevents_handle_noop; tick_broadcast_device.evtdev = dev; if (!cpumask_empty(tick_broadcast_mask)) tick_broadcast_start_periodic(dev); /* * Inform all cpus about this. We might be in a situation * where we did not switch to oneshot mode because the per cpu * devices are affected by CLOCK_EVT_FEAT_C3STOP and the lack * of a oneshot capable broadcast device. Without that * notification the systems stays stuck in periodic mode * forever. */ if (dev->features & CLOCK_EVT_FEAT_ONESHOT) tick_clock_notify(); } /* * 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); } static void err_broadcast(const struct cpumask *mask) { pr_crit_once("Failed to broadcast timer tick. Some CPUs may be unresponsive.\n"); } static void tick_device_setup_broadcast_func(struct clock_event_device *dev) { if (!dev->broadcast) dev->broadcast = tick_broadcast; if (!dev->broadcast) { pr_warn_once("%s depends on broadcast, but no broadcast function available\n", dev->name); dev->broadcast = err_broadcast; } } /* * 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) { struct clock_event_device *bc = tick_broadcast_device.evtdev; unsigned long flags; int ret; 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; tick_device_setup_broadcast_func(dev); cpumask_set_cpu(cpu, tick_broadcast_mask); if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) tick_broadcast_start_periodic(bc); else tick_broadcast_setup_oneshot(bc); ret = 1; } else { /* * Clear the broadcast bit for this cpu if the * device is not power state affected. */ if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) cpumask_clear_cpu(cpu, tick_broadcast_mask); else tick_device_setup_broadcast_func(dev); /* * Clear the broadcast bit if the CPU is not in * periodic broadcast on state. */ if (!cpumask_test_cpu(cpu, tick_broadcast_on)) cpumask_clear_cpu(cpu, tick_broadcast_mask); switch (tick_broadcast_device.mode) { case TICKDEV_MODE_ONESHOT: /* * If the system is in oneshot mode we can * unconditionally clear the oneshot mask bit, * because the CPU is running and therefore * not in an idle state which causes the power * state affected device to stop. Let the * caller initialize the device. */ tick_broadcast_clear_oneshot(cpu); ret = 0; break; case TICKDEV_MODE_PERIODIC: /* * If the system is in periodic mode, check * whether the broadcast device can be * switched off now. */ if (cpumask_empty(tick_broadcast_mask) && bc) clockevents_shutdown(bc); /* * If we kept the cpu in the broadcast mask, * tell the caller to leave the per cpu device * in shutdown state. The periodic interrupt * is delivered by the broadcast device. */ ret = cpumask_test_cpu(cpu, tick_broadcast_mask); break; default: /* Nothing to do */ ret = 0; break; } } raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); return ret; } #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST int tick_receive_broadcast(void) { struct tick_device *td = this_cpu_ptr(&tick_cpu_device); struct clock_event_device *evt = td->evtdev; if (!evt) return -ENODEV; if (!evt->event_handler) return -EINVAL; evt->event_handler(evt); return 0; } #endif /* * 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(tmpmask, cpu_online_mask, tick_broadcast_mask); tick_do_broadcast(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_broadcast_mask); switch (*reason) { case CLOCK_EVT_NOTIFY_BROADCAST_ON: case CLOCK_EVT_NOTIFY_BROADCAST_FORCE: cpumask_set_cpu(cpu, tick_broadcast_on); if (!cpumask_test_and_set_cpu(cpu, tick_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) break; cpumask_clear_cpu(cpu, tick_broadcast_on); if (!tick_device_is_functional(dev)) break; if (cpumask_test_and_clear_cpu(cpu, tick_broadcast_mask)) { if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) tick_setup_periodic(dev, 0); } break; } if (cpumask_empty(tick_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_broadcast_mask); cpumask_clear_cpu(cpu, tick_broadcast_on); if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) { if (bc && cpumask_empty(tick_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_broadcast_mask)) tick_broadcast_start_periodic(bc); broadcast = cpumask_test_cpu(smp_processor_id(), tick_broadcast_mask); break; case TICKDEV_MODE_ONESHOT: if (!cpumask_empty(tick_broadcast_mask)) broadcast = tick_resume_broadcast_oneshot(bc); break; } } raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); return broadcast; } #ifdef CONFIG_TICK_ONESHOT static cpumask_var_t tick_broadcast_oneshot_mask; static cpumask_var_t tick_broadcast_pending_mask; static cpumask_var_t tick_broadcast_force_mask; /* * Exposed for debugging: see timer_list.c */ struct cpumask *tick_get_broadcast_oneshot_mask(void) { return tick_broadcast_oneshot_mask; } /* * Called before going idle with interrupts disabled. Checks whether a * broadcast event from the other core is about to happen. We detected * that in tick_broadcast_oneshot_control(). The callsite can use this * to avoid a deep idle transition as we are about to get the * broadcast IPI right away. */ int tick_check_broadcast_expired(void) { return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask); }