/*
* The following two APIs (cpu_maps_update_begin/done) must be used when
* attempting to serialize the updates to cpu_online_mask & cpu_present_mask.
- * The APIs cpu_notifier_register_begin/done() must be used to protect CPU
- * hotplug callback (un)registration performed using __register_cpu_notifier()
- * or __unregister_cpu_notifier().
*/
void cpu_maps_update_begin(void)
{
mutex_lock(&cpu_add_remove_lock);
}
-EXPORT_SYMBOL(cpu_notifier_register_begin);
void cpu_maps_update_done(void)
{
mutex_unlock(&cpu_add_remove_lock);
}
-EXPORT_SYMBOL(cpu_notifier_register_done);
-
-static RAW_NOTIFIER_HEAD(cpu_chain);
/* If set, cpu_up and cpu_down will return -EBUSY and do nothing.
* Should always be manipulated under cpu_add_remove_lock
EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
#endif /* CONFIG_HOTPLUG_CPU */
-/* Need to know about CPUs going up/down? */
-int register_cpu_notifier(struct notifier_block *nb)
-{
- int ret;
- cpu_maps_update_begin();
- ret = raw_notifier_chain_register(&cpu_chain, nb);
- cpu_maps_update_done();
- return ret;
-}
-
-int __register_cpu_notifier(struct notifier_block *nb)
-{
- return raw_notifier_chain_register(&cpu_chain, nb);
-}
-
-static int __cpu_notify(unsigned long val, unsigned int cpu, int nr_to_call,
- int *nr_calls)
-{
- unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0;
- void *hcpu = (void *)(long)cpu;
-
- int ret;
-
- ret = __raw_notifier_call_chain(&cpu_chain, val | mod, hcpu, nr_to_call,
- nr_calls);
-
- return notifier_to_errno(ret);
-}
-
-static int cpu_notify(unsigned long val, unsigned int cpu)
-{
- return __cpu_notify(val, cpu, -1, NULL);
-}
-
-static void cpu_notify_nofail(unsigned long val, unsigned int cpu)
-{
- BUG_ON(cpu_notify(val, cpu));
-}
-
/* Notifier wrappers for transitioning to state machine */
-static int notify_prepare(unsigned int cpu)
-{
- int nr_calls = 0;
- int ret;
-
- ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls);
- if (ret) {
- nr_calls--;
- printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n",
- __func__, cpu);
- __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL);
- }
- return ret;
-}
-
-static int notify_online(unsigned int cpu)
-{
- cpu_notify(CPU_ONLINE, cpu);
- return 0;
-}
static int bringup_wait_for_ap(unsigned int cpu)
{
/* Arch-specific enabling code. */
ret = __cpu_up(cpu, idle);
irq_unlock_sparse();
- if (ret) {
- cpu_notify(CPU_UP_CANCELED, cpu);
+ if (ret)
return ret;
- }
ret = bringup_wait_for_ap(cpu);
BUG_ON(!cpu_online(cpu));
return ret;
BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE);
undo_cpu_down(cpu, st);
- /*
- * This is a momentary workaround to keep the notifier users
- * happy. Will go away once we got rid of the notifiers.
- */
- cpu_notify_nofail(CPU_DOWN_FAILED, cpu);
st->rollback = false;
} else {
/* Cannot happen .... */
kthread_unpark(this_cpu_read(cpuhp_state.thread));
}
-EXPORT_SYMBOL(register_cpu_notifier);
-EXPORT_SYMBOL(__register_cpu_notifier);
-void unregister_cpu_notifier(struct notifier_block *nb)
-{
- cpu_maps_update_begin();
- raw_notifier_chain_unregister(&cpu_chain, nb);
- cpu_maps_update_done();
-}
-EXPORT_SYMBOL(unregister_cpu_notifier);
-
-void __unregister_cpu_notifier(struct notifier_block *nb)
-{
- raw_notifier_chain_unregister(&cpu_chain, nb);
-}
-EXPORT_SYMBOL(__unregister_cpu_notifier);
-
#ifdef CONFIG_HOTPLUG_CPU
/**
* clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU
read_unlock(&tasklist_lock);
}
-static int notify_down_prepare(unsigned int cpu)
-{
- int err, nr_calls = 0;
-
- err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls);
- if (err) {
- nr_calls--;
- __cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL);
- pr_warn("%s: attempt to take down CPU %u failed\n",
- __func__, cpu);
- }
- return err;
-}
-
/* Take this CPU down. */
static int take_cpu_down(void *_param)
{
return 0;
}
-static int notify_dead(unsigned int cpu)
-{
- cpu_notify_nofail(CPU_DEAD, cpu);
- check_for_tasks(cpu);
- return 0;
-}
-
static void cpuhp_complete_idle_dead(void *arg)
{
struct cpuhp_cpu_state *st = arg;
}
#else
-#define notify_down_prepare NULL
#define takedown_cpu NULL
-#define notify_dead NULL
#endif
#ifdef CONFIG_HOTPLUG_CPU
hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE;
out:
cpu_hotplug_done();
- /* This post dead nonsense must die */
- if (!ret && hasdied)
- cpu_notify_nofail(CPU_POST_DEAD, cpu);
return ret;
}
.teardown.single = rcutree_dead_cpu,
},
/*
- * Preparatory and dead notifiers. Will be replaced once the notifiers
- * are converted to states.
- */
- [CPUHP_NOTIFY_PREPARE] = {
- .name = "notify:prepare",
- .startup.single = notify_prepare,
- .teardown.single = notify_dead,
- .skip_onerr = true,
- .cant_stop = true,
- },
- /*
* On the tear-down path, timers_dead_cpu() must be invoked
* before blk_mq_queue_reinit_notify() from notify_dead(),
* otherwise a RCU stall occurs.
.startup.single = rcutree_online_cpu,
.teardown.single = rcutree_offline_cpu,
},
-
- /*
- * Online/down_prepare notifiers. Will be removed once the notifiers
- * are converted to states.
- */
- [CPUHP_AP_NOTIFY_ONLINE] = {
- .name = "notify:online",
- .startup.single = notify_online,
- .teardown.single = notify_down_prepare,
- .skip_onerr = true,
- },
#endif
/*
* The dynamically registered state space is here
projects / platform / kernel / linux-rpi.git / blobdiff