#include <linux/lockdep.h>
#include <linux/tick.h>
#include <linux/irq.h>
+
#include <trace/events/power.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/cpuhp.h>
#include "smpboot.h"
+/**
+ * cpuhp_cpu_state - Per cpu hotplug state storage
+ * @state: The current cpu state
+ * @target: The target state
+ */
+struct cpuhp_cpu_state {
+ enum cpuhp_state state;
+ enum cpuhp_state target;
+};
+
+static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state);
+
+/**
+ * cpuhp_step - Hotplug state machine step
+ * @name: Name of the step
+ * @startup: Startup function of the step
+ * @teardown: Teardown function of the step
+ * @skip_onerr: Do not invoke the functions on error rollback
+ * Will go away once the notifiers are gone
+ */
+struct cpuhp_step {
+ const char *name;
+ int (*startup)(unsigned int cpu);
+ int (*teardown)(unsigned int cpu);
+ bool skip_onerr;
+};
+
+static struct cpuhp_step cpuhp_bp_states[];
+static struct cpuhp_step cpuhp_ap_states[];
+
+/**
+ * cpuhp_invoke_callback _ Invoke the callbacks for a given state
+ * @cpu: The cpu for which the callback should be invoked
+ * @step: The step in the state machine
+ * @cb: The callback function to invoke
+ *
+ * Called from cpu hotplug and from the state register machinery
+ */
+static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state step,
+ int (*cb)(unsigned int))
+{
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ int ret = 0;
+
+ if (cb) {
+ trace_cpuhp_enter(cpu, st->target, step, cb);
+ ret = cb(cpu);
+ trace_cpuhp_exit(cpu, st->state, step, ret);
+ }
+ return ret;
+}
+
#ifdef CONFIG_SMP
/* Serializes the updates to cpu_online_mask, cpu_present_mask */
static DEFINE_MUTEX(cpu_add_remove_lock);
+bool cpuhp_tasks_frozen;
+EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen);
/*
* The following two APIs (cpu_maps_update_begin/done) must be used when
return raw_notifier_chain_register(&cpu_chain, nb);
}
-static int __cpu_notify(unsigned long val, void *v, int nr_to_call,
+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, v, nr_to_call,
+ 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, void *v)
+static int cpu_notify(unsigned long val, unsigned int cpu)
{
- return __cpu_notify(val, v, -1, NULL);
+ return __cpu_notify(val, cpu, -1, NULL);
}
-#ifdef CONFIG_HOTPLUG_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 notify_starting(unsigned int cpu)
+{
+ cpu_notify(CPU_STARTING, cpu);
+ return 0;
+}
-static void cpu_notify_nofail(unsigned long val, void *v)
+static int bringup_cpu(unsigned int cpu)
{
- BUG_ON(cpu_notify(val, v));
+ struct task_struct *idle = idle_thread_get(cpu);
+ int ret;
+
+ /* Arch-specific enabling code. */
+ ret = __cpu_up(cpu, idle);
+ if (ret) {
+ cpu_notify(CPU_UP_CANCELED, cpu);
+ return ret;
+ }
+ BUG_ON(!cpu_online(cpu));
+ return 0;
}
+
+#ifdef CONFIG_HOTPLUG_CPU
EXPORT_SYMBOL(register_cpu_notifier);
EXPORT_SYMBOL(__register_cpu_notifier);
read_unlock(&tasklist_lock);
}
-struct take_cpu_down_param {
- unsigned long mod;
- void *hcpu;
-};
+static void cpu_notify_nofail(unsigned long val, unsigned int cpu)
+{
+ BUG_ON(cpu_notify(val, cpu));
+}
+
+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;
+}
+
+static int notify_dying(unsigned int cpu)
+{
+ cpu_notify(CPU_DYING, cpu);
+ return 0;
+}
/* Take this CPU down. */
static int take_cpu_down(void *_param)
{
- struct take_cpu_down_param *param = _param;
- int err;
+ struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
+ enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE);
+ int err, cpu = smp_processor_id();
/* Ensure this CPU doesn't handle any more interrupts. */
err = __cpu_disable();
if (err < 0)
return err;
- cpu_notify(CPU_DYING | param->mod, param->hcpu);
+ /* Invoke the former CPU_DYING callbacks */
+ for (; st->state > target; st->state--) {
+ struct cpuhp_step *step = cpuhp_ap_states + st->state;
+
+ cpuhp_invoke_callback(cpu, st->state, step->teardown);
+ }
/* Give up timekeeping duties */
tick_handover_do_timer();
/* Park the stopper thread */
- stop_machine_park((long)param->hcpu);
+ stop_machine_park(cpu);
return 0;
}
-/* Requires cpu_add_remove_lock to be held */
-static int _cpu_down(unsigned int cpu, int tasks_frozen)
+static int takedown_cpu(unsigned int cpu)
{
- int err, nr_calls = 0;
- void *hcpu = (void *)(long)cpu;
- unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
- struct take_cpu_down_param tcd_param = {
- .mod = mod,
- .hcpu = hcpu,
- };
-
- if (num_online_cpus() == 1)
- return -EBUSY;
-
- if (!cpu_online(cpu))
- return -EINVAL;
-
- cpu_hotplug_begin();
-
- err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
- if (err) {
- nr_calls--;
- __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL);
- pr_warn("%s: attempt to take down CPU %u failed\n",
- __func__, cpu);
- goto out_release;
- }
+ int err;
/*
* By now we've cleared cpu_active_mask, wait for all preempt-disabled
/*
* So now all preempt/rcu users must observe !cpu_active().
*/
- err = stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
+ err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu));
if (err) {
/* CPU didn't die: tell everyone. Can't complain. */
- cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu);
+ cpu_notify_nofail(CPU_DOWN_FAILED, cpu);
irq_unlock_sparse();
- goto out_release;
+ return err;
}
BUG_ON(cpu_online(cpu));
/* This actually kills the CPU. */
__cpu_die(cpu);
- /* CPU is completely dead: tell everyone. Too late to complain. */
tick_cleanup_dead_cpu(cpu);
- cpu_notify_nofail(CPU_DEAD | mod, hcpu);
+ return 0;
+}
+static int notify_dead(unsigned int cpu)
+{
+ cpu_notify_nofail(CPU_DEAD, cpu);
check_for_tasks(cpu);
+ return 0;
+}
+
+#else
+#define notify_down_prepare NULL
+#define takedown_cpu NULL
+#define notify_dead NULL
+#define notify_dying NULL
+#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st)
+{
+ for (st->state++; st->state < st->target; st->state++) {
+ struct cpuhp_step *step = cpuhp_bp_states + st->state;
+
+ if (!step->skip_onerr)
+ cpuhp_invoke_callback(cpu, st->state, step->startup);
+ }
+}
+
+/* Requires cpu_add_remove_lock to be held */
+static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
+ enum cpuhp_state target)
+{
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ int prev_state, ret = 0;
+ bool hasdied = false;
+
+ if (num_online_cpus() == 1)
+ return -EBUSY;
+
+ if (!cpu_online(cpu))
+ return -EINVAL;
+
+ cpu_hotplug_begin();
+
+ cpuhp_tasks_frozen = tasks_frozen;
+
+ prev_state = st->state;
+ st->target = target;
+ for (; st->state > st->target; st->state--) {
+ struct cpuhp_step *step = cpuhp_bp_states + st->state;
+
+ ret = cpuhp_invoke_callback(cpu, st->state, step->teardown);
+ if (ret) {
+ st->target = prev_state;
+ undo_cpu_down(cpu, st);
+ break;
+ }
+ }
+ hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE;
-out_release:
cpu_hotplug_done();
- if (!err)
- cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
- return err;
+ /* This post dead nonsense must die */
+ if (!ret && hasdied)
+ cpu_notify_nofail(CPU_POST_DEAD, cpu);
+ return ret;
}
-int cpu_down(unsigned int cpu)
+static int do_cpu_down(unsigned int cpu, enum cpuhp_state target)
{
int err;
goto out;
}
- err = _cpu_down(cpu, 0);
+ err = _cpu_down(cpu, 0, target);
out:
cpu_maps_update_done();
return err;
}
+int cpu_down(unsigned int cpu)
+{
+ return do_cpu_down(cpu, CPUHP_OFFLINE);
+}
EXPORT_SYMBOL(cpu_down);
#endif /*CONFIG_HOTPLUG_CPU*/
register_cpu_notifier(&smpboot_thread_notifier);
}
+/**
+ * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
+ * @cpu: cpu that just started
+ *
+ * This function calls the cpu_chain notifiers with CPU_STARTING.
+ * It must be called by the arch code on the new cpu, before the new cpu
+ * enables interrupts and before the "boot" cpu returns from __cpu_up().
+ */
+void notify_cpu_starting(unsigned int cpu)
+{
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE);
+
+ while (st->state < target) {
+ struct cpuhp_step *step;
+
+ st->state++;
+ step = cpuhp_ap_states + st->state;
+ cpuhp_invoke_callback(cpu, st->state, step->startup);
+ }
+}
+
+static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st)
+{
+ for (st->state--; st->state > st->target; st->state--) {
+ struct cpuhp_step *step = cpuhp_bp_states + st->state;
+
+ if (!step->skip_onerr)
+ cpuhp_invoke_callback(cpu, st->state, step->teardown);
+ }
+}
+
/* Requires cpu_add_remove_lock to be held */
-static int _cpu_up(unsigned int cpu, int tasks_frozen)
+static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target)
{
- int ret, nr_calls = 0;
- void *hcpu = (void *)(long)cpu;
- unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
struct task_struct *idle;
+ int prev_state, ret = 0;
cpu_hotplug_begin();
goto out;
}
+ /* Let it fail before we try to bring the cpu up */
idle = idle_thread_get(cpu);
if (IS_ERR(idle)) {
ret = PTR_ERR(idle);
goto out;
}
- ret = smpboot_create_threads(cpu);
- if (ret)
- goto out;
-
- ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
- if (ret) {
- nr_calls--;
- pr_warn("%s: attempt to bring up CPU %u failed\n",
- __func__, cpu);
- goto out_notify;
- }
-
- /* Arch-specific enabling code. */
- ret = __cpu_up(cpu, idle);
-
- if (ret != 0)
- goto out_notify;
- BUG_ON(!cpu_online(cpu));
+ cpuhp_tasks_frozen = tasks_frozen;
- /* Now call notifier in preparation. */
- cpu_notify(CPU_ONLINE | mod, hcpu);
+ prev_state = st->state;
+ st->target = target;
+ while (st->state < st->target) {
+ struct cpuhp_step *step;
-out_notify:
- if (ret != 0)
- __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
+ st->state++;
+ step = cpuhp_bp_states + st->state;
+ ret = cpuhp_invoke_callback(cpu, st->state, step->startup);
+ if (ret) {
+ st->target = prev_state;
+ undo_cpu_up(cpu, st);
+ break;
+ }
+ }
out:
cpu_hotplug_done();
-
return ret;
}
-int cpu_up(unsigned int cpu)
+static int do_cpu_up(unsigned int cpu, enum cpuhp_state target)
{
int err = 0;
goto out;
}
- err = _cpu_up(cpu, 0);
-
+ err = _cpu_up(cpu, 0, target);
out:
cpu_maps_update_done();
return err;
}
+
+int cpu_up(unsigned int cpu)
+{
+ return do_cpu_up(cpu, CPUHP_ONLINE);
+}
EXPORT_SYMBOL_GPL(cpu_up);
#ifdef CONFIG_PM_SLEEP_SMP
if (cpu == first_cpu)
continue;
trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
- error = _cpu_down(cpu, 1);
+ error = _cpu_down(cpu, 1, CPUHP_OFFLINE);
trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
if (!error)
cpumask_set_cpu(cpu, frozen_cpus);
for_each_cpu(cpu, frozen_cpus) {
trace_suspend_resume(TPS("CPU_ON"), cpu, true);
- error = _cpu_up(cpu, 1);
+ error = _cpu_up(cpu, 1, CPUHP_ONLINE);
trace_suspend_resume(TPS("CPU_ON"), cpu, false);
if (!error) {
pr_info("CPU%d is up\n", cpu);
#endif /* CONFIG_PM_SLEEP_SMP */
-/**
- * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
- * @cpu: cpu that just started
- *
- * This function calls the cpu_chain notifiers with CPU_STARTING.
- * It must be called by the arch code on the new cpu, before the new cpu
- * enables interrupts and before the "boot" cpu returns from __cpu_up().
- */
-void notify_cpu_starting(unsigned int cpu)
-{
- unsigned long val = CPU_STARTING;
+#endif /* CONFIG_SMP */
-#ifdef CONFIG_PM_SLEEP_SMP
- if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus))
- val = CPU_STARTING_FROZEN;
-#endif /* CONFIG_PM_SLEEP_SMP */
- cpu_notify(val, (void *)(long)cpu);
-}
+/* Boot processor state steps */
+static struct cpuhp_step cpuhp_bp_states[] = {
+ [CPUHP_OFFLINE] = {
+ .name = "offline",
+ .startup = NULL,
+ .teardown = NULL,
+ },
+#ifdef CONFIG_SMP
+ [CPUHP_CREATE_THREADS]= {
+ .name = "threads:create",
+ .startup = smpboot_create_threads,
+ .teardown = NULL,
+ },
+ [CPUHP_NOTIFY_PREPARE] = {
+ .name = "notify:prepare",
+ .startup = notify_prepare,
+ .teardown = notify_dead,
+ .skip_onerr = true,
+ },
+ [CPUHP_BRINGUP_CPU] = {
+ .name = "cpu:bringup",
+ .startup = bringup_cpu,
+ .teardown = NULL,
+ },
+ [CPUHP_TEARDOWN_CPU] = {
+ .name = "cpu:teardown",
+ .startup = NULL,
+ .teardown = takedown_cpu,
+ },
+ [CPUHP_NOTIFY_ONLINE] = {
+ .name = "notify:online",
+ .startup = notify_online,
+ .teardown = notify_down_prepare,
+ },
+#endif
+ [CPUHP_ONLINE] = {
+ .name = "online",
+ .startup = NULL,
+ .teardown = NULL,
+ },
+};
-#endif /* CONFIG_SMP */
+/* Application processor state steps */
+static struct cpuhp_step cpuhp_ap_states[] = {
+#ifdef CONFIG_SMP
+ [CPUHP_AP_NOTIFY_STARTING] = {
+ .name = "notify:starting",
+ .startup = notify_starting,
+ .teardown = notify_dying,
+ .skip_onerr = true,
+ },
+#endif
+ [CPUHP_ONLINE] = {
+ .name = "online",
+ .startup = NULL,
+ .teardown = NULL,
+ },
+};
/*
* cpu_bit_bitmap[] is a special, "compressed" data structure that
EXPORT_SYMBOL(cpu_all_bits);
#ifdef CONFIG_INIT_ALL_POSSIBLE
-static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly
- = CPU_BITS_ALL;
+struct cpumask __cpu_possible_mask __read_mostly
+ = {CPU_BITS_ALL};
#else
-static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly;
+struct cpumask __cpu_possible_mask __read_mostly;
#endif
-const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits);
-EXPORT_SYMBOL(cpu_possible_mask);
+EXPORT_SYMBOL(__cpu_possible_mask);
-static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly;
-const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits);
-EXPORT_SYMBOL(cpu_online_mask);
+struct cpumask __cpu_online_mask __read_mostly;
+EXPORT_SYMBOL(__cpu_online_mask);
-static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly;
-const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits);
-EXPORT_SYMBOL(cpu_present_mask);
+struct cpumask __cpu_present_mask __read_mostly;
+EXPORT_SYMBOL(__cpu_present_mask);
-static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly;
-const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits);
-EXPORT_SYMBOL(cpu_active_mask);
+struct cpumask __cpu_active_mask __read_mostly;
+EXPORT_SYMBOL(__cpu_active_mask);
-void set_cpu_possible(unsigned int cpu, bool possible)
+void init_cpu_present(const struct cpumask *src)
{
- if (possible)
- cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits));
- else
- cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits));
+ cpumask_copy(&__cpu_present_mask, src);
}
-void set_cpu_present(unsigned int cpu, bool present)
+void init_cpu_possible(const struct cpumask *src)
{
- if (present)
- cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits));
- else
- cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits));
+ cpumask_copy(&__cpu_possible_mask, src);
}
-void set_cpu_online(unsigned int cpu, bool online)
-{
- if (online) {
- cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits));
- cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits));
- } else {
- cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits));
- }
-}
-
-void set_cpu_active(unsigned int cpu, bool active)
+void init_cpu_online(const struct cpumask *src)
{
- if (active)
- cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits));
- else
- cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits));
+ cpumask_copy(&__cpu_online_mask, src);
}
-void init_cpu_present(const struct cpumask *src)
+/*
+ * Activate the first processor.
+ */
+void __init boot_cpu_init(void)
{
- cpumask_copy(to_cpumask(cpu_present_bits), src);
-}
+ int cpu = smp_processor_id();
-void init_cpu_possible(const struct cpumask *src)
-{
- cpumask_copy(to_cpumask(cpu_possible_bits), src);
+ /* Mark the boot cpu "present", "online" etc for SMP and UP case */
+ set_cpu_online(cpu, true);
+ set_cpu_active(cpu, true);
+ set_cpu_present(cpu, true);
+ set_cpu_possible(cpu, true);
}
-void init_cpu_online(const struct cpumask *src)
+/*
+ * Must be called _AFTER_ setting up the per_cpu areas
+ */
+void __init boot_cpu_state_init(void)
{
- cpumask_copy(to_cpumask(cpu_online_bits), src);
+ per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE;
}
projects / linux-beck.git / blobdiff