#include <linux/tick.h>
#include <linux/irq.h>
#include <linux/smpboot.h>
+#include <linux/relay.h>
+#include <linux/slab.h>
#include <trace/events/power.h>
#define CREATE_TRACE_POINTS
* @thread: Pointer to the hotplug thread
* @should_run: Thread should execute
* @rollback: Perform a rollback
- * @cb_stat: The state for a single callback (install/uninstall)
- * @cb: Single callback function (install/uninstall)
+ * @single: Single callback invocation
+ * @bringup: Single callback bringup or teardown selector
+ * @cb_state: The state for a single callback (install/uninstall)
* @result: Result of the operation
* @done: Signal completion to the issuer of the task
*/
struct task_struct *thread;
bool should_run;
bool rollback;
+ bool single;
+ bool bringup;
+ struct hlist_node *node;
enum cpuhp_state cb_state;
- int (*cb)(unsigned int cpu);
int result;
struct completion done;
#endif
* @cant_stop: Bringup/teardown can't be stopped at this step
*/
struct cpuhp_step {
- const char *name;
- int (*startup)(unsigned int cpu);
- int (*teardown)(unsigned int cpu);
- bool skip_onerr;
- bool cant_stop;
+ const char *name;
+ union {
+ int (*single)(unsigned int cpu);
+ int (*multi)(unsigned int cpu,
+ struct hlist_node *node);
+ } startup;
+ union {
+ int (*single)(unsigned int cpu);
+ int (*multi)(unsigned int cpu,
+ struct hlist_node *node);
+ } teardown;
+ struct hlist_head list;
+ bool skip_onerr;
+ bool cant_stop;
+ bool multi_instance;
};
static DEFINE_MUTEX(cpuhp_state_mutex);
static struct cpuhp_step cpuhp_bp_states[];
static struct cpuhp_step cpuhp_ap_states[];
+static bool cpuhp_is_ap_state(enum cpuhp_state state)
+{
+ /*
+ * The extra check for CPUHP_TEARDOWN_CPU is only for documentation
+ * purposes as that state is handled explicitly in cpu_down.
+ */
+ return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU;
+}
+
+static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state)
+{
+ struct cpuhp_step *sp;
+
+ sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states;
+ return sp + state;
+}
+
/**
* 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
+ * @bringup: True if the bringup callback should be invoked
*
- * Called from cpu hotplug and from the state register machinery
+ * 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))
+static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state,
+ bool bringup, struct hlist_node *node)
{
struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
- int ret = 0;
-
- if (cb) {
- trace_cpuhp_enter(cpu, st->target, step, cb);
+ struct cpuhp_step *step = cpuhp_get_step(state);
+ int (*cbm)(unsigned int cpu, struct hlist_node *node);
+ int (*cb)(unsigned int cpu);
+ int ret, cnt;
+
+ if (!step->multi_instance) {
+ cb = bringup ? step->startup.single : step->teardown.single;
+ if (!cb)
+ return 0;
+ trace_cpuhp_enter(cpu, st->target, state, cb);
ret = cb(cpu);
- trace_cpuhp_exit(cpu, st->state, step, ret);
+ trace_cpuhp_exit(cpu, st->state, state, ret);
+ return ret;
+ }
+ cbm = bringup ? step->startup.multi : step->teardown.multi;
+ if (!cbm)
+ return 0;
+
+ /* Single invocation for instance add/remove */
+ if (node) {
+ trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node);
+ ret = cbm(cpu, node);
+ trace_cpuhp_exit(cpu, st->state, state, ret);
+ return ret;
+ }
+
+ /* State transition. Invoke on all instances */
+ cnt = 0;
+ hlist_for_each(node, &step->list) {
+ trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node);
+ ret = cbm(cpu, node);
+ trace_cpuhp_exit(cpu, st->state, state, ret);
+ if (ret)
+ goto err;
+ cnt++;
+ }
+ return 0;
+err:
+ /* Rollback the instances if one failed */
+ cbm = !bringup ? step->startup.multi : step->teardown.multi;
+ if (!cbm)
+ return ret;
+
+ hlist_for_each(node, &step->list) {
+ if (!cnt--)
+ break;
+ cbm(cpu, node);
}
return ret;
}
/*
* 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
.wq = __WAIT_QUEUE_HEAD_INITIALIZER(cpu_hotplug.wq),
.lock = __MUTEX_INITIALIZER(cpu_hotplug.lock),
#ifdef CONFIG_DEBUG_LOCK_ALLOC
- .dep_map = {.name = "cpu_hotplug.lock" },
+ .dep_map = STATIC_LOCKDEP_MAP_INIT("cpu_hotplug.dep_map", &cpu_hotplug.dep_map),
#endif
};
}
EXPORT_SYMBOL_GPL(cpu_hotplug_disable);
-void cpu_hotplug_enable(void)
+static void __cpu_hotplug_enable(void)
{
- cpu_maps_update_begin();
- WARN_ON(--cpu_hotplug_disabled < 0);
- cpu_maps_update_done();
+ if (WARN_ONCE(!cpu_hotplug_disabled, "Unbalanced cpu hotplug enable\n"))
+ return;
+ cpu_hotplug_disabled--;
}
-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)
+void cpu_hotplug_enable(void)
{
- int ret;
cpu_maps_update_begin();
- ret = raw_notifier_chain_register(&cpu_chain, nb);
+ __cpu_hotplug_enable();
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));
}
+EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
+#endif /* 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 int bringup_wait_for_ap(unsigned int cpu)
{
struct task_struct *idle = idle_thread_get(cpu);
int ret;
+ /*
+ * Some architectures have to walk the irq descriptors to
+ * setup the vector space for the cpu which comes online.
+ * Prevent irq alloc/free across the bringup.
+ */
+ irq_lock_sparse();
+
/* Arch-specific enabling code. */
ret = __cpu_up(cpu, idle);
- if (ret) {
- cpu_notify(CPU_UP_CANCELED, cpu);
+ irq_unlock_sparse();
+ if (ret)
return ret;
- }
ret = bringup_wait_for_ap(cpu);
BUG_ON(!cpu_online(cpu));
return ret;
/*
* Hotplug state machine related functions
*/
-static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st,
- struct cpuhp_step *steps)
+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 = steps + st->state;
+ struct cpuhp_step *step = cpuhp_get_step(st->state);
if (!step->skip_onerr)
- cpuhp_invoke_callback(cpu, st->state, step->startup);
+ cpuhp_invoke_callback(cpu, st->state, true, NULL);
}
}
static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st,
- struct cpuhp_step *steps, enum cpuhp_state target)
+ enum cpuhp_state target)
{
enum cpuhp_state prev_state = st->state;
int ret = 0;
for (; st->state > target; st->state--) {
- struct cpuhp_step *step = steps + st->state;
-
- ret = cpuhp_invoke_callback(cpu, st->state, step->teardown);
+ ret = cpuhp_invoke_callback(cpu, st->state, false, NULL);
if (ret) {
st->target = prev_state;
- undo_cpu_down(cpu, st, steps);
+ undo_cpu_down(cpu, st);
break;
}
}
return ret;
}
-static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st,
- struct cpuhp_step *steps)
+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 = steps + st->state;
+ struct cpuhp_step *step = cpuhp_get_step(st->state);
if (!step->skip_onerr)
- cpuhp_invoke_callback(cpu, st->state, step->teardown);
+ cpuhp_invoke_callback(cpu, st->state, false, NULL);
}
}
static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st,
- struct cpuhp_step *steps, enum cpuhp_state target)
+ enum cpuhp_state target)
{
enum cpuhp_state prev_state = st->state;
int ret = 0;
while (st->state < target) {
- struct cpuhp_step *step;
-
st->state++;
- step = steps + st->state;
- ret = cpuhp_invoke_callback(cpu, st->state, step->startup);
+ ret = cpuhp_invoke_callback(cpu, st->state, true, NULL);
if (ret) {
st->target = prev_state;
- undo_cpu_up(cpu, st, steps);
+ undo_cpu_up(cpu, st);
break;
}
}
{
enum cpuhp_state target = max((int)st->target, CPUHP_TEARDOWN_CPU);
- return cpuhp_down_callbacks(cpu, st, cpuhp_ap_states, target);
+ return cpuhp_down_callbacks(cpu, st, target);
}
/* Execute the online startup callbacks. Used to be CPU_ONLINE */
static int cpuhp_ap_online(unsigned int cpu, struct cpuhp_cpu_state *st)
{
- return cpuhp_up_callbacks(cpu, st, cpuhp_ap_states, st->target);
+ return cpuhp_up_callbacks(cpu, st, st->target);
}
/*
st->should_run = false;
/* Single callback invocation for [un]install ? */
- if (st->cb) {
+ if (st->single) {
if (st->cb_state < CPUHP_AP_ONLINE) {
local_irq_disable();
- ret = cpuhp_invoke_callback(cpu, st->cb_state, st->cb);
+ ret = cpuhp_invoke_callback(cpu, st->cb_state,
+ st->bringup, st->node);
local_irq_enable();
} else {
- ret = cpuhp_invoke_callback(cpu, st->cb_state, st->cb);
+ ret = cpuhp_invoke_callback(cpu, st->cb_state,
+ st->bringup, st->node);
}
} else if (st->rollback) {
BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE);
- undo_cpu_down(cpu, st, cpuhp_ap_states);
- /*
- * 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);
+ undo_cpu_down(cpu, st);
st->rollback = false;
} else {
/* Cannot happen .... */
}
/* Invoke a single callback on a remote cpu */
-static int cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state,
- int (*cb)(unsigned int))
+static int
+cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state, bool bringup,
+ struct hlist_node *node)
{
struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
* we invoke the thread function directly.
*/
if (!st->thread)
- return cpuhp_invoke_callback(cpu, state, cb);
+ return cpuhp_invoke_callback(cpu, state, bringup, node);
st->cb_state = state;
- st->cb = cb;
+ st->single = true;
+ st->bringup = bringup;
+ st->node = node;
+
/*
* Make sure the above stores are visible before should_run becomes
* true. Paired with the mb() above in cpuhp_thread_fun()
static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st)
{
st->result = 0;
- st->cb = NULL;
+ st->single = false;
/*
* Make sure the above stores are visible before should_run becomes
* true. Paired with the mb() above in cpuhp_thread_fun()
}
#ifdef CONFIG_HOTPLUG_CPU
-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);
-
/**
* clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU
* @cpu: a CPU id
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;
-}
-
-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)
{
if (err < 0)
return err;
+ /*
+ * We get here while we are in CPUHP_TEARDOWN_CPU state and we must not
+ * do this step again.
+ */
+ WARN_ON(st->state != CPUHP_TEARDOWN_CPU);
+ st->state--;
/* Invoke the former CPU_DYING callbacks */
- for (; st->state > target; st->state--) {
- struct cpuhp_step *step = cpuhp_ap_states + st->state;
+ for (; st->state > target; st->state--)
+ cpuhp_invoke_callback(cpu, st->state, false, NULL);
- cpuhp_invoke_callback(cpu, st->state, step->teardown);
- }
/* Give up timekeeping duties */
tick_handover_do_timer();
/* Park the stopper thread */
BUG_ON(cpu_online(cpu));
/*
- * The migration_call() CPU_DYING callback will have removed all
+ * The CPUHP_AP_SCHED_MIGRATE_DYING callback will have removed all
* runnable tasks from the cpu, there's only the idle task left now
* that the migration thread is done doing the stop_machine thing.
*
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
-#define notify_dying NULL
#endif
#ifdef CONFIG_HOTPLUG_CPU
{
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;
* The AP brought itself down to CPUHP_TEARDOWN_CPU. So we need
* to do the further cleanups.
*/
- ret = cpuhp_down_callbacks(cpu, st, cpuhp_bp_states, target);
+ ret = cpuhp_down_callbacks(cpu, st, target);
if (ret && st->state > CPUHP_TEARDOWN_CPU && st->state < prev_state) {
st->target = prev_state;
st->rollback = true;
cpuhp_kick_ap_work(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;
}
#endif /*CONFIG_HOTPLUG_CPU*/
/**
- * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
+ * notify_cpu_starting(cpu) - Invoke the callbacks on the starting CPU
* @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().
*/
struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE);
+ rcu_cpu_starting(cpu); /* Enables RCU usage on this CPU. */
while (st->state < target) {
- struct cpuhp_step *step;
-
st->state++;
- step = cpuhp_ap_states + st->state;
- cpuhp_invoke_callback(cpu, st->state, step->startup);
+ cpuhp_invoke_callback(cpu, st->state, true, NULL);
}
}
* responsible for bringing it up to the target state.
*/
target = min((int)target, CPUHP_BRINGUP_CPU);
- ret = cpuhp_up_callbacks(cpu, st, cpuhp_bp_states, target);
+ ret = cpuhp_up_callbacks(cpu, st, target);
out:
cpu_hotplug_done();
return ret;
#ifdef CONFIG_PM_SLEEP_SMP
static cpumask_var_t frozen_cpus;
-int disable_nonboot_cpus(void)
+int freeze_secondary_cpus(int primary)
{
- int cpu, first_cpu, error = 0;
+ int cpu, error = 0;
cpu_maps_update_begin();
- first_cpu = cpumask_first(cpu_online_mask);
+ if (!cpu_online(primary))
+ primary = cpumask_first(cpu_online_mask);
/*
* We take down all of the non-boot CPUs in one shot to avoid races
* with the userspace trying to use the CPU hotplug at the same time
pr_info("Disabling non-boot CPUs ...\n");
for_each_online_cpu(cpu) {
- if (cpu == first_cpu)
+ if (cpu == primary)
continue;
trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
error = _cpu_down(cpu, 1, CPUHP_OFFLINE);
/* Allow everyone to use the CPU hotplug again */
cpu_maps_update_begin();
- WARN_ON(--cpu_hotplug_disabled < 0);
+ __cpu_hotplug_enable();
if (cpumask_empty(frozen_cpus))
goto out;
static struct cpuhp_step cpuhp_bp_states[] = {
[CPUHP_OFFLINE] = {
.name = "offline",
- .startup = NULL,
- .teardown = NULL,
+ .startup.single = NULL,
+ .teardown.single = NULL,
},
#ifdef CONFIG_SMP
[CPUHP_CREATE_THREADS]= {
- .name = "threads:create",
- .startup = smpboot_create_threads,
- .teardown = NULL,
+ .name = "threads:prepare",
+ .startup.single = smpboot_create_threads,
+ .teardown.single = NULL,
.cant_stop = true,
},
[CPUHP_PERF_PREPARE] = {
- .name = "perf prepare",
- .startup = perf_event_init_cpu,
- .teardown = perf_event_exit_cpu,
+ .name = "perf:prepare",
+ .startup.single = perf_event_init_cpu,
+ .teardown.single = perf_event_exit_cpu,
},
[CPUHP_WORKQUEUE_PREP] = {
- .name = "workqueue prepare",
- .startup = workqueue_prepare_cpu,
- .teardown = NULL,
+ .name = "workqueue:prepare",
+ .startup.single = workqueue_prepare_cpu,
+ .teardown.single = NULL,
},
[CPUHP_HRTIMERS_PREPARE] = {
- .name = "hrtimers prepare",
- .startup = hrtimers_prepare_cpu,
- .teardown = hrtimers_dead_cpu,
+ .name = "hrtimers:prepare",
+ .startup.single = hrtimers_prepare_cpu,
+ .teardown.single = hrtimers_dead_cpu,
},
[CPUHP_SMPCFD_PREPARE] = {
- .name = "SMPCFD prepare",
- .startup = smpcfd_prepare_cpu,
- .teardown = smpcfd_dead_cpu,
+ .name = "smpcfd:prepare",
+ .startup.single = smpcfd_prepare_cpu,
+ .teardown.single = smpcfd_dead_cpu,
},
- [CPUHP_RCUTREE_PREP] = {
- .name = "RCU-tree prepare",
- .startup = rcutree_prepare_cpu,
- .teardown = rcutree_dead_cpu,
+ [CPUHP_RELAY_PREPARE] = {
+ .name = "relay:prepare",
+ .startup.single = relay_prepare_cpu,
+ .teardown.single = NULL,
},
- /*
- * Preparatory and dead notifiers. Will be replaced once the notifiers
- * are converted to states.
- */
- [CPUHP_NOTIFY_PREPARE] = {
- .name = "notify:prepare",
- .startup = notify_prepare,
- .teardown = notify_dead,
- .skip_onerr = true,
- .cant_stop = true,
+ [CPUHP_SLAB_PREPARE] = {
+ .name = "slab:prepare",
+ .startup.single = slab_prepare_cpu,
+ .teardown.single = slab_dead_cpu,
+ },
+ [CPUHP_RCUTREE_PREP] = {
+ .name = "RCU/tree:prepare",
+ .startup.single = rcutree_prepare_cpu,
+ .teardown.single = rcutree_dead_cpu,
},
/*
* On the tear-down path, timers_dead_cpu() must be invoked
* otherwise a RCU stall occurs.
*/
[CPUHP_TIMERS_DEAD] = {
- .name = "timers dead",
- .startup = NULL,
- .teardown = timers_dead_cpu,
+ .name = "timers:dead",
+ .startup.single = NULL,
+ .teardown.single = timers_dead_cpu,
},
/* Kicks the plugged cpu into life */
[CPUHP_BRINGUP_CPU] = {
.name = "cpu:bringup",
- .startup = bringup_cpu,
- .teardown = NULL,
+ .startup.single = bringup_cpu,
+ .teardown.single = NULL,
.cant_stop = true,
},
[CPUHP_AP_SMPCFD_DYING] = {
- .startup = NULL,
- .teardown = smpcfd_dying_cpu,
+ .name = "smpcfd:dying",
+ .startup.single = NULL,
+ .teardown.single = smpcfd_dying_cpu,
},
/*
* Handled on controll processor until the plugged processor manages
*/
[CPUHP_TEARDOWN_CPU] = {
.name = "cpu:teardown",
- .startup = NULL,
- .teardown = takedown_cpu,
+ .startup.single = NULL,
+ .teardown.single = takedown_cpu,
.cant_stop = true,
},
#else
/* First state is scheduler control. Interrupts are disabled */
[CPUHP_AP_SCHED_STARTING] = {
.name = "sched:starting",
- .startup = sched_cpu_starting,
- .teardown = sched_cpu_dying,
+ .startup.single = sched_cpu_starting,
+ .teardown.single = sched_cpu_dying,
},
[CPUHP_AP_RCUTREE_DYING] = {
- .startup = NULL,
- .teardown = rcutree_dying_cpu,
- },
- /*
- * Low level startup/teardown notifiers. Run with interrupts
- * disabled. Will be removed once the notifiers are converted to
- * states.
- */
- [CPUHP_AP_NOTIFY_STARTING] = {
- .name = "notify:starting",
- .startup = notify_starting,
- .teardown = notify_dying,
- .skip_onerr = true,
- .cant_stop = true,
+ .name = "RCU/tree:dying",
+ .startup.single = NULL,
+ .teardown.single = rcutree_dying_cpu,
},
/* Entry state on starting. Interrupts enabled from here on. Transient
* state for synchronsization */
},
/* Handle smpboot threads park/unpark */
[CPUHP_AP_SMPBOOT_THREADS] = {
- .name = "smpboot:threads",
- .startup = smpboot_unpark_threads,
- .teardown = NULL,
+ .name = "smpboot/threads:online",
+ .startup.single = smpboot_unpark_threads,
+ .teardown.single = NULL,
},
[CPUHP_AP_PERF_ONLINE] = {
- .name = "perf online",
- .startup = perf_event_init_cpu,
- .teardown = perf_event_exit_cpu,
+ .name = "perf:online",
+ .startup.single = perf_event_init_cpu,
+ .teardown.single = perf_event_exit_cpu,
},
[CPUHP_AP_WORKQUEUE_ONLINE] = {
- .name = "workqueue online",
- .startup = workqueue_online_cpu,
- .teardown = workqueue_offline_cpu,
+ .name = "workqueue:online",
+ .startup.single = workqueue_online_cpu,
+ .teardown.single = workqueue_offline_cpu,
},
[CPUHP_AP_RCUTREE_ONLINE] = {
- .name = "RCU-tree online",
- .startup = rcutree_online_cpu,
- .teardown = 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 = notify_online,
- .teardown = notify_down_prepare,
- .skip_onerr = true,
+ .name = "RCU/tree:online",
+ .startup.single = rcutree_online_cpu,
+ .teardown.single = rcutree_offline_cpu,
},
#endif
/*
/* Last state is scheduler control setting the cpu active */
[CPUHP_AP_ACTIVE] = {
.name = "sched:active",
- .startup = sched_cpu_activate,
- .teardown = sched_cpu_deactivate,
+ .startup.single = sched_cpu_activate,
+ .teardown.single = sched_cpu_deactivate,
},
#endif
/* CPU is fully up and running. */
[CPUHP_ONLINE] = {
.name = "online",
- .startup = NULL,
- .teardown = NULL,
+ .startup.single = NULL,
+ .teardown.single = NULL,
},
};
return 0;
}
-static bool cpuhp_is_ap_state(enum cpuhp_state state)
+/*
+ * Returns a free for dynamic slot assignment of the Online state. The states
+ * are protected by the cpuhp_slot_states mutex and an empty slot is identified
+ * by having no name assigned.
+ */
+static int cpuhp_reserve_state(enum cpuhp_state state)
{
- /*
- * The extra check for CPUHP_TEARDOWN_CPU is only for documentation
- * purposes as that state is handled explicitely in cpu_down.
- */
- return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU;
-}
+ enum cpuhp_state i, end;
+ struct cpuhp_step *step;
-static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state)
-{
- struct cpuhp_step *sp;
+ switch (state) {
+ case CPUHP_AP_ONLINE_DYN:
+ step = cpuhp_ap_states + CPUHP_AP_ONLINE_DYN;
+ end = CPUHP_AP_ONLINE_DYN_END;
+ break;
+ case CPUHP_BP_PREPARE_DYN:
+ step = cpuhp_bp_states + CPUHP_BP_PREPARE_DYN;
+ end = CPUHP_BP_PREPARE_DYN_END;
+ break;
+ default:
+ return -EINVAL;
+ }
- sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states;
- return sp + state;
+ for (i = state; i <= end; i++, step++) {
+ if (!step->name)
+ return i;
+ }
+ WARN(1, "No more dynamic states available for CPU hotplug\n");
+ return -ENOSPC;
}
-static void cpuhp_store_callbacks(enum cpuhp_state state,
- const char *name,
- int (*startup)(unsigned int cpu),
- int (*teardown)(unsigned int cpu))
+static int cpuhp_store_callbacks(enum cpuhp_state state, const char *name,
+ int (*startup)(unsigned int cpu),
+ int (*teardown)(unsigned int cpu),
+ bool multi_instance)
{
/* (Un)Install the callbacks for further cpu hotplug operations */
struct cpuhp_step *sp;
+ int ret = 0;
mutex_lock(&cpuhp_state_mutex);
+
+ if (state == CPUHP_AP_ONLINE_DYN || state == CPUHP_BP_PREPARE_DYN) {
+ ret = cpuhp_reserve_state(state);
+ if (ret < 0)
+ goto out;
+ state = ret;
+ }
sp = cpuhp_get_step(state);
- sp->startup = startup;
- sp->teardown = teardown;
+ if (name && sp->name) {
+ ret = -EBUSY;
+ goto out;
+ }
+ sp->startup.single = startup;
+ sp->teardown.single = teardown;
sp->name = name;
+ sp->multi_instance = multi_instance;
+ INIT_HLIST_HEAD(&sp->list);
+out:
mutex_unlock(&cpuhp_state_mutex);
+ return ret;
}
static void *cpuhp_get_teardown_cb(enum cpuhp_state state)
{
- return cpuhp_get_step(state)->teardown;
+ return cpuhp_get_step(state)->teardown.single;
}
/*
* Call the startup/teardown function for a step either on the AP or
* on the current CPU.
*/
-static int cpuhp_issue_call(int cpu, enum cpuhp_state state,
- int (*cb)(unsigned int), bool bringup)
+static int cpuhp_issue_call(int cpu, enum cpuhp_state state, bool bringup,
+ struct hlist_node *node)
{
+ struct cpuhp_step *sp = cpuhp_get_step(state);
int ret;
- if (!cb)
+ if ((bringup && !sp->startup.single) ||
+ (!bringup && !sp->teardown.single))
return 0;
/*
* The non AP bound callbacks can fail on bringup. On teardown
*/
#ifdef CONFIG_SMP
if (cpuhp_is_ap_state(state))
- ret = cpuhp_invoke_ap_callback(cpu, state, cb);
+ ret = cpuhp_invoke_ap_callback(cpu, state, bringup, node);
else
- ret = cpuhp_invoke_callback(cpu, state, cb);
+ ret = cpuhp_invoke_callback(cpu, state, bringup, node);
#else
- ret = cpuhp_invoke_callback(cpu, state, cb);
+ ret = cpuhp_invoke_callback(cpu, state, bringup, node);
#endif
BUG_ON(ret && !bringup);
return ret;
* Note: The teardown callbacks for rollback are not allowed to fail!
*/
static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state,
- int (*teardown)(unsigned int cpu))
+ struct hlist_node *node)
{
int cpu;
- if (!teardown)
- return;
-
/* Roll back the already executed steps on the other cpus */
for_each_present_cpu(cpu) {
struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
/* Did we invoke the startup call on that cpu ? */
if (cpustate >= state)
- cpuhp_issue_call(cpu, state, teardown, false);
+ cpuhp_issue_call(cpu, state, false, node);
}
}
-/*
- * Returns a free for dynamic slot assignment of the Online state. The states
- * are protected by the cpuhp_slot_states mutex and an empty slot is identified
- * by having no name assigned.
- */
-static int cpuhp_reserve_state(enum cpuhp_state state)
+int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
+ bool invoke)
{
- enum cpuhp_state i;
+ struct cpuhp_step *sp;
+ int cpu;
+ int ret;
- mutex_lock(&cpuhp_state_mutex);
- for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) {
- if (cpuhp_ap_states[i].name)
+ sp = cpuhp_get_step(state);
+ if (sp->multi_instance == false)
+ return -EINVAL;
+
+ get_online_cpus();
+
+ if (!invoke || !sp->startup.multi)
+ goto add_node;
+
+ /*
+ * Try to call the startup callback for each present cpu
+ * depending on the hotplug state of the cpu.
+ */
+ for_each_present_cpu(cpu) {
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ int cpustate = st->state;
+
+ if (cpustate < state)
continue;
- cpuhp_ap_states[i].name = "Reserved";
- mutex_unlock(&cpuhp_state_mutex);
- return i;
+ ret = cpuhp_issue_call(cpu, state, true, node);
+ if (ret) {
+ if (sp->teardown.multi)
+ cpuhp_rollback_install(cpu, state, node);
+ goto err;
+ }
}
+add_node:
+ ret = 0;
+ mutex_lock(&cpuhp_state_mutex);
+ hlist_add_head(node, &sp->list);
mutex_unlock(&cpuhp_state_mutex);
- WARN(1, "No more dynamic states available for CPU hotplug\n");
- return -ENOSPC;
+
+err:
+ put_online_cpus();
+ return ret;
}
+EXPORT_SYMBOL_GPL(__cpuhp_state_add_instance);
/**
* __cpuhp_setup_state - Setup the callbacks for an hotplug machine state
- * @state: The state to setup
- * @invoke: If true, the startup function is invoked for cpus where
- * cpu state >= @state
- * @startup: startup callback function
- * @teardown: teardown callback function
+ * @state: The state to setup
+ * @invoke: If true, the startup function is invoked for cpus where
+ * cpu state >= @state
+ * @startup: startup callback function
+ * @teardown: teardown callback function
+ * @multi_instance: State is set up for multiple instances which get
+ * added afterwards.
*
- * Returns 0 if successful, otherwise a proper error code
+ * Returns:
+ * On success:
+ * Positive state number if @state is CPUHP_AP_ONLINE_DYN
+ * 0 for all other states
+ * On failure: proper (negative) error code
*/
int __cpuhp_setup_state(enum cpuhp_state state,
const char *name, bool invoke,
int (*startup)(unsigned int cpu),
- int (*teardown)(unsigned int cpu))
+ int (*teardown)(unsigned int cpu),
+ bool multi_instance)
{
int cpu, ret = 0;
- int dyn_state = 0;
+ bool dynstate;
if (cpuhp_cb_check(state) || !name)
return -EINVAL;
get_online_cpus();
- /* currently assignments for the ONLINE state are possible */
- if (state == CPUHP_AP_ONLINE_DYN) {
- dyn_state = 1;
- ret = cpuhp_reserve_state(state);
- if (ret < 0)
- goto out;
+ ret = cpuhp_store_callbacks(state, name, startup, teardown,
+ multi_instance);
+
+ dynstate = state == CPUHP_AP_ONLINE_DYN;
+ if (ret > 0 && dynstate) {
state = ret;
+ ret = 0;
}
- cpuhp_store_callbacks(state, name, startup, teardown);
-
- if (!invoke || !startup)
+ if (ret || !invoke || !startup)
goto out;
/*
if (cpustate < state)
continue;
- ret = cpuhp_issue_call(cpu, state, startup, true);
+ ret = cpuhp_issue_call(cpu, state, true, NULL);
if (ret) {
- cpuhp_rollback_install(cpu, state, teardown);
- cpuhp_store_callbacks(state, NULL, NULL, NULL);
+ if (teardown)
+ cpuhp_rollback_install(cpu, state, NULL);
+ cpuhp_store_callbacks(state, NULL, NULL, NULL, false);
goto out;
}
}
out:
put_online_cpus();
- if (!ret && dyn_state)
+ /*
+ * If the requested state is CPUHP_AP_ONLINE_DYN, return the
+ * dynamically allocated state in case of success.
+ */
+ if (!ret && dynstate)
return state;
return ret;
}
EXPORT_SYMBOL(__cpuhp_setup_state);
+int __cpuhp_state_remove_instance(enum cpuhp_state state,
+ struct hlist_node *node, bool invoke)
+{
+ struct cpuhp_step *sp = cpuhp_get_step(state);
+ int cpu;
+
+ BUG_ON(cpuhp_cb_check(state));
+
+ if (!sp->multi_instance)
+ return -EINVAL;
+
+ get_online_cpus();
+ if (!invoke || !cpuhp_get_teardown_cb(state))
+ goto remove;
+ /*
+ * Call the teardown callback for each present cpu depending
+ * on the hotplug state of the cpu. This function is not
+ * allowed to fail currently!
+ */
+ for_each_present_cpu(cpu) {
+ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
+ int cpustate = st->state;
+
+ if (cpustate >= state)
+ cpuhp_issue_call(cpu, state, false, node);
+ }
+
+remove:
+ mutex_lock(&cpuhp_state_mutex);
+ hlist_del(node);
+ mutex_unlock(&cpuhp_state_mutex);
+ put_online_cpus();
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__cpuhp_state_remove_instance);
/**
* __cpuhp_remove_state - Remove the callbacks for an hotplug machine state
* @state: The state to remove
*/
void __cpuhp_remove_state(enum cpuhp_state state, bool invoke)
{
- int (*teardown)(unsigned int cpu) = cpuhp_get_teardown_cb(state);
+ struct cpuhp_step *sp = cpuhp_get_step(state);
int cpu;
BUG_ON(cpuhp_cb_check(state));
get_online_cpus();
- if (!invoke || !teardown)
+ if (sp->multi_instance) {
+ WARN(!hlist_empty(&sp->list),
+ "Error: Removing state %d which has instances left.\n",
+ state);
+ goto remove;
+ }
+
+ if (!invoke || !cpuhp_get_teardown_cb(state))
goto remove;
/*
int cpustate = st->state;
if (cpustate >= state)
- cpuhp_issue_call(cpu, state, teardown, false);
+ cpuhp_issue_call(cpu, state, false, NULL);
}
remove:
- cpuhp_store_callbacks(state, NULL, NULL, NULL);
+ cpuhp_store_callbacks(state, NULL, NULL, NULL, false);
put_online_cpus();
}
EXPORT_SYMBOL(__cpuhp_remove_state);