12 #include <linux/sched/hotplug.h>
48  * struct cpuhp_cpu_state - Per cpu hotplug state storage
51  * @fail:	Current CPU hotplug callback state
52  * @thread:	Pointer to the hotplug thread
118  * struct cpuhp_step - Hotplug state machine step
165  * Called from cpu hotplug and from the state register machinery.
519 	 * We can't have hotplug operations before userspace starts running,  in lockdep_assert_cpus_held()
520 	 * and some init codepaths will knowingly not take the hotplug lock.  in lockdep_assert_cpus_held()
557  * Wait for currently running CPU hotplug operations to complete (if any) and
558  * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects
560  * hotplug path before performing hotplug operations. So acquiring that lock
561  * guarantees mutual exclusion from any currently running hotplug operations.
573 	if (WARN_ONCE(!cpu_hotplug_disabled, "Unbalanced cpu hotplug enable\n"))  in __cpu_hotplug_enable()
599  * Architectures that need SMT-specific errata handling during SMT hotplug
760 /* Regular hotplug invocation of the AP hotplug thread */
802 	/* Unpark the hotplug thread of the target cpu */  in bringup_wait_for_ap_online()
920  * Hotplug state machine related functions
1007 	 * When CPU hotplug is disabled, then taking the CPU down is not  in can_rollback_cpu()
1037  * The cpu hotplug threads manage the bringup and teardown of the cpus
1076 	 * The BP holds the hotplug lock, but we're now running on the AP,  in cpuhp_thread_fun()
1143 	 * If we are up and running, use the hotplug thread. For early calls  in cpuhp_invoke_ap_callback()
1170 	 * Clean up the leftovers so the next hotplug operation wont use stale  in cpuhp_invoke_ap_callback()
1318 		/* Unpark the hotplug thread so we can rollback there */  in takedown_cpu()
1419 	 * If the current CPU state is in the range of the AP hotplug thread,  in _cpu_down()
1433 		 * We might have stopped still in the range of the AP hotplug  in _cpu_down()
1478 	 * If the platform does not support hotplug, report it explicitly to  in cpu_down_maps_locked()
1605  * hotplug thread of the upcoming CPU up and then delegates the rest of the
1606  * online bringup to the hotplug thread.
1668 	 * If the current CPU state is in the range of the AP hotplug thread,  in _cpu_up()
1683 	 * CPUHP_BRINGUP_CPU. After that the AP hotplug thread is  in _cpu_up()
1915 	 * with the userspace trying to use the CPU hotplug at the same time  in freeze_secondary_cpus()
1969 	/* Allow everyone to use the CPU hotplug again */  in thaw_secondary_cpus()
2006  * When callbacks for CPU hotplug notifications are being executed, we must
2010  * Hence we need to prevent the freezer from racing with regular CPU hotplug.
2013  * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/
2045 	 * to disable cpu hotplug to avoid cpu hotplug race.  in cpu_hotplug_pm_sync_init()
2302 	WARN(1, "No more dynamic states available for CPU hotplug\n");  in cpuhp_reserve_state()
2311 	/* (Un)Install the callbacks for further cpu hotplug operations */  in cpuhp_store_callbacks()
2322 	 * dangling, which causes wreckage on the next hotplug operation.  in cpuhp_store_callbacks()
2425 	 * depending on the hotplug state of the cpu.  in __cpuhp_state_add_instance_cpuslocked()
2462  * __cpuhp_setup_state_cpuslocked - Setup the callbacks for an hotplug machine state
2509 	 * depending on the hotplug state of the cpu.  in __cpuhp_setup_state_cpuslocked()
2572 	 * on the hotplug state of the cpu. This function is not  in __cpuhp_state_remove_instance()
2593  * __cpuhp_remove_state_cpuslocked - Remove the callbacks for an hotplug machine state
2624 	 * on the hotplug state of the cpu. This function is not  in __cpuhp_remove_state_cpuslocked()
2689 		 * abusers of the hotplug machinery (thermal management).  in cpuhp_smt_disable()
2694 		 * called under the sysfs hotplug lock, so it is properly  in cpuhp_smt_disable()
2865 	.name = "hotplug",
2896 	.name = "hotplug",
3134 	 * regular CPU hotplug is properly serialized.  in set_cpu_online()
3138 	 * concurrent hotplug operations.  in set_cpu_online()