Merge tag 'locking-urgent-2022-05-08' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-microblaze.git] / include / linux / cpuhotplug.h
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __CPUHOTPLUG_H
3 #define __CPUHOTPLUG_H
4
5 #include <linux/types.h>
6
7 /*
8  * CPU-up                       CPU-down
9  *
10  * BP           AP              BP              AP
11  *
12  * OFFLINE                      OFFLINE
13  *   |                            ^
14  *   v                            |
15  * BRINGUP_CPU->AP_OFFLINE      BRINGUP_CPU  <- AP_IDLE_DEAD (idle thread/play_dead)
16  *                |                             AP_OFFLINE
17  *                v (IRQ-off)     ,---------------^
18  *              AP_ONLNE          | (stop_machine)
19  *                |             TEARDOWN_CPU <- AP_ONLINE_IDLE
20  *                |                               ^
21  *                v                               |
22  *              AP_ACTIVE                       AP_ACTIVE
23  */
24
25 /*
26  * CPU hotplug states. The state machine invokes the installed state
27  * startup callbacks sequentially from CPUHP_OFFLINE + 1 to CPUHP_ONLINE
28  * during a CPU online operation. During a CPU offline operation the
29  * installed teardown callbacks are invoked in the reverse order from
30  * CPU_ONLINE - 1 down to CPUHP_OFFLINE.
31  *
32  * The state space has three sections: PREPARE, STARTING and ONLINE.
33  *
34  * PREPARE: The callbacks are invoked on a control CPU before the
35  * hotplugged CPU is started up or after the hotplugged CPU has died.
36  *
37  * STARTING: The callbacks are invoked on the hotplugged CPU from the low level
38  * hotplug startup/teardown code with interrupts disabled.
39  *
40  * ONLINE: The callbacks are invoked on the hotplugged CPU from the per CPU
41  * hotplug thread with interrupts and preemption enabled.
42  *
43  * Adding explicit states to this enum is only necessary when:
44  *
45  * 1) The state is within the STARTING section
46  *
47  * 2) The state has ordering constraints vs. other states in the
48  *    same section.
49  *
50  * If neither #1 nor #2 apply, please use the dynamic state space when
51  * setting up a state by using CPUHP_PREPARE_DYN or CPUHP_PREPARE_ONLINE
52  * for the @state argument of the setup function.
53  *
54  * See Documentation/core-api/cpu_hotplug.rst for further information and
55  * examples.
56  */
57 enum cpuhp_state {
58         CPUHP_INVALID = -1,
59
60         /* PREPARE section invoked on a control CPU */
61         CPUHP_OFFLINE = 0,
62         CPUHP_CREATE_THREADS,
63         CPUHP_PERF_PREPARE,
64         CPUHP_PERF_X86_PREPARE,
65         CPUHP_PERF_X86_AMD_UNCORE_PREP,
66         CPUHP_PERF_POWER,
67         CPUHP_PERF_SUPERH,
68         CPUHP_X86_HPET_DEAD,
69         CPUHP_X86_APB_DEAD,
70         CPUHP_X86_MCE_DEAD,
71         CPUHP_VIRT_NET_DEAD,
72         CPUHP_SLUB_DEAD,
73         CPUHP_DEBUG_OBJ_DEAD,
74         CPUHP_MM_WRITEBACK_DEAD,
75         /* Must be after CPUHP_MM_VMSTAT_DEAD */
76         CPUHP_MM_DEMOTION_DEAD,
77         CPUHP_MM_VMSTAT_DEAD,
78         CPUHP_SOFTIRQ_DEAD,
79         CPUHP_NET_MVNETA_DEAD,
80         CPUHP_CPUIDLE_DEAD,
81         CPUHP_ARM64_FPSIMD_DEAD,
82         CPUHP_ARM_OMAP_WAKE_DEAD,
83         CPUHP_IRQ_POLL_DEAD,
84         CPUHP_BLOCK_SOFTIRQ_DEAD,
85         CPUHP_BIO_DEAD,
86         CPUHP_ACPI_CPUDRV_DEAD,
87         CPUHP_S390_PFAULT_DEAD,
88         CPUHP_BLK_MQ_DEAD,
89         CPUHP_FS_BUFF_DEAD,
90         CPUHP_PRINTK_DEAD,
91         CPUHP_MM_MEMCQ_DEAD,
92         CPUHP_XFS_DEAD,
93         CPUHP_PERCPU_CNT_DEAD,
94         CPUHP_RADIX_DEAD,
95         CPUHP_PAGE_ALLOC,
96         CPUHP_NET_DEV_DEAD,
97         CPUHP_PCI_XGENE_DEAD,
98         CPUHP_IOMMU_IOVA_DEAD,
99         CPUHP_LUSTRE_CFS_DEAD,
100         CPUHP_AP_ARM_CACHE_B15_RAC_DEAD,
101         CPUHP_PADATA_DEAD,
102         CPUHP_AP_DTPM_CPU_DEAD,
103         CPUHP_RANDOM_PREPARE,
104         CPUHP_WORKQUEUE_PREP,
105         CPUHP_POWER_NUMA_PREPARE,
106         CPUHP_HRTIMERS_PREPARE,
107         CPUHP_PROFILE_PREPARE,
108         CPUHP_X2APIC_PREPARE,
109         CPUHP_SMPCFD_PREPARE,
110         CPUHP_RELAY_PREPARE,
111         CPUHP_SLAB_PREPARE,
112         CPUHP_MD_RAID5_PREPARE,
113         CPUHP_RCUTREE_PREP,
114         CPUHP_CPUIDLE_COUPLED_PREPARE,
115         CPUHP_POWERPC_PMAC_PREPARE,
116         CPUHP_POWERPC_MMU_CTX_PREPARE,
117         CPUHP_XEN_PREPARE,
118         CPUHP_XEN_EVTCHN_PREPARE,
119         CPUHP_ARM_SHMOBILE_SCU_PREPARE,
120         CPUHP_SH_SH3X_PREPARE,
121         CPUHP_NET_FLOW_PREPARE,
122         CPUHP_TOPOLOGY_PREPARE,
123         CPUHP_NET_IUCV_PREPARE,
124         CPUHP_ARM_BL_PREPARE,
125         CPUHP_TRACE_RB_PREPARE,
126         CPUHP_MM_ZS_PREPARE,
127         CPUHP_MM_ZSWP_MEM_PREPARE,
128         CPUHP_MM_ZSWP_POOL_PREPARE,
129         CPUHP_KVM_PPC_BOOK3S_PREPARE,
130         CPUHP_ZCOMP_PREPARE,
131         CPUHP_TIMERS_PREPARE,
132         CPUHP_MIPS_SOC_PREPARE,
133         CPUHP_BP_PREPARE_DYN,
134         CPUHP_BP_PREPARE_DYN_END                = CPUHP_BP_PREPARE_DYN + 20,
135         CPUHP_BRINGUP_CPU,
136
137         /*
138          * STARTING section invoked on the hotplugged CPU in low level
139          * bringup and teardown code.
140          */
141         CPUHP_AP_IDLE_DEAD,
142         CPUHP_AP_OFFLINE,
143         CPUHP_AP_SCHED_STARTING,
144         CPUHP_AP_RCUTREE_DYING,
145         CPUHP_AP_CPU_PM_STARTING,
146         CPUHP_AP_IRQ_GIC_STARTING,
147         CPUHP_AP_IRQ_HIP04_STARTING,
148         CPUHP_AP_IRQ_APPLE_AIC_STARTING,
149         CPUHP_AP_IRQ_ARMADA_XP_STARTING,
150         CPUHP_AP_IRQ_BCM2836_STARTING,
151         CPUHP_AP_IRQ_MIPS_GIC_STARTING,
152         CPUHP_AP_IRQ_RISCV_STARTING,
153         CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
154         CPUHP_AP_ARM_MVEBU_COHERENCY,
155         CPUHP_AP_MICROCODE_LOADER,
156         CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
157         CPUHP_AP_PERF_X86_STARTING,
158         CPUHP_AP_PERF_X86_AMD_IBS_STARTING,
159         CPUHP_AP_PERF_X86_CQM_STARTING,
160         CPUHP_AP_PERF_X86_CSTATE_STARTING,
161         CPUHP_AP_PERF_XTENSA_STARTING,
162         CPUHP_AP_MIPS_OP_LOONGSON3_STARTING,
163         CPUHP_AP_ARM_SDEI_STARTING,
164         CPUHP_AP_ARM_VFP_STARTING,
165         CPUHP_AP_ARM64_DEBUG_MONITORS_STARTING,
166         CPUHP_AP_PERF_ARM_HW_BREAKPOINT_STARTING,
167         CPUHP_AP_PERF_ARM_ACPI_STARTING,
168         CPUHP_AP_PERF_ARM_STARTING,
169         CPUHP_AP_PERF_RISCV_STARTING,
170         CPUHP_AP_ARM_L2X0_STARTING,
171         CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
172         CPUHP_AP_ARM_ARCH_TIMER_STARTING,
173         CPUHP_AP_ARM_GLOBAL_TIMER_STARTING,
174         CPUHP_AP_JCORE_TIMER_STARTING,
175         CPUHP_AP_ARM_TWD_STARTING,
176         CPUHP_AP_QCOM_TIMER_STARTING,
177         CPUHP_AP_TEGRA_TIMER_STARTING,
178         CPUHP_AP_ARMADA_TIMER_STARTING,
179         CPUHP_AP_MARCO_TIMER_STARTING,
180         CPUHP_AP_MIPS_GIC_TIMER_STARTING,
181         CPUHP_AP_ARC_TIMER_STARTING,
182         CPUHP_AP_RISCV_TIMER_STARTING,
183         CPUHP_AP_CLINT_TIMER_STARTING,
184         CPUHP_AP_CSKY_TIMER_STARTING,
185         CPUHP_AP_TI_GP_TIMER_STARTING,
186         CPUHP_AP_HYPERV_TIMER_STARTING,
187         CPUHP_AP_KVM_STARTING,
188         CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
189         CPUHP_AP_KVM_ARM_VGIC_STARTING,
190         CPUHP_AP_KVM_ARM_TIMER_STARTING,
191         /* Must be the last timer callback */
192         CPUHP_AP_DUMMY_TIMER_STARTING,
193         CPUHP_AP_ARM_XEN_STARTING,
194         CPUHP_AP_ARM_CORESIGHT_STARTING,
195         CPUHP_AP_ARM_CORESIGHT_CTI_STARTING,
196         CPUHP_AP_ARM64_ISNDEP_STARTING,
197         CPUHP_AP_SMPCFD_DYING,
198         CPUHP_AP_X86_TBOOT_DYING,
199         CPUHP_AP_ARM_CACHE_B15_RAC_DYING,
200         CPUHP_AP_ONLINE,
201         CPUHP_TEARDOWN_CPU,
202
203         /* Online section invoked on the hotplugged CPU from the hotplug thread */
204         CPUHP_AP_ONLINE_IDLE,
205         CPUHP_AP_SCHED_WAIT_EMPTY,
206         CPUHP_AP_SMPBOOT_THREADS,
207         CPUHP_AP_X86_VDSO_VMA_ONLINE,
208         CPUHP_AP_IRQ_AFFINITY_ONLINE,
209         CPUHP_AP_BLK_MQ_ONLINE,
210         CPUHP_AP_ARM_MVEBU_SYNC_CLOCKS,
211         CPUHP_AP_X86_INTEL_EPB_ONLINE,
212         CPUHP_AP_PERF_ONLINE,
213         CPUHP_AP_PERF_X86_ONLINE,
214         CPUHP_AP_PERF_X86_UNCORE_ONLINE,
215         CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
216         CPUHP_AP_PERF_X86_AMD_POWER_ONLINE,
217         CPUHP_AP_PERF_X86_RAPL_ONLINE,
218         CPUHP_AP_PERF_X86_CQM_ONLINE,
219         CPUHP_AP_PERF_X86_CSTATE_ONLINE,
220         CPUHP_AP_PERF_X86_IDXD_ONLINE,
221         CPUHP_AP_PERF_S390_CF_ONLINE,
222         CPUHP_AP_PERF_S390_SF_ONLINE,
223         CPUHP_AP_PERF_ARM_CCI_ONLINE,
224         CPUHP_AP_PERF_ARM_CCN_ONLINE,
225         CPUHP_AP_PERF_ARM_HISI_DDRC_ONLINE,
226         CPUHP_AP_PERF_ARM_HISI_HHA_ONLINE,
227         CPUHP_AP_PERF_ARM_HISI_L3_ONLINE,
228         CPUHP_AP_PERF_ARM_HISI_PA_ONLINE,
229         CPUHP_AP_PERF_ARM_HISI_SLLC_ONLINE,
230         CPUHP_AP_PERF_ARM_HISI_PCIE_PMU_ONLINE,
231         CPUHP_AP_PERF_ARM_L2X0_ONLINE,
232         CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
233         CPUHP_AP_PERF_ARM_QCOM_L3_ONLINE,
234         CPUHP_AP_PERF_ARM_APM_XGENE_ONLINE,
235         CPUHP_AP_PERF_ARM_CAVIUM_TX2_UNCORE_ONLINE,
236         CPUHP_AP_PERF_ARM_MARVELL_CN10K_DDR_ONLINE,
237         CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE,
238         CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE,
239         CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
240         CPUHP_AP_PERF_POWERPC_TRACE_IMC_ONLINE,
241         CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE,
242         CPUHP_AP_PERF_POWERPC_HV_GPCI_ONLINE,
243         CPUHP_AP_PERF_CSKY_ONLINE,
244         CPUHP_AP_WATCHDOG_ONLINE,
245         CPUHP_AP_WORKQUEUE_ONLINE,
246         CPUHP_AP_RANDOM_ONLINE,
247         CPUHP_AP_RCUTREE_ONLINE,
248         CPUHP_AP_BASE_CACHEINFO_ONLINE,
249         CPUHP_AP_ONLINE_DYN,
250         CPUHP_AP_ONLINE_DYN_END         = CPUHP_AP_ONLINE_DYN + 30,
251         /* Must be after CPUHP_AP_ONLINE_DYN for node_states[N_CPU] update */
252         CPUHP_AP_MM_DEMOTION_ONLINE,
253         CPUHP_AP_X86_HPET_ONLINE,
254         CPUHP_AP_X86_KVM_CLK_ONLINE,
255         CPUHP_AP_ACTIVE,
256         CPUHP_ONLINE,
257 };
258
259 int __cpuhp_setup_state(enum cpuhp_state state, const char *name, bool invoke,
260                         int (*startup)(unsigned int cpu),
261                         int (*teardown)(unsigned int cpu), bool multi_instance);
262
263 int __cpuhp_setup_state_cpuslocked(enum cpuhp_state state, const char *name,
264                                    bool invoke,
265                                    int (*startup)(unsigned int cpu),
266                                    int (*teardown)(unsigned int cpu),
267                                    bool multi_instance);
268 /**
269  * cpuhp_setup_state - Setup hotplug state callbacks with calling the @startup
270  *                     callback
271  * @state:      The state for which the calls are installed
272  * @name:       Name of the callback (will be used in debug output)
273  * @startup:    startup callback function or NULL if not required
274  * @teardown:   teardown callback function or NULL if not required
275  *
276  * Installs the callback functions and invokes the @startup callback on
277  * the online cpus which have already reached the @state.
278  */
279 static inline int cpuhp_setup_state(enum cpuhp_state state,
280                                     const char *name,
281                                     int (*startup)(unsigned int cpu),
282                                     int (*teardown)(unsigned int cpu))
283 {
284         return __cpuhp_setup_state(state, name, true, startup, teardown, false);
285 }
286
287 /**
288  * cpuhp_setup_state_cpuslocked - Setup hotplug state callbacks with calling
289  *                                @startup callback from a cpus_read_lock()
290  *                                held region
291  * @state:      The state for which the calls are installed
292  * @name:       Name of the callback (will be used in debug output)
293  * @startup:    startup callback function or NULL if not required
294  * @teardown:   teardown callback function or NULL if not required
295  *
296  * Same as cpuhp_setup_state() except that it must be invoked from within a
297  * cpus_read_lock() held region.
298  */
299 static inline int cpuhp_setup_state_cpuslocked(enum cpuhp_state state,
300                                                const char *name,
301                                                int (*startup)(unsigned int cpu),
302                                                int (*teardown)(unsigned int cpu))
303 {
304         return __cpuhp_setup_state_cpuslocked(state, name, true, startup,
305                                               teardown, false);
306 }
307
308 /**
309  * cpuhp_setup_state_nocalls - Setup hotplug state callbacks without calling the
310  *                             @startup callback
311  * @state:      The state for which the calls are installed
312  * @name:       Name of the callback.
313  * @startup:    startup callback function or NULL if not required
314  * @teardown:   teardown callback function or NULL if not required
315  *
316  * Same as cpuhp_setup_state() except that the @startup callback is not
317  * invoked during installation. NOP if SMP=n or HOTPLUG_CPU=n.
318  */
319 static inline int cpuhp_setup_state_nocalls(enum cpuhp_state state,
320                                             const char *name,
321                                             int (*startup)(unsigned int cpu),
322                                             int (*teardown)(unsigned int cpu))
323 {
324         return __cpuhp_setup_state(state, name, false, startup, teardown,
325                                    false);
326 }
327
328 /**
329  * cpuhp_setup_state_nocalls_cpuslocked - Setup hotplug state callbacks without
330  *                                        invoking the @startup callback from
331  *                                        a cpus_read_lock() held region
332  *                             callbacks
333  * @state:      The state for which the calls are installed
334  * @name:       Name of the callback.
335  * @startup:    startup callback function or NULL if not required
336  * @teardown:   teardown callback function or NULL if not required
337  *
338  * Same as cpuhp_setup_state_nocalls() except that it must be invoked from
339  * within a cpus_read_lock() held region.
340  */
341 static inline int cpuhp_setup_state_nocalls_cpuslocked(enum cpuhp_state state,
342                                                      const char *name,
343                                                      int (*startup)(unsigned int cpu),
344                                                      int (*teardown)(unsigned int cpu))
345 {
346         return __cpuhp_setup_state_cpuslocked(state, name, false, startup,
347                                             teardown, false);
348 }
349
350 /**
351  * cpuhp_setup_state_multi - Add callbacks for multi state
352  * @state:      The state for which the calls are installed
353  * @name:       Name of the callback.
354  * @startup:    startup callback function or NULL if not required
355  * @teardown:   teardown callback function or NULL if not required
356  *
357  * Sets the internal multi_instance flag and prepares a state to work as a multi
358  * instance callback. No callbacks are invoked at this point. The callbacks are
359  * invoked once an instance for this state are registered via
360  * cpuhp_state_add_instance() or cpuhp_state_add_instance_nocalls()
361  */
362 static inline int cpuhp_setup_state_multi(enum cpuhp_state state,
363                                           const char *name,
364                                           int (*startup)(unsigned int cpu,
365                                                          struct hlist_node *node),
366                                           int (*teardown)(unsigned int cpu,
367                                                           struct hlist_node *node))
368 {
369         return __cpuhp_setup_state(state, name, false,
370                                    (void *) startup,
371                                    (void *) teardown, true);
372 }
373
374 int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
375                                bool invoke);
376 int __cpuhp_state_add_instance_cpuslocked(enum cpuhp_state state,
377                                           struct hlist_node *node, bool invoke);
378
379 /**
380  * cpuhp_state_add_instance - Add an instance for a state and invoke startup
381  *                            callback.
382  * @state:      The state for which the instance is installed
383  * @node:       The node for this individual state.
384  *
385  * Installs the instance for the @state and invokes the registered startup
386  * callback on the online cpus which have already reached the @state. The
387  * @state must have been earlier marked as multi-instance by
388  * cpuhp_setup_state_multi().
389  */
390 static inline int cpuhp_state_add_instance(enum cpuhp_state state,
391                                            struct hlist_node *node)
392 {
393         return __cpuhp_state_add_instance(state, node, true);
394 }
395
396 /**
397  * cpuhp_state_add_instance_nocalls - Add an instance for a state without
398  *                                    invoking the startup callback.
399  * @state:      The state for which the instance is installed
400  * @node:       The node for this individual state.
401  *
402  * Installs the instance for the @state. The @state must have been earlier
403  * marked as multi-instance by cpuhp_setup_state_multi. NOP if SMP=n or
404  * HOTPLUG_CPU=n.
405  */
406 static inline int cpuhp_state_add_instance_nocalls(enum cpuhp_state state,
407                                                    struct hlist_node *node)
408 {
409         return __cpuhp_state_add_instance(state, node, false);
410 }
411
412 /**
413  * cpuhp_state_add_instance_nocalls_cpuslocked - Add an instance for a state
414  *                                               without invoking the startup
415  *                                               callback from a cpus_read_lock()
416  *                                               held region.
417  * @state:      The state for which the instance is installed
418  * @node:       The node for this individual state.
419  *
420  * Same as cpuhp_state_add_instance_nocalls() except that it must be
421  * invoked from within a cpus_read_lock() held region.
422  */
423 static inline int
424 cpuhp_state_add_instance_nocalls_cpuslocked(enum cpuhp_state state,
425                                             struct hlist_node *node)
426 {
427         return __cpuhp_state_add_instance_cpuslocked(state, node, false);
428 }
429
430 void __cpuhp_remove_state(enum cpuhp_state state, bool invoke);
431 void __cpuhp_remove_state_cpuslocked(enum cpuhp_state state, bool invoke);
432
433 /**
434  * cpuhp_remove_state - Remove hotplug state callbacks and invoke the teardown
435  * @state:      The state for which the calls are removed
436  *
437  * Removes the callback functions and invokes the teardown callback on
438  * the online cpus which have already reached the @state.
439  */
440 static inline void cpuhp_remove_state(enum cpuhp_state state)
441 {
442         __cpuhp_remove_state(state, true);
443 }
444
445 /**
446  * cpuhp_remove_state_nocalls - Remove hotplug state callbacks without invoking
447  *                              the teardown callback
448  * @state:      The state for which the calls are removed
449  */
450 static inline void cpuhp_remove_state_nocalls(enum cpuhp_state state)
451 {
452         __cpuhp_remove_state(state, false);
453 }
454
455 /**
456  * cpuhp_remove_state_nocalls_cpuslocked - Remove hotplug state callbacks without invoking
457  *                                         teardown from a cpus_read_lock() held region.
458  * @state:      The state for which the calls are removed
459  *
460  * Same as cpuhp_remove_state nocalls() except that it must be invoked
461  * from within a cpus_read_lock() held region.
462  */
463 static inline void cpuhp_remove_state_nocalls_cpuslocked(enum cpuhp_state state)
464 {
465         __cpuhp_remove_state_cpuslocked(state, false);
466 }
467
468 /**
469  * cpuhp_remove_multi_state - Remove hotplug multi state callback
470  * @state:      The state for which the calls are removed
471  *
472  * Removes the callback functions from a multi state. This is the reverse of
473  * cpuhp_setup_state_multi(). All instances should have been removed before
474  * invoking this function.
475  */
476 static inline void cpuhp_remove_multi_state(enum cpuhp_state state)
477 {
478         __cpuhp_remove_state(state, false);
479 }
480
481 int __cpuhp_state_remove_instance(enum cpuhp_state state,
482                                   struct hlist_node *node, bool invoke);
483
484 /**
485  * cpuhp_state_remove_instance - Remove hotplug instance from state and invoke
486  *                               the teardown callback
487  * @state:      The state from which the instance is removed
488  * @node:       The node for this individual state.
489  *
490  * Removes the instance and invokes the teardown callback on the online cpus
491  * which have already reached @state.
492  */
493 static inline int cpuhp_state_remove_instance(enum cpuhp_state state,
494                                               struct hlist_node *node)
495 {
496         return __cpuhp_state_remove_instance(state, node, true);
497 }
498
499 /**
500  * cpuhp_state_remove_instance_nocalls - Remove hotplug instance from state
501  *                                       without invoking the teardown callback
502  * @state:      The state from which the instance is removed
503  * @node:       The node for this individual state.
504  *
505  * Removes the instance without invoking the teardown callback.
506  */
507 static inline int cpuhp_state_remove_instance_nocalls(enum cpuhp_state state,
508                                                       struct hlist_node *node)
509 {
510         return __cpuhp_state_remove_instance(state, node, false);
511 }
512
513 #ifdef CONFIG_SMP
514 void cpuhp_online_idle(enum cpuhp_state state);
515 #else
516 static inline void cpuhp_online_idle(enum cpuhp_state state) { }
517 #endif
518
519 #endif