GNU Linux-libre 5.15.54-gnu
[releases.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_RANDOM_PREPARE,
103         CPUHP_WORKQUEUE_PREP,
104         CPUHP_POWER_NUMA_PREPARE,
105         CPUHP_HRTIMERS_PREPARE,
106         CPUHP_PROFILE_PREPARE,
107         CPUHP_X2APIC_PREPARE,
108         CPUHP_SMPCFD_PREPARE,
109         CPUHP_RELAY_PREPARE,
110         CPUHP_SLAB_PREPARE,
111         CPUHP_MD_RAID5_PREPARE,
112         CPUHP_RCUTREE_PREP,
113         CPUHP_CPUIDLE_COUPLED_PREPARE,
114         CPUHP_POWERPC_PMAC_PREPARE,
115         CPUHP_POWERPC_MMU_CTX_PREPARE,
116         CPUHP_XEN_PREPARE,
117         CPUHP_XEN_EVTCHN_PREPARE,
118         CPUHP_ARM_SHMOBILE_SCU_PREPARE,
119         CPUHP_SH_SH3X_PREPARE,
120         CPUHP_NET_FLOW_PREPARE,
121         CPUHP_TOPOLOGY_PREPARE,
122         CPUHP_NET_IUCV_PREPARE,
123         CPUHP_ARM_BL_PREPARE,
124         CPUHP_TRACE_RB_PREPARE,
125         CPUHP_MM_ZS_PREPARE,
126         CPUHP_MM_ZSWP_MEM_PREPARE,
127         CPUHP_MM_ZSWP_POOL_PREPARE,
128         CPUHP_KVM_PPC_BOOK3S_PREPARE,
129         CPUHP_ZCOMP_PREPARE,
130         CPUHP_TIMERS_PREPARE,
131         CPUHP_MIPS_SOC_PREPARE,
132         CPUHP_BP_PREPARE_DYN,
133         CPUHP_BP_PREPARE_DYN_END                = CPUHP_BP_PREPARE_DYN + 20,
134         CPUHP_BRINGUP_CPU,
135
136         /*
137          * STARTING section invoked on the hotplugged CPU in low level
138          * bringup and teardown code.
139          */
140         CPUHP_AP_IDLE_DEAD,
141         CPUHP_AP_OFFLINE,
142         CPUHP_AP_SCHED_STARTING,
143         CPUHP_AP_RCUTREE_DYING,
144         CPUHP_AP_CPU_PM_STARTING,
145         CPUHP_AP_IRQ_GIC_STARTING,
146         CPUHP_AP_IRQ_HIP04_STARTING,
147         CPUHP_AP_IRQ_APPLE_AIC_STARTING,
148         CPUHP_AP_IRQ_ARMADA_XP_STARTING,
149         CPUHP_AP_IRQ_BCM2836_STARTING,
150         CPUHP_AP_IRQ_MIPS_GIC_STARTING,
151         CPUHP_AP_IRQ_RISCV_STARTING,
152         CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
153         CPUHP_AP_ARM_MVEBU_COHERENCY,
154         CPUHP_AP_MICROCODE_LOADER,
155         CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
156         CPUHP_AP_PERF_X86_STARTING,
157         CPUHP_AP_PERF_X86_AMD_IBS_STARTING,
158         CPUHP_AP_PERF_X86_CQM_STARTING,
159         CPUHP_AP_PERF_X86_CSTATE_STARTING,
160         CPUHP_AP_PERF_XTENSA_STARTING,
161         CPUHP_AP_MIPS_OP_LOONGSON3_STARTING,
162         CPUHP_AP_ARM_SDEI_STARTING,
163         CPUHP_AP_ARM_VFP_STARTING,
164         CPUHP_AP_ARM64_DEBUG_MONITORS_STARTING,
165         CPUHP_AP_PERF_ARM_HW_BREAKPOINT_STARTING,
166         CPUHP_AP_PERF_ARM_ACPI_STARTING,
167         CPUHP_AP_PERF_ARM_STARTING,
168         CPUHP_AP_ARM_L2X0_STARTING,
169         CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
170         CPUHP_AP_ARM_ARCH_TIMER_STARTING,
171         CPUHP_AP_ARM_GLOBAL_TIMER_STARTING,
172         CPUHP_AP_JCORE_TIMER_STARTING,
173         CPUHP_AP_ARM_TWD_STARTING,
174         CPUHP_AP_QCOM_TIMER_STARTING,
175         CPUHP_AP_TEGRA_TIMER_STARTING,
176         CPUHP_AP_ARMADA_TIMER_STARTING,
177         CPUHP_AP_MARCO_TIMER_STARTING,
178         CPUHP_AP_MIPS_GIC_TIMER_STARTING,
179         CPUHP_AP_ARC_TIMER_STARTING,
180         CPUHP_AP_RISCV_TIMER_STARTING,
181         CPUHP_AP_CLINT_TIMER_STARTING,
182         CPUHP_AP_CSKY_TIMER_STARTING,
183         CPUHP_AP_TI_GP_TIMER_STARTING,
184         CPUHP_AP_HYPERV_TIMER_STARTING,
185         CPUHP_AP_KVM_STARTING,
186         CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
187         CPUHP_AP_KVM_ARM_VGIC_STARTING,
188         CPUHP_AP_KVM_ARM_TIMER_STARTING,
189         /* Must be the last timer callback */
190         CPUHP_AP_DUMMY_TIMER_STARTING,
191         CPUHP_AP_ARM_XEN_STARTING,
192         CPUHP_AP_ARM_CORESIGHT_STARTING,
193         CPUHP_AP_ARM_CORESIGHT_CTI_STARTING,
194         CPUHP_AP_ARM64_ISNDEP_STARTING,
195         CPUHP_AP_SMPCFD_DYING,
196         CPUHP_AP_X86_TBOOT_DYING,
197         CPUHP_AP_ARM_CACHE_B15_RAC_DYING,
198         CPUHP_AP_ONLINE,
199         CPUHP_TEARDOWN_CPU,
200
201         /* Online section invoked on the hotplugged CPU from the hotplug thread */
202         CPUHP_AP_ONLINE_IDLE,
203         CPUHP_AP_SCHED_WAIT_EMPTY,
204         CPUHP_AP_SMPBOOT_THREADS,
205         CPUHP_AP_X86_VDSO_VMA_ONLINE,
206         CPUHP_AP_IRQ_AFFINITY_ONLINE,
207         CPUHP_AP_BLK_MQ_ONLINE,
208         CPUHP_AP_ARM_MVEBU_SYNC_CLOCKS,
209         CPUHP_AP_X86_INTEL_EPB_ONLINE,
210         CPUHP_AP_PERF_ONLINE,
211         CPUHP_AP_PERF_X86_ONLINE,
212         CPUHP_AP_PERF_X86_UNCORE_ONLINE,
213         CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
214         CPUHP_AP_PERF_X86_AMD_POWER_ONLINE,
215         CPUHP_AP_PERF_X86_RAPL_ONLINE,
216         CPUHP_AP_PERF_X86_CQM_ONLINE,
217         CPUHP_AP_PERF_X86_CSTATE_ONLINE,
218         CPUHP_AP_PERF_X86_IDXD_ONLINE,
219         CPUHP_AP_PERF_S390_CF_ONLINE,
220         CPUHP_AP_PERF_S390_SF_ONLINE,
221         CPUHP_AP_PERF_ARM_CCI_ONLINE,
222         CPUHP_AP_PERF_ARM_CCN_ONLINE,
223         CPUHP_AP_PERF_ARM_HISI_DDRC_ONLINE,
224         CPUHP_AP_PERF_ARM_HISI_HHA_ONLINE,
225         CPUHP_AP_PERF_ARM_HISI_L3_ONLINE,
226         CPUHP_AP_PERF_ARM_HISI_PA_ONLINE,
227         CPUHP_AP_PERF_ARM_HISI_SLLC_ONLINE,
228         CPUHP_AP_PERF_ARM_L2X0_ONLINE,
229         CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
230         CPUHP_AP_PERF_ARM_QCOM_L3_ONLINE,
231         CPUHP_AP_PERF_ARM_APM_XGENE_ONLINE,
232         CPUHP_AP_PERF_ARM_CAVIUM_TX2_UNCORE_ONLINE,
233         CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE,
234         CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE,
235         CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
236         CPUHP_AP_PERF_POWERPC_TRACE_IMC_ONLINE,
237         CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE,
238         CPUHP_AP_PERF_POWERPC_HV_GPCI_ONLINE,
239         CPUHP_AP_PERF_CSKY_ONLINE,
240         CPUHP_AP_WATCHDOG_ONLINE,
241         CPUHP_AP_WORKQUEUE_ONLINE,
242         CPUHP_AP_RANDOM_ONLINE,
243         CPUHP_AP_RCUTREE_ONLINE,
244         CPUHP_AP_BASE_CACHEINFO_ONLINE,
245         CPUHP_AP_ONLINE_DYN,
246         CPUHP_AP_ONLINE_DYN_END         = CPUHP_AP_ONLINE_DYN + 30,
247         /* Must be after CPUHP_AP_ONLINE_DYN for node_states[N_CPU] update */
248         CPUHP_AP_MM_DEMOTION_ONLINE,
249         CPUHP_AP_X86_HPET_ONLINE,
250         CPUHP_AP_X86_KVM_CLK_ONLINE,
251         CPUHP_AP_DTPM_CPU_ONLINE,
252         CPUHP_AP_ACTIVE,
253         CPUHP_ONLINE,
254 };
255
256 int __cpuhp_setup_state(enum cpuhp_state state, const char *name, bool invoke,
257                         int (*startup)(unsigned int cpu),
258                         int (*teardown)(unsigned int cpu), bool multi_instance);
259
260 int __cpuhp_setup_state_cpuslocked(enum cpuhp_state state, const char *name,
261                                    bool invoke,
262                                    int (*startup)(unsigned int cpu),
263                                    int (*teardown)(unsigned int cpu),
264                                    bool multi_instance);
265 /**
266  * cpuhp_setup_state - Setup hotplug state callbacks with calling the @startup
267  *                     callback
268  * @state:      The state for which the calls are installed
269  * @name:       Name of the callback (will be used in debug output)
270  * @startup:    startup callback function or NULL if not required
271  * @teardown:   teardown callback function or NULL if not required
272  *
273  * Installs the callback functions and invokes the @startup callback on
274  * the online cpus which have already reached the @state.
275  */
276 static inline int cpuhp_setup_state(enum cpuhp_state state,
277                                     const char *name,
278                                     int (*startup)(unsigned int cpu),
279                                     int (*teardown)(unsigned int cpu))
280 {
281         return __cpuhp_setup_state(state, name, true, startup, teardown, false);
282 }
283
284 /**
285  * cpuhp_setup_state_cpuslocked - Setup hotplug state callbacks with calling
286  *                                @startup callback from a cpus_read_lock()
287  *                                held region
288  * @state:      The state for which the calls are installed
289  * @name:       Name of the callback (will be used in debug output)
290  * @startup:    startup callback function or NULL if not required
291  * @teardown:   teardown callback function or NULL if not required
292  *
293  * Same as cpuhp_setup_state() except that it must be invoked from within a
294  * cpus_read_lock() held region.
295  */
296 static inline int cpuhp_setup_state_cpuslocked(enum cpuhp_state state,
297                                                const char *name,
298                                                int (*startup)(unsigned int cpu),
299                                                int (*teardown)(unsigned int cpu))
300 {
301         return __cpuhp_setup_state_cpuslocked(state, name, true, startup,
302                                               teardown, false);
303 }
304
305 /**
306  * cpuhp_setup_state_nocalls - Setup hotplug state callbacks without calling the
307  *                             @startup callback
308  * @state:      The state for which the calls are installed
309  * @name:       Name of the callback.
310  * @startup:    startup callback function or NULL if not required
311  * @teardown:   teardown callback function or NULL if not required
312  *
313  * Same as cpuhp_setup_state() except that the @startup callback is not
314  * invoked during installation. NOP if SMP=n or HOTPLUG_CPU=n.
315  */
316 static inline int cpuhp_setup_state_nocalls(enum cpuhp_state state,
317                                             const char *name,
318                                             int (*startup)(unsigned int cpu),
319                                             int (*teardown)(unsigned int cpu))
320 {
321         return __cpuhp_setup_state(state, name, false, startup, teardown,
322                                    false);
323 }
324
325 /**
326  * cpuhp_setup_state_nocalls_cpuslocked - Setup hotplug state callbacks without
327  *                                        invoking the @startup callback from
328  *                                        a cpus_read_lock() held region
329  *                             callbacks
330  * @state:      The state for which the calls are installed
331  * @name:       Name of the callback.
332  * @startup:    startup callback function or NULL if not required
333  * @teardown:   teardown callback function or NULL if not required
334  *
335  * Same as cpuhp_setup_state_nocalls() except that it must be invoked from
336  * within a cpus_read_lock() held region.
337  */
338 static inline int cpuhp_setup_state_nocalls_cpuslocked(enum cpuhp_state state,
339                                                      const char *name,
340                                                      int (*startup)(unsigned int cpu),
341                                                      int (*teardown)(unsigned int cpu))
342 {
343         return __cpuhp_setup_state_cpuslocked(state, name, false, startup,
344                                             teardown, false);
345 }
346
347 /**
348  * cpuhp_setup_state_multi - Add callbacks for multi state
349  * @state:      The state for which the calls are installed
350  * @name:       Name of the callback.
351  * @startup:    startup callback function or NULL if not required
352  * @teardown:   teardown callback function or NULL if not required
353  *
354  * Sets the internal multi_instance flag and prepares a state to work as a multi
355  * instance callback. No callbacks are invoked at this point. The callbacks are
356  * invoked once an instance for this state are registered via
357  * cpuhp_state_add_instance() or cpuhp_state_add_instance_nocalls()
358  */
359 static inline int cpuhp_setup_state_multi(enum cpuhp_state state,
360                                           const char *name,
361                                           int (*startup)(unsigned int cpu,
362                                                          struct hlist_node *node),
363                                           int (*teardown)(unsigned int cpu,
364                                                           struct hlist_node *node))
365 {
366         return __cpuhp_setup_state(state, name, false,
367                                    (void *) startup,
368                                    (void *) teardown, true);
369 }
370
371 int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
372                                bool invoke);
373 int __cpuhp_state_add_instance_cpuslocked(enum cpuhp_state state,
374                                           struct hlist_node *node, bool invoke);
375
376 /**
377  * cpuhp_state_add_instance - Add an instance for a state and invoke startup
378  *                            callback.
379  * @state:      The state for which the instance is installed
380  * @node:       The node for this individual state.
381  *
382  * Installs the instance for the @state and invokes the registered startup
383  * callback on the online cpus which have already reached the @state. The
384  * @state must have been earlier marked as multi-instance by
385  * cpuhp_setup_state_multi().
386  */
387 static inline int cpuhp_state_add_instance(enum cpuhp_state state,
388                                            struct hlist_node *node)
389 {
390         return __cpuhp_state_add_instance(state, node, true);
391 }
392
393 /**
394  * cpuhp_state_add_instance_nocalls - Add an instance for a state without
395  *                                    invoking the startup callback.
396  * @state:      The state for which the instance is installed
397  * @node:       The node for this individual state.
398  *
399  * Installs the instance for the @state. The @state must have been earlier
400  * marked as multi-instance by cpuhp_setup_state_multi. NOP if SMP=n or
401  * HOTPLUG_CPU=n.
402  */
403 static inline int cpuhp_state_add_instance_nocalls(enum cpuhp_state state,
404                                                    struct hlist_node *node)
405 {
406         return __cpuhp_state_add_instance(state, node, false);
407 }
408
409 /**
410  * cpuhp_state_add_instance_nocalls_cpuslocked - Add an instance for a state
411  *                                               without invoking the startup
412  *                                               callback from a cpus_read_lock()
413  *                                               held region.
414  * @state:      The state for which the instance is installed
415  * @node:       The node for this individual state.
416  *
417  * Same as cpuhp_state_add_instance_nocalls() except that it must be
418  * invoked from within a cpus_read_lock() held region.
419  */
420 static inline int
421 cpuhp_state_add_instance_nocalls_cpuslocked(enum cpuhp_state state,
422                                             struct hlist_node *node)
423 {
424         return __cpuhp_state_add_instance_cpuslocked(state, node, false);
425 }
426
427 void __cpuhp_remove_state(enum cpuhp_state state, bool invoke);
428 void __cpuhp_remove_state_cpuslocked(enum cpuhp_state state, bool invoke);
429
430 /**
431  * cpuhp_remove_state - Remove hotplug state callbacks and invoke the teardown
432  * @state:      The state for which the calls are removed
433  *
434  * Removes the callback functions and invokes the teardown callback on
435  * the online cpus which have already reached the @state.
436  */
437 static inline void cpuhp_remove_state(enum cpuhp_state state)
438 {
439         __cpuhp_remove_state(state, true);
440 }
441
442 /**
443  * cpuhp_remove_state_nocalls - Remove hotplug state callbacks without invoking
444  *                              the teardown callback
445  * @state:      The state for which the calls are removed
446  */
447 static inline void cpuhp_remove_state_nocalls(enum cpuhp_state state)
448 {
449         __cpuhp_remove_state(state, false);
450 }
451
452 /**
453  * cpuhp_remove_state_nocalls_cpuslocked - Remove hotplug state callbacks without invoking
454  *                                         teardown from a cpus_read_lock() held region.
455  * @state:      The state for which the calls are removed
456  *
457  * Same as cpuhp_remove_state nocalls() except that it must be invoked
458  * from within a cpus_read_lock() held region.
459  */
460 static inline void cpuhp_remove_state_nocalls_cpuslocked(enum cpuhp_state state)
461 {
462         __cpuhp_remove_state_cpuslocked(state, false);
463 }
464
465 /**
466  * cpuhp_remove_multi_state - Remove hotplug multi state callback
467  * @state:      The state for which the calls are removed
468  *
469  * Removes the callback functions from a multi state. This is the reverse of
470  * cpuhp_setup_state_multi(). All instances should have been removed before
471  * invoking this function.
472  */
473 static inline void cpuhp_remove_multi_state(enum cpuhp_state state)
474 {
475         __cpuhp_remove_state(state, false);
476 }
477
478 int __cpuhp_state_remove_instance(enum cpuhp_state state,
479                                   struct hlist_node *node, bool invoke);
480
481 /**
482  * cpuhp_state_remove_instance - Remove hotplug instance from state and invoke
483  *                               the teardown callback
484  * @state:      The state from which the instance is removed
485  * @node:       The node for this individual state.
486  *
487  * Removes the instance and invokes the teardown callback on the online cpus
488  * which have already reached @state.
489  */
490 static inline int cpuhp_state_remove_instance(enum cpuhp_state state,
491                                               struct hlist_node *node)
492 {
493         return __cpuhp_state_remove_instance(state, node, true);
494 }
495
496 /**
497  * cpuhp_state_remove_instance_nocalls - Remove hotplug instance from state
498  *                                       without invoking the teardown callback
499  * @state:      The state from which the instance is removed
500  * @node:       The node for this individual state.
501  *
502  * Removes the instance without invoking the teardown callback.
503  */
504 static inline int cpuhp_state_remove_instance_nocalls(enum cpuhp_state state,
505                                                       struct hlist_node *node)
506 {
507         return __cpuhp_state_remove_instance(state, node, false);
508 }
509
510 #ifdef CONFIG_SMP
511 void cpuhp_online_idle(enum cpuhp_state state);
512 #else
513 static inline void cpuhp_online_idle(enum cpuhp_state state) { }
514 #endif
515
516 #endif