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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_BP_PREPARE_DYN or CPUHP_AP_ONLINE_DYN
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 */
57enum 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_MCE_DEAD,
70 CPUHP_VIRT_NET_DEAD,
71 CPUHP_IBMVNIC_DEAD,
72 CPUHP_SLUB_DEAD,
73 CPUHP_DEBUG_OBJ_DEAD,
74 CPUHP_MM_WRITEBACK_DEAD,
75 CPUHP_MM_VMSTAT_DEAD,
76 CPUHP_SOFTIRQ_DEAD,
77 CPUHP_NET_MVNETA_DEAD,
78 CPUHP_CPUIDLE_DEAD,
79 CPUHP_ARM64_FPSIMD_DEAD,
80 CPUHP_ARM_OMAP_WAKE_DEAD,
81 CPUHP_IRQ_POLL_DEAD,
82 CPUHP_BLOCK_SOFTIRQ_DEAD,
83 CPUHP_BIO_DEAD,
84 CPUHP_ACPI_CPUDRV_DEAD,
85 CPUHP_S390_PFAULT_DEAD,
86 CPUHP_BLK_MQ_DEAD,
87 CPUHP_FS_BUFF_DEAD,
88 CPUHP_PRINTK_DEAD,
89 CPUHP_MM_MEMCQ_DEAD,
90 CPUHP_PERCPU_CNT_DEAD,
91 CPUHP_RADIX_DEAD,
92 CPUHP_PAGE_ALLOC,
93 CPUHP_NET_DEV_DEAD,
94 CPUHP_PCI_XGENE_DEAD,
95 CPUHP_IOMMU_IOVA_DEAD,
96 CPUHP_AP_ARM_CACHE_B15_RAC_DEAD,
97 CPUHP_PADATA_DEAD,
98 CPUHP_AP_DTPM_CPU_DEAD,
99 CPUHP_RANDOM_PREPARE,
100 CPUHP_WORKQUEUE_PREP,
101 CPUHP_POWER_NUMA_PREPARE,
102 CPUHP_HRTIMERS_PREPARE,
103 CPUHP_PROFILE_PREPARE,
104 CPUHP_X2APIC_PREPARE,
105 CPUHP_SMPCFD_PREPARE,
106 CPUHP_RELAY_PREPARE,
107 CPUHP_MD_RAID5_PREPARE,
108 CPUHP_RCUTREE_PREP,
109 CPUHP_CPUIDLE_COUPLED_PREPARE,
110 CPUHP_POWERPC_PMAC_PREPARE,
111 CPUHP_POWERPC_MMU_CTX_PREPARE,
112 CPUHP_XEN_PREPARE,
113 CPUHP_XEN_EVTCHN_PREPARE,
114 CPUHP_ARM_SHMOBILE_SCU_PREPARE,
115 CPUHP_SH_SH3X_PREPARE,
116 CPUHP_TOPOLOGY_PREPARE,
117 CPUHP_NET_IUCV_PREPARE,
118 CPUHP_ARM_BL_PREPARE,
119 CPUHP_TRACE_RB_PREPARE,
120 CPUHP_MM_ZS_PREPARE,
121 CPUHP_MM_ZSWP_POOL_PREPARE,
122 CPUHP_KVM_PPC_BOOK3S_PREPARE,
123 CPUHP_ZCOMP_PREPARE,
124 CPUHP_TIMERS_PREPARE,
125 CPUHP_MIPS_SOC_PREPARE,
126 CPUHP_BP_PREPARE_DYN,
127 CPUHP_BP_PREPARE_DYN_END = CPUHP_BP_PREPARE_DYN + 20,
128 CPUHP_BP_KICK_AP,
129 CPUHP_BRINGUP_CPU,
130
131 /*
132 * STARTING section invoked on the hotplugged CPU in low level
133 * bringup and teardown code.
134 */
135 CPUHP_AP_IDLE_DEAD,
136 CPUHP_AP_OFFLINE,
137 CPUHP_AP_CACHECTRL_STARTING,
138 CPUHP_AP_SCHED_STARTING,
139 CPUHP_AP_RCUTREE_DYING,
140 CPUHP_AP_CPU_PM_STARTING,
141 CPUHP_AP_IRQ_GIC_STARTING,
142 CPUHP_AP_IRQ_HIP04_STARTING,
143 CPUHP_AP_IRQ_APPLE_AIC_STARTING,
144 CPUHP_AP_IRQ_ARMADA_XP_STARTING,
145 CPUHP_AP_IRQ_BCM2836_STARTING,
146 CPUHP_AP_IRQ_MIPS_GIC_STARTING,
147 CPUHP_AP_IRQ_LOONGARCH_STARTING,
148 CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
149 CPUHP_AP_ARM_MVEBU_COHERENCY,
150 CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
151 CPUHP_AP_PERF_X86_STARTING,
152 CPUHP_AP_PERF_X86_AMD_IBS_STARTING,
153 CPUHP_AP_PERF_X86_CSTATE_STARTING,
154 CPUHP_AP_PERF_XTENSA_STARTING,
155 CPUHP_AP_ARM_VFP_STARTING,
156 CPUHP_AP_ARM64_DEBUG_MONITORS_STARTING,
157 CPUHP_AP_PERF_ARM_HW_BREAKPOINT_STARTING,
158 CPUHP_AP_PERF_ARM_ACPI_STARTING,
159 CPUHP_AP_PERF_ARM_STARTING,
160 CPUHP_AP_PERF_RISCV_STARTING,
161 CPUHP_AP_ARM_L2X0_STARTING,
162 CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
163 CPUHP_AP_ARM_ARCH_TIMER_STARTING,
164 CPUHP_AP_ARM_ARCH_TIMER_EVTSTRM_STARTING,
165 CPUHP_AP_ARM_GLOBAL_TIMER_STARTING,
166 CPUHP_AP_JCORE_TIMER_STARTING,
167 CPUHP_AP_ARM_TWD_STARTING,
168 CPUHP_AP_QCOM_TIMER_STARTING,
169 CPUHP_AP_TEGRA_TIMER_STARTING,
170 CPUHP_AP_ARMADA_TIMER_STARTING,
171 CPUHP_AP_MIPS_GIC_TIMER_STARTING,
172 CPUHP_AP_ARC_TIMER_STARTING,
173 CPUHP_AP_RISCV_TIMER_STARTING,
174 CPUHP_AP_CLINT_TIMER_STARTING,
175 CPUHP_AP_CSKY_TIMER_STARTING,
176 CPUHP_AP_TI_GP_TIMER_STARTING,
177 CPUHP_AP_HYPERV_TIMER_STARTING,
178 /* Must be the last timer callback */
179 CPUHP_AP_DUMMY_TIMER_STARTING,
180 CPUHP_AP_ARM_XEN_STARTING,
181 CPUHP_AP_ARM_XEN_RUNSTATE_STARTING,
182 CPUHP_AP_ARM_CORESIGHT_STARTING,
183 CPUHP_AP_ARM_CORESIGHT_CTI_STARTING,
184 CPUHP_AP_ARM64_ISNDEP_STARTING,
185 CPUHP_AP_SMPCFD_DYING,
186 CPUHP_AP_HRTIMERS_DYING,
187 CPUHP_AP_X86_TBOOT_DYING,
188 CPUHP_AP_ARM_CACHE_B15_RAC_DYING,
189 CPUHP_AP_ONLINE,
190 CPUHP_TEARDOWN_CPU,
191
192 /* Online section invoked on the hotplugged CPU from the hotplug thread */
193 CPUHP_AP_ONLINE_IDLE,
194 CPUHP_AP_HYPERV_ONLINE,
195 CPUHP_AP_KVM_ONLINE,
196 CPUHP_AP_SCHED_WAIT_EMPTY,
197 CPUHP_AP_SMPBOOT_THREADS,
198 CPUHP_AP_IRQ_AFFINITY_ONLINE,
199 CPUHP_AP_BLK_MQ_ONLINE,
200 CPUHP_AP_ARM_MVEBU_SYNC_CLOCKS,
201 CPUHP_AP_X86_INTEL_EPB_ONLINE,
202 CPUHP_AP_PERF_ONLINE,
203 CPUHP_AP_PERF_X86_ONLINE,
204 CPUHP_AP_PERF_X86_UNCORE_ONLINE,
205 CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
206 CPUHP_AP_PERF_X86_AMD_POWER_ONLINE,
207 CPUHP_AP_PERF_X86_RAPL_ONLINE,
208 CPUHP_AP_PERF_X86_CSTATE_ONLINE,
209 CPUHP_AP_PERF_S390_CF_ONLINE,
210 CPUHP_AP_PERF_S390_SF_ONLINE,
211 CPUHP_AP_PERF_ARM_CCI_ONLINE,
212 CPUHP_AP_PERF_ARM_CCN_ONLINE,
213 CPUHP_AP_PERF_ARM_HISI_CPA_ONLINE,
214 CPUHP_AP_PERF_ARM_HISI_DDRC_ONLINE,
215 CPUHP_AP_PERF_ARM_HISI_HHA_ONLINE,
216 CPUHP_AP_PERF_ARM_HISI_L3_ONLINE,
217 CPUHP_AP_PERF_ARM_HISI_PA_ONLINE,
218 CPUHP_AP_PERF_ARM_HISI_SLLC_ONLINE,
219 CPUHP_AP_PERF_ARM_HISI_PCIE_PMU_ONLINE,
220 CPUHP_AP_PERF_ARM_HNS3_PMU_ONLINE,
221 CPUHP_AP_PERF_ARM_L2X0_ONLINE,
222 CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
223 CPUHP_AP_PERF_ARM_QCOM_L3_ONLINE,
224 CPUHP_AP_PERF_ARM_APM_XGENE_ONLINE,
225 CPUHP_AP_PERF_ARM_CAVIUM_TX2_UNCORE_ONLINE,
226 CPUHP_AP_PERF_ARM_MARVELL_CN10K_DDR_ONLINE,
227 CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE,
228 CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE,
229 CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
230 CPUHP_AP_PERF_POWERPC_TRACE_IMC_ONLINE,
231 CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE,
232 CPUHP_AP_PERF_POWERPC_HV_GPCI_ONLINE,
233 CPUHP_AP_PERF_CSKY_ONLINE,
234 CPUHP_AP_WATCHDOG_ONLINE,
235 CPUHP_AP_WORKQUEUE_ONLINE,
236 CPUHP_AP_RANDOM_ONLINE,
237 CPUHP_AP_RCUTREE_ONLINE,
238 CPUHP_AP_BASE_CACHEINFO_ONLINE,
239 CPUHP_AP_ONLINE_DYN,
240 CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 40,
241 CPUHP_AP_X86_HPET_ONLINE,
242 CPUHP_AP_X86_KVM_CLK_ONLINE,
243 CPUHP_AP_ACTIVE,
244 CPUHP_ONLINE,
245};
246
247int __cpuhp_setup_state(enum cpuhp_state state, const char *name, bool invoke,
248 int (*startup)(unsigned int cpu),
249 int (*teardown)(unsigned int cpu), bool multi_instance);
250
251int __cpuhp_setup_state_cpuslocked(enum cpuhp_state state, const char *name,
252 bool invoke,
253 int (*startup)(unsigned int cpu),
254 int (*teardown)(unsigned int cpu),
255 bool multi_instance);
256/**
257 * cpuhp_setup_state - Setup hotplug state callbacks with calling the @startup
258 * callback
259 * @state: The state for which the calls are installed
260 * @name: Name of the callback (will be used in debug output)
261 * @startup: startup callback function or NULL if not required
262 * @teardown: teardown callback function or NULL if not required
263 *
264 * Installs the callback functions and invokes the @startup callback on
265 * the online cpus which have already reached the @state.
266 */
267static inline int cpuhp_setup_state(enum cpuhp_state state,
268 const char *name,
269 int (*startup)(unsigned int cpu),
270 int (*teardown)(unsigned int cpu))
271{
272 return __cpuhp_setup_state(state, name, true, startup, teardown, false);
273}
274
275/**
276 * cpuhp_setup_state_cpuslocked - Setup hotplug state callbacks with calling
277 * @startup callback from a cpus_read_lock()
278 * held region
279 * @state: The state for which the calls are installed
280 * @name: Name of the callback (will be used in debug output)
281 * @startup: startup callback function or NULL if not required
282 * @teardown: teardown callback function or NULL if not required
283 *
284 * Same as cpuhp_setup_state() except that it must be invoked from within a
285 * cpus_read_lock() held region.
286 */
287static inline int cpuhp_setup_state_cpuslocked(enum cpuhp_state state,
288 const char *name,
289 int (*startup)(unsigned int cpu),
290 int (*teardown)(unsigned int cpu))
291{
292 return __cpuhp_setup_state_cpuslocked(state, name, true, startup,
293 teardown, false);
294}
295
296/**
297 * cpuhp_setup_state_nocalls - Setup hotplug state callbacks without calling the
298 * @startup callback
299 * @state: The state for which the calls are installed
300 * @name: Name of the callback.
301 * @startup: startup callback function or NULL if not required
302 * @teardown: teardown callback function or NULL if not required
303 *
304 * Same as cpuhp_setup_state() except that the @startup callback is not
305 * invoked during installation. NOP if SMP=n or HOTPLUG_CPU=n.
306 */
307static inline int cpuhp_setup_state_nocalls(enum cpuhp_state state,
308 const char *name,
309 int (*startup)(unsigned int cpu),
310 int (*teardown)(unsigned int cpu))
311{
312 return __cpuhp_setup_state(state, name, false, startup, teardown,
313 false);
314}
315
316/**
317 * cpuhp_setup_state_nocalls_cpuslocked - Setup hotplug state callbacks without
318 * invoking the @startup callback from
319 * a cpus_read_lock() held region
320 * callbacks
321 * @state: The state for which the calls are installed
322 * @name: Name of the callback.
323 * @startup: startup callback function or NULL if not required
324 * @teardown: teardown callback function or NULL if not required
325 *
326 * Same as cpuhp_setup_state_nocalls() except that it must be invoked from
327 * within a cpus_read_lock() held region.
328 */
329static inline int cpuhp_setup_state_nocalls_cpuslocked(enum cpuhp_state state,
330 const char *name,
331 int (*startup)(unsigned int cpu),
332 int (*teardown)(unsigned int cpu))
333{
334 return __cpuhp_setup_state_cpuslocked(state, name, false, startup,
335 teardown, false);
336}
337
338/**
339 * cpuhp_setup_state_multi - Add callbacks for multi state
340 * @state: The state for which the calls are installed
341 * @name: Name of the callback.
342 * @startup: startup callback function or NULL if not required
343 * @teardown: teardown callback function or NULL if not required
344 *
345 * Sets the internal multi_instance flag and prepares a state to work as a multi
346 * instance callback. No callbacks are invoked at this point. The callbacks are
347 * invoked once an instance for this state are registered via
348 * cpuhp_state_add_instance() or cpuhp_state_add_instance_nocalls()
349 */
350static inline int cpuhp_setup_state_multi(enum cpuhp_state state,
351 const char *name,
352 int (*startup)(unsigned int cpu,
353 struct hlist_node *node),
354 int (*teardown)(unsigned int cpu,
355 struct hlist_node *node))
356{
357 return __cpuhp_setup_state(state, name, false,
358 (void *) startup,
359 (void *) teardown, true);
360}
361
362int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
363 bool invoke);
364int __cpuhp_state_add_instance_cpuslocked(enum cpuhp_state state,
365 struct hlist_node *node, bool invoke);
366
367/**
368 * cpuhp_state_add_instance - Add an instance for a state and invoke startup
369 * callback.
370 * @state: The state for which the instance is installed
371 * @node: The node for this individual state.
372 *
373 * Installs the instance for the @state and invokes the registered startup
374 * callback on the online cpus which have already reached the @state. The
375 * @state must have been earlier marked as multi-instance by
376 * cpuhp_setup_state_multi().
377 */
378static inline int cpuhp_state_add_instance(enum cpuhp_state state,
379 struct hlist_node *node)
380{
381 return __cpuhp_state_add_instance(state, node, true);
382}
383
384/**
385 * cpuhp_state_add_instance_nocalls - Add an instance for a state without
386 * invoking the startup callback.
387 * @state: The state for which the instance is installed
388 * @node: The node for this individual state.
389 *
390 * Installs the instance for the @state. The @state must have been earlier
391 * marked as multi-instance by cpuhp_setup_state_multi. NOP if SMP=n or
392 * HOTPLUG_CPU=n.
393 */
394static inline int cpuhp_state_add_instance_nocalls(enum cpuhp_state state,
395 struct hlist_node *node)
396{
397 return __cpuhp_state_add_instance(state, node, false);
398}
399
400/**
401 * cpuhp_state_add_instance_nocalls_cpuslocked - Add an instance for a state
402 * without invoking the startup
403 * callback from a cpus_read_lock()
404 * held region.
405 * @state: The state for which the instance is installed
406 * @node: The node for this individual state.
407 *
408 * Same as cpuhp_state_add_instance_nocalls() except that it must be
409 * invoked from within a cpus_read_lock() held region.
410 */
411static inline int
412cpuhp_state_add_instance_nocalls_cpuslocked(enum cpuhp_state state,
413 struct hlist_node *node)
414{
415 return __cpuhp_state_add_instance_cpuslocked(state, node, false);
416}
417
418void __cpuhp_remove_state(enum cpuhp_state state, bool invoke);
419void __cpuhp_remove_state_cpuslocked(enum cpuhp_state state, bool invoke);
420
421/**
422 * cpuhp_remove_state - Remove hotplug state callbacks and invoke the teardown
423 * @state: The state for which the calls are removed
424 *
425 * Removes the callback functions and invokes the teardown callback on
426 * the online cpus which have already reached the @state.
427 */
428static inline void cpuhp_remove_state(enum cpuhp_state state)
429{
430 __cpuhp_remove_state(state, true);
431}
432
433/**
434 * cpuhp_remove_state_nocalls - Remove hotplug state callbacks without invoking
435 * the teardown callback
436 * @state: The state for which the calls are removed
437 */
438static inline void cpuhp_remove_state_nocalls(enum cpuhp_state state)
439{
440 __cpuhp_remove_state(state, false);
441}
442
443/**
444 * cpuhp_remove_state_nocalls_cpuslocked - Remove hotplug state callbacks without invoking
445 * teardown from a cpus_read_lock() held region.
446 * @state: The state for which the calls are removed
447 *
448 * Same as cpuhp_remove_state nocalls() except that it must be invoked
449 * from within a cpus_read_lock() held region.
450 */
451static inline void cpuhp_remove_state_nocalls_cpuslocked(enum cpuhp_state state)
452{
453 __cpuhp_remove_state_cpuslocked(state, false);
454}
455
456/**
457 * cpuhp_remove_multi_state - Remove hotplug multi state callback
458 * @state: The state for which the calls are removed
459 *
460 * Removes the callback functions from a multi state. This is the reverse of
461 * cpuhp_setup_state_multi(). All instances should have been removed before
462 * invoking this function.
463 */
464static inline void cpuhp_remove_multi_state(enum cpuhp_state state)
465{
466 __cpuhp_remove_state(state, false);
467}
468
469int __cpuhp_state_remove_instance(enum cpuhp_state state,
470 struct hlist_node *node, bool invoke);
471
472/**
473 * cpuhp_state_remove_instance - Remove hotplug instance from state and invoke
474 * the teardown callback
475 * @state: The state from which the instance is removed
476 * @node: The node for this individual state.
477 *
478 * Removes the instance and invokes the teardown callback on the online cpus
479 * which have already reached @state.
480 */
481static inline int cpuhp_state_remove_instance(enum cpuhp_state state,
482 struct hlist_node *node)
483{
484 return __cpuhp_state_remove_instance(state, node, true);
485}
486
487/**
488 * cpuhp_state_remove_instance_nocalls - Remove hotplug instance from state
489 * without invoking the teardown callback
490 * @state: The state from which the instance is removed
491 * @node: The node for this individual state.
492 *
493 * Removes the instance without invoking the teardown callback.
494 */
495static inline int cpuhp_state_remove_instance_nocalls(enum cpuhp_state state,
496 struct hlist_node *node)
497{
498 return __cpuhp_state_remove_instance(state, node, false);
499}
500
501#ifdef CONFIG_SMP
502void cpuhp_online_idle(enum cpuhp_state state);
503#else
504static inline void cpuhp_online_idle(enum cpuhp_state state) { }
505#endif
506
507struct task_struct;
508
509void cpuhp_ap_sync_alive(void);
510void arch_cpuhp_sync_state_poll(void);
511void arch_cpuhp_cleanup_kick_cpu(unsigned int cpu);
512int arch_cpuhp_kick_ap_alive(unsigned int cpu, struct task_struct *tidle);
513bool arch_cpuhp_init_parallel_bringup(void);
514
515#ifdef CONFIG_HOTPLUG_CORE_SYNC_DEAD
516void cpuhp_ap_report_dead(void);
517void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu);
518#else
519static inline void cpuhp_ap_report_dead(void) { }
520static inline void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) { }
521#endif
522
523#endif