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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_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 */
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_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_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_HISI_PCIE_PMU_ONLINE,
229 CPUHP_AP_PERF_ARM_L2X0_ONLINE,
230 CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
231 CPUHP_AP_PERF_ARM_QCOM_L3_ONLINE,
232 CPUHP_AP_PERF_ARM_APM_XGENE_ONLINE,
233 CPUHP_AP_PERF_ARM_CAVIUM_TX2_UNCORE_ONLINE,
234 CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE,
235 CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE,
236 CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
237 CPUHP_AP_PERF_POWERPC_TRACE_IMC_ONLINE,
238 CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE,
239 CPUHP_AP_PERF_POWERPC_HV_GPCI_ONLINE,
240 CPUHP_AP_PERF_CSKY_ONLINE,
241 CPUHP_AP_WATCHDOG_ONLINE,
242 CPUHP_AP_WORKQUEUE_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_ACTIVE,
252 CPUHP_ONLINE,
253};
254
255int __cpuhp_setup_state(enum cpuhp_state state, const char *name, bool invoke,
256 int (*startup)(unsigned int cpu),
257 int (*teardown)(unsigned int cpu), bool multi_instance);
258
259int __cpuhp_setup_state_cpuslocked(enum cpuhp_state state, const char *name,
260 bool invoke,
261 int (*startup)(unsigned int cpu),
262 int (*teardown)(unsigned int cpu),
263 bool multi_instance);
264/**
265 * cpuhp_setup_state - Setup hotplug state callbacks with calling the @startup
266 * callback
267 * @state: The state for which the calls are installed
268 * @name: Name of the callback (will be used in debug output)
269 * @startup: startup callback function or NULL if not required
270 * @teardown: teardown callback function or NULL if not required
271 *
272 * Installs the callback functions and invokes the @startup callback on
273 * the online cpus which have already reached the @state.
274 */
275static inline int cpuhp_setup_state(enum cpuhp_state state,
276 const char *name,
277 int (*startup)(unsigned int cpu),
278 int (*teardown)(unsigned int cpu))
279{
280 return __cpuhp_setup_state(state, name, true, startup, teardown, false);
281}
282
283/**
284 * cpuhp_setup_state_cpuslocked - Setup hotplug state callbacks with calling
285 * @startup callback from a cpus_read_lock()
286 * held region
287 * @state: The state for which the calls are installed
288 * @name: Name of the callback (will be used in debug output)
289 * @startup: startup callback function or NULL if not required
290 * @teardown: teardown callback function or NULL if not required
291 *
292 * Same as cpuhp_setup_state() except that it must be invoked from within a
293 * cpus_read_lock() held region.
294 */
295static inline int cpuhp_setup_state_cpuslocked(enum cpuhp_state state,
296 const char *name,
297 int (*startup)(unsigned int cpu),
298 int (*teardown)(unsigned int cpu))
299{
300 return __cpuhp_setup_state_cpuslocked(state, name, true, startup,
301 teardown, false);
302}
303
304/**
305 * cpuhp_setup_state_nocalls - Setup hotplug state callbacks without calling the
306 * @startup callback
307 * @state: The state for which the calls are installed
308 * @name: Name of the callback.
309 * @startup: startup callback function or NULL if not required
310 * @teardown: teardown callback function or NULL if not required
311 *
312 * Same as cpuhp_setup_state() except that the @startup callback is not
313 * invoked during installation. NOP if SMP=n or HOTPLUG_CPU=n.
314 */
315static inline int cpuhp_setup_state_nocalls(enum cpuhp_state state,
316 const char *name,
317 int (*startup)(unsigned int cpu),
318 int (*teardown)(unsigned int cpu))
319{
320 return __cpuhp_setup_state(state, name, false, startup, teardown,
321 false);
322}
323
324/**
325 * cpuhp_setup_state_nocalls_cpuslocked - Setup hotplug state callbacks without
326 * invoking the @startup callback from
327 * a cpus_read_lock() held region
328 * callbacks
329 * @state: The state for which the calls are installed
330 * @name: Name of the callback.
331 * @startup: startup callback function or NULL if not required
332 * @teardown: teardown callback function or NULL if not required
333 *
334 * Same as cpuhp_setup_state_nocalls() except that it must be invoked from
335 * within a cpus_read_lock() held region.
336 */
337static inline int cpuhp_setup_state_nocalls_cpuslocked(enum cpuhp_state state,
338 const char *name,
339 int (*startup)(unsigned int cpu),
340 int (*teardown)(unsigned int cpu))
341{
342 return __cpuhp_setup_state_cpuslocked(state, name, false, startup,
343 teardown, false);
344}
345
346/**
347 * cpuhp_setup_state_multi - Add callbacks for multi state
348 * @state: The state for which the calls are installed
349 * @name: Name of the callback.
350 * @startup: startup callback function or NULL if not required
351 * @teardown: teardown callback function or NULL if not required
352 *
353 * Sets the internal multi_instance flag and prepares a state to work as a multi
354 * instance callback. No callbacks are invoked at this point. The callbacks are
355 * invoked once an instance for this state are registered via
356 * cpuhp_state_add_instance() or cpuhp_state_add_instance_nocalls()
357 */
358static inline int cpuhp_setup_state_multi(enum cpuhp_state state,
359 const char *name,
360 int (*startup)(unsigned int cpu,
361 struct hlist_node *node),
362 int (*teardown)(unsigned int cpu,
363 struct hlist_node *node))
364{
365 return __cpuhp_setup_state(state, name, false,
366 (void *) startup,
367 (void *) teardown, true);
368}
369
370int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
371 bool invoke);
372int __cpuhp_state_add_instance_cpuslocked(enum cpuhp_state state,
373 struct hlist_node *node, bool invoke);
374
375/**
376 * cpuhp_state_add_instance - Add an instance for a state and invoke startup
377 * callback.
378 * @state: The state for which the instance is installed
379 * @node: The node for this individual state.
380 *
381 * Installs the instance for the @state and invokes the registered startup
382 * callback on the online cpus which have already reached the @state. The
383 * @state must have been earlier marked as multi-instance by
384 * cpuhp_setup_state_multi().
385 */
386static inline int cpuhp_state_add_instance(enum cpuhp_state state,
387 struct hlist_node *node)
388{
389 return __cpuhp_state_add_instance(state, node, true);
390}
391
392/**
393 * cpuhp_state_add_instance_nocalls - Add an instance for a state without
394 * invoking the startup callback.
395 * @state: The state for which the instance is installed
396 * @node: The node for this individual state.
397 *
398 * Installs the instance for the @state. The @state must have been earlier
399 * marked as multi-instance by cpuhp_setup_state_multi. NOP if SMP=n or
400 * HOTPLUG_CPU=n.
401 */
402static inline int cpuhp_state_add_instance_nocalls(enum cpuhp_state state,
403 struct hlist_node *node)
404{
405 return __cpuhp_state_add_instance(state, node, false);
406}
407
408/**
409 * cpuhp_state_add_instance_nocalls_cpuslocked - Add an instance for a state
410 * without invoking the startup
411 * callback from a cpus_read_lock()
412 * held region.
413 * @state: The state for which the instance is installed
414 * @node: The node for this individual state.
415 *
416 * Same as cpuhp_state_add_instance_nocalls() except that it must be
417 * invoked from within a cpus_read_lock() held region.
418 */
419static inline int
420cpuhp_state_add_instance_nocalls_cpuslocked(enum cpuhp_state state,
421 struct hlist_node *node)
422{
423 return __cpuhp_state_add_instance_cpuslocked(state, node, false);
424}
425
426void __cpuhp_remove_state(enum cpuhp_state state, bool invoke);
427void __cpuhp_remove_state_cpuslocked(enum cpuhp_state state, bool invoke);
428
429/**
430 * cpuhp_remove_state - Remove hotplug state callbacks and invoke the teardown
431 * @state: The state for which the calls are removed
432 *
433 * Removes the callback functions and invokes the teardown callback on
434 * the online cpus which have already reached the @state.
435 */
436static inline void cpuhp_remove_state(enum cpuhp_state state)
437{
438 __cpuhp_remove_state(state, true);
439}
440
441/**
442 * cpuhp_remove_state_nocalls - Remove hotplug state callbacks without invoking
443 * the teardown callback
444 * @state: The state for which the calls are removed
445 */
446static inline void cpuhp_remove_state_nocalls(enum cpuhp_state state)
447{
448 __cpuhp_remove_state(state, false);
449}
450
451/**
452 * cpuhp_remove_state_nocalls_cpuslocked - Remove hotplug state callbacks without invoking
453 * teardown from a cpus_read_lock() held region.
454 * @state: The state for which the calls are removed
455 *
456 * Same as cpuhp_remove_state nocalls() except that it must be invoked
457 * from within a cpus_read_lock() held region.
458 */
459static inline void cpuhp_remove_state_nocalls_cpuslocked(enum cpuhp_state state)
460{
461 __cpuhp_remove_state_cpuslocked(state, false);
462}
463
464/**
465 * cpuhp_remove_multi_state - Remove hotplug multi state callback
466 * @state: The state for which the calls are removed
467 *
468 * Removes the callback functions from a multi state. This is the reverse of
469 * cpuhp_setup_state_multi(). All instances should have been removed before
470 * invoking this function.
471 */
472static inline void cpuhp_remove_multi_state(enum cpuhp_state state)
473{
474 __cpuhp_remove_state(state, false);
475}
476
477int __cpuhp_state_remove_instance(enum cpuhp_state state,
478 struct hlist_node *node, bool invoke);
479
480/**
481 * cpuhp_state_remove_instance - Remove hotplug instance from state and invoke
482 * the teardown callback
483 * @state: The state from which the instance is removed
484 * @node: The node for this individual state.
485 *
486 * Removes the instance and invokes the teardown callback on the online cpus
487 * which have already reached @state.
488 */
489static inline int cpuhp_state_remove_instance(enum cpuhp_state state,
490 struct hlist_node *node)
491{
492 return __cpuhp_state_remove_instance(state, node, true);
493}
494
495/**
496 * cpuhp_state_remove_instance_nocalls - Remove hotplug instance from state
497 * without invoking the teardown callback
498 * @state: The state from which the instance is removed
499 * @node: The node for this individual state.
500 *
501 * Removes the instance without invoking the teardown callback.
502 */
503static inline int cpuhp_state_remove_instance_nocalls(enum cpuhp_state state,
504 struct hlist_node *node)
505{
506 return __cpuhp_state_remove_instance(state, node, false);
507}
508
509#ifdef CONFIG_SMP
510void cpuhp_online_idle(enum cpuhp_state state);
511#else
512static inline void cpuhp_online_idle(enum cpuhp_state state) { }
513#endif
514
515#endif