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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_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_CPA_ONLINE,
226 CPUHP_AP_PERF_ARM_HISI_DDRC_ONLINE,
227 CPUHP_AP_PERF_ARM_HISI_HHA_ONLINE,
228 CPUHP_AP_PERF_ARM_HISI_L3_ONLINE,
229 CPUHP_AP_PERF_ARM_HISI_PA_ONLINE,
230 CPUHP_AP_PERF_ARM_HISI_SLLC_ONLINE,
231 CPUHP_AP_PERF_ARM_HISI_PCIE_PMU_ONLINE,
232 CPUHP_AP_PERF_ARM_L2X0_ONLINE,
233 CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
234 CPUHP_AP_PERF_ARM_QCOM_L3_ONLINE,
235 CPUHP_AP_PERF_ARM_APM_XGENE_ONLINE,
236 CPUHP_AP_PERF_ARM_CAVIUM_TX2_UNCORE_ONLINE,
237 CPUHP_AP_PERF_ARM_MARVELL_CN10K_DDR_ONLINE,
238 CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE,
239 CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE,
240 CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
241 CPUHP_AP_PERF_POWERPC_TRACE_IMC_ONLINE,
242 CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE,
243 CPUHP_AP_PERF_POWERPC_HV_GPCI_ONLINE,
244 CPUHP_AP_PERF_CSKY_ONLINE,
245 CPUHP_AP_WATCHDOG_ONLINE,
246 CPUHP_AP_WORKQUEUE_ONLINE,
247 CPUHP_AP_RANDOM_ONLINE,
248 CPUHP_AP_RCUTREE_ONLINE,
249 CPUHP_AP_BASE_CACHEINFO_ONLINE,
250 CPUHP_AP_ONLINE_DYN,
251 CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30,
252 /* Must be after CPUHP_AP_ONLINE_DYN for node_states[N_CPU] update */
253 CPUHP_AP_MM_DEMOTION_ONLINE,
254 CPUHP_AP_X86_HPET_ONLINE,
255 CPUHP_AP_X86_KVM_CLK_ONLINE,
256 CPUHP_AP_ACTIVE,
257 CPUHP_ONLINE,
258};
259
260int __cpuhp_setup_state(enum cpuhp_state state, const char *name, bool invoke,
261 int (*startup)(unsigned int cpu),
262 int (*teardown)(unsigned int cpu), bool multi_instance);
263
264int __cpuhp_setup_state_cpuslocked(enum cpuhp_state state, const char *name,
265 bool invoke,
266 int (*startup)(unsigned int cpu),
267 int (*teardown)(unsigned int cpu),
268 bool multi_instance);
269/**
270 * cpuhp_setup_state - Setup hotplug state callbacks with calling the @startup
271 * callback
272 * @state: The state for which the calls are installed
273 * @name: Name of the callback (will be used in debug output)
274 * @startup: startup callback function or NULL if not required
275 * @teardown: teardown callback function or NULL if not required
276 *
277 * Installs the callback functions and invokes the @startup callback on
278 * the online cpus which have already reached the @state.
279 */
280static inline int cpuhp_setup_state(enum cpuhp_state state,
281 const char *name,
282 int (*startup)(unsigned int cpu),
283 int (*teardown)(unsigned int cpu))
284{
285 return __cpuhp_setup_state(state, name, true, startup, teardown, false);
286}
287
288/**
289 * cpuhp_setup_state_cpuslocked - Setup hotplug state callbacks with calling
290 * @startup callback from a cpus_read_lock()
291 * held region
292 * @state: The state for which the calls are installed
293 * @name: Name of the callback (will be used in debug output)
294 * @startup: startup callback function or NULL if not required
295 * @teardown: teardown callback function or NULL if not required
296 *
297 * Same as cpuhp_setup_state() except that it must be invoked from within a
298 * cpus_read_lock() held region.
299 */
300static inline int cpuhp_setup_state_cpuslocked(enum cpuhp_state state,
301 const char *name,
302 int (*startup)(unsigned int cpu),
303 int (*teardown)(unsigned int cpu))
304{
305 return __cpuhp_setup_state_cpuslocked(state, name, true, startup,
306 teardown, false);
307}
308
309/**
310 * cpuhp_setup_state_nocalls - Setup hotplug state callbacks without calling the
311 * @startup callback
312 * @state: The state for which the calls are installed
313 * @name: Name of the callback.
314 * @startup: startup callback function or NULL if not required
315 * @teardown: teardown callback function or NULL if not required
316 *
317 * Same as cpuhp_setup_state() except that the @startup callback is not
318 * invoked during installation. NOP if SMP=n or HOTPLUG_CPU=n.
319 */
320static inline int cpuhp_setup_state_nocalls(enum cpuhp_state state,
321 const char *name,
322 int (*startup)(unsigned int cpu),
323 int (*teardown)(unsigned int cpu))
324{
325 return __cpuhp_setup_state(state, name, false, startup, teardown,
326 false);
327}
328
329/**
330 * cpuhp_setup_state_nocalls_cpuslocked - Setup hotplug state callbacks without
331 * invoking the @startup callback from
332 * a cpus_read_lock() held region
333 * callbacks
334 * @state: The state for which the calls are installed
335 * @name: Name of the callback.
336 * @startup: startup callback function or NULL if not required
337 * @teardown: teardown callback function or NULL if not required
338 *
339 * Same as cpuhp_setup_state_nocalls() except that it must be invoked from
340 * within a cpus_read_lock() held region.
341 */
342static inline int cpuhp_setup_state_nocalls_cpuslocked(enum cpuhp_state state,
343 const char *name,
344 int (*startup)(unsigned int cpu),
345 int (*teardown)(unsigned int cpu))
346{
347 return __cpuhp_setup_state_cpuslocked(state, name, false, startup,
348 teardown, false);
349}
350
351/**
352 * cpuhp_setup_state_multi - Add callbacks for multi state
353 * @state: The state for which the calls are installed
354 * @name: Name of the callback.
355 * @startup: startup callback function or NULL if not required
356 * @teardown: teardown callback function or NULL if not required
357 *
358 * Sets the internal multi_instance flag and prepares a state to work as a multi
359 * instance callback. No callbacks are invoked at this point. The callbacks are
360 * invoked once an instance for this state are registered via
361 * cpuhp_state_add_instance() or cpuhp_state_add_instance_nocalls()
362 */
363static inline int cpuhp_setup_state_multi(enum cpuhp_state state,
364 const char *name,
365 int (*startup)(unsigned int cpu,
366 struct hlist_node *node),
367 int (*teardown)(unsigned int cpu,
368 struct hlist_node *node))
369{
370 return __cpuhp_setup_state(state, name, false,
371 (void *) startup,
372 (void *) teardown, true);
373}
374
375int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
376 bool invoke);
377int __cpuhp_state_add_instance_cpuslocked(enum cpuhp_state state,
378 struct hlist_node *node, bool invoke);
379
380/**
381 * cpuhp_state_add_instance - Add an instance for a state and invoke startup
382 * callback.
383 * @state: The state for which the instance is installed
384 * @node: The node for this individual state.
385 *
386 * Installs the instance for the @state and invokes the registered startup
387 * callback on the online cpus which have already reached the @state. The
388 * @state must have been earlier marked as multi-instance by
389 * cpuhp_setup_state_multi().
390 */
391static inline int cpuhp_state_add_instance(enum cpuhp_state state,
392 struct hlist_node *node)
393{
394 return __cpuhp_state_add_instance(state, node, true);
395}
396
397/**
398 * cpuhp_state_add_instance_nocalls - Add an instance for a state without
399 * invoking the startup callback.
400 * @state: The state for which the instance is installed
401 * @node: The node for this individual state.
402 *
403 * Installs the instance for the @state. The @state must have been earlier
404 * marked as multi-instance by cpuhp_setup_state_multi. NOP if SMP=n or
405 * HOTPLUG_CPU=n.
406 */
407static inline int cpuhp_state_add_instance_nocalls(enum cpuhp_state state,
408 struct hlist_node *node)
409{
410 return __cpuhp_state_add_instance(state, node, false);
411}
412
413/**
414 * cpuhp_state_add_instance_nocalls_cpuslocked - Add an instance for a state
415 * without invoking the startup
416 * callback from a cpus_read_lock()
417 * held region.
418 * @state: The state for which the instance is installed
419 * @node: The node for this individual state.
420 *
421 * Same as cpuhp_state_add_instance_nocalls() except that it must be
422 * invoked from within a cpus_read_lock() held region.
423 */
424static inline int
425cpuhp_state_add_instance_nocalls_cpuslocked(enum cpuhp_state state,
426 struct hlist_node *node)
427{
428 return __cpuhp_state_add_instance_cpuslocked(state, node, false);
429}
430
431void __cpuhp_remove_state(enum cpuhp_state state, bool invoke);
432void __cpuhp_remove_state_cpuslocked(enum cpuhp_state state, bool invoke);
433
434/**
435 * cpuhp_remove_state - Remove hotplug state callbacks and invoke the teardown
436 * @state: The state for which the calls are removed
437 *
438 * Removes the callback functions and invokes the teardown callback on
439 * the online cpus which have already reached the @state.
440 */
441static inline void cpuhp_remove_state(enum cpuhp_state state)
442{
443 __cpuhp_remove_state(state, true);
444}
445
446/**
447 * cpuhp_remove_state_nocalls - Remove hotplug state callbacks without invoking
448 * the teardown callback
449 * @state: The state for which the calls are removed
450 */
451static inline void cpuhp_remove_state_nocalls(enum cpuhp_state state)
452{
453 __cpuhp_remove_state(state, false);
454}
455
456/**
457 * cpuhp_remove_state_nocalls_cpuslocked - Remove hotplug state callbacks without invoking
458 * teardown from a cpus_read_lock() held region.
459 * @state: The state for which the calls are removed
460 *
461 * Same as cpuhp_remove_state nocalls() except that it must be invoked
462 * from within a cpus_read_lock() held region.
463 */
464static inline void cpuhp_remove_state_nocalls_cpuslocked(enum cpuhp_state state)
465{
466 __cpuhp_remove_state_cpuslocked(state, false);
467}
468
469/**
470 * cpuhp_remove_multi_state - Remove hotplug multi state callback
471 * @state: The state for which the calls are removed
472 *
473 * Removes the callback functions from a multi state. This is the reverse of
474 * cpuhp_setup_state_multi(). All instances should have been removed before
475 * invoking this function.
476 */
477static inline void cpuhp_remove_multi_state(enum cpuhp_state state)
478{
479 __cpuhp_remove_state(state, false);
480}
481
482int __cpuhp_state_remove_instance(enum cpuhp_state state,
483 struct hlist_node *node, bool invoke);
484
485/**
486 * cpuhp_state_remove_instance - Remove hotplug instance from state and invoke
487 * the teardown callback
488 * @state: The state from which the instance is removed
489 * @node: The node for this individual state.
490 *
491 * Removes the instance and invokes the teardown callback on the online cpus
492 * which have already reached @state.
493 */
494static inline int cpuhp_state_remove_instance(enum cpuhp_state state,
495 struct hlist_node *node)
496{
497 return __cpuhp_state_remove_instance(state, node, true);
498}
499
500/**
501 * cpuhp_state_remove_instance_nocalls - Remove hotplug instance from state
502 * without invoking the teardown callback
503 * @state: The state from which the instance is removed
504 * @node: The node for this individual state.
505 *
506 * Removes the instance without invoking the teardown callback.
507 */
508static inline int cpuhp_state_remove_instance_nocalls(enum cpuhp_state state,
509 struct hlist_node *node)
510{
511 return __cpuhp_state_remove_instance(state, node, false);
512}
513
514#ifdef CONFIG_SMP
515void cpuhp_online_idle(enum cpuhp_state state);
516#else
517static inline void cpuhp_online_idle(enum cpuhp_state state) { }
518#endif
519
520#endif