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Commit | Line | Data |
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1da177e4 LT |
1 | /* CPU control. |
2 | * (C) 2001, 2002, 2003, 2004 Rusty Russell | |
3 | * | |
4 | * This code is licenced under the GPL. | |
5 | */ | |
6 | #include <linux/proc_fs.h> | |
7 | #include <linux/smp.h> | |
8 | #include <linux/init.h> | |
9 | #include <linux/notifier.h> | |
10 | #include <linux/sched.h> | |
11 | #include <linux/unistd.h> | |
12 | #include <linux/cpu.h> | |
cb79295e AV |
13 | #include <linux/oom.h> |
14 | #include <linux/rcupdate.h> | |
9984de1a | 15 | #include <linux/export.h> |
e4cc2f87 | 16 | #include <linux/bug.h> |
1da177e4 LT |
17 | #include <linux/kthread.h> |
18 | #include <linux/stop_machine.h> | |
81615b62 | 19 | #include <linux/mutex.h> |
5a0e3ad6 | 20 | #include <linux/gfp.h> |
79cfbdfa | 21 | #include <linux/suspend.h> |
a19423b9 | 22 | #include <linux/lockdep.h> |
345527b1 | 23 | #include <linux/tick.h> |
a8994181 | 24 | #include <linux/irq.h> |
cff7d378 | 25 | |
bb3632c6 | 26 | #include <trace/events/power.h> |
cff7d378 TG |
27 | #define CREATE_TRACE_POINTS |
28 | #include <trace/events/cpuhp.h> | |
1da177e4 | 29 | |
38498a67 TG |
30 | #include "smpboot.h" |
31 | ||
cff7d378 TG |
32 | /** |
33 | * cpuhp_cpu_state - Per cpu hotplug state storage | |
34 | * @state: The current cpu state | |
35 | * @target: The target state | |
36 | */ | |
37 | struct cpuhp_cpu_state { | |
38 | enum cpuhp_state state; | |
39 | enum cpuhp_state target; | |
40 | }; | |
41 | ||
42 | static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state); | |
43 | ||
44 | /** | |
45 | * cpuhp_step - Hotplug state machine step | |
46 | * @name: Name of the step | |
47 | * @startup: Startup function of the step | |
48 | * @teardown: Teardown function of the step | |
49 | * @skip_onerr: Do not invoke the functions on error rollback | |
50 | * Will go away once the notifiers are gone | |
51 | */ | |
52 | struct cpuhp_step { | |
53 | const char *name; | |
54 | int (*startup)(unsigned int cpu); | |
55 | int (*teardown)(unsigned int cpu); | |
56 | bool skip_onerr; | |
57 | }; | |
58 | ||
59 | static struct cpuhp_step cpuhp_bp_states[]; | |
4baa0afc | 60 | static struct cpuhp_step cpuhp_ap_states[]; |
cff7d378 TG |
61 | |
62 | /** | |
63 | * cpuhp_invoke_callback _ Invoke the callbacks for a given state | |
64 | * @cpu: The cpu for which the callback should be invoked | |
65 | * @step: The step in the state machine | |
66 | * @cb: The callback function to invoke | |
67 | * | |
68 | * Called from cpu hotplug and from the state register machinery | |
69 | */ | |
70 | static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state step, | |
71 | int (*cb)(unsigned int)) | |
72 | { | |
73 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
74 | int ret = 0; | |
75 | ||
76 | if (cb) { | |
77 | trace_cpuhp_enter(cpu, st->target, step, cb); | |
78 | ret = cb(cpu); | |
79 | trace_cpuhp_exit(cpu, st->state, step, ret); | |
80 | } | |
81 | return ret; | |
82 | } | |
83 | ||
98a79d6a | 84 | #ifdef CONFIG_SMP |
b3199c02 | 85 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
aa953877 | 86 | static DEFINE_MUTEX(cpu_add_remove_lock); |
090e77c3 TG |
87 | bool cpuhp_tasks_frozen; |
88 | EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen); | |
1da177e4 | 89 | |
79a6cdeb | 90 | /* |
93ae4f97 SB |
91 | * The following two APIs (cpu_maps_update_begin/done) must be used when |
92 | * attempting to serialize the updates to cpu_online_mask & cpu_present_mask. | |
93 | * The APIs cpu_notifier_register_begin/done() must be used to protect CPU | |
94 | * hotplug callback (un)registration performed using __register_cpu_notifier() | |
95 | * or __unregister_cpu_notifier(). | |
79a6cdeb LJ |
96 | */ |
97 | void cpu_maps_update_begin(void) | |
98 | { | |
99 | mutex_lock(&cpu_add_remove_lock); | |
100 | } | |
93ae4f97 | 101 | EXPORT_SYMBOL(cpu_notifier_register_begin); |
79a6cdeb LJ |
102 | |
103 | void cpu_maps_update_done(void) | |
104 | { | |
105 | mutex_unlock(&cpu_add_remove_lock); | |
106 | } | |
93ae4f97 | 107 | EXPORT_SYMBOL(cpu_notifier_register_done); |
79a6cdeb | 108 | |
5c113fbe | 109 | static RAW_NOTIFIER_HEAD(cpu_chain); |
1da177e4 | 110 | |
e3920fb4 RW |
111 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
112 | * Should always be manipulated under cpu_add_remove_lock | |
113 | */ | |
114 | static int cpu_hotplug_disabled; | |
115 | ||
79a6cdeb LJ |
116 | #ifdef CONFIG_HOTPLUG_CPU |
117 | ||
d221938c GS |
118 | static struct { |
119 | struct task_struct *active_writer; | |
87af9e7f DH |
120 | /* wait queue to wake up the active_writer */ |
121 | wait_queue_head_t wq; | |
122 | /* verifies that no writer will get active while readers are active */ | |
123 | struct mutex lock; | |
d221938c GS |
124 | /* |
125 | * Also blocks the new readers during | |
126 | * an ongoing cpu hotplug operation. | |
127 | */ | |
87af9e7f | 128 | atomic_t refcount; |
a19423b9 GS |
129 | |
130 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
131 | struct lockdep_map dep_map; | |
132 | #endif | |
31950eb6 LT |
133 | } cpu_hotplug = { |
134 | .active_writer = NULL, | |
87af9e7f | 135 | .wq = __WAIT_QUEUE_HEAD_INITIALIZER(cpu_hotplug.wq), |
31950eb6 | 136 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), |
a19423b9 GS |
137 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
138 | .dep_map = {.name = "cpu_hotplug.lock" }, | |
139 | #endif | |
31950eb6 | 140 | }; |
d221938c | 141 | |
a19423b9 GS |
142 | /* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */ |
143 | #define cpuhp_lock_acquire_read() lock_map_acquire_read(&cpu_hotplug.dep_map) | |
dd56af42 PM |
144 | #define cpuhp_lock_acquire_tryread() \ |
145 | lock_map_acquire_tryread(&cpu_hotplug.dep_map) | |
a19423b9 GS |
146 | #define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map) |
147 | #define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map) | |
148 | ||
62db99f4 | 149 | |
86ef5c9a | 150 | void get_online_cpus(void) |
a9d9baa1 | 151 | { |
d221938c GS |
152 | might_sleep(); |
153 | if (cpu_hotplug.active_writer == current) | |
aa953877 | 154 | return; |
a19423b9 | 155 | cpuhp_lock_acquire_read(); |
d221938c | 156 | mutex_lock(&cpu_hotplug.lock); |
87af9e7f | 157 | atomic_inc(&cpu_hotplug.refcount); |
d221938c | 158 | mutex_unlock(&cpu_hotplug.lock); |
a9d9baa1 | 159 | } |
86ef5c9a | 160 | EXPORT_SYMBOL_GPL(get_online_cpus); |
90d45d17 | 161 | |
86ef5c9a | 162 | void put_online_cpus(void) |
a9d9baa1 | 163 | { |
87af9e7f DH |
164 | int refcount; |
165 | ||
d221938c | 166 | if (cpu_hotplug.active_writer == current) |
aa953877 | 167 | return; |
075663d1 | 168 | |
87af9e7f DH |
169 | refcount = atomic_dec_return(&cpu_hotplug.refcount); |
170 | if (WARN_ON(refcount < 0)) /* try to fix things up */ | |
171 | atomic_inc(&cpu_hotplug.refcount); | |
172 | ||
173 | if (refcount <= 0 && waitqueue_active(&cpu_hotplug.wq)) | |
174 | wake_up(&cpu_hotplug.wq); | |
075663d1 | 175 | |
a19423b9 | 176 | cpuhp_lock_release(); |
d221938c | 177 | |
a9d9baa1 | 178 | } |
86ef5c9a | 179 | EXPORT_SYMBOL_GPL(put_online_cpus); |
a9d9baa1 | 180 | |
d221938c GS |
181 | /* |
182 | * This ensures that the hotplug operation can begin only when the | |
183 | * refcount goes to zero. | |
184 | * | |
185 | * Note that during a cpu-hotplug operation, the new readers, if any, | |
186 | * will be blocked by the cpu_hotplug.lock | |
187 | * | |
d2ba7e2a ON |
188 | * Since cpu_hotplug_begin() is always called after invoking |
189 | * cpu_maps_update_begin(), we can be sure that only one writer is active. | |
d221938c GS |
190 | * |
191 | * Note that theoretically, there is a possibility of a livelock: | |
192 | * - Refcount goes to zero, last reader wakes up the sleeping | |
193 | * writer. | |
194 | * - Last reader unlocks the cpu_hotplug.lock. | |
195 | * - A new reader arrives at this moment, bumps up the refcount. | |
196 | * - The writer acquires the cpu_hotplug.lock finds the refcount | |
197 | * non zero and goes to sleep again. | |
198 | * | |
199 | * However, this is very difficult to achieve in practice since | |
86ef5c9a | 200 | * get_online_cpus() not an api which is called all that often. |
d221938c GS |
201 | * |
202 | */ | |
b9d10be7 | 203 | void cpu_hotplug_begin(void) |
d221938c | 204 | { |
87af9e7f | 205 | DEFINE_WAIT(wait); |
d2ba7e2a | 206 | |
87af9e7f | 207 | cpu_hotplug.active_writer = current; |
a19423b9 | 208 | cpuhp_lock_acquire(); |
87af9e7f | 209 | |
d2ba7e2a ON |
210 | for (;;) { |
211 | mutex_lock(&cpu_hotplug.lock); | |
87af9e7f DH |
212 | prepare_to_wait(&cpu_hotplug.wq, &wait, TASK_UNINTERRUPTIBLE); |
213 | if (likely(!atomic_read(&cpu_hotplug.refcount))) | |
214 | break; | |
d221938c GS |
215 | mutex_unlock(&cpu_hotplug.lock); |
216 | schedule(); | |
d221938c | 217 | } |
87af9e7f | 218 | finish_wait(&cpu_hotplug.wq, &wait); |
d221938c GS |
219 | } |
220 | ||
b9d10be7 | 221 | void cpu_hotplug_done(void) |
d221938c GS |
222 | { |
223 | cpu_hotplug.active_writer = NULL; | |
224 | mutex_unlock(&cpu_hotplug.lock); | |
a19423b9 | 225 | cpuhp_lock_release(); |
d221938c | 226 | } |
79a6cdeb | 227 | |
16e53dbf SB |
228 | /* |
229 | * Wait for currently running CPU hotplug operations to complete (if any) and | |
230 | * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects | |
231 | * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the | |
232 | * hotplug path before performing hotplug operations. So acquiring that lock | |
233 | * guarantees mutual exclusion from any currently running hotplug operations. | |
234 | */ | |
235 | void cpu_hotplug_disable(void) | |
236 | { | |
237 | cpu_maps_update_begin(); | |
89af7ba5 | 238 | cpu_hotplug_disabled++; |
16e53dbf SB |
239 | cpu_maps_update_done(); |
240 | } | |
32145c46 | 241 | EXPORT_SYMBOL_GPL(cpu_hotplug_disable); |
16e53dbf SB |
242 | |
243 | void cpu_hotplug_enable(void) | |
244 | { | |
245 | cpu_maps_update_begin(); | |
89af7ba5 | 246 | WARN_ON(--cpu_hotplug_disabled < 0); |
16e53dbf SB |
247 | cpu_maps_update_done(); |
248 | } | |
32145c46 | 249 | EXPORT_SYMBOL_GPL(cpu_hotplug_enable); |
b9d10be7 | 250 | #endif /* CONFIG_HOTPLUG_CPU */ |
79a6cdeb | 251 | |
1da177e4 | 252 | /* Need to know about CPUs going up/down? */ |
71cf5aee | 253 | int register_cpu_notifier(struct notifier_block *nb) |
1da177e4 | 254 | { |
bd5349cf | 255 | int ret; |
d221938c | 256 | cpu_maps_update_begin(); |
bd5349cf | 257 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
d221938c | 258 | cpu_maps_update_done(); |
bd5349cf | 259 | return ret; |
1da177e4 | 260 | } |
65edc68c | 261 | |
71cf5aee | 262 | int __register_cpu_notifier(struct notifier_block *nb) |
93ae4f97 SB |
263 | { |
264 | return raw_notifier_chain_register(&cpu_chain, nb); | |
265 | } | |
266 | ||
090e77c3 | 267 | static int __cpu_notify(unsigned long val, unsigned int cpu, int nr_to_call, |
e9fb7631 AM |
268 | int *nr_calls) |
269 | { | |
090e77c3 TG |
270 | unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0; |
271 | void *hcpu = (void *)(long)cpu; | |
272 | ||
e6bde73b AM |
273 | int ret; |
274 | ||
090e77c3 | 275 | ret = __raw_notifier_call_chain(&cpu_chain, val | mod, hcpu, nr_to_call, |
e9fb7631 | 276 | nr_calls); |
e6bde73b AM |
277 | |
278 | return notifier_to_errno(ret); | |
e9fb7631 AM |
279 | } |
280 | ||
090e77c3 | 281 | static int cpu_notify(unsigned long val, unsigned int cpu) |
e9fb7631 | 282 | { |
090e77c3 | 283 | return __cpu_notify(val, cpu, -1, NULL); |
e9fb7631 AM |
284 | } |
285 | ||
ba997462 TG |
286 | /* Notifier wrappers for transitioning to state machine */ |
287 | static int notify_prepare(unsigned int cpu) | |
288 | { | |
289 | int nr_calls = 0; | |
290 | int ret; | |
291 | ||
292 | ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls); | |
293 | if (ret) { | |
294 | nr_calls--; | |
295 | printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", | |
296 | __func__, cpu); | |
297 | __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL); | |
298 | } | |
299 | return ret; | |
300 | } | |
301 | ||
302 | static int notify_online(unsigned int cpu) | |
303 | { | |
304 | cpu_notify(CPU_ONLINE, cpu); | |
305 | return 0; | |
306 | } | |
307 | ||
4baa0afc TG |
308 | static int notify_starting(unsigned int cpu) |
309 | { | |
310 | cpu_notify(CPU_STARTING, cpu); | |
311 | return 0; | |
312 | } | |
313 | ||
ba997462 TG |
314 | static int bringup_cpu(unsigned int cpu) |
315 | { | |
316 | struct task_struct *idle = idle_thread_get(cpu); | |
317 | int ret; | |
318 | ||
319 | /* Arch-specific enabling code. */ | |
320 | ret = __cpu_up(cpu, idle); | |
321 | if (ret) { | |
322 | cpu_notify(CPU_UP_CANCELED, cpu); | |
323 | return ret; | |
324 | } | |
325 | BUG_ON(!cpu_online(cpu)); | |
326 | return 0; | |
327 | } | |
328 | ||
00b9b0af | 329 | #ifdef CONFIG_HOTPLUG_CPU |
1da177e4 | 330 | EXPORT_SYMBOL(register_cpu_notifier); |
93ae4f97 | 331 | EXPORT_SYMBOL(__register_cpu_notifier); |
1da177e4 | 332 | |
71cf5aee | 333 | void unregister_cpu_notifier(struct notifier_block *nb) |
1da177e4 | 334 | { |
d221938c | 335 | cpu_maps_update_begin(); |
bd5349cf | 336 | raw_notifier_chain_unregister(&cpu_chain, nb); |
d221938c | 337 | cpu_maps_update_done(); |
1da177e4 LT |
338 | } |
339 | EXPORT_SYMBOL(unregister_cpu_notifier); | |
340 | ||
71cf5aee | 341 | void __unregister_cpu_notifier(struct notifier_block *nb) |
93ae4f97 SB |
342 | { |
343 | raw_notifier_chain_unregister(&cpu_chain, nb); | |
344 | } | |
345 | EXPORT_SYMBOL(__unregister_cpu_notifier); | |
346 | ||
e4cc2f87 AV |
347 | /** |
348 | * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU | |
349 | * @cpu: a CPU id | |
350 | * | |
351 | * This function walks all processes, finds a valid mm struct for each one and | |
352 | * then clears a corresponding bit in mm's cpumask. While this all sounds | |
353 | * trivial, there are various non-obvious corner cases, which this function | |
354 | * tries to solve in a safe manner. | |
355 | * | |
356 | * Also note that the function uses a somewhat relaxed locking scheme, so it may | |
357 | * be called only for an already offlined CPU. | |
358 | */ | |
cb79295e AV |
359 | void clear_tasks_mm_cpumask(int cpu) |
360 | { | |
361 | struct task_struct *p; | |
362 | ||
363 | /* | |
364 | * This function is called after the cpu is taken down and marked | |
365 | * offline, so its not like new tasks will ever get this cpu set in | |
366 | * their mm mask. -- Peter Zijlstra | |
367 | * Thus, we may use rcu_read_lock() here, instead of grabbing | |
368 | * full-fledged tasklist_lock. | |
369 | */ | |
e4cc2f87 | 370 | WARN_ON(cpu_online(cpu)); |
cb79295e AV |
371 | rcu_read_lock(); |
372 | for_each_process(p) { | |
373 | struct task_struct *t; | |
374 | ||
e4cc2f87 AV |
375 | /* |
376 | * Main thread might exit, but other threads may still have | |
377 | * a valid mm. Find one. | |
378 | */ | |
cb79295e AV |
379 | t = find_lock_task_mm(p); |
380 | if (!t) | |
381 | continue; | |
382 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); | |
383 | task_unlock(t); | |
384 | } | |
385 | rcu_read_unlock(); | |
386 | } | |
387 | ||
b728ca06 | 388 | static inline void check_for_tasks(int dead_cpu) |
1da177e4 | 389 | { |
b728ca06 | 390 | struct task_struct *g, *p; |
1da177e4 | 391 | |
a75a6068 ON |
392 | read_lock(&tasklist_lock); |
393 | for_each_process_thread(g, p) { | |
b728ca06 KT |
394 | if (!p->on_rq) |
395 | continue; | |
396 | /* | |
397 | * We do the check with unlocked task_rq(p)->lock. | |
398 | * Order the reading to do not warn about a task, | |
399 | * which was running on this cpu in the past, and | |
400 | * it's just been woken on another cpu. | |
401 | */ | |
402 | rmb(); | |
403 | if (task_cpu(p) != dead_cpu) | |
404 | continue; | |
405 | ||
406 | pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n", | |
407 | p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags); | |
a75a6068 ON |
408 | } |
409 | read_unlock(&tasklist_lock); | |
1da177e4 LT |
410 | } |
411 | ||
98458172 TG |
412 | static void cpu_notify_nofail(unsigned long val, unsigned int cpu) |
413 | { | |
414 | BUG_ON(cpu_notify(val, cpu)); | |
415 | } | |
416 | ||
417 | static int notify_down_prepare(unsigned int cpu) | |
418 | { | |
419 | int err, nr_calls = 0; | |
420 | ||
421 | err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls); | |
422 | if (err) { | |
423 | nr_calls--; | |
424 | __cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL); | |
425 | pr_warn("%s: attempt to take down CPU %u failed\n", | |
426 | __func__, cpu); | |
427 | } | |
428 | return err; | |
429 | } | |
430 | ||
4baa0afc TG |
431 | static int notify_dying(unsigned int cpu) |
432 | { | |
433 | cpu_notify(CPU_DYING, cpu); | |
434 | return 0; | |
435 | } | |
436 | ||
1da177e4 | 437 | /* Take this CPU down. */ |
71cf5aee | 438 | static int take_cpu_down(void *_param) |
1da177e4 | 439 | { |
4baa0afc TG |
440 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
441 | enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE); | |
090e77c3 | 442 | int err, cpu = smp_processor_id(); |
1da177e4 | 443 | |
1da177e4 LT |
444 | /* Ensure this CPU doesn't handle any more interrupts. */ |
445 | err = __cpu_disable(); | |
446 | if (err < 0) | |
f3705136 | 447 | return err; |
1da177e4 | 448 | |
4baa0afc TG |
449 | /* Invoke the former CPU_DYING callbacks */ |
450 | for (; st->state > target; st->state--) { | |
451 | struct cpuhp_step *step = cpuhp_ap_states + st->state; | |
452 | ||
453 | cpuhp_invoke_callback(cpu, st->state, step->teardown); | |
454 | } | |
52c063d1 TG |
455 | /* Give up timekeeping duties */ |
456 | tick_handover_do_timer(); | |
14e568e7 | 457 | /* Park the stopper thread */ |
090e77c3 | 458 | stop_machine_park(cpu); |
f3705136 | 459 | return 0; |
1da177e4 LT |
460 | } |
461 | ||
98458172 | 462 | static int takedown_cpu(unsigned int cpu) |
1da177e4 | 463 | { |
98458172 | 464 | int err; |
1da177e4 | 465 | |
6acce3ef PZ |
466 | /* |
467 | * By now we've cleared cpu_active_mask, wait for all preempt-disabled | |
468 | * and RCU users of this state to go away such that all new such users | |
469 | * will observe it. | |
470 | * | |
471 | * For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might | |
779de6ce | 472 | * not imply sync_sched(), so wait for both. |
106dd5af M |
473 | * |
474 | * Do sync before park smpboot threads to take care the rcu boost case. | |
6acce3ef | 475 | */ |
779de6ce PM |
476 | if (IS_ENABLED(CONFIG_PREEMPT)) |
477 | synchronize_rcu_mult(call_rcu, call_rcu_sched); | |
478 | else | |
479 | synchronize_rcu(); | |
6acce3ef | 480 | |
106dd5af M |
481 | smpboot_park_threads(cpu); |
482 | ||
6acce3ef | 483 | /* |
a8994181 TG |
484 | * Prevent irq alloc/free while the dying cpu reorganizes the |
485 | * interrupt affinities. | |
6acce3ef | 486 | */ |
a8994181 | 487 | irq_lock_sparse(); |
6acce3ef | 488 | |
a8994181 TG |
489 | /* |
490 | * So now all preempt/rcu users must observe !cpu_active(). | |
491 | */ | |
090e77c3 | 492 | err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu)); |
04321587 | 493 | if (err) { |
1da177e4 | 494 | /* CPU didn't die: tell everyone. Can't complain. */ |
090e77c3 | 495 | cpu_notify_nofail(CPU_DOWN_FAILED, cpu); |
a8994181 | 496 | irq_unlock_sparse(); |
98458172 | 497 | return err; |
8fa1d7d3 | 498 | } |
04321587 | 499 | BUG_ON(cpu_online(cpu)); |
1da177e4 | 500 | |
48c5ccae PZ |
501 | /* |
502 | * The migration_call() CPU_DYING callback will have removed all | |
503 | * runnable tasks from the cpu, there's only the idle task left now | |
504 | * that the migration thread is done doing the stop_machine thing. | |
51a96c77 PZ |
505 | * |
506 | * Wait for the stop thread to go away. | |
48c5ccae | 507 | */ |
528a25b0 | 508 | while (!per_cpu(cpu_dead_idle, cpu)) |
51a96c77 | 509 | cpu_relax(); |
528a25b0 PM |
510 | smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */ |
511 | per_cpu(cpu_dead_idle, cpu) = false; | |
1da177e4 | 512 | |
a8994181 TG |
513 | /* Interrupts are moved away from the dying cpu, reenable alloc/free */ |
514 | irq_unlock_sparse(); | |
515 | ||
345527b1 | 516 | hotplug_cpu__broadcast_tick_pull(cpu); |
1da177e4 LT |
517 | /* This actually kills the CPU. */ |
518 | __cpu_die(cpu); | |
519 | ||
a49b116d | 520 | tick_cleanup_dead_cpu(cpu); |
98458172 TG |
521 | return 0; |
522 | } | |
1da177e4 | 523 | |
98458172 TG |
524 | static int notify_dead(unsigned int cpu) |
525 | { | |
526 | cpu_notify_nofail(CPU_DEAD, cpu); | |
1da177e4 | 527 | check_for_tasks(cpu); |
98458172 TG |
528 | return 0; |
529 | } | |
530 | ||
cff7d378 TG |
531 | #else |
532 | #define notify_down_prepare NULL | |
533 | #define takedown_cpu NULL | |
534 | #define notify_dead NULL | |
4baa0afc | 535 | #define notify_dying NULL |
cff7d378 TG |
536 | #endif |
537 | ||
538 | #ifdef CONFIG_HOTPLUG_CPU | |
539 | static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st) | |
540 | { | |
541 | for (st->state++; st->state < st->target; st->state++) { | |
542 | struct cpuhp_step *step = cpuhp_bp_states + st->state; | |
543 | ||
544 | if (!step->skip_onerr) | |
545 | cpuhp_invoke_callback(cpu, st->state, step->startup); | |
546 | } | |
547 | } | |
548 | ||
98458172 | 549 | /* Requires cpu_add_remove_lock to be held */ |
af1f4045 TG |
550 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, |
551 | enum cpuhp_state target) | |
98458172 | 552 | { |
cff7d378 TG |
553 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
554 | int prev_state, ret = 0; | |
555 | bool hasdied = false; | |
98458172 TG |
556 | |
557 | if (num_online_cpus() == 1) | |
558 | return -EBUSY; | |
559 | ||
560 | if (!cpu_online(cpu)) | |
561 | return -EINVAL; | |
562 | ||
563 | cpu_hotplug_begin(); | |
564 | ||
565 | cpuhp_tasks_frozen = tasks_frozen; | |
566 | ||
cff7d378 | 567 | prev_state = st->state; |
af1f4045 | 568 | st->target = target; |
cff7d378 TG |
569 | for (; st->state > st->target; st->state--) { |
570 | struct cpuhp_step *step = cpuhp_bp_states + st->state; | |
98458172 | 571 | |
cff7d378 TG |
572 | ret = cpuhp_invoke_callback(cpu, st->state, step->teardown); |
573 | if (ret) { | |
574 | st->target = prev_state; | |
575 | undo_cpu_down(cpu, st); | |
576 | break; | |
577 | } | |
578 | } | |
579 | hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE; | |
1da177e4 | 580 | |
d221938c | 581 | cpu_hotplug_done(); |
cff7d378 TG |
582 | /* This post dead nonsense must die */ |
583 | if (!ret && hasdied) | |
090e77c3 | 584 | cpu_notify_nofail(CPU_POST_DEAD, cpu); |
cff7d378 | 585 | return ret; |
e3920fb4 RW |
586 | } |
587 | ||
af1f4045 | 588 | static int do_cpu_down(unsigned int cpu, enum cpuhp_state target) |
e3920fb4 | 589 | { |
9ea09af3 | 590 | int err; |
e3920fb4 | 591 | |
d221938c | 592 | cpu_maps_update_begin(); |
e761b772 MK |
593 | |
594 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 595 | err = -EBUSY; |
e761b772 MK |
596 | goto out; |
597 | } | |
598 | ||
af1f4045 | 599 | err = _cpu_down(cpu, 0, target); |
e3920fb4 | 600 | |
e761b772 | 601 | out: |
d221938c | 602 | cpu_maps_update_done(); |
1da177e4 LT |
603 | return err; |
604 | } | |
af1f4045 TG |
605 | int cpu_down(unsigned int cpu) |
606 | { | |
607 | return do_cpu_down(cpu, CPUHP_OFFLINE); | |
608 | } | |
b62b8ef9 | 609 | EXPORT_SYMBOL(cpu_down); |
1da177e4 LT |
610 | #endif /*CONFIG_HOTPLUG_CPU*/ |
611 | ||
00df35f9 PM |
612 | /* |
613 | * Unpark per-CPU smpboot kthreads at CPU-online time. | |
614 | */ | |
615 | static int smpboot_thread_call(struct notifier_block *nfb, | |
616 | unsigned long action, void *hcpu) | |
617 | { | |
618 | int cpu = (long)hcpu; | |
619 | ||
620 | switch (action & ~CPU_TASKS_FROZEN) { | |
621 | ||
64eaf974 | 622 | case CPU_DOWN_FAILED: |
00df35f9 PM |
623 | case CPU_ONLINE: |
624 | smpboot_unpark_threads(cpu); | |
625 | break; | |
626 | ||
627 | default: | |
628 | break; | |
629 | } | |
630 | ||
631 | return NOTIFY_OK; | |
632 | } | |
633 | ||
634 | static struct notifier_block smpboot_thread_notifier = { | |
635 | .notifier_call = smpboot_thread_call, | |
636 | .priority = CPU_PRI_SMPBOOT, | |
637 | }; | |
638 | ||
927da9df | 639 | void smpboot_thread_init(void) |
00df35f9 PM |
640 | { |
641 | register_cpu_notifier(&smpboot_thread_notifier); | |
642 | } | |
643 | ||
4baa0afc TG |
644 | /** |
645 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers | |
646 | * @cpu: cpu that just started | |
647 | * | |
648 | * This function calls the cpu_chain notifiers with CPU_STARTING. | |
649 | * It must be called by the arch code on the new cpu, before the new cpu | |
650 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). | |
651 | */ | |
652 | void notify_cpu_starting(unsigned int cpu) | |
653 | { | |
654 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
655 | enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE); | |
656 | ||
657 | while (st->state < target) { | |
658 | struct cpuhp_step *step; | |
659 | ||
660 | st->state++; | |
661 | step = cpuhp_ap_states + st->state; | |
662 | cpuhp_invoke_callback(cpu, st->state, step->startup); | |
663 | } | |
664 | } | |
665 | ||
cff7d378 TG |
666 | static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st) |
667 | { | |
668 | for (st->state--; st->state > st->target; st->state--) { | |
669 | struct cpuhp_step *step = cpuhp_bp_states + st->state; | |
670 | ||
671 | if (!step->skip_onerr) | |
672 | cpuhp_invoke_callback(cpu, st->state, step->teardown); | |
673 | } | |
674 | } | |
675 | ||
e3920fb4 | 676 | /* Requires cpu_add_remove_lock to be held */ |
af1f4045 | 677 | static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target) |
1da177e4 | 678 | { |
cff7d378 | 679 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
3bb5d2ee | 680 | struct task_struct *idle; |
cff7d378 | 681 | int prev_state, ret = 0; |
1da177e4 | 682 | |
d221938c | 683 | cpu_hotplug_begin(); |
38498a67 | 684 | |
5e5041f3 YI |
685 | if (cpu_online(cpu) || !cpu_present(cpu)) { |
686 | ret = -EINVAL; | |
687 | goto out; | |
688 | } | |
689 | ||
cff7d378 | 690 | /* Let it fail before we try to bring the cpu up */ |
3bb5d2ee SS |
691 | idle = idle_thread_get(cpu); |
692 | if (IS_ERR(idle)) { | |
693 | ret = PTR_ERR(idle); | |
38498a67 | 694 | goto out; |
3bb5d2ee | 695 | } |
38498a67 | 696 | |
ba997462 TG |
697 | cpuhp_tasks_frozen = tasks_frozen; |
698 | ||
cff7d378 | 699 | prev_state = st->state; |
af1f4045 | 700 | st->target = target; |
cff7d378 TG |
701 | while (st->state < st->target) { |
702 | struct cpuhp_step *step; | |
703 | ||
704 | st->state++; | |
705 | step = cpuhp_bp_states + st->state; | |
706 | ret = cpuhp_invoke_callback(cpu, st->state, step->startup); | |
707 | if (ret) { | |
708 | st->target = prev_state; | |
709 | undo_cpu_up(cpu, st); | |
710 | break; | |
711 | } | |
712 | } | |
38498a67 | 713 | out: |
d221938c | 714 | cpu_hotplug_done(); |
e3920fb4 RW |
715 | return ret; |
716 | } | |
717 | ||
af1f4045 | 718 | static int do_cpu_up(unsigned int cpu, enum cpuhp_state target) |
e3920fb4 RW |
719 | { |
720 | int err = 0; | |
cf23422b | 721 | |
e0b582ec | 722 | if (!cpu_possible(cpu)) { |
84117da5 FF |
723 | pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n", |
724 | cpu); | |
87d5e023 | 725 | #if defined(CONFIG_IA64) |
84117da5 | 726 | pr_err("please check additional_cpus= boot parameter\n"); |
73e753a5 KH |
727 | #endif |
728 | return -EINVAL; | |
729 | } | |
e3920fb4 | 730 | |
01b0f197 TK |
731 | err = try_online_node(cpu_to_node(cpu)); |
732 | if (err) | |
733 | return err; | |
cf23422b | 734 | |
d221938c | 735 | cpu_maps_update_begin(); |
e761b772 MK |
736 | |
737 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 738 | err = -EBUSY; |
e761b772 MK |
739 | goto out; |
740 | } | |
741 | ||
af1f4045 | 742 | err = _cpu_up(cpu, 0, target); |
e761b772 | 743 | out: |
d221938c | 744 | cpu_maps_update_done(); |
e3920fb4 RW |
745 | return err; |
746 | } | |
af1f4045 TG |
747 | |
748 | int cpu_up(unsigned int cpu) | |
749 | { | |
750 | return do_cpu_up(cpu, CPUHP_ONLINE); | |
751 | } | |
a513f6ba | 752 | EXPORT_SYMBOL_GPL(cpu_up); |
e3920fb4 | 753 | |
f3de4be9 | 754 | #ifdef CONFIG_PM_SLEEP_SMP |
e0b582ec | 755 | static cpumask_var_t frozen_cpus; |
e3920fb4 RW |
756 | |
757 | int disable_nonboot_cpus(void) | |
758 | { | |
e9a5f426 | 759 | int cpu, first_cpu, error = 0; |
e3920fb4 | 760 | |
d221938c | 761 | cpu_maps_update_begin(); |
e0b582ec | 762 | first_cpu = cpumask_first(cpu_online_mask); |
9ee349ad XF |
763 | /* |
764 | * We take down all of the non-boot CPUs in one shot to avoid races | |
e3920fb4 RW |
765 | * with the userspace trying to use the CPU hotplug at the same time |
766 | */ | |
e0b582ec | 767 | cpumask_clear(frozen_cpus); |
6ad4c188 | 768 | |
84117da5 | 769 | pr_info("Disabling non-boot CPUs ...\n"); |
e3920fb4 RW |
770 | for_each_online_cpu(cpu) { |
771 | if (cpu == first_cpu) | |
772 | continue; | |
bb3632c6 | 773 | trace_suspend_resume(TPS("CPU_OFF"), cpu, true); |
af1f4045 | 774 | error = _cpu_down(cpu, 1, CPUHP_OFFLINE); |
bb3632c6 | 775 | trace_suspend_resume(TPS("CPU_OFF"), cpu, false); |
feae3203 | 776 | if (!error) |
e0b582ec | 777 | cpumask_set_cpu(cpu, frozen_cpus); |
feae3203 | 778 | else { |
84117da5 | 779 | pr_err("Error taking CPU%d down: %d\n", cpu, error); |
e3920fb4 RW |
780 | break; |
781 | } | |
782 | } | |
86886e55 | 783 | |
89af7ba5 | 784 | if (!error) |
e3920fb4 | 785 | BUG_ON(num_online_cpus() > 1); |
89af7ba5 | 786 | else |
84117da5 | 787 | pr_err("Non-boot CPUs are not disabled\n"); |
89af7ba5 VK |
788 | |
789 | /* | |
790 | * Make sure the CPUs won't be enabled by someone else. We need to do | |
791 | * this even in case of failure as all disable_nonboot_cpus() users are | |
792 | * supposed to do enable_nonboot_cpus() on the failure path. | |
793 | */ | |
794 | cpu_hotplug_disabled++; | |
795 | ||
d221938c | 796 | cpu_maps_update_done(); |
e3920fb4 RW |
797 | return error; |
798 | } | |
799 | ||
d0af9eed SS |
800 | void __weak arch_enable_nonboot_cpus_begin(void) |
801 | { | |
802 | } | |
803 | ||
804 | void __weak arch_enable_nonboot_cpus_end(void) | |
805 | { | |
806 | } | |
807 | ||
71cf5aee | 808 | void enable_nonboot_cpus(void) |
e3920fb4 RW |
809 | { |
810 | int cpu, error; | |
811 | ||
812 | /* Allow everyone to use the CPU hotplug again */ | |
d221938c | 813 | cpu_maps_update_begin(); |
89af7ba5 | 814 | WARN_ON(--cpu_hotplug_disabled < 0); |
e0b582ec | 815 | if (cpumask_empty(frozen_cpus)) |
1d64b9cb | 816 | goto out; |
e3920fb4 | 817 | |
84117da5 | 818 | pr_info("Enabling non-boot CPUs ...\n"); |
d0af9eed SS |
819 | |
820 | arch_enable_nonboot_cpus_begin(); | |
821 | ||
e0b582ec | 822 | for_each_cpu(cpu, frozen_cpus) { |
bb3632c6 | 823 | trace_suspend_resume(TPS("CPU_ON"), cpu, true); |
af1f4045 | 824 | error = _cpu_up(cpu, 1, CPUHP_ONLINE); |
bb3632c6 | 825 | trace_suspend_resume(TPS("CPU_ON"), cpu, false); |
e3920fb4 | 826 | if (!error) { |
84117da5 | 827 | pr_info("CPU%d is up\n", cpu); |
e3920fb4 RW |
828 | continue; |
829 | } | |
84117da5 | 830 | pr_warn("Error taking CPU%d up: %d\n", cpu, error); |
e3920fb4 | 831 | } |
d0af9eed SS |
832 | |
833 | arch_enable_nonboot_cpus_end(); | |
834 | ||
e0b582ec | 835 | cpumask_clear(frozen_cpus); |
1d64b9cb | 836 | out: |
d221938c | 837 | cpu_maps_update_done(); |
1da177e4 | 838 | } |
e0b582ec | 839 | |
d7268a31 | 840 | static int __init alloc_frozen_cpus(void) |
e0b582ec RR |
841 | { |
842 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) | |
843 | return -ENOMEM; | |
844 | return 0; | |
845 | } | |
846 | core_initcall(alloc_frozen_cpus); | |
79cfbdfa | 847 | |
79cfbdfa SB |
848 | /* |
849 | * When callbacks for CPU hotplug notifications are being executed, we must | |
850 | * ensure that the state of the system with respect to the tasks being frozen | |
851 | * or not, as reported by the notification, remains unchanged *throughout the | |
852 | * duration* of the execution of the callbacks. | |
853 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. | |
854 | * | |
855 | * This synchronization is implemented by mutually excluding regular CPU | |
856 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ | |
857 | * Hibernate notifications. | |
858 | */ | |
859 | static int | |
860 | cpu_hotplug_pm_callback(struct notifier_block *nb, | |
861 | unsigned long action, void *ptr) | |
862 | { | |
863 | switch (action) { | |
864 | ||
865 | case PM_SUSPEND_PREPARE: | |
866 | case PM_HIBERNATION_PREPARE: | |
16e53dbf | 867 | cpu_hotplug_disable(); |
79cfbdfa SB |
868 | break; |
869 | ||
870 | case PM_POST_SUSPEND: | |
871 | case PM_POST_HIBERNATION: | |
16e53dbf | 872 | cpu_hotplug_enable(); |
79cfbdfa SB |
873 | break; |
874 | ||
875 | default: | |
876 | return NOTIFY_DONE; | |
877 | } | |
878 | ||
879 | return NOTIFY_OK; | |
880 | } | |
881 | ||
882 | ||
d7268a31 | 883 | static int __init cpu_hotplug_pm_sync_init(void) |
79cfbdfa | 884 | { |
6e32d479 FY |
885 | /* |
886 | * cpu_hotplug_pm_callback has higher priority than x86 | |
887 | * bsp_pm_callback which depends on cpu_hotplug_pm_callback | |
888 | * to disable cpu hotplug to avoid cpu hotplug race. | |
889 | */ | |
79cfbdfa SB |
890 | pm_notifier(cpu_hotplug_pm_callback, 0); |
891 | return 0; | |
892 | } | |
893 | core_initcall(cpu_hotplug_pm_sync_init); | |
894 | ||
f3de4be9 | 895 | #endif /* CONFIG_PM_SLEEP_SMP */ |
68f4f1ec MK |
896 | |
897 | #endif /* CONFIG_SMP */ | |
b8d317d1 | 898 | |
cff7d378 TG |
899 | /* Boot processor state steps */ |
900 | static struct cpuhp_step cpuhp_bp_states[] = { | |
901 | [CPUHP_OFFLINE] = { | |
902 | .name = "offline", | |
903 | .startup = NULL, | |
904 | .teardown = NULL, | |
905 | }, | |
906 | #ifdef CONFIG_SMP | |
907 | [CPUHP_CREATE_THREADS]= { | |
908 | .name = "threads:create", | |
909 | .startup = smpboot_create_threads, | |
910 | .teardown = NULL, | |
911 | }, | |
912 | [CPUHP_NOTIFY_PREPARE] = { | |
913 | .name = "notify:prepare", | |
914 | .startup = notify_prepare, | |
915 | .teardown = notify_dead, | |
916 | .skip_onerr = true, | |
917 | }, | |
918 | [CPUHP_BRINGUP_CPU] = { | |
919 | .name = "cpu:bringup", | |
920 | .startup = bringup_cpu, | |
4baa0afc TG |
921 | .teardown = NULL, |
922 | }, | |
923 | [CPUHP_TEARDOWN_CPU] = { | |
924 | .name = "cpu:teardown", | |
925 | .startup = NULL, | |
cff7d378 | 926 | .teardown = takedown_cpu, |
cff7d378 TG |
927 | }, |
928 | [CPUHP_NOTIFY_ONLINE] = { | |
929 | .name = "notify:online", | |
930 | .startup = notify_online, | |
931 | .teardown = notify_down_prepare, | |
932 | }, | |
933 | #endif | |
934 | [CPUHP_ONLINE] = { | |
935 | .name = "online", | |
936 | .startup = NULL, | |
937 | .teardown = NULL, | |
938 | }, | |
939 | }; | |
940 | ||
4baa0afc TG |
941 | /* Application processor state steps */ |
942 | static struct cpuhp_step cpuhp_ap_states[] = { | |
943 | #ifdef CONFIG_SMP | |
944 | [CPUHP_AP_NOTIFY_STARTING] = { | |
945 | .name = "notify:starting", | |
946 | .startup = notify_starting, | |
947 | .teardown = notify_dying, | |
948 | .skip_onerr = true, | |
949 | }, | |
950 | #endif | |
951 | [CPUHP_ONLINE] = { | |
952 | .name = "online", | |
953 | .startup = NULL, | |
954 | .teardown = NULL, | |
955 | }, | |
956 | }; | |
957 | ||
e56b3bc7 LT |
958 | /* |
959 | * cpu_bit_bitmap[] is a special, "compressed" data structure that | |
960 | * represents all NR_CPUS bits binary values of 1<<nr. | |
961 | * | |
e0b582ec | 962 | * It is used by cpumask_of() to get a constant address to a CPU |
e56b3bc7 LT |
963 | * mask value that has a single bit set only. |
964 | */ | |
b8d317d1 | 965 | |
e56b3bc7 | 966 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
4d51985e | 967 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
e56b3bc7 LT |
968 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
969 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) | |
970 | #define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4) | |
b8d317d1 | 971 | |
e56b3bc7 LT |
972 | const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { |
973 | ||
974 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), | |
975 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), | |
976 | #if BITS_PER_LONG > 32 | |
977 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), | |
978 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), | |
b8d317d1 MT |
979 | #endif |
980 | }; | |
e56b3bc7 | 981 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
2d3854a3 RR |
982 | |
983 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; | |
984 | EXPORT_SYMBOL(cpu_all_bits); | |
b3199c02 RR |
985 | |
986 | #ifdef CONFIG_INIT_ALL_POSSIBLE | |
4b804c85 | 987 | struct cpumask __cpu_possible_mask __read_mostly |
c4c54dd1 | 988 | = {CPU_BITS_ALL}; |
b3199c02 | 989 | #else |
4b804c85 | 990 | struct cpumask __cpu_possible_mask __read_mostly; |
b3199c02 | 991 | #endif |
4b804c85 | 992 | EXPORT_SYMBOL(__cpu_possible_mask); |
b3199c02 | 993 | |
4b804c85 RV |
994 | struct cpumask __cpu_online_mask __read_mostly; |
995 | EXPORT_SYMBOL(__cpu_online_mask); | |
b3199c02 | 996 | |
4b804c85 RV |
997 | struct cpumask __cpu_present_mask __read_mostly; |
998 | EXPORT_SYMBOL(__cpu_present_mask); | |
b3199c02 | 999 | |
4b804c85 RV |
1000 | struct cpumask __cpu_active_mask __read_mostly; |
1001 | EXPORT_SYMBOL(__cpu_active_mask); | |
3fa41520 | 1002 | |
3fa41520 RR |
1003 | void init_cpu_present(const struct cpumask *src) |
1004 | { | |
c4c54dd1 | 1005 | cpumask_copy(&__cpu_present_mask, src); |
3fa41520 RR |
1006 | } |
1007 | ||
1008 | void init_cpu_possible(const struct cpumask *src) | |
1009 | { | |
c4c54dd1 | 1010 | cpumask_copy(&__cpu_possible_mask, src); |
3fa41520 RR |
1011 | } |
1012 | ||
1013 | void init_cpu_online(const struct cpumask *src) | |
1014 | { | |
c4c54dd1 | 1015 | cpumask_copy(&__cpu_online_mask, src); |
3fa41520 | 1016 | } |
cff7d378 TG |
1017 | |
1018 | /* | |
1019 | * Activate the first processor. | |
1020 | */ | |
1021 | void __init boot_cpu_init(void) | |
1022 | { | |
1023 | int cpu = smp_processor_id(); | |
1024 | ||
1025 | /* Mark the boot cpu "present", "online" etc for SMP and UP case */ | |
1026 | set_cpu_online(cpu, true); | |
1027 | set_cpu_active(cpu, true); | |
1028 | set_cpu_present(cpu, true); | |
1029 | set_cpu_possible(cpu, true); | |
1030 | } | |
1031 | ||
1032 | /* | |
1033 | * Must be called _AFTER_ setting up the per_cpu areas | |
1034 | */ | |
1035 | void __init boot_cpu_state_init(void) | |
1036 | { | |
1037 | per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE; | |
1038 | } |