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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> |
4cb28ced | 25 | #include <linux/smpboot.h> |
cff7d378 | 26 | |
bb3632c6 | 27 | #include <trace/events/power.h> |
cff7d378 TG |
28 | #define CREATE_TRACE_POINTS |
29 | #include <trace/events/cpuhp.h> | |
1da177e4 | 30 | |
38498a67 TG |
31 | #include "smpboot.h" |
32 | ||
cff7d378 TG |
33 | /** |
34 | * cpuhp_cpu_state - Per cpu hotplug state storage | |
35 | * @state: The current cpu state | |
36 | * @target: The target state | |
4cb28ced TG |
37 | * @thread: Pointer to the hotplug thread |
38 | * @should_run: Thread should execute | |
39 | * @cb_stat: The state for a single callback (install/uninstall) | |
40 | * @cb: Single callback function (install/uninstall) | |
41 | * @result: Result of the operation | |
42 | * @done: Signal completion to the issuer of the task | |
cff7d378 TG |
43 | */ |
44 | struct cpuhp_cpu_state { | |
45 | enum cpuhp_state state; | |
46 | enum cpuhp_state target; | |
4cb28ced TG |
47 | #ifdef CONFIG_SMP |
48 | struct task_struct *thread; | |
49 | bool should_run; | |
50 | enum cpuhp_state cb_state; | |
51 | int (*cb)(unsigned int cpu); | |
52 | int result; | |
53 | struct completion done; | |
54 | #endif | |
cff7d378 TG |
55 | }; |
56 | ||
57 | static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state); | |
58 | ||
59 | /** | |
60 | * cpuhp_step - Hotplug state machine step | |
61 | * @name: Name of the step | |
62 | * @startup: Startup function of the step | |
63 | * @teardown: Teardown function of the step | |
64 | * @skip_onerr: Do not invoke the functions on error rollback | |
65 | * Will go away once the notifiers are gone | |
757c989b | 66 | * @cant_stop: Bringup/teardown can't be stopped at this step |
cff7d378 TG |
67 | */ |
68 | struct cpuhp_step { | |
69 | const char *name; | |
70 | int (*startup)(unsigned int cpu); | |
71 | int (*teardown)(unsigned int cpu); | |
72 | bool skip_onerr; | |
757c989b | 73 | bool cant_stop; |
cff7d378 TG |
74 | }; |
75 | ||
98f8cdce | 76 | static DEFINE_MUTEX(cpuhp_state_mutex); |
cff7d378 | 77 | static struct cpuhp_step cpuhp_bp_states[]; |
4baa0afc | 78 | static struct cpuhp_step cpuhp_ap_states[]; |
cff7d378 TG |
79 | |
80 | /** | |
81 | * cpuhp_invoke_callback _ Invoke the callbacks for a given state | |
82 | * @cpu: The cpu for which the callback should be invoked | |
83 | * @step: The step in the state machine | |
84 | * @cb: The callback function to invoke | |
85 | * | |
86 | * Called from cpu hotplug and from the state register machinery | |
87 | */ | |
88 | static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state step, | |
89 | int (*cb)(unsigned int)) | |
90 | { | |
91 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
92 | int ret = 0; | |
93 | ||
94 | if (cb) { | |
95 | trace_cpuhp_enter(cpu, st->target, step, cb); | |
96 | ret = cb(cpu); | |
97 | trace_cpuhp_exit(cpu, st->state, step, ret); | |
98 | } | |
99 | return ret; | |
100 | } | |
101 | ||
98a79d6a | 102 | #ifdef CONFIG_SMP |
b3199c02 | 103 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
aa953877 | 104 | static DEFINE_MUTEX(cpu_add_remove_lock); |
090e77c3 TG |
105 | bool cpuhp_tasks_frozen; |
106 | EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen); | |
1da177e4 | 107 | |
79a6cdeb | 108 | /* |
93ae4f97 SB |
109 | * The following two APIs (cpu_maps_update_begin/done) must be used when |
110 | * attempting to serialize the updates to cpu_online_mask & cpu_present_mask. | |
111 | * The APIs cpu_notifier_register_begin/done() must be used to protect CPU | |
112 | * hotplug callback (un)registration performed using __register_cpu_notifier() | |
113 | * or __unregister_cpu_notifier(). | |
79a6cdeb LJ |
114 | */ |
115 | void cpu_maps_update_begin(void) | |
116 | { | |
117 | mutex_lock(&cpu_add_remove_lock); | |
118 | } | |
93ae4f97 | 119 | EXPORT_SYMBOL(cpu_notifier_register_begin); |
79a6cdeb LJ |
120 | |
121 | void cpu_maps_update_done(void) | |
122 | { | |
123 | mutex_unlock(&cpu_add_remove_lock); | |
124 | } | |
93ae4f97 | 125 | EXPORT_SYMBOL(cpu_notifier_register_done); |
79a6cdeb | 126 | |
5c113fbe | 127 | static RAW_NOTIFIER_HEAD(cpu_chain); |
1da177e4 | 128 | |
e3920fb4 RW |
129 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
130 | * Should always be manipulated under cpu_add_remove_lock | |
131 | */ | |
132 | static int cpu_hotplug_disabled; | |
133 | ||
79a6cdeb LJ |
134 | #ifdef CONFIG_HOTPLUG_CPU |
135 | ||
d221938c GS |
136 | static struct { |
137 | struct task_struct *active_writer; | |
87af9e7f DH |
138 | /* wait queue to wake up the active_writer */ |
139 | wait_queue_head_t wq; | |
140 | /* verifies that no writer will get active while readers are active */ | |
141 | struct mutex lock; | |
d221938c GS |
142 | /* |
143 | * Also blocks the new readers during | |
144 | * an ongoing cpu hotplug operation. | |
145 | */ | |
87af9e7f | 146 | atomic_t refcount; |
a19423b9 GS |
147 | |
148 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
149 | struct lockdep_map dep_map; | |
150 | #endif | |
31950eb6 LT |
151 | } cpu_hotplug = { |
152 | .active_writer = NULL, | |
87af9e7f | 153 | .wq = __WAIT_QUEUE_HEAD_INITIALIZER(cpu_hotplug.wq), |
31950eb6 | 154 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), |
a19423b9 GS |
155 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
156 | .dep_map = {.name = "cpu_hotplug.lock" }, | |
157 | #endif | |
31950eb6 | 158 | }; |
d221938c | 159 | |
a19423b9 GS |
160 | /* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */ |
161 | #define cpuhp_lock_acquire_read() lock_map_acquire_read(&cpu_hotplug.dep_map) | |
dd56af42 PM |
162 | #define cpuhp_lock_acquire_tryread() \ |
163 | lock_map_acquire_tryread(&cpu_hotplug.dep_map) | |
a19423b9 GS |
164 | #define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map) |
165 | #define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map) | |
166 | ||
62db99f4 | 167 | |
86ef5c9a | 168 | void get_online_cpus(void) |
a9d9baa1 | 169 | { |
d221938c GS |
170 | might_sleep(); |
171 | if (cpu_hotplug.active_writer == current) | |
aa953877 | 172 | return; |
a19423b9 | 173 | cpuhp_lock_acquire_read(); |
d221938c | 174 | mutex_lock(&cpu_hotplug.lock); |
87af9e7f | 175 | atomic_inc(&cpu_hotplug.refcount); |
d221938c | 176 | mutex_unlock(&cpu_hotplug.lock); |
a9d9baa1 | 177 | } |
86ef5c9a | 178 | EXPORT_SYMBOL_GPL(get_online_cpus); |
90d45d17 | 179 | |
86ef5c9a | 180 | void put_online_cpus(void) |
a9d9baa1 | 181 | { |
87af9e7f DH |
182 | int refcount; |
183 | ||
d221938c | 184 | if (cpu_hotplug.active_writer == current) |
aa953877 | 185 | return; |
075663d1 | 186 | |
87af9e7f DH |
187 | refcount = atomic_dec_return(&cpu_hotplug.refcount); |
188 | if (WARN_ON(refcount < 0)) /* try to fix things up */ | |
189 | atomic_inc(&cpu_hotplug.refcount); | |
190 | ||
191 | if (refcount <= 0 && waitqueue_active(&cpu_hotplug.wq)) | |
192 | wake_up(&cpu_hotplug.wq); | |
075663d1 | 193 | |
a19423b9 | 194 | cpuhp_lock_release(); |
d221938c | 195 | |
a9d9baa1 | 196 | } |
86ef5c9a | 197 | EXPORT_SYMBOL_GPL(put_online_cpus); |
a9d9baa1 | 198 | |
d221938c GS |
199 | /* |
200 | * This ensures that the hotplug operation can begin only when the | |
201 | * refcount goes to zero. | |
202 | * | |
203 | * Note that during a cpu-hotplug operation, the new readers, if any, | |
204 | * will be blocked by the cpu_hotplug.lock | |
205 | * | |
d2ba7e2a ON |
206 | * Since cpu_hotplug_begin() is always called after invoking |
207 | * cpu_maps_update_begin(), we can be sure that only one writer is active. | |
d221938c GS |
208 | * |
209 | * Note that theoretically, there is a possibility of a livelock: | |
210 | * - Refcount goes to zero, last reader wakes up the sleeping | |
211 | * writer. | |
212 | * - Last reader unlocks the cpu_hotplug.lock. | |
213 | * - A new reader arrives at this moment, bumps up the refcount. | |
214 | * - The writer acquires the cpu_hotplug.lock finds the refcount | |
215 | * non zero and goes to sleep again. | |
216 | * | |
217 | * However, this is very difficult to achieve in practice since | |
86ef5c9a | 218 | * get_online_cpus() not an api which is called all that often. |
d221938c GS |
219 | * |
220 | */ | |
b9d10be7 | 221 | void cpu_hotplug_begin(void) |
d221938c | 222 | { |
87af9e7f | 223 | DEFINE_WAIT(wait); |
d2ba7e2a | 224 | |
87af9e7f | 225 | cpu_hotplug.active_writer = current; |
a19423b9 | 226 | cpuhp_lock_acquire(); |
87af9e7f | 227 | |
d2ba7e2a ON |
228 | for (;;) { |
229 | mutex_lock(&cpu_hotplug.lock); | |
87af9e7f DH |
230 | prepare_to_wait(&cpu_hotplug.wq, &wait, TASK_UNINTERRUPTIBLE); |
231 | if (likely(!atomic_read(&cpu_hotplug.refcount))) | |
232 | break; | |
d221938c GS |
233 | mutex_unlock(&cpu_hotplug.lock); |
234 | schedule(); | |
d221938c | 235 | } |
87af9e7f | 236 | finish_wait(&cpu_hotplug.wq, &wait); |
d221938c GS |
237 | } |
238 | ||
b9d10be7 | 239 | void cpu_hotplug_done(void) |
d221938c GS |
240 | { |
241 | cpu_hotplug.active_writer = NULL; | |
242 | mutex_unlock(&cpu_hotplug.lock); | |
a19423b9 | 243 | cpuhp_lock_release(); |
d221938c | 244 | } |
79a6cdeb | 245 | |
16e53dbf SB |
246 | /* |
247 | * Wait for currently running CPU hotplug operations to complete (if any) and | |
248 | * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects | |
249 | * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the | |
250 | * hotplug path before performing hotplug operations. So acquiring that lock | |
251 | * guarantees mutual exclusion from any currently running hotplug operations. | |
252 | */ | |
253 | void cpu_hotplug_disable(void) | |
254 | { | |
255 | cpu_maps_update_begin(); | |
89af7ba5 | 256 | cpu_hotplug_disabled++; |
16e53dbf SB |
257 | cpu_maps_update_done(); |
258 | } | |
32145c46 | 259 | EXPORT_SYMBOL_GPL(cpu_hotplug_disable); |
16e53dbf SB |
260 | |
261 | void cpu_hotplug_enable(void) | |
262 | { | |
263 | cpu_maps_update_begin(); | |
89af7ba5 | 264 | WARN_ON(--cpu_hotplug_disabled < 0); |
16e53dbf SB |
265 | cpu_maps_update_done(); |
266 | } | |
32145c46 | 267 | EXPORT_SYMBOL_GPL(cpu_hotplug_enable); |
b9d10be7 | 268 | #endif /* CONFIG_HOTPLUG_CPU */ |
79a6cdeb | 269 | |
1da177e4 | 270 | /* Need to know about CPUs going up/down? */ |
71cf5aee | 271 | int register_cpu_notifier(struct notifier_block *nb) |
1da177e4 | 272 | { |
bd5349cf | 273 | int ret; |
d221938c | 274 | cpu_maps_update_begin(); |
bd5349cf | 275 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
d221938c | 276 | cpu_maps_update_done(); |
bd5349cf | 277 | return ret; |
1da177e4 | 278 | } |
65edc68c | 279 | |
71cf5aee | 280 | int __register_cpu_notifier(struct notifier_block *nb) |
93ae4f97 SB |
281 | { |
282 | return raw_notifier_chain_register(&cpu_chain, nb); | |
283 | } | |
284 | ||
090e77c3 | 285 | static int __cpu_notify(unsigned long val, unsigned int cpu, int nr_to_call, |
e9fb7631 AM |
286 | int *nr_calls) |
287 | { | |
090e77c3 TG |
288 | unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0; |
289 | void *hcpu = (void *)(long)cpu; | |
290 | ||
e6bde73b AM |
291 | int ret; |
292 | ||
090e77c3 | 293 | ret = __raw_notifier_call_chain(&cpu_chain, val | mod, hcpu, nr_to_call, |
e9fb7631 | 294 | nr_calls); |
e6bde73b AM |
295 | |
296 | return notifier_to_errno(ret); | |
e9fb7631 AM |
297 | } |
298 | ||
090e77c3 | 299 | static int cpu_notify(unsigned long val, unsigned int cpu) |
e9fb7631 | 300 | { |
090e77c3 | 301 | return __cpu_notify(val, cpu, -1, NULL); |
e9fb7631 AM |
302 | } |
303 | ||
ba997462 TG |
304 | /* Notifier wrappers for transitioning to state machine */ |
305 | static int notify_prepare(unsigned int cpu) | |
306 | { | |
307 | int nr_calls = 0; | |
308 | int ret; | |
309 | ||
310 | ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls); | |
311 | if (ret) { | |
312 | nr_calls--; | |
313 | printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", | |
314 | __func__, cpu); | |
315 | __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL); | |
316 | } | |
317 | return ret; | |
318 | } | |
319 | ||
320 | static int notify_online(unsigned int cpu) | |
321 | { | |
322 | cpu_notify(CPU_ONLINE, cpu); | |
323 | return 0; | |
324 | } | |
325 | ||
4baa0afc TG |
326 | static int notify_starting(unsigned int cpu) |
327 | { | |
328 | cpu_notify(CPU_STARTING, cpu); | |
329 | return 0; | |
330 | } | |
331 | ||
ba997462 TG |
332 | static int bringup_cpu(unsigned int cpu) |
333 | { | |
334 | struct task_struct *idle = idle_thread_get(cpu); | |
335 | int ret; | |
336 | ||
337 | /* Arch-specific enabling code. */ | |
338 | ret = __cpu_up(cpu, idle); | |
339 | if (ret) { | |
340 | cpu_notify(CPU_UP_CANCELED, cpu); | |
341 | return ret; | |
342 | } | |
343 | BUG_ON(!cpu_online(cpu)); | |
344 | return 0; | |
345 | } | |
346 | ||
2e1a3483 TG |
347 | /* |
348 | * Hotplug state machine related functions | |
349 | */ | |
350 | static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st, | |
351 | struct cpuhp_step *steps) | |
352 | { | |
353 | for (st->state++; st->state < st->target; st->state++) { | |
354 | struct cpuhp_step *step = steps + st->state; | |
355 | ||
356 | if (!step->skip_onerr) | |
357 | cpuhp_invoke_callback(cpu, st->state, step->startup); | |
358 | } | |
359 | } | |
360 | ||
361 | static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, | |
362 | struct cpuhp_step *steps, enum cpuhp_state target) | |
363 | { | |
364 | enum cpuhp_state prev_state = st->state; | |
365 | int ret = 0; | |
366 | ||
367 | for (; st->state > target; st->state--) { | |
368 | struct cpuhp_step *step = steps + st->state; | |
369 | ||
370 | ret = cpuhp_invoke_callback(cpu, st->state, step->teardown); | |
371 | if (ret) { | |
372 | st->target = prev_state; | |
373 | undo_cpu_down(cpu, st, steps); | |
374 | break; | |
375 | } | |
376 | } | |
377 | return ret; | |
378 | } | |
379 | ||
380 | static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st, | |
381 | struct cpuhp_step *steps) | |
382 | { | |
383 | for (st->state--; st->state > st->target; st->state--) { | |
384 | struct cpuhp_step *step = steps + st->state; | |
385 | ||
386 | if (!step->skip_onerr) | |
387 | cpuhp_invoke_callback(cpu, st->state, step->teardown); | |
388 | } | |
389 | } | |
390 | ||
391 | static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, | |
392 | struct cpuhp_step *steps, enum cpuhp_state target) | |
393 | { | |
394 | enum cpuhp_state prev_state = st->state; | |
395 | int ret = 0; | |
396 | ||
397 | while (st->state < target) { | |
398 | struct cpuhp_step *step; | |
399 | ||
400 | st->state++; | |
401 | step = steps + st->state; | |
402 | ret = cpuhp_invoke_callback(cpu, st->state, step->startup); | |
403 | if (ret) { | |
404 | st->target = prev_state; | |
405 | undo_cpu_up(cpu, st, steps); | |
406 | break; | |
407 | } | |
408 | } | |
409 | return ret; | |
410 | } | |
411 | ||
4cb28ced TG |
412 | /* |
413 | * The cpu hotplug threads manage the bringup and teardown of the cpus | |
414 | */ | |
415 | static void cpuhp_create(unsigned int cpu) | |
416 | { | |
417 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
418 | ||
419 | init_completion(&st->done); | |
420 | } | |
421 | ||
422 | static int cpuhp_should_run(unsigned int cpu) | |
423 | { | |
424 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); | |
425 | ||
426 | return st->should_run; | |
427 | } | |
428 | ||
429 | /* Execute the teardown callbacks. Used to be CPU_DOWN_PREPARE */ | |
430 | static int cpuhp_ap_offline(unsigned int cpu, struct cpuhp_cpu_state *st) | |
431 | { | |
432 | enum cpuhp_state target = max((int)st->target, CPUHP_AP_ONLINE); | |
433 | ||
434 | return cpuhp_down_callbacks(cpu, st, cpuhp_ap_states, target); | |
435 | } | |
436 | ||
437 | /* Execute the online startup callbacks. Used to be CPU_ONLINE */ | |
438 | static int cpuhp_ap_online(unsigned int cpu, struct cpuhp_cpu_state *st) | |
439 | { | |
440 | return cpuhp_up_callbacks(cpu, st, cpuhp_ap_states, st->target); | |
441 | } | |
442 | ||
443 | /* | |
444 | * Execute teardown/startup callbacks on the plugged cpu. Also used to invoke | |
445 | * callbacks when a state gets [un]installed at runtime. | |
446 | */ | |
447 | static void cpuhp_thread_fun(unsigned int cpu) | |
448 | { | |
449 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); | |
450 | int ret = 0; | |
451 | ||
452 | /* | |
453 | * Paired with the mb() in cpuhp_kick_ap_work and | |
454 | * cpuhp_invoke_ap_callback, so the work set is consistent visible. | |
455 | */ | |
456 | smp_mb(); | |
457 | if (!st->should_run) | |
458 | return; | |
459 | ||
460 | st->should_run = false; | |
461 | ||
462 | /* Single callback invocation for [un]install ? */ | |
463 | if (st->cb) { | |
464 | if (st->cb_state < CPUHP_AP_ONLINE) { | |
465 | local_irq_disable(); | |
466 | ret = cpuhp_invoke_callback(cpu, st->cb_state, st->cb); | |
467 | local_irq_enable(); | |
468 | } else { | |
469 | ret = cpuhp_invoke_callback(cpu, st->cb_state, st->cb); | |
470 | } | |
471 | } else { | |
472 | /* Regular hotplug work */ | |
473 | if (st->state < st->target) | |
474 | ret = cpuhp_ap_online(cpu, st); | |
475 | else if (st->state > st->target) | |
476 | ret = cpuhp_ap_offline(cpu, st); | |
477 | } | |
478 | st->result = ret; | |
479 | complete(&st->done); | |
480 | } | |
481 | ||
482 | /* Invoke a single callback on a remote cpu */ | |
483 | static int cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state, | |
484 | int (*cb)(unsigned int)) | |
485 | { | |
486 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
487 | ||
488 | if (!cpu_online(cpu)) | |
489 | return 0; | |
490 | ||
491 | st->cb_state = state; | |
492 | st->cb = cb; | |
493 | /* | |
494 | * Make sure the above stores are visible before should_run becomes | |
495 | * true. Paired with the mb() above in cpuhp_thread_fun() | |
496 | */ | |
497 | smp_mb(); | |
498 | st->should_run = true; | |
499 | wake_up_process(st->thread); | |
500 | wait_for_completion(&st->done); | |
501 | return st->result; | |
502 | } | |
503 | ||
504 | /* Regular hotplug invocation of the AP hotplug thread */ | |
505 | static int cpuhp_kick_ap_work(unsigned int cpu) | |
506 | { | |
507 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
508 | enum cpuhp_state state = st->state; | |
509 | ||
510 | trace_cpuhp_enter(cpu, st->target, state, cpuhp_kick_ap_work); | |
511 | st->result = 0; | |
512 | st->cb = NULL; | |
513 | /* | |
514 | * Make sure the above stores are visible before should_run becomes | |
515 | * true. Paired with the mb() above in cpuhp_thread_fun() | |
516 | */ | |
517 | smp_mb(); | |
518 | st->should_run = true; | |
519 | wake_up_process(st->thread); | |
520 | wait_for_completion(&st->done); | |
521 | trace_cpuhp_exit(cpu, st->state, state, st->result); | |
522 | return st->result; | |
523 | } | |
524 | ||
525 | static struct smp_hotplug_thread cpuhp_threads = { | |
526 | .store = &cpuhp_state.thread, | |
527 | .create = &cpuhp_create, | |
528 | .thread_should_run = cpuhp_should_run, | |
529 | .thread_fn = cpuhp_thread_fun, | |
530 | .thread_comm = "cpuhp/%u", | |
531 | .selfparking = true, | |
532 | }; | |
533 | ||
534 | void __init cpuhp_threads_init(void) | |
535 | { | |
536 | BUG_ON(smpboot_register_percpu_thread(&cpuhp_threads)); | |
537 | kthread_unpark(this_cpu_read(cpuhp_state.thread)); | |
538 | } | |
539 | ||
00b9b0af | 540 | #ifdef CONFIG_HOTPLUG_CPU |
1da177e4 | 541 | EXPORT_SYMBOL(register_cpu_notifier); |
93ae4f97 | 542 | EXPORT_SYMBOL(__register_cpu_notifier); |
71cf5aee | 543 | void unregister_cpu_notifier(struct notifier_block *nb) |
1da177e4 | 544 | { |
d221938c | 545 | cpu_maps_update_begin(); |
bd5349cf | 546 | raw_notifier_chain_unregister(&cpu_chain, nb); |
d221938c | 547 | cpu_maps_update_done(); |
1da177e4 LT |
548 | } |
549 | EXPORT_SYMBOL(unregister_cpu_notifier); | |
550 | ||
71cf5aee | 551 | void __unregister_cpu_notifier(struct notifier_block *nb) |
93ae4f97 SB |
552 | { |
553 | raw_notifier_chain_unregister(&cpu_chain, nb); | |
554 | } | |
555 | EXPORT_SYMBOL(__unregister_cpu_notifier); | |
556 | ||
e4cc2f87 AV |
557 | /** |
558 | * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU | |
559 | * @cpu: a CPU id | |
560 | * | |
561 | * This function walks all processes, finds a valid mm struct for each one and | |
562 | * then clears a corresponding bit in mm's cpumask. While this all sounds | |
563 | * trivial, there are various non-obvious corner cases, which this function | |
564 | * tries to solve in a safe manner. | |
565 | * | |
566 | * Also note that the function uses a somewhat relaxed locking scheme, so it may | |
567 | * be called only for an already offlined CPU. | |
568 | */ | |
cb79295e AV |
569 | void clear_tasks_mm_cpumask(int cpu) |
570 | { | |
571 | struct task_struct *p; | |
572 | ||
573 | /* | |
574 | * This function is called after the cpu is taken down and marked | |
575 | * offline, so its not like new tasks will ever get this cpu set in | |
576 | * their mm mask. -- Peter Zijlstra | |
577 | * Thus, we may use rcu_read_lock() here, instead of grabbing | |
578 | * full-fledged tasklist_lock. | |
579 | */ | |
e4cc2f87 | 580 | WARN_ON(cpu_online(cpu)); |
cb79295e AV |
581 | rcu_read_lock(); |
582 | for_each_process(p) { | |
583 | struct task_struct *t; | |
584 | ||
e4cc2f87 AV |
585 | /* |
586 | * Main thread might exit, but other threads may still have | |
587 | * a valid mm. Find one. | |
588 | */ | |
cb79295e AV |
589 | t = find_lock_task_mm(p); |
590 | if (!t) | |
591 | continue; | |
592 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); | |
593 | task_unlock(t); | |
594 | } | |
595 | rcu_read_unlock(); | |
596 | } | |
597 | ||
b728ca06 | 598 | static inline void check_for_tasks(int dead_cpu) |
1da177e4 | 599 | { |
b728ca06 | 600 | struct task_struct *g, *p; |
1da177e4 | 601 | |
a75a6068 ON |
602 | read_lock(&tasklist_lock); |
603 | for_each_process_thread(g, p) { | |
b728ca06 KT |
604 | if (!p->on_rq) |
605 | continue; | |
606 | /* | |
607 | * We do the check with unlocked task_rq(p)->lock. | |
608 | * Order the reading to do not warn about a task, | |
609 | * which was running on this cpu in the past, and | |
610 | * it's just been woken on another cpu. | |
611 | */ | |
612 | rmb(); | |
613 | if (task_cpu(p) != dead_cpu) | |
614 | continue; | |
615 | ||
616 | pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n", | |
617 | p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags); | |
a75a6068 ON |
618 | } |
619 | read_unlock(&tasklist_lock); | |
1da177e4 LT |
620 | } |
621 | ||
98458172 TG |
622 | static void cpu_notify_nofail(unsigned long val, unsigned int cpu) |
623 | { | |
624 | BUG_ON(cpu_notify(val, cpu)); | |
625 | } | |
626 | ||
627 | static int notify_down_prepare(unsigned int cpu) | |
628 | { | |
629 | int err, nr_calls = 0; | |
630 | ||
631 | err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls); | |
632 | if (err) { | |
633 | nr_calls--; | |
634 | __cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL); | |
635 | pr_warn("%s: attempt to take down CPU %u failed\n", | |
636 | __func__, cpu); | |
637 | } | |
638 | return err; | |
639 | } | |
640 | ||
4baa0afc TG |
641 | static int notify_dying(unsigned int cpu) |
642 | { | |
643 | cpu_notify(CPU_DYING, cpu); | |
644 | return 0; | |
645 | } | |
646 | ||
1da177e4 | 647 | /* Take this CPU down. */ |
71cf5aee | 648 | static int take_cpu_down(void *_param) |
1da177e4 | 649 | { |
4baa0afc TG |
650 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
651 | enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE); | |
090e77c3 | 652 | int err, cpu = smp_processor_id(); |
1da177e4 | 653 | |
1da177e4 LT |
654 | /* Ensure this CPU doesn't handle any more interrupts. */ |
655 | err = __cpu_disable(); | |
656 | if (err < 0) | |
f3705136 | 657 | return err; |
1da177e4 | 658 | |
4baa0afc TG |
659 | /* Invoke the former CPU_DYING callbacks */ |
660 | for (; st->state > target; st->state--) { | |
661 | struct cpuhp_step *step = cpuhp_ap_states + st->state; | |
662 | ||
663 | cpuhp_invoke_callback(cpu, st->state, step->teardown); | |
664 | } | |
52c063d1 TG |
665 | /* Give up timekeeping duties */ |
666 | tick_handover_do_timer(); | |
14e568e7 | 667 | /* Park the stopper thread */ |
090e77c3 | 668 | stop_machine_park(cpu); |
f3705136 | 669 | return 0; |
1da177e4 LT |
670 | } |
671 | ||
98458172 | 672 | static int takedown_cpu(unsigned int cpu) |
1da177e4 | 673 | { |
98458172 | 674 | int err; |
1da177e4 | 675 | |
6acce3ef PZ |
676 | /* |
677 | * By now we've cleared cpu_active_mask, wait for all preempt-disabled | |
678 | * and RCU users of this state to go away such that all new such users | |
679 | * will observe it. | |
680 | * | |
681 | * For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might | |
779de6ce | 682 | * not imply sync_sched(), so wait for both. |
106dd5af M |
683 | * |
684 | * Do sync before park smpboot threads to take care the rcu boost case. | |
6acce3ef | 685 | */ |
779de6ce PM |
686 | if (IS_ENABLED(CONFIG_PREEMPT)) |
687 | synchronize_rcu_mult(call_rcu, call_rcu_sched); | |
688 | else | |
689 | synchronize_rcu(); | |
6acce3ef PZ |
690 | |
691 | /* | |
a8994181 TG |
692 | * Prevent irq alloc/free while the dying cpu reorganizes the |
693 | * interrupt affinities. | |
6acce3ef | 694 | */ |
a8994181 | 695 | irq_lock_sparse(); |
6acce3ef | 696 | |
a8994181 TG |
697 | /* |
698 | * So now all preempt/rcu users must observe !cpu_active(). | |
699 | */ | |
090e77c3 | 700 | err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu)); |
04321587 | 701 | if (err) { |
1da177e4 | 702 | /* CPU didn't die: tell everyone. Can't complain. */ |
090e77c3 | 703 | cpu_notify_nofail(CPU_DOWN_FAILED, cpu); |
a8994181 | 704 | irq_unlock_sparse(); |
98458172 | 705 | return err; |
8fa1d7d3 | 706 | } |
04321587 | 707 | BUG_ON(cpu_online(cpu)); |
1da177e4 | 708 | |
48c5ccae PZ |
709 | /* |
710 | * The migration_call() CPU_DYING callback will have removed all | |
711 | * runnable tasks from the cpu, there's only the idle task left now | |
712 | * that the migration thread is done doing the stop_machine thing. | |
51a96c77 PZ |
713 | * |
714 | * Wait for the stop thread to go away. | |
48c5ccae | 715 | */ |
528a25b0 | 716 | while (!per_cpu(cpu_dead_idle, cpu)) |
51a96c77 | 717 | cpu_relax(); |
528a25b0 PM |
718 | smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */ |
719 | per_cpu(cpu_dead_idle, cpu) = false; | |
1da177e4 | 720 | |
a8994181 TG |
721 | /* Interrupts are moved away from the dying cpu, reenable alloc/free */ |
722 | irq_unlock_sparse(); | |
723 | ||
345527b1 | 724 | hotplug_cpu__broadcast_tick_pull(cpu); |
1da177e4 LT |
725 | /* This actually kills the CPU. */ |
726 | __cpu_die(cpu); | |
727 | ||
a49b116d | 728 | tick_cleanup_dead_cpu(cpu); |
98458172 TG |
729 | return 0; |
730 | } | |
1da177e4 | 731 | |
98458172 TG |
732 | static int notify_dead(unsigned int cpu) |
733 | { | |
734 | cpu_notify_nofail(CPU_DEAD, cpu); | |
1da177e4 | 735 | check_for_tasks(cpu); |
98458172 TG |
736 | return 0; |
737 | } | |
738 | ||
cff7d378 TG |
739 | #else |
740 | #define notify_down_prepare NULL | |
741 | #define takedown_cpu NULL | |
742 | #define notify_dead NULL | |
4baa0afc | 743 | #define notify_dying NULL |
cff7d378 TG |
744 | #endif |
745 | ||
746 | #ifdef CONFIG_HOTPLUG_CPU | |
cff7d378 | 747 | |
98458172 | 748 | /* Requires cpu_add_remove_lock to be held */ |
af1f4045 TG |
749 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, |
750 | enum cpuhp_state target) | |
98458172 | 751 | { |
cff7d378 TG |
752 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
753 | int prev_state, ret = 0; | |
754 | bool hasdied = false; | |
98458172 TG |
755 | |
756 | if (num_online_cpus() == 1) | |
757 | return -EBUSY; | |
758 | ||
757c989b | 759 | if (!cpu_present(cpu)) |
98458172 TG |
760 | return -EINVAL; |
761 | ||
762 | cpu_hotplug_begin(); | |
763 | ||
764 | cpuhp_tasks_frozen = tasks_frozen; | |
765 | ||
cff7d378 | 766 | prev_state = st->state; |
af1f4045 | 767 | st->target = target; |
2e1a3483 | 768 | ret = cpuhp_down_callbacks(cpu, st, cpuhp_bp_states, target); |
98458172 | 769 | |
cff7d378 | 770 | hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE; |
1da177e4 | 771 | |
d221938c | 772 | cpu_hotplug_done(); |
cff7d378 TG |
773 | /* This post dead nonsense must die */ |
774 | if (!ret && hasdied) | |
090e77c3 | 775 | cpu_notify_nofail(CPU_POST_DEAD, cpu); |
cff7d378 | 776 | return ret; |
e3920fb4 RW |
777 | } |
778 | ||
af1f4045 | 779 | static int do_cpu_down(unsigned int cpu, enum cpuhp_state target) |
e3920fb4 | 780 | { |
9ea09af3 | 781 | int err; |
e3920fb4 | 782 | |
d221938c | 783 | cpu_maps_update_begin(); |
e761b772 MK |
784 | |
785 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 786 | err = -EBUSY; |
e761b772 MK |
787 | goto out; |
788 | } | |
789 | ||
af1f4045 | 790 | err = _cpu_down(cpu, 0, target); |
e3920fb4 | 791 | |
e761b772 | 792 | out: |
d221938c | 793 | cpu_maps_update_done(); |
1da177e4 LT |
794 | return err; |
795 | } | |
af1f4045 TG |
796 | int cpu_down(unsigned int cpu) |
797 | { | |
798 | return do_cpu_down(cpu, CPUHP_OFFLINE); | |
799 | } | |
b62b8ef9 | 800 | EXPORT_SYMBOL(cpu_down); |
1da177e4 LT |
801 | #endif /*CONFIG_HOTPLUG_CPU*/ |
802 | ||
4baa0afc TG |
803 | /** |
804 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers | |
805 | * @cpu: cpu that just started | |
806 | * | |
807 | * This function calls the cpu_chain notifiers with CPU_STARTING. | |
808 | * It must be called by the arch code on the new cpu, before the new cpu | |
809 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). | |
810 | */ | |
811 | void notify_cpu_starting(unsigned int cpu) | |
812 | { | |
813 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
814 | enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE); | |
815 | ||
816 | while (st->state < target) { | |
817 | struct cpuhp_step *step; | |
818 | ||
819 | st->state++; | |
820 | step = cpuhp_ap_states + st->state; | |
821 | cpuhp_invoke_callback(cpu, st->state, step->startup); | |
822 | } | |
823 | } | |
824 | ||
949338e3 TG |
825 | /* |
826 | * Called from the idle task. We need to set active here, so we can kick off | |
827 | * the stopper thread. | |
828 | */ | |
829 | static int cpuhp_set_cpu_active(unsigned int cpu) | |
830 | { | |
831 | /* The cpu is marked online, set it active now */ | |
832 | set_cpu_active(cpu, true); | |
833 | /* Unpark the stopper thread */ | |
834 | stop_machine_unpark(cpu); | |
835 | return 0; | |
836 | } | |
837 | ||
e3920fb4 | 838 | /* Requires cpu_add_remove_lock to be held */ |
af1f4045 | 839 | static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target) |
1da177e4 | 840 | { |
cff7d378 | 841 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
3bb5d2ee | 842 | struct task_struct *idle; |
2e1a3483 | 843 | int ret = 0; |
1da177e4 | 844 | |
d221938c | 845 | cpu_hotplug_begin(); |
38498a67 | 846 | |
757c989b | 847 | if (!cpu_present(cpu)) { |
5e5041f3 YI |
848 | ret = -EINVAL; |
849 | goto out; | |
850 | } | |
851 | ||
757c989b TG |
852 | /* |
853 | * The caller of do_cpu_up might have raced with another | |
854 | * caller. Ignore it for now. | |
855 | */ | |
856 | if (st->state >= target) | |
38498a67 | 857 | goto out; |
757c989b TG |
858 | |
859 | if (st->state == CPUHP_OFFLINE) { | |
860 | /* Let it fail before we try to bring the cpu up */ | |
861 | idle = idle_thread_get(cpu); | |
862 | if (IS_ERR(idle)) { | |
863 | ret = PTR_ERR(idle); | |
864 | goto out; | |
865 | } | |
3bb5d2ee | 866 | } |
38498a67 | 867 | |
ba997462 TG |
868 | cpuhp_tasks_frozen = tasks_frozen; |
869 | ||
af1f4045 | 870 | st->target = target; |
2e1a3483 | 871 | ret = cpuhp_up_callbacks(cpu, st, cpuhp_bp_states, target); |
38498a67 | 872 | out: |
d221938c | 873 | cpu_hotplug_done(); |
e3920fb4 RW |
874 | return ret; |
875 | } | |
876 | ||
af1f4045 | 877 | static int do_cpu_up(unsigned int cpu, enum cpuhp_state target) |
e3920fb4 RW |
878 | { |
879 | int err = 0; | |
cf23422b | 880 | |
e0b582ec | 881 | if (!cpu_possible(cpu)) { |
84117da5 FF |
882 | pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n", |
883 | cpu); | |
87d5e023 | 884 | #if defined(CONFIG_IA64) |
84117da5 | 885 | pr_err("please check additional_cpus= boot parameter\n"); |
73e753a5 KH |
886 | #endif |
887 | return -EINVAL; | |
888 | } | |
e3920fb4 | 889 | |
01b0f197 TK |
890 | err = try_online_node(cpu_to_node(cpu)); |
891 | if (err) | |
892 | return err; | |
cf23422b | 893 | |
d221938c | 894 | cpu_maps_update_begin(); |
e761b772 MK |
895 | |
896 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 897 | err = -EBUSY; |
e761b772 MK |
898 | goto out; |
899 | } | |
900 | ||
af1f4045 | 901 | err = _cpu_up(cpu, 0, target); |
e761b772 | 902 | out: |
d221938c | 903 | cpu_maps_update_done(); |
e3920fb4 RW |
904 | return err; |
905 | } | |
af1f4045 TG |
906 | |
907 | int cpu_up(unsigned int cpu) | |
908 | { | |
909 | return do_cpu_up(cpu, CPUHP_ONLINE); | |
910 | } | |
a513f6ba | 911 | EXPORT_SYMBOL_GPL(cpu_up); |
e3920fb4 | 912 | |
f3de4be9 | 913 | #ifdef CONFIG_PM_SLEEP_SMP |
e0b582ec | 914 | static cpumask_var_t frozen_cpus; |
e3920fb4 RW |
915 | |
916 | int disable_nonboot_cpus(void) | |
917 | { | |
e9a5f426 | 918 | int cpu, first_cpu, error = 0; |
e3920fb4 | 919 | |
d221938c | 920 | cpu_maps_update_begin(); |
e0b582ec | 921 | first_cpu = cpumask_first(cpu_online_mask); |
9ee349ad XF |
922 | /* |
923 | * We take down all of the non-boot CPUs in one shot to avoid races | |
e3920fb4 RW |
924 | * with the userspace trying to use the CPU hotplug at the same time |
925 | */ | |
e0b582ec | 926 | cpumask_clear(frozen_cpus); |
6ad4c188 | 927 | |
84117da5 | 928 | pr_info("Disabling non-boot CPUs ...\n"); |
e3920fb4 RW |
929 | for_each_online_cpu(cpu) { |
930 | if (cpu == first_cpu) | |
931 | continue; | |
bb3632c6 | 932 | trace_suspend_resume(TPS("CPU_OFF"), cpu, true); |
af1f4045 | 933 | error = _cpu_down(cpu, 1, CPUHP_OFFLINE); |
bb3632c6 | 934 | trace_suspend_resume(TPS("CPU_OFF"), cpu, false); |
feae3203 | 935 | if (!error) |
e0b582ec | 936 | cpumask_set_cpu(cpu, frozen_cpus); |
feae3203 | 937 | else { |
84117da5 | 938 | pr_err("Error taking CPU%d down: %d\n", cpu, error); |
e3920fb4 RW |
939 | break; |
940 | } | |
941 | } | |
86886e55 | 942 | |
89af7ba5 | 943 | if (!error) |
e3920fb4 | 944 | BUG_ON(num_online_cpus() > 1); |
89af7ba5 | 945 | else |
84117da5 | 946 | pr_err("Non-boot CPUs are not disabled\n"); |
89af7ba5 VK |
947 | |
948 | /* | |
949 | * Make sure the CPUs won't be enabled by someone else. We need to do | |
950 | * this even in case of failure as all disable_nonboot_cpus() users are | |
951 | * supposed to do enable_nonboot_cpus() on the failure path. | |
952 | */ | |
953 | cpu_hotplug_disabled++; | |
954 | ||
d221938c | 955 | cpu_maps_update_done(); |
e3920fb4 RW |
956 | return error; |
957 | } | |
958 | ||
d0af9eed SS |
959 | void __weak arch_enable_nonboot_cpus_begin(void) |
960 | { | |
961 | } | |
962 | ||
963 | void __weak arch_enable_nonboot_cpus_end(void) | |
964 | { | |
965 | } | |
966 | ||
71cf5aee | 967 | void enable_nonboot_cpus(void) |
e3920fb4 RW |
968 | { |
969 | int cpu, error; | |
970 | ||
971 | /* Allow everyone to use the CPU hotplug again */ | |
d221938c | 972 | cpu_maps_update_begin(); |
89af7ba5 | 973 | WARN_ON(--cpu_hotplug_disabled < 0); |
e0b582ec | 974 | if (cpumask_empty(frozen_cpus)) |
1d64b9cb | 975 | goto out; |
e3920fb4 | 976 | |
84117da5 | 977 | pr_info("Enabling non-boot CPUs ...\n"); |
d0af9eed SS |
978 | |
979 | arch_enable_nonboot_cpus_begin(); | |
980 | ||
e0b582ec | 981 | for_each_cpu(cpu, frozen_cpus) { |
bb3632c6 | 982 | trace_suspend_resume(TPS("CPU_ON"), cpu, true); |
af1f4045 | 983 | error = _cpu_up(cpu, 1, CPUHP_ONLINE); |
bb3632c6 | 984 | trace_suspend_resume(TPS("CPU_ON"), cpu, false); |
e3920fb4 | 985 | if (!error) { |
84117da5 | 986 | pr_info("CPU%d is up\n", cpu); |
e3920fb4 RW |
987 | continue; |
988 | } | |
84117da5 | 989 | pr_warn("Error taking CPU%d up: %d\n", cpu, error); |
e3920fb4 | 990 | } |
d0af9eed SS |
991 | |
992 | arch_enable_nonboot_cpus_end(); | |
993 | ||
e0b582ec | 994 | cpumask_clear(frozen_cpus); |
1d64b9cb | 995 | out: |
d221938c | 996 | cpu_maps_update_done(); |
1da177e4 | 997 | } |
e0b582ec | 998 | |
d7268a31 | 999 | static int __init alloc_frozen_cpus(void) |
e0b582ec RR |
1000 | { |
1001 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) | |
1002 | return -ENOMEM; | |
1003 | return 0; | |
1004 | } | |
1005 | core_initcall(alloc_frozen_cpus); | |
79cfbdfa | 1006 | |
79cfbdfa SB |
1007 | /* |
1008 | * When callbacks for CPU hotplug notifications are being executed, we must | |
1009 | * ensure that the state of the system with respect to the tasks being frozen | |
1010 | * or not, as reported by the notification, remains unchanged *throughout the | |
1011 | * duration* of the execution of the callbacks. | |
1012 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. | |
1013 | * | |
1014 | * This synchronization is implemented by mutually excluding regular CPU | |
1015 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ | |
1016 | * Hibernate notifications. | |
1017 | */ | |
1018 | static int | |
1019 | cpu_hotplug_pm_callback(struct notifier_block *nb, | |
1020 | unsigned long action, void *ptr) | |
1021 | { | |
1022 | switch (action) { | |
1023 | ||
1024 | case PM_SUSPEND_PREPARE: | |
1025 | case PM_HIBERNATION_PREPARE: | |
16e53dbf | 1026 | cpu_hotplug_disable(); |
79cfbdfa SB |
1027 | break; |
1028 | ||
1029 | case PM_POST_SUSPEND: | |
1030 | case PM_POST_HIBERNATION: | |
16e53dbf | 1031 | cpu_hotplug_enable(); |
79cfbdfa SB |
1032 | break; |
1033 | ||
1034 | default: | |
1035 | return NOTIFY_DONE; | |
1036 | } | |
1037 | ||
1038 | return NOTIFY_OK; | |
1039 | } | |
1040 | ||
1041 | ||
d7268a31 | 1042 | static int __init cpu_hotplug_pm_sync_init(void) |
79cfbdfa | 1043 | { |
6e32d479 FY |
1044 | /* |
1045 | * cpu_hotplug_pm_callback has higher priority than x86 | |
1046 | * bsp_pm_callback which depends on cpu_hotplug_pm_callback | |
1047 | * to disable cpu hotplug to avoid cpu hotplug race. | |
1048 | */ | |
79cfbdfa SB |
1049 | pm_notifier(cpu_hotplug_pm_callback, 0); |
1050 | return 0; | |
1051 | } | |
1052 | core_initcall(cpu_hotplug_pm_sync_init); | |
1053 | ||
f3de4be9 | 1054 | #endif /* CONFIG_PM_SLEEP_SMP */ |
68f4f1ec MK |
1055 | |
1056 | #endif /* CONFIG_SMP */ | |
b8d317d1 | 1057 | |
cff7d378 TG |
1058 | /* Boot processor state steps */ |
1059 | static struct cpuhp_step cpuhp_bp_states[] = { | |
1060 | [CPUHP_OFFLINE] = { | |
1061 | .name = "offline", | |
1062 | .startup = NULL, | |
1063 | .teardown = NULL, | |
1064 | }, | |
1065 | #ifdef CONFIG_SMP | |
1066 | [CPUHP_CREATE_THREADS]= { | |
1067 | .name = "threads:create", | |
1068 | .startup = smpboot_create_threads, | |
1069 | .teardown = NULL, | |
757c989b | 1070 | .cant_stop = true, |
cff7d378 TG |
1071 | }, |
1072 | [CPUHP_NOTIFY_PREPARE] = { | |
1073 | .name = "notify:prepare", | |
1074 | .startup = notify_prepare, | |
1075 | .teardown = notify_dead, | |
1076 | .skip_onerr = true, | |
757c989b | 1077 | .cant_stop = true, |
cff7d378 TG |
1078 | }, |
1079 | [CPUHP_BRINGUP_CPU] = { | |
1080 | .name = "cpu:bringup", | |
1081 | .startup = bringup_cpu, | |
4baa0afc | 1082 | .teardown = NULL, |
757c989b | 1083 | .cant_stop = true, |
4baa0afc TG |
1084 | }, |
1085 | [CPUHP_TEARDOWN_CPU] = { | |
1086 | .name = "cpu:teardown", | |
1087 | .startup = NULL, | |
cff7d378 | 1088 | .teardown = takedown_cpu, |
757c989b | 1089 | .cant_stop = true, |
cff7d378 | 1090 | }, |
949338e3 TG |
1091 | [CPUHP_CPU_SET_ACTIVE] = { |
1092 | .name = "cpu:active", | |
1093 | .startup = cpuhp_set_cpu_active, | |
1094 | .teardown = NULL, | |
1095 | }, | |
931ef163 TG |
1096 | [CPUHP_SMPBOOT_THREADS] = { |
1097 | .name = "smpboot:threads", | |
1098 | .startup = smpboot_unpark_threads, | |
1099 | .teardown = smpboot_park_threads, | |
1100 | }, | |
cff7d378 TG |
1101 | [CPUHP_NOTIFY_ONLINE] = { |
1102 | .name = "notify:online", | |
1103 | .startup = notify_online, | |
1104 | .teardown = notify_down_prepare, | |
757c989b | 1105 | .cant_stop = true, |
cff7d378 TG |
1106 | }, |
1107 | #endif | |
1108 | [CPUHP_ONLINE] = { | |
1109 | .name = "online", | |
1110 | .startup = NULL, | |
1111 | .teardown = NULL, | |
1112 | }, | |
1113 | }; | |
1114 | ||
4baa0afc TG |
1115 | /* Application processor state steps */ |
1116 | static struct cpuhp_step cpuhp_ap_states[] = { | |
1117 | #ifdef CONFIG_SMP | |
1118 | [CPUHP_AP_NOTIFY_STARTING] = { | |
1119 | .name = "notify:starting", | |
1120 | .startup = notify_starting, | |
1121 | .teardown = notify_dying, | |
1122 | .skip_onerr = true, | |
757c989b | 1123 | .cant_stop = true, |
4baa0afc TG |
1124 | }, |
1125 | #endif | |
1126 | [CPUHP_ONLINE] = { | |
1127 | .name = "online", | |
1128 | .startup = NULL, | |
1129 | .teardown = NULL, | |
1130 | }, | |
1131 | }; | |
1132 | ||
5b7aa87e TG |
1133 | /* Sanity check for callbacks */ |
1134 | static int cpuhp_cb_check(enum cpuhp_state state) | |
1135 | { | |
1136 | if (state <= CPUHP_OFFLINE || state >= CPUHP_ONLINE) | |
1137 | return -EINVAL; | |
1138 | return 0; | |
1139 | } | |
1140 | ||
98f8cdce TG |
1141 | static bool cpuhp_is_ap_state(enum cpuhp_state state) |
1142 | { | |
4cb28ced | 1143 | return (state >= CPUHP_AP_OFFLINE && state <= CPUHP_AP_ONLINE); |
98f8cdce TG |
1144 | } |
1145 | ||
1146 | static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state) | |
1147 | { | |
1148 | struct cpuhp_step *sp; | |
1149 | ||
1150 | sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states; | |
1151 | return sp + state; | |
1152 | } | |
1153 | ||
5b7aa87e TG |
1154 | static void cpuhp_store_callbacks(enum cpuhp_state state, |
1155 | const char *name, | |
1156 | int (*startup)(unsigned int cpu), | |
1157 | int (*teardown)(unsigned int cpu)) | |
1158 | { | |
1159 | /* (Un)Install the callbacks for further cpu hotplug operations */ | |
1160 | struct cpuhp_step *sp; | |
1161 | ||
1162 | mutex_lock(&cpuhp_state_mutex); | |
1163 | sp = cpuhp_get_step(state); | |
1164 | sp->startup = startup; | |
1165 | sp->teardown = teardown; | |
1166 | sp->name = name; | |
1167 | mutex_unlock(&cpuhp_state_mutex); | |
1168 | } | |
1169 | ||
1170 | static void *cpuhp_get_teardown_cb(enum cpuhp_state state) | |
1171 | { | |
1172 | return cpuhp_get_step(state)->teardown; | |
1173 | } | |
1174 | ||
1175 | /* Helper function to run callback on the target cpu */ | |
1176 | static void cpuhp_on_cpu_cb(void *__cb) | |
1177 | { | |
1178 | int (*cb)(unsigned int cpu) = __cb; | |
1179 | ||
1180 | BUG_ON(cb(smp_processor_id())); | |
1181 | } | |
1182 | ||
1183 | /* | |
1184 | * Call the startup/teardown function for a step either on the AP or | |
1185 | * on the current CPU. | |
1186 | */ | |
1187 | static int cpuhp_issue_call(int cpu, enum cpuhp_state state, | |
1188 | int (*cb)(unsigned int), bool bringup) | |
1189 | { | |
1190 | int ret; | |
1191 | ||
1192 | if (!cb) | |
1193 | return 0; | |
1194 | ||
1195 | /* | |
1196 | * This invokes the callback directly for now. In a later step we | |
1197 | * convert that to use cpuhp_invoke_callback(). | |
1198 | */ | |
1199 | if (cpuhp_is_ap_state(state)) { | |
1200 | /* | |
1201 | * Note, that a function called on the AP is not | |
1202 | * allowed to fail. | |
1203 | */ | |
1204 | if (cpu_online(cpu)) | |
1205 | smp_call_function_single(cpu, cpuhp_on_cpu_cb, cb, 1); | |
1206 | return 0; | |
1207 | } | |
1208 | ||
1209 | /* | |
1210 | * The non AP bound callbacks can fail on bringup. On teardown | |
1211 | * e.g. module removal we crash for now. | |
1212 | */ | |
1213 | ret = cb(cpu); | |
1214 | BUG_ON(ret && !bringup); | |
1215 | return ret; | |
1216 | } | |
1217 | ||
1218 | /* | |
1219 | * Called from __cpuhp_setup_state on a recoverable failure. | |
1220 | * | |
1221 | * Note: The teardown callbacks for rollback are not allowed to fail! | |
1222 | */ | |
1223 | static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state, | |
1224 | int (*teardown)(unsigned int cpu)) | |
1225 | { | |
1226 | int cpu; | |
1227 | ||
1228 | if (!teardown) | |
1229 | return; | |
1230 | ||
1231 | /* Roll back the already executed steps on the other cpus */ | |
1232 | for_each_present_cpu(cpu) { | |
1233 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
1234 | int cpustate = st->state; | |
1235 | ||
1236 | if (cpu >= failedcpu) | |
1237 | break; | |
1238 | ||
1239 | /* Did we invoke the startup call on that cpu ? */ | |
1240 | if (cpustate >= state) | |
1241 | cpuhp_issue_call(cpu, state, teardown, false); | |
1242 | } | |
1243 | } | |
1244 | ||
1245 | /* | |
1246 | * Returns a free for dynamic slot assignment of the Online state. The states | |
1247 | * are protected by the cpuhp_slot_states mutex and an empty slot is identified | |
1248 | * by having no name assigned. | |
1249 | */ | |
1250 | static int cpuhp_reserve_state(enum cpuhp_state state) | |
1251 | { | |
1252 | enum cpuhp_state i; | |
1253 | ||
1254 | mutex_lock(&cpuhp_state_mutex); | |
1255 | for (i = CPUHP_ONLINE_DYN; i <= CPUHP_ONLINE_DYN_END; i++) { | |
1256 | if (cpuhp_bp_states[i].name) | |
1257 | continue; | |
1258 | ||
1259 | cpuhp_bp_states[i].name = "Reserved"; | |
1260 | mutex_unlock(&cpuhp_state_mutex); | |
1261 | return i; | |
1262 | } | |
1263 | mutex_unlock(&cpuhp_state_mutex); | |
1264 | WARN(1, "No more dynamic states available for CPU hotplug\n"); | |
1265 | return -ENOSPC; | |
1266 | } | |
1267 | ||
1268 | /** | |
1269 | * __cpuhp_setup_state - Setup the callbacks for an hotplug machine state | |
1270 | * @state: The state to setup | |
1271 | * @invoke: If true, the startup function is invoked for cpus where | |
1272 | * cpu state >= @state | |
1273 | * @startup: startup callback function | |
1274 | * @teardown: teardown callback function | |
1275 | * | |
1276 | * Returns 0 if successful, otherwise a proper error code | |
1277 | */ | |
1278 | int __cpuhp_setup_state(enum cpuhp_state state, | |
1279 | const char *name, bool invoke, | |
1280 | int (*startup)(unsigned int cpu), | |
1281 | int (*teardown)(unsigned int cpu)) | |
1282 | { | |
1283 | int cpu, ret = 0; | |
1284 | int dyn_state = 0; | |
1285 | ||
1286 | if (cpuhp_cb_check(state) || !name) | |
1287 | return -EINVAL; | |
1288 | ||
1289 | get_online_cpus(); | |
1290 | ||
1291 | /* currently assignments for the ONLINE state are possible */ | |
1292 | if (state == CPUHP_ONLINE_DYN) { | |
1293 | dyn_state = 1; | |
1294 | ret = cpuhp_reserve_state(state); | |
1295 | if (ret < 0) | |
1296 | goto out; | |
1297 | state = ret; | |
1298 | } | |
1299 | ||
1300 | cpuhp_store_callbacks(state, name, startup, teardown); | |
1301 | ||
1302 | if (!invoke || !startup) | |
1303 | goto out; | |
1304 | ||
1305 | /* | |
1306 | * Try to call the startup callback for each present cpu | |
1307 | * depending on the hotplug state of the cpu. | |
1308 | */ | |
1309 | for_each_present_cpu(cpu) { | |
1310 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
1311 | int cpustate = st->state; | |
1312 | ||
1313 | if (cpustate < state) | |
1314 | continue; | |
1315 | ||
1316 | ret = cpuhp_issue_call(cpu, state, startup, true); | |
1317 | if (ret) { | |
1318 | cpuhp_rollback_install(cpu, state, teardown); | |
1319 | cpuhp_store_callbacks(state, NULL, NULL, NULL); | |
1320 | goto out; | |
1321 | } | |
1322 | } | |
1323 | out: | |
1324 | put_online_cpus(); | |
1325 | if (!ret && dyn_state) | |
1326 | return state; | |
1327 | return ret; | |
1328 | } | |
1329 | EXPORT_SYMBOL(__cpuhp_setup_state); | |
1330 | ||
1331 | /** | |
1332 | * __cpuhp_remove_state - Remove the callbacks for an hotplug machine state | |
1333 | * @state: The state to remove | |
1334 | * @invoke: If true, the teardown function is invoked for cpus where | |
1335 | * cpu state >= @state | |
1336 | * | |
1337 | * The teardown callback is currently not allowed to fail. Think | |
1338 | * about module removal! | |
1339 | */ | |
1340 | void __cpuhp_remove_state(enum cpuhp_state state, bool invoke) | |
1341 | { | |
1342 | int (*teardown)(unsigned int cpu) = cpuhp_get_teardown_cb(state); | |
1343 | int cpu; | |
1344 | ||
1345 | BUG_ON(cpuhp_cb_check(state)); | |
1346 | ||
1347 | get_online_cpus(); | |
1348 | ||
1349 | if (!invoke || !teardown) | |
1350 | goto remove; | |
1351 | ||
1352 | /* | |
1353 | * Call the teardown callback for each present cpu depending | |
1354 | * on the hotplug state of the cpu. This function is not | |
1355 | * allowed to fail currently! | |
1356 | */ | |
1357 | for_each_present_cpu(cpu) { | |
1358 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
1359 | int cpustate = st->state; | |
1360 | ||
1361 | if (cpustate >= state) | |
1362 | cpuhp_issue_call(cpu, state, teardown, false); | |
1363 | } | |
1364 | remove: | |
1365 | cpuhp_store_callbacks(state, NULL, NULL, NULL); | |
1366 | put_online_cpus(); | |
1367 | } | |
1368 | EXPORT_SYMBOL(__cpuhp_remove_state); | |
1369 | ||
98f8cdce TG |
1370 | #if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU) |
1371 | static ssize_t show_cpuhp_state(struct device *dev, | |
1372 | struct device_attribute *attr, char *buf) | |
1373 | { | |
1374 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); | |
1375 | ||
1376 | return sprintf(buf, "%d\n", st->state); | |
1377 | } | |
1378 | static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL); | |
1379 | ||
757c989b TG |
1380 | static ssize_t write_cpuhp_target(struct device *dev, |
1381 | struct device_attribute *attr, | |
1382 | const char *buf, size_t count) | |
1383 | { | |
1384 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); | |
1385 | struct cpuhp_step *sp; | |
1386 | int target, ret; | |
1387 | ||
1388 | ret = kstrtoint(buf, 10, &target); | |
1389 | if (ret) | |
1390 | return ret; | |
1391 | ||
1392 | #ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL | |
1393 | if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE) | |
1394 | return -EINVAL; | |
1395 | #else | |
1396 | if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE) | |
1397 | return -EINVAL; | |
1398 | #endif | |
1399 | ||
1400 | ret = lock_device_hotplug_sysfs(); | |
1401 | if (ret) | |
1402 | return ret; | |
1403 | ||
1404 | mutex_lock(&cpuhp_state_mutex); | |
1405 | sp = cpuhp_get_step(target); | |
1406 | ret = !sp->name || sp->cant_stop ? -EINVAL : 0; | |
1407 | mutex_unlock(&cpuhp_state_mutex); | |
1408 | if (ret) | |
1409 | return ret; | |
1410 | ||
1411 | if (st->state < target) | |
1412 | ret = do_cpu_up(dev->id, target); | |
1413 | else | |
1414 | ret = do_cpu_down(dev->id, target); | |
1415 | ||
1416 | unlock_device_hotplug(); | |
1417 | return ret ? ret : count; | |
1418 | } | |
1419 | ||
98f8cdce TG |
1420 | static ssize_t show_cpuhp_target(struct device *dev, |
1421 | struct device_attribute *attr, char *buf) | |
1422 | { | |
1423 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); | |
1424 | ||
1425 | return sprintf(buf, "%d\n", st->target); | |
1426 | } | |
757c989b | 1427 | static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target); |
98f8cdce TG |
1428 | |
1429 | static struct attribute *cpuhp_cpu_attrs[] = { | |
1430 | &dev_attr_state.attr, | |
1431 | &dev_attr_target.attr, | |
1432 | NULL | |
1433 | }; | |
1434 | ||
1435 | static struct attribute_group cpuhp_cpu_attr_group = { | |
1436 | .attrs = cpuhp_cpu_attrs, | |
1437 | .name = "hotplug", | |
1438 | NULL | |
1439 | }; | |
1440 | ||
1441 | static ssize_t show_cpuhp_states(struct device *dev, | |
1442 | struct device_attribute *attr, char *buf) | |
1443 | { | |
1444 | ssize_t cur, res = 0; | |
1445 | int i; | |
1446 | ||
1447 | mutex_lock(&cpuhp_state_mutex); | |
757c989b | 1448 | for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) { |
98f8cdce TG |
1449 | struct cpuhp_step *sp = cpuhp_get_step(i); |
1450 | ||
1451 | if (sp->name) { | |
1452 | cur = sprintf(buf, "%3d: %s\n", i, sp->name); | |
1453 | buf += cur; | |
1454 | res += cur; | |
1455 | } | |
1456 | } | |
1457 | mutex_unlock(&cpuhp_state_mutex); | |
1458 | return res; | |
1459 | } | |
1460 | static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL); | |
1461 | ||
1462 | static struct attribute *cpuhp_cpu_root_attrs[] = { | |
1463 | &dev_attr_states.attr, | |
1464 | NULL | |
1465 | }; | |
1466 | ||
1467 | static struct attribute_group cpuhp_cpu_root_attr_group = { | |
1468 | .attrs = cpuhp_cpu_root_attrs, | |
1469 | .name = "hotplug", | |
1470 | NULL | |
1471 | }; | |
1472 | ||
1473 | static int __init cpuhp_sysfs_init(void) | |
1474 | { | |
1475 | int cpu, ret; | |
1476 | ||
1477 | ret = sysfs_create_group(&cpu_subsys.dev_root->kobj, | |
1478 | &cpuhp_cpu_root_attr_group); | |
1479 | if (ret) | |
1480 | return ret; | |
1481 | ||
1482 | for_each_possible_cpu(cpu) { | |
1483 | struct device *dev = get_cpu_device(cpu); | |
1484 | ||
1485 | if (!dev) | |
1486 | continue; | |
1487 | ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group); | |
1488 | if (ret) | |
1489 | return ret; | |
1490 | } | |
1491 | return 0; | |
1492 | } | |
1493 | device_initcall(cpuhp_sysfs_init); | |
1494 | #endif | |
1495 | ||
e56b3bc7 LT |
1496 | /* |
1497 | * cpu_bit_bitmap[] is a special, "compressed" data structure that | |
1498 | * represents all NR_CPUS bits binary values of 1<<nr. | |
1499 | * | |
e0b582ec | 1500 | * It is used by cpumask_of() to get a constant address to a CPU |
e56b3bc7 LT |
1501 | * mask value that has a single bit set only. |
1502 | */ | |
b8d317d1 | 1503 | |
e56b3bc7 | 1504 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
4d51985e | 1505 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
e56b3bc7 LT |
1506 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
1507 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) | |
1508 | #define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4) | |
b8d317d1 | 1509 | |
e56b3bc7 LT |
1510 | const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { |
1511 | ||
1512 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), | |
1513 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), | |
1514 | #if BITS_PER_LONG > 32 | |
1515 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), | |
1516 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), | |
b8d317d1 MT |
1517 | #endif |
1518 | }; | |
e56b3bc7 | 1519 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
2d3854a3 RR |
1520 | |
1521 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; | |
1522 | EXPORT_SYMBOL(cpu_all_bits); | |
b3199c02 RR |
1523 | |
1524 | #ifdef CONFIG_INIT_ALL_POSSIBLE | |
4b804c85 | 1525 | struct cpumask __cpu_possible_mask __read_mostly |
c4c54dd1 | 1526 | = {CPU_BITS_ALL}; |
b3199c02 | 1527 | #else |
4b804c85 | 1528 | struct cpumask __cpu_possible_mask __read_mostly; |
b3199c02 | 1529 | #endif |
4b804c85 | 1530 | EXPORT_SYMBOL(__cpu_possible_mask); |
b3199c02 | 1531 | |
4b804c85 RV |
1532 | struct cpumask __cpu_online_mask __read_mostly; |
1533 | EXPORT_SYMBOL(__cpu_online_mask); | |
b3199c02 | 1534 | |
4b804c85 RV |
1535 | struct cpumask __cpu_present_mask __read_mostly; |
1536 | EXPORT_SYMBOL(__cpu_present_mask); | |
b3199c02 | 1537 | |
4b804c85 RV |
1538 | struct cpumask __cpu_active_mask __read_mostly; |
1539 | EXPORT_SYMBOL(__cpu_active_mask); | |
3fa41520 | 1540 | |
3fa41520 RR |
1541 | void init_cpu_present(const struct cpumask *src) |
1542 | { | |
c4c54dd1 | 1543 | cpumask_copy(&__cpu_present_mask, src); |
3fa41520 RR |
1544 | } |
1545 | ||
1546 | void init_cpu_possible(const struct cpumask *src) | |
1547 | { | |
c4c54dd1 | 1548 | cpumask_copy(&__cpu_possible_mask, src); |
3fa41520 RR |
1549 | } |
1550 | ||
1551 | void init_cpu_online(const struct cpumask *src) | |
1552 | { | |
c4c54dd1 | 1553 | cpumask_copy(&__cpu_online_mask, src); |
3fa41520 | 1554 | } |
cff7d378 TG |
1555 | |
1556 | /* | |
1557 | * Activate the first processor. | |
1558 | */ | |
1559 | void __init boot_cpu_init(void) | |
1560 | { | |
1561 | int cpu = smp_processor_id(); | |
1562 | ||
1563 | /* Mark the boot cpu "present", "online" etc for SMP and UP case */ | |
1564 | set_cpu_online(cpu, true); | |
1565 | set_cpu_active(cpu, true); | |
1566 | set_cpu_present(cpu, true); | |
1567 | set_cpu_possible(cpu, true); | |
1568 | } | |
1569 | ||
1570 | /* | |
1571 | * Must be called _AFTER_ setting up the per_cpu areas | |
1572 | */ | |
1573 | void __init boot_cpu_state_init(void) | |
1574 | { | |
1575 | per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE; | |
1576 | } |