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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 | { | |
1cf4f629 | 432 | enum cpuhp_state target = max((int)st->target, CPUHP_TEARDOWN_CPU); |
4cb28ced TG |
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 { | |
1cf4f629 TG |
472 | /* Cannot happen .... */ |
473 | BUG_ON(st->state < CPUHP_KICK_AP_THREAD); | |
474 | ||
4cb28ced TG |
475 | /* Regular hotplug work */ |
476 | if (st->state < st->target) | |
477 | ret = cpuhp_ap_online(cpu, st); | |
478 | else if (st->state > st->target) | |
479 | ret = cpuhp_ap_offline(cpu, st); | |
480 | } | |
481 | st->result = ret; | |
482 | complete(&st->done); | |
483 | } | |
484 | ||
485 | /* Invoke a single callback on a remote cpu */ | |
486 | static int cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state, | |
487 | int (*cb)(unsigned int)) | |
488 | { | |
489 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
490 | ||
491 | if (!cpu_online(cpu)) | |
492 | return 0; | |
493 | ||
494 | st->cb_state = state; | |
495 | st->cb = cb; | |
496 | /* | |
497 | * Make sure the above stores are visible before should_run becomes | |
498 | * true. Paired with the mb() above in cpuhp_thread_fun() | |
499 | */ | |
500 | smp_mb(); | |
501 | st->should_run = true; | |
502 | wake_up_process(st->thread); | |
503 | wait_for_completion(&st->done); | |
504 | return st->result; | |
505 | } | |
506 | ||
507 | /* Regular hotplug invocation of the AP hotplug thread */ | |
1cf4f629 | 508 | static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st) |
4cb28ced | 509 | { |
4cb28ced TG |
510 | st->result = 0; |
511 | st->cb = NULL; | |
512 | /* | |
513 | * Make sure the above stores are visible before should_run becomes | |
514 | * true. Paired with the mb() above in cpuhp_thread_fun() | |
515 | */ | |
516 | smp_mb(); | |
517 | st->should_run = true; | |
518 | wake_up_process(st->thread); | |
1cf4f629 TG |
519 | } |
520 | ||
521 | static int cpuhp_kick_ap_work(unsigned int cpu) | |
522 | { | |
523 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
524 | enum cpuhp_state state = st->state; | |
525 | ||
526 | trace_cpuhp_enter(cpu, st->target, state, cpuhp_kick_ap_work); | |
527 | __cpuhp_kick_ap_work(st); | |
4cb28ced TG |
528 | wait_for_completion(&st->done); |
529 | trace_cpuhp_exit(cpu, st->state, state, st->result); | |
530 | return st->result; | |
531 | } | |
532 | ||
533 | static struct smp_hotplug_thread cpuhp_threads = { | |
534 | .store = &cpuhp_state.thread, | |
535 | .create = &cpuhp_create, | |
536 | .thread_should_run = cpuhp_should_run, | |
537 | .thread_fn = cpuhp_thread_fun, | |
538 | .thread_comm = "cpuhp/%u", | |
539 | .selfparking = true, | |
540 | }; | |
541 | ||
542 | void __init cpuhp_threads_init(void) | |
543 | { | |
544 | BUG_ON(smpboot_register_percpu_thread(&cpuhp_threads)); | |
545 | kthread_unpark(this_cpu_read(cpuhp_state.thread)); | |
546 | } | |
547 | ||
00b9b0af | 548 | #ifdef CONFIG_HOTPLUG_CPU |
1da177e4 | 549 | EXPORT_SYMBOL(register_cpu_notifier); |
93ae4f97 | 550 | EXPORT_SYMBOL(__register_cpu_notifier); |
71cf5aee | 551 | void unregister_cpu_notifier(struct notifier_block *nb) |
1da177e4 | 552 | { |
d221938c | 553 | cpu_maps_update_begin(); |
bd5349cf | 554 | raw_notifier_chain_unregister(&cpu_chain, nb); |
d221938c | 555 | cpu_maps_update_done(); |
1da177e4 LT |
556 | } |
557 | EXPORT_SYMBOL(unregister_cpu_notifier); | |
558 | ||
71cf5aee | 559 | void __unregister_cpu_notifier(struct notifier_block *nb) |
93ae4f97 SB |
560 | { |
561 | raw_notifier_chain_unregister(&cpu_chain, nb); | |
562 | } | |
563 | EXPORT_SYMBOL(__unregister_cpu_notifier); | |
564 | ||
e4cc2f87 AV |
565 | /** |
566 | * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU | |
567 | * @cpu: a CPU id | |
568 | * | |
569 | * This function walks all processes, finds a valid mm struct for each one and | |
570 | * then clears a corresponding bit in mm's cpumask. While this all sounds | |
571 | * trivial, there are various non-obvious corner cases, which this function | |
572 | * tries to solve in a safe manner. | |
573 | * | |
574 | * Also note that the function uses a somewhat relaxed locking scheme, so it may | |
575 | * be called only for an already offlined CPU. | |
576 | */ | |
cb79295e AV |
577 | void clear_tasks_mm_cpumask(int cpu) |
578 | { | |
579 | struct task_struct *p; | |
580 | ||
581 | /* | |
582 | * This function is called after the cpu is taken down and marked | |
583 | * offline, so its not like new tasks will ever get this cpu set in | |
584 | * their mm mask. -- Peter Zijlstra | |
585 | * Thus, we may use rcu_read_lock() here, instead of grabbing | |
586 | * full-fledged tasklist_lock. | |
587 | */ | |
e4cc2f87 | 588 | WARN_ON(cpu_online(cpu)); |
cb79295e AV |
589 | rcu_read_lock(); |
590 | for_each_process(p) { | |
591 | struct task_struct *t; | |
592 | ||
e4cc2f87 AV |
593 | /* |
594 | * Main thread might exit, but other threads may still have | |
595 | * a valid mm. Find one. | |
596 | */ | |
cb79295e AV |
597 | t = find_lock_task_mm(p); |
598 | if (!t) | |
599 | continue; | |
600 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); | |
601 | task_unlock(t); | |
602 | } | |
603 | rcu_read_unlock(); | |
604 | } | |
605 | ||
b728ca06 | 606 | static inline void check_for_tasks(int dead_cpu) |
1da177e4 | 607 | { |
b728ca06 | 608 | struct task_struct *g, *p; |
1da177e4 | 609 | |
a75a6068 ON |
610 | read_lock(&tasklist_lock); |
611 | for_each_process_thread(g, p) { | |
b728ca06 KT |
612 | if (!p->on_rq) |
613 | continue; | |
614 | /* | |
615 | * We do the check with unlocked task_rq(p)->lock. | |
616 | * Order the reading to do not warn about a task, | |
617 | * which was running on this cpu in the past, and | |
618 | * it's just been woken on another cpu. | |
619 | */ | |
620 | rmb(); | |
621 | if (task_cpu(p) != dead_cpu) | |
622 | continue; | |
623 | ||
624 | pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n", | |
625 | p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags); | |
a75a6068 ON |
626 | } |
627 | read_unlock(&tasklist_lock); | |
1da177e4 LT |
628 | } |
629 | ||
98458172 TG |
630 | static void cpu_notify_nofail(unsigned long val, unsigned int cpu) |
631 | { | |
632 | BUG_ON(cpu_notify(val, cpu)); | |
633 | } | |
634 | ||
635 | static int notify_down_prepare(unsigned int cpu) | |
636 | { | |
637 | int err, nr_calls = 0; | |
638 | ||
639 | err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls); | |
640 | if (err) { | |
641 | nr_calls--; | |
642 | __cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL); | |
643 | pr_warn("%s: attempt to take down CPU %u failed\n", | |
644 | __func__, cpu); | |
645 | } | |
646 | return err; | |
647 | } | |
648 | ||
4baa0afc TG |
649 | static int notify_dying(unsigned int cpu) |
650 | { | |
651 | cpu_notify(CPU_DYING, cpu); | |
652 | return 0; | |
653 | } | |
654 | ||
1da177e4 | 655 | /* Take this CPU down. */ |
71cf5aee | 656 | static int take_cpu_down(void *_param) |
1da177e4 | 657 | { |
4baa0afc TG |
658 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
659 | enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE); | |
090e77c3 | 660 | int err, cpu = smp_processor_id(); |
1da177e4 | 661 | |
1da177e4 LT |
662 | /* Ensure this CPU doesn't handle any more interrupts. */ |
663 | err = __cpu_disable(); | |
664 | if (err < 0) | |
f3705136 | 665 | return err; |
1da177e4 | 666 | |
4baa0afc TG |
667 | /* Invoke the former CPU_DYING callbacks */ |
668 | for (; st->state > target; st->state--) { | |
669 | struct cpuhp_step *step = cpuhp_ap_states + st->state; | |
670 | ||
671 | cpuhp_invoke_callback(cpu, st->state, step->teardown); | |
672 | } | |
52c063d1 TG |
673 | /* Give up timekeeping duties */ |
674 | tick_handover_do_timer(); | |
14e568e7 | 675 | /* Park the stopper thread */ |
090e77c3 | 676 | stop_machine_park(cpu); |
f3705136 | 677 | return 0; |
1da177e4 LT |
678 | } |
679 | ||
98458172 | 680 | static int takedown_cpu(unsigned int cpu) |
1da177e4 | 681 | { |
98458172 | 682 | int err; |
1da177e4 | 683 | |
6acce3ef PZ |
684 | /* |
685 | * By now we've cleared cpu_active_mask, wait for all preempt-disabled | |
686 | * and RCU users of this state to go away such that all new such users | |
687 | * will observe it. | |
688 | * | |
689 | * For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might | |
779de6ce | 690 | * not imply sync_sched(), so wait for both. |
106dd5af M |
691 | * |
692 | * Do sync before park smpboot threads to take care the rcu boost case. | |
6acce3ef | 693 | */ |
779de6ce PM |
694 | if (IS_ENABLED(CONFIG_PREEMPT)) |
695 | synchronize_rcu_mult(call_rcu, call_rcu_sched); | |
696 | else | |
697 | synchronize_rcu(); | |
6acce3ef | 698 | |
1cf4f629 TG |
699 | /* Park the hotplug thread */ |
700 | kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread); | |
701 | ||
6acce3ef | 702 | /* |
a8994181 TG |
703 | * Prevent irq alloc/free while the dying cpu reorganizes the |
704 | * interrupt affinities. | |
6acce3ef | 705 | */ |
a8994181 | 706 | irq_lock_sparse(); |
6acce3ef | 707 | |
a8994181 TG |
708 | /* |
709 | * So now all preempt/rcu users must observe !cpu_active(). | |
710 | */ | |
090e77c3 | 711 | err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu)); |
04321587 | 712 | if (err) { |
1da177e4 | 713 | /* CPU didn't die: tell everyone. Can't complain. */ |
090e77c3 | 714 | cpu_notify_nofail(CPU_DOWN_FAILED, cpu); |
a8994181 | 715 | irq_unlock_sparse(); |
98458172 | 716 | return err; |
8fa1d7d3 | 717 | } |
04321587 | 718 | BUG_ON(cpu_online(cpu)); |
1da177e4 | 719 | |
48c5ccae PZ |
720 | /* |
721 | * The migration_call() CPU_DYING callback will have removed all | |
722 | * runnable tasks from the cpu, there's only the idle task left now | |
723 | * that the migration thread is done doing the stop_machine thing. | |
51a96c77 PZ |
724 | * |
725 | * Wait for the stop thread to go away. | |
48c5ccae | 726 | */ |
528a25b0 | 727 | while (!per_cpu(cpu_dead_idle, cpu)) |
51a96c77 | 728 | cpu_relax(); |
528a25b0 PM |
729 | smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */ |
730 | per_cpu(cpu_dead_idle, cpu) = false; | |
1da177e4 | 731 | |
a8994181 TG |
732 | /* Interrupts are moved away from the dying cpu, reenable alloc/free */ |
733 | irq_unlock_sparse(); | |
734 | ||
345527b1 | 735 | hotplug_cpu__broadcast_tick_pull(cpu); |
1da177e4 LT |
736 | /* This actually kills the CPU. */ |
737 | __cpu_die(cpu); | |
738 | ||
a49b116d | 739 | tick_cleanup_dead_cpu(cpu); |
98458172 TG |
740 | return 0; |
741 | } | |
1da177e4 | 742 | |
98458172 TG |
743 | static int notify_dead(unsigned int cpu) |
744 | { | |
745 | cpu_notify_nofail(CPU_DEAD, cpu); | |
1da177e4 | 746 | check_for_tasks(cpu); |
98458172 TG |
747 | return 0; |
748 | } | |
749 | ||
cff7d378 TG |
750 | #else |
751 | #define notify_down_prepare NULL | |
752 | #define takedown_cpu NULL | |
753 | #define notify_dead NULL | |
4baa0afc | 754 | #define notify_dying NULL |
cff7d378 TG |
755 | #endif |
756 | ||
757 | #ifdef CONFIG_HOTPLUG_CPU | |
cff7d378 | 758 | |
98458172 | 759 | /* Requires cpu_add_remove_lock to be held */ |
af1f4045 TG |
760 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, |
761 | enum cpuhp_state target) | |
98458172 | 762 | { |
cff7d378 TG |
763 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
764 | int prev_state, ret = 0; | |
765 | bool hasdied = false; | |
98458172 TG |
766 | |
767 | if (num_online_cpus() == 1) | |
768 | return -EBUSY; | |
769 | ||
757c989b | 770 | if (!cpu_present(cpu)) |
98458172 TG |
771 | return -EINVAL; |
772 | ||
773 | cpu_hotplug_begin(); | |
774 | ||
775 | cpuhp_tasks_frozen = tasks_frozen; | |
776 | ||
cff7d378 | 777 | prev_state = st->state; |
af1f4045 | 778 | st->target = target; |
1cf4f629 TG |
779 | /* |
780 | * If the current CPU state is in the range of the AP hotplug thread, | |
781 | * then we need to kick the thread. | |
782 | */ | |
783 | if (st->state >= CPUHP_KICK_AP_THREAD) { | |
784 | ret = cpuhp_kick_ap_work(cpu); | |
785 | /* | |
786 | * The AP side has done the error rollback already. Just | |
787 | * return the error code.. | |
788 | */ | |
789 | if (ret) | |
790 | goto out; | |
791 | ||
792 | /* | |
793 | * We might have stopped still in the range of the AP hotplug | |
794 | * thread. Nothing to do anymore. | |
795 | */ | |
796 | if (st->state >= CPUHP_KICK_AP_THREAD) | |
797 | goto out; | |
798 | } | |
799 | /* | |
800 | * The AP brought itself down below CPUHP_KICK_AP_THREAD. So we need | |
801 | * to do the further cleanups. | |
802 | */ | |
2e1a3483 | 803 | ret = cpuhp_down_callbacks(cpu, st, cpuhp_bp_states, target); |
98458172 | 804 | |
cff7d378 | 805 | hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE; |
1cf4f629 | 806 | out: |
d221938c | 807 | cpu_hotplug_done(); |
cff7d378 TG |
808 | /* This post dead nonsense must die */ |
809 | if (!ret && hasdied) | |
090e77c3 | 810 | cpu_notify_nofail(CPU_POST_DEAD, cpu); |
cff7d378 | 811 | return ret; |
e3920fb4 RW |
812 | } |
813 | ||
af1f4045 | 814 | static int do_cpu_down(unsigned int cpu, enum cpuhp_state target) |
e3920fb4 | 815 | { |
9ea09af3 | 816 | int err; |
e3920fb4 | 817 | |
d221938c | 818 | cpu_maps_update_begin(); |
e761b772 MK |
819 | |
820 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 821 | err = -EBUSY; |
e761b772 MK |
822 | goto out; |
823 | } | |
824 | ||
af1f4045 | 825 | err = _cpu_down(cpu, 0, target); |
e3920fb4 | 826 | |
e761b772 | 827 | out: |
d221938c | 828 | cpu_maps_update_done(); |
1da177e4 LT |
829 | return err; |
830 | } | |
af1f4045 TG |
831 | int cpu_down(unsigned int cpu) |
832 | { | |
833 | return do_cpu_down(cpu, CPUHP_OFFLINE); | |
834 | } | |
b62b8ef9 | 835 | EXPORT_SYMBOL(cpu_down); |
1da177e4 LT |
836 | #endif /*CONFIG_HOTPLUG_CPU*/ |
837 | ||
4baa0afc TG |
838 | /** |
839 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers | |
840 | * @cpu: cpu that just started | |
841 | * | |
842 | * This function calls the cpu_chain notifiers with CPU_STARTING. | |
843 | * It must be called by the arch code on the new cpu, before the new cpu | |
844 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). | |
845 | */ | |
846 | void notify_cpu_starting(unsigned int cpu) | |
847 | { | |
848 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
849 | enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE); | |
850 | ||
851 | while (st->state < target) { | |
852 | struct cpuhp_step *step; | |
853 | ||
854 | st->state++; | |
855 | step = cpuhp_ap_states + st->state; | |
856 | cpuhp_invoke_callback(cpu, st->state, step->startup); | |
857 | } | |
858 | } | |
859 | ||
949338e3 TG |
860 | /* |
861 | * Called from the idle task. We need to set active here, so we can kick off | |
862 | * the stopper thread. | |
863 | */ | |
864 | static int cpuhp_set_cpu_active(unsigned int cpu) | |
865 | { | |
1cf4f629 TG |
866 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
867 | ||
949338e3 TG |
868 | /* The cpu is marked online, set it active now */ |
869 | set_cpu_active(cpu, true); | |
1cf4f629 | 870 | /* Unpark the stopper thread and the hotplug thread */ |
949338e3 | 871 | stop_machine_unpark(cpu); |
1cf4f629 | 872 | kthread_unpark(st->thread); |
949338e3 TG |
873 | return 0; |
874 | } | |
875 | ||
e3920fb4 | 876 | /* Requires cpu_add_remove_lock to be held */ |
af1f4045 | 877 | static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target) |
1da177e4 | 878 | { |
cff7d378 | 879 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
3bb5d2ee | 880 | struct task_struct *idle; |
2e1a3483 | 881 | int ret = 0; |
1da177e4 | 882 | |
d221938c | 883 | cpu_hotplug_begin(); |
38498a67 | 884 | |
757c989b | 885 | if (!cpu_present(cpu)) { |
5e5041f3 YI |
886 | ret = -EINVAL; |
887 | goto out; | |
888 | } | |
889 | ||
757c989b TG |
890 | /* |
891 | * The caller of do_cpu_up might have raced with another | |
892 | * caller. Ignore it for now. | |
893 | */ | |
894 | if (st->state >= target) | |
38498a67 | 895 | goto out; |
757c989b TG |
896 | |
897 | if (st->state == CPUHP_OFFLINE) { | |
898 | /* Let it fail before we try to bring the cpu up */ | |
899 | idle = idle_thread_get(cpu); | |
900 | if (IS_ERR(idle)) { | |
901 | ret = PTR_ERR(idle); | |
902 | goto out; | |
903 | } | |
3bb5d2ee | 904 | } |
38498a67 | 905 | |
ba997462 TG |
906 | cpuhp_tasks_frozen = tasks_frozen; |
907 | ||
af1f4045 | 908 | st->target = target; |
1cf4f629 TG |
909 | /* |
910 | * If the current CPU state is in the range of the AP hotplug thread, | |
911 | * then we need to kick the thread once more. | |
912 | */ | |
913 | if (st->state >= CPUHP_KICK_AP_THREAD) { | |
914 | ret = cpuhp_kick_ap_work(cpu); | |
915 | /* | |
916 | * The AP side has done the error rollback already. Just | |
917 | * return the error code.. | |
918 | */ | |
919 | if (ret) | |
920 | goto out; | |
921 | } | |
922 | ||
923 | /* | |
924 | * Try to reach the target state. We max out on the BP at | |
925 | * CPUHP_KICK_AP_THREAD. After that the AP hotplug thread is | |
926 | * responsible for bringing it up to the target state. | |
927 | */ | |
928 | target = min((int)target, CPUHP_KICK_AP_THREAD); | |
2e1a3483 | 929 | ret = cpuhp_up_callbacks(cpu, st, cpuhp_bp_states, target); |
38498a67 | 930 | out: |
d221938c | 931 | cpu_hotplug_done(); |
e3920fb4 RW |
932 | return ret; |
933 | } | |
934 | ||
af1f4045 | 935 | static int do_cpu_up(unsigned int cpu, enum cpuhp_state target) |
e3920fb4 RW |
936 | { |
937 | int err = 0; | |
cf23422b | 938 | |
e0b582ec | 939 | if (!cpu_possible(cpu)) { |
84117da5 FF |
940 | pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n", |
941 | cpu); | |
87d5e023 | 942 | #if defined(CONFIG_IA64) |
84117da5 | 943 | pr_err("please check additional_cpus= boot parameter\n"); |
73e753a5 KH |
944 | #endif |
945 | return -EINVAL; | |
946 | } | |
e3920fb4 | 947 | |
01b0f197 TK |
948 | err = try_online_node(cpu_to_node(cpu)); |
949 | if (err) | |
950 | return err; | |
cf23422b | 951 | |
d221938c | 952 | cpu_maps_update_begin(); |
e761b772 MK |
953 | |
954 | if (cpu_hotplug_disabled) { | |
e3920fb4 | 955 | err = -EBUSY; |
e761b772 MK |
956 | goto out; |
957 | } | |
958 | ||
af1f4045 | 959 | err = _cpu_up(cpu, 0, target); |
e761b772 | 960 | out: |
d221938c | 961 | cpu_maps_update_done(); |
e3920fb4 RW |
962 | return err; |
963 | } | |
af1f4045 TG |
964 | |
965 | int cpu_up(unsigned int cpu) | |
966 | { | |
967 | return do_cpu_up(cpu, CPUHP_ONLINE); | |
968 | } | |
a513f6ba | 969 | EXPORT_SYMBOL_GPL(cpu_up); |
e3920fb4 | 970 | |
f3de4be9 | 971 | #ifdef CONFIG_PM_SLEEP_SMP |
e0b582ec | 972 | static cpumask_var_t frozen_cpus; |
e3920fb4 RW |
973 | |
974 | int disable_nonboot_cpus(void) | |
975 | { | |
e9a5f426 | 976 | int cpu, first_cpu, error = 0; |
e3920fb4 | 977 | |
d221938c | 978 | cpu_maps_update_begin(); |
e0b582ec | 979 | first_cpu = cpumask_first(cpu_online_mask); |
9ee349ad XF |
980 | /* |
981 | * We take down all of the non-boot CPUs in one shot to avoid races | |
e3920fb4 RW |
982 | * with the userspace trying to use the CPU hotplug at the same time |
983 | */ | |
e0b582ec | 984 | cpumask_clear(frozen_cpus); |
6ad4c188 | 985 | |
84117da5 | 986 | pr_info("Disabling non-boot CPUs ...\n"); |
e3920fb4 RW |
987 | for_each_online_cpu(cpu) { |
988 | if (cpu == first_cpu) | |
989 | continue; | |
bb3632c6 | 990 | trace_suspend_resume(TPS("CPU_OFF"), cpu, true); |
af1f4045 | 991 | error = _cpu_down(cpu, 1, CPUHP_OFFLINE); |
bb3632c6 | 992 | trace_suspend_resume(TPS("CPU_OFF"), cpu, false); |
feae3203 | 993 | if (!error) |
e0b582ec | 994 | cpumask_set_cpu(cpu, frozen_cpus); |
feae3203 | 995 | else { |
84117da5 | 996 | pr_err("Error taking CPU%d down: %d\n", cpu, error); |
e3920fb4 RW |
997 | break; |
998 | } | |
999 | } | |
86886e55 | 1000 | |
89af7ba5 | 1001 | if (!error) |
e3920fb4 | 1002 | BUG_ON(num_online_cpus() > 1); |
89af7ba5 | 1003 | else |
84117da5 | 1004 | pr_err("Non-boot CPUs are not disabled\n"); |
89af7ba5 VK |
1005 | |
1006 | /* | |
1007 | * Make sure the CPUs won't be enabled by someone else. We need to do | |
1008 | * this even in case of failure as all disable_nonboot_cpus() users are | |
1009 | * supposed to do enable_nonboot_cpus() on the failure path. | |
1010 | */ | |
1011 | cpu_hotplug_disabled++; | |
1012 | ||
d221938c | 1013 | cpu_maps_update_done(); |
e3920fb4 RW |
1014 | return error; |
1015 | } | |
1016 | ||
d0af9eed SS |
1017 | void __weak arch_enable_nonboot_cpus_begin(void) |
1018 | { | |
1019 | } | |
1020 | ||
1021 | void __weak arch_enable_nonboot_cpus_end(void) | |
1022 | { | |
1023 | } | |
1024 | ||
71cf5aee | 1025 | void enable_nonboot_cpus(void) |
e3920fb4 RW |
1026 | { |
1027 | int cpu, error; | |
1028 | ||
1029 | /* Allow everyone to use the CPU hotplug again */ | |
d221938c | 1030 | cpu_maps_update_begin(); |
89af7ba5 | 1031 | WARN_ON(--cpu_hotplug_disabled < 0); |
e0b582ec | 1032 | if (cpumask_empty(frozen_cpus)) |
1d64b9cb | 1033 | goto out; |
e3920fb4 | 1034 | |
84117da5 | 1035 | pr_info("Enabling non-boot CPUs ...\n"); |
d0af9eed SS |
1036 | |
1037 | arch_enable_nonboot_cpus_begin(); | |
1038 | ||
e0b582ec | 1039 | for_each_cpu(cpu, frozen_cpus) { |
bb3632c6 | 1040 | trace_suspend_resume(TPS("CPU_ON"), cpu, true); |
af1f4045 | 1041 | error = _cpu_up(cpu, 1, CPUHP_ONLINE); |
bb3632c6 | 1042 | trace_suspend_resume(TPS("CPU_ON"), cpu, false); |
e3920fb4 | 1043 | if (!error) { |
84117da5 | 1044 | pr_info("CPU%d is up\n", cpu); |
e3920fb4 RW |
1045 | continue; |
1046 | } | |
84117da5 | 1047 | pr_warn("Error taking CPU%d up: %d\n", cpu, error); |
e3920fb4 | 1048 | } |
d0af9eed SS |
1049 | |
1050 | arch_enable_nonboot_cpus_end(); | |
1051 | ||
e0b582ec | 1052 | cpumask_clear(frozen_cpus); |
1d64b9cb | 1053 | out: |
d221938c | 1054 | cpu_maps_update_done(); |
1da177e4 | 1055 | } |
e0b582ec | 1056 | |
d7268a31 | 1057 | static int __init alloc_frozen_cpus(void) |
e0b582ec RR |
1058 | { |
1059 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) | |
1060 | return -ENOMEM; | |
1061 | return 0; | |
1062 | } | |
1063 | core_initcall(alloc_frozen_cpus); | |
79cfbdfa | 1064 | |
79cfbdfa SB |
1065 | /* |
1066 | * When callbacks for CPU hotplug notifications are being executed, we must | |
1067 | * ensure that the state of the system with respect to the tasks being frozen | |
1068 | * or not, as reported by the notification, remains unchanged *throughout the | |
1069 | * duration* of the execution of the callbacks. | |
1070 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. | |
1071 | * | |
1072 | * This synchronization is implemented by mutually excluding regular CPU | |
1073 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ | |
1074 | * Hibernate notifications. | |
1075 | */ | |
1076 | static int | |
1077 | cpu_hotplug_pm_callback(struct notifier_block *nb, | |
1078 | unsigned long action, void *ptr) | |
1079 | { | |
1080 | switch (action) { | |
1081 | ||
1082 | case PM_SUSPEND_PREPARE: | |
1083 | case PM_HIBERNATION_PREPARE: | |
16e53dbf | 1084 | cpu_hotplug_disable(); |
79cfbdfa SB |
1085 | break; |
1086 | ||
1087 | case PM_POST_SUSPEND: | |
1088 | case PM_POST_HIBERNATION: | |
16e53dbf | 1089 | cpu_hotplug_enable(); |
79cfbdfa SB |
1090 | break; |
1091 | ||
1092 | default: | |
1093 | return NOTIFY_DONE; | |
1094 | } | |
1095 | ||
1096 | return NOTIFY_OK; | |
1097 | } | |
1098 | ||
1099 | ||
d7268a31 | 1100 | static int __init cpu_hotplug_pm_sync_init(void) |
79cfbdfa | 1101 | { |
6e32d479 FY |
1102 | /* |
1103 | * cpu_hotplug_pm_callback has higher priority than x86 | |
1104 | * bsp_pm_callback which depends on cpu_hotplug_pm_callback | |
1105 | * to disable cpu hotplug to avoid cpu hotplug race. | |
1106 | */ | |
79cfbdfa SB |
1107 | pm_notifier(cpu_hotplug_pm_callback, 0); |
1108 | return 0; | |
1109 | } | |
1110 | core_initcall(cpu_hotplug_pm_sync_init); | |
1111 | ||
f3de4be9 | 1112 | #endif /* CONFIG_PM_SLEEP_SMP */ |
68f4f1ec MK |
1113 | |
1114 | #endif /* CONFIG_SMP */ | |
b8d317d1 | 1115 | |
cff7d378 TG |
1116 | /* Boot processor state steps */ |
1117 | static struct cpuhp_step cpuhp_bp_states[] = { | |
1118 | [CPUHP_OFFLINE] = { | |
1119 | .name = "offline", | |
1120 | .startup = NULL, | |
1121 | .teardown = NULL, | |
1122 | }, | |
1123 | #ifdef CONFIG_SMP | |
1124 | [CPUHP_CREATE_THREADS]= { | |
1125 | .name = "threads:create", | |
1126 | .startup = smpboot_create_threads, | |
1127 | .teardown = NULL, | |
757c989b | 1128 | .cant_stop = true, |
cff7d378 TG |
1129 | }, |
1130 | [CPUHP_NOTIFY_PREPARE] = { | |
1131 | .name = "notify:prepare", | |
1132 | .startup = notify_prepare, | |
1133 | .teardown = notify_dead, | |
1134 | .skip_onerr = true, | |
757c989b | 1135 | .cant_stop = true, |
cff7d378 TG |
1136 | }, |
1137 | [CPUHP_BRINGUP_CPU] = { | |
1138 | .name = "cpu:bringup", | |
1139 | .startup = bringup_cpu, | |
4baa0afc | 1140 | .teardown = NULL, |
757c989b | 1141 | .cant_stop = true, |
4baa0afc TG |
1142 | }, |
1143 | [CPUHP_TEARDOWN_CPU] = { | |
1144 | .name = "cpu:teardown", | |
1145 | .startup = NULL, | |
cff7d378 | 1146 | .teardown = takedown_cpu, |
757c989b | 1147 | .cant_stop = true, |
cff7d378 | 1148 | }, |
949338e3 TG |
1149 | [CPUHP_CPU_SET_ACTIVE] = { |
1150 | .name = "cpu:active", | |
1151 | .startup = cpuhp_set_cpu_active, | |
1152 | .teardown = NULL, | |
1153 | }, | |
1cf4f629 TG |
1154 | [CPUHP_KICK_AP_THREAD] = { |
1155 | .name = "cpuhp:kickthread", | |
1156 | .startup = cpuhp_kick_ap_work, | |
1157 | .teardown = cpuhp_kick_ap_work, | |
cff7d378 TG |
1158 | }, |
1159 | #endif | |
1cf4f629 | 1160 | [CPUHP_BP_ONLINE] = { |
cff7d378 TG |
1161 | .name = "online", |
1162 | .startup = NULL, | |
1163 | .teardown = NULL, | |
1164 | }, | |
1165 | }; | |
1166 | ||
4baa0afc TG |
1167 | /* Application processor state steps */ |
1168 | static struct cpuhp_step cpuhp_ap_states[] = { | |
1169 | #ifdef CONFIG_SMP | |
1170 | [CPUHP_AP_NOTIFY_STARTING] = { | |
1171 | .name = "notify:starting", | |
1172 | .startup = notify_starting, | |
1173 | .teardown = notify_dying, | |
1174 | .skip_onerr = true, | |
757c989b | 1175 | .cant_stop = true, |
4baa0afc | 1176 | }, |
1cf4f629 TG |
1177 | [CPUHP_AP_SMPBOOT_THREADS] = { |
1178 | .name = "smpboot:threads", | |
1179 | .startup = smpboot_unpark_threads, | |
1180 | .teardown = smpboot_park_threads, | |
1181 | }, | |
1182 | [CPUHP_AP_NOTIFY_ONLINE] = { | |
1183 | .name = "notify:online", | |
1184 | .startup = notify_online, | |
1185 | .teardown = notify_down_prepare, | |
1186 | }, | |
4baa0afc TG |
1187 | #endif |
1188 | [CPUHP_ONLINE] = { | |
1189 | .name = "online", | |
1190 | .startup = NULL, | |
1191 | .teardown = NULL, | |
1192 | }, | |
1193 | }; | |
1194 | ||
5b7aa87e TG |
1195 | /* Sanity check for callbacks */ |
1196 | static int cpuhp_cb_check(enum cpuhp_state state) | |
1197 | { | |
1198 | if (state <= CPUHP_OFFLINE || state >= CPUHP_ONLINE) | |
1199 | return -EINVAL; | |
1200 | return 0; | |
1201 | } | |
1202 | ||
98f8cdce TG |
1203 | static bool cpuhp_is_ap_state(enum cpuhp_state state) |
1204 | { | |
1cf4f629 TG |
1205 | if (state >= CPUHP_AP_OFFLINE && state <= CPUHP_AP_ONLINE) |
1206 | return true; | |
1207 | return state > CPUHP_BP_ONLINE; | |
98f8cdce TG |
1208 | } |
1209 | ||
1210 | static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state) | |
1211 | { | |
1212 | struct cpuhp_step *sp; | |
1213 | ||
1214 | sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states; | |
1215 | return sp + state; | |
1216 | } | |
1217 | ||
5b7aa87e TG |
1218 | static void cpuhp_store_callbacks(enum cpuhp_state state, |
1219 | const char *name, | |
1220 | int (*startup)(unsigned int cpu), | |
1221 | int (*teardown)(unsigned int cpu)) | |
1222 | { | |
1223 | /* (Un)Install the callbacks for further cpu hotplug operations */ | |
1224 | struct cpuhp_step *sp; | |
1225 | ||
1226 | mutex_lock(&cpuhp_state_mutex); | |
1227 | sp = cpuhp_get_step(state); | |
1228 | sp->startup = startup; | |
1229 | sp->teardown = teardown; | |
1230 | sp->name = name; | |
1231 | mutex_unlock(&cpuhp_state_mutex); | |
1232 | } | |
1233 | ||
1234 | static void *cpuhp_get_teardown_cb(enum cpuhp_state state) | |
1235 | { | |
1236 | return cpuhp_get_step(state)->teardown; | |
1237 | } | |
1238 | ||
5b7aa87e TG |
1239 | /* |
1240 | * Call the startup/teardown function for a step either on the AP or | |
1241 | * on the current CPU. | |
1242 | */ | |
1243 | static int cpuhp_issue_call(int cpu, enum cpuhp_state state, | |
1244 | int (*cb)(unsigned int), bool bringup) | |
1245 | { | |
1246 | int ret; | |
1247 | ||
1248 | if (!cb) | |
1249 | return 0; | |
5b7aa87e TG |
1250 | /* |
1251 | * The non AP bound callbacks can fail on bringup. On teardown | |
1252 | * e.g. module removal we crash for now. | |
1253 | */ | |
1cf4f629 TG |
1254 | #ifdef CONFIG_SMP |
1255 | if (cpuhp_is_ap_state(state)) | |
1256 | ret = cpuhp_invoke_ap_callback(cpu, state, cb); | |
1257 | else | |
1258 | ret = cpuhp_invoke_callback(cpu, state, cb); | |
1259 | #else | |
1260 | ret = cpuhp_invoke_callback(cpu, state, cb); | |
1261 | #endif | |
5b7aa87e TG |
1262 | BUG_ON(ret && !bringup); |
1263 | return ret; | |
1264 | } | |
1265 | ||
1266 | /* | |
1267 | * Called from __cpuhp_setup_state on a recoverable failure. | |
1268 | * | |
1269 | * Note: The teardown callbacks for rollback are not allowed to fail! | |
1270 | */ | |
1271 | static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state, | |
1272 | int (*teardown)(unsigned int cpu)) | |
1273 | { | |
1274 | int cpu; | |
1275 | ||
1276 | if (!teardown) | |
1277 | return; | |
1278 | ||
1279 | /* Roll back the already executed steps on the other cpus */ | |
1280 | for_each_present_cpu(cpu) { | |
1281 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
1282 | int cpustate = st->state; | |
1283 | ||
1284 | if (cpu >= failedcpu) | |
1285 | break; | |
1286 | ||
1287 | /* Did we invoke the startup call on that cpu ? */ | |
1288 | if (cpustate >= state) | |
1289 | cpuhp_issue_call(cpu, state, teardown, false); | |
1290 | } | |
1291 | } | |
1292 | ||
1293 | /* | |
1294 | * Returns a free for dynamic slot assignment of the Online state. The states | |
1295 | * are protected by the cpuhp_slot_states mutex and an empty slot is identified | |
1296 | * by having no name assigned. | |
1297 | */ | |
1298 | static int cpuhp_reserve_state(enum cpuhp_state state) | |
1299 | { | |
1300 | enum cpuhp_state i; | |
1301 | ||
1302 | mutex_lock(&cpuhp_state_mutex); | |
1cf4f629 TG |
1303 | for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) { |
1304 | if (cpuhp_ap_states[i].name) | |
5b7aa87e TG |
1305 | continue; |
1306 | ||
1cf4f629 | 1307 | cpuhp_ap_states[i].name = "Reserved"; |
5b7aa87e TG |
1308 | mutex_unlock(&cpuhp_state_mutex); |
1309 | return i; | |
1310 | } | |
1311 | mutex_unlock(&cpuhp_state_mutex); | |
1312 | WARN(1, "No more dynamic states available for CPU hotplug\n"); | |
1313 | return -ENOSPC; | |
1314 | } | |
1315 | ||
1316 | /** | |
1317 | * __cpuhp_setup_state - Setup the callbacks for an hotplug machine state | |
1318 | * @state: The state to setup | |
1319 | * @invoke: If true, the startup function is invoked for cpus where | |
1320 | * cpu state >= @state | |
1321 | * @startup: startup callback function | |
1322 | * @teardown: teardown callback function | |
1323 | * | |
1324 | * Returns 0 if successful, otherwise a proper error code | |
1325 | */ | |
1326 | int __cpuhp_setup_state(enum cpuhp_state state, | |
1327 | const char *name, bool invoke, | |
1328 | int (*startup)(unsigned int cpu), | |
1329 | int (*teardown)(unsigned int cpu)) | |
1330 | { | |
1331 | int cpu, ret = 0; | |
1332 | int dyn_state = 0; | |
1333 | ||
1334 | if (cpuhp_cb_check(state) || !name) | |
1335 | return -EINVAL; | |
1336 | ||
1337 | get_online_cpus(); | |
1338 | ||
1339 | /* currently assignments for the ONLINE state are possible */ | |
1cf4f629 | 1340 | if (state == CPUHP_AP_ONLINE_DYN) { |
5b7aa87e TG |
1341 | dyn_state = 1; |
1342 | ret = cpuhp_reserve_state(state); | |
1343 | if (ret < 0) | |
1344 | goto out; | |
1345 | state = ret; | |
1346 | } | |
1347 | ||
1348 | cpuhp_store_callbacks(state, name, startup, teardown); | |
1349 | ||
1350 | if (!invoke || !startup) | |
1351 | goto out; | |
1352 | ||
1353 | /* | |
1354 | * Try to call the startup callback for each present cpu | |
1355 | * depending on the hotplug state of the cpu. | |
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 | continue; | |
1363 | ||
1364 | ret = cpuhp_issue_call(cpu, state, startup, true); | |
1365 | if (ret) { | |
1366 | cpuhp_rollback_install(cpu, state, teardown); | |
1367 | cpuhp_store_callbacks(state, NULL, NULL, NULL); | |
1368 | goto out; | |
1369 | } | |
1370 | } | |
1371 | out: | |
1372 | put_online_cpus(); | |
1373 | if (!ret && dyn_state) | |
1374 | return state; | |
1375 | return ret; | |
1376 | } | |
1377 | EXPORT_SYMBOL(__cpuhp_setup_state); | |
1378 | ||
1379 | /** | |
1380 | * __cpuhp_remove_state - Remove the callbacks for an hotplug machine state | |
1381 | * @state: The state to remove | |
1382 | * @invoke: If true, the teardown function is invoked for cpus where | |
1383 | * cpu state >= @state | |
1384 | * | |
1385 | * The teardown callback is currently not allowed to fail. Think | |
1386 | * about module removal! | |
1387 | */ | |
1388 | void __cpuhp_remove_state(enum cpuhp_state state, bool invoke) | |
1389 | { | |
1390 | int (*teardown)(unsigned int cpu) = cpuhp_get_teardown_cb(state); | |
1391 | int cpu; | |
1392 | ||
1393 | BUG_ON(cpuhp_cb_check(state)); | |
1394 | ||
1395 | get_online_cpus(); | |
1396 | ||
1397 | if (!invoke || !teardown) | |
1398 | goto remove; | |
1399 | ||
1400 | /* | |
1401 | * Call the teardown callback for each present cpu depending | |
1402 | * on the hotplug state of the cpu. This function is not | |
1403 | * allowed to fail currently! | |
1404 | */ | |
1405 | for_each_present_cpu(cpu) { | |
1406 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); | |
1407 | int cpustate = st->state; | |
1408 | ||
1409 | if (cpustate >= state) | |
1410 | cpuhp_issue_call(cpu, state, teardown, false); | |
1411 | } | |
1412 | remove: | |
1413 | cpuhp_store_callbacks(state, NULL, NULL, NULL); | |
1414 | put_online_cpus(); | |
1415 | } | |
1416 | EXPORT_SYMBOL(__cpuhp_remove_state); | |
1417 | ||
98f8cdce TG |
1418 | #if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU) |
1419 | static ssize_t show_cpuhp_state(struct device *dev, | |
1420 | struct device_attribute *attr, char *buf) | |
1421 | { | |
1422 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); | |
1423 | ||
1424 | return sprintf(buf, "%d\n", st->state); | |
1425 | } | |
1426 | static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL); | |
1427 | ||
757c989b TG |
1428 | static ssize_t write_cpuhp_target(struct device *dev, |
1429 | struct device_attribute *attr, | |
1430 | const char *buf, size_t count) | |
1431 | { | |
1432 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); | |
1433 | struct cpuhp_step *sp; | |
1434 | int target, ret; | |
1435 | ||
1436 | ret = kstrtoint(buf, 10, &target); | |
1437 | if (ret) | |
1438 | return ret; | |
1439 | ||
1440 | #ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL | |
1441 | if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE) | |
1442 | return -EINVAL; | |
1443 | #else | |
1444 | if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE) | |
1445 | return -EINVAL; | |
1446 | #endif | |
1447 | ||
1448 | ret = lock_device_hotplug_sysfs(); | |
1449 | if (ret) | |
1450 | return ret; | |
1451 | ||
1452 | mutex_lock(&cpuhp_state_mutex); | |
1453 | sp = cpuhp_get_step(target); | |
1454 | ret = !sp->name || sp->cant_stop ? -EINVAL : 0; | |
1455 | mutex_unlock(&cpuhp_state_mutex); | |
1456 | if (ret) | |
1457 | return ret; | |
1458 | ||
1459 | if (st->state < target) | |
1460 | ret = do_cpu_up(dev->id, target); | |
1461 | else | |
1462 | ret = do_cpu_down(dev->id, target); | |
1463 | ||
1464 | unlock_device_hotplug(); | |
1465 | return ret ? ret : count; | |
1466 | } | |
1467 | ||
98f8cdce TG |
1468 | static ssize_t show_cpuhp_target(struct device *dev, |
1469 | struct device_attribute *attr, char *buf) | |
1470 | { | |
1471 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); | |
1472 | ||
1473 | return sprintf(buf, "%d\n", st->target); | |
1474 | } | |
757c989b | 1475 | static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target); |
98f8cdce TG |
1476 | |
1477 | static struct attribute *cpuhp_cpu_attrs[] = { | |
1478 | &dev_attr_state.attr, | |
1479 | &dev_attr_target.attr, | |
1480 | NULL | |
1481 | }; | |
1482 | ||
1483 | static struct attribute_group cpuhp_cpu_attr_group = { | |
1484 | .attrs = cpuhp_cpu_attrs, | |
1485 | .name = "hotplug", | |
1486 | NULL | |
1487 | }; | |
1488 | ||
1489 | static ssize_t show_cpuhp_states(struct device *dev, | |
1490 | struct device_attribute *attr, char *buf) | |
1491 | { | |
1492 | ssize_t cur, res = 0; | |
1493 | int i; | |
1494 | ||
1495 | mutex_lock(&cpuhp_state_mutex); | |
757c989b | 1496 | for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) { |
98f8cdce TG |
1497 | struct cpuhp_step *sp = cpuhp_get_step(i); |
1498 | ||
1499 | if (sp->name) { | |
1500 | cur = sprintf(buf, "%3d: %s\n", i, sp->name); | |
1501 | buf += cur; | |
1502 | res += cur; | |
1503 | } | |
1504 | } | |
1505 | mutex_unlock(&cpuhp_state_mutex); | |
1506 | return res; | |
1507 | } | |
1508 | static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL); | |
1509 | ||
1510 | static struct attribute *cpuhp_cpu_root_attrs[] = { | |
1511 | &dev_attr_states.attr, | |
1512 | NULL | |
1513 | }; | |
1514 | ||
1515 | static struct attribute_group cpuhp_cpu_root_attr_group = { | |
1516 | .attrs = cpuhp_cpu_root_attrs, | |
1517 | .name = "hotplug", | |
1518 | NULL | |
1519 | }; | |
1520 | ||
1521 | static int __init cpuhp_sysfs_init(void) | |
1522 | { | |
1523 | int cpu, ret; | |
1524 | ||
1525 | ret = sysfs_create_group(&cpu_subsys.dev_root->kobj, | |
1526 | &cpuhp_cpu_root_attr_group); | |
1527 | if (ret) | |
1528 | return ret; | |
1529 | ||
1530 | for_each_possible_cpu(cpu) { | |
1531 | struct device *dev = get_cpu_device(cpu); | |
1532 | ||
1533 | if (!dev) | |
1534 | continue; | |
1535 | ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group); | |
1536 | if (ret) | |
1537 | return ret; | |
1538 | } | |
1539 | return 0; | |
1540 | } | |
1541 | device_initcall(cpuhp_sysfs_init); | |
1542 | #endif | |
1543 | ||
e56b3bc7 LT |
1544 | /* |
1545 | * cpu_bit_bitmap[] is a special, "compressed" data structure that | |
1546 | * represents all NR_CPUS bits binary values of 1<<nr. | |
1547 | * | |
e0b582ec | 1548 | * It is used by cpumask_of() to get a constant address to a CPU |
e56b3bc7 LT |
1549 | * mask value that has a single bit set only. |
1550 | */ | |
b8d317d1 | 1551 | |
e56b3bc7 | 1552 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
4d51985e | 1553 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
e56b3bc7 LT |
1554 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
1555 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) | |
1556 | #define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4) | |
b8d317d1 | 1557 | |
e56b3bc7 LT |
1558 | const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { |
1559 | ||
1560 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), | |
1561 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), | |
1562 | #if BITS_PER_LONG > 32 | |
1563 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), | |
1564 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), | |
b8d317d1 MT |
1565 | #endif |
1566 | }; | |
e56b3bc7 | 1567 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
2d3854a3 RR |
1568 | |
1569 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; | |
1570 | EXPORT_SYMBOL(cpu_all_bits); | |
b3199c02 RR |
1571 | |
1572 | #ifdef CONFIG_INIT_ALL_POSSIBLE | |
4b804c85 | 1573 | struct cpumask __cpu_possible_mask __read_mostly |
c4c54dd1 | 1574 | = {CPU_BITS_ALL}; |
b3199c02 | 1575 | #else |
4b804c85 | 1576 | struct cpumask __cpu_possible_mask __read_mostly; |
b3199c02 | 1577 | #endif |
4b804c85 | 1578 | EXPORT_SYMBOL(__cpu_possible_mask); |
b3199c02 | 1579 | |
4b804c85 RV |
1580 | struct cpumask __cpu_online_mask __read_mostly; |
1581 | EXPORT_SYMBOL(__cpu_online_mask); | |
b3199c02 | 1582 | |
4b804c85 RV |
1583 | struct cpumask __cpu_present_mask __read_mostly; |
1584 | EXPORT_SYMBOL(__cpu_present_mask); | |
b3199c02 | 1585 | |
4b804c85 RV |
1586 | struct cpumask __cpu_active_mask __read_mostly; |
1587 | EXPORT_SYMBOL(__cpu_active_mask); | |
3fa41520 | 1588 | |
3fa41520 RR |
1589 | void init_cpu_present(const struct cpumask *src) |
1590 | { | |
c4c54dd1 | 1591 | cpumask_copy(&__cpu_present_mask, src); |
3fa41520 RR |
1592 | } |
1593 | ||
1594 | void init_cpu_possible(const struct cpumask *src) | |
1595 | { | |
c4c54dd1 | 1596 | cpumask_copy(&__cpu_possible_mask, src); |
3fa41520 RR |
1597 | } |
1598 | ||
1599 | void init_cpu_online(const struct cpumask *src) | |
1600 | { | |
c4c54dd1 | 1601 | cpumask_copy(&__cpu_online_mask, src); |
3fa41520 | 1602 | } |
cff7d378 TG |
1603 | |
1604 | /* | |
1605 | * Activate the first processor. | |
1606 | */ | |
1607 | void __init boot_cpu_init(void) | |
1608 | { | |
1609 | int cpu = smp_processor_id(); | |
1610 | ||
1611 | /* Mark the boot cpu "present", "online" etc for SMP and UP case */ | |
1612 | set_cpu_online(cpu, true); | |
1613 | set_cpu_active(cpu, true); | |
1614 | set_cpu_present(cpu, true); | |
1615 | set_cpu_possible(cpu, true); | |
1616 | } | |
1617 | ||
1618 | /* | |
1619 | * Must be called _AFTER_ setting up the per_cpu areas | |
1620 | */ | |
1621 | void __init boot_cpu_state_init(void) | |
1622 | { | |
1623 | per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE; | |
1624 | } |