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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> | |
13 | #include <linux/oom.h> | |
14 | #include <linux/rcupdate.h> | |
15 | #include <linux/export.h> | |
16 | #include <linux/bug.h> | |
17 | #include <linux/kthread.h> | |
18 | #include <linux/stop_machine.h> | |
19 | #include <linux/mutex.h> | |
20 | #include <linux/gfp.h> | |
21 | #include <linux/suspend.h> | |
22 | ||
23 | #include "smpboot.h" | |
24 | ||
25 | #ifdef CONFIG_SMP | |
26 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ | |
27 | static DEFINE_MUTEX(cpu_add_remove_lock); | |
28 | ||
29 | /* | |
30 | * The following two API's must be used when attempting | |
31 | * to serialize the updates to cpu_online_mask, cpu_present_mask. | |
32 | */ | |
33 | void cpu_maps_update_begin(void) | |
34 | { | |
35 | mutex_lock(&cpu_add_remove_lock); | |
36 | } | |
37 | ||
38 | void cpu_maps_update_done(void) | |
39 | { | |
40 | mutex_unlock(&cpu_add_remove_lock); | |
41 | } | |
42 | ||
43 | static RAW_NOTIFIER_HEAD(cpu_chain); | |
44 | ||
45 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. | |
46 | * Should always be manipulated under cpu_add_remove_lock | |
47 | */ | |
48 | static int cpu_hotplug_disabled; | |
49 | ||
50 | #ifdef CONFIG_HOTPLUG_CPU | |
51 | ||
52 | static struct { | |
53 | struct task_struct *active_writer; | |
54 | struct mutex lock; /* Synchronizes accesses to refcount, */ | |
55 | /* | |
56 | * Also blocks the new readers during | |
57 | * an ongoing cpu hotplug operation. | |
58 | */ | |
59 | int refcount; | |
60 | } cpu_hotplug = { | |
61 | .active_writer = NULL, | |
62 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), | |
63 | .refcount = 0, | |
64 | }; | |
65 | ||
66 | void get_online_cpus(void) | |
67 | { | |
68 | might_sleep(); | |
69 | if (cpu_hotplug.active_writer == current) | |
70 | return; | |
71 | mutex_lock(&cpu_hotplug.lock); | |
72 | cpu_hotplug.refcount++; | |
73 | mutex_unlock(&cpu_hotplug.lock); | |
74 | ||
75 | } | |
76 | EXPORT_SYMBOL_GPL(get_online_cpus); | |
77 | ||
78 | void put_online_cpus(void) | |
79 | { | |
80 | if (cpu_hotplug.active_writer == current) | |
81 | return; | |
82 | mutex_lock(&cpu_hotplug.lock); | |
83 | ||
84 | if (WARN_ON(!cpu_hotplug.refcount)) | |
85 | cpu_hotplug.refcount++; /* try to fix things up */ | |
86 | ||
87 | if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer)) | |
88 | wake_up_process(cpu_hotplug.active_writer); | |
89 | mutex_unlock(&cpu_hotplug.lock); | |
90 | ||
91 | } | |
92 | EXPORT_SYMBOL_GPL(put_online_cpus); | |
93 | ||
94 | /* | |
95 | * This ensures that the hotplug operation can begin only when the | |
96 | * refcount goes to zero. | |
97 | * | |
98 | * Note that during a cpu-hotplug operation, the new readers, if any, | |
99 | * will be blocked by the cpu_hotplug.lock | |
100 | * | |
101 | * Since cpu_hotplug_begin() is always called after invoking | |
102 | * cpu_maps_update_begin(), we can be sure that only one writer is active. | |
103 | * | |
104 | * Note that theoretically, there is a possibility of a livelock: | |
105 | * - Refcount goes to zero, last reader wakes up the sleeping | |
106 | * writer. | |
107 | * - Last reader unlocks the cpu_hotplug.lock. | |
108 | * - A new reader arrives at this moment, bumps up the refcount. | |
109 | * - The writer acquires the cpu_hotplug.lock finds the refcount | |
110 | * non zero and goes to sleep again. | |
111 | * | |
112 | * However, this is very difficult to achieve in practice since | |
113 | * get_online_cpus() not an api which is called all that often. | |
114 | * | |
115 | */ | |
116 | void cpu_hotplug_begin(void) | |
117 | { | |
118 | cpu_hotplug.active_writer = current; | |
119 | ||
120 | for (;;) { | |
121 | mutex_lock(&cpu_hotplug.lock); | |
122 | if (likely(!cpu_hotplug.refcount)) | |
123 | break; | |
124 | __set_current_state(TASK_UNINTERRUPTIBLE); | |
125 | mutex_unlock(&cpu_hotplug.lock); | |
126 | schedule(); | |
127 | } | |
128 | } | |
129 | ||
130 | void cpu_hotplug_done(void) | |
131 | { | |
132 | cpu_hotplug.active_writer = NULL; | |
133 | mutex_unlock(&cpu_hotplug.lock); | |
134 | } | |
135 | ||
136 | /* | |
137 | * Wait for currently running CPU hotplug operations to complete (if any) and | |
138 | * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects | |
139 | * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the | |
140 | * hotplug path before performing hotplug operations. So acquiring that lock | |
141 | * guarantees mutual exclusion from any currently running hotplug operations. | |
142 | */ | |
143 | void cpu_hotplug_disable(void) | |
144 | { | |
145 | cpu_maps_update_begin(); | |
146 | cpu_hotplug_disabled = 1; | |
147 | cpu_maps_update_done(); | |
148 | } | |
149 | ||
150 | void cpu_hotplug_enable(void) | |
151 | { | |
152 | cpu_maps_update_begin(); | |
153 | cpu_hotplug_disabled = 0; | |
154 | cpu_maps_update_done(); | |
155 | } | |
156 | ||
157 | #endif /* CONFIG_HOTPLUG_CPU */ | |
158 | ||
159 | /* Need to know about CPUs going up/down? */ | |
160 | int __ref register_cpu_notifier(struct notifier_block *nb) | |
161 | { | |
162 | int ret; | |
163 | cpu_maps_update_begin(); | |
164 | ret = raw_notifier_chain_register(&cpu_chain, nb); | |
165 | cpu_maps_update_done(); | |
166 | return ret; | |
167 | } | |
168 | ||
169 | static int __cpu_notify(unsigned long val, void *v, int nr_to_call, | |
170 | int *nr_calls) | |
171 | { | |
172 | int ret; | |
173 | ||
174 | ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call, | |
175 | nr_calls); | |
176 | ||
177 | return notifier_to_errno(ret); | |
178 | } | |
179 | ||
180 | static int cpu_notify(unsigned long val, void *v) | |
181 | { | |
182 | return __cpu_notify(val, v, -1, NULL); | |
183 | } | |
184 | ||
185 | #ifdef CONFIG_HOTPLUG_CPU | |
186 | ||
187 | static void cpu_notify_nofail(unsigned long val, void *v) | |
188 | { | |
189 | BUG_ON(cpu_notify(val, v)); | |
190 | } | |
191 | EXPORT_SYMBOL(register_cpu_notifier); | |
192 | ||
193 | void __ref unregister_cpu_notifier(struct notifier_block *nb) | |
194 | { | |
195 | cpu_maps_update_begin(); | |
196 | raw_notifier_chain_unregister(&cpu_chain, nb); | |
197 | cpu_maps_update_done(); | |
198 | } | |
199 | EXPORT_SYMBOL(unregister_cpu_notifier); | |
200 | ||
201 | /** | |
202 | * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU | |
203 | * @cpu: a CPU id | |
204 | * | |
205 | * This function walks all processes, finds a valid mm struct for each one and | |
206 | * then clears a corresponding bit in mm's cpumask. While this all sounds | |
207 | * trivial, there are various non-obvious corner cases, which this function | |
208 | * tries to solve in a safe manner. | |
209 | * | |
210 | * Also note that the function uses a somewhat relaxed locking scheme, so it may | |
211 | * be called only for an already offlined CPU. | |
212 | */ | |
213 | void clear_tasks_mm_cpumask(int cpu) | |
214 | { | |
215 | struct task_struct *p; | |
216 | ||
217 | /* | |
218 | * This function is called after the cpu is taken down and marked | |
219 | * offline, so its not like new tasks will ever get this cpu set in | |
220 | * their mm mask. -- Peter Zijlstra | |
221 | * Thus, we may use rcu_read_lock() here, instead of grabbing | |
222 | * full-fledged tasklist_lock. | |
223 | */ | |
224 | WARN_ON(cpu_online(cpu)); | |
225 | rcu_read_lock(); | |
226 | for_each_process(p) { | |
227 | struct task_struct *t; | |
228 | ||
229 | /* | |
230 | * Main thread might exit, but other threads may still have | |
231 | * a valid mm. Find one. | |
232 | */ | |
233 | t = find_lock_task_mm(p); | |
234 | if (!t) | |
235 | continue; | |
236 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); | |
237 | task_unlock(t); | |
238 | } | |
239 | rcu_read_unlock(); | |
240 | } | |
241 | ||
242 | static inline void check_for_tasks(int cpu) | |
243 | { | |
244 | struct task_struct *p; | |
245 | cputime_t utime, stime; | |
246 | ||
247 | write_lock_irq(&tasklist_lock); | |
248 | for_each_process(p) { | |
249 | task_cputime(p, &utime, &stime); | |
250 | if (task_cpu(p) == cpu && p->state == TASK_RUNNING && | |
251 | (utime || stime)) | |
252 | printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d " | |
253 | "(state = %ld, flags = %x)\n", | |
254 | p->comm, task_pid_nr(p), cpu, | |
255 | p->state, p->flags); | |
256 | } | |
257 | write_unlock_irq(&tasklist_lock); | |
258 | } | |
259 | ||
260 | struct take_cpu_down_param { | |
261 | unsigned long mod; | |
262 | void *hcpu; | |
263 | }; | |
264 | ||
265 | /* Take this CPU down. */ | |
266 | static int __ref take_cpu_down(void *_param) | |
267 | { | |
268 | struct take_cpu_down_param *param = _param; | |
269 | int err; | |
270 | ||
271 | /* Ensure this CPU doesn't handle any more interrupts. */ | |
272 | err = __cpu_disable(); | |
273 | if (err < 0) | |
274 | return err; | |
275 | ||
276 | cpu_notify(CPU_DYING | param->mod, param->hcpu); | |
277 | /* Park the stopper thread */ | |
278 | kthread_park(current); | |
279 | return 0; | |
280 | } | |
281 | ||
282 | /* Requires cpu_add_remove_lock to be held */ | |
283 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) | |
284 | { | |
285 | int err, nr_calls = 0; | |
286 | void *hcpu = (void *)(long)cpu; | |
287 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; | |
288 | struct take_cpu_down_param tcd_param = { | |
289 | .mod = mod, | |
290 | .hcpu = hcpu, | |
291 | }; | |
292 | ||
293 | if (num_online_cpus() == 1) | |
294 | return -EBUSY; | |
295 | ||
296 | if (!cpu_online(cpu)) | |
297 | return -EINVAL; | |
298 | ||
299 | cpu_hotplug_begin(); | |
300 | ||
301 | err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls); | |
302 | if (err) { | |
303 | nr_calls--; | |
304 | __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL); | |
305 | printk("%s: attempt to take down CPU %u failed\n", | |
306 | __func__, cpu); | |
307 | goto out_release; | |
308 | } | |
309 | ||
310 | /* | |
311 | * By now we've cleared cpu_active_mask, wait for all preempt-disabled | |
312 | * and RCU users of this state to go away such that all new such users | |
313 | * will observe it. | |
314 | * | |
315 | * For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might | |
316 | * not imply sync_sched(), so explicitly call both. | |
317 | * | |
318 | * Do sync before park smpboot threads to take care the rcu boost case. | |
319 | */ | |
320 | #ifdef CONFIG_PREEMPT | |
321 | synchronize_sched(); | |
322 | #endif | |
323 | synchronize_rcu(); | |
324 | ||
325 | smpboot_park_threads(cpu); | |
326 | ||
327 | /* | |
328 | * So now all preempt/rcu users must observe !cpu_active(). | |
329 | */ | |
330 | ||
331 | err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); | |
332 | if (err) { | |
333 | /* CPU didn't die: tell everyone. Can't complain. */ | |
334 | smpboot_unpark_threads(cpu); | |
335 | cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu); | |
336 | goto out_release; | |
337 | } | |
338 | BUG_ON(cpu_online(cpu)); | |
339 | ||
340 | /* | |
341 | * The migration_call() CPU_DYING callback will have removed all | |
342 | * runnable tasks from the cpu, there's only the idle task left now | |
343 | * that the migration thread is done doing the stop_machine thing. | |
344 | * | |
345 | * Wait for the stop thread to go away. | |
346 | */ | |
347 | while (!idle_cpu(cpu)) | |
348 | cpu_relax(); | |
349 | ||
350 | /* This actually kills the CPU. */ | |
351 | __cpu_die(cpu); | |
352 | ||
353 | /* CPU is completely dead: tell everyone. Too late to complain. */ | |
354 | cpu_notify_nofail(CPU_DEAD | mod, hcpu); | |
355 | ||
356 | check_for_tasks(cpu); | |
357 | ||
358 | out_release: | |
359 | cpu_hotplug_done(); | |
360 | if (!err) | |
361 | cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu); | |
362 | return err; | |
363 | } | |
364 | ||
365 | int __ref cpu_down(unsigned int cpu) | |
366 | { | |
367 | int err; | |
368 | ||
369 | cpu_maps_update_begin(); | |
370 | ||
371 | if (cpu_hotplug_disabled) { | |
372 | err = -EBUSY; | |
373 | goto out; | |
374 | } | |
375 | ||
376 | err = _cpu_down(cpu, 0); | |
377 | ||
378 | out: | |
379 | cpu_maps_update_done(); | |
380 | return err; | |
381 | } | |
382 | EXPORT_SYMBOL(cpu_down); | |
383 | #endif /*CONFIG_HOTPLUG_CPU*/ | |
384 | ||
385 | /* Requires cpu_add_remove_lock to be held */ | |
386 | static int _cpu_up(unsigned int cpu, int tasks_frozen) | |
387 | { | |
388 | int ret, nr_calls = 0; | |
389 | void *hcpu = (void *)(long)cpu; | |
390 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; | |
391 | struct task_struct *idle; | |
392 | ||
393 | cpu_hotplug_begin(); | |
394 | ||
395 | if (cpu_online(cpu) || !cpu_present(cpu)) { | |
396 | ret = -EINVAL; | |
397 | goto out; | |
398 | } | |
399 | ||
400 | idle = idle_thread_get(cpu); | |
401 | if (IS_ERR(idle)) { | |
402 | ret = PTR_ERR(idle); | |
403 | goto out; | |
404 | } | |
405 | ||
406 | ret = smpboot_create_threads(cpu); | |
407 | if (ret) | |
408 | goto out; | |
409 | ||
410 | ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls); | |
411 | if (ret) { | |
412 | nr_calls--; | |
413 | printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", | |
414 | __func__, cpu); | |
415 | goto out_notify; | |
416 | } | |
417 | ||
418 | /* Arch-specific enabling code. */ | |
419 | ret = __cpu_up(cpu, idle); | |
420 | if (ret != 0) | |
421 | goto out_notify; | |
422 | BUG_ON(!cpu_online(cpu)); | |
423 | ||
424 | /* Wake the per cpu threads */ | |
425 | smpboot_unpark_threads(cpu); | |
426 | ||
427 | /* Now call notifier in preparation. */ | |
428 | cpu_notify(CPU_ONLINE | mod, hcpu); | |
429 | ||
430 | out_notify: | |
431 | if (ret != 0) | |
432 | __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL); | |
433 | out: | |
434 | cpu_hotplug_done(); | |
435 | ||
436 | return ret; | |
437 | } | |
438 | ||
439 | int cpu_up(unsigned int cpu) | |
440 | { | |
441 | int err = 0; | |
442 | ||
443 | if (!cpu_possible(cpu)) { | |
444 | printk(KERN_ERR "can't online cpu %d because it is not " | |
445 | "configured as may-hotadd at boot time\n", cpu); | |
446 | #if defined(CONFIG_IA64) | |
447 | printk(KERN_ERR "please check additional_cpus= boot " | |
448 | "parameter\n"); | |
449 | #endif | |
450 | return -EINVAL; | |
451 | } | |
452 | ||
453 | err = try_online_node(cpu_to_node(cpu)); | |
454 | if (err) | |
455 | return err; | |
456 | ||
457 | cpu_maps_update_begin(); | |
458 | ||
459 | if (cpu_hotplug_disabled) { | |
460 | err = -EBUSY; | |
461 | goto out; | |
462 | } | |
463 | ||
464 | err = _cpu_up(cpu, 0); | |
465 | ||
466 | out: | |
467 | cpu_maps_update_done(); | |
468 | return err; | |
469 | } | |
470 | EXPORT_SYMBOL_GPL(cpu_up); | |
471 | ||
472 | #ifdef CONFIG_PM_SLEEP_SMP | |
473 | static cpumask_var_t frozen_cpus; | |
474 | ||
475 | int disable_nonboot_cpus(void) | |
476 | { | |
477 | int cpu, first_cpu, error = 0; | |
478 | ||
479 | cpu_maps_update_begin(); | |
480 | first_cpu = cpumask_first(cpu_online_mask); | |
481 | /* | |
482 | * We take down all of the non-boot CPUs in one shot to avoid races | |
483 | * with the userspace trying to use the CPU hotplug at the same time | |
484 | */ | |
485 | cpumask_clear(frozen_cpus); | |
486 | ||
487 | printk("Disabling non-boot CPUs ...\n"); | |
488 | for_each_online_cpu(cpu) { | |
489 | if (cpu == first_cpu) | |
490 | continue; | |
491 | error = _cpu_down(cpu, 1); | |
492 | if (!error) | |
493 | cpumask_set_cpu(cpu, frozen_cpus); | |
494 | else { | |
495 | printk(KERN_ERR "Error taking CPU%d down: %d\n", | |
496 | cpu, error); | |
497 | break; | |
498 | } | |
499 | } | |
500 | ||
501 | if (!error) { | |
502 | BUG_ON(num_online_cpus() > 1); | |
503 | /* Make sure the CPUs won't be enabled by someone else */ | |
504 | cpu_hotplug_disabled = 1; | |
505 | } else { | |
506 | printk(KERN_ERR "Non-boot CPUs are not disabled\n"); | |
507 | } | |
508 | cpu_maps_update_done(); | |
509 | return error; | |
510 | } | |
511 | ||
512 | void __weak arch_enable_nonboot_cpus_begin(void) | |
513 | { | |
514 | } | |
515 | ||
516 | void __weak arch_enable_nonboot_cpus_end(void) | |
517 | { | |
518 | } | |
519 | ||
520 | void __ref enable_nonboot_cpus(void) | |
521 | { | |
522 | int cpu, error; | |
523 | ||
524 | /* Allow everyone to use the CPU hotplug again */ | |
525 | cpu_maps_update_begin(); | |
526 | cpu_hotplug_disabled = 0; | |
527 | if (cpumask_empty(frozen_cpus)) | |
528 | goto out; | |
529 | ||
530 | printk(KERN_INFO "Enabling non-boot CPUs ...\n"); | |
531 | ||
532 | arch_enable_nonboot_cpus_begin(); | |
533 | ||
534 | for_each_cpu(cpu, frozen_cpus) { | |
535 | error = _cpu_up(cpu, 1); | |
536 | if (!error) { | |
537 | printk(KERN_INFO "CPU%d is up\n", cpu); | |
538 | continue; | |
539 | } | |
540 | printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error); | |
541 | } | |
542 | ||
543 | arch_enable_nonboot_cpus_end(); | |
544 | ||
545 | cpumask_clear(frozen_cpus); | |
546 | out: | |
547 | cpu_maps_update_done(); | |
548 | } | |
549 | ||
550 | static int __init alloc_frozen_cpus(void) | |
551 | { | |
552 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) | |
553 | return -ENOMEM; | |
554 | return 0; | |
555 | } | |
556 | core_initcall(alloc_frozen_cpus); | |
557 | ||
558 | /* | |
559 | * When callbacks for CPU hotplug notifications are being executed, we must | |
560 | * ensure that the state of the system with respect to the tasks being frozen | |
561 | * or not, as reported by the notification, remains unchanged *throughout the | |
562 | * duration* of the execution of the callbacks. | |
563 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. | |
564 | * | |
565 | * This synchronization is implemented by mutually excluding regular CPU | |
566 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ | |
567 | * Hibernate notifications. | |
568 | */ | |
569 | static int | |
570 | cpu_hotplug_pm_callback(struct notifier_block *nb, | |
571 | unsigned long action, void *ptr) | |
572 | { | |
573 | switch (action) { | |
574 | ||
575 | case PM_SUSPEND_PREPARE: | |
576 | case PM_HIBERNATION_PREPARE: | |
577 | cpu_hotplug_disable(); | |
578 | break; | |
579 | ||
580 | case PM_POST_SUSPEND: | |
581 | case PM_POST_HIBERNATION: | |
582 | cpu_hotplug_enable(); | |
583 | break; | |
584 | ||
585 | default: | |
586 | return NOTIFY_DONE; | |
587 | } | |
588 | ||
589 | return NOTIFY_OK; | |
590 | } | |
591 | ||
592 | ||
593 | static int __init cpu_hotplug_pm_sync_init(void) | |
594 | { | |
595 | /* | |
596 | * cpu_hotplug_pm_callback has higher priority than x86 | |
597 | * bsp_pm_callback which depends on cpu_hotplug_pm_callback | |
598 | * to disable cpu hotplug to avoid cpu hotplug race. | |
599 | */ | |
600 | pm_notifier(cpu_hotplug_pm_callback, 0); | |
601 | return 0; | |
602 | } | |
603 | core_initcall(cpu_hotplug_pm_sync_init); | |
604 | ||
605 | #endif /* CONFIG_PM_SLEEP_SMP */ | |
606 | ||
607 | /** | |
608 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers | |
609 | * @cpu: cpu that just started | |
610 | * | |
611 | * This function calls the cpu_chain notifiers with CPU_STARTING. | |
612 | * It must be called by the arch code on the new cpu, before the new cpu | |
613 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). | |
614 | */ | |
615 | void notify_cpu_starting(unsigned int cpu) | |
616 | { | |
617 | unsigned long val = CPU_STARTING; | |
618 | ||
619 | #ifdef CONFIG_PM_SLEEP_SMP | |
620 | if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus)) | |
621 | val = CPU_STARTING_FROZEN; | |
622 | #endif /* CONFIG_PM_SLEEP_SMP */ | |
623 | cpu_notify(val, (void *)(long)cpu); | |
624 | } | |
625 | ||
626 | #endif /* CONFIG_SMP */ | |
627 | ||
628 | /* | |
629 | * cpu_bit_bitmap[] is a special, "compressed" data structure that | |
630 | * represents all NR_CPUS bits binary values of 1<<nr. | |
631 | * | |
632 | * It is used by cpumask_of() to get a constant address to a CPU | |
633 | * mask value that has a single bit set only. | |
634 | */ | |
635 | ||
636 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ | |
637 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) | |
638 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) | |
639 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) | |
640 | #define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4) | |
641 | ||
642 | const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { | |
643 | ||
644 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), | |
645 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), | |
646 | #if BITS_PER_LONG > 32 | |
647 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), | |
648 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), | |
649 | #endif | |
650 | }; | |
651 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); | |
652 | ||
653 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; | |
654 | EXPORT_SYMBOL(cpu_all_bits); | |
655 | ||
656 | #ifdef CONFIG_INIT_ALL_POSSIBLE | |
657 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly | |
658 | = CPU_BITS_ALL; | |
659 | #else | |
660 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly; | |
661 | #endif | |
662 | const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits); | |
663 | EXPORT_SYMBOL(cpu_possible_mask); | |
664 | ||
665 | static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly; | |
666 | const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits); | |
667 | EXPORT_SYMBOL(cpu_online_mask); | |
668 | ||
669 | static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly; | |
670 | const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits); | |
671 | EXPORT_SYMBOL(cpu_present_mask); | |
672 | ||
673 | static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly; | |
674 | const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits); | |
675 | EXPORT_SYMBOL(cpu_active_mask); | |
676 | ||
677 | void set_cpu_possible(unsigned int cpu, bool possible) | |
678 | { | |
679 | if (possible) | |
680 | cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits)); | |
681 | else | |
682 | cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits)); | |
683 | } | |
684 | ||
685 | void set_cpu_present(unsigned int cpu, bool present) | |
686 | { | |
687 | if (present) | |
688 | cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits)); | |
689 | else | |
690 | cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits)); | |
691 | } | |
692 | ||
693 | void set_cpu_online(unsigned int cpu, bool online) | |
694 | { | |
695 | if (online) | |
696 | cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits)); | |
697 | else | |
698 | cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits)); | |
699 | } | |
700 | ||
701 | void set_cpu_active(unsigned int cpu, bool active) | |
702 | { | |
703 | if (active) | |
704 | cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); | |
705 | else | |
706 | cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits)); | |
707 | } | |
708 | ||
709 | void init_cpu_present(const struct cpumask *src) | |
710 | { | |
711 | cpumask_copy(to_cpumask(cpu_present_bits), src); | |
712 | } | |
713 | ||
714 | void init_cpu_possible(const struct cpumask *src) | |
715 | { | |
716 | cpumask_copy(to_cpumask(cpu_possible_bits), src); | |
717 | } | |
718 | ||
719 | void init_cpu_online(const struct cpumask *src) | |
720 | { | |
721 | cpumask_copy(to_cpumask(cpu_online_bits), src); | |
722 | } |