Root/
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 | } |
723 |
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