projects/linux·blob v4.2-rc1 · refs

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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#include <linux/lockdep.h>
23#include <linux/tick.h>
24#include <trace/events/power.h>
25
26#include "smpboot.h"
27
28#ifdef CONFIG_SMP
29/* Serializes the updates to cpu_online_mask, cpu_present_mask */
30static DEFINE_MUTEX(cpu_add_remove_lock);
31
32/*
33 * The following two APIs (cpu_maps_update_begin/done) must be used when
34 * attempting to serialize the updates to cpu_online_mask & cpu_present_mask.
35 * The APIs cpu_notifier_register_begin/done() must be used to protect CPU
36 * hotplug callback (un)registration performed using __register_cpu_notifier()
37 * or __unregister_cpu_notifier().
38 */
39void cpu_maps_update_begin(void)
40{
41 mutex_lock(&cpu_add_remove_lock);
42}
43EXPORT_SYMBOL(cpu_notifier_register_begin);
44
45void cpu_maps_update_done(void)
46{
47 mutex_unlock(&cpu_add_remove_lock);
48}
49EXPORT_SYMBOL(cpu_notifier_register_done);
50
51static RAW_NOTIFIER_HEAD(cpu_chain);
52
53/* If set, cpu_up and cpu_down will return -EBUSY and do nothing.
54 * Should always be manipulated under cpu_add_remove_lock
55 */
56static int cpu_hotplug_disabled;
57
58#ifdef CONFIG_HOTPLUG_CPU
59
60static struct {
61 struct task_struct *active_writer;
62 /* wait queue to wake up the active_writer */
63 wait_queue_head_t wq;
64 /* verifies that no writer will get active while readers are active */
65 struct mutex lock;
66 /*
67 * Also blocks the new readers during
68 * an ongoing cpu hotplug operation.
69 */
70 atomic_t refcount;
71
72#ifdef CONFIG_DEBUG_LOCK_ALLOC
73 struct lockdep_map dep_map;
74#endif
75} cpu_hotplug = {
76 .active_writer = NULL,
77 .wq = __WAIT_QUEUE_HEAD_INITIALIZER(cpu_hotplug.wq),
78 .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock),
79#ifdef CONFIG_DEBUG_LOCK_ALLOC
80 .dep_map = {.name = "cpu_hotplug.lock" },
81#endif
82};
83
84/* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */
85#define cpuhp_lock_acquire_read() lock_map_acquire_read(&cpu_hotplug.dep_map)
86#define cpuhp_lock_acquire_tryread() \
87 lock_map_acquire_tryread(&cpu_hotplug.dep_map)
88#define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map)
89#define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map)
90
91
92void get_online_cpus(void)
93{
94 might_sleep();
95 if (cpu_hotplug.active_writer == current)
96 return;
97 cpuhp_lock_acquire_read();
98 mutex_lock(&cpu_hotplug.lock);
99 atomic_inc(&cpu_hotplug.refcount);
100 mutex_unlock(&cpu_hotplug.lock);
101}
102EXPORT_SYMBOL_GPL(get_online_cpus);
103
104bool try_get_online_cpus(void)
105{
106 if (cpu_hotplug.active_writer == current)
107 return true;
108 if (!mutex_trylock(&cpu_hotplug.lock))
109 return false;
110 cpuhp_lock_acquire_tryread();
111 atomic_inc(&cpu_hotplug.refcount);
112 mutex_unlock(&cpu_hotplug.lock);
113 return true;
114}
115EXPORT_SYMBOL_GPL(try_get_online_cpus);
116
117void put_online_cpus(void)
118{
119 int refcount;
120
121 if (cpu_hotplug.active_writer == current)
122 return;
123
124 refcount = atomic_dec_return(&cpu_hotplug.refcount);
125 if (WARN_ON(refcount < 0)) /* try to fix things up */
126 atomic_inc(&cpu_hotplug.refcount);
127
128 if (refcount <= 0 && waitqueue_active(&cpu_hotplug.wq))
129 wake_up(&cpu_hotplug.wq);
130
131 cpuhp_lock_release();
132
133}
134EXPORT_SYMBOL_GPL(put_online_cpus);
135
136/*
137 * This ensures that the hotplug operation can begin only when the
138 * refcount goes to zero.
139 *
140 * Note that during a cpu-hotplug operation, the new readers, if any,
141 * will be blocked by the cpu_hotplug.lock
142 *
143 * Since cpu_hotplug_begin() is always called after invoking
144 * cpu_maps_update_begin(), we can be sure that only one writer is active.
145 *
146 * Note that theoretically, there is a possibility of a livelock:
147 * - Refcount goes to zero, last reader wakes up the sleeping
148 * writer.
149 * - Last reader unlocks the cpu_hotplug.lock.
150 * - A new reader arrives at this moment, bumps up the refcount.
151 * - The writer acquires the cpu_hotplug.lock finds the refcount
152 * non zero and goes to sleep again.
153 *
154 * However, this is very difficult to achieve in practice since
155 * get_online_cpus() not an api which is called all that often.
156 *
157 */
158void cpu_hotplug_begin(void)
159{
160 DEFINE_WAIT(wait);
161
162 cpu_hotplug.active_writer = current;
163 cpuhp_lock_acquire();
164
165 for (;;) {
166 mutex_lock(&cpu_hotplug.lock);
167 prepare_to_wait(&cpu_hotplug.wq, &wait, TASK_UNINTERRUPTIBLE);
168 if (likely(!atomic_read(&cpu_hotplug.refcount)))
169 break;
170 mutex_unlock(&cpu_hotplug.lock);
171 schedule();
172 }
173 finish_wait(&cpu_hotplug.wq, &wait);
174}
175
176void cpu_hotplug_done(void)
177{
178 cpu_hotplug.active_writer = NULL;
179 mutex_unlock(&cpu_hotplug.lock);
180 cpuhp_lock_release();
181}
182
183/*
184 * Wait for currently running CPU hotplug operations to complete (if any) and
185 * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects
186 * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the
187 * hotplug path before performing hotplug operations. So acquiring that lock
188 * guarantees mutual exclusion from any currently running hotplug operations.
189 */
190void cpu_hotplug_disable(void)
191{
192 cpu_maps_update_begin();
193 cpu_hotplug_disabled = 1;
194 cpu_maps_update_done();
195}
196
197void cpu_hotplug_enable(void)
198{
199 cpu_maps_update_begin();
200 cpu_hotplug_disabled = 0;
201 cpu_maps_update_done();
202}
203
204#endif /* CONFIG_HOTPLUG_CPU */
205
206/* Need to know about CPUs going up/down? */
207int __ref register_cpu_notifier(struct notifier_block *nb)
208{
209 int ret;
210 cpu_maps_update_begin();
211 ret = raw_notifier_chain_register(&cpu_chain, nb);
212 cpu_maps_update_done();
213 return ret;
214}
215
216int __ref __register_cpu_notifier(struct notifier_block *nb)
217{
218 return raw_notifier_chain_register(&cpu_chain, nb);
219}
220
221static int __cpu_notify(unsigned long val, void *v, int nr_to_call,
222 int *nr_calls)
223{
224 int ret;
225
226 ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call,
227 nr_calls);
228
229 return notifier_to_errno(ret);
230}
231
232static int cpu_notify(unsigned long val, void *v)
233{
234 return __cpu_notify(val, v, -1, NULL);
235}
236
237#ifdef CONFIG_HOTPLUG_CPU
238
239static void cpu_notify_nofail(unsigned long val, void *v)
240{
241 BUG_ON(cpu_notify(val, v));
242}
243EXPORT_SYMBOL(register_cpu_notifier);
244EXPORT_SYMBOL(__register_cpu_notifier);
245
246void __ref unregister_cpu_notifier(struct notifier_block *nb)
247{
248 cpu_maps_update_begin();
249 raw_notifier_chain_unregister(&cpu_chain, nb);
250 cpu_maps_update_done();
251}
252EXPORT_SYMBOL(unregister_cpu_notifier);
253
254void __ref __unregister_cpu_notifier(struct notifier_block *nb)
255{
256 raw_notifier_chain_unregister(&cpu_chain, nb);
257}
258EXPORT_SYMBOL(__unregister_cpu_notifier);
259
260/**
261 * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU
262 * @cpu: a CPU id
263 *
264 * This function walks all processes, finds a valid mm struct for each one and
265 * then clears a corresponding bit in mm's cpumask. While this all sounds
266 * trivial, there are various non-obvious corner cases, which this function
267 * tries to solve in a safe manner.
268 *
269 * Also note that the function uses a somewhat relaxed locking scheme, so it may
270 * be called only for an already offlined CPU.
271 */
272void clear_tasks_mm_cpumask(int cpu)
273{
274 struct task_struct *p;
275
276 /*
277 * This function is called after the cpu is taken down and marked
278 * offline, so its not like new tasks will ever get this cpu set in
279 * their mm mask. -- Peter Zijlstra
280 * Thus, we may use rcu_read_lock() here, instead of grabbing
281 * full-fledged tasklist_lock.
282 */
283 WARN_ON(cpu_online(cpu));
284 rcu_read_lock();
285 for_each_process(p) {
286 struct task_struct *t;
287
288 /*
289 * Main thread might exit, but other threads may still have
290 * a valid mm. Find one.
291 */
292 t = find_lock_task_mm(p);
293 if (!t)
294 continue;
295 cpumask_clear_cpu(cpu, mm_cpumask(t->mm));
296 task_unlock(t);
297 }
298 rcu_read_unlock();
299}
300
301static inline void check_for_tasks(int dead_cpu)
302{
303 struct task_struct *g, *p;
304
305 read_lock_irq(&tasklist_lock);
306 do_each_thread(g, p) {
307 if (!p->on_rq)
308 continue;
309 /*
310 * We do the check with unlocked task_rq(p)->lock.
311 * Order the reading to do not warn about a task,
312 * which was running on this cpu in the past, and
313 * it's just been woken on another cpu.
314 */
315 rmb();
316 if (task_cpu(p) != dead_cpu)
317 continue;
318
319 pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n",
320 p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags);
321 } while_each_thread(g, p);
322 read_unlock_irq(&tasklist_lock);
323}
324
325struct take_cpu_down_param {
326 unsigned long mod;
327 void *hcpu;
328};
329
330/* Take this CPU down. */
331static int __ref take_cpu_down(void *_param)
332{
333 struct take_cpu_down_param *param = _param;
334 int err;
335
336 /* Ensure this CPU doesn't handle any more interrupts. */
337 err = __cpu_disable();
338 if (err < 0)
339 return err;
340
341 cpu_notify(CPU_DYING | param->mod, param->hcpu);
342 /* Give up timekeeping duties */
343 tick_handover_do_timer();
344 /* Park the stopper thread */
345 kthread_park(current);
346 return 0;
347}
348
349/* Requires cpu_add_remove_lock to be held */
350static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
351{
352 int err, nr_calls = 0;
353 void *hcpu = (void *)(long)cpu;
354 unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
355 struct take_cpu_down_param tcd_param = {
356 .mod = mod,
357 .hcpu = hcpu,
358 };
359
360 if (num_online_cpus() == 1)
361 return -EBUSY;
362
363 if (!cpu_online(cpu))
364 return -EINVAL;
365
366 cpu_hotplug_begin();
367
368 err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
369 if (err) {
370 nr_calls--;
371 __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL);
372 pr_warn("%s: attempt to take down CPU %u failed\n",
373 __func__, cpu);
374 goto out_release;
375 }
376
377 /*
378 * By now we've cleared cpu_active_mask, wait for all preempt-disabled
379 * and RCU users of this state to go away such that all new such users
380 * will observe it.
381 *
382 * For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might
383 * not imply sync_sched(), so explicitly call both.
384 *
385 * Do sync before park smpboot threads to take care the rcu boost case.
386 */
387#ifdef CONFIG_PREEMPT
388 synchronize_sched();
389#endif
390 synchronize_rcu();
391
392 smpboot_park_threads(cpu);
393
394 /*
395 * So now all preempt/rcu users must observe !cpu_active().
396 */
397
398 err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
399 if (err) {
400 /* CPU didn't die: tell everyone. Can't complain. */
401 cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu);
402 goto out_release;
403 }
404 BUG_ON(cpu_online(cpu));
405
406 /*
407 * The migration_call() CPU_DYING callback will have removed all
408 * runnable tasks from the cpu, there's only the idle task left now
409 * that the migration thread is done doing the stop_machine thing.
410 *
411 * Wait for the stop thread to go away.
412 */
413 while (!per_cpu(cpu_dead_idle, cpu))
414 cpu_relax();
415 smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */
416 per_cpu(cpu_dead_idle, cpu) = false;
417
418 hotplug_cpu__broadcast_tick_pull(cpu);
419 /* This actually kills the CPU. */
420 __cpu_die(cpu);
421
422 /* CPU is completely dead: tell everyone. Too late to complain. */
423 tick_cleanup_dead_cpu(cpu);
424 cpu_notify_nofail(CPU_DEAD | mod, hcpu);
425
426 check_for_tasks(cpu);
427
428out_release:
429 cpu_hotplug_done();
430 if (!err)
431 cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
432 return err;
433}
434
435int __ref cpu_down(unsigned int cpu)
436{
437 int err;
438
439 cpu_maps_update_begin();
440
441 if (cpu_hotplug_disabled) {
442 err = -EBUSY;
443 goto out;
444 }
445
446 err = _cpu_down(cpu, 0);
447
448out:
449 cpu_maps_update_done();
450 return err;
451}
452EXPORT_SYMBOL(cpu_down);
453#endif /*CONFIG_HOTPLUG_CPU*/
454
455/*
456 * Unpark per-CPU smpboot kthreads at CPU-online time.
457 */
458static int smpboot_thread_call(struct notifier_block *nfb,
459 unsigned long action, void *hcpu)
460{
461 int cpu = (long)hcpu;
462
463 switch (action & ~CPU_TASKS_FROZEN) {
464
465 case CPU_DOWN_FAILED:
466 case CPU_ONLINE:
467 smpboot_unpark_threads(cpu);
468 break;
469
470 default:
471 break;
472 }
473
474 return NOTIFY_OK;
475}
476
477static struct notifier_block smpboot_thread_notifier = {
478 .notifier_call = smpboot_thread_call,
479 .priority = CPU_PRI_SMPBOOT,
480};
481
482void smpboot_thread_init(void)
483{
484 register_cpu_notifier(&smpboot_thread_notifier);
485}
486
487/* Requires cpu_add_remove_lock to be held */
488static int _cpu_up(unsigned int cpu, int tasks_frozen)
489{
490 int ret, nr_calls = 0;
491 void *hcpu = (void *)(long)cpu;
492 unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
493 struct task_struct *idle;
494
495 cpu_hotplug_begin();
496
497 if (cpu_online(cpu) || !cpu_present(cpu)) {
498 ret = -EINVAL;
499 goto out;
500 }
501
502 idle = idle_thread_get(cpu);
503 if (IS_ERR(idle)) {
504 ret = PTR_ERR(idle);
505 goto out;
506 }
507
508 ret = smpboot_create_threads(cpu);
509 if (ret)
510 goto out;
511
512 ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
513 if (ret) {
514 nr_calls--;
515 pr_warn("%s: attempt to bring up CPU %u failed\n",
516 __func__, cpu);
517 goto out_notify;
518 }
519
520 /* Arch-specific enabling code. */
521 ret = __cpu_up(cpu, idle);
522 if (ret != 0)
523 goto out_notify;
524 BUG_ON(!cpu_online(cpu));
525
526 /* Now call notifier in preparation. */
527 cpu_notify(CPU_ONLINE | mod, hcpu);
528
529out_notify:
530 if (ret != 0)
531 __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
532out:
533 cpu_hotplug_done();
534
535 return ret;
536}
537
538int cpu_up(unsigned int cpu)
539{
540 int err = 0;
541
542 if (!cpu_possible(cpu)) {
543 pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n",
544 cpu);
545#if defined(CONFIG_IA64)
546 pr_err("please check additional_cpus= boot parameter\n");
547#endif
548 return -EINVAL;
549 }
550
551 err = try_online_node(cpu_to_node(cpu));
552 if (err)
553 return err;
554
555 cpu_maps_update_begin();
556
557 if (cpu_hotplug_disabled) {
558 err = -EBUSY;
559 goto out;
560 }
561
562 err = _cpu_up(cpu, 0);
563
564out:
565 cpu_maps_update_done();
566 return err;
567}
568EXPORT_SYMBOL_GPL(cpu_up);
569
570#ifdef CONFIG_PM_SLEEP_SMP
571static cpumask_var_t frozen_cpus;
572
573int disable_nonboot_cpus(void)
574{
575 int cpu, first_cpu, error = 0;
576
577 cpu_maps_update_begin();
578 first_cpu = cpumask_first(cpu_online_mask);
579 /*
580 * We take down all of the non-boot CPUs in one shot to avoid races
581 * with the userspace trying to use the CPU hotplug at the same time
582 */
583 cpumask_clear(frozen_cpus);
584
585 pr_info("Disabling non-boot CPUs ...\n");
586 for_each_online_cpu(cpu) {
587 if (cpu == first_cpu)
588 continue;
589 trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
590 error = _cpu_down(cpu, 1);
591 trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
592 if (!error)
593 cpumask_set_cpu(cpu, frozen_cpus);
594 else {
595 pr_err("Error taking CPU%d down: %d\n", cpu, error);
596 break;
597 }
598 }
599
600 if (!error) {
601 BUG_ON(num_online_cpus() > 1);
602 /* Make sure the CPUs won't be enabled by someone else */
603 cpu_hotplug_disabled = 1;
604 } else {
605 pr_err("Non-boot CPUs are not disabled\n");
606 }
607 cpu_maps_update_done();
608 return error;
609}
610
611void __weak arch_enable_nonboot_cpus_begin(void)
612{
613}
614
615void __weak arch_enable_nonboot_cpus_end(void)
616{
617}
618
619void __ref enable_nonboot_cpus(void)
620{
621 int cpu, error;
622
623 /* Allow everyone to use the CPU hotplug again */
624 cpu_maps_update_begin();
625 cpu_hotplug_disabled = 0;
626 if (cpumask_empty(frozen_cpus))
627 goto out;
628
629 pr_info("Enabling non-boot CPUs ...\n");
630
631 arch_enable_nonboot_cpus_begin();
632
633 for_each_cpu(cpu, frozen_cpus) {
634 trace_suspend_resume(TPS("CPU_ON"), cpu, true);
635 error = _cpu_up(cpu, 1);
636 trace_suspend_resume(TPS("CPU_ON"), cpu, false);
637 if (!error) {
638 pr_info("CPU%d is up\n", cpu);
639 continue;
640 }
641 pr_warn("Error taking CPU%d up: %d\n", cpu, error);
642 }
643
644 arch_enable_nonboot_cpus_end();
645
646 cpumask_clear(frozen_cpus);
647out:
648 cpu_maps_update_done();
649}
650
651static int __init alloc_frozen_cpus(void)
652{
653 if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO))
654 return -ENOMEM;
655 return 0;
656}
657core_initcall(alloc_frozen_cpus);
658
659/*
660 * When callbacks for CPU hotplug notifications are being executed, we must
661 * ensure that the state of the system with respect to the tasks being frozen
662 * or not, as reported by the notification, remains unchanged *throughout the
663 * duration* of the execution of the callbacks.
664 * Hence we need to prevent the freezer from racing with regular CPU hotplug.
665 *
666 * This synchronization is implemented by mutually excluding regular CPU
667 * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/
668 * Hibernate notifications.
669 */
670static int
671cpu_hotplug_pm_callback(struct notifier_block *nb,
672 unsigned long action, void *ptr)
673{
674 switch (action) {
675
676 case PM_SUSPEND_PREPARE:
677 case PM_HIBERNATION_PREPARE:
678 cpu_hotplug_disable();
679 break;
680
681 case PM_POST_SUSPEND:
682 case PM_POST_HIBERNATION:
683 cpu_hotplug_enable();
684 break;
685
686 default:
687 return NOTIFY_DONE;
688 }
689
690 return NOTIFY_OK;
691}
692
693
694static int __init cpu_hotplug_pm_sync_init(void)
695{
696 /*
697 * cpu_hotplug_pm_callback has higher priority than x86
698 * bsp_pm_callback which depends on cpu_hotplug_pm_callback
699 * to disable cpu hotplug to avoid cpu hotplug race.
700 */
701 pm_notifier(cpu_hotplug_pm_callback, 0);
702 return 0;
703}
704core_initcall(cpu_hotplug_pm_sync_init);
705
706#endif /* CONFIG_PM_SLEEP_SMP */
707
708/**
709 * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
710 * @cpu: cpu that just started
711 *
712 * This function calls the cpu_chain notifiers with CPU_STARTING.
713 * It must be called by the arch code on the new cpu, before the new cpu
714 * enables interrupts and before the "boot" cpu returns from __cpu_up().
715 */
716void notify_cpu_starting(unsigned int cpu)
717{
718 unsigned long val = CPU_STARTING;
719
720#ifdef CONFIG_PM_SLEEP_SMP
721 if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus))
722 val = CPU_STARTING_FROZEN;
723#endif /* CONFIG_PM_SLEEP_SMP */
724 cpu_notify(val, (void *)(long)cpu);
725}
726
727#endif /* CONFIG_SMP */
728
729/*
730 * cpu_bit_bitmap[] is a special, "compressed" data structure that
731 * represents all NR_CPUS bits binary values of 1<<nr.
732 *
733 * It is used by cpumask_of() to get a constant address to a CPU
734 * mask value that has a single bit set only.
735 */
736
737/* cpu_bit_bitmap[0] is empty - so we can back into it */
738#define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x))
739#define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1)
740#define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2)
741#define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4)
742
743const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = {
744
745 MASK_DECLARE_8(0), MASK_DECLARE_8(8),
746 MASK_DECLARE_8(16), MASK_DECLARE_8(24),
747#if BITS_PER_LONG > 32
748 MASK_DECLARE_8(32), MASK_DECLARE_8(40),
749 MASK_DECLARE_8(48), MASK_DECLARE_8(56),
750#endif
751};
752EXPORT_SYMBOL_GPL(cpu_bit_bitmap);
753
754const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL;
755EXPORT_SYMBOL(cpu_all_bits);
756
757#ifdef CONFIG_INIT_ALL_POSSIBLE
758static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly
759 = CPU_BITS_ALL;
760#else
761static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly;
762#endif
763const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits);
764EXPORT_SYMBOL(cpu_possible_mask);
765
766static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly;
767const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits);
768EXPORT_SYMBOL(cpu_online_mask);
769
770static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly;
771const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits);
772EXPORT_SYMBOL(cpu_present_mask);
773
774static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly;
775const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits);
776EXPORT_SYMBOL(cpu_active_mask);
777
778void set_cpu_possible(unsigned int cpu, bool possible)
779{
780 if (possible)
781 cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits));
782 else
783 cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits));
784}
785
786void set_cpu_present(unsigned int cpu, bool present)
787{
788 if (present)
789 cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits));
790 else
791 cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits));
792}
793
794void set_cpu_online(unsigned int cpu, bool online)
795{
796 if (online) {
797 cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits));
798 cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits));
799 } else {
800 cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits));
801 }
802}
803
804void set_cpu_active(unsigned int cpu, bool active)
805{
806 if (active)
807 cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits));
808 else
809 cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits));
810}
811
812void init_cpu_present(const struct cpumask *src)
813{
814 cpumask_copy(to_cpumask(cpu_present_bits), src);
815}
816
817void init_cpu_possible(const struct cpumask *src)
818{
819 cpumask_copy(to_cpumask(cpu_possible_bits), src);
820}
821
822void init_cpu_online(const struct cpumask *src)
823{
824 cpumask_copy(to_cpumask(cpu_online_bits), src);
825}