projects/linux·blob v4.2-rc5 · refs

836 lines · 20.2 KiB

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 <linux/irq.h>
25#include <trace/events/power.h>
26
27#include "smpboot.h"
28
29#ifdef CONFIG_SMP
30/* Serializes the updates to cpu_online_mask, cpu_present_mask */
31static DEFINE_MUTEX(cpu_add_remove_lock);
32
33/*
34 * The following two APIs (cpu_maps_update_begin/done) must be used when
35 * attempting to serialize the updates to cpu_online_mask & cpu_present_mask.
36 * The APIs cpu_notifier_register_begin/done() must be used to protect CPU
37 * hotplug callback (un)registration performed using __register_cpu_notifier()
38 * or __unregister_cpu_notifier().
39 */
40void cpu_maps_update_begin(void)
41{
42 mutex_lock(&cpu_add_remove_lock);
43}
44EXPORT_SYMBOL(cpu_notifier_register_begin);
45
46void cpu_maps_update_done(void)
47{
48 mutex_unlock(&cpu_add_remove_lock);
49}
50EXPORT_SYMBOL(cpu_notifier_register_done);
51
52static RAW_NOTIFIER_HEAD(cpu_chain);
53
54/* If set, cpu_up and cpu_down will return -EBUSY and do nothing.
55 * Should always be manipulated under cpu_add_remove_lock
56 */
57static int cpu_hotplug_disabled;
58
59#ifdef CONFIG_HOTPLUG_CPU
60
61static struct {
62 struct task_struct *active_writer;
63 /* wait queue to wake up the active_writer */
64 wait_queue_head_t wq;
65 /* verifies that no writer will get active while readers are active */
66 struct mutex lock;
67 /*
68 * Also blocks the new readers during
69 * an ongoing cpu hotplug operation.
70 */
71 atomic_t refcount;
72
73#ifdef CONFIG_DEBUG_LOCK_ALLOC
74 struct lockdep_map dep_map;
75#endif
76} cpu_hotplug = {
77 .active_writer = NULL,
78 .wq = __WAIT_QUEUE_HEAD_INITIALIZER(cpu_hotplug.wq),
79 .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock),
80#ifdef CONFIG_DEBUG_LOCK_ALLOC
81 .dep_map = {.name = "cpu_hotplug.lock" },
82#endif
83};
84
85/* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */
86#define cpuhp_lock_acquire_read() lock_map_acquire_read(&cpu_hotplug.dep_map)
87#define cpuhp_lock_acquire_tryread() \
88 lock_map_acquire_tryread(&cpu_hotplug.dep_map)
89#define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map)
90#define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map)
91
92
93void get_online_cpus(void)
94{
95 might_sleep();
96 if (cpu_hotplug.active_writer == current)
97 return;
98 cpuhp_lock_acquire_read();
99 mutex_lock(&cpu_hotplug.lock);
100 atomic_inc(&cpu_hotplug.refcount);
101 mutex_unlock(&cpu_hotplug.lock);
102}
103EXPORT_SYMBOL_GPL(get_online_cpus);
104
105bool try_get_online_cpus(void)
106{
107 if (cpu_hotplug.active_writer == current)
108 return true;
109 if (!mutex_trylock(&cpu_hotplug.lock))
110 return false;
111 cpuhp_lock_acquire_tryread();
112 atomic_inc(&cpu_hotplug.refcount);
113 mutex_unlock(&cpu_hotplug.lock);
114 return true;
115}
116EXPORT_SYMBOL_GPL(try_get_online_cpus);
117
118void put_online_cpus(void)
119{
120 int refcount;
121
122 if (cpu_hotplug.active_writer == current)
123 return;
124
125 refcount = atomic_dec_return(&cpu_hotplug.refcount);
126 if (WARN_ON(refcount < 0)) /* try to fix things up */
127 atomic_inc(&cpu_hotplug.refcount);
128
129 if (refcount <= 0 && waitqueue_active(&cpu_hotplug.wq))
130 wake_up(&cpu_hotplug.wq);
131
132 cpuhp_lock_release();
133
134}
135EXPORT_SYMBOL_GPL(put_online_cpus);
136
137/*
138 * This ensures that the hotplug operation can begin only when the
139 * refcount goes to zero.
140 *
141 * Note that during a cpu-hotplug operation, the new readers, if any,
142 * will be blocked by the cpu_hotplug.lock
143 *
144 * Since cpu_hotplug_begin() is always called after invoking
145 * cpu_maps_update_begin(), we can be sure that only one writer is active.
146 *
147 * Note that theoretically, there is a possibility of a livelock:
148 * - Refcount goes to zero, last reader wakes up the sleeping
149 * writer.
150 * - Last reader unlocks the cpu_hotplug.lock.
151 * - A new reader arrives at this moment, bumps up the refcount.
152 * - The writer acquires the cpu_hotplug.lock finds the refcount
153 * non zero and goes to sleep again.
154 *
155 * However, this is very difficult to achieve in practice since
156 * get_online_cpus() not an api which is called all that often.
157 *
158 */
159void cpu_hotplug_begin(void)
160{
161 DEFINE_WAIT(wait);
162
163 cpu_hotplug.active_writer = current;
164 cpuhp_lock_acquire();
165
166 for (;;) {
167 mutex_lock(&cpu_hotplug.lock);
168 prepare_to_wait(&cpu_hotplug.wq, &wait, TASK_UNINTERRUPTIBLE);
169 if (likely(!atomic_read(&cpu_hotplug.refcount)))
170 break;
171 mutex_unlock(&cpu_hotplug.lock);
172 schedule();
173 }
174 finish_wait(&cpu_hotplug.wq, &wait);
175}
176
177void cpu_hotplug_done(void)
178{
179 cpu_hotplug.active_writer = NULL;
180 mutex_unlock(&cpu_hotplug.lock);
181 cpuhp_lock_release();
182}
183
184/*
185 * Wait for currently running CPU hotplug operations to complete (if any) and
186 * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects
187 * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the
188 * hotplug path before performing hotplug operations. So acquiring that lock
189 * guarantees mutual exclusion from any currently running hotplug operations.
190 */
191void cpu_hotplug_disable(void)
192{
193 cpu_maps_update_begin();
194 cpu_hotplug_disabled = 1;
195 cpu_maps_update_done();
196}
197
198void cpu_hotplug_enable(void)
199{
200 cpu_maps_update_begin();
201 cpu_hotplug_disabled = 0;
202 cpu_maps_update_done();
203}
204
205#endif /* CONFIG_HOTPLUG_CPU */
206
207/* Need to know about CPUs going up/down? */
208int __ref register_cpu_notifier(struct notifier_block *nb)
209{
210 int ret;
211 cpu_maps_update_begin();
212 ret = raw_notifier_chain_register(&cpu_chain, nb);
213 cpu_maps_update_done();
214 return ret;
215}
216
217int __ref __register_cpu_notifier(struct notifier_block *nb)
218{
219 return raw_notifier_chain_register(&cpu_chain, nb);
220}
221
222static int __cpu_notify(unsigned long val, void *v, int nr_to_call,
223 int *nr_calls)
224{
225 int ret;
226
227 ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call,
228 nr_calls);
229
230 return notifier_to_errno(ret);
231}
232
233static int cpu_notify(unsigned long val, void *v)
234{
235 return __cpu_notify(val, v, -1, NULL);
236}
237
238#ifdef CONFIG_HOTPLUG_CPU
239
240static void cpu_notify_nofail(unsigned long val, void *v)
241{
242 BUG_ON(cpu_notify(val, v));
243}
244EXPORT_SYMBOL(register_cpu_notifier);
245EXPORT_SYMBOL(__register_cpu_notifier);
246
247void __ref unregister_cpu_notifier(struct notifier_block *nb)
248{
249 cpu_maps_update_begin();
250 raw_notifier_chain_unregister(&cpu_chain, nb);
251 cpu_maps_update_done();
252}
253EXPORT_SYMBOL(unregister_cpu_notifier);
254
255void __ref __unregister_cpu_notifier(struct notifier_block *nb)
256{
257 raw_notifier_chain_unregister(&cpu_chain, nb);
258}
259EXPORT_SYMBOL(__unregister_cpu_notifier);
260
261/**
262 * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU
263 * @cpu: a CPU id
264 *
265 * This function walks all processes, finds a valid mm struct for each one and
266 * then clears a corresponding bit in mm's cpumask. While this all sounds
267 * trivial, there are various non-obvious corner cases, which this function
268 * tries to solve in a safe manner.
269 *
270 * Also note that the function uses a somewhat relaxed locking scheme, so it may
271 * be called only for an already offlined CPU.
272 */
273void clear_tasks_mm_cpumask(int cpu)
274{
275 struct task_struct *p;
276
277 /*
278 * This function is called after the cpu is taken down and marked
279 * offline, so its not like new tasks will ever get this cpu set in
280 * their mm mask. -- Peter Zijlstra
281 * Thus, we may use rcu_read_lock() here, instead of grabbing
282 * full-fledged tasklist_lock.
283 */
284 WARN_ON(cpu_online(cpu));
285 rcu_read_lock();
286 for_each_process(p) {
287 struct task_struct *t;
288
289 /*
290 * Main thread might exit, but other threads may still have
291 * a valid mm. Find one.
292 */
293 t = find_lock_task_mm(p);
294 if (!t)
295 continue;
296 cpumask_clear_cpu(cpu, mm_cpumask(t->mm));
297 task_unlock(t);
298 }
299 rcu_read_unlock();
300}
301
302static inline void check_for_tasks(int dead_cpu)
303{
304 struct task_struct *g, *p;
305
306 read_lock_irq(&tasklist_lock);
307 do_each_thread(g, p) {
308 if (!p->on_rq)
309 continue;
310 /*
311 * We do the check with unlocked task_rq(p)->lock.
312 * Order the reading to do not warn about a task,
313 * which was running on this cpu in the past, and
314 * it's just been woken on another cpu.
315 */
316 rmb();
317 if (task_cpu(p) != dead_cpu)
318 continue;
319
320 pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n",
321 p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags);
322 } while_each_thread(g, p);
323 read_unlock_irq(&tasklist_lock);
324}
325
326struct take_cpu_down_param {
327 unsigned long mod;
328 void *hcpu;
329};
330
331/* Take this CPU down. */
332static int __ref take_cpu_down(void *_param)
333{
334 struct take_cpu_down_param *param = _param;
335 int err;
336
337 /* Ensure this CPU doesn't handle any more interrupts. */
338 err = __cpu_disable();
339 if (err < 0)
340 return err;
341
342 cpu_notify(CPU_DYING | param->mod, param->hcpu);
343 /* Give up timekeeping duties */
344 tick_handover_do_timer();
345 /* Park the stopper thread */
346 kthread_park(current);
347 return 0;
348}
349
350/* Requires cpu_add_remove_lock to be held */
351static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
352{
353 int err, nr_calls = 0;
354 void *hcpu = (void *)(long)cpu;
355 unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
356 struct take_cpu_down_param tcd_param = {
357 .mod = mod,
358 .hcpu = hcpu,
359 };
360
361 if (num_online_cpus() == 1)
362 return -EBUSY;
363
364 if (!cpu_online(cpu))
365 return -EINVAL;
366
367 cpu_hotplug_begin();
368
369 err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
370 if (err) {
371 nr_calls--;
372 __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL);
373 pr_warn("%s: attempt to take down CPU %u failed\n",
374 __func__, cpu);
375 goto out_release;
376 }
377
378 /*
379 * By now we've cleared cpu_active_mask, wait for all preempt-disabled
380 * and RCU users of this state to go away such that all new such users
381 * will observe it.
382 *
383 * For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might
384 * not imply sync_sched(), so explicitly call both.
385 *
386 * Do sync before park smpboot threads to take care the rcu boost case.
387 */
388#ifdef CONFIG_PREEMPT
389 synchronize_sched();
390#endif
391 synchronize_rcu();
392
393 smpboot_park_threads(cpu);
394
395 /*
396 * Prevent irq alloc/free while the dying cpu reorganizes the
397 * interrupt affinities.
398 */
399 irq_lock_sparse();
400
401 /*
402 * So now all preempt/rcu users must observe !cpu_active().
403 */
404 err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
405 if (err) {
406 /* CPU didn't die: tell everyone. Can't complain. */
407 cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu);
408 irq_unlock_sparse();
409 goto out_release;
410 }
411 BUG_ON(cpu_online(cpu));
412
413 /*
414 * The migration_call() CPU_DYING callback will have removed all
415 * runnable tasks from the cpu, there's only the idle task left now
416 * that the migration thread is done doing the stop_machine thing.
417 *
418 * Wait for the stop thread to go away.
419 */
420 while (!per_cpu(cpu_dead_idle, cpu))
421 cpu_relax();
422 smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */
423 per_cpu(cpu_dead_idle, cpu) = false;
424
425 /* Interrupts are moved away from the dying cpu, reenable alloc/free */
426 irq_unlock_sparse();
427
428 hotplug_cpu__broadcast_tick_pull(cpu);
429 /* This actually kills the CPU. */
430 __cpu_die(cpu);
431
432 /* CPU is completely dead: tell everyone. Too late to complain. */
433 tick_cleanup_dead_cpu(cpu);
434 cpu_notify_nofail(CPU_DEAD | mod, hcpu);
435
436 check_for_tasks(cpu);
437
438out_release:
439 cpu_hotplug_done();
440 if (!err)
441 cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
442 return err;
443}
444
445int __ref cpu_down(unsigned int cpu)
446{
447 int err;
448
449 cpu_maps_update_begin();
450
451 if (cpu_hotplug_disabled) {
452 err = -EBUSY;
453 goto out;
454 }
455
456 err = _cpu_down(cpu, 0);
457
458out:
459 cpu_maps_update_done();
460 return err;
461}
462EXPORT_SYMBOL(cpu_down);
463#endif /*CONFIG_HOTPLUG_CPU*/
464
465/*
466 * Unpark per-CPU smpboot kthreads at CPU-online time.
467 */
468static int smpboot_thread_call(struct notifier_block *nfb,
469 unsigned long action, void *hcpu)
470{
471 int cpu = (long)hcpu;
472
473 switch (action & ~CPU_TASKS_FROZEN) {
474
475 case CPU_DOWN_FAILED:
476 case CPU_ONLINE:
477 smpboot_unpark_threads(cpu);
478 break;
479
480 default:
481 break;
482 }
483
484 return NOTIFY_OK;
485}
486
487static struct notifier_block smpboot_thread_notifier = {
488 .notifier_call = smpboot_thread_call,
489 .priority = CPU_PRI_SMPBOOT,
490};
491
492void smpboot_thread_init(void)
493{
494 register_cpu_notifier(&smpboot_thread_notifier);
495}
496
497/* Requires cpu_add_remove_lock to be held */
498static int _cpu_up(unsigned int cpu, int tasks_frozen)
499{
500 int ret, nr_calls = 0;
501 void *hcpu = (void *)(long)cpu;
502 unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
503 struct task_struct *idle;
504
505 cpu_hotplug_begin();
506
507 if (cpu_online(cpu) || !cpu_present(cpu)) {
508 ret = -EINVAL;
509 goto out;
510 }
511
512 idle = idle_thread_get(cpu);
513 if (IS_ERR(idle)) {
514 ret = PTR_ERR(idle);
515 goto out;
516 }
517
518 ret = smpboot_create_threads(cpu);
519 if (ret)
520 goto out;
521
522 ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
523 if (ret) {
524 nr_calls--;
525 pr_warn("%s: attempt to bring up CPU %u failed\n",
526 __func__, cpu);
527 goto out_notify;
528 }
529
530 /* Arch-specific enabling code. */
531 ret = __cpu_up(cpu, idle);
532
533 if (ret != 0)
534 goto out_notify;
535 BUG_ON(!cpu_online(cpu));
536
537 /* Now call notifier in preparation. */
538 cpu_notify(CPU_ONLINE | mod, hcpu);
539
540out_notify:
541 if (ret != 0)
542 __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
543out:
544 cpu_hotplug_done();
545
546 return ret;
547}
548
549int cpu_up(unsigned int cpu)
550{
551 int err = 0;
552
553 if (!cpu_possible(cpu)) {
554 pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n",
555 cpu);
556#if defined(CONFIG_IA64)
557 pr_err("please check additional_cpus= boot parameter\n");
558#endif
559 return -EINVAL;
560 }
561
562 err = try_online_node(cpu_to_node(cpu));
563 if (err)
564 return err;
565
566 cpu_maps_update_begin();
567
568 if (cpu_hotplug_disabled) {
569 err = -EBUSY;
570 goto out;
571 }
572
573 err = _cpu_up(cpu, 0);
574
575out:
576 cpu_maps_update_done();
577 return err;
578}
579EXPORT_SYMBOL_GPL(cpu_up);
580
581#ifdef CONFIG_PM_SLEEP_SMP
582static cpumask_var_t frozen_cpus;
583
584int disable_nonboot_cpus(void)
585{
586 int cpu, first_cpu, error = 0;
587
588 cpu_maps_update_begin();
589 first_cpu = cpumask_first(cpu_online_mask);
590 /*
591 * We take down all of the non-boot CPUs in one shot to avoid races
592 * with the userspace trying to use the CPU hotplug at the same time
593 */
594 cpumask_clear(frozen_cpus);
595
596 pr_info("Disabling non-boot CPUs ...\n");
597 for_each_online_cpu(cpu) {
598 if (cpu == first_cpu)
599 continue;
600 trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
601 error = _cpu_down(cpu, 1);
602 trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
603 if (!error)
604 cpumask_set_cpu(cpu, frozen_cpus);
605 else {
606 pr_err("Error taking CPU%d down: %d\n", cpu, error);
607 break;
608 }
609 }
610
611 if (!error) {
612 BUG_ON(num_online_cpus() > 1);
613 /* Make sure the CPUs won't be enabled by someone else */
614 cpu_hotplug_disabled = 1;
615 } else {
616 pr_err("Non-boot CPUs are not disabled\n");
617 }
618 cpu_maps_update_done();
619 return error;
620}
621
622void __weak arch_enable_nonboot_cpus_begin(void)
623{
624}
625
626void __weak arch_enable_nonboot_cpus_end(void)
627{
628}
629
630void __ref enable_nonboot_cpus(void)
631{
632 int cpu, error;
633
634 /* Allow everyone to use the CPU hotplug again */
635 cpu_maps_update_begin();
636 cpu_hotplug_disabled = 0;
637 if (cpumask_empty(frozen_cpus))
638 goto out;
639
640 pr_info("Enabling non-boot CPUs ...\n");
641
642 arch_enable_nonboot_cpus_begin();
643
644 for_each_cpu(cpu, frozen_cpus) {
645 trace_suspend_resume(TPS("CPU_ON"), cpu, true);
646 error = _cpu_up(cpu, 1);
647 trace_suspend_resume(TPS("CPU_ON"), cpu, false);
648 if (!error) {
649 pr_info("CPU%d is up\n", cpu);
650 continue;
651 }
652 pr_warn("Error taking CPU%d up: %d\n", cpu, error);
653 }
654
655 arch_enable_nonboot_cpus_end();
656
657 cpumask_clear(frozen_cpus);
658out:
659 cpu_maps_update_done();
660}
661
662static int __init alloc_frozen_cpus(void)
663{
664 if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO))
665 return -ENOMEM;
666 return 0;
667}
668core_initcall(alloc_frozen_cpus);
669
670/*
671 * When callbacks for CPU hotplug notifications are being executed, we must
672 * ensure that the state of the system with respect to the tasks being frozen
673 * or not, as reported by the notification, remains unchanged *throughout the
674 * duration* of the execution of the callbacks.
675 * Hence we need to prevent the freezer from racing with regular CPU hotplug.
676 *
677 * This synchronization is implemented by mutually excluding regular CPU
678 * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/
679 * Hibernate notifications.
680 */
681static int
682cpu_hotplug_pm_callback(struct notifier_block *nb,
683 unsigned long action, void *ptr)
684{
685 switch (action) {
686
687 case PM_SUSPEND_PREPARE:
688 case PM_HIBERNATION_PREPARE:
689 cpu_hotplug_disable();
690 break;
691
692 case PM_POST_SUSPEND:
693 case PM_POST_HIBERNATION:
694 cpu_hotplug_enable();
695 break;
696
697 default:
698 return NOTIFY_DONE;
699 }
700
701 return NOTIFY_OK;
702}
703
704
705static int __init cpu_hotplug_pm_sync_init(void)
706{
707 /*
708 * cpu_hotplug_pm_callback has higher priority than x86
709 * bsp_pm_callback which depends on cpu_hotplug_pm_callback
710 * to disable cpu hotplug to avoid cpu hotplug race.
711 */
712 pm_notifier(cpu_hotplug_pm_callback, 0);
713 return 0;
714}
715core_initcall(cpu_hotplug_pm_sync_init);
716
717#endif /* CONFIG_PM_SLEEP_SMP */
718
719/**
720 * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
721 * @cpu: cpu that just started
722 *
723 * This function calls the cpu_chain notifiers with CPU_STARTING.
724 * It must be called by the arch code on the new cpu, before the new cpu
725 * enables interrupts and before the "boot" cpu returns from __cpu_up().
726 */
727void notify_cpu_starting(unsigned int cpu)
728{
729 unsigned long val = CPU_STARTING;
730
731#ifdef CONFIG_PM_SLEEP_SMP
732 if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus))
733 val = CPU_STARTING_FROZEN;
734#endif /* CONFIG_PM_SLEEP_SMP */
735 cpu_notify(val, (void *)(long)cpu);
736}
737
738#endif /* CONFIG_SMP */
739
740/*
741 * cpu_bit_bitmap[] is a special, "compressed" data structure that
742 * represents all NR_CPUS bits binary values of 1<<nr.
743 *
744 * It is used by cpumask_of() to get a constant address to a CPU
745 * mask value that has a single bit set only.
746 */
747
748/* cpu_bit_bitmap[0] is empty - so we can back into it */
749#define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x))
750#define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1)
751#define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2)
752#define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4)
753
754const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = {
755
756 MASK_DECLARE_8(0), MASK_DECLARE_8(8),
757 MASK_DECLARE_8(16), MASK_DECLARE_8(24),
758#if BITS_PER_LONG > 32
759 MASK_DECLARE_8(32), MASK_DECLARE_8(40),
760 MASK_DECLARE_8(48), MASK_DECLARE_8(56),
761#endif
762};
763EXPORT_SYMBOL_GPL(cpu_bit_bitmap);
764
765const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL;
766EXPORT_SYMBOL(cpu_all_bits);
767
768#ifdef CONFIG_INIT_ALL_POSSIBLE
769static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly
770 = CPU_BITS_ALL;
771#else
772static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly;
773#endif
774const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits);
775EXPORT_SYMBOL(cpu_possible_mask);
776
777static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly;
778const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits);
779EXPORT_SYMBOL(cpu_online_mask);
780
781static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly;
782const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits);
783EXPORT_SYMBOL(cpu_present_mask);
784
785static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly;
786const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits);
787EXPORT_SYMBOL(cpu_active_mask);
788
789void set_cpu_possible(unsigned int cpu, bool possible)
790{
791 if (possible)
792 cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits));
793 else
794 cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits));
795}
796
797void set_cpu_present(unsigned int cpu, bool present)
798{
799 if (present)
800 cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits));
801 else
802 cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits));
803}
804
805void set_cpu_online(unsigned int cpu, bool online)
806{
807 if (online) {
808 cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits));
809 cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits));
810 } else {
811 cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits));
812 }
813}
814
815void set_cpu_active(unsigned int cpu, bool active)
816{
817 if (active)
818 cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits));
819 else
820 cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits));
821}
822
823void init_cpu_present(const struct cpumask *src)
824{
825 cpumask_copy(to_cpumask(cpu_present_bits), src);
826}
827
828void init_cpu_possible(const struct cpumask *src)
829{
830 cpumask_copy(to_cpumask(cpu_possible_bits), src);
831}
832
833void init_cpu_online(const struct cpumask *src)
834{
835 cpumask_copy(to_cpumask(cpu_online_bits), src);
836}