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1 | /* |
2 | * padata.c - generic interface to process data streams in parallel |
3 | * |
4 | * Copyright (C) 2008, 2009 secunet Security Networks AG |
5 | * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com> |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify it |
8 | * under the terms and conditions of the GNU General Public License, |
9 | * version 2, as published by the Free Software Foundation. |
10 | * |
11 | * This program is distributed in the hope it will be useful, but WITHOUT |
12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
14 | * more details. |
15 | * |
16 | * You should have received a copy of the GNU General Public License along with |
17 | * this program; if not, write to the Free Software Foundation, Inc., |
18 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. |
19 | */ |
20 | |
21 | #include <linux/module.h> |
22 | #include <linux/cpumask.h> |
23 | #include <linux/err.h> |
24 | #include <linux/cpu.h> |
25 | #include <linux/padata.h> |
26 | #include <linux/mutex.h> |
27 | #include <linux/sched.h> |
28 | #include <linux/slab.h> |
29 | #include <linux/rcupdate.h> |
30 | |
31 | #define MAX_SEQ_NR INT_MAX - NR_CPUS |
32 | #define MAX_OBJ_NUM 1000 |
33 | |
34 | static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index) |
35 | { |
36 | int cpu, target_cpu; |
37 | |
38 | target_cpu = cpumask_first(pd->cpumask); |
39 | for (cpu = 0; cpu < cpu_index; cpu++) |
40 | target_cpu = cpumask_next(target_cpu, pd->cpumask); |
41 | |
42 | return target_cpu; |
43 | } |
44 | |
45 | static int padata_cpu_hash(struct padata_priv *padata) |
46 | { |
47 | int cpu_index; |
48 | struct parallel_data *pd; |
49 | |
50 | pd = padata->pd; |
51 | |
52 | /* |
53 | * Hash the sequence numbers to the cpus by taking |
54 | * seq_nr mod. number of cpus in use. |
55 | */ |
56 | cpu_index = padata->seq_nr % cpumask_weight(pd->cpumask); |
57 | |
58 | return padata_index_to_cpu(pd, cpu_index); |
59 | } |
60 | |
61 | static void padata_parallel_worker(struct work_struct *work) |
62 | { |
63 | struct padata_queue *queue; |
64 | struct parallel_data *pd; |
65 | struct padata_instance *pinst; |
66 | LIST_HEAD(local_list); |
67 | |
68 | local_bh_disable(); |
69 | queue = container_of(work, struct padata_queue, pwork); |
70 | pd = queue->pd; |
71 | pinst = pd->pinst; |
72 | |
73 | spin_lock(&queue->parallel.lock); |
74 | list_replace_init(&queue->parallel.list, &local_list); |
75 | spin_unlock(&queue->parallel.lock); |
76 | |
77 | while (!list_empty(&local_list)) { |
78 | struct padata_priv *padata; |
79 | |
80 | padata = list_entry(local_list.next, |
81 | struct padata_priv, list); |
82 | |
83 | list_del_init(&padata->list); |
84 | |
85 | padata->parallel(padata); |
86 | } |
87 | |
88 | local_bh_enable(); |
89 | } |
90 | |
91 | /** |
92 | * padata_do_parallel - padata parallelization function |
93 | * |
94 | * @pinst: padata instance |
95 | * @padata: object to be parallelized |
96 | * @cb_cpu: cpu the serialization callback function will run on, |
97 | * must be in the cpumask of padata. |
98 | * |
99 | * The parallelization callback function will run with BHs off. |
100 | * Note: Every object which is parallelized by padata_do_parallel |
101 | * must be seen by padata_do_serial. |
102 | */ |
103 | int padata_do_parallel(struct padata_instance *pinst, |
104 | struct padata_priv *padata, int cb_cpu) |
105 | { |
106 | int target_cpu, err; |
107 | struct padata_queue *queue; |
108 | struct parallel_data *pd; |
109 | |
110 | rcu_read_lock_bh(); |
111 | |
112 | pd = rcu_dereference(pinst->pd); |
113 | |
114 | err = 0; |
115 | if (!(pinst->flags & PADATA_INIT)) |
116 | goto out; |
117 | |
118 | err = -EBUSY; |
119 | if ((pinst->flags & PADATA_RESET)) |
120 | goto out; |
121 | |
122 | if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM) |
123 | goto out; |
124 | |
125 | err = -EINVAL; |
126 | if (!cpumask_test_cpu(cb_cpu, pd->cpumask)) |
127 | goto out; |
128 | |
129 | err = -EINPROGRESS; |
130 | atomic_inc(&pd->refcnt); |
131 | padata->pd = pd; |
132 | padata->cb_cpu = cb_cpu; |
133 | |
134 | if (unlikely(atomic_read(&pd->seq_nr) == pd->max_seq_nr)) |
135 | atomic_set(&pd->seq_nr, -1); |
136 | |
137 | padata->seq_nr = atomic_inc_return(&pd->seq_nr); |
138 | |
139 | target_cpu = padata_cpu_hash(padata); |
140 | queue = per_cpu_ptr(pd->queue, target_cpu); |
141 | |
142 | spin_lock(&queue->parallel.lock); |
143 | list_add_tail(&padata->list, &queue->parallel.list); |
144 | spin_unlock(&queue->parallel.lock); |
145 | |
146 | queue_work_on(target_cpu, pinst->wq, &queue->pwork); |
147 | |
148 | out: |
149 | rcu_read_unlock_bh(); |
150 | |
151 | return err; |
152 | } |
153 | EXPORT_SYMBOL(padata_do_parallel); |
154 | |
155 | /* |
156 | * padata_get_next - Get the next object that needs serialization. |
157 | * |
158 | * Return values are: |
159 | * |
160 | * A pointer to the control struct of the next object that needs |
161 | * serialization, if present in one of the percpu reorder queues. |
162 | * |
163 | * NULL, if all percpu reorder queues are empty. |
164 | * |
165 | * -EINPROGRESS, if the next object that needs serialization will |
166 | * be parallel processed by another cpu and is not yet present in |
167 | * the cpu's reorder queue. |
168 | * |
169 | * -ENODATA, if this cpu has to do the parallel processing for |
170 | * the next object. |
171 | */ |
172 | static struct padata_priv *padata_get_next(struct parallel_data *pd) |
173 | { |
174 | int cpu, num_cpus, empty, calc_seq_nr; |
175 | int seq_nr, next_nr, overrun, next_overrun; |
176 | struct padata_queue *queue, *next_queue; |
177 | struct padata_priv *padata; |
178 | struct padata_list *reorder; |
179 | |
180 | empty = 0; |
181 | next_nr = -1; |
182 | next_overrun = 0; |
183 | next_queue = NULL; |
184 | |
185 | num_cpus = cpumask_weight(pd->cpumask); |
186 | |
187 | for_each_cpu(cpu, pd->cpumask) { |
188 | queue = per_cpu_ptr(pd->queue, cpu); |
189 | reorder = &queue->reorder; |
190 | |
191 | /* |
192 | * Calculate the seq_nr of the object that should be |
193 | * next in this reorder queue. |
194 | */ |
195 | overrun = 0; |
196 | calc_seq_nr = (atomic_read(&queue->num_obj) * num_cpus) |
197 | + queue->cpu_index; |
198 | |
199 | if (unlikely(calc_seq_nr > pd->max_seq_nr)) { |
200 | calc_seq_nr = calc_seq_nr - pd->max_seq_nr - 1; |
201 | overrun = 1; |
202 | } |
203 | |
204 | if (!list_empty(&reorder->list)) { |
205 | padata = list_entry(reorder->list.next, |
206 | struct padata_priv, list); |
207 | |
208 | seq_nr = padata->seq_nr; |
209 | BUG_ON(calc_seq_nr != seq_nr); |
210 | } else { |
211 | seq_nr = calc_seq_nr; |
212 | empty++; |
213 | } |
214 | |
215 | if (next_nr < 0 || seq_nr < next_nr |
216 | || (next_overrun && !overrun)) { |
217 | next_nr = seq_nr; |
218 | next_overrun = overrun; |
219 | next_queue = queue; |
220 | } |
221 | } |
222 | |
223 | padata = NULL; |
224 | |
225 | if (empty == num_cpus) |
226 | goto out; |
227 | |
228 | reorder = &next_queue->reorder; |
229 | |
230 | if (!list_empty(&reorder->list)) { |
231 | padata = list_entry(reorder->list.next, |
232 | struct padata_priv, list); |
233 | |
234 | if (unlikely(next_overrun)) { |
235 | for_each_cpu(cpu, pd->cpumask) { |
236 | queue = per_cpu_ptr(pd->queue, cpu); |
237 | atomic_set(&queue->num_obj, 0); |
238 | } |
239 | } |
240 | |
241 | spin_lock(&reorder->lock); |
242 | list_del_init(&padata->list); |
243 | atomic_dec(&pd->reorder_objects); |
244 | spin_unlock(&reorder->lock); |
245 | |
246 | atomic_inc(&next_queue->num_obj); |
247 | |
248 | goto out; |
249 | } |
250 | |
251 | queue = per_cpu_ptr(pd->queue, smp_processor_id()); |
252 | if (queue->cpu_index == next_queue->cpu_index) { |
253 | padata = ERR_PTR(-ENODATA); |
254 | goto out; |
255 | } |
256 | |
257 | padata = ERR_PTR(-EINPROGRESS); |
258 | out: |
259 | return padata; |
260 | } |
261 | |
262 | static void padata_reorder(struct parallel_data *pd) |
263 | { |
264 | struct padata_priv *padata; |
265 | struct padata_queue *queue; |
266 | struct padata_instance *pinst = pd->pinst; |
267 | |
268 | /* |
269 | * We need to ensure that only one cpu can work on dequeueing of |
270 | * the reorder queue the time. Calculating in which percpu reorder |
271 | * queue the next object will arrive takes some time. A spinlock |
272 | * would be highly contended. Also it is not clear in which order |
273 | * the objects arrive to the reorder queues. So a cpu could wait to |
274 | * get the lock just to notice that there is nothing to do at the |
275 | * moment. Therefore we use a trylock and let the holder of the lock |
276 | * care for all the objects enqueued during the holdtime of the lock. |
277 | */ |
278 | if (!spin_trylock_bh(&pd->lock)) |
279 | return; |
280 | |
281 | while (1) { |
282 | padata = padata_get_next(pd); |
283 | |
284 | /* |
285 | * All reorder queues are empty, or the next object that needs |
286 | * serialization is parallel processed by another cpu and is |
287 | * still on it's way to the cpu's reorder queue, nothing to |
288 | * do for now. |
289 | */ |
290 | if (!padata || PTR_ERR(padata) == -EINPROGRESS) |
291 | break; |
292 | |
293 | /* |
294 | * This cpu has to do the parallel processing of the next |
295 | * object. It's waiting in the cpu's parallelization queue, |
296 | * so exit imediately. |
297 | */ |
298 | if (PTR_ERR(padata) == -ENODATA) { |
299 | del_timer(&pd->timer); |
300 | spin_unlock_bh(&pd->lock); |
301 | return; |
302 | } |
303 | |
304 | queue = per_cpu_ptr(pd->queue, padata->cb_cpu); |
305 | |
306 | spin_lock(&queue->serial.lock); |
307 | list_add_tail(&padata->list, &queue->serial.list); |
308 | spin_unlock(&queue->serial.lock); |
309 | |
310 | queue_work_on(padata->cb_cpu, pinst->wq, &queue->swork); |
311 | } |
312 | |
313 | spin_unlock_bh(&pd->lock); |
314 | |
315 | /* |
316 | * The next object that needs serialization might have arrived to |
317 | * the reorder queues in the meantime, we will be called again |
318 | * from the timer function if noone else cares for it. |
319 | */ |
320 | if (atomic_read(&pd->reorder_objects) |
321 | && !(pinst->flags & PADATA_RESET)) |
322 | mod_timer(&pd->timer, jiffies + HZ); |
323 | else |
324 | del_timer(&pd->timer); |
325 | |
326 | return; |
327 | } |
328 | |
329 | static void padata_reorder_timer(unsigned long arg) |
330 | { |
331 | struct parallel_data *pd = (struct parallel_data *)arg; |
332 | |
333 | padata_reorder(pd); |
334 | } |
335 | |
336 | static void padata_serial_worker(struct work_struct *work) |
337 | { |
338 | struct padata_queue *queue; |
339 | struct parallel_data *pd; |
340 | LIST_HEAD(local_list); |
341 | |
342 | local_bh_disable(); |
343 | queue = container_of(work, struct padata_queue, swork); |
344 | pd = queue->pd; |
345 | |
346 | spin_lock(&queue->serial.lock); |
347 | list_replace_init(&queue->serial.list, &local_list); |
348 | spin_unlock(&queue->serial.lock); |
349 | |
350 | while (!list_empty(&local_list)) { |
351 | struct padata_priv *padata; |
352 | |
353 | padata = list_entry(local_list.next, |
354 | struct padata_priv, list); |
355 | |
356 | list_del_init(&padata->list); |
357 | |
358 | padata->serial(padata); |
359 | atomic_dec(&pd->refcnt); |
360 | } |
361 | local_bh_enable(); |
362 | } |
363 | |
364 | /** |
365 | * padata_do_serial - padata serialization function |
366 | * |
367 | * @padata: object to be serialized. |
368 | * |
369 | * padata_do_serial must be called for every parallelized object. |
370 | * The serialization callback function will run with BHs off. |
371 | */ |
372 | void padata_do_serial(struct padata_priv *padata) |
373 | { |
374 | int cpu; |
375 | struct padata_queue *queue; |
376 | struct parallel_data *pd; |
377 | |
378 | pd = padata->pd; |
379 | |
380 | cpu = get_cpu(); |
381 | queue = per_cpu_ptr(pd->queue, cpu); |
382 | |
383 | spin_lock(&queue->reorder.lock); |
384 | atomic_inc(&pd->reorder_objects); |
385 | list_add_tail(&padata->list, &queue->reorder.list); |
386 | spin_unlock(&queue->reorder.lock); |
387 | |
388 | put_cpu(); |
389 | |
390 | padata_reorder(pd); |
391 | } |
392 | EXPORT_SYMBOL(padata_do_serial); |
393 | |
394 | /* Allocate and initialize the internal cpumask dependend resources. */ |
395 | static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst, |
396 | const struct cpumask *cpumask) |
397 | { |
398 | int cpu, cpu_index, num_cpus; |
399 | struct padata_queue *queue; |
400 | struct parallel_data *pd; |
401 | |
402 | cpu_index = 0; |
403 | |
404 | pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL); |
405 | if (!pd) |
406 | goto err; |
407 | |
408 | pd->queue = alloc_percpu(struct padata_queue); |
409 | if (!pd->queue) |
410 | goto err_free_pd; |
411 | |
412 | if (!alloc_cpumask_var(&pd->cpumask, GFP_KERNEL)) |
413 | goto err_free_queue; |
414 | |
415 | cpumask_and(pd->cpumask, cpumask, cpu_active_mask); |
416 | |
417 | for_each_cpu(cpu, pd->cpumask) { |
418 | queue = per_cpu_ptr(pd->queue, cpu); |
419 | |
420 | queue->pd = pd; |
421 | |
422 | queue->cpu_index = cpu_index; |
423 | cpu_index++; |
424 | |
425 | INIT_LIST_HEAD(&queue->reorder.list); |
426 | INIT_LIST_HEAD(&queue->parallel.list); |
427 | INIT_LIST_HEAD(&queue->serial.list); |
428 | spin_lock_init(&queue->reorder.lock); |
429 | spin_lock_init(&queue->parallel.lock); |
430 | spin_lock_init(&queue->serial.lock); |
431 | |
432 | INIT_WORK(&queue->pwork, padata_parallel_worker); |
433 | INIT_WORK(&queue->swork, padata_serial_worker); |
434 | atomic_set(&queue->num_obj, 0); |
435 | } |
436 | |
437 | num_cpus = cpumask_weight(pd->cpumask); |
438 | pd->max_seq_nr = (MAX_SEQ_NR / num_cpus) * num_cpus - 1; |
439 | |
440 | setup_timer(&pd->timer, padata_reorder_timer, (unsigned long)pd); |
441 | atomic_set(&pd->seq_nr, -1); |
442 | atomic_set(&pd->reorder_objects, 0); |
443 | atomic_set(&pd->refcnt, 0); |
444 | pd->pinst = pinst; |
445 | spin_lock_init(&pd->lock); |
446 | |
447 | return pd; |
448 | |
449 | err_free_queue: |
450 | free_percpu(pd->queue); |
451 | err_free_pd: |
452 | kfree(pd); |
453 | err: |
454 | return NULL; |
455 | } |
456 | |
457 | static void padata_free_pd(struct parallel_data *pd) |
458 | { |
459 | free_cpumask_var(pd->cpumask); |
460 | free_percpu(pd->queue); |
461 | kfree(pd); |
462 | } |
463 | |
464 | /* Flush all objects out of the padata queues. */ |
465 | static void padata_flush_queues(struct parallel_data *pd) |
466 | { |
467 | int cpu; |
468 | struct padata_queue *queue; |
469 | |
470 | for_each_cpu(cpu, pd->cpumask) { |
471 | queue = per_cpu_ptr(pd->queue, cpu); |
472 | flush_work(&queue->pwork); |
473 | } |
474 | |
475 | del_timer_sync(&pd->timer); |
476 | |
477 | if (atomic_read(&pd->reorder_objects)) |
478 | padata_reorder(pd); |
479 | |
480 | for_each_cpu(cpu, pd->cpumask) { |
481 | queue = per_cpu_ptr(pd->queue, cpu); |
482 | flush_work(&queue->swork); |
483 | } |
484 | |
485 | BUG_ON(atomic_read(&pd->refcnt) != 0); |
486 | } |
487 | |
488 | /* Replace the internal control stucture with a new one. */ |
489 | static void padata_replace(struct padata_instance *pinst, |
490 | struct parallel_data *pd_new) |
491 | { |
492 | struct parallel_data *pd_old = pinst->pd; |
493 | |
494 | pinst->flags |= PADATA_RESET; |
495 | |
496 | rcu_assign_pointer(pinst->pd, pd_new); |
497 | |
498 | synchronize_rcu(); |
499 | |
500 | padata_flush_queues(pd_old); |
501 | padata_free_pd(pd_old); |
502 | |
503 | pinst->flags &= ~PADATA_RESET; |
504 | } |
505 | |
506 | /** |
507 | * padata_set_cpumask - set the cpumask that padata should use |
508 | * |
509 | * @pinst: padata instance |
510 | * @cpumask: the cpumask to use |
511 | */ |
512 | int padata_set_cpumask(struct padata_instance *pinst, |
513 | cpumask_var_t cpumask) |
514 | { |
515 | struct parallel_data *pd; |
516 | int err = 0; |
517 | |
518 | mutex_lock(&pinst->lock); |
519 | |
520 | get_online_cpus(); |
521 | |
522 | pd = padata_alloc_pd(pinst, cpumask); |
523 | if (!pd) { |
524 | err = -ENOMEM; |
525 | goto out; |
526 | } |
527 | |
528 | cpumask_copy(pinst->cpumask, cpumask); |
529 | |
530 | padata_replace(pinst, pd); |
531 | |
532 | out: |
533 | put_online_cpus(); |
534 | |
535 | mutex_unlock(&pinst->lock); |
536 | |
537 | return err; |
538 | } |
539 | EXPORT_SYMBOL(padata_set_cpumask); |
540 | |
541 | static int __padata_add_cpu(struct padata_instance *pinst, int cpu) |
542 | { |
543 | struct parallel_data *pd; |
544 | |
545 | if (cpumask_test_cpu(cpu, cpu_active_mask)) { |
546 | pd = padata_alloc_pd(pinst, pinst->cpumask); |
547 | if (!pd) |
548 | return -ENOMEM; |
549 | |
550 | padata_replace(pinst, pd); |
551 | } |
552 | |
553 | return 0; |
554 | } |
555 | |
556 | /** |
557 | * padata_add_cpu - add a cpu to the padata cpumask |
558 | * |
559 | * @pinst: padata instance |
560 | * @cpu: cpu to add |
561 | */ |
562 | int padata_add_cpu(struct padata_instance *pinst, int cpu) |
563 | { |
564 | int err; |
565 | |
566 | mutex_lock(&pinst->lock); |
567 | |
568 | get_online_cpus(); |
569 | cpumask_set_cpu(cpu, pinst->cpumask); |
570 | err = __padata_add_cpu(pinst, cpu); |
571 | put_online_cpus(); |
572 | |
573 | mutex_unlock(&pinst->lock); |
574 | |
575 | return err; |
576 | } |
577 | EXPORT_SYMBOL(padata_add_cpu); |
578 | |
579 | static int __padata_remove_cpu(struct padata_instance *pinst, int cpu) |
580 | { |
581 | struct parallel_data *pd; |
582 | |
583 | if (cpumask_test_cpu(cpu, cpu_online_mask)) { |
584 | pd = padata_alloc_pd(pinst, pinst->cpumask); |
585 | if (!pd) |
586 | return -ENOMEM; |
587 | |
588 | padata_replace(pinst, pd); |
589 | } |
590 | |
591 | return 0; |
592 | } |
593 | |
594 | /** |
595 | * padata_remove_cpu - remove a cpu from the padata cpumask |
596 | * |
597 | * @pinst: padata instance |
598 | * @cpu: cpu to remove |
599 | */ |
600 | int padata_remove_cpu(struct padata_instance *pinst, int cpu) |
601 | { |
602 | int err; |
603 | |
604 | mutex_lock(&pinst->lock); |
605 | |
606 | get_online_cpus(); |
607 | cpumask_clear_cpu(cpu, pinst->cpumask); |
608 | err = __padata_remove_cpu(pinst, cpu); |
609 | put_online_cpus(); |
610 | |
611 | mutex_unlock(&pinst->lock); |
612 | |
613 | return err; |
614 | } |
615 | EXPORT_SYMBOL(padata_remove_cpu); |
616 | |
617 | /** |
618 | * padata_start - start the parallel processing |
619 | * |
620 | * @pinst: padata instance to start |
621 | */ |
622 | void padata_start(struct padata_instance *pinst) |
623 | { |
624 | mutex_lock(&pinst->lock); |
625 | pinst->flags |= PADATA_INIT; |
626 | mutex_unlock(&pinst->lock); |
627 | } |
628 | EXPORT_SYMBOL(padata_start); |
629 | |
630 | /** |
631 | * padata_stop - stop the parallel processing |
632 | * |
633 | * @pinst: padata instance to stop |
634 | */ |
635 | void padata_stop(struct padata_instance *pinst) |
636 | { |
637 | mutex_lock(&pinst->lock); |
638 | pinst->flags &= ~PADATA_INIT; |
639 | mutex_unlock(&pinst->lock); |
640 | } |
641 | EXPORT_SYMBOL(padata_stop); |
642 | |
643 | #ifdef CONFIG_HOTPLUG_CPU |
644 | static int padata_cpu_callback(struct notifier_block *nfb, |
645 | unsigned long action, void *hcpu) |
646 | { |
647 | int err; |
648 | struct padata_instance *pinst; |
649 | int cpu = (unsigned long)hcpu; |
650 | |
651 | pinst = container_of(nfb, struct padata_instance, cpu_notifier); |
652 | |
653 | switch (action) { |
654 | case CPU_ONLINE: |
655 | case CPU_ONLINE_FROZEN: |
656 | if (!cpumask_test_cpu(cpu, pinst->cpumask)) |
657 | break; |
658 | mutex_lock(&pinst->lock); |
659 | err = __padata_add_cpu(pinst, cpu); |
660 | mutex_unlock(&pinst->lock); |
661 | if (err) |
662 | return notifier_from_errno(err); |
663 | break; |
664 | |
665 | case CPU_DOWN_PREPARE: |
666 | case CPU_DOWN_PREPARE_FROZEN: |
667 | if (!cpumask_test_cpu(cpu, pinst->cpumask)) |
668 | break; |
669 | mutex_lock(&pinst->lock); |
670 | err = __padata_remove_cpu(pinst, cpu); |
671 | mutex_unlock(&pinst->lock); |
672 | if (err) |
673 | return notifier_from_errno(err); |
674 | break; |
675 | |
676 | case CPU_UP_CANCELED: |
677 | case CPU_UP_CANCELED_FROZEN: |
678 | if (!cpumask_test_cpu(cpu, pinst->cpumask)) |
679 | break; |
680 | mutex_lock(&pinst->lock); |
681 | __padata_remove_cpu(pinst, cpu); |
682 | mutex_unlock(&pinst->lock); |
683 | |
684 | case CPU_DOWN_FAILED: |
685 | case CPU_DOWN_FAILED_FROZEN: |
686 | if (!cpumask_test_cpu(cpu, pinst->cpumask)) |
687 | break; |
688 | mutex_lock(&pinst->lock); |
689 | __padata_add_cpu(pinst, cpu); |
690 | mutex_unlock(&pinst->lock); |
691 | } |
692 | |
693 | return NOTIFY_OK; |
694 | } |
695 | #endif |
696 | |
697 | /** |
698 | * padata_alloc - allocate and initialize a padata instance |
699 | * |
700 | * @cpumask: cpumask that padata uses for parallelization |
701 | * @wq: workqueue to use for the allocated padata instance |
702 | */ |
703 | struct padata_instance *padata_alloc(const struct cpumask *cpumask, |
704 | struct workqueue_struct *wq) |
705 | { |
706 | struct padata_instance *pinst; |
707 | struct parallel_data *pd; |
708 | |
709 | pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL); |
710 | if (!pinst) |
711 | goto err; |
712 | |
713 | get_online_cpus(); |
714 | |
715 | pd = padata_alloc_pd(pinst, cpumask); |
716 | if (!pd) |
717 | goto err_free_inst; |
718 | |
719 | if (!alloc_cpumask_var(&pinst->cpumask, GFP_KERNEL)) |
720 | goto err_free_pd; |
721 | |
722 | rcu_assign_pointer(pinst->pd, pd); |
723 | |
724 | pinst->wq = wq; |
725 | |
726 | cpumask_copy(pinst->cpumask, cpumask); |
727 | |
728 | pinst->flags = 0; |
729 | |
730 | #ifdef CONFIG_HOTPLUG_CPU |
731 | pinst->cpu_notifier.notifier_call = padata_cpu_callback; |
732 | pinst->cpu_notifier.priority = 0; |
733 | register_hotcpu_notifier(&pinst->cpu_notifier); |
734 | #endif |
735 | |
736 | put_online_cpus(); |
737 | |
738 | mutex_init(&pinst->lock); |
739 | |
740 | return pinst; |
741 | |
742 | err_free_pd: |
743 | padata_free_pd(pd); |
744 | err_free_inst: |
745 | kfree(pinst); |
746 | put_online_cpus(); |
747 | err: |
748 | return NULL; |
749 | } |
750 | EXPORT_SYMBOL(padata_alloc); |
751 | |
752 | /** |
753 | * padata_free - free a padata instance |
754 | * |
755 | * @padata_inst: padata instance to free |
756 | */ |
757 | void padata_free(struct padata_instance *pinst) |
758 | { |
759 | padata_stop(pinst); |
760 | |
761 | synchronize_rcu(); |
762 | |
763 | #ifdef CONFIG_HOTPLUG_CPU |
764 | unregister_hotcpu_notifier(&pinst->cpu_notifier); |
765 | #endif |
766 | get_online_cpus(); |
767 | padata_flush_queues(pinst->pd); |
768 | put_online_cpus(); |
769 | |
770 | padata_free_pd(pinst->pd); |
771 | free_cpumask_var(pinst->cpumask); |
772 | kfree(pinst); |
773 | } |
774 | EXPORT_SYMBOL(padata_free); |
775 |
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javiroman/ks7010
jz-2.6.34
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9