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16295bec SK |
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> | |
5a0e3ad6 | 28 | #include <linux/slab.h> |
16295bec SK |
29 | #include <linux/rcupdate.h> |
30 | ||
31 | #define MAX_SEQ_NR INT_MAX - NR_CPUS | |
97e3d94a | 32 | #define MAX_OBJ_NUM 1000 |
16295bec SK |
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 | static struct padata_priv *padata_get_next(struct parallel_data *pd) | |
156 | { | |
157 | int cpu, num_cpus, empty, calc_seq_nr; | |
158 | int seq_nr, next_nr, overrun, next_overrun; | |
159 | struct padata_queue *queue, *next_queue; | |
160 | struct padata_priv *padata; | |
161 | struct padata_list *reorder; | |
162 | ||
163 | empty = 0; | |
164 | next_nr = -1; | |
165 | next_overrun = 0; | |
166 | next_queue = NULL; | |
167 | ||
168 | num_cpus = cpumask_weight(pd->cpumask); | |
169 | ||
170 | for_each_cpu(cpu, pd->cpumask) { | |
171 | queue = per_cpu_ptr(pd->queue, cpu); | |
172 | reorder = &queue->reorder; | |
173 | ||
174 | /* | |
175 | * Calculate the seq_nr of the object that should be | |
176 | * next in this queue. | |
177 | */ | |
178 | overrun = 0; | |
179 | calc_seq_nr = (atomic_read(&queue->num_obj) * num_cpus) | |
180 | + queue->cpu_index; | |
181 | ||
182 | if (unlikely(calc_seq_nr > pd->max_seq_nr)) { | |
183 | calc_seq_nr = calc_seq_nr - pd->max_seq_nr - 1; | |
184 | overrun = 1; | |
185 | } | |
186 | ||
187 | if (!list_empty(&reorder->list)) { | |
188 | padata = list_entry(reorder->list.next, | |
189 | struct padata_priv, list); | |
190 | ||
191 | seq_nr = padata->seq_nr; | |
192 | BUG_ON(calc_seq_nr != seq_nr); | |
193 | } else { | |
194 | seq_nr = calc_seq_nr; | |
195 | empty++; | |
196 | } | |
197 | ||
198 | if (next_nr < 0 || seq_nr < next_nr | |
199 | || (next_overrun && !overrun)) { | |
200 | next_nr = seq_nr; | |
201 | next_overrun = overrun; | |
202 | next_queue = queue; | |
203 | } | |
204 | } | |
205 | ||
206 | padata = NULL; | |
207 | ||
208 | if (empty == num_cpus) | |
209 | goto out; | |
210 | ||
211 | reorder = &next_queue->reorder; | |
212 | ||
213 | if (!list_empty(&reorder->list)) { | |
214 | padata = list_entry(reorder->list.next, | |
215 | struct padata_priv, list); | |
216 | ||
217 | if (unlikely(next_overrun)) { | |
218 | for_each_cpu(cpu, pd->cpumask) { | |
219 | queue = per_cpu_ptr(pd->queue, cpu); | |
220 | atomic_set(&queue->num_obj, 0); | |
221 | } | |
222 | } | |
223 | ||
224 | spin_lock(&reorder->lock); | |
225 | list_del_init(&padata->list); | |
226 | atomic_dec(&pd->reorder_objects); | |
227 | spin_unlock(&reorder->lock); | |
228 | ||
229 | atomic_inc(&next_queue->num_obj); | |
230 | ||
231 | goto out; | |
232 | } | |
233 | ||
234 | if (next_nr % num_cpus == next_queue->cpu_index) { | |
235 | padata = ERR_PTR(-ENODATA); | |
236 | goto out; | |
237 | } | |
238 | ||
239 | padata = ERR_PTR(-EINPROGRESS); | |
240 | out: | |
241 | return padata; | |
242 | } | |
243 | ||
244 | static void padata_reorder(struct parallel_data *pd) | |
245 | { | |
246 | struct padata_priv *padata; | |
247 | struct padata_queue *queue; | |
248 | struct padata_instance *pinst = pd->pinst; | |
249 | ||
250 | try_again: | |
251 | if (!spin_trylock_bh(&pd->lock)) | |
252 | goto out; | |
253 | ||
254 | while (1) { | |
255 | padata = padata_get_next(pd); | |
256 | ||
257 | if (!padata || PTR_ERR(padata) == -EINPROGRESS) | |
258 | break; | |
259 | ||
260 | if (PTR_ERR(padata) == -ENODATA) { | |
261 | spin_unlock_bh(&pd->lock); | |
262 | goto out; | |
263 | } | |
264 | ||
265 | queue = per_cpu_ptr(pd->queue, padata->cb_cpu); | |
266 | ||
267 | spin_lock(&queue->serial.lock); | |
268 | list_add_tail(&padata->list, &queue->serial.list); | |
269 | spin_unlock(&queue->serial.lock); | |
270 | ||
271 | queue_work_on(padata->cb_cpu, pinst->wq, &queue->swork); | |
272 | } | |
273 | ||
274 | spin_unlock_bh(&pd->lock); | |
275 | ||
276 | if (atomic_read(&pd->reorder_objects)) | |
277 | goto try_again; | |
278 | ||
279 | out: | |
280 | return; | |
281 | } | |
282 | ||
283 | static void padata_serial_worker(struct work_struct *work) | |
284 | { | |
285 | struct padata_queue *queue; | |
286 | struct parallel_data *pd; | |
287 | LIST_HEAD(local_list); | |
288 | ||
289 | local_bh_disable(); | |
290 | queue = container_of(work, struct padata_queue, swork); | |
291 | pd = queue->pd; | |
292 | ||
293 | spin_lock(&queue->serial.lock); | |
294 | list_replace_init(&queue->serial.list, &local_list); | |
295 | spin_unlock(&queue->serial.lock); | |
296 | ||
297 | while (!list_empty(&local_list)) { | |
298 | struct padata_priv *padata; | |
299 | ||
300 | padata = list_entry(local_list.next, | |
301 | struct padata_priv, list); | |
302 | ||
303 | list_del_init(&padata->list); | |
304 | ||
305 | padata->serial(padata); | |
306 | atomic_dec(&pd->refcnt); | |
307 | } | |
308 | local_bh_enable(); | |
309 | } | |
310 | ||
311 | /* | |
312 | * padata_do_serial - padata serialization function | |
313 | * | |
314 | * @padata: object to be serialized. | |
315 | * | |
316 | * padata_do_serial must be called for every parallelized object. | |
317 | * The serialization callback function will run with BHs off. | |
318 | */ | |
319 | void padata_do_serial(struct padata_priv *padata) | |
320 | { | |
321 | int cpu; | |
322 | struct padata_queue *queue; | |
323 | struct parallel_data *pd; | |
324 | ||
325 | pd = padata->pd; | |
326 | ||
327 | cpu = get_cpu(); | |
328 | queue = per_cpu_ptr(pd->queue, cpu); | |
329 | ||
330 | spin_lock(&queue->reorder.lock); | |
331 | atomic_inc(&pd->reorder_objects); | |
332 | list_add_tail(&padata->list, &queue->reorder.list); | |
333 | spin_unlock(&queue->reorder.lock); | |
334 | ||
335 | put_cpu(); | |
336 | ||
337 | padata_reorder(pd); | |
338 | } | |
339 | EXPORT_SYMBOL(padata_do_serial); | |
340 | ||
341 | static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst, | |
342 | const struct cpumask *cpumask) | |
343 | { | |
344 | int cpu, cpu_index, num_cpus; | |
345 | struct padata_queue *queue; | |
346 | struct parallel_data *pd; | |
347 | ||
348 | cpu_index = 0; | |
349 | ||
350 | pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL); | |
351 | if (!pd) | |
352 | goto err; | |
353 | ||
354 | pd->queue = alloc_percpu(struct padata_queue); | |
355 | if (!pd->queue) | |
356 | goto err_free_pd; | |
357 | ||
358 | if (!alloc_cpumask_var(&pd->cpumask, GFP_KERNEL)) | |
359 | goto err_free_queue; | |
360 | ||
7b389b2c SK |
361 | cpumask_and(pd->cpumask, cpumask, cpu_active_mask); |
362 | ||
363 | for_each_cpu(cpu, pd->cpumask) { | |
16295bec SK |
364 | queue = per_cpu_ptr(pd->queue, cpu); |
365 | ||
366 | queue->pd = pd; | |
367 | ||
7b389b2c SK |
368 | queue->cpu_index = cpu_index; |
369 | cpu_index++; | |
16295bec SK |
370 | |
371 | INIT_LIST_HEAD(&queue->reorder.list); | |
372 | INIT_LIST_HEAD(&queue->parallel.list); | |
373 | INIT_LIST_HEAD(&queue->serial.list); | |
374 | spin_lock_init(&queue->reorder.lock); | |
375 | spin_lock_init(&queue->parallel.lock); | |
376 | spin_lock_init(&queue->serial.lock); | |
377 | ||
378 | INIT_WORK(&queue->pwork, padata_parallel_worker); | |
379 | INIT_WORK(&queue->swork, padata_serial_worker); | |
380 | atomic_set(&queue->num_obj, 0); | |
381 | } | |
382 | ||
16295bec SK |
383 | num_cpus = cpumask_weight(pd->cpumask); |
384 | pd->max_seq_nr = (MAX_SEQ_NR / num_cpus) * num_cpus - 1; | |
385 | ||
386 | atomic_set(&pd->seq_nr, -1); | |
387 | atomic_set(&pd->reorder_objects, 0); | |
388 | atomic_set(&pd->refcnt, 0); | |
389 | pd->pinst = pinst; | |
390 | spin_lock_init(&pd->lock); | |
391 | ||
392 | return pd; | |
393 | ||
394 | err_free_queue: | |
395 | free_percpu(pd->queue); | |
396 | err_free_pd: | |
397 | kfree(pd); | |
398 | err: | |
399 | return NULL; | |
400 | } | |
401 | ||
402 | static void padata_free_pd(struct parallel_data *pd) | |
403 | { | |
404 | free_cpumask_var(pd->cpumask); | |
405 | free_percpu(pd->queue); | |
406 | kfree(pd); | |
407 | } | |
408 | ||
409 | static void padata_replace(struct padata_instance *pinst, | |
410 | struct parallel_data *pd_new) | |
411 | { | |
412 | struct parallel_data *pd_old = pinst->pd; | |
413 | ||
414 | pinst->flags |= PADATA_RESET; | |
415 | ||
416 | rcu_assign_pointer(pinst->pd, pd_new); | |
417 | ||
418 | synchronize_rcu(); | |
419 | ||
420 | while (atomic_read(&pd_old->refcnt) != 0) | |
421 | yield(); | |
422 | ||
423 | flush_workqueue(pinst->wq); | |
424 | ||
425 | padata_free_pd(pd_old); | |
426 | ||
427 | pinst->flags &= ~PADATA_RESET; | |
428 | } | |
429 | ||
430 | /* | |
431 | * padata_set_cpumask - set the cpumask that padata should use | |
432 | * | |
433 | * @pinst: padata instance | |
434 | * @cpumask: the cpumask to use | |
435 | */ | |
436 | int padata_set_cpumask(struct padata_instance *pinst, | |
437 | cpumask_var_t cpumask) | |
438 | { | |
439 | struct parallel_data *pd; | |
440 | int err = 0; | |
441 | ||
16295bec SK |
442 | mutex_lock(&pinst->lock); |
443 | ||
6751fb3c SK |
444 | get_online_cpus(); |
445 | ||
16295bec SK |
446 | pd = padata_alloc_pd(pinst, cpumask); |
447 | if (!pd) { | |
448 | err = -ENOMEM; | |
449 | goto out; | |
450 | } | |
451 | ||
452 | cpumask_copy(pinst->cpumask, cpumask); | |
453 | ||
454 | padata_replace(pinst, pd); | |
455 | ||
456 | out: | |
6751fb3c SK |
457 | put_online_cpus(); |
458 | ||
16295bec SK |
459 | mutex_unlock(&pinst->lock); |
460 | ||
461 | return err; | |
462 | } | |
463 | EXPORT_SYMBOL(padata_set_cpumask); | |
464 | ||
465 | static int __padata_add_cpu(struct padata_instance *pinst, int cpu) | |
466 | { | |
467 | struct parallel_data *pd; | |
468 | ||
469 | if (cpumask_test_cpu(cpu, cpu_active_mask)) { | |
470 | pd = padata_alloc_pd(pinst, pinst->cpumask); | |
471 | if (!pd) | |
472 | return -ENOMEM; | |
473 | ||
474 | padata_replace(pinst, pd); | |
475 | } | |
476 | ||
477 | return 0; | |
478 | } | |
479 | ||
480 | /* | |
481 | * padata_add_cpu - add a cpu to the padata cpumask | |
482 | * | |
483 | * @pinst: padata instance | |
484 | * @cpu: cpu to add | |
485 | */ | |
486 | int padata_add_cpu(struct padata_instance *pinst, int cpu) | |
487 | { | |
488 | int err; | |
489 | ||
16295bec SK |
490 | mutex_lock(&pinst->lock); |
491 | ||
6751fb3c | 492 | get_online_cpus(); |
16295bec SK |
493 | cpumask_set_cpu(cpu, pinst->cpumask); |
494 | err = __padata_add_cpu(pinst, cpu); | |
6751fb3c | 495 | put_online_cpus(); |
16295bec SK |
496 | |
497 | mutex_unlock(&pinst->lock); | |
498 | ||
499 | return err; | |
500 | } | |
501 | EXPORT_SYMBOL(padata_add_cpu); | |
502 | ||
503 | static int __padata_remove_cpu(struct padata_instance *pinst, int cpu) | |
504 | { | |
505 | struct parallel_data *pd; | |
506 | ||
507 | if (cpumask_test_cpu(cpu, cpu_online_mask)) { | |
508 | pd = padata_alloc_pd(pinst, pinst->cpumask); | |
509 | if (!pd) | |
510 | return -ENOMEM; | |
511 | ||
512 | padata_replace(pinst, pd); | |
513 | } | |
514 | ||
515 | return 0; | |
516 | } | |
517 | ||
518 | /* | |
519 | * padata_remove_cpu - remove a cpu from the padata cpumask | |
520 | * | |
521 | * @pinst: padata instance | |
522 | * @cpu: cpu to remove | |
523 | */ | |
524 | int padata_remove_cpu(struct padata_instance *pinst, int cpu) | |
525 | { | |
526 | int err; | |
527 | ||
16295bec SK |
528 | mutex_lock(&pinst->lock); |
529 | ||
6751fb3c | 530 | get_online_cpus(); |
16295bec SK |
531 | cpumask_clear_cpu(cpu, pinst->cpumask); |
532 | err = __padata_remove_cpu(pinst, cpu); | |
6751fb3c | 533 | put_online_cpus(); |
16295bec SK |
534 | |
535 | mutex_unlock(&pinst->lock); | |
536 | ||
537 | return err; | |
538 | } | |
539 | EXPORT_SYMBOL(padata_remove_cpu); | |
540 | ||
541 | /* | |
542 | * padata_start - start the parallel processing | |
543 | * | |
544 | * @pinst: padata instance to start | |
545 | */ | |
546 | void padata_start(struct padata_instance *pinst) | |
547 | { | |
16295bec SK |
548 | mutex_lock(&pinst->lock); |
549 | pinst->flags |= PADATA_INIT; | |
550 | mutex_unlock(&pinst->lock); | |
551 | } | |
552 | EXPORT_SYMBOL(padata_start); | |
553 | ||
554 | /* | |
555 | * padata_stop - stop the parallel processing | |
556 | * | |
557 | * @pinst: padata instance to stop | |
558 | */ | |
559 | void padata_stop(struct padata_instance *pinst) | |
560 | { | |
16295bec SK |
561 | mutex_lock(&pinst->lock); |
562 | pinst->flags &= ~PADATA_INIT; | |
563 | mutex_unlock(&pinst->lock); | |
564 | } | |
565 | EXPORT_SYMBOL(padata_stop); | |
566 | ||
e2cb2f1c | 567 | #ifdef CONFIG_HOTPLUG_CPU |
975d2603 HK |
568 | static int padata_cpu_callback(struct notifier_block *nfb, |
569 | unsigned long action, void *hcpu) | |
16295bec SK |
570 | { |
571 | int err; | |
572 | struct padata_instance *pinst; | |
573 | int cpu = (unsigned long)hcpu; | |
574 | ||
575 | pinst = container_of(nfb, struct padata_instance, cpu_notifier); | |
576 | ||
577 | switch (action) { | |
578 | case CPU_ONLINE: | |
579 | case CPU_ONLINE_FROZEN: | |
580 | if (!cpumask_test_cpu(cpu, pinst->cpumask)) | |
581 | break; | |
582 | mutex_lock(&pinst->lock); | |
583 | err = __padata_add_cpu(pinst, cpu); | |
584 | mutex_unlock(&pinst->lock); | |
585 | if (err) | |
586 | return NOTIFY_BAD; | |
587 | break; | |
588 | ||
589 | case CPU_DOWN_PREPARE: | |
590 | case CPU_DOWN_PREPARE_FROZEN: | |
591 | if (!cpumask_test_cpu(cpu, pinst->cpumask)) | |
592 | break; | |
593 | mutex_lock(&pinst->lock); | |
594 | err = __padata_remove_cpu(pinst, cpu); | |
595 | mutex_unlock(&pinst->lock); | |
596 | if (err) | |
597 | return NOTIFY_BAD; | |
598 | break; | |
599 | ||
600 | case CPU_UP_CANCELED: | |
601 | case CPU_UP_CANCELED_FROZEN: | |
602 | if (!cpumask_test_cpu(cpu, pinst->cpumask)) | |
603 | break; | |
604 | mutex_lock(&pinst->lock); | |
605 | __padata_remove_cpu(pinst, cpu); | |
606 | mutex_unlock(&pinst->lock); | |
607 | ||
608 | case CPU_DOWN_FAILED: | |
609 | case CPU_DOWN_FAILED_FROZEN: | |
610 | if (!cpumask_test_cpu(cpu, pinst->cpumask)) | |
611 | break; | |
612 | mutex_lock(&pinst->lock); | |
613 | __padata_add_cpu(pinst, cpu); | |
614 | mutex_unlock(&pinst->lock); | |
615 | } | |
616 | ||
617 | return NOTIFY_OK; | |
618 | } | |
e2cb2f1c | 619 | #endif |
16295bec SK |
620 | |
621 | /* | |
622 | * padata_alloc - allocate and initialize a padata instance | |
623 | * | |
624 | * @cpumask: cpumask that padata uses for parallelization | |
625 | * @wq: workqueue to use for the allocated padata instance | |
626 | */ | |
627 | struct padata_instance *padata_alloc(const struct cpumask *cpumask, | |
628 | struct workqueue_struct *wq) | |
629 | { | |
16295bec SK |
630 | struct padata_instance *pinst; |
631 | struct parallel_data *pd; | |
632 | ||
633 | pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL); | |
634 | if (!pinst) | |
635 | goto err; | |
636 | ||
6751fb3c SK |
637 | get_online_cpus(); |
638 | ||
16295bec SK |
639 | pd = padata_alloc_pd(pinst, cpumask); |
640 | if (!pd) | |
641 | goto err_free_inst; | |
642 | ||
74781387 SK |
643 | if (!alloc_cpumask_var(&pinst->cpumask, GFP_KERNEL)) |
644 | goto err_free_pd; | |
645 | ||
16295bec SK |
646 | rcu_assign_pointer(pinst->pd, pd); |
647 | ||
648 | pinst->wq = wq; | |
649 | ||
650 | cpumask_copy(pinst->cpumask, cpumask); | |
651 | ||
652 | pinst->flags = 0; | |
653 | ||
e2cb2f1c | 654 | #ifdef CONFIG_HOTPLUG_CPU |
16295bec SK |
655 | pinst->cpu_notifier.notifier_call = padata_cpu_callback; |
656 | pinst->cpu_notifier.priority = 0; | |
e2cb2f1c SK |
657 | register_hotcpu_notifier(&pinst->cpu_notifier); |
658 | #endif | |
16295bec | 659 | |
6751fb3c SK |
660 | put_online_cpus(); |
661 | ||
16295bec SK |
662 | mutex_init(&pinst->lock); |
663 | ||
664 | return pinst; | |
665 | ||
666 | err_free_pd: | |
667 | padata_free_pd(pd); | |
668 | err_free_inst: | |
669 | kfree(pinst); | |
6751fb3c | 670 | put_online_cpus(); |
16295bec SK |
671 | err: |
672 | return NULL; | |
673 | } | |
674 | EXPORT_SYMBOL(padata_alloc); | |
675 | ||
676 | /* | |
677 | * padata_free - free a padata instance | |
678 | * | |
679 | * @ padata_inst: padata instance to free | |
680 | */ | |
681 | void padata_free(struct padata_instance *pinst) | |
682 | { | |
683 | padata_stop(pinst); | |
684 | ||
685 | synchronize_rcu(); | |
686 | ||
687 | while (atomic_read(&pinst->pd->refcnt) != 0) | |
688 | yield(); | |
689 | ||
e2cb2f1c | 690 | #ifdef CONFIG_HOTPLUG_CPU |
16295bec | 691 | unregister_hotcpu_notifier(&pinst->cpu_notifier); |
e2cb2f1c | 692 | #endif |
16295bec | 693 | padata_free_pd(pinst->pd); |
74781387 | 694 | free_cpumask_var(pinst->cpumask); |
16295bec SK |
695 | kfree(pinst); |
696 | } | |
697 | EXPORT_SYMBOL(padata_free); |