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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 | ||
0198ffd1 | 91 | /** |
16295bec SK |
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 | ||
0198ffd1 SK |
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 | */ | |
16295bec SK |
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 | |
0198ffd1 | 193 | * next in this reorder queue. |
16295bec SK |
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 | ||
d46a5ac7 SK |
251 | queue = per_cpu_ptr(pd->queue, smp_processor_id()); |
252 | if (queue->cpu_index == next_queue->cpu_index) { | |
16295bec SK |
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 | ||
0198ffd1 SK |
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 | */ | |
16295bec | 278 | if (!spin_trylock_bh(&pd->lock)) |
d46a5ac7 | 279 | return; |
16295bec SK |
280 | |
281 | while (1) { | |
282 | padata = padata_get_next(pd); | |
283 | ||
0198ffd1 SK |
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 | */ | |
16295bec SK |
290 | if (!padata || PTR_ERR(padata) == -EINPROGRESS) |
291 | break; | |
292 | ||
0198ffd1 SK |
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 | */ | |
16295bec | 298 | if (PTR_ERR(padata) == -ENODATA) { |
d46a5ac7 | 299 | del_timer(&pd->timer); |
16295bec | 300 | spin_unlock_bh(&pd->lock); |
d46a5ac7 | 301 | return; |
16295bec SK |
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 | ||
0198ffd1 SK |
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 | */ | |
d46a5ac7 SK |
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); | |
16295bec | 325 | |
16295bec SK |
326 | return; |
327 | } | |
328 | ||
d46a5ac7 SK |
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 | ||
16295bec SK |
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 | ||
0198ffd1 | 364 | /** |
16295bec SK |
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 | ||
0198ffd1 | 394 | /* Allocate and initialize the internal cpumask dependend resources. */ |
16295bec SK |
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 | ||
7b389b2c SK |
415 | cpumask_and(pd->cpumask, cpumask, cpu_active_mask); |
416 | ||
417 | for_each_cpu(cpu, pd->cpumask) { | |
16295bec SK |
418 | queue = per_cpu_ptr(pd->queue, cpu); |
419 | ||
420 | queue->pd = pd; | |
421 | ||
7b389b2c SK |
422 | queue->cpu_index = cpu_index; |
423 | cpu_index++; | |
16295bec SK |
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 | ||
16295bec SK |
437 | num_cpus = cpumask_weight(pd->cpumask); |
438 | pd->max_seq_nr = (MAX_SEQ_NR / num_cpus) * num_cpus - 1; | |
439 | ||
d46a5ac7 | 440 | setup_timer(&pd->timer, padata_reorder_timer, (unsigned long)pd); |
16295bec SK |
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 | ||
0198ffd1 | 464 | /* Flush all objects out of the padata queues. */ |
2b73b07a SK |
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 | ||
0198ffd1 | 488 | /* Replace the internal control stucture with a new one. */ |
16295bec SK |
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 | ||
2b73b07a | 500 | padata_flush_queues(pd_old); |
16295bec SK |
501 | padata_free_pd(pd_old); |
502 | ||
503 | pinst->flags &= ~PADATA_RESET; | |
504 | } | |
505 | ||
0198ffd1 | 506 | /** |
16295bec SK |
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 | ||
16295bec SK |
518 | mutex_lock(&pinst->lock); |
519 | ||
6751fb3c SK |
520 | get_online_cpus(); |
521 | ||
16295bec SK |
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: | |
6751fb3c SK |
533 | put_online_cpus(); |
534 | ||
16295bec SK |
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 | ||
0198ffd1 | 556 | /** |
16295bec SK |
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 | ||
16295bec SK |
566 | mutex_lock(&pinst->lock); |
567 | ||
6751fb3c | 568 | get_online_cpus(); |
16295bec SK |
569 | cpumask_set_cpu(cpu, pinst->cpumask); |
570 | err = __padata_add_cpu(pinst, cpu); | |
6751fb3c | 571 | put_online_cpus(); |
16295bec SK |
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 | ||
0198ffd1 | 594 | /** |
16295bec SK |
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 | ||
16295bec SK |
604 | mutex_lock(&pinst->lock); |
605 | ||
6751fb3c | 606 | get_online_cpus(); |
16295bec SK |
607 | cpumask_clear_cpu(cpu, pinst->cpumask); |
608 | err = __padata_remove_cpu(pinst, cpu); | |
6751fb3c | 609 | put_online_cpus(); |
16295bec SK |
610 | |
611 | mutex_unlock(&pinst->lock); | |
612 | ||
613 | return err; | |
614 | } | |
615 | EXPORT_SYMBOL(padata_remove_cpu); | |
616 | ||
0198ffd1 | 617 | /** |
16295bec SK |
618 | * padata_start - start the parallel processing |
619 | * | |
620 | * @pinst: padata instance to start | |
621 | */ | |
622 | void padata_start(struct padata_instance *pinst) | |
623 | { | |
16295bec SK |
624 | mutex_lock(&pinst->lock); |
625 | pinst->flags |= PADATA_INIT; | |
626 | mutex_unlock(&pinst->lock); | |
627 | } | |
628 | EXPORT_SYMBOL(padata_start); | |
629 | ||
0198ffd1 | 630 | /** |
16295bec SK |
631 | * padata_stop - stop the parallel processing |
632 | * | |
633 | * @pinst: padata instance to stop | |
634 | */ | |
635 | void padata_stop(struct padata_instance *pinst) | |
636 | { | |
16295bec SK |
637 | mutex_lock(&pinst->lock); |
638 | pinst->flags &= ~PADATA_INIT; | |
639 | mutex_unlock(&pinst->lock); | |
640 | } | |
641 | EXPORT_SYMBOL(padata_stop); | |
642 | ||
e2cb2f1c | 643 | #ifdef CONFIG_HOTPLUG_CPU |
975d2603 HK |
644 | static int padata_cpu_callback(struct notifier_block *nfb, |
645 | unsigned long action, void *hcpu) | |
16295bec SK |
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) | |
80b5184c | 662 | return notifier_from_errno(err); |
16295bec SK |
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) | |
80b5184c | 673 | return notifier_from_errno(err); |
16295bec SK |
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 | } | |
e2cb2f1c | 695 | #endif |
16295bec | 696 | |
0198ffd1 | 697 | /** |
16295bec SK |
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 | { | |
16295bec SK |
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 | ||
6751fb3c SK |
713 | get_online_cpus(); |
714 | ||
16295bec SK |
715 | pd = padata_alloc_pd(pinst, cpumask); |
716 | if (!pd) | |
717 | goto err_free_inst; | |
718 | ||
74781387 SK |
719 | if (!alloc_cpumask_var(&pinst->cpumask, GFP_KERNEL)) |
720 | goto err_free_pd; | |
721 | ||
16295bec SK |
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 | ||
e2cb2f1c | 730 | #ifdef CONFIG_HOTPLUG_CPU |
16295bec SK |
731 | pinst->cpu_notifier.notifier_call = padata_cpu_callback; |
732 | pinst->cpu_notifier.priority = 0; | |
e2cb2f1c SK |
733 | register_hotcpu_notifier(&pinst->cpu_notifier); |
734 | #endif | |
16295bec | 735 | |
6751fb3c SK |
736 | put_online_cpus(); |
737 | ||
16295bec SK |
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); | |
6751fb3c | 746 | put_online_cpus(); |
16295bec SK |
747 | err: |
748 | return NULL; | |
749 | } | |
750 | EXPORT_SYMBOL(padata_alloc); | |
751 | ||
0198ffd1 | 752 | /** |
16295bec SK |
753 | * padata_free - free a padata instance |
754 | * | |
0198ffd1 | 755 | * @padata_inst: padata instance to free |
16295bec SK |
756 | */ |
757 | void padata_free(struct padata_instance *pinst) | |
758 | { | |
759 | padata_stop(pinst); | |
760 | ||
761 | synchronize_rcu(); | |
762 | ||
e2cb2f1c | 763 | #ifdef CONFIG_HOTPLUG_CPU |
16295bec | 764 | unregister_hotcpu_notifier(&pinst->cpu_notifier); |
e2cb2f1c | 765 | #endif |
3789ae7d | 766 | get_online_cpus(); |
2b73b07a | 767 | padata_flush_queues(pinst->pd); |
3789ae7d SK |
768 | put_online_cpus(); |
769 | ||
16295bec | 770 | padata_free_pd(pinst->pd); |
74781387 | 771 | free_cpumask_var(pinst->cpumask); |
16295bec SK |
772 | kfree(pinst); |
773 | } | |
774 | EXPORT_SYMBOL(padata_free); |