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1 | /* |
2 | * padata.c - generic interface to process data streams in parallel |
3 | * |
4 | * See Documentation/padata.txt for an api documentation. |
5 | * |
6 | * Copyright (C) 2008, 2009 secunet Security Networks AG |
7 | * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com> |
8 | * |
9 | * This program is free software; you can redistribute it and/or modify it |
10 | * under the terms and conditions of the GNU General Public License, |
11 | * version 2, as published by the Free Software Foundation. |
12 | * |
13 | * This program is distributed in the hope it will be useful, but WITHOUT |
14 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
15 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
16 | * more details. |
17 | * |
18 | * You should have received a copy of the GNU General Public License along with |
19 | * this program; if not, write to the Free Software Foundation, Inc., |
20 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. |
21 | */ |
22 | |
23 | #include <linux/export.h> |
24 | #include <linux/cpumask.h> |
25 | #include <linux/err.h> |
26 | #include <linux/cpu.h> |
27 | #include <linux/padata.h> |
28 | #include <linux/mutex.h> |
29 | #include <linux/sched.h> |
30 | #include <linux/slab.h> |
31 | #include <linux/sysfs.h> |
32 | #include <linux/rcupdate.h> |
33 | |
34 | #define MAX_OBJ_NUM 1000 |
35 | |
36 | static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index) |
37 | { |
38 | int cpu, target_cpu; |
39 | |
40 | target_cpu = cpumask_first(pd->cpumask.pcpu); |
41 | for (cpu = 0; cpu < cpu_index; cpu++) |
42 | target_cpu = cpumask_next(target_cpu, pd->cpumask.pcpu); |
43 | |
44 | return target_cpu; |
45 | } |
46 | |
47 | static int padata_cpu_hash(struct parallel_data *pd) |
48 | { |
49 | int cpu_index; |
50 | |
51 | /* |
52 | * Hash the sequence numbers to the cpus by taking |
53 | * seq_nr mod. number of cpus in use. |
54 | */ |
55 | |
56 | spin_lock(&pd->seq_lock); |
57 | cpu_index = pd->seq_nr % cpumask_weight(pd->cpumask.pcpu); |
58 | pd->seq_nr++; |
59 | spin_unlock(&pd->seq_lock); |
60 | |
61 | return padata_index_to_cpu(pd, cpu_index); |
62 | } |
63 | |
64 | static void padata_parallel_worker(struct work_struct *parallel_work) |
65 | { |
66 | struct padata_parallel_queue *pqueue; |
67 | struct parallel_data *pd; |
68 | struct padata_instance *pinst; |
69 | LIST_HEAD(local_list); |
70 | |
71 | local_bh_disable(); |
72 | pqueue = container_of(parallel_work, |
73 | struct padata_parallel_queue, work); |
74 | pd = pqueue->pd; |
75 | pinst = pd->pinst; |
76 | |
77 | spin_lock(&pqueue->parallel.lock); |
78 | list_replace_init(&pqueue->parallel.list, &local_list); |
79 | spin_unlock(&pqueue->parallel.lock); |
80 | |
81 | while (!list_empty(&local_list)) { |
82 | struct padata_priv *padata; |
83 | |
84 | padata = list_entry(local_list.next, |
85 | struct padata_priv, list); |
86 | |
87 | list_del_init(&padata->list); |
88 | |
89 | padata->parallel(padata); |
90 | } |
91 | |
92 | local_bh_enable(); |
93 | } |
94 | |
95 | /** |
96 | * padata_do_parallel - padata parallelization function |
97 | * |
98 | * @pinst: padata instance |
99 | * @padata: object to be parallelized |
100 | * @cb_cpu: cpu the serialization callback function will run on, |
101 | * must be in the serial cpumask of padata(i.e. cpumask.cbcpu). |
102 | * |
103 | * The parallelization callback function will run with BHs off. |
104 | * Note: Every object which is parallelized by padata_do_parallel |
105 | * must be seen by padata_do_serial. |
106 | */ |
107 | int padata_do_parallel(struct padata_instance *pinst, |
108 | struct padata_priv *padata, int cb_cpu) |
109 | { |
110 | int target_cpu, err; |
111 | struct padata_parallel_queue *queue; |
112 | struct parallel_data *pd; |
113 | |
114 | rcu_read_lock_bh(); |
115 | |
116 | pd = rcu_dereference(pinst->pd); |
117 | |
118 | err = -EINVAL; |
119 | if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID) |
120 | goto out; |
121 | |
122 | if (!cpumask_test_cpu(cb_cpu, pd->cpumask.cbcpu)) |
123 | goto out; |
124 | |
125 | err = -EBUSY; |
126 | if ((pinst->flags & PADATA_RESET)) |
127 | goto out; |
128 | |
129 | if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM) |
130 | goto out; |
131 | |
132 | err = 0; |
133 | atomic_inc(&pd->refcnt); |
134 | padata->pd = pd; |
135 | padata->cb_cpu = cb_cpu; |
136 | |
137 | target_cpu = padata_cpu_hash(pd); |
138 | queue = per_cpu_ptr(pd->pqueue, target_cpu); |
139 | |
140 | spin_lock(&queue->parallel.lock); |
141 | list_add_tail(&padata->list, &queue->parallel.list); |
142 | spin_unlock(&queue->parallel.lock); |
143 | |
144 | queue_work_on(target_cpu, pinst->wq, &queue->work); |
145 | |
146 | out: |
147 | rcu_read_unlock_bh(); |
148 | |
149 | return err; |
150 | } |
151 | EXPORT_SYMBOL(padata_do_parallel); |
152 | |
153 | /* |
154 | * padata_get_next - Get the next object that needs serialization. |
155 | * |
156 | * Return values are: |
157 | * |
158 | * A pointer to the control struct of the next object that needs |
159 | * serialization, if present in one of the percpu reorder queues. |
160 | * |
161 | * NULL, if all percpu reorder queues are empty. |
162 | * |
163 | * -EINPROGRESS, if the next object that needs serialization will |
164 | * be parallel processed by another cpu and is not yet present in |
165 | * the cpu's reorder queue. |
166 | * |
167 | * -ENODATA, if this cpu has to do the parallel processing for |
168 | * the next object. |
169 | */ |
170 | static struct padata_priv *padata_get_next(struct parallel_data *pd) |
171 | { |
172 | int cpu, num_cpus; |
173 | unsigned int next_nr, next_index; |
174 | struct padata_parallel_queue *next_queue; |
175 | struct padata_priv *padata; |
176 | struct padata_list *reorder; |
177 | |
178 | num_cpus = cpumask_weight(pd->cpumask.pcpu); |
179 | |
180 | /* |
181 | * Calculate the percpu reorder queue and the sequence |
182 | * number of the next object. |
183 | */ |
184 | next_nr = pd->processed; |
185 | next_index = next_nr % num_cpus; |
186 | cpu = padata_index_to_cpu(pd, next_index); |
187 | next_queue = per_cpu_ptr(pd->pqueue, cpu); |
188 | |
189 | padata = NULL; |
190 | |
191 | reorder = &next_queue->reorder; |
192 | |
193 | if (!list_empty(&reorder->list)) { |
194 | padata = list_entry(reorder->list.next, |
195 | struct padata_priv, list); |
196 | |
197 | spin_lock(&reorder->lock); |
198 | list_del_init(&padata->list); |
199 | atomic_dec(&pd->reorder_objects); |
200 | spin_unlock(&reorder->lock); |
201 | |
202 | pd->processed++; |
203 | |
204 | goto out; |
205 | } |
206 | |
207 | if (__this_cpu_read(pd->pqueue->cpu_index) == next_queue->cpu_index) { |
208 | padata = ERR_PTR(-ENODATA); |
209 | goto out; |
210 | } |
211 | |
212 | padata = ERR_PTR(-EINPROGRESS); |
213 | out: |
214 | return padata; |
215 | } |
216 | |
217 | static void padata_reorder(struct parallel_data *pd) |
218 | { |
219 | int cb_cpu; |
220 | struct padata_priv *padata; |
221 | struct padata_serial_queue *squeue; |
222 | struct padata_instance *pinst = pd->pinst; |
223 | |
224 | /* |
225 | * We need to ensure that only one cpu can work on dequeueing of |
226 | * the reorder queue the time. Calculating in which percpu reorder |
227 | * queue the next object will arrive takes some time. A spinlock |
228 | * would be highly contended. Also it is not clear in which order |
229 | * the objects arrive to the reorder queues. So a cpu could wait to |
230 | * get the lock just to notice that there is nothing to do at the |
231 | * moment. Therefore we use a trylock and let the holder of the lock |
232 | * care for all the objects enqueued during the holdtime of the lock. |
233 | */ |
234 | if (!spin_trylock_bh(&pd->lock)) |
235 | return; |
236 | |
237 | while (1) { |
238 | padata = padata_get_next(pd); |
239 | |
240 | /* |
241 | * All reorder queues are empty, or the next object that needs |
242 | * serialization is parallel processed by another cpu and is |
243 | * still on it's way to the cpu's reorder queue, nothing to |
244 | * do for now. |
245 | */ |
246 | if (!padata || PTR_ERR(padata) == -EINPROGRESS) |
247 | break; |
248 | |
249 | /* |
250 | * This cpu has to do the parallel processing of the next |
251 | * object. It's waiting in the cpu's parallelization queue, |
252 | * so exit immediately. |
253 | */ |
254 | if (PTR_ERR(padata) == -ENODATA) { |
255 | del_timer(&pd->timer); |
256 | spin_unlock_bh(&pd->lock); |
257 | return; |
258 | } |
259 | |
260 | cb_cpu = padata->cb_cpu; |
261 | squeue = per_cpu_ptr(pd->squeue, cb_cpu); |
262 | |
263 | spin_lock(&squeue->serial.lock); |
264 | list_add_tail(&padata->list, &squeue->serial.list); |
265 | spin_unlock(&squeue->serial.lock); |
266 | |
267 | queue_work_on(cb_cpu, pinst->wq, &squeue->work); |
268 | } |
269 | |
270 | spin_unlock_bh(&pd->lock); |
271 | |
272 | /* |
273 | * The next object that needs serialization might have arrived to |
274 | * the reorder queues in the meantime, we will be called again |
275 | * from the timer function if no one else cares for it. |
276 | */ |
277 | if (atomic_read(&pd->reorder_objects) |
278 | && !(pinst->flags & PADATA_RESET)) |
279 | mod_timer(&pd->timer, jiffies + HZ); |
280 | else |
281 | del_timer(&pd->timer); |
282 | |
283 | return; |
284 | } |
285 | |
286 | static void padata_reorder_timer(unsigned long arg) |
287 | { |
288 | struct parallel_data *pd = (struct parallel_data *)arg; |
289 | |
290 | padata_reorder(pd); |
291 | } |
292 | |
293 | static void padata_serial_worker(struct work_struct *serial_work) |
294 | { |
295 | struct padata_serial_queue *squeue; |
296 | struct parallel_data *pd; |
297 | LIST_HEAD(local_list); |
298 | |
299 | local_bh_disable(); |
300 | squeue = container_of(serial_work, struct padata_serial_queue, work); |
301 | pd = squeue->pd; |
302 | |
303 | spin_lock(&squeue->serial.lock); |
304 | list_replace_init(&squeue->serial.list, &local_list); |
305 | spin_unlock(&squeue->serial.lock); |
306 | |
307 | while (!list_empty(&local_list)) { |
308 | struct padata_priv *padata; |
309 | |
310 | padata = list_entry(local_list.next, |
311 | struct padata_priv, list); |
312 | |
313 | list_del_init(&padata->list); |
314 | |
315 | padata->serial(padata); |
316 | atomic_dec(&pd->refcnt); |
317 | } |
318 | local_bh_enable(); |
319 | } |
320 | |
321 | /** |
322 | * padata_do_serial - padata serialization function |
323 | * |
324 | * @padata: object to be serialized. |
325 | * |
326 | * padata_do_serial must be called for every parallelized object. |
327 | * The serialization callback function will run with BHs off. |
328 | */ |
329 | void padata_do_serial(struct padata_priv *padata) |
330 | { |
331 | int cpu; |
332 | struct padata_parallel_queue *pqueue; |
333 | struct parallel_data *pd; |
334 | |
335 | pd = padata->pd; |
336 | |
337 | cpu = get_cpu(); |
338 | pqueue = per_cpu_ptr(pd->pqueue, cpu); |
339 | |
340 | spin_lock(&pqueue->reorder.lock); |
341 | atomic_inc(&pd->reorder_objects); |
342 | list_add_tail(&padata->list, &pqueue->reorder.list); |
343 | spin_unlock(&pqueue->reorder.lock); |
344 | |
345 | put_cpu(); |
346 | |
347 | padata_reorder(pd); |
348 | } |
349 | EXPORT_SYMBOL(padata_do_serial); |
350 | |
351 | static int padata_setup_cpumasks(struct parallel_data *pd, |
352 | const struct cpumask *pcpumask, |
353 | const struct cpumask *cbcpumask) |
354 | { |
355 | if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL)) |
356 | return -ENOMEM; |
357 | |
358 | cpumask_and(pd->cpumask.pcpu, pcpumask, cpu_online_mask); |
359 | if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL)) { |
360 | free_cpumask_var(pd->cpumask.cbcpu); |
361 | return -ENOMEM; |
362 | } |
363 | |
364 | cpumask_and(pd->cpumask.cbcpu, cbcpumask, cpu_online_mask); |
365 | return 0; |
366 | } |
367 | |
368 | static void __padata_list_init(struct padata_list *pd_list) |
369 | { |
370 | INIT_LIST_HEAD(&pd_list->list); |
371 | spin_lock_init(&pd_list->lock); |
372 | } |
373 | |
374 | /* Initialize all percpu queues used by serial workers */ |
375 | static void padata_init_squeues(struct parallel_data *pd) |
376 | { |
377 | int cpu; |
378 | struct padata_serial_queue *squeue; |
379 | |
380 | for_each_cpu(cpu, pd->cpumask.cbcpu) { |
381 | squeue = per_cpu_ptr(pd->squeue, cpu); |
382 | squeue->pd = pd; |
383 | __padata_list_init(&squeue->serial); |
384 | INIT_WORK(&squeue->work, padata_serial_worker); |
385 | } |
386 | } |
387 | |
388 | /* Initialize all percpu queues used by parallel workers */ |
389 | static void padata_init_pqueues(struct parallel_data *pd) |
390 | { |
391 | int cpu_index, cpu; |
392 | struct padata_parallel_queue *pqueue; |
393 | |
394 | cpu_index = 0; |
395 | for_each_cpu(cpu, pd->cpumask.pcpu) { |
396 | pqueue = per_cpu_ptr(pd->pqueue, cpu); |
397 | pqueue->pd = pd; |
398 | pqueue->cpu_index = cpu_index; |
399 | cpu_index++; |
400 | |
401 | __padata_list_init(&pqueue->reorder); |
402 | __padata_list_init(&pqueue->parallel); |
403 | INIT_WORK(&pqueue->work, padata_parallel_worker); |
404 | atomic_set(&pqueue->num_obj, 0); |
405 | } |
406 | } |
407 | |
408 | /* Allocate and initialize the internal cpumask dependend resources. */ |
409 | static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst, |
410 | const struct cpumask *pcpumask, |
411 | const struct cpumask *cbcpumask) |
412 | { |
413 | struct parallel_data *pd; |
414 | |
415 | pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL); |
416 | if (!pd) |
417 | goto err; |
418 | |
419 | pd->pqueue = alloc_percpu(struct padata_parallel_queue); |
420 | if (!pd->pqueue) |
421 | goto err_free_pd; |
422 | |
423 | pd->squeue = alloc_percpu(struct padata_serial_queue); |
424 | if (!pd->squeue) |
425 | goto err_free_pqueue; |
426 | if (padata_setup_cpumasks(pd, pcpumask, cbcpumask) < 0) |
427 | goto err_free_squeue; |
428 | |
429 | padata_init_pqueues(pd); |
430 | padata_init_squeues(pd); |
431 | setup_timer(&pd->timer, padata_reorder_timer, (unsigned long)pd); |
432 | pd->seq_nr = 0; |
433 | atomic_set(&pd->reorder_objects, 0); |
434 | atomic_set(&pd->refcnt, 0); |
435 | pd->pinst = pinst; |
436 | spin_lock_init(&pd->lock); |
437 | |
438 | return pd; |
439 | |
440 | err_free_squeue: |
441 | free_percpu(pd->squeue); |
442 | err_free_pqueue: |
443 | free_percpu(pd->pqueue); |
444 | err_free_pd: |
445 | kfree(pd); |
446 | err: |
447 | return NULL; |
448 | } |
449 | |
450 | static void padata_free_pd(struct parallel_data *pd) |
451 | { |
452 | free_cpumask_var(pd->cpumask.pcpu); |
453 | free_cpumask_var(pd->cpumask.cbcpu); |
454 | free_percpu(pd->pqueue); |
455 | free_percpu(pd->squeue); |
456 | kfree(pd); |
457 | } |
458 | |
459 | /* Flush all objects out of the padata queues. */ |
460 | static void padata_flush_queues(struct parallel_data *pd) |
461 | { |
462 | int cpu; |
463 | struct padata_parallel_queue *pqueue; |
464 | struct padata_serial_queue *squeue; |
465 | |
466 | for_each_cpu(cpu, pd->cpumask.pcpu) { |
467 | pqueue = per_cpu_ptr(pd->pqueue, cpu); |
468 | flush_work(&pqueue->work); |
469 | } |
470 | |
471 | del_timer_sync(&pd->timer); |
472 | |
473 | if (atomic_read(&pd->reorder_objects)) |
474 | padata_reorder(pd); |
475 | |
476 | for_each_cpu(cpu, pd->cpumask.cbcpu) { |
477 | squeue = per_cpu_ptr(pd->squeue, cpu); |
478 | flush_work(&squeue->work); |
479 | } |
480 | |
481 | BUG_ON(atomic_read(&pd->refcnt) != 0); |
482 | } |
483 | |
484 | static void __padata_start(struct padata_instance *pinst) |
485 | { |
486 | pinst->flags |= PADATA_INIT; |
487 | } |
488 | |
489 | static void __padata_stop(struct padata_instance *pinst) |
490 | { |
491 | if (!(pinst->flags & PADATA_INIT)) |
492 | return; |
493 | |
494 | pinst->flags &= ~PADATA_INIT; |
495 | |
496 | synchronize_rcu(); |
497 | |
498 | get_online_cpus(); |
499 | padata_flush_queues(pinst->pd); |
500 | put_online_cpus(); |
501 | } |
502 | |
503 | /* Replace the internal control structure with a new one. */ |
504 | static void padata_replace(struct padata_instance *pinst, |
505 | struct parallel_data *pd_new) |
506 | { |
507 | struct parallel_data *pd_old = pinst->pd; |
508 | int notification_mask = 0; |
509 | |
510 | pinst->flags |= PADATA_RESET; |
511 | |
512 | rcu_assign_pointer(pinst->pd, pd_new); |
513 | |
514 | synchronize_rcu(); |
515 | |
516 | if (!cpumask_equal(pd_old->cpumask.pcpu, pd_new->cpumask.pcpu)) |
517 | notification_mask |= PADATA_CPU_PARALLEL; |
518 | if (!cpumask_equal(pd_old->cpumask.cbcpu, pd_new->cpumask.cbcpu)) |
519 | notification_mask |= PADATA_CPU_SERIAL; |
520 | |
521 | padata_flush_queues(pd_old); |
522 | padata_free_pd(pd_old); |
523 | |
524 | if (notification_mask) |
525 | blocking_notifier_call_chain(&pinst->cpumask_change_notifier, |
526 | notification_mask, |
527 | &pd_new->cpumask); |
528 | |
529 | pinst->flags &= ~PADATA_RESET; |
530 | } |
531 | |
532 | /** |
533 | * padata_register_cpumask_notifier - Registers a notifier that will be called |
534 | * if either pcpu or cbcpu or both cpumasks change. |
535 | * |
536 | * @pinst: A poineter to padata instance |
537 | * @nblock: A pointer to notifier block. |
538 | */ |
539 | int padata_register_cpumask_notifier(struct padata_instance *pinst, |
540 | struct notifier_block *nblock) |
541 | { |
542 | return blocking_notifier_chain_register(&pinst->cpumask_change_notifier, |
543 | nblock); |
544 | } |
545 | EXPORT_SYMBOL(padata_register_cpumask_notifier); |
546 | |
547 | /** |
548 | * padata_unregister_cpumask_notifier - Unregisters cpumask notifier |
549 | * registered earlier using padata_register_cpumask_notifier |
550 | * |
551 | * @pinst: A pointer to data instance. |
552 | * @nlock: A pointer to notifier block. |
553 | */ |
554 | int padata_unregister_cpumask_notifier(struct padata_instance *pinst, |
555 | struct notifier_block *nblock) |
556 | { |
557 | return blocking_notifier_chain_unregister( |
558 | &pinst->cpumask_change_notifier, |
559 | nblock); |
560 | } |
561 | EXPORT_SYMBOL(padata_unregister_cpumask_notifier); |
562 | |
563 | |
564 | /* If cpumask contains no active cpu, we mark the instance as invalid. */ |
565 | static bool padata_validate_cpumask(struct padata_instance *pinst, |
566 | const struct cpumask *cpumask) |
567 | { |
568 | if (!cpumask_intersects(cpumask, cpu_online_mask)) { |
569 | pinst->flags |= PADATA_INVALID; |
570 | return false; |
571 | } |
572 | |
573 | pinst->flags &= ~PADATA_INVALID; |
574 | return true; |
575 | } |
576 | |
577 | static int __padata_set_cpumasks(struct padata_instance *pinst, |
578 | cpumask_var_t pcpumask, |
579 | cpumask_var_t cbcpumask) |
580 | { |
581 | int valid; |
582 | struct parallel_data *pd; |
583 | |
584 | valid = padata_validate_cpumask(pinst, pcpumask); |
585 | if (!valid) { |
586 | __padata_stop(pinst); |
587 | goto out_replace; |
588 | } |
589 | |
590 | valid = padata_validate_cpumask(pinst, cbcpumask); |
591 | if (!valid) |
592 | __padata_stop(pinst); |
593 | |
594 | out_replace: |
595 | pd = padata_alloc_pd(pinst, pcpumask, cbcpumask); |
596 | if (!pd) |
597 | return -ENOMEM; |
598 | |
599 | cpumask_copy(pinst->cpumask.pcpu, pcpumask); |
600 | cpumask_copy(pinst->cpumask.cbcpu, cbcpumask); |
601 | |
602 | padata_replace(pinst, pd); |
603 | |
604 | if (valid) |
605 | __padata_start(pinst); |
606 | |
607 | return 0; |
608 | } |
609 | |
610 | /** |
611 | * padata_set_cpumasks - Set both parallel and serial cpumasks. The first |
612 | * one is used by parallel workers and the second one |
613 | * by the wokers doing serialization. |
614 | * |
615 | * @pinst: padata instance |
616 | * @pcpumask: the cpumask to use for parallel workers |
617 | * @cbcpumask: the cpumsak to use for serial workers |
618 | */ |
619 | int padata_set_cpumasks(struct padata_instance *pinst, cpumask_var_t pcpumask, |
620 | cpumask_var_t cbcpumask) |
621 | { |
622 | int err; |
623 | |
624 | mutex_lock(&pinst->lock); |
625 | get_online_cpus(); |
626 | |
627 | err = __padata_set_cpumasks(pinst, pcpumask, cbcpumask); |
628 | |
629 | put_online_cpus(); |
630 | mutex_unlock(&pinst->lock); |
631 | |
632 | return err; |
633 | |
634 | } |
635 | EXPORT_SYMBOL(padata_set_cpumasks); |
636 | |
637 | /** |
638 | * padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value |
639 | * equivalent to @cpumask. |
640 | * |
641 | * @pinst: padata instance |
642 | * @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding |
643 | * to parallel and serial cpumasks respectively. |
644 | * @cpumask: the cpumask to use |
645 | */ |
646 | int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, |
647 | cpumask_var_t cpumask) |
648 | { |
649 | struct cpumask *serial_mask, *parallel_mask; |
650 | int err = -EINVAL; |
651 | |
652 | mutex_lock(&pinst->lock); |
653 | get_online_cpus(); |
654 | |
655 | switch (cpumask_type) { |
656 | case PADATA_CPU_PARALLEL: |
657 | serial_mask = pinst->cpumask.cbcpu; |
658 | parallel_mask = cpumask; |
659 | break; |
660 | case PADATA_CPU_SERIAL: |
661 | parallel_mask = pinst->cpumask.pcpu; |
662 | serial_mask = cpumask; |
663 | break; |
664 | default: |
665 | goto out; |
666 | } |
667 | |
668 | err = __padata_set_cpumasks(pinst, parallel_mask, serial_mask); |
669 | |
670 | out: |
671 | put_online_cpus(); |
672 | mutex_unlock(&pinst->lock); |
673 | |
674 | return err; |
675 | } |
676 | EXPORT_SYMBOL(padata_set_cpumask); |
677 | |
678 | static int __padata_add_cpu(struct padata_instance *pinst, int cpu) |
679 | { |
680 | struct parallel_data *pd; |
681 | |
682 | if (cpumask_test_cpu(cpu, cpu_online_mask)) { |
683 | pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu, |
684 | pinst->cpumask.cbcpu); |
685 | if (!pd) |
686 | return -ENOMEM; |
687 | |
688 | padata_replace(pinst, pd); |
689 | |
690 | if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) && |
691 | padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) |
692 | __padata_start(pinst); |
693 | } |
694 | |
695 | return 0; |
696 | } |
697 | |
698 | /** |
699 | * padata_add_cpu - add a cpu to one or both(parallel and serial) |
700 | * padata cpumasks. |
701 | * |
702 | * @pinst: padata instance |
703 | * @cpu: cpu to add |
704 | * @mask: bitmask of flags specifying to which cpumask @cpu shuld be added. |
705 | * The @mask may be any combination of the following flags: |
706 | * PADATA_CPU_SERIAL - serial cpumask |
707 | * PADATA_CPU_PARALLEL - parallel cpumask |
708 | */ |
709 | |
710 | int padata_add_cpu(struct padata_instance *pinst, int cpu, int mask) |
711 | { |
712 | int err; |
713 | |
714 | if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL))) |
715 | return -EINVAL; |
716 | |
717 | mutex_lock(&pinst->lock); |
718 | |
719 | get_online_cpus(); |
720 | if (mask & PADATA_CPU_SERIAL) |
721 | cpumask_set_cpu(cpu, pinst->cpumask.cbcpu); |
722 | if (mask & PADATA_CPU_PARALLEL) |
723 | cpumask_set_cpu(cpu, pinst->cpumask.pcpu); |
724 | |
725 | err = __padata_add_cpu(pinst, cpu); |
726 | put_online_cpus(); |
727 | |
728 | mutex_unlock(&pinst->lock); |
729 | |
730 | return err; |
731 | } |
732 | EXPORT_SYMBOL(padata_add_cpu); |
733 | |
734 | static int __padata_remove_cpu(struct padata_instance *pinst, int cpu) |
735 | { |
736 | struct parallel_data *pd = NULL; |
737 | |
738 | if (cpumask_test_cpu(cpu, cpu_online_mask)) { |
739 | |
740 | if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) || |
741 | !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) |
742 | __padata_stop(pinst); |
743 | |
744 | pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu, |
745 | pinst->cpumask.cbcpu); |
746 | if (!pd) |
747 | return -ENOMEM; |
748 | |
749 | padata_replace(pinst, pd); |
750 | |
751 | cpumask_clear_cpu(cpu, pd->cpumask.cbcpu); |
752 | cpumask_clear_cpu(cpu, pd->cpumask.pcpu); |
753 | } |
754 | |
755 | return 0; |
756 | } |
757 | |
758 | /** |
759 | * padata_remove_cpu - remove a cpu from the one or both(serial and parallel) |
760 | * padata cpumasks. |
761 | * |
762 | * @pinst: padata instance |
763 | * @cpu: cpu to remove |
764 | * @mask: bitmask specifying from which cpumask @cpu should be removed |
765 | * The @mask may be any combination of the following flags: |
766 | * PADATA_CPU_SERIAL - serial cpumask |
767 | * PADATA_CPU_PARALLEL - parallel cpumask |
768 | */ |
769 | int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask) |
770 | { |
771 | int err; |
772 | |
773 | if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL))) |
774 | return -EINVAL; |
775 | |
776 | mutex_lock(&pinst->lock); |
777 | |
778 | get_online_cpus(); |
779 | if (mask & PADATA_CPU_SERIAL) |
780 | cpumask_clear_cpu(cpu, pinst->cpumask.cbcpu); |
781 | if (mask & PADATA_CPU_PARALLEL) |
782 | cpumask_clear_cpu(cpu, pinst->cpumask.pcpu); |
783 | |
784 | err = __padata_remove_cpu(pinst, cpu); |
785 | put_online_cpus(); |
786 | |
787 | mutex_unlock(&pinst->lock); |
788 | |
789 | return err; |
790 | } |
791 | EXPORT_SYMBOL(padata_remove_cpu); |
792 | |
793 | /** |
794 | * padata_start - start the parallel processing |
795 | * |
796 | * @pinst: padata instance to start |
797 | */ |
798 | int padata_start(struct padata_instance *pinst) |
799 | { |
800 | int err = 0; |
801 | |
802 | mutex_lock(&pinst->lock); |
803 | |
804 | if (pinst->flags & PADATA_INVALID) |
805 | err =-EINVAL; |
806 | |
807 | __padata_start(pinst); |
808 | |
809 | mutex_unlock(&pinst->lock); |
810 | |
811 | return err; |
812 | } |
813 | EXPORT_SYMBOL(padata_start); |
814 | |
815 | /** |
816 | * padata_stop - stop the parallel processing |
817 | * |
818 | * @pinst: padata instance to stop |
819 | */ |
820 | void padata_stop(struct padata_instance *pinst) |
821 | { |
822 | mutex_lock(&pinst->lock); |
823 | __padata_stop(pinst); |
824 | mutex_unlock(&pinst->lock); |
825 | } |
826 | EXPORT_SYMBOL(padata_stop); |
827 | |
828 | #ifdef CONFIG_HOTPLUG_CPU |
829 | |
830 | static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu) |
831 | { |
832 | return cpumask_test_cpu(cpu, pinst->cpumask.pcpu) || |
833 | cpumask_test_cpu(cpu, pinst->cpumask.cbcpu); |
834 | } |
835 | |
836 | |
837 | static int padata_cpu_callback(struct notifier_block *nfb, |
838 | unsigned long action, void *hcpu) |
839 | { |
840 | int err; |
841 | struct padata_instance *pinst; |
842 | int cpu = (unsigned long)hcpu; |
843 | |
844 | pinst = container_of(nfb, struct padata_instance, cpu_notifier); |
845 | |
846 | switch (action) { |
847 | case CPU_ONLINE: |
848 | case CPU_ONLINE_FROZEN: |
849 | case CPU_DOWN_FAILED: |
850 | case CPU_DOWN_FAILED_FROZEN: |
851 | if (!pinst_has_cpu(pinst, cpu)) |
852 | break; |
853 | mutex_lock(&pinst->lock); |
854 | err = __padata_add_cpu(pinst, cpu); |
855 | mutex_unlock(&pinst->lock); |
856 | if (err) |
857 | return notifier_from_errno(err); |
858 | break; |
859 | |
860 | case CPU_DOWN_PREPARE: |
861 | case CPU_DOWN_PREPARE_FROZEN: |
862 | case CPU_UP_CANCELED: |
863 | case CPU_UP_CANCELED_FROZEN: |
864 | if (!pinst_has_cpu(pinst, cpu)) |
865 | break; |
866 | mutex_lock(&pinst->lock); |
867 | err = __padata_remove_cpu(pinst, cpu); |
868 | mutex_unlock(&pinst->lock); |
869 | if (err) |
870 | return notifier_from_errno(err); |
871 | break; |
872 | } |
873 | |
874 | return NOTIFY_OK; |
875 | } |
876 | #endif |
877 | |
878 | static void __padata_free(struct padata_instance *pinst) |
879 | { |
880 | #ifdef CONFIG_HOTPLUG_CPU |
881 | unregister_hotcpu_notifier(&pinst->cpu_notifier); |
882 | #endif |
883 | |
884 | padata_stop(pinst); |
885 | padata_free_pd(pinst->pd); |
886 | free_cpumask_var(pinst->cpumask.pcpu); |
887 | free_cpumask_var(pinst->cpumask.cbcpu); |
888 | kfree(pinst); |
889 | } |
890 | |
891 | #define kobj2pinst(_kobj) \ |
892 | container_of(_kobj, struct padata_instance, kobj) |
893 | #define attr2pentry(_attr) \ |
894 | container_of(_attr, struct padata_sysfs_entry, attr) |
895 | |
896 | static void padata_sysfs_release(struct kobject *kobj) |
897 | { |
898 | struct padata_instance *pinst = kobj2pinst(kobj); |
899 | __padata_free(pinst); |
900 | } |
901 | |
902 | struct padata_sysfs_entry { |
903 | struct attribute attr; |
904 | ssize_t (*show)(struct padata_instance *, struct attribute *, char *); |
905 | ssize_t (*store)(struct padata_instance *, struct attribute *, |
906 | const char *, size_t); |
907 | }; |
908 | |
909 | static ssize_t show_cpumask(struct padata_instance *pinst, |
910 | struct attribute *attr, char *buf) |
911 | { |
912 | struct cpumask *cpumask; |
913 | ssize_t len; |
914 | |
915 | mutex_lock(&pinst->lock); |
916 | if (!strcmp(attr->name, "serial_cpumask")) |
917 | cpumask = pinst->cpumask.cbcpu; |
918 | else |
919 | cpumask = pinst->cpumask.pcpu; |
920 | |
921 | len = bitmap_scnprintf(buf, PAGE_SIZE, cpumask_bits(cpumask), |
922 | nr_cpu_ids); |
923 | if (PAGE_SIZE - len < 2) |
924 | len = -EINVAL; |
925 | else |
926 | len += sprintf(buf + len, "\n"); |
927 | |
928 | mutex_unlock(&pinst->lock); |
929 | return len; |
930 | } |
931 | |
932 | static ssize_t store_cpumask(struct padata_instance *pinst, |
933 | struct attribute *attr, |
934 | const char *buf, size_t count) |
935 | { |
936 | cpumask_var_t new_cpumask; |
937 | ssize_t ret; |
938 | int mask_type; |
939 | |
940 | if (!alloc_cpumask_var(&new_cpumask, GFP_KERNEL)) |
941 | return -ENOMEM; |
942 | |
943 | ret = bitmap_parse(buf, count, cpumask_bits(new_cpumask), |
944 | nr_cpumask_bits); |
945 | if (ret < 0) |
946 | goto out; |
947 | |
948 | mask_type = !strcmp(attr->name, "serial_cpumask") ? |
949 | PADATA_CPU_SERIAL : PADATA_CPU_PARALLEL; |
950 | ret = padata_set_cpumask(pinst, mask_type, new_cpumask); |
951 | if (!ret) |
952 | ret = count; |
953 | |
954 | out: |
955 | free_cpumask_var(new_cpumask); |
956 | return ret; |
957 | } |
958 | |
959 | #define PADATA_ATTR_RW(_name, _show_name, _store_name) \ |
960 | static struct padata_sysfs_entry _name##_attr = \ |
961 | __ATTR(_name, 0644, _show_name, _store_name) |
962 | #define PADATA_ATTR_RO(_name, _show_name) \ |
963 | static struct padata_sysfs_entry _name##_attr = \ |
964 | __ATTR(_name, 0400, _show_name, NULL) |
965 | |
966 | PADATA_ATTR_RW(serial_cpumask, show_cpumask, store_cpumask); |
967 | PADATA_ATTR_RW(parallel_cpumask, show_cpumask, store_cpumask); |
968 | |
969 | /* |
970 | * Padata sysfs provides the following objects: |
971 | * serial_cpumask [RW] - cpumask for serial workers |
972 | * parallel_cpumask [RW] - cpumask for parallel workers |
973 | */ |
974 | static struct attribute *padata_default_attrs[] = { |
975 | &serial_cpumask_attr.attr, |
976 | ¶llel_cpumask_attr.attr, |
977 | NULL, |
978 | }; |
979 | |
980 | static ssize_t padata_sysfs_show(struct kobject *kobj, |
981 | struct attribute *attr, char *buf) |
982 | { |
983 | struct padata_instance *pinst; |
984 | struct padata_sysfs_entry *pentry; |
985 | ssize_t ret = -EIO; |
986 | |
987 | pinst = kobj2pinst(kobj); |
988 | pentry = attr2pentry(attr); |
989 | if (pentry->show) |
990 | ret = pentry->show(pinst, attr, buf); |
991 | |
992 | return ret; |
993 | } |
994 | |
995 | static ssize_t padata_sysfs_store(struct kobject *kobj, struct attribute *attr, |
996 | const char *buf, size_t count) |
997 | { |
998 | struct padata_instance *pinst; |
999 | struct padata_sysfs_entry *pentry; |
1000 | ssize_t ret = -EIO; |
1001 | |
1002 | pinst = kobj2pinst(kobj); |
1003 | pentry = attr2pentry(attr); |
1004 | if (pentry->show) |
1005 | ret = pentry->store(pinst, attr, buf, count); |
1006 | |
1007 | return ret; |
1008 | } |
1009 | |
1010 | static const struct sysfs_ops padata_sysfs_ops = { |
1011 | .show = padata_sysfs_show, |
1012 | .store = padata_sysfs_store, |
1013 | }; |
1014 | |
1015 | static struct kobj_type padata_attr_type = { |
1016 | .sysfs_ops = &padata_sysfs_ops, |
1017 | .default_attrs = padata_default_attrs, |
1018 | .release = padata_sysfs_release, |
1019 | }; |
1020 | |
1021 | /** |
1022 | * padata_alloc_possible - Allocate and initialize padata instance. |
1023 | * Use the cpu_possible_mask for serial and |
1024 | * parallel workers. |
1025 | * |
1026 | * @wq: workqueue to use for the allocated padata instance |
1027 | */ |
1028 | struct padata_instance *padata_alloc_possible(struct workqueue_struct *wq) |
1029 | { |
1030 | return padata_alloc(wq, cpu_possible_mask, cpu_possible_mask); |
1031 | } |
1032 | EXPORT_SYMBOL(padata_alloc_possible); |
1033 | |
1034 | /** |
1035 | * padata_alloc - allocate and initialize a padata instance and specify |
1036 | * cpumasks for serial and parallel workers. |
1037 | * |
1038 | * @wq: workqueue to use for the allocated padata instance |
1039 | * @pcpumask: cpumask that will be used for padata parallelization |
1040 | * @cbcpumask: cpumask that will be used for padata serialization |
1041 | */ |
1042 | struct padata_instance *padata_alloc(struct workqueue_struct *wq, |
1043 | const struct cpumask *pcpumask, |
1044 | const struct cpumask *cbcpumask) |
1045 | { |
1046 | struct padata_instance *pinst; |
1047 | struct parallel_data *pd = NULL; |
1048 | |
1049 | pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL); |
1050 | if (!pinst) |
1051 | goto err; |
1052 | |
1053 | get_online_cpus(); |
1054 | if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL)) |
1055 | goto err_free_inst; |
1056 | if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) { |
1057 | free_cpumask_var(pinst->cpumask.pcpu); |
1058 | goto err_free_inst; |
1059 | } |
1060 | if (!padata_validate_cpumask(pinst, pcpumask) || |
1061 | !padata_validate_cpumask(pinst, cbcpumask)) |
1062 | goto err_free_masks; |
1063 | |
1064 | pd = padata_alloc_pd(pinst, pcpumask, cbcpumask); |
1065 | if (!pd) |
1066 | goto err_free_masks; |
1067 | |
1068 | rcu_assign_pointer(pinst->pd, pd); |
1069 | |
1070 | pinst->wq = wq; |
1071 | |
1072 | cpumask_copy(pinst->cpumask.pcpu, pcpumask); |
1073 | cpumask_copy(pinst->cpumask.cbcpu, cbcpumask); |
1074 | |
1075 | pinst->flags = 0; |
1076 | |
1077 | put_online_cpus(); |
1078 | |
1079 | BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier); |
1080 | kobject_init(&pinst->kobj, &padata_attr_type); |
1081 | mutex_init(&pinst->lock); |
1082 | |
1083 | #ifdef CONFIG_HOTPLUG_CPU |
1084 | pinst->cpu_notifier.notifier_call = padata_cpu_callback; |
1085 | pinst->cpu_notifier.priority = 0; |
1086 | register_hotcpu_notifier(&pinst->cpu_notifier); |
1087 | #endif |
1088 | |
1089 | return pinst; |
1090 | |
1091 | err_free_masks: |
1092 | free_cpumask_var(pinst->cpumask.pcpu); |
1093 | free_cpumask_var(pinst->cpumask.cbcpu); |
1094 | err_free_inst: |
1095 | kfree(pinst); |
1096 | put_online_cpus(); |
1097 | err: |
1098 | return NULL; |
1099 | } |
1100 | EXPORT_SYMBOL(padata_alloc); |
1101 | |
1102 | /** |
1103 | * padata_free - free a padata instance |
1104 | * |
1105 | * @padata_inst: padata instance to free |
1106 | */ |
1107 | void padata_free(struct padata_instance *pinst) |
1108 | { |
1109 | kobject_put(&pinst->kobj); |
1110 | } |
1111 | EXPORT_SYMBOL(padata_free); |
1112 |
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