Commit | Line | Data |
---|---|---|
16295bec SK |
1 | /* |
2 | * padata.c - generic interface to process data streams in parallel | |
3 | * | |
107f8bda SK |
4 | * See Documentation/padata.txt for an api documentation. |
5 | * | |
16295bec SK |
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 | ||
9984de1a | 23 | #include <linux/export.h> |
16295bec SK |
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> | |
5a0e3ad6 | 30 | #include <linux/slab.h> |
5e017dc3 | 31 | #include <linux/sysfs.h> |
16295bec SK |
32 | #include <linux/rcupdate.h> |
33 | ||
97e3d94a | 34 | #define MAX_OBJ_NUM 1000 |
16295bec SK |
35 | |
36 | static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index) | |
37 | { | |
38 | int cpu, target_cpu; | |
39 | ||
e15bacbe | 40 | target_cpu = cpumask_first(pd->cpumask.pcpu); |
16295bec | 41 | for (cpu = 0; cpu < cpu_index; cpu++) |
e15bacbe | 42 | target_cpu = cpumask_next(target_cpu, pd->cpumask.pcpu); |
16295bec SK |
43 | |
44 | return target_cpu; | |
45 | } | |
46 | ||
2dc9b5db | 47 | static int padata_cpu_hash(struct parallel_data *pd) |
16295bec | 48 | { |
0b6b098e | 49 | unsigned int seq_nr; |
16295bec | 50 | int cpu_index; |
16295bec SK |
51 | |
52 | /* | |
53 | * Hash the sequence numbers to the cpus by taking | |
54 | * seq_nr mod. number of cpus in use. | |
55 | */ | |
2dc9b5db | 56 | |
0b6b098e MK |
57 | seq_nr = atomic_inc_return(&pd->seq_nr); |
58 | cpu_index = seq_nr % cpumask_weight(pd->cpumask.pcpu); | |
16295bec SK |
59 | |
60 | return padata_index_to_cpu(pd, cpu_index); | |
61 | } | |
62 | ||
e15bacbe | 63 | static void padata_parallel_worker(struct work_struct *parallel_work) |
16295bec | 64 | { |
e15bacbe | 65 | struct padata_parallel_queue *pqueue; |
16295bec SK |
66 | struct parallel_data *pd; |
67 | struct padata_instance *pinst; | |
68 | LIST_HEAD(local_list); | |
69 | ||
70 | local_bh_disable(); | |
e15bacbe DK |
71 | pqueue = container_of(parallel_work, |
72 | struct padata_parallel_queue, work); | |
73 | pd = pqueue->pd; | |
16295bec SK |
74 | pinst = pd->pinst; |
75 | ||
e15bacbe DK |
76 | spin_lock(&pqueue->parallel.lock); |
77 | list_replace_init(&pqueue->parallel.list, &local_list); | |
78 | spin_unlock(&pqueue->parallel.lock); | |
16295bec SK |
79 | |
80 | while (!list_empty(&local_list)) { | |
81 | struct padata_priv *padata; | |
82 | ||
83 | padata = list_entry(local_list.next, | |
84 | struct padata_priv, list); | |
85 | ||
86 | list_del_init(&padata->list); | |
87 | ||
88 | padata->parallel(padata); | |
89 | } | |
90 | ||
91 | local_bh_enable(); | |
92 | } | |
93 | ||
0198ffd1 | 94 | /** |
16295bec SK |
95 | * padata_do_parallel - padata parallelization function |
96 | * | |
97 | * @pinst: padata instance | |
98 | * @padata: object to be parallelized | |
99 | * @cb_cpu: cpu the serialization callback function will run on, | |
e15bacbe | 100 | * must be in the serial cpumask of padata(i.e. cpumask.cbcpu). |
16295bec SK |
101 | * |
102 | * The parallelization callback function will run with BHs off. | |
103 | * Note: Every object which is parallelized by padata_do_parallel | |
104 | * must be seen by padata_do_serial. | |
105 | */ | |
106 | int padata_do_parallel(struct padata_instance *pinst, | |
107 | struct padata_priv *padata, int cb_cpu) | |
108 | { | |
109 | int target_cpu, err; | |
e15bacbe | 110 | struct padata_parallel_queue *queue; |
16295bec SK |
111 | struct parallel_data *pd; |
112 | ||
113 | rcu_read_lock_bh(); | |
114 | ||
c0e656b7 | 115 | pd = rcu_dereference_bh(pinst->pd); |
16295bec | 116 | |
83f619f3 | 117 | err = -EINVAL; |
7424713b | 118 | if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID) |
16295bec SK |
119 | goto out; |
120 | ||
e15bacbe | 121 | if (!cpumask_test_cpu(cb_cpu, pd->cpumask.cbcpu)) |
16295bec SK |
122 | goto out; |
123 | ||
124 | err = -EBUSY; | |
125 | if ((pinst->flags & PADATA_RESET)) | |
126 | goto out; | |
127 | ||
128 | if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM) | |
129 | goto out; | |
130 | ||
83f619f3 | 131 | err = 0; |
16295bec SK |
132 | atomic_inc(&pd->refcnt); |
133 | padata->pd = pd; | |
134 | padata->cb_cpu = cb_cpu; | |
135 | ||
2dc9b5db | 136 | target_cpu = padata_cpu_hash(pd); |
e15bacbe | 137 | queue = per_cpu_ptr(pd->pqueue, target_cpu); |
16295bec SK |
138 | |
139 | spin_lock(&queue->parallel.lock); | |
140 | list_add_tail(&padata->list, &queue->parallel.list); | |
141 | spin_unlock(&queue->parallel.lock); | |
142 | ||
e15bacbe | 143 | queue_work_on(target_cpu, pinst->wq, &queue->work); |
16295bec SK |
144 | |
145 | out: | |
146 | rcu_read_unlock_bh(); | |
147 | ||
148 | return err; | |
149 | } | |
150 | EXPORT_SYMBOL(padata_do_parallel); | |
151 | ||
0198ffd1 SK |
152 | /* |
153 | * padata_get_next - Get the next object that needs serialization. | |
154 | * | |
155 | * Return values are: | |
156 | * | |
157 | * A pointer to the control struct of the next object that needs | |
158 | * serialization, if present in one of the percpu reorder queues. | |
159 | * | |
160 | * NULL, if all percpu reorder queues are empty. | |
161 | * | |
162 | * -EINPROGRESS, if the next object that needs serialization will | |
163 | * be parallel processed by another cpu and is not yet present in | |
164 | * the cpu's reorder queue. | |
165 | * | |
166 | * -ENODATA, if this cpu has to do the parallel processing for | |
167 | * the next object. | |
168 | */ | |
16295bec SK |
169 | static struct padata_priv *padata_get_next(struct parallel_data *pd) |
170 | { | |
5f1a8c1b | 171 | int cpu, num_cpus; |
2dc9b5db | 172 | unsigned int next_nr, next_index; |
f0fcf200 | 173 | struct padata_parallel_queue *next_queue; |
16295bec SK |
174 | struct padata_priv *padata; |
175 | struct padata_list *reorder; | |
176 | ||
e15bacbe | 177 | num_cpus = cpumask_weight(pd->cpumask.pcpu); |
16295bec | 178 | |
5f1a8c1b SK |
179 | /* |
180 | * Calculate the percpu reorder queue and the sequence | |
181 | * number of the next object. | |
182 | */ | |
183 | next_nr = pd->processed; | |
184 | next_index = next_nr % num_cpus; | |
185 | cpu = padata_index_to_cpu(pd, next_index); | |
e15bacbe | 186 | next_queue = per_cpu_ptr(pd->pqueue, cpu); |
5f1a8c1b | 187 | |
16295bec SK |
188 | padata = NULL; |
189 | ||
16295bec SK |
190 | reorder = &next_queue->reorder; |
191 | ||
192 | if (!list_empty(&reorder->list)) { | |
193 | padata = list_entry(reorder->list.next, | |
194 | struct padata_priv, list); | |
195 | ||
16295bec SK |
196 | spin_lock(&reorder->lock); |
197 | list_del_init(&padata->list); | |
198 | atomic_dec(&pd->reorder_objects); | |
199 | spin_unlock(&reorder->lock); | |
200 | ||
5f1a8c1b | 201 | pd->processed++; |
16295bec SK |
202 | |
203 | goto out; | |
204 | } | |
205 | ||
f0fcf200 | 206 | if (__this_cpu_read(pd->pqueue->cpu_index) == next_queue->cpu_index) { |
16295bec SK |
207 | padata = ERR_PTR(-ENODATA); |
208 | goto out; | |
209 | } | |
210 | ||
211 | padata = ERR_PTR(-EINPROGRESS); | |
212 | out: | |
213 | return padata; | |
214 | } | |
215 | ||
216 | static void padata_reorder(struct parallel_data *pd) | |
217 | { | |
3047817b | 218 | int cb_cpu; |
16295bec | 219 | struct padata_priv *padata; |
e15bacbe | 220 | struct padata_serial_queue *squeue; |
16295bec SK |
221 | struct padata_instance *pinst = pd->pinst; |
222 | ||
0198ffd1 SK |
223 | /* |
224 | * We need to ensure that only one cpu can work on dequeueing of | |
225 | * the reorder queue the time. Calculating in which percpu reorder | |
226 | * queue the next object will arrive takes some time. A spinlock | |
227 | * would be highly contended. Also it is not clear in which order | |
228 | * the objects arrive to the reorder queues. So a cpu could wait to | |
229 | * get the lock just to notice that there is nothing to do at the | |
230 | * moment. Therefore we use a trylock and let the holder of the lock | |
231 | * care for all the objects enqueued during the holdtime of the lock. | |
232 | */ | |
16295bec | 233 | if (!spin_trylock_bh(&pd->lock)) |
d46a5ac7 | 234 | return; |
16295bec SK |
235 | |
236 | while (1) { | |
237 | padata = padata_get_next(pd); | |
238 | ||
0198ffd1 SK |
239 | /* |
240 | * All reorder queues are empty, or the next object that needs | |
241 | * serialization is parallel processed by another cpu and is | |
242 | * still on it's way to the cpu's reorder queue, nothing to | |
243 | * do for now. | |
244 | */ | |
16295bec SK |
245 | if (!padata || PTR_ERR(padata) == -EINPROGRESS) |
246 | break; | |
247 | ||
0198ffd1 SK |
248 | /* |
249 | * This cpu has to do the parallel processing of the next | |
250 | * object. It's waiting in the cpu's parallelization queue, | |
25985edc | 251 | * so exit immediately. |
0198ffd1 | 252 | */ |
16295bec | 253 | if (PTR_ERR(padata) == -ENODATA) { |
d46a5ac7 | 254 | del_timer(&pd->timer); |
16295bec | 255 | spin_unlock_bh(&pd->lock); |
d46a5ac7 | 256 | return; |
16295bec SK |
257 | } |
258 | ||
3047817b SK |
259 | cb_cpu = padata->cb_cpu; |
260 | squeue = per_cpu_ptr(pd->squeue, cb_cpu); | |
16295bec | 261 | |
e15bacbe DK |
262 | spin_lock(&squeue->serial.lock); |
263 | list_add_tail(&padata->list, &squeue->serial.list); | |
264 | spin_unlock(&squeue->serial.lock); | |
16295bec | 265 | |
3047817b | 266 | queue_work_on(cb_cpu, pinst->wq, &squeue->work); |
16295bec SK |
267 | } |
268 | ||
269 | spin_unlock_bh(&pd->lock); | |
270 | ||
0198ffd1 SK |
271 | /* |
272 | * The next object that needs serialization might have arrived to | |
273 | * the reorder queues in the meantime, we will be called again | |
25985edc | 274 | * from the timer function if no one else cares for it. |
0198ffd1 | 275 | */ |
d46a5ac7 SK |
276 | if (atomic_read(&pd->reorder_objects) |
277 | && !(pinst->flags & PADATA_RESET)) | |
278 | mod_timer(&pd->timer, jiffies + HZ); | |
279 | else | |
280 | del_timer(&pd->timer); | |
16295bec | 281 | |
16295bec SK |
282 | return; |
283 | } | |
284 | ||
d46a5ac7 SK |
285 | static void padata_reorder_timer(unsigned long arg) |
286 | { | |
287 | struct parallel_data *pd = (struct parallel_data *)arg; | |
288 | ||
289 | padata_reorder(pd); | |
290 | } | |
291 | ||
e15bacbe | 292 | static void padata_serial_worker(struct work_struct *serial_work) |
16295bec | 293 | { |
e15bacbe | 294 | struct padata_serial_queue *squeue; |
16295bec SK |
295 | struct parallel_data *pd; |
296 | LIST_HEAD(local_list); | |
297 | ||
298 | local_bh_disable(); | |
e15bacbe DK |
299 | squeue = container_of(serial_work, struct padata_serial_queue, work); |
300 | pd = squeue->pd; | |
16295bec | 301 | |
e15bacbe DK |
302 | spin_lock(&squeue->serial.lock); |
303 | list_replace_init(&squeue->serial.list, &local_list); | |
304 | spin_unlock(&squeue->serial.lock); | |
16295bec SK |
305 | |
306 | while (!list_empty(&local_list)) { | |
307 | struct padata_priv *padata; | |
308 | ||
309 | padata = list_entry(local_list.next, | |
310 | struct padata_priv, list); | |
311 | ||
312 | list_del_init(&padata->list); | |
313 | ||
314 | padata->serial(padata); | |
315 | atomic_dec(&pd->refcnt); | |
316 | } | |
317 | local_bh_enable(); | |
318 | } | |
319 | ||
0198ffd1 | 320 | /** |
16295bec SK |
321 | * padata_do_serial - padata serialization function |
322 | * | |
323 | * @padata: object to be serialized. | |
324 | * | |
325 | * padata_do_serial must be called for every parallelized object. | |
326 | * The serialization callback function will run with BHs off. | |
327 | */ | |
328 | void padata_do_serial(struct padata_priv *padata) | |
329 | { | |
330 | int cpu; | |
e15bacbe | 331 | struct padata_parallel_queue *pqueue; |
16295bec SK |
332 | struct parallel_data *pd; |
333 | ||
334 | pd = padata->pd; | |
335 | ||
336 | cpu = get_cpu(); | |
e15bacbe | 337 | pqueue = per_cpu_ptr(pd->pqueue, cpu); |
16295bec | 338 | |
e15bacbe | 339 | spin_lock(&pqueue->reorder.lock); |
16295bec | 340 | atomic_inc(&pd->reorder_objects); |
e15bacbe DK |
341 | list_add_tail(&padata->list, &pqueue->reorder.list); |
342 | spin_unlock(&pqueue->reorder.lock); | |
16295bec SK |
343 | |
344 | put_cpu(); | |
345 | ||
346 | padata_reorder(pd); | |
347 | } | |
348 | EXPORT_SYMBOL(padata_do_serial); | |
349 | ||
e15bacbe DK |
350 | static int padata_setup_cpumasks(struct parallel_data *pd, |
351 | const struct cpumask *pcpumask, | |
352 | const struct cpumask *cbcpumask) | |
16295bec | 353 | { |
e15bacbe DK |
354 | if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL)) |
355 | return -ENOMEM; | |
16295bec | 356 | |
13614e0f | 357 | cpumask_and(pd->cpumask.pcpu, pcpumask, cpu_online_mask); |
e15bacbe DK |
358 | if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL)) { |
359 | free_cpumask_var(pd->cpumask.cbcpu); | |
360 | return -ENOMEM; | |
361 | } | |
16295bec | 362 | |
13614e0f | 363 | cpumask_and(pd->cpumask.cbcpu, cbcpumask, cpu_online_mask); |
e15bacbe DK |
364 | return 0; |
365 | } | |
16295bec | 366 | |
e15bacbe DK |
367 | static void __padata_list_init(struct padata_list *pd_list) |
368 | { | |
369 | INIT_LIST_HEAD(&pd_list->list); | |
370 | spin_lock_init(&pd_list->lock); | |
371 | } | |
16295bec | 372 | |
e15bacbe DK |
373 | /* Initialize all percpu queues used by serial workers */ |
374 | static void padata_init_squeues(struct parallel_data *pd) | |
375 | { | |
376 | int cpu; | |
377 | struct padata_serial_queue *squeue; | |
7b389b2c | 378 | |
e15bacbe DK |
379 | for_each_cpu(cpu, pd->cpumask.cbcpu) { |
380 | squeue = per_cpu_ptr(pd->squeue, cpu); | |
381 | squeue->pd = pd; | |
382 | __padata_list_init(&squeue->serial); | |
383 | INIT_WORK(&squeue->work, padata_serial_worker); | |
384 | } | |
385 | } | |
16295bec | 386 | |
e15bacbe DK |
387 | /* Initialize all percpu queues used by parallel workers */ |
388 | static void padata_init_pqueues(struct parallel_data *pd) | |
389 | { | |
2dc9b5db | 390 | int cpu_index, cpu; |
e15bacbe | 391 | struct padata_parallel_queue *pqueue; |
16295bec | 392 | |
e15bacbe DK |
393 | cpu_index = 0; |
394 | for_each_cpu(cpu, pd->cpumask.pcpu) { | |
395 | pqueue = per_cpu_ptr(pd->pqueue, cpu); | |
396 | pqueue->pd = pd; | |
397 | pqueue->cpu_index = cpu_index; | |
7b389b2c | 398 | cpu_index++; |
16295bec | 399 | |
e15bacbe DK |
400 | __padata_list_init(&pqueue->reorder); |
401 | __padata_list_init(&pqueue->parallel); | |
402 | INIT_WORK(&pqueue->work, padata_parallel_worker); | |
403 | atomic_set(&pqueue->num_obj, 0); | |
16295bec | 404 | } |
e15bacbe | 405 | } |
16295bec | 406 | |
e15bacbe DK |
407 | /* Allocate and initialize the internal cpumask dependend resources. */ |
408 | static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst, | |
409 | const struct cpumask *pcpumask, | |
410 | const struct cpumask *cbcpumask) | |
411 | { | |
412 | struct parallel_data *pd; | |
16295bec | 413 | |
e15bacbe DK |
414 | pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL); |
415 | if (!pd) | |
416 | goto err; | |
16295bec | 417 | |
e15bacbe DK |
418 | pd->pqueue = alloc_percpu(struct padata_parallel_queue); |
419 | if (!pd->pqueue) | |
420 | goto err_free_pd; | |
421 | ||
422 | pd->squeue = alloc_percpu(struct padata_serial_queue); | |
423 | if (!pd->squeue) | |
424 | goto err_free_pqueue; | |
425 | if (padata_setup_cpumasks(pd, pcpumask, cbcpumask) < 0) | |
426 | goto err_free_squeue; | |
16295bec | 427 | |
e15bacbe DK |
428 | padata_init_pqueues(pd); |
429 | padata_init_squeues(pd); | |
d46a5ac7 | 430 | setup_timer(&pd->timer, padata_reorder_timer, (unsigned long)pd); |
0b6b098e | 431 | atomic_set(&pd->seq_nr, -1); |
16295bec SK |
432 | atomic_set(&pd->reorder_objects, 0); |
433 | atomic_set(&pd->refcnt, 0); | |
434 | pd->pinst = pinst; | |
435 | spin_lock_init(&pd->lock); | |
436 | ||
437 | return pd; | |
438 | ||
e15bacbe DK |
439 | err_free_squeue: |
440 | free_percpu(pd->squeue); | |
441 | err_free_pqueue: | |
442 | free_percpu(pd->pqueue); | |
16295bec SK |
443 | err_free_pd: |
444 | kfree(pd); | |
445 | err: | |
446 | return NULL; | |
447 | } | |
448 | ||
449 | static void padata_free_pd(struct parallel_data *pd) | |
450 | { | |
e15bacbe DK |
451 | free_cpumask_var(pd->cpumask.pcpu); |
452 | free_cpumask_var(pd->cpumask.cbcpu); | |
453 | free_percpu(pd->pqueue); | |
454 | free_percpu(pd->squeue); | |
16295bec SK |
455 | kfree(pd); |
456 | } | |
457 | ||
0198ffd1 | 458 | /* Flush all objects out of the padata queues. */ |
2b73b07a SK |
459 | static void padata_flush_queues(struct parallel_data *pd) |
460 | { | |
461 | int cpu; | |
e15bacbe DK |
462 | struct padata_parallel_queue *pqueue; |
463 | struct padata_serial_queue *squeue; | |
2b73b07a | 464 | |
e15bacbe DK |
465 | for_each_cpu(cpu, pd->cpumask.pcpu) { |
466 | pqueue = per_cpu_ptr(pd->pqueue, cpu); | |
467 | flush_work(&pqueue->work); | |
2b73b07a SK |
468 | } |
469 | ||
470 | del_timer_sync(&pd->timer); | |
471 | ||
472 | if (atomic_read(&pd->reorder_objects)) | |
473 | padata_reorder(pd); | |
474 | ||
e15bacbe DK |
475 | for_each_cpu(cpu, pd->cpumask.cbcpu) { |
476 | squeue = per_cpu_ptr(pd->squeue, cpu); | |
477 | flush_work(&squeue->work); | |
2b73b07a SK |
478 | } |
479 | ||
480 | BUG_ON(atomic_read(&pd->refcnt) != 0); | |
481 | } | |
482 | ||
4c879170 SK |
483 | static void __padata_start(struct padata_instance *pinst) |
484 | { | |
485 | pinst->flags |= PADATA_INIT; | |
486 | } | |
487 | ||
ee836555 SK |
488 | static void __padata_stop(struct padata_instance *pinst) |
489 | { | |
490 | if (!(pinst->flags & PADATA_INIT)) | |
491 | return; | |
492 | ||
493 | pinst->flags &= ~PADATA_INIT; | |
494 | ||
495 | synchronize_rcu(); | |
496 | ||
497 | get_online_cpus(); | |
498 | padata_flush_queues(pinst->pd); | |
499 | put_online_cpus(); | |
500 | } | |
501 | ||
25985edc | 502 | /* Replace the internal control structure with a new one. */ |
16295bec SK |
503 | static void padata_replace(struct padata_instance *pinst, |
504 | struct parallel_data *pd_new) | |
505 | { | |
506 | struct parallel_data *pd_old = pinst->pd; | |
e15bacbe | 507 | int notification_mask = 0; |
16295bec SK |
508 | |
509 | pinst->flags |= PADATA_RESET; | |
510 | ||
511 | rcu_assign_pointer(pinst->pd, pd_new); | |
512 | ||
513 | synchronize_rcu(); | |
514 | ||
e15bacbe DK |
515 | if (!cpumask_equal(pd_old->cpumask.pcpu, pd_new->cpumask.pcpu)) |
516 | notification_mask |= PADATA_CPU_PARALLEL; | |
517 | if (!cpumask_equal(pd_old->cpumask.cbcpu, pd_new->cpumask.cbcpu)) | |
518 | notification_mask |= PADATA_CPU_SERIAL; | |
519 | ||
2b73b07a | 520 | padata_flush_queues(pd_old); |
16295bec SK |
521 | padata_free_pd(pd_old); |
522 | ||
e15bacbe DK |
523 | if (notification_mask) |
524 | blocking_notifier_call_chain(&pinst->cpumask_change_notifier, | |
c635696c SK |
525 | notification_mask, |
526 | &pd_new->cpumask); | |
16295bec SK |
527 | |
528 | pinst->flags &= ~PADATA_RESET; | |
529 | } | |
530 | ||
0198ffd1 | 531 | /** |
e15bacbe DK |
532 | * padata_register_cpumask_notifier - Registers a notifier that will be called |
533 | * if either pcpu or cbcpu or both cpumasks change. | |
16295bec | 534 | * |
e15bacbe DK |
535 | * @pinst: A poineter to padata instance |
536 | * @nblock: A pointer to notifier block. | |
16295bec | 537 | */ |
e15bacbe DK |
538 | int padata_register_cpumask_notifier(struct padata_instance *pinst, |
539 | struct notifier_block *nblock) | |
16295bec | 540 | { |
e15bacbe DK |
541 | return blocking_notifier_chain_register(&pinst->cpumask_change_notifier, |
542 | nblock); | |
543 | } | |
544 | EXPORT_SYMBOL(padata_register_cpumask_notifier); | |
545 | ||
546 | /** | |
547 | * padata_unregister_cpumask_notifier - Unregisters cpumask notifier | |
548 | * registered earlier using padata_register_cpumask_notifier | |
549 | * | |
550 | * @pinst: A pointer to data instance. | |
551 | * @nlock: A pointer to notifier block. | |
552 | */ | |
553 | int padata_unregister_cpumask_notifier(struct padata_instance *pinst, | |
554 | struct notifier_block *nblock) | |
555 | { | |
556 | return blocking_notifier_chain_unregister( | |
557 | &pinst->cpumask_change_notifier, | |
558 | nblock); | |
559 | } | |
560 | EXPORT_SYMBOL(padata_unregister_cpumask_notifier); | |
561 | ||
562 | ||
33e54450 SK |
563 | /* If cpumask contains no active cpu, we mark the instance as invalid. */ |
564 | static bool padata_validate_cpumask(struct padata_instance *pinst, | |
565 | const struct cpumask *cpumask) | |
566 | { | |
13614e0f | 567 | if (!cpumask_intersects(cpumask, cpu_online_mask)) { |
33e54450 SK |
568 | pinst->flags |= PADATA_INVALID; |
569 | return false; | |
570 | } | |
571 | ||
572 | pinst->flags &= ~PADATA_INVALID; | |
573 | return true; | |
574 | } | |
575 | ||
65ff577e SK |
576 | static int __padata_set_cpumasks(struct padata_instance *pinst, |
577 | cpumask_var_t pcpumask, | |
578 | cpumask_var_t cbcpumask) | |
579 | { | |
580 | int valid; | |
16295bec | 581 | struct parallel_data *pd; |
65ff577e SK |
582 | |
583 | valid = padata_validate_cpumask(pinst, pcpumask); | |
584 | if (!valid) { | |
585 | __padata_stop(pinst); | |
586 | goto out_replace; | |
587 | } | |
588 | ||
589 | valid = padata_validate_cpumask(pinst, cbcpumask); | |
590 | if (!valid) | |
591 | __padata_stop(pinst); | |
592 | ||
593 | out_replace: | |
594 | pd = padata_alloc_pd(pinst, pcpumask, cbcpumask); | |
595 | if (!pd) | |
596 | return -ENOMEM; | |
597 | ||
598 | cpumask_copy(pinst->cpumask.pcpu, pcpumask); | |
599 | cpumask_copy(pinst->cpumask.cbcpu, cbcpumask); | |
600 | ||
601 | padata_replace(pinst, pd); | |
602 | ||
603 | if (valid) | |
604 | __padata_start(pinst); | |
605 | ||
606 | return 0; | |
607 | } | |
608 | ||
e15bacbe DK |
609 | /** |
610 | * padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value | |
611 | * equivalent to @cpumask. | |
16295bec SK |
612 | * |
613 | * @pinst: padata instance | |
e15bacbe DK |
614 | * @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding |
615 | * to parallel and serial cpumasks respectively. | |
16295bec SK |
616 | * @cpumask: the cpumask to use |
617 | */ | |
e15bacbe DK |
618 | int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, |
619 | cpumask_var_t cpumask) | |
620 | { | |
621 | struct cpumask *serial_mask, *parallel_mask; | |
65ff577e SK |
622 | int err = -EINVAL; |
623 | ||
624 | mutex_lock(&pinst->lock); | |
6751fb3c SK |
625 | get_online_cpus(); |
626 | ||
e15bacbe DK |
627 | switch (cpumask_type) { |
628 | case PADATA_CPU_PARALLEL: | |
629 | serial_mask = pinst->cpumask.cbcpu; | |
630 | parallel_mask = cpumask; | |
631 | break; | |
632 | case PADATA_CPU_SERIAL: | |
633 | parallel_mask = pinst->cpumask.pcpu; | |
634 | serial_mask = cpumask; | |
635 | break; | |
636 | default: | |
65ff577e | 637 | goto out; |
16295bec SK |
638 | } |
639 | ||
65ff577e | 640 | err = __padata_set_cpumasks(pinst, parallel_mask, serial_mask); |
16295bec SK |
641 | |
642 | out: | |
6751fb3c | 643 | put_online_cpus(); |
16295bec SK |
644 | mutex_unlock(&pinst->lock); |
645 | ||
646 | return err; | |
647 | } | |
648 | EXPORT_SYMBOL(padata_set_cpumask); | |
649 | ||
19d795b6 AB |
650 | /** |
651 | * padata_start - start the parallel processing | |
652 | * | |
653 | * @pinst: padata instance to start | |
654 | */ | |
655 | int padata_start(struct padata_instance *pinst) | |
656 | { | |
657 | int err = 0; | |
658 | ||
659 | mutex_lock(&pinst->lock); | |
660 | ||
661 | if (pinst->flags & PADATA_INVALID) | |
662 | err = -EINVAL; | |
663 | ||
664 | __padata_start(pinst); | |
665 | ||
666 | mutex_unlock(&pinst->lock); | |
667 | ||
668 | return err; | |
669 | } | |
670 | EXPORT_SYMBOL(padata_start); | |
671 | ||
672 | /** | |
673 | * padata_stop - stop the parallel processing | |
674 | * | |
675 | * @pinst: padata instance to stop | |
676 | */ | |
677 | void padata_stop(struct padata_instance *pinst) | |
678 | { | |
679 | mutex_lock(&pinst->lock); | |
680 | __padata_stop(pinst); | |
681 | mutex_unlock(&pinst->lock); | |
682 | } | |
683 | EXPORT_SYMBOL(padata_stop); | |
684 | ||
685 | #ifdef CONFIG_HOTPLUG_CPU | |
686 | ||
16295bec SK |
687 | static int __padata_add_cpu(struct padata_instance *pinst, int cpu) |
688 | { | |
689 | struct parallel_data *pd; | |
690 | ||
13614e0f | 691 | if (cpumask_test_cpu(cpu, cpu_online_mask)) { |
e15bacbe DK |
692 | pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu, |
693 | pinst->cpumask.cbcpu); | |
16295bec SK |
694 | if (!pd) |
695 | return -ENOMEM; | |
696 | ||
697 | padata_replace(pinst, pd); | |
33e54450 | 698 | |
e15bacbe DK |
699 | if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) && |
700 | padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) | |
33e54450 | 701 | __padata_start(pinst); |
16295bec SK |
702 | } |
703 | ||
704 | return 0; | |
705 | } | |
706 | ||
16295bec SK |
707 | static int __padata_remove_cpu(struct padata_instance *pinst, int cpu) |
708 | { | |
33e54450 | 709 | struct parallel_data *pd = NULL; |
16295bec SK |
710 | |
711 | if (cpumask_test_cpu(cpu, cpu_online_mask)) { | |
33e54450 | 712 | |
e15bacbe | 713 | if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) || |
b89661df | 714 | !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) |
33e54450 | 715 | __padata_stop(pinst); |
33e54450 | 716 | |
e15bacbe DK |
717 | pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu, |
718 | pinst->cpumask.cbcpu); | |
16295bec SK |
719 | if (!pd) |
720 | return -ENOMEM; | |
721 | ||
722 | padata_replace(pinst, pd); | |
96120905 SK |
723 | |
724 | cpumask_clear_cpu(cpu, pd->cpumask.cbcpu); | |
725 | cpumask_clear_cpu(cpu, pd->cpumask.pcpu); | |
16295bec SK |
726 | } |
727 | ||
728 | return 0; | |
729 | } | |
730 | ||
e15bacbe | 731 | /** |
25985edc | 732 | * padata_remove_cpu - remove a cpu from the one or both(serial and parallel) |
e15bacbe | 733 | * padata cpumasks. |
16295bec SK |
734 | * |
735 | * @pinst: padata instance | |
736 | * @cpu: cpu to remove | |
e15bacbe DK |
737 | * @mask: bitmask specifying from which cpumask @cpu should be removed |
738 | * The @mask may be any combination of the following flags: | |
739 | * PADATA_CPU_SERIAL - serial cpumask | |
740 | * PADATA_CPU_PARALLEL - parallel cpumask | |
16295bec | 741 | */ |
e15bacbe | 742 | int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask) |
16295bec SK |
743 | { |
744 | int err; | |
745 | ||
e15bacbe DK |
746 | if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL))) |
747 | return -EINVAL; | |
748 | ||
16295bec SK |
749 | mutex_lock(&pinst->lock); |
750 | ||
6751fb3c | 751 | get_online_cpus(); |
e15bacbe DK |
752 | if (mask & PADATA_CPU_SERIAL) |
753 | cpumask_clear_cpu(cpu, pinst->cpumask.cbcpu); | |
754 | if (mask & PADATA_CPU_PARALLEL) | |
755 | cpumask_clear_cpu(cpu, pinst->cpumask.pcpu); | |
756 | ||
16295bec | 757 | err = __padata_remove_cpu(pinst, cpu); |
6751fb3c | 758 | put_online_cpus(); |
16295bec SK |
759 | |
760 | mutex_unlock(&pinst->lock); | |
761 | ||
762 | return err; | |
763 | } | |
764 | EXPORT_SYMBOL(padata_remove_cpu); | |
765 | ||
e15bacbe DK |
766 | static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu) |
767 | { | |
768 | return cpumask_test_cpu(cpu, pinst->cpumask.pcpu) || | |
769 | cpumask_test_cpu(cpu, pinst->cpumask.cbcpu); | |
770 | } | |
771 | ||
772 | ||
975d2603 HK |
773 | static int padata_cpu_callback(struct notifier_block *nfb, |
774 | unsigned long action, void *hcpu) | |
16295bec SK |
775 | { |
776 | int err; | |
777 | struct padata_instance *pinst; | |
778 | int cpu = (unsigned long)hcpu; | |
779 | ||
780 | pinst = container_of(nfb, struct padata_instance, cpu_notifier); | |
781 | ||
782 | switch (action) { | |
783 | case CPU_ONLINE: | |
784 | case CPU_ONLINE_FROZEN: | |
9c823f9f CG |
785 | case CPU_DOWN_FAILED: |
786 | case CPU_DOWN_FAILED_FROZEN: | |
e15bacbe | 787 | if (!pinst_has_cpu(pinst, cpu)) |
16295bec SK |
788 | break; |
789 | mutex_lock(&pinst->lock); | |
790 | err = __padata_add_cpu(pinst, cpu); | |
791 | mutex_unlock(&pinst->lock); | |
792 | if (err) | |
80b5184c | 793 | return notifier_from_errno(err); |
16295bec SK |
794 | break; |
795 | ||
796 | case CPU_DOWN_PREPARE: | |
797 | case CPU_DOWN_PREPARE_FROZEN: | |
9c823f9f CG |
798 | case CPU_UP_CANCELED: |
799 | case CPU_UP_CANCELED_FROZEN: | |
e15bacbe | 800 | if (!pinst_has_cpu(pinst, cpu)) |
16295bec SK |
801 | break; |
802 | mutex_lock(&pinst->lock); | |
803 | err = __padata_remove_cpu(pinst, cpu); | |
804 | mutex_unlock(&pinst->lock); | |
805 | if (err) | |
80b5184c | 806 | return notifier_from_errno(err); |
16295bec | 807 | break; |
16295bec SK |
808 | } |
809 | ||
810 | return NOTIFY_OK; | |
811 | } | |
e2cb2f1c | 812 | #endif |
16295bec | 813 | |
5e017dc3 DK |
814 | static void __padata_free(struct padata_instance *pinst) |
815 | { | |
816 | #ifdef CONFIG_HOTPLUG_CPU | |
817 | unregister_hotcpu_notifier(&pinst->cpu_notifier); | |
818 | #endif | |
819 | ||
820 | padata_stop(pinst); | |
821 | padata_free_pd(pinst->pd); | |
822 | free_cpumask_var(pinst->cpumask.pcpu); | |
823 | free_cpumask_var(pinst->cpumask.cbcpu); | |
824 | kfree(pinst); | |
825 | } | |
826 | ||
827 | #define kobj2pinst(_kobj) \ | |
828 | container_of(_kobj, struct padata_instance, kobj) | |
829 | #define attr2pentry(_attr) \ | |
830 | container_of(_attr, struct padata_sysfs_entry, attr) | |
831 | ||
832 | static void padata_sysfs_release(struct kobject *kobj) | |
833 | { | |
834 | struct padata_instance *pinst = kobj2pinst(kobj); | |
835 | __padata_free(pinst); | |
836 | } | |
837 | ||
838 | struct padata_sysfs_entry { | |
839 | struct attribute attr; | |
840 | ssize_t (*show)(struct padata_instance *, struct attribute *, char *); | |
841 | ssize_t (*store)(struct padata_instance *, struct attribute *, | |
842 | const char *, size_t); | |
843 | }; | |
844 | ||
845 | static ssize_t show_cpumask(struct padata_instance *pinst, | |
846 | struct attribute *attr, char *buf) | |
847 | { | |
848 | struct cpumask *cpumask; | |
849 | ssize_t len; | |
850 | ||
851 | mutex_lock(&pinst->lock); | |
852 | if (!strcmp(attr->name, "serial_cpumask")) | |
853 | cpumask = pinst->cpumask.cbcpu; | |
854 | else | |
855 | cpumask = pinst->cpumask.pcpu; | |
856 | ||
4497da6f TH |
857 | len = snprintf(buf, PAGE_SIZE, "%*pb\n", |
858 | nr_cpu_ids, cpumask_bits(cpumask)); | |
5e017dc3 | 859 | mutex_unlock(&pinst->lock); |
4497da6f | 860 | return len < PAGE_SIZE ? len : -EINVAL; |
5e017dc3 DK |
861 | } |
862 | ||
863 | static ssize_t store_cpumask(struct padata_instance *pinst, | |
864 | struct attribute *attr, | |
865 | const char *buf, size_t count) | |
866 | { | |
867 | cpumask_var_t new_cpumask; | |
868 | ssize_t ret; | |
869 | int mask_type; | |
870 | ||
871 | if (!alloc_cpumask_var(&new_cpumask, GFP_KERNEL)) | |
872 | return -ENOMEM; | |
873 | ||
874 | ret = bitmap_parse(buf, count, cpumask_bits(new_cpumask), | |
875 | nr_cpumask_bits); | |
876 | if (ret < 0) | |
877 | goto out; | |
878 | ||
879 | mask_type = !strcmp(attr->name, "serial_cpumask") ? | |
880 | PADATA_CPU_SERIAL : PADATA_CPU_PARALLEL; | |
881 | ret = padata_set_cpumask(pinst, mask_type, new_cpumask); | |
882 | if (!ret) | |
883 | ret = count; | |
884 | ||
885 | out: | |
886 | free_cpumask_var(new_cpumask); | |
887 | return ret; | |
888 | } | |
889 | ||
890 | #define PADATA_ATTR_RW(_name, _show_name, _store_name) \ | |
891 | static struct padata_sysfs_entry _name##_attr = \ | |
892 | __ATTR(_name, 0644, _show_name, _store_name) | |
893 | #define PADATA_ATTR_RO(_name, _show_name) \ | |
894 | static struct padata_sysfs_entry _name##_attr = \ | |
895 | __ATTR(_name, 0400, _show_name, NULL) | |
896 | ||
897 | PADATA_ATTR_RW(serial_cpumask, show_cpumask, store_cpumask); | |
898 | PADATA_ATTR_RW(parallel_cpumask, show_cpumask, store_cpumask); | |
899 | ||
900 | /* | |
901 | * Padata sysfs provides the following objects: | |
902 | * serial_cpumask [RW] - cpumask for serial workers | |
903 | * parallel_cpumask [RW] - cpumask for parallel workers | |
904 | */ | |
905 | static struct attribute *padata_default_attrs[] = { | |
906 | &serial_cpumask_attr.attr, | |
907 | ¶llel_cpumask_attr.attr, | |
908 | NULL, | |
909 | }; | |
910 | ||
911 | static ssize_t padata_sysfs_show(struct kobject *kobj, | |
912 | struct attribute *attr, char *buf) | |
913 | { | |
914 | struct padata_instance *pinst; | |
915 | struct padata_sysfs_entry *pentry; | |
916 | ssize_t ret = -EIO; | |
917 | ||
918 | pinst = kobj2pinst(kobj); | |
919 | pentry = attr2pentry(attr); | |
920 | if (pentry->show) | |
921 | ret = pentry->show(pinst, attr, buf); | |
922 | ||
923 | return ret; | |
924 | } | |
925 | ||
926 | static ssize_t padata_sysfs_store(struct kobject *kobj, struct attribute *attr, | |
927 | const char *buf, size_t count) | |
928 | { | |
929 | struct padata_instance *pinst; | |
930 | struct padata_sysfs_entry *pentry; | |
931 | ssize_t ret = -EIO; | |
932 | ||
933 | pinst = kobj2pinst(kobj); | |
934 | pentry = attr2pentry(attr); | |
935 | if (pentry->show) | |
936 | ret = pentry->store(pinst, attr, buf, count); | |
937 | ||
938 | return ret; | |
939 | } | |
940 | ||
941 | static const struct sysfs_ops padata_sysfs_ops = { | |
942 | .show = padata_sysfs_show, | |
943 | .store = padata_sysfs_store, | |
944 | }; | |
945 | ||
946 | static struct kobj_type padata_attr_type = { | |
947 | .sysfs_ops = &padata_sysfs_ops, | |
948 | .default_attrs = padata_default_attrs, | |
949 | .release = padata_sysfs_release, | |
950 | }; | |
951 | ||
0198ffd1 | 952 | /** |
e6cc1170 SK |
953 | * padata_alloc_possible - Allocate and initialize padata instance. |
954 | * Use the cpu_possible_mask for serial and | |
955 | * parallel workers. | |
16295bec | 956 | * |
16295bec SK |
957 | * @wq: workqueue to use for the allocated padata instance |
958 | */ | |
e6cc1170 | 959 | struct padata_instance *padata_alloc_possible(struct workqueue_struct *wq) |
e15bacbe | 960 | { |
e6cc1170 | 961 | return padata_alloc(wq, cpu_possible_mask, cpu_possible_mask); |
e15bacbe | 962 | } |
e6cc1170 | 963 | EXPORT_SYMBOL(padata_alloc_possible); |
e15bacbe DK |
964 | |
965 | /** | |
e6cc1170 SK |
966 | * padata_alloc - allocate and initialize a padata instance and specify |
967 | * cpumasks for serial and parallel workers. | |
16295bec | 968 | * |
16295bec | 969 | * @wq: workqueue to use for the allocated padata instance |
e15bacbe DK |
970 | * @pcpumask: cpumask that will be used for padata parallelization |
971 | * @cbcpumask: cpumask that will be used for padata serialization | |
16295bec | 972 | */ |
e6cc1170 SK |
973 | struct padata_instance *padata_alloc(struct workqueue_struct *wq, |
974 | const struct cpumask *pcpumask, | |
975 | const struct cpumask *cbcpumask) | |
16295bec | 976 | { |
16295bec | 977 | struct padata_instance *pinst; |
33e54450 | 978 | struct parallel_data *pd = NULL; |
16295bec SK |
979 | |
980 | pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL); | |
981 | if (!pinst) | |
982 | goto err; | |
983 | ||
6751fb3c | 984 | get_online_cpus(); |
e15bacbe | 985 | if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL)) |
16295bec | 986 | goto err_free_inst; |
e15bacbe DK |
987 | if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) { |
988 | free_cpumask_var(pinst->cpumask.pcpu); | |
16295bec | 989 | goto err_free_inst; |
33e54450 | 990 | } |
e15bacbe DK |
991 | if (!padata_validate_cpumask(pinst, pcpumask) || |
992 | !padata_validate_cpumask(pinst, cbcpumask)) | |
993 | goto err_free_masks; | |
16295bec | 994 | |
e15bacbe DK |
995 | pd = padata_alloc_pd(pinst, pcpumask, cbcpumask); |
996 | if (!pd) | |
997 | goto err_free_masks; | |
74781387 | 998 | |
16295bec SK |
999 | rcu_assign_pointer(pinst->pd, pd); |
1000 | ||
1001 | pinst->wq = wq; | |
1002 | ||
e15bacbe DK |
1003 | cpumask_copy(pinst->cpumask.pcpu, pcpumask); |
1004 | cpumask_copy(pinst->cpumask.cbcpu, cbcpumask); | |
16295bec SK |
1005 | |
1006 | pinst->flags = 0; | |
1007 | ||
6751fb3c SK |
1008 | put_online_cpus(); |
1009 | ||
e15bacbe | 1010 | BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier); |
5e017dc3 | 1011 | kobject_init(&pinst->kobj, &padata_attr_type); |
16295bec SK |
1012 | mutex_init(&pinst->lock); |
1013 | ||
b8b4a416 RW |
1014 | #ifdef CONFIG_HOTPLUG_CPU |
1015 | pinst->cpu_notifier.notifier_call = padata_cpu_callback; | |
1016 | pinst->cpu_notifier.priority = 0; | |
1017 | register_hotcpu_notifier(&pinst->cpu_notifier); | |
1018 | #endif | |
1019 | ||
16295bec SK |
1020 | return pinst; |
1021 | ||
e15bacbe DK |
1022 | err_free_masks: |
1023 | free_cpumask_var(pinst->cpumask.pcpu); | |
1024 | free_cpumask_var(pinst->cpumask.cbcpu); | |
16295bec SK |
1025 | err_free_inst: |
1026 | kfree(pinst); | |
6751fb3c | 1027 | put_online_cpus(); |
16295bec SK |
1028 | err: |
1029 | return NULL; | |
1030 | } | |
16295bec | 1031 | |
0198ffd1 | 1032 | /** |
16295bec SK |
1033 | * padata_free - free a padata instance |
1034 | * | |
0198ffd1 | 1035 | * @padata_inst: padata instance to free |
16295bec SK |
1036 | */ |
1037 | void padata_free(struct padata_instance *pinst) | |
1038 | { | |
5e017dc3 | 1039 | kobject_put(&pinst->kobj); |
16295bec SK |
1040 | } |
1041 | EXPORT_SYMBOL(padata_free); |