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Commit | Line | Data |
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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 | 32 | #include <linux/rcupdate.h> |
30e92153 | 33 | #include <linux/module.h> |
16295bec | 34 | |
97e3d94a | 35 | #define MAX_OBJ_NUM 1000 |
16295bec SK |
36 | |
37 | static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index) | |
38 | { | |
39 | int cpu, target_cpu; | |
40 | ||
e15bacbe | 41 | target_cpu = cpumask_first(pd->cpumask.pcpu); |
16295bec | 42 | for (cpu = 0; cpu < cpu_index; cpu++) |
e15bacbe | 43 | target_cpu = cpumask_next(target_cpu, pd->cpumask.pcpu); |
16295bec SK |
44 | |
45 | return target_cpu; | |
46 | } | |
47 | ||
2dc9b5db | 48 | static int padata_cpu_hash(struct parallel_data *pd) |
16295bec | 49 | { |
0b6b098e | 50 | unsigned int seq_nr; |
16295bec | 51 | int cpu_index; |
16295bec SK |
52 | |
53 | /* | |
54 | * Hash the sequence numbers to the cpus by taking | |
55 | * seq_nr mod. number of cpus in use. | |
56 | */ | |
2dc9b5db | 57 | |
0b6b098e MK |
58 | seq_nr = atomic_inc_return(&pd->seq_nr); |
59 | cpu_index = seq_nr % cpumask_weight(pd->cpumask.pcpu); | |
16295bec SK |
60 | |
61 | return padata_index_to_cpu(pd, cpu_index); | |
62 | } | |
63 | ||
e15bacbe | 64 | static void padata_parallel_worker(struct work_struct *parallel_work) |
16295bec | 65 | { |
e15bacbe | 66 | struct padata_parallel_queue *pqueue; |
16295bec SK |
67 | LIST_HEAD(local_list); |
68 | ||
69 | local_bh_disable(); | |
e15bacbe DK |
70 | pqueue = container_of(parallel_work, |
71 | struct padata_parallel_queue, work); | |
16295bec | 72 | |
e15bacbe DK |
73 | spin_lock(&pqueue->parallel.lock); |
74 | list_replace_init(&pqueue->parallel.list, &local_list); | |
75 | spin_unlock(&pqueue->parallel.lock); | |
16295bec SK |
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, | |
e15bacbe | 97 | * must be in the serial cpumask of padata(i.e. cpumask.cbcpu). |
16295bec SK |
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; | |
e15bacbe | 107 | struct padata_parallel_queue *queue; |
16295bec SK |
108 | struct parallel_data *pd; |
109 | ||
110 | rcu_read_lock_bh(); | |
111 | ||
c0e656b7 | 112 | pd = rcu_dereference_bh(pinst->pd); |
16295bec | 113 | |
83f619f3 | 114 | err = -EINVAL; |
7424713b | 115 | if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID) |
16295bec SK |
116 | goto out; |
117 | ||
e15bacbe | 118 | if (!cpumask_test_cpu(cb_cpu, pd->cpumask.cbcpu)) |
16295bec SK |
119 | goto out; |
120 | ||
121 | err = -EBUSY; | |
122 | if ((pinst->flags & PADATA_RESET)) | |
123 | goto out; | |
124 | ||
125 | if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM) | |
126 | goto out; | |
127 | ||
83f619f3 | 128 | err = 0; |
16295bec SK |
129 | atomic_inc(&pd->refcnt); |
130 | padata->pd = pd; | |
131 | padata->cb_cpu = cb_cpu; | |
132 | ||
2dc9b5db | 133 | target_cpu = padata_cpu_hash(pd); |
e15bacbe | 134 | queue = per_cpu_ptr(pd->pqueue, target_cpu); |
16295bec SK |
135 | |
136 | spin_lock(&queue->parallel.lock); | |
137 | list_add_tail(&padata->list, &queue->parallel.list); | |
138 | spin_unlock(&queue->parallel.lock); | |
139 | ||
e15bacbe | 140 | queue_work_on(target_cpu, pinst->wq, &queue->work); |
16295bec SK |
141 | |
142 | out: | |
143 | rcu_read_unlock_bh(); | |
144 | ||
145 | return err; | |
146 | } | |
147 | EXPORT_SYMBOL(padata_do_parallel); | |
148 | ||
0198ffd1 SK |
149 | /* |
150 | * padata_get_next - Get the next object that needs serialization. | |
151 | * | |
152 | * Return values are: | |
153 | * | |
154 | * A pointer to the control struct of the next object that needs | |
155 | * serialization, if present in one of the percpu reorder queues. | |
156 | * | |
157 | * NULL, if all percpu reorder queues are empty. | |
158 | * | |
159 | * -EINPROGRESS, if the next object that needs serialization will | |
160 | * be parallel processed by another cpu and is not yet present in | |
161 | * the cpu's reorder queue. | |
162 | * | |
163 | * -ENODATA, if this cpu has to do the parallel processing for | |
164 | * the next object. | |
165 | */ | |
16295bec SK |
166 | static struct padata_priv *padata_get_next(struct parallel_data *pd) |
167 | { | |
5f1a8c1b | 168 | int cpu, num_cpus; |
2dc9b5db | 169 | unsigned int next_nr, next_index; |
f0fcf200 | 170 | struct padata_parallel_queue *next_queue; |
16295bec SK |
171 | struct padata_priv *padata; |
172 | struct padata_list *reorder; | |
173 | ||
e15bacbe | 174 | num_cpus = cpumask_weight(pd->cpumask.pcpu); |
16295bec | 175 | |
5f1a8c1b SK |
176 | /* |
177 | * Calculate the percpu reorder queue and the sequence | |
178 | * number of the next object. | |
179 | */ | |
180 | next_nr = pd->processed; | |
181 | next_index = next_nr % num_cpus; | |
182 | cpu = padata_index_to_cpu(pd, next_index); | |
e15bacbe | 183 | next_queue = per_cpu_ptr(pd->pqueue, cpu); |
5f1a8c1b | 184 | |
16295bec SK |
185 | padata = NULL; |
186 | ||
16295bec SK |
187 | reorder = &next_queue->reorder; |
188 | ||
189 | if (!list_empty(&reorder->list)) { | |
190 | padata = list_entry(reorder->list.next, | |
191 | struct padata_priv, list); | |
192 | ||
16295bec SK |
193 | spin_lock(&reorder->lock); |
194 | list_del_init(&padata->list); | |
195 | atomic_dec(&pd->reorder_objects); | |
196 | spin_unlock(&reorder->lock); | |
197 | ||
5f1a8c1b | 198 | pd->processed++; |
16295bec SK |
199 | |
200 | goto out; | |
201 | } | |
202 | ||
f0fcf200 | 203 | if (__this_cpu_read(pd->pqueue->cpu_index) == next_queue->cpu_index) { |
16295bec SK |
204 | padata = ERR_PTR(-ENODATA); |
205 | goto out; | |
206 | } | |
207 | ||
208 | padata = ERR_PTR(-EINPROGRESS); | |
209 | out: | |
210 | return padata; | |
211 | } | |
212 | ||
213 | static void padata_reorder(struct parallel_data *pd) | |
214 | { | |
3047817b | 215 | int cb_cpu; |
16295bec | 216 | struct padata_priv *padata; |
e15bacbe | 217 | struct padata_serial_queue *squeue; |
16295bec SK |
218 | struct padata_instance *pinst = pd->pinst; |
219 | ||
0198ffd1 SK |
220 | /* |
221 | * We need to ensure that only one cpu can work on dequeueing of | |
222 | * the reorder queue the time. Calculating in which percpu reorder | |
223 | * queue the next object will arrive takes some time. A spinlock | |
224 | * would be highly contended. Also it is not clear in which order | |
225 | * the objects arrive to the reorder queues. So a cpu could wait to | |
226 | * get the lock just to notice that there is nothing to do at the | |
227 | * moment. Therefore we use a trylock and let the holder of the lock | |
228 | * care for all the objects enqueued during the holdtime of the lock. | |
229 | */ | |
16295bec | 230 | if (!spin_trylock_bh(&pd->lock)) |
d46a5ac7 | 231 | return; |
16295bec SK |
232 | |
233 | while (1) { | |
234 | padata = padata_get_next(pd); | |
235 | ||
0198ffd1 SK |
236 | /* |
237 | * All reorder queues are empty, or the next object that needs | |
238 | * serialization is parallel processed by another cpu and is | |
239 | * still on it's way to the cpu's reorder queue, nothing to | |
240 | * do for now. | |
241 | */ | |
16295bec SK |
242 | if (!padata || PTR_ERR(padata) == -EINPROGRESS) |
243 | break; | |
244 | ||
0198ffd1 SK |
245 | /* |
246 | * This cpu has to do the parallel processing of the next | |
247 | * object. It's waiting in the cpu's parallelization queue, | |
25985edc | 248 | * so exit immediately. |
0198ffd1 | 249 | */ |
16295bec | 250 | if (PTR_ERR(padata) == -ENODATA) { |
d46a5ac7 | 251 | del_timer(&pd->timer); |
16295bec | 252 | spin_unlock_bh(&pd->lock); |
d46a5ac7 | 253 | return; |
16295bec SK |
254 | } |
255 | ||
3047817b SK |
256 | cb_cpu = padata->cb_cpu; |
257 | squeue = per_cpu_ptr(pd->squeue, cb_cpu); | |
16295bec | 258 | |
e15bacbe DK |
259 | spin_lock(&squeue->serial.lock); |
260 | list_add_tail(&padata->list, &squeue->serial.list); | |
261 | spin_unlock(&squeue->serial.lock); | |
16295bec | 262 | |
3047817b | 263 | queue_work_on(cb_cpu, pinst->wq, &squeue->work); |
16295bec SK |
264 | } |
265 | ||
266 | spin_unlock_bh(&pd->lock); | |
267 | ||
0198ffd1 SK |
268 | /* |
269 | * The next object that needs serialization might have arrived to | |
270 | * the reorder queues in the meantime, we will be called again | |
25985edc | 271 | * from the timer function if no one else cares for it. |
0198ffd1 | 272 | */ |
d46a5ac7 SK |
273 | if (atomic_read(&pd->reorder_objects) |
274 | && !(pinst->flags & PADATA_RESET)) | |
275 | mod_timer(&pd->timer, jiffies + HZ); | |
276 | else | |
277 | del_timer(&pd->timer); | |
16295bec | 278 | |
16295bec SK |
279 | return; |
280 | } | |
281 | ||
d46a5ac7 SK |
282 | static void padata_reorder_timer(unsigned long arg) |
283 | { | |
284 | struct parallel_data *pd = (struct parallel_data *)arg; | |
285 | ||
286 | padata_reorder(pd); | |
287 | } | |
288 | ||
e15bacbe | 289 | static void padata_serial_worker(struct work_struct *serial_work) |
16295bec | 290 | { |
e15bacbe | 291 | struct padata_serial_queue *squeue; |
16295bec SK |
292 | struct parallel_data *pd; |
293 | LIST_HEAD(local_list); | |
294 | ||
295 | local_bh_disable(); | |
e15bacbe DK |
296 | squeue = container_of(serial_work, struct padata_serial_queue, work); |
297 | pd = squeue->pd; | |
16295bec | 298 | |
e15bacbe DK |
299 | spin_lock(&squeue->serial.lock); |
300 | list_replace_init(&squeue->serial.list, &local_list); | |
301 | spin_unlock(&squeue->serial.lock); | |
16295bec SK |
302 | |
303 | while (!list_empty(&local_list)) { | |
304 | struct padata_priv *padata; | |
305 | ||
306 | padata = list_entry(local_list.next, | |
307 | struct padata_priv, list); | |
308 | ||
309 | list_del_init(&padata->list); | |
310 | ||
311 | padata->serial(padata); | |
312 | atomic_dec(&pd->refcnt); | |
313 | } | |
314 | local_bh_enable(); | |
315 | } | |
316 | ||
0198ffd1 | 317 | /** |
16295bec SK |
318 | * padata_do_serial - padata serialization function |
319 | * | |
320 | * @padata: object to be serialized. | |
321 | * | |
322 | * padata_do_serial must be called for every parallelized object. | |
323 | * The serialization callback function will run with BHs off. | |
324 | */ | |
325 | void padata_do_serial(struct padata_priv *padata) | |
326 | { | |
327 | int cpu; | |
e15bacbe | 328 | struct padata_parallel_queue *pqueue; |
16295bec SK |
329 | struct parallel_data *pd; |
330 | ||
331 | pd = padata->pd; | |
332 | ||
333 | cpu = get_cpu(); | |
e15bacbe | 334 | pqueue = per_cpu_ptr(pd->pqueue, cpu); |
16295bec | 335 | |
e15bacbe | 336 | spin_lock(&pqueue->reorder.lock); |
16295bec | 337 | atomic_inc(&pd->reorder_objects); |
e15bacbe DK |
338 | list_add_tail(&padata->list, &pqueue->reorder.list); |
339 | spin_unlock(&pqueue->reorder.lock); | |
16295bec SK |
340 | |
341 | put_cpu(); | |
342 | ||
343 | padata_reorder(pd); | |
344 | } | |
345 | EXPORT_SYMBOL(padata_do_serial); | |
346 | ||
e15bacbe DK |
347 | static int padata_setup_cpumasks(struct parallel_data *pd, |
348 | const struct cpumask *pcpumask, | |
349 | const struct cpumask *cbcpumask) | |
16295bec | 350 | { |
e15bacbe DK |
351 | if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL)) |
352 | return -ENOMEM; | |
16295bec | 353 | |
13614e0f | 354 | cpumask_and(pd->cpumask.pcpu, pcpumask, cpu_online_mask); |
e15bacbe DK |
355 | if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL)) { |
356 | free_cpumask_var(pd->cpumask.cbcpu); | |
357 | return -ENOMEM; | |
358 | } | |
16295bec | 359 | |
13614e0f | 360 | cpumask_and(pd->cpumask.cbcpu, cbcpumask, cpu_online_mask); |
e15bacbe DK |
361 | return 0; |
362 | } | |
16295bec | 363 | |
e15bacbe DK |
364 | static void __padata_list_init(struct padata_list *pd_list) |
365 | { | |
366 | INIT_LIST_HEAD(&pd_list->list); | |
367 | spin_lock_init(&pd_list->lock); | |
368 | } | |
16295bec | 369 | |
e15bacbe DK |
370 | /* Initialize all percpu queues used by serial workers */ |
371 | static void padata_init_squeues(struct parallel_data *pd) | |
372 | { | |
373 | int cpu; | |
374 | struct padata_serial_queue *squeue; | |
7b389b2c | 375 | |
e15bacbe DK |
376 | for_each_cpu(cpu, pd->cpumask.cbcpu) { |
377 | squeue = per_cpu_ptr(pd->squeue, cpu); | |
378 | squeue->pd = pd; | |
379 | __padata_list_init(&squeue->serial); | |
380 | INIT_WORK(&squeue->work, padata_serial_worker); | |
381 | } | |
382 | } | |
16295bec | 383 | |
e15bacbe DK |
384 | /* Initialize all percpu queues used by parallel workers */ |
385 | static void padata_init_pqueues(struct parallel_data *pd) | |
386 | { | |
2dc9b5db | 387 | int cpu_index, cpu; |
e15bacbe | 388 | struct padata_parallel_queue *pqueue; |
16295bec | 389 | |
e15bacbe DK |
390 | cpu_index = 0; |
391 | for_each_cpu(cpu, pd->cpumask.pcpu) { | |
392 | pqueue = per_cpu_ptr(pd->pqueue, cpu); | |
393 | pqueue->pd = pd; | |
394 | pqueue->cpu_index = cpu_index; | |
7b389b2c | 395 | cpu_index++; |
16295bec | 396 | |
e15bacbe DK |
397 | __padata_list_init(&pqueue->reorder); |
398 | __padata_list_init(&pqueue->parallel); | |
399 | INIT_WORK(&pqueue->work, padata_parallel_worker); | |
400 | atomic_set(&pqueue->num_obj, 0); | |
16295bec | 401 | } |
e15bacbe | 402 | } |
16295bec | 403 | |
e15bacbe DK |
404 | /* Allocate and initialize the internal cpumask dependend resources. */ |
405 | static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst, | |
406 | const struct cpumask *pcpumask, | |
407 | const struct cpumask *cbcpumask) | |
408 | { | |
409 | struct parallel_data *pd; | |
16295bec | 410 | |
e15bacbe DK |
411 | pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL); |
412 | if (!pd) | |
413 | goto err; | |
16295bec | 414 | |
e15bacbe DK |
415 | pd->pqueue = alloc_percpu(struct padata_parallel_queue); |
416 | if (!pd->pqueue) | |
417 | goto err_free_pd; | |
418 | ||
419 | pd->squeue = alloc_percpu(struct padata_serial_queue); | |
420 | if (!pd->squeue) | |
421 | goto err_free_pqueue; | |
422 | if (padata_setup_cpumasks(pd, pcpumask, cbcpumask) < 0) | |
423 | goto err_free_squeue; | |
16295bec | 424 | |
e15bacbe DK |
425 | padata_init_pqueues(pd); |
426 | padata_init_squeues(pd); | |
d46a5ac7 | 427 | setup_timer(&pd->timer, padata_reorder_timer, (unsigned long)pd); |
0b6b098e | 428 | atomic_set(&pd->seq_nr, -1); |
16295bec SK |
429 | atomic_set(&pd->reorder_objects, 0); |
430 | atomic_set(&pd->refcnt, 0); | |
431 | pd->pinst = pinst; | |
432 | spin_lock_init(&pd->lock); | |
433 | ||
434 | return pd; | |
435 | ||
e15bacbe DK |
436 | err_free_squeue: |
437 | free_percpu(pd->squeue); | |
438 | err_free_pqueue: | |
439 | free_percpu(pd->pqueue); | |
16295bec SK |
440 | err_free_pd: |
441 | kfree(pd); | |
442 | err: | |
443 | return NULL; | |
444 | } | |
445 | ||
446 | static void padata_free_pd(struct parallel_data *pd) | |
447 | { | |
e15bacbe DK |
448 | free_cpumask_var(pd->cpumask.pcpu); |
449 | free_cpumask_var(pd->cpumask.cbcpu); | |
450 | free_percpu(pd->pqueue); | |
451 | free_percpu(pd->squeue); | |
16295bec SK |
452 | kfree(pd); |
453 | } | |
454 | ||
0198ffd1 | 455 | /* Flush all objects out of the padata queues. */ |
2b73b07a SK |
456 | static void padata_flush_queues(struct parallel_data *pd) |
457 | { | |
458 | int cpu; | |
e15bacbe DK |
459 | struct padata_parallel_queue *pqueue; |
460 | struct padata_serial_queue *squeue; | |
2b73b07a | 461 | |
e15bacbe DK |
462 | for_each_cpu(cpu, pd->cpumask.pcpu) { |
463 | pqueue = per_cpu_ptr(pd->pqueue, cpu); | |
464 | flush_work(&pqueue->work); | |
2b73b07a SK |
465 | } |
466 | ||
467 | del_timer_sync(&pd->timer); | |
468 | ||
469 | if (atomic_read(&pd->reorder_objects)) | |
470 | padata_reorder(pd); | |
471 | ||
e15bacbe DK |
472 | for_each_cpu(cpu, pd->cpumask.cbcpu) { |
473 | squeue = per_cpu_ptr(pd->squeue, cpu); | |
474 | flush_work(&squeue->work); | |
2b73b07a SK |
475 | } |
476 | ||
477 | BUG_ON(atomic_read(&pd->refcnt) != 0); | |
478 | } | |
479 | ||
4c879170 SK |
480 | static void __padata_start(struct padata_instance *pinst) |
481 | { | |
482 | pinst->flags |= PADATA_INIT; | |
483 | } | |
484 | ||
ee836555 SK |
485 | static void __padata_stop(struct padata_instance *pinst) |
486 | { | |
487 | if (!(pinst->flags & PADATA_INIT)) | |
488 | return; | |
489 | ||
490 | pinst->flags &= ~PADATA_INIT; | |
491 | ||
492 | synchronize_rcu(); | |
493 | ||
494 | get_online_cpus(); | |
495 | padata_flush_queues(pinst->pd); | |
496 | put_online_cpus(); | |
497 | } | |
498 | ||
25985edc | 499 | /* Replace the internal control structure with a new one. */ |
16295bec SK |
500 | static void padata_replace(struct padata_instance *pinst, |
501 | struct parallel_data *pd_new) | |
502 | { | |
503 | struct parallel_data *pd_old = pinst->pd; | |
e15bacbe | 504 | int notification_mask = 0; |
16295bec SK |
505 | |
506 | pinst->flags |= PADATA_RESET; | |
507 | ||
508 | rcu_assign_pointer(pinst->pd, pd_new); | |
509 | ||
510 | synchronize_rcu(); | |
511 | ||
e15bacbe DK |
512 | if (!cpumask_equal(pd_old->cpumask.pcpu, pd_new->cpumask.pcpu)) |
513 | notification_mask |= PADATA_CPU_PARALLEL; | |
514 | if (!cpumask_equal(pd_old->cpumask.cbcpu, pd_new->cpumask.cbcpu)) | |
515 | notification_mask |= PADATA_CPU_SERIAL; | |
516 | ||
2b73b07a | 517 | padata_flush_queues(pd_old); |
16295bec SK |
518 | padata_free_pd(pd_old); |
519 | ||
e15bacbe DK |
520 | if (notification_mask) |
521 | blocking_notifier_call_chain(&pinst->cpumask_change_notifier, | |
c635696c SK |
522 | notification_mask, |
523 | &pd_new->cpumask); | |
16295bec SK |
524 | |
525 | pinst->flags &= ~PADATA_RESET; | |
526 | } | |
527 | ||
0198ffd1 | 528 | /** |
e15bacbe DK |
529 | * padata_register_cpumask_notifier - Registers a notifier that will be called |
530 | * if either pcpu or cbcpu or both cpumasks change. | |
16295bec | 531 | * |
e15bacbe DK |
532 | * @pinst: A poineter to padata instance |
533 | * @nblock: A pointer to notifier block. | |
16295bec | 534 | */ |
e15bacbe DK |
535 | int padata_register_cpumask_notifier(struct padata_instance *pinst, |
536 | struct notifier_block *nblock) | |
16295bec | 537 | { |
e15bacbe DK |
538 | return blocking_notifier_chain_register(&pinst->cpumask_change_notifier, |
539 | nblock); | |
540 | } | |
541 | EXPORT_SYMBOL(padata_register_cpumask_notifier); | |
542 | ||
543 | /** | |
544 | * padata_unregister_cpumask_notifier - Unregisters cpumask notifier | |
545 | * registered earlier using padata_register_cpumask_notifier | |
546 | * | |
547 | * @pinst: A pointer to data instance. | |
548 | * @nlock: A pointer to notifier block. | |
549 | */ | |
550 | int padata_unregister_cpumask_notifier(struct padata_instance *pinst, | |
551 | struct notifier_block *nblock) | |
552 | { | |
553 | return blocking_notifier_chain_unregister( | |
554 | &pinst->cpumask_change_notifier, | |
555 | nblock); | |
556 | } | |
557 | EXPORT_SYMBOL(padata_unregister_cpumask_notifier); | |
558 | ||
559 | ||
33e54450 SK |
560 | /* If cpumask contains no active cpu, we mark the instance as invalid. */ |
561 | static bool padata_validate_cpumask(struct padata_instance *pinst, | |
562 | const struct cpumask *cpumask) | |
563 | { | |
13614e0f | 564 | if (!cpumask_intersects(cpumask, cpu_online_mask)) { |
33e54450 SK |
565 | pinst->flags |= PADATA_INVALID; |
566 | return false; | |
567 | } | |
568 | ||
569 | pinst->flags &= ~PADATA_INVALID; | |
570 | return true; | |
571 | } | |
572 | ||
65ff577e SK |
573 | static int __padata_set_cpumasks(struct padata_instance *pinst, |
574 | cpumask_var_t pcpumask, | |
575 | cpumask_var_t cbcpumask) | |
576 | { | |
577 | int valid; | |
16295bec | 578 | struct parallel_data *pd; |
65ff577e SK |
579 | |
580 | valid = padata_validate_cpumask(pinst, pcpumask); | |
581 | if (!valid) { | |
582 | __padata_stop(pinst); | |
583 | goto out_replace; | |
584 | } | |
585 | ||
586 | valid = padata_validate_cpumask(pinst, cbcpumask); | |
587 | if (!valid) | |
588 | __padata_stop(pinst); | |
589 | ||
590 | out_replace: | |
591 | pd = padata_alloc_pd(pinst, pcpumask, cbcpumask); | |
592 | if (!pd) | |
593 | return -ENOMEM; | |
594 | ||
595 | cpumask_copy(pinst->cpumask.pcpu, pcpumask); | |
596 | cpumask_copy(pinst->cpumask.cbcpu, cbcpumask); | |
597 | ||
598 | padata_replace(pinst, pd); | |
599 | ||
600 | if (valid) | |
601 | __padata_start(pinst); | |
602 | ||
603 | return 0; | |
604 | } | |
605 | ||
e15bacbe DK |
606 | /** |
607 | * padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value | |
608 | * equivalent to @cpumask. | |
16295bec SK |
609 | * |
610 | * @pinst: padata instance | |
e15bacbe DK |
611 | * @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding |
612 | * to parallel and serial cpumasks respectively. | |
16295bec SK |
613 | * @cpumask: the cpumask to use |
614 | */ | |
e15bacbe DK |
615 | int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, |
616 | cpumask_var_t cpumask) | |
617 | { | |
618 | struct cpumask *serial_mask, *parallel_mask; | |
65ff577e SK |
619 | int err = -EINVAL; |
620 | ||
621 | mutex_lock(&pinst->lock); | |
6751fb3c SK |
622 | get_online_cpus(); |
623 | ||
e15bacbe DK |
624 | switch (cpumask_type) { |
625 | case PADATA_CPU_PARALLEL: | |
626 | serial_mask = pinst->cpumask.cbcpu; | |
627 | parallel_mask = cpumask; | |
628 | break; | |
629 | case PADATA_CPU_SERIAL: | |
630 | parallel_mask = pinst->cpumask.pcpu; | |
631 | serial_mask = cpumask; | |
632 | break; | |
633 | default: | |
65ff577e | 634 | goto out; |
16295bec SK |
635 | } |
636 | ||
65ff577e | 637 | err = __padata_set_cpumasks(pinst, parallel_mask, serial_mask); |
16295bec SK |
638 | |
639 | out: | |
6751fb3c | 640 | put_online_cpus(); |
16295bec SK |
641 | mutex_unlock(&pinst->lock); |
642 | ||
643 | return err; | |
644 | } | |
645 | EXPORT_SYMBOL(padata_set_cpumask); | |
646 | ||
19d795b6 AB |
647 | /** |
648 | * padata_start - start the parallel processing | |
649 | * | |
650 | * @pinst: padata instance to start | |
651 | */ | |
652 | int padata_start(struct padata_instance *pinst) | |
653 | { | |
654 | int err = 0; | |
655 | ||
656 | mutex_lock(&pinst->lock); | |
657 | ||
658 | if (pinst->flags & PADATA_INVALID) | |
659 | err = -EINVAL; | |
660 | ||
661 | __padata_start(pinst); | |
662 | ||
663 | mutex_unlock(&pinst->lock); | |
664 | ||
665 | return err; | |
666 | } | |
667 | EXPORT_SYMBOL(padata_start); | |
668 | ||
669 | /** | |
670 | * padata_stop - stop the parallel processing | |
671 | * | |
672 | * @pinst: padata instance to stop | |
673 | */ | |
674 | void padata_stop(struct padata_instance *pinst) | |
675 | { | |
676 | mutex_lock(&pinst->lock); | |
677 | __padata_stop(pinst); | |
678 | mutex_unlock(&pinst->lock); | |
679 | } | |
680 | EXPORT_SYMBOL(padata_stop); | |
681 | ||
682 | #ifdef CONFIG_HOTPLUG_CPU | |
683 | ||
16295bec SK |
684 | static int __padata_add_cpu(struct padata_instance *pinst, int cpu) |
685 | { | |
686 | struct parallel_data *pd; | |
687 | ||
13614e0f | 688 | if (cpumask_test_cpu(cpu, cpu_online_mask)) { |
e15bacbe DK |
689 | pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu, |
690 | pinst->cpumask.cbcpu); | |
16295bec SK |
691 | if (!pd) |
692 | return -ENOMEM; | |
693 | ||
694 | padata_replace(pinst, pd); | |
33e54450 | 695 | |
e15bacbe DK |
696 | if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) && |
697 | padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) | |
33e54450 | 698 | __padata_start(pinst); |
16295bec SK |
699 | } |
700 | ||
701 | return 0; | |
702 | } | |
703 | ||
16295bec SK |
704 | static int __padata_remove_cpu(struct padata_instance *pinst, int cpu) |
705 | { | |
33e54450 | 706 | struct parallel_data *pd = NULL; |
16295bec SK |
707 | |
708 | if (cpumask_test_cpu(cpu, cpu_online_mask)) { | |
33e54450 | 709 | |
e15bacbe | 710 | if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) || |
b89661df | 711 | !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) |
33e54450 | 712 | __padata_stop(pinst); |
33e54450 | 713 | |
e15bacbe DK |
714 | pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu, |
715 | pinst->cpumask.cbcpu); | |
16295bec SK |
716 | if (!pd) |
717 | return -ENOMEM; | |
718 | ||
719 | padata_replace(pinst, pd); | |
96120905 SK |
720 | |
721 | cpumask_clear_cpu(cpu, pd->cpumask.cbcpu); | |
722 | cpumask_clear_cpu(cpu, pd->cpumask.pcpu); | |
16295bec SK |
723 | } |
724 | ||
725 | return 0; | |
726 | } | |
727 | ||
e15bacbe | 728 | /** |
25985edc | 729 | * padata_remove_cpu - remove a cpu from the one or both(serial and parallel) |
e15bacbe | 730 | * padata cpumasks. |
16295bec SK |
731 | * |
732 | * @pinst: padata instance | |
733 | * @cpu: cpu to remove | |
e15bacbe DK |
734 | * @mask: bitmask specifying from which cpumask @cpu should be removed |
735 | * The @mask may be any combination of the following flags: | |
736 | * PADATA_CPU_SERIAL - serial cpumask | |
737 | * PADATA_CPU_PARALLEL - parallel cpumask | |
16295bec | 738 | */ |
e15bacbe | 739 | int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask) |
16295bec SK |
740 | { |
741 | int err; | |
742 | ||
e15bacbe DK |
743 | if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL))) |
744 | return -EINVAL; | |
745 | ||
16295bec SK |
746 | mutex_lock(&pinst->lock); |
747 | ||
6751fb3c | 748 | get_online_cpus(); |
e15bacbe DK |
749 | if (mask & PADATA_CPU_SERIAL) |
750 | cpumask_clear_cpu(cpu, pinst->cpumask.cbcpu); | |
751 | if (mask & PADATA_CPU_PARALLEL) | |
752 | cpumask_clear_cpu(cpu, pinst->cpumask.pcpu); | |
753 | ||
16295bec | 754 | err = __padata_remove_cpu(pinst, cpu); |
6751fb3c | 755 | put_online_cpus(); |
16295bec SK |
756 | |
757 | mutex_unlock(&pinst->lock); | |
758 | ||
759 | return err; | |
760 | } | |
761 | EXPORT_SYMBOL(padata_remove_cpu); | |
762 | ||
e15bacbe DK |
763 | static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu) |
764 | { | |
765 | return cpumask_test_cpu(cpu, pinst->cpumask.pcpu) || | |
766 | cpumask_test_cpu(cpu, pinst->cpumask.cbcpu); | |
767 | } | |
768 | ||
30e92153 | 769 | static int padata_cpu_online(unsigned int cpu, struct hlist_node *node) |
16295bec | 770 | { |
16295bec | 771 | struct padata_instance *pinst; |
30e92153 | 772 | int ret; |
16295bec | 773 | |
30e92153 SAS |
774 | pinst = hlist_entry_safe(node, struct padata_instance, node); |
775 | if (!pinst_has_cpu(pinst, cpu)) | |
776 | return 0; | |
16295bec | 777 | |
30e92153 SAS |
778 | mutex_lock(&pinst->lock); |
779 | ret = __padata_add_cpu(pinst, cpu); | |
780 | mutex_unlock(&pinst->lock); | |
781 | return ret; | |
782 | } | |
16295bec | 783 | |
30e92153 SAS |
784 | static int padata_cpu_prep_down(unsigned int cpu, struct hlist_node *node) |
785 | { | |
786 | struct padata_instance *pinst; | |
787 | int ret; | |
788 | ||
789 | pinst = hlist_entry_safe(node, struct padata_instance, node); | |
790 | if (!pinst_has_cpu(pinst, cpu)) | |
791 | return 0; | |
16295bec | 792 | |
30e92153 SAS |
793 | mutex_lock(&pinst->lock); |
794 | ret = __padata_remove_cpu(pinst, cpu); | |
795 | mutex_unlock(&pinst->lock); | |
796 | return ret; | |
16295bec | 797 | } |
30e92153 SAS |
798 | |
799 | static enum cpuhp_state hp_online; | |
e2cb2f1c | 800 | #endif |
16295bec | 801 | |
5e017dc3 DK |
802 | static void __padata_free(struct padata_instance *pinst) |
803 | { | |
804 | #ifdef CONFIG_HOTPLUG_CPU | |
30e92153 | 805 | cpuhp_state_remove_instance_nocalls(hp_online, &pinst->node); |
5e017dc3 DK |
806 | #endif |
807 | ||
808 | padata_stop(pinst); | |
809 | padata_free_pd(pinst->pd); | |
810 | free_cpumask_var(pinst->cpumask.pcpu); | |
811 | free_cpumask_var(pinst->cpumask.cbcpu); | |
812 | kfree(pinst); | |
813 | } | |
814 | ||
815 | #define kobj2pinst(_kobj) \ | |
816 | container_of(_kobj, struct padata_instance, kobj) | |
817 | #define attr2pentry(_attr) \ | |
818 | container_of(_attr, struct padata_sysfs_entry, attr) | |
819 | ||
820 | static void padata_sysfs_release(struct kobject *kobj) | |
821 | { | |
822 | struct padata_instance *pinst = kobj2pinst(kobj); | |
823 | __padata_free(pinst); | |
824 | } | |
825 | ||
826 | struct padata_sysfs_entry { | |
827 | struct attribute attr; | |
828 | ssize_t (*show)(struct padata_instance *, struct attribute *, char *); | |
829 | ssize_t (*store)(struct padata_instance *, struct attribute *, | |
830 | const char *, size_t); | |
831 | }; | |
832 | ||
833 | static ssize_t show_cpumask(struct padata_instance *pinst, | |
834 | struct attribute *attr, char *buf) | |
835 | { | |
836 | struct cpumask *cpumask; | |
837 | ssize_t len; | |
838 | ||
839 | mutex_lock(&pinst->lock); | |
840 | if (!strcmp(attr->name, "serial_cpumask")) | |
841 | cpumask = pinst->cpumask.cbcpu; | |
842 | else | |
843 | cpumask = pinst->cpumask.pcpu; | |
844 | ||
4497da6f TH |
845 | len = snprintf(buf, PAGE_SIZE, "%*pb\n", |
846 | nr_cpu_ids, cpumask_bits(cpumask)); | |
5e017dc3 | 847 | mutex_unlock(&pinst->lock); |
4497da6f | 848 | return len < PAGE_SIZE ? len : -EINVAL; |
5e017dc3 DK |
849 | } |
850 | ||
851 | static ssize_t store_cpumask(struct padata_instance *pinst, | |
852 | struct attribute *attr, | |
853 | const char *buf, size_t count) | |
854 | { | |
855 | cpumask_var_t new_cpumask; | |
856 | ssize_t ret; | |
857 | int mask_type; | |
858 | ||
859 | if (!alloc_cpumask_var(&new_cpumask, GFP_KERNEL)) | |
860 | return -ENOMEM; | |
861 | ||
862 | ret = bitmap_parse(buf, count, cpumask_bits(new_cpumask), | |
863 | nr_cpumask_bits); | |
864 | if (ret < 0) | |
865 | goto out; | |
866 | ||
867 | mask_type = !strcmp(attr->name, "serial_cpumask") ? | |
868 | PADATA_CPU_SERIAL : PADATA_CPU_PARALLEL; | |
869 | ret = padata_set_cpumask(pinst, mask_type, new_cpumask); | |
870 | if (!ret) | |
871 | ret = count; | |
872 | ||
873 | out: | |
874 | free_cpumask_var(new_cpumask); | |
875 | return ret; | |
876 | } | |
877 | ||
878 | #define PADATA_ATTR_RW(_name, _show_name, _store_name) \ | |
879 | static struct padata_sysfs_entry _name##_attr = \ | |
880 | __ATTR(_name, 0644, _show_name, _store_name) | |
881 | #define PADATA_ATTR_RO(_name, _show_name) \ | |
882 | static struct padata_sysfs_entry _name##_attr = \ | |
883 | __ATTR(_name, 0400, _show_name, NULL) | |
884 | ||
885 | PADATA_ATTR_RW(serial_cpumask, show_cpumask, store_cpumask); | |
886 | PADATA_ATTR_RW(parallel_cpumask, show_cpumask, store_cpumask); | |
887 | ||
888 | /* | |
889 | * Padata sysfs provides the following objects: | |
890 | * serial_cpumask [RW] - cpumask for serial workers | |
891 | * parallel_cpumask [RW] - cpumask for parallel workers | |
892 | */ | |
893 | static struct attribute *padata_default_attrs[] = { | |
894 | &serial_cpumask_attr.attr, | |
895 | ¶llel_cpumask_attr.attr, | |
896 | NULL, | |
897 | }; | |
898 | ||
899 | static ssize_t padata_sysfs_show(struct kobject *kobj, | |
900 | struct attribute *attr, char *buf) | |
901 | { | |
902 | struct padata_instance *pinst; | |
903 | struct padata_sysfs_entry *pentry; | |
904 | ssize_t ret = -EIO; | |
905 | ||
906 | pinst = kobj2pinst(kobj); | |
907 | pentry = attr2pentry(attr); | |
908 | if (pentry->show) | |
909 | ret = pentry->show(pinst, attr, buf); | |
910 | ||
911 | return ret; | |
912 | } | |
913 | ||
914 | static ssize_t padata_sysfs_store(struct kobject *kobj, struct attribute *attr, | |
915 | const char *buf, size_t count) | |
916 | { | |
917 | struct padata_instance *pinst; | |
918 | struct padata_sysfs_entry *pentry; | |
919 | ssize_t ret = -EIO; | |
920 | ||
921 | pinst = kobj2pinst(kobj); | |
922 | pentry = attr2pentry(attr); | |
923 | if (pentry->show) | |
924 | ret = pentry->store(pinst, attr, buf, count); | |
925 | ||
926 | return ret; | |
927 | } | |
928 | ||
929 | static const struct sysfs_ops padata_sysfs_ops = { | |
930 | .show = padata_sysfs_show, | |
931 | .store = padata_sysfs_store, | |
932 | }; | |
933 | ||
934 | static struct kobj_type padata_attr_type = { | |
935 | .sysfs_ops = &padata_sysfs_ops, | |
936 | .default_attrs = padata_default_attrs, | |
937 | .release = padata_sysfs_release, | |
938 | }; | |
939 | ||
0198ffd1 | 940 | /** |
e6cc1170 SK |
941 | * padata_alloc_possible - Allocate and initialize padata instance. |
942 | * Use the cpu_possible_mask for serial and | |
943 | * parallel workers. | |
16295bec | 944 | * |
16295bec SK |
945 | * @wq: workqueue to use for the allocated padata instance |
946 | */ | |
e6cc1170 | 947 | struct padata_instance *padata_alloc_possible(struct workqueue_struct *wq) |
e15bacbe | 948 | { |
e6cc1170 | 949 | return padata_alloc(wq, cpu_possible_mask, cpu_possible_mask); |
e15bacbe | 950 | } |
e6cc1170 | 951 | EXPORT_SYMBOL(padata_alloc_possible); |
e15bacbe DK |
952 | |
953 | /** | |
e6cc1170 SK |
954 | * padata_alloc - allocate and initialize a padata instance and specify |
955 | * cpumasks for serial and parallel workers. | |
16295bec | 956 | * |
16295bec | 957 | * @wq: workqueue to use for the allocated padata instance |
e15bacbe DK |
958 | * @pcpumask: cpumask that will be used for padata parallelization |
959 | * @cbcpumask: cpumask that will be used for padata serialization | |
16295bec | 960 | */ |
e6cc1170 SK |
961 | struct padata_instance *padata_alloc(struct workqueue_struct *wq, |
962 | const struct cpumask *pcpumask, | |
963 | const struct cpumask *cbcpumask) | |
16295bec | 964 | { |
16295bec | 965 | struct padata_instance *pinst; |
33e54450 | 966 | struct parallel_data *pd = NULL; |
16295bec SK |
967 | |
968 | pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL); | |
969 | if (!pinst) | |
970 | goto err; | |
971 | ||
6751fb3c | 972 | get_online_cpus(); |
e15bacbe | 973 | if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL)) |
16295bec | 974 | goto err_free_inst; |
e15bacbe DK |
975 | if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) { |
976 | free_cpumask_var(pinst->cpumask.pcpu); | |
16295bec | 977 | goto err_free_inst; |
33e54450 | 978 | } |
e15bacbe DK |
979 | if (!padata_validate_cpumask(pinst, pcpumask) || |
980 | !padata_validate_cpumask(pinst, cbcpumask)) | |
981 | goto err_free_masks; | |
16295bec | 982 | |
e15bacbe DK |
983 | pd = padata_alloc_pd(pinst, pcpumask, cbcpumask); |
984 | if (!pd) | |
985 | goto err_free_masks; | |
74781387 | 986 | |
16295bec SK |
987 | rcu_assign_pointer(pinst->pd, pd); |
988 | ||
989 | pinst->wq = wq; | |
990 | ||
e15bacbe DK |
991 | cpumask_copy(pinst->cpumask.pcpu, pcpumask); |
992 | cpumask_copy(pinst->cpumask.cbcpu, cbcpumask); | |
16295bec SK |
993 | |
994 | pinst->flags = 0; | |
995 | ||
6751fb3c SK |
996 | put_online_cpus(); |
997 | ||
e15bacbe | 998 | BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier); |
5e017dc3 | 999 | kobject_init(&pinst->kobj, &padata_attr_type); |
16295bec SK |
1000 | mutex_init(&pinst->lock); |
1001 | ||
b8b4a416 | 1002 | #ifdef CONFIG_HOTPLUG_CPU |
30e92153 | 1003 | cpuhp_state_add_instance_nocalls(hp_online, &pinst->node); |
b8b4a416 | 1004 | #endif |
16295bec SK |
1005 | return pinst; |
1006 | ||
e15bacbe DK |
1007 | err_free_masks: |
1008 | free_cpumask_var(pinst->cpumask.pcpu); | |
1009 | free_cpumask_var(pinst->cpumask.cbcpu); | |
16295bec SK |
1010 | err_free_inst: |
1011 | kfree(pinst); | |
6751fb3c | 1012 | put_online_cpus(); |
16295bec SK |
1013 | err: |
1014 | return NULL; | |
1015 | } | |
16295bec | 1016 | |
0198ffd1 | 1017 | /** |
16295bec SK |
1018 | * padata_free - free a padata instance |
1019 | * | |
0198ffd1 | 1020 | * @padata_inst: padata instance to free |
16295bec SK |
1021 | */ |
1022 | void padata_free(struct padata_instance *pinst) | |
1023 | { | |
5e017dc3 | 1024 | kobject_put(&pinst->kobj); |
16295bec SK |
1025 | } |
1026 | EXPORT_SYMBOL(padata_free); | |
30e92153 SAS |
1027 | |
1028 | #ifdef CONFIG_HOTPLUG_CPU | |
1029 | ||
1030 | static __init int padata_driver_init(void) | |
1031 | { | |
1032 | int ret; | |
1033 | ||
1034 | ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "padata:online", | |
1035 | padata_cpu_online, | |
1036 | padata_cpu_prep_down); | |
1037 | if (ret < 0) | |
1038 | return ret; | |
1039 | hp_online = ret; | |
1040 | return 0; | |
1041 | } | |
1042 | module_init(padata_driver_init); | |
1043 | ||
1044 | static __exit void padata_driver_exit(void) | |
1045 | { | |
1046 | cpuhp_remove_multi_state(hp_online); | |
1047 | } | |
1048 | module_exit(padata_driver_exit); | |
1049 | #endif |