2 * padata.c - generic interface to process data streams in parallel
4 * Copyright (C) 2008, 2009 secunet Security Networks AG
5 * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
21 #include <linux/module.h>
22 #include <linux/cpumask.h>
23 #include <linux/err.h>
24 #include <linux/cpu.h>
25 #include <linux/padata.h>
26 #include <linux/mutex.h>
27 #include <linux/sched.h>
28 #include <linux/slab.h>
29 #include <linux/sysfs.h>
30 #include <linux/rcupdate.h>
32 #define MAX_SEQ_NR (INT_MAX - NR_CPUS)
33 #define MAX_OBJ_NUM 1000
35 static int padata_index_to_cpu(struct parallel_data
*pd
, int cpu_index
)
39 target_cpu
= cpumask_first(pd
->cpumask
.pcpu
);
40 for (cpu
= 0; cpu
< cpu_index
; cpu
++)
41 target_cpu
= cpumask_next(target_cpu
, pd
->cpumask
.pcpu
);
46 static int padata_cpu_hash(struct padata_priv
*padata
)
49 struct parallel_data
*pd
;
54 * Hash the sequence numbers to the cpus by taking
55 * seq_nr mod. number of cpus in use.
57 cpu_index
= padata
->seq_nr
% cpumask_weight(pd
->cpumask
.pcpu
);
59 return padata_index_to_cpu(pd
, cpu_index
);
62 static void padata_parallel_worker(struct work_struct
*parallel_work
)
64 struct padata_parallel_queue
*pqueue
;
65 struct parallel_data
*pd
;
66 struct padata_instance
*pinst
;
67 LIST_HEAD(local_list
);
70 pqueue
= container_of(parallel_work
,
71 struct padata_parallel_queue
, work
);
75 spin_lock(&pqueue
->parallel
.lock
);
76 list_replace_init(&pqueue
->parallel
.list
, &local_list
);
77 spin_unlock(&pqueue
->parallel
.lock
);
79 while (!list_empty(&local_list
)) {
80 struct padata_priv
*padata
;
82 padata
= list_entry(local_list
.next
,
83 struct padata_priv
, list
);
85 list_del_init(&padata
->list
);
87 padata
->parallel(padata
);
94 * padata_do_parallel - padata parallelization function
96 * @pinst: padata instance
97 * @padata: object to be parallelized
98 * @cb_cpu: cpu the serialization callback function will run on,
99 * must be in the serial cpumask of padata(i.e. cpumask.cbcpu).
101 * The parallelization callback function will run with BHs off.
102 * Note: Every object which is parallelized by padata_do_parallel
103 * must be seen by padata_do_serial.
105 int padata_do_parallel(struct padata_instance
*pinst
,
106 struct padata_priv
*padata
, int cb_cpu
)
109 struct padata_parallel_queue
*queue
;
110 struct parallel_data
*pd
;
114 pd
= rcu_dereference(pinst
->pd
);
117 if (!(pinst
->flags
& PADATA_INIT
))
120 if (!cpumask_test_cpu(cb_cpu
, pd
->cpumask
.cbcpu
))
124 if ((pinst
->flags
& PADATA_RESET
))
127 if (atomic_read(&pd
->refcnt
) >= MAX_OBJ_NUM
)
131 atomic_inc(&pd
->refcnt
);
133 padata
->cb_cpu
= cb_cpu
;
135 if (unlikely(atomic_read(&pd
->seq_nr
) == pd
->max_seq_nr
))
136 atomic_set(&pd
->seq_nr
, -1);
138 padata
->seq_nr
= atomic_inc_return(&pd
->seq_nr
);
140 target_cpu
= padata_cpu_hash(padata
);
141 queue
= per_cpu_ptr(pd
->pqueue
, target_cpu
);
143 spin_lock(&queue
->parallel
.lock
);
144 list_add_tail(&padata
->list
, &queue
->parallel
.list
);
145 spin_unlock(&queue
->parallel
.lock
);
147 queue_work_on(target_cpu
, pinst
->wq
, &queue
->work
);
150 rcu_read_unlock_bh();
154 EXPORT_SYMBOL(padata_do_parallel
);
157 * padata_get_next - Get the next object that needs serialization.
161 * A pointer to the control struct of the next object that needs
162 * serialization, if present in one of the percpu reorder queues.
164 * NULL, if all percpu reorder queues are empty.
166 * -EINPROGRESS, if the next object that needs serialization will
167 * be parallel processed by another cpu and is not yet present in
168 * the cpu's reorder queue.
170 * -ENODATA, if this cpu has to do the parallel processing for
173 static struct padata_priv
*padata_get_next(struct parallel_data
*pd
)
176 int next_nr
, next_index
;
177 struct padata_parallel_queue
*queue
, *next_queue
;
178 struct padata_priv
*padata
;
179 struct padata_list
*reorder
;
181 num_cpus
= cpumask_weight(pd
->cpumask
.pcpu
);
184 * Calculate the percpu reorder queue and the sequence
185 * number of the next object.
187 next_nr
= pd
->processed
;
188 next_index
= next_nr
% num_cpus
;
189 cpu
= padata_index_to_cpu(pd
, next_index
);
190 next_queue
= per_cpu_ptr(pd
->pqueue
, cpu
);
192 if (unlikely(next_nr
> pd
->max_seq_nr
)) {
193 next_nr
= next_nr
- pd
->max_seq_nr
- 1;
194 next_index
= next_nr
% num_cpus
;
195 cpu
= padata_index_to_cpu(pd
, next_index
);
196 next_queue
= per_cpu_ptr(pd
->pqueue
, cpu
);
202 reorder
= &next_queue
->reorder
;
204 if (!list_empty(&reorder
->list
)) {
205 padata
= list_entry(reorder
->list
.next
,
206 struct padata_priv
, list
);
208 BUG_ON(next_nr
!= padata
->seq_nr
);
210 spin_lock(&reorder
->lock
);
211 list_del_init(&padata
->list
);
212 atomic_dec(&pd
->reorder_objects
);
213 spin_unlock(&reorder
->lock
);
220 queue
= per_cpu_ptr(pd
->pqueue
, smp_processor_id());
221 if (queue
->cpu_index
== next_queue
->cpu_index
) {
222 padata
= ERR_PTR(-ENODATA
);
226 padata
= ERR_PTR(-EINPROGRESS
);
231 static void padata_reorder(struct parallel_data
*pd
)
233 struct padata_priv
*padata
;
234 struct padata_serial_queue
*squeue
;
235 struct padata_instance
*pinst
= pd
->pinst
;
238 * We need to ensure that only one cpu can work on dequeueing of
239 * the reorder queue the time. Calculating in which percpu reorder
240 * queue the next object will arrive takes some time. A spinlock
241 * would be highly contended. Also it is not clear in which order
242 * the objects arrive to the reorder queues. So a cpu could wait to
243 * get the lock just to notice that there is nothing to do at the
244 * moment. Therefore we use a trylock and let the holder of the lock
245 * care for all the objects enqueued during the holdtime of the lock.
247 if (!spin_trylock_bh(&pd
->lock
))
251 padata
= padata_get_next(pd
);
254 * All reorder queues are empty, or the next object that needs
255 * serialization is parallel processed by another cpu and is
256 * still on it's way to the cpu's reorder queue, nothing to
259 if (!padata
|| PTR_ERR(padata
) == -EINPROGRESS
)
263 * This cpu has to do the parallel processing of the next
264 * object. It's waiting in the cpu's parallelization queue,
265 * so exit imediately.
267 if (PTR_ERR(padata
) == -ENODATA
) {
268 del_timer(&pd
->timer
);
269 spin_unlock_bh(&pd
->lock
);
273 squeue
= per_cpu_ptr(pd
->squeue
, padata
->cb_cpu
);
275 spin_lock(&squeue
->serial
.lock
);
276 list_add_tail(&padata
->list
, &squeue
->serial
.list
);
277 spin_unlock(&squeue
->serial
.lock
);
279 queue_work_on(padata
->cb_cpu
, pinst
->wq
, &squeue
->work
);
282 spin_unlock_bh(&pd
->lock
);
285 * The next object that needs serialization might have arrived to
286 * the reorder queues in the meantime, we will be called again
287 * from the timer function if noone else cares for it.
289 if (atomic_read(&pd
->reorder_objects
)
290 && !(pinst
->flags
& PADATA_RESET
))
291 mod_timer(&pd
->timer
, jiffies
+ HZ
);
293 del_timer(&pd
->timer
);
298 static void padata_reorder_timer(unsigned long arg
)
300 struct parallel_data
*pd
= (struct parallel_data
*)arg
;
305 static void padata_serial_worker(struct work_struct
*serial_work
)
307 struct padata_serial_queue
*squeue
;
308 struct parallel_data
*pd
;
309 LIST_HEAD(local_list
);
312 squeue
= container_of(serial_work
, struct padata_serial_queue
, work
);
315 spin_lock(&squeue
->serial
.lock
);
316 list_replace_init(&squeue
->serial
.list
, &local_list
);
317 spin_unlock(&squeue
->serial
.lock
);
319 while (!list_empty(&local_list
)) {
320 struct padata_priv
*padata
;
322 padata
= list_entry(local_list
.next
,
323 struct padata_priv
, list
);
325 list_del_init(&padata
->list
);
327 padata
->serial(padata
);
328 atomic_dec(&pd
->refcnt
);
334 * padata_do_serial - padata serialization function
336 * @padata: object to be serialized.
338 * padata_do_serial must be called for every parallelized object.
339 * The serialization callback function will run with BHs off.
341 void padata_do_serial(struct padata_priv
*padata
)
344 struct padata_parallel_queue
*pqueue
;
345 struct parallel_data
*pd
;
350 pqueue
= per_cpu_ptr(pd
->pqueue
, cpu
);
352 spin_lock(&pqueue
->reorder
.lock
);
353 atomic_inc(&pd
->reorder_objects
);
354 list_add_tail(&padata
->list
, &pqueue
->reorder
.list
);
355 spin_unlock(&pqueue
->reorder
.lock
);
361 EXPORT_SYMBOL(padata_do_serial
);
363 static int padata_setup_cpumasks(struct parallel_data
*pd
,
364 const struct cpumask
*pcpumask
,
365 const struct cpumask
*cbcpumask
)
367 if (!alloc_cpumask_var(&pd
->cpumask
.pcpu
, GFP_KERNEL
))
370 cpumask_and(pd
->cpumask
.pcpu
, pcpumask
, cpu_active_mask
);
371 if (!alloc_cpumask_var(&pd
->cpumask
.cbcpu
, GFP_KERNEL
)) {
372 free_cpumask_var(pd
->cpumask
.cbcpu
);
376 cpumask_and(pd
->cpumask
.cbcpu
, cbcpumask
, cpu_active_mask
);
380 static void __padata_list_init(struct padata_list
*pd_list
)
382 INIT_LIST_HEAD(&pd_list
->list
);
383 spin_lock_init(&pd_list
->lock
);
386 /* Initialize all percpu queues used by serial workers */
387 static void padata_init_squeues(struct parallel_data
*pd
)
390 struct padata_serial_queue
*squeue
;
392 for_each_cpu(cpu
, pd
->cpumask
.cbcpu
) {
393 squeue
= per_cpu_ptr(pd
->squeue
, cpu
);
395 __padata_list_init(&squeue
->serial
);
396 INIT_WORK(&squeue
->work
, padata_serial_worker
);
400 /* Initialize all percpu queues used by parallel workers */
401 static void padata_init_pqueues(struct parallel_data
*pd
)
403 int cpu_index
, num_cpus
, cpu
;
404 struct padata_parallel_queue
*pqueue
;
407 for_each_cpu(cpu
, pd
->cpumask
.pcpu
) {
408 pqueue
= per_cpu_ptr(pd
->pqueue
, cpu
);
410 pqueue
->cpu_index
= cpu_index
;
413 __padata_list_init(&pqueue
->reorder
);
414 __padata_list_init(&pqueue
->parallel
);
415 INIT_WORK(&pqueue
->work
, padata_parallel_worker
);
416 atomic_set(&pqueue
->num_obj
, 0);
419 num_cpus
= cpumask_weight(pd
->cpumask
.pcpu
);
420 pd
->max_seq_nr
= num_cpus
? (MAX_SEQ_NR
/ num_cpus
) * num_cpus
- 1 : 0;
423 /* Allocate and initialize the internal cpumask dependend resources. */
424 static struct parallel_data
*padata_alloc_pd(struct padata_instance
*pinst
,
425 const struct cpumask
*pcpumask
,
426 const struct cpumask
*cbcpumask
)
428 struct parallel_data
*pd
;
430 pd
= kzalloc(sizeof(struct parallel_data
), GFP_KERNEL
);
434 pd
->pqueue
= alloc_percpu(struct padata_parallel_queue
);
438 pd
->squeue
= alloc_percpu(struct padata_serial_queue
);
440 goto err_free_pqueue
;
441 if (padata_setup_cpumasks(pd
, pcpumask
, cbcpumask
) < 0)
442 goto err_free_squeue
;
444 padata_init_pqueues(pd
);
445 padata_init_squeues(pd
);
446 setup_timer(&pd
->timer
, padata_reorder_timer
, (unsigned long)pd
);
447 atomic_set(&pd
->seq_nr
, -1);
448 atomic_set(&pd
->reorder_objects
, 0);
449 atomic_set(&pd
->refcnt
, 0);
451 spin_lock_init(&pd
->lock
);
456 free_percpu(pd
->squeue
);
458 free_percpu(pd
->pqueue
);
465 static void padata_free_pd(struct parallel_data
*pd
)
467 free_cpumask_var(pd
->cpumask
.pcpu
);
468 free_cpumask_var(pd
->cpumask
.cbcpu
);
469 free_percpu(pd
->pqueue
);
470 free_percpu(pd
->squeue
);
474 /* Flush all objects out of the padata queues. */
475 static void padata_flush_queues(struct parallel_data
*pd
)
478 struct padata_parallel_queue
*pqueue
;
479 struct padata_serial_queue
*squeue
;
481 for_each_cpu(cpu
, pd
->cpumask
.pcpu
) {
482 pqueue
= per_cpu_ptr(pd
->pqueue
, cpu
);
483 flush_work(&pqueue
->work
);
486 del_timer_sync(&pd
->timer
);
488 if (atomic_read(&pd
->reorder_objects
))
491 for_each_cpu(cpu
, pd
->cpumask
.cbcpu
) {
492 squeue
= per_cpu_ptr(pd
->squeue
, cpu
);
493 flush_work(&squeue
->work
);
496 BUG_ON(atomic_read(&pd
->refcnt
) != 0);
499 static void __padata_start(struct padata_instance
*pinst
)
501 pinst
->flags
|= PADATA_INIT
;
504 static void __padata_stop(struct padata_instance
*pinst
)
506 if (!(pinst
->flags
& PADATA_INIT
))
509 pinst
->flags
&= ~PADATA_INIT
;
514 padata_flush_queues(pinst
->pd
);
518 /* Replace the internal control stucture with a new one. */
519 static void padata_replace(struct padata_instance
*pinst
,
520 struct parallel_data
*pd_new
)
522 struct parallel_data
*pd_old
= pinst
->pd
;
523 int notification_mask
= 0;
525 pinst
->flags
|= PADATA_RESET
;
527 rcu_assign_pointer(pinst
->pd
, pd_new
);
531 if (!cpumask_equal(pd_old
->cpumask
.pcpu
, pd_new
->cpumask
.pcpu
))
532 notification_mask
|= PADATA_CPU_PARALLEL
;
533 if (!cpumask_equal(pd_old
->cpumask
.cbcpu
, pd_new
->cpumask
.cbcpu
))
534 notification_mask
|= PADATA_CPU_SERIAL
;
536 padata_flush_queues(pd_old
);
537 padata_free_pd(pd_old
);
539 if (notification_mask
)
540 blocking_notifier_call_chain(&pinst
->cpumask_change_notifier
,
541 notification_mask
, pinst
);
543 pinst
->flags
&= ~PADATA_RESET
;
547 * padata_register_cpumask_notifier - Registers a notifier that will be called
548 * if either pcpu or cbcpu or both cpumasks change.
550 * @pinst: A poineter to padata instance
551 * @nblock: A pointer to notifier block.
553 int padata_register_cpumask_notifier(struct padata_instance
*pinst
,
554 struct notifier_block
*nblock
)
556 return blocking_notifier_chain_register(&pinst
->cpumask_change_notifier
,
559 EXPORT_SYMBOL(padata_register_cpumask_notifier
);
562 * padata_unregister_cpumask_notifier - Unregisters cpumask notifier
563 * registered earlier using padata_register_cpumask_notifier
565 * @pinst: A pointer to data instance.
566 * @nlock: A pointer to notifier block.
568 int padata_unregister_cpumask_notifier(struct padata_instance
*pinst
,
569 struct notifier_block
*nblock
)
571 return blocking_notifier_chain_unregister(
572 &pinst
->cpumask_change_notifier
,
575 EXPORT_SYMBOL(padata_unregister_cpumask_notifier
);
578 /* If cpumask contains no active cpu, we mark the instance as invalid. */
579 static bool padata_validate_cpumask(struct padata_instance
*pinst
,
580 const struct cpumask
*cpumask
)
582 if (!cpumask_intersects(cpumask
, cpu_active_mask
)) {
583 pinst
->flags
|= PADATA_INVALID
;
587 pinst
->flags
&= ~PADATA_INVALID
;
592 * padata_get_cpumask: Fetch serial or parallel cpumask from the
593 * given padata instance and copy it to @out_mask
595 * @pinst: A pointer to padata instance
596 * @cpumask_type: Specifies which cpumask will be copied.
597 * Possible values are PADATA_CPU_SERIAL *or* PADATA_CPU_PARALLEL
598 * corresponding to serial and parallel cpumask respectively.
599 * @out_mask: A pointer to cpumask structure where selected
600 * cpumask will be copied.
602 int padata_get_cpumask(struct padata_instance
*pinst
,
603 int cpumask_type
, struct cpumask
*out_mask
)
605 struct parallel_data
*pd
;
609 pd
= rcu_dereference(pinst
->pd
);
610 switch (cpumask_type
) {
611 case PADATA_CPU_SERIAL
:
612 cpumask_copy(out_mask
, pd
->cpumask
.cbcpu
);
614 case PADATA_CPU_PARALLEL
:
615 cpumask_copy(out_mask
, pd
->cpumask
.pcpu
);
621 rcu_read_unlock_bh();
624 EXPORT_SYMBOL(padata_get_cpumask
);
627 * padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value
628 * equivalent to @cpumask.
630 * @pinst: padata instance
631 * @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding
632 * to parallel and serial cpumasks respectively.
633 * @cpumask: the cpumask to use
635 int padata_set_cpumask(struct padata_instance
*pinst
, int cpumask_type
,
636 cpumask_var_t cpumask
)
638 struct cpumask
*serial_mask
, *parallel_mask
;
640 switch (cpumask_type
) {
641 case PADATA_CPU_PARALLEL
:
642 serial_mask
= pinst
->cpumask
.cbcpu
;
643 parallel_mask
= cpumask
;
645 case PADATA_CPU_SERIAL
:
646 parallel_mask
= pinst
->cpumask
.pcpu
;
647 serial_mask
= cpumask
;
653 return __padata_set_cpumasks(pinst
, parallel_mask
, serial_mask
);
655 EXPORT_SYMBOL(padata_set_cpumask
);
658 * __padata_set_cpumasks - Set both parallel and serial cpumasks. The first
659 * one is used by parallel workers and the second one
660 * by the wokers doing serialization.
662 * @pinst: padata instance
663 * @pcpumask: the cpumask to use for parallel workers
664 * @cbcpumask: the cpumsak to use for serial workers
666 int __padata_set_cpumasks(struct padata_instance
*pinst
,
667 cpumask_var_t pcpumask
, cpumask_var_t cbcpumask
)
671 struct parallel_data
*pd
= NULL
;
673 mutex_lock(&pinst
->lock
);
676 valid
= padata_validate_cpumask(pinst
, pcpumask
);
678 __padata_stop(pinst
);
682 valid
= padata_validate_cpumask(pinst
, cbcpumask
);
684 __padata_stop(pinst
);
687 pd
= padata_alloc_pd(pinst
, pcpumask
, cbcpumask
);
693 cpumask_copy(pinst
->cpumask
.pcpu
, pcpumask
);
694 cpumask_copy(pinst
->cpumask
.cbcpu
, cbcpumask
);
696 padata_replace(pinst
, pd
);
699 __padata_start(pinst
);
703 mutex_unlock(&pinst
->lock
);
708 EXPORT_SYMBOL(__padata_set_cpumasks
);
710 static int __padata_add_cpu(struct padata_instance
*pinst
, int cpu
)
712 struct parallel_data
*pd
;
714 if (cpumask_test_cpu(cpu
, cpu_active_mask
)) {
715 pd
= padata_alloc_pd(pinst
, pinst
->cpumask
.pcpu
,
716 pinst
->cpumask
.cbcpu
);
720 padata_replace(pinst
, pd
);
722 if (padata_validate_cpumask(pinst
, pinst
->cpumask
.pcpu
) &&
723 padata_validate_cpumask(pinst
, pinst
->cpumask
.cbcpu
))
724 __padata_start(pinst
);
731 * padata_add_cpu - add a cpu to one or both(parallel and serial)
734 * @pinst: padata instance
736 * @mask: bitmask of flags specifying to which cpumask @cpu shuld be added.
737 * The @mask may be any combination of the following flags:
738 * PADATA_CPU_SERIAL - serial cpumask
739 * PADATA_CPU_PARALLEL - parallel cpumask
742 int padata_add_cpu(struct padata_instance
*pinst
, int cpu
, int mask
)
746 if (!(mask
& (PADATA_CPU_SERIAL
| PADATA_CPU_PARALLEL
)))
749 mutex_lock(&pinst
->lock
);
752 if (mask
& PADATA_CPU_SERIAL
)
753 cpumask_set_cpu(cpu
, pinst
->cpumask
.cbcpu
);
754 if (mask
& PADATA_CPU_PARALLEL
)
755 cpumask_set_cpu(cpu
, pinst
->cpumask
.pcpu
);
757 err
= __padata_add_cpu(pinst
, cpu
);
760 mutex_unlock(&pinst
->lock
);
764 EXPORT_SYMBOL(padata_add_cpu
);
766 static int __padata_remove_cpu(struct padata_instance
*pinst
, int cpu
)
768 struct parallel_data
*pd
= NULL
;
770 if (cpumask_test_cpu(cpu
, cpu_online_mask
)) {
772 if (!padata_validate_cpumask(pinst
, pinst
->cpumask
.pcpu
) ||
773 !padata_validate_cpumask(pinst
, pinst
->cpumask
.cbcpu
))
774 __padata_stop(pinst
);
776 pd
= padata_alloc_pd(pinst
, pinst
->cpumask
.pcpu
,
777 pinst
->cpumask
.cbcpu
);
781 padata_replace(pinst
, pd
);
788 * padata_remove_cpu - remove a cpu from the one or both(serial and paralell)
791 * @pinst: padata instance
792 * @cpu: cpu to remove
793 * @mask: bitmask specifying from which cpumask @cpu should be removed
794 * The @mask may be any combination of the following flags:
795 * PADATA_CPU_SERIAL - serial cpumask
796 * PADATA_CPU_PARALLEL - parallel cpumask
798 int padata_remove_cpu(struct padata_instance
*pinst
, int cpu
, int mask
)
802 if (!(mask
& (PADATA_CPU_SERIAL
| PADATA_CPU_PARALLEL
)))
805 mutex_lock(&pinst
->lock
);
808 if (mask
& PADATA_CPU_SERIAL
)
809 cpumask_clear_cpu(cpu
, pinst
->cpumask
.cbcpu
);
810 if (mask
& PADATA_CPU_PARALLEL
)
811 cpumask_clear_cpu(cpu
, pinst
->cpumask
.pcpu
);
813 err
= __padata_remove_cpu(pinst
, cpu
);
816 mutex_unlock(&pinst
->lock
);
820 EXPORT_SYMBOL(padata_remove_cpu
);
823 * padata_start - start the parallel processing
825 * @pinst: padata instance to start
827 int padata_start(struct padata_instance
*pinst
)
831 mutex_lock(&pinst
->lock
);
833 if (pinst
->flags
& PADATA_INVALID
)
836 __padata_start(pinst
);
838 mutex_unlock(&pinst
->lock
);
842 EXPORT_SYMBOL(padata_start
);
845 * padata_stop - stop the parallel processing
847 * @pinst: padata instance to stop
849 void padata_stop(struct padata_instance
*pinst
)
851 mutex_lock(&pinst
->lock
);
852 __padata_stop(pinst
);
853 mutex_unlock(&pinst
->lock
);
855 EXPORT_SYMBOL(padata_stop
);
857 #ifdef CONFIG_HOTPLUG_CPU
859 static inline int pinst_has_cpu(struct padata_instance
*pinst
, int cpu
)
861 return cpumask_test_cpu(cpu
, pinst
->cpumask
.pcpu
) ||
862 cpumask_test_cpu(cpu
, pinst
->cpumask
.cbcpu
);
866 static int padata_cpu_callback(struct notifier_block
*nfb
,
867 unsigned long action
, void *hcpu
)
870 struct padata_instance
*pinst
;
871 int cpu
= (unsigned long)hcpu
;
873 pinst
= container_of(nfb
, struct padata_instance
, cpu_notifier
);
877 case CPU_ONLINE_FROZEN
:
878 if (!pinst_has_cpu(pinst
, cpu
))
880 mutex_lock(&pinst
->lock
);
881 err
= __padata_add_cpu(pinst
, cpu
);
882 mutex_unlock(&pinst
->lock
);
887 case CPU_DOWN_PREPARE
:
888 case CPU_DOWN_PREPARE_FROZEN
:
889 if (!pinst_has_cpu(pinst
, cpu
))
891 mutex_lock(&pinst
->lock
);
892 err
= __padata_remove_cpu(pinst
, cpu
);
893 mutex_unlock(&pinst
->lock
);
898 case CPU_UP_CANCELED
:
899 case CPU_UP_CANCELED_FROZEN
:
900 if (!pinst_has_cpu(pinst
, cpu
))
902 mutex_lock(&pinst
->lock
);
903 __padata_remove_cpu(pinst
, cpu
);
904 mutex_unlock(&pinst
->lock
);
906 case CPU_DOWN_FAILED
:
907 case CPU_DOWN_FAILED_FROZEN
:
908 if (!pinst_has_cpu(pinst
, cpu
))
910 mutex_lock(&pinst
->lock
);
911 __padata_add_cpu(pinst
, cpu
);
912 mutex_unlock(&pinst
->lock
);
919 static void __padata_free(struct padata_instance
*pinst
)
921 #ifdef CONFIG_HOTPLUG_CPU
922 unregister_hotcpu_notifier(&pinst
->cpu_notifier
);
926 padata_free_pd(pinst
->pd
);
927 free_cpumask_var(pinst
->cpumask
.pcpu
);
928 free_cpumask_var(pinst
->cpumask
.cbcpu
);
932 #define kobj2pinst(_kobj) \
933 container_of(_kobj, struct padata_instance, kobj)
934 #define attr2pentry(_attr) \
935 container_of(_attr, struct padata_sysfs_entry, attr)
937 static void padata_sysfs_release(struct kobject
*kobj
)
939 struct padata_instance
*pinst
= kobj2pinst(kobj
);
940 __padata_free(pinst
);
943 struct padata_sysfs_entry
{
944 struct attribute attr
;
945 ssize_t (*show
)(struct padata_instance
*, struct attribute
*, char *);
946 ssize_t (*store
)(struct padata_instance
*, struct attribute
*,
947 const char *, size_t);
950 static ssize_t
show_cpumask(struct padata_instance
*pinst
,
951 struct attribute
*attr
, char *buf
)
953 struct cpumask
*cpumask
;
956 mutex_lock(&pinst
->lock
);
957 if (!strcmp(attr
->name
, "serial_cpumask"))
958 cpumask
= pinst
->cpumask
.cbcpu
;
960 cpumask
= pinst
->cpumask
.pcpu
;
962 len
= bitmap_scnprintf(buf
, PAGE_SIZE
, cpumask_bits(cpumask
),
964 if (PAGE_SIZE
- len
< 2)
967 len
+= sprintf(buf
+ len
, "\n");
969 mutex_unlock(&pinst
->lock
);
973 static ssize_t
store_cpumask(struct padata_instance
*pinst
,
974 struct attribute
*attr
,
975 const char *buf
, size_t count
)
977 cpumask_var_t new_cpumask
;
981 if (!alloc_cpumask_var(&new_cpumask
, GFP_KERNEL
))
984 ret
= bitmap_parse(buf
, count
, cpumask_bits(new_cpumask
),
989 mask_type
= !strcmp(attr
->name
, "serial_cpumask") ?
990 PADATA_CPU_SERIAL
: PADATA_CPU_PARALLEL
;
991 ret
= padata_set_cpumask(pinst
, mask_type
, new_cpumask
);
996 free_cpumask_var(new_cpumask
);
1000 #define PADATA_ATTR_RW(_name, _show_name, _store_name) \
1001 static struct padata_sysfs_entry _name##_attr = \
1002 __ATTR(_name, 0644, _show_name, _store_name)
1003 #define PADATA_ATTR_RO(_name, _show_name) \
1004 static struct padata_sysfs_entry _name##_attr = \
1005 __ATTR(_name, 0400, _show_name, NULL)
1007 PADATA_ATTR_RW(serial_cpumask
, show_cpumask
, store_cpumask
);
1008 PADATA_ATTR_RW(parallel_cpumask
, show_cpumask
, store_cpumask
);
1011 * Padata sysfs provides the following objects:
1012 * serial_cpumask [RW] - cpumask for serial workers
1013 * parallel_cpumask [RW] - cpumask for parallel workers
1015 static struct attribute
*padata_default_attrs
[] = {
1016 &serial_cpumask_attr
.attr
,
1017 ¶llel_cpumask_attr
.attr
,
1021 static ssize_t
padata_sysfs_show(struct kobject
*kobj
,
1022 struct attribute
*attr
, char *buf
)
1024 struct padata_instance
*pinst
;
1025 struct padata_sysfs_entry
*pentry
;
1028 pinst
= kobj2pinst(kobj
);
1029 pentry
= attr2pentry(attr
);
1031 ret
= pentry
->show(pinst
, attr
, buf
);
1036 static ssize_t
padata_sysfs_store(struct kobject
*kobj
, struct attribute
*attr
,
1037 const char *buf
, size_t count
)
1039 struct padata_instance
*pinst
;
1040 struct padata_sysfs_entry
*pentry
;
1043 pinst
= kobj2pinst(kobj
);
1044 pentry
= attr2pentry(attr
);
1046 ret
= pentry
->store(pinst
, attr
, buf
, count
);
1051 static const struct sysfs_ops padata_sysfs_ops
= {
1052 .show
= padata_sysfs_show
,
1053 .store
= padata_sysfs_store
,
1056 static struct kobj_type padata_attr_type
= {
1057 .sysfs_ops
= &padata_sysfs_ops
,
1058 .default_attrs
= padata_default_attrs
,
1059 .release
= padata_sysfs_release
,
1063 * padata_alloc - Allocate and initialize padata instance.
1064 * Use default cpumask(cpu_possible_mask)
1065 * for serial and parallel workes.
1067 * @wq: workqueue to use for the allocated padata instance
1069 struct padata_instance
*padata_alloc(struct workqueue_struct
*wq
)
1071 return __padata_alloc(wq
, cpu_possible_mask
, cpu_possible_mask
);
1073 EXPORT_SYMBOL(padata_alloc
);
1076 * __padata_alloc - allocate and initialize a padata instance
1077 * and specify cpumasks for serial and parallel workers.
1079 * @wq: workqueue to use for the allocated padata instance
1080 * @pcpumask: cpumask that will be used for padata parallelization
1081 * @cbcpumask: cpumask that will be used for padata serialization
1083 struct padata_instance
*__padata_alloc(struct workqueue_struct
*wq
,
1084 const struct cpumask
*pcpumask
,
1085 const struct cpumask
*cbcpumask
)
1087 struct padata_instance
*pinst
;
1088 struct parallel_data
*pd
= NULL
;
1090 pinst
= kzalloc(sizeof(struct padata_instance
), GFP_KERNEL
);
1095 if (!alloc_cpumask_var(&pinst
->cpumask
.pcpu
, GFP_KERNEL
))
1097 if (!alloc_cpumask_var(&pinst
->cpumask
.cbcpu
, GFP_KERNEL
)) {
1098 free_cpumask_var(pinst
->cpumask
.pcpu
);
1101 if (!padata_validate_cpumask(pinst
, pcpumask
) ||
1102 !padata_validate_cpumask(pinst
, cbcpumask
))
1103 goto err_free_masks
;
1105 pd
= padata_alloc_pd(pinst
, pcpumask
, cbcpumask
);
1107 goto err_free_masks
;
1109 rcu_assign_pointer(pinst
->pd
, pd
);
1113 cpumask_copy(pinst
->cpumask
.pcpu
, pcpumask
);
1114 cpumask_copy(pinst
->cpumask
.cbcpu
, cbcpumask
);
1118 #ifdef CONFIG_HOTPLUG_CPU
1119 pinst
->cpu_notifier
.notifier_call
= padata_cpu_callback
;
1120 pinst
->cpu_notifier
.priority
= 0;
1121 register_hotcpu_notifier(&pinst
->cpu_notifier
);
1126 BLOCKING_INIT_NOTIFIER_HEAD(&pinst
->cpumask_change_notifier
);
1127 kobject_init(&pinst
->kobj
, &padata_attr_type
);
1128 mutex_init(&pinst
->lock
);
1133 free_cpumask_var(pinst
->cpumask
.pcpu
);
1134 free_cpumask_var(pinst
->cpumask
.cbcpu
);
1141 EXPORT_SYMBOL(__padata_alloc
);
1144 * padata_free - free a padata instance
1146 * @padata_inst: padata instance to free
1148 void padata_free(struct padata_instance
*pinst
)
1150 kobject_put(&pinst
->kobj
);
1152 EXPORT_SYMBOL(padata_free
);