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 = (MAX_SEQ_NR / num_cpus) * num_cpus - 1;
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);
533 padata_flush_queues(pd_old);
534 if (!cpumask_equal(pd_old->cpumask.pcpu, pd_new->cpumask.pcpu))
535 notification_mask |= PADATA_CPU_PARALLEL;
536 if (!cpumask_equal(pd_old->cpumask.cbcpu, pd_new->cpumask.cbcpu))
537 notification_mask |= PADATA_CPU_SERIAL;
539 padata_free_pd(pd_old);
540 if (notification_mask)
541 blocking_notifier_call_chain(&pinst->cpumask_change_notifier,
542 notification_mask, pinst);
545 pinst->flags &= ~PADATA_RESET;
549 * padata_register_cpumask_notifier - Registers a notifier that will be called
550 * if either pcpu or cbcpu or both cpumasks change.
552 * @pinst: A poineter to padata instance
553 * @nblock: A pointer to notifier block.
555 int padata_register_cpumask_notifier(struct padata_instance *pinst,
556 struct notifier_block *nblock)
558 return blocking_notifier_chain_register(&pinst->cpumask_change_notifier,
561 EXPORT_SYMBOL(padata_register_cpumask_notifier);
564 * padata_unregister_cpumask_notifier - Unregisters cpumask notifier
565 * registered earlier using padata_register_cpumask_notifier
567 * @pinst: A pointer to data instance.
568 * @nlock: A pointer to notifier block.
570 int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
571 struct notifier_block *nblock)
573 return blocking_notifier_chain_unregister(
574 &pinst->cpumask_change_notifier,
577 EXPORT_SYMBOL(padata_unregister_cpumask_notifier);
580 /* If cpumask contains no active cpu, we mark the instance as invalid. */
581 static bool padata_validate_cpumask(struct padata_instance *pinst,
582 const struct cpumask *cpumask)
584 if (!cpumask_intersects(cpumask, cpu_active_mask)) {
585 pinst->flags |= PADATA_INVALID;
589 pinst->flags &= ~PADATA_INVALID;
594 * padata_get_cpumask: Fetch serial or parallel cpumask from the
595 * given padata instance and copy it to @out_mask
597 * @pinst: A pointer to padata instance
598 * @cpumask_type: Specifies which cpumask will be copied.
599 * Possible values are PADATA_CPU_SERIAL *or* PADATA_CPU_PARALLEL
600 * corresponding to serial and parallel cpumask respectively.
601 * @out_mask: A pointer to cpumask structure where selected
602 * cpumask will be copied.
604 int padata_get_cpumask(struct padata_instance *pinst,
605 int cpumask_type, struct cpumask *out_mask)
607 struct parallel_data *pd;
611 pd = rcu_dereference(pinst->pd);
612 switch (cpumask_type) {
613 case PADATA_CPU_SERIAL:
614 cpumask_copy(out_mask, pd->cpumask.cbcpu);
616 case PADATA_CPU_PARALLEL:
617 cpumask_copy(out_mask, pd->cpumask.pcpu);
623 rcu_read_unlock_bh();
626 EXPORT_SYMBOL(padata_get_cpumask);
629 * padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value
630 * equivalent to @cpumask.
632 * @pinst: padata instance
633 * @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding
634 * to parallel and serial cpumasks respectively.
635 * @cpumask: the cpumask to use
637 int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
638 cpumask_var_t cpumask)
640 struct cpumask *serial_mask, *parallel_mask;
642 switch (cpumask_type) {
643 case PADATA_CPU_PARALLEL:
644 serial_mask = pinst->cpumask.cbcpu;
645 parallel_mask = cpumask;
647 case PADATA_CPU_SERIAL:
648 parallel_mask = pinst->cpumask.pcpu;
649 serial_mask = cpumask;
655 return __padata_set_cpumasks(pinst, parallel_mask, serial_mask);
657 EXPORT_SYMBOL(padata_set_cpumask);
660 * __padata_set_cpumasks - Set both parallel and serial cpumasks. The first
661 * one is used by parallel workers and the second one
662 * by the wokers doing serialization.
664 * @pinst: padata instance
665 * @pcpumask: the cpumask to use for parallel workers
666 * @cbcpumask: the cpumsak to use for serial workers
668 int __padata_set_cpumasks(struct padata_instance *pinst,
669 cpumask_var_t pcpumask, cpumask_var_t cbcpumask)
673 struct parallel_data *pd = NULL;
675 mutex_lock(&pinst->lock);
677 valid = padata_validate_cpumask(pinst, pcpumask);
679 __padata_stop(pinst);
683 valid = padata_validate_cpumask(pinst, cbcpumask);
685 __padata_stop(pinst);
691 pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
698 cpumask_copy(pinst->cpumask.pcpu, pcpumask);
699 cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
701 padata_replace(pinst, pd);
704 __padata_start(pinst);
709 mutex_unlock(&pinst->lock);
714 EXPORT_SYMBOL(__padata_set_cpumasks);
716 static int __padata_add_cpu(struct padata_instance *pinst, int cpu)
718 struct parallel_data *pd;
720 if (cpumask_test_cpu(cpu, cpu_active_mask)) {
721 pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
722 pinst->cpumask.cbcpu);
726 padata_replace(pinst, pd);
728 if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) &&
729 padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
730 __padata_start(pinst);
737 * padata_add_cpu - add a cpu to one or both(parallel and serial)
740 * @pinst: padata instance
742 * @mask: bitmask of flags specifying to which cpumask @cpu shuld be added.
743 * The @mask may be any combination of the following flags:
744 * PADATA_CPU_SERIAL - serial cpumask
745 * PADATA_CPU_PARALLEL - parallel cpumask
748 int padata_add_cpu(struct padata_instance *pinst, int cpu, int mask)
752 if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL)))
755 mutex_lock(&pinst->lock);
758 if (mask & PADATA_CPU_SERIAL)
759 cpumask_set_cpu(cpu, pinst->cpumask.cbcpu);
760 if (mask & PADATA_CPU_PARALLEL)
761 cpumask_set_cpu(cpu, pinst->cpumask.pcpu);
763 err = __padata_add_cpu(pinst, cpu);
766 mutex_unlock(&pinst->lock);
770 EXPORT_SYMBOL(padata_add_cpu);
772 static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
774 struct parallel_data *pd = NULL;
776 if (cpumask_test_cpu(cpu, cpu_online_mask)) {
778 if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) ||
779 !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) {
780 __padata_stop(pinst);
781 padata_replace(pinst, pd);
785 pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
786 pinst->cpumask.cbcpu);
790 padata_replace(pinst, pd);
798 * padata_remove_cpu - remove a cpu from the one or both(serial and paralell)
801 * @pinst: padata instance
802 * @cpu: cpu to remove
803 * @mask: bitmask specifying from which cpumask @cpu should be removed
804 * The @mask may be any combination of the following flags:
805 * PADATA_CPU_SERIAL - serial cpumask
806 * PADATA_CPU_PARALLEL - parallel cpumask
808 int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask)
812 if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL)))
815 mutex_lock(&pinst->lock);
818 if (mask & PADATA_CPU_SERIAL)
819 cpumask_clear_cpu(cpu, pinst->cpumask.cbcpu);
820 if (mask & PADATA_CPU_PARALLEL)
821 cpumask_clear_cpu(cpu, pinst->cpumask.pcpu);
823 err = __padata_remove_cpu(pinst, cpu);
826 mutex_unlock(&pinst->lock);
830 EXPORT_SYMBOL(padata_remove_cpu);
833 * padata_start - start the parallel processing
835 * @pinst: padata instance to start
837 int padata_start(struct padata_instance *pinst)
841 mutex_lock(&pinst->lock);
843 if (pinst->flags & PADATA_INVALID)
846 __padata_start(pinst);
848 mutex_unlock(&pinst->lock);
852 EXPORT_SYMBOL(padata_start);
855 * padata_stop - stop the parallel processing
857 * @pinst: padata instance to stop
859 void padata_stop(struct padata_instance *pinst)
861 mutex_lock(&pinst->lock);
862 __padata_stop(pinst);
863 mutex_unlock(&pinst->lock);
865 EXPORT_SYMBOL(padata_stop);
867 #ifdef CONFIG_HOTPLUG_CPU
869 static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu)
871 return cpumask_test_cpu(cpu, pinst->cpumask.pcpu) ||
872 cpumask_test_cpu(cpu, pinst->cpumask.cbcpu);
876 static int padata_cpu_callback(struct notifier_block *nfb,
877 unsigned long action, void *hcpu)
880 struct padata_instance *pinst;
881 int cpu = (unsigned long)hcpu;
883 pinst = container_of(nfb, struct padata_instance, cpu_notifier);
887 case CPU_ONLINE_FROZEN:
888 if (!pinst_has_cpu(pinst, cpu))
890 mutex_lock(&pinst->lock);
891 err = __padata_add_cpu(pinst, cpu);
892 mutex_unlock(&pinst->lock);
897 case CPU_DOWN_PREPARE:
898 case CPU_DOWN_PREPARE_FROZEN:
899 if (!pinst_has_cpu(pinst, cpu))
901 mutex_lock(&pinst->lock);
902 err = __padata_remove_cpu(pinst, cpu);
903 mutex_unlock(&pinst->lock);
908 case CPU_UP_CANCELED:
909 case CPU_UP_CANCELED_FROZEN:
910 if (!pinst_has_cpu(pinst, cpu))
912 mutex_lock(&pinst->lock);
913 __padata_remove_cpu(pinst, cpu);
914 mutex_unlock(&pinst->lock);
916 case CPU_DOWN_FAILED:
917 case CPU_DOWN_FAILED_FROZEN:
918 if (!pinst_has_cpu(pinst, cpu))
920 mutex_lock(&pinst->lock);
921 __padata_add_cpu(pinst, cpu);
922 mutex_unlock(&pinst->lock);
929 static void __padata_free(struct padata_instance *pinst)
931 #ifdef CONFIG_HOTPLUG_CPU
932 unregister_hotcpu_notifier(&pinst->cpu_notifier);
936 padata_free_pd(pinst->pd);
937 free_cpumask_var(pinst->cpumask.pcpu);
938 free_cpumask_var(pinst->cpumask.cbcpu);
942 #define kobj2pinst(_kobj) \
943 container_of(_kobj, struct padata_instance, kobj)
944 #define attr2pentry(_attr) \
945 container_of(_attr, struct padata_sysfs_entry, attr)
947 static void padata_sysfs_release(struct kobject *kobj)
949 struct padata_instance *pinst = kobj2pinst(kobj);
950 __padata_free(pinst);
953 struct padata_sysfs_entry {
954 struct attribute attr;
955 ssize_t (*show)(struct padata_instance *, struct attribute *, char *);
956 ssize_t (*store)(struct padata_instance *, struct attribute *,
957 const char *, size_t);
960 static ssize_t show_cpumask(struct padata_instance *pinst,
961 struct attribute *attr, char *buf)
963 struct cpumask *cpumask;
966 mutex_lock(&pinst->lock);
967 if (!strcmp(attr->name, "serial_cpumask"))
968 cpumask = pinst->cpumask.cbcpu;
970 cpumask = pinst->cpumask.pcpu;
972 len = bitmap_scnprintf(buf, PAGE_SIZE, cpumask_bits(cpumask),
974 if (PAGE_SIZE - len < 2)
977 len += sprintf(buf + len, "\n");
979 mutex_unlock(&pinst->lock);
983 static ssize_t store_cpumask(struct padata_instance *pinst,
984 struct attribute *attr,
985 const char *buf, size_t count)
987 cpumask_var_t new_cpumask;
991 if (!alloc_cpumask_var(&new_cpumask, GFP_KERNEL))
994 ret = bitmap_parse(buf, count, cpumask_bits(new_cpumask),
999 mask_type = !strcmp(attr->name, "serial_cpumask") ?
1000 PADATA_CPU_SERIAL : PADATA_CPU_PARALLEL;
1001 ret = padata_set_cpumask(pinst, mask_type, new_cpumask);
1006 free_cpumask_var(new_cpumask);
1010 #define PADATA_ATTR_RW(_name, _show_name, _store_name) \
1011 static struct padata_sysfs_entry _name##_attr = \
1012 __ATTR(_name, 0644, _show_name, _store_name)
1013 #define PADATA_ATTR_RO(_name, _show_name) \
1014 static struct padata_sysfs_entry _name##_attr = \
1015 __ATTR(_name, 0400, _show_name, NULL)
1017 PADATA_ATTR_RW(serial_cpumask, show_cpumask, store_cpumask);
1018 PADATA_ATTR_RW(parallel_cpumask, show_cpumask, store_cpumask);
1021 * Padata sysfs provides the following objects:
1022 * serial_cpumask [RW] - cpumask for serial workers
1023 * parallel_cpumask [RW] - cpumask for parallel workers
1025 static struct attribute *padata_default_attrs[] = {
1026 &serial_cpumask_attr.attr,
1027 ¶llel_cpumask_attr.attr,
1031 static ssize_t padata_sysfs_show(struct kobject *kobj,
1032 struct attribute *attr, char *buf)
1034 struct padata_instance *pinst;
1035 struct padata_sysfs_entry *pentry;
1038 pinst = kobj2pinst(kobj);
1039 pentry = attr2pentry(attr);
1041 ret = pentry->show(pinst, attr, buf);
1046 static ssize_t padata_sysfs_store(struct kobject *kobj, struct attribute *attr,
1047 const char *buf, size_t count)
1049 struct padata_instance *pinst;
1050 struct padata_sysfs_entry *pentry;
1053 pinst = kobj2pinst(kobj);
1054 pentry = attr2pentry(attr);
1056 ret = pentry->store(pinst, attr, buf, count);
1061 static const struct sysfs_ops padata_sysfs_ops = {
1062 .show = padata_sysfs_show,
1063 .store = padata_sysfs_store,
1066 static struct kobj_type padata_attr_type = {
1067 .sysfs_ops = &padata_sysfs_ops,
1068 .default_attrs = padata_default_attrs,
1069 .release = padata_sysfs_release,
1073 * padata_alloc - Allocate and initialize padata instance.
1074 * Use default cpumask(cpu_possible_mask)
1075 * for serial and parallel workes.
1077 * @wq: workqueue to use for the allocated padata instance
1079 struct padata_instance *padata_alloc(struct workqueue_struct *wq)
1081 return __padata_alloc(wq, cpu_possible_mask, cpu_possible_mask);
1083 EXPORT_SYMBOL(padata_alloc);
1086 * __padata_alloc - allocate and initialize a padata instance
1087 * and specify cpumasks for serial and parallel workers.
1089 * @wq: workqueue to use for the allocated padata instance
1090 * @pcpumask: cpumask that will be used for padata parallelization
1091 * @cbcpumask: cpumask that will be used for padata serialization
1093 struct padata_instance *__padata_alloc(struct workqueue_struct *wq,
1094 const struct cpumask *pcpumask,
1095 const struct cpumask *cbcpumask)
1097 struct padata_instance *pinst;
1098 struct parallel_data *pd = NULL;
1100 pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL);
1105 if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL))
1107 if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) {
1108 free_cpumask_var(pinst->cpumask.pcpu);
1111 if (!padata_validate_cpumask(pinst, pcpumask) ||
1112 !padata_validate_cpumask(pinst, cbcpumask))
1113 goto err_free_masks;
1115 pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
1117 goto err_free_masks;
1119 rcu_assign_pointer(pinst->pd, pd);
1123 cpumask_copy(pinst->cpumask.pcpu, pcpumask);
1124 cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
1128 #ifdef CONFIG_HOTPLUG_CPU
1129 pinst->cpu_notifier.notifier_call = padata_cpu_callback;
1130 pinst->cpu_notifier.priority = 0;
1131 register_hotcpu_notifier(&pinst->cpu_notifier);
1136 BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier);
1137 kobject_init(&pinst->kobj, &padata_attr_type);
1138 mutex_init(&pinst->lock);
1143 free_cpumask_var(pinst->cpumask.pcpu);
1144 free_cpumask_var(pinst->cpumask.cbcpu);
1151 EXPORT_SYMBOL(__padata_alloc);
1154 * padata_free - free a padata instance
1156 * @padata_inst: padata instance to free
1158 void padata_free(struct padata_instance *pinst)
1160 kobject_put(&pinst->kobj);
1162 EXPORT_SYMBOL(padata_free);