2 * padata.c - generic interface to process data streams in parallel
4 * See Documentation/padata.txt for an api documentation.
6 * Copyright (C) 2008, 2009 secunet Security Networks AG
7 * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
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.
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
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.
23 #include <linux/export.h>
24 #include <linux/cpumask.h>
25 #include <linux/err.h>
26 #include <linux/cpu.h>
27 #include <linux/padata.h>
28 #include <linux/mutex.h>
29 #include <linux/sched.h>
30 #include <linux/slab.h>
31 #include <linux/sysfs.h>
32 #include <linux/rcupdate.h>
34 #define MAX_OBJ_NUM 1000
36 static void padata_free_pd(struct parallel_data *pd);
38 static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index)
42 target_cpu = cpumask_first(pd->cpumask.pcpu);
43 for (cpu = 0; cpu < cpu_index; cpu++)
44 target_cpu = cpumask_next(target_cpu, pd->cpumask.pcpu);
49 static int padata_cpu_hash(struct parallel_data *pd)
55 * Hash the sequence numbers to the cpus by taking
56 * seq_nr mod. number of cpus in use.
59 seq_nr = atomic_inc_return(&pd->seq_nr);
60 cpu_index = seq_nr % cpumask_weight(pd->cpumask.pcpu);
62 return padata_index_to_cpu(pd, cpu_index);
65 static void padata_parallel_worker(struct work_struct *parallel_work)
67 struct padata_parallel_queue *pqueue;
68 LIST_HEAD(local_list);
71 pqueue = container_of(parallel_work,
72 struct padata_parallel_queue, work);
74 spin_lock(&pqueue->parallel.lock);
75 list_replace_init(&pqueue->parallel.list, &local_list);
76 spin_unlock(&pqueue->parallel.lock);
78 while (!list_empty(&local_list)) {
79 struct padata_priv *padata;
81 padata = list_entry(local_list.next,
82 struct padata_priv, list);
84 list_del_init(&padata->list);
86 padata->parallel(padata);
93 * padata_do_parallel - padata parallelization function
95 * @pinst: padata instance
96 * @padata: object to be parallelized
97 * @cb_cpu: cpu the serialization callback function will run on,
98 * must be in the serial cpumask of padata(i.e. cpumask.cbcpu).
100 * The parallelization callback function will run with BHs off.
101 * Note: Every object which is parallelized by padata_do_parallel
102 * must be seen by padata_do_serial.
104 int padata_do_parallel(struct padata_instance *pinst,
105 struct padata_priv *padata, int cb_cpu)
108 struct padata_parallel_queue *queue;
109 struct parallel_data *pd;
113 pd = rcu_dereference_bh(pinst->pd);
116 if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID)
119 if (!cpumask_test_cpu(cb_cpu, pd->cpumask.cbcpu))
123 if ((pinst->flags & PADATA_RESET))
126 if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM)
130 atomic_inc(&pd->refcnt);
132 padata->cb_cpu = cb_cpu;
134 target_cpu = padata_cpu_hash(pd);
135 padata->cpu = target_cpu;
136 queue = per_cpu_ptr(pd->pqueue, target_cpu);
138 spin_lock(&queue->parallel.lock);
139 list_add_tail(&padata->list, &queue->parallel.list);
140 spin_unlock(&queue->parallel.lock);
142 queue_work_on(target_cpu, pinst->wq, &queue->work);
145 rcu_read_unlock_bh();
149 EXPORT_SYMBOL(padata_do_parallel);
152 * padata_get_next - Get the next object that needs serialization.
156 * A pointer to the control struct of the next object that needs
157 * serialization, if present in one of the percpu reorder queues.
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.
163 * -ENODATA, if this cpu has to do the parallel processing for
166 static struct padata_priv *padata_get_next(struct parallel_data *pd)
168 struct padata_parallel_queue *next_queue;
169 struct padata_priv *padata;
170 struct padata_list *reorder;
173 next_queue = per_cpu_ptr(pd->pqueue, cpu);
174 reorder = &next_queue->reorder;
176 spin_lock(&reorder->lock);
177 if (!list_empty(&reorder->list)) {
178 padata = list_entry(reorder->list.next,
179 struct padata_priv, list);
181 list_del_init(&padata->list);
182 atomic_dec(&pd->reorder_objects);
184 pd->cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu, -1,
187 spin_unlock(&reorder->lock);
190 spin_unlock(&reorder->lock);
192 if (__this_cpu_read(pd->pqueue->cpu_index) == next_queue->cpu_index) {
193 padata = ERR_PTR(-ENODATA);
197 padata = ERR_PTR(-EINPROGRESS);
202 static void padata_reorder(struct parallel_data *pd)
205 struct padata_priv *padata;
206 struct padata_serial_queue *squeue;
207 struct padata_instance *pinst = pd->pinst;
208 struct padata_parallel_queue *next_queue;
211 * We need to ensure that only one cpu can work on dequeueing of
212 * the reorder queue the time. Calculating in which percpu reorder
213 * queue the next object will arrive takes some time. A spinlock
214 * would be highly contended. Also it is not clear in which order
215 * the objects arrive to the reorder queues. So a cpu could wait to
216 * get the lock just to notice that there is nothing to do at the
217 * moment. Therefore we use a trylock and let the holder of the lock
218 * care for all the objects enqueued during the holdtime of the lock.
220 if (!spin_trylock_bh(&pd->lock))
224 padata = padata_get_next(pd);
227 * If the next object that needs serialization is parallel
228 * processed by another cpu and is still on it's way to the
229 * cpu's reorder queue, nothing to do for now.
231 if (PTR_ERR(padata) == -EINPROGRESS)
235 * This cpu has to do the parallel processing of the next
236 * object. It's waiting in the cpu's parallelization queue,
237 * so exit immediately.
239 if (PTR_ERR(padata) == -ENODATA) {
240 spin_unlock_bh(&pd->lock);
244 cb_cpu = padata->cb_cpu;
245 squeue = per_cpu_ptr(pd->squeue, cb_cpu);
247 spin_lock(&squeue->serial.lock);
248 list_add_tail(&padata->list, &squeue->serial.list);
249 spin_unlock(&squeue->serial.lock);
251 queue_work_on(cb_cpu, pinst->wq, &squeue->work);
254 spin_unlock_bh(&pd->lock);
257 * The next object that needs serialization might have arrived to
258 * the reorder queues in the meantime.
260 * Ensure reorder queue is read after pd->lock is dropped so we see
261 * new objects from another task in padata_do_serial. Pairs with
262 * smp_mb__after_atomic in padata_do_serial.
266 next_queue = per_cpu_ptr(pd->pqueue, pd->cpu);
267 if (!list_empty(&next_queue->reorder.list))
268 queue_work(pinst->wq, &pd->reorder_work);
271 static void invoke_padata_reorder(struct work_struct *work)
273 struct parallel_data *pd;
276 pd = container_of(work, struct parallel_data, reorder_work);
281 static void padata_serial_worker(struct work_struct *serial_work)
283 struct padata_serial_queue *squeue;
284 struct parallel_data *pd;
285 LIST_HEAD(local_list);
289 squeue = container_of(serial_work, struct padata_serial_queue, work);
292 spin_lock(&squeue->serial.lock);
293 list_replace_init(&squeue->serial.list, &local_list);
294 spin_unlock(&squeue->serial.lock);
298 while (!list_empty(&local_list)) {
299 struct padata_priv *padata;
301 padata = list_entry(local_list.next,
302 struct padata_priv, list);
304 list_del_init(&padata->list);
306 padata->serial(padata);
311 if (atomic_sub_and_test(cnt, &pd->refcnt))
316 * padata_do_serial - padata serialization function
318 * @padata: object to be serialized.
320 * padata_do_serial must be called for every parallelized object.
321 * The serialization callback function will run with BHs off.
323 void padata_do_serial(struct padata_priv *padata)
325 struct parallel_data *pd = padata->pd;
326 struct padata_parallel_queue *pqueue = per_cpu_ptr(pd->pqueue,
329 spin_lock(&pqueue->reorder.lock);
330 list_add_tail(&padata->list, &pqueue->reorder.list);
331 atomic_inc(&pd->reorder_objects);
332 spin_unlock(&pqueue->reorder.lock);
335 * Ensure the addition to the reorder list is ordered correctly
336 * with the trylock of pd->lock in padata_reorder. Pairs with smp_mb
339 smp_mb__after_atomic();
343 EXPORT_SYMBOL(padata_do_serial);
345 static int padata_setup_cpumasks(struct parallel_data *pd,
346 const struct cpumask *pcpumask,
347 const struct cpumask *cbcpumask)
349 if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL))
352 cpumask_and(pd->cpumask.pcpu, pcpumask, cpu_online_mask);
353 if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL)) {
354 free_cpumask_var(pd->cpumask.pcpu);
358 cpumask_and(pd->cpumask.cbcpu, cbcpumask, cpu_online_mask);
362 static void __padata_list_init(struct padata_list *pd_list)
364 INIT_LIST_HEAD(&pd_list->list);
365 spin_lock_init(&pd_list->lock);
368 /* Initialize all percpu queues used by serial workers */
369 static void padata_init_squeues(struct parallel_data *pd)
372 struct padata_serial_queue *squeue;
374 for_each_cpu(cpu, pd->cpumask.cbcpu) {
375 squeue = per_cpu_ptr(pd->squeue, cpu);
377 __padata_list_init(&squeue->serial);
378 INIT_WORK(&squeue->work, padata_serial_worker);
382 /* Initialize all percpu queues used by parallel workers */
383 static void padata_init_pqueues(struct parallel_data *pd)
386 struct padata_parallel_queue *pqueue;
389 for_each_possible_cpu(cpu) {
390 pqueue = per_cpu_ptr(pd->pqueue, cpu);
392 if (!cpumask_test_cpu(cpu, pd->cpumask.pcpu)) {
393 pqueue->cpu_index = -1;
397 pqueue->cpu_index = cpu_index;
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);
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)
412 struct parallel_data *pd;
414 pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL);
418 pd->pqueue = alloc_percpu(struct padata_parallel_queue);
422 pd->squeue = alloc_percpu(struct padata_serial_queue);
424 goto err_free_pqueue;
425 if (padata_setup_cpumasks(pd, pcpumask, cbcpumask) < 0)
426 goto err_free_squeue;
428 padata_init_pqueues(pd);
429 padata_init_squeues(pd);
430 atomic_set(&pd->seq_nr, -1);
431 atomic_set(&pd->reorder_objects, 0);
432 atomic_set(&pd->refcnt, 1);
434 spin_lock_init(&pd->lock);
435 pd->cpu = cpumask_first(pd->cpumask.pcpu);
436 INIT_WORK(&pd->reorder_work, invoke_padata_reorder);
441 free_percpu(pd->squeue);
443 free_percpu(pd->pqueue);
450 static void padata_free_pd(struct parallel_data *pd)
452 free_cpumask_var(pd->cpumask.pcpu);
453 free_cpumask_var(pd->cpumask.cbcpu);
454 free_percpu(pd->pqueue);
455 free_percpu(pd->squeue);
459 static void __padata_start(struct padata_instance *pinst)
461 pinst->flags |= PADATA_INIT;
464 static void __padata_stop(struct padata_instance *pinst)
466 if (!(pinst->flags & PADATA_INIT))
469 pinst->flags &= ~PADATA_INIT;
474 /* Replace the internal control structure with a new one. */
475 static void padata_replace(struct padata_instance *pinst,
476 struct parallel_data *pd_new)
478 struct parallel_data *pd_old = pinst->pd;
479 int notification_mask = 0;
481 pinst->flags |= PADATA_RESET;
483 rcu_assign_pointer(pinst->pd, pd_new);
487 if (!cpumask_equal(pd_old->cpumask.pcpu, pd_new->cpumask.pcpu))
488 notification_mask |= PADATA_CPU_PARALLEL;
489 if (!cpumask_equal(pd_old->cpumask.cbcpu, pd_new->cpumask.cbcpu))
490 notification_mask |= PADATA_CPU_SERIAL;
492 if (atomic_dec_and_test(&pd_old->refcnt))
493 padata_free_pd(pd_old);
495 if (notification_mask)
496 blocking_notifier_call_chain(&pinst->cpumask_change_notifier,
500 pinst->flags &= ~PADATA_RESET;
504 * padata_register_cpumask_notifier - Registers a notifier that will be called
505 * if either pcpu or cbcpu or both cpumasks change.
507 * @pinst: A poineter to padata instance
508 * @nblock: A pointer to notifier block.
510 int padata_register_cpumask_notifier(struct padata_instance *pinst,
511 struct notifier_block *nblock)
513 return blocking_notifier_chain_register(&pinst->cpumask_change_notifier,
516 EXPORT_SYMBOL(padata_register_cpumask_notifier);
519 * padata_unregister_cpumask_notifier - Unregisters cpumask notifier
520 * registered earlier using padata_register_cpumask_notifier
522 * @pinst: A pointer to data instance.
523 * @nlock: A pointer to notifier block.
525 int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
526 struct notifier_block *nblock)
528 return blocking_notifier_chain_unregister(
529 &pinst->cpumask_change_notifier,
532 EXPORT_SYMBOL(padata_unregister_cpumask_notifier);
535 /* If cpumask contains no active cpu, we mark the instance as invalid. */
536 static bool padata_validate_cpumask(struct padata_instance *pinst,
537 const struct cpumask *cpumask)
539 if (!cpumask_intersects(cpumask, cpu_online_mask)) {
540 pinst->flags |= PADATA_INVALID;
544 pinst->flags &= ~PADATA_INVALID;
548 static int __padata_set_cpumasks(struct padata_instance *pinst,
549 cpumask_var_t pcpumask,
550 cpumask_var_t cbcpumask)
553 struct parallel_data *pd;
555 valid = padata_validate_cpumask(pinst, pcpumask);
557 __padata_stop(pinst);
561 valid = padata_validate_cpumask(pinst, cbcpumask);
563 __padata_stop(pinst);
566 pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
570 cpumask_copy(pinst->cpumask.pcpu, pcpumask);
571 cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
573 padata_replace(pinst, pd);
576 __padata_start(pinst);
582 * padata_set_cpumasks - Set both parallel and serial cpumasks. The first
583 * one is used by parallel workers and the second one
584 * by the wokers doing serialization.
586 * @pinst: padata instance
587 * @pcpumask: the cpumask to use for parallel workers
588 * @cbcpumask: the cpumsak to use for serial workers
590 int padata_set_cpumasks(struct padata_instance *pinst, cpumask_var_t pcpumask,
591 cpumask_var_t cbcpumask)
595 mutex_lock(&pinst->lock);
598 err = __padata_set_cpumasks(pinst, pcpumask, cbcpumask);
601 mutex_unlock(&pinst->lock);
606 EXPORT_SYMBOL(padata_set_cpumasks);
609 * padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value
610 * equivalent to @cpumask.
612 * @pinst: padata instance
613 * @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding
614 * to parallel and serial cpumasks respectively.
615 * @cpumask: the cpumask to use
617 int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
618 cpumask_var_t cpumask)
620 struct cpumask *serial_mask, *parallel_mask;
624 mutex_lock(&pinst->lock);
626 switch (cpumask_type) {
627 case PADATA_CPU_PARALLEL:
628 serial_mask = pinst->cpumask.cbcpu;
629 parallel_mask = cpumask;
631 case PADATA_CPU_SERIAL:
632 parallel_mask = pinst->cpumask.pcpu;
633 serial_mask = cpumask;
639 err = __padata_set_cpumasks(pinst, parallel_mask, serial_mask);
642 mutex_unlock(&pinst->lock);
647 EXPORT_SYMBOL(padata_set_cpumask);
649 static int __padata_add_cpu(struct padata_instance *pinst, int cpu)
651 struct parallel_data *pd;
653 if (cpumask_test_cpu(cpu, cpu_online_mask)) {
654 pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
655 pinst->cpumask.cbcpu);
659 padata_replace(pinst, pd);
661 if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) &&
662 padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
663 __padata_start(pinst);
670 * padata_add_cpu - add a cpu to one or both(parallel and serial)
673 * @pinst: padata instance
675 * @mask: bitmask of flags specifying to which cpumask @cpu shuld be added.
676 * The @mask may be any combination of the following flags:
677 * PADATA_CPU_SERIAL - serial cpumask
678 * PADATA_CPU_PARALLEL - parallel cpumask
681 int padata_add_cpu(struct padata_instance *pinst, int cpu, int mask)
685 if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL)))
688 mutex_lock(&pinst->lock);
691 if (mask & PADATA_CPU_SERIAL)
692 cpumask_set_cpu(cpu, pinst->cpumask.cbcpu);
693 if (mask & PADATA_CPU_PARALLEL)
694 cpumask_set_cpu(cpu, pinst->cpumask.pcpu);
696 err = __padata_add_cpu(pinst, cpu);
699 mutex_unlock(&pinst->lock);
703 EXPORT_SYMBOL(padata_add_cpu);
705 static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
707 struct parallel_data *pd = NULL;
709 if (cpumask_test_cpu(cpu, cpu_online_mask)) {
711 if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) ||
712 !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
713 __padata_stop(pinst);
715 pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
716 pinst->cpumask.cbcpu);
720 padata_replace(pinst, pd);
722 cpumask_clear_cpu(cpu, pd->cpumask.cbcpu);
723 cpumask_clear_cpu(cpu, pd->cpumask.pcpu);
730 * padata_remove_cpu - remove a cpu from the one or both(serial and parallel)
733 * @pinst: padata instance
734 * @cpu: cpu to remove
735 * @mask: bitmask specifying from which cpumask @cpu should be removed
736 * The @mask may be any combination of the following flags:
737 * PADATA_CPU_SERIAL - serial cpumask
738 * PADATA_CPU_PARALLEL - parallel cpumask
740 int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask)
744 if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL)))
747 mutex_lock(&pinst->lock);
750 if (mask & PADATA_CPU_SERIAL)
751 cpumask_clear_cpu(cpu, pinst->cpumask.cbcpu);
752 if (mask & PADATA_CPU_PARALLEL)
753 cpumask_clear_cpu(cpu, pinst->cpumask.pcpu);
755 err = __padata_remove_cpu(pinst, cpu);
758 mutex_unlock(&pinst->lock);
762 EXPORT_SYMBOL(padata_remove_cpu);
765 * padata_start - start the parallel processing
767 * @pinst: padata instance to start
769 int padata_start(struct padata_instance *pinst)
773 mutex_lock(&pinst->lock);
775 if (pinst->flags & PADATA_INVALID)
778 __padata_start(pinst);
780 mutex_unlock(&pinst->lock);
784 EXPORT_SYMBOL(padata_start);
787 * padata_stop - stop the parallel processing
789 * @pinst: padata instance to stop
791 void padata_stop(struct padata_instance *pinst)
793 mutex_lock(&pinst->lock);
794 __padata_stop(pinst);
795 mutex_unlock(&pinst->lock);
797 EXPORT_SYMBOL(padata_stop);
799 #ifdef CONFIG_HOTPLUG_CPU
801 static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu)
803 return cpumask_test_cpu(cpu, pinst->cpumask.pcpu) ||
804 cpumask_test_cpu(cpu, pinst->cpumask.cbcpu);
808 static int padata_cpu_callback(struct notifier_block *nfb,
809 unsigned long action, void *hcpu)
812 struct padata_instance *pinst;
813 int cpu = (unsigned long)hcpu;
815 pinst = container_of(nfb, struct padata_instance, cpu_notifier);
819 case CPU_ONLINE_FROZEN:
820 case CPU_DOWN_FAILED:
821 case CPU_DOWN_FAILED_FROZEN:
822 if (!pinst_has_cpu(pinst, cpu))
824 mutex_lock(&pinst->lock);
825 err = __padata_add_cpu(pinst, cpu);
826 mutex_unlock(&pinst->lock);
828 return notifier_from_errno(err);
831 case CPU_DOWN_PREPARE:
832 case CPU_DOWN_PREPARE_FROZEN:
833 case CPU_UP_CANCELED:
834 case CPU_UP_CANCELED_FROZEN:
835 if (!pinst_has_cpu(pinst, cpu))
837 mutex_lock(&pinst->lock);
838 err = __padata_remove_cpu(pinst, cpu);
839 mutex_unlock(&pinst->lock);
841 return notifier_from_errno(err);
849 static void __padata_free(struct padata_instance *pinst)
851 #ifdef CONFIG_HOTPLUG_CPU
852 unregister_hotcpu_notifier(&pinst->cpu_notifier);
856 padata_free_pd(pinst->pd);
857 free_cpumask_var(pinst->cpumask.pcpu);
858 free_cpumask_var(pinst->cpumask.cbcpu);
862 #define kobj2pinst(_kobj) \
863 container_of(_kobj, struct padata_instance, kobj)
864 #define attr2pentry(_attr) \
865 container_of(_attr, struct padata_sysfs_entry, attr)
867 static void padata_sysfs_release(struct kobject *kobj)
869 struct padata_instance *pinst = kobj2pinst(kobj);
870 __padata_free(pinst);
873 struct padata_sysfs_entry {
874 struct attribute attr;
875 ssize_t (*show)(struct padata_instance *, struct attribute *, char *);
876 ssize_t (*store)(struct padata_instance *, struct attribute *,
877 const char *, size_t);
880 static ssize_t show_cpumask(struct padata_instance *pinst,
881 struct attribute *attr, char *buf)
883 struct cpumask *cpumask;
886 mutex_lock(&pinst->lock);
887 if (!strcmp(attr->name, "serial_cpumask"))
888 cpumask = pinst->cpumask.cbcpu;
890 cpumask = pinst->cpumask.pcpu;
892 len = snprintf(buf, PAGE_SIZE, "%*pb\n",
893 nr_cpu_ids, cpumask_bits(cpumask));
894 mutex_unlock(&pinst->lock);
895 return len < PAGE_SIZE ? len : -EINVAL;
898 static ssize_t store_cpumask(struct padata_instance *pinst,
899 struct attribute *attr,
900 const char *buf, size_t count)
902 cpumask_var_t new_cpumask;
906 if (!alloc_cpumask_var(&new_cpumask, GFP_KERNEL))
909 ret = bitmap_parse(buf, count, cpumask_bits(new_cpumask),
914 mask_type = !strcmp(attr->name, "serial_cpumask") ?
915 PADATA_CPU_SERIAL : PADATA_CPU_PARALLEL;
916 ret = padata_set_cpumask(pinst, mask_type, new_cpumask);
921 free_cpumask_var(new_cpumask);
925 #define PADATA_ATTR_RW(_name, _show_name, _store_name) \
926 static struct padata_sysfs_entry _name##_attr = \
927 __ATTR(_name, 0644, _show_name, _store_name)
928 #define PADATA_ATTR_RO(_name, _show_name) \
929 static struct padata_sysfs_entry _name##_attr = \
930 __ATTR(_name, 0400, _show_name, NULL)
932 PADATA_ATTR_RW(serial_cpumask, show_cpumask, store_cpumask);
933 PADATA_ATTR_RW(parallel_cpumask, show_cpumask, store_cpumask);
936 * Padata sysfs provides the following objects:
937 * serial_cpumask [RW] - cpumask for serial workers
938 * parallel_cpumask [RW] - cpumask for parallel workers
940 static struct attribute *padata_default_attrs[] = {
941 &serial_cpumask_attr.attr,
942 ¶llel_cpumask_attr.attr,
946 static ssize_t padata_sysfs_show(struct kobject *kobj,
947 struct attribute *attr, char *buf)
949 struct padata_instance *pinst;
950 struct padata_sysfs_entry *pentry;
953 pinst = kobj2pinst(kobj);
954 pentry = attr2pentry(attr);
956 ret = pentry->show(pinst, attr, buf);
961 static ssize_t padata_sysfs_store(struct kobject *kobj, struct attribute *attr,
962 const char *buf, size_t count)
964 struct padata_instance *pinst;
965 struct padata_sysfs_entry *pentry;
968 pinst = kobj2pinst(kobj);
969 pentry = attr2pentry(attr);
971 ret = pentry->store(pinst, attr, buf, count);
976 static const struct sysfs_ops padata_sysfs_ops = {
977 .show = padata_sysfs_show,
978 .store = padata_sysfs_store,
981 static struct kobj_type padata_attr_type = {
982 .sysfs_ops = &padata_sysfs_ops,
983 .default_attrs = padata_default_attrs,
984 .release = padata_sysfs_release,
988 * padata_alloc_possible - Allocate and initialize padata instance.
989 * Use the cpu_possible_mask for serial and
992 * @wq: workqueue to use for the allocated padata instance
994 struct padata_instance *padata_alloc_possible(struct workqueue_struct *wq)
996 return padata_alloc(wq, cpu_possible_mask, cpu_possible_mask);
998 EXPORT_SYMBOL(padata_alloc_possible);
1001 * padata_alloc - allocate and initialize a padata instance and specify
1002 * cpumasks for serial and parallel workers.
1004 * @wq: workqueue to use for the allocated padata instance
1005 * @pcpumask: cpumask that will be used for padata parallelization
1006 * @cbcpumask: cpumask that will be used for padata serialization
1008 struct padata_instance *padata_alloc(struct workqueue_struct *wq,
1009 const struct cpumask *pcpumask,
1010 const struct cpumask *cbcpumask)
1012 struct padata_instance *pinst;
1013 struct parallel_data *pd = NULL;
1015 pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL);
1020 if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL))
1022 if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) {
1023 free_cpumask_var(pinst->cpumask.pcpu);
1026 if (!padata_validate_cpumask(pinst, pcpumask) ||
1027 !padata_validate_cpumask(pinst, cbcpumask))
1028 goto err_free_masks;
1030 pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
1032 goto err_free_masks;
1034 rcu_assign_pointer(pinst->pd, pd);
1038 cpumask_copy(pinst->cpumask.pcpu, pcpumask);
1039 cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
1045 BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier);
1046 kobject_init(&pinst->kobj, &padata_attr_type);
1047 mutex_init(&pinst->lock);
1049 #ifdef CONFIG_HOTPLUG_CPU
1050 pinst->cpu_notifier.notifier_call = padata_cpu_callback;
1051 pinst->cpu_notifier.priority = 0;
1052 register_hotcpu_notifier(&pinst->cpu_notifier);
1058 free_cpumask_var(pinst->cpumask.pcpu);
1059 free_cpumask_var(pinst->cpumask.cbcpu);
1066 EXPORT_SYMBOL(padata_alloc);
1069 * padata_free - free a padata instance
1071 * @padata_inst: padata instance to free
1073 void padata_free(struct padata_instance *pinst)
1075 kobject_put(&pinst->kobj);
1077 EXPORT_SYMBOL(padata_free);