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>
33 #include <linux/module.h>
35 #define MAX_OBJ_NUM 1000
37 static void padata_free_pd(struct parallel_data *pd);
39 static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index)
43 target_cpu = cpumask_first(pd->cpumask.pcpu);
44 for (cpu = 0; cpu < cpu_index; cpu++)
45 target_cpu = cpumask_next(target_cpu, pd->cpumask.pcpu);
50 static int padata_cpu_hash(struct parallel_data *pd)
56 * Hash the sequence numbers to the cpus by taking
57 * seq_nr mod. number of cpus in use.
60 seq_nr = atomic_inc_return(&pd->seq_nr);
61 cpu_index = seq_nr % cpumask_weight(pd->cpumask.pcpu);
63 return padata_index_to_cpu(pd, cpu_index);
66 static void padata_parallel_worker(struct work_struct *parallel_work)
68 struct padata_parallel_queue *pqueue;
69 LIST_HEAD(local_list);
72 pqueue = container_of(parallel_work,
73 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_bh(pinst->pd);
117 if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID)
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 target_cpu = padata_cpu_hash(pd);
136 padata->cpu = target_cpu;
137 queue = per_cpu_ptr(pd->pqueue, target_cpu);
139 spin_lock(&queue->parallel.lock);
140 list_add_tail(&padata->list, &queue->parallel.list);
141 spin_unlock(&queue->parallel.lock);
143 queue_work_on(target_cpu, pinst->wq, &queue->work);
146 rcu_read_unlock_bh();
150 EXPORT_SYMBOL(padata_do_parallel);
153 * padata_get_next - Get the next object that needs serialization.
157 * A pointer to the control struct of the next object that needs
158 * serialization, if present in one of the percpu reorder queues.
160 * -EINPROGRESS, if the next object that needs serialization will
161 * be parallel processed by another cpu and is not yet present in
162 * the cpu's reorder queue.
164 * -ENODATA, if this cpu has to do the parallel processing for
167 static struct padata_priv *padata_get_next(struct parallel_data *pd)
169 struct padata_parallel_queue *next_queue;
170 struct padata_priv *padata;
171 struct padata_list *reorder;
174 next_queue = per_cpu_ptr(pd->pqueue, cpu);
175 reorder = &next_queue->reorder;
177 spin_lock(&reorder->lock);
178 if (!list_empty(&reorder->list)) {
179 padata = list_entry(reorder->list.next,
180 struct padata_priv, list);
182 list_del_init(&padata->list);
183 atomic_dec(&pd->reorder_objects);
185 pd->cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu, -1,
188 spin_unlock(&reorder->lock);
191 spin_unlock(&reorder->lock);
193 if (__this_cpu_read(pd->pqueue->cpu_index) == next_queue->cpu_index) {
194 padata = ERR_PTR(-ENODATA);
198 padata = ERR_PTR(-EINPROGRESS);
203 static void padata_reorder(struct parallel_data *pd)
206 struct padata_priv *padata;
207 struct padata_serial_queue *squeue;
208 struct padata_instance *pinst = pd->pinst;
209 struct padata_parallel_queue *next_queue;
212 * We need to ensure that only one cpu can work on dequeueing of
213 * the reorder queue the time. Calculating in which percpu reorder
214 * queue the next object will arrive takes some time. A spinlock
215 * would be highly contended. Also it is not clear in which order
216 * the objects arrive to the reorder queues. So a cpu could wait to
217 * get the lock just to notice that there is nothing to do at the
218 * moment. Therefore we use a trylock and let the holder of the lock
219 * care for all the objects enqueued during the holdtime of the lock.
221 if (!spin_trylock_bh(&pd->lock))
225 padata = padata_get_next(pd);
228 * If the next object that needs serialization is parallel
229 * processed by another cpu and is still on it's way to the
230 * cpu's reorder queue, nothing to do for now.
232 if (PTR_ERR(padata) == -EINPROGRESS)
236 * This cpu has to do the parallel processing of the next
237 * object. It's waiting in the cpu's parallelization queue,
238 * so exit immediately.
240 if (PTR_ERR(padata) == -ENODATA) {
241 spin_unlock_bh(&pd->lock);
245 cb_cpu = padata->cb_cpu;
246 squeue = per_cpu_ptr(pd->squeue, cb_cpu);
248 spin_lock(&squeue->serial.lock);
249 list_add_tail(&padata->list, &squeue->serial.list);
250 spin_unlock(&squeue->serial.lock);
252 queue_work_on(cb_cpu, pinst->wq, &squeue->work);
255 spin_unlock_bh(&pd->lock);
258 * The next object that needs serialization might have arrived to
259 * the reorder queues in the meantime.
261 * Ensure reorder queue is read after pd->lock is dropped so we see
262 * new objects from another task in padata_do_serial. Pairs with
263 * smp_mb__after_atomic in padata_do_serial.
267 next_queue = per_cpu_ptr(pd->pqueue, pd->cpu);
268 if (!list_empty(&next_queue->reorder.list))
269 queue_work(pinst->wq, &pd->reorder_work);
272 static void invoke_padata_reorder(struct work_struct *work)
274 struct parallel_data *pd;
277 pd = container_of(work, struct parallel_data, reorder_work);
282 static void padata_serial_worker(struct work_struct *serial_work)
284 struct padata_serial_queue *squeue;
285 struct parallel_data *pd;
286 LIST_HEAD(local_list);
290 squeue = container_of(serial_work, struct padata_serial_queue, work);
293 spin_lock(&squeue->serial.lock);
294 list_replace_init(&squeue->serial.list, &local_list);
295 spin_unlock(&squeue->serial.lock);
299 while (!list_empty(&local_list)) {
300 struct padata_priv *padata;
302 padata = list_entry(local_list.next,
303 struct padata_priv, list);
305 list_del_init(&padata->list);
307 padata->serial(padata);
312 if (atomic_sub_and_test(cnt, &pd->refcnt))
317 * padata_do_serial - padata serialization function
319 * @padata: object to be serialized.
321 * padata_do_serial must be called for every parallelized object.
322 * The serialization callback function will run with BHs off.
324 void padata_do_serial(struct padata_priv *padata)
326 struct parallel_data *pd = padata->pd;
327 struct padata_parallel_queue *pqueue = per_cpu_ptr(pd->pqueue,
330 spin_lock(&pqueue->reorder.lock);
331 list_add_tail(&padata->list, &pqueue->reorder.list);
332 atomic_inc(&pd->reorder_objects);
333 spin_unlock(&pqueue->reorder.lock);
336 * Ensure the addition to the reorder list is ordered correctly
337 * with the trylock of pd->lock in padata_reorder. Pairs with smp_mb
340 smp_mb__after_atomic();
344 EXPORT_SYMBOL(padata_do_serial);
346 static int padata_setup_cpumasks(struct parallel_data *pd,
347 const struct cpumask *pcpumask,
348 const struct cpumask *cbcpumask)
350 if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL))
353 cpumask_and(pd->cpumask.pcpu, pcpumask, cpu_online_mask);
354 if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL)) {
355 free_cpumask_var(pd->cpumask.pcpu);
359 cpumask_and(pd->cpumask.cbcpu, cbcpumask, cpu_online_mask);
363 static void __padata_list_init(struct padata_list *pd_list)
365 INIT_LIST_HEAD(&pd_list->list);
366 spin_lock_init(&pd_list->lock);
369 /* Initialize all percpu queues used by serial workers */
370 static void padata_init_squeues(struct parallel_data *pd)
373 struct padata_serial_queue *squeue;
375 for_each_cpu(cpu, pd->cpumask.cbcpu) {
376 squeue = per_cpu_ptr(pd->squeue, cpu);
378 __padata_list_init(&squeue->serial);
379 INIT_WORK(&squeue->work, padata_serial_worker);
383 /* Initialize all percpu queues used by parallel workers */
384 static void padata_init_pqueues(struct parallel_data *pd)
387 struct padata_parallel_queue *pqueue;
390 for_each_possible_cpu(cpu) {
391 pqueue = per_cpu_ptr(pd->pqueue, cpu);
393 if (!cpumask_test_cpu(cpu, pd->cpumask.pcpu)) {
394 pqueue->cpu_index = -1;
398 pqueue->cpu_index = cpu_index;
401 __padata_list_init(&pqueue->reorder);
402 __padata_list_init(&pqueue->parallel);
403 INIT_WORK(&pqueue->work, padata_parallel_worker);
404 atomic_set(&pqueue->num_obj, 0);
408 /* Allocate and initialize the internal cpumask dependend resources. */
409 static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst,
410 const struct cpumask *pcpumask,
411 const struct cpumask *cbcpumask)
413 struct parallel_data *pd;
415 pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL);
419 pd->pqueue = alloc_percpu(struct padata_parallel_queue);
423 pd->squeue = alloc_percpu(struct padata_serial_queue);
425 goto err_free_pqueue;
426 if (padata_setup_cpumasks(pd, pcpumask, cbcpumask) < 0)
427 goto err_free_squeue;
429 padata_init_pqueues(pd);
430 padata_init_squeues(pd);
431 atomic_set(&pd->seq_nr, -1);
432 atomic_set(&pd->reorder_objects, 0);
433 atomic_set(&pd->refcnt, 1);
435 spin_lock_init(&pd->lock);
436 pd->cpu = cpumask_first(pd->cpumask.pcpu);
437 INIT_WORK(&pd->reorder_work, invoke_padata_reorder);
442 free_percpu(pd->squeue);
444 free_percpu(pd->pqueue);
451 static void padata_free_pd(struct parallel_data *pd)
453 free_cpumask_var(pd->cpumask.pcpu);
454 free_cpumask_var(pd->cpumask.cbcpu);
455 free_percpu(pd->pqueue);
456 free_percpu(pd->squeue);
460 static void __padata_start(struct padata_instance *pinst)
462 pinst->flags |= PADATA_INIT;
465 static void __padata_stop(struct padata_instance *pinst)
467 if (!(pinst->flags & PADATA_INIT))
470 pinst->flags &= ~PADATA_INIT;
475 /* Replace the internal control structure with a new one. */
476 static void padata_replace(struct padata_instance *pinst,
477 struct parallel_data *pd_new)
479 struct parallel_data *pd_old = pinst->pd;
480 int notification_mask = 0;
482 pinst->flags |= PADATA_RESET;
484 rcu_assign_pointer(pinst->pd, pd_new);
488 if (!cpumask_equal(pd_old->cpumask.pcpu, pd_new->cpumask.pcpu))
489 notification_mask |= PADATA_CPU_PARALLEL;
490 if (!cpumask_equal(pd_old->cpumask.cbcpu, pd_new->cpumask.cbcpu))
491 notification_mask |= PADATA_CPU_SERIAL;
493 if (atomic_dec_and_test(&pd_old->refcnt))
494 padata_free_pd(pd_old);
496 if (notification_mask)
497 blocking_notifier_call_chain(&pinst->cpumask_change_notifier,
501 pinst->flags &= ~PADATA_RESET;
505 * padata_register_cpumask_notifier - Registers a notifier that will be called
506 * if either pcpu or cbcpu or both cpumasks change.
508 * @pinst: A poineter to padata instance
509 * @nblock: A pointer to notifier block.
511 int padata_register_cpumask_notifier(struct padata_instance *pinst,
512 struct notifier_block *nblock)
514 return blocking_notifier_chain_register(&pinst->cpumask_change_notifier,
517 EXPORT_SYMBOL(padata_register_cpumask_notifier);
520 * padata_unregister_cpumask_notifier - Unregisters cpumask notifier
521 * registered earlier using padata_register_cpumask_notifier
523 * @pinst: A pointer to data instance.
524 * @nlock: A pointer to notifier block.
526 int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
527 struct notifier_block *nblock)
529 return blocking_notifier_chain_unregister(
530 &pinst->cpumask_change_notifier,
533 EXPORT_SYMBOL(padata_unregister_cpumask_notifier);
536 /* If cpumask contains no active cpu, we mark the instance as invalid. */
537 static bool padata_validate_cpumask(struct padata_instance *pinst,
538 const struct cpumask *cpumask)
540 if (!cpumask_intersects(cpumask, cpu_online_mask)) {
541 pinst->flags |= PADATA_INVALID;
545 pinst->flags &= ~PADATA_INVALID;
549 static int __padata_set_cpumasks(struct padata_instance *pinst,
550 cpumask_var_t pcpumask,
551 cpumask_var_t cbcpumask)
554 struct parallel_data *pd;
556 valid = padata_validate_cpumask(pinst, pcpumask);
558 __padata_stop(pinst);
562 valid = padata_validate_cpumask(pinst, cbcpumask);
564 __padata_stop(pinst);
567 pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
571 cpumask_copy(pinst->cpumask.pcpu, pcpumask);
572 cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
574 padata_replace(pinst, pd);
577 __padata_start(pinst);
583 * padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value
584 * equivalent to @cpumask.
586 * @pinst: padata instance
587 * @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding
588 * to parallel and serial cpumasks respectively.
589 * @cpumask: the cpumask to use
591 int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
592 cpumask_var_t cpumask)
594 struct cpumask *serial_mask, *parallel_mask;
598 mutex_lock(&pinst->lock);
600 switch (cpumask_type) {
601 case PADATA_CPU_PARALLEL:
602 serial_mask = pinst->cpumask.cbcpu;
603 parallel_mask = cpumask;
605 case PADATA_CPU_SERIAL:
606 parallel_mask = pinst->cpumask.pcpu;
607 serial_mask = cpumask;
613 err = __padata_set_cpumasks(pinst, parallel_mask, serial_mask);
616 mutex_unlock(&pinst->lock);
621 EXPORT_SYMBOL(padata_set_cpumask);
624 * padata_start - start the parallel processing
626 * @pinst: padata instance to start
628 int padata_start(struct padata_instance *pinst)
632 mutex_lock(&pinst->lock);
634 if (pinst->flags & PADATA_INVALID)
637 __padata_start(pinst);
639 mutex_unlock(&pinst->lock);
643 EXPORT_SYMBOL(padata_start);
646 * padata_stop - stop the parallel processing
648 * @pinst: padata instance to stop
650 void padata_stop(struct padata_instance *pinst)
652 mutex_lock(&pinst->lock);
653 __padata_stop(pinst);
654 mutex_unlock(&pinst->lock);
656 EXPORT_SYMBOL(padata_stop);
658 #ifdef CONFIG_HOTPLUG_CPU
660 static int __padata_add_cpu(struct padata_instance *pinst, int cpu)
662 struct parallel_data *pd;
664 if (cpumask_test_cpu(cpu, cpu_online_mask)) {
665 pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
666 pinst->cpumask.cbcpu);
670 padata_replace(pinst, pd);
672 if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) &&
673 padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
674 __padata_start(pinst);
680 static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
682 struct parallel_data *pd = NULL;
684 if (cpumask_test_cpu(cpu, cpu_online_mask)) {
686 if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) ||
687 !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
688 __padata_stop(pinst);
690 pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
691 pinst->cpumask.cbcpu);
695 padata_replace(pinst, pd);
697 cpumask_clear_cpu(cpu, pd->cpumask.cbcpu);
698 cpumask_clear_cpu(cpu, pd->cpumask.pcpu);
705 * padata_remove_cpu - remove a cpu from the one or both(serial and parallel)
708 * @pinst: padata instance
709 * @cpu: cpu to remove
710 * @mask: bitmask specifying from which cpumask @cpu should be removed
711 * The @mask may be any combination of the following flags:
712 * PADATA_CPU_SERIAL - serial cpumask
713 * PADATA_CPU_PARALLEL - parallel cpumask
715 int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask)
719 if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL)))
722 mutex_lock(&pinst->lock);
725 if (mask & PADATA_CPU_SERIAL)
726 cpumask_clear_cpu(cpu, pinst->cpumask.cbcpu);
727 if (mask & PADATA_CPU_PARALLEL)
728 cpumask_clear_cpu(cpu, pinst->cpumask.pcpu);
730 err = __padata_remove_cpu(pinst, cpu);
733 mutex_unlock(&pinst->lock);
737 EXPORT_SYMBOL(padata_remove_cpu);
739 static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu)
741 return cpumask_test_cpu(cpu, pinst->cpumask.pcpu) ||
742 cpumask_test_cpu(cpu, pinst->cpumask.cbcpu);
745 static int padata_cpu_online(unsigned int cpu, struct hlist_node *node)
747 struct padata_instance *pinst;
750 pinst = hlist_entry_safe(node, struct padata_instance, node);
751 if (!pinst_has_cpu(pinst, cpu))
754 mutex_lock(&pinst->lock);
755 ret = __padata_add_cpu(pinst, cpu);
756 mutex_unlock(&pinst->lock);
760 static int padata_cpu_prep_down(unsigned int cpu, struct hlist_node *node)
762 struct padata_instance *pinst;
765 pinst = hlist_entry_safe(node, struct padata_instance, node);
766 if (!pinst_has_cpu(pinst, cpu))
769 mutex_lock(&pinst->lock);
770 ret = __padata_remove_cpu(pinst, cpu);
771 mutex_unlock(&pinst->lock);
775 static enum cpuhp_state hp_online;
778 static void __padata_free(struct padata_instance *pinst)
780 #ifdef CONFIG_HOTPLUG_CPU
781 cpuhp_state_remove_instance_nocalls(hp_online, &pinst->node);
785 padata_free_pd(pinst->pd);
786 free_cpumask_var(pinst->cpumask.pcpu);
787 free_cpumask_var(pinst->cpumask.cbcpu);
791 #define kobj2pinst(_kobj) \
792 container_of(_kobj, struct padata_instance, kobj)
793 #define attr2pentry(_attr) \
794 container_of(_attr, struct padata_sysfs_entry, attr)
796 static void padata_sysfs_release(struct kobject *kobj)
798 struct padata_instance *pinst = kobj2pinst(kobj);
799 __padata_free(pinst);
802 struct padata_sysfs_entry {
803 struct attribute attr;
804 ssize_t (*show)(struct padata_instance *, struct attribute *, char *);
805 ssize_t (*store)(struct padata_instance *, struct attribute *,
806 const char *, size_t);
809 static ssize_t show_cpumask(struct padata_instance *pinst,
810 struct attribute *attr, char *buf)
812 struct cpumask *cpumask;
815 mutex_lock(&pinst->lock);
816 if (!strcmp(attr->name, "serial_cpumask"))
817 cpumask = pinst->cpumask.cbcpu;
819 cpumask = pinst->cpumask.pcpu;
821 len = snprintf(buf, PAGE_SIZE, "%*pb\n",
822 nr_cpu_ids, cpumask_bits(cpumask));
823 mutex_unlock(&pinst->lock);
824 return len < PAGE_SIZE ? len : -EINVAL;
827 static ssize_t store_cpumask(struct padata_instance *pinst,
828 struct attribute *attr,
829 const char *buf, size_t count)
831 cpumask_var_t new_cpumask;
835 if (!alloc_cpumask_var(&new_cpumask, GFP_KERNEL))
838 ret = bitmap_parse(buf, count, cpumask_bits(new_cpumask),
843 mask_type = !strcmp(attr->name, "serial_cpumask") ?
844 PADATA_CPU_SERIAL : PADATA_CPU_PARALLEL;
845 ret = padata_set_cpumask(pinst, mask_type, new_cpumask);
850 free_cpumask_var(new_cpumask);
854 #define PADATA_ATTR_RW(_name, _show_name, _store_name) \
855 static struct padata_sysfs_entry _name##_attr = \
856 __ATTR(_name, 0644, _show_name, _store_name)
857 #define PADATA_ATTR_RO(_name, _show_name) \
858 static struct padata_sysfs_entry _name##_attr = \
859 __ATTR(_name, 0400, _show_name, NULL)
861 PADATA_ATTR_RW(serial_cpumask, show_cpumask, store_cpumask);
862 PADATA_ATTR_RW(parallel_cpumask, show_cpumask, store_cpumask);
865 * Padata sysfs provides the following objects:
866 * serial_cpumask [RW] - cpumask for serial workers
867 * parallel_cpumask [RW] - cpumask for parallel workers
869 static struct attribute *padata_default_attrs[] = {
870 &serial_cpumask_attr.attr,
871 ¶llel_cpumask_attr.attr,
875 static ssize_t padata_sysfs_show(struct kobject *kobj,
876 struct attribute *attr, char *buf)
878 struct padata_instance *pinst;
879 struct padata_sysfs_entry *pentry;
882 pinst = kobj2pinst(kobj);
883 pentry = attr2pentry(attr);
885 ret = pentry->show(pinst, attr, buf);
890 static ssize_t padata_sysfs_store(struct kobject *kobj, struct attribute *attr,
891 const char *buf, size_t count)
893 struct padata_instance *pinst;
894 struct padata_sysfs_entry *pentry;
897 pinst = kobj2pinst(kobj);
898 pentry = attr2pentry(attr);
900 ret = pentry->store(pinst, attr, buf, count);
905 static const struct sysfs_ops padata_sysfs_ops = {
906 .show = padata_sysfs_show,
907 .store = padata_sysfs_store,
910 static struct kobj_type padata_attr_type = {
911 .sysfs_ops = &padata_sysfs_ops,
912 .default_attrs = padata_default_attrs,
913 .release = padata_sysfs_release,
917 * padata_alloc - allocate and initialize a padata instance and specify
918 * cpumasks for serial and parallel workers.
920 * @wq: workqueue to use for the allocated padata instance
921 * @pcpumask: cpumask that will be used for padata parallelization
922 * @cbcpumask: cpumask that will be used for padata serialization
924 * Must be called from a cpus_read_lock() protected region
926 static struct padata_instance *padata_alloc(struct workqueue_struct *wq,
927 const struct cpumask *pcpumask,
928 const struct cpumask *cbcpumask)
930 struct padata_instance *pinst;
931 struct parallel_data *pd = NULL;
933 pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL);
937 if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL))
939 if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) {
940 free_cpumask_var(pinst->cpumask.pcpu);
943 if (!padata_validate_cpumask(pinst, pcpumask) ||
944 !padata_validate_cpumask(pinst, cbcpumask))
947 pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
951 rcu_assign_pointer(pinst->pd, pd);
955 cpumask_copy(pinst->cpumask.pcpu, pcpumask);
956 cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
960 BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier);
961 kobject_init(&pinst->kobj, &padata_attr_type);
962 mutex_init(&pinst->lock);
964 #ifdef CONFIG_HOTPLUG_CPU
965 cpuhp_state_add_instance_nocalls_cpuslocked(hp_online, &pinst->node);
970 free_cpumask_var(pinst->cpumask.pcpu);
971 free_cpumask_var(pinst->cpumask.cbcpu);
979 * padata_alloc_possible - Allocate and initialize padata instance.
980 * Use the cpu_possible_mask for serial and
983 * @wq: workqueue to use for the allocated padata instance
985 * Must be called from a cpus_read_lock() protected region
987 struct padata_instance *padata_alloc_possible(struct workqueue_struct *wq)
989 lockdep_assert_cpus_held();
990 return padata_alloc(wq, cpu_possible_mask, cpu_possible_mask);
992 EXPORT_SYMBOL(padata_alloc_possible);
995 * padata_free - free a padata instance
997 * @padata_inst: padata instance to free
999 void padata_free(struct padata_instance *pinst)
1001 kobject_put(&pinst->kobj);
1003 EXPORT_SYMBOL(padata_free);
1005 #ifdef CONFIG_HOTPLUG_CPU
1007 static __init int padata_driver_init(void)
1011 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "padata:online",
1013 padata_cpu_prep_down);
1019 module_init(padata_driver_init);
1021 static __exit void padata_driver_exit(void)
1023 cpuhp_remove_multi_state(hp_online);
1025 module_exit(padata_driver_exit);