1 // SPDX-License-Identifier: GPL-2.0
3 * padata.c - generic interface to process data streams in parallel
5 * See Documentation/padata.txt for an api documentation.
7 * Copyright (C) 2008, 2009 secunet Security Networks AG
8 * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms and conditions of the GNU General Public License,
12 * version 2, as published by the Free Software Foundation.
14 * This program is distributed in the hope it will be useful, but WITHOUT
15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
19 * You should have received a copy of the GNU General Public License along with
20 * this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
24 #include <linux/export.h>
25 #include <linux/cpumask.h>
26 #include <linux/err.h>
27 #include <linux/cpu.h>
28 #include <linux/padata.h>
29 #include <linux/mutex.h>
30 #include <linux/sched.h>
31 #include <linux/slab.h>
32 #include <linux/sysfs.h>
33 #include <linux/rcupdate.h>
34 #include <linux/module.h>
36 #define MAX_OBJ_NUM 1000
38 static void padata_free_pd(struct parallel_data *pd);
40 static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index)
44 target_cpu = cpumask_first(pd->cpumask.pcpu);
45 for (cpu = 0; cpu < cpu_index; cpu++)
46 target_cpu = cpumask_next(target_cpu, pd->cpumask.pcpu);
51 static int padata_cpu_hash(struct parallel_data *pd, unsigned int seq_nr)
54 * Hash the sequence numbers to the cpus by taking
55 * seq_nr mod. number of cpus in use.
57 int cpu_index = 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 LIST_HEAD(local_list);
68 pqueue = container_of(parallel_work,
69 struct padata_parallel_queue, work);
71 spin_lock(&pqueue->parallel.lock);
72 list_replace_init(&pqueue->parallel.list, &local_list);
73 spin_unlock(&pqueue->parallel.lock);
75 while (!list_empty(&local_list)) {
76 struct padata_priv *padata;
78 padata = list_entry(local_list.next,
79 struct padata_priv, list);
81 list_del_init(&padata->list);
83 padata->parallel(padata);
90 * padata_do_parallel - padata parallelization function
93 * @padata: object to be parallelized
94 * @cb_cpu: pointer to the CPU that the serialization callback function should
95 * run on. If it's not in the serial cpumask of @pinst
96 * (i.e. cpumask.cbcpu), this function selects a fallback CPU and if
97 * none found, returns -EINVAL.
99 * The parallelization callback function will run with BHs off.
100 * Note: Every object which is parallelized by padata_do_parallel
101 * must be seen by padata_do_serial.
103 int padata_do_parallel(struct padata_shell *ps,
104 struct padata_priv *padata, int *cb_cpu)
106 struct padata_instance *pinst = ps->pinst;
107 int i, cpu, cpu_index, target_cpu, err;
108 struct padata_parallel_queue *queue;
109 struct parallel_data *pd;
113 pd = rcu_dereference_bh(ps->pd);
116 if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID)
119 if (!cpumask_test_cpu(*cb_cpu, pd->cpumask.cbcpu)) {
120 if (!cpumask_weight(pd->cpumask.cbcpu))
123 /* Select an alternate fallback CPU and notify the caller. */
124 cpu_index = *cb_cpu % cpumask_weight(pd->cpumask.cbcpu);
126 cpu = cpumask_first(pd->cpumask.cbcpu);
127 for (i = 0; i < cpu_index; i++)
128 cpu = cpumask_next(cpu, pd->cpumask.cbcpu);
134 if ((pinst->flags & PADATA_RESET))
137 if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM)
141 atomic_inc(&pd->refcnt);
143 padata->cb_cpu = *cb_cpu;
145 padata->seq_nr = atomic_inc_return(&pd->seq_nr);
146 target_cpu = padata_cpu_hash(pd, padata->seq_nr);
147 padata->cpu = target_cpu;
148 queue = per_cpu_ptr(pd->pqueue, target_cpu);
150 spin_lock(&queue->parallel.lock);
151 list_add_tail(&padata->list, &queue->parallel.list);
152 spin_unlock(&queue->parallel.lock);
154 queue_work(pinst->parallel_wq, &queue->work);
157 rcu_read_unlock_bh();
161 EXPORT_SYMBOL(padata_do_parallel);
164 * padata_find_next - Find the next object that needs serialization.
168 * A pointer to the control struct of the next object that needs
169 * serialization, if present in one of the percpu reorder queues.
171 * NULL, if the next object that needs serialization will
172 * be parallel processed by another cpu and is not yet present in
173 * the cpu's reorder queue.
175 static struct padata_priv *padata_find_next(struct parallel_data *pd,
178 struct padata_parallel_queue *next_queue;
179 struct padata_priv *padata;
180 struct padata_list *reorder;
183 next_queue = per_cpu_ptr(pd->pqueue, cpu);
184 reorder = &next_queue->reorder;
186 spin_lock(&reorder->lock);
187 if (list_empty(&reorder->list)) {
188 spin_unlock(&reorder->lock);
192 padata = list_entry(reorder->list.next, struct padata_priv, list);
195 * Checks the rare case where two or more parallel jobs have hashed to
196 * the same CPU and one of the later ones finishes first.
198 if (padata->seq_nr != pd->processed) {
199 spin_unlock(&reorder->lock);
204 list_del_init(&padata->list);
205 atomic_dec(&pd->reorder_objects);
207 pd->cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu, -1, false);
210 spin_unlock(&reorder->lock);
214 static void padata_reorder(struct parallel_data *pd)
216 struct padata_instance *pinst = pd->ps->pinst;
218 struct padata_priv *padata;
219 struct padata_serial_queue *squeue;
220 struct padata_parallel_queue *next_queue;
223 * We need to ensure that only one cpu can work on dequeueing of
224 * the reorder queue the time. Calculating in which percpu reorder
225 * queue the next object will arrive takes some time. A spinlock
226 * would be highly contended. Also it is not clear in which order
227 * the objects arrive to the reorder queues. So a cpu could wait to
228 * get the lock just to notice that there is nothing to do at the
229 * moment. Therefore we use a trylock and let the holder of the lock
230 * care for all the objects enqueued during the holdtime of the lock.
232 if (!spin_trylock_bh(&pd->lock))
236 padata = padata_find_next(pd, true);
239 * If the next object that needs serialization is parallel
240 * processed by another cpu and is still on it's way to the
241 * cpu's reorder queue, nothing to do for now.
246 cb_cpu = padata->cb_cpu;
247 squeue = per_cpu_ptr(pd->squeue, cb_cpu);
249 spin_lock(&squeue->serial.lock);
250 list_add_tail(&padata->list, &squeue->serial.list);
251 spin_unlock(&squeue->serial.lock);
253 queue_work_on(cb_cpu, pinst->serial_wq, &squeue->work);
256 spin_unlock_bh(&pd->lock);
259 * The next object that needs serialization might have arrived to
260 * the reorder queues in the meantime.
262 * Ensure reorder queue is read after pd->lock is dropped so we see
263 * new objects from another task in padata_do_serial. Pairs with
264 * smp_mb__after_atomic in padata_do_serial.
268 next_queue = per_cpu_ptr(pd->pqueue, pd->cpu);
269 if (!list_empty(&next_queue->reorder.list) &&
270 padata_find_next(pd, false))
271 queue_work(pinst->serial_wq, &pd->reorder_work);
274 static void invoke_padata_reorder(struct work_struct *work)
276 struct parallel_data *pd;
279 pd = container_of(work, struct parallel_data, reorder_work);
284 static void padata_serial_worker(struct work_struct *serial_work)
286 struct padata_serial_queue *squeue;
287 struct parallel_data *pd;
288 LIST_HEAD(local_list);
292 squeue = container_of(serial_work, struct padata_serial_queue, work);
295 spin_lock(&squeue->serial.lock);
296 list_replace_init(&squeue->serial.list, &local_list);
297 spin_unlock(&squeue->serial.lock);
301 while (!list_empty(&local_list)) {
302 struct padata_priv *padata;
304 padata = list_entry(local_list.next,
305 struct padata_priv, list);
307 list_del_init(&padata->list);
309 padata->serial(padata);
314 if (atomic_sub_and_test(cnt, &pd->refcnt))
319 * padata_do_serial - padata serialization function
321 * @padata: object to be serialized.
323 * padata_do_serial must be called for every parallelized object.
324 * The serialization callback function will run with BHs off.
326 void padata_do_serial(struct padata_priv *padata)
328 struct parallel_data *pd = padata->pd;
329 struct padata_parallel_queue *pqueue = per_cpu_ptr(pd->pqueue,
331 struct padata_priv *cur;
333 spin_lock(&pqueue->reorder.lock);
334 /* Sort in ascending order of sequence number. */
335 list_for_each_entry_reverse(cur, &pqueue->reorder.list, list)
336 if (cur->seq_nr < padata->seq_nr)
338 list_add(&padata->list, &cur->list);
339 atomic_inc(&pd->reorder_objects);
340 spin_unlock(&pqueue->reorder.lock);
343 * Ensure the addition to the reorder list is ordered correctly
344 * with the trylock of pd->lock in padata_reorder. Pairs with smp_mb
347 smp_mb__after_atomic();
351 EXPORT_SYMBOL(padata_do_serial);
353 static int padata_setup_cpumasks(struct padata_instance *pinst)
355 struct workqueue_attrs *attrs;
358 attrs = alloc_workqueue_attrs();
362 /* Restrict parallel_wq workers to pd->cpumask.pcpu. */
363 cpumask_copy(attrs->cpumask, pinst->cpumask.pcpu);
364 err = apply_workqueue_attrs(pinst->parallel_wq, attrs);
365 free_workqueue_attrs(attrs);
370 static int pd_setup_cpumasks(struct parallel_data *pd,
371 const struct cpumask *pcpumask,
372 const struct cpumask *cbcpumask)
376 if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL))
378 if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL))
381 cpumask_copy(pd->cpumask.pcpu, pcpumask);
382 cpumask_copy(pd->cpumask.cbcpu, cbcpumask);
387 free_cpumask_var(pd->cpumask.pcpu);
392 static void __padata_list_init(struct padata_list *pd_list)
394 INIT_LIST_HEAD(&pd_list->list);
395 spin_lock_init(&pd_list->lock);
398 /* Initialize all percpu queues used by serial workers */
399 static void padata_init_squeues(struct parallel_data *pd)
402 struct padata_serial_queue *squeue;
404 for_each_cpu(cpu, pd->cpumask.cbcpu) {
405 squeue = per_cpu_ptr(pd->squeue, cpu);
407 __padata_list_init(&squeue->serial);
408 INIT_WORK(&squeue->work, padata_serial_worker);
412 /* Initialize all percpu queues used by parallel workers */
413 static void padata_init_pqueues(struct parallel_data *pd)
416 struct padata_parallel_queue *pqueue;
418 for_each_cpu(cpu, pd->cpumask.pcpu) {
419 pqueue = per_cpu_ptr(pd->pqueue, cpu);
421 __padata_list_init(&pqueue->reorder);
422 __padata_list_init(&pqueue->parallel);
423 INIT_WORK(&pqueue->work, padata_parallel_worker);
424 atomic_set(&pqueue->num_obj, 0);
428 /* Allocate and initialize the internal cpumask dependend resources. */
429 static struct parallel_data *padata_alloc_pd(struct padata_shell *ps)
431 struct padata_instance *pinst = ps->pinst;
432 const struct cpumask *cbcpumask;
433 const struct cpumask *pcpumask;
434 struct parallel_data *pd;
436 cbcpumask = pinst->rcpumask.cbcpu;
437 pcpumask = pinst->rcpumask.pcpu;
439 pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL);
443 pd->pqueue = alloc_percpu(struct padata_parallel_queue);
447 pd->squeue = alloc_percpu(struct padata_serial_queue);
449 goto err_free_pqueue;
452 if (pd_setup_cpumasks(pd, pcpumask, cbcpumask))
453 goto err_free_squeue;
455 padata_init_pqueues(pd);
456 padata_init_squeues(pd);
457 atomic_set(&pd->seq_nr, -1);
458 atomic_set(&pd->reorder_objects, 0);
459 atomic_set(&pd->refcnt, 1);
460 spin_lock_init(&pd->lock);
461 pd->cpu = cpumask_first(pd->cpumask.pcpu);
462 INIT_WORK(&pd->reorder_work, invoke_padata_reorder);
467 free_percpu(pd->squeue);
469 free_percpu(pd->pqueue);
476 static void padata_free_pd(struct parallel_data *pd)
478 free_cpumask_var(pd->cpumask.pcpu);
479 free_cpumask_var(pd->cpumask.cbcpu);
480 free_percpu(pd->pqueue);
481 free_percpu(pd->squeue);
485 static void __padata_start(struct padata_instance *pinst)
487 pinst->flags |= PADATA_INIT;
490 static void __padata_stop(struct padata_instance *pinst)
492 if (!(pinst->flags & PADATA_INIT))
495 pinst->flags &= ~PADATA_INIT;
500 /* Replace the internal control structure with a new one. */
501 static int padata_replace_one(struct padata_shell *ps)
503 struct parallel_data *pd_new;
505 pd_new = padata_alloc_pd(ps);
509 ps->opd = rcu_dereference_protected(ps->pd, 1);
510 rcu_assign_pointer(ps->pd, pd_new);
515 static int padata_replace(struct padata_instance *pinst, int cpu)
517 int notification_mask = 0;
518 struct padata_shell *ps;
521 pinst->flags |= PADATA_RESET;
523 cpumask_copy(pinst->omask, pinst->rcpumask.pcpu);
524 cpumask_and(pinst->rcpumask.pcpu, pinst->cpumask.pcpu,
527 cpumask_clear_cpu(cpu, pinst->rcpumask.pcpu);
528 if (!cpumask_equal(pinst->omask, pinst->rcpumask.pcpu))
529 notification_mask |= PADATA_CPU_PARALLEL;
531 cpumask_copy(pinst->omask, pinst->rcpumask.cbcpu);
532 cpumask_and(pinst->rcpumask.cbcpu, pinst->cpumask.cbcpu,
535 cpumask_clear_cpu(cpu, pinst->rcpumask.cbcpu);
536 if (!cpumask_equal(pinst->omask, pinst->rcpumask.cbcpu))
537 notification_mask |= PADATA_CPU_SERIAL;
539 list_for_each_entry(ps, &pinst->pslist, list) {
540 err = padata_replace_one(ps);
547 list_for_each_entry_continue_reverse(ps, &pinst->pslist, list)
548 if (atomic_dec_and_test(&ps->opd->refcnt))
549 padata_free_pd(ps->opd);
551 if (notification_mask)
552 blocking_notifier_call_chain(&pinst->cpumask_change_notifier,
556 pinst->flags &= ~PADATA_RESET;
562 * padata_register_cpumask_notifier - Registers a notifier that will be called
563 * if either pcpu or cbcpu or both cpumasks change.
565 * @pinst: A poineter to padata instance
566 * @nblock: A pointer to notifier block.
568 int padata_register_cpumask_notifier(struct padata_instance *pinst,
569 struct notifier_block *nblock)
571 return blocking_notifier_chain_register(&pinst->cpumask_change_notifier,
574 EXPORT_SYMBOL(padata_register_cpumask_notifier);
577 * padata_unregister_cpumask_notifier - Unregisters cpumask notifier
578 * registered earlier using padata_register_cpumask_notifier
580 * @pinst: A pointer to data instance.
581 * @nlock: A pointer to notifier block.
583 int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
584 struct notifier_block *nblock)
586 return blocking_notifier_chain_unregister(
587 &pinst->cpumask_change_notifier,
590 EXPORT_SYMBOL(padata_unregister_cpumask_notifier);
593 /* If cpumask contains no active cpu, we mark the instance as invalid. */
594 static bool padata_validate_cpumask(struct padata_instance *pinst,
595 const struct cpumask *cpumask)
597 if (!cpumask_intersects(cpumask, cpu_online_mask)) {
598 pinst->flags |= PADATA_INVALID;
602 pinst->flags &= ~PADATA_INVALID;
606 static int __padata_set_cpumasks(struct padata_instance *pinst,
607 cpumask_var_t pcpumask,
608 cpumask_var_t cbcpumask)
613 valid = padata_validate_cpumask(pinst, pcpumask);
615 __padata_stop(pinst);
619 valid = padata_validate_cpumask(pinst, cbcpumask);
621 __padata_stop(pinst);
624 cpumask_copy(pinst->cpumask.pcpu, pcpumask);
625 cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
627 err = padata_setup_cpumasks(pinst) ?: padata_replace(pinst, -1);
630 __padata_start(pinst);
636 * padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value
637 * equivalent to @cpumask.
639 * @pinst: padata instance
640 * @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding
641 * to parallel and serial cpumasks respectively.
642 * @cpumask: the cpumask to use
644 int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
645 cpumask_var_t cpumask)
647 struct cpumask *serial_mask, *parallel_mask;
650 mutex_lock(&pinst->lock);
653 switch (cpumask_type) {
654 case PADATA_CPU_PARALLEL:
655 serial_mask = pinst->cpumask.cbcpu;
656 parallel_mask = cpumask;
658 case PADATA_CPU_SERIAL:
659 parallel_mask = pinst->cpumask.pcpu;
660 serial_mask = cpumask;
666 err = __padata_set_cpumasks(pinst, parallel_mask, serial_mask);
670 mutex_unlock(&pinst->lock);
674 EXPORT_SYMBOL(padata_set_cpumask);
677 * padata_start - start the parallel processing
679 * @pinst: padata instance to start
681 int padata_start(struct padata_instance *pinst)
685 mutex_lock(&pinst->lock);
687 if (pinst->flags & PADATA_INVALID)
690 __padata_start(pinst);
692 mutex_unlock(&pinst->lock);
696 EXPORT_SYMBOL(padata_start);
699 * padata_stop - stop the parallel processing
701 * @pinst: padata instance to stop
703 void padata_stop(struct padata_instance *pinst)
705 mutex_lock(&pinst->lock);
706 __padata_stop(pinst);
707 mutex_unlock(&pinst->lock);
709 EXPORT_SYMBOL(padata_stop);
711 #ifdef CONFIG_HOTPLUG_CPU
713 static int __padata_add_cpu(struct padata_instance *pinst, int cpu)
717 if (cpumask_test_cpu(cpu, cpu_online_mask)) {
718 err = padata_replace(pinst, -1);
720 if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) &&
721 padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
722 __padata_start(pinst);
728 static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
732 if (cpumask_test_cpu(cpu, cpu_online_mask)) {
733 if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) ||
734 !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
735 __padata_stop(pinst);
737 err = padata_replace(pinst, cpu);
744 * padata_remove_cpu - remove a cpu from the one or both(serial and parallel)
747 * @pinst: padata instance
748 * @cpu: cpu to remove
749 * @mask: bitmask specifying from which cpumask @cpu should be removed
750 * The @mask may be any combination of the following flags:
751 * PADATA_CPU_SERIAL - serial cpumask
752 * PADATA_CPU_PARALLEL - parallel cpumask
754 int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask)
758 if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL)))
761 mutex_lock(&pinst->lock);
764 if (mask & PADATA_CPU_SERIAL)
765 cpumask_clear_cpu(cpu, pinst->cpumask.cbcpu);
766 if (mask & PADATA_CPU_PARALLEL)
767 cpumask_clear_cpu(cpu, pinst->cpumask.pcpu);
769 err = __padata_remove_cpu(pinst, cpu);
772 mutex_unlock(&pinst->lock);
776 EXPORT_SYMBOL(padata_remove_cpu);
778 static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu)
780 return cpumask_test_cpu(cpu, pinst->cpumask.pcpu) ||
781 cpumask_test_cpu(cpu, pinst->cpumask.cbcpu);
784 static int padata_cpu_online(unsigned int cpu, struct hlist_node *node)
786 struct padata_instance *pinst;
789 pinst = hlist_entry_safe(node, struct padata_instance, node);
790 if (!pinst_has_cpu(pinst, cpu))
793 mutex_lock(&pinst->lock);
794 ret = __padata_add_cpu(pinst, cpu);
795 mutex_unlock(&pinst->lock);
799 static int padata_cpu_prep_down(unsigned int cpu, struct hlist_node *node)
801 struct padata_instance *pinst;
804 pinst = hlist_entry_safe(node, struct padata_instance, node);
805 if (!pinst_has_cpu(pinst, cpu))
808 mutex_lock(&pinst->lock);
809 ret = __padata_remove_cpu(pinst, cpu);
810 mutex_unlock(&pinst->lock);
814 static enum cpuhp_state hp_online;
817 static void __padata_free(struct padata_instance *pinst)
819 #ifdef CONFIG_HOTPLUG_CPU
820 cpuhp_state_remove_instance_nocalls(hp_online, &pinst->node);
823 WARN_ON(!list_empty(&pinst->pslist));
826 free_cpumask_var(pinst->omask);
827 free_cpumask_var(pinst->rcpumask.cbcpu);
828 free_cpumask_var(pinst->rcpumask.pcpu);
829 free_cpumask_var(pinst->cpumask.pcpu);
830 free_cpumask_var(pinst->cpumask.cbcpu);
831 destroy_workqueue(pinst->serial_wq);
832 destroy_workqueue(pinst->parallel_wq);
836 #define kobj2pinst(_kobj) \
837 container_of(_kobj, struct padata_instance, kobj)
838 #define attr2pentry(_attr) \
839 container_of(_attr, struct padata_sysfs_entry, attr)
841 static void padata_sysfs_release(struct kobject *kobj)
843 struct padata_instance *pinst = kobj2pinst(kobj);
844 __padata_free(pinst);
847 struct padata_sysfs_entry {
848 struct attribute attr;
849 ssize_t (*show)(struct padata_instance *, struct attribute *, char *);
850 ssize_t (*store)(struct padata_instance *, struct attribute *,
851 const char *, size_t);
854 static ssize_t show_cpumask(struct padata_instance *pinst,
855 struct attribute *attr, char *buf)
857 struct cpumask *cpumask;
860 mutex_lock(&pinst->lock);
861 if (!strcmp(attr->name, "serial_cpumask"))
862 cpumask = pinst->cpumask.cbcpu;
864 cpumask = pinst->cpumask.pcpu;
866 len = snprintf(buf, PAGE_SIZE, "%*pb\n",
867 nr_cpu_ids, cpumask_bits(cpumask));
868 mutex_unlock(&pinst->lock);
869 return len < PAGE_SIZE ? len : -EINVAL;
872 static ssize_t store_cpumask(struct padata_instance *pinst,
873 struct attribute *attr,
874 const char *buf, size_t count)
876 cpumask_var_t new_cpumask;
880 if (!alloc_cpumask_var(&new_cpumask, GFP_KERNEL))
883 ret = bitmap_parse(buf, count, cpumask_bits(new_cpumask),
888 mask_type = !strcmp(attr->name, "serial_cpumask") ?
889 PADATA_CPU_SERIAL : PADATA_CPU_PARALLEL;
890 ret = padata_set_cpumask(pinst, mask_type, new_cpumask);
895 free_cpumask_var(new_cpumask);
899 #define PADATA_ATTR_RW(_name, _show_name, _store_name) \
900 static struct padata_sysfs_entry _name##_attr = \
901 __ATTR(_name, 0644, _show_name, _store_name)
902 #define PADATA_ATTR_RO(_name, _show_name) \
903 static struct padata_sysfs_entry _name##_attr = \
904 __ATTR(_name, 0400, _show_name, NULL)
906 PADATA_ATTR_RW(serial_cpumask, show_cpumask, store_cpumask);
907 PADATA_ATTR_RW(parallel_cpumask, show_cpumask, store_cpumask);
910 * Padata sysfs provides the following objects:
911 * serial_cpumask [RW] - cpumask for serial workers
912 * parallel_cpumask [RW] - cpumask for parallel workers
914 static struct attribute *padata_default_attrs[] = {
915 &serial_cpumask_attr.attr,
916 ¶llel_cpumask_attr.attr,
919 ATTRIBUTE_GROUPS(padata_default);
921 static ssize_t padata_sysfs_show(struct kobject *kobj,
922 struct attribute *attr, char *buf)
924 struct padata_instance *pinst;
925 struct padata_sysfs_entry *pentry;
928 pinst = kobj2pinst(kobj);
929 pentry = attr2pentry(attr);
931 ret = pentry->show(pinst, attr, buf);
936 static ssize_t padata_sysfs_store(struct kobject *kobj, struct attribute *attr,
937 const char *buf, size_t count)
939 struct padata_instance *pinst;
940 struct padata_sysfs_entry *pentry;
943 pinst = kobj2pinst(kobj);
944 pentry = attr2pentry(attr);
946 ret = pentry->store(pinst, attr, buf, count);
951 static const struct sysfs_ops padata_sysfs_ops = {
952 .show = padata_sysfs_show,
953 .store = padata_sysfs_store,
956 static struct kobj_type padata_attr_type = {
957 .sysfs_ops = &padata_sysfs_ops,
958 .default_groups = padata_default_groups,
959 .release = padata_sysfs_release,
963 * padata_alloc - allocate and initialize a padata instance and specify
964 * cpumasks for serial and parallel workers.
966 * @name: used to identify the instance
967 * @pcpumask: cpumask that will be used for padata parallelization
968 * @cbcpumask: cpumask that will be used for padata serialization
970 static struct padata_instance *padata_alloc(const char *name,
971 const struct cpumask *pcpumask,
972 const struct cpumask *cbcpumask)
974 struct padata_instance *pinst;
976 pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL);
980 pinst->parallel_wq = alloc_workqueue("%s_parallel", WQ_UNBOUND, 0,
982 if (!pinst->parallel_wq)
987 pinst->serial_wq = alloc_workqueue("%s_serial", WQ_MEM_RECLAIM |
988 WQ_CPU_INTENSIVE, 1, name);
989 if (!pinst->serial_wq)
992 if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL))
993 goto err_free_serial_wq;
994 if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) {
995 free_cpumask_var(pinst->cpumask.pcpu);
996 goto err_free_serial_wq;
998 if (!padata_validate_cpumask(pinst, pcpumask) ||
999 !padata_validate_cpumask(pinst, cbcpumask))
1000 goto err_free_masks;
1002 if (!alloc_cpumask_var(&pinst->rcpumask.pcpu, GFP_KERNEL))
1003 goto err_free_masks;
1004 if (!alloc_cpumask_var(&pinst->rcpumask.cbcpu, GFP_KERNEL))
1005 goto err_free_rcpumask_pcpu;
1006 if (!alloc_cpumask_var(&pinst->omask, GFP_KERNEL))
1007 goto err_free_rcpumask_cbcpu;
1009 INIT_LIST_HEAD(&pinst->pslist);
1011 cpumask_copy(pinst->cpumask.pcpu, pcpumask);
1012 cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
1013 cpumask_and(pinst->rcpumask.pcpu, pcpumask, cpu_online_mask);
1014 cpumask_and(pinst->rcpumask.cbcpu, cbcpumask, cpu_online_mask);
1016 if (padata_setup_cpumasks(pinst))
1017 goto err_free_omask;
1021 BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier);
1022 kobject_init(&pinst->kobj, &padata_attr_type);
1023 mutex_init(&pinst->lock);
1025 #ifdef CONFIG_HOTPLUG_CPU
1026 cpuhp_state_add_instance_nocalls_cpuslocked(hp_online, &pinst->node);
1034 free_cpumask_var(pinst->omask);
1035 err_free_rcpumask_cbcpu:
1036 free_cpumask_var(pinst->rcpumask.cbcpu);
1037 err_free_rcpumask_pcpu:
1038 free_cpumask_var(pinst->rcpumask.pcpu);
1040 free_cpumask_var(pinst->cpumask.pcpu);
1041 free_cpumask_var(pinst->cpumask.cbcpu);
1043 destroy_workqueue(pinst->serial_wq);
1046 destroy_workqueue(pinst->parallel_wq);
1054 * padata_alloc_possible - Allocate and initialize padata instance.
1055 * Use the cpu_possible_mask for serial and
1058 * @name: used to identify the instance
1060 struct padata_instance *padata_alloc_possible(const char *name)
1062 return padata_alloc(name, cpu_possible_mask, cpu_possible_mask);
1064 EXPORT_SYMBOL(padata_alloc_possible);
1067 * padata_free - free a padata instance
1069 * @padata_inst: padata instance to free
1071 void padata_free(struct padata_instance *pinst)
1073 kobject_put(&pinst->kobj);
1075 EXPORT_SYMBOL(padata_free);
1078 * padata_alloc_shell - Allocate and initialize padata shell.
1080 * @pinst: Parent padata_instance object.
1082 struct padata_shell *padata_alloc_shell(struct padata_instance *pinst)
1084 struct parallel_data *pd;
1085 struct padata_shell *ps;
1087 ps = kzalloc(sizeof(*ps), GFP_KERNEL);
1094 pd = padata_alloc_pd(ps);
1100 mutex_lock(&pinst->lock);
1101 RCU_INIT_POINTER(ps->pd, pd);
1102 list_add(&ps->list, &pinst->pslist);
1103 mutex_unlock(&pinst->lock);
1112 EXPORT_SYMBOL(padata_alloc_shell);
1115 * padata_free_shell - free a padata shell
1117 * @ps: padata shell to free
1119 void padata_free_shell(struct padata_shell *ps)
1121 struct padata_instance *pinst = ps->pinst;
1123 mutex_lock(&pinst->lock);
1124 list_del(&ps->list);
1125 padata_free_pd(rcu_dereference_protected(ps->pd, 1));
1126 mutex_unlock(&pinst->lock);
1130 EXPORT_SYMBOL(padata_free_shell);
1132 #ifdef CONFIG_HOTPLUG_CPU
1134 static __init int padata_driver_init(void)
1138 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "padata:online",
1140 padata_cpu_prep_down);
1146 module_init(padata_driver_init);
1148 static __exit void padata_driver_exit(void)
1150 cpuhp_remove_multi_state(hp_online);
1152 module_exit(padata_driver_exit);