| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * padata.c - generic interface to process data streams in parallel |
| * |
| * See Documentation/padata.txt for an api documentation. |
| * |
| * Copyright (C) 2008, 2009 secunet Security Networks AG |
| * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com> |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms and conditions of the GNU General Public License, |
| * version 2, as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| * more details. |
| * |
| * You should have received a copy of the GNU General Public License along with |
| * this program; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. |
| */ |
| |
| #include <linux/export.h> |
| #include <linux/cpumask.h> |
| #include <linux/err.h> |
| #include <linux/cpu.h> |
| #include <linux/padata.h> |
| #include <linux/mutex.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/sysfs.h> |
| #include <linux/rcupdate.h> |
| #include <linux/module.h> |
| |
| #define MAX_OBJ_NUM 1000 |
| |
| static void padata_free_pd(struct parallel_data *pd); |
| |
| static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index) |
| { |
| int cpu, target_cpu; |
| |
| target_cpu = cpumask_first(pd->cpumask.pcpu); |
| for (cpu = 0; cpu < cpu_index; cpu++) |
| target_cpu = cpumask_next(target_cpu, pd->cpumask.pcpu); |
| |
| return target_cpu; |
| } |
| |
| static int padata_cpu_hash(struct parallel_data *pd, unsigned int seq_nr) |
| { |
| /* |
| * Hash the sequence numbers to the cpus by taking |
| * seq_nr mod. number of cpus in use. |
| */ |
| int cpu_index = seq_nr % cpumask_weight(pd->cpumask.pcpu); |
| |
| return padata_index_to_cpu(pd, cpu_index); |
| } |
| |
| static void padata_parallel_worker(struct work_struct *parallel_work) |
| { |
| struct padata_parallel_queue *pqueue; |
| LIST_HEAD(local_list); |
| |
| local_bh_disable(); |
| pqueue = container_of(parallel_work, |
| struct padata_parallel_queue, work); |
| |
| spin_lock(&pqueue->parallel.lock); |
| list_replace_init(&pqueue->parallel.list, &local_list); |
| spin_unlock(&pqueue->parallel.lock); |
| |
| while (!list_empty(&local_list)) { |
| struct padata_priv *padata; |
| |
| padata = list_entry(local_list.next, |
| struct padata_priv, list); |
| |
| list_del_init(&padata->list); |
| |
| padata->parallel(padata); |
| } |
| |
| local_bh_enable(); |
| } |
| |
| /** |
| * padata_do_parallel - padata parallelization function |
| * |
| * @ps: padatashell |
| * @padata: object to be parallelized |
| * @cb_cpu: pointer to the CPU that the serialization callback function should |
| * run on. If it's not in the serial cpumask of @pinst |
| * (i.e. cpumask.cbcpu), this function selects a fallback CPU and if |
| * none found, returns -EINVAL. |
| * |
| * The parallelization callback function will run with BHs off. |
| * Note: Every object which is parallelized by padata_do_parallel |
| * must be seen by padata_do_serial. |
| */ |
| int padata_do_parallel(struct padata_shell *ps, |
| struct padata_priv *padata, int *cb_cpu) |
| { |
| struct padata_instance *pinst = ps->pinst; |
| int i, cpu, cpu_index, target_cpu, err; |
| struct padata_parallel_queue *queue; |
| struct parallel_data *pd; |
| |
| rcu_read_lock_bh(); |
| |
| pd = rcu_dereference_bh(ps->pd); |
| |
| err = -EINVAL; |
| if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID) |
| goto out; |
| |
| if (!cpumask_test_cpu(*cb_cpu, pd->cpumask.cbcpu)) { |
| if (!cpumask_weight(pd->cpumask.cbcpu)) |
| goto out; |
| |
| /* Select an alternate fallback CPU and notify the caller. */ |
| cpu_index = *cb_cpu % cpumask_weight(pd->cpumask.cbcpu); |
| |
| cpu = cpumask_first(pd->cpumask.cbcpu); |
| for (i = 0; i < cpu_index; i++) |
| cpu = cpumask_next(cpu, pd->cpumask.cbcpu); |
| |
| *cb_cpu = cpu; |
| } |
| |
| err = -EBUSY; |
| if ((pinst->flags & PADATA_RESET)) |
| goto out; |
| |
| if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM) |
| goto out; |
| |
| err = 0; |
| atomic_inc(&pd->refcnt); |
| padata->pd = pd; |
| padata->cb_cpu = *cb_cpu; |
| |
| padata->seq_nr = atomic_inc_return(&pd->seq_nr); |
| target_cpu = padata_cpu_hash(pd, padata->seq_nr); |
| padata->cpu = target_cpu; |
| queue = per_cpu_ptr(pd->pqueue, target_cpu); |
| |
| spin_lock(&queue->parallel.lock); |
| list_add_tail(&padata->list, &queue->parallel.list); |
| spin_unlock(&queue->parallel.lock); |
| |
| queue_work(pinst->parallel_wq, &queue->work); |
| |
| out: |
| rcu_read_unlock_bh(); |
| |
| return err; |
| } |
| EXPORT_SYMBOL(padata_do_parallel); |
| |
| /* |
| * padata_find_next - Find the next object that needs serialization. |
| * |
| * Return values are: |
| * |
| * A pointer to the control struct of the next object that needs |
| * serialization, if present in one of the percpu reorder queues. |
| * |
| * NULL, if the next object that needs serialization will |
| * be parallel processed by another cpu and is not yet present in |
| * the cpu's reorder queue. |
| */ |
| static struct padata_priv *padata_find_next(struct parallel_data *pd, |
| bool remove_object) |
| { |
| struct padata_parallel_queue *next_queue; |
| struct padata_priv *padata; |
| struct padata_list *reorder; |
| int cpu = pd->cpu; |
| |
| next_queue = per_cpu_ptr(pd->pqueue, cpu); |
| reorder = &next_queue->reorder; |
| |
| spin_lock(&reorder->lock); |
| if (list_empty(&reorder->list)) { |
| spin_unlock(&reorder->lock); |
| return NULL; |
| } |
| |
| padata = list_entry(reorder->list.next, struct padata_priv, list); |
| |
| /* |
| * Checks the rare case where two or more parallel jobs have hashed to |
| * the same CPU and one of the later ones finishes first. |
| */ |
| if (padata->seq_nr != pd->processed) { |
| spin_unlock(&reorder->lock); |
| return NULL; |
| } |
| |
| if (remove_object) { |
| list_del_init(&padata->list); |
| atomic_dec(&pd->reorder_objects); |
| ++pd->processed; |
| pd->cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu, -1, false); |
| } |
| |
| spin_unlock(&reorder->lock); |
| return padata; |
| } |
| |
| static void padata_reorder(struct parallel_data *pd) |
| { |
| struct padata_instance *pinst = pd->ps->pinst; |
| int cb_cpu; |
| struct padata_priv *padata; |
| struct padata_serial_queue *squeue; |
| struct padata_parallel_queue *next_queue; |
| |
| /* |
| * We need to ensure that only one cpu can work on dequeueing of |
| * the reorder queue the time. Calculating in which percpu reorder |
| * queue the next object will arrive takes some time. A spinlock |
| * would be highly contended. Also it is not clear in which order |
| * the objects arrive to the reorder queues. So a cpu could wait to |
| * get the lock just to notice that there is nothing to do at the |
| * moment. Therefore we use a trylock and let the holder of the lock |
| * care for all the objects enqueued during the holdtime of the lock. |
| */ |
| if (!spin_trylock_bh(&pd->lock)) |
| return; |
| |
| while (1) { |
| padata = padata_find_next(pd, true); |
| |
| /* |
| * If the next object that needs serialization is parallel |
| * processed by another cpu and is still on it's way to the |
| * cpu's reorder queue, nothing to do for now. |
| */ |
| if (!padata) |
| break; |
| |
| cb_cpu = padata->cb_cpu; |
| squeue = per_cpu_ptr(pd->squeue, cb_cpu); |
| |
| spin_lock(&squeue->serial.lock); |
| list_add_tail(&padata->list, &squeue->serial.list); |
| spin_unlock(&squeue->serial.lock); |
| |
| queue_work_on(cb_cpu, pinst->serial_wq, &squeue->work); |
| } |
| |
| spin_unlock_bh(&pd->lock); |
| |
| /* |
| * The next object that needs serialization might have arrived to |
| * the reorder queues in the meantime. |
| * |
| * Ensure reorder queue is read after pd->lock is dropped so we see |
| * new objects from another task in padata_do_serial. Pairs with |
| * smp_mb__after_atomic in padata_do_serial. |
| */ |
| smp_mb(); |
| |
| next_queue = per_cpu_ptr(pd->pqueue, pd->cpu); |
| if (!list_empty(&next_queue->reorder.list) && |
| padata_find_next(pd, false)) |
| queue_work(pinst->serial_wq, &pd->reorder_work); |
| } |
| |
| static void invoke_padata_reorder(struct work_struct *work) |
| { |
| struct parallel_data *pd; |
| |
| local_bh_disable(); |
| pd = container_of(work, struct parallel_data, reorder_work); |
| padata_reorder(pd); |
| local_bh_enable(); |
| } |
| |
| static void padata_serial_worker(struct work_struct *serial_work) |
| { |
| struct padata_serial_queue *squeue; |
| struct parallel_data *pd; |
| LIST_HEAD(local_list); |
| int cnt; |
| |
| local_bh_disable(); |
| squeue = container_of(serial_work, struct padata_serial_queue, work); |
| pd = squeue->pd; |
| |
| spin_lock(&squeue->serial.lock); |
| list_replace_init(&squeue->serial.list, &local_list); |
| spin_unlock(&squeue->serial.lock); |
| |
| cnt = 0; |
| |
| while (!list_empty(&local_list)) { |
| struct padata_priv *padata; |
| |
| padata = list_entry(local_list.next, |
| struct padata_priv, list); |
| |
| list_del_init(&padata->list); |
| |
| padata->serial(padata); |
| cnt++; |
| } |
| local_bh_enable(); |
| |
| if (atomic_sub_and_test(cnt, &pd->refcnt)) |
| padata_free_pd(pd); |
| } |
| |
| /** |
| * padata_do_serial - padata serialization function |
| * |
| * @padata: object to be serialized. |
| * |
| * padata_do_serial must be called for every parallelized object. |
| * The serialization callback function will run with BHs off. |
| */ |
| void padata_do_serial(struct padata_priv *padata) |
| { |
| struct parallel_data *pd = padata->pd; |
| struct padata_parallel_queue *pqueue = per_cpu_ptr(pd->pqueue, |
| padata->cpu); |
| struct padata_priv *cur; |
| |
| spin_lock(&pqueue->reorder.lock); |
| /* Sort in ascending order of sequence number. */ |
| list_for_each_entry_reverse(cur, &pqueue->reorder.list, list) |
| if (cur->seq_nr < padata->seq_nr) |
| break; |
| list_add(&padata->list, &cur->list); |
| atomic_inc(&pd->reorder_objects); |
| spin_unlock(&pqueue->reorder.lock); |
| |
| /* |
| * Ensure the addition to the reorder list is ordered correctly |
| * with the trylock of pd->lock in padata_reorder. Pairs with smp_mb |
| * in padata_reorder. |
| */ |
| smp_mb__after_atomic(); |
| |
| padata_reorder(pd); |
| } |
| EXPORT_SYMBOL(padata_do_serial); |
| |
| static int padata_setup_cpumasks(struct padata_instance *pinst) |
| { |
| struct workqueue_attrs *attrs; |
| int err; |
| |
| attrs = alloc_workqueue_attrs(); |
| if (!attrs) |
| return -ENOMEM; |
| |
| /* Restrict parallel_wq workers to pd->cpumask.pcpu. */ |
| cpumask_copy(attrs->cpumask, pinst->cpumask.pcpu); |
| err = apply_workqueue_attrs(pinst->parallel_wq, attrs); |
| free_workqueue_attrs(attrs); |
| |
| return err; |
| } |
| |
| static int pd_setup_cpumasks(struct parallel_data *pd, |
| const struct cpumask *pcpumask, |
| const struct cpumask *cbcpumask) |
| { |
| int err = -ENOMEM; |
| |
| if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL)) |
| goto out; |
| if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL)) |
| goto free_pcpu_mask; |
| |
| cpumask_copy(pd->cpumask.pcpu, pcpumask); |
| cpumask_copy(pd->cpumask.cbcpu, cbcpumask); |
| |
| return 0; |
| |
| free_pcpu_mask: |
| free_cpumask_var(pd->cpumask.pcpu); |
| out: |
| return err; |
| } |
| |
| static void __padata_list_init(struct padata_list *pd_list) |
| { |
| INIT_LIST_HEAD(&pd_list->list); |
| spin_lock_init(&pd_list->lock); |
| } |
| |
| /* Initialize all percpu queues used by serial workers */ |
| static void padata_init_squeues(struct parallel_data *pd) |
| { |
| int cpu; |
| struct padata_serial_queue *squeue; |
| |
| for_each_cpu(cpu, pd->cpumask.cbcpu) { |
| squeue = per_cpu_ptr(pd->squeue, cpu); |
| squeue->pd = pd; |
| __padata_list_init(&squeue->serial); |
| INIT_WORK(&squeue->work, padata_serial_worker); |
| } |
| } |
| |
| /* Initialize all percpu queues used by parallel workers */ |
| static void padata_init_pqueues(struct parallel_data *pd) |
| { |
| int cpu; |
| struct padata_parallel_queue *pqueue; |
| |
| for_each_cpu(cpu, pd->cpumask.pcpu) { |
| pqueue = per_cpu_ptr(pd->pqueue, cpu); |
| |
| __padata_list_init(&pqueue->reorder); |
| __padata_list_init(&pqueue->parallel); |
| INIT_WORK(&pqueue->work, padata_parallel_worker); |
| atomic_set(&pqueue->num_obj, 0); |
| } |
| } |
| |
| /* Allocate and initialize the internal cpumask dependend resources. */ |
| static struct parallel_data *padata_alloc_pd(struct padata_shell *ps) |
| { |
| struct padata_instance *pinst = ps->pinst; |
| const struct cpumask *cbcpumask; |
| const struct cpumask *pcpumask; |
| struct parallel_data *pd; |
| |
| cbcpumask = pinst->rcpumask.cbcpu; |
| pcpumask = pinst->rcpumask.pcpu; |
| |
| pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL); |
| if (!pd) |
| goto err; |
| |
| pd->pqueue = alloc_percpu(struct padata_parallel_queue); |
| if (!pd->pqueue) |
| goto err_free_pd; |
| |
| pd->squeue = alloc_percpu(struct padata_serial_queue); |
| if (!pd->squeue) |
| goto err_free_pqueue; |
| |
| pd->ps = ps; |
| if (pd_setup_cpumasks(pd, pcpumask, cbcpumask)) |
| goto err_free_squeue; |
| |
| padata_init_pqueues(pd); |
| padata_init_squeues(pd); |
| atomic_set(&pd->seq_nr, -1); |
| atomic_set(&pd->reorder_objects, 0); |
| atomic_set(&pd->refcnt, 1); |
| spin_lock_init(&pd->lock); |
| pd->cpu = cpumask_first(pd->cpumask.pcpu); |
| INIT_WORK(&pd->reorder_work, invoke_padata_reorder); |
| |
| return pd; |
| |
| err_free_squeue: |
| free_percpu(pd->squeue); |
| err_free_pqueue: |
| free_percpu(pd->pqueue); |
| err_free_pd: |
| kfree(pd); |
| err: |
| return NULL; |
| } |
| |
| static void padata_free_pd(struct parallel_data *pd) |
| { |
| free_cpumask_var(pd->cpumask.pcpu); |
| free_cpumask_var(pd->cpumask.cbcpu); |
| free_percpu(pd->pqueue); |
| free_percpu(pd->squeue); |
| kfree(pd); |
| } |
| |
| static void __padata_start(struct padata_instance *pinst) |
| { |
| pinst->flags |= PADATA_INIT; |
| } |
| |
| static void __padata_stop(struct padata_instance *pinst) |
| { |
| if (!(pinst->flags & PADATA_INIT)) |
| return; |
| |
| pinst->flags &= ~PADATA_INIT; |
| |
| synchronize_rcu(); |
| } |
| |
| /* Replace the internal control structure with a new one. */ |
| static int padata_replace_one(struct padata_shell *ps) |
| { |
| struct parallel_data *pd_new; |
| |
| pd_new = padata_alloc_pd(ps); |
| if (!pd_new) |
| return -ENOMEM; |
| |
| ps->opd = rcu_dereference_protected(ps->pd, 1); |
| rcu_assign_pointer(ps->pd, pd_new); |
| |
| return 0; |
| } |
| |
| static int padata_replace(struct padata_instance *pinst) |
| { |
| int notification_mask = 0; |
| struct padata_shell *ps; |
| int err = 0; |
| |
| pinst->flags |= PADATA_RESET; |
| |
| cpumask_copy(pinst->omask, pinst->rcpumask.pcpu); |
| cpumask_and(pinst->rcpumask.pcpu, pinst->cpumask.pcpu, |
| cpu_online_mask); |
| if (!cpumask_equal(pinst->omask, pinst->rcpumask.pcpu)) |
| notification_mask |= PADATA_CPU_PARALLEL; |
| |
| cpumask_copy(pinst->omask, pinst->rcpumask.cbcpu); |
| cpumask_and(pinst->rcpumask.cbcpu, pinst->cpumask.cbcpu, |
| cpu_online_mask); |
| if (!cpumask_equal(pinst->omask, pinst->rcpumask.cbcpu)) |
| notification_mask |= PADATA_CPU_SERIAL; |
| |
| list_for_each_entry(ps, &pinst->pslist, list) { |
| err = padata_replace_one(ps); |
| if (err) |
| break; |
| } |
| |
| synchronize_rcu(); |
| |
| list_for_each_entry_continue_reverse(ps, &pinst->pslist, list) |
| if (atomic_dec_and_test(&ps->opd->refcnt)) |
| padata_free_pd(ps->opd); |
| |
| if (notification_mask) |
| blocking_notifier_call_chain(&pinst->cpumask_change_notifier, |
| notification_mask, |
| &pinst->cpumask); |
| |
| pinst->flags &= ~PADATA_RESET; |
| |
| return err; |
| } |
| |
| /** |
| * padata_register_cpumask_notifier - Registers a notifier that will be called |
| * if either pcpu or cbcpu or both cpumasks change. |
| * |
| * @pinst: A poineter to padata instance |
| * @nblock: A pointer to notifier block. |
| */ |
| int padata_register_cpumask_notifier(struct padata_instance *pinst, |
| struct notifier_block *nblock) |
| { |
| return blocking_notifier_chain_register(&pinst->cpumask_change_notifier, |
| nblock); |
| } |
| EXPORT_SYMBOL(padata_register_cpumask_notifier); |
| |
| /** |
| * padata_unregister_cpumask_notifier - Unregisters cpumask notifier |
| * registered earlier using padata_register_cpumask_notifier |
| * |
| * @pinst: A pointer to data instance. |
| * @nlock: A pointer to notifier block. |
| */ |
| int padata_unregister_cpumask_notifier(struct padata_instance *pinst, |
| struct notifier_block *nblock) |
| { |
| return blocking_notifier_chain_unregister( |
| &pinst->cpumask_change_notifier, |
| nblock); |
| } |
| EXPORT_SYMBOL(padata_unregister_cpumask_notifier); |
| |
| |
| /* If cpumask contains no active cpu, we mark the instance as invalid. */ |
| static bool padata_validate_cpumask(struct padata_instance *pinst, |
| const struct cpumask *cpumask) |
| { |
| if (!cpumask_intersects(cpumask, cpu_online_mask)) { |
| pinst->flags |= PADATA_INVALID; |
| return false; |
| } |
| |
| pinst->flags &= ~PADATA_INVALID; |
| return true; |
| } |
| |
| static int __padata_set_cpumasks(struct padata_instance *pinst, |
| cpumask_var_t pcpumask, |
| cpumask_var_t cbcpumask) |
| { |
| int valid; |
| int err; |
| |
| valid = padata_validate_cpumask(pinst, pcpumask); |
| if (!valid) { |
| __padata_stop(pinst); |
| goto out_replace; |
| } |
| |
| valid = padata_validate_cpumask(pinst, cbcpumask); |
| if (!valid) |
| __padata_stop(pinst); |
| |
| out_replace: |
| cpumask_copy(pinst->cpumask.pcpu, pcpumask); |
| cpumask_copy(pinst->cpumask.cbcpu, cbcpumask); |
| |
| err = padata_setup_cpumasks(pinst) ?: padata_replace(pinst); |
| |
| if (valid) |
| __padata_start(pinst); |
| |
| return err; |
| } |
| |
| /** |
| * padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value |
| * equivalent to @cpumask. |
| * |
| * @pinst: padata instance |
| * @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding |
| * to parallel and serial cpumasks respectively. |
| * @cpumask: the cpumask to use |
| */ |
| int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, |
| cpumask_var_t cpumask) |
| { |
| struct cpumask *serial_mask, *parallel_mask; |
| int err = -EINVAL; |
| |
| get_online_cpus(); |
| mutex_lock(&pinst->lock); |
| |
| switch (cpumask_type) { |
| case PADATA_CPU_PARALLEL: |
| serial_mask = pinst->cpumask.cbcpu; |
| parallel_mask = cpumask; |
| break; |
| case PADATA_CPU_SERIAL: |
| parallel_mask = pinst->cpumask.pcpu; |
| serial_mask = cpumask; |
| break; |
| default: |
| goto out; |
| } |
| |
| err = __padata_set_cpumasks(pinst, parallel_mask, serial_mask); |
| |
| out: |
| mutex_unlock(&pinst->lock); |
| put_online_cpus(); |
| |
| return err; |
| } |
| EXPORT_SYMBOL(padata_set_cpumask); |
| |
| /** |
| * padata_start - start the parallel processing |
| * |
| * @pinst: padata instance to start |
| */ |
| int padata_start(struct padata_instance *pinst) |
| { |
| int err = 0; |
| |
| mutex_lock(&pinst->lock); |
| |
| if (pinst->flags & PADATA_INVALID) |
| err = -EINVAL; |
| |
| __padata_start(pinst); |
| |
| mutex_unlock(&pinst->lock); |
| |
| return err; |
| } |
| EXPORT_SYMBOL(padata_start); |
| |
| /** |
| * padata_stop - stop the parallel processing |
| * |
| * @pinst: padata instance to stop |
| */ |
| void padata_stop(struct padata_instance *pinst) |
| { |
| mutex_lock(&pinst->lock); |
| __padata_stop(pinst); |
| mutex_unlock(&pinst->lock); |
| } |
| EXPORT_SYMBOL(padata_stop); |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| |
| static int __padata_add_cpu(struct padata_instance *pinst, int cpu) |
| { |
| int err = 0; |
| |
| if (cpumask_test_cpu(cpu, cpu_online_mask)) { |
| err = padata_replace(pinst); |
| |
| if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) && |
| padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) |
| __padata_start(pinst); |
| } |
| |
| return err; |
| } |
| |
| static int __padata_remove_cpu(struct padata_instance *pinst, int cpu) |
| { |
| int err = 0; |
| |
| if (!cpumask_test_cpu(cpu, cpu_online_mask)) { |
| if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) || |
| !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) |
| __padata_stop(pinst); |
| |
| err = padata_replace(pinst); |
| } |
| |
| return err; |
| } |
| |
| /** |
| * padata_remove_cpu - remove a cpu from the one or both(serial and parallel) |
| * padata cpumasks. |
| * |
| * @pinst: padata instance |
| * @cpu: cpu to remove |
| * @mask: bitmask specifying from which cpumask @cpu should be removed |
| * The @mask may be any combination of the following flags: |
| * PADATA_CPU_SERIAL - serial cpumask |
| * PADATA_CPU_PARALLEL - parallel cpumask |
| */ |
| int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask) |
| { |
| int err; |
| |
| if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL))) |
| return -EINVAL; |
| |
| mutex_lock(&pinst->lock); |
| |
| get_online_cpus(); |
| if (mask & PADATA_CPU_SERIAL) |
| cpumask_clear_cpu(cpu, pinst->cpumask.cbcpu); |
| if (mask & PADATA_CPU_PARALLEL) |
| cpumask_clear_cpu(cpu, pinst->cpumask.pcpu); |
| |
| err = __padata_remove_cpu(pinst, cpu); |
| put_online_cpus(); |
| |
| mutex_unlock(&pinst->lock); |
| |
| return err; |
| } |
| EXPORT_SYMBOL(padata_remove_cpu); |
| |
| static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu) |
| { |
| return cpumask_test_cpu(cpu, pinst->cpumask.pcpu) || |
| cpumask_test_cpu(cpu, pinst->cpumask.cbcpu); |
| } |
| |
| static int padata_cpu_online(unsigned int cpu, struct hlist_node *node) |
| { |
| struct padata_instance *pinst; |
| int ret; |
| |
| pinst = hlist_entry_safe(node, struct padata_instance, cpu_online_node); |
| if (!pinst_has_cpu(pinst, cpu)) |
| return 0; |
| |
| mutex_lock(&pinst->lock); |
| ret = __padata_add_cpu(pinst, cpu); |
| mutex_unlock(&pinst->lock); |
| return ret; |
| } |
| |
| static int padata_cpu_dead(unsigned int cpu, struct hlist_node *node) |
| { |
| struct padata_instance *pinst; |
| int ret; |
| |
| pinst = hlist_entry_safe(node, struct padata_instance, cpu_dead_node); |
| if (!pinst_has_cpu(pinst, cpu)) |
| return 0; |
| |
| mutex_lock(&pinst->lock); |
| ret = __padata_remove_cpu(pinst, cpu); |
| mutex_unlock(&pinst->lock); |
| return ret; |
| } |
| |
| static enum cpuhp_state hp_online; |
| #endif |
| |
| static void __padata_free(struct padata_instance *pinst) |
| { |
| #ifdef CONFIG_HOTPLUG_CPU |
| cpuhp_state_remove_instance_nocalls(CPUHP_PADATA_DEAD, |
| &pinst->cpu_dead_node); |
| cpuhp_state_remove_instance_nocalls(hp_online, &pinst->cpu_online_node); |
| #endif |
| |
| WARN_ON(!list_empty(&pinst->pslist)); |
| |
| padata_stop(pinst); |
| free_cpumask_var(pinst->omask); |
| free_cpumask_var(pinst->rcpumask.cbcpu); |
| free_cpumask_var(pinst->rcpumask.pcpu); |
| free_cpumask_var(pinst->cpumask.pcpu); |
| free_cpumask_var(pinst->cpumask.cbcpu); |
| destroy_workqueue(pinst->serial_wq); |
| destroy_workqueue(pinst->parallel_wq); |
| kfree(pinst); |
| } |
| |
| #define kobj2pinst(_kobj) \ |
| container_of(_kobj, struct padata_instance, kobj) |
| #define attr2pentry(_attr) \ |
| container_of(_attr, struct padata_sysfs_entry, attr) |
| |
| static void padata_sysfs_release(struct kobject *kobj) |
| { |
| struct padata_instance *pinst = kobj2pinst(kobj); |
| __padata_free(pinst); |
| } |
| |
| struct padata_sysfs_entry { |
| struct attribute attr; |
| ssize_t (*show)(struct padata_instance *, struct attribute *, char *); |
| ssize_t (*store)(struct padata_instance *, struct attribute *, |
| const char *, size_t); |
| }; |
| |
| static ssize_t show_cpumask(struct padata_instance *pinst, |
| struct attribute *attr, char *buf) |
| { |
| struct cpumask *cpumask; |
| ssize_t len; |
| |
| mutex_lock(&pinst->lock); |
| if (!strcmp(attr->name, "serial_cpumask")) |
| cpumask = pinst->cpumask.cbcpu; |
| else |
| cpumask = pinst->cpumask.pcpu; |
| |
| len = snprintf(buf, PAGE_SIZE, "%*pb\n", |
| nr_cpu_ids, cpumask_bits(cpumask)); |
| mutex_unlock(&pinst->lock); |
| return len < PAGE_SIZE ? len : -EINVAL; |
| } |
| |
| static ssize_t store_cpumask(struct padata_instance *pinst, |
| struct attribute *attr, |
| const char *buf, size_t count) |
| { |
| cpumask_var_t new_cpumask; |
| ssize_t ret; |
| int mask_type; |
| |
| if (!alloc_cpumask_var(&new_cpumask, GFP_KERNEL)) |
| return -ENOMEM; |
| |
| ret = bitmap_parse(buf, count, cpumask_bits(new_cpumask), |
| nr_cpumask_bits); |
| if (ret < 0) |
| goto out; |
| |
| mask_type = !strcmp(attr->name, "serial_cpumask") ? |
| PADATA_CPU_SERIAL : PADATA_CPU_PARALLEL; |
| ret = padata_set_cpumask(pinst, mask_type, new_cpumask); |
| if (!ret) |
| ret = count; |
| |
| out: |
| free_cpumask_var(new_cpumask); |
| return ret; |
| } |
| |
| #define PADATA_ATTR_RW(_name, _show_name, _store_name) \ |
| static struct padata_sysfs_entry _name##_attr = \ |
| __ATTR(_name, 0644, _show_name, _store_name) |
| #define PADATA_ATTR_RO(_name, _show_name) \ |
| static struct padata_sysfs_entry _name##_attr = \ |
| __ATTR(_name, 0400, _show_name, NULL) |
| |
| PADATA_ATTR_RW(serial_cpumask, show_cpumask, store_cpumask); |
| PADATA_ATTR_RW(parallel_cpumask, show_cpumask, store_cpumask); |
| |
| /* |
| * Padata sysfs provides the following objects: |
| * serial_cpumask [RW] - cpumask for serial workers |
| * parallel_cpumask [RW] - cpumask for parallel workers |
| */ |
| static struct attribute *padata_default_attrs[] = { |
| &serial_cpumask_attr.attr, |
| ¶llel_cpumask_attr.attr, |
| NULL, |
| }; |
| ATTRIBUTE_GROUPS(padata_default); |
| |
| static ssize_t padata_sysfs_show(struct kobject *kobj, |
| struct attribute *attr, char *buf) |
| { |
| struct padata_instance *pinst; |
| struct padata_sysfs_entry *pentry; |
| ssize_t ret = -EIO; |
| |
| pinst = kobj2pinst(kobj); |
| pentry = attr2pentry(attr); |
| if (pentry->show) |
| ret = pentry->show(pinst, attr, buf); |
| |
| return ret; |
| } |
| |
| static ssize_t padata_sysfs_store(struct kobject *kobj, struct attribute *attr, |
| const char *buf, size_t count) |
| { |
| struct padata_instance *pinst; |
| struct padata_sysfs_entry *pentry; |
| ssize_t ret = -EIO; |
| |
| pinst = kobj2pinst(kobj); |
| pentry = attr2pentry(attr); |
| if (pentry->show) |
| ret = pentry->store(pinst, attr, buf, count); |
| |
| return ret; |
| } |
| |
| static const struct sysfs_ops padata_sysfs_ops = { |
| .show = padata_sysfs_show, |
| .store = padata_sysfs_store, |
| }; |
| |
| static struct kobj_type padata_attr_type = { |
| .sysfs_ops = &padata_sysfs_ops, |
| .default_groups = padata_default_groups, |
| .release = padata_sysfs_release, |
| }; |
| |
| /** |
| * padata_alloc - allocate and initialize a padata instance and specify |
| * cpumasks for serial and parallel workers. |
| * |
| * @name: used to identify the instance |
| * @pcpumask: cpumask that will be used for padata parallelization |
| * @cbcpumask: cpumask that will be used for padata serialization |
| */ |
| static struct padata_instance *padata_alloc(const char *name, |
| const struct cpumask *pcpumask, |
| const struct cpumask *cbcpumask) |
| { |
| struct padata_instance *pinst; |
| |
| pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL); |
| if (!pinst) |
| goto err; |
| |
| pinst->parallel_wq = alloc_workqueue("%s_parallel", WQ_UNBOUND, 0, |
| name); |
| if (!pinst->parallel_wq) |
| goto err_free_inst; |
| |
| get_online_cpus(); |
| |
| pinst->serial_wq = alloc_workqueue("%s_serial", WQ_MEM_RECLAIM | |
| WQ_CPU_INTENSIVE, 1, name); |
| if (!pinst->serial_wq) |
| goto err_put_cpus; |
| |
| if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL)) |
| goto err_free_serial_wq; |
| if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) { |
| free_cpumask_var(pinst->cpumask.pcpu); |
| goto err_free_serial_wq; |
| } |
| if (!padata_validate_cpumask(pinst, pcpumask) || |
| !padata_validate_cpumask(pinst, cbcpumask)) |
| goto err_free_masks; |
| |
| if (!alloc_cpumask_var(&pinst->rcpumask.pcpu, GFP_KERNEL)) |
| goto err_free_masks; |
| if (!alloc_cpumask_var(&pinst->rcpumask.cbcpu, GFP_KERNEL)) |
| goto err_free_rcpumask_pcpu; |
| if (!alloc_cpumask_var(&pinst->omask, GFP_KERNEL)) |
| goto err_free_rcpumask_cbcpu; |
| |
| INIT_LIST_HEAD(&pinst->pslist); |
| |
| cpumask_copy(pinst->cpumask.pcpu, pcpumask); |
| cpumask_copy(pinst->cpumask.cbcpu, cbcpumask); |
| cpumask_and(pinst->rcpumask.pcpu, pcpumask, cpu_online_mask); |
| cpumask_and(pinst->rcpumask.cbcpu, cbcpumask, cpu_online_mask); |
| |
| if (padata_setup_cpumasks(pinst)) |
| goto err_free_omask; |
| |
| pinst->flags = 0; |
| |
| BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier); |
| kobject_init(&pinst->kobj, &padata_attr_type); |
| mutex_init(&pinst->lock); |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| cpuhp_state_add_instance_nocalls_cpuslocked(hp_online, |
| &pinst->cpu_online_node); |
| cpuhp_state_add_instance_nocalls_cpuslocked(CPUHP_PADATA_DEAD, |
| &pinst->cpu_dead_node); |
| #endif |
| |
| put_online_cpus(); |
| |
| return pinst; |
| |
| err_free_omask: |
| free_cpumask_var(pinst->omask); |
| err_free_rcpumask_cbcpu: |
| free_cpumask_var(pinst->rcpumask.cbcpu); |
| err_free_rcpumask_pcpu: |
| free_cpumask_var(pinst->rcpumask.pcpu); |
| err_free_masks: |
| free_cpumask_var(pinst->cpumask.pcpu); |
| free_cpumask_var(pinst->cpumask.cbcpu); |
| err_free_serial_wq: |
| destroy_workqueue(pinst->serial_wq); |
| err_put_cpus: |
| put_online_cpus(); |
| destroy_workqueue(pinst->parallel_wq); |
| err_free_inst: |
| kfree(pinst); |
| err: |
| return NULL; |
| } |
| |
| /** |
| * padata_alloc_possible - Allocate and initialize padata instance. |
| * Use the cpu_possible_mask for serial and |
| * parallel workers. |
| * |
| * @name: used to identify the instance |
| */ |
| struct padata_instance *padata_alloc_possible(const char *name) |
| { |
| return padata_alloc(name, cpu_possible_mask, cpu_possible_mask); |
| } |
| EXPORT_SYMBOL(padata_alloc_possible); |
| |
| /** |
| * padata_free - free a padata instance |
| * |
| * @padata_inst: padata instance to free |
| */ |
| void padata_free(struct padata_instance *pinst) |
| { |
| kobject_put(&pinst->kobj); |
| } |
| EXPORT_SYMBOL(padata_free); |
| |
| /** |
| * padata_alloc_shell - Allocate and initialize padata shell. |
| * |
| * @pinst: Parent padata_instance object. |
| */ |
| struct padata_shell *padata_alloc_shell(struct padata_instance *pinst) |
| { |
| struct parallel_data *pd; |
| struct padata_shell *ps; |
| |
| ps = kzalloc(sizeof(*ps), GFP_KERNEL); |
| if (!ps) |
| goto out; |
| |
| ps->pinst = pinst; |
| |
| get_online_cpus(); |
| pd = padata_alloc_pd(ps); |
| put_online_cpus(); |
| |
| if (!pd) |
| goto out_free_ps; |
| |
| mutex_lock(&pinst->lock); |
| RCU_INIT_POINTER(ps->pd, pd); |
| list_add(&ps->list, &pinst->pslist); |
| mutex_unlock(&pinst->lock); |
| |
| return ps; |
| |
| out_free_ps: |
| kfree(ps); |
| out: |
| return NULL; |
| } |
| EXPORT_SYMBOL(padata_alloc_shell); |
| |
| /** |
| * padata_free_shell - free a padata shell |
| * |
| * @ps: padata shell to free |
| */ |
| void padata_free_shell(struct padata_shell *ps) |
| { |
| struct padata_instance *pinst = ps->pinst; |
| |
| mutex_lock(&pinst->lock); |
| list_del(&ps->list); |
| padata_free_pd(rcu_dereference_protected(ps->pd, 1)); |
| mutex_unlock(&pinst->lock); |
| |
| kfree(ps); |
| } |
| EXPORT_SYMBOL(padata_free_shell); |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| |
| static __init int padata_driver_init(void) |
| { |
| int ret; |
| |
| ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "padata:online", |
| padata_cpu_online, NULL); |
| if (ret < 0) |
| return ret; |
| hp_online = ret; |
| |
| ret = cpuhp_setup_state_multi(CPUHP_PADATA_DEAD, "padata:dead", |
| NULL, padata_cpu_dead); |
| if (ret < 0) { |
| cpuhp_remove_multi_state(hp_online); |
| return ret; |
| } |
| return 0; |
| } |
| module_init(padata_driver_init); |
| |
| static __exit void padata_driver_exit(void) |
| { |
| cpuhp_remove_multi_state(CPUHP_PADATA_DEAD); |
| cpuhp_remove_multi_state(hp_online); |
| } |
| module_exit(padata_driver_exit); |
| #endif |