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![Shan Wei](/assets/img/avatar_default.png)
For bottom halves off, __this_cpu_read is better. Signed-off-by: Shan Wei <davidshan@tencent.com> Reviewed-by: Christoph Lameter <cl@linux.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
1123 lines
27 KiB
C
1123 lines
27 KiB
C
/*
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* padata.c - generic interface to process data streams in parallel
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*
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* See Documentation/padata.txt for an api documentation.
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*
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* Copyright (C) 2008, 2009 secunet Security Networks AG
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* Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include <linux/export.h>
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#include <linux/cpumask.h>
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#include <linux/err.h>
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#include <linux/cpu.h>
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#include <linux/padata.h>
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#include <linux/mutex.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/sysfs.h>
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#include <linux/rcupdate.h>
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#define MAX_OBJ_NUM 1000
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static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index)
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{
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int cpu, target_cpu;
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target_cpu = cpumask_first(pd->cpumask.pcpu);
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for (cpu = 0; cpu < cpu_index; cpu++)
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target_cpu = cpumask_next(target_cpu, pd->cpumask.pcpu);
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return target_cpu;
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}
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static int padata_cpu_hash(struct parallel_data *pd)
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{
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int cpu_index;
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/*
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* Hash the sequence numbers to the cpus by taking
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* seq_nr mod. number of cpus in use.
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*/
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spin_lock(&pd->seq_lock);
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cpu_index = pd->seq_nr % cpumask_weight(pd->cpumask.pcpu);
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pd->seq_nr++;
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spin_unlock(&pd->seq_lock);
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return padata_index_to_cpu(pd, cpu_index);
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}
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static void padata_parallel_worker(struct work_struct *parallel_work)
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{
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struct padata_parallel_queue *pqueue;
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struct parallel_data *pd;
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struct padata_instance *pinst;
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LIST_HEAD(local_list);
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local_bh_disable();
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pqueue = container_of(parallel_work,
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struct padata_parallel_queue, work);
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pd = pqueue->pd;
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pinst = pd->pinst;
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spin_lock(&pqueue->parallel.lock);
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list_replace_init(&pqueue->parallel.list, &local_list);
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spin_unlock(&pqueue->parallel.lock);
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while (!list_empty(&local_list)) {
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struct padata_priv *padata;
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padata = list_entry(local_list.next,
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struct padata_priv, list);
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list_del_init(&padata->list);
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padata->parallel(padata);
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}
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local_bh_enable();
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}
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/**
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* padata_do_parallel - padata parallelization function
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*
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* @pinst: padata instance
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* @padata: object to be parallelized
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* @cb_cpu: cpu the serialization callback function will run on,
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* must be in the serial cpumask of padata(i.e. cpumask.cbcpu).
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*
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* The parallelization callback function will run with BHs off.
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* Note: Every object which is parallelized by padata_do_parallel
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* must be seen by padata_do_serial.
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*/
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int padata_do_parallel(struct padata_instance *pinst,
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struct padata_priv *padata, int cb_cpu)
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{
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int target_cpu, err;
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struct padata_parallel_queue *queue;
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struct parallel_data *pd;
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rcu_read_lock_bh();
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pd = rcu_dereference(pinst->pd);
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err = -EINVAL;
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if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID)
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goto out;
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if (!cpumask_test_cpu(cb_cpu, pd->cpumask.cbcpu))
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goto out;
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err = -EBUSY;
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if ((pinst->flags & PADATA_RESET))
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goto out;
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if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM)
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goto out;
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err = 0;
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atomic_inc(&pd->refcnt);
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padata->pd = pd;
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padata->cb_cpu = cb_cpu;
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target_cpu = padata_cpu_hash(pd);
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queue = per_cpu_ptr(pd->pqueue, target_cpu);
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spin_lock(&queue->parallel.lock);
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list_add_tail(&padata->list, &queue->parallel.list);
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spin_unlock(&queue->parallel.lock);
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queue_work_on(target_cpu, pinst->wq, &queue->work);
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out:
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rcu_read_unlock_bh();
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return err;
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}
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EXPORT_SYMBOL(padata_do_parallel);
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/*
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* padata_get_next - Get the next object that needs serialization.
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*
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* Return values are:
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*
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* A pointer to the control struct of the next object that needs
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* serialization, if present in one of the percpu reorder queues.
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*
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* NULL, if all percpu reorder queues are empty.
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*
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* -EINPROGRESS, if the next object that needs serialization will
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* be parallel processed by another cpu and is not yet present in
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* the cpu's reorder queue.
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*
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* -ENODATA, if this cpu has to do the parallel processing for
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* the next object.
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*/
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static struct padata_priv *padata_get_next(struct parallel_data *pd)
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{
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int cpu, num_cpus;
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unsigned int next_nr, next_index;
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struct padata_parallel_queue *next_queue;
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struct padata_priv *padata;
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struct padata_list *reorder;
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num_cpus = cpumask_weight(pd->cpumask.pcpu);
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/*
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* Calculate the percpu reorder queue and the sequence
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* number of the next object.
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*/
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next_nr = pd->processed;
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next_index = next_nr % num_cpus;
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cpu = padata_index_to_cpu(pd, next_index);
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next_queue = per_cpu_ptr(pd->pqueue, cpu);
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padata = NULL;
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reorder = &next_queue->reorder;
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if (!list_empty(&reorder->list)) {
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padata = list_entry(reorder->list.next,
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struct padata_priv, list);
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spin_lock(&reorder->lock);
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list_del_init(&padata->list);
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atomic_dec(&pd->reorder_objects);
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spin_unlock(&reorder->lock);
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pd->processed++;
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goto out;
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}
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if (__this_cpu_read(pd->pqueue->cpu_index) == next_queue->cpu_index) {
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padata = ERR_PTR(-ENODATA);
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goto out;
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}
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padata = ERR_PTR(-EINPROGRESS);
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out:
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return padata;
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}
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static void padata_reorder(struct parallel_data *pd)
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{
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int cb_cpu;
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struct padata_priv *padata;
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struct padata_serial_queue *squeue;
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struct padata_instance *pinst = pd->pinst;
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/*
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* We need to ensure that only one cpu can work on dequeueing of
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* the reorder queue the time. Calculating in which percpu reorder
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* queue the next object will arrive takes some time. A spinlock
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* would be highly contended. Also it is not clear in which order
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* the objects arrive to the reorder queues. So a cpu could wait to
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* get the lock just to notice that there is nothing to do at the
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* moment. Therefore we use a trylock and let the holder of the lock
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* care for all the objects enqueued during the holdtime of the lock.
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*/
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if (!spin_trylock_bh(&pd->lock))
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return;
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while (1) {
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padata = padata_get_next(pd);
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/*
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* All reorder queues are empty, or the next object that needs
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* serialization is parallel processed by another cpu and is
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* still on it's way to the cpu's reorder queue, nothing to
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* do for now.
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*/
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if (!padata || PTR_ERR(padata) == -EINPROGRESS)
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break;
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/*
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* This cpu has to do the parallel processing of the next
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* object. It's waiting in the cpu's parallelization queue,
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* so exit immediately.
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*/
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if (PTR_ERR(padata) == -ENODATA) {
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del_timer(&pd->timer);
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spin_unlock_bh(&pd->lock);
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return;
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}
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cb_cpu = padata->cb_cpu;
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squeue = per_cpu_ptr(pd->squeue, cb_cpu);
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spin_lock(&squeue->serial.lock);
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list_add_tail(&padata->list, &squeue->serial.list);
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spin_unlock(&squeue->serial.lock);
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queue_work_on(cb_cpu, pinst->wq, &squeue->work);
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}
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spin_unlock_bh(&pd->lock);
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/*
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* The next object that needs serialization might have arrived to
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* the reorder queues in the meantime, we will be called again
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* from the timer function if no one else cares for it.
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*/
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if (atomic_read(&pd->reorder_objects)
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&& !(pinst->flags & PADATA_RESET))
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mod_timer(&pd->timer, jiffies + HZ);
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else
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del_timer(&pd->timer);
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return;
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}
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static void padata_reorder_timer(unsigned long arg)
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{
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struct parallel_data *pd = (struct parallel_data *)arg;
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padata_reorder(pd);
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}
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static void padata_serial_worker(struct work_struct *serial_work)
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{
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struct padata_serial_queue *squeue;
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struct parallel_data *pd;
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LIST_HEAD(local_list);
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local_bh_disable();
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squeue = container_of(serial_work, struct padata_serial_queue, work);
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pd = squeue->pd;
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spin_lock(&squeue->serial.lock);
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list_replace_init(&squeue->serial.list, &local_list);
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spin_unlock(&squeue->serial.lock);
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while (!list_empty(&local_list)) {
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struct padata_priv *padata;
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padata = list_entry(local_list.next,
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struct padata_priv, list);
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list_del_init(&padata->list);
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padata->serial(padata);
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atomic_dec(&pd->refcnt);
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}
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local_bh_enable();
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}
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/**
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* padata_do_serial - padata serialization function
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*
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* @padata: object to be serialized.
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*
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* padata_do_serial must be called for every parallelized object.
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* The serialization callback function will run with BHs off.
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*/
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void padata_do_serial(struct padata_priv *padata)
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{
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int cpu;
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struct padata_parallel_queue *pqueue;
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struct parallel_data *pd;
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pd = padata->pd;
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cpu = get_cpu();
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pqueue = per_cpu_ptr(pd->pqueue, cpu);
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spin_lock(&pqueue->reorder.lock);
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atomic_inc(&pd->reorder_objects);
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list_add_tail(&padata->list, &pqueue->reorder.list);
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spin_unlock(&pqueue->reorder.lock);
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put_cpu();
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padata_reorder(pd);
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}
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EXPORT_SYMBOL(padata_do_serial);
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static int padata_setup_cpumasks(struct parallel_data *pd,
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const struct cpumask *pcpumask,
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const struct cpumask *cbcpumask)
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{
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if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL))
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return -ENOMEM;
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cpumask_and(pd->cpumask.pcpu, pcpumask, cpu_online_mask);
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if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL)) {
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free_cpumask_var(pd->cpumask.cbcpu);
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return -ENOMEM;
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}
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cpumask_and(pd->cpumask.cbcpu, cbcpumask, cpu_online_mask);
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return 0;
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}
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static void __padata_list_init(struct padata_list *pd_list)
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{
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INIT_LIST_HEAD(&pd_list->list);
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spin_lock_init(&pd_list->lock);
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}
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/* Initialize all percpu queues used by serial workers */
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static void padata_init_squeues(struct parallel_data *pd)
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{
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int cpu;
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struct padata_serial_queue *squeue;
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for_each_cpu(cpu, pd->cpumask.cbcpu) {
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squeue = per_cpu_ptr(pd->squeue, cpu);
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squeue->pd = pd;
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__padata_list_init(&squeue->serial);
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INIT_WORK(&squeue->work, padata_serial_worker);
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}
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}
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/* Initialize all percpu queues used by parallel workers */
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static void padata_init_pqueues(struct parallel_data *pd)
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{
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int cpu_index, cpu;
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struct padata_parallel_queue *pqueue;
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cpu_index = 0;
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for_each_cpu(cpu, pd->cpumask.pcpu) {
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pqueue = per_cpu_ptr(pd->pqueue, cpu);
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pqueue->pd = pd;
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pqueue->cpu_index = cpu_index;
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cpu_index++;
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__padata_list_init(&pqueue->reorder);
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__padata_list_init(&pqueue->parallel);
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INIT_WORK(&pqueue->work, padata_parallel_worker);
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atomic_set(&pqueue->num_obj, 0);
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}
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}
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/* Allocate and initialize the internal cpumask dependend resources. */
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static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst,
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const struct cpumask *pcpumask,
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const struct cpumask *cbcpumask)
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{
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struct parallel_data *pd;
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pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL);
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if (!pd)
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goto err;
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pd->pqueue = alloc_percpu(struct padata_parallel_queue);
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if (!pd->pqueue)
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goto err_free_pd;
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pd->squeue = alloc_percpu(struct padata_serial_queue);
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if (!pd->squeue)
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goto err_free_pqueue;
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if (padata_setup_cpumasks(pd, pcpumask, cbcpumask) < 0)
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goto err_free_squeue;
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padata_init_pqueues(pd);
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padata_init_squeues(pd);
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setup_timer(&pd->timer, padata_reorder_timer, (unsigned long)pd);
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pd->seq_nr = 0;
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atomic_set(&pd->reorder_objects, 0);
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atomic_set(&pd->refcnt, 0);
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pd->pinst = pinst;
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spin_lock_init(&pd->lock);
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return pd;
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err_free_squeue:
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free_percpu(pd->squeue);
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err_free_pqueue:
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free_percpu(pd->pqueue);
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err_free_pd:
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kfree(pd);
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err:
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return NULL;
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}
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|
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static void padata_free_pd(struct parallel_data *pd)
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{
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free_cpumask_var(pd->cpumask.pcpu);
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free_cpumask_var(pd->cpumask.cbcpu);
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free_percpu(pd->pqueue);
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free_percpu(pd->squeue);
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kfree(pd);
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}
|
|
|
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/* Flush all objects out of the padata queues. */
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static void padata_flush_queues(struct parallel_data *pd)
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{
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int cpu;
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struct padata_parallel_queue *pqueue;
|
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struct padata_serial_queue *squeue;
|
|
|
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for_each_cpu(cpu, pd->cpumask.pcpu) {
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pqueue = per_cpu_ptr(pd->pqueue, cpu);
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flush_work(&pqueue->work);
|
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}
|
|
|
|
del_timer_sync(&pd->timer);
|
|
|
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if (atomic_read(&pd->reorder_objects))
|
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padata_reorder(pd);
|
|
|
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for_each_cpu(cpu, pd->cpumask.cbcpu) {
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squeue = per_cpu_ptr(pd->squeue, cpu);
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flush_work(&squeue->work);
|
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}
|
|
|
|
BUG_ON(atomic_read(&pd->refcnt) != 0);
|
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}
|
|
|
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static void __padata_start(struct padata_instance *pinst)
|
|
{
|
|
pinst->flags |= PADATA_INIT;
|
|
}
|
|
|
|
static void __padata_stop(struct padata_instance *pinst)
|
|
{
|
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if (!(pinst->flags & PADATA_INIT))
|
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return;
|
|
|
|
pinst->flags &= ~PADATA_INIT;
|
|
|
|
synchronize_rcu();
|
|
|
|
get_online_cpus();
|
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padata_flush_queues(pinst->pd);
|
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put_online_cpus();
|
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}
|
|
|
|
/* Replace the internal control structure with a new one. */
|
|
static void padata_replace(struct padata_instance *pinst,
|
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struct parallel_data *pd_new)
|
|
{
|
|
struct parallel_data *pd_old = pinst->pd;
|
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int notification_mask = 0;
|
|
|
|
pinst->flags |= PADATA_RESET;
|
|
|
|
rcu_assign_pointer(pinst->pd, pd_new);
|
|
|
|
synchronize_rcu();
|
|
|
|
if (!cpumask_equal(pd_old->cpumask.pcpu, pd_new->cpumask.pcpu))
|
|
notification_mask |= PADATA_CPU_PARALLEL;
|
|
if (!cpumask_equal(pd_old->cpumask.cbcpu, pd_new->cpumask.cbcpu))
|
|
notification_mask |= PADATA_CPU_SERIAL;
|
|
|
|
padata_flush_queues(pd_old);
|
|
padata_free_pd(pd_old);
|
|
|
|
if (notification_mask)
|
|
blocking_notifier_call_chain(&pinst->cpumask_change_notifier,
|
|
notification_mask,
|
|
&pd_new->cpumask);
|
|
|
|
pinst->flags &= ~PADATA_RESET;
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
struct parallel_data *pd;
|
|
|
|
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:
|
|
pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
|
|
if (!pd)
|
|
return -ENOMEM;
|
|
|
|
cpumask_copy(pinst->cpumask.pcpu, pcpumask);
|
|
cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
|
|
|
|
padata_replace(pinst, pd);
|
|
|
|
if (valid)
|
|
__padata_start(pinst);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* padata_set_cpumasks - Set both parallel and serial cpumasks. The first
|
|
* one is used by parallel workers and the second one
|
|
* by the wokers doing serialization.
|
|
*
|
|
* @pinst: padata instance
|
|
* @pcpumask: the cpumask to use for parallel workers
|
|
* @cbcpumask: the cpumsak to use for serial workers
|
|
*/
|
|
int padata_set_cpumasks(struct padata_instance *pinst, cpumask_var_t pcpumask,
|
|
cpumask_var_t cbcpumask)
|
|
{
|
|
int err;
|
|
|
|
mutex_lock(&pinst->lock);
|
|
get_online_cpus();
|
|
|
|
err = __padata_set_cpumasks(pinst, pcpumask, cbcpumask);
|
|
|
|
put_online_cpus();
|
|
mutex_unlock(&pinst->lock);
|
|
|
|
return err;
|
|
|
|
}
|
|
EXPORT_SYMBOL(padata_set_cpumasks);
|
|
|
|
/**
|
|
* 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;
|
|
|
|
mutex_lock(&pinst->lock);
|
|
get_online_cpus();
|
|
|
|
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:
|
|
put_online_cpus();
|
|
mutex_unlock(&pinst->lock);
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(padata_set_cpumask);
|
|
|
|
static int __padata_add_cpu(struct padata_instance *pinst, int cpu)
|
|
{
|
|
struct parallel_data *pd;
|
|
|
|
if (cpumask_test_cpu(cpu, cpu_online_mask)) {
|
|
pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
|
|
pinst->cpumask.cbcpu);
|
|
if (!pd)
|
|
return -ENOMEM;
|
|
|
|
padata_replace(pinst, pd);
|
|
|
|
if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) &&
|
|
padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
|
|
__padata_start(pinst);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* padata_add_cpu - add a cpu to one or both(parallel and serial)
|
|
* padata cpumasks.
|
|
*
|
|
* @pinst: padata instance
|
|
* @cpu: cpu to add
|
|
* @mask: bitmask of flags specifying to which cpumask @cpu shuld be added.
|
|
* The @mask may be any combination of the following flags:
|
|
* PADATA_CPU_SERIAL - serial cpumask
|
|
* PADATA_CPU_PARALLEL - parallel cpumask
|
|
*/
|
|
|
|
int padata_add_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_set_cpu(cpu, pinst->cpumask.cbcpu);
|
|
if (mask & PADATA_CPU_PARALLEL)
|
|
cpumask_set_cpu(cpu, pinst->cpumask.pcpu);
|
|
|
|
err = __padata_add_cpu(pinst, cpu);
|
|
put_online_cpus();
|
|
|
|
mutex_unlock(&pinst->lock);
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(padata_add_cpu);
|
|
|
|
static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
|
|
{
|
|
struct parallel_data *pd = NULL;
|
|
|
|
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);
|
|
|
|
pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
|
|
pinst->cpumask.cbcpu);
|
|
if (!pd)
|
|
return -ENOMEM;
|
|
|
|
padata_replace(pinst, pd);
|
|
|
|
cpumask_clear_cpu(cpu, pd->cpumask.cbcpu);
|
|
cpumask_clear_cpu(cpu, pd->cpumask.pcpu);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
|
|
/**
|
|
* 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 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_callback(struct notifier_block *nfb,
|
|
unsigned long action, void *hcpu)
|
|
{
|
|
int err;
|
|
struct padata_instance *pinst;
|
|
int cpu = (unsigned long)hcpu;
|
|
|
|
pinst = container_of(nfb, struct padata_instance, cpu_notifier);
|
|
|
|
switch (action) {
|
|
case CPU_ONLINE:
|
|
case CPU_ONLINE_FROZEN:
|
|
if (!pinst_has_cpu(pinst, cpu))
|
|
break;
|
|
mutex_lock(&pinst->lock);
|
|
err = __padata_add_cpu(pinst, cpu);
|
|
mutex_unlock(&pinst->lock);
|
|
if (err)
|
|
return notifier_from_errno(err);
|
|
break;
|
|
|
|
case CPU_DOWN_PREPARE:
|
|
case CPU_DOWN_PREPARE_FROZEN:
|
|
if (!pinst_has_cpu(pinst, cpu))
|
|
break;
|
|
mutex_lock(&pinst->lock);
|
|
err = __padata_remove_cpu(pinst, cpu);
|
|
mutex_unlock(&pinst->lock);
|
|
if (err)
|
|
return notifier_from_errno(err);
|
|
break;
|
|
|
|
case CPU_UP_CANCELED:
|
|
case CPU_UP_CANCELED_FROZEN:
|
|
if (!pinst_has_cpu(pinst, cpu))
|
|
break;
|
|
mutex_lock(&pinst->lock);
|
|
__padata_remove_cpu(pinst, cpu);
|
|
mutex_unlock(&pinst->lock);
|
|
|
|
case CPU_DOWN_FAILED:
|
|
case CPU_DOWN_FAILED_FROZEN:
|
|
if (!pinst_has_cpu(pinst, cpu))
|
|
break;
|
|
mutex_lock(&pinst->lock);
|
|
__padata_add_cpu(pinst, cpu);
|
|
mutex_unlock(&pinst->lock);
|
|
}
|
|
|
|
return NOTIFY_OK;
|
|
}
|
|
#endif
|
|
|
|
static void __padata_free(struct padata_instance *pinst)
|
|
{
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
unregister_hotcpu_notifier(&pinst->cpu_notifier);
|
|
#endif
|
|
|
|
padata_stop(pinst);
|
|
padata_free_pd(pinst->pd);
|
|
free_cpumask_var(pinst->cpumask.pcpu);
|
|
free_cpumask_var(pinst->cpumask.cbcpu);
|
|
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 = bitmap_scnprintf(buf, PAGE_SIZE, cpumask_bits(cpumask),
|
|
nr_cpu_ids);
|
|
if (PAGE_SIZE - len < 2)
|
|
len = -EINVAL;
|
|
else
|
|
len += sprintf(buf + len, "\n");
|
|
|
|
mutex_unlock(&pinst->lock);
|
|
return len;
|
|
}
|
|
|
|
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,
|
|
};
|
|
|
|
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_attrs = padata_default_attrs,
|
|
.release = padata_sysfs_release,
|
|
};
|
|
|
|
/**
|
|
* padata_alloc_possible - Allocate and initialize padata instance.
|
|
* Use the cpu_possible_mask for serial and
|
|
* parallel workers.
|
|
*
|
|
* @wq: workqueue to use for the allocated padata instance
|
|
*/
|
|
struct padata_instance *padata_alloc_possible(struct workqueue_struct *wq)
|
|
{
|
|
return padata_alloc(wq, cpu_possible_mask, cpu_possible_mask);
|
|
}
|
|
EXPORT_SYMBOL(padata_alloc_possible);
|
|
|
|
/**
|
|
* padata_alloc - allocate and initialize a padata instance and specify
|
|
* cpumasks for serial and parallel workers.
|
|
*
|
|
* @wq: workqueue to use for the allocated padata instance
|
|
* @pcpumask: cpumask that will be used for padata parallelization
|
|
* @cbcpumask: cpumask that will be used for padata serialization
|
|
*/
|
|
struct padata_instance *padata_alloc(struct workqueue_struct *wq,
|
|
const struct cpumask *pcpumask,
|
|
const struct cpumask *cbcpumask)
|
|
{
|
|
struct padata_instance *pinst;
|
|
struct parallel_data *pd = NULL;
|
|
|
|
pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL);
|
|
if (!pinst)
|
|
goto err;
|
|
|
|
get_online_cpus();
|
|
if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL))
|
|
goto err_free_inst;
|
|
if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) {
|
|
free_cpumask_var(pinst->cpumask.pcpu);
|
|
goto err_free_inst;
|
|
}
|
|
if (!padata_validate_cpumask(pinst, pcpumask) ||
|
|
!padata_validate_cpumask(pinst, cbcpumask))
|
|
goto err_free_masks;
|
|
|
|
pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
|
|
if (!pd)
|
|
goto err_free_masks;
|
|
|
|
rcu_assign_pointer(pinst->pd, pd);
|
|
|
|
pinst->wq = wq;
|
|
|
|
cpumask_copy(pinst->cpumask.pcpu, pcpumask);
|
|
cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
|
|
|
|
pinst->flags = 0;
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
pinst->cpu_notifier.notifier_call = padata_cpu_callback;
|
|
pinst->cpu_notifier.priority = 0;
|
|
register_hotcpu_notifier(&pinst->cpu_notifier);
|
|
#endif
|
|
|
|
put_online_cpus();
|
|
|
|
BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier);
|
|
kobject_init(&pinst->kobj, &padata_attr_type);
|
|
mutex_init(&pinst->lock);
|
|
|
|
return pinst;
|
|
|
|
err_free_masks:
|
|
free_cpumask_var(pinst->cpumask.pcpu);
|
|
free_cpumask_var(pinst->cpumask.cbcpu);
|
|
err_free_inst:
|
|
kfree(pinst);
|
|
put_online_cpus();
|
|
err:
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(padata_alloc);
|
|
|
|
/**
|
|
* 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);
|