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1c4cafd115
padata_do_parallel() calls cpumask_weight() to check if any bit of a given cpumask is set. We can do it more efficiently with cpumask_empty() because cpumask_empty() stops traversing the cpumask as soon as it finds first set bit, while cpumask_weight() counts all bits unconditionally. Signed-off-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
1142 lines
27 KiB
C
1142 lines
27 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* padata.c - generic interface to process data streams in parallel
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*
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* See Documentation/core-api/padata.rst for more information.
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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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* Copyright (c) 2020 Oracle and/or its affiliates.
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* Author: Daniel Jordan <daniel.m.jordan@oracle.com>
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*/
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#include <linux/completion.h>
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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 PADATA_WORK_ONSTACK 1 /* Work's memory is on stack */
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struct padata_work {
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struct work_struct pw_work;
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struct list_head pw_list; /* padata_free_works linkage */
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void *pw_data;
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};
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static DEFINE_SPINLOCK(padata_works_lock);
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static struct padata_work *padata_works;
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static LIST_HEAD(padata_free_works);
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struct padata_mt_job_state {
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spinlock_t lock;
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struct completion completion;
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struct padata_mt_job *job;
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int nworks;
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int nworks_fini;
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unsigned long chunk_size;
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};
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static void padata_free_pd(struct parallel_data *pd);
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static void __init padata_mt_helper(struct work_struct *work);
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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, unsigned int seq_nr)
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{
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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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int cpu_index = seq_nr % cpumask_weight(pd->cpumask.pcpu);
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return padata_index_to_cpu(pd, cpu_index);
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}
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static struct padata_work *padata_work_alloc(void)
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{
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struct padata_work *pw;
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lockdep_assert_held(&padata_works_lock);
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if (list_empty(&padata_free_works))
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return NULL; /* No more work items allowed to be queued. */
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pw = list_first_entry(&padata_free_works, struct padata_work, pw_list);
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list_del(&pw->pw_list);
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return pw;
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}
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static void padata_work_init(struct padata_work *pw, work_func_t work_fn,
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void *data, int flags)
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{
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if (flags & PADATA_WORK_ONSTACK)
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INIT_WORK_ONSTACK(&pw->pw_work, work_fn);
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else
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INIT_WORK(&pw->pw_work, work_fn);
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pw->pw_data = data;
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}
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static int __init padata_work_alloc_mt(int nworks, void *data,
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struct list_head *head)
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{
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int i;
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spin_lock(&padata_works_lock);
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/* Start at 1 because the current task participates in the job. */
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for (i = 1; i < nworks; ++i) {
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struct padata_work *pw = padata_work_alloc();
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if (!pw)
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break;
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padata_work_init(pw, padata_mt_helper, data, 0);
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list_add(&pw->pw_list, head);
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}
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spin_unlock(&padata_works_lock);
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return i;
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}
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static void padata_work_free(struct padata_work *pw)
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{
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lockdep_assert_held(&padata_works_lock);
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list_add(&pw->pw_list, &padata_free_works);
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}
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static void __init padata_works_free(struct list_head *works)
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{
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struct padata_work *cur, *next;
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if (list_empty(works))
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return;
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spin_lock(&padata_works_lock);
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list_for_each_entry_safe(cur, next, works, pw_list) {
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list_del(&cur->pw_list);
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padata_work_free(cur);
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}
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spin_unlock(&padata_works_lock);
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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_work *pw = container_of(parallel_work, struct padata_work,
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pw_work);
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struct padata_priv *padata = pw->pw_data;
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local_bh_disable();
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padata->parallel(padata);
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spin_lock(&padata_works_lock);
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padata_work_free(pw);
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spin_unlock(&padata_works_lock);
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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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* @ps: padatashell
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* @padata: object to be parallelized
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* @cb_cpu: pointer to the CPU that the serialization callback function should
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* run on. If it's not in the serial cpumask of @pinst
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* (i.e. cpumask.cbcpu), this function selects a fallback CPU and if
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* none found, returns -EINVAL.
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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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* Return: 0 on success or else negative error code.
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*/
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int padata_do_parallel(struct padata_shell *ps,
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struct padata_priv *padata, int *cb_cpu)
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{
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struct padata_instance *pinst = ps->pinst;
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int i, cpu, cpu_index, err;
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struct parallel_data *pd;
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struct padata_work *pw;
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rcu_read_lock_bh();
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pd = rcu_dereference_bh(ps->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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if (cpumask_empty(pd->cpumask.cbcpu))
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goto out;
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/* Select an alternate fallback CPU and notify the caller. */
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cpu_index = *cb_cpu % cpumask_weight(pd->cpumask.cbcpu);
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cpu = cpumask_first(pd->cpumask.cbcpu);
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for (i = 0; i < cpu_index; i++)
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cpu = cpumask_next(cpu, pd->cpumask.cbcpu);
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*cb_cpu = cpu;
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}
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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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refcount_inc(&pd->refcnt);
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padata->pd = pd;
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padata->cb_cpu = *cb_cpu;
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spin_lock(&padata_works_lock);
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padata->seq_nr = ++pd->seq_nr;
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pw = padata_work_alloc();
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spin_unlock(&padata_works_lock);
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rcu_read_unlock_bh();
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if (pw) {
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padata_work_init(pw, padata_parallel_worker, padata, 0);
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queue_work(pinst->parallel_wq, &pw->pw_work);
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} else {
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/* Maximum works limit exceeded, run in the current task. */
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padata->parallel(padata);
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}
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return 0;
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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_find_next - Find the next object that needs serialization.
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*
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* Return:
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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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* * NULL, 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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static struct padata_priv *padata_find_next(struct parallel_data *pd,
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bool remove_object)
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{
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struct padata_priv *padata;
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struct padata_list *reorder;
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int cpu = pd->cpu;
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reorder = per_cpu_ptr(pd->reorder_list, cpu);
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spin_lock(&reorder->lock);
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if (list_empty(&reorder->list)) {
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spin_unlock(&reorder->lock);
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return NULL;
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}
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padata = list_entry(reorder->list.next, struct padata_priv, list);
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/*
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* Checks the rare case where two or more parallel jobs have hashed to
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* the same CPU and one of the later ones finishes first.
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*/
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if (padata->seq_nr != pd->processed) {
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spin_unlock(&reorder->lock);
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return NULL;
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}
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if (remove_object) {
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list_del_init(&padata->list);
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++pd->processed;
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pd->cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu, -1, false);
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}
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spin_unlock(&reorder->lock);
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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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struct padata_instance *pinst = pd->ps->pinst;
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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_list *reorder;
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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_find_next(pd, true);
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/*
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* If the next object that needs serialization is parallel
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* processed by another cpu and is still on it's way to the
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* cpu's reorder queue, nothing to do for now.
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*/
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if (!padata)
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break;
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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->serial_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.
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*
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* Ensure reorder queue is read after pd->lock is dropped so we see
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* new objects from another task in padata_do_serial. Pairs with
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* smp_mb in padata_do_serial.
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*/
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smp_mb();
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reorder = per_cpu_ptr(pd->reorder_list, pd->cpu);
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if (!list_empty(&reorder->list) && padata_find_next(pd, false))
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queue_work(pinst->serial_wq, &pd->reorder_work);
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}
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static void invoke_padata_reorder(struct work_struct *work)
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{
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struct parallel_data *pd;
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local_bh_disable();
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pd = container_of(work, struct parallel_data, reorder_work);
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padata_reorder(pd);
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local_bh_enable();
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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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int cnt;
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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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cnt = 0;
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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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cnt++;
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}
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local_bh_enable();
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if (refcount_sub_and_test(cnt, &pd->refcnt))
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padata_free_pd(pd);
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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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struct parallel_data *pd = padata->pd;
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int hashed_cpu = padata_cpu_hash(pd, padata->seq_nr);
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struct padata_list *reorder = per_cpu_ptr(pd->reorder_list, hashed_cpu);
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struct padata_priv *cur;
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spin_lock(&reorder->lock);
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/* Sort in ascending order of sequence number. */
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list_for_each_entry_reverse(cur, &reorder->list, list)
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if (cur->seq_nr < padata->seq_nr)
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break;
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list_add(&padata->list, &cur->list);
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spin_unlock(&reorder->lock);
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/*
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* Ensure the addition to the reorder list is ordered correctly
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* with the trylock of pd->lock in padata_reorder. Pairs with smp_mb
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* in padata_reorder.
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*/
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smp_mb();
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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 padata_instance *pinst)
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{
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struct workqueue_attrs *attrs;
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int err;
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attrs = alloc_workqueue_attrs();
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if (!attrs)
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return -ENOMEM;
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/* Restrict parallel_wq workers to pd->cpumask.pcpu. */
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cpumask_copy(attrs->cpumask, pinst->cpumask.pcpu);
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err = apply_workqueue_attrs(pinst->parallel_wq, attrs);
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free_workqueue_attrs(attrs);
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return err;
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}
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static void __init padata_mt_helper(struct work_struct *w)
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{
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struct padata_work *pw = container_of(w, struct padata_work, pw_work);
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struct padata_mt_job_state *ps = pw->pw_data;
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struct padata_mt_job *job = ps->job;
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bool done;
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spin_lock(&ps->lock);
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while (job->size > 0) {
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unsigned long start, size, end;
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start = job->start;
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/* So end is chunk size aligned if enough work remains. */
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size = roundup(start + 1, ps->chunk_size) - start;
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size = min(size, job->size);
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end = start + size;
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job->start = end;
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job->size -= size;
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spin_unlock(&ps->lock);
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job->thread_fn(start, end, job->fn_arg);
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spin_lock(&ps->lock);
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}
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++ps->nworks_fini;
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done = (ps->nworks_fini == ps->nworks);
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spin_unlock(&ps->lock);
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if (done)
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complete(&ps->completion);
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}
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/**
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* padata_do_multithreaded - run a multithreaded job
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* @job: Description of the job.
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*
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* See the definition of struct padata_mt_job for more details.
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*/
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void __init padata_do_multithreaded(struct padata_mt_job *job)
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{
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/* In case threads finish at different times. */
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static const unsigned long load_balance_factor = 4;
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struct padata_work my_work, *pw;
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struct padata_mt_job_state ps;
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LIST_HEAD(works);
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int nworks;
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if (job->size == 0)
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return;
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/* Ensure at least one thread when size < min_chunk. */
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nworks = max(job->size / job->min_chunk, 1ul);
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nworks = min(nworks, job->max_threads);
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if (nworks == 1) {
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/* Single thread, no coordination needed, cut to the chase. */
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job->thread_fn(job->start, job->start + job->size, job->fn_arg);
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return;
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}
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spin_lock_init(&ps.lock);
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init_completion(&ps.completion);
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ps.job = job;
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ps.nworks = padata_work_alloc_mt(nworks, &ps, &works);
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ps.nworks_fini = 0;
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/*
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* Chunk size is the amount of work a helper does per call to the
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* thread function. Load balance large jobs between threads by
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* increasing the number of chunks, guarantee at least the minimum
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* chunk size from the caller, and honor the caller's alignment.
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*/
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ps.chunk_size = job->size / (ps.nworks * load_balance_factor);
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ps.chunk_size = max(ps.chunk_size, job->min_chunk);
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ps.chunk_size = roundup(ps.chunk_size, job->align);
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list_for_each_entry(pw, &works, pw_list)
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queue_work(system_unbound_wq, &pw->pw_work);
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/* Use the current thread, which saves starting a workqueue worker. */
|
|
padata_work_init(&my_work, padata_mt_helper, &ps, PADATA_WORK_ONSTACK);
|
|
padata_mt_helper(&my_work.pw_work);
|
|
|
|
/* Wait for all the helpers to finish. */
|
|
wait_for_completion(&ps.completion);
|
|
|
|
destroy_work_on_stack(&my_work.pw_work);
|
|
padata_works_free(&works);
|
|
}
|
|
|
|
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 per-CPU reorder lists */
|
|
static void padata_init_reorder_list(struct parallel_data *pd)
|
|
{
|
|
int cpu;
|
|
struct padata_list *list;
|
|
|
|
for_each_cpu(cpu, pd->cpumask.pcpu) {
|
|
list = per_cpu_ptr(pd->reorder_list, cpu);
|
|
__padata_list_init(list);
|
|
}
|
|
}
|
|
|
|
/* 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;
|
|
struct parallel_data *pd;
|
|
|
|
pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL);
|
|
if (!pd)
|
|
goto err;
|
|
|
|
pd->reorder_list = alloc_percpu(struct padata_list);
|
|
if (!pd->reorder_list)
|
|
goto err_free_pd;
|
|
|
|
pd->squeue = alloc_percpu(struct padata_serial_queue);
|
|
if (!pd->squeue)
|
|
goto err_free_reorder_list;
|
|
|
|
pd->ps = ps;
|
|
|
|
if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL))
|
|
goto err_free_squeue;
|
|
if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL))
|
|
goto err_free_pcpu;
|
|
|
|
cpumask_and(pd->cpumask.pcpu, pinst->cpumask.pcpu, cpu_online_mask);
|
|
cpumask_and(pd->cpumask.cbcpu, pinst->cpumask.cbcpu, cpu_online_mask);
|
|
|
|
padata_init_reorder_list(pd);
|
|
padata_init_squeues(pd);
|
|
pd->seq_nr = -1;
|
|
refcount_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_pcpu:
|
|
free_cpumask_var(pd->cpumask.pcpu);
|
|
err_free_squeue:
|
|
free_percpu(pd->squeue);
|
|
err_free_reorder_list:
|
|
free_percpu(pd->reorder_list);
|
|
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->reorder_list);
|
|
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)
|
|
{
|
|
struct padata_shell *ps;
|
|
int err = 0;
|
|
|
|
pinst->flags |= PADATA_RESET;
|
|
|
|
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 (refcount_dec_and_test(&ps->opd->refcnt))
|
|
padata_free_pd(ps->opd);
|
|
|
|
pinst->flags &= ~PADATA_RESET;
|
|
|
|
return err;
|
|
}
|
|
|
|
/* 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
|
|
*
|
|
* Return: 0 on success or negative error code
|
|
*/
|
|
int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
|
|
cpumask_var_t cpumask)
|
|
{
|
|
struct cpumask *serial_mask, *parallel_mask;
|
|
int err = -EINVAL;
|
|
|
|
cpus_read_lock();
|
|
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);
|
|
cpus_read_unlock();
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(padata_set_cpumask);
|
|
|
|
#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;
|
|
}
|
|
|
|
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));
|
|
|
|
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
|
|
* @name: used to identify the instance
|
|
*
|
|
* Return: new instance on success, NULL on error
|
|
*/
|
|
struct padata_instance *padata_alloc(const char *name)
|
|
{
|
|
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;
|
|
|
|
cpus_read_lock();
|
|
|
|
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;
|
|
}
|
|
|
|
INIT_LIST_HEAD(&pinst->pslist);
|
|
|
|
cpumask_copy(pinst->cpumask.pcpu, cpu_possible_mask);
|
|
cpumask_copy(pinst->cpumask.cbcpu, cpu_possible_mask);
|
|
|
|
if (padata_setup_cpumasks(pinst))
|
|
goto err_free_masks;
|
|
|
|
__padata_start(pinst);
|
|
|
|
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
|
|
|
|
cpus_read_unlock();
|
|
|
|
return pinst;
|
|
|
|
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:
|
|
cpus_read_unlock();
|
|
destroy_workqueue(pinst->parallel_wq);
|
|
err_free_inst:
|
|
kfree(pinst);
|
|
err:
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(padata_alloc);
|
|
|
|
/**
|
|
* padata_free - free a padata instance
|
|
*
|
|
* @pinst: 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.
|
|
*
|
|
* Return: new shell on success, NULL on error
|
|
*/
|
|
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;
|
|
|
|
cpus_read_lock();
|
|
pd = padata_alloc_pd(ps);
|
|
cpus_read_unlock();
|
|
|
|
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)
|
|
{
|
|
if (!ps)
|
|
return;
|
|
|
|
mutex_lock(&ps->pinst->lock);
|
|
list_del(&ps->list);
|
|
padata_free_pd(rcu_dereference_protected(ps->pd, 1));
|
|
mutex_unlock(&ps->pinst->lock);
|
|
|
|
kfree(ps);
|
|
}
|
|
EXPORT_SYMBOL(padata_free_shell);
|
|
|
|
void __init padata_init(void)
|
|
{
|
|
unsigned int i, possible_cpus;
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
int ret;
|
|
|
|
ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "padata:online",
|
|
padata_cpu_online, NULL);
|
|
if (ret < 0)
|
|
goto err;
|
|
hp_online = ret;
|
|
|
|
ret = cpuhp_setup_state_multi(CPUHP_PADATA_DEAD, "padata:dead",
|
|
NULL, padata_cpu_dead);
|
|
if (ret < 0)
|
|
goto remove_online_state;
|
|
#endif
|
|
|
|
possible_cpus = num_possible_cpus();
|
|
padata_works = kmalloc_array(possible_cpus, sizeof(struct padata_work),
|
|
GFP_KERNEL);
|
|
if (!padata_works)
|
|
goto remove_dead_state;
|
|
|
|
for (i = 0; i < possible_cpus; ++i)
|
|
list_add(&padata_works[i].pw_list, &padata_free_works);
|
|
|
|
return;
|
|
|
|
remove_dead_state:
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
cpuhp_remove_multi_state(CPUHP_PADATA_DEAD);
|
|
remove_online_state:
|
|
cpuhp_remove_multi_state(hp_online);
|
|
err:
|
|
#endif
|
|
pr_warn("padata: initialization failed\n");
|
|
}
|