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![Daniel Jordan](/assets/img/avatar_default.png)
syzbot reports,
WARNING: inconsistent lock state
5.9.0-rc2-syzkaller #0 Not tainted
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
syz-executor.0/26715 takes:
(padata_works_lock){+.?.}-{2:2}, at: padata_do_parallel kernel/padata.c:220
{IN-SOFTIRQ-W} state was registered at:
spin_lock include/linux/spinlock.h:354 [inline]
padata_do_parallel kernel/padata.c:220
...
__do_softirq kernel/softirq.c:298
...
sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1091
asm_sysvec_apic_timer_interrupt arch/x86/include/asm/idtentry.h:581
Possible unsafe locking scenario:
CPU0
----
lock(padata_works_lock);
<Interrupt>
lock(padata_works_lock);
padata_do_parallel() takes padata_works_lock with softirqs enabled, so a
deadlock is possible if, on the same CPU, the lock is acquired in
process context and then softirq handling done in an interrupt leads to
the same path.
Fix by leaving softirqs disabled while do_parallel holds
padata_works_lock.
Reported-by: syzbot+f4b9f49e38e25eb4ef52@syzkaller.appspotmail.com
Fixes: 4611ce2246
("padata: allocate work structures for parallel jobs from a pool")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
1154 lines
28 KiB
C
1154 lines
28 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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* 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/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_weight(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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atomic_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 (atomic_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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|
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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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|
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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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|
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spin_lock(&ps->lock);
|
|
|
|
while (job->size > 0) {
|
|
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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}
|
|
|
|
++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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}
|
|
|
|
/**
|
|
* padata_do_multithreaded - run a multithreaded job
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* @job: Description of the job.
|
|
*
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|
* See the definition of struct padata_mt_job for more details.
|
|
*/
|
|
void __init padata_do_multithreaded(struct padata_mt_job *job)
|
|
{
|
|
/* In case threads finish at different times. */
|
|
static const unsigned long load_balance_factor = 4;
|
|
struct padata_work my_work, *pw;
|
|
struct padata_mt_job_state ps;
|
|
LIST_HEAD(works);
|
|
int nworks;
|
|
|
|
if (job->size == 0)
|
|
return;
|
|
|
|
/* Ensure at least one thread when size < min_chunk. */
|
|
nworks = max(job->size / job->min_chunk, 1ul);
|
|
nworks = min(nworks, job->max_threads);
|
|
|
|
if (nworks == 1) {
|
|
/* Single thread, no coordination needed, cut to the chase. */
|
|
job->thread_fn(job->start, job->start + job->size, job->fn_arg);
|
|
return;
|
|
}
|
|
|
|
spin_lock_init(&ps.lock);
|
|
init_completion(&ps.completion);
|
|
ps.job = job;
|
|
ps.nworks = padata_work_alloc_mt(nworks, &ps, &works);
|
|
ps.nworks_fini = 0;
|
|
|
|
/*
|
|
* Chunk size is the amount of work a helper does per call to the
|
|
* thread function. Load balance large jobs between threads by
|
|
* increasing the number of chunks, guarantee at least the minimum
|
|
* chunk size from the caller, and honor the caller's alignment.
|
|
*/
|
|
ps.chunk_size = job->size / (ps.nworks * load_balance_factor);
|
|
ps.chunk_size = max(ps.chunk_size, job->min_chunk);
|
|
ps.chunk_size = roundup(ps.chunk_size, job->align);
|
|
|
|
list_for_each_entry(pw, &works, pw_list)
|
|
queue_work(system_unbound_wq, &pw->pw_work);
|
|
|
|
/* 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;
|
|
atomic_set(&pd->refcnt, 1);
|
|
spin_lock_init(&pd->lock);
|
|
pd->cpu = cpumask_first(pd->cpumask.pcpu);
|
|
INIT_WORK(&pd->reorder_work, invoke_padata_reorder);
|
|
|
|
return pd;
|
|
|
|
err_free_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 (atomic_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;
|
|
|
|
get_online_cpus();
|
|
mutex_lock(&pinst->lock);
|
|
|
|
switch (cpumask_type) {
|
|
case PADATA_CPU_PARALLEL:
|
|
serial_mask = pinst->cpumask.cbcpu;
|
|
parallel_mask = cpumask;
|
|
break;
|
|
case PADATA_CPU_SERIAL:
|
|
parallel_mask = pinst->cpumask.pcpu;
|
|
serial_mask = cpumask;
|
|
break;
|
|
default:
|
|
goto out;
|
|
}
|
|
|
|
err = __padata_set_cpumasks(pinst, parallel_mask, serial_mask);
|
|
|
|
out:
|
|
mutex_unlock(&pinst->lock);
|
|
put_online_cpus();
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(padata_set_cpumask);
|
|
|
|
#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;
|
|
|
|
get_online_cpus();
|
|
|
|
pinst->serial_wq = alloc_workqueue("%s_serial", WQ_MEM_RECLAIM |
|
|
WQ_CPU_INTENSIVE, 1, name);
|
|
if (!pinst->serial_wq)
|
|
goto err_put_cpus;
|
|
|
|
if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL))
|
|
goto err_free_serial_wq;
|
|
if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) {
|
|
free_cpumask_var(pinst->cpumask.pcpu);
|
|
goto err_free_serial_wq;
|
|
}
|
|
|
|
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
|
|
|
|
put_online_cpus();
|
|
|
|
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:
|
|
put_online_cpus();
|
|
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;
|
|
|
|
get_online_cpus();
|
|
pd = padata_alloc_pd(ps);
|
|
put_online_cpus();
|
|
|
|
if (!pd)
|
|
goto out_free_ps;
|
|
|
|
mutex_lock(&pinst->lock);
|
|
RCU_INIT_POINTER(ps->pd, pd);
|
|
list_add(&ps->list, &pinst->pslist);
|
|
mutex_unlock(&pinst->lock);
|
|
|
|
return ps;
|
|
|
|
out_free_ps:
|
|
kfree(ps);
|
|
out:
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(padata_alloc_shell);
|
|
|
|
/**
|
|
* padata_free_shell - free a padata shell
|
|
*
|
|
* @ps: padata shell to free
|
|
*/
|
|
void padata_free_shell(struct padata_shell *ps)
|
|
{
|
|
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");
|
|
}
|