68 lines
1.6 KiB
C
68 lines
1.6 KiB
C
/*
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* CPU notifier helper code for blk-mq
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*
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* Copyright (C) 2013-2014 Jens Axboe
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/blkdev.h>
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#include <linux/list.h>
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#include <linux/llist.h>
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#include <linux/smp.h>
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#include <linux/cpu.h>
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#include <linux/blk-mq.h>
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#include "blk-mq.h"
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static LIST_HEAD(blk_mq_cpu_notify_list);
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static DEFINE_RAW_SPINLOCK(blk_mq_cpu_notify_lock);
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static int blk_mq_main_cpu_notify(struct notifier_block *self,
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unsigned long action, void *hcpu)
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{
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unsigned int cpu = (unsigned long) hcpu;
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struct blk_mq_cpu_notifier *notify;
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int ret = NOTIFY_OK;
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raw_spin_lock(&blk_mq_cpu_notify_lock);
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list_for_each_entry(notify, &blk_mq_cpu_notify_list, list) {
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ret = notify->notify(notify->data, action, cpu);
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if (ret != NOTIFY_OK)
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break;
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}
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raw_spin_unlock(&blk_mq_cpu_notify_lock);
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return ret;
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}
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void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier)
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{
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BUG_ON(!notifier->notify);
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raw_spin_lock(&blk_mq_cpu_notify_lock);
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list_add_tail(¬ifier->list, &blk_mq_cpu_notify_list);
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raw_spin_unlock(&blk_mq_cpu_notify_lock);
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}
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void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier)
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{
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raw_spin_lock(&blk_mq_cpu_notify_lock);
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list_del(¬ifier->list);
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raw_spin_unlock(&blk_mq_cpu_notify_lock);
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}
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void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier,
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int (*fn)(void *, unsigned long, unsigned int),
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void *data)
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{
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notifier->notify = fn;
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notifier->data = data;
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}
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void __init blk_mq_cpu_init(void)
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{
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hotcpu_notifier(blk_mq_main_cpu_notify, 0);
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}
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