linux-sg2042/block/blk-mq-cpu.c

68 lines
1.6 KiB
C

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